JP7129024B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

2. Description of the Related Art Conventionally, there is known an image forming apparatus equipped with a cleaning device that cleans residual toner remaining on an image bearing member without being transferred onto a transfer receiving member.

Japanese Patent Application Laid-Open No. 2002-100002 discloses an image forming apparatus in which a spiral brush member is arranged upstream of a cleaning blade, which is a cleaning member, in the direction in which the surface of the image carrier moves, in order to suppress filming of the image carrier. Have been described. Filming on the image carrier is removed by rotating the spiral brush member and polishing the surface of the image carrier with the brush portion of the spiral brush member. Further, the spiral brush member functions as a conveying member that conveys residual toner on the image carrier blocked by the cleaning blade in a direction perpendicular to the direction of surface movement of the image carrier.

However, in the image forming apparatus described in Patent Document 1, there is still room for improvement in suppressing filming on the image carrier.

In order to solve the above-described problems, the present invention provides an image forming apparatus equipped with a cleaning device that cleans residual toner remaining on an image bearing member without being transferred to a transfer receiving member.
The image carrier is an intermediate transfer belt having a Martens hardness of 180 [N/mm ² ] or less stretched over a plurality of tension rollers, and the cleaning device cleans the toner on the intermediate transfer belt . forming a toner image for image density detection on the intermediate transfer belt , and detecting the toner adhesion amount of the toner image for image density detection to adjust the image density; and the toner image for image density detection is formed on the upstream side of the conveying member in the conveying direction in which the toner on the intermediate transfer belt is conveyed, out of the sheet passing areas on both sides of the intermediate transfer belt. The toner image for image density detection is formed outside the paper passing area and is input to the conveying member as an untransferred toner image.

According to the present invention, filming can be suppressed satisfactorily.

FIG. 2 is a configuration explanatory diagram showing the schematic configuration of the image forming apparatus according to the present embodiment as viewed from the front; Detail view of the intermediate transfer unit. 5 is a graph showing Vsg variation of a PI intermediate transfer belt α manufactured by centrifugal molding over a belt circumferential length of 100 mm. 5 is a graph showing Vsg variation of a PPS intermediate transfer belt β manufactured by extrusion over a belt circumferential length of 100 mm. 10 is a graph showing the result of measuring specular reflection output (initial stage of belt) with an optical sensor when a gradation pattern composed of 10 toner patches with different adhesion amounts is created on the intermediate transfer belt α. 7 is a graph showing the result of measuring the specular reflection output (initial stage of the belt) with an optical sensor after creating a gradation pattern composed of ten toner patches on the intermediate transfer belt β. 7 is a graph showing the results of examining the Martens hardness and If increase rate of an intermediate transfer belt; FIG. 4 is an enlarged view of the vicinity of a belt cleaning device of an intermediate transfer unit; The perspective view which shows some spiral brush members. FIG. 4 is a perspective view showing an intermediate transfer belt and a spiral brush member viewed from the cleaning blade side; FIG. 4 is a diagram showing an example of a gradation pattern formed on an intermediate transfer belt; FIG. 8 is a diagram showing another example of a gradation pattern formed on an intermediate transfer belt; FIG. 10 is a diagram showing still another example of the gradation pattern formed on the intermediate transfer belt; 7 is a graph showing the relationship between the number of sheets passed under each condition and the glossiness of the intermediate transfer belt;

FIG. 1 is a configuration explanatory diagram showing a schematic configuration of an image forming apparatus according to the present embodiment as viewed from the front.
As shown in FIG. 1, the image forming apparatus of the present embodiment is a quadruple tandem type intermediate transfer type color printer 100 that forms a color image from yellow, magenta, cyan, and black toners. The color printer 100 has a body case 2 and a new toner container 32 (32Y, 32C, 32M, 32K) disposed above the body case 2 and individually containing the four color new toners. An image forming unit 3 is arranged substantially in the center of the main body case 2 and forms a single-color toner image from each of the four color toners, and photoreceptors 1 (1Y, 1C, 1M , 1K) as exposure means for writing an electrostatic latent image. The optical unit 4 irradiates the photoreceptors 1Y, 1M, 1C, and 1K with laser light emitted from the light source through a plurality of optical lenses and mirrors while scanning with a polygon mirror rotated by a motor.

Paper feed means including paper feed cassettes 5-1 and 5-2 and a paper feed roller 31 incorporated therein are disposed below the optical unit 4 as an exposure device in the figure. The paper feed cassettes 5-1 and 5-2 store a plurality of sheets of recording paper, and the paper feed roller 31 is in contact with the uppermost recording paper. When the paper feed roller 31 is rotated counterclockwise in the figure by the drive means, for example, the uppermost recording paper of the paper feed cassette 5-1 is fed by the paper feed roller 31 and is moved between the rollers of the registration roller pair 28. is sent to

The registration roller pair 28 rotates to sandwich the recording paper, but the rotation is temporarily stopped as soon as the recording paper is sandwiched. Then, the registration roller pair 28 feeds the recording paper toward a secondary transfer nip, which will be described later, at appropriate timing.

In the image forming section 3, four process cartridges (6Y, 6M, 6C, 6K) corresponding to respective colors (yellow: Y, magenta: M, cyan: C, black: K) are arranged side by side. Most of the process cartridges are composed of multiple devices including a developing device and a charging device. In FIG. 1, the color printer 100 includes four process cartridges 6Y, 6M, 6C, and 6K for forming toner images of yellow: Y, magenta: M, cyan: C, and black: K, respectively. .

These process cartridges 6Y, 6M, 6C, and 6K are detachable from the main body of the color printer 100 and can be replaced as consumable parts at once. These process cartridges 6Y, 6M, 6C, and 6K use toners of different colors Y, M, C, and K as image forming substances, but otherwise have the same configuration.

Taking the process cartridge 6Y for forming a Y toner image as an example, it includes a drum-shaped photoreceptor 1Y as an image carrier, a drum cleaning device, a static elimination device, a charging device, a developing device, etc., which are integrated. ing.

Above the process cartridges 6Y, 6M, 6C, and 6K in the drawing, an intermediate transfer unit 15 moves an endless intermediate transfer belt 11 as an intermediate transfer member, which is an image bearing member, while being stretched by a plurality of rollers. are arranged.

The intermediate transfer unit 15 includes an intermediate transfer belt 11, four primary transfer bias rollers 9Y, 9M, 9C, and 9K, a belt cleaning device 21, a secondary transfer backup roller 13, a cleaning facing roller 18, tension rollers 14 and 17, and the like. is also provided.

The intermediate transfer belt 11 is stretched around a secondary transfer backup roller 13, a cleaning counter roller 18, tension rollers 14 and 17, and tension rollers 16 and 19, and at least one of the rollers is driven to rotate by a rotation drive unit. By doing so, it is moved counterclockwise in the figure. In this embodiment, the secondary transfer backup roller 13 is used as a driving roller, and the secondary transfer backup roller 13 is rotationally driven by a rotation driving section.

The intermediate transfer belt 11 is made of fluororesin, PVD sheet, or polyimide resin, which has little elongation. It may be made of extruded PVDF, PPS, PEEK, PC, or the like. Although this example has a single-layer structure, the surface may be covered with a coating layer having good smoothness, such as a fluororesin.

The primary transfer bias rollers 9Y, 9M, 9C, and 9K sandwich the thus moved intermediate transfer belt 11 with the photosensitive members 1Y, 1M, 1C, and 1K to form primary transfer nips. .

The primary transfer bias rollers 9Y, 9M, 9C, and 9K are applied from a high-voltage power supply with a transfer bias having a polarity opposite to that of the toner (for example, positive) to the back surface of the intermediate transfer belt 11 (inner peripheral surface of the loop). All the rollers 14, 16, 17 except the primary transfer bias rollers 9Y, 9M, 9C, 9K are electrically grounded.

As the intermediate transfer belt 11 moves, it sequentially passes through the primary transfer nips for Y, M, C, and K. In this process, Y, M, and C on the photoreceptors 1Y, 1M, 1C, and 1K are transferred. , K toner images are superimposed on the belt surface and primarily transferred. As a result, a four-color superimposed toner image (four-color toner image: full-color image) is formed on the intermediate transfer belt 11 .

The secondary transfer backup roller 13 sandwiches the intermediate transfer belt 11 between itself and a secondary transfer roller 51 as transfer means to form a secondary transfer nip, and a transfer bias is applied to the secondary transfer roller 51 from a high-voltage power supply. be done. The four-color superimposed toner image formed on the intermediate transfer belt 11 is transferred onto the recording paper from the registration roller pair 28 by the secondary transfer roller 51 at the secondary transfer nip.

After passing through the secondary transfer nip, transfer residual toner that has not been transferred onto the recording paper adheres to the intermediate transfer belt 11 . It is cleaned by the belt cleaning device 21 . The belt cleaning device 21 is arranged above the intermediate transfer belt 11, which is an intermediate transfer member, in the direction of gravity.

In the secondary transfer nip, the recording paper is sandwiched between the intermediate transfer belt 11 and the secondary transfer roller 51 whose surfaces move in the forward direction, and is conveyed in the direction opposite to the registration roller pair 28 side. be. The recording paper sent out from the secondary transfer nip passes through the fixing device 30 arranged above the secondary transfer roller 51 . When passing through the fixing device 30, the four-color superimposed toner image transferred to the surface is fixed by heat and pressure. After that, the recording paper passes between the paper discharge roller pair 33 and is discharged to the paper discharge section 29 where the recording paper is stacked.

FIG. 2 is a detailed diagram of the intermediate transfer unit 15. As shown in FIG.
As shown in FIG. 2 , the intermediate transfer unit 15 has an intermediate transfer belt 11 and a belt cleaning device 21 .

The intermediate transfer belt 11 is made of fluororesin, PVD sheet, or polyimide resin, which has little elongation. It may be made of extruded PVDF, PPS, PEEK, PC, or the like. Further, in the present embodiment, the intermediate transfer belt 11 has a single layer structure, but the surface may be covered with a smooth coat layer such as fluorine-based resin. Above the cleaning opposing roller 18, a belt cleaning device 21 is arranged for removing transfer residual toner remaining on the intermediate transfer belt 11 after secondary transfer onto the recording paper by the secondary transfer roller 51. FIG. The intermediate transfer belt 11 moves endlessly in the arrow A direction in the figure.

The belt cleaning device 21 has a cleaning blade 22 as a cleaning member and a spiral brush member 23 as a conveying member. The spiral brush member 23 is arranged upstream of the cleaning blade 22 in the surface movement direction of the intermediate transfer belt 11 (hereinafter referred to as belt movement direction). The cleaning blade 22 and the spiral brush member 23 are in contact with the cleaning facing roller 18 with the intermediate transfer belt 11 interposed therebetween.

Further, on the upstream side of the spiral brush member 23 in the belt movement direction (between the tension roller 19 and the spiral brush member 23), a push-down roller is arranged to push down the intermediate transfer belt 11 inward. there is

Also, an optical sensor 111 is provided between the primary transfer nip and the secondary transfer nip for K color as a toner adhesion amount detection means for detecting the toner adhesion amount of the toner image on the intermediate transfer belt.

In the color printer 100 of this embodiment, a process control operation is executed to optimize the image density of each color when power is turned on or after a predetermined number of sheets have been fed. In the process control operation, first, a gradation pattern of each color is formed on the intermediate transfer belt 11, which is composed of a plurality of toner patches with different adhesion amounts of toner of each color. When creating a gradation pattern, by sequentially switching the charging bias and the development bias at appropriate timing, a gradation pattern composed of a plurality of toner patches having different adhesion amounts is created. The gradation pattern formed on the intermediate transfer belt 11 passes through a position facing the optical sensor 111 as the intermediate transfer belt 11 moves endlessly. At this time, the optical sensor 111 receives an amount of light corresponding to the amount of toner adhered per unit area to each toner patch of the gradation pattern.

Next, although the specific description is omitted, the adhesion amount of each toner pattern of each color in each toner patch is calculated from the output voltage of the optical sensor 111 when each color toner patch is detected and the adhesion amount conversion algorithm. The image forming conditions are adjusted based on the obtained adhesion amount. Specifically, a linear function (y=ax+b) representing the current development capability is calculated by regression analysis based on the result of detecting the toner adhesion amount in the toner patch and the development potential when each toner patch is imaged. do. Then, by substituting the target value of the image density into this function, an appropriate developing bias value is calculated, and the exposure power, charging bias, and developing bias for Y, M, C, and K are specified. Further, when the developing device employs a two-component developing method using a two-component developer consisting of toner and carrier, the image density may be controlled by changing the toner density control target value in the developing device. Specifically, by changing the toner concentration control target value in the developing device based on the detection result of the optical sensor 111, the maximum target adhesion amount (adhesion amount for obtaining the target ID) can be set to the desired value.

The optical sensor 111 is a reflective optical sensor in which an LED (light-emitting diode) as a light-emitting element (light-emitting means) and a PD (photodiode) or PTr (phototransistor) as a light-receiving element (light-receiving means) are combined. . The optical sensor 111 detects only specularly reflected light from each toner patch of the gradation pattern, only diffusely reflected light from the toner pattern for density detection, and both reflected light. A target configuration can be used.

In any configuration, it is necessary to accurately detect the amount of reflected light, and if the intermediate transfer belt surface becomes less glossy due to filming or scratches on the surface of the intermediate transfer belt, the detection performance may deteriorate. Further, if the surface roughness of the surface of the intermediate transfer belt is large, the detection performance is degraded, so the surface roughness should be small.

As the intermediate transfer belt 11 used in these printers, a resin belt having a high elastic modulus (Young's modulus) such as PI (polyimide) is often used. On the other hand, since a low-cost image forming apparatus is desired, the demand for the low-cost intermediate transfer belt 11 is increasing. Therefore, PAI (polyamide imide), PVDF (polyvinylidene fluoride), PC (polycarbonate), PPS (polyphenylene sulfide), PEEK (polyether ether ketone), TPI (thermoplastic polyimide), etc., which are lower cost than PI belts. Use of a belt is preferred.

The reason why PVDF, PC, PEEK, TPI, PPS, etc. are low cost is that although the material cost is high, they have high production efficiency due to continuous extrusion molding, and they are thermoplastic resins that can be extruded. Due to something.

On the other hand, the reasons for the high cost of PI belts are the high material cost, low production efficiency due to batch processing of centrifugal molding, high heat resistance, high drying temperature, and long production time. .

The surface roughness of a belt manufactured by centrifugal molding is determined by the roughness of the mold used during molding. Therefore, by controlling the surface roughness of the mold, it is possible to control the surface roughness of the belt surface, and it is possible to obtain a surface roughness that allows good optical detection. As for glossiness, PI and PAI belts manufactured by centrifugal molding have sufficient glossiness for optical detection when new.

On the other hand, the surface roughness of extrusion-molded belts may vary due to variations in temperature over the entire surface of the belt and other manufacturing processes, and the surface roughness is generally not as small as that of centrifugal-molded belts. For this reason, in some cases, extrusion-molded belts are subjected to surface polishing or surface coating to maintain surface smoothness and glossiness. However, such surface treatment increases manufacturing costs.

The above-described reflective optical sensor 111 has a specular reflection output (hereinafter referred to as “Vsg”) of the background portion of the intermediate transfer belt 11 (a portion where toner is not attached) of a predetermined value (for example, 4.0±0.5 V). The current (LED current) flowing to the light emitting element is adjusted so that This adjustment operation is called "Vsg adjustment", and the LED current determined by the Vsg adjustment operation is defined as "Vsg adjustment current" or "Ifsg". This Vsg adjustment operation is performed before executing the process control operation. By performing the Vsg adjustment operation in this way, it is possible to obtain accurate detection results over time.

FIG. 3 is a graph obtained by measuring Vsg variation of a PI intermediate transfer belt α manufactured by centrifugal molding over a belt circumferential length of 100 mm. FIG. 4 is a graph obtained by measuring Vsg variation of the PPS intermediate transfer belt β manufactured by extrusion over a belt circumferential length of 100 mm. FIG. 5 is a graph showing the result of measuring the specular reflection output (initial stage of the belt) with the optical sensor 111 after creating a gradation pattern composed of ten toner patches with different adhesion amounts on the intermediate transfer belt α. be. FIG. 6 is a graph showing the result of measuring the specular reflection output (initial stage of the belt) with the optical sensor 111 after creating a gradation pattern composed of ten toner patches on the intermediate transfer belt β.

The test/measurement results shown in FIGS. 3 to 6 were obtained using imagio MP C2201 manufactured by Ricoh Co., Ltd. (corresponding to the basic configuration of the image forming apparatus shown in FIG.・It is obtained by changing the specifications. As shown in FIGS. 3 and 4, Isfg was adjusted so that Vsg was 4V. The Isfg of the intermediate transfer belt α was 8.6 [mA], and the Isfg of the intermediate transfer belt β was 7.0 [mA].

The belt surface roughness of the intermediate transfer belt α was Rz: 0.15 [μm], while that of the intermediate transfer belt β was Rz: 0.72 [μm]. Further, the belt surface glossiness (measured at 20°) was 135 for the intermediate transfer belt α and 117 for the intermediate transfer belt β. From this, it can be seen that the stability of Vsg tends to improve as the belt surface roughness decreases and as the glossiness of the belt surface increases. The surface roughness Rz is measured according to the Rz specified in the JIS-'01 standard.

As shown in FIGS. 4 and 6, the detection accuracy of the intermediate transfer belt β with large Vsg fluctuation is worse than that of the intermediate transfer belt α with small Vsg fluctuation shown in FIGS. 3 and 5 . However, the difference between the peak voltages Max and Min of Vsg of the intermediate transfer belt β is about 0.5 V, and within this range the minimum detection accuracy can be ensured. Therefore, it was found that the intermediate transfer belt β manufactured by extrusion can ensure the minimum detection accuracy in the initial state.

Next, using these intermediate transfer belts α and β, MyPaper manufactured by Ricoh Co., Ltd. was used as recording paper, and 10,000 prints were tested using the same original. As a result, there was no problem with the intermediate transfer belt α, but with the intermediate transfer belt β, paper dust adhered to areas where there was no image over 10,000 sheets (hereinafter referred to as paper dust filming), and belt glossiness decreased. , there was a problem that Ifsg increased with use over time. If the surface of the intermediate transfer belt becomes rough over time or if some substance adheres to it, the amount of specularly reflected light decreases. In that case, the LED current is increased to maintain the output of the background portion. That is, there is a correlation between the belt surface change and Ifsg. The increase rate when this Isfg increases compared to the initial value (new belt) is called "If increase rate".

Therefore, the degree of filming is measured by quantifying the change in filming over time by the If increase rate (=If current amount over time/initial If×100). As the If increase rate increases, the specular reflection output (for example, 4.0±0.5 V) decreases, so it is necessary to increase the current (LED current) flowing through the light emitting element in order to compensate for this. However, if the current flowing through the light-emitting element continues to increase in order to obtain a constant specular reflection output value, the light-emitting element will be damaged. Since the light reflectance varies depending on the belt material and surface roughness, the upper limit of the If increase rate varies depending on the belt. The If increase rate of the intermediate transfer belt β manufactured by the extrusion molding exceeds the upper limit earlier than the intermediate transfer belt α. As described above, the intermediate transfer belt β manufactured by extrusion has a problem that light amount detection cannot be performed accurately due to early filming, and image density control cannot be performed accurately.

Therefore, the applicant of the present invention analyzed the paper dust adhering to the intermediate transfer belt β manufactured by extrusion molding, and found that the adhering paper dust was mainly calcium carbonate. The paper powder containing calcium carbonate as a main component was a hard fine powder, and could not be wiped off even if it was lightly wiped off with a nonwoven fabric. From this, the applicant considered that the paper dust stuck to the surface of the intermediate transfer belt β.

Here, the PI intermediate transfer belt α manufactured by centrifugal molding, which does not cause paper dust filming (sticking of paper dust), is a PPS manufactured by extrusion molding in which paper dust sticks and paper dust filming occurs. It was harder than the intermediate transfer belt β manufactured by Based on this, it is believed that the ease with which paper dust sticks (easiness of occurrence of paper dust filming) is related to the hardness of the belt. investigated the relationship.

FIG. 7 is a graph showing the results of examining the Martens hardness of the intermediate transfer belt 11 and the If increase rate.
FIG. 7 is a graph of a PPS intermediate transfer belt having different Martens hardness, a PAI intermediate transfer belt produced by centrifugal molding, and a PI intermediate transfer belt produced by centrifugal molding. In addition, Isfg of the non-image area of the belt having passed 10,000 sheets under the same conditions as above was measured, and the rate of increase from the initial Isfg was defined as the rate of increase in If.

The cleaning blade 22 used at this time for cleaning the intermediate transfer belt 11 is a two-layer blade consisting of a contact layer that contacts the belt and a backup layer that is connected and fixed to the holder. The contact layer and the backup layer are composed of urethane rubber, and the contact layer has a rubber hardness of 75 degrees (JIS-A scale) and the backup layer has a rubber hardness of 70 degrees (JIS-A scale) as measured with a rubber durometer. used. The cleaning blade 22 has a Martens hardness of 0.5 [N/mm ² ], a blade thickness of 2 [mm], and a blade contact linear pressure of 20 [gf/m].

As can be seen from FIG. 7, paper dust filming did not occur in belts with a Martens hardness of 230 [N/mm ² ] or more, and Ifsg did not increase and remained at 100%. This is probably because the belt surface was sufficiently hard, so that the paper dust did not stick to it.

On the other hand, when the Martens hardness of the belt was 180 [N/mm ² ] or less, the higher the Martens hardness, the higher the If increase rate. If the Martens hardness is 180 or less, paper dust sticks to the belt, but if the Martens hardness is low, the cleaning blade 22 scrapes the belt surface to remove paper dust filming. From this, if the Martens hardness of the extrusion-molded belt is lowered, the If increase rate can be suppressed.

Further, conventionally, there is a technique of applying a lubricant to a photoreceptor for the purpose of prolonging the life of the photoreceptor. Lubricant materials include zinc stearate, boron nitride, alumina, and the like, and mixtures thereof have been applied to photoreceptors to protect them from charging hazards. When the lubricant is applied to the photoreceptor in this manner, filming may occur on the surface of the intermediate transfer belt. This is because the lubricant applied to the photoreceptor is transferred to the intermediate transfer belt 11 in contact with the photoreceptor, and the lubricant acts as a binder material between the silica contained in the toner and the belt. Specifically, silica adheres to the belt surface using the lubricant as a "glue" substance. As the image forming operation continues, this filming spreads over the entire belt and the belt glossiness is lowered. This filming also destabilizes the control of the process control, like the filming of the inexpensive and low-hardness belt described above. In addition, when a lubricant containing boron nitride is applied to the photoreceptor using a belt having a rough surface and a low hardness as described above, the degree of filming on the belt is further aggravated.

Therefore, in order to suppress filming on the belt surface described above, the surface of the intermediate transfer belt is polished by a belt cleaning device to remove the filming. [N/mm ² ] or less) Even in an image forming apparatus using an intermediate transfer belt, the If increase rate is suppressed, and good process control can be performed over time.

FIG. 8 is an enlarged view of the vicinity of the belt cleaning device 21 of the intermediate transfer unit.
As shown in FIG. 8, the belt cleaning device 21 of this embodiment has a cleaning blade 22 and a spiral brush member 23 . The spiral brush member 23 is arranged upstream of the cleaning blade in the belt moving direction. The spiral brush member 23 is rotationally driven in the direction of arrow C in FIG. As the spiral brush member 23 is rotationally driven, the brush portion 23 a (see FIG. 9) of the spiral brush member 23 rubs against the surface of the intermediate transfer belt 11 to polish the surface of the intermediate transfer belt 11 . Thereby, the filming of the intermediate transfer belt 11 can be peeled off.

Untransferred toner remaining on the intermediate transfer belt 11 without being transferred to the recording paper by the secondary transfer roller 51 passes through the spiral brush member 23, is blocked by the cleaning blade 22, and is transferred to the spiral brush. It temporarily accumulates in the contact area between the member 23 and the intermediate transfer belt 11 . The toner accumulated in this contact area is conveyed on the surface of the intermediate transfer belt 11 in a direction orthogonal to the belt moving direction by the rotation of the spiral brush member 23 . During this transportation, the toner rubs against the intermediate transfer belt 11, and the surface of the intermediate transfer belt 11 is polished. As a result, filming of the intermediate transfer belt 11 can be removed. Also, the filming material peeled off from the surface of the intermediate transfer belt by polishing is adhered to itself and collected. As a result, the removed filming substance can be prevented from reattaching to the intermediate transfer belt 11, and the filming can be effectively removed from the intermediate transfer belt. Then, the toner with the filming substance that has been transported to the downstream side of the spiral brush member 23 in the toner transport direction is transported to the waste toner collection path 61 (see FIG. 10) arranged at the end of the intermediate transfer belt, It is recovered to the waste toner recovery path 61 .

By using the spiral brush member 23 in this manner, the surface of the intermediate transfer belt 11 can be polished, and the toner removed by the cleaning blade 22 can be conveyed to the waste toner collection path 61 . As a result, the number of parts can be reduced compared to the case where a polishing member for polishing the surface of the intermediate transfer belt 11 and a conveying member for conveying the removed toner to the waste toner collecting path 61 are provided. Cost can be reduced.

Further, by conveying the toner on the intermediate transfer belt 11 in the width direction of the belt with the spiral brush member, for example, even when images with a low image area ratio are continuously taken, the toner does not exist at a portion of the belt. Therefore, it is possible to obtain the effect of toner polishing and filming recovery evenly in the belt width direction.

The cleaning blade 22 and the spiral brush member 23 are in contact with the cleaning facing roller 18 with the intermediate transfer belt 11 interposed therebetween. A push-down roller 25 is arranged upstream of the spiral brush member 23 in the surface movement direction of the intermediate transfer belt 11 . By pressing down the intermediate transfer belt 11 inwardly of the cleaning opposing roller 18 with the pressing roller 25, the range of the intermediate transfer belt 11 wrapped around the cleaning opposing roller 18 can be widened, and the cleaning blade 22 and the spiral brush member 23 can be expanded. can be brought into contact with the cleaning opposing roller 18 with the intermediate transfer belt 11 interposed therebetween.

By bringing the spiral brush member 23 into contact with the cleaning opposing roller 18 with the intermediate transfer belt 11 interposed therebetween, the contact pressure of the spiral brush member 23 against the intermediate transfer belt 11 can be increased. In addition, the effect of adhering the filming substance by the toner can be enhanced, and the effect of removing the filming can be enhanced.

Further, the belt cleaning device 21 has a sealing member 24 for preventing the toner scattered from the spiral brush member 23 from leaking to the belt cleaning device side.

The spiral brush member 23 is rotated in the direction of the arrow C in the figure by the drive mechanism, and moves on the surface in the opposite direction (counter direction) to the moving direction of the intermediate transfer belt 11 at the contact position with the intermediate transfer belt 11 . is driven to rotate.

FIG. 9 is a perspective view showing part of the spiral brush member 23. FIG.
As shown in FIG. 9, the spiral brush member 23 has a brush portion 23a in which brush fibers are helically flocked on the outer circumference of the shaft member, and a spiral non-brush portion 23b in which the bristles are not flocked. . Brush fibers may be either conductive or insulating. Suitable fiber materials include polyester, acrylic, rayon, and nylon. In this embodiment, conductive polyester is used. Also, the flocking density is preferably 5 to 15 [10,000/inch ² ]. If the flocking density is too low, the ability to remove filming will decrease. On the other hand, if it is too high, the toner is retained too much, resulting in serious toner scattering. Also, the length of the pile is preferably 4 to 7 [mm]. In this embodiment, 5 [mm] is used. Further, in the present embodiment, only one helical brush portion 23a is provided on the outer periphery of the shaft member, but a plurality of helical brush portions may be provided.

FIG. 10 is a perspective view showing the intermediate transfer belt 11 and the spiral brush member 23 viewed from the cleaning blade 22 side.
In FIG. 10, the filming of the intermediate transfer belt 11 is displayed with gradation. Areas where filming is worse are displayed in white, and areas where filming is not occurring are displayed in black.
Since the filming grows as it is stretched in the direction of belt movement by the cleaning blade 22, it becomes streaks extending in the direction of belt movement. In addition, depending on the image pattern, there are areas where filming is bad and areas where filming is not so much occurring, and a striped pattern of filming is produced on the intermediate transfer belt. A slight step is formed at the end of the portion where the filming is poor.

As shown in FIG. 10, the toner T held back by the cleaning blade 22 is rubbed against the surface of the intermediate transfer belt by the spiral brush member 23 to remove filming while moving in the direction of arrow B in the drawing. . Then, when it moves to the right end in the drawing, it drops into the waste toner collection path 61 and is sent to the waste toner bottle.

As shown in FIG. 10, the filming grows along the direction of belt movement, and thus forms streaks. By rotating the spiral brush member 23, the brush portion 23a rubs in a substantially oblique direction with respect to the moving direction of the belt. Therefore, the sliding friction force of the brush portion works in the direction of the spiral axis (the direction perpendicular to the moving direction of the belt), and the shearing force in the direction of the spiral axis is generated. Further, since the toner is transported in the direction of the spiral axis by the spiral brush member, the friction force of the toner acts in the direction of the spiral axis. As a result, the brush portion 23a and the toner rubbing force (shearing force) acts from the streak-like filming end portion, which is slightly stepped, and the filming is more easily peeled off from the intermediate transfer belt, and the filming is improved. can be removed. This can eliminate significant axial differences in filming.

Further, the end portion of the brush portion 23a of the spiral brush member 23 (the boundary portion with the non-brush portion 23b) freely falls on the non-brush portion 23b, thereby widening the oblique rubbing range of the brush portion 23a. be able to.

In the first place, striped pattern filming occurs as a result of image pattern dependence, in which the filming does not deteriorate where the toner input is large, but the filming deteriorates where the toner input is small. The spiral brush member 23 conveys the toner on the intermediate transfer belt in the direction of the spiral axis (in the belt width direction), so that the toner can be evenly distributed on the intermediate transfer belt in the belt width direction, thereby forming an image. It is possible to suppress the occurrence of striped pattern filming that occurs as a result of pattern dependency.

Further, in this embodiment, as indicated by arrow C in the drawing, the spiral brush member 23 is surface-moved in the opposite direction (counter direction) to the moving direction of the intermediate transfer belt 11 at the contact position with the intermediate transfer belt 11 . It is driven to rotate like this. By rotating the spiral brush member 23 in the counter direction, the speed difference between the spiral brush member 23 and the intermediate transfer belt 11 can be increased compared to the case of rotating in the trailing direction opposite to the counter direction. can be done. Thereby, the sliding friction force of the brush portion 23a of the spiral brush member 23 can be increased. Further, the scattering direction of the toner that scatters with the rotation of the spiral brush member can be set to the upstream side in the belt moving direction. As a result, the toner scattered along with the rotation of the spiral brush member 23 can be input to the spiral brush member 23 again by driving the belt, thereby contributing to filming removal.

However, when the toner input to the spiral brush member 23 is only residual toner remaining on the intermediate transfer belt 11 without being transferred to the recording paper by the secondary transfer roller 51, the toner input to the spiral brush member 23 is The amount of toner used was small, and the polishing effect and collection effect of the toner were insufficient. Therefore, in this embodiment, an input mode is provided in which an untransferred toner image that is not secondarily transferred to the recording paper, which is a transfer receiving member, is input to the spiral brush member 23 . As a result, the amount of toner conveyed by the spiral brush member 23 in the direction perpendicular to the belt moving direction is increased, the polishing effect of the toner can be enhanced, and the filming removal capability of the spiral brush member can be enhanced.

In this embodiment, the input mode is a process control operation as an image density correction mode.

In the example shown in FIG. 11, the gradation pattern 62 is formed on the upstream side of the spiral brush member 23 in the toner conveying direction (arrow B direction in the figure) outside the paper passing area α on both sides of the intermediate transfer belt 11 . . The gradation pattern 62 formed on the intermediate transfer belt 11 is transferred without being secondarily transferred onto the recording paper, and is input to the upstream side of the spiral brush member 23 in the toner transfer direction. In this manner, by inputting the gradation pattern 62 as an untransferred toner image to the upstream side of the spiral brush member 23 in the toner conveying direction, one end of the belt (upstream in the toner conveying direction) is shifted to the other end (toner conveying direction). The surface of the intermediate transfer belt 11 can be polished and the filming substance can be collected with the toner that has formed the gradation pattern up to the direction downstream), and the toner can be used efficiently.

In addition, by forming a gradation pattern, which is an untransferred toner image, outside the paper-passing area, process control can be executed without pausing the image forming operation, which can lead to downtime of the apparatus. do not have.

In this embodiment, the gradation pattern 62 consisting of 10 toner patches for each color, 40 toner patches in total, is created outside the paper passing area α. Also, the gradation pattern is formed at least within the area where the brush fibers of the spiral brush member 23 come into contact with the intermediate transfer belt. This suppresses the generation of toner remaining on the intermediate transfer belt without being conveyed to the end portion of the belt by the spiral vertical brush member.

In the present embodiment, process control is performed once for every 20 images, but the timing of process control (the timing of inputting the untransferred toner image to the spiral brush member) is set appropriately. It is a thing.

FIG. 12 is a diagram showing another example of the gradation pattern formed on the intermediate transfer belt 11. As shown in FIG.
In the example shown in FIG. 12, gradation patterns 62 are formed outside the paper passing area α on both sides of the intermediate transfer belt 11 . By forming the gradation pattern 62 at a plurality of locations in the width direction of the intermediate transfer belt 11 in this way, it is possible to correct variations in toner density in the main scanning direction and improve the accuracy of process control.

13A and 13B are diagrams showing still another example of the gradation pattern formed on the intermediate transfer belt 11. FIG.
FIG. 13 shows an example of creating a gradation pattern inside the paper passing area α. In FIG. 13, a toner patch is formed in the paper interval β. In addition, by forming the toner patch at the upstream end of the spiral brush member in the paper passing area as much as possible in the toner direction, the surface of the intermediate transfer belt 11 is covered with the gradation pattern toner from one end to the other end of the paper passing area. can be polished.

Further, it is preferable to add a small amount of an inorganic abrasive such as cerium oxide or strontium titanate to the toner. By adding an abrasive to the toner, the abrasive effect of the toner on the surface of the intermediate transfer belt can be enhanced, and the filming removal efficiency can be improved.

In this embodiment, the input mode is a process control operation as an image adjustment mode, but a mode for inputting an untransferred toner image to the spiral brush member may be provided separately from the process control operation. Further, the input mode may be a refresh mode that is executed when an image with a small image area continues. The refresh mode is an operation in which the image forming operation with a small image area is continued, and the degraded toner, which remains in the developing device for a long time and has deteriorated toner charging characteristics, is forcibly ejected from the developing device onto the photoreceptor. When the refresh mode is executed, a toner consumption pattern is created as a toner pattern between images (between sheets) on the photosensitive member. This toner consumption pattern is transferred to the intermediate transfer belt and input to the spiral brush member 23 .

Next, evaluation tests conducted by the applicant will be described.
In the evaluation test, an intermediate transfer belt (glossiness: about 20) with filming at a level that hindered process control was set in a test machine equipped with the spiral brush member described above. Then, 10,000 sheets (10K sheets) were tested under conditions 1 to 5 shown below. After 5000 sheets (5K sheets) and 10000 sheets (10K sheets) were fed, the intermediate transfer belt was taken out and the glossiness of the surface of the intermediate transfer belt was measured.

Condition 1: The paper feed test was performed under the conditions that the image area ratio was 0%, the periodical toner input to the upstream side of the spiral brush member in the toner conveying direction was not performed, and the toner was not input to the spiral brush member at all. did.

Condition 2: A paper feed test was performed under the same conditions as Condition 1, except that an untransferred toner image was periodically input to the upstream side of the spiral brush member in the toner conveying direction. The untransferred toner image input to the upstream side of the spiral brush member in the toner conveying direction is a toner patch consisting of toner patches of 10 [mm]×15 [mm] for each color and a toner adhesion amount of 0.4 [mg/cm ² ]. It's a pattern. In addition, this toner pattern was created once every 10 sheets passed, at the sheet interval timing.

Condition 3: A paper feed test was performed under the same conditions as Condition 1 except that the image area ratio was set to 5% and the transfer residual toner was input to the spiral brush member.

Condition 4: A paper feeding test was performed under the same conditions as Condition 2, except that the image area ratio was set to 5% and the untransferred toner was input to the spiral brush member.

Condition 5: A paper threading test was performed under the same conditions as Condition 4, except that the spiral brush member was not opposed to the opposed cleaning roller via the intermediate transfer belt.

Table 1 below shows various conditions and results. FIG. 14 is a graph showing the relationship between the number of sheets passed under each condition and the glossiness of the intermediate transfer belt 11 . The dashed line shown in FIG. 14 is the glossiness at a level that does not interfere with process control, and the two-dot chain line is the glossiness of a new intermediate transfer belt.

As can be seen from Table 1 and FIG. 14, under condition 1 in which no toner was input to the spiral brush member, the glossiness of the intermediate transfer belt after passing 10,000 sheets was 25, and only 5 was recovered. . Further, under condition 3 in which the residual toner was input to the spiral brush member, the intermediate transfer belt had a glossiness of 50 after passing 10,000 sheets.

Under condition 2, in which the untransferred toner image was periodically input to the upstream side of the spiral brush member in the toner conveying direction, the glossiness of the intermediate transfer belt recovered to 80 after passing 10,000 sheets of paper, which hindered process control. The glossiness of the intermediate belt was restored to a level that does not cause deterioration.

Under condition 4, in which the amount of residual toner and the amount of untransferred toner image are input, the glossiness has already recovered to a level that does not interfere with process control after 5,000 sheets have been passed, and 10,000 sheets have been passed. After paper, the glossiness of the intermediate transfer belt recovered to 130.

Further, in condition 5, in which the spiral brush member was not opposed to the cleaning facing roller via the intermediate transfer belt, 10,000 toner images were obtained even though the remaining toner image and the untransferred toner image were input. The glossiness of the intermediate transfer belt after sheet feeding was 30, and only 10 glossiness was recovered.

From the above evaluation test, it can be seen that the filming removing effect at the brush portion of the spiral brush member is almost negligible, and that the filming removing effect is remarkably improved by the presence of the toner. In particular, it is found that inputting the untransferred toner image to the spiral brush member is most effective for removing filming. It has also been found that having an opposing roller behind the contact area of the helical brush member is important in enhancing toner removal.

Additives such as silica are attached to the surface of the toner in order to ensure its fluidity, prevent aggregation, and ensure charging performance. The polishing effect of the silica and other additives removes the filming from the intermediate transfer belt. In addition to the above functions, the following functions are considered to be highly effective in removing filming. That is, the additive falls off every time the agitation stress in the developing device, the development process to the photosensitive member, and the transfer process are passed through. Therefore, the toner that reaches the cleaning device has a reduced amount of additive on the surface. Since the toner itself is a resin and is softer than silica, which is an inorganic substance, it is considered that the toner with a small amount of additive adheres and collects the filming substance such as silica on the transfer belt. In this way, the toner has a function of recovering filming in addition to polishing the surface of the intermediate transfer belt, so it is considered that the filming removal effect is high.

On the other hand, when there is no toner input to the spiral brush member as in Condition 1, the filming substance removed by the brush portion 23a of the spiral brush member 23 is not collected, and the filming substance is removed by the cleaning blade 22. It is considered that the glossiness was hardly recovered because the toner was again rubbed against the intermediate transfer belt at , and re-adhered to the intermediate transfer belt 11 . In particular, in this embodiment, the belt cleaning device 21 is arranged above the intermediate transfer belt, and the filming removed by the spiral brush member stays on the intermediate transfer belt, so that the cleaning blade tends to reattach the filming. , it is considered that the glossiness hardly recovered.

In addition, in the configuration in which only the untransferred toner is input to the spiral brush member 23 as in Condition 3, the amount of toner is not small, and the removed filming material cannot be sufficiently recovered with the toner. It is thought that

On the other hand, under conditions 2 and 4, in which an untransferred toner image was input to the spiral brush member 23, the removed filming substance could be recovered well with toner, and the glossiness could be restored to a level that does not hinder process control. Conceivable. Therefore, by periodically inputting an untransferred toner image to the spiral brush member 23, filming can be effectively suppressed.

The reason why it is important to have the opposite roller on the back side of the contact area of the spiral brush member is considered as follows. In other words, the toner adhered to the brush cannot adhere to the filming substance on the surface of the belt only by contacting the filming substance on the belt surface. This is presumably because when the toner is pressed against the material by the brush, the toner adheres to itself the belt-like filming material as described above and can be collected.

Next, toner will be described. In order to improve image quality, it is preferable to use a polymerized toner produced by a suspension polymerization method, an emulsion polymerization method, or a dispersion polymerization method, which facilitates high circularity and small particle size. In particular, it is preferable to use a polymerized toner having a circularity of 0.97 or more and a volume average particle diameter of 5.5 [μm] or less. By using particles having an average circularity of 0.97 or more and a volume average particle size of 5.5 [μm], an image with higher resolution can be formed.

The "circularity" referred to here is the average circularity measured by a flow type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics Co., Ltd., trade name). Specifically, 0.1 to 0.5 [ml] of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersing agent to 100 to 150 [ml] of water from which impure solids have been previously removed in a container. Then, about 0.1 to 0.5 [g] of a measurement sample (toner) is added. After that, the suspension in which the toner is dispersed is subjected to dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser so that the concentration of the dispersion becomes 3000 to 1 [10,000 particles/μl]. to measure the shape and distribution of the toner. Then, based on this measurement result, C2/C1 is obtained when C1 is the outer peripheral length of the actual toner projection shape, S is the projected area, and C2 is the outer peripheral length of a perfect circle showing the same area as the projected area S. The average value was taken as the degree of circularity.

Further, a toner suitable for use in color printers is obtained by the following method. That is, a polyester prepolymer having a functional group containing at least a nitrogen atom, a toner material liquid prepared by dispersing a polyester, a colorant, and a release agent in an organic solvent are mixed in an aqueous solvent for cross-linking and elongation reactions. Allow at least one reaction.

In this embodiment, the spiral brush member is used. However, as described above, it is possible to sandwich the toner between itself and the opposing roller and to convey the toner on the intermediate transfer belt in the belt width direction. I wish I had. Therefore, a rotating shaft may be spirally wound with a polyurethane member or a rubber material (for example, EPDM). Even with such a configuration, the toner can be held between the members wound around the rotating shaft, and the toner on the intermediate transfer belt can be transported in the belt width direction. Further, the toner can be pressed against the filming substance of the intermediate transfer belt by a member wound around the rotation shaft, such as a polyurethane member or a rubber material, so that the filming substance can adhere to the toner.

Also, instead of the spiral brush member, a rubber roller having spiral grooves formed on the surface thereof may be used. Even with such a configuration, the toner can be held in the spiral grooves and conveyed in the belt width direction. Further, the toner enters between the rubber roller and the intermediate transfer belt, and the rubber roller can press the toner against the filming substance of the intermediate transfer belt 11, so that the toner can adhere to the filming substance.

Also, in this embodiment, filming removal on the intermediate transfer belt 11 has been described, but the filming removal on the photoreceptor 1 can also be applied. The toner collected by photoreceptor cleaning also has silica falling off from the agitation stress in the developer and when the toner is developed from the developer onto the photoreceptor, resulting in toner that is not completely covered with silica. there is Therefore, the filming of the photoreceptor is effectively suppressed by providing the spiral brush member in front of the photoreceptor cleaning blade and periodically inputting the untransferred toner image to the spiral brush member. be able to.

What has been described above is only an example, and each of the following aspects has a unique effect.
(Aspect 1)
A color printer equipped with a cleaning device such as a belt cleaning device 21 that cleans residual toner remaining on an image bearing member such as an intermediate transfer belt 11 without being transferred onto a transfer receiving member such as recording paper with a cleaning member such as a cleaning blade 22. 100, the cleaning device has a conveying member such as a spiral brush member 23 for conveying the toner on the image carrier in a direction orthogonal to the surface moving direction of the image carrier. It has an input mode for inputting an untransferred toner image.
Since the toner on the image carrier rubs against the surface of the image carrier, the surface of the image carrier can be polished by the toner, and an effect of removing filming on the surface of the image carrier can be expected. Furthermore, the removed filming substance can adhere to itself and can be collected, and reattachment of the removed filming substance to the image carrier can be suppressed.
Further, as in the image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 2002-200010, the toner on the image carrier is transported in a direction orthogonal to the surface movement direction of the image carrier by a spiral brush member serving as a transport member. A shearing force can be applied by the toner to the ends of the streak-like filming extending in the movement direction of the surface of the body, and the effect of removing the filming can be enhanced. Further, the toner can be distributed evenly in the direction perpendicular to the surface movement direction of the image carrier, and the polishing effect of the toner and the filming substance recovery can be achieved evenly in the direction perpendicular to the surface movement direction of the image carrier. effect can be obtained.
However, in the image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 2002-200012, the toner input to the spiral brush member as the conveying member is the residual toner after the transfer, and the amount of the toner is very small. Therefore, the above effects of the toner are insufficient.
Therefore, in mode 1, by providing an input mode for inputting an untransferred toner image to the conveying member, the amount of toner input to the conveying member can be made larger than that disclosed in Japanese Patent Application Laid-Open No. 2002-200013. Therefore, the effect of polishing the surface of the image bearing member with the toner and the effect of recovering the filming substance can be sufficiently obtained, and filming can be better suppressed as compared with the method disclosed in Japanese Patent Laid-Open No. 2002-200012.

(Aspect 2)
In Mode 1, the untransferred toner image is formed at the most upstream position in the conveying direction in which the conveying member such as the spiral brush member 23 conveys the toner on the image carrier such as the intermediate transfer belt 11 .
According to this, as described in the embodiment, the toner of the untransferred toner image is used to polish the surface of the image carrier and recover the filming substance from one end to the other end in the surface moving direction of the image carrier. It is possible to use the toner efficiently.

(Aspect 3)
In mode 1 or 2, in the input mode, an image density detection toner image such as the gradation pattern 62 is formed on an image carrier such as the intermediate transfer belt 11, and the toner adhesion amount of the image density detection toner image is detected. This is an image adjustment mode such as a process control operation for image density adjustment.
According to this, image adjustment and input of an untransferred toner image to a conveying member such as a spiral brush member can be performed.

(Aspect 4)
In mode 3, a plurality of toner images for image density detection such as a gradation pattern are formed at different positions in the conveying direction of the toner of the image carrier of the conveying member such as the spiral brush member 23 .
According to this, as described in the embodiment, it is possible to detect variations in the toner density in the conveying direction. As a result, it is possible to correct variations in toner density in the conveying direction, and to perform good image adjustment.

(Aspect 5)
In any one of modes 1 to 4, the conveying member such as the helical brush member 23 has a rotating shaft and a screw brush formed so as to wind around the rotating shaft.
According to this, as described in the embodiment, the non-brush portion can hold the toner and convey the toner in the direction orthogonal to the surface moving direction of the image carrier, and the brush can move the toner to the image carrier. can be pressed against the surface of the image carrier, the filming substance can be well adhered to the toner, and the filming on the image carrier can be recovered.

(Aspect 6)
In any one of modes 1 to 4, the conveying member has a rotating shaft and a polyurethane member spirally wound around the rotating shaft.
Even with such a configuration, as described in the embodiment, the toner can be held between the polyurethane members and conveyed in the direction orthogonal to the surface movement direction of the image carrier, and the polyurethane member can carry the toner as an image. It can be pressed against the surface of the body, the filming substance can be well adhered to the toner, and the filming on the image carrier can be recovered.

(Aspect 7)
In any one of Modes 1 to 4, the conveying member is a rubber roller having spiral grooves formed on its surface.
Even with such a configuration, as described in the embodiments, the toner can be held in the spiral grooves and conveyed in the direction orthogonal to the surface movement direction of the image carrier, and the toner can be transported on the surface of the rubber roller. can be pressed against the surface of the image carrier, the filming substance can adhere well to the toner, and the filming on the image carrier can be recovered.

(Aspect 8)
In any one of modes 1 to 7, the image carrier is an image carrier belt such as an intermediate transfer belt 11 stretched by a plurality of tension rollers, and the conveying member moves the surface of the image carrier belt more than the cleaning member. It is arranged on the upstream side in the direction and faces, with the image bearing belt interposed therebetween, a cleaning facing roller facing the cleaning member with the image bearing belt interposed therebetween.
According to this, as described in the embodiment, the toner held back by the cleaning member can be conveyed in the direction orthogonal to the surface moving direction of the image carrier and transferred to the waste toner collection path. Further, by facing the conveying member to the cleaning facing roller with the image bearing belt interposed therebetween, the filming substance can be adhered to the toner well, and the filming substance on the image bearing member can be well collected. .

(Aspect 9)
In the eighth aspect, the push-down roller 25 that pushes down the image carrier belt inward is arranged on the upstream side of the conveying member such as the spiral brush member 23 in the surface movement direction of the image carrier belt.
According to this, as described in the embodiment, the range in which the image carrier belt is wound around the cleaning facing roller can be widened, and the cleaning member and the conveying member can be easily arranged to face the cleaning member with the image carrier belt interposed therebetween. It can be opposed to a roller.

(Mode 10)
In mode 8 or 9, the conveying member such as the spiral brush member 23 also serves as a waste toner conveying member that conveys the residual toner removed by the cleaning member such as the cleaning blade 22 to the outside of the cleaning device.
According to this, the residual toner removed by the cleaning member can be used for polishing the surface of the image carrier and for recovering filming substances. In addition, the number of parts can be reduced and the cost of the apparatus can be reduced as compared with the case where a waste toner conveying member for conveying the waste toner to the outside of the cleaning device is separately provided.

(Aspect 11)
In any one of Aspects 1 to 10, the toner contains an abrasive.
According to this, as described in the embodiment, when the surface of the image carrier is conveyed by the conveying member such as the spiral brush member 23 in the direction orthogonal to the moving direction of the image carrier surface, the surface of the image carrier can be satisfactorily maintained. can be polished.

(Aspect 12)
In aspect 11, the abrasive is strontium titanate.
According to this, as described in the embodiment, the polishing effect of the toner on the surface of the image carrier can be enhanced.

Reference Signs List 1: Photoreceptor 3: Image forming section 6: Process cartridge 11: Intermediate transfer belt 15: Intermediate transfer unit 18: Cleaning facing roller 21: Belt cleaning device 22: Cleaning blade 23: Spiral brush member 23a: Brush portion 23b: Non Brush portion 24 : Sealing member 25 : Push-down roller 61 : Waste toner collection path 62 : Gradation pattern 100 : Color printer 111 : Optical sensor

JP-A-2003-287979

Claims (10)

An image forming apparatus equipped with a cleaning device that cleans residual toner remaining on an image bearing member without being transferred to a transfer receiving member with a cleaning member,
The image carrier is an intermediate transfer belt having a Martens hardness of 180 [N/mm ² ] or less stretched over a plurality of tension rollers,
The cleaning device has a conveying member that conveys the toner on the intermediate transfer belt in a direction orthogonal to a surface movement direction of the intermediate transfer belt,
an image adjustment mode in which a toner image for image density detection is formed on the intermediate transfer belt and a toner adhesion amount of the toner image for image density detection is detected to adjust the image density;
The toner image for image density detection is formed outside the paper passing area on both sides of the intermediate transfer belt , and outside the paper passing area on the upstream side of the conveying direction in which the toner on the intermediate transfer belt is conveyed by the conveying member, An image forming apparatus, wherein the toner image for image density detection is input to the conveying member as an untransferred toner image. The image forming apparatus according to claim 1,
An image forming apparatus, wherein a plurality of toner images for image density detection are formed at different positions in a conveying direction in which toner is conveyed on the intermediate transfer belt of the conveying member. 3. The image forming apparatus according to claim 1, wherein
An image forming apparatus, wherein the conveying member has a rotating shaft and a screw brush wound around the rotating shaft. The image forming apparatus according to any one of claims 1 to 3,
An image forming apparatus, wherein the conveying member has a rotating shaft and a polyurethane member spirally wound around the rotating shaft. The image forming apparatus according to any one of claims 1 to 3,
1. An image forming apparatus according to claim 1, wherein said conveying member is a rubber roller having spiral grooves formed on its surface. The image forming apparatus according to any one of claims 1 to 5 ,
The conveying member is arranged upstream of the cleaning member in the surface movement direction of the intermediate transfer belt , and sandwiches the intermediate transfer belt between cleaning facing rollers facing the cleaning member with the intermediate transfer belt therebetween. An image forming apparatus characterized by facing each other. The image forming apparatus according to claim 6,
An image forming apparatus, comprising: a pressing roller that presses down the intermediate transfer belt inward is arranged on the upstream side of the conveying member in the surface movement direction of the intermediate transfer belt. The image forming apparatus according to claim 6 or 7,
The image forming apparatus, wherein the conveying member also serves as a waste toner conveying member for conveying residual toner removed by the cleaning member to the outside of the cleaning device. The image forming apparatus according to any one of claims 1 to 8,
The image forming apparatus, wherein the toner contains an abrasive. The image forming apparatus according to claim 9,
The image forming apparatus, wherein the abrasive is strontium titanate.

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