JP4496175B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  As a conventional image forming apparatus employing an electrophotographic system such as a laser printer or a copying machine, a photosensitive drum, a developing device that has toner inside and supplies toner to the surface of the photosensitive drum to develop a toner image, There are devices including a toner container that contains toner to be supplied to the developing device, and a toner replenishing device for supplying toner from the toner container to the developing device.

  The development performance of such an image forming apparatus is easily affected by the environment in which it is used, the printing method, and the like. For example, when the image ratio in the output image of the image forming apparatus is low, the developing device is close to the idling state and the toner in the developing device is loaded, so that the toner deteriorates.

Therefore, Patent Document 1 prevents the deterioration of the developer by stably consuming the toner of the two-component developer in the developing device even when the image ratio of the original image is small, and the density is sufficient. An image forming apparatus capable of stably obtaining an image is disclosed. The image forming apparatus of Patent Document 1 forms a patch image on a photosensitive drum, detects its density, and controls the frequency of toner replenishment, solid formation, and density detection based on the detected density, thereby developing two components. The development performance of the device is stabilized.
JP 2000-162838 A

  However, when the image forming apparatus of Patent Document 1 is applied to a one-component developing apparatus, stable printing performance can be maintained when printing is repeated at a certain printing rate, but particularly at a low printing rate of 2% or less or intermittently. When the above printing is repeated, the toner fluidity in the developing device is remarkably lowered. Then, toner aggregation or cavitation occurs in the vicinity of the sensor for detecting the toner amount in the developing device, and a false detection that the sensor detects “not” even when the toner is in a predetermined amount occurs. As a result, the toner is oversupplied into the developing device.

  If this state continues, a load is applied to the toner in the developing device, so that the toner agglomerates further increase, and the stirring member for stirring the toner in the developing device is locked. These phenomena shorten the life of the developing device. This phenomenon is particularly noticeable in an image forming apparatus such as a high-speed machine. Therefore, in order to extend the life of the developing device, it is necessary to stabilize the developing performance regardless of the use environment, the printing method, and the like.

  Therefore, the present invention can be applied to a one-component and two-component developing device, and even when only low density printing and intermittent printing are repeated, the toner amount in the developing device is kept constant, and the toner agglomerates develop performance. And an image forming apparatus that suppresses an influence on a portion such as a stirring member.

In order to solve the above-described problems, the first aspect of the present invention provides a development in which toner is supplied to an image carrier and an electrostatic latent image formed on the image carrier is developed as a toner image based on image data acquired from the outside. An image forming apparatus including an apparatus, a toner replenishing device that replenishes toner to the developing device, and a fixing device that fixes a toner image developed by the developing device to a recording medium further includes the following means.
◎ Print rate calculating means for calculating the print rate of the image data for each recording medium on which the toner image is fixed by the fixing device ◎ Accumulating means for accumulating the print rate calculated by the print rate calculating means ◎ The fixing results printing rate of all the recording medium on which the toner image is fixed is compared by the comparing means ◎ said comparing means for comparing the total cumulative printing ratio with a predetermined first printing ratio that is accumulated by said accumulating means by the device, Control means for prohibiting the toner replenishing device from replenishing the developing device with toner when the total cumulative printing rate is equal to or lower than the predetermined first printing rate.

Here, when the number of recording media on which the toner image has been fixed by the fixing device satisfies a predetermined number, the comparison unit accumulates the printing rate of the predetermined number of recording media by the accumulating unit. When the first total cumulative printing rate is compared with a predetermined second printing rate, and the comparison result by the comparing means shows that the first total cumulative printing rate is less than or equal to the predetermined second printing rate, the control means the controls given of the developing device so as to forcibly consume the toner amount corresponding to the second printing ratio determined by subtracting said first total cumulative printing rate from the printing rate, the accumulation means, the first sum An image forming apparatus for adding the subtracted printing rate to the cumulative printing rate is provided.

  In general, the cumulative printing rate A when only low-printing printing or intermittent printing is repeated over a long period is lower than the cumulative printing rate B when a plurality of printings are continuously performed. Here, the printing rate corresponding to the amount of toner that should be consumed in order to maintain the necessary minimum fluidity so that the toner in the developing device does not aggregate is defined as “predetermined first printing rate C”. When the cumulative printing rate A is lower than the predetermined first printing rate C, the image forming apparatus prohibits the toner replenishing device from replenishing the developing device with toner. In this case, when the developing device develops the electrostatic latent image, the toner already in the developing device is used. This prevents the toner in the developing device from being replenished even though the toner in the developing device is not consumed so much that the fluidity of the toner in the developing device is deteriorated and toner agglomerates are generated. be able to. Therefore, it is possible to suppress the influence of the toner agglomerates in the developing device on the developing performance and other parts in the image forming apparatus, and to extend the life of the developing device.

  Further, since less toner is consumed, the toner fluidity in the developing device is deteriorated, and toner condensation can be prevented.

Invention 2 supplies toner to the image carrier and develops an electrostatic latent image formed on the image carrier as a toner image based on image data acquired from the outside, and toner to the developer An image forming apparatus including a toner replenishing device for replenishing toner and a fixing device for fixing a toner image developed by the developing device to a recording medium further includes the following means.
◎ Print rate calculating means for calculating the print rate of the image data for each recording medium on which the toner image is fixed by the fixing device ◎ Accumulating means for accumulating the print rate calculated by the print rate calculating means ◎ The fixing results printing rate of all the recording medium on which the toner image is fixed is compared by the comparing means ◎ said comparing means for comparing the total cumulative printing ratio with a predetermined first printing ratio that is accumulated by said accumulating means by the device, Control means for prohibiting the toner replenishing device from replenishing the developing device with toner when the total cumulative printing rate is equal to or lower than the predetermined first printing rate.
Here, the comparing means compares the second total accumulated printing rate in which the printing rate of the recording medium is accumulated for a predetermined period by the accumulating unit with a predetermined second printing rate every elapse of a predetermined period , As a result of comparison by the comparison means, when the second total cumulative printing rate is equal to or less than the predetermined second printing rate, the control unit subtracts the second total cumulative printing rate from the predetermined second printing rate. The developing device is controlled to forcibly consume a toner amount corresponding to a printing rate, and the accumulation unit provides an image forming apparatus that adds the subtracted printing rate to the second total accumulated printing rate.

This prevents the toner in the developing device from being replenished even though the toner in the developing device is not consumed so much that the fluidity of the toner in the developing device is deteriorated and toner agglomerates are generated. be able to. Therefore, it is possible to suppress the influence of the toner agglomerates in the developing device on the developing performance and other parts in the image forming apparatus, and to extend the life of the developing device.
Further, since less toner is consumed, the toner fluidity in the developing device is deteriorated, and toner condensation can be prevented.

According to a third aspect of the present invention, in the first and second aspects, when the total cumulative printing rate is higher than the predetermined first printing rate as a result of the comparison by the comparing unit, the control unit performs a toner replenishing operation of the toner replenishing device. Provided is an image forming apparatus that cancels the prohibition.

  According to this apparatus, when the cumulative printing rate A is higher than the predetermined first printing rate C, there is little possibility of oversupply, and thus toner is supplied into the developing device. As a result, the toner remaining inside the developing device is mixed with newly supplied toner, and the fluidity of the toner is improved. Therefore, it is possible to prevent problems such as agglomeration caused by the deterioration of the fluidity of the toner, for example, causing the toner stirring member in the developing device or the toner container to be locked.

  A fourth aspect of the present invention further includes a remaining toner amount detecting unit that detects the remaining amount of toner in the developing device according to the first to third aspects, wherein the control unit is configured to detect the remaining toner amount detected by the remaining toner amount detecting unit. An image forming apparatus is provided that controls the toner replenishing device to replenish toner to the developing device until the toner reaches a predetermined amount or more.

  For example, the amount of toner held in the developing device when the image forming apparatus is started to be used is defined as a “predetermined amount”. That is, the toner replenishing device replenishes the toner until the toner in the developing device reaches the amount of toner held in the developing device at the start of use of the image forming apparatus. As a result, the toner remaining in the developing device is mixed with a predetermined amount of new toner, so that the fluidity of the toner is restored. Furthermore, the developing device can always maintain a certain amount of toner.

  According to the present invention, even when only low density printing and intermittent printing are repeated, the toner amount in the developing device is kept constant, so that no load is applied to the toner. Thereby, since toner agglomerates are unlikely to occur, the influence of toner agglomerates such as locking of the stirring member in the developing device can be prevented. Accordingly, the life of the developing device can be extended.

<Embodiment>
(1) Configuration of Color Printer FIG. 1 is a schematic sectional view of a color printer according to an embodiment of the present invention. The color printer 1 in FIG. 1 is a tandem color printer, and is connected to a computer or the like as shown in FIG. 3, and can print a color image on paper based on image data sent from the computer or the like. Device.

  The color printer 1 includes image forming units 2M, 2Y, 2C, and 2B for each color for forming a color image, toner containers 3M, 3Y, 3C, and 3B for each color, a transfer device 4, a paper feed mechanism 6, a fixing device 7, and discharge. Part 8 and control part 9 are included.

  The image forming units 2M, 2Y, 2C, and 2B are sequentially arranged in the lateral direction along a conveyance transfer belt 4a (described later) in the transfer device 4 from the upstream side in the conveyance direction of the paper, and magenta, yellow, cyan, A black toner image is formed. Each of these image forming units 2M, 2Y, 2C, 2B has a photosensitive drum 10.

  The photosensitive drum 10 has a photosensitive layer made of amorphous silicon or the like as an image carrier, and an electrostatic latent image is formed on the surface based on image data acquired from the outside. Around the photosensitive drum 10, a main charger 11, an exposure device 12, a developing device 13, and a cleaning mechanism 14 are arranged in this order.

  The main charger 11 uniformly charges the surface of the photosensitive drum 10.

  The exposure device 12 exposes the surface of the photosensitive drum 10.

  The developing device 13 supplies toner to the photoconductive drum 10 and develops the electrostatic latent image on the surface of the photoconductive drum 10 as a toner image, and inside thereof, as shown in FIG. 1 and FIG. , Developing roller 131, stirring roller 132, and partition wall 133.

  The cleaning mechanism 14 removes residual toner on the photosensitive drum 10 after development.

  Each of the image forming units 2M, 2Y, 2C, and 2B includes a toner replenishing device 15 and a toner remaining amount detecting device 16. The toner replenishing device 15 is for replenishing toner to the developing device 13 and is connected to the toner containers 3M, 3Y, 3C, 3B and the developing device 13. The toner remaining amount detection device 16 is for detecting the remaining amount of toner in the developing device 13, and has a configuration including, for example, a light emitting unit and a light receiving unit. The toner remaining amount detecting device 16 outputs “L” when the remaining amount of toner in the developing device 13 is equal to or less than a predetermined amount, and outputs “H” when it is equal to or larger than the predetermined amount.

  Each color toner container 3M, 3Y, 3C, 3B is disposed above each image forming unit 2M, 2Y, 2C, 2B, and contains magenta, yellow, cyan, and black toners inside. ing.

  The transfer device 4 is a device that transfers the toner image on the photosensitive drum 10 onto a recording sheet, and includes a transfer transfer belt 4a, a driving roller 20, a driven roller 21, and first to fourth transfer rollers 5M, 5Y, 5C, 5B is included. The conveyance transfer belt 4 a is circulated and driven between a driving roller 20 and a driven roller 21, and the recording paper conveyed from the paper feeding mechanism 6 via a paper feeding conveyance path 22 (described later). It is sucked and conveyed to the fixing device 7. The drive roller 20 is connected to a conveyance drive mechanism including a motor and a speed reducer (not shown). The first to fourth transfer rollers 5M, 5Y, 5C, and 5B are arranged so as to face the photosensitive drum 10 of each image forming unit via the conveyance transfer belt 4a.

  The paper feed conveyance path 22 is composed of a guide member serving as a conveyance guide and a plurality of roller pairs. On the most downstream side of the paper feed conveyance path 22, toner image formation and recording paper conveyance are performed. A registration roller pair 25 is provided for synchronizing the two. Further, between the registration roller pair 25 and the first transfer roller 5M, an adsorption for applying a bias voltage for adsorption to the leading edge or the entire surface of the sheet in order to attract the recording sheet to the transport transfer belt 4a. A roller 26 is provided.

  The fixing device 7 includes a heating roller having a heater therein and a pressure roller pressed by the heating roller, and fixes the toner image transferred onto the recording paper.

  The discharge unit 8 is formed on the upper surface of the color printer 1, and the recording paper that has passed through the fixing device 7 passes upward via a paper discharge conveyance path 27 installed between the discharge unit 8 and the fixing device 7. It is conveyed and discharged to the upper surface of the color printer 1. The paper discharge conveyance path 27 is composed of a guide member and a plurality of roller pairs, like the paper feed conveyance path 22.

  The control unit 9 is composed of a microcomputer including a CPU and a memory. As shown in the block diagram of FIG. 3, the control unit 9 can communicate with an external personal computer, the image forming unit 2, the transfer device, and the like. 4. It is connected to the fixing device 7 and other input / output units. Other input / output units include, for example, a paper feed mechanism 6 and a discharge unit 8. The memory stores image data acquired from the outside by the communication unit 31 and stores various control programs and image processing programs executed by the CPU. Here, the control unit 9 functions as a printing rate calculation unit 9a, an accumulation unit 9b, a comparison unit 9c, and an operation control unit 9d. Hereinafter, each function of the control unit 9 will be described.

(1-1) Print Rate Calculation Unit The control unit 9 serving as the print rate calculation unit 9a determines the print rate of image data received from the outside by the communication unit 31 for each recording sheet on which the toner image is fixed by the fixing device 7. calculate.

(1-2) Accumulating unit The control unit 9 as the accumulating unit 9b accumulates the printing rate calculated by the printing rate calculating unit 9a. Further, the control unit 9 as the accumulating unit 9b calculates a printing rate corresponding to the toner amount consumed by the developing device 13, and adds it to the accumulative calculation.

(1-3) Comparison Unit The control unit 9 as the comparison unit 9c compares the accumulated printing rate accumulated by the accumulation unit 9b with a predetermined printing rate.

  Specifically, the comparison unit 9c compares the second printing rate A and the cumulative printing rate when the number of recording sheets on which the toner image is fixed reaches a predetermined number. Further, when the cumulative printing rate is higher than the second printing rate, the comparison unit 9c compares the first printing rate C with the cumulative printing rate. That is, in the present embodiment, it is assumed that the relationship “second printing rate A <first printing rate C” is established between the second printing rate A and the first printing rate C.

(1-4) Operation Control Unit The control unit 9 as the operation control unit 9d controls the operation of the toner replenishing device 15 or the developing device 13 based on the comparison result of the comparison unit 9c.

  Specifically, when the comparison unit 9c compares the cumulative printing rate with the first printing rate C and determines that the cumulative printing rate is equal to or lower than the first printing rate C, the operation control unit 9d includes the toner supply device 15. Prohibits the operation of supplying toner to the developing device 13. When the comparison unit 9c determines that the cumulative printing rate is higher than the first printing rate C, the operation control unit 9d cancels the prohibition of the toner supply operation of the toner supply device 15. In this case, the toner replenishing device 15 replenishes the developing device 13 with toner.

  When the comparison unit 9c compares the cumulative printing rate with the second printing rate A and determines that the cumulative printing rate is equal to or lower than the second printing rate A, the operation control unit 9d performs the cumulative printing from the second printing rate A. The toner amount corresponding to the printing rate obtained by subtracting the printing rate is calculated, and the developing device 13 is controlled so as to forcibly consume this toner amount.

  Further, the control unit 9 as the operation control means 9d is configured so that the toner replenishing device 15 keeps the developing device 13 until the toner amount in the developing device 13 becomes a predetermined amount or more based on the detection result from the toner remaining amount detecting device 16. The toner is replenished with toner.

(2) Operation of Color Printer Next, the operation of the color printer 1 will be described. FIG. 4 is a flowchart for explaining the operation of the color printer 1. In the following, it is assumed that the control unit 9 as the comparison unit 9c compares whether or not the toner of the developing device is forcibly consumed for every eight recording sheets on which the toner images are fixed. “N” represents the number of recording sheets on which the toner image is fixed.

  Step S1: The communication unit 31 stands by until image data is received from an external personal computer.

  Step S2: When the communication unit 31 receives the image data, it transfers it to the control unit 9. The printing rate calculation unit 9a calculates the printing rate AN of the acquired image data. Further, the printing rate calculation means 9a converts the printing rate into A4 size. For example, if the acquired image data is A3 size and the printing rate is calculated as “4%”, the printing rate calculation unit 9a sets this to “8%”.

  Steps S3-4: The accumulating unit 9b obtains the total printing rate AX using the calculated printing rate AN, and increases the number of recording sheets “N” by one. Here, the “total printing rate AX” is the total value of the printing rates of the 8 recording sheets on which the toner images are fixed.

  Step S5: The comparison means 9c determines whether or not the number N of recording sheets is 8 or more.

  Step S6: When the number N of recording sheets is 8 or less in step S5, the operation control means 9d prohibits the toner replenishing operation of the toner replenishing device 15.

  Steps S7 to S8: If the number N of recording sheets is 8 or more in step S5, the comparison means 9c resets the number of recording sheets N, and the total printing rate AX and the second printing rate A of the 8 recording sheets. And compare.

  Steps S9 to 10: When the total printing rate AX of the eight recording sheets is smaller than the second printing rate A in step S8, the operation control means 9d prints the printing rate obtained by subtracting the total printing rate AX from the second printing rate A. The toner amount corresponding to B is calculated, and the developing device 13 is controlled to forcibly consume this toner amount. Then, the accumulating unit 9b adds a printing rate B obtained by subtracting the total printing rate AX from the second printing rate A to the total printing rate AX per eight recording sheets.

  Steps S11 to 12: When the total printing rate AX of the eight recording sheets is larger than the second printing rate A in Step S8, or when the printing rate B is added to the total printing rate A in Step S10, the accumulating unit 9b After adding the total printing rate AX per 8 recording papers to the total printing rate Cn, the total printing rate AX per 8 recording papers is reset. Here, the “total printing rate Cn” is a total value of the printing rates of all the recording sheets on which the toner images are fixed.

  Step S13: The comparison means 9c compares the total printing rate Cn with the first printing rate C. As a result of the comparison, when the total printing rate Cn is smaller than the first printing rate C, the operation control unit 9d executes Step S6.

  Steps S14 to 16: In step S13, if the total printing rate Cn is greater than the first printing rate C and the detection result of the toner remaining amount detection device 16 is “L”, the operation control means 9d. Cancels the prohibition of the toner supply operation of the toner supply device 15. The toner replenishing device 15 replenishes the developing device 13 with toner.

  Steps S17 to S18: When the detection result of the toner remaining amount detection device 16 is “H” in step S14, the accumulating unit 9d determines that the toner in the developing device 13 has been sufficiently supplied, and the total printing rate Reset Cn. The operation control unit 9d stops the toner supply operation of the toner supply device 15.

(3) Effect In the color printer 1 according to the present embodiment, when the total printing rate Cn is lower than the first printing rate C, the toner supply device 15 prohibits the operation of supplying toner to the developing device 13. As a result, the toner in the developing device 13 is replenished even though the toner in the developing device 13 is not consumed so much that the fluidity of the toner in the developing device 13 is deteriorated and toner agglomerates are generated. Can be prevented. When the total printing rate Cn is higher than the first printing rate C, the color printer 1 cancels the prohibition of the toner supply operation of the toner supply device 15. As a result, the toner remaining in the developing device 13 is mixed with the newly supplied toner, so that the fluidity of the toner is improved. Accordingly, it is possible to prevent problems such as agglomeration of toner causing, for example, locking of the toner stirring member in the developing device 13. Accordingly, the life of the developing device 13 can be extended.

  Further, when the total printing rate AX per 8 sheets is lower than the second printing rate A, the color printer 1 controls the developing device 13 to forcibly consume the toner. As a result, since less toner is consumed, the fluidity of the toner in the developing device 13 is deteriorated, and toner condensation can be further prevented. Accordingly, better development performance such as image density can be obtained as compared with the case where this control is not performed.

  When the toner remaining amount detecting device 16 detects that the remaining amount of toner in the developing device 13 is equal to or less than a predetermined amount, the toner replenishing device 15 replenishes the toner inside the developing device 13. As a result, the toner remaining in the developing device 13 and the new toner are mixed, so that the fluidity of the toner is restored. Further, the developing device 13 can always maintain a constant amount of toner.

<Example>
An experiment was performed using the color printer 1 according to the above embodiment under the following printing conditions and toner supply control conditions.

  (A) Printing conditions

(B) Toner replenishment control conditions First example: Toner replenishment operation prohibition / prohibition release control and no forced toner consumption.

  Second example: There is a prohibition / prohibition release control of the toner replenishment operation. No forced toner consumption.

  Third example: Inhibition / prohibition release control of toner supply operation and forcible consumption of toner.

After printing each number of sheets under each of the above conditions, the toner weight and the image density of the toner image in the developing device 13 were measured.
[Toner weight]
The evaluation results of the toner weight are shown in Table 2.

In Table 2, “◯” indicates that the weight of the toner in the developing device 13 is in the range of 100 to 200 g, and “X” indicates that the weight of the toner is lower than 100 g or higher than 200 g. Indicates.

According to Table 2 above, in the first example, in the case of intermittent printing with a printing rate of “0.5%”, the toner weight was not kept within a predetermined range, but in the second and third examples, the printing conditions were Regardless, the toner weight was kept within the predetermined range.
[Image density]
Table 3 shows the evaluation results of the image density.

In Table 3, “◯” indicates that the image density is “1.3” or more, and “Δ” indicates that the image density is within the range of “1.3 to 1.1”. “X” indicates that the image density is less than “1.1”.

  According to Table 3 above, in the first example, the image density decreased when the printing condition was 1. In the second example, the image density was slightly lower than 1.3 in both printing conditions 1 and 2. On the other hand, in the third example, a good image density was obtained under both printing conditions 1 and 2.

  To summarize the results of Tables 2 and 3, in the color printer 1 of this embodiment, the toner weight can be kept within a predetermined range at least when the toner replenishment operation inhibition / prohibition release control is performed. It was found that good image density can be obtained by forcibly consuming.

<Other embodiments>
(A) In the above embodiment, the control unit 9 determines whether or not the toner is forcibly consumed when the number of recording sheets reaches a predetermined number, but the color printer 1 is started to be used. This determination may be performed every time a predetermined period has elapsed. FIG. 5 shows a flowchart of an operation for executing a determination as to whether or not toner is forcibly consumed every elapse of a predetermined period. Hereinafter, only differences between FIG. 5 and the operation flowchart of FIG. 4 according to the embodiment will be described.

  After the accumulating unit 9b obtains the total printing rate AX in step S103, the comparing unit 9c determines, for example, whether a predetermined period has elapsed after receiving the image data (S104). Until the predetermined period elapses, the operation control unit 9d prohibits the toner supply operation (S105). After a predetermined period, the operation control unit 9d compares the total printing rate AX with the second printing rate A (S106). Step S106 and subsequent steps are the same as those after step S8 in FIG.

  (B) In the above-described embodiment, the control unit 9 determines whether or not toner is forcibly consumed for every eight recording sheets. However, this determination may be performed for each number of sheets.

  The image forming apparatus of the present invention can be applied to various types of copiers, printers, and facsimile machines, and as a multifunction machine having these functions.

1 is a schematic diagram of a color printer in which an image forming apparatus according to an embodiment is employed. FIG. 1 is a block diagram schematically showing the configuration of an image forming apparatus. An operation flowchart of the color printer. 10 is an operation flowchart of a color printer according to another embodiment.

DESCRIPTION OF SYMBOLS 1 Color printer 2 Image forming part 7 Fixing device 9 Control part 13 Developing device 15 Toner replenishing device 16 Toner remaining amount detecting device

Claims (4)

A developing device that supplies toner to the image carrier and develops an electrostatic latent image formed on the image carrier as a toner image based on image data acquired from outside, and a toner that replenishes toner to the developing device An image forming apparatus comprising: a replenishing device; and a fixing device that fixes a toner image developed by the developing device to a recording medium,
A printing rate calculating means for calculating a printing rate of the image data for each recording medium on which a toner image is fixed by the fixing device;
Accumulating means for accumulating the print ratio calculated by the print ratio calculating means;
A comparison unit that compares the total accumulated printing rate in which the printing rates of all the recording media on which the toner images are fixed by the fixing device are accumulated by the accumulation unit with a predetermined first printing rate;
Control means for prohibiting the toner replenishing device from replenishing toner to the developing device when the total accumulated printing rate is equal to or lower than the predetermined first printing rate as a result of the comparison by the comparing unit;
Including
In the comparison unit, when the number of recording media on which the toner image has been fixed by the fixing device satisfies a predetermined number, the print rate of the predetermined number of recording media is accumulated by the accumulation unit. 1. Compare the total cumulative printing rate with the predetermined second printing rate,
As a result of the comparison by the comparison means, if the first total cumulative printing rate is less than or equal to the predetermined second printing rate, the control means subtracts the first total cumulative printing rate from the predetermined second printing rate. Controlling the developing device so as to forcibly consume a toner amount corresponding to the printed rate,
The accumulation unit is an image forming apparatus that adds the subtracted printing rate to the first total accumulated printing rate. A developing device that supplies toner to the image carrier and develops an electrostatic latent image formed on the image carrier as a toner image based on image data acquired from outside, and a toner that replenishes toner to the developing device An image forming apparatus comprising: a replenishing device; and a fixing device that fixes a toner image developed by the developing device to a recording medium,
A printing rate calculating means for calculating a printing rate of the image data for each recording medium on which a toner image is fixed by the fixing device;
Accumulating means for accumulating the print ratio calculated by the print ratio calculating means;
A comparison unit that compares the total accumulated printing rate in which the printing rates of all the recording media on which the toner images are fixed by the fixing device are accumulated by the accumulation unit with a predetermined first printing rate;
Control means for prohibiting the toner replenishing device from replenishing toner to the developing device when the total accumulated printing rate is equal to or lower than the predetermined first printing rate as a result of the comparison by the comparing unit;
Including
The comparing means compares the second total accumulated printing rate in which the printing rate of the recording medium is accumulated for a predetermined period by the accumulating unit with a predetermined second printing rate every elapse of a predetermined period ;
As a result of the comparison by the comparison means, when the second total cumulative printing rate is equal to or lower than the predetermined second printing rate, the control means subtracts the second total cumulative printing rate from the predetermined second printing rate. Controlling the developing device so as to forcibly consume a toner amount corresponding to the printed rate,
The image forming apparatus, wherein the accumulating unit adds the subtracted printing rate to the second total accumulated printing rate. 3. The control unit cancels the prohibition of the toner replenishment operation of the toner replenishing device when the total accumulated printing rate is higher than the predetermined first printing rate as a result of the comparison by the comparing unit. The image forming apparatus described in 1. A toner remaining amount detecting means for detecting the remaining amount of toner in the developing device;
The control unit controls the toner replenishing device to replenish toner to the developing device until the toner remaining amount detected by the toner remaining amount detecting unit becomes a predetermined amount or more. The image forming apparatus described in 1.