CN100480881C - Image-forming device - Google Patents

Abstract

An image forming device includes: a housing; an endless belt; a plurality of processing units; and a plurality of scanning units. Each scanning unit and each processing unit are inclined relative to the vertical direction. At least a portion of each processing unit is inserted into and removed from the housing in an oblique direction.

Description

imaging device

technical field

The present invention relates to an image forming apparatus for forming an image on a recording medium, and more particularly, to an image forming apparatus equipped with a plurality of scanning units and processing units, and an endless belt for image formation that transfers a developer image or recording medium.

Background technique

There has been proposed an image forming apparatus equipped with: an endless belt that conveys a developer image or a recording medium; a plurality of process units equipped with a plurality of photosensitive drums corresponding to a plurality of colors, each of which faces the belt; a plurality of scanning units, each of which is used to expose and scan the surface of the corresponding photosensitive drum to form an electrostatic latent image, which is developed by the corresponding processing unit by using a developer of a corresponding color; The developer image on the surface of the photosensitive drum is transferred to the recording medium conveyed by the endless belt or to a transfer unit on the endless belt itself.

US Patent Application Publication No. US2003/0147678A1 has proposed a type of image forming device in which the endless belt is an intermediate transfer belt for supporting the developer. This type of imaging device performs an imaging process as follows.

When the scanning unit exposes and scans a corresponding photosensitive drum of one color according to the image data to form an electrostatic latent image, the corresponding processing unit develops the electrostatic latent image by using a developer of the color. The developer image is transferred onto the intermediate transfer belt by the transfer roller. Once the developer images of all colors are superimposed thereon, the developer images are transferred to the recording medium.

Another type of image forming apparatus has been proposed in Japanese Patent Laid-Open No. 7-234622, in which the endless belt is a conveyor belt for conveying recording media. In this type of image forming apparatus, a developer image is directly superimposed on a recording medium, and the recording medium is conveyed by a conveyor belt to form a superimposed image on the recording medium.

Contents of the invention

An object of the present invention is to provide an image forming apparatus which can be easily made compact and which has excellent maintainability for a processing unit therein.

In order to achieve the above and other objects, the present invention provides an image forming apparatus comprising: a casing; an endless belt; a plurality of processing units; a plurality of scanning units; a transfer portion; . The endless belt is installed in the casing and conveys either one of a developer image and a recording medium. A plurality of processing units are installed in the housing, corresponding to each of the colors, each of the processing units includes a plurality of photosensitive drums, and each photosensitive drum faces the endless belt. A plurality of scanning units are installed in the casing, and one scanning unit is provided for each photosensitive drum, each scanning unit scans the surface of the corresponding photosensitive drum with light to form an electrostatic latent image, and each processing unit uses a developer of a corresponding color Develops an electrostatic latent image. The transfer portion is installed in the housing and transfers the developer image formed on each photosensitive drum to either the endless belt or the recording medium conveyed by the endless belt. A cartridge accommodating a recording medium is detachably mounted in the housing at a position below the endless belt. Scanning units and processing units are alternately arranged in a horizontal direction. Each scanning unit and each processing unit are inclined relative to the vertical direction. At least a portion of each processing unit is inserted into or removed from the housing in an oblique orientation. The loop is arranged such that its height increases in the direction in which the cartridge is pushed out of the housing.

Due to such a structure, the imaging device can be made compact, and at least a part of the processing unit can be easily attached to or detached from the imaging device.

Description of drawings

Read following description to preferred embodiment in conjunction with following accompanying drawing, above-mentioned and other objects of the present invention, feature and advantage will be more apparent:

1 is a side sectional view of the overall structure of a color laser printer according to a first embodiment of the present invention;

Figure 2 illustrates how to replace the process cartridge in the color laser printer of Figure 1;

3 is a side sectional view showing a modified overall structure of the paper output tray of FIG. 1;

4 illustrates the state of the image forming portion from which the process cartridge is removed to adjust the orientation of the scanning unit by using a screwdriver;

5 is a perspective view of a scanning unit installed on a scanner support frame;

Fig. 6 is a plan view showing the inside of the scanning unit seen from the side of the scanner support frame;

7(A) is a plan view showing the exterior of the scanning unit fixed to the scanner support frame in FIG. 5; FIG. 7(B) is taken from the line VIIB-VIIB in FIG. Side sectional view of the scanning unit on the support frame;

8 is an enlarged side sectional view illustrating how protrusions of the scanning unit are disposed on recesses of the scanner support frame;

9 is a side sectional view of a modified overall structure of the color laser printer of FIG. 1;

10 is a perspective view of a scanning unit mounted to a scanner support frame according to a second embodiment and corresponds to FIG. 5 of the first embodiment;

FIG. 11(A) is a plan view showing the exterior of the scanning unit fixed to the scanner support frame shown in FIG. 10 and corresponds to FIG. 7(A);

11(B) is a cross-sectional view of the scanning unit fixed to the scanner support frame taken on line XIB-XIB in FIG. 11(A) and corresponds to FIG. 7(B);

12 is an enlarged side sectional view illustrating how the rotating shaft of the scanning unit is mounted to the bearing portion of the scanner support frame;

13 is a side sectional view of a color laser printer according to a third embodiment;

Fig. 14 is a side sectional view showing a state in which the paper feeding cassette is withdrawn from the color printer of Fig. 13;

Fig. 15 is a side sectional view showing a state in which the paper feeding cassette and the tape unit are withdrawn from the color printer of Fig. 13;

Fig. 16 is a side sectional view of a state in which the conveyor belt and the belt cleaning device are removed from the belt unit of Fig. 15;

Figure 17 is a front sectional view taken from line XVII-XVII of the color laser printer of Figure 13;

Figure 18 is a bottom view of the strap unit;

FIG. 19 is a perspective view of an axial end portion of the transfer roller shown in FIG. 18;

Figure 20 is a perspective view of the connection between the neutralization bias line and the neutralization comb shown in Figure 18; and

Fig. 21 is a side sectional view of a modification of the third embodiment.

Detailed ways

An imaging device according to a preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings, wherein the same parts and components are denoted by the same reference numerals to avoid repeated descriptions.

<First embodiment>

First, a color laser printer 1 according to a first embodiment will be described with reference to FIGS. 1 to 8 .

In the following description, expressions such as "front", "rear", "above", "below", "right", and "left" are used to define each part.

The laser printer 1 is of a horizontal tandem type in which a plurality of image forming sections 17 are aligned in a horizontal direction. The laser printer 1 has a main casing 2 in which a paper feeding section 4 , an image forming section 5 and a paper unloading section 6 are provided.

The paper feeding section 4 is for feeding paper P as a recording medium. The image forming section 5 is for forming an image on the paper P supplied from the paper feeding section 4 . The paper unloading section 6 is for unloading the paper P on which the image forming section 5 forms an image.

The main casing 2 serves as the casing of the color laser printer 1 . The main casing 2 is box-shaped, and its upper opening is covered by a paper output tray 52 . Therefore, the output tray 52 functions as a top cover. The output tray 52 is rotatably supported to the main casing 2 via a hinge 52 a, and can be opened and closed relative to the main casing 2 .

The paper feeding section 4 is located at the lower part of the main casing 2 and includes: a paper tray 9, a support plate 3c, a separation pad 3a, a spring 3b, a pair of paper feeding rollers 10 and 11; a paper feeding cassette frame 71; a pair of conveying rollers 13 ( front conveying roller 13 a and rear conveying roller 13 b ); paper feed side U-shaped path 12 ; and a pair of registration rollers 14 . The paper tray 9, the support plate 3c, the separation pad 3a, the spring 3b and the front conveying roller 13a are mounted on the paper supply cassette frame 71 and enter the paper supply cassette 70 as an integral unit. The paper feeding section 4 further includes a paper feeding port 42a.

The image forming section 5 includes: four image forming sections 17 ( 17M, 17Y, 17C, 17K); a transfer section 18 ; and a fixing section 19 .

The image forming section 17M is used to form a magenta toner image, the image forming section 17Y is used to form a yellow toner image, the image forming section 17C is used to form a cyan toner image, and the image forming section 17K is used to form a black toner image. The imaging sections 17M, 17Y, 17C, and 17K are disposed slightly higher than the center of the main casing 2 in the vertical direction.

Each image forming section 17 has a scanning unit 20 and a process cartridge 30 . The scanning unit 20 is supported on a scanner support frame 260 which in turn is fastened to the main housing 2 . The orientation of scanning unit 20 relative to scanner support frame 260 is adjustable as described below.

The transfer portion 18 is disposed above the paper feeding portion 4 and below the image forming portion 17 inside the main casing 2, and extends in the front-rear direction. The transfer section 18 includes: a driving roller 36 , a driven roller 37 , a transfer belt 38 , a plurality of transfer rollers 39 , and a belt cleaning unit 40 . The conveyor belt 38 is provided below and faces the four image forming sections 17 .

The fixing section 19 is provided behind the transfer section 18 . The fixing section 19 includes a heat roller 48 and a pressure roller 49 .

The discharge section 6 has a discharge-side U-shaped path 50 , a pair of discharge rollers 51 , and a discharge tray 52 .

<Paper Feed Section>

The paper supply section 4 will be described in more detail below.

In the paper feeding section 4 , a paper feeding cassette 70 is detachably mounted in the main casing 2 . The paper feeding cassette 70 can be ejected from the storage position shown by the solid line in FIG. 1 to the ejected position shown by the dashed-two dotted line in FIG. 1, and in the ejected state, the recording paper P can be properly replenished. Thus, the sheet feeding cassette 70 can be inserted and removed horizontally at the front of the main casing 2 .

Paper feed cassette 70 has paper tray 9 . The support plate 3 c is mounted on the paper tray 9 . The support plate 3 c is pushed upward by a spring (not shown) which is also mounted on the paper tray 9 .

Note that each roller other than the front conveying roller 13a is rotatably provided at a predetermined position of the main casing 2 and driven by a driving source (not shown) which is also used to drive the image forming sections 17M, 17Y, 17C and 17K.

The separation pad 3 a and the spring 3 b are installed in the paper feed cassette 70 .

A pair of paper feed rollers 10 and 11 are installed in the main casing 2 at a position above the support plate 3c.

When the paper feed cassette 70 is mounted to a predetermined position of the main casing 2, the separation pad 3a is pressed into contact with the paper feed roller 11 by the elastic force of the spring 3b.

The paper feed rollers 10 and 11 separate the recording paper P stacked on the support plate 3 c one at a time and feed the separated paper in a direction toward the transport roller 13 . More specifically, the paper feed roller 10 located on the rear side among the pair of paper feed rollers 10 and 11 conveys the uppermost sheet of the recording paper P stacked on the support plate 3 c to the paper feed roller 11 . The paper feed roller 11 on the front side presses against the separation pad 3a, separates the recording paper P one at a time and conveys it. The paper feed roller 10 functions as a pickup roller.

Of the pair of conveying rollers 13 , the front conveying roller 13 a is installed in the paper feed cassette 70 , and the rear conveying roller 13 b is installed in the main casing 2 . A pair of transport rollers 13 transports the recording paper P cooperatively.

A pair of conveying rollers 13 and a pair of registration rollers 14 are sequentially disposed along a paper-feeding-side U-shaped path 12 along which recording paper P is conveyed from paper-feeding rollers 11 to an image forming portion 17 . Before the image forming section 17 starts its image forming operation, the registration roller 14 temporarily stops conveying the recording paper P, calibrates the orientation of the recording paper P by nipping its leading edge, and conveys the recording paper P to the image forming section 17 .

The paper-feeding-side U-shaped path 12 serves as a long U-shaped conveying path for conveying paper. The paper-feeding-side U-shaped path 12 extends from its upstream side edge to its downstream side edge through its middle.

In this embodiment, the paper feed side U-shaped path 12 is located at its upstream side edge adjacent to the paper feed roller 11, and the paper is conveyed forward at the upstream side edge. The transport roller 13 is located in the middle of the U-shaped path 12 on the paper feeding side. The paper feed side U-shaped path 12 is located at its downstream side edge adjacent to the registration roller 14, and conveys the paper backward.

Therefore, the recording paper P is first conveyed in the forward direction at the upstream side edge of the paper-feeding-side U-shaped path 12 and then conveyed by the conveying roller 13 in the middle of the paper-feeding-side U-shaped path 12 . When the paper P is conveyed by the conveying roller 13 in the middle of the U-shaped path 12 on the paper feeding side, the conveying direction of the paper P is reversed. After being oriented by the registration rollers 14, the paper P is conveyed out from the paper-feeding-side U-shaped path 12 in a backward direction.

The paper supply port 42 a is used to manually supply the recording paper P to the color printer 1 . The paper feed port 42a is located in the lower part of the main casing 2 on the front side from which the paper feed cassette 70 is pulled out. The recording paper P supplied from the paper feed port 42 a is conveyed to the nip portion between the registration rollers 14 by the paper feed roller 42 b , where the paper P is oriented before being sent to the image forming portion 17 .

<Imaging part 5>

Next, the imaging section 5 will be described in more detail.

In the imaging section 5, the four imaging sections 17M, 17Y, 17C, and 17K are arranged in this order from front to back in the front-rear direction. In each image forming section 17 , a corresponding scanning unit 20 and a corresponding process cartridge 30 are installed in the main casing 2 . The scanning unit 20 is fixedly installed in the main housing 2, and its orientation can be adjusted. The process cartridge 30 is detachably installed in the main casing 2 . When the process cartridges 30 are installed in all the image forming sections 17, the scanning units 20 and the process cartridges 30 are alternately arranged in the front-to-back direction.

The scanning unit 20 is arranged to form an angle with its forwardly inclined upper end. When the process cartridge 30 is installed in the image forming portion 17, the process cartridge 30 is also arranged to form an angle with its forwardly inclined upper end. The angle at which the process cartridge is inclined with respect to the front-rear (horizontal) direction is substantially the same as the angle at which the scanning unit 20 is inclined.

More specifically, the main housing 2 has a front inner wall 2a and a rear inner wall 2b, both of which extend obliquely forward and upward. Four scanner support frames 260 are disposed between the front inner wall 2a and the rear inner wall 2b, and also all extend obliquely forward and upward. The scanner support frame 260, the front inner wall 2a and the rear inner wall 2b extend substantially parallel to each other. The scanning unit 20 is installed on the scanner support frame 260 to extend along the scanner support frame 260 .

When the process cartridges 30 of all colors are installed in the main housing 2, the black process cartridge 30 is positioned between the black scanning unit 20 and the turquoise scanner support frame 260 to follow the turquoise scanner support frame 260. Extending, the turquoise process cartridge 30 is located between the turquoise scanning unit 20 and the yellow scanner support frame 260 to extend along the yellow scanner support frame 260, and the yellow process cartridge 30 is located between the yellow scanning unit 20 and the yellow scanner support frame 260. Between the red scanner support frame 260 to extend along the magenta scanner support frame 260, the magenta process cartridge 30 is located between the magenta scanning unit 20 and the front inner wall 2a to extend along the front inner wall 2a.

Next, the imaging section 17 will be described in more detail. The imaging sections 17 ( 17M, 17Y, 17C and 17K) have the same structure as each other.

Each process cartridge 30 is equipped with: a supply roller 31 ; a developing roller 32 ; a photosensitive drum 33 ; a scorotron charging device 34 ; and a toner container 35 .

The photosensitive drum 33 is rotatably supported at the lower end inside the process cartridge 30 .

The photosensitive drum 33 includes: a cylindrical main drum body 33b; and a drum shaft 33a extending along the axial center of the main drum body 33b in its axial direction. The process cartridge 30 is installed in the main body 2 , and the drum shaft (rotation shaft) 33 a extends in the width direction of the main casing 2 . The main drum body 33b has a photosensitive layer formed of polycarbonate or the like having a positive charging property on its outer surface. The drum shaft 33 a is fastened to two widthwise side plates (right side plate and left side plate) constituting the process cartridge 30 . The drum shaft 33a cannot rotate relative to the side plate. The main drum body 33b is rotatably supported on the drum shaft 33a. In this way, the photosensitive drum 33 is rotatably supported inside the process cartridge 30 .

During image formation, the photosensitive drum 33 is driven to rotate in the clockwise direction in the figure, so the photosensitive drum 33 moves in the same direction as the conveyor belt 38 at the position where it contacts the conveyor belt 38 .

The scorotron charging device 34 is of the forward charging type and has a charging wire and a grid for generating corona discharge. A scorotron charging device 34 is provided at the rear of the photosensitive drum 33 . The scorotron charging device 34 is opposite to the photosensitive drum 33 but separated from the photosensitive drum 33 by a certain distance without being in contact with it.

The developing roller 32 is disposed on and opposed to the photosensitive drum 33 . The developing roller 32 is pressed against the photosensitive drum 33 . The developing roller 32 has a metal roller shaft 32a covered by a roller body 32b made of an elastic material, specifically, a conductive rubber material. More specifically, the roller body portion 32b of the developing roller 32 has a two-layer structure including: an elastic roller body portion made of conductive urethane rubber, silicone rubber or EPDM rubber and containing carbon powder; and mainly made of urethane rubber, Coating layer made of polyurethane resin or polyimide resin. The roller shaft 32 a is rotatably supported by a pair of widthwise side plates of the process cartridge 30 .

The supply roller 31 is disposed above and opposed to the developing roller 32 . The supply roller 31 has a metal roller shaft 31a covered by a roller body 31b made of a conductive foam material. The roller shaft 31 a is rotatably supported by a pair of widthwise side walls of the process cartridge 30 .

A toner container 35 is defined in the upper portion of the supply roller 31 in the process cartridge 30 . The toner cartridge 35 in the process cartridge 30 of the image forming section 17M stores therein magenta toner. The toner cartridge 35 in the process cartridge 30 of the image forming section 17Y stores therein yellow toner. The toner cartridge 35 in the process cartridge 30 of the image forming section 17C stores therein cyan toner. The toner cartridge 35 in the process cartridge 30 of the image forming section 17K stores black toner therein. The toner is a non-magnetic single-component polymer toner with positive charging properties.

In this embodiment, each color toner is a polymer toner having substantially spherical particles.

Polymeric toners include a binder resin as their main component. Each binder resin is produced by copolymerizing polymerized monomers by a known polymerization method such as suspension polymerization. Examples of polymerizable monomers include: styrene monomers such as styrene, acrylic monomers such as acrylic acid, alkyl (C1-C4) acrylate, alkyl (C1-C4) metaacrylate.

Primary toner particles are formed by adding colorants, charge regulators and paraffin to the binding resin. In this embodiment, the stains are yellow, magenta, cyan and black stains. Examples of charge regulators that can be used include charge regulator resins obtained by copolymerizing ionic monomers and copolymerizable monomers. In this case, the ionic monomer may be an ammonium salt or other monomer with ionic functional groups. Copolymerizable monomers can be copolymerized with ionic monomers and can be styrene monomers, acrylic monomers, or other monomers with ionic functional groups.

External additives such as silica are added to primary toner particles to increase the fluidity of the toner. Various inorganic substance powders can be used as the external additive. For example, powders of metal oxides, carbides, and metal salts can be used as external additives. Metal oxide powders that can be used as external additives include silica, aluminum oxide (aluminate), titanium oxide, strontium titanate, cerium oxide, magnesium oxide.

The scanning unit includes 20 : a scanner housing 26 ; and various optical components mounted in the scanner housing 26 . The optical element comprises: a laser diode (not shown) emitting a laser beam L; a polygon mirror 22 reflecting the laser beam L in a scanning direction perpendicular to the paper of FIG. 1; a fθ lens 24 transmitting the laser beam L from the polygon mirror 22; A folding mirror 23 that receives the laser beam L reflected by the polygon mirror 22 and reflects the laser beam L back toward the photosensitive drum 33 of the corresponding process cartridge 30 , and a cylindrical lens 25 that transmits the laser beam L reflected from the folding mirror 23 .

Note that the scanner housing 26 is formed on one side of the corresponding process cartridge 30 with an exposure hole 26a. An optical member such as a protective mirror is provided on the scanner housing 26 to cover the exposure hole 26a.

The folding mirror 23 is arranged near the upper end of the process box 30, along the imaginary plane (parallel to the plane of the drawing) perpendicular to the scanning direction, the optical path and the folding mirror of the laser beam L between the fθ lens 24 and the folding mirror 23 23 and the optical path of the laser beam L between the cylindrical lens 25 form an angle α of about 15 degrees.

This ensures that the scanning unit 20 and the process cartridge 30 are arranged in close proximity, making the entire apparatus 1 compact. The length of the optical path of the laser beam L required for exposing the photosensitive drum 33 from near the upper end of the scanning unit 20 to the photosensitive drum 33 near the lower end of the process cartridge 30 can be sufficiently secured. Elements such as the fθ lens 24 can be made compact, making the entire device 1 compact.

Also, since the laser beam L is reflected near the upper end of the scanning unit 20, the exposure hole 26a can be disposed above the vertical center of the scanning unit 20 so as to be sufficiently away from the position of the photosensitive drum 33 located at the lower end of the process cartridge 30. A protective mirror covering the exposure hole 26a prevents contamination by toner.

In each image forming section 17 , a laser beam L is emitted from a laser diode (not shown in the figure) according to image data and is reflected by a polygon mirror 22 and reflected by a folding mirror 23 during image forming. The laser beam L then exits the scanning unit 20 through the exposure hole 26 a and reaches the photosensitive drum 33 .

The toner stored in the toner container 35 is supplied to the supply roller 31 . Due to the rotation of the supply roller 31 , toner is supplied to the developing roller 32 . When the toner is supplied from the supply roller 31 to the developing roller 32, the toner is positively charged due to friction between the supply roller 31 and the developing roller 32 to which a developing bias is applied.

The scorotron charging device 34 is applied with a charging bias to generate corona discharge, thereby uniformly and positively charging the surface of the photosensitive drum 33 . Due to the rotation of the photosensitive drum 33 , the surface of the positively charged photosensitive drum 33 is exposed to high-speed scanning of the laser beam emitted from the scanning unit 20 . As a result, an electrostatic latent image corresponding to an image to be formed on the sheet is formed on the surface of the photosensitive drum 33 .

As the photosensitive drum 33 further rotates, the positively charged toner carried on the surface of the developing roller 32 is brought into contact with the photosensitive drum 33 . At this time, the toner on the developing roller 32 is supplied to the low potential area of the electrostatic latent image on the photosensitive drum 33 exposed by the laser beam. As a result, the toner is selectively carried on the photosensitive drum 33 so that the electrostatic latent image is developed into a visible toner image.

Each process cartridge 30 is installed in the main casing 2 and is inclined forward at a position adjacent to the process cartridge 30 higher than the rear side thereof. More specifically, the mounting position of each process cartridge 30 is shifted by a predetermined amount higher than the adjacent process cartridges 30 on the rear side thereof.

More specifically, the offset between the installation position of the process cartridge 30 in the black image forming section 17K and the installation position of the process cartridge 30 in the cyan image forming section 17C, the processing in the cyan image forming section 17C The offset between the installation position of the cartridge 30 and the installation position of the process cartridge 30 in the yellow image forming section 17Y, the installation position of the process cartridge 30 in the yellow image forming section 17Y and the process cartridge in the magenta image forming section 17M The offsets between the installation positions of 30 are all equal to the preset value.

This has just ensured that when the process cartridges 30 of all colors are installed in the image forming section 5 in the main casing 2, the photosensitive drums 33 in the process cartridges 30 are arranged so that the straight line connecting the lower sides of the respective photosensitive drums 33 Extending forward and upward at a predetermined angle with respect to the horizontal. Therefore, the space defined below the image forming portion 5 and above the sheet feeding cassette 70 has a tapered profile in which the height in the vertical direction narrows rearward when viewed from one side. The transfer portion 18 is provided in the space of this tapered profile.

Next, the transfer portion 18 will be described in detail.

The drive roller 36 is provided behind the photosensitive drum 33 in the process cartridge 30 installed in the black image forming section 17K. The drive roller 36 is provided at a position displaced entirely in the vertical direction from the photosensitive drum 33 . During image formation, the drive roller 36 is driven to rotate in a direction opposite to that of the photosensitive drum 33 (counterclockwise in the drawing).

The driven roller 37 is provided in front of the photosensitive drum 33 of the process cartridge 30 installed in the magenta image forming portion 17M. The driven roller 37 is provided at a position higher than the driving roller 36 . When the driving roller 36 rotates, the driven roller 37 also rotates (counterclockwise in the drawing), and its portion in contact with the conveyor belt 38 moves in the same direction as the conveyor belt 38 moves.

Each process cartridge 30 is installed such that the axial direction of the photosensitive drum 33 is substantially parallel to the axial directions of the driving roller 36 and the driven roller 37 .

The conveyor belt 38 is an endless belt formed of a resin such as conductive polycarbonate or polyimide in which conductive particles such as carbon particles are dispersed. The conveyor belt 38 is wound around the driving roller 36 and the driven roller 37 . The conveyor belt 38 has an upper portion 38 a provided above the driving roller 36 and the driven roller 37 , and a lower portion 38 b provided below the driving roller 36 and the driven roller 37 . Both the upper portion 38a and the lower portion 38b extend along a flat slope or an inclination that increases in height as it moves forward. When each process cartridge 30 is installed in the main casing 2, the upper side portion 38a of the conveyor belt 38 contacts the photosensitive drum 33 of the process cartridge 30 from below. The contact portion between the photosensitive drum 33 and the upper side portion 38a of the transfer belt 38 will hereinafter be referred to as an image transfer position.

Note that the driven roller 37 is provided on the upstream side in the direction of movement of the upper side portion 38a of the conveyor belt 38, and the driving roller 36 is on the downstream side. On the other hand, the driven roller 37 is provided on the downstream side in the moving direction of the lower side portion 38b of the conveyor belt 38, and the driving roller 36 is on the upstream side.

When the drive roller 36 rotates counterclockwise, the conveyor belt 38 rotates counterclockwise around the drive roller 36 and driven roller 37, and the upper portion 38a moves in the same direction as the photosensitive drum 33 at its image transfer position. The drive roller 36 is provided on the downstream side in the moving direction of the upper side portion 38a of the conveyance belt 38 at the image transfer position, and the driven roller 37 is provided on the upstream side. Therefore, slack in the upper side portion 38a of the conveyor belt 38 can be prevented. For this reason, the paper P can be accurately conveyed by the upper side portion 38 a of the conveyance belt 38 .

Four transfer rollers 39 are provided between the upper side portion 38 a and the lower side portion 38 b of the conveyor belt 38 . The transfer roller 39 is located at an image transfer position where the upper side portion 38 a of the conveyor belt 38 is in contact with the photosensitive drum 33 . Each transfer roller 39 faces the corresponding photosensitive drum 33 with the upper side portion 38 a sandwiched therebetween.

Each transfer roller 39 has a metal roller shaft 39a, and it is covered with a roller body portion 39b made of an elastic backing substance such as a conductive rubber material. Both end portions of the roller shaft 39a of each transfer roller 39 are rotatably supported in the main housing 2 via bearings and compression springs (not shown).

The transfer roller 39 is pressed upward by a compression spring (not shown in the figure), thereby pressing the conveyor belt 38 against the photosensitive drum 33 at each image transfer position. At each image transfer position, a nip is formed between the photosensitive drum 33 and the transfer belt 38 .

A transfer bias voltage is applied to each transfer roller 39 . Each transfer roller 39 rotates in the counterclockwise direction in the drawing to move in the same direction as the conveyor belt 38 at the image transfer position.

The paper P supplied from the paper supply section 4 is conveyed from front to rear by the conveyance belt 38 which is moved around by the driving of the driving roller 36 and the movement of the driven roller 37, successively passing between the conveyance belt 38 and the photosensitive drum 33 of the image forming section 17. image transfer position. During conveyance, the toner images of each color carried by the corresponding photosensitive drum 33 of each image forming section 17 are successively transferred onto the paper P, so that images of a plurality of colors are formed on the paper P.

In other words, the paper P is first transferred by transferring the magenta toner image carried on the surface of the photosensitive drum 33 of the magenta image forming portion 17M, and then by transferring the magenta toner image carried on the surface of the photosensitive drum 33 of the yellow image forming portion 17Y. on the magenta toner image that has been transferred onto the paper P, and similarly the cyan toner image carried on the surface of the photosensitive drum 33 of the cyan image forming section 17C, and the cyan toner image carried on the The black toner image on the surface of the photosensitive drum 33 of the black image forming section 17B is transferred onto the previous image on the paper P, so that images of various colors can be formed on the paper P.

The belt cleaning device 40 is provided under the conveyor belt 38 in a relatively large space formed near the driven roller 37 side, that is, in a space larger than that formed near the driving roller 36 side.

The belt cleaning device 40 has a cleaning case 46 and a cleaning roller 47 .

The cleaning box 46 has a box-like outline, and a hole is formed at a portion thereof facing the lower side portion 38b of the conveyor belt 38 . The inner space of the cleaning box 46 is formed as a collection portion for collecting substances attached to the conveyor belt 38 and removed from the conveyor belt 38 by the cleaning roller 47 .

The cleaning roller 47 is a metal roller rotatably supported at a hole portion in the cleaning case 46 , and is in contact with the lower side surface of the lower side portion 38 b of the conveyor belt 38 . During cleaning, a cleaning bias voltage is applied to the cleaning roller 47 . The cleaning roller 47 is driven to rotate counterclockwise in the drawing. Therefore, the cleaning roller 47 moves in a direction opposite to the direction of movement of the conveyor belt 38 at its portion in contact with the conveyor belt 38 .

It is to be noted here that toner adheres to the conveyor belt 38 while the conveyor belt 38 is in contact with the photosensitive drum 33 . Paper dust adheres to the conveyor belt 38 when the paper P comes into contact with the conveyor belt 38 . Matters such as toner and paper dust are captured by the cleaning roller 47 by electrostatic force when the conveyor belt 38 brings these substances to a position opposite to the cleaning roller 47 . The matter thus trapped is removed from the cleaning roller 47 and collected in a collecting portion of the cleaning box 46 .

In this way, when the cleaning roller 47 is in contact with the outer surface or lower surface of the lower side portion 38a of the conveying belt 38, the cleaning roller 47 recovers the toner adhered to the surface of the conveying belt 38 when the toner is scattered from the photosensitive drum 33. With paper dust adhering to the surface of the conveyor belt 38 when the paper is conveyed on the conveyor belt 38 .

The fixing section 19 will be described below.

The heat roller 48 is constituted by a metal tube having a release layer formed on its surface. A halogen lamp extending in the axial direction of the heating roller 48 is housed in the heating roller 48 . The halogen lamp heats the surface of the heating roller 48 to a fixing temperature. The pressure roller 49 is in pressure contact with the heating roller 48 .

In this fixing section 19, the recording paper P with the toner image thereon is sandwiched between the heat roller 48 and the pressure roller 49, and the toner image is heat-fixed on the paper P by pressure.

<Unloading part 6>

The discharge-side U-shaped path 50 is formed as a conveyance path of a substantially U-shaped profile of the paper P extending upward from its upstream end portion to its downstream end portion. The upstream end portion of the discharge-side U-shaped path 50 is in the vicinity of the fixing portion 19 and conveys the paper P backward. The downstream end portion of the discharge-side U-shaped path 50 is in the vicinity of the paper output tray 52 and conveys the paper P forward.

The discharge rollers 51 are provided in pairs at the ends of the downstream side of the discharge-side U-shaped path 50 .

The output tray 52 defines the upper surface of the main casing 2 as a slanted wall inclined from the front to the rear.

The conveyed sheet from the fixing portion 19 is supplied backward at the upstream end portion of the discharge-side U-shaped path 50 , where its conveyance direction is reversed, and conveyed forward by the discharge roller 51 to output tray 52.

The paper output tray 52 is configured such that the entire tray can rotate about the center of a hinge 52 a provided under the paper discharge roller 51 . Each of the process cartridges 30 can be removed from the main casing 2 by turning the paper output tray 52 upward to open the mechanism, as shown in FIG.

As described above, according to the present embodiment, the color laser printer 1 is of the tandem type in which a plurality of process cartridges 30 (one for each color) are provided in a plurality of image forming sections 17, respectively. According to this, the formation of an image of each color proceeds at substantially the same speed as that of a monochrome image, making it possible to rapidly form an image of multiple colors. For this reason, images of various colors can be formed while maintaining the compactness of the device.

More specifically, a photosensitive drum 33 is rotatably supported in each process cartridge 30 near the lower end of the process cartridge 30 . The scorotron charging device 34 charges the surface of the photosensitive drum 33 . The toner cartridge 35 is provided at a position above the photosensitive drum 33 . A supply roller 31 and a developing roller 32 are provided at positions below the toner container 35 . Toner is supplied onto the surface of the photosensitive drum 33 by the operation of the supply roller 31 and the development roller 32 . The electrostatic latent image is formed on the surface of the photosensitive drum 33 by the laser beam L emitted from the scanning unit 20 , and thereafter the electrostatic latent image is developed by supplying toner to the surface of the photosensitive drum 33 by the developing roller 32 . The photosensitive drum 33 faces the transfer roller 39 with the conveyor belt 38 sandwiched therebetween. A transfer bias voltage is applied to the transfer roller 39 . Accordingly, the toner for developing the electrostatic latent image on the photosensitive drum 33 is transferred onto the recording paper P conveyed on the conveying belt 38 . This causes color images of magenta, yellow, cyan, and black to be sequentially formed on the recording paper P. As shown in FIG. The recording paper P passing under each image forming section 17 is then supplied to the fixing section 19 . The recording paper P on which the image is fixed by the fixing portion 19 is then conveyed by a pair of discharge rollers 51 and sent out onto a discharge tray 52 on top of the main casing 2 .

As shown in FIG. 2, in each image forming portion 17, the process cartridge 30 is inserted or removed in a direction D which is inclined in the horizontal direction (front-rear direction) and the vertical direction (thickness direction of the paper P). , in other words, tilt in a forward-upward direction. Ease of operation for inserting or removing the process cartridge 30 can thus be improved.

Also, a plurality of process cartridges 30 and a corresponding plurality of scanning units 20 are alternately arranged in the front-rear direction of the color printer 1 . Such an efficient arrangement can make the device more compact.

More specifically, the scanning units 20 and the process cassettes 30 are alternately arranged in the direction in which the sheet P is transported by the transport belt 38 under the scanning unit 20 and the process cassettes 30 at the image transfer position. Therefore, the scanning unit 20 and the process cartridge 30 can be efficiently arranged in the color laser printer 1, making the color laser printer 1 compact.

The scanning unit 20 and the process cartridge 30 are inclined such that their upper ends face upward and forward. This makes it possible to lower the height of the apparatus, making it more compact compared to the comparative example in which the scanning unit 20 and the process cartridge 30 are not inclined but stand vertically.

Note here that although the scanning unit 20 and the process cartridge 30 are arranged at an angle in the color laser printer 1, the depth dimension (front-to-rear dimension) of the color laser printer 1 is not greatly increased from that of the comparative example. This is because the paper feed cassette 70 is inserted and removed in the depth direction, and because the depth dimension of the comparative example printer is larger than the entire depth dimension of all the vertical upright scanning units 20 and the process box 30 by the length of an interval, the interval is set at the main Between the scanning unit 20 next in the depth direction in the housing 2 and the process cartridge 30 is to accommodate other components such as various rollers installed therein.

Also, each process cartridge 30 is inserted or removed in a forwardly inclined direction (direction indicated by arrow D in FIG. 2) which is inclined forwardly in a direction parallel to the front inner wall 2a and the rear inner wall 2b.

In other words, each process cartridge 30 is inserted or removed in a direction oblique with respect to the direction in which the paper P is conveyed at its image transfer position below its associated process cartridge 30 and the paper thickness direction perpendicular to the conveying direction. Insertion or removal of the process cartridge is thereby facilitated.

Moreover, since the operation of replenishing the recording paper P in the paper supply cassette 70 and the operation of removing the recording paper P from the paper output tray 52 are performed from the front in a manner similar to inserting or removing each process cassette 30, the present embodiment ensures The operation of this device is greatly improved.

With this embodiment, the conveyor belt 38 is arranged obliquely so that its front is higher than its rear. In other words, the conveyor belt 38 descends downward on the downstream side in the toner transfer direction. For this reason, a wide space is formed under the front side of the conveyor belt 38 so that components such as the paper feed rollers 10 and 11 can be installed under the front side of the conveyor belt 38 .

Since the conveyor belt 38 is inclined, the depth dimension of the device can be reduced. The whole device can be made more compact.

The direction in which the conveyor belt 38 is inclined and the direction in which the process cartridges 30 are inclined form a space on the downstream side of each photosensitive drum 33 in the direction of rotation thereof. This enables a relatively large scorotron charging device 34 to be disposed on the downstream side of each photosensitive drum 33 in its rotational direction without increasing the size of the device 1 .

Also, by ensuring that the height of the scanning unit matches that of the process cartridge 30, the apparatus 1 can be made more compact.

More specifically, a straight line connecting the scanning unit 20 and the upper end of the process cartridge 30 extends at a predetermined angle with respect to the horizontal direction to be inclined upward and forward. A straight line connecting the upper end surface of the scanning unit 20 and the upper end surface of the process cartridge 30 is parallel to the direction of inclination of the conveyor belt 38 . The device 1 can thus be made more compact.

The output tray 52 is disposed along the upper ends of the scanning unit 20 and the process box 30 . The output tray 52 extends in a direction substantially parallel to the conveyor belt 38 . Therefore, an air flow of a fixed width is generated on the lower side of the tray 52 , that is, between the output tray 52 and the scanning unit 20 and the process cartridge 30 . For this reason, the apparatus 1 can be made relatively compact while ensuring ventilation near the upper end of the process cartridge 30 . This can facilitate the dissipation of heat.

A folding mirror 23 is located near the top of each scanning unit 20 . The photosensitive drum 33 is near the lower end of the process cartridge 30 . Therefore, the laser light is irradiated from near the upper end of the scanning unit 20 to near the lower end of the process cartridge 30 before the exposure scanning of the photosensitive drum 33 is performed. Therefore, the long length of the exposure optical path can be maintained and the scanning unit 20 can be made compact by reducing the size of the lens installed therein.

Also, since exposure scanning is performed from a position at a distance from the photosensitive drum 33, toner contamination of optical components mounted in the scanning unit 20 can be prevented. Therefore the device can be more compact and can form sharper images.

The upper end of the scanner housing 26 is made narrower in the rearward direction. The upper end of each toner container 35 is enlarged by the same amount in the rearward direction to protrude toward the narrowed upper end of the scanner housing 26 .

More specifically, each scanner housing 26 has: an upper portion extending from an upper end 26U of the scanner housing 26 to a middle portion; and a lower portion extending from a middle portion of the scanner housing 26 to a lower end 26D. Each process cartridge 30 has: an upper portion extending from an upper end 30U of the process cartridge 30 to a middle portion; and a lower portion extending from a middle portion of the process cartridge 30 to a lower end 30D. In the lower part, the scanner housing 26 has a uniform depth (width in the front-rear direction) from the lower end 26D to the middle. Also, in the lower portion of the process cartridge 30, the process cartridge 30 has a uniform depth (width in the front-rear direction) from the lower end 30D to the middle. In contrast, the upper portion of each scanner housing 26 has a depth (width in the front-rear direction) that decreases from the middle portion to the upper end 26U by narrowing toward the rearward direction of the upper end 26U. The upper portion of each process cartridge 30 has a depth (width in the front-rear direction) that increases from the middle portion to the upper end 30U by protruding toward the rearward direction toward the upper end.

In this way, the depth of each scanning unit 20 (the width of each scanning unit 20 in the direction in which the scanning units 20 and the process cartridges 30 are alternately arranged) becomes narrow near the upper end of the scanning unit 20, and the depth of each process cartridge 30 The depth (the width of each process cartridge 30 in the same direction) widens near the upper end of the process cartridge 30 to match or complement the narrowed portion of the scanning unit 20 . Therefore, the sum of the depth of the scanning unit 20 and the depth of the processing unit 31 is uniform from the lower end to the upper end thereof.

Therefore, the amount of toner that can be stored in the toner container 35 can be increased without making the device 1 larger, reducing the frequency of replacement and improving maintainability. It is thereby possible to make the color laser printer 1 relatively compact and improve its maintainability.

In the color laser printer 1, the paper P is guided forward by the pickup roller 10 in the paper feeding section 4, the paper P is conveyed backward at the image transfer position, and the paper P is conveyed forward by the paper discharging roller 51 in the paper discharging section 6. . Therefore, the device can be made compact while securing the conveyance path of the paper P.

As described above, according to the present embodiment, the color laser printer 1 has the scanning unit 20 and the process cartridge 30 which are arranged alternately in the front-rear direction with their upper ends inclined forward at an angle. Since the scanning unit 20 and the process cartridge 30 are inclined, the height of the apparatus 1 can be reduced and the apparatus 1 can be made more compact as compared with a comparative example in which the process cartridge 30 stands vertically above the conveyor belt 38 .

Since each process cartridge 30 can be inserted and removed in a direction inclined with respect to the forward direction, the insertion and removal of the process cartridges 30 is easier compared with the comparative example in which the process cartridges 30 stand vertically and must be pulled out in the vertical direction.

Also, the conveyor belt 38 is set at an angle such that its front end is higher than its rear end, so the device 1 can be made more compact.

<Modification of Output Tray>

In the above description, the output tray 52 is provided so as to cover all the image forming sections 17M to 17K. Alternatively, as shown in FIG. 3 , a plurality of output trays 152 may be provided to cover the image forming portions 17M to 17K, respectively. Each output tray 152 can be opened or closed independently by its hinge 152a.

In this modification, only one output tray 152 corresponding to the process cartridge 30 requiring maintenance needs to be opened or closed. Operation becomes simplified.

<Details of scanning unit>

The structure of the scanner supporting frame 260 and the scanning unit 20 will be described in more detail with reference to FIGS. 4-8 .

As shown in FIG. 4 , four support frames 260 corresponding to magenta, yellow, cyan and black are fixedly installed in the main housing 2 parallel to the front and rear inner side walls 2 a and 2 b ( FIG. 1 ). The scanning unit 20 is installed on each support frame 260 .

As shown in FIG. 5, the support frame 260 has a substantially rectangular bottom plate 260a. The bottom plate 260a has an inner surface 260aa and an outer surface 260ab facing each other. The support frame 260 also has a side wall 260b disposed around the periphery of the bottom plate 260a. The side wall 260b surrounds the inner surface 260aa of the bottom plate 260a and stands vertically from the inner surface 260aa. The supporting frame 260 is fixedly installed in the main housing 2 , and the bottom plate 260a extends obliquely forward and upward, and the inner surface 260aa faces forward and downward.

As shown in FIGS. 4 to 6, the scanner housing 26 of the scanning unit 20 has a bottom plate 26b formed with an exposure hole 26a. The bottom plate 26b has a flat portion 26bf and an inclined portion 26bs. The flat portion 26bf extends from the lower edge 26D of the scanner housing 26 to the middle of the scanner housing 26, while the sloped portion 26bs extends from the middle of the scanner housing 26 to the upper edge 26U of the scanner housing. The inclined portion 26bs is inclined with respect to the flat portion 26bf. The bottom plate 26b has an inner surface 26b1 and an outer surface 26b2 facing each other. The scanner housing 26 also has a side wall 26c disposed around the periphery of the bottom plate 26b. The side wall 26c surrounds the inner surface 26b1 and stands vertically from the inner surface 26b1. The side wall 26c has a top end surface 26ce. As shown in FIG. 4, the height of a portion of the side wall 26c upright from the flat portion 26bf of the bottom plate 26 is substantially uniform over the entire flat portion 26bf, while the height of the remaining portion of the side wall 26c upright from the inclined portion 26bs of the bottom plate 26b reaches the upper end 26U. decrease.

The scanning unit 20 is installed on the supporting frame 260 , and the inner surface 26b1 of the bottom plate 26b and the top surface 26ce of the side wall 26c face the inner surface 260aa of the supporting frame 260 . Note that the right end 26R and the left end 26L of the scanning unit 20 face rightward and leftward in the main casing 2 . The upper end 26U and the lower end 26D of the scanning unit 20 face up and down in the main casing 2 .

As shown in FIG. 6, the polygon mirror 22, the f? lens 24, and the cylindrical lens 25 are mounted on the inner surface 26b1 of the bottom plate 26b. Also, a collimator lens 255, a slot device 256, a cylindrical lens 257, mirrors 258a, 258b, and 258c, and a BD sensor 259 are mounted on the inner surface 26b1 of the base plate 26b. Laser diode 254 is attached to side wall 26c on lower edge 26D of scanner housing 26 . The folding mirror 13 is attached to the side wall 26C on the upper edge 26U of the scanner housing 26 .

The laser diode 254 emits a laser beam L. After passing through the collimator lens 255 , the slot device 256 , and the cylindrical lens 257 , the laser beam L is reflected by the reflection mirror 258 a before reaching the polygon mirror 22 . The polygon mirror 22 reflects the laser beam L in the scanning direction, that is, the direction from left to right. The laser beam L passes through the fθ lens 24 before reaching the folding mirror 23 . The laser beam L is reflected by the folding mirror 23 to be directed toward the hole 26 a through the cylindrical lens 25 . The laser beam L reaches the photosensitive drum 33 after passing through the hole 26a.

Polygonal mirror 22, fθ lens 24, folding mirror 23, the position of cylindrical lens 25 and exposure hole 26a and the orientation of the mirror surface of folding mirror are arranged so that the optical path extending from folding mirror 23 through cylindrical lens 25 to exposure hole 26a There is an angular offset of the amount α (15 degrees in this example) along an imaginary plane perpendicular to the scanning direction from the optical path from the polygon mirror 22 through the fθ lens 24 to the folding mirror 23 .

When the laser beam L is scanned by the polygon mirror 22 , the laser beam L from the fθ lens 24 reaches the folding mirror 23 or the reflection mirror 258 b disposed adjacent to the folding mirror 23 . When the laser beam L reaches the reflection mirror 258 b, the laser beam L is reflected by the reflection mirror 258 b and the reflection mirror 258 c before being incident on the BD sensor 259 .

The rotation period and the rotation time of the polygon mirror 22 are set to ensure that when the laser beam L is incident on the reflection mirror 258b, the corner edge of the polygon mirror 22 is not on the optical path of the laser beam L between the reflection mirror 258c and the BD sensor 259, As shown by the solid line in Figure 6.

The laser diode 254 is controlled to be turned on and off at a timing synchronized with the rotation of the polygon mirror 22 according to image data. The position at which an image starts to be written on the photosensitive drum 33 in the scanning direction is appropriately fixed by controlling this on/off time depending on the time when the laser beam L is incident on the BD sensor 259 .

Next, how to install the scanning unit 20 on the supporting frame 260 attached to the main casing 2 will be described.

As shown in FIGS. 6 and 7(B), the scanner housing 26 has a right side extension 26e extending rightward from the side wall 26c at the right end 26R and being thinner than the side wall 26c. The right side extension 26e has: a surface 26e1 facing the inner surface 260aa of the bottom plate 260a of the scanner support frame 260; and another surface 26e2 opposite to the surface 26e1. The surface 26e1 is continuous with the top end surface 26ce of the side wall 26c.

A pair of protrusions 27 are formed on the surface 26e1 of the right side extension 26e. The pair of protrusions 27 are arranged along a straight line extending perpendicular to the scanning direction (right-to-left direction).

As shown in FIG. 8, each protrusion 27 has a substantially semicircular profile in its cross section along an imaginary plane extending parallel to the scanning direction (left-right direction) and perpendicular to the surfaces 26e1 and 26e2.

The leaf spring 261 is fixed at one end thereof to the inner surface 260aa of the scanner support frame 260 by a bolt 267 . The other end of the leaf spring 261 presses the surface 26e2 of the right extension 26e in a direction toward the bottom plate 260a. Accordingly, the pair of protrusions 27 are pressed against the bottom plate 260a by the leaf spring 261 .

A pair of depressions 262 are formed on the inner surface 260aa of the bottom plate 260a. Each recess 262 is positioned to face the corresponding protrusion 27, as shown in FIG. 8 . The depression 262 has a V-shaped profile in cross-section along an imaginary plane extending parallel to the scanning direction (left-right direction) and perpendicular to the inner surface 260aa.

The protrusion 27 is placed in the center of the recess 262 by the urging force of the leaf spring 261 . The depth of the recess 262 is sufficiently small so that the top surface 26ce of the side wall 26c and the surface 26e1 of the right extension 26e do not contact the inner surface 260aa of the bottom plate 260a when the protrusion 27 is placed in the center of the recess 262 .

As shown in FIGS. 6-7(B), the flange portion 26d protrudes leftward from the side wall 26c at the left end 26L of the scanner housing 26 . The flange portion 26d has: a surface 26d1 facing the inner surface 260aa of the bottom plate 260a; and another surface 26d2 opposing the surface 26e1. A steel plate 28 is fastened to a surface 26d1 of the flange portion 26d.

The bolt 263 passes through the bottom plate 260a with its bolt head 263a on the outer surface 260ab side and its tip 263b on the inner surface 260aa side. Therefore, the bolt 263 is engaged with the bottom plate 260a.

A leaf spring 264 is provided near the bolt 263 . That is, the leaf spring 264 is fixed at one end thereof to the outer surface 260ab of the scanner support frame 260 by a bolt 266 . The other end of the leaf spring 264 presses the surface 26d2 of the flange portion 26d in a direction toward the bottom plate 260a. Accordingly, the leaf spring 264 presses the flange portion 26d in a direction toward the bottom plate 260a to bring the top end 263b of the bolt 263 into contact with the steel plate 28 .

With the above structure, when the engagement amount of the bolt 263 is adjusted to change the distance between the bottom plate 260 a and the flange portion 26 d , the scanning unit 20 swings about the contact point between the protrusion 27 and the recess 262 . Accordingly, the orientation of the scanning unit 20 relative to the support frame 260 may be adjusted in the left-right direction.

After the adjustment of the engaging amount of the bolt 263 is completed, when the scanning unit 20 is supported by three points (the bolt 263 and a pair of protrusions 27 ), the scanning unit 20 is fastened to the supporting frame 260 with the adjusted orientation.

The scanning unit 20 has a relatively long and flat structure in the left and right directions in which the light beam scans. The scanning unit 20 is supported at both end portions 26R and 26L in the longitudinal direction thereof by a combination of a protrusion 27 and a recess 262 and a combination of a bolt 263 and a leaf spring 264 , respectively. Since the distance between the scanning unit 20 and the supporting frame 260 at the left end 26L is determined by the adjusting bolt 263, the assembly of the scanning unit 20 and the supporting frame 260 is extremely stable after adjusting the distance. After the distance adjustment is completed, no further fixing operations are required.

As shown in FIGS. 5 and 7(A), a through hole 265 is formed through the bottom plate 260 a at a position close to the leaf spring 264 . The through hole 265 facilitates adjustment of the engagement amount of the bolt 263 .

More specifically, as shown in FIG. 4, the orientation adjustment of each scanning unit 20 can be performed when the process cartridge 30 is removed from the main casing 2, and a sensor such as a CCD is provided on the conveyor belt 38.

The orientation of each scanning unit 20 can be adjusted by inserting a screwdriver into the through hole 265, as shown by the dotted line in FIG. 4, even when a plurality of scanning units 20 are installed in the main housing 2.

In this example, only the through-holes 265 for adjusting the engagement amount of the bolts 263 are provided on the scanner support frame 260 . However, another through hole 265 can also be additionally formed through the scanner support frame 260 so that the engaging amount of the bolt 266 fixing the leaf spring 264 can be adjusted.

Therefore, according to the present embodiment, the scanner support frame 260 is arranged in parallel in multiple stages in the main housing 2 . Optical scanning units 20 each having a scanner housing 26 are mounted on a scanner support frame 260 . A through hole 265 is formed on each support frame 260 to allow insertion of a screwdriver to perform adjustment of the engaging amount of the bolt 263 in the next scanning unit 20 in the forward direction of the corresponding scanning unit 20 .

It should be noted here that because the color laser printer 1 is in series, the multiple scanning units 20 are arranged parallel to each other in multiple stages. In this type of device, the orientation of each scanning unit 20 must be adjusted. According to the present embodiment, the orientation of each scanning unit 20 can be adjusted by adjusting the engaging amount of the bolt 263 .

Also, a through hole 265 is formed in the support frame 260 of each stage for inserting a screwdriver to adjust the engaging amount of the bolt 263 of the adjacent scanning unit 20 . The orientation of the scanner housing 26 of each scanning unit 20 can be adjusted without moving the other scanning units 20 installed in the main housing 2 . The orientation of each scanning unit 20 can therefore be adjusted in an extremely simple manner without interfering with other scanning units 20, even when the scanning units 20 are arranged in parallel in multiple stages.

As described above, according to the present embodiment, the leaf spring 261 presses the protrusion 27 formed on the surface 26e1 of the right side extension 26e from the opposite side 26e2 in the direction toward the bottom plate 260a of the support frame 260, thereby aligning the protrusion 27 with the protrusion 27 formed on the right side. The recess 262 on the bottom plate 260a makes contact. The bolt 263 passes through the bottom plate 260a from the outer surface 260ab to the inner surface 260aa so that its top end 263b faces the flange portion 26d of the scanning unit 20 . Therefore, the bolt 263 is engaged with the bottom plate 260a. A leaf spring 264 is fixedly mounted on the bottom plate 260a in the vicinity of the bolt 263 to press the flange portion 26d in a direction toward the bottom plate 260a. The orientation of the scanning unit 20 relative to the support frame 260 can be adjusted by adjusting the engaging amount of the bolt 263 . Therefore, the ease of operation of attaching the scanning unit 20 to the support frame 260 can be improved.

The combination of the protrusion 27 and the recess 262 adjusts the position of the scanner housing 26 relative to the scanner support frame 260 by bringing the protrusion 27 and the recess 262 into contact with each other, thereby maintaining a certain amount between the scanner housing 26 and the scanner support frame 260. interval. The scanner housing 26 is thus held such that a gap is formed between the scanner housing 26 and the support frame 260 .

Accordingly, the orientation of the scanner housing 26 can be adjusted in a simple manner by pivoting the scanner housing 26 about the contact portion between the protrusion 27 and the recess 262 while maintaining the scanner housing 26 with the support frame. 260 intervals. In this case, adjustment of the bolt 263 pivots the scanner housing 26 about the contact portion to adjust the orientation of the scanner housing 26 . Even with the simple structure of the protrusion 27 and the recess 262, the position of the pivot center is not shifted, so the orientation of the scanner housing 26 can be adjusted in a simple manner. Moreover, after adjustment, the scanner housing 26 can be more firmly supported on the supporting frame 260 .

As described above, each scanning unit 20 of the color laser printer 1 can be adjusted in a simple manner by only adjusting the engaging amount of the bolt 263, and the position of the scanning unit is not shifted after the adjustment. Therefore, the operation of fixing the scanning unit 20 to the scanner support frame 260 can be facilitated so that the ease of operation can be improved.

The flange 26 d of the left end 26L of the scanner housing 26 is sandwiched between the leaf spring 264 and the bolt 263 . Therefore, the flange 26d can be firmly fixed to the scanner support frame 260 while adjusting the bolt 263, regardless of this simple structure. Therefore, the scanning unit 20 can be stably supported on the supporting frame 260 after adjustment.

Since the plurality of protrusions 27 are arranged along a straight line in a direction perpendicular to the scanning direction of the laser beam L in each scanning unit 20, the scanning unit 20 can be prevented from rotating about the center of the axis parallel to the scanning direction. This simplifies the adjustment of the orientation of the scanning unit 20 .

The folding mirror 23 reflects the laser beam L in such a manner that the angle formed between the laser beam L before reflection and the laser beam L after reflection on an imaginary sectional plane perpendicular to the scanning direction is approximately 15 degrees. By adjusting the engagement amount of the bolt 263 to adjust the orientation of the scanning unit 20 in the scanning direction, the scanning direction (ie, the direction of the scanning line formed on the photosensitive drum 33 ) can be adjusted to be parallel to the rotation axis of the photosensitive drum 33 . Therefore the accuracy of image formation can be improved.

Note here that the angle α formed between the light beam before being reflected by the folding mirror 23 and the light beam after being reflected by the folding mirror 23 on the imaginary section plane perpendicular to the scanning direction may not be equal to 15 degrees. Preferably, the angle α satisfies the inequality 0<α<45 degrees. Under such circumstances, the degree of parallelism between the axis of the photosensitive drum 33 and the scanning direction that most affects the image quality can be ensured by adjusting the orientation of the scanning unit 20 around the axis perpendicular to the scanning direction, and the quality of the image formed after the adjustment can be improved. Improved.

Note here that another protrusion 27' can be additionally provided on the surface 26e1 of the right extension 26e, as shown by the dotted line in Fig. 6 . The additional protrusion 27' is located on the same line as the protrusion 27 in a direction perpendicular to the scanning direction of the laser beam L. The additional protrusion 27' extends continuously on the straight line on which the protrusion 27 is disposed. The additional protrusion 27' has the same shape and dimensions as the protrusion 27 in cross-section, as shown in FIG. 8 .

In this case, although not shown in the drawing, another depression is additionally formed on the inner surface 260aa of the bottom plate 260a of the support frame 260 . The additional depression is located on the same straight line as the depression 262 in the direction perpendicular to the scanning direction of the laser beam L. As shown in FIG. The additional depression is located at a position facing the additional protrusion 27', and extends continuously with the same length as the additional protrusion 27' on the line on which the depression 262 is provided. The additional depressions have the same shape and dimensions as the depressions 262 in cross-section, as shown in FIG. 8 . By adjusting the engagement amount of the bolt 263, the scanning unit 20 can be pivoted about the contact positions between the protrusion 27 and the recess 262 and between the additional protrusion 27' and the additional recess.

Note that when an additional extended protrusion 27' is provided on the scanner housing 26 and an additional extended recess is provided on the scanner support frame 260, the protrusion 27 may be omitted from the scanner housing 26 and the recess 262 may be is omitted from the scanner support frame 260. In this case, the scanner housing 26 is supported on the scanner support frame 260 at two points, that is, at the contact portion between the additionally extended protrusion 27' and the additionally extended recess and The contact portion between the flange 26d and the bolt 263 .

Alternatively, the protrusions 27 and/or the additionally extended protrusions 27' may be provided on the support frame 260, while the recesses 262 and/or the additionally extended recesses may be provided on the scanner housing 26.

(Modification of the first embodiment)

In the first embodiment described above, the toner is directly transferred from each photosensitive drum 33 to the recording paper P conveyed by the conveying belt 38 . However, in this modification, the structure is modified into a color laser printer 201 as shown in FIG. onto the intermediate transfer belt.

More specifically, an additional transfer roller 139 is provided in this modification so that the conveyance belt 38 is sandwiched between the additional transfer roller 139 and the driven roller 37 . The additional transfer roller 139 is applied with a transfer bias.

All the toner images of the four colors are superimposed one on top of the other on the upper side portion 38a of the conveyor belt 38 while being conveyed in the backward direction. Next, the toner image is transferred by the lower side portion 38b of the transfer belt 38 in the forward direction before finally reaching the nip portion between the transfer belt 38 and the additional transfer roller 139. The toner image and a sheet of recording paper P supplied from the conveying roller 13 pass through the nip simultaneously with each other, and the toner image is transferred onto the recording paper P.

In this modification, although the transport path for transporting the recording paper is different from that of the first embodiment, the apparatus 201 can still be made compact by arranging the transport belt 38 to be inclined upward toward the front side.

(second embodiment)

Next, a color laser printer 301 according to a second embodiment will be described with reference to FIG. 1 and FIGS. 10 to 12 .

The color laser printer 301 is compatible with the color laser printer 301 except for the combination of the scanning unit 320 and the scanner supporting frame 360 which replaces the combination of the scanning unit 20 and the scanner supporting frame 260 in the first embodiment for each image forming section 17. Printer 1 is the same,.

The scanning unit 320 is the same as the scanning unit 20 except that it has a scanner housing 326 instead of the scanner housing 26 in the first embodiment.

The scanner housing 326 is the same as the scanner housing 26 in the first embodiment except for the following points.

The described scanner housing 326 does not have the protrusion 27 but instead has a rotation axis 329 . The pivot shaft 329 protrudes from the scanner housing 326 at its lower end 326D. The rotating shaft 329 is located on the scanner housing 326 at a substantially central position in the optical scanning path of the light beam L scanned by the polygon mirror 22 . The rotational axis 329 extends in a direction perpendicular to the scanning direction of the laser beam L and substantially parallel to the top end surface 26ce of the side wall 26c of the scanner housing 326 . As shown in FIG. 12, the rotation shaft 329 has a substantially circular shape in its section along an imaginary plane extending parallel to the scanning direction (left-to-right direction) and perpendicular to the top end surface 26ce.

At the left end 326L, the scanner housing 326 does not form the flange portion 26d or the steel plate 28, but instead forms the flange portion 326d and the steel plate 328, which are larger in size than the flange portion 26d and the steel plate 328 in the first embodiment. Steel plate 28 small. The flange portion 326d has mutually facing surfaces 326d1 and 326d2. The steel plate 328 is fixed to a surface 326d1 of the flange portion 326d facing the scanner support frame 360 .

Instead of the bolt 263 in the first embodiment, the bolt 363 passes through the bottom plate 260a of the scanner support frame 360 from the outer surface 260aa of the bottom plate 260a to the inner surface 260ab of the bottom plate 260a. The bolt 363 further passes through the steel plate 328 and the flange portion 326d. Thus, the bolt head 363a of the bolt 363 is located on the outer surface 260ab side, and the bolt tip 363b of the bolt 363 is located on the surface 326d2 side. Thus, scanning unit 320 engages scanner support frame 360 at its left end 326L.

The support frame 360 is the same as the support frame 260 in the first embodiment except for the following points.

The support frame 360 does not form the recess 262, but instead forms a bearing portion 360d on its side wall 260b for receiving the rotating shaft 329.

The support frame 360 is not installed with the leaf spring 264 or the bolt 266 in the first embodiment.

The bearing portion 360d is opened in a V shape as shown in FIG. 12, and thus has a V-shaped cross section along an imaginary plane extending parallel to the scanning direction (left-right direction) and the bottom plate 260a.

The opening depth of the bearing portion 360d is sufficiently small that when the scanning unit 320 is supported on the support frame 360 with the rotation shaft 329 received in the bearing portion 360d, the side wall of the scanner housing 326 facing the bottom plate 260a Top end surface 26ce of 26c is not in contact with bottom plate 260a. This structure can adjust the orientation of the scanning unit 320 by pivoting the scanning unit 320 about the contact portion between the rotation shaft 329 and the bearing portion 360d.

Also, the right end 326R of the housing 326 is urged in the direction toward the bottom plate 260a by the combination of the bolt 267 and the leaf spring 261 in the same manner as in the first embodiment. Accordingly, the orientation of the scanning unit 320 can be adjusted by adjusting the engagement amount of the bolt 363 that engages the scanning unit 320 with the support frame 360 near the left end 326L of the housing 326 .

Also in the second embodiment, the orientation of the scanning unit 320 can be easily adjusted, and the scanning unit 320 can be fastened to the supporting frame 360 while the adjustment is completed. For this reason, the operation of fixing each scanning unit 320 to the corresponding support frame 360 is simple, and the ease of operation can be improved.

In addition, because the orientation of the scanning unit 320 is adjusted around the axis of the rotation axis 329 perpendicular to the scanning direction, the scanning unit 320 can be prevented from rotating around the center of the axis parallel to the scanning direction, making the above-mentioned orientation adjustment easier.

Since the bearing portion 360d has the above structure, even with such a simple structure, the rotating shaft 329 can be held at a fixed position without erroneously shifting from the position.

Because the rotation axis 329 is perpendicular to the scanning direction, the scanning unit 320 is prevented from rotating around the axis parallel to the scanning direction, which further simplifies the orientation adjustment of the scanning unit 320 and ensures that the orientation of the scanning unit 320 is in the direction relative to the photosensitive drum 33. right direction.

Further, the right end portion 326R of the scanner housing 326 in the scanning direction is urged toward the inner surface 260aa of the support frame 360 by the leaf spring 261, and the distance between the left end portion 326L of the support frame 360 and the surface 260aa is adjusted by the bolt 363. In this way, the scanning unit 320 may be firmly fixed to the support frame 360 while the orientation of the scanning unit 320 is adjusted relative to the support frame 360 . The scanning unit 320 can thus be stably supported on the supporting frame 360 after adjustment.

(third embodiment)

Next, a color laser printer 401 of a third embodiment will be described with reference to FIGS. 13 to 20. FIG.

The color laser printer 401 described is the same as the color laser printer 1 in the first embodiment except for points to be stated below.

In the first embodiment, the image forming sections 17K, 17C, 17Y, and 17M for four colors of black, cyan, yellow, and magenta are arranged in this order from back to front. On the other hand, in the third embodiment, the image forming sections 17K, 17C, 17M, and 17Y for four colors of black, cyan, magenta, and yellow are arranged in this order from back to front.

By combining the transfer section 18 (drive roller 36, driven roller 37, transfer belt 38, transfer roller 39, and belt cleaning unit 40), pickup roller 10, paper feed roller 11, rear transfer roller 13b, and a pair of register The rollers 14 are fitted into the belt unit frame 61, and constitute the belt unit 60 by integrating them together to form a unit. The strap unit 60 is movable horizontally (from the front to the rear direction), and can be inserted into and removed from the front side of the main case 2 .

When the belt unit 60 is installed in the main casing 2 at its installation position, as shown in FIG. A terminal 91 (to be described below) of the main housing 2 is in contact with an electrode 92 (to be described below). When the belt unit 60 is moved in the forward direction to separate from the installation position, the conveyor belt 38 is separated from the photosensitive drum 33, and thereafter the rear edge 91c of the terminal 91 is separated from the electrode 92 to be described later.

Note that, as shown in FIG. 15, similarly to the first embodiment, the vertical position of each process cartridge 30 is higher than the adjacent process cartridge 30 on its rear side by a predetermined amount (hereinafter referred to as called amount "A"). That is, the offset between the vertical position of the process cartridge 30 in the black image forming section 17K and the vertical position of the process cartridge 30 in the cyan image forming section 17C, the vertical position of the process cartridge 30 in the cyan image forming section 17C and the vertical position of the process cartridge 30 in the magenta image forming section 17M, and the difference between the vertical position of the process cartridge 30 in the magenta image forming section 17M and the vertical position of the process cartridge 30 in the yellow image forming section 17Y The offset between them is equal to the preset amount A. Therefore, when the process cartridges 30 of all colors are installed in the image forming section 17, the photosensitive drums 33 in the process cartridges 30 of different colors are arranged in such a manner that the straight line connecting the lower sides of the respective photosensitive drums 33 is placed on the belt unit 60. The upstream side of the installation direction of the belt unit 60 is higher, and the belt unit 60 is inclined downward on the downstream side of the installation direction.

Similar to that in the first embodiment, the space below the image forming section 5 and above the sheet feeding cassette 70 has a shape in which the height in the vertical direction becomes smaller toward the rear when viewed from the side. Said strap unit 60 is installed in the tapered space, so the strap unit 60 is formed to have an integral shape viewed from the side, which becomes smaller toward the rear side in the vertical direction, corresponding to the taper of the installation space. corresponding to the shape. That is, similarly to the first embodiment, the driven roller 37 is disposed higher than the driving roller 36 .

When the belt unit 60 is mounted at the mounting position of the main casing 2, the driven roller 37 is disposed from the front of the photosensitive drum 33 of the process cartridge 30 mounted in the yellow image forming portion 17Y.

The upper side portion 38a of the conveyor belt 38 is inclined, and is formed between the moving direction of the upper side portion 38a caused by the driving of the drive roller 36 and the horizontal direction (the direction in which the belt unit 60 is pulled out from the color laser printer 1). An angle such that the contact between the surface of the conveyor belt 38 and the respective photosensitive drums 33 is simultaneously released when the belt unit 60 is moved from the installation position in the forward direction to be removed from the main casing 2 .

As shown in FIG. 17 , the belt unit frame 61 includes: a left side plate 65 and a right side plate 66 ; a bottom plate 62 ; and a paper guide member 64 . The left side plate 65 and the right side plate 66 face each other with a certain separation distance in the width direction. The bottom plate 62 is suspended between a left side plate 65 and a right side plate 66 . As shown in Figure 13, the described paper guide member 64 is placed on the front end of the bottom plate 62 between the left side plate 65 and the right side plate 66 to hang in a swingable manner, and is used to guide the U-shaped path passing through the paper supply side. The conveyed paper P is guided onto the conveying belt 38 .

The pickup roller 10, paper feed roller 11, rear transport roller 13b, pair of registration rollers 14, driving roller 36, and driven roller 37 are rotatably mounted on the left side plate 65 of the belt unit frame 61 And hang between the right side plate 66.

The transfer rollers 39 are suspended between the left side plate 65 and the right side plate 66 such that each transfer roller 39 is rotatable about its axis and movable in the vertical direction.

Each transfer roller 39 is urged upward by a compression spring 44 as will be described later with reference to FIG. 19 . Therefore, when the belt unit 60 is installed in the installation position in the main casing 2 as shown in FIG.

More specifically, as will be described later with reference to FIG. 18 , the left and right ends of the roller shaft 39 a of each transfer roller 39 are rotatably supported by left and right bearings 43 , respectively. The bearing 43 is supported so as to be movable vertically in the belt unit frame 61 . Left and right compression springs 44 are also installed in the belt unit frame 61 for urging the transfer roller 39 upward. Therefore, when the belt unit 60 is located in the installed position as shown in FIG. .

As shown in FIG. 13, the bottom plate 62 has a front region 62a and a middle-rear region 62b arranged in the front-rear direction. Said front area 62 a faces the driven roller 37 of the conveyor belt 38 . Said mid-rear region 62b is positioned lower than the front region 62a and thus defines thereon a depression 103 which is sunken lower than the front region 62a. Said belt cleaning device 40 is arranged at a front in the recess 103 .

As shown in FIGS. 13 and 18 , a positioning slot 102 and a plurality (six in this example) of terminal slots 104 are formed at the rear edge of the bottom plate 62 . As shown in FIG. 13, each terminal slot 104 has a vertical wall 104a and a horizontal wall 104b.

As shown in FIG. 17, the lower end portion of each left side plate 65 and right side plate 66 is bent inwardly in the width direction to form a paper feeder guide 67 for guiding the insertion of the paper feeder frame 71 of the paper feeder 70. The paper feeding cassette 70 is or removed from the paper feeding cassette 70 .

The paper cassette frame 71 has: a left side panel 72 and a right side panel 73; and a front panel 74 (see FIG. 13). The left side plate 72 and the right side plate 73 are arranged to face each other in the width direction with a certain separation distance. The front panel 74 is suspended between the front end portions of the left side panel 72 and the right side panel 73 . The position of the paper cassette frame 71 behind the front plate 74 holds the paper tray 9 between the left side plate 72 and the right side plate 73 .

The left side plate 72 faces the left side plate 65 of the belt unit frame 61 with a predetermined interval between the two, and the right side plate 73 faces the right side plate 66 of the belt unit frame 61 with a space between the two. preset interval.

Each of the left side panel 72 and the right side panel 73 has an extension 75 . The extension portion 75 extends from the upper end of the corresponding side plate 72 or 73 toward the outside in the width direction and extends in the front-to-rear direction. The extended portions 75 of the left and right side plates 72 and 73 are joined to the paper feeding unit guide 67 of the belt unit frame 61 from above. The paper feeding cassette frame 71 is thus held on the belt unit frame 61 so that the paper feeding cassette frame 71 can slide horizontally along the paper feeding unit guide 67 .

The main case 2 has a left main case side plate 81 and a right main case side plate 82 . When the belt unit 60 is installed in the main case 2, the left main case side plate 81 faces the left side plate 65 with a preset interval therebetween, and the right main case side plate 82 faces The right side plate 66 of the belt unit frame 61 has a predetermined interval therebetween.

Each of the left main case side plate 81 and the right main case side plate 82 forms a belt unit guide 83 at its lower end. The belt unit guide 83 protrudes inwardly in the width direction and extends in the front-rear direction by a length long enough to receive the entire length of the belt unit frame 61 . Each belt unit guide 83 forms a guide portion 85 . The guide portion 85 is a rectangular slit formed on the upper edge of the belt unit guide 83, and along the inner side of the belt unit guide 83 in the width direction along the entire length of the belt unit guide 83 in the length direction. extend. The belt unit frame 61 can slide horizontally along the guide portion 85 of the belt unit guide 83 when the lower ends of the left side plate 65 and the right side plate 66 are installed on the guide portion 85 .

As shown in FIG. 13 , the main case 2 is also provided with an electrode holder 86 . When the belt unit 60 is installed in the main case 2 , the electrode holder 86 is disposed at a position where the electrode holder 86 faces the rear edge of the belt unit frame 61 . As shown in FIG. 18 , a plurality of (six in this embodiment) electrodes 92 are supported on the electrode holder 86 . The electrodes 92 are arranged in the width direction. Each electrode 92 extends forward.

As shown in FIG. 18, a positioning protrusion 101 protrudes forward from the front surface of the electrode holder 86 at its central portion in the width direction. The positioning protrusion 101 has a substantially rectangular shape viewed from the bottom, as shown in FIG. 18 .

As shown in FIGS. 13 and 18 , the terminals 81 are disposed in terminal slots 104 in the rear edge of the belt unit frame 61 . The terminals 91 are used as power supply terminals, which are brought into contact with the corresponding electrodes 92 when the belt unit 60 is installed in the main case 2 .

As shown in FIG. 13, each terminal 91 has an L-shape and has a vertically extending portion 91a and a horizontally extending portion 91b. The vertically extending portion 91 a vertically extends along the front facing surface of the vertical wall 104 a of the terminal slot 104 . At the upper end of the vertically extending portion 91a, the terminal 91 is bent backward so that the horizontally extending portion 91b protrudes outward from the inside of the belt unit frame 61 to the outside of the belt unit frame 61 through the vertical wall 104a. The horizontally extending portion 91b extends horizontally (rearward) along the lower side surface of the horizontal wall 104b of the terminal groove 104 . Thus, when the belt unit frame 61 is installed in the main case 2 as shown in FIG.

The distance between the rear edge 91c of the terminal 91 and each transfer roller 39 is greater than or equal to the distance between the contact point 92a of the electrode 92 and the corresponding photosensitive drum 33 . More specifically, the distance between the rear edge 91c and the black transfer roller 39 is greater than or equal to the distance between the contact point 92a and the black photosensitive drum 33 . The distance between the rear edge 91 c and the cyan transfer roller 39 is greater than or equal to the distance between the contact point 92 a and the cyan photosensitive drum 33 . The distance between the rear edge 91 c and the magenta transfer roller 39 is greater than or equal to the distance between the contact point 92 a and the magenta photosensitive drum 33 . The distance between the rear edge 91c and the yellow transfer roller 39 is greater than or equal to the distance between the contact point 92a and the yellow photosensitive drum 33 . Note that, in the front-rear direction, the distances between the black and cyan photosensitive drums 33, the distances between the cyan and magenta photosensitive drums 33, and the distances between the magenta and yellow photosensitive drums 33 are equal to the black and cyan photosensitive drums 33, respectively. The distance between the cyan transfer rollers 39 , the distance between the cyan and magenta transfer rollers 39 , and the distance between the magenta and yellow transfer rollers 39 . Therefore, when the belt unit 60 is inserted into the main case 2 from the front side thereof and moved backward, the transfer roller 39 is accurately positioned while or after the rear edge 91c of the terminal 91 comes into contact with the contact point 92a of the electrode 92. 13 to reach the position below the corresponding photosensitive drum 33. In other words, when the belt unit 60 is inserted into the main case 2 and moved backward, the belt unit 60 reaches the position shown in FIG. The installation position where the conveyor belt 38 is in contact with the photosensitive drum 33 .

As shown in FIG. 18 , when the belt unit frame 61 is installed in the main housing 2 , the positioning protrusion 101 is fitted into the positioning groove 102 . The belt unit frame 61 may be positioned relative to the main case 2 in the width direction by fitting the positioning protrusion 101 into the positioning groove 102 .

Wrong positioning of the terminals 91 provided on the belt unit frame 61 in the width direction relative to the electrodes 92 supported on the electrode holder 86 can be achieved by using the positioning protrusions 101 as positioning the belt unit frame 61 in the width direction relative to the main case 2. reference to prevent. For this reason, a reliable connection between the terminal 91 and the corresponding electrode 92 can be achieved.

The belt unit frame 61 further supports therein: four transfer bias lines 93 for supplying transfer bias to the four transfer rollers 39; cleaning bias lines for supplying cleaning bias to the cleaning roller 47 94; and a neutralization bias line 96 for supplying a neutralization bias to the four neutralization combs 95. Each neutralization comb 95 is disposed along a corresponding transfer roller 39 .

Note that each transfer roller 39 and each neutralization comb 95 are located between the upper side portion 38 a and the lower side portion 38 b of the endless belt 38 in the vertical direction. In this example, the conveyor belt 38 is constituted by a plurality of endless belt strips which are wound around the drive roller 36 and the driven roller 37 and which are arranged adjacent to each other in the width direction. A small amount of widthwise gap (interstrip gap) is formed between every two adjacent endless belt strips.

Each transfer bias line 93 has one end connected to one of the terminals 91 and the other end connected to the left end of the corresponding transfer roller 39 . More specifically, the transfer bias line 93 extends forward from the terminal end 91, and then bends upward so as to enter the upper side portion and the lower side of the conveyor belt 38 through the interstrip gap between two adjacent endless belt strips. The space between portions 38a and 38b then bends to the left before finally reaching the left end of the respective transfer roller 39 .

Note that, as shown in FIG. 18 , the left and right ends of the roller shaft 39 a of each transfer roller 39 are rotatably supported by left and right bearings 43 , respectively. Left and right bearings 43 are electrically conductive and mounted on left and right compression springs 44, respectively. The left and right compression springs 44 are also electrically conductive and are supported by left and right side plates 65 and 66 respectively. Figure 19 shows how the left end of the roller shaft 39a is supported by the left bearing 43, and shows how the left bearing 43 is supported on the left compression spring 44. Each bearing 43 is upwardly driven by a corresponding compression spring 44 . As shown in FIG. 18 , the left and right bearings 43 are respectively guided by left and right plates 65 and 66 so that the bearings 43 can slide vertically along the left and right plates 65 and 66 . As shown in FIG. 19 , the transfer bias line 93 is connected to the left compression spring 44 . The transfer bias line 93 is thus connected to the left end of the transfer roller 39 through the left compression spring 44 and the left bearing 43 .

Thus, each transfer bias line 93 is connected to the compression spring 44 connected to the bearing 43 of the corresponding transfer roller 39 . A transfer bias is thus applied to each transfer roller 39 from a respective transfer bias line 93 via a respective compression spring 44 and bearing 43 .

The cleaning bias line 94 has one end connected to the corresponding terminal 91 and the other end connected to the right side end of the cleaning roller 47 . More specifically, the cleaning bias line 94 extends forward from the corresponding terminal end 91 and then bends rightward and upward before finally reaching the right end of the cleaning roller 47 .

The neutralization bias line 96 has one end connected to a corresponding terminal 91 . Said neutralizing bias line 96 extends rearwardly from terminal end 91, then bends upwards through the inter-strip gap between two adjacent endless belt strips and enters between the upper and lower portions 38a and 38a of the conveyor belt 38. The spaces between 38b are then curved so as to extend forward to connect with the neutralizing combs 95 for the imaging portions 17K, 17C, 17M and 17Y in sequence.

As shown in FIG. 20, each neutralization comb 95 forms a through hole through which a neutralization bias line 96 passes, and is connected to the neutralization bias line 96 through a conductive material 97 such as a solder material. The upper edge portion of each neutralization comb 95 forms a large number of mountain-shaped protrusions, and is in contact with the lower surface of the upper side portion 38 a of the conveyor belt 38 .

According to the above structure, the strap unit 60 can be inserted into the main case 2 or removed from the main case by sliding the strap unit frame 61 along the guide portion 85 of the strap unit guide 83 along the linear insertion/removal path 100 extending horizontally from the front. 2, as shown in Figure 15.

The paper feeding cassette 70 can also be horizontally inserted or removed from the front of the main casing 2 and belt unit 60 by sliding the paper feeding cassette frame 71 along the paper feeding unit guide 67 as shown in FIG. 14 .

This ensures that the paper feeding cassette 70 can be inserted into or removed from the main casing 2 alone, as shown in FIG. 14 .

In addition, the tape unit 60 can be inserted into or removed from the main casing 2 together with the sheet feeding cassette 70 .

More specifically, as shown in FIGS. 14 and 15, the belt unit 60 and the sheet feeding cassette 70 are arranged to partially overlap each other in the vertical direction. Therefore, as shown in FIG. 15, when the belt unit 60 wants to be removed from the main casing 2, by withdrawing the belt unit 60 forward, the lower front part of the belt unit 60, that is, for example, the rollers 13a and 11 pushes the paper feeding forward. Cassette 70 , thus enabling the tape unit 60 and paper feeding cassette 70 to be removed from the main casing 2 together. When the belt unit 60 and the paper feeding cassette 70 are intended to be installed in the main casing 2, the integral unit of the belt unit 60 and the paper feeding cassette 70 is moved backward by pushing the front surface of the paper feeding cassette 70 backward, and as a result, The upper front portion of the sheet feeding cassette 70 , ie, eg, the roller 13 b and the separation pad 3 a pushes the belt unit 60 backward, thus enabling the belt unit 60 and the sheet feeding cassette 70 to be installed into the main casing 2 together. In this manner, the integral unit of the belt unit 60 and the sheet feeding cassette 70 is inserted into or removed from the main casing 2 in the same direction as the sheet feeding cassette 70 alone is inserted or removed. For this reason, the tape unit 60 and the sheet feeding cassette 70 can be inserted or removed by a single operation. As a result, the ease of handling during insertion or removal of the tape unit 60 and sheet feeding cassette 70 can be improved.

Also, when the belt unit 60 and paper feeding cassette 70 are withdrawn from the main casing 2 as shown in FIG. 15, a large space is formed under the image forming section 5. When the paper P is jammed in, for example, the fixing portion 19, the user can easily take out the paper P from the inside of the main casing 2 by reaching into this large space from the front.

With this color laser printer 401, the insertion/removal path 100 extends horizontally without bending, and the belt unit 60 can move in a straight line from the start of ejection of the main case 2 to the end of ejection. In addition, the strap unit 60 is movable in a straight line along the insertion/removal path 100 relative to the main housing 2 from the beginning to the end of installation. For this reason, the operation of inserting or removing the belt unit 60 with respect to the main case 2 can be performed extremely easily.

After withdrawing the belt unit 60 from the main case 2 as shown in FIG. 16, by turning up the paper guide member 64, the conveyor belt 38 and the belt cleaning device 40 can be lifted from the belt unit 60, together or separately, And the conveyor belt 38 and the belt cleaning device 40 are taken out of the belt unit frame 61 . This facilitates replacement or maintenance of the conveyor belt 38 and belt cleaning device 40 .

According to this embodiment, the belt unit 60 including the conveyor belt 38 can be removed along a linear insertion/removal path 100 . In addition, an angle is formed between the direction in which the upper side portion 38a of the conveyor belt 38 is driven by the drive roller 36 to move and the direction in which the belt unit 60 is withdrawn, so that the contact between the conveyor belt 38 and the photosensitive drum 33 is carried out by pulling the belt. Unit 60 exits to release.

That is, the upper side portions 38a of the conveyor belt 38 are inclined upward with respect to the forward direction (exit direction of the belt unit 60), and the upper side portions 38a are in contact with the photosensitive drums 33 from their front lower ends. This ensures that withdrawal or movement of the belt unit 60 in the forward direction releases the contact between the surface of the conveyor belt 38 and the photosensitive drum 33 . Thus, when the belt unit 60 is ejected along the linear insertion/removal (horizontal) path 100 in the forward direction, the contact between the surface of the conveyor belt 38 and the photosensitive drum 33 is released along with the ejection. Therefore, in order to separate the transfer belt 38 from the photosensitive drum 33, no additional operation is required to move the belt unit 60 in a direction across the horizontal direction, and thus the ease in the operation of withdrawing the belt unit 60 from the main casing 2 can be improved.

On the other hand, when the belt unit 60 is inserted into the main housing 2, installing the belt unit 60 along the linear insertion/removal path 100 can ensure that the surface of the conveyor belt 38 is in contact with the photosensitive drum 33 after the installation of the belt unit 60 is completed. . In this manner, the conveyor belt 38 does not come into contact with the photosensitive drum 33 until the belt unit 60 completes movement in the direction of the insertion/removal path. Therefore, an additional operation of moving the belt unit 60 in a direction passing through or across the horizontal direction is not required, and thus the ease of operation in mounting the belt unit 60 to the main casing 2 can be improved.

In this way, no additional movement of the strap unit 60 across the direction of movement along the insertion/removal path 100 is necessary during the operation of inserting or removing the strap unit 60 relative to the main housing 2 . Therefore, the structure for guiding the tape unit 60 can be simplified, and the production cost can be reduced.

Since the direction in which the belt unit 60 is withdrawn is substantially horizontal, the belt unit 60 can be withdrawn from the main case 2 in a simple manner. This means that the ease of insertion or removal of the belt unit 60 can be improved.

In addition, since the belt unit 60 withdraws in a direction perpendicular to the rotation shaft 33a of the photosensitive drum 33, the contact between the surface of the conveyor belt 38 and the photosensitive drum 33 can start to move in the direction in which the belt unit 60 withdraws from the installation position of the belt unit 60. Immediately thereafter it was released. For this reason, sliding contact between the conveyor belt 38 and each photosensitive drum 33 can be prevented. This prevents damage to the photosensitive drum 33 or the transfer belt 38 due to sliding contact between the transfer belt 38 and the photosensitive drum 33 .

The photosensitive drum 33 is disposed along the moving direction of the conveyor belt 38 of the belt unit 61 . When the belt unit frame 61 starts moving in the withdrawing direction from the installed position in FIG. 13 , the conveyor belts 38 are separated from the respective photosensitive drums 33 at the same time as each other.

Since the movement of the belt unit 60 is guided by the belt unit guide 83, the belt unit 60 can be withdrawn from the main casing 2 in a simple manner. This improves the ease of insertion and removal of the belt unit 60 .

As shown in FIG. 13 , the tape unit 60 and the paper cassette 70 are arranged to partially overlap each other in the exit direction of the tape unit 60 , that is, in the horizontal direction, so that the size of the color laser printer 1 in the horizontal direction can be reduced.

In addition, as shown in FIG. 15 , the tape unit 60 and the paper feed cassette 70 are arranged to partially overlap each other in a direction perpendicular to the ejection direction of the tape unit 60 , that is, in the vertical direction, so that the vertical size of the color laser printer 1 can be reduced. Therefore, by moving the belt unit 60 in the removal direction, the lower front portion of the belt unit 60 pushes the paper feeding cassette 70 forward, so that the belt unit 60 and the paper feeding cassette 70 can be removed from the main casing 2 together.

Further, since the terminal 91 is provided at one end on the downstream side in the installation direction of the strap unit 60, the terminal 91 is not exposed until the strap unit 60 is completely removed from the main case 2. In this way, the user can be prevented from touching the terminal 91 .

In addition, since the electrode 92 is disposed on the downstream side in the main case 2 in the installation direction of the belt unit 60 thereof, it is possible to prevent the user from touching the electrode 92 . In this way, contamination of the terminal 91 and the electrode 92 can be prevented.

Since the terminals 91 are arranged in a row in the width direction, when the belt unit 60 is mounted in the main case 2, connection between a plurality of terminals 91 and electrodes 92 can be simultaneously achieved.

Terminal 91 and electrode 92 are set to such a positional relationship, in the process that belt unit 60 is installed in main casing 2, reach connection between terminal 91 and electrode 92 at the same time or after, conveyer belt 38 just contacts with photosensitive drum. 33 contacts. Therefore, after the conveyor belt 38 comes into contact with the photosensitive drum 33 , it is not necessary to move the belt unit 60 further in the backward direction for connection between the terminal 91 and the electrode 92 . Sliding contact between the conveyor belt 38 and the photosensitive drum 33 can be prevented. Thus, damage to the photosensitive drum 33 or the transfer belt 38 due to the sliding contact between the transfer belt 38 and the photosensitive drum 33 can be prevented.

When the belt unit 60 is withdrawn from the main casing 2 and the nip of each photosensitive drum 33 and the transfer belt 38 is released, each transfer roller 39 moves upward due to the elastic force of the compression spring 44 . As a result, the upper side portion 38a of the conveyor belt 38 moves upward as shown in FIG. 15 .

Note that the vertical position of each process cartridge 30 is higher by a predetermined amount A than the process cartridge 30 adjacent to its rear side. When the belt unit 60 is mounted on the installation position in the main housing 2 as shown in FIG. 13, each transfer roller 39 is pushed up by the compression spring 44 (see FIG. Between the transfer roller 39 and the corresponding photosensitive drum 33 . The moving direction in which the belt unit 60 withdraws from the installed position is the horizontal direction, and thus is perpendicular to the direction in which the transfer roller 39 is urged by the compression spring 44 . Therefore, when the belt unit 60 is moved forward from the installation position to withdraw from the main housing 2, the transfer roller 39 is moved upward by an amount B due to the elastic force of the compression spring 44, so that the conveyor belt 38 is upward, that is, under the compression spring 44. The direction of action is raised by an amount B.

According to the present embodiment, the offset A between the vertical positions of the adjacent image forming portions 17 in the front-rear direction, that is, the offset A between the lower edges of the adjacent photosensitive drums 33 has such a value , that is, the value C obtained after subtracting the lift amount B of the conveyor belt 38 from the offset amount A is greater than 0. In other words, the offset A is greater than the lift B.

In this way, the belt unit 60 supports each transfer roller 39 in such a manner that the lift amount B′ of the conveyor belt 38 at the associated transfer roller 39 that occurs when the belt unit 60 moves in the forward direction from the installation position is larger than The offset A between the vertical installation positions of the imaging sections 17 arranged to be adjacent to each other in the front-rear direction is small.

For this reason, when the belt unit 60 is moved forward from the installation position so as to be withdrawn from the main casing 2, it is ensured that a gap is formed between the conveyor belt 38 and the lower edge of the photosensitive drum 33. The conveyor belt 38 is not in contact with the lower edge of the photosensitive drum 33 . Therefore, even in the case where the conveyor belt 38 is lifted, the sliding contact between the conveyor belt 38 and the photosensitive drum 33 can be reliably prevented. As a result, damage to the photosensitive drum 33 or the transfer belt 38 due to friction between the transfer belt 38 and the photosensitive drum 33 can be prevented.

According to the present embodiment, a plurality of photosensitive drums 33 are arranged along the moving direction of the conveyor belt 38 . By the movement of the belt unit 60 in the withdrawing direction, the contact between the conveyor belt 38 and the plurality of photosensitive drums 33 is released simultaneously with each other. Therefore, an additional operation of moving the belt unit 60 in a direction passing through or across the moving direction is not required, which improves the ease of operation in removing the belt unit 60 from the main casing 2 .

<Modify>

In the above-described embodiment, the conveyor belt 38 is composed of a plurality of strips arranged in the width direction with interstrip gaps between the strips. However, the conveyor belt 38 may consist of a single conveyor belt with no gaps in between.

In this case, each bias line 93 is modified to first extend outwardly from the terminal end 91 toward the width edge of the conveyor belt 38 in the width direction, and then upwardly before finally reaching the left or right end of the corresponding transfer roller 39. Bend so as to pass through the gap between the width edge of the conveyor belt 38 and the left or right side plate 65 or 66 . Bias line 96 may be modified similarly to bias line 93 .

The terminal 91 may further include a terminal for electrically grounding the strap unit frame 61 .

Similar to the modified color laser printer 201 according to the first embodiment, the structure of this embodiment can be modified into a color laser printer 501 as shown in FIG. Before the transfer belt 38 transfers to the recording paper P, the toner is temporarily transferred onto the intermediate transfer belt. In this case, an additional transfer roller 139 is installed in the belt unit 60 .

Although the present invention has been described in detail in conjunction with specific embodiments, it is obvious to those skilled in the art that various modifications and changes can be made to the present invention without departing from the spirit of the present invention.

For example, in the above-described embodiments, four colors of magenta, yellow, cyan, and black are used for imaging. However, it is also possible to image using only three colors of magenta, yellow, and cyan, using only two colors, or using only one color.

The present invention can be applied to other various kinds of image forming apparatuses, such as image forming apparatuses equipped with a facsimile function.

In the above-described embodiment, the photosensitive drum 33 and the toner container 35 are replaced with the process cartridge 30 as a whole. However, this structure can be modified so that only the toner container 35 can be replaced. More specifically, the process cartridge 30 may be constituted by a combination of an N developing cartridge and a drum cartridge. The developing cartridge may include a toner cartridge 35 , supply roller 31 and developing roller 32 , and the drum cartridge may include a photosensitive drum 33 . The developing cartridge can be detachably engaged with the drum cartridge. The developing cartridge can be detached from the drum cartridge and removed from the main cartridge casing 2 while the drum cartridge is still installed in the main casing 2 .

In the first embodiment, the image forming sections 17 for black, cyan, yellow, and magenta are arranged in this order from back to front. In the second embodiment, the image forming sections 17 for black, cyan, magenta, and yellow are arranged in this order from back to front. However, the image forming portions of these four colors can be arranged in any order.

In the first embodiment, the combination of the protrusion 27 and the recess 262 is located at one end of the scanner housing 26 along the scanning direction to adjust one end of the scanning unit 20 not to be in contact with the supporting frame 260, and the bolt 263 is located at the end of the scanner housing 26 along the scanning direction. The other end is used to adjust the distance between the left end of the scanning unit 20 and the supporting frame 260 . However, the combination of the protrusion 27 and the recess 262 may be located closer to one end in the scanning direction, and the bolt 263 may be located closer to the end in the scanning direction than the other end.

Also, in the second embodiment, the leaf spring 261 is located at one end of the scanner housing 326 in the scanning direction, and the bolt 363 is located at the other end of the scanner housing 326 in the scanning direction. However, leaf spring 261 may be located closer to one end of scanner housing 326 in the scanning direction and bolt 363 may be located closer to the other end of scanner housing 326 in the scanning direction.

In the first and third embodiments, the combination of the protrusion 27 and the recess 262 is used to adjust the scanning unit 20 out of contact with the supporting frame 260 , and the bolt 363 is used to adjust the distance between the scanning unit 20 and the supporting frame 260 . In the second embodiment, the combination of the rotating shaft 329 and the bearing portion 360d is used to adjust the scanning unit 320 out of contact with the supporting frame 360 , and the bolt 363 is used to adjust the distance between the scanning unit 320 and the supporting frame 360 . However, there are many other configurations that can be used to adjust the scanning unit not in contact with the supporting frame and to adjust the distance between the scanning unit and the supporting frame.

Claims (39)

1. an imaging device is characterized in that, this imaging device comprises:

Shell;

Install in the enclosure and transmit any the endless belt in developer image and the recording medium;

Install in the enclosure, with a plurality of one to one processing units of multiple color, these a plurality of processing units comprise a plurality of photosensitive drums respectively, each photosensitive drums is in the face of endless belt;

Installation in the enclosure and for each photosensitive drums is provided with a plurality of scanning elements of one, each scanning element uses the surface of the corresponding photosensitive drums of photoscanning to form electrostatic latent image, each processing unit developer developing electrostatic latent image of respective color; And

Install in the enclosure and will be formed on the transfer section above recording medium that the developer image on each photosensitive drum surface transmits to endless belt with by endless belt any; With

The box that holds recording medium, described box are installed in the position below the interior described endless belt of described shell separably;

Scanning element and processing unit are arranged alternately in the horizontal direction;

Each scanning element and each processing unit tilt for vertical direction;

At least a portion of each processing unit is inserted in the shell or in shell with the direction that tilts and removes,

Described endless belt is configured to its height to be increased from the direction that shell withdraws from described box.

2. imaging device as claimed in claim 1 is characterized in that,

The direction that each scanning element and each processing unit are pulled down from described shell to described box tilts.

3. imaging device as claimed in claim 1 is characterized in that, this imaging device comprises further and be attached to shell with from the top a plurality of lids that mutually cover a plurality of processing units correspondingly that these a plurality of lids can open and close independently of each other.

4. imaging device as claimed in claim 1, it is characterized in that, wherein endless belt is in direction of transfer transmission recording medium in the above, and endless belt is configured to, and its position in the part in direction of transfer downstream is lower than its position in the part of direction of transfer upstream side.

5. imaging device as claimed in claim 1 is characterized in that, the straight line that wherein connects scanning element upper end face and processing unit upper end face is arranged essentially parallel to the vergence direction of endless belt.

6. imaging device as claimed in claim 1, it is characterized in that, this imaging device further comprises admits the paper discharge tray that is formed with the record images medium, described paper discharge tray is set at scanning element and processing unit top, and described paper discharge tray tilts in the direction of the vergence direction that is arranged essentially parallel to endless belt.

7. imaging device as claimed in claim 1 is characterized in that, wherein each photosensitive drums rotatably is supported in the corresponding processing unit near its lower end, and photosensitive drums is by beam flying, and described light beam penetrates near the upper end of respective scan cells.

8. imaging device as claimed in claim 2, it is characterized in that, wherein this part that comprises its upper end at least of each scanning element alternately has a width on the direction of arrangement at scanning element and processing unit, this at least a portion of each scanning element goes up to the upper end in the opposite direction in the side that is withdrawed from main casing with described box and narrows down, and described width reduces towards the upper end of scanning element;

Wherein, each processing unit to be this part of comprising its upper end at least alternately have a width on the direction of arrangement at scanning element and processing unit, this at least a portion of each processing unit the side that is withdrawed from main casing with described box in the opposite direction on upwards distal process go out, described width increases towards the upper end of processing unit.

9. imaging device as claimed in claim 1 is characterized in that, wherein each scanning element comprises:

The scanner shell;

Be installed in the light source in the scanner shell; And

Be installed in the scanner shell and light beam that the deflection light source sends with the deflection unit on the surface of scanning corresponding photosensitive drums; And

Further comprise:

A plurality of bracing frames, each bracing frame are fixedly mounted in the described shell and support corresponding scanner shell thereon;

At least a portion that is used to adjust the scanner shell makes its adjustment unit away from support frame as described above; And

Be used to regulate the regulon of scanner shell with respect to the orientation of bracing frame.

10. imaging device as claimed in claim 9 is characterized in that, wherein:

The scanner shell has the scanner surface in the face of bracing frame;

Bracing frame has the framework surface in the face of the scanner surface;

Adjustment unit has:

The outstanding projection in a surface from scanner surface and framework surface;

The receiving portion of the described projection of admittance that another surface in scanner surface and framework surface forms; With

Make the regulon of the contact portion pivot rotation of scanner shell between projection and receiving portion with the orientation of adjusting scanner shell.

11. imaging device as claimed in claim 10 is characterized in that, wherein receiving portion comprises the depression with V-arrangement xsect that is formed on another surface in scanner surface and the framework surface.

12. imaging device as claimed in claim 10 is characterized in that, wherein adjustment unit comprises the promotion member that projection and receiving portion are promoted towards approaching mutually direction.

13. imaging device as claimed in claim 10 is characterized in that, wherein the scanner surface has first end section and second end section on the direction of deflection unit scanning light beam;

In projection and the receiving portion any one is formed on a side on scanner surface, and the distance between this side and the first end section is less than the distance between itself and the second end section; With

Regulon comprises the distance adjustment unit, the distance adjustment unit is arranged on the opposite side on scanner surface, distance between this opposite side and the second end section is less than the distance between itself and the first end section, and regulates the second end section on scanner surface and the distance between the framework surface.

14. imaging device as claimed in claim 13 is characterized in that, wherein the scanner surface has a plurality of positions on the direction perpendicular to the direction of scanning, and the frame table mask has and a plurality of one to one positions, the lip-deep described a plurality of positions of scanner,

In projection and the receiving portion any one is formed on each position in lip-deep these a plurality of positions of scanner,

In projection and the receiving portion another is formed on the lip-deep relevant position of framework.

15. imaging device as claimed in claim 13 is characterized in that, wherein projection and receiving portion are all along extending continuously perpendicular to the direction of direction of scanning.

16. imaging device as claimed in claim 13 is characterized in that, wherein the distance adjustment unit comprises:

Promote the sheet spring of the second end section on scanner surface towards the framework surface; With

Overcome the expulsive force of sheet spring, regulate the bolt with respect to the position on framework surface of second end section, scanner surface.

17. imaging device as claimed in claim 9 is characterized in that, wherein:

The scanner shell has the scanner surface that is positioned to face bracing frame;

Bracing frame has the framework surface that is positioned to face the scanner surface;

Adjustment unit comprises:

Be arranged on the turning axle to extend in the scanner shell along the direction on scanner surface; With

Along being defined as the outstanding bearing portions of direction that extend on the surface from frame table towards scanner, this bearing portions is rotatably admitted turning axle from the framework surface; With

Regulon rotates to regulate the orientation of scanner shell with respect to bracing frame the contact portion pivot of scanner shell between turning axle and bearing portions.

18. imaging device as claimed in claim 17 is characterized in that, wherein bearing portions comprises the projection of its leading edge opening forming V-shape xsect.

19. the imaging device shown in claim 17 is characterized in that, wherein turning axle is located substantially on the middle body of the scanning pattern of deflection unit scanning light beam, and extends perpendicular to the direction of scanning;

The scanner surface has first end section and second end section at deflection unit along the direction of scanning of scanning pattern scanning light beam; With

Regulon comprises:

Be arranged on a side on scanner surface, the distance between this side and the first end section is less than the distance between itself and the second end section and the first end section is pushed to the sheet spring on framework surface; With

Be arranged on the opposite side on scanner surface, the distance between this opposite side and the second end section is resisted the bolt of the expulsive force of sheet spring less than distance between itself and the first end section and the second end section of regulating the scanner surface with the distance between the framework surface.

20. imaging device as claimed in claim 16 is characterized in that, wherein the scanner shell also has reception by the light beam of deflection unit scanning and reflect the catoptron of this light beam to photosensitive drums; With,

The angle [alpha] that forms along the imaginary plane perpendicular to the direction of scanning between the light beam after the light beam before the mirror reflection that is reflected and the mirror reflection that is reflected satisfies inequality 0 degree＜α＜45 degree.

21. imaging device as claimed in claim 20 is characterized in that, wherein bracing frame is multistage in the enclosure is provided with abreast,

Pass each bracing frame and be formed with through hole, make turnscrew can pass this through hole and insert, be arranged on the engagement amount of the bolt on the scanner shell in order to adjustment, described scanner shell is supported on the next bracing frame of each bracing frame.

22. imaging device as claimed in claim 1 is characterized in that, this imaging device further comprises:

Support a plurality of rollers of endless belt, this endless belt can be made around the movement around described a plurality of rollers; And

Support these a plurality of rollers and endless belt and these a plurality of roll formings be integral become the belt of belt unit unit framework,

Described shell has the straight line of qualification and inserts/remove the wall in path, the belt unit framework can be along this path movement to be installed in the described shell separably, insert/remove path definition along straight line in the enclosure predetermined installation site is arranged, the belt unit framework can insert/remove path movement to this predetermined installation site along straight line in direction of insertion, and insert/remove the path along straight line and remove removing direction from predetermined installation site

When the belt unit was mounted in the enclosure installation site, the surface of endless belt contacted with each photosensitive drums,

The direction shape that exit axis and endless belt move on its surface and each photosensitive drums position contacting at an angle, when the belt unit begins from the installation site when mobile with exit axis, this angle is removed the surface of endless belt and the contact between each photosensitive drums.

23. imaging device as claimed in claim 22 is characterized in that, its cathetus inserts/removes the path and extends in the horizontal direction basically.

24. imaging device as claimed in claim 22 is characterized in that, wherein each photosensitive drums can be around its axle rotation, and the turning axle that the axle of described photosensitive drums is arranged essentially parallel to roller extends; And

Exit axis is substantially perpendicular to the axle of each photosensitive drums.

25. imaging device as claimed in claim 22 is characterized in that, wherein said shell wall comprises along the guide member that inserts/remove route guidance belt unit framework.

26. imaging device as claimed in claim 22 is characterized in that, this imaging device comprises further and holds recording medium and in the enclosure box is installed separably that this box can withdraw from the shell with the direction identical with the exit axis of belt unit.

27. imaging device as claimed in claim 26 is characterized in that, wherein belt unit and box can be removed together from shell.

28. imaging device as claimed in claim 26 is characterized in that, wherein when the belt unit is mounted in the enclosure in the installation site, the part of belt unit is overlapping with box on the direction that belt unit and box withdraw from.

29. imaging device as claimed in claim 22, it is characterized in that, wherein the belt unit framework comprises that a part to the belt unit provides the power terminal of electric power, this power terminal is positioned at an end of belt unit framework, and this end is positioned at the downstream end of belt unit with respect to the direction of insertion of described shell.

30. imaging device as claimed in claim 29 is characterized in that, wherein power terminal comprises along a plurality of power terminals of the axial array of the turning axle of roller.

31. imaging device as claimed in claim 30 is characterized in that, wherein shell comprises a plurality of electrodes, and when the belt unit was mounted in the enclosure in the installation site, this electrode was connected to power terminal;

When the belt unit moves in the installation site of direction of insertion in shell, after power terminal is connected to electrode, endless belt contact photosensitive drums.

32. imaging device as claimed in claim 29 is characterized in that, wherein:

Transfer section comprises and a plurality of one to one transfer rolls of a plurality of photosensitive drums,

The belt unit framework further supports described a plurality of transfer rolls,

Power terminal comprises the transfer bias terminal, and this transfer bias terminal provides transfer bias to transfer roll, with towards the direction of endless belt from each photosensitive drums transfer printing developer image.

33. imaging device as claimed in claim 32 is characterized in that, wherein:

The belt unit framework further supports clearer, this clearer cleaning endless belt and in and the neutralisation unit of endless belt,

Power terminal further comprises at least one following terminal:

Provide the cleaning bias voltage terminal of cleaning bias voltage to clearer with the cleaning endless belt;

In neutralisation unit provides and bias voltage with in the charge neutrality endless belt and bias voltage terminal;

Make the grounding terminals of belt unit framework ground connection.

34. imaging device as claimed in claim 22 is characterized in that, wherein

A plurality of photosensitive drums are arranged along the direction that described endless belt moves; And

When the endless belt framework begins from the installation site when mobile at exit axis, endless belt separates mutually simultaneously with a plurality of photosensitive drums.

35. imaging device as claimed in claim 34 is characterized in that,

Wherein each photosensitive drums with the position of all vertical vertical direction of the turning axle of exit axis and roller, from side-play amount of another photosensitive drums skew of the upstream side that is positioned at each photosensitive drums on the exit axis, and

Wherein the belt unit framework further supports a pushing unit thereon, when the belt unit is being removed on the direction when move the installation site, this pushing unit make endless belt be positioned at the installation site in the belt unit time contact portion that contacts with photosensitive drums move an amount of movement in vertical direction, this amount of movement is littler than described side-play amount.

36. imaging device as claimed in claim 22 is characterized in that, wherein endless belt transmits the recording medium on it.

37. imaging device as claimed in claim 36 is characterized in that, this imaging device further comprises:

When the belt unit is mounted in the enclosure, picks up recording medium and recording medium is offered the feeding unit of endless belt from box; And

Receive and discharge the deliverying unit of recording medium, described recording medium is transmitted by endless belt and forms the developer image by photosensitive drums,

Processing unit is set at endless belt and along it recording medium is sent on the path of deliverying unit from feeding unit, forms versicolor developer image thereby be docile and obedient preface on recording medium,

Feeding unit picks up the direction of recording medium and deliverying unit from box, and to discharge the direction of recording medium opposite with the medium direction of transfer, and endless belt transmission recording medium makes it by forming the image space of image on described medium direction of transfer.

38. imaging device as claimed in claim 37 is characterized in that, wherein processing unit inserts or removes along the direction that the thickness direction with respect to medium direction of transfer and recording medium vertical with the medium direction of transfer, that transmitted by endless belt tilts.

39. imaging device as claimed in claim 37 is characterized in that, wherein processing unit and scanning element are arranged alternately at the medium direction of transfer.

Images