JP2012078558A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of downsizing and cost reduction by integrating units which directly contribute to image formation.SOLUTION: The image forming device comprises: multiple image holders 21 which are rotatably provided; multiple developing means 24 each of which includes a rotatable developer holding body 241 for holding developer including toner and which develops electrostatic latent images formed on the image holders 21 by the toner of respective colors; and a belt-like intermediate transfer body 31 which is stretched around multiple support rolls 32a, 32b and rotatably formed, and on which toner images formed on the image holders 21 are sequentially transferred. The intermediate transfer body 31, the image holders 21 and the developing means 24, both ends of which in respective axis directions are attached to a support member 30F in common, are formed as integrated imaging means 5.

Description

  The present invention relates to an image forming apparatus.

  Conventionally, in an image forming apparatus such as a copying machine or a printer using an electrophotographic system, replacement parts such as a photosensitive drum, a charging device, and a developing device are integrated into a unit so that the image forming apparatus can be attached to and detached from the main body. A so-called process cartridge type image forming apparatus is known (see, for example, Patent Documents 1 to 5).

  Here, Patent Document 1 discloses an image forming apparatus in which an electrical board is disposed between a discharge tray and an intermediate transfer belt.

  Patent Document 2 discloses an image forming apparatus in which an image forming unit and an electrical component are arranged in a column with an intermediate transfer belt interposed therebetween.

  Further, Patent Document 3 discloses an image forming apparatus installed on a process frame from which image forming means such as a photosensitive drum and an intermediate transfer unit can be pulled out.

  Patent Document 4 discloses an image forming apparatus configured such that only a cleaning blade is disposed between adjacent photosensitive drums.

  Patent Document 5 discloses an image forming apparatus configured such that each of a plurality of photoreceptor units is independently positioned and held by an intermediate transfer body unit.

JP-A-2005-351938 JP 2007-072256 A JP 2002-091129 A JP 2001-356549 A JP 2004-145060 A

  An object of the present invention is to provide an image forming apparatus in which units that directly contribute to image formation are integrated to reduce the size and cost.

  In order to achieve the above object, an image forming apparatus according to claim 1 has a plurality of image holders formed to be rotatable and a rotatable developer holder for holding a developer containing toner. And a plurality of developing means for developing the electrostatic latent image formed on the image holding body with toner of each color and a toner formed on the image holding body around a plurality of support rolls. A belt-shaped intermediate transfer body on which images are sequentially transferred, and the intermediate transfer body, the image holding body, and the developing unit are attached to a common support member at both axial ends. And is formed as an integral image forming means.

  According to a second aspect of the present invention, in the configuration of the first aspect, the image holding member and the developing unit are disposed below the intermediate transfer member, and the common support member is the belt. It is characterized in that it is formed by extending the supports at both axial ends of the intermediate transfer member downward.

  According to a third aspect of the present invention, in the configuration of the first or second aspect, the image forming apparatus further includes a driving unit that rotationally drives each of the intermediate transfer member, the image holding member, and the developing unit via a power transmission member. At least the power transmission member is integrally installed on the common support member.

  An image forming apparatus according to a fourth aspect of the present invention further includes a power supply substrate that supplies power to each of the intermediate transfer body, the image holding body, and the developing unit in the configuration according to any one of the first to third aspects, The power supply board is provided integrally with the integrated image forming means.

  According to a fifth aspect of the present invention, the image forming apparatus according to the first aspect further includes a latent image forming unit that forms an electrostatic latent image on the image carrier, and the latent image forming unit. Is arranged between the image carrier and the developing means, and is formed integrally with the image carrier.

  According to a sixth aspect of the present invention, the image forming apparatus according to any one of the first to fifth aspects further includes a paper feeding unit that supplies a recording medium to the integrated image forming unit, and the integrated image forming unit. Is fixedly installed on the paper feeding means.

  According to the first aspect of the present invention, it is possible to improve the positioning accuracy of the constituent devices and contribute to the downsizing, space saving, and cost reduction of the apparatus.

  According to the second aspect of the present invention, the common support member can be easily realized by using the support (housing) of the intermediate transfer member.

  According to invention of Claim 3, it can contribute to the rigidity improvement of a supporting member, and suppression of the speed fluctuation of a rotating member.

  According to the fourth aspect of the present invention, it is possible to improve the conduction reliability at the contact point with the power supply terminal, the ground terminal and the like.

  According to the fifth aspect of the present invention, it is possible to contribute to further miniaturization of the image forming means by effectively utilizing the space.

  According to the sixth aspect of the present invention, it is possible to further contribute to the improvement of the assembly property and the miniaturization of the entire apparatus.

1 is a schematic diagram for explaining a schematic configuration of an image forming apparatus according to an embodiment. 1 is a perspective view illustrating an appearance of an image forming apparatus according to an embodiment. It is typical sectional drawing which shows the structure of the integrated image formation unit which concerns on this Embodiment. It is an enlarged view for explaining a configuration of an image forming unit according to the present embodiment. It is a schematic diagram for explaining an assembly procedure of the image forming apparatus according to the present embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2 are schematic diagrams showing a schematic configuration of a printer as an example of an image forming apparatus according to the present invention, FIG. 3 is a schematic diagram for explaining a configuration of an integrated image forming unit, and FIG. FIG. 5 is a schematic diagram for explaining the configuration of the image forming unit, and FIG. 5 is a schematic diagram for explaining the assembly procedure of the printer according to the present embodiment.

  As schematically shown in FIG. 1, a printer 1 as an image forming apparatus according to the present embodiment includes a hollow, substantially rectangular parallelepiped device housing 10, and an image is displayed below the inside of the device housing 10. A paper supply device 4 that houses and supplies recording paper 9 as a recording medium to be formed is disposed. Further, an image forming unit 2, an intermediate transfer unit 3, a secondary transfer roll 35, a fixing device 45, and the like are disposed above the sheet supply device 4. On the other hand, on the upper part of the apparatus main body 10, a discharge storage portion 12 is formed in which the recording paper 9 after the image is formed is discharged and stored.

  As shown in FIG. 2, toner cartridges 11Y, 11M, 11M, 11M, 11M, 11M, 11M, 11M, 11M, 10M, 11M Cartridge housing portions 8Y, 8M, 8C, and 8K that detachably accommodate 11C and 11K are provided, and the toner cartridges 11Y, 11M, 11C, and 11K are configured to be replaceable (detachable) with respect to the printer main body 10. It has become.

  In the present embodiment, the printer 1 is a digital printer that forms a color image or a monochrome image, and an image processing apparatus (not shown) is provided inside. The image processing apparatus performs image processing on image data sent from a personal computer or the like.

  In addition, four image forming units 2Y, 2M, 2C, and 2K corresponding to the respective colors Y, M, C, and K are arranged in the approximate center inside the printer body 10, and the image forming units 2Y, 2M, and 2K are arranged. An intermediate transfer unit 3 is provided above 2C and 2K.

  In the present embodiment, the image forming units 2Y, 2M, 2C, and 2K and the intermediate transfer unit 3 are integrally formed by attaching both end portions in the axial direction to a common support member (support frame). These are formed as an integral image forming means (integrated image forming unit) 5 in which the subframe for each unit is omitted. Details of the component devices will be described below.

  As shown in FIG. 3, the image forming unit 2 includes four developer (toner) images for four colors of yellow (Y), magenta (M), cyan (C), and black (K). The image forming units 2Y, 2M, 2C, and 2K are used. In the present embodiment, the image forming units 2Y, 2M, 2C, and 2K are arranged in a state where the installation positions are gradually increased (inclined) in the order of black, cyan, magenta, and yellow.

  Each image forming unit 2 (Y, M, C, K) has the same configuration, and the photosensitive unit 20 (Y, M, C, K) and the photosensitive unit 20 (Y, M, C, K). ) And the developing unit 24 (Y, M, C, K) provided on the lower side. Reference symbol S is a conventionally known optical sensor for detecting image density and the like.

  As shown in an enlarged view in FIG. 4, the photosensitive unit 20 is provided with a photosensitive drum 21 as an image carrier that is rotationally driven in a predetermined direction (direction indicated by an arrow). Further, there are a charging device 22 that uniformly charges the photosensitive drum 21 in contact with the surface of the photosensitive drum 21 and a latent image forming unit that irradiates the surface of the photosensitive drum 21 with exposure light. The LED print head 23 and a drum cleaning device 25 for cleaning the surface of the photosensitive drum 21 after transfer are integrally disposed along the peripheral surface of the photosensitive drum 21.

  Further, on the downstream side of the LED print head 23, a developing unit (developing device) 24 that visualizes the electrostatic latent image formed on the surface of the photosensitive drum 21 with toner (toner image) is disposed. .

  As the photosensitive drum 21, a cylindrical photosensitive member that rotates about a support shaft 216 is used. The photosensitive drum 21 is fitted and fixed to a drum main body 213 having a photosensitive layer 212 formed on the outer peripheral surface of a cylindrical base material 211 and open insides at both ends of the base material 211, and a bearing. A pair of flanges 215A and 215B in which the holes 214 are formed, and a support shaft 216 that passes through the bearing holes 214 of the flanges 215A and 215B and rotatably holds the drum body 213. The photosensitive layer 212 is a light induction layer formed of an organic photosensitive material or the like, and includes a surface protective layer. The surface portion of the substrate 211 on which the photosensitive layer 212 is formed becomes a photosensitive surface. One flange 215B of the pair of flanges 215A and 215B is formed as a transmitted gear whose large diameter portion (outer peripheral portion thereof) meshes with a drive transmission gear of a drive transmission device (not shown).

  In the present embodiment, the photosensitive drum 21 is supported in a state where the support shaft 216 is fixed to a support hole 216h that also functions as a positioning function formed in a support frame 30F of the intermediate transfer unit 3 described later. Further, the photosensitive drum 21 forms a bearing hole 214 having a shape penetrating through a flange 215 configured using a synthetic resin having excellent slidability with respect to the support shaft 216, and penetrates the bearing hole 214. The support shaft 216 is attached to the support shaft 216 attached in the state of being rotated.

  As the charging device 22, a contact charging type charging device is used in which a charging roll 221 that rotates while being pressed and in contact with the photosensitive surface of the photosensitive drum 21 is used. The charging device 22 uses a charging roll 221 having a structure in which an elastic layer 223 adjusted to a predetermined resistance value with respect to the shaft 222 is formed. The charging roll 221 is configured to come into pressure contact with the photosensitive drum 21 with a predetermined contact pressure by a compression spring (not shown) or the like. A cleaning roll 227 that removes toner and the like attached to the surface of the charging roll 221 is rotatably disposed on the outer peripheral surface of the charging roll 221 opposite to the photosensitive drum 21.

  As the exposure device 23, an LED print head in which a plurality of LEDs 26 are arranged in a line along the axial direction of the photosensitive drum 21 is used. The LED print head 23 includes a light emitting unit 231 on which a plurality of LEDs 26 arranged in a line along the axial direction of the photosensitive drum 21 are mounted, and a SELFOC that converges light emitted from each LED 26 of the light emitting unit 231. The light emitting unit 28 includes a lens (registered trademark) 27 and a holding unit (housing) 232 that holds a distance between the LED 26 of the light emitting unit 231 and the Selfoc lens 27. In the light emitting unit 231, the corresponding LED 26 is driven to blink based on an image signal transmitted from an image processing unit (not shown) via a connection line. In the present embodiment, the LED print head 23 includes the photosensitive drum 21 and the developing unit 24 so that the Selfoc lens 27 of the light emitting unit 28 faces the photosensitive surface (image forming area) of the photosensitive drum 21. It is arranged in the space between the two so as to be sandwiched between. As described above, the LED print head 23 as the latent image forming means is arranged using the space between the photosensitive drum 21 and the developing unit 24, thereby further reducing the size of the image forming unit 2. .

  As the drum cleaning device 25, a drum cleaning device 25 in which an elastic blade 251 that is pressed against and contacts the photosensitive surface of the photosensitive drum 21 is used. The elastic blade 251 is arranged so that the tip of the blade comes into contact with the photosensitive surface of the photosensitive drum 21 with a predetermined amount of biting. Reference numeral 253 denotes a rotary conveying member that collects the adhering matter such as toner scraped off by the elastic blade 251 and conveys the adhering matter to a collecting unit (not shown). Reference numeral 254 denotes an adhering matter such as toner floating outside. It is a film-like sealing material for preventing leakage.

  The developing unit 24 is a unit that develops the electrostatic latent image formed on the photosensitive drum 21 with exposure light with each color developer (toner), and has a predetermined interval with respect to the photosensitive surface of the photosensitive drum 21. A developing roller 241 that rotates in the provided state is provided, and the developing roller 241 conveys a two-component developer composed of toner and carrier to the developing region. The developing unit 24 includes a developer accommodating portion that accommodates the developer and a housing 240 having a developing opening that opens toward the photosensitive drum 21, and the developing roller 241 is provided in the developing opening of the housing 240. Is held rotatably with only a part of it exposed. The developing roll 241 has a structure in which a roll-shaped magnet portion 243 is disposed on a shaft 242 and a cylindrical sleeve 244 that rotates in the direction indicated by an arrow around the magnet portion 243 is disposed.

  Further, the photosensitive drum 21 and the developing roll 241 are positioned at both ends of the developing roll 241 by contacting the surface (circumferential surface) of the photosensitive drum 21 (that is, the photosensitive drum 21 and the developing roll 241 are determined in advance). A positioning portion (not shown) that sets and secures the separation distance is formed. This positioning portion is formed in a disk shape having a radius larger than the radius of the developing sleeve 244 by the above-mentioned separation distance at both ends of the shaft 242.

  Further, the developer container is provided with an agitating / conveying member (rotary screw) 248 that conveys the developer with stirring so that the developer can be supplied to the developing roll 241, and the developer held on the developing roll 241 is preliminarily loaded. A layer thickness regulating roll (trimmer) 249 that regulates to a predetermined thickness (layer) is disposed adjacent to the developing roll 241. Note that an opening (not shown) through which the toner from the toner cartridge 11 is supplied is formed at one axial end of the developer accommodating portion. Further, the developing roll 241 and the stirring and conveying member 248 are driven by driving means including a motor and a gear (not shown).

  In the present embodiment, the photosensitive unit 20 and the developing unit 24 described above are developed in such a manner that the positioning portions at both ends in the axial direction of the developing roll 241 are in contact with the circumferential surfaces at both ends in the axial direction of the photosensitive drum 21. The roll 241 and the photosensitive drum 21 are coupled to each other by an elastic member such as a tension spring (not shown) so that a predetermined separation distance is ensured. A charging voltage and a developing bias voltage are applied to the charging roll 221 and the developing roll 241 from a power supply device (not shown).

  The intermediate transfer unit 3 has an endless shape in which each color toner image formed on the photosensitive drum 21 (Y, M, C, K) of each image forming unit 2Y, 2M, 2C, 2K is transferred to the outer peripheral surface. An intermediate transfer belt 31 as an intermediate transfer member, a plurality of support rolls 32 a and 32 b that rotate the intermediate transfer belt 31 so as to be in contact with each photosensitive drum 21, and an inner side of the intermediate transfer belt 31. And four primary transfer rolls 33Y, 33M, 33C, and 33K as four primary transfer members for transferring each toner image on each photosensitive drum 21 onto the outer peripheral surface of the intermediate transfer belt 31.

  The intermediate transfer belt 31 is wound with a constant tension between a drive roll 32b disposed opposite to the secondary transfer roll 35 and driven by a motor (not shown), and a tension roll 32a. Circulation drive is performed in the direction of the arrow in FIG. 1 (counterclockwise direction).

  The primary transfer rolls 33 (Y, M, C, K) sandwich the intermediate transfer belt 31 so as to come into contact with the inner peripheral surface of the intermediate transfer belt 31 and press the outer peripheral surface of the belt 31 against the photosensitive surface of the photosensitive drum 21. Are arranged to face each photosensitive drum 21 (Y, M, C, K). Further, a transfer bias voltage having a polarity opposite to the toner polarity (positive polarity as an example in the present embodiment) is applied to the primary transfer roll 33 (Y, M, C, K).

  The toner images are electrostatically transferred from the photosensitive drums 21 (Y, M, C, K) to the outer peripheral surface of the intermediate transfer belt 31 by the action of the primary transfer rolls 33 (Y, M, C, K). Primary transcription. On the outer peripheral surface of the intermediate transfer belt 31, a toner image or a single color toner image in which a plurality of color toner images are superimposed is held by primary transfer.

  A belt cleaning device (not shown) is provided on the outer peripheral surface of the intermediate transfer belt 31 where the tension roll 32a is provided so as to remove residual toner and paper dust on the intermediate transfer belt 31. It has become.

  The secondary transfer roll 35 is for secondary transfer of the toner image, which is superimposed on the outer peripheral surface of the intermediate transfer belt 31 and primarily transferred, onto the recording paper 9. The secondary transfer roll 35 is disposed so as to be driven and rotated in contact with the outer peripheral surface of the portion of the intermediate transfer belt 31 that is hung on the drive roll 32b, so that a secondary transfer bias voltage is applied. It has become. Then, an unfixed toner image held on the intermediate transfer belt 31 is electrostatically applied to the recording paper 9 which is conveyed and supplied to the pressure contact portion between the intermediate transfer belt 31 and the secondary transfer roll 35. Secondary transfer. Note that a transfer bias voltage having a polarity opposite to the toner polarity is also applied to the secondary transfer roll 35.

  The fixing device 45 fixes the secondary transferred unfixed toner image on the recording paper 9 and is disposed above the secondary transfer roll 35. The fixing device 45 includes a heated heating roll 46 and a pressure roll 47 pressed against the heating roll 46. Here, the recording paper 9 onto which the toner image of each color has been transferred by the secondary transfer roll 35 is fixed by heat and pressure at the pressure contact portion between the heating roll 46 and the pressure roll 47, and the recording paper 9 is transported downstream in the conveyance direction. The paper is discharged to a discharge container (discharge tray) 12 provided at the upper part of the printer main body 10 by a paper discharge roll 48 provided in the printer.

  On the other hand, below the image forming unit 2, a paper supply device 4 in which recording paper 9 is stored is disposed. In this paper supply device 4, after the paper at the top of the recording paper 9 accommodated in the paper container 41 is fed out by the supply roll 42, the supply roll 42 and the separating roll 43 in contact with the roll 42 are provided. As a result, the recording paper 9 is turned and fed one by one. The sent recording paper 9 is temporarily stopped by the registration roll 44 and then conveyed between the intermediate transfer unit 3 and the secondary transfer roll 35 (secondary transfer position) at a predetermined timing.

  In the present embodiment, the lifetimes of main components such as the photosensitive drum 21, the intermediate transfer belt 31, and the developing device 24 constituting the integrated image forming unit 5 are set to be equal to the lifetime of the printer 1. In other words, the configuration eliminates the need for periodic parts replacement. That is, for example, when printing about 50,000 sheets, the main components and the image forming apparatus main body are used up, and the user replaceable components are basically only toner cartridges. .

  In the image forming apparatus 1 according to the present embodiment configured as described above, an image is created as follows. First, the photosensitive surface of the rotating photosensitive drum 21 is charged to a predetermined potential via the charging roll 221 of the charging device 22 and then input to the image forming apparatus 1 with respect to the charged photosensitive drum 21. Light based on image information is emitted from the LED print head 23 to form an electrostatic latent image of each color component. Subsequently, the electrostatic latent images of the respective color components on the respective photosensitive drums 21 are developed with the developer supplied via the developing roll 241 of the developing device 24 that accommodates the developer of the corresponding color, and four colors ( Y, M, C, and K) toner images are formed. The toner images on the respective photosensitive drums 21 are sequentially primary-transferred in a multiplex manner onto the intermediate transfer belt 31 by the primary transfer roll 33.

  The respective color toner images transferred onto the intermediate transfer belt 31 are secondarily transferred onto the recording paper 9 conveyed from the paper supply device 4 by the secondary transfer roll 35. Then, the toner images of the respective colors on the recording paper 9 are fixed by the fixing device 45, and the recording paper 9 after fixing is discharged to a discharge container (discharge tray) 12. The drum cleaning device 25 removes residual toner, paper dust, and the like from the surface of the photosensitive drum 21 after the toner image transfer process is completed. Residual toner, paper dust, and the like on the intermediate transfer belt 31 are removed by a belt cleaning device.

  Next, a manufacturing method (assembly procedure) of the image forming apparatus 1 according to the present embodiment will be described with reference to FIG.

  As schematically shown in FIG. 5A, first, the image forming unit 2 is configured by combining the photosensitive unit 20 and the developing unit 24 integrated with the LED print head 23 and the like. Specifically, the corresponding photosensitive unit 20 is placed on each developing unit 24, and these are arranged in parallel to form the image forming unit 2. At this time, the photosensitive drum 21 is in a state where the support shaft 216 is pulled out. Reference numeral 23 f denotes a signal transmission harness to the LED print head 23.

  Next, the intermediate transfer unit 3 is placed on the image forming unit 2 (photosensitive unit 20 + developing unit 24) integrally arranged in parallel.

  Here, the intermediate transfer unit 3 according to the present embodiment has a frame-like support frame including a pair of plate-like side frames. As schematically shown in FIG. Support frames (side frames) 30F at both ends in the direction are formed of insulating resin. The side frame 30F is extended and extended downward so that the support frame 30F covers the side surfaces of both ends in the axial direction of the image forming unit 2 (photosensitive unit 20 + developing unit 24). Further, a pair of support frames 30F at both ends in the axial direction are provided with rotating members of constituent units (photosensitive unit 20, developing unit 24, intermediate transfer unit 3) and the like (for example, belt supporting rolls 32a and 32b, photosensitive drum 21). , Developing rolls 241, etc.), a mounting hole to which a power transmission member such as a gear or the like for rotating the rotating member is attached.

  Specifically, four power supply terminals 33p (Y, M, C, K) as power supply portions to the primary transfer roll 33 are provided on the support frame 30F, and the power supply terminals 33p (Y , M, C, K), a substantially semicircular mounting portion 21g (Y, M, C, K) or the like to which a power transmission member such as a gear for rotating and driving each photosensitive drum 21 is mounted is formed. Has been. Further, four support holes 216h (Y, M, C, K) into which the support shaft 216 of the photosensitive drum 21 is inserted are formed in the approximate center of the support frame 30F, and the support holes 216h (Y, A substantially semicircular mounting portion 24g (Y, M, C, K) to which a power transmission member such as a gear for rotating the developing roll 241 is mounted is formed below M, C, K). Yes.

  5B, the intermediate transfer unit 3 is placed on the image forming unit 2, and the support shaft 216 of the photosensitive drum 21 is inserted into the support hole 216h of the support frame 30F via the drum 21. At the same time, the integrated image forming unit 5 is formed by mounting a power transmission member such as a gear on the mounting portions 21g and 24g so as to drive the rotating members of the corresponding components.

  In the integrated image forming unit 5 configured as described above, the side frames 30F at both ends in the axial direction of the intermediate transfer unit 3 are used as a common (single) support frame 30F, and belt support rolls 32a and 32b, the photosensitive drum 21, Components such as the developing roll 241 and the primary transfer roll 33 are integrally attached to and supported by the support frame 30F. This makes it possible to eliminate the accumulation of mounting tolerances and improve the positioning accuracy of the components compared to the conventional configuration in which each unit is attached to the subframe and these subframes are attached to the main frame. it can. In addition, units that directly contribute to image formation (in this example, the image forming unit 2 and the intermediate transfer unit 3) are integrated to reduce the number of frames, and movable units such as a positioning mechanism and a retracting mechanism for each unit. Can be omitted, contributing to downsizing, space saving, and cost reduction.

  Further, by attaching at least a power transmission member such as a gear to the support frame 30F, the rigidity of the support member can be improved and the speed fluctuation of the rotating member can be suppressed.

  Next, as shown in FIG. 5C, the integrated image forming unit 5 is placed on the paper supply device 4, and is fixed to the portal fixed frame 4 f of the paper supply device 4 by screws or the like. (See FIG. 5 (d)).

  Further, as shown in FIG. 5E, a high-voltage power supply substrate for supplying a bias voltage is integrally attached to the upper portion of the integrated image forming unit 5, and the fixing device 45 and the like are arranged to complete the image forming apparatus 1. To do.

  As described above, since the image forming apparatus 1 according to the present embodiment is simply configured by sequentially stacking and stacking the units, it is possible to improve assemblability.

  Further, by fixing the power supply board integrally with the integrated image forming unit 5, the contact with the power supply terminal, the ground terminal, etc. is fixed, and the conduction reliability at the contact can be improved.

  The technical scope of the present invention is not limited to the above-described embodiments, and various modifications or improvements can be added without departing from the scope of the present invention described in the claims. is there. For example, in the above-described embodiment, application to a so-called tandem type color image forming apparatus having a photosensitive drum of each color has been exemplified, but it may be applied to a monochrome monochrome printer or the like. Moreover, you may comprise so that the LED print head 23 may be attached to the common side frame 30F.

  1: Image forming apparatus, 2Y, 2M, 2C, 2K: Image forming unit, 3: Intermediate transfer unit, 4: Paper supply device, 4f: Fixed frame, 5: Integrated image forming unit, 8Y, 8M, 8C, 8K : Cartridge housing part, 9: Recording paper, 10: Main body, 11Y, 11M, 11C, 11K: Toner cartridge, 12: Discharge housing part, 20: Photoconductor unit, 21Y, 21M, 21C, 21K: Photosensitive drum, 22Y , 22M, 22C, 22K: charging device, 23Y, 23M, 23C, 23K: LED print head, 23f: signal transmission harness, 24: development unit, 25Y, 25M, 25C, 25K: drum cleaning device, 30F: support frame, 31: Intermediate transfer belt, 32a, 32b: Belt support roll, 33Y, 33M, 33C, 33K: Primary Continuous roll, 33p: feeding terminal, 35: second transfer roller, 45: fixing device, 21g, 24 g: mounting portion, 216: support shaft, 216h: supporting hole

Claims (6)

A plurality of image holders formed rotatably;
A plurality of developing means having a rotatable developer holding body for holding a developer containing toner, and developing the electrostatic latent image formed on the image holding body with toner of each color;
A belt-like intermediate transfer member formed on a plurality of support rolls and rotatably formed with a toner image formed on the image holding member being sequentially transferred;
The image forming apparatus, wherein the intermediate transfer member, the image holding member, and the developing unit are formed as an integral image forming unit by attaching both end portions in the axial direction to a common support member.   The image holding member and the developing unit are disposed below the intermediate transfer member, and the common support member is formed by extending the support members at both axial ends of the belt-like intermediate transfer member downward. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. And further comprising a driving means for rotating each of the intermediate transfer body, the image holding body and the developing means via a power transmission member,
The image forming apparatus according to claim 1, wherein at least the power transmission member is integrally installed on the common support member.   2. The power supply board for supplying power to each of the intermediate transfer member, the image carrier, and the developing means, and the power supply board is installed integrally with the integral image forming means. 4. The image forming apparatus according to any one of items 3 to 3.   The image forming member further includes a latent image forming unit that forms an electrostatic latent image on the image holding member. The latent image forming unit is disposed between the image holding member and the developing unit, and is integrated with the image holding member. The image forming apparatus according to claim 1, wherein the image forming apparatus is formed as described above. A sheet feeding means for supplying a recording medium to the integral image forming means;
The image forming apparatus according to claim 1, wherein the integrated image forming unit is fixedly installed on the sheet feeding unit.

Images