JP2006030863A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus having inexpensive constitution by which the transition of an accumulation amount of waste toner can be notified beforehand at any time, wherein the accumulation amount of the waste toner can more accurately be grasped than in the conventional example. <P>SOLUTION: In the electrophotographic image forming apparatus where a toner image formed on an image carrier is transferred to transfer material and the waste toner remaining on the image carrier after transferring is removed and recovered to a recovery part, the accumulation amount of the recovered waste toner is calculated from the covering area of the toner image occupying the surface of the image carrier. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus using an electrophotographic system, for example, an image forming apparatus such as a copying machine, a printer, and a facsimile machine.

  The configuration of an image forming apparatus using an intermediate transfer member is often employed in, for example, an image forming apparatus having a full color or multiple image forming function.

  This corresponds to a target full-color image or a plurality of color component images of multiple images by an appropriate image forming process means on a first image carrier (photosensitive drum) such as an electrophotographic photosensitive member or an electrostatic recording dielectric. Intermediate transfer is performed by sequentially forming component color toner images and sequentially superimposing and transferring these component color toner images onto an intermediate transfer member as a second image carrier, which is generally a rotating belt type, at a primary transfer portion. A full-color image or multiple toner image corresponding to the target full-color image or multiple image is synthesized and formed on the body. The toner image synthesized and formed on the intermediate transfer member is collectively transferred to a transfer material at the secondary transfer portion, and the transfer material is introduced into a fixing device to fix the image, thereby obtaining a full-color image formed product.

  Here, an image forming apparatus when a belt body is employed as the second image carrier (intermediate transfer body) will be described with reference to FIG. In FIG. 16, the intermediate transfer unit 100 and the cleaner unit 120 are mainly shown.

  Primary transfer in which component color toner images corresponding to a plurality of color component images formed on the photosensitive drum 101 (101Y, 101M, 101C, 101K) are formed at the nip between the photosensitive drum 101 and the primary transfer counter roller 102. The images are sequentially transferred at the portion T1 (T1Y, T1M, T1C, T1K), and a target full-color image is formed on the intermediate transfer belt 103. The full-color image on the intermediate transfer belt 103 is collectively transferred to the transfer material P by the secondary transfer portion T2 formed by the secondary transfer roller 118 and the secondary transfer counter roller 105, and the image is fixed by a fixing device (not shown). To obtain a full color product.

  The intermediate transfer unit 100 includes a primary transfer counter roller 102, an intermediate transfer belt 103, a triaxial drive roller 104 that supports the intermediate transfer belt 103, a secondary transfer counter roller 105, and a tension roller 106 as a movable roller. It can be detached from the apparatus main body.

  The intermediate transfer belt 103 is held at a constant tension by pressing a bearing 107 of a swingable tension roller 106 with a compression spring 108.

  A cleaner unit 120 is disposed around the intermediate transfer belt 103 for cleaning toner that is not transferred by secondary transfer but remains on the intermediate transfer belt 103 as a transfer residue. The cleaner unit 120 includes a cleaning blade 121 as a cleaning member that contacts the intermediate transfer belt 103, a cleaner container 122 that stores the residual toner removed by the cleaning blade 121, and a screw 123 that conveys the removed waste toner 131. is doing. The cleaning blade 121 is held in the cleaner container 122.

  In addition, a tension roller 106 is disposed as a backup roller at the opposite portion of the cleaning blade 121. The cleaner unit 120 is positioned by bearing members at both ends of the tension roller 106 and fixed to the intermediate transfer unit 100. Therefore, the cleaning performance can be maintained with a simple configuration. The waste toner 131 removed by the cleaning blade 121 is sent by the screw 123 and discharged to the waste toner bottle 130. When the waste toner 131 stored in the waste toner bottle 130 becomes full, the optical axis of the light transmission type waste toner full detection sensor 132 disposed near the entrance of the waste toner bottle 130 is blocked, so the main body is stopped. Therefore, the waste toner 131 does not overflow and does not contaminate the inside and the surroundings of the machine.

  However, in the above conventional example, since the full state of the waste toner bottle 130 is detected when the optical axis of the full detection sensor 132 is blocked, the main body suddenly stops even during the job, and printing is performed. Could not continue.

  In addition, there is another method in which another set of similar sensors is arranged parallel to and below the full-tank detection sensor 132, and a full-fill notice is issued when the lower optical axis is blocked. There was a variation in the number of prints possible until the tank was full. Furthermore, it has been a problem that the cost is increased by increasing the number of sensors.

  Therefore, a method of estimating the amount of accumulated waste toner from the amount of consumed toner is known as means for sequentially knowing the amount of accumulated waste toner without increasing the cost (see, for example, Patent Document 1).

JP 2003-316224 A

  However, although there is a correlation between the amount of waste toner generated and the amount of consumed toner, sufficient accuracy cannot be obtained. For example, in the above conventional example, monochrome printing and full-color printing, or low-density printing and high-density printing in which a plurality of colors are overlapped, etc., the transfer efficiency is different even if the amount of toner consumed is the same, and the amount of waste toner generated is Due to the difference, there is a problem that the estimation accuracy deteriorates.

  Since the present invention has been made in view of the above problems, an object of the present invention is an image forming apparatus having a configuration capable of notifying the transition of the accumulated amount of waste toner at any time at a low cost as compared with the conventional example. This is to improve the accuracy of grasping the accumulated amount of waste toner.

  In order to achieve the above object, a typical configuration of the present invention is such that a toner image formed on an image carrier is transferred to a transfer material, and waste toner remaining on the image carrier after the transfer is removed to a collection unit. In the image forming apparatus to be collected, the accumulated amount of the collected waste toner is calculated from the toner covering area and the transfer efficiency.

  According to the present invention, it is possible to notify the user of the amount of waste toner accumulated in the collection unit from the amount of toner replenished and the transfer efficiency, so that it is possible to obtain an accurate amount of waste toner accumulation sequentially. It is done.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
[Overall Description of Image Forming Apparatus]
First, the overall configuration of the color image forming apparatus will be schematically described with reference to FIG.

  FIG. 1 is an explanatory diagram of the overall configuration of a laser printer which is an embodiment of a color image forming apparatus.

  As shown in FIG. 1, the color laser printer is a photosensitive drum 1 (1Y, 1M, 1C, 1K) which is an electrophotographic photosensitive member that rotates at a constant speed for each color of yellow Y, magenta M, cyan C, and black Bk. And an image forming unit having a color developing unit, and an intermediate transfer member 18 that holds the color image developed and transferred in multiple by the image forming unit and further transfers it to the transfer material 2 fed from the feeding unit. The transfer material 2 to which the color image has been transferred is conveyed to the fixing unit 50 to fix the color image on the transfer material 2 and discharged to the discharge unit 65 on the upper surface of the apparatus by the discharge roller. The four color developing devices are individually detachable from the printer body.

  Next, the configuration of each part of the image forming apparatus will be sequentially described in detail.

[Photosensitive drum]
The photosensitive drum 1 is integrally formed with a container 3 (3Y, 3M, 3C, 3K) of a holder of the developing device, and this developing unit is detachably supported with respect to the printer body, and the life of the photosensitive drum 1 is achieved. The unit can be easily replaced in accordance with The photosensitive drum 1 according to the present embodiment is configured by applying an organic photoconductor layer to the outside of an aluminum cylinder, and is rotatably supported by a container 3 of a holder of the photosensitive drum 1. Further, by transmitting a driving force of a driving motor (not shown) to one end on the rear side in the drawing, the photosensitive drum 1 is rotated counterclockwise in the drawing according to an image forming operation.

[Charging means]
The charging means 5 uses a roller charging method and uniformly charges the surface of the photosensitive drum 1 with an applied voltage by a charging roller.

[Exposure means]
The exposure to the photosensitive drum 1 is performed from the scanner unit 6 (6Y, 6M, 6C, 6K). That is, when an image signal is given to the laser diode, the laser diode irradiates the polygon mirror 6a (6Ya, 6Ma, 6Ca, 6Ka) with image light corresponding to the image signal. The polygon mirror 6a is rotated at a high speed by a scanner motor, and the surface of the photosensitive drum 1 on which the image light reflected by the polygon mirror 6a rotates at a constant speed via the imaging lens 6b (6Yb, 6Mb, 6Cb, 6Kb) is selected. As a result, an electrostatic latent image is formed on the photosensitive drum 1.

[Development means]
The developing means is composed of four developing units 4 (4Y, 4M, 4C, 4K) capable of developing each color of yellow, magenta, cyan, and black in order to visualize the electrostatic latent image. The In each of the four color developing devices 4, sleeves 3S (3YS, 3MS, 3CS, 3KS) are arranged at a position opposite to the photosensitive drum 1 with a minute interval with respect to the photosensitive drum 1, and each color toner is applied to the photosensitive drum 1. A visible image is formed.

  Each color developing device 4 feeds toner in a container by a feeding mechanism, and a powder in which toner (nonmagnetic) and developer (magnetic) are mixed on the outer periphery of the sleeve 3S on the outer periphery of the sleeve 3S rotating clockwise in the figure. Coat. Thereafter, the toner in the powder is developed with toner corresponding to the electrostatic latent image on the photosensitive drum 1.

  Further, each color developer 4 is supplied with toner from toner containers 4T (4TY, 4TM, 4TC, 4TK) separately arranged at any time. Further, the amount of toner replenished from the toner container 4T is controlled by the number of rotations of the toner feed screw, and the amount of toner replenished from the number of rotations of the screw and the remaining toner amount are measured as needed.

[Intermediate transfer member]
The intermediate transfer member 18 serving as an image carrier rotates in the clockwise direction in synchronism with the outer peripheral speed of the photosensitive drum 1 in order to multiplex-transfer the toner image on the photosensitive drum 1 visualized by each developing unit during the color image forming operation. The intermediate transfer member 18 that has been rotated and subjected to multiple transfer sandwiches and conveys the transfer material 2 by a secondary transfer roller 60 to which a voltage is applied, thereby transferring the color toner images on the intermediate transfer member to the transfer material 2. Simultaneous multiple transfer.

  The intermediate transfer member (intermediate transfer belt) 18 according to the present embodiment is formed of a seamless resin belt having a circumferential length of about 1000 mm, and is stretched around three axes: a drive roller 14, a secondary transfer counter roller 15, and a tension roller 16. Even if the tension roller 16 is loaded on both ends of the tension roller 16 with a spring 21 and the peripheral length of the intermediate transfer body 18 changes due to temperature and humidity changes in the main body and changes with time, the amount of change can be absorbed.

  Guide ribs 19 made of rubber are attached to the entire circumference of both edges inside the intermediate transfer member 18 with an adhesive. Further, flanges 20 and 20 ′ made of resin are disposed at both end portions of the tension roller 16, and the guide rib 19 and the flanges 20 and 20 ′ are arranged in a direction perpendicular to the traveling direction of the intermediate transfer member 18. It regulates movement (hereinafter referred to as “slip”). When the intermediate transfer member 18 is deviated, one of the guide ribs 19 provided in the intermediate transfer member 18 hits one gradient of the flanges 20 and 20 ′ disposed at both ends of the tension roller 16, and further deviates. It is regulated.

  The intermediate transfer member 18 is supported by the main body with the driving roller 14 as a fulcrum, and transmits the driving force of a driving motor (not shown) to one end on the rear side of the driving roller 14 in accordance with the image forming operation. And rotate clockwise in the figure. Further, the intermediate transfer unit 13 can be easily attached and detached in the right direction in the figure.

[Paper Feeder]
The paper feeding unit feeds the transfer material 2 to the image forming unit, and includes a cassette 7 containing a plurality of transfer materials 2, a paper feeding roller 8, a feeding roller 9, a multi-feed preventing retard roller 10, The sheet feeding guide 11, the conveyance roller pair 61, and the registration roller pair 12 are mainly configured.

  At the time of image formation, the paper feed roller 8 is driven and rotated in accordance with the image forming operation to separate and feed the transfer material 2 in the cassette 7 one by one, and is guided by the paper feed guide 11, and passes through the transport roller pair 61. To the registration roller pair 12. During the image forming operation, the registration roller pair 12 performs a non-rotation operation for causing the transfer material 2 to stand still and a rotation operation for conveying the transfer material 2 toward the intermediate transfer body 18 in a predetermined sequence. The image and the transfer material 2 in a certain transfer process are aligned.

[Transfer section]
The transfer unit is composed of a swingable transfer roller 60. The transfer roller 60 has a metal shaft wound with a medium-resistance foamed elastic body, is movable up and down in the drawing, and has a drive. In order to prevent the toner image on the intermediate transfer member 18 from being disturbed during the formation of the four-color toner image, that is, until the toner image on the intermediate transfer member 18 reaches the secondary transfer portion T2, the dotted line in FIG. As shown, the transfer roller 60 is positioned below and separated from the intermediate transfer member 18.

  Thereafter, in accordance with the timing of transferring the color image to the transfer material 2, the transfer roller 60 is positioned at an upper position indicated by a solid line by a cam member (not shown), that is, a predetermined pressure is applied to the intermediate transfer body 18 via the transfer material 2. Pressed with. At this time, a bias is simultaneously applied to the transfer roller 60, and the toner image on the intermediate transfer body 18 is transferred to the transfer material 2. Here, since the intermediate transfer body 18 and the transfer roller 60 are respectively driven, the transfer material 2 sandwiched between the two is conveyed at a predetermined speed in the left direction in the drawing at the same time as the transfer process is performed. It is sent toward the fixing unit 50 which is a process.

[Intermediate transfer member cleaning section]
The cleaner unit 30 for cleaning the intermediate transfer member 18 includes a cleaning blade 31, a pressure spring 36 for pressing the cleaning blade 31 against the intermediate transfer member 18, and a cleaner container 34 for holding them.

  The material of the cleaning blade 31 is formed on a blade holding plate 33 made of urethane rubber and made of a metal plate, and a predetermined spring is applied to the intermediate transfer body 18 by a pressure spring 36 around a shaft 32 held in the cleaner container 34. Since it is pressed at an angle, it can be brought into contact with the intermediate transfer member 18 uniformly.

  Note that a tension roller 16 is disposed as a backup roller at the opposite portion of the cleaning blade 31 so that the cleaning blade 31 can contact the intermediate transfer member 18 with a predetermined contact pressure. The toner image is scraped off from the intermediate transfer member 18 at the point where the cleaning blade 31 comes into contact, and the intermediate transfer member 18 is cleaned.

  The waste toner collected by the cleaning blade 31 is collected in the cleaner container 34 and is sent to the waste toner bottle 40 separately disposed in the main body by the screw 35 disposed in the lowermost part of the cleaner container 34 and collected. . The screw 35 is rotated in the conveying direction of the screw 35 by transmitting a driving force of a driving motor (not shown) to one end at the rear of the drawing.

[Waste toner bottle]
As shown in FIG. 2, the waste toner bottle 40 is configured such that the discharge port δ of the cleaner unit 30 is inserted into the waste toner intake port γ, and toner leakage at the connecting portion of both units can be prevented. Further, the waste toner bottle 40 is held by a waste toner bottle holding member 70 disposed in the main body, and even if the waste toner is accumulated, no load is applied to the connection portion. Further, the waste toner bottle holding member 70 is configured to move up and down in conjunction with the contact / separation operation of the intermediate transfer body unit 13, and is not relevant when replacing other unrelated consumables or during jam processing. Sometimes it is not necessary to put on and take off.

[Fixing part]
The fixing unit 50 fixes the toner image formed on the transfer material 2 by way of the intermediate transfer body 18 with the toner image formed by the developing means. As shown in FIG. And a pressure roller 52 for bringing the transfer material 2 into pressure contact with the fixing roller 51. Each roller is a hollow roller and has a heater (not shown) therein and is rotated. The transfer material 2 is driven and transported simultaneously. That is, the transfer material 2 holding the toner image is conveyed by the fixing roller 51 and the pressure roller 52 and is applied with heat and pressure, whereby the toner is fixed to the transfer material 2.

[Image forming operation]
Next, an operation when image formation is performed by the apparatus configured as described above will be described.

  First, the sheet feeding roller 8 shown in FIG. 1 is rotated to separate one transfer material 2 in the sheet feeding cassette 1 and conveyed to the registration roller pair 12.

  On the other hand, the photosensitive drum 1 and the intermediate transfer member 18 rotate in the direction indicated by the arrow at a predetermined peripheral speed V (hereinafter referred to as “process speed”).

  When an arbitrary point on the outer periphery of the intermediate transfer member 18 reaches the position S in FIG. 1, the photosensitive drum 1 whose surface is uniformly charged by the charging means 5 is exposed at the exposure position E (EY, EM) in FIG. , EC, EK) to form an image by receiving laser exposure. The distance from the exposure position E of the photosensitive drum 1 counterclockwise to the contact portion T1 (T1Y, T1M, T1C, T1K) with the intermediate transfer member 18 is equal to the distance from the point S shown in the drawing of the intermediate transfer member 18 to T1. Therefore, after the elapse of time, the exposure position E at the beginning of image writing coincides with the point S on the intermediate transfer body 18 at the position T1. That is, the image is formed counterclockwise with respect to the intermediate transfer member 18 with the point S as the tip.

  The scanner unit 6Y irradiates a yellow image with a laser to form a yellow latent image on the photosensitive drum 1. Simultaneously with the formation of the latent image, the yellow developing device 4Y is driven, and a voltage having the same polarity as the charging polarity of the photosensitive drum 1 is applied so that yellow toner adheres to the latent image on the photosensitive drum 1. Perform yellow development. At the same time, the yellow toner image on the photosensitive drum 1 is primarily transferred onto the outer periphery of the intermediate transfer member 18 at the first transfer position T1Y slightly downstream of the developing unit. At this time, primary transfer is performed by applying a voltage having a reverse characteristic to that of the yellow toner to the intermediate transfer member 18.

  When the image to be formed is A3 size, the length is 420 mm, and an image is formed from the outer periphery S point to the L1 point of the intermediate transfer member 18.

  Similarly, magenta, cyan, and black color images are sequentially formed on the photosensitive drums 1M, 1C, and 1K, and the toner images are sequentially superimposed and transferred to the intermediate transfer member 18.

  As described above, latent image formation and development and toner transfer to the intermediate transfer member 18 are performed in the order of yellow, magenta, cyan, and black at the primary transfer positions T1Y, T1M, T1C, and T1K, respectively. Thus, a full-color image composed of four types of toners of magenta, cyan, and black is formed.

  Before the transfer of the black toner to the intermediate transfer body 18 is completed, that is, the primary transfer of the black toner of the fourth color is completed and the image leading edge S of the intermediate transfer body 18 that has formed a full color image reaches the secondary transfer portion T2. The transfer material 2 that has been waiting by the above-described registration roller pair 12 is started to be conveyed in time.

  At the time of image formation of each color on the four-color intermediate transfer body 18, the apparatus waits downward, and the transfer roller 60 that is not in contact with the intermediate transfer body 18 is simultaneously moved upward by a cam (not shown) and transferred. By simultaneously pressing the material 2 at the secondary transfer portion T2 of the intermediate transfer member 18 and applying a bias having a reverse characteristic to the toner to the transfer roller 60, the full color image on the intermediate transfer member 18 is simultaneously applied to the transfer material 2 in four colors. Transcript.

  The transfer material 2 that has passed through the secondary transfer portion T2 is peeled off from the intermediate transfer body 18 and conveyed to the fixing portion 50, and after toner fixing, the transfer material 2 is placed on a discharge tray 65 on the upper portion of the main body via discharge roller pairs 62, 63, 64. The image is discharged with the image surface facing downward, and the image forming operation ends.

[Waste toner collection configuration]
Next, a configuration for collecting waste toner will be described in detail with reference to FIGS.

  As shown in the perspective view of FIG. 3, the intermediate transfer body unit 13 has two bosses 24 and 24 ′ for positioning the cleaner unit 30. The bosses 24 and 24 'are formed integrally with the tensioners 17 and 17' at both ends of the tension roller 16, and even if the tension roller 16 moves, the axis O of the tension roller shaft 16a The line O ′ connecting the axes of the bosses 24, 24 ′ is always kept parallel. One of the tensioners 17 ′ at the rear of FIG. 3 has an oblong hole 25 into which the screw drive input portion 41 of the cleaner unit 30 is fitted, and functions as a detent when the cleaner unit 30 is set. Further, the cleaner unit 30 has a rotation prevention member 42 in the front of the figure, and the rotation prevention member 42 is positioned on one of the tensioners 17 in the front of the illustration.

  Further, positioning grooves 43 and 43 ′ provided in the cleaner unit 30 are fitted into the bosses 24 and 24 ′, and the cleaner unit 30 is positioned with respect to the intermediate transfer body unit 13 by latches 44 and 44 ′. be able to. Further, as shown in FIG. 6, a cleaning blade 31 for cleaning the intermediate transfer member 18 is disposed in the cleaner container 34 at the opposite portion of the tension roller 16, and the swing shaft 32 is the center of rotation. The intermediate transfer member 18 is held so as to abut at a predetermined angle. The cleaning blade 31 is configured to contact with a predetermined contact pressure by a compression spring 36. The cleaning blade 31 is fixed to a blade holding plate 33.

  Therefore, since the cleaning blade 31 can always maintain a constant contact state regardless of the position of the tension roller 16, it is possible to maintain a good cleaning performance with a very simple configuration and low cost. Become.

  As shown in FIG. 2, the waste toner 90 that remains on the intermediate transfer member 18 and is collected by the cleaning blade 31 is not transferred to the transfer material 2 at the secondary transfer portion T2, and is collected in the cleaner container 34 as shown in FIG. The toner is transported forward by a waste toner transport screw 35 disposed at the lower portion, and dropped into the waste toner bottle 40 from the connecting portion between the cleaner container 34 and the waste toner bottle 40 and collected. The waste toner conveying screw 35 is rotated by a driving force transmitted from a driving motor (not shown) to a driving input portion 41 (see FIG. 3) at one rear end.

  Further, the connecting portion of the cleaner unit 30 has a shutter that opens and closes in accordance with the attaching / detaching operation of the waste toner bottle 40, and the waste toner 90 does not leak when the cleaner unit 30 is carried alone. Yes.

  The driving source of the waste toner conveying screw 35 is a fixing driving source, so that the number of motors can be reduced and the structure is simplified.

  Further, if the life of the intermediate transfer body unit 13 and the life of the cleaner unit 30 do not match, it is inefficient to replace both units at the same time.

  As shown in FIGS. 2 and 4, the waste toner bottle 40 is held by a waste toner bottle holding member 70 disposed on the main body side plate 53, and the waste toner intake port γ above the waste toner bottle 40 is The outlet δ of the cleaner unit 30 is fitted and connected for positioning. At this time, the waste toner bottle 40 is held by the waste toner bottle holding member 70 while maintaining a gap in the illustrated horizontal direction, and does not affect the positioning unit between the cleaner unit 30 and the waste toner bottle 40. The configuration of the waste toner bottle 40 can be maintained.

  Accordingly, the position of the tension roller 16 is changed (horizontal and horizontal direction in FIG. 4) in accordance with the change of the intermediate transfer member 18 with time and the expansion and contraction due to heat, and the discharge port δ of the cleaner unit 30 is changed accordingly. Thus, even if the position of the connecting portion with the waste toner bottle 40 is changed, the waste toner bottle holding member 70 is also moved and held following this.

  For this reason, the weight of the waste toner bottle 40, which increases when the waste toner 90 is accumulated in the waste toner bottle 40, can be supported by the waste toner bottle holding member 70, and is discharged to the discharge port δ of the cleaner unit 30. The waste toner conveying screw 35 is deflected by applying an unnecessary external force, and noise is not generated or a driving torque increases.

  Thus, since the waste toner bottle 40 is configured to move in synchronization with the cleaner unit 30, the cleaner unit 30 can be directly connected to the waste toner bottle 40 without a connection member, and the number of parts can be reduced. And the configuration can be simplified. Furthermore, since the connecting portion can be fitted, the sealing performance can be improved without using a separate sealing member.

  As shown in FIG. 5, the waste toner bottle 40 is provided with a shutter 73 for preventing the waste toner 90 collected from the waste toner inlet γ from easily spilling when removed from the main body. Yes. A seal member 74 is affixed to the shutter 73, and the waste toner inlet γ is completely sealed while the shutter 73 is biased to the waste toner inlet γ by a spring 75. It has become. As shown in FIG. 2, the shutter 73 follows a guide disposed in the waste toner bottle 40 when the waste toner discharge port δ of the cleaner unit 30 is inserted into the waste toner intake port γ. It is configured to be pushed in and open.

  As shown in FIGS. 6 and 7, the cleaner unit 30 prevents the waste toner 90 scraped off by the cleaning blade 31 from scattering or leaking out of the cleaner unit 30. In order to reliably collect the toner in the cleaner container 34, end seals 37 are arranged in the vicinity of both ends of the cleaning blade 31 to close the gap between the cleaner container 34 and the intermediate transfer body 18. The end seal 37 is formed of an elastic body such as sponge. The end seal 37 in the present embodiment uses a PTFE fiber pile bonded to maltoprene. Further, a squeeze sheet 38 is disposed in the cleaner container 34 so as to be in contact with the intermediate transfer body 18 upstream of the contact position of the cleaning blade 31 in parallel with the cleaning blade 31. The squeeze sheet 38 is affixed to a sheet metal 39 with a double-sided tape, and the sheet metal 39 is affixed to the cleaner container 34 with a double-sided tape.

[Waste toner amount detection method]
Next, a method for detecting the accumulated amount of waste toner, which is the center of the present invention, will be described in detail with reference to FIGS. 8, 9, and 12 to 15. FIG.

  In the present embodiment, the accumulated amount of the waste toner 90 is calculated by calculation, and the user is notified of the life (full tank state) of the waste toner bottle 40 and the life warning.

  First, the detection configuration will be described with reference to the configuration diagram 1 of FIG.

From the image data before area gradation processing such as dither sent from the host computer 400 to the controller 410 of the image forming apparatus, the toner covering area Sa (cm ² ) on the image carrier is calculated. The calculation method is to identify the presence / absence of colored data for each pixel of image data composed of (M × N) pixels, and obtain the covering area from the number of pixels where the colored data exists. At this time, the image data may be RGB data or YMCK data, and if any color data exists, the color data exists, and if it is colorless (no printing), the color data. Suppose that does not exist. In other words, in the case of RGB data represented by 256 gradations, colored data does not exist in the pixel only when (R, G, B) = (255, 255, 255), otherwise colored Data will exist. Similarly, in the case of YMCK data represented by 256 gradations, colored data does not exist only when (Y, M, C, K) = (0, 0, 0, 0), otherwise Colored data exists.

  The presence of the colored data is identified by the counter 411 in the controller 410, and the number of pixels in which the colored data of the identification result exists is stored in the memory 414. Based on the number of pixels in which colored data exists, the operation unit 415 obtains a waste toner bottle filling rate and sends it to the engine unit 420 of the image forming apparatus as appropriate. Alternatively, a command for prohibiting the printing operation is issued based on the filling rate.

  On the other hand, the image data is subjected to area gradation processing such as dithering at 412, converted into a laser emission signal by the PWM control unit 413, and sent to the engine 420.

  Next, an example of the procedure for calculating the coverage area will be described with reference to the flowchart of FIG.

  In step 201, the calculation is started with the cumulative number of colored pixels P = 0 accumulated in the memory 414.

  In step 202, the counter 411 determines the presence / absence of colored data for the pixel at the position (m, n) that has not yet been determined. If colored data exists, the process proceeds to step 203; otherwise, the process proceeds to step 204 without doing anything.

  In step 203, 1 is added to P stored in the memory 414.

  If there is a pixel in the image data that has not been determined in step 204, the process returns to step 202 to determine a new pixel. When the discrimination of all the pixels in the image data is completed, the process proceeds to step 205.

In step 205, the calculation unit 415 calculates the covering area Sa (cm 2) from the cumulative number of colored pixels P (pixel) and the area Sp (cm ² / pixel) occupying the image carrier surface per pixel.
Sa = P × Sp
Calculated by

  The waste toner filling rate is calculated from the coating area thus obtained.

  An example of a procedure for obtaining the waste toner filling rate will be described with reference to the flowchart of FIG.

  In step 211, the waste toner storage amount ΣTw (g) stored in the memory 414 is reset when a new product or a new waste toner bottle is attached.

ΣTw = 0
In step 212, a printing operation is performed at the request of the user or the image forming apparatus.

  In step 213, the calculation unit 415 obtains the waste toner generation amount Tw (g) by the printing operation by multiplying the coverage area Sa in the printing operation by the transfer residual coefficient Tr.

Tw = Sa × Rt
Here, the transfer residual coefficient Rt (g / cm ² ) is the amount of waste toner generated per unit area, and is determined for each printer from the transfer efficiency in the secondary transfer portion, and depends on the use environment, the type of transfer material, and the like. It is changed appropriately.

  In step 214, the calculation unit 415 adds the waste toner generation amount Tw due to the printing operation to the waste toner accumulation amount ΣTw accumulated in the memory 414.

ΣTw = ΣTw + Tw
In step 215, the calculation unit 415 calculates a waste toner filling rate Wa. If the capacity of the waste toner bottle 40 is W (about 1000 cc in this embodiment) and the bulk density Dw of the waste toner in the waste toner bottle (about 0.5 g / cc in this embodiment), the waste toner bottle The filling rate Wa of the bottle 40 is
Wa = {ΣTw / (Dw × W)} × λ × 100
It is. Here, λ represents a safety factor (for example, 1.05) for preventing the waste toner bottle 40 from overflowing.

  In step 216, the calculation unit 415 determines whether the waste toner filling rate has reached 100%. If the waste toner filling rate Wa has not reached 100%, the process returns to step 212, and if Wa has reached 100%, the process proceeds to step 217.

  In step 217, the calculation unit 415 notifies the engine 420 that the waste toner bottle is full. As a result, the image forming apparatus performs operations such as prohibiting the printing operation and requesting the user to replace the waste toner bottle.

  In addition to notifying full tank, the amount of waste toner accumulated in the waste toner bottle 40 can be grasped at any time, so that the user can be notified of the filling rate Wa of the waste toner bottle 40 at an appropriate time, for example, Wa = 80 ( %), It is also possible to notify the user of a full tank notice.

  Hereinafter, the difference from the conventional example of the calculation result according to the present embodiment when the waste toner amount is actually calculated from the image data will be described with reference to FIGS. 13 and 15.

  (1) and (2) of FIG. 13 are examples of image data composed of character data.

  In the figure, (1) is composed of a primary color (for example, Y single color) character group 80 and another primary color (for example, M single color) character group 81, and (2) is a secondary color (for example, Red) character group. It consists of a group 82. Assume that (1) and (2) consume the same amount of toner, but (2) assumes that the coverage area of the toner image is half that of (1).

  As a result of studies by the present inventor, it has been found that the amount of waste toner has a strong correlation with the covering area of the surface of the image carrier. The graph of FIG. 15 shows the number of printed sheets on the horizontal axis and the amount of waste toner on the vertical axis. The actual amount of waste toner generated is indicated by x, the calculation result according to the present embodiment is indicated by a solid line, and the conventional result is indicated by a broken line. The calculation result by an example is shown. The graphs (a) and (b) of (1) are the generation amounts and the calculation results when the image data of (1) or (2) in FIG. 13 is continuously printed, respectively. As can be seen in (a) and (b) of (1), the amount of waste toner actually generated in the image data of (b) is about half that of the image data of (1). However, in the conventional method of estimating the amount of waste toner generated from the amount of toner consumed, the amount of toner consumed in (a) and (b) is the same, so that the amount of generated waste toner is the same, resulting in an error. Will occur.

  However, according to the present embodiment, since the amount of waste toner is calculated from the covering area in consideration of the overlap of two or more colors, more accurate estimation is possible.

  By calculating the amount of waste toner from the coverage area of the toner image as described above, it is possible to grasp the transition of the accumulated amount of waste toner at any time at low cost, and more accurately than in the conventional example. It becomes.

<Embodiment 2>
Next, an embodiment of the waste toner amount detection method will be described with reference to FIGS. 10, 12, 14 and 15. FIG.

  As shown in the configuration diagram 2 of FIG. 12, the present embodiment is different from the first embodiment in that the coverage area is calculated based on the image data after the area gradation processing 412 is processed. ing. In general, when area gradation processing such as dithering is performed, the covering area on the image data changes compared to before processing.

  Therefore, in this embodiment, in order to obtain a more accurate coverage area, the coverage area Sa ′ obtained from image data after area gradation processing such as dither is used instead. Since the basic configuration of the apparatus is the same as that of the above-described embodiment, only a detection configuration different from the above-described embodiment will be described here.

  A method for calculating the covering area Sa 'occupying the surface of the image carrier based on the image data after the area gradation processing will be described below.

  The first embodiment is different from the first embodiment in that the calculation is performed after the image data is already decomposed into YMCK color image data. If the coverage areas of the image data for each color are simply added together for four colors, an overlap occurs, so that a calculation procedure slightly different from that in Embodiment 1 needs to be performed. Therefore, in the following example, the presence or absence of colored data is confirmed in the order of Y, M, C, K for the pixels at the same position in the image data of each color, and if any one of the colored data exists, If there is color data in a pixel and no color data exists in any image data, it is determined that there is no color data in that pixel.

  An example of the calculation procedure is shown using the flowchart of FIG.

  In step 221, the calculation starts with the cumulative number of colored pixels P ′ = 0 accumulated in the memory 414.

  In step 222, the counter 411 determines the presence / absence of colored data for a pixel that has not yet been determined at the position (m, n) in the Y image data. If colored data exists, the process proceeds to step 226Y, and if not, the process proceeds to step 223 without doing anything.

  In step 223, the counter 411 determines the presence / absence of colored data for a pixel in the M image data at the same position (m, n) as the pixel determined in the Y image data in step 222. . If colored data exists, the process proceeds to step 226Y. If not, the process proceeds to step 224 without doing anything.

  In step 224, the counter 411 determines the presence / absence of colored data for a pixel in the C image data at the same position (m, n) as the pixel determined in the Y image data in step 222. . If colored data exists, the process proceeds to step 226Y. If not, the process proceeds to step 225 without doing anything.

  In step 225, the counter 411 determines the presence or absence of colored data for a pixel in the K image data at the same position (m, n) as the pixel determined in the Y image data in step 222. . If colored data exists, the process proceeds to step 226Y, and if not, the process proceeds to step 226N without doing anything.

  In step 226Y, 1 is added to P ′ accumulated in the memory 414, and the process proceeds to step 227.

  In step 226N, the process proceeds to step 227 without performing processing for P '.

  If there is a pixel in the image data that has not been determined in step 227, the process returns to step 222 to determine a new pixel. When the discrimination of all the pixels in the image data is completed, the process proceeds to step 228.

In step 228, the calculation unit 415 calculates the covering area Sa ′ (cm ² ) from the cumulative number of colored pixels P ′ (pixel) and the area Sp (cm ² / pixel) occupying the surface of the image carrier per pixel.
Sa ′ = P ′ × Sp
Calculated by

Since the following procedure is the same as that of the first embodiment, the flowchart is omitted and only the outline is described. From the covering area Sa ′, the waste toner generation amount Tw ′ is
Tw ′ = Sa ′ × Rt
It becomes. Waste toner accumulation amount ΣTw '
ΣTw '= ΣTw' + Tw '
It becomes. The filling rate Wa of the waste toner bottle is
Wa = {ΣTw ′ / (Dw × W)} × λ × 100
It becomes.

  Hereinafter, the difference between the effect of the calculation result according to the present embodiment and the first embodiment will be described with reference to FIGS. 14 and 15.

  FIG. 14 shows an example of image data (1) before dither processing and image data (2) after dither processing as an example of area gradation processing. Each part is an enlarged portion of the image, and the squares shown by broken lines in the figure represent pixels, and here, only nine pixels are shown.

  The image data (1) before the dithering process is a 50% halftone image, and by performing the dithering process on this, the image data (2) after the dithering process is changed. Here, the result of the dither processing is an example, and the result varies depending on the image forming apparatus.

  In general, when a dither process is performed on a halftone image, as seen in the image data (2), it is divided into pixels that are printed and pixels that are not printed, and the coverage area of the toner image is reduced. Accordingly, in this example, the number of pixels counted in the image data (1) before dither processing is 9 because there is colored data, whereas the number of pixels in image data (2) after dither processing is 4. .

  The graph of Embodiment 2 in FIG. 15 is the amount of waste toner generated when the halftone image is continuously printed. A solid line indicates a calculation result according to the first embodiment, and a broken line indicates a calculation result according to the first embodiment. As can be seen from the graph, by calculating the covering area based on the image data after the dither processing, it was possible to perform calculation with higher accuracy.

  As described above, according to the present embodiment, the amount of waste toner generated can be calculated with higher accuracy, particularly in printing including halftone images, in consideration of the change in coverage due to area gradation processing such as dithering. It becomes possible.

  As described above, the embodiment has been described in which the amount of waste toner generated is calculated by the image forming apparatus. However, the calculation is performed by the host computer that is the transmission source of the image data, and the calculation result is transmitted to the image forming apparatus together with the image data. Also good. In this case, there is an advantage that even if the image forming apparatus does not have a high-speed arithmetic processing capability, it is not necessary to apply a load that affects the image processing to the image forming apparatus.

  The configuration described in each of the above-described embodiments exemplifies an image forming apparatus that uses an intermediate transfer belt as the intermediate transfer body 18, but is not limited thereto, and image formation using a photosensitive belt or a transfer belt is possible. The configuration is also effective for the apparatus.

  In each of the above-described embodiments, the toner remaining on the intermediate transfer member 18 is removed and collected by the cleaner unit 30. However, the cleaner unit according to the present invention transfers the toner remaining on the photosensitive drum as an image carrier. The remaining toner may be removed and collected.

1 is a main cross-sectional view illustrating an outline of an overall configuration of an image forming apparatus. FIG. 4 is a cross-sectional view illustrating a relationship between a cleaner unit and a waste toner bottle. FIG. 4 is a perspective view showing a relationship between an intermediate transfer body unit and a cleaner unit. FIG. 6 is a front view showing the shape of a waste toner intake port portion of a cleaner unit and a waste toner bottle. FIG. 4 is a cross-sectional view illustrating a state where a waste toner bottle is removed from a main body. FIG. 5 is a cross-sectional view showing a relationship between a cleaner unit and an intermediate transfer body unit. It is a top view which shows a cleaner unit. It is a flowchart which shows an example of the calculation method of the covering area in Embodiment 1 of this invention. 4 is a flowchart illustrating an example of a method for calculating a waste toner filling rate according to Embodiment 1 of the present invention. It is a flowchart which shows an example of the calculation method of the covering area in Embodiment 2 of this invention. FIG. 6 is a cross-sectional view illustrating a state where the waste toner bottle is full of waste toner. 3 is a configuration diagram illustrating an example of a waste toner amount detection configuration according to Embodiments 1 and 2 of the present invention. FIG. It is an example of the image data which shows the effect by Embodiment 1 of this invention. It is an example of the image data which shows the effect by Embodiment 2 of this invention. It is a graph which shows the correlation with the calculation result by Embodiment 1 and 2 of this invention, and an actual examination result. It is a main sectional view showing a conventional example.

Explanation of symbols

γ Waste toner inlet δ Outlet E Exposure position O Axis T1 Primary transfer position T2 Secondary transfer part 1 Photosensitive drum 2 Transfer material 3S Sleeve 4 Developer 4T Toner container 5 Charging means 6 Scanner part 6a Polygon mirror 6b Imaging lens 7 cassette 8 paper feed roller 9 feed roller 10 retard roller 11 paper feed guide 12 registration roller pair 13 intermediate transfer body unit 14 drive roller 15 secondary transfer counter roller 16 tension roller 16a tension roller shaft 17, 17 'tensioner 18 intermediate transfer Body 19 Guide rib 20, 20 'Flange 21 Spring 24, 24' Boss 25 Long round hole 30 Cleaner unit 31 Cleaning blade 32 Oscillating shaft 33 Blade holding plate 34 Cleaner container 35 Screw 36 Pressure spring 37 End seal 38 Squishy 39 Sheet metal 40 Waste toner bottle 41 Screw drive input part 42 Non-rotating member 43, 43 'Positioning groove 44, 44' Latch 50 Fixing part 51 Fixing roller 52 Pressure roller 53 Main body side plate 60 Secondary transfer roller 61 Conveying roller pair 62 ~ 64 discharge roller pair 65 discharge tray 70 waste toner bottle holding member 71 full sensor 71a light emitting portion 71b light receiving portion 73 shutter 74 sealing member 75 spring 80 primary color character group 81 primary color character group 82 secondary color character group 82 Character group 90 Waste toner 100 Intermediate transfer unit 101 Photosensitive drum 102 Primary transfer counter roller 103 Intermediate transfer belt 104 Drive roller 105 Secondary transfer counter roller 106 Tension roller 107 Bearing 108 Compression spring 118 Secondary transfer counter roller 120 Cleaner unit 121 Leaning blade 122 cleaner container 123 screw 130 waste controller 411 counter 412 area gradation processing such as 413 PWM of the toner bottle 131 waste toner 132 waste toner full detecting sensor 400 the host computer 410 the image forming apparatus
414 Memory 415 Calculation unit 420 Engine of image forming apparatus

Claims (5)

In an image forming apparatus that transfers a toner image formed on an image carrier to a transfer material, removes waste toner remaining on the image carrier after the transfer, and collects the toner in a collection unit.
The collected waste toner generation amount Tw was determined using a toner image covering area Sa occupying the surface of the image carrier and a transfer residual coefficient Rt representing the waste toner generation amount per unit area.
Tw = Sa × Rt
An image forming apparatus characterized in that it is calculated by the following formula. The coated area is an image in which a toner image of at least two colors or more is transferred onto an image carrier, transferred to a transfer material, and waste toner remaining on the image carrier after the transfer is removed and collected in a collection unit. A forming device,
The image forming apparatus according to claim 1, wherein the image forming apparatus has an area where a toner image of at least one color is present in consideration of an overlap of two or more colors.   3. The image forming apparatus according to claim 1, wherein the covering area is calculated from image data in a controller of the image forming apparatus.   The image forming apparatus according to claim 3, wherein the covering area is calculated from image data after area gradation processing by a controller of the image forming apparatus.   3. The image forming apparatus according to claim 1, wherein the coverage area is calculated by a host computer that is a source of image data and is transmitted to the image forming apparatus together with the image data.

Images