JP2010210943A - Image forming apparatus and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize deterioration in convenience and productivity of an image forming apparatus resulting from forcible supply of toner in the image forming apparatus. <P>SOLUTION: When a print job for a monochrome image is performed, a process for supplying color toner is performed in steps S40 to S50. This causes a printer to continuously perform a monochrome image print job and to continuously inhibit a color image print job. Consequently, even when toner in each developing section for color is used only under stabilization control, the toner is supplied to the color developing section when a monochrome image print job is performed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus capable of forming an image with toner and a control method thereof.

  Some image forming apparatuses perform image formation using toner. In such an image forming apparatus, toner filled in a toner bottle or the like is appropriately supplied to a developing device to form an image.

  2. Description of the Related Art Conventionally, in an image forming apparatus that forms a full-color image, a toner pattern image is formed on an image carrier, and the toner pattern image or the transferred toner pattern image is detected. Control for always forming an appropriate image against the fluctuation of the image, so-called image stabilization control is executed.

  Such stabilization control is generally performed periodically, such as every predetermined number of prints. As an image forming apparatus that executes such stabilization control, for example, Japanese Patent Application Laid-Open No. 2007-57929 (Patent Document 1) discloses an image forming apparatus capable of image formation in a monochrome mode and a color mode. Has been. In this image forming apparatus, when the stabilization control is performed a predetermined number of times or more during the period in which the monochrome mode image formation is continued, the color toner is forcibly supplied in consideration of the consumption of the color toner in the stabilization control. Is done.

JP 2007-57929 A

  In the image forming apparatus as described above, if the replenishment cannot catch up in the normal toner replenishment mode, the toner is replenished to the developing device in the forced toner replenishment mode. The forced toner supply mode is a mode in which an image forming operation or the like in the image forming apparatus is stopped to supply toner. The normal toner replenishment mode is a mode in which the amount of toner in the developing device is detected during a printing operation, and when it is detected that the remaining amount of toner is below a predetermined amount, the toner is replenished to the developing device. is there.

  Conventionally, some image forming apparatuses can form a color image and a monochrome image. However, in the normal toner replenishment mode of such an image forming apparatus, color toner is replenished when a color image is formed. When a monochrome image is formed, monochrome toner is replenished.

  In the stabilization control described above, both the monochrome toner and the color toner are consumed for forming the toner pattern image.

  Therefore, in the conventional image forming apparatus, when the monochrome image is continuously formed, the color toner is not replenished with the toner in the normal toner replenishment mode, but is stabilized. In control, toner is consumed. Therefore, when monochrome image formation is continuously performed, it is necessary to perform color toner replenishment in the forced toner replenishment mode in order to replenish color toner.

  In Patent Document 1 described above, when the stabilization control is performed a predetermined number of times or more, the color is forcibly replenished.

  However, forced toner replenishment takes a relatively long time, and during that time, the image forming operation cannot be performed, resulting in a decrease in convenience and productivity of the image forming apparatus.

  The present invention has been conceived in view of such circumstances, and an object of the present invention is to avoid as much as possible a decrease in convenience and productivity due to forced replenishment of toner in the image forming apparatus.

  An image forming apparatus according to the present invention includes a first developing unit that performs development using a first toner, a second developing unit that performs development using a second toner, and a first developing unit. Control means comprising: first detection means for detecting toner amount; first supply means for supplying toner to the first developing unit; and control means for controlling a toner supply mode by the first supply means. When the first detection unit detects that the amount of toner in the first development unit is less than a predetermined amount during the execution of the image forming operation by the second development unit, Toner is replenished to one developing unit.

  The image forming apparatus of the present invention further includes a second detection unit that detects the amount of toner in the second developing unit, and a second supply unit that supplies toner to the second developing unit, and includes a control unit. Further controls the toner supply mode by the second supply unit, and causes the first supply unit to supply toner to the first development unit during the execution of the image forming operation by the second development unit. In addition, when the replenishment of toner to the first developing unit is completed before the end of the image forming operation, the second detection unit detects that the toner amount in the second developing unit is less than a certain amount. It is preferable that the second replenishing unit replenishes toner to the second developing unit on the condition of the above.

  Further, in the image forming apparatus of the present invention, the control unit performs the first operation when the toner supply to the first developing unit by the first supplying unit is completed during the execution of the image forming operation by the second developing unit. When the remaining amount of the image forming operation by the second developing unit is less than the specific amount, the second replenishing unit supplies toner to the second developing unit during the execution of the image forming operation by the second developing unit. It is preferable not to let

  An image forming apparatus control method according to the present invention includes an image forming apparatus including a first developing unit that performs development using a first toner and a second developing unit that performs development using a second toner. In the control method, during the execution of the image forming operation by the second developing unit, detecting whether or not the toner amount in the first developing unit is less than a predetermined amount, and the image by the second developing unit A step of replenishing toner to the first developing unit when the toner amount in the first developing unit is less than a predetermined amount during execution of the forming operation.

  The image forming apparatus control method according to the present invention provides a case in which toner supply to the first developing unit is completed before the end of the image forming operation during execution of the image forming operation by the second developing unit. Detecting whether the toner amount in the second developing unit is less than a certain amount, and detecting that the toner amount in the second developing unit is less than the certain amount, the second developing unit Preferably, the method further comprises a step of replenishing toner.

  The image forming apparatus control method according to the present invention provides a case in which toner supply to the first developing unit is completed before the end of the image forming operation during execution of the image forming operation by the second developing unit. When the remaining amount of the image forming operation by the second developing unit is less than the specific amount, it is preferable not to execute toner supply to the second developing unit during the execution of the image forming operation by the second developing unit. .

  According to the present invention, during the execution of the image forming operation by the second developing unit, the toner amount in the first developing unit is detected, and it is detected that the toner amount is less than the predetermined amount. Then, the toner is supplied to the first developing unit.

  Accordingly, in an image forming apparatus provided with a plurality of developing units, image formation using only some of the developing units is continuously performed, and toner in other developing units is used only by stabilization control. Even in such a case, at the time of image formation using only the part of the developing units, toner is replenished in other developing units.

  Therefore, in the above case, it is possible to suppress execution of forced toner replenishment control that interrupts the image forming operation to the other developing units. A situation that reduces productivity can be avoided as much as possible.

FIG. 2 is a schematic diagram illustrating a specific example of a cross section of a central portion of a printer which is an embodiment of an image forming apparatus of the present invention. FIG. 2 is a control block diagram of the printer of FIG. 1. FIG. 2 is a diagram for explaining an internal configuration of a toner bottle of the printer of FIG. 1. FIG. 2 is a diagram for explaining an internal configuration of a cartridge of the printer in FIG. 1. 3 is a flowchart of toner supply control processing executed in the printer of FIG. 1. 6 is a flowchart of a first modification of the toner supply control process of FIG. 5. 6 is a flowchart of a second modification of the toner supply control process of FIG. 5.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same.

[1. Configuration of image forming apparatus]
The image forming apparatus according to the present invention includes a printer, a copier, a facsimile, and an MFP (Multi Function Peripheral) that is a device that combines these functions. In this embodiment, it is assumed that the image forming apparatus is a tandem color printer (hereinafter abbreviated as a printer).

  FIG. 1 is a schematic diagram illustrating a specific example of a cross section of a central portion of a printer 1 according to the present embodiment. Referring to FIG. 1, a printer 1 according to the present embodiment is mainly configured to include an image forming unit and a paper conveyance unit that is a printing medium.

  The image forming unit includes an annular intermediate transfer belt 2 that is an intermediate transfer member and is suspended from the inside by a plurality of rollers, which is disposed at a substantially central portion inside the printer 1. The intermediate transfer belt 2 is connected to the main motor 18 and is rotated by the rotation of the main motor 18. Along the intermediate transfer belt 2, cartridges 28a, 28b, 28c, and 28d corresponding to the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are arranged. These are representatively referred to as a cartridge 28. In the cartridge 28, as toner image forming means for forming a toner image by an electrostatic recording method, photoconductors 3a, 3b, 3c, 3d for transferring the toner image onto the intermediate transfer belt 2, and the surface of the photoconductor are respectively provided. Charger 5a, 5b, 5c, 5d for uniformly charging, exposure unit 6a, 6b, 6c, 6d for exposing and sequentially forming image patterns of respective colors on the photosensitive member, and supplying toner to the photosensitive member Thus, the developing units 4a, 4b, 4c and 4d for developing the toner image on the photosensitive member are included. These are representatively referred to as a photoreceptor 3, a charging unit 5, an exposure unit 6, and a developing unit 4. Of the cartridges 28, the developing mechanism of the color cartridge is connected to the developing motor 20, and the developing mechanism of the monochrome cartridge is connected to the developing motor 21, and each of them is driven to rotate.

  Further, the image forming unit accommodates the intermediate transfer belt cleaner 7 disposed around the intermediate transfer belt 2 and separating the residual toner remaining on the intermediate transfer belt 2 from the intermediate transfer belt 2 and the separated residual toner. Waste toner box 15 and toner bottles 25a, 25b, 25c, and 25d for supplying toner to cartridges 28a, 28b, 28c, and 28d by incorporating and operating stirring blades 26a, 26b, 26c, and 26d, respectively. included.

  The toner bottle 25a is connected to the toner supply motor 23a, the toner bottle 25b is connected to the toner supply motor 23b, the toner bottle 25c is connected to the toner supply motor 23c, and the toner bottle 25d is connected to the toner supply motor 23d. As a result, the stirring blades 26a, 26b, 26c, and 26d operate.

  Further, in the image forming unit, a toner image transferred onto the intermediate transfer belt 2 that forms a pair with the intermediate transfer belt 2 sandwiched between the roller that suspends the intermediate transfer belt 2 from the inside is transferred onto the conveyed paper. The secondary transfer roller 11 is included.

In addition, the image forming unit is provided with a static eliminating cloth 33 for eliminating the charge of the recording medium.
The transport unit includes a paper feed roller 8 that feeds paper from a storage unit 16 that is a cassette for storing paper, and a transport roller 30 that transports the supplied paper. The timing roller 10 for temporarily stopping the paper sheet, the secondary transfer roller 11 described above, and a heater that is arranged with the conveyed paper interposed therebetween and that heats and fixes the toner image transferred onto the paper sheet. A pair of fixing rollers 12 a and 12 b (representing them as the fixing roller 12), a paper discharge roller 13 that discharges or conveys the fixed paper to the double-sided conveyance path 29, and timing via the double-sided conveyance path 29 Double-sided path conveying rollers 14 a and 14 b that convey the sheet to the roller 10 are included. The paper feed roller 8, the timing roller 10, and the secondary transfer roller 11 are connected to the main motor 18 and are rotated by the rotational drive of the main motor 18. The fixing roller 12 is connected to the fixing motor 19 and is rotated by the rotation driving of the fixing motor 19. The double-side path transport rollers 14 a and 14 b are connected to the double-side path transport motor 22 and are rotated by the rotational drive of the double-side path transport motor 22. The transport roller 30 is connected to the transport motor 31 and is rotated by the rotational drive of the transport motor 31.

  In addition, a sheet detection sensor 27 is disposed at a position in the conveyance path immediately after the sheet passes through the secondary transfer roller 11, and the leading edge of the sheet has passed the position and / or the trailing edge of the sheet has passed. Detected.

  Further, the printer 1 includes an engine unit 100 that controls the whole and a controller unit 200 that performs image processing in accordance with a control signal from the engine unit 100. FIG. 2 is a control block diagram of the printer 1 of FIG.

  Referring to FIG. 2, the engine unit 100 includes a paper feed / conveyance control unit 101, a storage medium control unit 102, an I / F (interface) control unit 103, a fixing control unit 104, and an image formation control unit 105. And a toner replenishment control unit 106.

  The engine unit 100 includes a CPU (Central Processing Unit). The storage medium control unit 102 is connected to a storage medium such as a RAM (Random Access Memory) 107 and a ROM (Read Only Memory) 108.

  When the CPU reads out and executes a necessary program from the RAM 107 or the ROM 108, each control unit described above is configured on the CPU. Each control unit may be configured using at least a part of the hardware configuration illustrated in FIG. 1 or FIG. In addition, the storage medium control unit 102 can store data measured by the CPU in the storage medium.

  The I / F control unit 103 is connected to the controller unit 200 and exchanges various types of information. The controller unit 200 is connected to the operation panel 201 and inputs an operation signal from the operation panel 201 to the I / F control unit 103. The I / F control unit 103 passes a print request and information specifying the paper size and type, and inputs a control signal for performing image processing to the controller unit 200. The controller unit 200 includes an image processing unit (not shown) that performs image processing in accordance with a control signal from the engine unit 100. The controller unit 200 inputs a digital image signal as an image processing result to the I / F control unit 103.

  The paper feed conveyance control unit 101 is connected to the paper detection sensor 27 and receives a detection signal from the paper detection sensor 27. When the printer 1 includes other detection sensors, the detection signals may be received from the other detection sensors. The CPU generates a control signal for controlling each unit based on the detection signal and the operation signal.

  The sheet feeding / conveying control unit 101 is further connected to a load related to conveyance such as the motors 18, 22, and 31. The fixing control unit 104 is connected to a load related to a fixing process such as the fixing roller 12 and the fixing motor 19 which are also heaters. The paper feed conveyance control unit 101 and the fixing control unit 104 determine the paper conveyance timing, conveyance speed and fixing temperature, and fixing timing based on the detection signal, and accordingly, the motors 18, 22, 31 and the fixing unit respectively. A control signal for rotating or stopping the motor 19 or heating the fixing roller 12 is output.

  The image formation control unit 105 generates a control signal based on a digital image signal that is an image processing result in the controller unit 200, and the photosensitive member 3, the developing unit 4, the charging unit 5, the exposure unit 6, and the motors 20 and 21. Output for. The exposure unit 6 irradiates laser light according to the control signal. Thereby, an electrostatic latent image is formed on the surface of the photoreceptor 3 for each color.

  In the printer 1, the type of paper being conveyed is determined. As described above, the conveyance roller 30 rotates by the transmission of the conveyance motor 31 and conveys the paper. Therefore, as an example, the paper type can be determined using the transport motor 31. Of course, it is also possible to determine the type of paper in the same manner using another transport motor. However, the transport motor 31 is a dedicated motor for driving the transport roller 30, and the transport roller 30 is used to transport the paper immediately after being fed. Therefore, determining the paper type using the motor 31 determines the type of paper immediately after feeding. Therefore, when it is determined that the paper type is inappropriate for the printer 1, the paper is prevented from being transported when it has passed the transport roller 30, thereby reducing damage to the apparatus at an earlier stage. be able to.

[2. Configuration of image forming unit]
As described above, the image forming unit of the printer 1 according to the present embodiment includes the toner bottle 25 and the cartridge 28 for each color of YMCK.

  FIG. 3 is a diagram for explaining the internal configuration of the toner bottle 25 (toner bottles 25a, 25b, 25c, and 25d).

  With reference to FIG. 3A, the toner bottle 25 includes a toner storage unit 251, a preliminary stirring unit 252, and a buffer unit 253.

  The preliminary stirring unit 252 includes a toner level sensor 2520 (toner level sensors 2520a, 2520b, 2520c, and 2520d) for detecting the amount of toner in the preliminary stirring unit 252, and a cartridge 28 (cartridges 28a, 28b, 28c, 28d) is provided with a hopper for dropping the toner.

A longitudinal sectional view of the hopper is shown in FIG.
Referring to FIG. 3B, hopper 2521 accommodates stirring blades 26 (stirring blades 26a, 26b, 26c, and 26d). Then, the stirring blade 26 is rotated by rotating the toner supply motor 23 (toner supply motors 23a, 23b, 23c, and 23d). As a result, the toner in the toner storage unit 251 falls to the cartridge 28 via the hopper 2521, whereby the toner can be supplied to the cartridge 28.

[3. Cartridge configuration]
FIG. 4 is a diagram schematically showing the internal configuration of the cartridge 28 (cartridges 28a, 28b, 28c, 28d).

  Referring to FIG. 4, a toner replenishing port 280 serving as an inlet for the toner supplied from the toner bottle 25 is provided on the upper surface of the cartridge 28. The toner supplied to the cartridge 28 through the toner supply port 280 is temporarily stored in the storage unit 285. Then, the paper is conveyed in the longitudinal direction by the replenishing roller 282 and replenished to the buffer unit 286 sequentially. The toner supplied to the buffer unit 286 is stirred by the stirring member 283. Since the blades 283A of the agitating member 283 are attached obliquely with respect to the longitudinal direction of the agitating member 283, both ends in the major axis direction rise and fall alternately by the rotation of the rotating shaft 283X, and stir the toner in a zigzag manner. As a result, the toner is agitated in an oblique direction, so that the toner is conveyed in the longitudinal direction and is also agitated in the depth direction.

  The agitated toner is supplied to the surface of a developing roller (not shown) by rotation of a supply roller (not shown).

  The storage unit 285 is provided with a toner level sensor 281 for detecting the toner density in the storage unit 285. The toner level sensor 281 includes, for example, optically, that is, a light emitting element and a light receiving element, and detects the toner amount based on the intensity of light detected by the light receiving element. Cleaning of the received light amount detection window of the light receiving element in the toner level sensor 281 is performed by the cleaning member 284. The cleaning member 284 cleans the detection window by, for example, reciprocating in the double arrow direction in FIG. 4 using the developing motors 20 and 21 as drive sources.

[4. General toner replenishment method]
In the printer 1, when an image forming operation is executed in response to an image forming instruction from an external device such as a personal computer, the amount of toner consumed in the image forming operation is calculated. Will be replenished.

  As for the toner consumption amount, the toner consumption amount for each color is calculated based on the number of dots for each color in the image data to be image formed, acquired from the controller during the image forming operation.

  Here, by rotating the toner supply motor 23 (toner supply motors 23a, 23b, 23c, and 23d) for a predetermined time, the stirring blades 26 are rotated and the toner supplied from the toner bottle 25 to the cartridge 28 is rotated. Let the amount be the amount of toner that can be replenished in one replenishment operation. When the toner consumption calculated as described above exceeds the amount of toner that can be replenished by one replenishment operation, the image forming operation is stopped and the mode is changed to a mode in which the toner replenishment operation is performed. Is done. The mode in which the image forming operation is interrupted and the toner is replenished is hereinafter referred to as “forced toner replenishment mode” in the present specification.

[5. Toner supply control process]
In the printer 1, when an instruction for an image forming operation is input via the controller unit 200, control processing for the image forming control unit 105 to execute a job is started according to the instruction, and the toner supply control unit 106 Then, the toner supply control process is executed. The toner supply control process will be described with reference to FIG. 5 which is a flowchart of the process.

  Referring to FIG. 5, in toner replenishment control processing, toner replenishment control unit 106 first determines in step S10 whether the instructed image forming operation is a monochrome image print job, and prints a color image. If it is determined that the job is a job, the process proceeds to step S20. If it is determined that the job is a monochrome image print job, the process proceeds to step S40.

  In step S20, the toner replenishment control unit 106 detects the remaining amount of toner of all colors in the cartridge 1 in the cartridge 28, and each toner level sensor 281 (toner level sensor) of each cartridge 28a, 28b, 28c, 28d. 281 is provided in each of the cartridges 28a, 28b, 28c, and 28d.) When the remaining amount of toner detected by the cartridge 28a, 28b, 28c, and 28d is less than a predetermined amount that does not require toner supply for at least one color ( In an empty state), in step S30, a process for supplying toner for that color is executed. On the other hand, when the remaining amount of toner detected by the toner level sensor 281 is equal to or greater than the predetermined amount (full state), the toner supply control unit 106 ends the toner supply control process.

  In step S40, the toner replenishment controller 106 detects the color toner level, that is, detects the remaining amount of toner in the cartridges 28a, 28b, and 28c, and at least one of the remaining amounts of toner in each cartridge 28 is detected. It is determined whether or not the amount is less than the predetermined amount described above, and if it is determined that it is (empty state), the process proceeds to step S50.

  In step S50, the toner replenishment control unit 106 executes a color toner replenishment mode in which toner is replenished to the toner cartridge 28 in which the remaining amount of toner is less than the predetermined amount, and the process returns to step S40.

  On the other hand, if all the remaining amount of toner in the color cartridges 28a, 28b, 28c is equal to or greater than the predetermined amount in step S40, the toner replenishment control unit 106 advances the process to step S60.

  In step S60, the toner replenishment control unit 106 determines whether or not the remaining amount of toner in the black (K) cartridge 28d is less than the predetermined amount (step S60). In S70, the monochrome toner supply mode is executed, and the process returns to Step S10. If it is determined in step S60 that the remaining amount of toner in the black cartridge 28d is equal to or greater than the predetermined amount, the toner supply control unit 106 ends the toner supply control process. The predetermined amount for the black cartridge 28d in the present embodiment corresponds to the specific amount of the present invention.

  In the present embodiment described above, the developing units 4a, 4b, and 4c constitute the first developing unit that performs development using the first toner. Here, each color toner of YMC corresponds to the first toner. In the present embodiment, the developing unit 4d constitutes a second developing unit that performs development using the second toner. The K toner corresponds to the second toner.

  In the toner supply control process described above, when a monochrome image print job is executed, a process for supplying color toner is executed in steps S40 to S50. As a result, the printer 1 continuously performs monochrome image print jobs and does not perform color image print jobs, and the toner in each color developing unit is used only by stabilization control. Even in such a case, toner is supplied to the color developing unit during a monochrome image print job.

[6. Second Embodiment]
Next, a second embodiment of the image forming apparatus of the present invention will be described.

  The printer of the present embodiment has the same configuration as the printer 1 of the first embodiment, and the contents of the toner replenishment control process to be executed are different.

FIG. 6 is a flowchart of a first modification of the toner supply control process.
Referring to FIG. 6, in the toner replenishment control process, toner replenishment control unit 106 first determines in step S10 whether the instructed image forming operation is a monochrome image print job, and prints a color image. If it is determined that the job is a job, the process proceeds to step S20. If it is determined that the job is a monochrome image print job, the process proceeds to step S40.

  In step S20, the toner replenishment control unit 106 detects the remaining amount of toner for all colors in the cartridge 28 in the printer 1, and when the remaining amount of toner for at least one color is smaller than the predetermined amount (empty state). In step S30, a process for replenishing toner for that color is executed. On the other hand, when the remaining amount of toner of all colors detected by the toner level sensor 281 is equal to or more than the predetermined amount (full state), the toner supply control unit 106 ends the toner supply control process.

  In step S40, the toner replenishment controller 106 detects the color toner level, that is, detects the remaining amount of toner in the cartridges 28a, 28b, and 28c, and at least one of the remaining amounts of toner in each cartridge 28 is detected. It is determined whether or not the amount is less than the predetermined amount described above, and if it is determined that it is (empty state), the process proceeds to step S50.

  In step S50, the toner replenishment control unit 106 executes a color toner replenishment mode in which toner is replenished to the toner cartridge 28 whose remaining amount of toner is less than the predetermined amount, and the process proceeds to step S52.

  In step S52, the toner replenishment control unit 106 determines whether or not the job executed by the image formation control unit 105 has been completed. If it is determined that the job is still being executed, the process proceeds to step S54, and the job When it is determined that the toner supply control is completed, the toner supply control process is terminated.

  In step S54, as in step S40, the toner replenishment control unit 106 detects the color toner level, and determines whether or not at least one of the remaining amount of toner in each cartridge 28 is less than the predetermined amount. If it is determined that this is the case (empty state), the process returns to step S52. On the other hand, if it is determined that all the remaining amount of toner is equal to or greater than the predetermined amount, the process proceeds to step S56.

  In step S56, the toner replenishment control unit 106 causes the image formation control unit 105 to switch the operation mode to the job suspension replenishment mode, and proceeds to step S60. The job suspension supply mode is a mode in which the image forming control unit 105 stops a job being executed. In the printer 1, it is assumed that the toner replenishment is completed on the condition that the remaining amount of toner in the cartridge 28 that is the target of toner replenishment has reached a predetermined amount.

  In step S60, the toner replenishment control unit 106 determines whether or not the remaining amount of toner in the black cartridge 28d is less than the predetermined amount (empty state). The monochrome toner supply mode is executed, and the process returns to step S10. If it is determined in step S60 that the remaining amount of toner in the black cartridge 28d is equal to or greater than the predetermined amount, the toner supply control unit 106 ends the toner supply control process.

  In the toner replenishment control process of the present embodiment described above, when a monochrome image print job is executed, a process for supplying color toner is executed. When the color toner supply is completed, the process shifts to the print pause supply mode, the print job being executed is paused, and the monochrome toner supply in steps S60 to S70 is performed. When the replenishment is completed, the print job is resumed. As a result, it is possible to avoid operating the developing unit 4 (particularly, the developing motor 20 of the developing mechanism of the color cartridge) unnecessarily.

[7. Third Embodiment]
Next, a third embodiment of the image forming apparatus of the present invention will be described.

  The printer of the present embodiment has the same configuration as the printer 1 of the first embodiment, and the contents of the toner replenishment control process to be executed are different.

  Referring to FIG. 7, in the toner replenishment control process of the present embodiment, the process of step S55 is performed between step S54 and step S56 of the toner replenishment control process in the second embodiment described with reference to FIG. Corresponds to the one added.

  In step S54 of the toner replenishment control process of the present embodiment, the toner replenishment control unit 106 detects the color toner level, and determines whether at least one of the remaining amount of toner in each cartridge 28 is less than the predetermined amount. If it is determined that this is the case (empty state), the process returns to step S52. On the other hand, if it is determined that all the remaining amount of toner is equal to or greater than the predetermined amount, the process proceeds to step S55.

  In step S55, the toner replenishment control unit 106 receives an instruction from the controller unit 200 and determines whether or not the number n of jobs waiting for execution in the image formation control unit 105 is equal to or less than a predetermined set value m. If it is determined that it is greater than or equal to m, the process of step S56 is executed and then the process proceeds to step S60. If it is determined that it is less than m, the process proceeds directly to step S56.

  In step S56, the toner replenishment control unit 106 causes the image formation control unit 105 to switch the operation mode to the job suspension replenishment mode, and proceeds to step S60.

  In the present embodiment described above, when a monochrome image print job is executed, a process for replenishing color toner is executed. However, the print job being executed ends and the printer 1 On condition that the number of registered jobs waiting to be executed is equal to or more than a predetermined number m, the process shifts to the print pause replenishment mode, pauses the print job being executed, and then steps S60 to S70. The monochrome toner is replenished, and when the monochrome toner replenishment is completed, the print job is resumed. Thus, if the number of remaining jobs to be executed by the image formation control unit 105 is small, the monochrome toner is replenished while the image forming operation is continued without interruption. In step S55, whether or not to execute step S56 may be determined based on the number of remaining prints instead of the number of remaining jobs.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 printer, 2 intermediate transfer belt, 3, 3a, 3b, 3c, 3d photoconductor, 4, 4a, 4b, 4c, 4d developing unit, 5, 5a, 5b, 5c, 5d charging unit, 6, 6a, 6b, 6c, 6d Exposure section, 7 Intermediate transfer belt cleaner, 8 Feed roller, 10 Timing roller, 11 Secondary transfer roller, 12, 12a, 12b Fixing roller, 13 Paper discharge roller, 14a, 14b Double-side path transport roller, 15 Waste Toner box, 16 storage section, 18 main motor, 19 fixing motor, 20 color developing motor, 21 developing motor, 22 double-sided path conveying motor, 23, 23a, 23b, 23c, 23d toner replenishing motor, 25a, 25b, 25c, 25d Toner bottle, 26a, 26b, 26c, 26d Stirring blade, 27 Paper detection sensor, 28, 28a, 2 b, 28c, 28d Cartridge, 29 Double-sided transport path, 30 Transport roller, 31 Transport motor, 100 Engine section, 101 Paper feed transport control section, 102 Storage medium control section, 103 I / F control section, 104 Fixing control section, 105 Image formation control unit, 106 toner supply control unit, 107 RAM, 108 ROM, 200 controller unit, 201 operation panel, 281, 281a, 281b, 281c, 281d toner level sensor.

Claims (6)

A first developing section that performs development using the first toner;
A second developing section that performs development using the second toner;
First detecting means for detecting a toner amount in the first developing unit;
First supply means for supplying toner to the first developing section;
Control means for controlling a toner supply mode by the first supply means,
When the first detecting unit detects that the toner amount in the first developing unit is less than a predetermined amount during execution of the image forming operation by the second developing unit, An image forming apparatus that causes a first supply unit to supply toner to the first developing unit. Second detection means for detecting a toner amount in the second developing section;
A second replenishing unit for replenishing toner to the second developing unit;
The control means includes
Furthermore, the toner supply mode by the second supply means is controlled,
When the first replenishing unit replenishes toner to the first developing unit during the execution of the image forming operation by the second developing unit, the first developing is completed before the end of the image forming operation. When the replenishment of the toner to the portion is completed, the second replenishing unit is conditioned on the condition that the second detecting unit detects that the toner amount in the second developing unit is less than a certain amount. The image forming apparatus according to claim 1, wherein toner is supplied to the two developing units.   The control unit is configured to control the second developing unit when toner replenishment to the first developing unit is completed by the first replenishing unit during the execution of the image forming operation by the second developing unit. When the remaining amount of the image forming operation is less than a specific amount, the second replenishing unit is not allowed to replenish the toner to the second developing unit during the execution of the image forming operation by the second developing unit. The image forming apparatus according to claim 2. A control method of an image forming apparatus including a first developing unit that performs development using a first toner and a second developing unit that performs development using a second toner,
Detecting whether or not a toner amount in the first developing unit is less than a predetermined amount during execution of an image forming operation by the second developing unit;
A step of replenishing toner to the first developing unit when the amount of toner in the first developing unit is less than a predetermined amount during execution of an image forming operation by the second developing unit. Control method of forming apparatus. During the execution of the image forming operation by the second developing unit, when the toner supply to the first developing unit is completed before the end of the image forming operation, the toner amount in the second developing unit is Detecting whether it is less than a certain amount;
The image forming apparatus according to claim 4, further comprising a step of replenishing toner to the second developing unit when it is detected that the toner amount in the second developing unit is less than the predetermined amount. Control method.   During the execution of the image forming operation by the second developing unit, when the toner supply to the first developing unit is completed before the end of the image forming operation, the image forming operation by the second developing unit 6. The image forming apparatus according to claim 5, wherein when the remaining amount of the toner is less than a specific amount, toner replenishment to the second developing unit is not performed during execution of an image forming operation by the second developing unit. Control method.

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