JP4821099B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer or a copier that employs an electrophotographic method, and in particular, residual transfer toner remaining on an image carrier such as a photosensitive drum or an intermediate transfer member is temporarily stored by a temporary toner holding member. In particular, the present invention relates to a cleaning cycle control technique in which the cleaning cycle is held, transported and discarded at a predetermined timing.

JP-A-4-29283 JP 2001-074448 A JP 2002-372902 A

  Conventionally, in image forming apparatuses such as printers and copiers that employ this type of electrophotographic method, a toner image is formed on the surface of a photosensitive drum in accordance with image data, and then the toner image is transferred to a recording sheet. The transferred toner image is heat-fixed on a recording sheet to obtain a recorded image. Also, in recent full-color printers and full-color copying machines, the toner image formed on the photosensitive drum is primarily transferred to an intermediate transfer member, and yellow, magenta, cyan, and black toners are transferred onto the intermediate transfer member. It is also known to form a full-color recording image by superimposing images and collectively transferring these synthetic toner images onto a recording sheet.

  The toner image transfer efficiency is affected by changes in the resistance value of the recording sheet and the intermediate transfer member due to changes in the surface condition of the photosensitive drum and intermediate transfer member, and temperature and humidity. The toner remains on the surface of the photosensitive drum or the intermediate transfer body, which is the transfer source of the toner image, even after the transfer of the toner image. For this reason, conventionally, for image carriers such as photosensitive drums and intermediate transfer members, a cleaning device is provided on the downstream side of the transfer portion of the toner image to remove residual toner prior to the next toner image formation. Has been done.

  As this type of cleaning device, as disclosed in Japanese Patent Laid-Open No. 4-29283, a brush roll planted with countless rubbing hairs is brought into contact with an image carrier such as a photosensitive drum, A configuration is known in which a potential difference corresponding to the charging polarity of the toner is applied between the image carrier and the residual toner is electrostatically adsorbed from the image carrier to the brush roll. There is also known a cleaning device configured such that a soft roll made of a soft elastic body instead of a brush roll is brought into contact with the image carrier, and residual toner is electrostatically adsorbed from the image carrier to the surface of the soft roll. .

  In any configuration, there is a limit to the amount of toner that can be held by the brush roll or soft roll, and if a large amount of toner is held in contact with the image carrier, the cleaning capability itself will be reduced. For this reason, a so-called detoning mechanism for separating and collecting toner from these brush rolls and soft rolls is required. For example, for a brush roll, a protrusion called a flicker bar is provided within the rotation range of the rubbing hair, and the toner is forcibly knocked off from the brush roll by hitting the rubbing hair against the flicker bar. This is collected in a collection box using a transport means such as an auger.

  However, when such a detoning mechanism is provided, the cleaning device becomes large. In particular, in a so-called tandem color image forming apparatus provided with a photosensitive drum for each of four colors of yellow, magenta, cyan and black, it is necessary to provide a cleaning device for each photosensitive drum. In an image forming apparatus that transfers a toner image to a recording sheet via an intermediate transfer member, it is necessary to provide a cleaning device for the intermediate transfer member. For this reason, in miniaturization of color printers, color copying machines, etc., it is extremely important how the cleaning device is miniaturized and simplified.

  From this point of view, the color image forming apparatus disclosed in Japanese Patent Laid-Open Nos. 2001-074448 and 2002-372902 is provided with a brush roll for removing residual toner for each of the plurality of intermediate transfer members. However, no detoning mechanism is provided for these brush rolls, and the toner adhering to each brush roll is collected and collected in one place at the end of the print job. Specifically, the brush roll provided on each intermediate transfer member cleans and holds the residual toner during a print job so as not to interfere with toner image formation and transfer, while at the end of the print job. The toner held by these brush rolls is discharged onto the intermediate transfer member and transferred to the downstream roll in the same manner as the transfer of the toner image, and the recovery provided for the final roll. It is configured so that it can be collected at once by the device.

  In this way, when the toner held by each brush roll is collected in one place and collected at once, the cleaning device itself for cleaning each image carrier becomes very simple and must be cleaned. In a color image forming apparatus having a large number of image carriers that must be reduced, the size can be reduced extremely advantageously.

  However, the conventional technique has the following problems. That is, in image forming apparatuses such as printers and copiers employing the above-described electrophotographic method, functional device parts such as a developing unit for developing a photosensitive drum or an electrostatic latent image are worn and deteriorated over time, and recording is performed. Since it affects the image quality of the image, it is necessary to set the replacement time of these parts and replace the parts regularly. In recent printers, etc., parts to be replaced such as the photosensitive drum and developing device constitute a unit as a process cartridge in order to reduce the trouble of replacing each part individually. By doing so, a plurality of parts can be exchanged together. The progress of wear and deterioration of each part of the process cartridge varies depending on the usage environment such as the number of continuous recording sheets, the image density of recorded images, temperature, and humidity in one print job. Although it is difficult to define the image clearly, generally, it is assumed that the cartridge is used under standard use conditions, and the cumulative number of recording sheets has simply reached the predetermined number. Whether or not to replace the process cartridge is determined based on whether or not it is.

  As the standard use conditions described above, it is assumed that the number of continuous recording sheets in a single print job is 3 or 4, but before and after each print job, preparation for an image forming operation is performed. There are processing and end processing, and in these preparation processing and end processing, the process cartridge is driven for a fixed time regardless of the number of recording sheets to be passed in each print job. For this reason, if the actual continuous sheet passing number of recording sheets in each print job is less than the assumed use condition, that is, 3 to 4 sheets, the time required for the print job preparation process and end process will be reduced. Since it increases relative to the paper time, the life of parts such as the photosensitive drum included in the process cartridge is shortened accordingly, and the process cartridge must be replaced early in order to maintain the image quality of the recorded image. I have to.

  In particular, in the apparatus configured to clean the transfer residual toner on the intermediate transfer member and the photosensitive drum using a brush roll not equipped with a detoning mechanism, such as the color image forming apparatus described above, the print job end process is performed. Subsequently, a collection sequence for collectively collecting the transfer residual toner captured by the brush roll is performed, and the length of the collection sequence is 3 or 4 consecutive recording sheets in one print job. It is determined assuming a certain case. For this reason, if the actual number of continuous sheets of recording sheets in each print job is less than the estimated number of sheets to be passed, the length of the collection sequence will be longer than the amount of captured toner remaining on the brush roll during one print job. The time required to drive the image carrier is unnecessarily increased regardless of the formation of the recorded image. Therefore, the image forming apparatus provided with such a brush roll has a problem that the actual life of the process cartridge is increasingly different from the standard life expected.

  Accordingly, the present applicant has solved the above-mentioned problems and cleaned the image carrier by cleaning the image carrier such as a photosensitive drum or an intermediate transfer member with a toner temporary holding member that does not have a detoning mechanism. It is possible to reduce the size of the apparatus even in colorization by simply configuring the mechanism, and to suppress the time for driving the image carrier regardless of the formation of the recorded image from being unnecessarily long, An image forming apparatus capable of preventing the life of the process cartridge from being extremely shortened has already been proposed (Japanese Patent Application No. 2003-137161).

  The image forming apparatus according to Japanese Patent Application No. 2003-137161 includes a toner temporary holding member that removes unnecessary toner adhering to the surface of the image carrier and temporarily holds the toner, and a toner image is formed and transferred. After that, in the image forming apparatus configured to discharge the unnecessary toner held by the temporary toner holding member onto the image carrier and execute a collection sequence for capturing by the final collection unit to end the print job. It is checked whether or not the number of recording sheets passed in one print job is less than a preset standard number, and if it is determined that the number is less than the standard number, the print sequence is not performed at all. End the job or shorten the execution time of the collection sequence from the execution time for the standard number of sheets, thereby Reducing the dynamic time as possible, it is intended to prevent the shortening of the process cartridge in which the image bearing member is mounted.

  However, in the case of the image forming apparatus according to the above Japanese Patent Application No. 2003-137161, the collection sequence is performed at the same speed as the normal image formation cycle, but is applied to the image carrier when the collection sequence is performed. When the voltage value is relatively high, the potential difference between the image carrier and the toner temporary holding member in the collection sequence becomes large, and the toner captured from the toner temporary holding member is discharged and becomes clean. The frictional force resulting from the electrostatic attraction force at the portion where the temporary holding member comes into contact with the image carrier increases. For this reason, in the case of the image forming apparatus according to the above proposal, the toner temporary holding member rotates while the bristles of the brush constituting the toner temporary holding member rotate with the frictional force attached to the surface of the image carrier. When the force that moves the bristles in the rotational direction exceeds the frictional force against the surface of the image carrier, a so-called “stick-slip phenomenon” occurs in which the brush bristles repeatedly slip on the surface of the image carrier. The “stick-slip phenomenon” causes a problem that the entire toner temporary holding member resonates and noise is generated.

  In particular, when the number of image carriers to be cleaned is large and the toner transport path to be collected is long, such as a so-called tandem color image forming apparatus, the image on the upstream photosensitive drum or the like is used. Even after the collection sequence from the carrier is completed, all the image carriers and the temporary toner holding members are in rotation until the toner collection by the final collection unit is completed. The generation of abnormal noise caused by the “stick-slip phenomenon” lasted for a relatively long period of time and had the problem of being harsh.

  According to the studies by the present inventors, it has been found that the problem that this abnormal noise occurs is more likely to occur as the rotational speed of the image carrier is lower.

  Accordingly, the present invention has been made to solve the above-described problems of the prior art, and its object is to use a temporary toner holding member that does not have a detoning mechanism, such as a photosensitive drum or an intermediate transfer member. By cleaning the image carrier, the cleaning mechanism for the image carrier can be simply configured to reduce the size of the apparatus even in colorization. Another object of the present invention is to provide an image forming apparatus capable of preventing the generation of abnormal noise in the capture toner collection sequence.

In order to achieve the above object, the invention described in claim 1 forms a toner image corresponding to image information on an image carrier and uses the toner image formed on the image carrier for primary intermediate transfer. An image forming apparatus that executes a print job to be transferred to a recording sheet via an image carrier and an image carrier for secondary intermediate transfer,
A member that rotates following the image carrier to remove unnecessary toner adhering to the surface of the image carrier and temporarily holds the toner, the image carrier, an image carrier for primary intermediate transfer, a secondary intermediate A toner temporary holding member composed of a brush roll having a brush-like surface in contact with the image carrier for transfer is provided, and after the toner image is formed and transferred, it is unnecessary to be held on the toner temporary holding member. Depending on the potential difference between the toner temporary holding member and the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer image carrier, the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer In the image forming apparatus configured to discharge the image on the image carrier and execute a collection sequence captured by a final collection unit provided on the image carrier for secondary intermediate transfer to end the print job.
A voltage value applied to the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer image carrier when executing the recovery sequence is set so as to be relatively higher in order,
The recovery sequence is performed at a speed higher than a normal process speed capable of suppressing a stick-slip phenomenon generated between the image carrier and the temporary toner holding member among a plurality of set process speeds . together is rotated the toner temporary holding member of the toner temporary holding member and the primary intermediate transfer image carrier to said image bearing member and the primary intermediate transfer image carrier, the toner provisional the secondary intermediate transfer image carrier An image forming apparatus comprising a control unit that performs control by rotating a holding member .

According to a second aspect of the present invention, a toner image corresponding to image information is formed on an image carrier, and the toner image formed on the image carrier is converted into a primary intermediate transfer image carrier and a secondary image. An image forming apparatus that executes a print job to be transferred to a recording sheet via an intermediate transfer image carrier.
A member that rotates following the image carrier to remove unnecessary toner adhering to the surface of the image carrier and temporarily holds the toner, the image carrier, an image carrier for primary intermediate transfer, a secondary intermediate A toner temporary holding member composed of a brush roll having a brush-like surface in contact with the image carrier for transfer is provided, and after the toner image is formed and transferred, it is unnecessary to be held on the toner temporary holding member. Depending on the potential difference between the toner temporary holding member and the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer image carrier, the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer In the image forming apparatus configured to discharge the image on the image carrier and execute a collection sequence captured by a final collection unit provided on the image carrier for secondary intermediate transfer to end the print job.
A voltage value applied to the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer image carrier when executing the recovery sequence is set so as to be relatively higher in order,
The toner temporary holding member of the image carrier at the fastest process speed capable of suppressing the stick-slip phenomenon generated between the image carrier and the toner temporary holding member among the plurality of process speeds set in the collection sequence. And the toner temporary holding member of the image carrier for primary intermediate transfer is driven to rotate following the image carrier and the image carrier for primary intermediate transfer, and the toner temporary holding member of the image carrier for secondary intermediate transfer is rotated. An image forming apparatus comprising a control unit that performs control by driving.

The invention described in claim 3 is characterized in that only the initial predetermined time of the recovery sequence is executed at a speed faster than the normal process speed or at the fastest process speed. The image forming apparatus described.

  According to the present invention, by cleaning the image carrier such as the photosensitive drum and the intermediate transfer member with the toner temporary holding member that does not have the detoning mechanism, the cleaning mechanism for the image carrier can be simply configured, and the color carrier In addition, it is possible to reduce the size of the apparatus even in the case of the image forming, and it is possible to prevent the generation of abnormal noise in the collection sequence of the captured toner from the temporary toner holding member. Can be provided.

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

Embodiment 1
1 shows an image forming unit of a tandem type full-color printer as an image forming apparatus according to Embodiment 1 of the present invention, and FIG. 2 shows a tandem as an image forming apparatus according to Embodiment 1 of the present invention. A type full-color printer is shown. In addition, the arrow in FIG. 1 has shown the rotation direction of each rotation member.

  As shown in FIG. 1 and FIG. 2, the full-color printer 01 includes photosensitive drums (image carriers) 11, 12, 11 for yellow (Y), magenta (M), cyan (C), and black (K). Image forming units 1, 2, 3, 4 having 13, 14, and charging rolls (charging means) 21, 23, 24 for primary charging that are in contact with or close to these photosensitive drums 11, 12, 13, 14 The laser optical unit shown in FIG. 2 that writes an electrostatic latent image by irradiating laser beams 31, 32, 33, and 34 of yellow (Y), magenta (M), cyan (C), and black (K). (Latent image writing means) 03, developing device (developing means) 41, 42, 43, 44, and two of the four photosensitive drums 11, 12, 13, and 14 in contact with the photosensitive drums 11 and 12 The first primary intermediate transfer drum (image carrier) 51 and the second primary intermediate transfer drum (image carrier) in contact with the other two photosensitive drums 13 and 14 Body) 52, a secondary intermediate transfer drum (image carrier) 53 in contact with the first and second primary intermediate transfer drums 51, 52, and a transfer roll (transfer member) in contact with the secondary intermediate transfer drum 53 ) 60 and its main part is composed.

  As shown in FIG. 1, the photosensitive drums 11, 12, 13, and 14 are arranged in parallel to each other at a constant interval so as to have a common tangential plane m. Further, the first primary intermediate transfer drum 51 and the second primary intermediate transfer drum 52 are surfaces whose rotational axes are parallel to the photosensitive drums 11, 12, 13, and 14 and have predetermined symmetry planes as boundaries. They are arranged in a symmetrical relationship. Further, the secondary intermediate transfer drum 53 is arranged so that the rotation axis thereof is parallel to the photosensitive drums 11, 12, 13, and 14.

  Signals corresponding to the image information for each color are rasterized by an image processing unit (not shown) and input to the laser optical unit 03 shown in FIG. In the laser optical unit 03, yellow (Y), magenta (M), cyan (C), and black (K) laser beams 31, 32, 33, and 34 are modulated in accordance with image information, and the corresponding colors. The photosensitive drums 11, 12, 13, and 14 are irradiated to write an electrostatic latent image.

  Around each of the photosensitive drums 11, 12, 13, and 14, an image forming process for each color is executed by a well-known electrophotographic method. First, as the photoconductor drums 11, 12, 13, and 14, for example, photoconductor drums using an OPC photoconductor having a diameter of 24 mm are used. These photoconductor drums 11, 12, 13, and 14 are, for example, It is rotationally driven at a predetermined rotational speed. As shown in FIG. 3, the surfaces of the photosensitive drums 11, 12, 13, and 14 are applied with a DC voltage of about -800 V to charging rolls 21, 22, 23, and 24 as contact-type charging means. For example, it is charged to about -300V. The contact type charging means includes a roll type, a film type, a brush type, etc., but any type may be used. In this embodiment, a charging roll generally used in an electrophotographic apparatus in recent years is employed. Further, in order to charge the surfaces of the photosensitive drums 11, 12, 13, and 14, in this embodiment, a charging method in which only DC is applied is used, but a charging method in which AC + DC is applied may be used.

  Thereafter, the surfaces of the photosensitive drums 11, 12, 13, and 14 correspond to yellow (Y), magenta (M), cyan (C), and black (K) colors by a laser optical unit 03 as an exposure unit. The laser beams 31, 32, 33, and 34 are irradiated, and an electrostatic latent image corresponding to input image information for each color is formed. When the electrostatic latent image is written by the laser optical unit 03, the surface potential of the image exposure portion of the photosensitive drums 11, 12, 13, and 14 is discharged to about −60 V or less.

  Further, the electrostatic latent images corresponding to the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) formed on the surfaces of the photosensitive drums 11, 12, 13, and 14 are compatible. Are developed by the developing devices 41, 42, 43, and 44, and yellow (Y), magenta (M), cyan (C), and black (K) are provided on the photosensitive drums 11, 12, 13, and 14, respectively. Visualized as a toner image.

  In this embodiment, a magnetic brush contact type two-component development method is adopted as the developing devices 41, 42, 43, 44. However, the present invention is not limited to this development method. Of course, the present invention can be sufficiently applied to other development systems such as a contact development system.

The developing devices 41, 42, 43, and 44 are filled with two-component developers including yellow (Y), magenta (M), cyan (C), and black (K) toners and carriers, each having a different color. Has been. When the toner is replenished from the toner cartridges 04Y, 04M, 04C, 04K shown in FIG. 2, these replenishing toners 41, 42, 43, 44 are supplied to the auger 404 as shown in FIG. Is sufficiently agitated with the carrier and triboelectrically charged. Inside the developing roll 401, a magnet roll (not shown) having a plurality of magnetic poles arranged at a predetermined angle is fixed. By the paddle 403 that conveys the developer to the developing roll 401, the amount of the developer conveyed to the vicinity of the surface of the developing roll 401 is regulated by the developer amount regulating member 402. In this embodiment, the amount of the developer is 30 to 50 g / m ² , and the charge amount of the toner existing on the developing roll 401 at this time is approximately about −20 to 35 μC / g.

The toner used in the developing devices 41, 42, 43, 44 has a shape factor MLS2 defined by the following equation of 100 to 140, for example, MLS2 = 130, and an average particle size of 3 μm to 10 μm. So-called “spherical toner” is used.
MLS2 = {(absolute maximum length of toner particles) ² )}
/ {(Projection area of toner particles) × π × 1/4 × 100}

  The toner supplied onto the developing roll 401 is in the form of a magnetic brush composed of a carrier and toner by the magnetic force of the magnet roll, and this magnetic brush comes into contact with the photosensitive drums 11, 12, 13, and 14. ing. A developing bias voltage of AC + DC is applied to the developing roll 401 to develop the toner on the developing roll 401 into an electrostatic latent image formed on the photosensitive drums 11, 12, 13, and 14. It is formed. In this embodiment, the development bias voltage is about 4 kHz for AC, 1.5 kVpp, and about −230 V for DC.

  Next, the yellow (Y), magenta (M), cyan (C), and black (K) toner images formed on the photosensitive drums 11, 12, 13, and 14 are first primary images. The secondary transfer is electrostatically performed on the intermediate transfer drum 51 and the second primary intermediate transfer drum 52. The yellow (Y) and magenta (M) color toner images formed on the photoconductive drums 11 and 12 are formed on the first primary intermediate transfer drum 51 and cyan (on the photoconductive drums 13 and 14). The toner images of C) and black (K) are transferred onto the second primary intermediate transfer drum 52, respectively. Therefore, on the first primary intermediate transfer drum 51, the single color image transferred from either the photosensitive drum 11 or 12 and the two color toner images transferred from both the photosensitive drums 11 and 12 are superimposed. A double color image is formed. In addition, similar single-color images and double-color images are also formed on the second primary intermediate transfer drum 52 from the photosensitive drums 13 and 14.

  The surface potential necessary for electrostatically transferring the toner image from the photosensitive drums 11, 12, 13, 14 onto the first and second primary intermediate transfer drums 51, 52 is about +250 to 500V. It is. This surface potential is set to an optimum value depending on the charged state of the toner, the ambient temperature, and the humidity. As shown in FIG. 2, the ambient temperature and humidity are detected by an environmental sensor that detects the ambient temperature and humidity. As described above, when the charge amount of the toner is in the range of −20 to 35 μC / g and is in a normal temperature and humidity environment, the surface potential of the first and second primary intermediate transfer drums 51 and 52 is + 380V is desirable.

The first and second primary intermediate transfer drums 51 and 52 used in this embodiment have an outer diameter of 42 mm, for example, and a resistance value of about 10 ⁸ Ω. The first and second primary intermediate transfer drums 51 and 52 are cylindrical rotating bodies having a single layer or a plurality of layers whose surfaces are flexible or elastic, and are generally made of Fe, Al, or the like. A low resistance elastic rubber layer (R = 10 ² to 10 ³ Ω) typified by conductive silicone rubber or the like is provided on a metal pipe as a metal core as described above to a thickness of about 0.1 to 10 mm. Further, the outermost surfaces of the first and second intermediate transfer drums 51 and 52 are typically made of a high release layer (R = 10 ⁵ to 10 ⁹ Ω) and bonded with a silane coupling agent-based adhesive (primer). What is important here is the resistance value and the releasability of the surface, and the resistance value of the high release layer is about R = 10 ⁵ to 10 ⁹ Ω. It is not limited.

  The single-color or double-color toner images formed on the first and second primary intermediate transfer drums 51 and 52 in this way are electrostatically secondary-transferred onto the secondary intermediate transfer drum 53. Accordingly, a final toner image from a single color image to a quadruple color image of yellow (Y), magenta (M), cyan (C), and black (K) is formed on the secondary intermediate transfer drum 53. Will be.

  The surface potential necessary for electrostatically transferring the toner image from the first and second primary intermediate transfer drums 51 and 52 onto the secondary intermediate transfer drum 53 is about +600 to 1200V. This surface potential is the same as when the toner is transferred from the photosensitive drums 11, 12, 13, 14 to the first primary intermediate transfer drum 51 and the second primary intermediate transfer drum 52. Will be set to the optimum value. Further, since what is necessary for the transfer is a potential difference between the first and second primary intermediate transfer drums 51 and 52 and the secondary intermediate transfer drum 53, the first and second primary intermediate transfer drums 51 and 52 have different potentials. It is necessary to set the value according to the surface potential. As described above, the charge amount of the toner is in the range of −20 to 35 μC / g, and the surface potential of the first and second primary intermediate transfer drums 51 and 52 is +380 V in a normal temperature and humidity environment. The surface potential of the secondary intermediate transfer drum 53 is about +880 V, that is, the potential difference between the first and second primary intermediate transfer drums 51 and 52 and the secondary intermediate transfer drum 53 is + It is desirable to set it to about 500V.

The secondary intermediate transfer drum 53 used in this embodiment is formed to have the same outer diameter as that of the first and second primary intermediate transfer drums 51 and 52, for example, 42 mm, and the resistance value is set to about 10 ¹¹ Ω. . Similarly to the first and second primary intermediate transfer drums 51 and 52, the secondary intermediate transfer drum 53 is a cylindrical rotating body having a single layer or a plurality of layers whose surface is flexible or elastic. In general, a low resistance elastic rubber layer (R = 10 ² to 10 ³ Ω) typified by conductive silicone rubber or the like is formed on a metal pipe as a metal core made of Fe or Al. It is provided at about 0.1-10mm. Further, the outermost surface of the secondary intermediate transfer drum 53 is typically formed by forming a fluororubber in which fluororesin fine particles are dispersed as a high release layer having a thickness of 3 to 100 μm, and a silane coupling agent-based adhesive. (Primer). Here, the resistance value of the secondary intermediate transfer drum 53 needs to be set higher than that of the first and second primary intermediate transfer drums 51 and 52. Otherwise, the secondary intermediate transfer drum 53 will charge the first and second primary intermediate transfer drums 51, 52, making it difficult to control the surface potential of the first and second primary intermediate transfer drums 51, 52. Become. The material is not particularly limited as long as the material satisfies such conditions.

  Next, a final toner image from a single color image to a quadruple color image formed on the secondary intermediate transfer drum 53 is subjected to the tertiary transfer onto the recording sheet 100 passing through the paper conveyance path P by the final transfer roll 60. Transcribed. As shown in FIG. 2, the recording sheet 100 passes through a registration roller 90 through a paper feeding process from a paper feeding cassette 05 and is fed into a nip portion between the secondary intermediate transfer drum 53 and the transfer roll 60. After this final transfer process, the final toner image formed on the recording sheet 100 is fixed by heat and pressure by the fixing device 70, and is discharged onto a discharge tray T provided on the upper part of the full-color printer 01. A series of image forming processes is completed.

The final transfer roll 60 has, for example, an outer diameter of 20 mm and a resistance value of about 10 ⁸ Ω. The final transfer roll 60 is configured, for example, by providing a coating layer made of urethane rubber or the like on a metal shaft and coating it as necessary. The optimum voltage applied to the final transfer roll 60 varies depending on the ambient temperature, humidity, recording sheet type (resistance value, etc.) and the like, and is approximately +1200 to 5000V. In this embodiment, a constant current method is employed, and a current of about +10 μA is applied in a normal temperature and humidity environment to obtain a substantially appropriate transfer voltage (+1600 to 2000 V).

  When images are formed on both sides of the recording sheet 100, as shown in FIG. 2, the recording sheet 100 on which the image is formed on one side is not directly discharged onto the discharge tray T, but is turned upside down. In this state, the recording sheet 100 is conveyed again to the transfer section via the double-sided paper conveyance path 07, and an image is formed on the back surface of the recording sheet 100.

  In FIG. 2, reference numeral 08 denotes a paper feed roll that conveys a recording sheet 100 supplied from a manual feed tray (not shown), 09 denotes a control circuit, and 10 denotes a power supply circuit.

  By the way, in this embodiment, there is provided an image forming apparatus for forming a toner image corresponding to image information on an image carrier and executing a print job for transferring the toner image onto a recording sheet. A toner temporary holding member that removes unnecessary toner adhering to the toner and temporarily holds the toner, and after the toner image is formed and transferred, the unnecessary toner held on the toner temporary holding member is placed on the image carrier. In the image forming apparatus configured to finish the print job by executing a recovery sequence that is ejected and captured by a final recovery unit, at least a part of the recovery sequence is any one of a plurality of set process speeds. It is configured to include control means for controlling to execute at one or a speed different from the normal process speed.

  In this embodiment, the image forming apparatus executes a print job for forming a toner image corresponding to image information on an image carrier and transferring the toner image onto a recording sheet. A toner temporary holding member that removes unnecessary toner adhering to the toner and temporarily holds the toner, and after the toner image is formed and transferred, the unnecessary toner held on the toner temporary holding member is placed on the image carrier. In the image forming apparatus configured to execute the recovery sequence that is ejected and captured by the final recovery unit to end the print job, at least a part of the recovery sequence is the fastest among a plurality of set process speeds. Provide control means to control to run at a specific speed set faster than the process speed or normal process speed It has been made.

  In this embodiment, all of the collection sequences are executed at a speed higher than the normal process speed.

  That is, in the full color printer according to this embodiment, as shown in FIG. 1, toner is applied to each of the photosensitive drums 11, 12, 13, 14, the primary intermediate transfer drums 51, 52, and the secondary intermediate transfer drum 53. A temporary holding member is disposed.

  First, the toner temporary holding member disposed with respect to the photosensitive drum 11 is a refresher brush 215 in which conductive rubbing hairs stand up around the metal rotation shaft to prevent toner from adhering to the charging roll 21. Therefore, it is positioned upstream of the charging roll 21 with respect to the rotation direction of the photosensitive drum 11. Further, a cleaning bias is applied to the refresher brush 215, and the toner whose polarity is reversed at each transfer portion is temporarily collected from the surface of the photosensitive drum 11, and a cleaning mode described later is started. The toner is held for a while. That is, the toner is charged to (−) polarity in the developing device 41, and in each transfer process, the toner image is transferred toward a higher potential direction. Such a toner having an initially charged polarity is referred to as a positive toner. However, when such a toner image repeatedly passes through the transfer part of each transfer process, a part of the (−) charged toner is inverted to the opposite polarity, that is, charged to the (+) polarity by Paschen discharge or charge injection. In this case, the toner whose polarity is reversed in this way is not transferred to the next process but flows backward to the upstream side. Such a polarity-reversed toner is called a reverse polarity toner. Finally, it is transferred to the photosensitive drum 11 and eventually adhered to the charging roll 21. The refresher brush 215 is provided to catch such reverse polarity toner before the charging roll 21 and prevent the toner from adhering to the charging roll 21. Therefore, at the time of forming a toner image, −400 V, which is a potential lower than the surface potential of the photosensitive drum 11 −300 V, is applied to the refresher brush 215. The refresher brush 215 is not provided with any driving means, and the refresher brush 215 rotates the photosensitive drum 11 by the frictional force acting between the sliding bristles and the photosensitive drum 11. I'm taking you around.

  In the above description, the refresher brush 215 provided for the photosensitive drum 11 has been described. However, the refresher brushes 216, 217, and 218 having the same structure are also applied to the other photosensitive drums 12, 13, and 14. Is provided.

  On the other hand, for the primary intermediate transfer drums 51 and 52, first and second brush rolls 220 and 221 are used as temporary toner holding members each having conductive sliding bristles standing around a metal rotation shaft. Has been placed. The first brush roll 220 is in a position where the toner remaining on the surface of the primary intermediate transfer drum 51 after the completion of the secondary transfer is blocked on the front side of the photosensitive drum 12, and the second brush roll 221 is in the secondary transfer. The toner remaining on the surface of the primary intermediate transfer drum 52 after the end of the process is disposed at a position where the toner is blocked on the front side of the photosensitive drum 14.

  A cleaning bias is applied to the first and second brush rolls 220 and 221, but the polarity is opposite to that applied to the refresher brush 215. In the primary transfer, each photosensitive drum transfers only one color toner image to the primary intermediate transfer drums 51 and 52. Therefore, the transfer efficiency can be set to a certain extent, and a cleaning device that dares to collect residual toner. Even if the image forming apparatus is not provided, a large support is not generated in image formation, and color mixing does not occur in each of the developing devices 41, 42, 43, and 44. However, in the secondary transfer, toner images of two colors that overlap each other are transferred to the secondary intermediate transfer drum 53, so that a large amount of toner remains on the primary intermediate transfer drums 51 and 52 without being transferred, and such residual toner is cleaned. This is because if the image is not collected by the apparatus, a ghost is generated in the toner image to be transferred next. Therefore, the first and second toners are charged so that the residual toner charged to the (−) polarity is electrostatically transferred from the primary intermediate transfer drums 51 and 52 to the first and second brush rolls 220 and 221. A cleaning bias (for example, +600 V) higher than the surface potential of the primary intermediate transfer drums 51 and 52 is applied to the second brush rolls 220 and 221. Of course, if the atmospheric environment such as temperature and humidity changes and the surface potential of the primary intermediate transfer drums 51 and 52 changes, the first and second brush rolls 220 and 221 and the primary intermediate transfer drums 51 and 52 may be changed. In order to secure the potential difference, it is necessary to change the cleaning bias. Also, the first and second brush rolls 220 and 221 are not provided with any driving means, and act between the rubbing hairs and the primary intermediate transfer drums 51 and 52, similarly to the refresher brush 215. The primary intermediate transfer drums 51 and 52 are rotated by the frictional force.

  Further, a third brush roll 230 as a temporary toner holding member for removing the toner remaining in the tertiary transfer is also disposed on the secondary intermediate transfer drum 53. Unlike the first and second brush rolls 220 and 221 and the refresher brushes 215, 216, 217 and 218, the third brush roll 230 is rotated in the rotational direction of the secondary intermediate transfer drum 53 by a motor (not shown). It is driven to rotate in the opposite direction. A cleaning bias is also applied to the third brush roll 230, but for the purpose of removing residual toner generated in the third transfer from the surface of the secondary intermediate transfer drum 53, the polarity is the first and second polarities. This is the same as that applied to the brush rolls 220 and 221. That is, the residual toner (positive toner) charged with (−) polarity is transferred to the third brush roll 230 from the secondary intermediate transfer drum 53 to the third brush roll 230 in an electrostatic manner. A cleaning bias (for example, +1080 V) higher than the surface potential of the secondary intermediate transfer drum 53 is applied.

  FIG. 3 schematically shows the flow of toner during a print job, that is, while a toner image formed on a photosensitive drum is being transferred to a recording sheet. During the print job, the positive toner charged to the (−) polarity is finally transferred from the photosensitive drum to the recording sheet 100 via the primary intermediate transfer drum 51 and the secondary intermediate transfer drum 53. However, the secondary transfer residual toner that has not been transferred from the primary intermediate transfer drum 51 to the secondary intermediate transfer drum 53 is captured by the first brush roll 220 on the way to the photosensitive drum 11. Further, the residual toner of the third transfer that has not been transferred from the secondary intermediate transfer drum 53 to the recording sheet 100 is captured by the third brush roll 230 on the way to the primary intermediate transfer drum 53. On the other hand, the reverse polarity toner in which the charge of the reverse polarity is injected at the transfer portion and the charge polarity is reversed to (+) is reverse to the positive toner, and passes through the primary intermediate transfer drum from the secondary intermediate transfer drum to the photosensitive drum. The image is transferred back to the end and finally captured by a refresher brush 215 provided for the photosensitive drum.

  Thus, the refresher brushes 215, 216, 217, 218, the first and second brush rolls 220, 221 and the third brush roll 230 are respectively opposed to the photosensitive drums 11, 12, 13, 14 opposed to each other. Although the toner is captured from the primary intermediate transfer drums 51 and 52 and the secondary intermediate transfer drum 53, it has no mechanical configuration for discharging the captured toner, that is, no detoning mechanism. Therefore, when a toner image is repeatedly formed during a print job, the captured toner overflows from between the rubbing hairs of each brush roll. Therefore, in the printer according to this embodiment, in order to collect the toner captured by each brush roll, the following collection sequence is performed following the end of the print job, and the toner is temporarily captured by each brush roll. As shown in FIG. 1, the collected toner is collected by a collective collecting device 80 provided for the transfer roll 60.

  In this collection sequence, first, the same potential as that at the time of toner image formation is charged rolls 21, 22, 23, 24, photosensitive drums 11, 12, 13, 14, primary intermediate transfer drums 51, 52, secondary intermediate While being applied to the transfer drum 53 and the final transfer roll 60, the first to third brush rolls 220, 221, and 230 are given a potential having a polarity opposite to that at the time of image formation. The positive toner adhering to the brush rolls 220 and 221 and the third brush roll 230 is transferred to the final transfer roll 60 in order as shown in FIG. The collection is performed by the collection device 80. In the collective collection device 80, a cleaning blade 801 made of an elastic material such as silicon rubber is in contact with the peripheral surface of the transfer roll 60, and the toner transferred to the transfer roll 60 is scraped off by the cleaning blade 801 and collected in the device. It is supposed to be. Therefore, when such a cleaning operation is started, the positive toner held on the first and second brush rolls 220 and 221 and the third brush roll 230 is transferred to the primary intermediate transfer drums 51 and 52 and the second intermediate transfer drums 51 and 52, respectively. The toner is discharged onto the next intermediate transfer drum 53, reaches the final transfer roll 60 via the secondary intermediate transfer drum 53, and is collected by the collective collecting device 80, as in the case of normal toner image transfer.

  When the collection of the positive toner is completed in this way, the charging rolls 21, 22, 23, 24, the refresher brushes 215, 216, 217, 218, the photosensitive drums 11, 12, 13, 14, the primary intermediate transfer drum To the 51, 52, the secondary intermediate transfer drum 53, and the final transfer roll 60, voltages having a potential gradient are sequentially applied so that the final transfer roll 60 has the highest negative potential. As a result, the reverse polarity toner collected and held by the refresher brushes 215, 216, 217, and 218 during the printing operation is discharged onto the photosensitive drums 11, 12, 13, and 14 as shown in FIG. The transfer roll 60 is sequentially transferred to the transfer roll 60 and is collected by a collective collection device 80 provided in contact with the final transfer roll 60. As a result, the refresher brushes 215, 216, 217, and 218 return to a clean state.

  Thus, as shown in FIG. 6, the collection sequence is composed of a combination of a positive toner collection sequence and a reverse toner collection sequence, and the number of continuous sheets of recording sheets in a print job exceeds a predetermined number. If it exceeds, the print job is temporarily interrupted, and each brush roll is sequentially returned to a clean state. In addition, this is always performed at the end of the print job, and each brush roll immediately returns to a clean state after the print job and prepares for the next print job.

  Here, the amount of unnecessary toner captured by each brush roll in a print job is the content of the print job, for example, the number of recording sheets passed, the image density of the formed toner image, and the recording sheet to which the toner image is finally transferred. Since it differs depending on the type, in order to return each brush roll to a clean state in the collection sequence, it is necessary to carry out the collection sequence for a time corresponding to the contents of the print job. However, in the positive toner collection sequence, for example, a large amount of positive toner is transferred from the first and second brush rolls 220 and 221 and the third brush roll 230 to the primary intermediate transfer drum 51, for a few seconds from the start of the collection sequence. 52 or secondary intermediate transfer drum 53 is discharged, but after a few seconds, the discharge amount of the positive toner decreases, and after that, even if the recovery sequence continues, only a very small amount of positive toner tends to be discharged. is there. The same applies to the reverse polarity toner collection sequence. Therefore, even if the collection sequence execution time is unnecessarily extended even if the number of recording sheets passed through the print job and the image density of the toner image are large, there is not much effect in terms of cleaning the brush roll. On the contrary, the recovery sequence performed by applying a voltage to the photosensitive drums 11, 12, 13, 14, the primary intermediate transfer drums 51, 52, and the secondary intermediate transfer drum 53 accelerates the deterioration of these members. The longer the execution time, the shorter the life of the image forming unit 1.

  For this reason, in the printer according to the present embodiment, when the continuous sheet passing number of recording sheets at the end of the print job is equal to or larger than the predetermined standard sheet number, the execution is performed at the end of the print job regardless of the sheet passing number. When the standard collection sequence with a fixed time is executed, but the number of continuous sheets to be passed at the end of the print job is less than the predetermined standard number, the execution time is shorter than the execution time of the standard collection sequence. Depending on the number of sheets, a reduced collection sequence having a different execution time is executed, or the execution of the collection sequence itself is omitted.

  As shown in FIG. 7, during a print job, every time the number of continuous sheets of recording sheets in the print job reaches a predetermined number N, the print job is interrupted and a collection sequence for a certain execution time is performed. ing. Accordingly, the amount of unnecessary toner held by each brush roll at the end of the print job corresponds to the number of continuous sheets n after the end of the second collection sequence in the example of FIG. Thus, with regard to the collection sequence to be performed at the end of the print job, the execution time may be determined by paying attention to this last continuous sheet passing number n. Therefore, in the present invention, it is checked whether or not the continuous sheet passing number of recording sheets at the end of the print job is less than a predetermined standard sheet passing number.

  Further, in this embodiment, it is configured to include control means for controlling all of the collection sequences to be executed at the fastest process speed among a plurality of set process speeds.

  In the printer 01 according to this embodiment, as the process speed, the fastest monochrome process speed = 225 mm / sec, the next fastest full color process speed = 161 mm / sec, and the next fastest high-gloss image The high-gloss process speed is 112.5 mm / sec and the super-high-gloss process speed is 75 mm / sec for the slowest ultra-high gloss image, as shown in FIG. In addition, the CPU 300 as the control means disposed in the control circuit 09 is configured to execute the printing operation by appropriately switching these four process speeds.

  Therefore, in this embodiment, the CPU 300 performs control so that all of the collection sequences are executed at a black and white process speed = 225 mm / sec, which is the fastest process speed among a plurality of set process speeds. At this time, the third brush roll 230 that collects toner from the secondary intermediate transfer drum 53 is also rotationally driven at a speed corresponding to the black and white process speed = 225 mm / sec, which is the fastest process speed. ing.

  More specifically, in the full color printer 01, for example, the full color printing operation is set to be executed at a full color process speed = 161 mm / sec, which is slower than the black and white process speed (225 mm / sec). However, the collection sequence after the completion of the full-color printing operation is performed by switching to a monochrome process speed (225 mm / sec) that is faster than the full-color process speed. Similarly, even when the printing operation is executed at the high gloss process speed or the super high gloss process speed, the collection sequence is all faster than the full color process speed (225 mm / sec). To be implemented.

  In the above configuration, in the full-color printer according to this embodiment, the image carrier such as the photosensitive drum or the intermediate transfer member is cleaned with the toner temporary holding member that does not have the detoning mechanism as follows. Such an image carrier cleaning mechanism can be simply configured so that the size of the apparatus can be reduced even in colorization. It is possible to prevent the generation of sound.

  That is, in the full-color printer 01 according to this embodiment, as shown in FIGS. 1 and 2, the image forming units 1 for the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are provided. In 2, 3, and 4, toner images of yellow (Y), magenta (M), cyan (C), and black (K) are formed on the photosensitive drums 11, 12, 13, and 14, respectively. The toner images of the respective colors formed on the photosensitive drums 11, 12, 13, and 14 are transferred by the transfer roll 60 via the first and second primary intermediate transfer drums 51 and 52 and the secondary intermediate transfer drum 53. After the image is finally transferred onto the recording sheet 100, a fixing process is performed by the fixing device 70, and a full color image is printed.

  At that time, in the full color printer 01, when transferring the toner image from the yellow (Y) and magenta (M) photosensitive drums 11 and 12 to the first primary intermediate transfer drum 51, and cyan (C) and When the toner image is transferred from the photosensitive drums 13 and 14 of black (K) to the second primary intermediate transfer drum 52, the secondary intermediate transfer is performed from the first and second primary intermediate transfer drums 51 and 52. When the toner images of each color of yellow (Y), magenta (M), cyan (C), and black (K) are collectively transferred to the drum 53, and finally from the secondary intermediate transfer drum 53 onto the recording sheet 100 When the full-color toner image is finally transferred, the toner is transferred onto the photosensitive drums 11, 12, 13, 14, the first and second primary intermediate transfer drums 51, 52, and the secondary intermediate transfer drum 53. Will remain.

  Incidentally, the toner remaining on the photosensitive drums 11, 12, 13, and 14, the first and second primary intermediate transfer drums 51 and 52, and the secondary intermediate transfer drum 53, as shown in FIG. The refresher brushes 215, 216, 217, 218, the first and second brush rolls 220, 221, and the third brush roll 230 are removed and temporarily held.

  After that, the toner removed and temporarily held by the refresher brushes 215, 216, 217, 218, the first and second brush rolls 220, 221 and the third brush roll 230 is the above-mentioned toner. As described above, the toner is collected in the collection sequence of the positive toner and the reverse toner performed after the print sequence, and is collected and removed by the collective collecting device 80 provided in contact with the final transfer roll 60.

  At this time, in the full-color printer 01, the CPU 300 controls all of the collection sequences to be executed at a black and white process speed = 225 mm / sec, which is the fastest process speed among a plurality of set process speeds. .

  Therefore, in the collection sequence, the refresher brushes 215, 216, 217, 218 and the first and second brush rolls 220, 221 are moved to the photosensitive drums 11, 12, 13, 14 and the first and second primary. The rotational speed of the intermediate transfer drums 51 and 52 is increased, and the rotational speed of the third brush roll 230 that is driven to rotate is increased. The refresher brushes 215, 216, 217, 218, and the first and second The brush rolls 220 and 221 or the third brush roll 230 include the photosensitive drums 11, 12, 13, and 14, the first and second primary intermediate transfer drums 51 and 52, and the secondary intermediate transfer drum 53. The relative speed with respect to becomes faster. As a result, when the discharge efficiency of the toner from the refresher brushes 215, 216, 217, 218 and the first to third brush rolls 220, 221, 239 is constant (theoretical value), FIG. As shown in FIG. 5, the discharge amount per unit time increases, and it becomes possible to execute the toner collection sequence effectively in a single time.

  The refresher brushes 215, 216, 217, 218, the first and second brush rolls 220, 221 or the third brush roll 230 are provided on the photosensitive drums 11, 12, 13, 14 and the first, Since the relative speed with respect to the second primary intermediate transfer drums 51 and 52 and the secondary intermediate transfer drum 53 is increased, the “stick-slip phenomenon” is mitigated or suppressed, and abnormal noise caused by the “stick-slip phenomenon” is reduced. It can be suppressed or prevented to such an extent that generation does not become a problem.

Embodiment 2
FIG. 9 shows a second embodiment of the present invention. The same reference numerals are given to the same parts as those in the first embodiment. In the second embodiment, the toner temporary holding member is shown in FIG. The process speed is controlled to an optimum specific speed in accordance with the toner discharge characteristics.

  That is, in the second embodiment, as shown in FIG. 9, the refresher brushes 215, 216, 217, 218 as the temporary toner holding members, the first and second brush rolls 220, 221, or the third The brush roll 230 has such a characteristic that the toner discharge amount per unit time shows a peak at a certain linear velocity.

  More specifically, the refresher brushes 215, 216, 217, 218, the first and second brush rolls 220, 221, or the third brush roll 230 as the toner temporary holding member have a low linear velocity, It takes a long time to discharge the toner, and as a result, the amount of toner discharged per unit time is small, but at a specific speed, the effects of electric field, flicking, and centrifugal force are most likely to occur, and the amount of toner discharged per unit time is If the peak is too fast, the effect of the electric field is difficult to produce, the brush hair does not move, the toner in the back is hard to be discharged, and the toner movement does not follow the brush, resulting in toner per unit time. The discharge amount will decrease.

  For this reason, in the second embodiment, as shown in FIG. 9, the collection sequence is executed with a brush having a diameter of about 14 mm and a process speed at which the toner discharge amount per unit time is substantially peaked = 150 mm / sec. It is configured.

  Further, if the process speed is a certain speed (for example, 150 mm / sec) or more as the recovery sequence, an effect can be obtained for suppressing abnormal noise caused by the “stick-slip phenomenon”.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

  In the above-described embodiment, a case has been described in which the entire recovery sequence is configured to be executed at a speed higher than the normal process speed. However, only the initial predetermined time of the recovery sequence is used as a normal process. It may be configured to execute at a speed higher than the speed.

1 is a schematic diagram illustrating a configuration of an image forming unit of a full color laser beam printer to which the present invention is applied. It is the schematic which shows the structure of the full color laser beam printer to which this invention is applied. FIG. 6 is a schematic diagram illustrating a toner flow during a print job. FIG. 6 is a schematic diagram illustrating a flow of collecting positive toner during a collection sequence. FIG. 6 is a schematic diagram illustrating a flow of reverse polarity toner recovery during a recovery sequence. 6 is a timing chart showing the execution timing of a collection sequence for one print job. 6 is a timing chart showing the execution timing of a collection sequence for one print job. 6 is a graph showing a relationship between a linear velocity and a toner discharge amount per unit time. It is a graph which shows the relationship between the linear velocity which concerns on Embodiment 2 of this invention, and the toner discharge amount per unit time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11-14 ... Photosensitive drum, 51, 52 ... Primary intermediate transfer drum, 53 ... Secondary intermediate transfer drum, 215-218 ... Refresher brush, 220, 221 ... First brush roll, 230 ... Second brush roll

Claims (3)

A toner image corresponding to image information is formed on an image carrier, and the toner image formed on the image carrier is formed on a recording sheet via a primary intermediate transfer image carrier and a secondary intermediate transfer image carrier. An image forming apparatus that executes a print job to be transferred,
A member that rotates following the image carrier to remove unnecessary toner adhering to the surface of the image carrier and temporarily holds the toner, the image carrier, an image carrier for primary intermediate transfer, a secondary intermediate A toner temporary holding member composed of a brush roll having a brush-like surface in contact with the image carrier for transfer is provided, and after the toner image is formed and transferred, it is unnecessary to be held on the toner temporary holding member. Depending on the potential difference between the toner temporary holding member and the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer image carrier, the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer In the image forming apparatus configured to discharge the image on the image carrier and execute a collection sequence captured by a final collection unit provided on the image carrier for secondary intermediate transfer to end the print job.
A voltage value applied to the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer image carrier when executing the recovery sequence is set so as to be relatively higher in order,
The recovery sequence is performed at a speed higher than a normal process speed capable of suppressing a stick-slip phenomenon generated between the image carrier and the temporary toner holding member among a plurality of set process speeds . together is rotated the toner temporary holding member of the toner temporary holding member and the primary intermediate transfer image carrier to said image bearing member and the primary intermediate transfer image carrier, the toner provisional the secondary intermediate transfer image carrier An image forming apparatus comprising a control unit that performs control by rotating a holding member . A toner image corresponding to image information is formed on an image carrier, and the toner image formed on the image carrier is formed on a recording sheet via a primary intermediate transfer image carrier and a secondary intermediate transfer image carrier. An image forming apparatus that executes a print job to be transferred,
A member that rotates following the image carrier to remove unnecessary toner adhering to the surface of the image carrier and temporarily holds the toner, the image carrier, an image carrier for primary intermediate transfer, a secondary intermediate A toner temporary holding member composed of a brush roll having a brush-like surface in contact with the image carrier for transfer is provided, and after the toner image is formed and transferred, it is unnecessary to be held on the toner temporary holding member. Depending on the potential difference between the toner temporary holding member and the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer image carrier, the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer In the image forming apparatus configured to discharge the image on the image carrier and execute a collection sequence captured by a final collection unit provided on the image carrier for secondary intermediate transfer to end the print job.
A voltage value applied to the image carrier, the primary intermediate transfer image carrier, and the secondary intermediate transfer image carrier when executing the recovery sequence is set so as to be relatively higher in order,
The toner temporary holding member of the image carrier at the fastest process speed capable of suppressing the stick-slip phenomenon generated between the image carrier and the toner temporary holding member among the plurality of process speeds set in the collection sequence. And the toner temporary holding member of the image carrier for primary intermediate transfer is driven to rotate following the image carrier and the image carrier for primary intermediate transfer, and the toner temporary holding member of the image carrier for secondary intermediate transfer is rotated. An image forming apparatus comprising control means for controlling to be executed by being driven.   3. The image forming apparatus according to claim 1, wherein only the initial predetermined time of the collection sequence is executed at a speed faster than a normal process speed or a fastest process speed.

Images