JP2013007810A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that prevents paper powder and un-transferred toner from accumulating on an edge of a cleaning blade for cleaning an image carrier or a belt cleaning blade for cleaning a belt member, and that makes it difficult for both the members to cause a friction between them even in a case where the image carrier and belt member are driven to rotate in opposite directions.SOLUTION: Driving parts 50 to 60 that drive the belt member 8 and the image carrier 1K in a predetermined direction are configured to exert a reverse rotation drive mode in which the image carrier 1K is rotated and driven in a reverse direction, with driving force un-transmitted to the belt member 8. When the reverse rotation drive mode is exerted, a voltage is applied to a transfer member 9K such that the belt member 8 is electrostatically attracted to the image carrier 1K and runs in an opposite direction.

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a complex machine thereof, and in particular, a cleaning blade for cleaning an image carrier such as a photosensitive drum, an intermediate transfer belt, a transfer conveyance belt, and the like. The present invention relates to an image forming apparatus provided with a belt cleaning blade for cleaning a belt member.

Conventionally, in an image forming apparatus such as a copying machine or a printer, a tandem type image forming apparatus in which a plurality of photosensitive drums (image carriers) are arranged in parallel so as to face a belt member such as an intermediate transfer belt is widely known. (See, for example, Patent Document 1).
In the image forming apparatus in Patent Document 1 or the like, four photosensitive drums (image carriers) are arranged side by side so as to face the intermediate transfer belt (belt member). On these four photosensitive drums, black (black), yellow, magenta, and cyan toner images are formed, respectively. Then, the toner images of the respective colors formed on the respective photosensitive drums are transferred (primary transfer) while being superimposed on the intermediate transfer belt. Further, the toner images of a plurality of colors carried on the intermediate transfer belt are transferred onto a recording medium as a color image at a contact position (nip portion) between the intermediate transfer belt and the secondary transfer roller (secondary transfer member). (Secondary transfer). Thereafter, the recording medium on which the color image is secondarily transferred is conveyed to the position of the fixing unit, and the toner image on the recording medium is fixed at that position by heat and pressure.

  In such an image forming apparatus, a cleaning blade is installed so as to be in contact with four photosensitive drums (image carriers), and untransferred toner remaining on the photosensitive drum is cleaned by the cleaning blade. . Further, a belt cleaning blade is provided so as to contact the intermediate transfer belt (belt member), and untransferred toner remaining on the intermediate transfer belt is cleaned by the belt cleaning blade.

  On the other hand, in Patent Document 2 and the like, after the image forming operation is completed, the transfer is performed for the purpose of preventing a problem that paper dust accumulates on the edge of the cleaning blade for cleaning the transfer material carrier and the cleaning performance is deteriorated. A technique is disclosed in which a material carrier is driven to travel in a direction opposite to a traveling direction during an image forming operation.

  In a conventional tandem type image forming apparatus, paper dust, untransferred toner or the like accumulates on the edge of a belt cleaning blade for cleaning a belt member such as an intermediate transfer belt, and a minute gap is formed at the edge portion. As the cleaning performance deteriorates, paper dust and untransferred toner accumulate on the edge of the cleaning blade that cleans each of the image bearing members such as a plurality of photosensitive drums, and a minute gap is formed at the edge. There was a problem that the cleaning performance deteriorated.

  In order to solve such a problem, after applying the technique of Patent Document 2 and the like, after the image forming operation is completed, the belt member is driven to travel in a direction opposite to the traveling direction at the time of the image forming operation. There can be considered a method in which a plurality of image carriers are rotationally driven in directions opposite to the rotation direction during the image forming operation. However, the driving unit that drives the belt member includes a driving unit that drives at least one of the plurality of image carriers (for example, a black image carrier that forms a black toner image) and a driving source. Is common, so the timing when the image carrier starts to rotate in the reverse direction and the belt member starts to drive in the reverse direction due to the backlash of the gear train in the drive unit. There was a gap in the timing when it was done. As a result, the belt member and the image carrier are rubbed for the amount of time that the misalignment has occurred, causing damage to the surface of the belt member and the image carrier.

  Further, such a problem is not limited to an image forming apparatus using an intermediate transfer belt as a belt member, and even in a tandem type image forming apparatus using another belt member such as a transfer conveyance belt, As long as the belt member and the image carrier are reversely driven, they are common.

  The present invention has been made to solve the above-described problems. Paper dust and untransferred toner are deposited on the edge of a cleaning blade for cleaning an image carrier and a cleaning blade for a belt for cleaning a belt member. In addition, an object of the present invention is to provide an image forming apparatus in which friction between both members hardly occurs even when the image carrier and the belt member are driven in reverse.

  According to a first aspect of the present invention, an image forming apparatus rotates in a predetermined direction, travels in a predetermined direction, and has a plurality of image carriers on which toner images of respective colors are formed. A belt member arranged side by side so that the image carriers are opposed to each other, and the plurality of image carriers are opposed to each other via the belt member, and a predetermined voltage is applied to the image members on the plurality of image carriers. A plurality of transfer members that respectively transfer the formed toner images to the belt member or a recording medium; a plurality of cleaning blades that respectively contact the plurality of image carriers to clean the surface of the image carrier; and the belt A belt cleaning blade that contacts the member and cleans the surface of the belt member; and at least one image of the plurality of image carriers. A drive unit that rotationally drives the holder in the predetermined direction and that drives the belt member to travel in the predetermined direction, and the drive unit transmits the driving force to the belt member without transmitting the driving force to the belt member. A reverse drive mode for rotating the image carrier in a direction opposite to the predetermined direction can be executed. When the reverse drive mode is executed, the belt member is electrostatically applied to the image carrier. A voltage is applied to the transfer member so that the transfer member travels in the opposite direction to the predetermined direction.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the one image carrier is a black image carrier on which a toner image is formed with black toner. The image carrier other than the black image carrier among the plurality of image carriers is a color image carrier on which a toner image is formed by color toner, and the color image carrier is placed in a predetermined direction. A second drive unit that rotationally drives the color image carrier in a direction opposite to the predetermined direction when the reverse drive mode is executed; and the color image carrier is the belt member. And a contact / separation mechanism for making the contact with / separate relative to each other, and maintaining the color image carrier in contact with the belt member by the contact / separation mechanism when the reverse drive mode is executed. When done In addition, a voltage is applied to all of the plurality of transfer members such that the belt member is electrostatically attracted to the black image carrier and the color image carrier and travels in a direction opposite to the predetermined direction. Applied.

  According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the one image carrier is a black image carrier on which a toner image is formed with black toner. The image carrier other than the black image carrier among the plurality of image carriers is a color image carrier on which a toner image is formed with color toner, and the driving unit is configured to provide the black image carrier. The color image carrier is rotated in a predetermined direction as the body is rotated in the predetermined direction, and the color image carrier is moved in the predetermined direction when the reverse drive mode is executed. When the reverse drive mode is executed, the belt member is electrostatically attracted to the black image carrier and the color image carrier to perform the predetermined rotation. Reverse to direction All of said plurality of transfer members so as to travel in direction in which a voltage is applied.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the driving unit is configured to move the belt member in one direction. A one-way clutch that transmits only the driving force is provided.

  An image forming apparatus according to a fifth aspect of the present invention is the image forming apparatus according to any one of the first to fourth aspects, wherein the drive unit is configured to perform the image when the reverse drive mode is executed. The carrier and the belt member are each moved at least 1.5 mm in opposite directions.

  An image forming apparatus according to a sixth aspect of the present invention is the image forming apparatus according to any one of the first to fifth aspects, wherein the belt member is an intermediate transfer belt, and the transfer member is 1 The secondary transfer roller further includes a secondary transfer member that secondary-transfers the toner image primarily transferred onto the intermediate transfer belt to a recording medium.

  According to the present invention, a drive unit that travels and drives the belt member in conjunction with the rotational drive of the image carrier is configured so that the image carrier can be rotationally driven in the reverse direction without transmitting a driving force to the belt member. . When the reverse rotation of the image carrier is performed, a voltage is applied to the transfer member so that the belt member is electrostatically attracted to the image carrier and travels in the reverse direction. As a result, even when the image carrier and the belt member are driven in reverse without causing paper dust or untransferred toner to accumulate on the edge of the cleaning blade for cleaning the image carrier or the belt cleaning blade for cleaning the belt member. It is possible to provide an image forming apparatus in which friction is unlikely to occur between both members.

1 is an overall configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. It is sectional drawing which shows an image formation part. FIG. 4 is a diagram illustrating a driving unit of a photosensitive drum and an intermediate transfer belt. FIG. 4 is a diagram illustrating a state in the vicinity of an intermediate transfer belt in a monochrome mode. FIG. 6 is a diagram illustrating a state in the vicinity of an intermediate transfer belt in a reverse drive mode. It is a timing chart which shows control when reverse rotation drive mode is performed at the time of monochrome mode. It is a timing chart which shows control when reverse rotation drive mode is performed at the time of color mode. It is a figure which shows the drive part of the photosensitive drum of another form, and an intermediate transfer belt.

Embodiment.
Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

First, the configuration and operation of the entire image forming apparatus will be described.
As shown in FIG. 1, four toner containers 32Y, 32M, 32C, and 32K corresponding to the respective colors (yellow, magenta, cyan, and black) are attached to and detached from the toner container accommodating portion 31 above the image forming apparatus main body 100. It is installed freely (changeable).
The exposure device 7 is disposed below the toner container housing portion 31, and the image forming portions 6Y, 6M, 6C, and 6K and the intermediate transfer unit 15 are disposed below the exposure device 7. The image forming units 6Y, 6M, 6C, and 6K corresponding to the respective colors (yellow, magenta, cyan, and black) are arranged in parallel so as to face the intermediate transfer belt 8 (belt member) of the intermediate transfer unit 15.
Although illustration is omitted, toner replenishing devices are respectively disposed below the toner containers 32Y, 32M, 32C, and 32K. The toners stored in the toner containers 32Y, 32M, 32C, and 32K are respectively supplied (supplied) into the developing devices of the image forming units 6Y, 6M, 6C, and 6K by the toner replenishing device.

  Referring to FIG. 2, an image forming unit 6K corresponding to black (black) includes a photosensitive drum 1K as an image carrier, a charging unit 4K disposed around the photosensitive drum 1K, and a developing device 5K ( The developing unit), the cleaning unit 2K, the charge eliminating unit (not shown), and the like. Then, an image forming process (charging process, exposure process, developing process, transfer process, cleaning process) is performed on the photosensitive drum 1K, and a black image (monochrome image) is formed on the photosensitive drum 1K. become.

  The other three image forming units 6Y, 6M, and 6C have substantially the same configuration as that of the image forming unit 6K corresponding to black except that the color of the toner to be used is different. A corresponding image is formed. Hereinafter, description of the other three image forming units 6Y, 6M, and 6C will be omitted as appropriate, and only the image forming unit 6K corresponding to black will be described. In the following description, the black photosensitive drum 1K as the black image carrier is referred to as a “black photosensitive drum” as appropriate, and the color photosensitive drum 1Y as the color image carrier. 1M and 1C are called “color photosensitive drums”.

Referring to FIG. 2, photosensitive drum 1K is driven to rotate clockwise in FIG. 2 by a drive motor (not shown). Then, the surface of the photosensitive drum 1K is uniformly charged at the position of the charging unit 4K (a charging process).
Thereafter, the surface of the photosensitive drum 1K reaches the irradiation position of the laser beam L emitted from the exposure device 7 (see FIG. 1), and the electrostatic latent image corresponding to black by the exposure scanning at this position. Is formed (this is an exposure step).

Thereafter, the surface of the photosensitive drum 1K reaches a position facing the developing device 5K, and the electrostatic latent image is developed at this position to form a black toner image (developing process).
Specifically, referring to FIG. 2, a two-component developer G composed of toner and a carrier (magnetic carrier) is accommodated in the developing device 5K. The developer G in the developing device 5K is adjusted so that the toner concentration (the ratio of the toner in the developer G) detected by a magnetic sensor (not shown) is within a predetermined range. That is, according to the toner consumption in the developing device 5K, the toner (replenishment toner) is replenished into the second developer transport unit 504K through the toner replenishment port 64K by the toner replenishment device.
The toner replenishing device is connected to the toner container 32K shown in FIG. Although not shown, the toner replenishing device is stored in a drive system that rotates and drives the toner container 32K (toner bottle), a toner tank that stores toner discharged from the toner container 32K, and a toner tank. A toner conveying section that conveys the toner toward the toner dropping path, and a toner falling path that causes the toner conveyed by the toner conveying section to fall by its own weight toward the developing device 5K (second developer conveying section 504K). Has been.

Referring to FIG. 2, the toner (supplemented toner) replenished into the second developer conveying unit 504K through the toner replenishing port 64K is then mixed with the developer G by the two conveying screws 505K and 506K. While being stirred, the first developer transport unit 503K and the second developer transport unit 504K separated by the partition member are circulated.
Thus, the toner in the developer G circulating in the circulation path is attracted to the carrier by frictional charging with the carrier and is carried together with the carrier on the developing roller 501K in which a plurality of magnetic poles are formed. The developer G carried on the developing roller 501K is conveyed as the developing roller 501K rotates in the direction of the arrow, and reaches the position of the doctor blade 502K. The developer G on the developing roller 501K is regulated to an appropriate amount at this position, and then conveyed to a position facing the photosensitive drum 1K (developing area). The toner is attracted to the latent image formed on the photosensitive drum 1K by the electric field (developing electric field) formed in the developing area.
Here, the developer in the developing device 5K is adjusted so that the ratio of the toner in the developer (toner concentration) is within a predetermined range. Specifically, according to the consumption of toner in the developing device 5K, the toner stored in the toner bottle 32K is supplied into the second developer transport unit 504K through the toner supply port 64K by the toner supply device.

Referring to FIG. 2, after the development process described above, the surface of photoconductor drum 1K reaches the position facing intermediate transfer belt 8 and first transfer roller 9K, and the toner on photoconductor drum 1K is at this position. The image is transferred onto an intermediate transfer belt 8 as a belt member (this is a primary transfer step). At this time, a small amount of untransferred toner remains on the photosensitive drum 1K.
Thereafter, the surface of the photosensitive drum 1K reaches a position facing the cleaning unit 2K, and untransferred toner remaining on the photosensitive drum 1K at this position is mechanically collected by the cleaning blade 2a (in the cleaning process). is there.). The cleaning blade 2a is a substantially plate-like member made of urethane rubber, and comes into contact with the photosensitive drum 1K with a predetermined contact angle or contact pressure (about 0.2 N / cm). The adhering matter such as untransferred toner and paper dust attached to the surface of the drum 1K is cleaned.
Finally, the surface of the photosensitive drum 1K reaches a position facing an unillustrated neutralization unit, and the residual potential on the photosensitive drum 1K is removed at this position.
Thus, a series of image forming processes performed on the photosensitive drum 1K is completed.

The image forming process described above is performed in the other image forming units 6Y, 6M, and 6C in the same manner as the black image forming unit 6K. That is, a laser beam L based on image information is irradiated from the exposure unit 7 disposed above the image forming unit onto the photosensitive drums 1Y, 1M, and 1C of the image forming units 6Y, 6M, and 6C. Is done. Specifically, the exposure unit 7 emits a laser beam L from a light source and scans the laser beam L on the photosensitive drums 1Y, 1M, and 1C via a plurality of optical elements while scanning with a polygon mirror that is rotationally driven. Irradiate.
Thereafter, the toner images of the respective colors formed on the photosensitive drums 1Y, 1M, and 1C through the developing process are transferred onto the intermediate transfer belt 8 (belt member) as a belt member in an overlapping manner. In this way, a color image is formed on the intermediate transfer belt 8.

  Referring to FIG. 1, the intermediate transfer unit 15 includes an intermediate transfer belt 8 (belt member), primary transfer rollers 9Y, 9M, 9C, and 9K as secondary transfer members, and a secondary transfer counter roller 12 ( Drive roller), first tension roller 13, second tension roller 14, third tension roller 15, fourth tension roller 16, intermediate transfer cleaning unit 10, lubricant supply unit 11, and the like. The intermediate transfer belt 8 is stretched and supported by a plurality of roller members 9Y, 9M, 9C, 9K, and 12 to 16, and is rotated by one roller member 12 (secondary transfer counter roller) in FIG. It is moved endlessly in the direction of the arrow.

The four primary transfer rollers 9Y, 9M, 9C, and 9K (transfer members) respectively sandwich the intermediate transfer belt 8 with the photosensitive drums 1Y, 1M, 1C, and 1K to form primary transfer nips. Yes. Then, the high-voltage power supply units 40Y, 40M, 40C, and 40K (see FIG. 3) are respectively applied to the primary transfer rollers 9Y, 9M, 9C, and 9K with a transfer bias (a voltage of about + 1800V) opposite to the polarity of the toner. Is applied). The primary transfer rollers 9Y, 9M, 9C, and 9K (transfer members) are in contact with the intermediate transfer belt 8 with a pressure contact force of about 3N by a compression spring (not shown).
The intermediate transfer belt 8 travels in the direction of the arrow, and sequentially passes through the primary transfer nips of the primary transfer rollers 9Y, 9M, 9C, and 9K. In this way, the toner images of the respective colors on the photosensitive drums 1Y, 1M, 1C, and 1K are primarily transferred while being superimposed on the intermediate transfer belt 8.

  Thereafter, the intermediate transfer belt 8 onto which the toner images of the respective colors are transferred in an overlapping manner reaches a position facing the secondary transfer roller 19 as a secondary transfer member. At this position, the intermediate transfer belt 8 is sandwiched between the secondary transfer counter roller 12 and the secondary transfer roller 19 as a secondary transfer member to form a nip portion (secondary transfer nip). A secondary transfer bias opposite to the polarity of the toner is applied to the secondary transfer roller 19 (constant current control with a current of about −30 μA). As a result, the color toner image carried on the intermediate transfer belt 8 (belt member) as a belt member is transferred onto a recording medium P such as transfer paper conveyed to the position of the transfer nip portion. At this time, untransferred toner that has not been transferred to the recording medium P remains on the intermediate transfer belt 8.

Thereafter, the intermediate transfer belt 8 reaches the position of the intermediate transfer cleaning unit 10. At this position, the untransferred toner on the intermediate transfer belt 8 is mechanically collected by the belt cleaning blade 10a. The belt cleaning blade 10a is a substantially plate-like member made of urethane rubber, and is in contact with the intermediate transfer belt 8 with a predetermined contact angle or contact pressure (about 0.2 N / cm). The adhering matter such as non-transferred toner and paper powder adhered to the surface of the intermediate transfer belt 8 is cleaned.
Thus, a series of transfer processes performed on the intermediate transfer belt 8 is completed.

In the present embodiment, the lubricant supply unit 11 is installed at a position downstream of the intermediate transfer cleaning unit 10 (on the downstream side in the running direction of the intermediate transfer belt 8). The lubricant supply unit 11 includes a brush roller that is in sliding contact with the intermediate transfer belt 8 and the solid lubricant, a solid lubricant composed of zinc stearate, a compression spring that biases the solid lubricant toward the brush roller, and the like. The lubricant is applied on the intermediate transfer belt 8. As a result, the wear of the intermediate transfer belt 8 and the belt cleaning blade 10a is reduced, and the cleaning performance by the belt cleaning blade 10a is improved.
Further, the second tension roller 14 is in pressure contact with the belt cleaning blade 10a via the intermediate transfer belt 8, and the cleaning performance by the belt cleaning blade 10a is enhanced. The third tension roller 15 is in pressure contact with the brush roller of the lubricant supply unit 11 via the intermediate transfer belt 8, so that the lubricant supply performance by the lubricant supply unit 11 is enhanced. The fourth tension roller 16 is configured to apply tension from the outer peripheral surface side of the intermediate transfer belt 8, and in the monochrome mode, which will be described later, between the primary transfer roller 9K for black and the primary transfer roller for color. The intermediate transfer roller 8 is stretched and supported without passing through 9Y, 9M, and 9C (see FIG. 4).

Here, the recording medium P transported to the position of the secondary transfer nip is transported from a paper feeding unit 26 disposed below the apparatus main body 100 via a paper feeding roller 27, a registration roller pair 28, and the like. It is a thing.
Specifically, a plurality of recording media P such as transfer paper are stored in the paper supply unit 26 in a stacked manner. When the paper feed roller 27 is driven to rotate counterclockwise in FIG. 1, the uppermost recording medium P is fed toward the rollers of the registration roller pair 28.

  The recording medium P transported to the registration roller pair 28 temporarily stops at the position of the roller nip of the registration roller pair 28 whose rotation drive has been stopped. Then, the registration roller pair 28 is rotationally driven in synchronization with the color image on the intermediate transfer belt 8, and the recording medium P is conveyed toward the secondary transfer nip. In this way, a desired color image is transferred onto the recording medium P.

Thereafter, the recording medium P on which the color image is transferred at the position of the secondary transfer nip portion is conveyed to the position of the fixing portion 20 (fixing device). At this position, the color image (toner image) transferred onto the surface of the recording medium P is fixed on the recording medium P by heat and pressure generated by the fixing roller and the pressure roller.
Thereafter, the recording medium P is discharged to the outside of the apparatus through the rollers of the discharge roller pair 29. The recording media P discharged to the outside of the apparatus by the discharge roller pair 29 are sequentially stacked on the stack unit 30 as an output image.
In this way, a series of image forming processes at the time of normal image formation in the image forming apparatus is completed.
In the image forming apparatus 100 according to the present embodiment, the process linear velocity (or the conveyance speed of the recording medium P) is set to about 150 mm / second.

In this embodiment, the intermediate transfer belt 8 as a belt member is made of PVDF (vinylidene fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), PI (polyimide), PC (polycarbonate), or the like. The belt member is composed of a single layer or a plurality of layers and in which a conductive material such as carbon black is dispersed. The intermediate transfer belt 8 has a volume resistivity of about 10 ⁸ to 10 ¹² Ωcm and a surface resistivity of about 10 ⁹ to 10 ¹³ Ωcm.
If necessary, a release layer can be coated on the surface of the intermediate transfer belt 8. At that time, materials used for the coating are ETFE (ethylene-tetrafluoroethylene copolymer), PTFE (polytetrafluoroethylene), PVDF (vinylidene fluoride), PEA (perfluoroalkoxy fluororesin), FEP (four A fluororesin such as fluorinated ethylene-hexafluoropropylene copolymer) or PVF (vinyl fluoride) can be used, but is not limited thereto.
Further, as a method for manufacturing the intermediate transfer belt 8, there are a casting method, a centrifugal molding method, and the like, and a step of polishing the surface is performed as necessary.

Further, the secondary transfer counter roller 12 that is in contact with the inner peripheral surface of the intermediate transfer belt 8 is in contact with the secondary transfer roller 19 (secondary transfer member) via the intermediate transfer belt 8 as a belt member.
The secondary transfer roller 19 (secondary transfer member) has an elastic layer (conductive rubber layer) having a resistance value of about 10 ⁶ to 10 ¹⁰ Ω made of a urethane material (urethane rubber) formed on a cored bar. Roller member. The secondary transfer roller 19 is in contact with the secondary transfer counter roller 12 via the intermediate transfer belt 8 with a pressure contact force of about 30 N to form a secondary transfer nip.

Hereinafter, the characteristic configuration and operation of the image forming apparatus according to the present embodiment will be described in detail.
2 and 3, image forming apparatus 100 according to the present embodiment includes at least one photosensitive drum (for black) among four photosensitive drums 1Y, 1M, 1C, and 1K (image carrier). The photosensitive drum 1K is driven in a predetermined direction, and driving units 50 to 60 (first driving unit) for driving the intermediate transfer belt 8 (belt member) in a predetermined direction are installed.
Specifically, as shown in FIG. 3, the first drive unit includes a first drive motor 50, a drive gear 51, a first gear 52, idler gears 53 to 59, a second gear 60, and the like. Then, during a normal image forming operation, the drive gear 51 fixed to the motor shaft of the first drive motor 50 rotates counterclockwise in FIG. The driving force is transmitted to the rotation shaft of the photosensitive drum 1K), and the black photosensitive drum 1K is rotationally driven in the clockwise direction in FIG. At the same time, a driving force is applied from the driving gear 51 to the second gear 60 (fixed to the rotating shaft of the secondary transfer counter roller 12 that drives the intermediate transfer belt 8) via the plurality of idler gears 53 to 59. Then, the intermediate transfer belt 8 is driven to run counterclockwise in FIG. 3 by the frictional resistance with the secondary transfer counter roller 12.

Referring to FIG. 3, image forming apparatus 100 according to the present embodiment includes first driving units 50 to 60 that drive black photosensitive drum 1K and intermediate transfer belt 8 during a normal image forming operation. Separately, second driving units 70 to 75 that rotationally drive the color photosensitive drums 1Y, 1M, and 1C (an image carrier other than the black image carrier) are installed.
Specifically, the second drive unit includes a second drive motor 70, a drive gear 71, a first gear 72, a second gear 73, an idler gear 74, a third gear 75, and the like. In the normal image forming operation, the drive gear 71 fixed to the motor shaft of the second drive motor 70 rotates counterclockwise in FIG. The driving force is transmitted to the rotation shaft of the photosensitive drum 1Y), and the yellow photosensitive drum 1Y is rotated in the clockwise direction in FIG. At the same time, the driving force is transmitted from the driving gear 71 to the second gear 73 (fixed to the rotating shaft of the magenta photosensitive drum 1M), so that the magenta photosensitive drum 1M is rotated clockwise in FIG. Will be driven to rotate. Further, the driving force is transmitted from the driving gear 71 to the third gear 75 (fixed to the rotating shaft of the cyan photosensitive drum 1C) via the second gear 73 and idler gear 74, and the cyan photosensitive member. The drum 1C is rotated in the clockwise direction in FIG.

Here, referring to FIG. 4, the image forming apparatus 100 according to the present embodiment includes a contact / separation mechanism 80 that makes the color photosensitive drums 1 </ b> Y, 1 </ b> M, and 1 </ b> C contact and separate from the intermediate transfer belt 8. Is installed. The contact / separation mechanism 80 is a mechanism configured to be able to move the color primary transfer rollers 9Y, 9M, and 9C in a state where the primary transfer nip is formed in the white arrow direction (downward) in FIG. A cam mechanism or a link mechanism connected to the separation motor), and the primary transfer rollers 9Y, 9M, and 9C are moved up and down by moving the contact / separation motor on and off. The body drums 1Y, 1M, and 1C are brought into contact with and separated from the intermediate transfer belt 8.
Specifically, when the primary transfer rollers 9Y, 9M, and 9C are moved upward by the contact / separation mechanism 80, the color photosensitive drums 1Y, 1M, and 1C contact the intermediate transfer belt 8 together with the black photosensitive drum 1K. In this state (four-color full-color image formation) is performed (this is the full-color mode). On the other hand, when the primary transfer rollers 9Y, 9M, and 9C are moved downward by the contact / separation mechanism 80, the color photoconductor drums 1Y, 1M, and 1C are separated from the intermediate transfer belt 8 and the black photoconductor. Only the drum 1K is in contact with the intermediate transfer belt 8 (the state shown in FIG. 4), and in this state, only black image formation is performed (monochrome mode). As described above, in the monochrome mode, the color photoconductor drums 1Y, 1M, and 1C and the color primary transfer rollers 9Y, 9M, and 9C are separated from the intermediate transfer belt 8, thereby the intermediate transfer belt 8 and the color photoconductors. The wear deterioration of the drums 1Y, 1M, and 1C and the color primary transfer rollers 9Y, 9M, and 9C can be reduced, and the color toner can be reliably prevented from being mixed into the monochrome image.

Here, the first drive units 50 to 60 (drive units) move the black photosensitive drum 1K in the reverse direction with respect to a predetermined direction without transmitting the drive force to the intermediate transfer belt 8 (secondary transfer counter roller 12). It is configured to be able to execute a “reverse rotation drive mode” for rotationally driving in a counterclockwise direction with respect to the clockwise direction in FIG.
Specifically, the first drive motor 50 is a forward / reverse bidirectional rotation type motor, and the drive gear 51 is moved in the forward direction (the arrow direction in FIG. 3 and the counterclockwise direction) under the control of the control unit 45. ) As well as in the opposite direction (in the direction of the arrow in FIG. 5 and in the clockwise direction). Referring to FIG. 2, the secondary transfer counter roller 12 that functions as a driving roller for driving the intermediate transfer belt 8 is provided with a one-way clutch 12a on its rotating shaft. The one-way clutch 12a transmits only a driving force in one direction that causes the intermediate transfer belt 8 to travel in a predetermined direction (the direction of the arrow in FIG. 2 is the forward direction), and causes the intermediate transfer belt 8 to move in the reverse direction. When a driving force for traveling in the direction opposite to the direction of the arrow in FIG. 2 is applied, it is configured to idle and not transmit the drive.
That is, during the normal image forming operation, when the first drive motor 50 is driven in the forward direction by the control unit 45, the black photosensitive drum 1K is driven to rotate in the forward direction and is secondary through the one-way clutch 12. The driving force is transmitted to the transfer counter roller 12 and the intermediate transfer belt 8 is also driven to travel in the forward direction (the state shown in FIG. 3). On the other hand, when the first drive motor 50 is driven in the reverse direction by the controller 45 in the reverse drive mode, the black photosensitive drum 1K is rotationally driven in the reverse direction (the state shown in FIG. 5). The one-way clutch 12 does not transmit the driving force from the first driving motor 50 to the secondary transfer counter roller 12.

Further, when such a reverse drive mode is executed, the intermediate transfer belt 8 is electrostatically attracted to the black photosensitive drum 1K and travels in the reverse direction (clockwise in FIG. 5). A voltage is applied to the black primary transfer roller 9K. Specifically, in the reverse drive mode, a voltage of about +3000 V is applied from the black high voltage power supply unit 40K to the black primary transfer roller 9K, and the intermediate transfer belt 8 is electrostatically attracted to the black photosensitive drum 1K. In this state, the intermediate transfer belt 8 in a state in which the drive transmission from the first drive motor 50 is released travels (follows) in the reverse direction by the suction force following the rotation of the black photosensitive drum 1K.
In the reverse drive mode performed in this way, the timing at which the intermediate transfer belt 8 starts to run in the reverse direction and the timing at which the black photosensitive drum 1K starts to rotate in the reverse direction can be made substantially coincident. That is, the first and second rotational driving of the black photosensitive drum 1K and the forward and reverse driving of the intermediate transfer belt 8 (secondary transfer opposing roller 12) are performed without installing the one-way clutch 12a and the like. When this is performed in conjunction with the forward / reverse driving of the single drive motor 50, the timing at which the intermediate transfer belt 8 starts to run in the reverse direction due to the backlash of the gear trains 51 to 60, and the black photosensitive member. There is a deviation from the timing at which the body drum 1K starts to rotate in the reverse direction. Therefore, the intermediate transfer belt 8 and the photosensitive drum 1K (1Y, 1M, 1C) are strongly rubbed for the amount of time that the deviation has occurred, and the surfaces of both members are damaged.
In contrast, in the present embodiment, in the reverse rotation drive mode, the timing at which the intermediate transfer belt 8 starts to run in the reverse direction and the timing at which the black photosensitive drum 1K starts to rotate in the reverse direction are substantially matched. Therefore, it is possible to reduce a problem that damages are generated on the surfaces of both members.

Such a reverse drive mode has a problem that untransferred toner or paper dust accumulates on the edge of the cleaning blade 2a in contact with the photosensitive drum 1K (1Y, 1M, 1C), and the cleaning performance is deteriorated. A series of image forming operations is performed in order to simultaneously solve the problem that untransferred toner or paper dust accumulates on the edge of the belt cleaning blade 10a contacting the belt 8 and the cleaning performance deteriorates. It is executed every time it ends. It is to be noted that the driving of the photosensitive drum 1K and the intermediate transfer belt 8 in the reverse direction can prevent deposits from being deposited on the edges of the cleaning blade 2a and the belt cleaning blade 10a. This is because the wedge shape formed between the counterparts 1K and 8 in contact with the edge of 10a collapses.
In this embodiment, the reverse drive mode is set to be executed every time a series of image forming operations are completed, but the image forming operation is ended every time the cumulative time during which the image forming operation is performed reaches a predetermined value. The reverse drive mode may be executed later.

  Further, in the present embodiment, the photosensitive drum 1K is used in the reverse drive mode so that the effect of preventing the deposit of the deposits on the edges of the cleaning blade 2a and the belt cleaning blade 10a is reliably exhibited. The execution time of the reverse drive mode is set so that the intermediate transfer belt 8 and the intermediate transfer belt 8 each move at least 1.5 mm in the opposite direction.

Here, in the present embodiment, the second driving units 70 to 75 that drive the color photoconductor drums 1Y, 1M, and 1C also perform the color photoconductor drums 1Y, 1M, and 1C when the reverse drive mode is executed. Can be rotated in the reverse direction (counterclockwise in FIG. 5).
Specifically, the second drive motor 70 is also a forward / reverse bidirectional rotation type motor, and the drive gear 71 is moved in the forward direction (the arrow direction in FIG. 3 and the counterclockwise direction) under the control of the control unit 45. ) As well as in the opposite direction (in the direction of the arrow in FIG. 5 and in the clockwise direction).

When the reverse drive mode is executed, the color photosensitive drums 1Y, 1M, and 1C are maintained in contact with the intermediate transfer belt 8 by the contact / separation mechanism 80, and the intermediate transfer belt 8 is in black photosensitive state. A voltage is applied to all the primary transfer rollers 9Y, 9M, 9C, and 9K so as to be electrostatically attracted to the body drum 1K and the color photosensitive drums 1Y, 1M, and 1C and run in the reverse direction.
Specifically, in the reverse drive mode, in addition to voltage application from the black high-voltage power supply unit 40K to the black primary transfer roller 9K, the color primary transfer rollers 9Y, 9M, and 9C also include the color high-voltage power supply unit 40Y, A voltage of about +3000 V is applied from each of 40M and 40C, and the intermediate transfer belt 8 is electrostatically attracted to the color photosensitive drums 1Y, 1M, and 1C in addition to the black photosensitive drum 1K. The intermediate transfer belt 8 in a state where the drive transmission from the first drive motor 50 is released travels (follows) in the reverse direction following the rotation of the four photosensitive drums 1Y, 1M, 1C, and 1K (see FIG. 5).
As described above, by adsorbing the intermediate transfer belt 8 to the four photosensitive drums 1Y, 1M, 1C, and 1K, the holding force (adsorption force) to the intermediate transfer belt 8 is improved, and the intermediate transfer belt 8 is moved in the reverse direction. Driving will be performed stably and reliably.

FIG. 6 is a timing chart showing the control when the reverse drive mode is executed in the monochrome mode (the state of FIG. 4).
As shown in FIG. 6, when the image forming operation in the monochrome mode is performed (until time T1), the first drive motor 50 is rotated forward (driven in the forward direction). . At this time, the contact / separation mechanism 80 (contact / separation motor) is in an OFF state, and the color photosensitive drums 1Y, 1M, 1C and the color primary transfer rollers 9Y, 9M, 9C are separated from the intermediate transfer belt 8. It is in a separated state (the state of FIG. 4). The second drive motor 70 is in an off state (drive stop).
Thereafter, when the image forming operation in the monochrome mode is completed, the driving of the first drive motor 50 is stopped and the contact / separation mechanism 80 (contact / separation motor) is turned on at time T1 to T2, and the color photosensitive drum. 1Y, 1M, and 1C and the color primary transfer rollers 9Y, 9M, and 9C are in contact with the intermediate transfer belt 8 (the state shown in FIG. 3).
Thereafter, the reverse drive mode is executed from time T2 to T3. That is, when the contact between the color photosensitive drums 1Y, 1M, and 1C and the color primary transfer rollers 9Y, 9M, and 9C on the intermediate transfer belt 8 is completed, the first drive motor 50 is operated at time T2 to T3. The second drive motor 70 is also reversely rotated (reverse direction drive) while being reversely rotated (reverse direction drive). At this time, predetermined voltages are respectively applied to the four primary transfer rollers 9Y, 9M, 9C, and 9K, and the intermediate transfer belt 8 is attracted to the four photosensitive drums 1Y, 1M, 1C, and 1K in the reverse direction. Drive (the state shown in FIG. 5).
When the reverse drive mode ends, the driving of the first drive motor 50 and the second drive motor 70 are stopped and the four primary transfer rollers 9Y, 9M, 9C, and 9K are stopped at times T3 to T4. The voltage application is stopped. Further, from time T4, the color photosensitive drums 1Y, 1M, and 1C and the color primary transfer rollers 9Y, 9M, and 9C are separated from the intermediate transfer belt 8 by the separation operation by the contact / separation mechanism 80 ( This is the state of FIG. 4), and a series of operations ends.

FIG. 7 is a timing chart showing the control when the reverse drive mode is executed in the color mode (the state shown in FIG. 3).
As shown in FIG. 7, when the image forming operation in the full color mode is performed (until time T1), the first drive motor 50 and the second drive motor 70 rotate in the forward direction (in the forward direction). Is driven.) At this time, the contact / separation mechanism 80 (contact / separation motor) is in an OFF state, and the color photosensitive drums 1Y, 1M, 1C and the color primary transfer rollers 9Y, 9M, 9C are attached to the intermediate transfer belt 8. It is in a contact state (the state of FIG. 3).
Thereafter, when the image forming operation in the color mode is finished, the driving of the first drive motor 50 and the second drive motor 70 is stopped at times T1 to T2.
Thereafter, the reverse drive mode is executed from time T2 to T3. That is, the first drive motor 50 is operated at time T2 to T3 while the color photosensitive drums 1Y, 1M, and 1C and the color primary transfer rollers 9Y, 9M, and 9C are in contact with the intermediate transfer belt 8. The second drive motor 70 is also reversely rotated (reverse direction drive) while being reversely rotated (reverse direction drive). At this time, predetermined voltages are respectively applied to the four primary transfer rollers 9Y, 9M, 9C, and 9K, and the intermediate transfer belt 8 is attracted to the four photosensitive drums 1Y, 1M, 1C, and 1K in the reverse direction. Drive (the state shown in FIG. 5).
When the reverse drive mode ends, the driving of the first drive motor 50 and the second drive motor 70 are stopped and the four primary transfer rollers 9Y, 9M, 9C, and 9K are stopped at times T3 to T4. The voltage application is stopped. Further, from time T4, the color photosensitive drums 1Y, 1M, and 1C and the color primary transfer rollers 9Y, 9M, and 9C are separated from the intermediate transfer belt 8 by the contact / separation mechanism 80 (FIG. 4). A series of operations are completed.

In this embodiment, the second driving units 70 to 75 are provided separately from the first driving units 50 to 60, and the four photosensitive drums 1Y, 1M, 1C, 1K, and the intermediate are provided by these two driving units. The transfer belt 8 was driven.
On the other hand, as shown in FIG. 8, the four photosensitive drums 1Y, 1M, 1C, and 1K and the intermediate transfer belt 8 can be driven by one driving unit. At this time, as the black photosensitive drum 1K is rotationally driven in the forward direction, the driving unit rotationally drives the color photosensitive drums 1Y, 1M, and 1C in the forward direction and the reverse driving mode is executed. Sometimes the color photoconductor drums 1Y, 1M, and 1C are rotated in the reverse direction together with the black photoconductor drum 1K. Even in such a case, when the reverse drive mode is executed, the intermediate transfer belt 8 is electrostatically attracted to the black photosensitive drum 1K and the color photosensitive drums 1Y, 1M, and 1C. By applying a voltage to all of the four primary transfer rollers 9Y, 9M, 9C, and 9K so as to run in the opposite direction, the same effect as in the present embodiment can be obtained.

  Specifically, as shown in FIG. 8, the drive unit includes forward / reverse bidirectional rotation type drive motor 80, drive gear 81, first gear 52, second gear 75, third gear 73, fourth gear 72, The fifth gear 60 and the idler gears 55 to 59, 82, and 83 are configured. Then, during a normal image forming operation, the drive gear 81 fixed to the motor shaft of the drive motor 80 rotates counterclockwise in FIG. The cyan photosensitive drum 1C is rotationally driven in the clockwise direction in FIG. 8, and is transmitted from the driving gear 81 through the second gear 75 and the idler gear 82. Thus, the driving force is transmitted to the first gear 52 (fixed to the rotating shaft of the black photosensitive drum 1K), and the black photosensitive drum 1K is rotationally driven in the clockwise direction in FIG. . At the same time, the driving force is transmitted from the driving gear 81 to the third gear 73 (fixed to the rotating shaft of the magenta photosensitive drum 1M), so that the magenta photosensitive drum 1M is rotated clockwise in FIG. Driven by rotation, the driving force is transmitted from the driving gear 81 to the fourth gear 72 (fixed to the rotating shaft of the yellow photosensitive drum 1Y) via the third gear 73 and the idler gear 83, and the yellow photosensitive is transmitted. The body drum 1Y is rotationally driven in the clockwise direction in FIG. Further, from the drive gear 51 to the fifth gear 60 (fixed to the rotation shaft of the secondary transfer counter roller 12 that drives the intermediate transfer belt 8) via the third gear 73 and idler gears 83, 55 to 59. The driving force is transmitted, and the intermediate transfer belt 8 is driven to run counterclockwise in FIG. 8 by the frictional resistance with the secondary transfer counter roller 12. Here, a gear 60 is installed on the rotation shaft of the secondary transfer counter roller 12 via a one-way clutch 12a that transmits a driving force only in the forward direction, as in the present embodiment.

Also in the image forming apparatus shown in FIG. 8, in the reverse drive mode, the drive motor 80 is driven in the reverse direction, and the four primary transfer rollers 9Y from the four high-voltage power supply units 40Y, 40M, 40C, and 40K. A voltage is applied to 9M, 9C, and 9K. As a result, the four photosensitive drums 1Y, 1M, 1C, and 1K are rotationally driven in the reverse direction, and the intermediate transfer belt 8 is reversed in the reverse direction by being attracted to the photosensitive drums 1Y, 1M, 1C, and 1K at the same timing. Driven (followed).
In such an image forming apparatus, although the color photosensitive drums 1Y, 1M, and 1C are not contacted / separated, as in the case of the present embodiment, the cleaning blade 2a and the belt cleaning blade 10a are connected to each other. Accumulation of deposits is surely reduced.

  As described above, in the present embodiment, the first drive unit 50 to drive the intermediate transfer belt 8 (belt member) in conjunction with the rotational drive of the black photosensitive drum 1K (black image carrier). 60 (driving unit) is configured so that the photosensitive drum 1K can be rotationally driven in the reverse direction without transmitting a driving force to the intermediate transfer belt 8. When the photosensitive drum 1K is driven in reverse, the voltage is applied to the primary transfer roller 9K (transfer member) so that the intermediate transfer belt 8 is electrostatically attracted to the photosensitive drum 1K and travels in the reverse direction. Is applied. Thus, the photosensitive drum 1K and the intermediate transfer belt 8 are not deposited on the edge of the cleaning blade 2a for cleaning the photosensitive drum 1K and the edge of the belt cleaning blade 10a for cleaning the intermediate transfer belt 8, without depositing paper dust or untransferred toner. Even if the reverse rotation driving is performed, friction between the members 1K and 8 is less likely to occur.

In the present embodiment, the present invention is applied to the image forming apparatus 100 using the intermediate transfer belt 8 as a belt member. On the other hand, other belt members (for example, transfer and transfer belts that sequentially transfer toner images respectively formed on a plurality of opposed image bearing members onto the recording medium while conveying the recording medium) are used. The present invention can be applied to any image forming apparatus provided that a belt cleaning blade for cleaning the belt member is installed. In this case, the plurality of transfer members respectively facing the plurality of image carriers through the belt member transfer a toner image formed on the plurality of image carriers to a recording medium by applying a predetermined voltage. become.
Even in such a case, the same effect as in the present embodiment can be obtained by performing the reverse drive mode as in the present embodiment.

In the present embodiment, the present invention is applied to the image forming apparatus 100 using the primary transfer rollers 9Y, 9M, 9C, and 9K as transfer members. In contrast, the present invention can naturally be applied to the image forming apparatus 100 using a transfer charger (a transfer member that performs charging by wire discharge) as a transfer member.
In this embodiment, the one-way clutch 12a is installed to restrict the reverse driving force from being transmitted to the secondary transfer opposing roller 12, but other mechanisms (for example, the reverse driving force is transmitted). This is a mechanism for releasing the meshing of the gear train when it is done.), And it is possible to restrict the reverse driving force from being transmitted to the secondary transfer counter roller 12.
In these cases, the same effect as in the present embodiment can be obtained by performing the reverse drive mode as in the present embodiment.

  It should be noted that the present invention is not limited to the present embodiment, and it is obvious that the present embodiment can be modified as appropriate within the scope of the technical idea of the present invention, other than suggested in the present embodiment. is there. In addition, the number, position, shape, and the like of the constituent members are not limited to the present embodiment, and the number, position, shape, and the like suitable for implementing the present invention can be achieved.

1Y, 1M, 1C, 1K photosensitive drum (image carrier),
2K cleaning section,
2a cleaning blade,
6Y, 6M, 6C, 6K imaging unit,
8 Intermediate transfer belt (belt member),
9Y, 9M, 9C, 9K primary transfer roller (transfer member),
10 Intermediate transfer cleaning unit,
10a Belt cleaning blade,
12 Secondary transfer counter roller,
12a one-way clutch,
15 Intermediate transfer unit,
19 Secondary transfer roller (secondary transfer member),
40Y, 40M, 40C, 40K high voltage power supply,
50 1st drive motor (drive part),
70 second drive motor (second drive unit),
80 contact / separation mechanism,
100 Image forming apparatus body (apparatus body), P recording medium.

JP 2009-294312 A Japanese Patent No. 3769356

Claims (6)

A plurality of image carriers each rotating in a predetermined direction and having a toner image of each color formed thereon;
A belt member that travels in a predetermined direction and is arranged in parallel so that the plurality of image carriers face each other;
A plurality of toner images respectively facing the plurality of image carriers through the belt member and transferring a toner image formed on each of the plurality of image carriers to the belt member or the recording medium by applying a predetermined voltage. A transfer member of
A plurality of cleaning blades that respectively contact the plurality of image carriers and clean the surface of the image carrier;
A belt cleaning blade that contacts the belt member and cleans the surface of the belt member;
A driving unit that rotationally drives at least one image carrier among the plurality of image carriers in the predetermined direction and that drives the belt member to travel in the predetermined direction;
With
The drive unit is configured to be able to execute a reverse drive mode in which the at least one image carrier is rotationally driven in a reverse direction with respect to the predetermined direction without transmitting a drive force to the belt member,
When the reverse drive mode is executed, a voltage is applied to the transfer member so that the belt member is electrostatically attracted to the image carrier and travels in a direction opposite to the predetermined direction. An image forming apparatus. The one image carrier is a black image carrier on which a toner image is formed with black toner,
The image carrier other than the black image carrier among the plurality of image carriers is a color image carrier on which a toner image is formed with color toner,
A second drive unit that rotationally drives the color image carrier in a predetermined direction and that rotates the color image carrier in a direction opposite to the predetermined direction when the reverse drive mode is executed;
An approach / separation mechanism for making the color image bearing member contact / separate relative to the belt member;
Further comprising
When the reverse drive mode is executed, the color image carrier is maintained in contact with the belt member by the contact / separation mechanism, and the belt member is in contact with the black image carrier and the color member. 2. The image forming apparatus according to claim 1, wherein a voltage is applied to all of the plurality of transfer members so as to be electrostatically attracted to the image carrier and run in a direction opposite to the predetermined direction. apparatus. The one image carrier is a black image carrier on which a toner image is formed with black toner,
The image carrier other than the black image carrier among the plurality of image carriers is a color image carrier on which a toner image is formed with color toner,
The drive unit rotates the color image carrier in a predetermined direction as the black image carrier is driven to rotate in the predetermined direction, and the color when the reverse drive mode is executed. The image carrier is configured to rotate in a direction opposite to the predetermined direction,
When the reverse drive mode is executed, the belt member is electrostatically attracted to the black image carrier and the color image carrier and travels in a direction opposite to the predetermined direction. The image forming apparatus according to claim 1, wherein a voltage is applied to all of the plurality of transfer members.   The image forming apparatus according to claim 1, wherein the driving unit includes a one-way clutch that transmits only a driving force in one direction that causes the belt member to travel in the predetermined direction. .   5. The drive unit according to claim 1, wherein the drive unit moves the image carrier and the belt member in opposite directions by at least 1.5 mm when the reverse drive mode is executed. An image forming apparatus according to claim 1. The belt member is an intermediate transfer belt,
The transfer member is a primary transfer roller,
The image forming apparatus according to claim 1, further comprising a secondary transfer member that secondarily transfers the toner image primarily transferred onto the intermediate transfer belt to a recording medium. .

Images