Image forming device
Patent Information
- Application Number
- JP2019062594
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2019-03-28
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2039-03-28
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to an image forming apparatus capable of mounting a drum cartridge and a toner cartridge.
Background Art
[0002] Conventionally, an image forming apparatus capable of mounting a drum cartridge and a toner cartridge has been known (see Patent Document 1). In this image forming apparatus, the toner cartridge is assembled to the drum cartridge and then mounted on the apparatus main body.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Generally, the life of a drum cartridge is longer than that of a toner cartridge. For this reason, there are cases where a plurality of toner cartridges are replaced and used for one drum cartridge. However, due to the deterioration of the drum cartridge, the characteristics of the photosensitive drum change, and there is a risk that the printing density will change between when printing with the first toner cartridge and when printing with the second and subsequent toner cartridges.
[0005] Therefore, an object of the present disclosure is to stabilize the printing density of an image forming apparatus.
Means for Solving the Problems
[0006] To solve the above-mentioned problems, the image forming apparatus comprises a main unit, a drum cartridge, a toner cartridge, and a control device. The drum cartridge has a photoreceptor drum, a transfer roller or a cleaning roller facing the photoreceptor drum, and a drum memory that stores the cumulative number of drum rotations of the photoreceptor drum, and is detachable from the main unit. The toner cartridge has a housing capable of containing toner, a developing roller, and a toner memory that stores the cumulative dot count. When the first toner cartridge is used to form an image on the drum cartridge, the control device, based on the cumulative number of drum rotations, sets the initial transfer current I1 to be transferred to the transfer roller when image formation is performed with the first toner cartridge, or the initial cleaning bias V to be applied to the cleaning member. C1 The process of determining the initial transfer current I1, or the initial cleaning bias V C1 After the determination is made, if a second toner cartridge, different from the first toner cartridge, is used for the drum cartridge and image formation is performed, then, based on the cumulative number of drum rotations, an initial transfer current I2 different from the initial transfer current I1, or an initial cleaning bias V C1 The initial cleaning bias V is different. C2 The process of determining and executing is possible.
[0007] This configuration allows for stable print density in the image forming apparatus even when multiple toner cartridges are used with a single drum cartridge.
[0008] In the above configuration, the control device may be configured to change the transfer current applied to the transfer roller or the cleaning bias applied to the cleaning roller in accordance with the increase in the cumulative drum rotation count and the cumulative dot count.
[0009] According to this method, the transfer current is changed in response to both the deterioration of the photoconductor drum and the deterioration of the toner, so the amount of toner transferred can be kept constant.
[0010] In the above-described configuration, the control device may be configured to increase the transfer current or the absolute value of the cleaning bias as the cumulative dot count increases.
[0011] In the above-described configuration, the control device may be configured to increase the transfer current or the absolute value of the cleaning bias as the cumulative drum rotation count increases.
[0012] In the above-described configuration, it may be configured such that I2 > I1 or |V C2 | > |V C1 |.
[0013] According to this, the toner transfer amount when using the second toner cartridge can be made closer to the toner transfer amount when using the first toner cartridge. For this reason, the printing density of the image forming apparatus can be stabilized.
[0014] In the above-described configuration, the toner cartridge may be configured to be detachable from the drum cartridge.
[0015] In the above-described configuration, the drum cartridge has a transfer roller and a cleaning roller, and the control device determines an initial transfer current I1 and an initial cleaning bias V C1 After the initial transfer current I1 and the initial cleaning bias V C1 are determined, when a second toner cartridge different from the first toner cartridge is used for the drum cartridge and image formation is performed, the control device is based on the cumulative drum rotation count, and an initial transfer current I2 different from the initial transfer current I1 and an initial cleaning bias V C1 and an initial cleaning bias V[[ID=3,4]] C2 different from that may be determined.
Advantages of the Invention
[0016] According to the image forming apparatus of this disclosure, the print density can be stabilized. [Brief explanation of the drawing]
[0017] [Figure 1] This is a cross-sectional view of an image forming apparatus according to an embodiment. [Figure 2] This diagram illustrates the application circuits for charge bias, transfer current, and cleaning bias. [Figure 3] This graph shows the relationship between cumulative drum rotations and charge bias. [Figure 4] Graph (a) shows the relationship between cumulative dot count and transfer current reference value, and graph (b) shows the relationship between cumulative dot count and cleaning bias reference value. [Figure 5] Graph (a) shows the relationship between cumulative drum rotations and transfer current correction amount, and graph (b) shows the dot count (cumulative drum rotations) and transfer current when multiple developing cartridges are used interchangeably with a single drum cartridge. [Figure 6] Graph (a) shows the relationship between cumulative drum rotations and cleaning bias correction amount, and graph (b) shows the dot count (cumulative drum rotations) and cleaning bias when multiple developing cartridges are used interchangeably with a single drum cartridge. [Modes for carrying out the invention]
[0018] Next, embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate. As shown in Figure 1, the image forming apparatus 1 is a monochrome laser printer. The image forming apparatus 1 comprises a main body 2, a feeder unit 3, an image forming unit 4, and a control device 100.
[0019] The main body of the device 2 is a hollow case. The main body of the device 2 has a pair of left and right side walls 21 and a front wall 22 connecting the side walls 21. The front wall 22 has a main body opening 22A. The front wall 22 is provided with a front cover 23 that opens and closes the main body opening 22A.
[0020] The feeder unit 3 comprises a supply tray 31 and a supply mechanism 32. The supply tray 31 is detachably mounted on the lower part of the main body 2 of the device. The supply mechanism 32 feeds the supply tray 31 and the sheets S in the supply tray 31 toward the image forming unit 4.
[0021] The image forming unit 4 comprises a scanner unit 5, a fuser unit 7, a drum cartridge 8, and a toner cartridge 9.
[0022] The scanner unit 5 is located at the top of the main body 2 of the device and includes a laser light-emitting unit (not shown), a polygon mirror, a lens, and a reflector. This scanner unit 5 irradiates the surface of the photoreceptor drum 81 (described later) with a laser beam at high speed.
[0023] The control device 100 includes, for example, a CPU, RAM, ROM, and input / output circuits, and performs printing control by performing calculations based on information about the installed cartridge and programs and data stored in the ROM.
[0024] The drum cartridge 8 is located between the feeder unit 3 and the scanner unit 5. The drum cartridge 8 is detachable from the device body 2. Specifically, the drum cartridge 8 is detachable from the device body 2 through a body opening 22A that is opened and closed by the front cover 23 of the device body 2. The toner cartridge 9 is detachable from the drum cartridge 8. The toner cartridge 9 is attached to and detached from the device body 2 while assembled with the drum cartridge 8.
[0025] The lifespan of the drum cartridge 8 is longer than that of the toner cartridge 9. Here, "longer lifespan" refers to a larger total number of printable pages or a higher total dot count. Therefore, multiple toner cartridges 9 can be used interchangeably with a single drum cartridge 8. For example, three to five toner cartridges 9 can be used interchangeably with a single drum cartridge 8.
[0026] The drum cartridge 8 comprises a frame 80, a photoconductor drum 81, a transfer roller 82, a charger 83, a cleaning roller 84, and a drum memory 85. The frame 80 is capable of mounting a toner cartridge 9. The photoconductor drum 81 is rotatably supported on the frame 80. The transfer roller 82 is positioned opposite the photoconductor drum 81.
[0027] The cleaning roller 84 is located in a different position from the transfer roller 84 and faces the photoreceptor drum 81. The cleaning roller 84 cleans any residual toner or foreign matter on the photoreceptor drum 81.
[0028] The toner cartridge 9 comprises a housing 90, a developing roller 91, a supply roller 92, a blade 93, and a toner memory 95. The housing 90 is capable of housing toner internally. The developing roller 91 supplies toner to the photoreceptor drum 81. The supply roller 92 supplies toner from the housing 90 to the developing roller 91. The blade 93 regulates the thickness of the toner layer supplied to the developing roller 91.
[0029] In this drum cartridge 8, the surface of the rotating photoreceptor drum 81 is uniformly charged by the charger 83, and then exposed by high-speed scanning of a laser beam from the scanner unit 5. As a result, the potential of the exposed area decreases, and an electrostatic latent image based on the image data is formed on the surface of the photoreceptor drum 81.
[0030] Next, the toner in the toner cartridge 9 is supplied to the electrostatic latent image on the photoreceptor drum 81 by the rotating developing roller 91, and a toner image is formed on the surface of the photoreceptor drum 81. After that, the sheet S is transported between the photoreceptor drum 81 and the transfer roller 82, and the toner image carried on the surface of the photoreceptor drum 81 is transferred onto the sheet S.
[0031] The fixing device 7 includes a heating roller 71 and a pressure roller 72. The pressure roller 72 is positioned opposite the heating roller 71. The pressure roller 72 presses against the heating roller 71. The fixing device 7 heat-fixes the toner transferred onto the sheet S as the sheet S passes between the heating roller 71 and the pressure roller 72.
[0032] The sheet S, which has been heat-fixed by the fixing device 7, is transported to the paper discharge roller 24 located downstream of the fixing device 7, and is then sent out onto the paper discharge tray 25 from the paper discharge roller 24.
[0033] The drum memory 85 is a medium for storing information, such as an IC chip, and is not limited to an IC chip. The drum memory 85 stores the cumulative number of drum rotations of the photoreceptor drum 81.
[0034] The toner memory 95 is a medium for storing information, such as an IC chip, and is not limited to an IC chip. The toner memory 95 stores, for example, the cumulative number of rotations of the developing roller 91, the number of used dots, and the remaining amount of toner. In this embodiment, the toner memory 95 stores the cumulative number of used dots.
[0035] As shown in Figure 2, the image forming apparatus 1 further includes a charge bias application circuit 210, a transfer current application circuit 270, and a cleaning bias application circuit 280.
[0036] In this embodiment, a positively charged toner is used. Corresponding to the positively charged toner, the charging bias application circuit 210 applies a positive potential bias V T It is applied.
[0037] The charge bias application circuit 210 applies a charge bias V to the charger 83. T This is a circuit for applying a charge bias. The charge bias application circuit 210 is controlled by the control device 100. Specifically, as shown in Figure 3, the control device 100 gradually applies a charge bias V as the cumulative number of drum rotations of the photoreceptor drum 81 increases. TIncrease the charge bias V. T The relationship between the cumulative number of drum rotations (Figure 3) is determined by pre-acquired experimental data so that the surface potential of the photoreceptor drum 81 remains constant. In this way, the charging performance of the photoreceptor drum 81, which deteriorates as the cumulative number of drum rotations increases, is compensated for.
[0038] Returning to Figure 2, the transfer current application circuit 270 is a circuit for applying a transfer current I to the transfer roller 82. The control device 100 determines the transfer current I to be applied to the transfer roller 82 according to the cumulative drum rotation count and the cumulative dot count.
[0039] Specifically, the transfer current I is a reference value I of the transfer current according to the cumulative dot count. n And, the transfer current correction amount I according to the cumulative drum rotation count. N It is determined by adding (I=I n +I N ).
[0040] As shown in Figure 4(a), the reference value of the transfer current I n I0 is the value when the cumulative dot count is zero (n=0). Reference value of transfer current I n This value gradually increases as the cumulative dot count increases. Here, the reference value of the transfer current when the cumulative dot count is n is I. n This is stated. Furthermore, the reference value for the transcription current is I. n The relationship between the dot count and the cumulative dot count (Figure 4) is determined by experimental data acquired in advance. In this way, even if the toner deteriorates as the dot count increases, the amount of toner transferred remains constant.
[0041] As shown in Figure 5(a), the transfer current correction amount I N This value is zero when the cumulative number of drum rotations is zero (N=0). Transfer current correction amount I N This is set to gradually increase as the cumulative number of drum rotations increases. Here, the transfer current correction amount when the cumulative number of drum rotations is N is set to I NThis is stated. Furthermore, the transfer current correction amount I N The relationship between the cumulative drum rotation count and the cumulative drum rotation count (Figure 5(a)) is determined by experimental data acquired in advance. In this way, even if the photoreceptor drum 81 deteriorates as the cumulative drum rotation count increases, the amount of toner transferred remains constant.
[0042] In this embodiment, an image is formed using a first toner cartridge, which is the first toner cartridge used for one drum cartridge, and then an image is formed using a second toner cartridge, which is different from the first toner cartridge. Furthermore, an image is formed using a third, fourth, and fifth toner cartridge in the same procedure.
[0043] As shown in Figure 5(b), the control device 100 can perform the following processes: determining the initial transfer current I1 when image formation is performed with the first toner cartridge, and determining the initial transfer current I2 when image formation is performed with the second toner cartridge. Similarly, it can perform the following processes: determining the initial transfer currents I3, I4, and I5 when image formation is performed with the third, fourth, and fifth toner cartridges.
[0044] The initial transfer current is determined based on the cumulative number of drum rotations. When the drum cartridge is new, the cumulative number of drum rotations is zero, so the initial transfer current I1 = I0 when the first drum cartridge is installed. The initial transfer current I2 when the second toner cartridge is installed is derived from the transfer current correction amount shown in Figure 5(a). When the cumulative number of drum rotations is N1, the transfer current correction amount is I N1 Therefore, the initial transfer current I2 = I0 + I when the second toner cartridge is installed is calculated as follows. N1 This is the result.
[0045] In other words, the initial transfer current I2 when the second toner cartridge is installed is a different value from the initial transfer current I1 when the first toner cartridge is installed. In this embodiment, the initial transfer current I2 is greater than the initial transfer current I1 (I2 > I1).
[0046] Similarly, when the third, fourth, and fifth toner cartridges are mounted on the first drum cartridge to perform image formation, the control device 100 increases the absolute value of the initial supply bias in proportion to the cumulative number of drum rotations (I5>I4>I3>I2).
[0047] After the initial transfer current has been determined, the control device 100 changes the transfer current I applied to the transfer roller 82 in accordance with the increase in the cumulative drum rotation count and the cumulative dot count. Specifically, the control device 100 gradually increases the transfer current I in accordance with the increase in the cumulative dot count and also gradually increases the transfer current I in accordance with the increase in the cumulative drum rotation count.
[0048] Returning to Figure 2, the cleaning bias application circuit 280 applies a cleaning bias V to the cleaning roller 84. C This is a circuit for applying a cleaning bias V. The control device 100 applies a cleaning bias V to the cleaning roller 84 according to the cumulative drum rotation count and the cumulative dot count. C To decide.
[0049] Specifically, cleaning bias V C This is the cleaning bias reference value V according to the cumulative dot count. Cn And, the cleaning bias correction amount V according to the cumulative drum rotation count. CN Determined by adding (V C =V Cn +V CN ).
[0050] As shown in Figure 4(b), the reference value of the transfer current I n When the cumulative dot count is zero (n=0), V C0 This is the cleaning bias reference value V. Cn This value gradually increases as the cumulative dot count increases. Here, the reference value of the transfer current when the cumulative dot count is n is V. Cn This is the stated value. Furthermore, the cleaning bias standard value V CnThe relationship between the dot count and the cumulative dot count (Figure 4(b)) is determined by previously acquired experimental data. In this way, the amount of cleaning remains constant even as the toner deteriorates as the dot count increases.
[0051] As shown in Figure 6(a), the cleaning bias correction amount V CN This value is zero when the cumulative drum rotation count is zero (N=0). Cleaning bias correction amount V CN This is set to gradually increase as the cumulative number of drum rotations increases. Here, the cleaning bias correction amount when the cumulative number of drum rotations is N is V. CN This is stated. Furthermore, the cleaning bias correction amount V CN The relationship between the cumulative drum rotation count and the total number of drum rotations (Figure 6(a)) is determined by experimental data acquired in advance. In this way, the amount of cleaning remains constant even as the photoreceptor drum 81 deteriorates as the cumulative drum rotation count increases.
[0052] In this embodiment, an image is formed using a first toner cartridge, which is the first toner cartridge used for one drum cartridge, and then an image is formed using a second toner cartridge, which is different from the first toner cartridge. Furthermore, an image is formed using a third, fourth, and fifth toner cartridge in the same procedure.
[0053] As shown in Figure 6(b), the control device 100 sets the initial cleaning bias V when image formation is performed with the first toner cartridge. C1 The process of determining the initial cleaning bias V when image formation is performed with the second toner cartridge. C2 The process of determining and executing is possible. Similarly, the initial cleaning bias V when image formation is performed with the third, fourth, and fifth toner cartridges. C3 ,V C4 ,V C5 It is possible to perform the process of determining this.
[0054] The initial cleaning bias is determined based on the cumulative drum rotation count. When the drum cartridge is new, the cumulative drum rotation count is zero, so the initial cleaning bias V when the first drum cartridge is installed is... C1 =V C0 This is the initial cleaning bias V when the second toner cartridge is installed. C2 This is derived from the cleaning bias correction amount shown in Figure 6(a). When the cumulative drum rotation count is N1, the cleaning bias correction amount is V CN1 This is the result. Initial cleaning bias V when the second toner cartridge is installed. C2 =V C0 +V CN1 This is the result.
[0055] In other words, the initial cleaning bias V when the second toner cartridge is installed. C2 This is the initial cleaning bias V when the first toner cartridge is installed. C1 This is a different value from the initial cleaning bias V. In this embodiment, the initial cleaning bias V C2 The initial cleaning bias V C1 (V) C2 >V C1 ).
[0056] Similarly, when the third, fourth, and fifth toner cartridges are mounted on the first drum cartridge to perform image formation, the control device 100 increases the absolute value of the initial cleaning bias in proportion to the cumulative number of drum rotations (V C5 >V C4 >V C3 >V C2 ).
[0057] After the initial cleaning bias has been determined, the control device 100 applies a cleaning bias V to the cleaning roller 84 in accordance with the increase in the cumulative drum rotation count and the cumulative dot count. C The cleaning bias V is changed as the cumulative dot count increases. Specifically, the control device 100 changes the cleaning bias V CAs the cleaning bias V is gradually increased, the cleaning bias V increases in proportion to the cumulative number of drum rotations. C Gradually increase the size.
[0058] As described above, the image forming apparatus 1 of this embodiment provides the following effects.
[0059] After the initial transfer current I1 is determined, if a second toner cartridge, different from the first toner cartridge, is used for image formation in the drum cartridge, the control device 100 determines an initial transfer current I2, which is different from the initial transfer current I1, based on the cumulative number of drum rotations. Therefore, even if the photoreceptor drum 81 deteriorates as the cumulative number of drum rotations increases, the amount of toner transferred remains constant. Similarly, the control device 100 determines the initial cleaning bias V C1 After this has been determined, if a second toner cartridge, different from the first toner cartridge, is used for image formation in the drum cartridge, the initial cleaning bias V is determined based on the cumulative number of drum rotations. C1 The initial cleaning bias V is different. C2 This determines the amount of cleaning required. As a result, even if the photoreceptor drum 81 deteriorates as the cumulative drum rotation count increases, the amount of cleaning remains constant. Consequently, the image forming apparatus 1 can stabilize the print density even when multiple toner cartridges are used with a single drum cartridge.
[0060] Furthermore, the control device 100 changes the transfer current I applied to the transfer roller 82 in accordance with the increase in the cumulative drum rotation count and the cumulative dot count. Therefore, the transfer current I can be changed in accordance with both the deterioration of the photoreceptor drum 81 and the deterioration of the toner. As a result, the amount of toner transferred can be kept constant. Similarly, the control device 100 applies a cleaning bias V to the cleaning roller 84 as the cumulative drum rotation count and cumulative dot count increase. CSince this changes the cleaning bias V, it will be adjusted according to both the deterioration of the photoconductor drum 81 and the deterioration of the toner. C This can be changed. Therefore, the amount of toner used for cleaning can be kept constant.
[0061] Furthermore, the control device 100 increases the transfer current I as the cumulative dot count increases. This allows the amount of toner transferred to remain constant even if the toner in the toner cartridge 9 deteriorates. This is because, although the toner's power decreases as it deteriorates, increasing the transfer current I can suppress the decrease in the amount of toner transferred. Similarly, the control device 100 adjusts the cleaning bias V as the cumulative dot count increases. C The absolute value of is increased. Therefore, even if the toner in the toner cartridge 9 deteriorates, the amount of toner cleaning can be kept constant. This is because when the toner deteriorates, the toner's charging power decreases, but the cleaning bias V C This is because increasing the absolute value of [the value] can suppress the decrease in the amount of cleaning.
[0062] Furthermore, the control device 100 increases the transfer current I in accordance with the increase in the cumulative number of drum rotations. This allows the amount of toner transferred to remain constant even if the photoreceptor drum 81 deteriorates. This is because, although the surface of the photoreceptor drum 81 becomes rougher as it deteriorates, increasing the transfer current I can suppress the decrease in the amount of toner transferred. Similarly, the control device 100 adjusts the cleaning bias V as the cumulative number of drum rotations increases. C The absolute value of is increased. Therefore, even if the photoconductor drum 81 deteriorates, the amount of toner cleaning can be kept constant. This is because when the photoconductor drum 81 deteriorates, the surface of the photoconductor drum 81 becomes rough and the adhesion force of the toner increases, but the cleaning bias V C This is because increasing the absolute value of [the value] helps to suppress the reduction in the amount of cleaning required.
[0063] Furthermore, the control device 100 sets the initial transfer current I2 of the second toner cartridge to a value greater than I1 (I2 > I1). This makes it possible to bring the amount of toner transferred when using the second toner cartridge closer to the amount of toner transferred when using the first toner cartridge. As a result, the print density of the image forming apparatus 1 can be stabilized. This is because, when multiple toner cartridges are used for one drum cartridge, the photoreceptor drum 81 deteriorates when the second and subsequent toner cartridges are installed. Similarly, the control device 100 sets the absolute value of the initial cleaning bias of the second toner cartridge |V|. C2 | to | V C1 |Let it be a value greater than (|V C2 |>|V C1 Therefore, the amount of toner cleaning when using the second toner cartridge can be brought closer to the amount of toner cleaning when using the first toner cartridge. As a result, the print density of the image forming apparatus 1 can be stabilized.
[0064] This disclosure is not limited to the embodiments described above and can be used in various forms as illustrated below.
[0065] In the embodiments described above, a positively charged toner was used, but a negatively charged toner may also be used. In this case, a negative potential bias should be applied to the charging bias application circuit 210 and the cleaning bias application circuit.
[0066] In the embodiments described above, the control device controls the initial transfer current I1 and the initial cleaning bias V C1 Determine the initial transfer current I1 and the initial cleaning bias V. C1 After this is determined, the control device, when a second toner cartridge different from the first toner cartridge is used for image formation in the drum cartridge, determines an initial transfer current I2 different from the initial transfer current I1, and an initial cleaning bias V based on the cumulative number of drum rotations.C1 and a different initial cleaning bias V C2 was determined. However, the control device determines an initial transfer current I1 or an initial cleaning bias V C1 and, after the initial transfer current I1 or the initial cleaning bias V is determined, when a second toner cartridge different from the first toner cartridge is used for the drum cartridge and image formation is performed, the control device, based on the cumulative drum rotation count, determines an initial transfer current I2 different from the initial transfer current I1 or an initial cleaning bias V C1 and a different initial cleaning bias V C1 may be configured to be determined. C2 In the above-described embodiment, the control device 100 increased the transfer current I as the cumulative dot count of the drum cartridge 8 increased, but it may be configured to determine the current value according to the cumulative drum rotation count or the toner remaining amount instead of the cumulative dot count.
[0067] [[ID= / / ]] In the above-described embodiment, a monochrome laser printer was exemplified as the image forming apparatus, but the image forming apparatus may be a color laser printer or a copying machine or a multifunction peripheral.
[0068] The elements described in the above-described embodiment and the modification examples can also be implemented by arbitrarily combining them.
[0069] [[ / END]]
[0070]
Description of Reference Numerals
Claims
1. An image forming apparatus, A device body, a drum cartridge detachably attached to the device main body, the drum cartridge having a photosensitive drum, a transfer roller facing the photosensitive drum or a cleaning roller facing the photosensitive drum, and a drum memory for storing the cumulative number of drum rotations of the photosensitive drum; a toner cartridge having a housing capable of containing toner, a developing roller, and a toner memory for storing a cumulative dot count; a control device; The control device When the first toner cartridge is used for the drum cartridge to form an image, an initial transfer current I1 to be transferred to the transfer roller when image formation is performed with the first toner cartridge is determined based on the cumulative number of drum rotations, or an initial cleaning bias V to be applied to the cleaning member. C1 and determining The initial transfer current I1 or the initial cleaning bias V C1 After the initial transfer current I1 is determined, when a second toner cartridge different from the first toner cartridge is used for the drum cartridge and image formation is performed, an initial transfer current I2 different from the initial transfer current I1 or an initial cleaning bias V C1 and different initial cleaning bias V C2 and determining An image forming apparatus characterized in that it is capable of executing the above.
2. The image forming apparatus according to claim 1, characterized in that the control device changes the transfer current applied to the transfer roller or the cleaning bias applied to the cleaning roller in accordance with an increase in the cumulative number of drum rotations and the cumulative dot count.
3. 3. The image forming apparatus according to claim 2, wherein the control device increases the transfer current or increases the absolute value of the cleaning bias as the cumulative dot count increases.
4. 4. The image forming apparatus according to claim 2, wherein the control device increases the transfer current or increases the absolute value of the cleaning bias as the cumulative number of drum rotations increases.
5. I2>I1, or |V C2 |>|V C1 5. The image forming apparatus according to claim 1, wherein: |
6. 6. The image forming apparatus according to claim 1, wherein the toner cartridge is detachable from the drum cartridge.
7. the drum cartridge has the transfer roller and the cleaning roller, The control device controls the initial transfer current I1 and the initial cleaning bias V C1 Determine The initial transfer current I1 and the initial cleaning bias V C1 After the initial transfer current I1 is determined, when a second toner cartridge different from the first toner cartridge is used for the drum cartridge and image formation is performed, the control device determines an initial transfer current I2 different from the initial transfer current I1 and an initial cleaning bias V based on the cumulative number of drum rotations. C1 and different initial cleaning bias V C2 7. The image forming apparatus according to claim 1, wherein the image forming apparatus determines whether or not the image forming apparatus is a multi-image forming apparatus.