JP2006011480A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that enables an image carrier to be replaced, and that is small-sized and can form multicolor images. <P>SOLUTION: The image forming apparatus, having a plurality of developing means of developing latent images with toner corresponding to respective color components, a primary transfer means of transferring toner images to an intermediate transfer body one after another, a secondary transfer means of transferring a multicolor image formed on the intermediate transfer body at a time, a fixing means of fixing the multicolor image to a recording material, a 1st recording material conveyance path conveying the recording material from the secondary transfer means to the fixing means, and a 2nd recording material conveyance path for conveying the recording material from the device body, has a support means for detachable supporting, a coupling means of coupling the developing means with the support means, and a moving means of moving the support means to move the developing means to a developing position or non-developing position. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a copying machine, a printer, a facsimile, and other image forming apparatuses using electrophotography. In particular, the present invention relates to an image forming apparatus capable of forming a multicolor image.

  As an image forming apparatus that forms a latent image corresponding to each color component on an image carrier, develops the latent image with toner corresponding to each color component, and sequentially superimposes the toner images to obtain a multicolor image, Conventionally, various configurations have been proposed.

  An image forming apparatus using such an electrophotographic method has a problem that the configuration is complicated, the apparatus is large, and the maintainability of the apparatus is poor.

  In order to improve the maintainability of the apparatus, for example, Japanese Patent Application Laid-Open No. 3-249765 and Japanese Patent Application Laid-Open No. 7-199768 have been proposed as image forming apparatuses that facilitate the supply and replacement of consumables.

  Japanese Patent Laid-Open No. 3-249765 discloses a configuration in which an image carrier, a plurality of developing means, and the like are integrated into a unit, and these units are attached and detached.

  However, an image forming apparatus that forms a multicolor image has a plurality of developing units unlike an image forming apparatus that forms a single color (for example, black only) image, and the image carrier is relatively large. Therefore, if these are integrated into a unit, the unit becomes quite large and heavy. In an image forming apparatus for forming a multicolor image, it is very difficult in practice to replace such a unit.

  Further, since the toner consumption amounts of the plurality of developing units are different from each other, if they are integrated as a unit, the other developing units must be replaced when all the toner of any developing unit is consumed. It is useless.

  Therefore, it is necessary that the image carrier and the plurality of developing units can be replaced separately.

  As the latent image forming means, a so-called laser scanning optical system that scans an image carrier with laser light is generally used, which is very sensitive to vibrations and shocks. When a deviation occurs in the optical components constituting the optical system, even if the deviation is not a problem in an image forming apparatus that forms a monochromatic image, the color deviation is caused in an image forming apparatus that forms a multicolor image. appear. Therefore, it is necessary to be able to replace the image carrier, the developing means, etc. without moving the latent image forming means.

  Furthermore, when replacing the image carrier, the developing means, etc., there may be an impact on the latent image forming means due to accidents such as accidentally dropping them on the apparatus body, so that the impact is minimized. It is necessary to dispose the latent image forming means so that the locus when the image carrier or the developing means is attached or detached does not pass above the latent image forming means.

  Japanese Patent Application Laid-Open No. 7-199768 discloses a configuration in which an image carrier, a developing unit, and the like are attached to and detached from each other in the axial direction of the image carrier.

  However, since the image carrier, the developing means, and the like have an elongated shape in the axial direction of the image carrier, it is difficult to insert the other end into the attachment / detachment opening of the apparatus main body while holding only one end thereof. . Generally, the drive part or electrode part of the image carrier or developing means is arranged on the side opposite to the side that is held when the image carrier or developing means is attached / detached, and is inserted into the attachment / detachment opening of the apparatus main body. Therefore, if it is damaged by colliding with the attachment / detachment opening at the time of insertion, a new image carrier or developing means may become unusable.

  In image forming apparatuses that form single-color images, A4 has been the mainstream recording material. However, image forming apparatuses that form multicolor images have recently increased in demand for multicolor printing. There is a demand for compatibility with recording materials larger than A4, such as A3 or paper larger than A3. For this reason, in image forming apparatuses corresponding to recording materials larger than A4 in particular, an image carrier is required. Since the developing means and the like have a longer shape in the axial direction of the image carrier, it becomes more difficult to attach and detach them in the axial direction of the image carrier.

  Further, as a means for assisting in the attachment / detachment of the image carrier having an elongated shape in the axial direction of the image carrier or the developing means to the apparatus main body, for example, the image carrier, the developing means or the like is moved in the axial direction. In the past, there have been proposed a structure in which a movable base or the like for moving a guide groove, an image carrier, developing means, and the like is provided on the apparatus main body side, and further, such auxiliary means can be pulled out from the apparatus main body. . However, the attachment / detachment in the axial direction is longer than the attachment / detachment in the direction perpendicular to the axial direction because the distance for moving the image carrier, the developing means, etc. from the attachment / detachment port to the attachment position in the apparatus main body is long. When the linearity of the guide groove is insufficient, it becomes difficult to attach and detach. In addition, since the guide groove is long, foreign matter is likely to be caught in the guide groove, and the attachment / detachment is also difficult.

  In addition, when attaching or detaching an image carrier having an elongated shape in the axial direction of the image carrier, developing means, or the like to the apparatus main body in the axial direction, the other end is attached to the apparatus main body while holding only one end thereof. Since it is inserted into the outlet, the image carrier and the developing means that are cantilevered are likely to bend or distort.

  In particular, the developing means used in the image forming apparatus for forming a multicolor image has a part thereof, for example, a side surface or the like when the developing means is mounted in the apparatus main body in order to repeatedly move away from and in contact with the image carrier in the apparatus main body. In a configuration in which only the both ends are supported and moved, or a movable member such as a roller is brought into contact with and supported by the lower part of the developing unit, the developing unit is easily bent and distorted, and a stable and good image can be obtained. Can't get.

  For this reason, it is necessary to give the image carrier and developing means sufficient strength so as not to bend in the axial direction. This is one of the factors that increase the cost of these replacement members. Yes.

In the configuration in which the image carrier having a shape elongated in the axial direction of the image carrier and the developing means are attached to and detached from the apparatus main body in the axial direction, the image carrier and the like are attached and detached in a direction perpendicular to the paper transport direction. Therefore, if the image carrier is accidentally attached or detached while the paper is jammed in the main body, the image carrier will be damaged by the jammed paper, or the paper may be torn and It may move inside the device main body (especially the back side opposite to the attachment / detachment port which is difficult to reach) and damage the entire device. Further, in such a configuration, it is necessary to provide a means for removing paper jammed in the apparatus main body separately from the attachment / detachment opening of the image carrier and the developing means.
JP-A-3-249765 JP-A-7-199768

  As described above, the present invention comprehensively examines the configuration and arrangement of the image carrier, the intermediate transfer member, the latent image forming unit, the developing unit, the transfer unit, the fixing unit, the recording material storage unit, and the recording material conveyance path. An image forming apparatus capable of forming a small and multi-color image with a simple structure that facilitates replacement of a developing unit that requires replenishment of a consumable member, a recording material storage unit, and an image carrier that needs to be replaced due to its life. It is intended to provide.

  In order to solve the above-described problems, the first invention provides a latent image forming unit for forming a latent image corresponding to each color component on an image carrier, and a latent image on the image carrier for each color. A plurality of developing means for developing with toner corresponding to the components; a primary transfer means for sequentially transferring the toner image on the image carrier onto the intermediate transfer body; and the intermediate on the recording material conveyed from the recording material storage means. A secondary transfer unit that collectively transfers the multicolor image formed on the transfer body; a fixing unit that fixes the multicolor image to the recording material; and a recording material in the recording material storage unit that transfers the recording material to the secondary transfer unit. An image forming apparatus having a first recording material conveyance path that conveys the recording material from the fixing means to the fixing means, and a second recording material conveyance path that discharges the recording material conveyed from the fixing means from the apparatus main body. Support means for detachably supporting the developing means; A connecting means for connecting the developing means to the supporting means; and a moving means for moving the supporting means to move the developing means connected to the supporting means to a developing position or a non-developing position. To do.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect of the invention, a frame structure that supports the plurality of support means corresponding to the plurality of the developing means, and the frame structure is fixed to the frame structure via the support means. The frame structure may be rotated to move the developing means to a first position where the developing means is urged to the image carrier and a second position where the developing means is released from the image carrier.

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect of the present invention, the image forming apparatus further comprises bistable means for bringing the frame structure into a bistable state between the first position and the second position.

  According to a fourth aspect of the present invention, in the image forming apparatus of the third aspect of the invention, the developing unit is attached and detached with the frame structure opened to the second position and the toner containing portion of the developing unit positioned downward. It is possible.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the first aspect of the invention, the connecting means includes a pin provided on one of the developing means or the supporting means and engaged with the other, and the developing means or the supporting means. It is characterized by comprising an insertion portion provided on one side into which the other pin is inserted and a cam for urging the pin inserted into the insertion portion in a predetermined direction.

  According to a sixth aspect of the present invention, in the image forming apparatus of the fifth aspect, the predetermined direction is a direction in which the developing unit is urged toward the image carrier and a direction in which the developing unit is urged toward the support unit. It is characterized by that.

A latent image forming unit that forms a latent image corresponding to each color component on the image carrier of the present invention, a plurality of developing units that develop the latent image on the image carrier with toner corresponding to each color component, and the image A primary transfer unit that sequentially transfers a toner image on the carrier onto the intermediate transfer member and a multicolor image formed on the intermediate transfer member onto the recording material conveyed from the recording material storage unit are collectively transferred. A secondary transfer means, a fixing means for fixing the multicolor image on the recording material, and a first recording material conveyance path for conveying the recording material in the recording material storage means from the secondary transfer means to the fixing means; And a second recording material conveyance path for discharging the recording material conveyed from the fixing unit from the apparatus main body, a support unit for detachably supporting the developing unit, and the developing unit Connecting means for connecting the support means to the support means; A developing device having an elongated shape in the axial direction of the image carrier is provided by a structure having moving means for moving the supporting means to move the developing means connected to the developing means to a developing position or a non-developing position. It can be supported and moved without causing bending or distortion in the body.
A frame structure that supports the plurality of support means according to the plurality of development means, and a first structure that biases the development means fixed to the frame structure via the support means to the image carrier. With the configuration in which the frame structure is rotationally moved to move to a position and a second position released from the image carrier, the developing means can be accurately positioned with respect to the image carrier with a simple configuration.
The frame structure that supports the developing unit can be easily configured by opening the frame structure to the second position and allowing the developing unit to be attached and detached with the toner storage portion of the developing unit positioned below. It can be stabilized at a predetermined position by the configuration.
With the structure in which the frame structure is opened to the second position, and the developing means is detachable with the toner accommodating portion of the developing means positioned below, the scattering of the toner due to the detachment of the developing means is prevented. be able to.
The connecting means includes a pin that is provided on one of the developing means or the supporting means and engages with the other, an insertion portion that is provided on one of the developing means or the supporting means and into which the other pin is inserted, The developing means can be attached to and detached from the frame structure with a simple configuration by a configuration comprising a cam for urging the pin inserted into the inserted portion in a predetermined direction.
The predetermined direction is a direction in which the developing unit is urged to the image carrier and a direction in which the developing unit is urged to the support unit, so that the developing unit is securely fixed to the frame structure with a simple configuration. can do.

  Embodiments of the present invention will be described with reference to the drawings, taking as an example an apparatus for forming a color image.

  FIG. 1 is a sectional view showing an image forming apparatus according to the present invention, which is a color image forming apparatus using a belt-shaped intermediate transfer member.

  The overall configuration and operation of this apparatus will be described with reference to FIG.

  In FIG. 1, a drum-shaped photoreceptor 1 (image carrier) is rotationally driven in the direction of arrow D by a drive source such as a motor (not shown). A charging means 2 such as a charging roller is disposed on the outer periphery of the photosensitive member 1, and the surface of the photosensitive member 1 is uniformly charged while rotating in contact with the photosensitive member 1.

  The photosensitive member 1 having a uniformly charged surface is selectively scanned and exposed in accordance with, for example, yellow image information as a first color by a latent image forming unit 3 such as a laser scanning optical system. An image is formed.

  On the downstream side in the rotation direction of the photosensitive member 1 on which the electrostatic latent image is recorded, yellow, magenta, cyan, and black toners are respectively stored as developing agents. 5, 6 and 7 are arranged, and the yellow electrostatic latent image thus formed is developed only by the yellow developing means 4 in contact with the photoreceptor 1, whereby a yellow toner image is formed.

  An intermediate transfer belt 8 is disposed adjacent to the photoreceptor 1 on the downstream side in the rotation direction of the photoreceptor 1 on which the toner image is formed. The intermediate transfer belt 8 is wound around a drive roller 9, a backup roller 10, a tension roller 11, and a scissor roller 12, and is driven at the same speed as the peripheral speed of the photoreceptor 1. Further, the driving force of the photosensitive member 1 is transmitted to the driving roller 9 so that the photosensitive member 1 and the intermediate transfer belt 8 are driven synchronously.

  The primary transfer roller 13 is urged toward the photoreceptor 1 via the intermediate transfer belt 8, and a high pressure (not shown) is provided at a primary transfer position where the intermediate transfer belt 8 is sandwiched between the photoreceptor 1 and the primary transfer roller 13. By supplying a voltage from the power source to the primary transfer roller 13, the yellow toner image formed by the above-described procedure is transferred onto the surface of the intermediate transfer belt 8.

  The photoreceptor 1 having transferred the yellow toner image to the intermediate transfer belt 8 further rotates in the direction of arrow D, and the toner remaining on the surface of the photoreceptor 1 is scraped off by the photoreceptor cleaner 14 constituted by a cleaner blade or the like. Image formation becomes possible again.

  By repeating the same procedure for the second to fourth color images (magenta, cyan, and black), four color toner images are sequentially superimposed and recorded on the intermediate transfer belt 8.

  When the superposition of the four color toner images on the intermediate transfer belt 8 is completed, the recording material 17 is fed from the paper cassette 80 (recording material storage means) by the paper feed roller 20 and the pair of paper transport rollers 15 and 16. Synchronously, the secondary transfer roller 18 rotates in the direction of arrow E around the secondary transfer fulcrum shaft 19 by a clutch mechanism and a cam mechanism (not shown) and comes into contact with the backup roller 10 via the intermediate transfer belt 8, thereby recording material 17. In the secondary transfer position where the intermediate transfer belt 8 is sandwiched between the backup roller 10 and the secondary transfer roller 18, a voltage is applied to the secondary transfer roller 18 from a high voltage power source (not shown), so that The color toner images are collectively transferred to the recording material 17. An intermediate transfer belt cleaner 21 composed of a cleaner blade or the like is rotated and brought into contact with the intermediate transfer belt 8 after the secondary transfer in the direction of arrow F by a clutch mechanism and a cam mechanism (not shown). The toner remaining on the toner is scraped off, and when the scraping is completed, the intermediate transfer body cleaner 21 rotates in the direction opposite to the arrow F and retracts.

  The recording material 17 onto which the four color toner images have been transferred reaches the fixing means 22 from the secondary transfer position via the first recording material conveyance path for conveying the recording material 17 substantially in parallel with the apparatus main body. The toner image is fixed by being nipped and conveyed while being heated and pressurized. The recording material 17 to which the toner image has been fixed is changed in its conveying direction by the fixing means 22 toward the upper surface of the apparatus main body, and the recording material 17 is conveyed from the fixing means 22 substantially perpendicularly to the apparatus main body and reaches the upper surface of the apparatus. The paper is discharged to the upper surface of the apparatus by a pair of paper discharge rollers 23 and 24 installed in the second recording material conveyance path, and the color image recording is completed.

  Further, some configurations of the present apparatus in FIG. 1 will be supplementarily described.

  A control panel 31 for displaying an instruction for controlling the image forming apparatus and a state of the image forming apparatus is installed on the front cover of the apparatus main body. The surface on which the control panel 31 is installed is used as a normal use state surface of the user in this apparatus. In addition, the control panel 31 may be installed on the upper surface cover. In this case, the surface of the control panel 31 that faces the control panel 31 is used in this apparatus so that the visibility and operability of the control panel 31 are improved. It is a normal use state surface of a person and is used as a front surface. In the present apparatus, the front surface of the apparatus main body is a surface substantially parallel to the axis of the image carrier.

  As the photoreceptor 1, a drum-shaped member having an outer diameter of 90 mmφ or less, more preferably 80 mmφ or less is used. As the radius of curvature of the photosensitive member 1 increases (the photosensitive member approaches a flat surface), the developing electric field gradually changes before and after the developing position at each developing position where the photosensitive member and each developing unit face each other. There is a problem that toner tends to adhere excessively to the downstream side of the developing position (the rear end portion of the latent image) when viewed from the direction of rotation of the body, and the image becomes thicker or darker. By using this drum-shaped photoconductor, the development electric field at each development position where the photoconductor and each developing means face each other can be changed abruptly before and after the development position, and a good image can be obtained. I can do it.

  The developing means 4, 5, 6, and 7 are juxtaposed around the photoreceptor 1, and the angle formed from the most upstream developing means 4 to the most downstream developing means 7 with respect to the center of the photoreceptor 1 is 140. By configuring the developing means 4 at a position almost immediately above the photoreceptor, the space for the lower part of the photoreceptor 1, that is, the primary transfer position, is configured so that the angle is less than or equal to °, more preferably less than or equal to 125 °. Can be secured more widely. Therefore, when an intermediate transfer belt is used as the intermediate transfer member, the intermediate transfer belt 8 can be wound around the photosensitive member 1 in a wide area, or a plurality of rollers can be arranged near the primary transfer position.

  The developing means 4, 5, 6, and 7 are detachably supported by the frame 25, and the frame 25 is configured to be rotatably supported around the frame fulcrum shaft 26. The frame 25 may be configured to be drawable on the front side of the apparatus main body, for example, in a direction substantially parallel to the apparatus main body. In such a configuration, the position of the frame 25 is changed each time the frame 25 is moved to the photoconductor 1 side. Since the positions of the developing means 4, 5, 6, and 7 with respect to the photosensitive member 1 are not stable unless the four points at both the upper and lower ends of the frame 25 are positioned, the frame 25 has the frame fulcrum shaft 26 as in this apparatus. It is preferable to have a structure that is rotatably supported at the center. With such a configuration, since the position of the lower portion of the frame 25 is stabilized by the frame fulcrum shaft 26, only the two points at both ends of the upper portion of the frame 25 are accurately positioned. The positions of the developing units 4, 5, 6, and 7 can be stabilized with higher positioning accuracy.

  Further, in this apparatus, the developing means 4 is arranged at a position almost immediately above the photosensitive member. However, when the frame 25 is moved substantially parallel to the apparatus main body, the developing device 4 and the photosensitive member 1 come into contact with each other and are damaged. There is a case. Therefore, as in this apparatus, the frame 25 is configured to rotate and the frame fulcrum shaft 26 is disposed at an appropriate position so that the developing means 4 is disposed at a position almost directly above the photoconductor. The contact between the developing means 4 and the photosensitive member 1 due to the movement of 25 can be prevented.

  The driving roller 9 for driving the intermediate transfer belt 8 is disposed on the back side of the apparatus main body. For this reason, the driving source and the drive transmission means for driving the photoreceptor 1 and the intermediate transfer belt 8 are integrated on the back side of the apparatus main body. The apparatus main body can be reduced in size.

  Since the backup roller 10 is disposed on the lower surface side of the apparatus main body and the secondary transfer position is disposed on the lower surface side of the apparatus main body, gravity is applied to the recording material 17 after transfer at the secondary transfer position. Since it can act in the peeling direction from the intermediate transfer belt 8, it is not necessary to provide a peeling means for peeling the recording material 17 from the intermediate transfer belt 8. Therefore, the configuration of the apparatus can be simplified and the apparatus main body can be reduced in size.

  The tension roller 11 is disposed on the front side of the apparatus main body. Further, although a specific configuration will be described later, in this apparatus, replacement of the developing means, removal of paper jammed in the recording material conveyance path, and the like are performed on the front side of the apparatus main body. Therefore, even if an exchange member, a hand, or the like accidentally touches the intermediate transfer belt 8 during the processing, the contact position becomes the peripheral position of the tension roller 10, and therefore the intermediate transfer belt 8 Can be quickly absorbed by the displacement of the tension roller 10, and damage to the intermediate transfer belt 8 can be prevented.

  In this apparatus, the intermediate transfer belt 8 is stretched substantially parallel to the apparatus main body. Further, the portion of the intermediate transfer belt 8 from the backup roller 10 to the tension roller 11 is configured to be substantially parallel to the second recording material conveyance path. For this reason, the intermediate transfer belt 8, the first recording material conveyance path, and the recording material storage means 80 are arranged so as to overlap each other in the substantially horizontal direction, and a part of the intermediate transfer belt 8 is disposed in the second recording material conveyance path. And a small image forming apparatus in which the installation area of the apparatus main body is approximately the same size as the recording material accommodating means.

  The fixing unit 22 is for applying a release agent such as silicone oil to the heat roller 27, the first pressure roller 28, the second pressure roller 29, and the heat roller 27 including a heating unit such as a halogen lamp. Or a pad-shaped or roller-shaped release agent coating means 30 for cleaning the surface of the heat roller 27.

  In this apparatus, the paper transport direction changing means for changing the paper transport direction significantly is not arranged downstream of the fixing means 22, and the fixing means 22 also serves as the paper transport direction changing means. Here, the paper transport direction changing means is a means for changing the paper transport direction by at least 45 ° or more by means of a claw or a guide plate, and for example, the paper transport direction is changed from a substantially parallel direction to a substantially vertical direction in the apparatus main body. It is a means for making it change.

  It is possible to use a configuration in which the paper conveyance direction changing unit is arranged on the downstream side of the fixing unit 22 and the conveyance direction of the recording material 17 is changed. If the paper transport direction changing means is a plate-like member formed on a curved surface, there is a problem that a paper is easily loaded at the position where the paper enters the paper transport direction changing means and paper jam is likely to occur. However, in this apparatus, the fixing unit 22 also serves as a paper conveyance direction changing unit and changes the conveyance direction of the recording material 17. In the recording material conveyance path before and after the fixing unit 22, the paper is substantially parallel to the apparatus main body. Or since it is conveyed in the fixed direction of the substantially vertical direction, generation | occurrence | production of a paper jam can be prevented.

  In the present apparatus, the angle formed from the first pressure roller 28 to the second pressure roller 29 with respect to the center of the heat roller 27 is in a range of 45 ° or more and 90 ° or less. More preferably, it is configured to be 60 ° or more and 80 ° or less. As described above, the angle formed from the first pressure roller 28 to the second pressure roller 29 is 45 ° or more, more preferably 60 ° or more, so that the first recording material conveyance path and the apparatus main body are substantially omitted. The recording material conveyed in parallel can be guided in a substantially vertical direction by changing the conveyance direction of the recording material without separately providing a paper conveyance direction changing unit downstream of the fixing unit. Since the material can be wound sufficiently, the toner is sufficiently melted and excellent in color development and light transmittance, especially when the base material forms a multi-color image having light transmittance on a transparent recording material. Images can be formed. Further, by making the angle formed by the first pressure roller 28 to the second pressure roller 29 to be 90 °, more preferably 80 ° or less, a recording material made of a laminate of a plurality of paper such as envelopes is conveyed. Even when the recording material surface is in contact with the heat roller 27 and the recording material surface in contact with the first pressure roller 28 and the second pressure roller 29, the double-sided deviation or wrinkle is reduced. In addition, even when a stiff recording material such as a plastic film for forming a transmission image is used, the recording material can be prevented from being clogged in the fixing unit 22.

  In the present apparatus, the second recording material conveyance path is configured to convey the recording material in a substantially vertical direction on the front side of the apparatus main body and discharge the recording material onto the upper surface of the apparatus main body. If the user accidentally gives an impact to the device during operation, the impact is often applied to the front side of the device body, which is the normal use surface, but this device forms a multicolor image. If the user gives an impact accidentally when the user is in a single color image, even if the impact is so small that it does not cause a problem with a single color image, a misalignment of several tens of μm or more is required for a multicolor image in which a plurality of color images are superimposed. Therefore, it is necessary to reduce the impact and prevent the color misregistration of the image. By arranging the second recording material conveyance path like this device, the impact from the front side of the main body of the apparatus is mitigated by the cavity of the recording material conveyance path, so that the impact and vibration to the main body of the apparatus are reduced. Can do. Even if vibration is propagated to the recording material being conveyed through the second recording material conveyance path, the image is already fixed on the recording material by the fixing means 22 because the recording material conveyed here is not disturbed. Does not occur.

  Further, in this apparatus, the second recording material conveyance path is disposed substantially above the fixing unit 22, and the fixing unit 22 and the developing units 4, 5, 6, 7 disposed above the fixing unit 22 are provided. Since the arrangement is made so that they do not overlap in the vertical direction, even when an exhaust fan (not shown) for exhausting the inside of the apparatus main body is stopped simultaneously with the power-off of the apparatus, the heat of the fixing means 22 is the second recording material. Since the air is naturally exhausted upward via the conveyance path, it is possible to minimize the influence of heat on the developing unit and the intermediate transfer member disposed in the vicinity of the fixing unit.

  Further, since the second recording material conveyance path is arranged substantially vertically above the fixing unit 22, the installation area of the apparatus can be reduced.

  FIG. 2 is a cross-sectional view of the apparatus showing a state in which the cover of the image forming apparatus of the present invention is opened. In addition, the same number is attached | subjected to the member same as FIG. 1, and description is abbreviate | omitted.

  The attaching / detaching operation of the developing means 4, 5, 6, 7 and the recording material storage means 80 will be briefly described with reference to FIG.

  The front cover 81 and the upper cover 82 of the apparatus main body are configured to be openable by fulcrums (not shown).

  When the front cover 81 is moved in the opening direction by being tilted to the front side of the apparatus main body, the fixing means 22 is also moved integrally with the front cover 81 and is opened to the front side of the apparatus main body together with the front cover 81.

  By opening the front cover 81, a first recording material conveyance path from the secondary transfer position to the fixing unit 22, and a discharge roller pair 23 and 24 for discharging the recording material 17 from the fixing unit 22 to the upper surface of the apparatus. Is exposed outside the apparatus. Therefore, even if the recording material 17 is jammed in either the first recording material conveyance path or the second recording material conveyance path, the jammed recording material can be removed from the front side of the apparatus main body only by opening the front cover 81. Can be removed.

  Further, a waste toner storage container (not shown) that is installed at one end of the intermediate transfer body cleaner 21 and stores the waste toner collected by the intermediate transfer body cleaner 21 is opened, and the front cover 81 is opened. It can also be replaced from the front side.

  Further, the release agent applying means 30 constituting the fixing means 22 can be replaced from the front side of the apparatus main body as indicated by an arrow in the figure simply by opening the front cover 81. In this apparatus, the example in which only the release agent coating unit 30 is replaced has been shown, but the fixing unit 22 can also be replaced integrally.

  In this apparatus, the fixing unit 22 moves with the front cover 81, but the fixing unit 22 may not move even when the front cover 81 moves. Even with such a configuration, as described above, in the present apparatus, it is not necessary to arrange the paper conveyance direction changing means downstream of the fixing means 22, and the fixing means 22 is arranged close to the front side of the apparatus main body. Therefore, the release agent coating means 30 or the fixing means 22 can be replaced from the front side of the apparatus main body. Further, since the fixing unit 22 is not exposed to the outside of the apparatus when a paper jam occurs, the temperature of the fixing unit 22 does not easily decrease when the paper jam occurs. Image formation can be started by returning the temperature.

  Alternatively, if necessary, a cover for replacing the release agent coating means 30 or the fixing means 22 from the front side of the apparatus main body may be installed on the front face of the apparatus main body separately from the front cover 81. With such a configuration, even if the front cover 81 is released when a paper jam occurs, the temperature of the fixing unit 22 is unlikely to decrease, and even if the front cover 81 moves, the fixing unit 22 does not move. The coating unit 30 or the fixing unit 22 can be more easily replaced from the front side of the apparatus main body.

  Note that, as in the present apparatus, the configuration in which the fixing unit 22 moves together with the front cover 81 does not move the fixing unit 22 even when the front cover 81 moves. The path can be opened wider, and the jammed paper can be easily removed, and the intermediate transfer member cleaner 21 disposed near the fixing unit or the waste toner storage container for storing the waste toner can be easily replaced. This is a preferred configuration.

  Even if the top cover 82 is not opened, the developing means 7 can be attached to and detached from the frame 25 as shown by an arrow in the figure by opening the front cover 81. Therefore, the black developing means that is frequently used and frequently exchanged is used as the developing means 7, so that the black developing means can be replaced more easily.

  After the front cover 81 is opened, when the upper cover 82 is lifted to the upper surface side of the apparatus main body and further moved partially to the rear side to move in the opening direction, all the developing means 4, 5 supported by the frame 25. , 6 and 7 are exposed to the outside of the apparatus.

  By opening the upper surface cover 82 together with the front cover 81, the opening on the front side of the apparatus main body is opened further than when only the front cover 81 is opened. It becomes easier to remove a paper jam in the recording material conveyance path and replace the fixing unit 22 and the release agent coating unit 30. Since the substantially front side of the apparatus main body is largely opened, the visibility is good, and the member to be replaced can be easily attached and detached.

  By opening the top cover 82 together with the front cover 81, the developing means 4, 5, 6, and 7 supported by the frame 25 are exposed to the outside of the apparatus, so that each developing means can be detached from the front side of the apparatus main body. Can be exchanged. Since the developing means 4, 5, 6, and 7 are arranged on the front side of the apparatus main body with respect to the photoreceptor 1, the developing means 4, 5, 6, and 7 are attached to and detached from the rear side (developer housing part). Therefore, the front side of the developing means 4, 5, 6, and 7 (the developing opening for attaching the toner to the photosensitive member 1) is accidentally touched and installed in the developing opening of the developing means. The developing roller or the like is not damaged, or the hand is not soiled by the toner exposed to the developing opening.

  The paper cassette 80 can be attached and detached in the direction of the arrow in the figure from the front side of the apparatus main body to replenish the recording material 17 irrespective of the opening of the front cover 81 and the upper cover 82. In this apparatus, the paper cassette 80 is used as the recording material storage means, but a paper tray may be used instead of the paper cassette. Further, the recording material storage means and the paper feed roller 20 and the paper transport roller pairs 15 and 16 may be integrally configured so as to be able to be pulled out to the front side of the apparatus main body. Even when the recording material is jammed in the recording material conveyance path from the recording material storage means to the secondary transfer position, the recording material can be more easily removed from the front side of the apparatus main body.

  In the present apparatus, the control panel 31 is moved together with the front cover 81. However, the control panel 31 is installed on the front cover at a position outside the second recording material conveyance path, and the second recording is performed. Only the front cover corresponding to the material conveyance path may be configured to be openable, and the control panel 31 may be configured not to move regardless of the opening of the front cover.

  FIG. 3 is a cross-sectional view of the apparatus showing a state in which a frame structure that integrally supports a plurality of developing means of the image forming apparatus of the present invention is opened. In addition, the same number is attached | subjected to the member same as FIG. 1, and description is abbreviate | omitted.

  With reference to FIG. 3, the attaching / detaching operation of the image carrier 1 or the like will be briefly described.

  The developing means 4, 5, 6, 7 are detachably supported on the frame 25 as described above, and the frame 25 is configured to be rotatable about the frame fulcrum shaft 26.

  After opening the front cover 81 and the top cover 82 of the apparatus main body, when the frame 25 is moved in the opening direction by tilting it toward the front side of the apparatus main body, the photosensitive member 1 is exposed to the outside of the apparatus.

  By opening the frame 25 in this way, the photoreceptor 1 can be attached and detached from the front side of the apparatus main body in the direction of the arrow in the figure.

  Further, the photoconductor cleaner 14 can be exposed by opening the frame 25 and then moving the photoconductor 1 out of the apparatus. In this state, the photoconductor cleaner 14 is installed at one end of the photoconductor cleaner 14. A waste toner storage container (not shown) for storing the collected waste toner can be replaced from the front side of the apparatus main body. Further, although an example in which only the waste toner storage container is replaced has been shown, the photoconductor cleaner 14 and the waste toner storage container can be replaced together, and the waste toner storage container or the photoconductor cleaner 14 can be replaced with the photoconductor 1. It can also be configured as an integral unit and replaced as a photoreceptor unit.

  In this apparatus, a belt-like photosensitive member can be used as the image carrier, but it is preferable to use a drum-like photosensitive member.

  In general, a belt-like photoreceptor is a belt photoreceptor unit configured integrally with a plurality of rollers for driving the belt and applying tension to the belt, and a support member for supporting these rollers at predetermined positions. Exchanged. Further, in general, a belt-shaped photoconductor is formed with a long flat portion parallel to the rotation direction of the photoconductor as a surface facing the developing device in order to arrange a plurality of developing devices in parallel. In order to easily attach and detach the belt-shaped photoconductor, it is preferable to attach and detach the belt-shaped photoconductor in a direction substantially parallel to the plane portion. However, since the plane portion is long, the movement required to attach and detach the belt-shaped photoconductor is required. The distance gets longer.

  On the other hand, the drum-shaped photoconductor is simpler, cheaper, and lighter than the belt-shaped photoconductor, and further, the moving distance at the time of replacement can be shortened. Therefore, replacement is easy and requires replacement. The configuration is suitable for use as a consumable member.

  In this apparatus, as described above, the developing means 4, 5, 6, and 7 can be attached and detached while the frame 25 is urged toward the photosensitive member 1, but the frame 25 is further opened. However, the developing means 4, 5, 6, and 7 can be attached and detached, respectively. In a state where the frame 25 is opened, the developing means 4, 5, 6, 7 are each in a posture in which the developing opening portion faces upward and the developer accommodating portion faces downward. Therefore, when the developing units 4, 5, 6, and 7 are attached and detached, the toner stored in the developing unit is moved to the developer storing unit side, so that the toner can be prevented from scattering from the developing opening. .

  Further, in a state where the frame 25 is opened, the developing means 4, 5, 6, 7 are further drawn out to the front side of the apparatus main body, so that the developing means can be easily attached and detached from the front side of the apparatus main body. 1 can be easily attached and detached.

  As described above, the arrangement and attaching / detaching method of the image carrier, the developing unit, the recording material storage unit, and the like in the apparatus have been described with reference to FIGS. 1, 2, and 3. A member having an elongated shape in the axial direction of the image carrier by attaching and detaching the image carrier, developing means, recording material storage means, etc. from the front side of the apparatus main body in a direction substantially perpendicular to the axis of the image carrier. Can be easily replaced without damaging the member to be replaced and the apparatus main body, and without giving an impact to the latent image forming means.

  FIG. 4 is an operation schematic diagram showing the rotational movement of the frame structure that integrally supports a plurality of developing means of the image forming apparatus of the present invention. In addition, the same number is attached | subjected to the member same as FIG. 1, and description is abbreviate | omitted.

  With reference to FIG. 4, a mechanism for rotating and moving the frame 25 to the first position for urging the photosensitive member to the photosensitive member and the second position for releasing the photosensitive member from the photosensitive member, and setting the frame 25 in a stable state at each position. Briefly described.

  The frame 25 is centered about the frame fulcrum shaft 26 between a first position (solid line in the figure) urged to the photosensitive member and a second position (two-dot chain line in the figure) released from the photosensitive member. It is configured to be rotatable.

  One end of a spring 33 is fixed to the frame 25 in order to stabilize the frame 25 at each position at a first position where the frame 25 is biased toward the photosensitive member and a second position where the frame 25 is released from the photosensitive member. The other end of the spring 33 is fixed to the arm 34.

  The arm 34 is attached to a side plate of the apparatus main body (not shown) via an arm fulcrum shaft 32, and is supported so as to be rotatable about the arm fulcrum shaft 32.

  First, it is assumed that the frame 25 is in the first position.

  When the frame 25 is to be moved, the spring 33 is pulled accordingly. Due to the force generated by the extension of the spring 33, the frame 25 is urged in a direction to return the frame 25 to the first position. Therefore, when the frame 25 is further rotated in the direction of arrow G and moved from the first position to the second position, the arm 34 is moved in the direction of arrow H by the force generated by the extension of the spring 33, and the extension of the spring 33 is increased. Is resolved.

  Next, when trying to move the frame 25 from the second position, the spring 33 is pulled. Due to the force generated by the extension of the spring 33, the frame 25 is urged in a direction to return the frame 25 to the second position. Therefore, when the frame 25 is further rotated in the direction opposite to the arrow G direction and moved from the second position to the first position, the arm 34 moves in the direction opposite to the arrow H direction due to the force generated by the extension of the spring 33. And the extension of the spring 33 is eliminated.

  Therefore, when the frame 25 is at the first position and the second position, the frame 25 is biased by the spring 33 in a direction in which the frame 25 becomes stable at each position.

  With the configuration shown in FIG. 4, since the frame 25 can be in a two-position stable state, the developing means 4, 5, 6, 7 supported by the frame 25 can be used as a photosensitive member or the like during image formation. Regardless of the vibration associated with the driving of the intermediate transfer member or the vibration associated with the separation / contact operation of the developing means with respect to the photosensitive member, the photosensitive member can be brought close to or contacted stably. Further, when the photosensitive member is replaced, it is possible to prevent accidents such as accidentally touching the frame 25 in the release position and closing the frame 25 to damage the photosensitive member or the like.

  FIG. 5 is a side sectional view of a frame structure that integrally supports a plurality of developing means of the image forming apparatus of the present invention. In addition, the same number is attached | subjected to the member same as FIG. 1, and description is abbreviate | omitted.

  The operation of the developing means 4, 5, 6, 7 that is detachably supported on the frame 25 will be briefly described with reference to FIG. 5.

  The frame 25 is provided with support means 55, 56, 57, 58 for detachably supporting the developing means 4, 5, 6, 7 respectively.

  The support means 55, 56, 57, 58 have a shape composed of a bottom plate for placing the developing means 4, 5, 6, 7 and a side plate that is integrally bent upward at both ends of the bottom plate.

  The support means 55, 56, 57, 58 are respectively attached to the frame 25 via detachment fulcrum shafts 39, 40, 41, 42, and the detachment fulcrum shafts 39, 40, 41, 42 are the center. Is supported to be rotatable.

  Further, the side plates of the support means 55, 56, 57, 58 support the driving force for rotating the support means 55, 56, 57, 58 about the fulcrum shafts 39, 40, 41, 42 for connection / disconnection. Separating / connecting pins 47, 48, 49, 50 for transmitting to the means 55, 56, 57, 58 are provided, respectively.

  Further, the frame 25 is provided with a driving force for rotating the supporting means 55, 56, 57, 58 around the fulcrum shafts 39, 40, 41, 42 for connecting / disconnecting pins 47, 48, 49, The connecting / disconnecting cams 43, 44, 45, 46 for transmitting to 50 are rotatably installed. The separation cams 43, 44, 45 and 46 are eccentric cams.

  Furthermore, between the frame 25 and the support means 55, 56, 57, 58, the separation pins 47, 48, 49, 50 and the separation cams 43, 44, 45, 46 are always in contact. A biasing member (not shown) such as a spring for biasing is installed.

  Developing rollers 35, 36, 37, and 38 are installed in the developing openings of the developing units 4, 5, 6, and 7, respectively.

  In order to selectively move the developing means 4, 5, 6, 7 to the separation position (non-development position) with respect to the photosensitive member, or the proximity or contact position (development position), a separation cam is provided by a drive source (not shown). 43, 44, 45, 46 are selectively rotated, and support means 55, via connecting / disconnecting pins 47, 48, 49, 50 which contact the outer peripheral surfaces of the connecting / disconnecting cams 43, 44, 45, 46. 56, 57, 58, that is, the developing means 4, 5, 6, 7 supported by the supporting means 55, 56, 57, 58 can be selectively moved.

  On the side plates of the support means 55, 56, 57, 58, notch grooves for inserting the fixing pins 63, 64, 65, 66 arranged on the side surfaces of the developing means 4, 5, 6, 7 are formed. Is done.

  Further, on the side plates of the support means 55, 56, 57, 58, fixing cams 59, 60, for fixing the fixing pins 63, 64, 65, 66 inserted in the cutout grooves to the cutout grooves, 61 and 62 are rotatably supported. The fixing cams 59, 60, 61, 62 are grooved cams having grooves for guiding the fixing pins 63, 64, 65, 66, and the grooves are the fixing cams 59, 60, 61, 62. It is formed so as to be eccentric with respect to the rotation center. Further, the fixing cams 59, 60, 61, 62 have protrusions for hooking a finger to manually rotate the fixing cam.

  Positioning pins 52 for engaging the developing means 5, 6, 7 and positioning the developing means 5, 6, 7 with respect to the supporting means 56, 57, 58 on the bottom plate of the supporting means 56, 57, 58 53 and 54 are arranged.

  The developing means 5, 6, 7 have engaging grooves (not shown) for engaging with the positioning pins 52, 53, 54 of the supporting means 56, 57, 58.

  For example, the developing means 7 has an engaging portion 67 provided substantially parallel to the lower surface of the developing means 7 on its side surface, and the engaging portion 67 engages with the positioning pin 54 of the support means 58. An engaging groove is formed.

  The developing means 7 is attached to and detached from the support means 58 in the direction of the arrow in the figure. FIG. 5 shows a state in which the developing unit 7 is detached from the support unit 58 of the frame 25.

  In order to attach the developing means 7 to the support means 58, the developing means 7 is inserted substantially parallel to the support means 58. When the developer containing portion at the rear of the developing means 7 is held by hand and the developing means 7 is inserted into the supporting means 58 with the developing opening at the top, the fixing pin 66 of the developing means 7 is fixed to the supporting means 58. Is inserted into a notch groove formed in the rear portion of the side plate. When the fixing cam 62 of the supporting means 58 is manually rotated in a predetermined direction, the fixing pin 66 of the developing means 7 inserted into the notch groove of the side plate of the supporting means 7 is a groove formed in the fixing cam 62. As a result, the developing means 7 is guided in the direction to advance toward the photosensitive member. When the developing means 7 is further moved to the photosensitive member side by rotating the fixing cam 62, the engaging groove of the engaging portion 67 of the developing means 7 and the positioning pin 54 of the supporting means 58 are engaged, and the developing means 7 Is positioned. When the engaging portion 67 of the developing means 7 and the positioning pin 54 of the supporting means 58 are engaged, further movement of the developing means 7 and rotation of the fixing cam 62 become impossible, and the developing means 7 is fixed to the supporting means 58. The

  Similarly to the developing means 7, the developing means 5 and 6 are connected to the notch grooves of the side plates of the supporting means 56 and 57 by the fixing pins 64 and 65 of the developing means 5 and 6. The fixing cams 60 and 61 of the support means 56 and 57 are developed so that the engaging grooves of the portions and the positioning pins 52 and 53 of the support means 56 and 57 are connected and the connection between the pins and the grooves is fixed. The developing means 5 and 6 are fixed to the support means 56 and 57 by urging the fixing pins 64 and 65 of the means 5 and 6.

  Similarly to the developing unit 7, the developing unit 4 is also fixed to the support unit 55. However, the developing means 4 is a pin-shaped positioning unit integrally formed on the lower surface of the developing means 4 as an engaging part corresponding to the engaging part 67 in which the engaging groove of the developing means 7 is formed. On the other hand, the supporting means 55 having the protrusion 51 and supporting the developing means 4 replaces the positioning pin 54 of the supporting means 58 and corresponds to the positioning protrusion of the developing means 4 on the bottom plate of the supporting means 55. A positioning hole (not shown) for engaging with 51 is provided. Therefore, in the developing means 4, the fixing pin 63 of the developing means 4 is connected to the notch groove of the side plate of the supporting means 55, the positioning projection 51 of the developing means 4 and the positioning hole of the supporting means 55 are connected, and The fixing means 59 of the supporting means 55 urges the fixing pins 63 of the developing means 4 so that the respective connections are fixed, whereby the developing means 4 is fixed to the supporting means 55.

  By adopting a configuration such as this apparatus, a means for moving the developing means away from and in contact with the photosensitive member is provided on the frame 25 and not provided on the photosensitive member side, so that the photosensitive member from the apparatus main body is provided. The attachment / detachment can be facilitated and the cost of the photosensitive unit can be reduced.

  In this apparatus, the lower surface of the developing means 4, 5, 6, 7 is supported in a state where the entire surface is in surface contact with the upper surface of the bottom plate of the supporting means 55, 56, 57, 58. If the surface accuracy of the lower surface or the bottom plate of the support means is insufficient, rattling may occur between the developing means and the support means. It is also possible to prevent the play between the developing means and the supporting means.

  Further, in this apparatus, the bottom plate of the supporting means is configured to have sufficient strength so that it does not bend even when the developing means is placed. Therefore, even if the developing unit has a shape elongated in the axial direction of the image carrier, the developing unit does not bend or distort, and an image can be formed stably.

  Although the bottom plate and the side plate of the support means can be separated, it is preferable to form the bottom plate and the side plate by bending them together because the rigidity of the support means is improved.

  In this apparatus, almost the entire lower surface of the developing unit is in contact with the bottom plate of the supporting unit. However, a plurality of convex portions are formed on the lower surface of the developing unit or the bottom plate of the supporting unit to support the lower surface of the developing unit. Only a part of the bottom plate of the means may be in contact with each other. In such a configuration, it is preferable that the plurality of convex portions formed on the lower surface of the developing unit or the bottom plate of the supporting unit have a shape that is continuous in the axial direction in order to prevent the developing unit from being bent. Alternatively, the plurality of convex portions formed on the lower surface of the developing means or the bottom plate of the supporting means may not have a shape that is continuous in the axial direction, but supports the end portion and the central portion of the developing means as viewed from the axial direction. Thus, it is preferable that convex portions are formed in at least three places having different positions as viewed from the axial direction.

  Further, the fixing cams 59, 60, 61, 62 of the supporting means 55, 56, 57, 58 are connected to the fixing pins 63, 64, 65, 66 of the developing means 4, 5, 6, 7, developing means 4, 5, 6 and 7 are urged in a direction to be fixed to the support means 55, 56, 57 and 58, and the fixing cams 4, 5, 6 and 7 rotate in the direction opposite to the direction in which the developing means is fixed. In order to prevent the fixing means 59, 60, 61, 62 from rotating, the developing means 4, 5, 6, 7 and the supporting means 55, 56, 57, 58 are not loosened. Forbidden means may be provided.

  In this apparatus, the developing means 4 has a positioning projection 51 as a part of the means connected to the supporting means 55, and the supporting means 55 has a positioning hole corresponding thereto, while the developing means 5, 6 and 7 have positioning grooves as part of the means for connecting to the support means 56, 57 and 58, and the support means 56, 57 and 58 have the positioning pins 52, 53 and 54 corresponding thereto. A positioning protrusion similar to that of the developing means 4 may be provided on all the developing means, and a positioning hole similar to that of the supporting means 55 may be provided on all of the supporting means. Conversely, the positioning grooves similar to the developing means 7 may be provided in all the developing means, and the positioning pins similar to the supporting means 58 may be provided in all the supporting means.

  Further, if the type, arrangement and number of the positioning projections or positioning grooves of the developing means and the positioning holes or positioning pins of the corresponding supporting means are different for each developing means and the corresponding supporting means, the developing means Incorrect insertion can be prevented.

  FIG. 6 is a schematic view of a supporting means for supporting the developing means of the image forming apparatus of the present invention. In addition, the same number is attached | subjected to the member same as FIG. 5, and description is abbreviate | omitted.

  With reference to FIG. 6, the support means that is rotatably supported by the frame structure and supports the developing means will be briefly described by taking the support means 58 as an example. 6A is a schematic top view of the support means 58, and FIG. 6B is a schematic side view of the support means 58.

  The support means 58 has a shape including a bottom plate on which the developing means is placed and a side plate that is integrally bent upward at both ends of the bottom plate.

  The support means 58 is attached to the frame via a detachable fulcrum shaft 42 formed on the side plate of the support means 58, and is supported so as to be rotatable about the detachable fulcrum shaft 42.

  Further, on the side plate of the support means 58, a detachment pin 50 for transmitting a driving force for rotating the support means 58 about the detachment fulcrum shaft 42 to the support means 58 is installed.

  The detachment pin 50 receives a driving force by a detachment cam that is rotatably supported by the frame. Note that a coating made of a lubricating resin may be formed on the contact portion of the separation pin 50 with the separation cam.

  The side plate of the support means 58 is formed with a notch for inserting a fixing pin disposed on the side surface of the developing means.

  Further, on the side plate of the support means 58, a fixing cam 62 for fixing the fixing pin of the developing means inserted in the notch groove to the notch groove can be rotated by the fixing cam rotation support shaft 68. Supported.

  The fixing cam 62 is a grooved cam having a groove for guiding the fixing pin, and the groove is eccentric with respect to the rotation center of the fixing cam 62, that is, the fixing cam rotation support shaft 68. It is formed.

  On the bottom plate of the support means 58, positioning pins 54 for engaging the developing means and positioning the developing means with respect to the support means 58 are disposed.

  FIG. 7 is a schematic view of the developing means of the image forming apparatus of the present invention. In addition, the same number is attached | subjected to the member same as FIG. 5, and description is abbreviate | omitted.

  With reference to FIG. 7, the developing unit will be briefly described by taking the developing unit 7 as an example. FIG. 7A is a schematic top sectional view of the developing means 7, and FIG. 7B is a schematic side view of the developing means 7.

  A developing roller 38 is installed in the developing opening of the developing means 7. The developing roller 38 has shafts 69 at both ends, and the shaft 69 is rotatably supported on the side surface of the developing unit 7 and is driven by a driving source and a driving transmission unit (not shown).

  A fixing pin 66 is formed on the side surface of the developing means 7 so as to be inserted into the notch groove of the side plate of the supporting means.

  An engaging portion having an engaging groove for engaging with a positioning pin formed on the bottom plate of the supporting means is formed on the side surface of the developing means 7.

  FIG. 8 is an operation schematic diagram showing the attaching / detaching operation of the developing means of the supporting means of the image forming apparatus of the present invention. The same members as those in FIGS. 5 and 6 are denoted by the same reference numerals, and the description thereof is omitted.

  With reference to FIG. 8, the operation of attaching and detaching the developing means by the supporting means that detachably supports the developing means will be briefly described by taking the supporting means 58 and the developing means 7 as examples. 8A is a schematic side view of the support means 58 showing the operation of releasing the developing means 7 from the support means 58, and FIG. 8B is a support means showing the action of fixing the developing means 7 to the support means 58. 58 is a schematic side view of 58. FIG.

  In FIG. 8A, the developing means 7, the fixing pin 66 formed on the side surface of the developing means 7, and the fixing cam 66 rotatably supported on the side surface of the supporting means 58 are indicated by two-dot chain lines. The developing unit 7 is fixed to the supporting unit 58 at the position.

  When the fixing cam 66 is rotated in the direction of the arrow M around the fixing cam rotation support shaft 68, the fixing pin 66 formed on the side surface of the developing means 7 is supported by the eccentric groove of the fixing cam 62. It is guided along a notch groove (not shown) formed in the side plate of the means 58 so as to be pushed backward from the support means 58 in the direction of the arrow in the figure. Due to the movement of the fixing pin 66, the distance between the photosensitive member and the developing means 7 is increased, that is, the developing means 7 moves to the rear of the supporting means 58, and is positioned for positioning (not shown) formed on the bottom plate of the supporting means 58. The engagement between the pin and the engaging groove of the engaging portion (not shown) of the developing means 7 is released, and the developing means 7 is released from the support means 58.

  The developing means 7, the fixing pin 66 formed on the side surface of the developing means 7, and the fixing cam 66 rotatably supported on the side surface of the supporting means 58 are respectively supported by the developing means 7 at the positions indicated by solid lines. The state released from 58 is shown.

  When the developing unit 7 moves in a direction to be released from the support unit 58, at least a part of the developer accommodating portion of the developing unit 7, that is, the rear portion of the developing unit 7 is protruded from the rear portion of the support unit 58.

  With this apparatus configuration, when the fixing cam 66 for fixing the developing means 7 is rotated so as to release the developing means 7, the developing means 7 always moves in a direction away from the photosensitive member 1. It is possible to prevent the developing means 7 from coming into contact with the photosensitive member 1 at the time of release and damaging the developing means 7 or the photosensitive member 1. Further, since the rear portion of the developing means 7 protrudes from the rear portion of the supporting means 58 when the developing means 7 is released, the developing means 7 can be easily taken out of the supporting means 58 by hand.

  In FIG. 8B, the developing means 7, the fixing pin 66 formed on the side surface of the developing means 7, and the fixing cam 66 rotatably supported on the side surface of the supporting means 58 are indicated by two-dot chain lines. In the position, the developing means 7 is not fixed to the supporting means 58.

  When the developing means 7 is pushed into the supporting means 58 in a direction substantially parallel to the bottom plate of the supporting means 58, a fixing pin 66 formed on the side surface of the developing means 7 is formed on the side surface of the supporting means 58 (not shown). It is inserted into the notch.

  When the developing means 7 is further pushed in, the fixing pin 66 further moves while being guided by a notch groove (not shown) formed on the side surface of the support means 58, and the distance between the photosensitive member and the developing means 7 approaches. That is, the developing means 7 moves to the front of the support means 58.

  When the developing means 7 is pushed in, the fixing pin 66 of the developing means 7 moves along a notch groove (not shown) formed on the side surface of the support means 58 and is fixed to be supported rotatably on the side surface of the support means. The cam 66 is inserted into the eccentric groove.

  When the fixing pin 66 of the developing means 7 comes into contact with the fixing cam 66 of the supporting means, the developing means 7 cannot be pushed further from that position, and the movement of the developing means 7 is temporarily stopped.

  When the fixing pin 66 of the developing means 7 moves to a position where it contacts the fixing cam 66 of the supporting means, the fixing cam 62 is rotated in the direction of arrow N about the fixing cam rotation support shaft 68. The fixing pin 66 formed on the side surface of the developing means 7 is moved forward from the supporting means 58 along the notch groove (not shown) formed in the side plate of the supporting means 58 by the eccentric groove of the fixing cam 62 and It is guided so as to be pushed downward in the direction of the arrow in the figure.

  By the movement of the fixing pin 66, the developing means 7 moves forward and downward of the support means 58, and a positioning pin (not shown) formed on the bottom plate of the support means 58 and an engaging groove of an engaging portion (not shown) of the developing means 7 are formed. Is engaged, and the lower surface of the developing means 7 is brought into close contact with the upper surface of the bottom plate of the supporting means 58 so that the developing means 7 is fixed to the supporting means 58.

  The developing means 7, the fixing pin 66 formed on the side surface of the developing means 7, and the fixing cam 66 rotatably supported on the side surface of the supporting means 58 are respectively supported by the developing means 7 at the positions indicated by solid lines. The state fixed to 58 is shown.

  With the configuration of this apparatus, when the developing means 7 is inserted into the support means 58, the developing means 7 is closer to the front side than the position where it is fixed to the support means 58, that is, the developing means 7 is sufficiently separated from the photoreceptor. Therefore, even if the user accidentally inserts the developing means 7 into the support means 58 with an excessive force, the developing means 7 collides with the photosensitive member 1 and the developing means 7 or the photosensitive member 1. Will not be damaged.

  Further, when the fixing cam 66 for fixing the developing means 7 to the support means 58 is rotated so as to fix the developing means 7, the developing means 7 and the positioning pins (not shown) formed on the bottom plate of the support means 58 are developed. The direction in which the engaging groove of the engaging portion (not shown) of the means 7 engages (that is, the front direction of the supporting means 58) and the direction in which the lower surface of the developing means 7 is in close contact with the upper surface of the bottom plate of the supporting means 58 (that is, the supporting means). Since the developing means 7 is not rattled to the support means 58 and is securely fixed, the image can be stably formed even in long-term use. it can.

  FIG. 9 is an operation schematic diagram showing the separation operation of the developing means of the image forming apparatus of the present invention with respect to the photosensitive member. In addition, the same number is attached | subjected to the member same as FIG. 5, and description is abbreviate | omitted.

  With reference to FIG. 9, the operation of the developing unit moving to the developing position in contact with or close to the photosensitive member and the non-developing position separated from the photosensitive member will be briefly described by taking the developing unit 7 and the supporting unit 58 as an example.

  In FIG. 9, the developing means 7 is rotatably supported on the side surface of the supporting means 62 by a fixing pin 66 formed on the side surface of the developing means 7 inserted in a notch groove formed on the side surface of the supporting means 58. The fixing cam 62 is rotated in the direction to fix the developing means 7 to the support means 58, whereby the positioning pin 54 formed on the bottom plate of the support means 58 and the engaging groove of the engaging portion (not shown) of the developing means 7 Are engaged and fixed to the support means 58.

  The operation of selectively moving the developing means 7 to the non-developing position or the developing position is carried out by selectively moving the separating cam 46 rotatably supported by a frame (not shown) by a driving source (not shown) in the direction of the arrow in the figure. This is done by rotating.

  A separating pin 50 formed on the side plate of the support means 58 is in contact with the outer peripheral surface of the separating cam 46, and the separating cam 46 is rotated by a predetermined angle about the separating cam rotation support shaft 70. Then, since the separating cam 46 is an eccentric cam, the separating pin 50 moves a predetermined distance.

  A detachable fulcrum shaft 42 is formed on the side surface of the support means 58, and the support means 58 is rotatably supported by the frame via the detachment fulcrum shaft 42.

  Therefore, when the separating cam 46 is rotated by a predetermined angle and the separating pin 50 is moved, the supporting means 58, that is, the developing means 7 fixed to the supporting means 58 causes the separating and supporting fulcrum shaft 42 to move. It rotates as indicated by an arrow in the figure as the center, and moves to either position V or position W. In this manner, the developing opening of the developing unit 7 reciprocates between the position V and the position W in accordance with the rotation of the separation cam 46 so that the developing unit 7 develops with respect to the photosensitive member. It can be selectively moved to a position or a non-development position.

  In this apparatus, the support means 58 directs the development opening of the developing means 7 to the position V, and the support means 58 directs the development opening of the developing means 7 to the position W. The shape and rotation angle of the separation cam 46 are set so that the position becomes the non-development position.

  Since the developing units 4, 5, 6, and 7 have different positions with respect to the photoreceptor, the developing units 4, 5, and 6 other than the developing unit 7 have the developing position and the non-developing position in the developing unit 7. Are not necessarily the same, and may be appropriately selected. That is, depending on the position of each developing means, one position of the reciprocating movement position V or W of the developing means by the rotation of the contact cam is set as the developing position and the other position is set as the non-developing position. Good.

As described above, the embodiments have been described using the image forming apparatus in which a plurality of developing units are juxtaposed on the outer peripheral surface of the image carrier. However, a plurality of developing units are supported by a rotatable frame structure, and the frame structure is supported. This is also applied to an image forming apparatus of a type that performs development by selectively moving the developing means sequentially to substantially the same development position facing the image carrier by the rotation of.

1 is an apparatus cross-sectional view illustrating an overall configuration of an image forming apparatus of the present invention. FIG. 2 is a cross-sectional view of the image forming apparatus according to the present invention, illustrating a state where a cover is opened. FIG. 3 is a cross-sectional view of the apparatus showing a state in which a frame structure of the image forming apparatus of the present invention is opened. FIG. 5 is an operation schematic diagram showing the rotational movement of the frame structure of the image forming apparatus of the present invention. It is a sectional side view of the frame structure of the image forming apparatus of the present invention. FIG. 3 is a schematic view of a supporting unit that supports the developing unit of the image forming apparatus of the present invention. FIG. 2 is a schematic view of developing means of the image forming apparatus of the present invention. FIG. 6 is an operation schematic diagram showing an attaching / detaching operation of the developing means of the supporting means of the image forming apparatus of the present invention. FIG. 6 is an operation schematic diagram illustrating a separation operation of the developing unit of the image forming apparatus according to the present invention with respect to the image carrier.

Explanation of symbols

  1: Photoconductor, 3: Latent image forming means, 4, 5, 6, 7: Developing means, 22: Fixing means, 25: Frame, 80: Recording material storage means, 81: Front cover, 82: Top cover

Claims (6)

A latent image forming means for forming a latent image corresponding to each color component on the image carrier; a plurality of developing means for developing the latent image on the image carrier with toner corresponding to each color component; Primary transfer means for sequentially transferring the toner images onto the intermediate transfer body, and secondary transfer for collectively transferring the multicolor images formed on the intermediate transfer body onto the recording material conveyed from the recording material storage means Fixing means for fixing the multicolor image to the recording material, a first recording material conveyance path for conveying the recording material in the recording material storage means from the secondary transfer means to the fixing means, and the fixing And a second recording material conveyance path for discharging the recording material conveyed from the image forming apparatus from a main body of the image forming apparatus, a supporting means for detachably supporting the developing means, and the supporting means for supporting the developing means. Connecting means for connecting to the means, and the support means An image forming apparatus, comprising a moving means for moving said support means for moving the focusing has been the developing unit to the developing position or a non-developing position. A frame structure that supports the plurality of support means according to the plurality of development means, and a first structure that biases the development means fixed to the frame structure via the support means to the image carrier. The image forming apparatus according to claim 1, wherein the frame structure is rotated to move to a position and a second position released from the image carrier. 3. The image forming apparatus according to claim 2, further comprising bistable means for bringing the frame structure into a bistable state between the first position and the second position. 4. The image forming apparatus according to claim 3, wherein the developing unit is detachable in a posture in which the frame structure is opened to the second position and a toner storage portion of the developing unit is positioned below. . The connecting means includes a pin provided on one of the developing means or the supporting means and engaged with the other, and an insertion portion provided on one of the developing means or the supporting means and into which the other pin is inserted. 2. The image forming apparatus according to claim 1, further comprising a cam for urging the pin inserted into the inserted portion in a predetermined direction. 6. The image forming apparatus according to claim 5, wherein the predetermined direction is a direction in which the developing unit is urged toward the image carrier and a direction in which the developing unit is urged toward the support unit.

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