Image forming apparatus

Abstract

To provide an image forming apparatus that can identify a factor that causes an image defect and perform adjustment in the apparatus to remove the factor.SOLUTION: An image forming apparatus is of an electrophotographic system, and includes: analysis means that analyzes an attachment attached to a surface of an image carrier in a non-contact manner, every time the image forming apparatus forms images on a predetermined number of recording media; and adjustment means that adjusts the state of the surface of the image carrier according to a result of analysis performed by the analysis means.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an electrophotographic image forming apparatus.

Background Art

[0002] In an electrophotographic image forming apparatus, the surface of an image carrier such as a photoreceptor is charged, exposed to light on the charged surface of the image carrier to form an electrostatic latent image, developed by attaching toner as a developer, and the obtained toner image is transferred to a recording medium such as paper, and heat and pressure are applied to fix the toner image on the recording medium to form an image.

[0003] As an image forming apparatus capable of obtaining a large amount of high-quality images permanently, there is known an image forming apparatus provided with a fluorescent X-ray analyzer for measuring the types and amounts of constituent inorganic component elements of toner stored in a replenishing container (see, for example, Patent Document 1). This image forming apparatus controls the supply of toner in the replenishing container to be performed or stopped based on the measurement results.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described conventional image forming apparatus, there has been a problem that the cause of image defects cannot be specified and the apparatus cannot be adjusted to remove the cause.

[0005] Therefore, there is a demand for providing an image forming apparatus capable of specifying the cause of image defects and adjusting the apparatus to remove the cause.

Means for Solving the Problems

[0006] In view of the above problems, the present invention is an electrophotographic image forming apparatus, analyzing means for non-contact analysis of deposits adhering to the surface of the image carrier, adjusting means for adjusting the state of the surface of the image carrier according to the analysis result of the analyzing means An image forming apparatus including [the following components] is provided.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide an image forming apparatus that can identify the cause of image defects and can adjust within the apparatus to remove the cause.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0009] FIG. 1 is a diagram showing a configuration example of an electrophotographic image forming apparatus according to the present embodiment. The image forming apparatus 10 is, for example, an image forming apparatus that performs color image formation, and includes four image forming units 11 to 14 for forming images of four colors. The four colors are yellow, magenta, cyan, and black corresponding to the color separation components of a color image. Note that the image forming apparatus may be an image forming apparatus that forms a monochrome image of only one color, black. Further, in the case of a color image forming apparatus, the colors of the images to be formed are not limited to the above four colors, and may be three colors of cyan, magenta, and yellow, or other colors may be added to make five or more colors.

[0010] Each image forming unit 11 to 14 includes a drum-shaped photoreceptor 15, a charging unit 16 as charging means for charging the surface of the photoreceptor 15, a developing unit 17 as developing means for supplying toner as a developer to the surface of the photoreceptor 15 to form a visible image (toner image), and a cleaning unit 18 as cleaning means for cleaning the surface of the photoreceptor 15.

[0011] The image forming apparatus 10 includes an exposure unit 19 that exposes the surface of each photoreceptor 15 charged by the charging unit 16 to form a latent image invisible to the human eye on the surface of each photoreceptor 15. The image forming apparatus 10 also includes a paper feeding unit 20 that supplies paper as a recording medium, a transfer unit 21 that transfers the toner image formed on each photoreceptor 15 to the paper, a fixing unit 22 that fixes the toner image transferred to the paper, and a paper discharging unit 23 that discharges the paper on which the toner image is fixed. Since the photoreceptor 15 carries the toner image, it is one of the image carriers.

[0012] The transfer unit 21 includes an intermediate transfer belt 24 as an intermediate transfer member stretched by a plurality of rollers, four primary transfer rollers 25 as a primary transfer member that transfers the toner images of each color on each photoreceptor 15 to the intermediate transfer belt 24, and a secondary transfer roller 26 as a secondary transfer member that transfers the toner image transferred to the intermediate transfer belt 24 to the paper. Since the intermediate transfer belt 24 also carries the toner image, it is one of the image carriers.

[0013] Each of the four primary transfer rollers 25 is in contact with each photoreceptor 15 via the intermediate transfer belt 24. As a result, each photoreceptor 15 and the intermediate transfer belt 24 are in contact with each other, and a primary transfer nip is formed therebetween. The secondary transfer roller 26 is in contact with one of the four rollers via the intermediate transfer belt 24. As a result, a secondary transfer nip is formed between the intermediate transfer belt 24 and the secondary transfer roller 26.

[0014] The image forming apparatus 10 includes a pair of timing rollers 27 for timing the paper feed midway from the paper feeding unit 20 to the secondary transfer nip.

[0015] Next, with reference to FIG. 1, the image forming operation performed by the image forming apparatus 10 will be described. When the image forming apparatus 10 receives an instruction to start image formation, each photoreceptor 15 is rotationally driven in a certain direction, and the surface of each photoreceptor 15 is charged by the charging unit 16.

[0016] The image forming apparatus 10 acquires an image to be formed, such as a document image, and based on the acquired image, the exposure unit 19 exposes the surface of each photoreceptor 15 to form a latent image on the surface of each photoreceptor 15. For the latent image formed on the surface of each photoreceptor 15, the image forming apparatus 10 supplies toner of each color from each developing unit 17, attaches the toner of each color, and forms a toner image on each photoreceptor 15.

[0017] When the toner image formed on each photoreceptor 15 reaches the primary transfer nip as each photoreceptor 15 rotates, it is transferred to the intermediate transfer belt 24 by the primary transfer roller 25. The toner image transferred to the intermediate transfer belt 24 is conveyed to the secondary transfer nip as the intermediate transfer belt 24 moves. The paper is fed from the paper feeding unit 20, temporarily stopped by the timing roller 27, and conveyed to the secondary transfer nip at the timing when the toner image reaches the secondary transfer nip. At the secondary transfer nip, the toner image on the intermediate transfer belt 24 is transferred to the paper by the secondary transfer roller 26. Thereby, a full-color toner image is carried on the paper.

[0018] After the toner image is transferred to the intermediate transfer belt 24, the toner remaining on each photoreceptor 15 is removed by the cleaning unit 18. Then, in order to form the next image, each photoreceptor 15 is charged by the charging unit 16.

[0019] The paper on which the toner image has been transferred is conveyed to the fixing unit 22, heat and pressure are applied by the fixing unit 22, and the toner image is fixed to the paper. Thereafter, the paper is discharged outside the apparatus by the paper discharging unit 23. Thereby, a series of image forming operations is completed.

[0020] The image forming apparatus 10 further includes an analyzer 28 as an analyzing means in each image forming unit 11 to 14. Every time an image is formed on a predetermined number of sheets of paper, the analyzer 28 analyzes the deposits adhering to the surface of the photoreceptor 15 without contact, and returns (feeds back) the analysis result to the control unit that controls the entire image forming apparatus 10. The control unit functions as an adjusting means and adjusts the state of the surface of the photoreceptor 15 according to the analysis result.

[0021] The control unit includes a processor such as a CPU (Central Processing Unit) and a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory). By the processor executing the program stored in the memory, the control unit controls the operation of the entire image forming apparatus 10 and executes the function of adjusting the state of the surface of the photoreceptor 15 described above. Note that, in order to execute the above function, the control unit may use hardware such as an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), or an FPGA (Field Programmable Gate Array) designed to execute the above function instead of a program.

[0022] Before explaining the image forming units 11 to 14 in detail, the fixing unit 22 that can be used in the image forming apparatus 10 according to the present embodiment will be briefly described.

[0023] FIG. 2 is a diagram showing a configuration example of the fixing unit 22 that can be used in the image forming apparatus 10 according to the present embodiment. FIG. 2(a) is a diagram showing a configuration example of a heater type fixing unit 22, and FIG. 2(b) is a diagram showing a configuration example of an induction heating type fixing unit 22.

[0024] The heater type fixing unit 22 shown in Fig. 2(a) includes a hollow cylindrical fixing sleeve 30, a pressure roller 31 that contacts the outer peripheral surface of the fixing sleeve 30 to form a nip portion, a heater 32 that heats the fixing sleeve 30, a heater folder 33 that holds the heater 32, and a stay 34 that supports the heater folder 33.

[0025] The fixing sleeve 30 is formed by forming a release layer made of a fluororesin on a cylindrical base made of polyimide, nickel, etc. in order to enhance durability and ensure release properties. An elastic layer made of rubber or the like may be provided between the base and the release layer.

[0026] The pressure roller 31 is formed by forming an elastic layer on the surface of an iron core and a release layer on the outside of the elastic layer. It is pressed against the heater 32 via the fixing sleeve 30 to form a nip portion between the fixing sleeve 30 and the pressure roller 31. The pressure roller 31 is configured to be rotationally driven by driving means, and the fixing sleeve 30 is driven to rotate passively as the pressure roller 31 rotates.

[0027] The heater 32 is a planar heating means provided over the width direction of the fixing sleeve 30, in which a resistive heating element provided on a base material is covered with an insulating layer. The heater 32 contacts the inner peripheral surface of the fixing sleeve 30 and transfers the heat generated by the heater 32 to the fixing sleeve 30.

[0028] Since the heater folder 33 is likely to become high temperature due to the heat of the heater 32, it is formed of a heat-resistant material. The heater folder 33 and the stay 34 hold and support the heater 32 so that the heater 32 reliably receives the pressing force of the pressure roller 31 and stably forms a nip portion.

[0029] The paper 35 with the toner image transferred is conveyed to the nip portion between the fixing sleeve 30 heated by the heater 32 and the rotationally driven pressure roller 31 as shown by the arrow. The toner image is heated and pressed at the nip portion and fixed to the paper 35.

[0030] The dielectric heating type fixing unit 22 shown in Fig. 2(b) includes a fixing sleeve 30 and a pressure roller 31, similar to the heater type fixing unit 22. Since the fixing sleeve 30 and the pressure roller 31 are the same as those of the heater type fixing unit 22, the description thereof is omitted here. Note that the fixing sleeve 30 has a base formed of a metal such as nickel or stainless steel.

[0031] The dielectric heating type fixing unit 22 includes a nip facing member (sliding member) 36 provided inside the fixing sleeve 30, an IH (Induction Heating) heating unit 37 provided in place of the heater 32, and a static eliminator needle 38.

[0032] The nip facing member 36 receives the load from the pressure roller 31 facing the fixing sleeve 30 inside the fixing sleeve 30 via the fixing sleeve 30. Thereby, a load is applied to the fixing sleeve 30 by the pressure roller 31, and a nip portion is formed.

[0033] The IH heating unit 37 includes an IH coil and a group of magnets such as an arch core, and heats the outer peripheral surface of the fixing sleeve 30 installed inside the IH heating unit 37. The IH heating unit 37 generates a high-frequency magnetic field by passing a high-frequency alternating current through the IH coil, generates eddy currents in the metal part (base body) constituting the fixing sleeve 30 by the magnetic field, and heats the fixing sleeve 30 by the self-heating of the metal part due to its resistance.

[0034] The paper 35 with the toner image transferred is conveyed to the nip portion between the fixing sleeve 30 heated by the IH heating unit 37 and the rotationally driven pressure roller 31. The toner image is heated and pressed at the nip portion and fixed to the paper 35.

[0035] The magnet group is arranged around the IH coil to prevent magnetic leakage generated by the IH coil. When friction occurs between the paper 35 passing through the nip portion and the fixing sleeve 30 and the fixing sleeve 30 becomes charged, the static eliminator needle 38 eliminates the charge of the fixing sleeve 30. The static eliminator needle 38 is, for example, a conductive brush, has a plurality of brush hairs with elasticity, and abuts against the fixing sleeve 30.

[0036] Figure 3 is a diagram showing a configuration example of an image forming unit included in the image forming apparatus. The image forming unit 40 includes four image forming units 11 to 14 and a transfer unit 21. Since the four image forming units 11 to 14 all have the same configuration, here, one image forming unit 11 is extracted, and the image forming unit 40 will be described as being composed of one image forming unit 11 and a transfer unit 21.

[0037] The image forming unit 40 includes a photoreceptor 15, a charging unit 16, a developing unit 17, a cleaning unit 18, a transfer unit 21, a transport roller 41 that transports the paper fed from the paper feeding unit 20, and an analyzer 28.

[0038] The developing unit 17 includes a developing roller 42 that rotates in contact with the surface of the photoreceptor 15. The developing unit 17 applies toner to the surface of the photoreceptor 15 by the developing roller 42 and adheres the toner to the surface of the photoreceptor 15.

[0039] The transfer unit 21 includes a primary transfer roller 25, a driving roller 43, and a driven roller 44. The driving roller 43 is driven by a driving means and rotates in a predetermined direction. The driven roller 44 is a roller that is driven along with the rotation of the driving roller 43.

[0040] The cleaning unit 18 includes a cleaning blade 45, a solid lubricant 46, a holding holder 47 that holds the solid lubricant 46, a spring 48 that extrudes from the holding holder 47 every time the solid lubricant 46 is supplied, a supply roller 49 that supplies the lubricant, and a cleaning brush 50.

[0041] The cleaning blade 45 is formed of, for example, urethane rubber or the like, and its tip is brought into contact with the surface of the photoreceptor 15 to wipe off toner.

[0042] The solid lubricant 46 is supplied to the surface of the supply roller 49, adheres to the brush bristles of the cleaning brush 50 by the rotation of the supply roller 49, and is applied to the surface of the photoreceptor 15 by the rotation of the cleaning brush 50.

[0043] The lubricant prevents damage to the photoreceptor 15, imparts abrasion resistance, improves transfer efficiency, and prevents deterioration of image quality. Further, the lubricant improves the sliding of the cleaning blade 45, prevents the cleaning blade 45 from curling, and extends its life. Furthermore, the lubricant also prevents the occurrence of filming in which the toner captured between the member in contact with the surface of the photoreceptor 15 such as the cleaning blade 45 and the surface of the photoreceptor 15 melts due to friction and adheres to the surface of the photoreceptor 15.

[0044] When the application amount of the lubricant to the photoreceptor 15 is insufficient, filming occurs, the lubricity of the surface of the photoreceptor 15 decreases, the tip of the cleaning blade 45 curls, or the surface of the photoreceptor 15 is damaged, resulting in a problem of poor cleaning. On the other hand, when the application amount of the lubricant is excessive, the contamination of the charging roller of the charging unit 16 is promoted, and when the contamination accumulates, charging failure occurs and vertical streaks or the like occur. Therefore, the application amount of the lubricant to the photoreceptor 15 becomes one of the causes of image defects in the image formed on the paper discharged from the image forming apparatus 10.

[0045] The analyzer 28 analyzes the surface of the photoreceptor 15 after the lubricant is applied in order to identify the cause of the occurrence of image defects. Therefore, it is desirable that the analyzer 28 be disposed behind the cleaning unit 18 in the direction in which the photoreceptor 15 rotates. However, since the application amount of the lubricant affects the charging unit 16, it is desirable that the analyzer 28 be disposed in front of the charging unit 16 in the direction in which the photoreceptor 15 rotates. From these facts, the analyzer 28 can be disposed at a position between the cleaning unit 18 and the charging unit 16.

[0046] As the analysis device 28, a fluorescence X-ray analyzer, a Raman spectrometer, or the like that performs non-destructive and non-contact analysis can be used. A fluorescence X-ray analyzer is a device that irradiates a substance with X-rays, which are a type of electromagnetic wave, analyzes the generated fluorescence X-rays, and can obtain information regarding the elemental composition of a specific substance. The fluorescence X-ray analyzer detects the ratio of each element as a characteristic value in atomic% (Atomic%).

[0047] A Raman spectrometer is a device that irradiates a substance with light, disperses the Raman scattered light generated when the light interacts with the substance, and can obtain information regarding the elemental composition of a specific substance from the obtained spectrum. Since the concentration of an element depends on the peak intensity of the spectrum, the Raman spectrometer detects the characteristic value as the ratio of each element in peak intensity (Abs.).

[0048] Since the analysis device 28 performs non-contact analysis, it is disposed at a position separated from the photoreceptor 15. When a fluorescence X-ray analyzer or a Raman spectrometer is used as the analysis device 28, these devices can be disposed at a position where the distance from the surface of the photoreceptor 15 is 5 mm to 200 mm. Note that the analysis device 28 may use both a fluorescence X-ray analyzer and a Raman spectrometer.

[0049] FIG. 4 is a diagram showing a configuration example of a fluorescence X-ray analyzer as an example of the analysis device 28. The analysis device 28 includes an X-ray source 61 that irradiates X-rays 60 toward an analysis target on the surface of the photoreceptor 15, and an X-ray detector 63 that detects the generated fluorescence X-rays 62. When the X-rays 60 are irradiated onto an element, the electrons of that element are collided with, and the electrons collided with by the X-rays are excited and their orbits are displaced. The element that has no electrons in that orbit becomes unstable, and the electrons in the outer shell move in. Fluorescence X-rays are generated by the energy generated at this time. The X-ray detector 63 detects the generated fluorescence X-rays.

[0050] The energy of fluorescent X-rays varies depending on the element. Therefore, by analyzing the energy of the detected fluorescent X-rays, it is possible to detect what element has that energy. Also, the content of that element can be detected from the intensity of the energy.

[0051] From this, the analyzer 28 includes a signal amplifier 64 that amplifies the energy of the detected fluorescent X-rays and a multi-channel analyzer 65 that analyzes the amplified energy of the fluorescent X-rays. Note that FIG. 4 shows a fluorescent X-ray analyzer control unit 66 that constitutes a part of the control unit.

[0052] The analysis result of the multi-channel analyzer 65 includes the contained element and its content, and is sent (fed back) to the fluorescent X-ray analyzer control unit 66. The fluorescent X-ray analyzer control unit 66 determines whether the elemental ratio derived from the lubricant is appropriate based on the analysis result.

[0053] The fluorescent X-ray analyzer control unit 66 determines whether it is an appropriate value based on whether the elemental ratio derived from the lubricant is within the target value range or outside it in the analysis result. If it is within the target value range, it is determined to be an appropriate value, and if it is outside, it is determined whether it is more or less than the appropriate value.

[0054] If it is more or less than the appropriate value, the supply amount of the lubricant can be controlled to keep the amount of the lubricant on the surface of the photoreceptor 15 at an appropriate value.

[0055] FIG. 5 is a diagram showing a first example of an operation of analyzing the surface of the photoreceptor 15 and adjusting the state of the surface. The operation of analyzing the surface of the photoreceptor 15 can be performed when the power of the image forming apparatus 10 is turned on (ON), but it may also be performed before the power is turned off (OFF) when the power is turned off.

[0056] Starting from step 100, in step 101, it is determined whether a predetermined number of sheets of paper have reached between the photoreceptor 15 and the transfer unit 21. The predetermined number is, for example, 100 sheets, and it is determined whether 100 sheets of paper have reached since the previous measurement. The number of sheets of paper can be measured by a sensor, for example. Note that the number of sheets of paper may be the number of sheets fed from the paper feeding unit 20, or may be the number of sheets of paper discharged from the paper discharging unit 23. The predetermined number is not limited to the above 100 sheets. Note that analysis may be performed for each sheet or for several sheets, but the state of the surface of the photoreceptor 15 hardly changes with these numbers of sheets, and it is not efficient, so it is desirable to perform analysis at least every several tens of sheets.

[0057] In step 102, the analyzer 28 calculates, for example, the analysis result of fluorescent X-rays. In step 103, the fluorescent X-ray analyzer control unit 66 determines whether the elemental ratio derived from the lubricant is appropriate. If it is determined that it is appropriate, the process proceeds to step 104, and since there is no problem with the current supply amount of the lubricant, the supply amount of the lubricant is not adjusted.

[0058] If it is determined that it is not appropriate, the process proceeds to step 105, and it is determined whether the elemental ratio derived from the lubricant is more than the appropriate value. If it is determined that it is more than the appropriate value, the process proceeds to step 106, and since the amount of the lubricant on the surface of the photoreceptor 15 is large, the supply amount of the lubricant is decreased. On the other hand, in step 105, if it is determined that the elemental ratio derived from the lubricant is not more than the appropriate value, it means that it is less than the appropriate value, and the process proceeds to step 107. In step 107, since the amount of the lubricant on the surface of the photoreceptor 15 is small, the supply amount of the lubricant is increased.

[0059] The fluorescent X-ray analyzer control unit 66 can increase the supply amount of the lubricant, for example, by increasing the rotation speed of the supply roller 49, and can also decrease it, for example, by decreasing the rotation speed of the supply roller 49.

[0060] FIG. 6 is a diagram showing a second example of an operation for analyzing the surface of the photoreceptor 15 and adjusting the state of the surface. Image defects are caused not only by the amount of lubricant on the surface of the photoreceptor 15 but also by deposits adhering to the surface of the photoreceptor 15. The deposits are solidified melted toner.

[0061] Similar to the example shown in FIG. 5, when the power of the image forming apparatus 10 is turned on or before the power is turned off when the power is turned off, the process starts from step 200. In step 201, it is determined whether a predetermined number of sheets of paper have reached between the photoreceptor 15 and the transfer unit 21.

[0062] In step 202, the analyzer 28 calculates, for example, the analysis result of fluorescent X-rays. In step 203, the fluorescent X-ray analyzer control unit 66 determines whether the elemental ratio derived from the toner components is appropriate.

[0063] The toner is mainly composed of a polymer resin such as a polyester resin or an acrylic resin, wax, and a pigment. The polymer resin is a material that forms the basis of the toner particles, melts by heating, and is fixed to the paper under pressure. The wax prevents the toner from adhering to the fixing sleeve 30 or the pressure roller 31. The pigment is a coloring material that gives color to the toner.

[0064] The toner may further contain a charge control agent for stably imparting an electrostatic charge and an external additive for imparting stability of chargeability and improvement of fluidity. The elements derived from the toner components may be any elements of these materials. For example, it is possible to determine whether the elemental ratio derived from the external additive is appropriate.

[0065] If it is determined in step 203 that the elemental ratio derived from the external additive is appropriate, the process proceeds to step 204, and it is assumed that image defects due to deposits do not occur, and there is no additional process. On the other hand, if it is determined in step 203 that the elemental ratio derived from the external additive is not appropriate, the process proceeds to step 205, and it is determined whether the elemental ratio is greater than the appropriate value.

[0066] In step 205, if it is determined that the element ratio is greater than the appropriate value, the process proceeds to step 206. Assuming that there is a large amount of deposits and image defects occur, the surface of the photoreceptor 15 is excavated. The excavation of the surface of the photoreceptor 15 means scraping off the deposits adhering to the surface thereof. For example, by increasing the pressure at which the cleaning blade 45 contacts the surface of the photoreceptor 15, the deposits can be scraped off.

[0067] In step 205, if it is determined that the element ratio is not greater than the appropriate value, it means that it is less than the appropriate value. Being less than the appropriate value means that the deposits adhering to the surface of the photoreceptor 15 are even less than when at the appropriate value. Assuming that image defects due to deposits do not occur, the process proceeds to step 207 and there is no additional process.

[0068] The operations shown in FIGS. 5 and 6 are repeatedly performed every time a predetermined number of sheets is reached.

[0069] So far, the analyzer 28 has been described as analyzing the deposits on the surface of the photoreceptor 15, but it is not limited thereto, and it may analyze the deposits on the surface of the intermediate transfer belt 24. A similar cleaning unit is also provided for the intermediate transfer belt 24. Similar to the photoreceptor 15, it is determined whether the element ratio derived from the lubricant and the element ratio derived from the external additive are appropriate. If they are not appropriate, the supply amount of the lubricant can be controlled, and the deposits can be scraped off with a cleaning blade or the like. When the analyzer 28 is also provided for the intermediate transfer belt 24, it can be arranged at a position behind the cleaning unit in the rotation direction of the intermediate transfer belt 24 and before reaching the primary transfer nip between the photoreceptor 15 and the primary transfer roller 25. Note that the analyzer 28 may be installed only on the photoreceptor 15, only on the intermediate transfer belt 24, or on both the photoreceptor 15 and the intermediate transfer belt 24.

[0070] The image forming apparatus 10 incorporates such an analyzer 28 and includes adjustment means such as the fluorescent X-ray analyzer control unit 66 as a control unit for adjusting the surface state of the photoreceptor 15. By doing so, it is possible to know the surface state of image carriers such as the photoreceptor 15 and the intermediate transfer belt 24 during image formation, and to identify the causes of image defects. Also, by identifying the causes, it is possible to control the supply amount of the lubricant within the apparatus or increase the pressure of the cleaning blade 45 to scrape off surface deposits so as not to cause image defects, thereby properly maintaining the surface state of the image carrier. As a result, it becomes possible to stably and favorably perform image formation over a long period of time.

[0071] So far, the image forming apparatus of the present invention has been described with the above-described embodiments. However, the present invention is not limited to the above-described embodiments and can be modified within the scope that those skilled in the art can conceive, such as other embodiments, additions, changes, deletions, etc. Also, as long as the functions and effects of the present invention are exhibited in any aspect, they are included in the scope of the present invention.

Explanation of Reference Numerals

[0072] 10…Image forming apparatus, 11 - 14…Image forming units, 15…Photoreceptor, 16…Charging unit, 17…Developing unit, 18…Cleaning unit, 19…Exposure unit, 20…Paper feeding unit, 21…Transfer unit, 22…Fixing unit, 23…Paper discharging unit, 24…Intermediate transfer belt, 25…Primary transfer roller, 26…Secondary transfer roller, 27…Timing roller, 28…Analyzer, 30…Fixing sleeve, 31…Pressing roller, 32…Heater, 33…Heater folder, 34…Stay, 35…Paper, 36…Nip opposing member, 37…IH heating unit, 38…Charge removing needle, 40…Image forming section, 41…Conveyor roller, 42…Developing roller, 43…Drive roller, 44…Driven roller, 45…Cleaning blade, 46…Solid lubricant, 47…Holding holder, 48…Spring, 49…Supply roller, 50…Cleaning brush, 60…X-ray, 61…X-ray source, 62…Fluorescent X-ray, 63…X-ray detector, 64…Signal amplifier, 65…Multi-channel analyzer, 66…Fluorescent X-ray analyzer control unit

Prior Art Documents

Patent Documents

[0073]

Patent Document 1

Claims

1. An electrophotographic image forming apparatus, comprising: analyzing means for non-contact analysis of deposits adhering to the surface of an image carrier; adjusting means for adjusting the state of the surface of the image carrier according to the analysis result of the analyzing means An image forming apparatus comprising:

2. The image forming apparatus according to claim 1, wherein the analyzing means is an X-ray fluorescence analyzer that performs analysis using X-ray fluorescence, a Raman spectrometer that performs analysis using Raman scattered light, or both.

3. The image carrier is a photoreceptor that rotates in a predetermined direction, The analyzing means is installed at a position separated from the photoreceptor between a charging means for charging the surface of the photoreceptor and a first cleaning means for exposing, developing, and cleaning the surface after transfer to a transfer member. The image forming apparatus according to claim 1 or 2.

4. The image carrier is a transfer member that rotates in a predetermined direction onto which an image formed on the surface of the photoreceptor is transferred, The analyzing means is installed at a position separated from the transfer member between a second cleaning means for cleaning the surface of the transfer member after the image transferred to the transfer member is transferred to a recording medium and the photoreceptor. The image forming apparatus according to claim 1 or 2.

5. The image forming apparatus according to claim 1 or 2, wherein the analyzing means performs analysis of the deposits when the power supply of the image forming apparatus is turned on.

6. The image forming apparatus according to claim 1 or 2, wherein the analyzing means receives an instruction to cut off the power supply of the image forming apparatus and performs analysis of the deposits before cutting off the power supply.

7. The X-ray fluorescence analyzer according to claim 2 detects characteristic values represented in atomic% as the analysis result.

8. The X-ray fluorescence analyzer according to claim 2 is installed at a position separated from the image carrier by 5 mm to 200 mm.

9. The Raman spectrometer according to claim 2 detects characteristic values represented by peak intensity (Abs.) as the analysis result.

10. The Raman spectrometer according to claim 2 is installed at a position separated from the image carrier by 5 mm to 200 mm.

11. The adjusting means according to claim 1 or 2 adjusts the amount of lubricant supplied to the surface of the image carrier.

12. The image forming apparatus according to claim 1 or 2, wherein the adjusting means scrapes off the adhered matter adhering to the surface of the image carrier.

Images