JP7147151B2 - Image forming apparatus, calculation method, and calculation program - Google Patents

Description

The present disclosure relates to an image forming apparatus, calculation method, and calculation program.

2. Description of the Related Art Conventionally, an image forming apparatus using a photoreceptor having a film on its outer periphery has been proposed. For example, Japanese Patent Application Laid-Open No. 2002-200002 proposes a technique for detecting the life of a photoreceptor by measuring the amount of reduction in the film thickness of the photoreceptor using the rotation time of the photoreceptor.

JP-A-10-39691

In recent years, there has been a demand for a proposal of a technique for measuring the reduction amount of the film of the photoreceptor, which is more accurate than the technique disclosed in JP-A-2003-200016.

The present disclosure has been conceived in view of such circumstances, and an object of the present disclosure relates to an image forming apparatus, a calculation method, and a calculation program for accurately calculating the amount of reduction in film thickness of a photoreceptor.

According to one aspect of the present disclosure, an image forming unit uses an image carrier to form an image on one side of a sheet and both sides of the sheet; a first counting unit that counts as a first parameter when forming images on both sides of a sheet; a second counting unit that counts the parameter as a second parameter when forming images on both sides of a sheet; and a first coefficient for the first parameter. an image forming apparatus comprising: a calculation unit that calculates the amount of decrease in the film thickness based on the applied value and a value obtained by applying a second coefficient different from the first coefficient to the second parameter. is provided.

Preferably, the calculator calculates the decrease in the film thickness based on a value obtained by multiplying the first parameter by the first coefficient and a value obtained by multiplying the second parameter by the second coefficient. A quantity is calculated, the second factor being greater than the first factor.

Preferably, the image forming section includes a fixing section that fixes a toner image formed on paper with toner, and the first coefficient and the second coefficient are related values related to the amount of heat generated from the fixing section. is a coefficient according to

Preferably, said relevant value includes paper thickness.
Preferably, the relevant value includes the transport speed of the paper.

Preferably, said relevant value includes paper size.
Preferably, said associated value includes the number of sheets of paper imaged per unit of time.

According to another aspect of the present disclosure, there is provided a calculation method for calculating an amount of decrease in film thickness of an image carrier in an image forming apparatus that forms images on one side and both sides of a sheet using the image carrier. a procedure for acquiring a parameter relating to the reduction in film thickness of the image carrier as a first parameter during image formation on one side of a sheet; and acquiring the parameter as a second parameter during image formation on both sides of the sheet. Based on the procedure, a value obtained by applying a first coefficient to the first parameter, and a value obtained by applying a second coefficient different from the first coefficient to the second parameter, the film thickness is determined. A calculation method is provided comprising: calculating the amount of reduction.

According to another aspect of the present disclosure, an image forming apparatus that uses an image carrier to form images on one side of a sheet of paper and on both sides of the sheet of paper is provided with parameters related to the reduction in film thickness of the image carrier. a procedure for acquiring the parameter as a first parameter during formation, a procedure for acquiring the parameter as a second parameter during image formation on both sides of a sheet, a value obtained by applying the first coefficient to the first parameter, and A calculation program is provided for executing a procedure for calculating the amount of decrease in the film thickness based on a value obtained by applying a second coefficient different from the first coefficient to the second parameter.

According to the present disclosure, it is possible to accurately calculate the reduction amount of the film thickness of the photoreceptor.

1 is a diagram showing the overall configuration of an image forming apparatus; FIG. 2 is a cross-sectional view of a photoreceptor; FIG. FIG. 3 is a diagram showing the results of durability tests of photoreceptors; FIG. 8 is a diagram showing that the reduction amount of the photoreceptor film differs between single-sided printing and double-sided printing. 2 illustrates the hardware configuration of an image forming apparatus; FIG. It is a figure which shows a 1st coefficient and a 2nd coefficient. It is a figure which shows life speed etc. FIG. 10 is a diagram showing a reduction amount of a photoreceptor film; 2 is a diagram illustrating an example of the functional configuration of an image forming apparatus; FIG. 4 is a flow chart of the image forming apparatus; It is a figure which shows a 1st coefficient and a 2nd coefficient. It is a figure which shows a 1st coefficient and a 2nd coefficient. It is a figure which shows a 1st coefficient and a 2nd coefficient. It is a figure which shows a 1st coefficient and a 2nd coefficient. FIG. 5 is a diagram showing life prediction of a photoreceptor; 1 illustrates an image forming system; FIG.

A fixing device and an image forming apparatus according to embodiments of the present invention will be described below with reference to the drawings. In the embodiments described below, when referring to the number, amount, etc., the scope of the present invention is not necessarily limited to the number, amount, etc., unless otherwise specified. The same reference numbers are given to the same parts and equivalent parts, and redundant description may not be repeated. In addition, it is planned from the beginning to use the configurations in each embodiment in combination as appropriate. Hereinafter, "forming an image" is also referred to as "printing".

[Configuration of Image Forming Apparatus]
A schematic configuration of an image forming apparatus 1501 according to the embodiment will be described with reference to FIG. FIG. 1 is a diagram showing the overall configuration of an image forming apparatus 1501. As shown in FIG. An image forming apparatus 1501 according to the embodiment includes an intermediate transfer belt 1502 as a belt member in a substantially central portion inside the apparatus.

Below the lower horizontal portion of the intermediate transfer belt 1502 are four image forming units 1506Y, 1506M, 1506C, and 1506K respectively corresponding to yellow (Y), magenta (M), cyan (C), and black (K). are arranged side by side along the intermediate transfer belt 1502 .

The image forming units 1506Y, 1506M, 1506C and 1506K have photosensitive drums 1507Y, 1507M, 1507C and 1507K, respectively. Around the photosensitive drums 1507Y, 1507M, 1507C, and 1507K, a charging roller 1508 that charges the photosensitive drums, a print head unit 1509, a developing device 1510, and an intermediate transfer belt 1502 are arranged in order along the direction of rotation. Primary transfer rollers 1511Y, 1511M, 1511C, and 1511K are arranged to face the photosensitive drums 1507Y, 1507M, 1507C, and 1507K, respectively.

A secondary transfer roller 1503 is pressed against a portion of the intermediate transfer belt 1502 supported by the intermediate transfer belt drive roller 1505, and a nip portion between the secondary transfer roller 1503 and the intermediate transfer belt 1502 is a secondary transfer area. It is now 1530. A fixing device 100 is arranged downstream of the transport path 1541 on the trailing side of the secondary transfer area 1530 .

A paper feed cassette 1517 is detachably arranged at the bottom of the image forming apparatus 1501 . Sheets P stacked and accommodated inside the sheet feeding cassette 1517 are sent to the conveying path 1540 sheet by sheet from the uppermost sheet by the rotation of the sheet feeding roller 1518 . An image density (AIDC) sensor 1519 also serving as a registration sensor is installed between the image forming unit 1506K on the most downstream side of the intermediate transfer belt 1502 and the secondary transfer area 1530 .

Next, a schematic operation of the image forming apparatus 1501 configured as above will be described. An image signal is input from an external device (for example, a personal computer) to an image signal processing unit (not shown) of the image forming apparatus 1501 . The image signal processing unit to which the image signal is input creates a digital image signal by color-converting the image signal into yellow, cyan, magenta, and black. The print head portions 1509 of the image forming units 1506Y, 1506M, 1506C and 1506K emit light based on the digital image signals, and expose the photosensitive drums 1507Y, 1507M, 1507C and 1507K.

The electrostatic latent images formed on the photosensitive drums 1507Y, 1507M, 1507C, and 1507K are developed by the developing devices 1510 to form toner images of the respective colors. The toner images of the respective colors are sequentially superimposed and primarily transferred onto the intermediate transfer belt 1502 moving in the arrow A direction by the action of the primary transfer rollers 1511Y, 1511M, 1511C, and 1511K.

The toner image formed on intermediate transfer belt 1502 reaches secondary transfer area 1530 as intermediate transfer belt 1502 moves. In the secondary transfer area 1530 , the superimposed toner images of respective colors are secondary-transferred collectively onto the sheet P by the action of the secondary transfer roller 1503 .

The toner image secondarily transferred onto the paper P reaches the fixing device 100 . The toner image is fixed on the paper P by high-temperature pressure contact by the fixing device 100 . In FIG. 1, a process of transferring a toner image formed by developing an electrostatic latent image formed on an electrostatic latent image carrier with toner onto an intermediate transfer belt 1502 and a process of transferring the toner image onto the intermediate transfer belt 1502 . An example in which the fixing device 100 is applied to an image forming apparatus including a step of transferring a toner image onto a sheet (image support) will be described. However, the fixing device 100 may be applied to other image forming apparatuses. Another image forming apparatus is, for example, an image forming apparatus that directly transfers a toner image formed by developing an electrostatic latent image formed on an electrostatic latent image carrier with toner onto a sheet of paper (image support). may be Hereinafter, the photoreceptor drums 1507Y, 1507M, 1507C, and 1507K are collectively referred to as "photoreceptor 1507". Also, the photoreceptor 1507 is an example of an image carrier.

FIG. 2 shows a cross-sectional view of the photoreceptor 1507. As shown in FIG. As shown in FIG. 2, the photoreceptor 1507 has a columnar main body 70 and a photoreceptor film 72 around the main body 70 . The body portion 70 is typically made of an aluminum base or the like. Photoreceptor film 72 is typically composed of an undercoat layer, a charge generation layer, and a charge transport layer in order from the inside. The undercoat layer is a layer that prevents counter charges (+) generated by charging from being injected into the inside of the photoreceptor. The charge generation layer is a layer that generates charges (+, -) by photoelectric conversion. The charge transport layer is a layer that can be charged on the surface, transports the charge (+) generated in the charge generation layer, and neutralizes the charge (-) charged on the surface. The photoconductor film 72 of this embodiment is an organic photoconductor (OPC: Organic Photoconductor). The photoreceptor film 72 is scraped off (reduced) more as the flowing current (applied voltage) increases. The photoreceptor film 72 has a cylindrical shape, and the amount of decrease in the photoreceptor film 72 is the amount of decrease in the direction perpendicular to the axis of the cylinder. Reduction of the photoreceptor film 72 is also referred to as “film reduction” or “film thickness reduction”.

[Thought of this embodiment]
Next, the concept of this embodiment will be described. Due to the recent trend of declining click prices and environmental friendliness, there is a demand for longer service life of replacement parts of image forming apparatuses (hereinafter referred to as MFPs: Multifunction Peripherals) and further improvement of replacement timing accuracy. Among MFP replacement parts, the photoreceptor has a relatively short life. Therefore, it is necessary to further improve the accuracy of predicting the life of the photoreceptor.

The thickness (film thickness) of the photoreceptor film 72 is the main factor in the life of the photoreceptor. When the photoreceptor film 72 is worn down to a certain limit, the life of the photoreceptor is reached. The cleaning blade is the main cause of wear of the photoreceptor. Another factor is the current that flows during charging. In particular, if a large amount of current flows when an AC (alternating current) voltage is applied, such as in a charging roller system, film abrasion of the photoreceptor is accelerated.

In addition to the means disclosed in Patent Document 1, the applicant has conducted a durability test of a photoreceptor in a durability test with only single-sided printing and a durability test with only double-sided printing. It was found that the amount of reduction of the photoreceptor film 72 (the amount of scraping of the photoreceptor film 72) is different. In other words, the applicant has found that the life of the photoreceptor differs between single-sided printing and double-sided printing. The reason for this is that in double-sided printing, the paper that has passed through the fixing device passes through the secondary transfer section again, so the temperature around the photoreceptor inside the machine rises, and the resistance of the charging roller decreases. I had a lot of leaks.

FIG. 3 is a diagram showing the results of an endurance test. In the example of FIG. 3, the horizontal axis indicates the number of rotations of the photoreceptor 1507, and the vertical axis indicates the reduction amount of the photoreceptor film 72. In FIG. "krot" in FIG. 3 indicates 1000 rotations. Further, the dashed line shows the transition of the reduction amount of the photoreceptor film when only double-sided printing is performed, and the solid line shows the transition of the reduction amount of the photoreceptor film when only single-sided printing is performed.

As shown in FIG. 3, with only single-sided printing, the reduction amount of the photosensitive film 72 reaches 20 μm at 2000 krot, whereas with only double-sided printing, the reduction amount of the photosensitive film 72 reaches 20 μm with 1145 krot. As described above, the reduction amount of the photoreceptor film per rotation of the photoreceptor is larger in the case of double-sided printing than in the case of single-sided printing.

The thickness of the photoreceptor film 72 of the photoreceptor is usually several tens of micrometers. When the photoreceptor film 72 is reduced, the chargeability of the surface potential cannot be maintained, and attenuation of the photoreceptor occurs during exposure, resulting in the end of the life of the photoreceptor.

In this embodiment, when the photoreceptor film 72 is shaved by 20 μm from the initial state of the photoreceptor, the life of the photoreceptor film 72 is reached. As described above and also shown in FIG. 3, the reduction amount of the photoreceptor film 72 of the photoreceptor differs between single-sided printing and double-sided printing. Then, the reduction amount of the photoreceptor film 72 of the photoreceptor differs between single-sided printing and double-sided printing. Life expectancy differs between printing and printing.

FIG. 4 is a diagram for explaining that the reduction amount of the photoreceptor film differs between single-sided printing and double-sided printing. As shown in FIG. 4, during double-sided printing, heat generated by the fixing device 100 that performs high-temperature pressure contact processing on the paper is radiated into the image forming apparatus (see α in FIG. 4). Furthermore, during double-sided printing, when the paper heated by passing through the fixing device 100 (the paper after printing on the first side) passes through the secondary transfer area 1530 again, the paper comes into contact with the intermediate transfer belt 1502 . As a result, heat is conducted to the intermediate transfer belt 1502 (see β in FIG. 4). Then, the heat is transmitted to the photoreceptor 1507, so that the temperature of the photoreceptor 1507 rises and the resistance of the charging roller 1508 in contact with the photoreceptor 1507 decreases. Therefore, a large amount of current flows through the photosensitive member 1507 . As a result, the reduction amount of the photoreceptor film 72 increases.

[Hardware Configuration Example of Image Forming Apparatus 1501]
FIG. 5 is a diagram showing the hardware configuration of the image forming apparatus 1501. As shown in FIG. 5, an image forming apparatus 1501 includes a CPU (Central Processing Unit) 101 for executing programs, a ROM (Read Only Memory) 102 for nonvolatilely storing data, and a RAM for volatilely storing data. (Random Access Memory) 103 , flash memory 104 , touch screen 105 , and speaker 106 .

The touch screen 105 is composed of a display 1051 as a display device and a touch panel 1052 as an input device. Specifically, the touch screen 105 is realized by positioning and fixing the touch panel 1052 on the display 1051 (for example, a liquid crystal display). The touch screen is also called a touch panel display, a display with a touch panel, or a touch panel monitor. In addition, in the touch screen 105, for example, a resistive film method or a capacitance method can be used as a method of detecting a touch position.

Flash memory 104 is a non-volatile semiconductor memory. The flash memory 104 stores an operating system and various programs executed by the CPU 101, various contents and data. Further, the flash memory 104 volatilely stores various data such as data generated by the image forming apparatus 1501 and data obtained from an external device of the image forming apparatus 1501 .

A speaker 106 generates a sound according to a command from the CPU 101 . CPU 101 specifies an input position based on the output from touch panel 1052, and performs screen display based on the specified input position.

Processing in the image forming apparatus 1501 is implemented by each piece of hardware and software executed by the CPU 101 . Such software may be pre-stored in flash memory 104 . Each component constituting the image forming apparatus 1501 shown in the figure is a general one. Therefore, it can be said that the essential part of the present invention is software stored in the flash memory 104, memory card or other storage medium, or software downloadable via a network. Since the operation of each hardware of image forming apparatus 1501 is well known, detailed description thereof will not be repeated.

The recording medium is not limited to DVD-ROM, CD-ROM, FD (Flexible Disk), hard disk, magnetic tape, cassette tape, optical disk (MO (Magnetic OptiDal Disc) / MD (Mini Disc) / DVD (Digital Versatile Disc)), optical card, mask ROM, EPROM (ElectroniDally Programmable Read-Only Memory), EEPROM (ElectroniDally Erasable Programmable Read-Only Memory), semiconductor memory such as flash ROM, etc. . Also, the recording medium is a non-transitory medium in which the program or the like can be read by the computer.

The program here includes not only a program that can be directly executed by the CPU, but also a program in source program format, a compressed program, an encrypted program, and the like.

[Functions of this embodiment]
Next, functions of this embodiment will be described. The image forming apparatus 1501 measures the reduction amount of the photoreceptor film 72 using the parameters related to the film thickness reduction of the photoreceptor 1507 . In this embodiment, this parameter is the number of rotations of the photoreceptor (the amount of rotation of the photoreceptor 1507 or the amount of movement of the photoreceptor 1507). The image forming apparatus 1501 includes counters (second counters to be described later) that measure the amount of rotation of each of the four photoconductors (photoconductor drums 1507Y, 1507M, 1507C, and 1507K) in printing (image formation) on one side of a sheet of paper. 1 measurement unit) and a counter (second measurement unit, which will be described later) that measures the amount of rotation of the photosensitive member in printing (image formation) on both sides of the paper. These counters are reset when the photoreceptor 1507 is replaced, and continue counting as long as the photoreceptor is not replaced.

Also, in this embodiment, coefficients (weighting) are applied to the parameters measured by these counters. In the present embodiment, the coefficient is a value obtained by dividing the amount of decrease (scraping amount) of the photoreceptor film 72 (thickness) by the number of rotations (rotation amount) of the photoreceptor. The unit of coefficient is “μm/100 krot”. Hereinafter, the coefficient for single-sided printing will be referred to as "first coefficient", and the coefficient for double-sided printing will be referred to as "second coefficient".

As explained in FIG. 3, when single-sided printing is performed on the photoreceptor, 20 μm is shaved (reduced) at 2000 krot, and when double-sided printing is performed, 20 μm is shaved (reduced) at 1145 krot. Then, the first coefficient is "1 (μm/100 krot)" and the second coefficient is "1.75 (μm/100 krot)".

FIG. 6 is a diagram showing the first coefficient and the second coefficient. In FIG. 6, the first side refers to printing on the front side, and the second side refers to printing on the back side. Also, the coefficient is 2.5 only for the second surface. The second coefficient is "1.75", which is the average value of the first and second surfaces.

Next, a method for predicting the life of the photoreceptor 1507 based on the calculated reduction amount of the photoreceptor film 72 will be described. In this embodiment, based on the decrease amount of the photoreceptor film 72 and the number of days from the initial date of the photoreceptor 1507 (for example, the date when the photoreceptor 1507 was first used) to the date when the decrease amount was calculated, The life of photoreceptor 1507 is predicted. FIG. 7 is a diagram for explaining this technique. First, let's talk about the current situation. Assume that the number of rotations of the photoreceptor 1507 is 1000 krot, and 100 days have passed since the first day, as shown in the current column in FIG. Assume that the number of revolutions is 695 krot for single-sided printing and 305 krot for double-sided printing. Also, the life coefficient is calculated by multiplying the number of revolutions by the aforementioned coefficient. In other words, the life coefficient corresponds to the reduction amount of the photosensitive film 72 . The life factor is calculated by the following formula (1).

Life factor = (Number of rotations for single-sided printing x 1st factor) + (Number of rotations for double-sided printing x 2nd factor) (1)
Substituting specific values into the formula (1) yields the following.

Life factor = (1 x 695/100) + (1.75 x 305/100) = 12.3 µm
In the following description, regarding the amount of decrease in the photoreceptor film 72, the amount of decrease judged to be the end of the life of the photoreceptor 1507 is referred to as the limit amount of decrease. If the limit reduction amount is 20 μm, the life of the photoreceptor 1507 is 7.7 μm remaining at the present time (100th day from the first day), so it can be said that there is a sufficient margin. Therefore, from the viewpoint of reduction of the photoreceptor film 72, the life of the photoreceptor 1507 is not reached. Assuming that the life speed is a value obtained by dividing the life coefficient (decrease amount of the photoreceptor film 72) by the rotational speed, the life speed is 0.0123 (μm/krot).

Next, as shown in column A, the case where the current life rate (=0.0123 (μm/krot)) is maintained in the future (no change) will be described. In this case, since the life coefficient of the photoreceptor 1507 to the limit reduction amount remains 7.7 μm, it takes 626 revolutions (≈7.7/ 0.0123) can be expected. Then, since it took 100 days for the rotational speed of the photoreceptor 1507 to reach 1000 krot, it can be predicted that the photoreceptor 1507 will reach the end of its service life in about 63 days. The life prediction timing for predicting the life of the photosensitive member 1507 includes, for example, the timing when the power of the image forming apparatus 1501 is turned on, the timing when a predetermined number of sheets are printed, every predetermined time, and another member (for example, an intermediate member). It includes at least one of the timing when the transfer belt) is replaced, the timing when the user executes a predetermined life expectancy operation, and the like.

Next, the case where the life speed is changed (corrected) in the future will be described using item B in FIG. For example, the image forming apparatus 1501 measures the life speed one day after the current time (100th day from the first day). to be corrected. It can be predicted that the image forming apparatus 1501 can make 770 rotations (≈7.7/0.01) before reaching the limit reduction amount. Then, since it took 100 days for the rotational speed of the photoreceptor 1507 to reach 1000 krot, it can be predicted that the life of the photoreceptor 1507 will expire after about 77 days.

In the item B of FIG. 7, if the life rate measured one day after the current time (100th day from the first day) is 0.02 (μm/krot), it is corrected to this life rate. It can be predicted that the image forming apparatus 1501 can make 385 rotations (≈7.7/0.02) before reaching the limit reduction amount. Then, since it took 100 days for the number of rotations of the photoreceptor 1507 to reach 1000 krot, it can be predicted that the life of the photoreceptor 1507 will be reached in about 38 days.

FIG. 8 is a graph showing the lifespan and the like described in FIG. In FIG. 8, the horizontal axis indicates the number of rotations of the photoreceptor 1507, and the vertical axis indicates the reduction amount of the photoreceptor film 72. In FIG. Also, in FIG. 8, as explained in FIG. 7, one day after the present time, if the life rate is not changed (as shown in the item A in FIG. 7, 0.0123 (μm/krot) is maintained), when the life rate was changed to 0.01 (μm/krot) (see item B in FIG. 7), and when the life rate was changed to 0.02 (μm/krot) (See item B in FIG. 7). In FIG. 8, the solid line indicates the case where the life rate is maintained at 0.0123 (μm/krot), the dashed line indicates the case where the life rate is changed to 0.01 (μm/krot), and the life rate is 0.01 (μm/krot). 02 (μm/krot) is indicated by a two-dot chain line.

In this way, the image forming apparatus 1501 can correct the predicted lifespan date by calculating the lifespan at the timing of calculating the lifespan, thereby further improving the accuracy of the predicted lifespan date.

[Example of functional configuration of control unit]
Next, a functional configuration example of the image forming apparatus 1501 will be described. FIG. 9 is a diagram showing a functional configuration example of the image forming apparatus 1501. As shown in FIG. As shown in FIG. 9, the image forming apparatus 1501 functionally has a control section 220 and an image forming section 230 . The image forming section 230 forms (prints) images on one side and both sides of the paper. The image forming unit 230 is a component for printing on paper, such as the photoreceptor 1507 and the fixing device 100 . The control unit 220 is implemented by the CPU 101, ROM 102, RAM 103, etc. of the image forming apparatus 1501. FIG.

The functions of control unit 220 include the functions of coefficient storage unit 250 , first counting unit 252 , second counting unit 254 , and calculation unit 256 .

The first counting unit 252 counts a parameter (in this embodiment, the number of rotations of the photoreceptor 1507) relating to the reduction of the photoreceptor film 72 as the first parameter during single-sided printing of the paper. For example, image forming section 230 transmits a single-sided pulse signal indicating one rotation to first counting section 252 when photoreceptor 1507 makes one rotation during single-sided printing. The first counting unit 252 counts the number of rotations of the photoreceptor 1507 in single-sided printing every time it receives this single-sided pulse signal. The first parameter is the number of rotations of the photoreceptor 1507 during single-sided printing executed when a user inputs a single-sided printing job.

A second counting unit 254 counts the number of rotations of the photosensitive member 1507 as a second parameter during double-sided printing of paper. For example, image forming section 230 transmits a double-sided pulse signal indicating one rotation to second counting section 254 when photoreceptor 1507 makes one rotation when double-sided printing is executed. The second counting unit 254 counts the number of rotations of the photoreceptor 1507 in double-sided printing every time it receives this double-sided pulse signal. The second parameter is the number of rotations of the photoreceptor 1507 during double-sided printing which is executed when a double-sided printing job is input by the user.

The first parameter from the first counting section 252 and the second parameter from the second counting section 254 are input to the calculating section 256 respectively. The techniques of the first counting section 252 and the second counting section 254 are not limited to these techniques, and other techniques may be used.

The calculation unit 256 calculates a value obtained by applying the first coefficient to the first parameter from the first counting unit 252 (hereinafter referred to as the amount of decrease during single-sided printing), and a value different from the first coefficient for the second parameter. The amount of reduction of the photoreceptor film 72 is calculated based on the value obtained by applying the 2nd factor (hereinafter referred to as the amount of reduction during double-sided printing).

Here, the first coefficient and the second coefficient are those shown in FIG. Thus, the first coefficient and the second coefficient are values determined in advance by simulation, test, or the like. The first coefficient and the second coefficient may be stored in the coefficient storage unit 250 in advance. Also, the first coefficient and the second coefficient may be changed by the administrator of the image forming apparatus 1501 or the like.

Further, the calculation unit 256 of the present embodiment, as shown in the above equation (1), the single-sided printing reduction amount is a value obtained by multiplying the first parameter by the first coefficient. The double-sided printing reduction amount is a value obtained by multiplying the second parameter by the second coefficient.

Then, the calculation unit 256 calculates the reduction amount of the photosensitive film 72 by adding the reduction amount during single-sided printing and the reduction amount during double-sided printing. This calculated decrease amount is input to the prediction unit 258 . The prediction unit 258 predicts the life based on the difference between this reduction amount and a predetermined limit reduction amount.

The prediction unit 258 notifies the user or the like of the prediction result. For example, prediction unit 258 displays on the display unit (for example, touch screen 105 in FIG. 5).

FIG. 10 is a diagram showing a flowchart of the image forming apparatus of this embodiment. In S2, the calculation unit 256 calculates the number of rotations counted by the first counting unit 252 (the number of rotations of the photosensitive member 1507 during single-sided printing: the first parameter) and the number of rotations counted by the second counting unit 254 (both sides The number of rotations of the photoreceptor 1507 during printing: second parameter).

Although S2 is described as a step of acquiring both the first parameter and the second parameter, the step of acquiring the first parameter and the step of acquiring the second parameter may be separated. good.

Next, in S4, the calculation unit 256 multiplies the number of rotations of the photoreceptor 1507 during single-sided printing by the first coefficient, and multiplies the number of rotations of the photoreceptor 1507 during double-sided printing by the second coefficient. The reduction amount of the photosensitive film 72 is calculated by multiplying and calculating the sum of them. Next, in S6, the prediction unit 258 predicts the life of the photoreceptor based on this decrease amount.

According to such a configuration, the amount of decrease in the thickness of the photoreceptor film 72 is calculated in consideration of the heat conduction described in terms of α and β in FIG. Typically, with respect to a parameter (in this embodiment, the number of rotations of the photoreceptor 1507) related to the reduction in film thickness of the photoreceptor, a first coefficient during single-sided printing and a second coefficient during double-sided printing are used. is applied (multiplied), the reduction amount of the photosensitive film 72 is calculated. Therefore, compared with the conventional art, the reduction amount of the photoreceptor film 72 can be calculated with high accuracy, and the life of the photoreceptor 1507 can be predicted with high accuracy.

Next, modified examples of the first coefficient and the second coefficient will be described. In this embodiment, the first coefficient and the second coefficient are coefficients according to related values related to the amount of heat generated from the fixing device 100 . This related value is the amount of heat generated by the fixing device 100 and also a value related to whether or not the sheet heat-fixed by the fixing device 100 passes through the secondary transfer area 1530 . Variations of this associated value are described below.

[Related value (Part 1)]
FIG. 11 is a diagram for explaining related values (1). The related value (No. 1) is a value focused on the thickness of the paper. As the thickness of the paper increases (the basis weight increases), the heat capacity increases. Taking this into consideration, the control unit 220 of the image forming apparatus 1501 increases the fixing temperature of the fixing device if the thickness of the paper is thick. As a result, the temperature inside the image forming apparatus 1501 rises (see α in FIG. 3), so there is a phenomenon that the degree of decrease in the photoreceptor film 72 increases.

In this related value (No. 1), the first coefficient and the second coefficient are set so as to correspond to the thickness of the paper. FIG. 11 shows the first coefficient and the second coefficient based on the related value (part 1). In the example of FIG. 11, paper with a basis weight of up to 90 g/m ³ is normal paper, paper with a basis weight of 91 to 120 g/m ³ is thick paper 1, and paper basis weight is 121 to 210 g/m ³ . Thick paper 2 is the paper up to the weight of the paper, and thick paper 3 is the paper with a basis weight of 211 to 250 g/m ³ .

As also shown in FIG. 11, the first coefficient is "1" regardless of the thickness of the paper. In this way, the reason why the first coefficient does not change regardless of the thickness of the paper is that the paper on which only the first side is printed has not returned to the secondary transfer area 1530 when it passes through the fixing device 100. , is based on the fact that heat is not conducted to the intermediate transfer belt 1502 .

On the other hand, the second coefficient is set to increase as the thickness of the paper increases. This is because the amount of heat emitted from the fixing device 100 is greater when double-sided printing is performed on thick paper than when double-sided printing is performed on thin paper. Based on In the example of FIG. 11, the second coefficient for plain paper is 1.75, while the second coefficient for thick paper 3 is 1.90.

Thus, by using the first coefficient and the second coefficient corresponding to the related value (part 1) including the thickness of the paper, it is possible to calculate the reduction amount of the photoreceptor film 72 corresponding to the thickness of the paper. Therefore, the image forming apparatus 1501 can accurately calculate the reduction amount of the photoreceptor film 72 and predict the life of the photoreceptor 1507 .

[Related value (Part 2)]
FIG. 12 is a diagram showing related values (part 2). The related value (No. 2) is a value focused on the paper transport speed. The paper transport speed may be the paper transport speed in the image forming apparatus 1501 , the paper transport speed before image formation, or the paper transport speed when the paper is transported into the fixing device 100 .

When the paper is conveyed at a high speed, if the heating temperature of the fixing device 100 is low, the image may not be properly fixed. In view of this case, the control unit 220 of the image forming apparatus 1501 increases the fixing temperature of the fixing device if the sheet conveying speed is high. As a result, the temperature inside the image forming apparatus 1501 rises (see α in FIG. 3), so there is a phenomenon that the degree of decrease in the photoreceptor film 72 increases.

In this related value (part 2), the first coefficient and the second coefficient are set to be coefficients corresponding to the paper transport speed. FIG. 12 shows the first coefficient and the second coefficient considering the related value (part 2). In the example of FIG. 12, there are full speed (fast) and half speed (slow) as the paper transport speed. Half speed is a conveying speed that is half of full speed.

As also shown in FIG. 12, the first coefficient is "1" regardless of the paper transport speed. In this way, the reason why the first coefficient does not change regardless of the paper transport speed is that the paper on which only the first side has been printed has not returned to the secondary transfer area 1530 when it passes through the fixing device 100. , is based on the fact that heat is not conducted to the intermediate transfer belt 1502 .

On the other hand, the second coefficient is set to increase as the paper transport speed increases. This is because the amount of heat emitted from the fixing device 100 is greater when double-sided printing is performed on paper with a fast conveying speed than when double-sided printing is performed on paper with a slow conveying speed. Based on In the example of FIG. 12, the second factor for full speed is 1.75, while the second factor for half speed is 1.60.

Thus, by using the first coefficient and the second coefficient corresponding to the related value (part 2) including the sheet conveying speed, it is possible to calculate the reduction amount of the photoreceptor film 72 according to the sheet conveying speed. Therefore, the image forming apparatus 1501 can accurately calculate the reduction amount of the photoreceptor film 72 and predict the life of the photoreceptor 1507 .

[Related value (3)]
FIG. 13 is a diagram showing related values (part 3). The related value (3) is a value focused on the paper size. When the size of the paper is large, if the heating temperature of the fixing device 100 is low, the image may not be fixed properly. In view of this case, the control unit 220 of the image forming apparatus 1501 increases the fixing temperature of the fixing device if the paper size is large. As a result, the temperature inside the image forming apparatus 1501 rises (see α in FIG. 3), so there is a phenomenon that the degree of decrease in the photoreceptor film 72 increases.

In this related value (No. 3), the first coefficient and the second coefficient are set so as to correspond to the paper size. FIG. 13 shows the first coefficient and the second coefficient considering the related value (No. 3). In the example of FIG. 13, there are A4 size and A3 size as paper sizes.

As also shown in FIG. 13, the first coefficient is "1" regardless of the paper size. Thus, the reason why the first coefficient does not change regardless of the paper size is that the paper on which only the first side is printed has not returned to the secondary transfer area 1530 when it passes through the fixing device 100. This is based on the fact that heat is not conducted to the intermediate transfer belt 1502 .

On the other hand, the second coefficient is set to increase as the paper size increases. This is based on the fact that the amount of heat emitted from the fixing device 100 is greater when double-sided printing is performed on large-sized paper than when double-sided printing is performed on small-sized paper. there is

In the example of FIG. 13, the second coefficient of A4 is 1.75, while the second coefficient of A3 is 1.85.

Thus, by using the first coefficient and the second coefficient corresponding to the related value (part 3) including the paper size, it is possible to calculate the reduction amount of the photoreceptor film 72 according to the paper size. Therefore, the image forming apparatus 1501 can accurately calculate the reduction amount of the photoreceptor film 72 and predict the life of the photoreceptor 1507 .

[Related value (4)]
FIG. 14 is a diagram showing related values (part 4). The related value (No. 4) is a value focused on the number of printed sheets per unit time (hereinafter also simply referred to as "the number of printed sheets"). Assume that the unit time is, for example, one hour. When the number of printed sheets is large, the number of heat fixing processes per unit time is increased, so the temperature inside the image forming apparatus 1501 per unit time is increased. Then, there is a phenomenon that the degree of reduction of the photoreceptor film 72 increases.

In this related value (No. 4), the first coefficient and the second coefficient are set to be coefficients corresponding to the number of printed sheets per unit time. FIG. 14 shows the first coefficient and the second coefficient considering the related value (No. 4).

In the example of FIG. 14, the number of printed sheets per unit time is 5 or less, 6 or more and 10 or less, or 11 or more and 50 or less. , 51 to 100 sheets, 101 to 1000 sheets, 1001 to 2000 sheets, and 2001 sheets or more. ing. In each of these ranges, the coefficient for double-sided printing is set to be larger than the coefficient for single-sided printing.

Next, estimation of the life of the photoreceptor 1507 when this related value (part 4) is adopted will be described. FIG. 15 is a diagram for explaining this life expectancy estimation. In the example of FIG. 15, the number of rotations of the photoreceptor 1507 is 1000 krot, and the breakdown is 600 krot for single-sided printing and 400 krot for double-sided printing. It is also assumed that the range of the number of printed sheets per unit time is the seven types shown in FIG. During single-sided printing, the reduction amount of the photoreceptor film 72 is calculated by multiplying the number of rotations of the photoreceptor 1507 by the first coefficient. Also, during double-sided printing, the reduction amount of the photoreceptor film 72 is calculated by multiplying the number of rotations of the photoreceptor 1507 by the second coefficient.

For example, in single-sided printing, when the number of printed sheets is 5 per unit time, the reduction amount of the photosensitive film 72 is 2.00 μm. Then, in single-sided printing and double-sided printing, the total value of the amount of decrease shown on the right end of FIG. 15 is 13.44 μm. This is the reduction amount of the photoreceptor film 72 when the rotation speed of the photoreceptor 1507 is 1000 krot.

As described above, even if the reduction amount of the photoreceptor film 72 is calculated according to the number of printed sheets per unit time, the life of the photoreceptor 1507 can be predicted appropriately.

[Other examples of parameters and coefficients]
Also, the associated values for the aforementioned coefficients may be other values. The relevant value may include at least one of the number of photoreceptor rotations per unit time (rotation amount, movement amount) and the application time to the charging roller 1508 .

In the above-described embodiment, the parameter related to the reduction of the photoreceptor film 72 is the number of rotations (amount of rotation, amount of movement) of the photoreceptor 1507 . However, this parameter may be any one of the number of prints per unit time, the application time to the charging roller 1508, and the number of rotations (amount of rotation, amount of movement) of the photosensitive member 1507 while the charging roller 1508 is applying a voltage. .

[In the image forming system]
FIG. 16 is a diagram showing an image forming system 120. As shown in FIG. As shown in FIG. 16, the image forming system 120 includes N (N is a natural number) image forming apparatuses 1501, . . . , 150N and a server device 700. FIG. N (N is a natural number) image forming apparatuses 1501, . . . , 150N and the server apparatus 700 are connected by a network 650. FIG. The network 650 is constructed by a WAN (Wide Area Network) or a LAN (Local Area Network).

In the above-described embodiment, the image forming apparatus 1501 executes the process of calculating the reduction amount of the photoreceptor film 72 and the process of predicting the life of the photoreceptor 1507 . However, server device 700 may perform at least one of these processes. In this case, the image forming apparatus 1501 transmits to the server device 700 data necessary for processing executed by the server device 700 . With such a configuration, it is possible to reduce the processing load of the image forming apparatus.

Further, each of the N image forming apparatuses transmits to the server apparatus 700 operation information that can specify the operation status of the image forming apparatus. The server device 700 may predict the life of the photosensitive member of each of the N image forming apparatuses from this operation information. The operating information includes at least one of information indicating the humidity in the image forming apparatus and the brand of paper, information indicating physical properties (size and thickness) of the paper, information about the image to be formed (printed), and the like. . In this case, for example, the coefficient of one of the N image forming apparatuses and the limit reduction amount are obtained. Then, the acquired coefficient and limit reduction amount may be transmitted to other image forming apparatuses among the N image forming apparatuses that have the same or similar operational status as the one image forming apparatus. good. According to such a configuration, it is possible to update more accurate coefficients, limit reduction amounts, and the like for other image forming apparatuses.

Further, the server apparatus 700 may acquire the status information of each image forming apparatus from these image forming apparatuses. The situational information is, for example, the area where the image forming apparatus is installed, the season in this area, the company or business type where this image forming apparatus is installed, and the like.

The area information is information indicating whether the area is a high temperature area or a low temperature area, that is, whether the ambient temperature inside the image forming apparatus 1501 is high or low. If the area information is information indicating that the area has a high temperature, for example, server device 700 sets a large limit amount of decrease (increases the period during which the photoreceptor can be used). , the image forming apparatus that has transmitted the information of this area is changed to a larger limit reduction amount.

Further, the company or business type information may be, for example, a company or type of business that needs to print clear images, or a company or type of business that prints characters instead of images, depending on the company or business type. The server apparatus 700 sets a small marginal reduction amount for a company or business type that requires printing of clear images. As a result, the photoreceptor can be replaced early, so that the image quality can be prevented from deteriorating. On the other hand, the server device 700 sets a large marginal reduction amount for a company or business type that does not need to print clear images (a company or business type that prints characters). As a result, it is possible to prevent the user from being dissatisfied with the quality of the image, and to allow the photoreceptor to be used for a long period of time.

[others]
(1) In the present embodiment, the calculation unit 256 calculates the decrease in film thickness based on the value obtained by multiplying the first parameter by the first coefficient and the value obtained by multiplying the second parameter by the second coefficient. Quantities were calculated and the second factor was described as being greater than the first factor.

However, the calculation unit 256 calculates the film thickness based on the value obtained by applying the first coefficient to the first parameter and the value obtained by applying the second coefficient different from the first coefficient to the second parameter. Other calculation methods may be used as long as they calculate the amount of decrease.

For example, the calculation unit 256 calculates the film thickness reduction amount based on a value obtained by dividing the first parameter by the first coefficient and a value obtained by dividing the second parameter by the second coefficient. may In this case, the second coefficient will be smaller than the first coefficient. Even an image forming apparatus employing such a configuration has the same effect as the present embodiment.

(2) The essential part of the present invention can be said to be software stored in a flash memory or other storage medium, or software downloadable via a network. Recording media are not limited to DVD-ROMs, CD-ROMs, FDs, and hard disks, but fixed devices such as magnetic tapes, cassette tapes, optical disks, optical cards, mask ROMs, EPROMs, EEPROMs, flash ROMs, and other semiconductor memories. It may be a medium that carries the program on it. Also, the recording medium is a non-transitory medium in which the program or the like can be read by the computer. The program here includes not only a program that can be directly executed by the CPU, but also a program in source program format, a compressed program, an encrypted program, and the like.

Moreover, each embodiment disclosed this time should be considered as an illustration and not restrictive in all respects. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. In addition, the inventions described in the embodiments and modifications are intended to be implemented either singly or in combination as much as possible.

72 photosensitive film, 220 control unit, 230 image forming unit, 250 coefficient storage unit, 252 first counting unit, 254 second counting unit, 256 calculation unit, 258 prediction unit.

Claims (9)

an image forming unit that forms images on one side and both sides of a sheet of paper using an image carrier that is charged by a charging roller ;
a first counting unit that counts, as a first parameter, the number of rotations of the image carrier during image formation on one side of a sheet;
a second counting unit that counts, as a second parameter, the number of rotations of the image carrier during image formation on both sides of a sheet;
A value obtained by applying a first coefficient, which is a reduction ratio of the film thickness of the image carrier with respect to the rotation of the image carrier, to the first parameter when forming an image on one side of a sheet, and when forming an image on both sides of the sheet and a value obtained by applying a second coefficient, which is a rate of decrease in the film thickness of the image carrier with respect to the rotation of the image carrier, to the second parameter. and
The image forming unit includes a fixing unit that heats and fixes a toner image formed on paper with toner,
The thicker the paper, the greater the amount of heat generated from the fixing unit.
As the amount of heat increases, the current value flowing from the charging roller to the image bearing member increases.
The greater the current value, the greater the decrease in the film thickness,
The related value related to the amount of heat generated from the fusing unit includes the thickness of paper,
The image forming apparatus , wherein the thicker the thickness, the larger the second coefficient . an image forming unit that forms images on one side and both sides of a sheet of paper using an image carrier that is charged by a charging roller;
a first counting unit that counts, as a first parameter, the number of rotations of the image carrier during image formation on one side of a sheet;
a second counting unit that counts, as a second parameter, the number of rotations of the image carrier during image formation on both sides of a sheet;
A value obtained by applying a first coefficient, which is a reduction ratio of the film thickness of the image carrier with respect to the rotation of the image carrier, to the first parameter when forming an image on one side of a sheet, and when forming an image on both sides of the sheet and a value obtained by applying a second coefficient, which is a rate of decrease in the film thickness of the image carrier with respect to the rotation of the image carrier, to the second parameter. and
The image forming unit includes a fixing unit that heats and fixes a toner image formed on paper with toner,
The faster the sheet is conveyed, the more heat is generated from the fixing section.
As the amount of heat increases, the current value flowing from the charging roller to the image bearing member increases,
The greater the current value, the greater the decrease in the film thickness,
the relevant value related to the amount of heat generated from the fixing unit includes a paper transport speed;
The image forming apparatus, wherein the higher the transport speed, the larger the second coefficient. The calculation unit calculates the decrease amount of the film thickness based on a value obtained by multiplying the first parameter by the first coefficient and a value obtained by multiplying the second parameter by the second coefficient. death,
3. The image forming apparatus according to claim 1, wherein said second coefficient is greater than said first coefficient. the associated value includes paper size;
The image forming apparatus according to any one of claims 1 to 3, wherein the larger the size, the larger the second coefficient . 5. The image forming apparatus according to claim 1 , wherein said related value includes the number of sheets of paper on which images are formed per unit time. 1. A calculation method for calculating a decrease in film thickness of an image carrier in an image forming apparatus that forms images on one side and both sides of a sheet of paper using the image carrier charged by a charging roller , comprising:
a procedure for obtaining as a first parameter the number of rotations of the image carrier during image formation on one side of a sheet;
a procedure for obtaining, as a second parameter, the number of rotations of the image carrier during image formation on both sides of a sheet;
A value obtained by applying a first coefficient, which is a reduction ratio of the film thickness of the image carrier with respect to the rotation of the image carrier, to the first parameter when forming an image on one side of a sheet, and when forming an image on both sides of the sheet a step of calculating the reduction amount of the film thickness based on a value obtained by applying a second coefficient, which is a reduction ratio of the film thickness of the image carrier with respect to the rotation of the image carrier, to the second parameter; with
The image forming apparatus includes a fixing section that heats and fixes a toner image formed on paper with toner,
The thicker the paper, the greater the amount of heat generated from the fixing unit.
As the amount of heat increases, the current value flowing from the charging roller to the image bearing member increases,
The greater the current value, the greater the decrease in the film thickness,
The relevant value related to the amount of heat generated from the fusing unit includes the thickness of paper,
The calculation method , wherein the thicker the thickness, the larger the second coefficient . 1. A calculation method for calculating a decrease in film thickness of an image carrier in an image forming apparatus that forms images on one side and both sides of a sheet of paper using the image carrier charged by a charging roller, comprising:
a procedure for obtaining as a first parameter the number of rotations of the image carrier during image formation on one side of a sheet;
a procedure for obtaining, as a second parameter, the number of rotations of the image carrier during image formation on both sides of a sheet;
A value obtained by applying a first coefficient, which is a reduction ratio of the film thickness of the image carrier with respect to the rotation of the image carrier, to the first parameter when forming an image on one side of a sheet, and when forming an image on both sides of the sheet a step of calculating the reduction amount of the film thickness based on a value obtained by applying a second coefficient, which is a reduction ratio of the film thickness of the image carrier with respect to the rotation of the image carrier, to the second parameter; with
The image forming apparatus includes a fixing section that heats and fixes a toner image formed on paper with toner,
The faster the sheet is conveyed, the more heat is generated from the fixing section.
As the amount of heat increases, the current value flowing from the charging roller to the image bearing member increases,
The greater the current value, the greater the decrease in the film thickness,
the relevant value related to the amount of heat generated from the fixing unit includes a paper transport speed;
The calculation method, wherein the higher the transport speed, the larger the second coefficient. An image forming apparatus that forms images on one side and both sides of a sheet of paper using an image carrier that is charged by a charging roller ,
a procedure for obtaining as a first parameter the number of rotations of the image carrier during image formation on one side of a sheet;
a procedure for obtaining, as a second parameter, the number of rotations of the image carrier during image formation on both sides of a sheet;
A value obtained by applying a first coefficient, which is a reduction ratio of the film thickness of the image carrier with respect to the rotation of the image carrier, to the first parameter when forming an image on one side of a sheet, and when forming an image on both sides of the sheet a step of calculating the reduction amount of the film thickness based on a value obtained by applying a second coefficient, which is a reduction ratio of the film thickness of the image carrier with respect to the rotation of the image carrier, to the second parameter; A calculation program for executing
The image forming apparatus includes a fixing section that heats and fixes a toner image formed on paper with toner,
The thicker the paper, the greater the amount of heat generated from the fixing unit.
As the amount of heat increases, the current value flowing from the charging roller to the image bearing member increases,
The greater the current value, the greater the decrease in the film thickness,
The relevant value related to the amount of heat generated from the fusing unit includes the thickness of paper,
The calculation program , wherein the thicker the thickness, the larger the second coefficient . An image forming apparatus that forms images on one side and both sides of a sheet of paper using an image carrier that is charged by a charging roller,
a procedure for obtaining as a first parameter the number of rotations of the image carrier during image formation on one side of a sheet;
a procedure for obtaining, as a second parameter, the number of rotations of the image carrier during image formation on both sides of a sheet;
A value obtained by applying a first coefficient, which is a reduction ratio of the film thickness of the image carrier with respect to the rotation of the image carrier, to the first parameter when forming an image on one side of a sheet, and when forming an image on both sides of the sheet a step of calculating the reduction amount of the film thickness based on a value obtained by applying a second coefficient, which is a reduction ratio of the film thickness of the image carrier with respect to the rotation of the image carrier, to the second parameter; A calculation program for executing
The image forming apparatus includes a fixing section that heats and fixes a toner image formed on paper with toner,
The faster the sheet is conveyed, the more heat is generated from the fixing section.
As the amount of heat increases, the current value flowing from the charging roller to the image bearing member increases,
The greater the current value, the greater the decrease in the film thickness,
the relevant value related to the amount of heat generated from the fixing unit includes a paper transport speed;
The calculation program, wherein the higher the conveying speed, the larger the second coefficient.

Images