JP5173169B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer, a facsimile machine, and a copier.

  In an image forming apparatus, it is required to appropriately control the timing of replenishment or replacement of various consumables. In particular, it is important to perform the timing of these operations so that the image forming operation is not interrupted (time down).

As an example, Patent Document 1 discloses a near full means for detecting a waste toner tank near full by detecting that the amount of toner remaining on the photoreceptor and collected by the cleaning unit exceeds a certain value. In this case, a means for detecting a near-full state of waste toner is used by using a detecting means for detecting the toner adhesion amount of the photosensitive member and a counting means for counting the number of pixels to be printed. According to Patent Document 1, this makes it possible to clarify the actual tank replacement time and reduce the occurrence of time-down.
JP 2005-326814 A (released on November 24, 2005)

  In an image forming apparatus having a replenishment mechanism for replenishing toner to the developing device, the timing of toner replenishment is also important. As this timing, for example, after the image forming operation is completed or when the power is turned on, the remaining amount of toner in the developing device is detected, and when it is detected that the remaining amount of toner is below a predetermined value, the developing device is full of toner. It is conceivable to replenish toner until

  However, an image forming apparatus in which development is not possible during toner replenishment, such as a rotary type developer unit in which a toner container for replenishing toner and a developing unit are not always connected, and the toner container and developing unit are connected during replenishment. In many such image forming apparatuses, image formation cannot be performed until the toner supply operation is completed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a highly convenient image forming apparatus that can shorten the waiting time due to developer replenishment.

A first image forming apparatus includes a developer tank that holds a developer, and that can execute an image forming job for forming a developer image on a recording medium based on image data. The image forming job A job management unit capable of reserving the developer, a developer amount detection unit for detecting the amount of developer in the developer tank, a developer supply unit for supplying developer to the developer tank, and an image forming job in a predetermined period A job frequency acquisition unit that acquires the frequency of the image, and if the frequency is less than the threshold, if there is no reservation for the next image forming job, a predetermined amount of developer is replenished after the end of the image forming job, If the reservation is, the next image forming job is executed without supplying the developer. On the other hand, if the frequency is equal to or higher than the threshold value, the detection result of the developer amount detecting unit is not executed when the image forming job is not executed. In the developer tank Control that controls the developer replenishing unit and the developing device so that the developer is replenished until the detection result of the developer amount detecting unit indicates that the developer is full when the amount of developer is below the lower limit. And providing.

  When the image forming job is frequently executed, the developer replenishment is performed unless the next image forming job is reserved, thereby reducing the time required for one developer replenishment. be able to. Therefore, it is possible to reduce the time during which operations other than the replenishment operation are on standby or interrupted by one developer replenishment.

The second image forming apparatus is the first image forming apparatus, and the control unit has a reservation for the next image forming job when the frequency is less than the threshold value and the next image forming apparatus. When the amount of developer required for the job is equal to or less than the amount of developer in the developer tank, the next image forming job is executed without replenishing the developer, and the amount of developer required for the next image forming job is When the developer amount in the developer tank is exceeded, the developer replenishing unit and the developing device are controlled so that the image forming job is executed after the amount of developer necessary for the next image forming job is replenished.

  As a result, an amount of developer necessary for an image forming job can always be ensured in the developer tank, and an effect that an image defect or the like hardly occurs can be achieved.

  In the image forming apparatus of the present invention, when the image forming job is frequently executed, the developer replenishment is executed unless the next image forming job is reserved, thereby reducing the time required for one developer replenishment. Can be reduced. Therefore, it is possible to reduce the time during which operations other than the replenishment operation are on standby or interrupted by one developer replenishment.

  Hereinafter, an MFP 100 will be described as an example of an image reading apparatus according to the present invention with reference to the drawings. The multi-function device 100 has a plurality of processing modes, that is, a copy mode, a facsimile mode, and a printer mode.

<1. Configuration of image forming unit>
FIG. 1 is a front view illustrating a main configuration of an image forming unit of the multifunction peripheral 100 according to the present embodiment. As shown in FIG. 1, the multifunction peripheral 100 includes a photosensitive drum (image carrier) 1 that can rotate in a direction indicated by an arrow, and a photosensitive drum around the photosensitive drum 1 along the rotation direction. A charging roller 2 for charging 1, a laser unit 3 for forming an electrostatic latent image by irradiating light on the photosensitive drum 1, a developing device 4 for developing the electrostatic latent image as a toner image, and on the photosensitive drum 1 An intermediate transfer device 5 for primary transfer of the toner image and a cleaning device 6 for removing residual toner on the photosensitive drum 1 after the primary transfer. In addition, the multifunction peripheral 100 includes a secondary transfer device 7 that secondary-transfers the toner image after the primary transfer onto the paper, a fixing device 8 that fixes the toner image onto the paper after the secondary transfer, and a paper storage (not shown). A secondary transfer device 7, a conveying belt 9 that discharges to the outside of the multifunction peripheral 100 through the fixing device 8, a toner replenishing device 20 (developer replenishing portion) that replenishes toner in the toner tank 42, and the like.

  The photoreceptor drum 1 is not particularly limited as long as it can carry an electrostatic latent image. As the photosensitive drum 1, a photosensitive drum that has been used in a conventional electrophotographic image forming apparatus can be preferably used.

  The charging roller 2 is applied with a voltage from a charging bias applying unit (not shown), and uniformly charges the surface of the photosensitive drum 1. Instead of the charging roller 2, a conventionally known charging member that can charge the surface of the photosensitive drum 1 can be appropriately used.

  The laser unit 3 includes a laser light source and a movable mirror. The laser unit 3 forms an electrostatic latent image by neutralizing the surface of the photosensitive drum 1 charged by the charging roller 2 with light from the laser light source.

  The developing device 4 is a so-called rotary developing device and includes a rotating shaft parallel to the rotating shaft of the photosensitive drum 1, and four developing devices 41 (41Y, 41M, 41C, 41K) are provided around the rotating shaft. Are provided in this order. Each of the developing devices 41 includes a toner tank (developer tank) 42 that contains toner, an agitation unit 43 that agitates and charges the toner, a developing roller 44 for conveying the charged toner to the photosensitive drum 1, and a developing device 41. A replenishing port 45 for replenishing toner into the toner tank 42 from the outside is provided. The developing roller 44 can convey the toner onto the photosensitive drum 1. At the time of development, the developing device 4 sequentially arranges the four developing devices 41 at the developing position by rotation. The developing position is a position where the developing roller 44 of the developing device 41 is held so as to face the photosensitive drum 1 with a certain gap, and the developing roller 44 applies toner onto the photosensitive drum 1. It is a position that can be transported.

  The intermediate transfer device 5 includes an intermediate transfer belt (intermediate transfer member) 51 movable in the direction of an arrow, an intermediate transfer roller 52 provided so as to sandwich the intermediate transfer belt 51 between the photosensitive drum 1, and an intermediate transfer belt 51. The cleaning member 53 is provided downstream of the secondary transfer unit 7 in the moving direction.

  During the primary transfer, the toner image is transferred from the photosensitive drum 1 to the intermediate transfer belt 51. Development by the developing device 4 and primary transfer by the intermediate transfer roller 52 are sequentially executed for the four color toners, so that the four color toner images are superimposed on the intermediate transfer belt 51.

  The cleaning device 6 removes toner remaining on the photosensitive drum 1 after the primary transfer. About the cleaning apparatus 6, the form can be changed suitably, such as a blade shape and a roll brush shape.

  The fixing device 8 is provided downstream of the secondary transfer device 7 in the moving direction of the conveyance belt 9 and fixes the toner image on the paper by thermocompression bonding.

  The toner replenishing device 20 is inserted into four toner containers 21 (21 (21K, 21Y, 21M, 21C)) that respectively accommodate four color toners and a replenishing port 45, and the toner is supplied from each container to the corresponding developing device 41. It includes four nozzles 22 (22K, 22Y, 22M, and 22C) for feeding, while the developing device 41 rotates and the toner supply device 20 is fixed to the image forming apparatus main body 101. That is, the developing device. It can also be said that 41 is movably attached to the toner replenishing device 20. In this embodiment, the toner replenishing device 20 is placed in the toner tank 42 of the developing device at the developing position among the four developing devices 41. However, the present invention is not limited to this, and the toner replenishing device 20 is provided in the developing device 41 located at a position other than the developing position. It may be the one to replenish the toner.

<2. Configuration of control system>
FIG. 2 is a block diagram showing the configuration of the control system of the multifunction machine 100. As shown in FIG. As shown in this figure, the multi-function device 100 further includes a receiving unit 60, a control unit 30, a job frequency acquisition unit 31, a toner consumption acquisition unit 32, a job management unit 33, a toner full sensor 34, and a toner empty sensor 35. .

  The accepting unit 60 can accept jobs such as image forming jobs. Specifically, a modem 61 connected to the line 200, an interface (I / F) 62 connected to the computer (PC) 201, hard keys, and An operation panel 63 that accepts input from a user via a soft key on a display screen, a scanner 64 that reads a document on a mounting table (not shown), and the like are provided.

  The control unit 30 transmits and receives data signals and control signals to and from each unit of the multifunction peripheral 100 to control the copying operation and the printing operation in general, and to perform facsimile transmission control including a circulation transfer function. To do.

  The toner consumption acquisition unit 32 and the toner amount sensor 34 function as a developer amount detection unit. The toner consumption acquisition unit 32 acquires the toner consumption based on the number of dots obtained from the image data. The present invention is not limited to this, and any apparatus that can acquire the toner consumption can be used instead of the toner consumption acquisition unit 80 as appropriate. The toner full sensor 35 may be any sensor as long as it can at least detect that the amount of toner in the toner tank 42 has reached the upper limit and the lower limit of a suitable range, and a known technique can be suitably used. Examples of these sensors include sensors that detect the amount of toner in the toner tank 42 using light transmittance, magnetic permeability, and the like. In the present embodiment, the toner amount sensor 34 that shows an output value corresponding to T / C (toner / carrier) by the magnetic permeability is used.

  The job frequency acquisition unit 31 can acquire the frequency of the image forming job within N hours from the reception status of the reception unit 60 within the past N hours (predetermined period).

  The job management unit 33 manages the reservation status of a plurality of jobs when a plurality of processing execution instructions are received. In other words, when an execution command for a plurality of jobs is received, the processing mode of each job and various conditions (printing conditions, etc.) are stored in the memory in the order of acceptance, and each processing operation is executed while switching the processing mode in this reservation order. Is to control.

  The control unit 30, the toner consumption acquisition unit 32, the job frequency acquisition unit 31, and the like can be configured by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU can digitize the image information from the scanner 64 to create image data and perform various calculations. The ROM stores a program related to control performed by the CPU, a program related to the operation of each unit in the multifunction peripheral 100, and the like. In addition to functioning as a work area for the CPU, the RAM also includes an area for holding contents received by the receiving unit 60 such as input contents from the user to the operation panel 63, an area for holding image data received from the PC 201, and the like. Have.

<3. Toner replenishment timing>
The timing of toner replenishment by the toner replenishing device 20 will be specifically described with reference to FIGS. FIG. 3 is a flowchart of the processing operation when the toner supply mode is selected, and FIGS. 4 and 5 are flowcharts showing the first and second toner supply modes, respectively.

(3-1) Supply Mode Selection As shown in FIG. 3, the job frequency acquisition unit 31 monitors the job reception status and calculates the frequency P of the interval between image forming jobs in the past N hours (S1). The control unit 30 compares the frequency P with the threshold A, and if P <A (Yes in S2), selects the first supply mode. On the other hand, if P ≧ A (No in S2), the second supply mode is selected.

  N is a number that can be arbitrarily set, and the job frequency acquisition unit 31 can acquire the frequency P of the interval between image forming jobs in the past 30 minutes, 1 hour, 2 hours, or the previous day (one day), for example. it can.

  In addition, it is preferable that the job frequency acquisition unit 31 always acquires the image job reception status within the past N hours while the MFP 100 is powered on. In accordance with this, it is preferable that the control unit 30 also always performs this mode selection based on the acquisition result of the job frequency acquisition unit 31 while the MFP 100 is turned on.

  However, the present invention is not limited to this, and an acquisition period for acquiring the job status and a holding period for holding the selected result may be provided. In this case, for example, the job frequency acquisition unit 31 acquires the image job reception status in N hours (for example, N hours from power ON) within a specific period, and the control unit 30 selects the mode selected based on the acquisition result. You may hold | maintain until the mode is newly set after the end of the next acquisition period.

  The frequency P only needs to represent the frequency of accepting image forming jobs in the past N hours.

  For example, the job frequency acquisition unit 31 totals the time from reception of one image formation job to reception of the next image formation job over the past N hours, and acquires the average time as the frequency P. May be. In this case, the control unit 30 has a threshold A corresponding to the average time (for example, 5 minutes, 10 minutes, or 30 minutes can be changed as appropriate), and compares the frequency P with the threshold A. It only has to be like this.

  As another example, the job frequency acquisition unit 31 may count the number of image forming jobs in the past N hours and set this as the frequency P. In this case, the control unit 30 has a threshold A corresponding to the number of jobs (for example, 5 times, 10 times, or 30 times can be changed as appropriate), and the frequency P is compared with the threshold A. It only has to be like this.

(3-2) First Supply Mode As shown in FIG. 4, in the first supply mode, after the image forming job is completed (S11), if there is no reserved job (No in S12), a predetermined amount of toner is supplied ( S13).

  The “predetermined amount” is not particularly limited as long as the amount of toner in the toner tank 42 can be maintained so that image formation is smoothly performed. The “predetermined amount” may be, for example, a toner consumption amount from the previous toner supply to the completion of one image forming job in step S11. This toner consumption amount can be obtained by the toner consumption amount acquisition unit 32. In addition, the “predetermined amount” may be a predetermined value (for example, 1 g or 2 g). In addition, the “predetermined amount” can be set to an amount that the toner amount in the toner tank 42 exceeds a preset reference value. In this case, for example, a constant reference value may be provided for T / C, and the toner may be replenished so that the T / C obtained by the toner amount sensor 34 is kept above this reference value. The reference value is preferably larger than the lower limit value of the toner amount described in the following (3-3) column and smaller than the upper limit value.

  The MFP 100 may include a replenishment amount acquisition unit (not shown), and the replenishment amount acquisition unit may detect whether or not the replenishment amount has reached this “predetermined amount”. The replenishment amount acquisition unit can obtain the toner amount replenished by the toner replenishment device 20 from the replenishment speed and replenishment time of the toner replenishment device 20.

On the other hand, when the next image forming job is reserved when the image forming job is completed (Yes in S12), the control unit 30 determines the output value of the toner amount sensor 34 from the acquisition result of the toner consumption acquisition unit 32 or The amount of toner remaining in the toner tank 42 obtained from the above is compared with the amount of toner necessary for the next image forming job. As a result, it is possible to determine whether or not toner that can execute the next image forming job remains in the toner tank 42. Note that the toner amount necessary for the next image forming job can be predicted by obtaining the printing rate from the image data.
If the toner amount is not sufficient to execute the next image forming job (No in S14), the toner replenishing device 20 is controlled to perform the toner replenishing operation (S15). At this time, the toner replenishing device 20 may replenish the amount necessary for the next image forming job, or may replenish the “predetermined amount” described above. On the other hand, if the toner amount is sufficient to execute the next image forming job (Yes in S14), the image forming job is executed without toner replenishment (S16).

(3-3) Second Supply Mode As shown in FIG. 5, in the second supply mode, the output value of the toner amount sensor 34 is read by the control unit 30 during non-image formation (S21). When no toner is indicated (Yes in S22), toner replenishment is executed. In this mode, the toner supply device 20 continues to supply toner until the output value of the toner amount sensor 34 detects that the toner is full. While the output value of the toner amount sensor 34 indicates that there is a remaining amount of toner (No in S22), the toner supply device 20 does not supply toner.

  “No toner remaining” means that the toner amount has fallen below a preset lower limit value, and “toner full” means that the toner amount has reached a preset upper limit value. The lower limit value and the upper limit value herein are a range of toner amount suitable for executing image formation, and are not particularly limited, and are values that can be appropriately changed depending on the structure of the image forming unit.

  As described in (3-1) to (3-3) above, the multifunction peripheral 100 according to the present embodiment is in the first replenishment mode when the number of image forming jobs is equal to or greater than the threshold value in the past N hours, and less than the threshold value. If there is, the second supply mode can be selected. In the first replenishment mode, toner replenishment is executed every time an image forming job is completed unless there is a reservation for the next image forming job. In the second supply mode, the image forming job is continuously executed until the remaining amount of toner in the toner tank 42 runs out, and the toner is supplied all at once when the remaining amount of toner runs out.

  That is, when the image formation request is not frequent, the multi-function device 100 reduces the number of toner replenishment times and increases the amount of toner to be replenished at one time as the second replenishment mode. On the other hand, when the image formation request is frequent, the toner supply interval is made smaller in the first supply mode than in the second supply mode, that is, the number of toner supply times is increased, and the remaining amount of toner is eliminated. Toner can be replenished before By doing so, the amount of toner to be replenished at one time is reduced, so that the time down due to one toner replenishment can be shortened. Further, in the first mode of the present embodiment, when the next image forming job is reserved, the necessary amount of toner is replenished only when the remaining amount of toner is less than the amount necessary to execute the job. To do. By doing so, the time down due to toner replenishment can be further shortened.

  In the present embodiment, a rotary developing device is employed as described in the section <1.>. As described above, in the image forming apparatus in which the developing device 41, that is, the toner tank 42 performs the developing operation while moving with respect to the toner replenishing device 20, toner replenishment cannot execute image formation. Down is easy to occur, and the effect obtained by adopting the present invention is great. However, the effect of the present invention is not limited to this, and the present invention is used for an image forming apparatus that cannot execute a normal image forming job, such as causing a time down during or after developer replenishment. can do. As an example, there is a case where after supplying the developer, if the supplied developer and the old developer are not uniformly stirred, a defect occurs in the image.

  In this embodiment, the multifunction peripheral 100 develops an image using a two-component developer. However, the present invention is not limited to this, and a single-component developer may be used. .

FIG. 2 is a front view illustrating a configuration of a main part of an image forming unit of a multifunction machine that is an embodiment of the present invention. The block diagram which shows the principal part structure of the control system of the said multifunctional device. 6 is a flowchart showing a processing operation for selecting a toner replenishment mode in the multifunction machine. 6 is a flowchart showing a processing operation in a first supply mode in the multifunction machine. 9 is a flowchart showing a processing operation in a second supply mode in the multifunction machine.

Explanation of symbols

100 MFP (image forming device)
20 Toner supply part (Developer supply part)
DESCRIPTION OF SYMBOLS 30 Control part 31 Job frequency acquisition part 32 Toner consumption acquisition part 33 Job management part 34 Toner amount sensor 4 Developing apparatus 42 Toner tank (developer tank)
60 Reception Department

Claims (2)

A rotary developing device that includes a developer tank that holds a developer, and that can execute an image forming job for forming a developer image on a recording medium based on image data;
A job management unit capable of reserving the image forming job;
A developer amount detector for detecting the amount of developer in the developer tank;
A developer replenishing section for replenishing the developer in the developer tank;
A job frequency acquisition unit for obtaining an interval between image forming jobs for which the job management unit has received a reservation during a predetermined period;
When the interval is less than the threshold value and the next image forming job is reserved and the amount of developer required for the next image forming job is less than or equal to the amount of developer in the developer tank, the developer is replenished. If the amount of developer required for the next image forming job exceeds the amount of developer in the developer tank, the amount of developer required for the next image forming job is replenished. to perform the image forming job from, if there is no reservation for the next image forming job, while replenishing a predetermined amount of the developer after the image forming job completion, when the distance is equal to or greater than the threshold value, the image forming The detection result of the developer amount detection unit indicates that the developer is full when the detection result of the developer amount detection unit indicates that the developer amount in the developer tank has fallen below the lower limit when the job is not executed. So that the developer is replenished until A replenishment unit, and a control unit for controlling the developing device,
An image forming apparatus comprising: A rotary developing device that includes a developer tank that holds a developer, and that can execute an image forming job for forming a developer image on a recording medium based on image data;
A job management unit capable of reserving the image forming job;
A developer amount detector for detecting the amount of developer in the developer tank;
A developer replenishing section for replenishing the developer in the developer tank;
A job frequency acquisition unit that obtains the number of image forming jobs of the image forming job for which the job management unit has received a reservation during a predetermined period;
When the number of image forming jobs is equal to or greater than the threshold value, and there is a reservation for the next image forming job and the amount of developer required for the next image forming job is equal to or less than the amount of developer in the developer tank, When the next image forming job is executed without replenishing the developer, and the amount of developer required for the next image forming job exceeds the amount of developer in the developer tank, the amount of development required for the next image forming job When the image forming job is executed after replenishing the agent and there is no reservation for the next image forming job, a predetermined amount of developer is replenished after the end of the image forming job, while the number of image forming jobs is less than the threshold value. When the image forming job is not executed, when the detection result of the developer amount detection unit indicates that the developer amount in the developer tank is below the lower limit value, the detection result of the developer amount detection unit Until developer is full As replenished, and controlling the developer supply unit and the developing device,
An image forming apparatus comprising:

Images