JP2015219475A - Image forming apparatus and control method of image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can form uniform images irrespective of the types of sheets, and a control method of the same.SOLUTION: An image forming apparatus includes: an intermediate transfer belt 6 as an image carrier carrying images; a lubricant supply part that supplies a lubricant to the intermediate transfer belt 6; and a control part 100 that detects the type of a sheet P and controls the amount of the lubricant to be supplied to the intermediate transfer belt 6 on the basis of the type of the sheet P.

Description

  The present invention relates to an image forming apparatus and a method for controlling the image forming apparatus.

  2. Description of the Related Art Conventionally, there is known an image forming apparatus that forms a full-color image by arranging a plurality of photosensitive drums so as to face one transfer member. In this image forming apparatus, an image is formed on a sheet through a series of processes of transferring the image onto the sheet and fixing the transferred image on the sheet. For example, in an intermediate transfer type image forming apparatus, first, the photosensitive drum is uniformly charged, and the charge is erased (exposed) in accordance with image data to form an electrostatic latent image on the photosensitive drum. Next, a toner is attached to the electrostatic latent image on the photosensitive drum using a developing unit, whereby the electrostatic latent image on the photosensitive drum is made visible. The image (toner image) formed on the photosensitive drum is primarily transferred to the intermediate transfer belt by the primary transfer roller, and the image transferred to the intermediate transfer belt is secondarily transferred to the sheet by the secondary transfer roller.

  Here, for example, Patent Document 1 discloses an image forming apparatus that applies a lubricant to an image carrier on which a toner image is formed in order to improve cleaning performance. The image forming apparatus includes a cleaning unit that cleans the transferred image carrier with a cleaning blade, a lubricant application unit that applies a lubricant to the image carrier, and a control unit that controls the lubricant application unit. . This control means controls the lubricant application means so as to increase the application amount in accordance with the progress of the degree of wear of the cleaning blade.

JP 2003-330320 A

  In this type of image forming apparatus, it is desired to handle not only plain paper but also various paper types such as uneven paper. Here, the concavo-convex paper corresponds to a paper such as embossed paper or rough paper whose surface condition is not less than a specified surface roughness. In such a concavo-convex paper, there is a problem that the toner is difficult to be transferred to the concave portion of the paper surface and the density of the image tends to be non-uniform. Specifically, the concentration of the recesses is thinner than that of the projections, or the recesses are hollow.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an image forming apparatus capable of forming a uniform image regardless of the type of paper and a control method thereof.

  In order to solve this problem, a first invention includes an image carrier that carries an image, a lubricant supply unit that supplies a lubricant to the image carrier, a paper type detection unit that detects the paper type of the paper, and a paper There is provided an image forming apparatus comprising: a control unit that controls an amount of lubricant supplied to an image carrier based on a paper type detected by a seed detection unit.

  Here, in the present invention, the control unit determines whether or not the surface state of the paper is a concavo-convex paper whose surface roughness is equal to or greater than a specified surface roughness based on the paper type of the paper detected by the paper type detection unit, It is preferable to control the amount of lubricant supplied to the image carrier based on the determination result.

  Further, in the present invention, when the control unit determines that the paper type is uneven paper, the lubricant supplied to the image carrier compared to the case where the paper type is non-concave paper. It is preferred to increase the amount.

  Further, in the present invention, the image carrier is an intermediate transfer member to which an image formed on the photosensitive drum is primarily transferred, and the control unit is configured to apply the amount of lubricant applied to the surface of the photosensitive drum, the intermediate transfer member. The amount of lubricant applied to the surface of the toner, the pressing force of the primary transfer member that transfers the image formed on the photosensitive drum to the intermediate transfer member, and the secondary transfer member that transfers the image formed on the intermediate transfer member to the sheet It is preferable to control at least one of the pressing force and the amount of lubricant applied to the surface of the secondary transfer body.

  The second invention provides a control method of an image forming apparatus including a lubricant supply unit that supplies a lubricant to an image carrier that carries an image. This control method includes a first step of detecting the paper type of the paper, and a second step of controlling the amount of lubricant supplied to the image carrier based on the detected paper type of the paper. doing.

  Here, in the second invention, whether the second step is a concavo-convex paper whose surface condition is not less than a specified surface roughness based on the paper type detected by the paper type detection unit. It is preferable to determine whether or not to control the amount of lubricant supplied to the image carrier based on the determination result.

  In the second invention, when the second step determines that the paper type of the paper is an uneven paper, the image is compared with the case where the paper type of the paper is a non-concave paper. It is preferable to increase the amount of lubricant supplied to the carrier.

  Furthermore, in the second invention, the image carrier is preferably an intermediate transfer member on which an image formed on the photosensitive drum is primarily transferred. In this case, the second step transfers the amount of lubricant applied to the surface of the photosensitive drum, the amount of lubricant applied to the surface of the intermediate transfer member, and the image formed on the photosensitive drum to the intermediate transfer member. At least one of the pressing force of the primary transfer member, the pressing force of the secondary transfer member that transfers the image formed on the intermediate transfer member to the sheet, and the amount of lubricant applied to the surface of the secondary transfer member. It is desirable to control.

  According to the present invention, the amount of lubricant supplied to the image carrier is appropriately controlled according to the paper type. Therefore, even if the paper type deteriorates the image transferability, the image transfer can be appropriately realized by controlling the lubricant amount. As a result, it is possible to suppress a situation in which the image density is non-uniform, and thus it is possible to provide an image forming apparatus capable of forming a uniform image regardless of the paper type.

Configuration diagram schematically showing an image forming apparatus Explanatory drawing schematically showing the detailed configuration of the drum cleaner Explanatory drawing which shows the structure of a secondary transfer roller typically Configuration diagram schematically showing details of belt cleaning section Flowchart showing control procedure in image forming apparatus Explanatory drawing which shows the relationship between the transfer rank in the recessed part of paper, and the rotational speed of an application brush.

  FIG. 1 is a configuration diagram schematically illustrating an image forming apparatus according to the present embodiment. This image forming apparatus is, for example, an electrophotographic image forming apparatus, and forms a full-color image by arranging a plurality of photosensitive drums facing a single intermediate transfer belt in a vertical direction, so-called tandem. Type color image forming apparatus.

  The image forming apparatus mainly includes a document reading device SC, image forming units 10Y, 10M, 10C, and 10K, a fixing device 70, and a control unit 100, which are housed in a single casing.

  The document reader SC scans and exposes an image of the document with the optical system of the scanning exposure device, reads the reflected light with a line image sensor, and obtains an image signal. The image signal is subjected to processing such as A / D conversion, shading correction, and compression, and then input to the control unit 100 as image data. Note that the image data input to the control unit 100 is not limited to data read by the document reading device SC. For example, data received from a personal computer connected to the image forming device or another image forming device, or USB It may be stored in a portable recording medium such as a memory.

  The image forming units 10Y, 10M, 10C, and 10K are an image forming unit 10Y that forms a yellow (Y) image, an image forming unit 10M that forms a magenta (M) image, and an image that forms a cyan (C) image. The image forming unit 10C corresponds to the image forming unit 10K that forms a black (K) image.

  The image forming unit 10Y includes a photosensitive drum 1Y that carries an image of a predetermined color (yellow (Y)), a charging unit 2Y, an optical writing unit 3Y, a developing device 4Y, and a drum cleaner 5Y that are arranged around the photosensitive drum 1Y. It is configured.

  The photosensitive drum 1Y is uniformly charged by the charging unit 2Y, and a latent image is formed on the photosensitive drum 1Y by scanning exposure by the optical writing unit 3Y. The developing device 4Y develops the latent image on the photosensitive drum 1Y by developing with toner. As a result, an image (toner image) corresponding to yellow is formed on the photosensitive drum 1Y.

  The image formed on the photosensitive drum 1Y is transferred to a predetermined position on the intermediate transfer belt 6 as an intermediate transfer member by the primary transfer roller 7Y. In the present embodiment, the intermediate transfer belt 6 corresponds to an image carrier that carries an image as well as an intermediate transfer member.

  FIG. 2 is an explanatory diagram schematically showing detailed configurations of the primary transfer roller 7Y and the drum cleaner 5Y. The primary transfer roller 7Y is disposed to face the photoreceptor drum 1Y with the intermediate transfer belt 6 interposed therebetween.

  The primary transfer roller 7Y is provided with a roller pressing portion 70Y. The roller pressing unit 70Y presses the primary transfer roller 7Y against the intermediate transfer belt 6, and is configured to be able to switch the pressing force of the primary transfer roller 7Y. For example, the roller pressing portion 70Y includes a coil spring that presses the primary transfer roller 7Y toward the intermediate transfer belt 6 and a rotatable cam that contacts the base end portion of the coil spring. When the position of the base end portion of the coil spring is displaced according to the angle of the cam, the elastic force of the coil spring fluctuates, whereby the pressing force of the primary transfer roller 7Y can be switched.

  The drum cleaner 5Y removes toner remaining on the surface of the photosensitive drum 1Y after transfer to the intermediate transfer belt 6. The drum cleaner 5Y mainly includes a cleaning blade 51Y, a coating roller 52Y, a leveling blade 53Y, a lubricant supply body 54Y, and a lubricant pressing portion 55Y. The cleaning blade 51Y, the application roller 52Y, and the leveling blade 53Y are arranged in this order from upstream to downstream in the rotation direction of the photosensitive drum 1Y.

  The cleaning blade 51Y scrapes off the toner adhering to the photosensitive drum 1Y and removes it. The cleaning blade 51Y is formed, for example, by processing polyurethane rubber into a predetermined shape. The cleaning blade 51Y is bonded to a holding metal plate (not shown) with a hot melt adhesive, and is arranged so that its tip is pressed against the photosensitive drum 1Y.

  The application roller 52Y applies a lubricant to the surface of the photoreceptor drum 1Y. The application roller 52Y is rotatably supported and is disposed in parallel with the photosensitive drum 1Y so as to contact the surface thereof. As a method for applying the lubricant to the photosensitive drum 1Y, a roller or the like can be used in addition to the brush.

  The lubricant supply body 54Y supplies a lubricant to the application roller 52Y, and is provided below the application roller 52Y. The lubricant supply body 54Y is obtained by, for example, melt-molding zinc stearate powder.

  The lubricant pressing portion 55Y presses the lubricant supply body 54Y against the application roller 52Y, and is configured to be able to switch the pressing force of the lubricant supply body 54Y. For example, the lubricant pressing portion 55Y includes a coil spring that presses the lubricant supply body 54Y to the application roller 52Y side, and a rotatable cam that abuts on the base end portion of the coil spring. When the position of the base end portion of the coil spring is displaced according to the angle of the cam, the elastic force of the coil spring fluctuates, whereby the pressing force of the lubricant supply body 54Y can be switched.

  According to the switching of the pressing force of the lubricant supply body 54Y by the lubricant pressing portion 55Y, the amount of lubricant scraped off from the lubricant supply body 54Y by the application roller 52Y is switched, and the amount of lubricant applied to the photosensitive drum 1Y can be adjusted. it can. Specifically, when the pressing force of the lubricant supply 54Y is increased, the amount of lubricant applied to the photosensitive drum 1Y is increased, and when the pressing force of the lubricant supply 54Y is decreased, the lubricant is applied to the photosensitive drum 1Y. The amount of lubricant is reduced.

  Here, the application roller 52Y, the lubricant supply body 54Y, and the lubricant pressing portion 55Y directly supply the lubricant to the photosensitive drum 1Y, and the lubricant is supplied to the intermediate transfer belt 6 through the photosensitive drum 1Y. And can be applied. That is, the application roller 52Y, the lubricant supply body 54Y, and the lubricant pressing portion 55Y function as a lubricant supply portion that supplies the lubricant to the intermediate transfer belt 6.

  The leveling blade 53Y makes the thickness of the lubricant on the surface of the photosensitive drum 1Y uniform. As with the cleaning blade 51Y, the leveling blade 53Y is formed by processing polyurethane rubber into a predetermined shape, for example. The leveling blade 53Y is adhered to a holding sheet metal (not shown) with a hot-melt adhesive, and is arranged so that its tip is pressed against the photosensitive drum 1Y.

  Referring to FIG. 1, the image forming units 10M, 10C, and 10K include photoconductor drums 1M, 1C, and 1K, and charging units 2M, 2C, and 2K, and optical writing units 3M, 3C, and 3K disposed in the periphery thereof. The developing devices 4M, 4C, and 4K and the drum cleaners 5M, 5C, and 5K are the same as those in the image forming unit 10Y.

  The image composed of each color transferred onto the intermediate transfer belt 6 is transferred onto the paper P conveyed at a predetermined timing by a secondary transfer roller 9 as a secondary transfer body. The secondary transfer roller 9 is disposed in pressure contact with the intermediate transfer belt 6 to form a nip (transfer nip) and transfer an image onto the paper P.

  FIG. 3 is an explanatory diagram schematically showing the configuration of the secondary transfer roller 9. The secondary transfer roller 9 is provided with a roller pressing portion 90. The roller pressing unit 90 presses the secondary transfer roller 9 against the intermediate transfer belt 6 and is configured to be able to switch the pressing force of the secondary transfer roller 9. For example, the roller pressing unit 90 includes a coil spring that presses the secondary transfer roller 9 toward the intermediate transfer belt 6 and a rotatable cam that contacts the base end of the coil spring. When the position of the base end portion of the coil spring is displaced according to the angle of the cam, the elastic force of the coil spring fluctuates, whereby the pressing force of the secondary transfer roller 9 can be switched.

  Around the secondary transfer roller 9, a cleaning blade 91, an application brush 92, a lubricant supply body 93, and a lubricant pressing portion 94 are disposed.

  The cleaning blade 91 scrapes off the toner adhering to the secondary transfer roller 9 and removes it. The cleaning blade 91 is formed by processing polyurethane rubber into a predetermined shape, for example. The cleaning blade 91 is bonded to a holding sheet metal (not shown) with a hot melt adhesive, and is arranged so that the tip portion thereof is pressed against the secondary transfer roller 9.

  The application brush 92 applies a lubricant to the surface of the secondary transfer roller 9. The application brush 92 is rotatably supported and is disposed in parallel with the secondary transfer roller 9 so as to contact the surface thereof. In addition, as a method of applying the lubricant to the secondary transfer roller 9, a roller or the like can be used in addition to using a brush.

  The lubricant supply body 93 supplies the lubricant to the application brush 92 and is provided below the application brush 92. The lubricant supplier 93 is obtained by, for example, melt-molding zinc stearate powder.

  The lubricant pressing portion 94 presses the lubricant supply body 93 against the application brush 92, and is configured to be able to switch the pressing force of the lubricant supply body 93. For example, the lubricant pressing portion 94 includes a coil spring that presses the lubricant supply body 93 toward the application brush 92 and a rotatable cam that abuts against the base end portion of the coil spring. When the position of the base end portion of the coil spring is displaced according to the angle of the cam, the elastic force of the coil spring fluctuates, whereby the pressing force of the lubricant supply body 93 can be switched.

  The amount of lubricant scraped off from the lubricant supply body 93 by the application brush 92 is switched in accordance with the switching of the pressing force of the lubricant supply body 93 by the lubricant pressing portion 94, and the amount of lubricant applied to the secondary transfer roller 9 is adjusted. Can do. Specifically, when the pressing force of the lubricant supply body 93 is increased, the amount of lubricant applied to the secondary transfer roller 9 is increased, and when the pressing force of the lubricant supply body 93 is decreased, the secondary transfer roller 9 is The amount of lubricant applied is reduced.

  Here, the application brush 92, the lubricant supply body 93 </ b> Y, and the lubricant pressing portion 94 directly supply the lubricant to the secondary transfer roller 9, and the lubricant is transferred to the intermediate transfer belt through the secondary transfer roller 9. 6 can be applied. That is, the application brush 92, the lubricant supply body 93, and the lubricant pressing unit 94 function as a lubricant supply unit that supplies the lubricant to the intermediate transfer belt 6.

  The belt cleaning unit 8 cleans the surface of the intermediate transfer belt 6 that has finished transferring the image. Here, FIG. 4 is a configuration diagram schematically showing details of the belt cleaning unit 8. The belt cleaning unit 8 is mainly configured by a cleaning blade 81, an application brush 82, a lubricant supply body 83, and a lubricant pressing unit 84. The application brush 82 and the cleaning blade 81 are arranged in this order from upstream to downstream in the rotation direction of the intermediate transfer belt 6.

  The cleaning blade 81 scrapes off the toner adhering to the intermediate transfer belt 6 and removes it. The cleaning blade 81 is formed by processing polyurethane rubber into a predetermined shape, for example. The cleaning blade 51Y is bonded to a holding metal plate (not shown) with a hot melt adhesive, and is arranged so that its tip is pressed against the photosensitive drum 1Y.

  The application brush 82 applies a lubricant to the surface of the intermediate transfer belt 6. The application brush 82 is rotatably supported and is disposed in parallel with the intermediate transfer belt 6 so as to contact the surface thereof.

  The lubricant supply body 83 supplies a lubricant to the application brush 82 and is provided above the application brush 82. The lubricant supply body 83 is obtained by, for example, melt-molding zinc stearate powder.

  The lubricant pressing portion 84 presses the lubricant supply body 83 against the application brush 82, and is configured to be able to switch the pressing force of the lubricant supply body 83. For example, the lubricant pressing portion 84 includes a coil spring that presses the lubricant supply body 83 against the application brush 82 and a rotatable cam that abuts against the base end portion of the coil spring. When the position of the base end portion of the coil spring is displaced according to the angle of the cam, the elastic force of the coil spring fluctuates, whereby the pressing force of the lubricant supply body 83 can be switched.

  According to switching of the pressing force of the lubricant supply body 83 by the lubricant pressing portion 84, the amount of lubricant scraped off from the lubricant supply body 83 by the application brush 82 is switched, and the amount of lubricant supplied to the intermediate transfer belt 6 is adjusted. Can do. Specifically, when the pressing force of the lubricant supply body 83 is increased, the amount of lubricant applied to the intermediate transfer belt 6 is increased, and when the pressing force of the lubricant supply body 54Y is decreased, the lubricant is applied to the intermediate transfer belt 6. The amount of lubricant is reduced.

  The application brush 82, the lubricant supply body 83, and the lubricant pressing unit 84 function as a lubricant supply unit that supplies the lubricant to the intermediate transfer belt 6.

  Referring to FIG. 1, the paper transport unit 20 transports the paper P along a transport path. The paper P is stored in the paper feed tray 21, and the paper P stored in the paper feed tray 21 is taken in by the paper feed unit 22 and sent out to the transport path. In the transport path, a plurality of transport means for transporting the paper P is provided upstream of the transfer nip portion. Each of the conveying means is composed of a pair of rollers that are in pressure contact with each other, and at least one of the rollers is rotationally driven through an electric motor that is a driving means. The conveying means conveys the paper P by sandwiching and rotating the paper P. In addition to the configuration of the pair of rollers, the conveyance unit can widely employ a configuration including a pair of rotating members such as a combination of belts or a combination of a belt and a roller.

  The fixing device 70 is a device that performs a fixing process for fixing the image on the paper P to which the image has been transferred. The fixing device 70 includes, for example, a fixing roller 71 and a pressure roller 72 that form a nip (fixing nip) by being placed in pressure contact with each other, and a fixing heater 73 that heats the fixing roller 71. The fixing device 70 conveys the paper P and fixes the image on the paper P by performing pressure fixing with the fixing roller 51 and the pressure roller 72 and heat fixing with the fixing heater 73.

  The paper P on which the fixing process has been performed by the fixing device 70 is discharged by a paper discharge roller 28 to a paper discharge tray 29 attached to the outer side surface of the housing. When image formation is also performed on the back surface of the paper P, the paper P on which image formation on the paper surface has been completed is conveyed by the switching gate 30 to the reverse roller 31 below. The reversing roller 31 pinches the rear end of the conveyed paper P, reverses the paper P by reverse feeding, and sends it out to the refeed conveyance path. The paper P sent out to the re-feed transport path is transported by a plurality of transport means for re-feeding, and the paper P is returned to the transfer position.

  The control unit 100 has a function of controlling the image forming apparatus in an integrated manner, and a microcomputer mainly composed of a CPU, a ROM, a RAM, and an I / O interface can be used. The control unit 100 forms an image on the paper P by controlling the image forming units 10Y, 10M, 10C, and 10K, the fixing device 70, and the like.

  Various types of information are input to the control unit 100 from the operation unit 110. The operation unit 110 is, for example, a touch panel that can perform an input operation according to information displayed on the display. The operation unit 110 outputs to the control unit 100 printing conditions (for example, the paper type of the paper P, the image density and magnification) set through the user's input operation.

  In relation to the present embodiment, the control unit 100 detects the paper type of the paper P used for image formation (paper type detection unit). The control unit 100 controls the amount of lubricant supplied to the intermediate transfer belt 6 based on the detected paper type of the paper P.

  FIG. 5 is a flowchart showing a control procedure in the image forming apparatus according to the present embodiment. The operation of the image forming apparatus according to this embodiment will be described below. The processing of the flowchart shown in FIG. 5 is called together with job execution and executed by the control unit 100.

  First, in step 1, the control unit 100 detects the paper type of the paper P. The detection of the paper type by the control unit 100 is performed by referring to the paper type information designated by the user through the operation unit 110. In addition, since the detection of the paper type in Step 1 is to specify the surface state of the paper P, the user may specify the surface state of the paper P as the paper type information. Further, the control unit 100 may directly detect the paper type of the paper P (surface state of the paper P) by scanning the surface of the paper P using an optical method or detecting surface resistance. Good.

  In step 2, the control unit 100 controls the amount of lubricant supplied to the intermediate transfer belt 6. When the surface state of the paper P is rough, there is a possibility that the toner cannot be sufficiently transferred in the concave portion of the paper P and an image defect may occur. Therefore, when the paper P having a rough surface state is used, the amount of lubricant supplied to the intermediate transfer belt 6 is increased, thereby improving the transferability of the toner image onto the paper.

  Therefore, the control unit 100 determines the surface state of the paper P based on the detected paper type of the paper P. Specifically, for each paper type of the paper P, the control unit 100 holds data indicating whether or not the surface state of the paper P corresponds to an uneven paper having a specified surface roughness or more. . Then, the control unit 100 determines whether the detected paper type of the paper P corresponds to a concavo-convex paper or a paper other than the concavo-convex paper (hereinafter referred to as “non-concave paper”). As an example, the specified surface roughness is such that the difference between the concave and convex portions is 50 μm, a value that is equal to or greater than this value corresponds to the uneven paper, and a value that is smaller than this value corresponds to the non-concave paper. .

  When the paper type of the paper P is detected as the surface state of the paper P, the control unit 100 defines the relationship between whether the surface state corresponds to the uneven paper for each of various surface states. Data is stored in advance. Then, the control unit 100 determines whether the paper P corresponds to the uneven paper or the non-concave paper according to the surface state of the paper P.

  Next, the control unit 100 controls the amount of lubricant supplied to the intermediate transfer belt 6 according to the surface state of the paper P. The amount of lubricant supplied to the intermediate transfer belt 6 can be controlled using at least one of the following methods.

(First method)
As shown in FIG. 4, the control unit 100 controls the amount of lubricant supplied to the intermediate transfer belt 6 through the rotation speed of the application brush 82 installed on the intermediate transfer belt 6. That is, the amount of lubricant supplied to the intermediate transfer belt 6 can be increased by increasing the rotation speed of the application brush 82. When the paper P is non-concave paper, the control unit 100 controls the rotation speed of the application brush 82 with a reference value that is normally used. On the other hand, when the paper P is uneven paper, the control unit 100 controls the rotation speed of the application brush 82 with a value increased from the reference value.

  FIG. 6 is an explanatory diagram showing the relationship between the transfer rank G in the concave portion of the paper P and the rotational speed θ of the application brush 82. The transfer rank G is 5 steps from G1 to G5, and the larger the subscript, the better the transfer performance in the concave portion of the paper P. As an example, when the reference value of the rotation speed θ of the application brush 82 is “0.8”, the transfer rank G is “G2”. However, when the rotation speed θ of the application brush 82 is set to “1.2” which is 1.5 times the reference value, the transfer rank G is “G4”. Further, when the rotation speed θ of the application brush 82 is set to “1.6 or more” which is 2.0 times or more of the reference value, the transfer rank G is “G5”. Thus, the control unit 100 desirably sets the rotation speed θ of the application brush 82 to 1.5 times or more of the reference value, and more preferably 2.0 times or more. If the amount of the lubricant is excessive, a cleaning failure will be caused. Therefore, the rotation speed θ of the application brush 82 is preferably 4.0 times or less at the maximum.

(Second method)
As shown in FIG. 4, the controller 100 controls the amount of lubricant supplied to the intermediate transfer belt 6 through the pressing force of the lubricant supplier 83 installed on the application brush 82. That is, the amount of lubricant supplied to the intermediate transfer belt 6 can be increased by increasing the pressing force of the lubricant supplier 83. When the paper P is non-concave paper, the control unit 100 controls the pressing force of the lubricant supply body 83 with a reference value that is normally used. On the other hand, when the paper P is a concavo-convex paper, the control unit 100 controls the pressing force of the lubricant supplier 83 with a value increased from the reference value. For example, the control unit 100 desirably sets the pressing force of the lubricant supply body 83 to 1.5 times or more of the reference value, and more preferably 2.0 times to 4.0 times.

(Third method)
As shown in FIG. 2, the control unit 100 controls the amount of lubricant supplied to the intermediate transfer belt 6 through the rotation speed of the application roller 52Y installed on the photosensitive drum 1Y. That is, by increasing the rotation speed of the application roller 52Y, the amount of lubricant applied to the photoreceptor drum 1Y increases, and as a result, the amount of lubricant supplied to the intermediate transfer belt 6 can be increased. When the paper P is non-concave paper, the control unit 100 controls the rotation speed of the application roller 52Y with a reference value that is normally used. On the other hand, when the paper P is uneven paper, the control unit 100 controls the rotation speed of the application roller 52Y with a value increased from the reference value. For example, the control unit 100 desirably sets the rotation speed of the application roller 52Y to 1.5 times or more of the reference value, and more preferably 2.0 times to 4.0 times. Note that the control unit 100 performs the same control for the amount of lubricant related to the other photosensitive drums 1M, 1C, and 1K.

(Fourth method)
As shown in FIG. 2, the control unit 100 controls the amount of lubricant supplied to the intermediate transfer belt 6 through the pressing force of the roller pressing unit 70Y disposed on the primary transfer roller 7Y. That is, by increasing the pressing force of the roller pressing portion 70Y, the amount of lubricant transferred from the photosensitive drum 1Y to the intermediate transfer belt 6 increases, and as a result, the amount of lubricant supplied to the intermediate transfer belt 6 is increased. be able to. When the paper P is non-concave paper, the control unit 100 controls the pressing force of the roller pressing unit 70Y with a reference value that is normally used. On the other hand, when the paper P is uneven paper, the control unit 100 controls the pressing force of the roller pressing unit 70Y with a value increased from the reference value. For example, the control unit 100 desirably sets the pressing force of the lubricant supply body 83 to 1.5 times or more of the reference value, and more preferably 2.0 times to 3.0 times. Note that the control unit 100 performs the same control for the amount of lubricant related to the other primary transfer rollers 7M, 7C, and 7K.

(Fifth technique)
As shown in FIG. 3, the control unit 100 controls the amount of lubricant supplied to the intermediate transfer belt 6 through the pressing force of the roller pressing unit 90 disposed on the secondary transfer roller 9. That is, by increasing the pressing force of the roller pressing portion 90, the amount of lubricant transferred from the secondary transfer roller 9 to the intermediate transfer belt 6 increases, and as a result, the amount of lubricant supplied to the intermediate transfer belt 6 increases. Can be made. When the paper P is non-concave paper, the control unit 100 controls the pressing force of the roller pressing unit 90 with a reference value that is normally used. On the other hand, when the paper P is uneven paper, the control unit 100 controls the pressing force of the roller pressing unit 90 with a value increased from the reference value. For example, the control unit 100 desirably sets the pressing force of the lubricant supply body 83 to 1.5 times or more of the reference value, and more preferably 2.0 times to 3.0 times.

(Sixth method)
As shown in FIG. 3, the controller 100 controls the amount of lubricant supplied to the intermediate transfer belt 6 through the pressing force of the lubricant supplier 93 installed on the application brush 92. That is, by increasing the pressing force of the lubricant supply 93, the amount of lubricant transferred to the secondary transfer roller 9 increases, and as a result, the amount of lubricant supplied to the intermediate transfer belt 6 can be increased. When the paper P is non-concave paper, the control unit 100 controls the pressing force of the lubricant supply body 93 with a reference value that is normally used. On the other hand, when the paper P is a concavo-convex paper, the control unit 100 controls the pressing force of the lubricant supply body 93 with a value increased from the reference value. For example, the control unit 100 desirably sets the pressing force of the lubricant supply body 83 to 1.5 times or more of the reference value, and more preferably 2.0 times to 4.0 times.

  Note that the control unit 100 may perform control by combining two or more of the above-described methods.

  In step 3, the control unit 100 determines whether or not the currently transported paper P is the final paper. If the determination in step 3 is affirmative, that is, if the paper P is the final paper, this processing is terminated. On the other hand, if a negative determination is made in step 3, that is, if the paper P is not the final paper, the processing returns to step 3.

  As described above, in this embodiment, the image forming apparatus detects the intermediate transfer belt 6 as an image carrier that carries an image, the lubricant supply unit that supplies lubricant to the intermediate transfer belt 6, and the paper type of the paper P. And a control unit 100 that controls the amount of lubricant supplied to the intermediate transfer belt 6 based on the paper type of the paper P.

  According to this configuration, the amount of lubricant supplied to the intermediate transfer belt 6 is appropriately controlled according to the paper type of the paper P. Therefore, the toner image can be appropriately transferred by controlling the amount of the lubricant even if the paper type causes the toner image transferability to deteriorate. As a result, a situation in which the density of the image becomes nonuniform can be suppressed, and a uniform image can be formed regardless of the paper type.

  Further, the control unit 100 determines whether or not the surface state of the paper is a concavo-convex paper having a surface roughness equal to or greater than a specified surface roughness based on the detected paper type of the paper P, and performs intermediate transfer based on the determination result. The amount of lubricant supplied to the belt 6 is controlled.

  According to such a configuration, the amount of lubricant can be controlled in accordance with the uneven paper and the non-concave paper by appropriately separating the paper P from the paper type as being the uneven paper or the non-concave paper. As a result, the transferability of the toner image can be ensured appropriately, and a uniform image can be formed regardless of the paper type.

  Further, in this embodiment, when the control unit 100 determines that the paper type of the paper P is uneven paper, the intermediate transfer belt 6 is compared with the case where the paper type of the paper P is non-concave paper. The amount of lubricant supplied to the plant is to be increased.

  According to this configuration, the amount of lubricant increases when the surface state of the paper P is uneven. As a result, it is possible to improve the transferability of the toner image and suppress the situation where the density of the image is not uniform.

  In the present embodiment, the control unit 100 also determines the amount of lubricant applied to the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1K, the amount of lubricant applied to the surface of the intermediate transfer belt 6, and the primary transfer roller 7Y, At least one of the pressing force of 7M, 7C, and 7K, the pressing force of the secondary transfer roller 9, and the amount of lubricant applied to the surface of the secondary transfer roller 9 is controlled.

  According to this configuration, the amount of lubricant supplied to the intermediate transfer belt 6 can be appropriately controlled. Moreover, the control part 100 can also control combining 2 or more of the above-mentioned methods. Thereby, finer control can be realized.

  The image forming apparatus according to the embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the invention. . For example, according to the present embodiment, an intermediate transfer type image forming apparatus having an intermediate transfer belt as a transfer body has been described. However, the present invention is applicable to a direct transfer type image forming apparatus having a direct transfer belt as a transfer body. Is also possible. Here, in the direct transfer type image forming apparatus, the photosensitive drum is directly opposed to the transfer belt, and the toner image on the photosensitive drum is directly transferred to the paper while the transfer paper is conveyed by the direct transfer belt. This is a device for forming a full-color image.

SC Document reading device 10Y to 10K Image forming unit 1Y to 1K Photosensitive drum 3Y to 3K Optical writing unit 4Y to 4K Developing device 5Y to 5K Drum cleaner 6 Intermediate transfer belt 8 Belt cleaner 9 Secondary transfer roller 20 Paper transport unit 70 Fixing device 100 control unit

Claims (8)

An image carrier for carrying an image;
A lubricant supply section for supplying a lubricant to the image carrier;
A paper type detection unit for detecting the paper type of the paper;
A control unit for controlling the amount of lubricant supplied to the image carrier based on the paper type of the paper detected by the paper type detection unit;
An image forming apparatus comprising:   The control unit determines whether the surface state of the sheet is uneven paper having a surface roughness equal to or greater than a specified surface roughness based on the sheet type of the sheet detected by the sheet type detection unit, and based on the determination result. The image forming apparatus according to claim 1, wherein the amount of lubricant supplied to the image carrier is controlled.   When determining that the paper type of the paper is uneven paper, the control unit determines the amount of lubricant supplied to the image carrier as compared to the case where the paper type of the paper is non-concave paper. The image forming apparatus according to claim 1, wherein the image forming apparatus is increased. The image carrier is an intermediate transfer body on which an image formed on the photosensitive drum is primarily transferred,
The control unit includes a primary transfer member that transfers an amount of lubricant applied to the surface of the photosensitive drum, an amount of lubricant applied to the surface of the intermediate transfer member, and an image formed on the photosensitive drum to the intermediate transfer member. Controlling at least one of the following pressure, the pressing force of the secondary transfer member that transfers the image formed on the intermediate transfer member to the sheet, and the amount of lubricant applied to the surface of the secondary transfer member. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. In a control method of an image forming apparatus including a lubricant supply unit that supplies a lubricant to an image carrier that carries an image,
A first step of detecting a paper type of the paper;
A second step of controlling the amount of lubricant supplied to the image carrier based on the detected paper type;
A control method for an image forming apparatus, comprising:   In the second step, based on the detected paper type, it is determined whether the surface state of the paper is a concavo-convex paper having a specified surface roughness or more, and the image is determined based on the determination result. 6. The method of controlling an image forming apparatus according to claim 5, wherein the amount of lubricant supplied to the carrier is controlled.   In the second step, when it is determined that the paper type of the paper is uneven paper, the lubricant supplied to the image carrier is compared with the case where the paper type of the paper is non-concave paper. 7. The method of controlling an image forming apparatus according to claim 5, wherein the amount is increased. The image carrier is an intermediate transfer body on which an image formed on the photosensitive drum is primarily transferred,
In the second step, the amount of lubricant applied to the surface of the photosensitive drum, the amount of lubricant applied to the surface of the intermediate transfer member, and an image formed on the photosensitive drum are transferred to the intermediate transfer member. Control at least one of the pressing force of the transfer member, the pressing force of the secondary transfer member that transfers the image formed on the intermediate transfer member to the sheet, and the amount of lubricant applied to the surface of the secondary transfer member. 8. A method for controlling an image forming apparatus according to claim 5, wherein the image forming apparatus controls the image forming apparatus.

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