Image forming device

Abstract

To form an image with an appropriate density when a black toner cartridge and a toner cartridge of a color other than black are mounted. [Solution] The image forming device 1 includes a toner cartridge 6, a drum cartridge 5, a bias application circuit, and a control unit. The toner cartridge 6 has a toner storage chamber 61, a developing roller 62, and a toner memory 65. When a first toner cartridge 6B containing a first black toner TB and having first toner information stored in the toner memory 65 is installed, the control unit applies a first developing bias Vb1 to the developing roller 62 based on the first toner information. When a second toner cartridge 6M containing a second toner TM of a color different from black and having second toner information stored in the toner memory 65 is installed, the control unit applies a second developing bias Vb2, different from the first developing bias Vb1, to the developing roller 62 based on the second toner information.

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus to which a toner cartridge can be attached. [Background technology]

[0002] Conventionally, an image forming device capable of mounting a toner cartridge has been known (see Patent Document 1). In this image forming device, a toner cartridge containing black toner or a toner cartridge containing red toner can be selectively mounted. A magnet corresponding to the color of the toner is disposed on the top plate of the toner cartridge, and by detecting the magnet, the toner color of the mounted toner cartridge can be determined. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 61-245177 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to form an appropriate image, it is necessary to apply a bias appropriate to the toner, and therefore it is necessary to obtain information for applying an appropriate bias to the toner contained in the black toner cartridge and the toner of a color other than black.

[0005] Therefore, an object of the present invention is to form images with appropriate densities when black toner cartridges and toner cartridges of colors other than black are installed. [Means for solving the problem]

[0006] An image forming apparatus for achieving the above object includes a toner cartridge, a drum cartridge, a main body of the apparatus, a bias application circuit, and a control unit. The toner cartridge has a toner storage chamber for storing toner, a developing roller, and a toner memory. The drum cartridge has a photosensitive drum. The toner cartridge and the drum cartridge can be attached to the device main body. The bias application circuit can apply a bias. The control unit controls the bias application circuit to apply a first development bias to the development roller based on the first toner information when an image is formed in a state in which a first toner cartridge is attached, the first toner cartridge containing a black first toner in the toner storage chamber and having first toner information, which is information about the first toner, stored in the toner memory. The control unit controls the bias application circuit to apply a second developing bias different from the first developing bias to the developing roller based on the second toner information when forming an image with a second toner cartridge attached, the second toner cartridge containing a second toner of a color different from black in the toner storage chamber and having second toner information stored in the toner memory.

[0007] When the first toner cartridge is installed, the control unit applies a first development bias to the development roller based on the first toner information stored in the toner memory, and when the second toner cartridge is installed, the control unit applies a second development bias based on the second toner information stored in the toner memory, so that when a black toner cartridge or a toner cartridge of a color other than black is installed, images can be formed at appropriate densities.

[0008] Furthermore, the apparatus main body may be configured such that only one of the first toner cartridge and the second toner cartridge can be attached.

[0009] The drum cartridge may be capable of receiving a toner cartridge, and the main body of the apparatus may be capable of receiving the toner cartridge in a state where it is attached to the drum cartridge.

[0010] By mounting the toner cartridge in the drum cartridge, the toner cartridge can be easily mounted in the device body.

[0011] The drum cartridge may have a charger that charges the photosensitive drum. The control unit may control the bias application circuit to apply a first charging bias to the charger based on first toner information when forming an image with the first toner cartridge installed. The control unit may control the bias application circuit to apply a second charging bias, different from the first charging bias, to the charger based on second toner information when forming an image with the second toner cartridge installed.

[0012] The control unit applies a first charging bias to the charger when the first toner cartridge is installed, and applies a second charging bias when the second toner cartridge is installed, so that images can be formed at appropriate densities for black and toner cartridges of colors other than black.

[0013] The first toner information may include a value of a first development bias, and the second toner information may include a value of a second development bias.

[0014] The first toner information includes the value of the first developing bias, and the second toner information includes the value of the second developing bias, so that an appropriate developing bias corresponding to the first toner and the second toner can be applied.

[0015] The device may further include a main memory in which a value of the reference developing bias is stored, and the second toner information may include an offset value of the second developing bias from the reference developing bias.

[0016] Since the second toner information includes an offset value of the second developing bias from the reference developing bias, it is possible to apply an appropriate developing bias value corresponding to the first toner and the second toner.

[0017] The device body may have a display unit that displays information, and the control unit may be configured to display the color of the toner contained in the installed toner cartridge on the display unit based on the first toner information or the second toner information read from the toner memory.

[0018] By displaying the color of the toner contained in the installed toner cartridge on the display unit, it is easy to see the color of the toner in the installed toner cartridge.

[0019] The drum cartridge may have a cleaning roller that rotates in contact with the outer peripheral surface of the photosensitive drum. The first toner and the second toner may be positive toner. The control unit may apply a positive cleaning bias to the cleaning roller when forming an image with the first toner cartridge or the second toner cartridge installed.

[0020] When a positive bias is applied to the cleaning roller, negatively charged paper dust is collected by the cleaning roller, but positively charged residual toner is not collected by the cleaning roller.

[0021] The drum cartridge may have a secondary cleaning roller that rotates in contact with the outer peripheral surface of the cleaning roller, and the control unit may control the bias application circuit to apply a bias of a higher positive polarity to the secondary cleaning roller than to the cleaning roller.

[0022] By applying a bias of a higher positive polarity to the secondary cleaning roller than to the cleaning roller, paper dust adhering to the cleaning roller can be efficiently collected.

[0023] The drum cartridge may further include a drum memory, and the control unit may store in the drum memory a usage history of image formation using the first toner cartridge and a usage history of image formation using the second toner cartridge.

[0024] The use history of the first toner cartridge and the use history of the second toner cartridge can be checked to appropriately change the control of image formation.

[0025] An image forming apparatus for achieving the above object includes a process cartridge, an apparatus main body, a bias application circuit, and a control unit. The process cartridge has a toner storage chamber for storing toner, a developing roller, a photosensitive drum, and a toner memory. The process cartridge can be attached to the main body of the apparatus. The bias application circuit can apply a bias. The control unit controls the bias application circuit to apply a first developing bias to the developing roller based on the first toner information when forming an image with a first process cartridge attached, the first process cartridge containing a black first toner in the toner storage chamber and having first toner information stored in the toner memory. The control unit controls the bias application circuit to apply a second developing bias different from the first developing bias to the developing roller based on the second toner information when an image is formed in a state in which a second process cartridge is attached, the second process cartridge containing a second toner of a color different from black in the toner storage chamber and having second toner information stored in the toner memory.

[0026] When the first process cartridge is installed, the control unit applies a first developing bias to the developing roller based on the first toner information stored in the toner memory, and when the second process cartridge is installed, the control unit applies a second developing bias based on the second toner information stored in the toner memory, so that when a black process cartridge or a color other than black is installed, images can be formed at appropriate densities. [Effects of the Invention]

[0027] According to the present disclosure, when a toner cartridge of black or a color other than black is installed, images can be formed with appropriate densities for each. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a cross-sectional view of an image forming apparatus according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a state in which the drum cartridge and the toner cartridge are removed from the main body of the apparatus. [Figure 3] FIG. 2 is a diagram illustrating application of a bias by a bias application circuit. [Figure 4] 5 is a flowchart showing the operation of a control unit according to the first embodiment. [Figure 5] 10 is a flowchart showing the operation of a control unit according to the second embodiment. [Figure 6] 10 is a table showing examples of image formation when the toner color and bias value are changed in a type A toner cartridge. [Figure 7] 10 is a table showing examples of image formation when the toner color and bias value are changed in a toner cartridge of type B. DETAILED DESCRIPTION OF THE INVENTION

[0029] Next, a first embodiment of the present invention will be described with reference to the drawings as appropriate. In the following description, the right side of the image forming apparatus 1 in Fig. 1 will be referred to as the "front", the left side as the "rear", the near side as the "left", and the far side as the "right". Also, the up and down directions in Fig. 1 will be referred to as the "up and down".

[0030] As shown in Fig. 1, the image forming apparatus 1 is a laser printer. The image forming apparatus 1 is a monochrome printer capable of printing in only one color. The image forming apparatus 1 includes a main body 2, a supply unit 3, an exposure device 4, a drum cartridge 5, a toner cartridge 6, and a fixing device 7.

[0031] The device main body 2 has a front cover 21 and a display unit 22. The front cover 21 is located at the front of the device main body 2. The front cover 21 can move between a closed position shown in FIG. 1 and an open position shown in FIG. 2 to open and close the device main body 2. When the front cover 21 is located in the closed position, it covers the opening 2A of the device main body 2. When the front cover 21 is located in the open position, it opens the opening 2A of the device main body 2. The display unit 22 is located on the top surface of the device main body 2. The display unit 22 displays information. The display unit 22 is, for example, a liquid crystal panel.

[0032] The supply unit 3 is disposed at the bottom of the device body 2. The supply unit 3 includes a supply tray 31, a pressure plate 32, and a paper feed mechanism 33. The supply tray 31 stores sheets S. The pressure plate 32 pushes the sheets S stored in the supply tray 31 upward. The paper feed mechanism 33 supplies the sheets S pushed upward by the pressure plate 32 toward the drum cartridge 5.

[0033] The exposure device 4 is disposed on top of the apparatus main body 2. The exposure device 4 has a laser emitting unit (not shown), a polygon mirror (shown without reference numerals), a lens, a reflecting mirror, etc. In this exposure device 4, a laser beam (see dashed line) based on image data emitted from the laser emitting unit is scanned at high speed over the surface of the photosensitive drum 52, thereby exposing the surface of the photosensitive drum 52.

[0034] The drum cartridge 5 is disposed below the exposure device 4. The drum cartridge 5 is detachable from the apparatus main body 2. The drum cartridge 5 has a drum frame 51, a photosensitive drum 52, a charger 53, a transfer roller 54, a cleaning roller 55, a secondary cleaning roller 56, and a drum memory 57.

[0035] The photosensitive drum 52, the transfer roller 54, the cleaning roller 55, and the secondary cleaning roller 56 are rotatably supported by the drum frame 51. The charger 53 and the drum memory 57 are also supported by the drum frame 51.

[0036] The charger 53 is positioned opposite the photosensitive drum 52. The charger 53 charges the photosensitive drum 52.

[0037] The transfer roller 54 is positioned opposite the photosensitive drum 52. The transfer roller 54 transfers the toner image formed on the photosensitive drum 52 onto the sheet S between the transfer roller 54 and the photosensitive drum 52.

[0038] The cleaning roller 55 is positioned opposite the photosensitive drum 52. The cleaning roller 55 rotates in contact with the outer circumferential surface of the photosensitive drum 52. The cleaning roller 55 is a roller for removing dust and paper powder from the outer circumferential surface of the photosensitive drum 52.

[0039] The secondary cleaning roller 56 is positioned opposite the cleaning roller 55. The secondary cleaning roller 56 rotates in contact with the outer circumferential surface of the cleaning roller 55. The secondary cleaning roller 56 is a roller for collecting the dirt and paper dust collected by the cleaning roller 55.

[0040] The drum memory 57 is a storage medium that stores information about the drum cartridge 5. The drum memory 57 is, for example, an IC chip having NVM (Non-Volatile Memory). The information about the drum cartridge 5 includes, for example, a serial number, the cumulative number of printed sheets, and the cumulative number of rotations of the photosensitive drum 52.

[0041] The toner cartridge 6 is disposed below the exposure device 4. The toner cartridge 6 is detachable from the apparatus main body 2. The toner cartridge 6 is mountable to the drum cartridge 5. In this embodiment, the toner cartridge 6 is disposed inside the apparatus main body 2 while mounted in the drum cartridge 5. The toner cartridge 6 has a toner storage chamber 61, a developing roller 62, a supply roller 63, a layer thickness regulating blade 64, and a toner memory 65.

[0042] The toner storage chamber 61 stores toner therein. In this embodiment, the toner is positive toner. The developing roller 62 supplies the toner to the photosensitive drum 52. The supply roller 63 supplies the toner in the toner storage chamber 61 to the developing roller 62. The layer thickness regulating blade 64 regulates the toner supplied onto the developing roller 62 to a constant thickness.

[0043] The toner memory 65 is a storage medium that stores toner cartridge information. The toner memory 65 is, for example, an IC chip that has NVM (Non-Volatile Memory). The toner cartridge information includes, for example, a serial number, the cumulative number of printed pages, and the cumulative number of rotations of the developing roller 62.

[0044] In the drum cartridge 5, the surface of the photosensitive drum 52 is uniformly positively charged by the charger 53 and then exposed to high-speed scanning of laser light from the exposure device 4. This reduces the potential of the exposed area, and an electrostatic latent image based on the image data is formed on the photosensitive drum 52. Furthermore, toner in the toner storage chamber 61 is supplied to the developing roller 62 via a supply roller 63. The toner supplied onto the developing roller 62 is carried on the developing roller 62 as a thin layer of a uniform thickness by a layer thickness regulating blade 64.

[0045] The toner carried on the developing roller 62 is supplied from the developing roller 62 to the electrostatic latent image formed on the photosensitive drum 52. This makes the electrostatic latent image visible, and a toner image is formed on the photosensitive drum 52. Thereafter, the sheet S is transported between the photosensitive drum 52 and the transfer roller 54, so that the toner image on the photosensitive drum 52 is transferred onto the sheet S.

[0046] The fixing device 7 is disposed behind the drum cartridge 5. The fixing device 7 includes a heating unit 71 and a pressure roller 72. The heating unit 71 includes a halogen heater, a fixing belt, a nip plate, and other components (reference numerals omitted). The pressure roller 72 sandwiches the fixing belt between itself and the nip plate of the heating unit 71. In the fixing device 7, the toner image transferred onto the sheet S is thermally fixed while the sheet S passes between the heating unit 71 and the pressure roller 72. The sheet S with the thermally fixed toner image is discharged onto a discharge tray 24 by discharge rollers 23.

[0047] Furthermore, this image forming apparatus 1 employs a so-called cleanerless system in which residual toner remaining on the photosensitive drum 52 without being transferred to the sheet S is collected and reused by the toner cartridge 6. Specifically, when collecting the residual toner, the surface of the photosensitive drum 52 is once charged by the charger 53, so that the surface potential of the photosensitive drum 52 is made higher than the potential of the developing roller 62. As a result, the positively charged residual toner on the photosensitive drum 52 moves to the developing roller 62 and is returned to the toner storage chamber 61.

[0048] 2, the drum cartridge 5 and the toner cartridge 6 are attached and detached through an opening 2A that is exposed when the front cover 21 is in the open position. Only one of the first toner cartridge 6B and the second toner cartridge 6M can be attached to the device main body 2.

[0049] The first toner cartridge 6B is a toner cartridge that contains a black first toner TB. When the first toner cartridge 6B is installed in the device main body 2, an image is formed using the black first toner TB. First toner information is stored in the toner memory 65B of the first toner cartridge 6B.

[0050] The first toner information includes the value of the first charging bias Vg1 and the value of the first developing bias Vb1. The value of the first charging bias Vg1 is the optimum value for forming an image with the first black toner TB, for example, the value of the first charging bias Vg1 is 850V. The value of the first developing bias Vb1 is the optimum value for forming an image with the first black toner TB, and is, for example, 300V.

[0051] The second toner cartridge 6M is a toner cartridge that contains magenta second toner TM. Magenta is an example of a color different from black. When the second toner cartridge 6M is installed in the device main body 2, an image is formed using the magenta second toner TM. Second toner information is stored in the toner memory 65M of the second toner cartridge 6M.

[0052] The second toner information includes the value of the second charging bias Vg2 and the value of the second developing bias Vb2. The value of the second charging bias Vg2 is the optimum value for forming an image using the magenta second toner TM. The optimum value for forming an image using the magenta second toner TM is different from the optimum value for forming an image using the black second toner TM. For example, the value of the second charging bias Vg2 is 950V. The value of the second developing bias Vb2 is the optimum value for forming an image using the magenta second toner TM. The optimum value for forming an image using the magenta second toner TM is different from the optimum value for forming an image using the black second toner TM. For example, the value of the second developing bias Vb2 is 200V.

[0053] As shown in FIG. 3, the image forming apparatus 1 further includes a control unit 100, a main body memory 110, and a bias application circuit 120.

[0054] The control unit 100 includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and input / output circuits, and performs various arithmetic processing based on programs and data stored in the ROM, etc., thereby controlling the image forming apparatus 1. The control unit 100 can read and write data from the main body memory 110, the drum memory 57, and the toner memory 65.

[0055] The main body memory 110 is a memory arranged inside the device main body 2.

[0056] The bias application circuit 120 is capable of applying bias to the charger 53, the transfer roller 54, the cleaning roller 55, the secondary cleaning roller 56, and the developing roller 62. In this embodiment, the charger 53 is a scorotron charger. The charger 53 has a charging wire 53A and a grid electrode 53B.

[0057] The bias application circuit 120 applies a positive bias to the developing roller 62 .

[0058] The bias application circuit 120 applies a voltage to the charging wire 53A, thereby applying a charging bias to the charger 53. The bias application circuit 120 controls the voltage applied to the charging wire 53A so that the voltage of the grid electrode 53B becomes a target charging bias.

[0059] When forming an image, the bias application circuit 120 applies a negative bias to the transfer roller 54. When collecting residual toner, the bias application circuit 120 applies a positive bias to the transfer roller 54.

[0060] When forming an image, the bias application circuit 120 applies a cleaning bias of positive polarity, which has a smaller absolute value than the charging bias, to the cleaning roller 55. The surface of the cleaning roller 55 has a higher potential than the exposed portion of the photosensitive drum 52. Therefore, the cleaning roller 55 electrostatically attracts and collects negatively charged paper dust adhering to the photosensitive drum 52, but does not collect toner remaining on the exposed portion of the photosensitive drum 52.

[0061] The bias application circuit 120 applies a positive bias to the secondary cleaning roller 56. The positive bias applied to the secondary cleaning roller 56 has an absolute value greater than that of the bias applied to the cleaning roller 55. This causes the secondary cleaning roller 56 to electrostatically collect the paper dust collected on the cleaning roller 55.

[0062] Next, the operation performed by the control unit 100 when forming an image in the first embodiment will be described.

[0063] When forming an image with the first toner cartridge 6B attached to the apparatus main body 2, the control unit 100 controls the bias application circuit 120 based on the first toner information read out from the toner memory 65. Specifically, when the first toner cartridge 6B is installed, the control unit 100 applies a first charging bias Vg1 to the charger 53 and a first developing bias Vb1 to the developing roller 62. The first charging bias Vg1 and the first developing bias Vb1 differ depending on the specifications of the image forming apparatus 1 and the type of toner, and are values ​​that are determined in advance based on the results of a printing test.

[0064] Furthermore, when forming an image with the first toner cartridge 6B attached to the apparatus main body 2, the control unit 100 displays black, which is the color of the toner, on the display unit 22 based on the first toner information.

[0065] When forming an image with the second toner cartridge 6M attached to the apparatus main body 2, the control unit 100 controls the bias application circuit 120 based on the second toner information read out from the toner memory 65. Specifically, when the second toner cartridge 6M is installed, the control unit 100 applies a second charging bias Vg2 to the charger 53 and a second developing bias Vb2 to the developing roller 62. In this embodiment, the second charging bias Vg2 is different from the first charging bias Vg1, and the second developing bias Vb2 is different from the first developing bias Vb1. The second charging bias Vg2 and the second developing bias Vb2 differ depending on the specifications of the image forming apparatus 1 and the type of toner, and are values ​​that are determined in advance based on the results of a printing test.

[0066] Furthermore, when forming an image with the second toner cartridge 6M attached to the apparatus main body 2, the control unit 100 displays magenta, which is the color of the toner, on the display unit 22 based on the second toner information.

[0067] The control unit 100 applies a cleaning bias of positive polarity to the cleaning roller 55 when forming an image with the first toner cartridge 6B or the second toner cartridge 6M attached.

[0068] The control unit 100 applies a bias of a positive polarity greater than that of the cleaning roller 55 to the secondary cleaning roller 56 when forming an image with the first toner cartridge 6B or the second toner cartridge 6M attached.

[0069] The control unit 100 stores the usage history of image formation using the first toner cartridge 6B and the usage history of image formation using the second toner cartridge 6M in the drum memory 57. The image formation history includes, for example, the cumulative number of printed sheets, the cumulative number of rotations of the developing roller 62, etc.

[0070] Next, an example of the operation executed by the control unit 100 in the first embodiment will be described with reference to the flowchart shown in FIG.

[0071] As shown in FIG. 4, when the control unit 100 determines that the image forming apparatus 1 is powered on or the front cover 21 is closed (S11, Yes), the toner cartridge 6 may have been replaced, so the control unit 100 reads toner information from the toner memory 65 (S12).

[0072] After step S12, the control unit 100 applies a bias with the charging bias value included in the toner information (S13). For example, when the first toner cartridge 6B containing the first black toner TB is installed, the first toner information stores the first charging bias Vg1 as 850 V. Therefore, the control unit 100 applies the first charging bias Vg1 of 850 V to the charger 53. When the second toner cartridge 6M containing the second magenta toner TM is installed, the second toner information stores the second charging bias value Vg2 of 950 V. Therefore, the control unit 100 applies the second charging bias Vg2 of 950 V to the charger 53.

[0073] After step S13, the control unit 100 applies a bias with the development bias value included in the toner information (S14). For example, when the first toner cartridge 6B containing the first black toner TB is installed, the first toner information stores the first developing bias Vb1 as 300 V. Therefore, the control unit 100 applies the first developing bias Vb1 of 300 V to the developing roller 62. When the second toner cartridge 6M containing the magenta second toner TM is installed, the second toner information stores the second developing bias value Vb2 of 200 V. Therefore, the control unit 100 applies the second developing bias Vb2 of 200 V to the developing roller 62.

[0074] After step S14, the control unit 100 displays the color of the toner on the display unit 22 based on the toner information (S15). For example, when the first toner cartridge 6B containing the first black toner TB is installed, the first toner information stores that the toner is black, and the control unit 100 displays on the display unit 22 that the toner is black. When the second toner cartridge 6M containing the magenta second toner TM is installed, the second toner information stores that the toner is magenta, and the control unit 100 therefore displays on the display unit 22 that the toner is magenta.

[0075] According to the image forming apparatus 1, the following effects can be obtained. When the first toner cartridge 6B is installed, the control unit 100 applies a first developing bias Vb1 to the developing roller 62 based on the first toner information stored in the toner memory 65. When the second toner cartridge 6M is installed, the control unit 100 applies a second developing bias Vb2 based on the second toner information stored in the toner memory 65. Therefore, when a toner cartridge 6 of black or a color other than black is installed, images can be formed with appropriate densities.

[0076] Furthermore, in the image forming apparatus 1, the toner cartridge 6 is attached to the drum cartridge 5 before being installed in the apparatus main body 2. This makes it easier to install the drum cartridge 5 and toner cartridge 6 in the apparatus main body 2 compared to installing the drum cartridge 5 and toner cartridge 6 separately in the apparatus main body 2.

[0077] Furthermore, when the first toner cartridge 6B is installed, the control unit 100 applies a first charging bias Vg1 to the charger 53. Furthermore, when the second toner cartridge 6M is installed, the control unit 100 applies a second charging bias Vg2. As a result, images can be formed at appropriate densities for the black toner cartridge 6 and the toner cartridges 6 of colors other than black.

[0078] Furthermore, since the first toner information includes the value of the first developing bias Vb1 and the second toner information includes the value of the second developing bias Vb2, the control unit 100 can apply appropriate developing biases corresponding to the first toner TB and the second toner TM.

[0079] Furthermore, the control unit 100 displays the color of the toner contained in the toner cartridge 6 attached to the device main body 2 on the display unit 22. This makes it easy to see the color of the toner in the toner cartridge 6 attached to the device main body 2.

[0080] Furthermore, when forming an image with the first toner cartridge 6B or the second toner cartridge 6M attached, the control unit 100 applies a positive cleaning bias to the cleaning roller 55. As a result, negatively charged paper dust is collected by the cleaning roller 55, and positively charged remaining toner is not collected by the cleaning roller 55 and can be re-collected in the toner storage chamber 61.

[0081] Furthermore, the control unit 100 applies a bias of a higher positive polarity to the secondary cleaning roller 56 than to the cleaning roller 55. Therefore, the paper dust adhering to the cleaning roller 55 can be efficiently collected by the secondary cleaning roller 56.

[0082] Furthermore, the control unit 100 stores the usage history of images formed using the first toner cartridge 6B and the usage history of images formed using the second toner cartridge 6M in the drum memory 57. This allows the control of image formation to be appropriately changed by referring to the usage history of the first toner cartridge 6B and the usage history of the second toner cartridge 6M. For example, when the second toner cartridge 6M is installed in the drum cartridge 5, if there is a usage history of the first toner cartridge 6B having been used immediately before, the control unit 100 can extend the time for the preparatory rotation operation of the photosensitive drum 52 and the developing roller 62 before printing, thereby allowing the first toner TB remaining on the photosensitive drum 52 to be collected by the second toner cartridge 6M.

[0083] Next, a second embodiment will be described. In the first embodiment, the first toner information and the second toner information include a bias value. In contrast, in the second embodiment, the first toner information and the second toner information do not include the bias value itself, but instead include an offset value from a reference bias, which is different from the first embodiment.

[0084] In the second embodiment, the value of the reference charging bias and the value of the reference developing bias when performing image formation are stored in the main body memory 110. As an example, the reference charging bias is 850V, and the reference developing bias is 300V.

[0085] The first toner information includes an offset value from the reference charging bias and an offset value from the reference developing bias. For example, the offset value from the reference charging bias of the first toner information is 0V, and the offset value from the reference developing bias is 0V. The second toner information includes an offset value from the reference charging bias and an offset value from the reference developing bias. For example, the offset value from the reference charging bias of the first toner information is +100V, and the offset value from the reference developing bias is −100V.

[0086] When the first toner cartridge 6B is installed, the control unit 100 applies a first charging bias Vg1 (=850V+0V) that is offset from the reference charging bias (850V) by an offset value (0V) to the charger 53. Furthermore, when the first toner cartridge 6B is installed, the control unit 100 applies a developing bias Vb (=300V+0V) that is offset from the reference developing bias (300V) by an offset value (0V) to the developing roller 62. In this embodiment, the offset values ​​of the charging bias and developing bias of the first toner cartridge 6B are 0V, so the reference charging bias and developing bias are applied as is.

[0087] When the second toner cartridge 6M is installed, the control unit 100 applies a charging bias Vg (=850V+100V) that is offset from the reference charging bias (850V) by an offset value (+100V) to the charger 53. Furthermore, when the second toner cartridge 6M is installed, the control unit 100 applies a developing bias Vb (=300V-100V) that is offset from the reference developing bias (300V) by an offset value (-100V) to the developing roller 62.

[0088] Next, an example of the operation executed by the control unit 100 in the second embodiment will be described according to the flowchart shown in Fig. 5. Only steps that are different from the first embodiment will be described, and explanations of steps that are the same as those in the first embodiment will be omitted.

[0089] As shown in FIG. 5, after step S12, the control unit 100 calculates a charging bias offset from the reference charging bias based on the toner information, and applies the calculated charging bias (S23).

[0090] After step S23, the control unit 100 calculates a development bias Vb offset from the reference development bias based on the toner information, and applies the calculated development bias (S24).

[0091] In the second embodiment described above, the first toner information includes an offset value of the first developing bias Vb1 from the reference developing bias, so that an appropriate developing bias Vb value corresponding to the first toner TB can be applied. Also, the second toner information includes an offset value of the second developing bias Vb2 from the reference developing bias, so that an appropriate developing bias Vb value corresponding to the second toner TM can be applied.

[0092] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. The specific configurations can be appropriately changed without departing from the spirit of the present invention.

[0093] In the above embodiment, magenta is used as an example of a color different from black, but the color different from black is not particularly limited and may be yellow, cyan, red, blue, light blue, green, brown, gray, etc.

[0094] In the above embodiment, the toner is positive toner, but negative toner may also be used. When negative toner is used, the bias application circuit 120 should apply a bias of the opposite polarity to that when positive toner is used.

[0095] In the above embodiment, the toner cartridge 6 can be attached to the device main body 2 while attached to the drum cartridge 5, but the toner cartridge 6 and the drum cartridge 5 may be attached to the device main body 2 separately.

[0096] In the above embodiment, the toner cartridge 6 can be attached to the device main body 2 while attached to the drum cartridge 5, but the device may also be configured so that a process cartridge having a toner storage chamber, a developing roller, a photosensitive drum, and a toner memory can be attached to the device main body 2.

[0097] For example, only one of the first process cartridge and the second process cartridge can be attached to the main body of the apparatus. The first process cartridge is a process cartridge that contains a first black toner. When the first process cartridge is installed in the device main body, an image is formed using the first black toner. First toner information is stored in the toner memory of the first process cartridge. The second process cartridge is a process cartridge that contains a second toner of a color other than black. When the second process cartridge is installed in the device main body, an image is formed using the second toner of a color other than black. Second toner information is stored in the toner memory of the second process cartridge. When forming an image with the first process cartridge attached, the control section applies a first developing bias to the developing roller based on the first toner information. When forming an image with the second process cartridge attached, the control section applies a first developing bias to the developing roller based on the second toner information.

[0098] Even in this form, when the first process cartridge is installed, the control unit applies a first development bias to the development roller based on the first toner information stored in the toner memory, and when the second process cartridge is installed, the control unit applies a second development bias based on the second toner information stored in the toner memory, so that when a black process cartridge and a process cartridge of a color other than black are installed, images can be formed at appropriate densities.

[0099] In the above embodiment, an example was shown in which the second charging bias Vg2 was different from the first charging bias Vg1 and the second developing bias Vb2 was different from the first developing bias Vb1, but the second charging bias Vg2 may be the same as the first charging bias Vg1 and the second developing bias Vb2 may be different from the first developing bias Vb1. Also, the second charging bias Vg2 may be different from the first charging bias Vg1 and the second developing bias Vb2 may be the same as the first developing bias Vb1.

[0100] In the above embodiment, the control unit 100 stores the usage history of image formation using the first toner cartridge 6B and the usage history of image formation using the second toner cartridge 6M in the drum memory 57, but the usage history of the first toner cartridge 6B and the usage history of the second toner cartridge 6M may also be stored in the main body memory 110.

[0101] In the above embodiment, the present invention is applied to the image forming apparatus 1, but the present invention is not limited to this, and may be applied to other image forming apparatuses, such as copying machines and multifunction machines.

[0102] The elements described in the above-described embodiment and modifications may be implemented in any combination. [Example]

[0103] Next, with reference to the tables of FIGS. 6 and 7, an example will be described in which the difference in image formation quality when the toner color, charging bias Vg, and developing bias Vb in the toner cartridge 6 are changed.

[0104] [Example 1] In Example 1, the quality of image formation was confirmed by appropriately changing the charging bias and developing bias Vb for each of the two color toners, black and magenta, in an image forming apparatus of Type A. The image forming apparatus of Type A is an apparatus that forms images at a standard speed.

[0105] As shown in Figure 6, images were formed under seven conditions, Conditions 1 to 7, using a Type A image forming apparatus, and the "density" and "fog" were visually observed to determine whether they were suitable for actual use. "Density" refers to the density of the toner used in forming the image, and values ​​within the standard range were considered "appropriate." "Fog" is toner adhering to unintended areas. Absolutely no fogging was rated "A," almost no fogging was rated "B," some fogging was rated "C," slightly noticeable fogging was rated "D," and very noticeable fogging was rated "E." The suitability for practical use was judged by a number of judges, taking into consideration "density" and "fog."

[0106] Condition 1 (black, Vg=850V, Vb=300V) was the optimum condition for black in the type A toner cartridge.

[0107] When a magenta image was formed under the same bias as the optimum condition for black, as in condition 2, the density was high and fog was quite noticeable, so it was determined to be unsuitable for use.

[0108] When the developing bias Vb was set to half the optimum value (150 V) of the optimum condition for black as in condition 3, the density was slightly high but there was almost no fogging, and it was judged to be suitable for use.

[0109] When the developing bias Vb was increased to slightly more than half (200 V) of the optimum conditions for black, as in condition 4, the density became appropriate, there was almost no fogging, and it was determined that the toner was suitable for use.

[0110] As in condition 5, when the charging bias Vg was increased by 100 V (950 V) and the developing bias Vb was decreased by 50 V (250 V) from the optimal conditions for black, the density was appropriate, but fogging occurred and it was determined that the toner was not suitable for use.

[0111] As in condition 6, when the charging bias Vg was increased by 100 V (950 V) from the optimum conditions for black and the developing bias Vb was decreased by 100 V (200 V), the density was appropriate, there was no fogging at all, and it was determined to be the most suitable for use.

[0112] When the charging bias Vg was increased by 150 V (to 1000 V) from the optimum condition for black, as in condition 7, the density became too high and fogging became noticeable, so it was determined that this was not suitable for use.

[0113] From the above results, it was confirmed that in the image forming apparatus of type A, when forming an image with magenta toner, the optimum conditions are a charging bias Vg of +100 V and a developing bias Vb of -100 V, compared to the conditions for forming an image with black toner.

[0114] [Example 2] In Example 2, the quality of image formation was confirmed by appropriately changing the charging bias and developing bias Vb for each of the two color toners, black and magenta, in an image forming apparatus of Type B. The image forming apparatus of Type B is an apparatus that forms images at 1.5 times the speed of the image forming apparatus of Type A.

[0115] As shown in Figure 7, images were formed under three conditions, conditions 8 to 10, using an image forming apparatus of type B, and the "density" and "fogging" were visually observed in the same manner as in Example 1 to determine whether they were suitable for practical use.

[0116] Condition 8 (black, Vg=850V, Vb=400V) was the optimum condition for black in the type B toner cartridge.

[0117] When a magenta image was formed under the same bias as the optimum condition for black, as in condition 9, the density was low and it was determined that this was not suitable for use.

[0118] When the developing bias Vb was increased by 100 V (500 V) from the optimum condition for black, as in condition 10, the density was appropriate, there was no fogging, and it was determined to be the most suitable for use.

[0119] From the above results, it was confirmed that in the image forming apparatus of type B, when forming an image with magenta toner, the optimum condition is to set the development bias Vb to +100V compared to the condition when forming an image with black toner. [Explanation of symbols]

[0120] 1. Image forming device 2. Device body 5 Drum Cartridge 6 Toner cartridge 6B 1st Toner Cartridge 6M 2nd Toner Cartridge 52 Photosensitive drum 61 Toner Storage Room 62 Developing roller 63 Supply roller 65 Toner Memory 100 control section TB 1st Toner TM 2nd Toner Vb Development bias Vb1 1st development bias Vb2 Second development bias

Claims

1. a toner cartridge having a toner storage chamber for storing toner, a developing roller, and a toner memory; a drum cartridge having a photosensitive drum; an apparatus main body into which the toner cartridge and the drum cartridge can be attached; a bias application circuit capable of applying a bias; a control unit, The control unit controls the bias application circuit, When an image is formed in a state in which a first toner cartridge is mounted, the toner cartridge contains a first black toner in the toner storage chamber and first toner information, which is information about the first toner, is stored in the toner memory, a first developing bias is applied to the developing roller based on the first toner information, When forming an image with a second toner cartridge installed, the toner cartridge contains a second toner of a color different from black in the toner storage chamber, and second toner information, which is information about the second toner, is stored in the toner memory, the image forming device applies a second developing bias, which is different from the first developing bias, to the developing roller based on the second toner information.

2. 2. The image forming apparatus according to claim 1, wherein only one of the first toner cartridge and the second toner cartridge can be attached to the main body of the apparatus.

3. the toner cartridge can be attached to the drum cartridge; 2. The image forming apparatus according to claim 1, wherein the toner cartridge can be mounted in the drum cartridge in the main body.

4. The drum cartridge has a charger that charges the photosensitive drum, The control unit controls the bias application circuit, When forming an image with the first toner cartridge attached, a first charging bias is applied to the charger based on the first toner information; 2. The image forming apparatus according to claim 1, wherein when forming an image with the second toner cartridge installed, a second charging bias different from the first charging bias is applied to the charger based on the second toner information.

5. the first toner information includes a value of the first developing bias; 2. The image forming apparatus according to claim 1, wherein the second toner information includes a value of the second developing bias.

6. Further provided is a main body memory in which a value of a reference developing bias is stored, 2. The image forming apparatus according to claim 1, wherein the second toner information includes an offset value of the second developing bias from the reference developing bias.

7. the device body has a display unit that displays information, The image forming apparatus according to claim 1, characterized in that the control unit displays the color of the toner contained in the installed toner cartridge on the display unit based on the first toner information or the second toner information read from the toner memory.

8. The drum cartridge has a cleaning roller that rotates in contact with the outer peripheral surface of the photosensitive drum, the first toner and the second toner are toners of positive polarity, The control unit 2. The image forming apparatus according to claim 1, wherein when forming an image with the first toner cartridge or the second toner cartridge installed, a cleaning bias of positive polarity is applied to the cleaning roller.

9. the drum cartridge has a secondary cleaning roller that rotates in contact with the outer circumferential surface of the cleaning roller, 9. The image forming apparatus according to claim 8, wherein the control section controls the bias application circuit to apply a bias to the secondary cleaning roller that is higher in positive polarity than that of the cleaning roller.

10. the drum cartridge further includes a drum memory; 2. The image forming apparatus according to claim 1, wherein the control unit stores in the drum memory a usage history of image formation using the first toner cartridge and a usage history of image formation using the second toner cartridge.

11. a process cartridge having a toner storage chamber for storing toner, a developing roller, a photosensitive drum, and a toner memory; an apparatus main body into which the process cartridge can be attached; a bias application circuit capable of applying a bias; a control unit, The control unit controls the bias application circuit, When an image is formed in a state in which a first process cartridge is mounted, the first process cartridge containing a black first toner in the toner storage chamber and having first toner information stored in the toner memory, a first developing bias is applied to the developing roller based on the first toner information, When an image is formed in a state in which a second process cartridge is attached, in which a second toner of a color different from black is accommodated in the toner storage chamber and second toner information, which is information about the second toner, is stored in the toner memory, an image forming device characterized in that a second developing bias different from the first developing bias is applied to the developing roller based on the second toner information.

Images