JP5459429B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  In conventional image forming apparatuses such as copying machines and printers, the following patent documents 1 to 5 describe techniques for solving problems such as image quality degradation due to distortion of the apparatus caused by unevenness of the floor surface. The technology is known in the art.

  Japanese Patent Application Laid-Open No. 2000-310930 as Patent Document 1 discloses a feed roller (11), a retard roller pair (12), a transport roller pair (13), a registration roller pair (14), an intermediate transfer belt (16), A secondary transfer roller (17), a fixing device (15), and a discharge roller pair (19a, 19b) are provided in the base unit (2), and four photosensitive drums (31), a charging means (32), a developing means ( 33), the core unit (1) having the cleaning means (34) and the optical scanning system (18Y, 18M, 18C, 18Bk) is separated from the base unit (2) by three housing receiving members (4a, 4b). 4c), the technology of preventing the distortion of the base unit (2) due to the unevenness of the installation surface from affecting the optical scanning system (18Y to 18Bk), the photosensitive drum, and the like. It has been mounting.

Patent Document 1 also describes a configuration in which an intermediate transfer belt (16), a secondary transfer roller (17), and a registration roller pair (14) are also provided in the core unit (1). In this configuration, the recording sheet from the base unit (2) is carried in on the side of the housing support member (3a) supported at two points of the housing receiving members (4a, 4b, 4c), and the registration rollers The secondary transfer regions of the pair (14) and the secondary transfer roller (17) are disposed at positions away from both the housing support members (3a, 3b).
Further, in Patent Document 1, one photosensitive drum (30), one optical scanning system (18), one intermediate transfer belt (36), a secondary transfer roller (37), a pair of registration rollers ( 14) and a configuration in which a rotary, so-called rotary developing unit (35) is provided in the core unit (1).

  In Japanese Patent Application Laid-Open No. 2003-186372 as Patent Document 2, the image forming apparatus has a main body frame (51), a photosensitive drum (20), a charging device (21), a cleaning device (27), an intermediate transfer belt. (30) The engaging shafts (67, 68) of the image forming unit (61) having the belt cleaning device (36) are engaged grooves (52, 52) formed on the pair of front and rear walls of the main body frame (51). 53), and the engagement piece (69) of the image forming unit (61) is supported by the engaged recess (54) formed on the side wall of the main body frame (51).

In Japanese Patent Laid-Open No. 10-194506 as Patent Document 3, a color copying machine (1) has an apparatus main body frame (2), and a belt unit (3) having an endless belt (4) includes a first support portion. (12), the technology supported by the apparatus main body frame (2) at three points of the second support part (14) and the third support part (17) is described.
In Japanese Patent Application Laid-Open No. 10-104998 as Patent Document 4, an image forming apparatus (100) has a front main body side plate (42) and a rear main body side plate (43) as a frame, and an endless belt. A technique is described in which a belt unit device (20) having (3) is supported in a state of being positioned at three points on a main body side plate (42, 43) by three pins (37, 38, 39). .

  Japanese Patent Application Laid-Open No. 2007-226007 as Patent Document 5 discloses a photoreceptor unit (50) that supports a photoreceptor drum (52) and the like, a developing unit (40) having a developing device (42), and an intermediate transfer member. In the image forming apparatus provided with the image forming unit (30) having the transfer unit (60) for supporting (62) and the like, the accommodating portion (10a) as a frame of the image forming apparatus for accommodating the image forming unit (30). ) Describes a structure in which three support legs (41b, 51b) and engagement holes (10d) are used for support.

JP 2000-310930 A (“0018” to “0022”, “0025”, “0027”, FIG. 2, FIG. 4, FIG. 7 to FIG. 10) JP 2003-186372 A ("0027" to "0028", FIGS. 3 to 7) JP-A-10-194506 ("0014" to "0018", FIGS. 1 to 3) Japanese Patent Laid-Open No. 10-104998 (“0043” to “0048”, FIG. 1 and FIG. 2) JP 2007-226007 A (“0015” to “0016”, “0030” to “0042”, FIGS. 1 to 3)

  An object of the present invention is to reduce a deviation between a medium and an image recorded on the medium.

In order to solve the technical problem, an image forming apparatus according to claim 1 is provided.
A medium conveying unit having a medium conveying member for conveying a medium on which an image is recorded, and a carry-out port from which the medium is carried out;
An image recording unit having an image recording apparatus for recording an image on a medium transported from the medium transport unit in an image recording area disposed on the transport outlet side;
A first support portion and a second support portion which are arranged on the carry-out port side in the image recording unit and arranged at positions separated in the width direction of the medium to be conveyed; and the carry-out port in the image recording unit; And a third support portion disposed on the opposite side, and at least the first support portion and the second support portion are supported on the carry-out side of the medium transport unit, and the medium A recording unit support for the image recording unit to be detachably supported with respect to the medium transport unit for a user using
A drive source supported by the image recording unit and driving the image recording apparatus;
A member for transmitting the drive of the drive source to the medium transport member;
A low-voltage power supply board for supplying power to the drive source, and a high-voltage power supply board for supplying power to the image recording apparatus, and a power supply circuit supported by the image recording unit;
A wiring guide member that is provided in the medium transport unit and guides wiring electrically connected to the power supply circuit;
It is provided with.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect,
An image holding body that rotates while holding an image on the surface, and an endless belt-like body. The image on the surface of the image holding body is transferred, and the image transferred from the image holding body in the image forming area is transferred to the medium. The image recording unit comprising: an intermediate transfer member to be transferred; and a primary transfer unit that transfers an image on the surface of the image carrier to the intermediate transfer member;
A fixing unit having a fixing device for fixing the image transferred to the medium;
A fixing unit support provided on the image recording area side of the image recording unit and supporting the fixing unit;
It is provided with.

According to the first aspect of the present invention, the displacement between the medium and the image recorded on the medium can be reduced as compared with the case where the configuration of the present invention is not provided.
According to the second aspect of the present invention, the positional deviation between the fixing unit and the image recording area can be reduced as compared with the case where the fixing unit is not supported by the image recording unit.

FIG. 1 is an overall explanatory view of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is an explanatory diagram of a main part of the unit main body of the image recording unit according to the first embodiment. FIG. 3 is an explanatory view showing a state in which the drive unit is attached to the unit main body shown in FIG. FIG. 4 is an explanatory diagram of a state in which a circuit board or the like is attached to the state shown in FIG. FIG. 5 is an enlarged view of the main part of the fixing unit support part, FIG. 5A is an explanatory diagram of a state in which the supported part of the fixing unit is being attached to the fixing unit support part, and FIG. 5B is the supported part of the fixing unit. FIG. 6 is an explanatory diagram of a state where the fixing unit support portion is mounted. FIG. 6 is a perspective view illustrating a main part of a medium transport unit as an example of a second unit according to the first embodiment. FIG. 7 is an explanatory diagram of a state in which the medium transport unit and the image recording unit are connected. FIG. 8 is an explanatory view of the main part of the first fixing part. FIG. 9 is a perspective view of the medium transport unit and the image recording unit viewed from diagonally right and rear in a connected state. FIG. 10 is an explanatory diagram of a state where the exterior member is mounted, and is a perspective view seen from the right rear side. FIG. 11 is an explanatory diagram of a state in which the exterior member is mounted, and is a perspective view seen from the right front side. FIG. 12 is an explanatory diagram of the influence of the distortion of the image recording unit. FIG. 12A is an explanatory diagram in the case of Example 1 in which the image recording area is arranged on the two-point support side on the carry-out side, and FIG. It is explanatory drawing in the conventional case where the image recording area | region is arrange | positioned in the position away from the point support side and the carrying-out port. FIG. 13 is an explanatory diagram for explaining the relationship between the fixing direction of the image recording unit of Example 1 and the allowable distortion.

Next, examples as specific examples of embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following examples.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The direction indicated by Z and -Z or the indicated side is defined as the front side, the rear side, the right side, the left side, the upper side, the lower side, or the front side, the rear side, the right side, the left side, the upper side, and the lower side, respectively.
In the figure, “•” in “○” means an arrow heading from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.
In the following description using the drawings, illustrations other than members necessary for the description are omitted as appropriate for easy understanding.

FIG. 1 is an overall explanatory view of an image forming apparatus according to Embodiment 1 of the present invention.
In FIG. 1, the printer U according to the first exemplary embodiment of the image forming apparatus of the present invention is provided with a discharge tray TRh as an example of a discharge unit from which a sheet S as an example of a medium is discharged at the upper end. Below the discharge tray TRh, a control board SC on which various control circuits, storage media and the like are arranged is arranged. The control board SC includes a control unit C that performs various controls of the printer U, an image processing unit GS whose operation is controlled by the control unit C, a latent image forming device drive circuit DL, and a power supply circuit as an example of a power supply device. E etc. are provided. The power supply circuit E applies voltages to charging rollers CRy to CRk as an example of a charger to be described later, developing rollers G1y to G1k as an example of a developer holding member, and transfer rollers T1y to T1k as an example of a transfer device. .

The image processing unit GS converts print information input from a personal computer PC or the like as an example of an external image information transmission device into four colors of yellow, magenta, cyan, and black, that is, Y, M, C, and K. The image information is converted into latent image forming image information corresponding to the image, and is output to the latent image forming device drive circuit DL at a predetermined timing.
When the document image is a single color image, so-called monochrome, only black image information is input to the latent image forming device drive circuit DL.
The latent image forming device drive circuit DL has drive circuits for the respective colors Y, M, C, and K (not shown), and a latent image arranged for each color at a predetermined time according to the input image information. Output to LED heads LHy, LHm, LHc, and LHk as an example of a forming apparatus.

Visible image forming apparatuses UY, UM, UC, and UK that form toner images as examples of visible images of yellow, magenta, cyan, and black are disposed at the lower center of the printer U. In FIG. 4, the black, that is, K-color visible image forming device UK has a photoconductor Pk as an example of a rotating image carrier. Around the photosensitive member Pk, a charging roll CRk as an example of a charger for charging the photosensitive member surface Pk, an LED head LHk as an example of a latent image forming device for forming an electrostatic latent image on the photosensitive member surface, a photosensitive member A developing device Gk that develops the electrostatic latent image on the body surface into a visible image, a photoreceptor cleaner CLk as an example of an image carrier cleaner that removes the developer remaining on the surface of the photoreceptor Pk, and the like are disposed.
The visible image forming apparatuses UY, UM, and UC of other colors are also configured in the same manner as the black visible image forming apparatus UK.

  The photoreceptors Py to Pk are uniformly charged on the surface by the charging rolls CRy to CRk at the charging areas Q1y, Q1m, Q1c, and Q1k facing the charging rolls CRy to CRk, and then the latent image forming areas Q2y, Q2m, A latent image is written by the LED heads LHy to LHk at Q2c and Q2k. The written electrostatic latent image is developed into a toner image in the development areas Q3y, Q3m, Q3c, and Q3k facing the developing devices Gy to Gk. The developed toner image is conveyed to primary transfer regions Q4y, Q4m, Q4c, and Q4k that are in contact with an intermediate transfer belt B as an example of an intermediate transfer member. The intermediate transfer belt B of Example 1 is configured by an endless belt-like member, a so-called belt-like member, and is an example of a belt driving roll Rd as an example of a driving member, a driven member, and a secondary transfer counter member. An intermediate transfer support system including a backup roll T2a as an example and the primary transfer rolls T1y, T1m, T1c, and T1k disposed to face the respective photoreceptors Py to Pk is rotatably supported. The intermediate transfer member is not limited to a belt shape, and a conventionally known form such as a drum shape can be employed.

  The primary transfer rolls T1y, T1m, T1c, and T1k as an example of the primary transfer unit disposed on the back side of the intermediate transfer belt B in the primary transfer regions Q4y, Q4m, Q4c, and Q4k are controlled by the control unit C. The primary transfer voltage having a polarity opposite to the toner charging polarity is applied from the power supply circuit E at a preset time. Accordingly, the toner images on the respective photoreceptors Py to Pk are primarily transferred onto the intermediate transfer belt B by the primary transfer rolls T1y, T1m, T1c, and T1k.

  Residues and deposits such as transfer residual toner and discharge products on the surface of the photoreceptors Py, Pm, Pc, and Pk after the primary transfer are cleaned by the photoreceptor cleaners CLy, CLm, CLc, and CLk. The cleaned surfaces of the photoreceptors Py, Pm, Pc, and Pk are recharged by the charging rollers CRy, CRm, CRc, and CRk. It should be noted that a residue that cannot be removed by the photoconductor cleaners CLy to CLk and adheres to the charging rollers CRy to CRk is a charger as an example of a charger cleaning member disposed in contact with the charging rollers CRy to CRk. Cleaning is performed by the cleaners CCy, CCm, CCc, and CCk.

  On the upper rear side of the intermediate transfer belt B, a belt cleaner CLb as an example of an intermediate transfer body cleaner is disposed. The belt cleaner CLb is for a belt as an example of a cleaning container CLb1 and a cleaning member that is supported by the cleaning container CLb1 and that contacts the intermediate transfer belt B to remove residues remaining on the surface of the intermediate transfer belt B and cleans them. The cleaning blade CLb2, the film CLb3 as an example of a leakage preventing member for preventing the residue removed by the belt cleaning blade CLb2 from scattering and leaking, and the cleaning blade CLb2 disposed in the cleaning container CLb1 and removed. And a residue conveying member CLb4 for conveying and discharging the residue. The cleaning container CLb1 according to the first embodiment is disposed at a position corresponding to the upper side of the black photoconductor cleaner CLk.

A secondary transfer roll T2b as an example of a secondary transfer member is disposed so as to face the surface of the intermediate transfer belt B in contact with the backup roll T2a. The backup roll T2a and the secondary transfer roll T2b constitute a secondary transfer device T2 of Example 1. Further, a secondary transfer area Q5 as an example of an image recording area is formed by the areas where the secondary transfer roll T2b and the intermediate transfer belt B face each other.
The single-color or multi-color toner images transferred in sequence on the intermediate transfer belt B by the primary transfer rolls T1y, T1m, T1c, and T1k in the primary transfer areas Q4y, Q4m, Q4c, and Q4k are the secondary transfer. It is conveyed to area Q5.
The visible image forming devices UY to UK, the intermediate transfer belt B, and the like constitute image recording devices UY to UK + B that form an image recorded on the recording sheet S.

The primary transfer rolls T1y to T1k, the intermediate transfer belt B, the secondary transfer device T2, and the like constitute a transfer device T1 + T2 + B of Example 1.
As shown in FIG. 1, the intermediate transfer belt B of Example 1 is disposed in a state where the primary transfer regions Q1y to Q1k are inclined downward toward the rear side with respect to the horizontal plane, Correspondingly, the visible image forming devices UY to UK are also arranged at positions shifted downward in the gravitational direction as they go downstream in the belt rotation direction.

  Below the visible image forming apparatuses UY to UK, a paper feed tray TR1 as an example of a medium storage unit is provided. The paper feed tray TR1 includes a bottom wall TR1a as an example of a lower wall, a rear end wall TR1b extending upward from the rear end of the bottom wall TR1a, and an upper wall TR1c disposed to face the upper side of the bottom wall TR1a. And have. A replenishing port TR1d for replenishing a new recording sheet S is formed at the front end of the paper feed tray TR1. The front end portion of the upper wall TR1c is formed so as to incline upward toward the outside of the replenishing port TR1d, that is, the front side. Therefore, the replenishment port TR1d is formed such that the distance between the upper wall TR1c and the bottom wall TR1a increases as it goes to the front side, and widens as the replenishment port TR1d goes to the front side.

On the bottom wall TR1a, an elevating plate PL1 as an example of a medium stacking unit that supports the sheet S so as to be rotatable about the rotation center PL1a and stacks the sheet S and raises and lowers the sheet S is disposed. A lifting spring PL2 as an example of a biasing member that biases the rear end of the lifting plate PL1 upward is disposed at the rear end of the lifting plate PL1. When the image is not formed, the elevating plate PL1 is in a lowered position where the elevating plate PL1 is held in a state parallel to the bottom wall TR1a by the eccentric cam-like push-down members PL3 arranged at both left and right ends. Moving. While the image is being formed, the push-down member PL3 is rotated and supported by the lift spring PL2 so as to be movable between the lift position shown in FIG. 1 where the lift plate PL1 is lifted.
Accordingly, when the replenishing port cover U2 as an example of the replenishing port opening / closing member is opened, the replenishing port TR1d is opened, and a new bundle of recording sheets S is inserted until it hits the rear end wall TR1b. It is accommodated in a state of being loaded on the lifting plate PL1.

Behind the upper wall TR1c, a paper feed roll Rp, which is an example of a medium conveying member and an example of a sending member, is disposed. The sheet feeding roll Rp is disposed at a position where the uppermost recording sheet S of the bundle of stacked recording sheets S is pressed by the spring force of the lifting spring PL2 in a state where the lifting plate PL1 is moved to the raised position. ing. Above the rear end wall TR1b, a retard roll Rs is disposed as an example of a whisper member.
The recording sheets S stacked on the paper feed tray TR1 are sent out by the paper feed roll Rp, separated one by one in the contact area between the retard roll Rs and the paper feed roll Rp, and then fed to the medium transport path SH. Be transported. The recording sheet S in the medium conveyance path SH is an example of a medium conveyance member, and is conveyed to a registration roll Rr as an example of a timing adjustment member that adjusts the conveyance timing of the sheet S, that is, a so-called timing. The recording sheet S conveyed to the registration roll Rr is sent out from the carry-out port Rr1 of the registration roll Rr to the secondary transfer area Q5 in accordance with the timing when the toner image on the intermediate transfer belt B reaches the secondary transfer area Q5.

The intermediate transfer belt B after the toner image is transferred in the secondary transfer region Q5 is cleaned by removing residual toner and discharge products remaining on the surface by the belt cleaner CLb.
The recording sheet S to which the toner image has been transferred is conveyed to the fixing region Q6 of the fixing device F. The fixing device F includes a heating roll Fh as an example of a heat fixing member and a pressure roll Fp as an example of a pressure fixing member, and the heating roll Fh and the pressure roll Fp are set in advance. The fixing area Q6 is constituted by the area that is in contact with the pressure. The unfixed toner image on the surface of the recording sheet S is fixed by heat and pressure when passing through the fixing region Q6.
The recording medium S on which the image is fixed is transported through the medium transport path SH and is discharged from a discharge roller Rh as an example of a medium discharge member to a discharge tray TRh.

FIG. 2 is an explanatory diagram of a main part of the unit main body of the image recording unit according to the first embodiment.
FIG. 3 is an explanatory view showing a state in which the drive unit is attached to the unit main body shown in FIG.
FIG. 4 is an explanatory diagram of a state in which a circuit board or the like is attached to the state shown in FIG.
FIG. 5 is an enlarged view of the main part of the fixing unit support part, FIG. 5A is an explanatory diagram of a state in which the supported part of the fixing unit is being attached to the fixing unit support part, and FIG. 5B is the supported part of the fixing unit. FIG. 6 is an explanatory diagram of a state where the fixing unit support portion is mounted.
FIG. 6 is a perspective view illustrating a main part of a medium transport unit as an example of a second unit according to the first embodiment.
FIG. 7 is an explanatory diagram of a state in which the medium transport unit and the image recording unit are connected.
FIG. 8 is an explanatory view of the main part of the first fixing part.
FIG. 9 is a perspective view of the medium transport unit and the image recording unit viewed from diagonally right and rear in a connected state.
FIG. 10 is an explanatory diagram of a state where the exterior member is mounted, and is a perspective view seen from the right rear side.
FIG. 11 is an explanatory diagram of a state in which the exterior member is mounted, and is a perspective view seen from the right front side.
In addition, in each drawing, illustrations other than components required for description are abbreviate | omitted suitably for easy understanding and description. For example, the drive unit is not shown in FIG. 7, and the display of the developing device and the like is omitted in FIGS.

(Description of image recording unit)
2 to 4, the image recording unit 1 as an example of the first unit of the first embodiment includes a recording unit main body 2. In FIG. 2, the recording unit main body 2 has a plate-like left end wall 3 and right end wall 4 as an example of side walls, and between the left end wall 3 and the right end wall 4, the photoreceptors Py to Pk and intermediate The backup roll T2a that supports the transfer belt B, the belt cleaner CLb, the charging rolls CRy to CRk, the charger cleaners CCy to CCk, the photoreceptor cleaners CLy to CLk, and the LED heads LHy to LHk are supported and unitized. Each color developing device Gy, Gm, Gc, Gk is also supported at the bottom.

A left fixing portion 6 as an example of a first support portion is formed on the rear lower portion of the left end wall 3, that is, on the side of the carry-out port Rr1 and below the backup roll T2a. As an example of the first positioning portion, the left fixing portion 6 is formed with a U-shaped left positioning groove 6a extending from the rear lower side to the front upper side. As an example of the fixing portion, left screw passage holes 6b and 6c through which screws can pass are formed.
In FIG. 11, a right fixing portion 7 having the same configuration as the left end wall 2 is formed as an example of the second support portion also on the side of the outlet Rr1 of the right end wall 4, that is, the lower portion on the rear side. A right positioning groove 7a as an example of the second positioning portion and a right screw passage 7b, 7c as an example of the second fixing portion are formed.

2 and 3, fixing unit support portions 8 and 9 as an example of a third unit support portion are provided on the upper rear side of each end wall 3 and 4, that is, above the backup roll T2a. .
2 and 5, the fixing unit support portions 8 and 9 have positioning and fixing portions 8 a and 9 a that protrude rearward from the rear surfaces of the end walls 3 and 4. In addition, screw holes 8b and 9b are formed in the positioning and fixing portions 8a and 9a.
2 and 5, cylindrical fixing positioning portions 8c and 9c are formed on the upper surfaces of the fixing unit support portions 8 and 9 as an example of a third unit positioning portion. Behind the fixing positioning portions 8c and 9c are formed inclined surfaces 8d and 9d that are inclined downward as they go forward, and positioning lower surfaces 8e and 9e formed below the fixing positioning portions 8c and 9c. ing.

On the front side of the fixing unit support portions 8 and 9, a high-voltage power supply support portion 11 is supported as an example of a first substrate support portion. In the high-voltage power supply support part 11 of the first embodiment, an accommodation space 11a for accommodating circuit elements used in the high-voltage power supply substrate is formed.
A plate-like control board support section 12 is formed on the front side of the high-voltage power supply support section 11 as an example of the second board support section. A pair of left and right front positioning pieces 13 protruding forward are formed at the front end of the control board support 12 as an example of a third positioning portion. A front screw hole 14 is formed in the front surface of the recording unit main body 2 below the front positioning piece 13 as an example of a third fixing portion.
Therefore, the front fixing piece 13 and the front screw hole 14 are disposed on the opposite side of the image recording unit 1 from the carry-out port Rr1, that is, on the front side. 13 + 14 is configured. Further, the left fixing portion 6, the right fixing portion 7, and the front fixing portion 13 + 14 constitute the recording unit support portion 6 + 7 + 13 + 14 of the first embodiment.
In the specification of the present application, for the “carrying port side” and “the side opposite to the carrying port”, “when the medium transport unit is divided into three in the horizontal direction, that is, in the center, one side, and the other side, The side is the carry-out side and the other side is the opposite side of the carry-out port. Note that the medium transport unit 31 to be described later is not divided into three when the replenishing port cover U2 is open, but is divided into three when it is closed.

  In FIG. 3, the drive unit 16 is supported on the left surface of the recording unit main body 2. The drive unit 16 includes, as an example of a drive source, a drive roll Rd that drives the photoreceptors Py to Pk and the intermediate transfer belt B, a drive motor 17 that drives the development rolls G1y to G1k of the developing devices Gy to Gk, and the like. The drive unit 16 houses a transmission system (not shown) having a plurality of gears for transmitting the drive of the drive motor 17 to the photoreceptors Py to Pk, a clutch for controlling rotation transmission and cutting, and the like. Note that a plate-like terminal substrate support 18 that extends in the vertical direction is supported at the rear of the drive unit 16 as an example of a third substrate support.

In FIG. 4, power is supplied to the right part of the control board support unit 12 from a power supply external to the printer U via a harness that is a supply line (not shown), and a voltage supplied to a motor, a sensor, and the like is generated. The low-voltage power supply substrate 21 is supported. On the left side of the low-voltage power supply board 21, a control board 22 electrically connected to the low-voltage power supply board 21 and provided with circuits such as the control unit C and the image processing unit GS is supported.
The high-voltage power supply support unit 11 is electrically connected to the low-voltage power supply substrate 21 and is applied to the charging voltage applied to the charging rolls CRy to CRk, the developing voltage applied to the developing rolls G1y to G1k, and the primary transfer rolls T1y to T1k. A high voltage power supply substrate 23 that generates an applied primary transfer voltage or the like is supported. A circuit installed on the low-voltage power supply substrate 21 and the high-voltage power supply substrate 23 constitutes a power supply circuit E according to the first embodiment.

The terminal board support 18 supports a terminal board 24 that is electrically connected to the computer PC and receives and outputs image information and control signals. An additional substrate 26 electrically connected to each of the substrates 21 to 24 is supported on the front side of the left surface of the drive unit 16.
A cooling fan 27 is supported above the drive motor 17 as an example of a blower.
The image recording unit 1 according to the first embodiment is configured by the members denoted by the reference numerals 2 to 27.

(Description of media transport unit)
6 and 7, the medium transport unit 31 according to the first embodiment has a bottom wall 32. A pair of left and right exterior fixing portions 33 and 34 extending in the vertical direction are formed at the front end portion of the bottom wall 32. Lower fixing screw holes 33a, 34a for fixing the exterior are formed at the lower ends of the exterior fixing portions 33, 34. Behind the exterior fixing portions 33, 34 are formed a left side wall 36 and a right side wall 37 that extend rearward and constitute the left and right side walls of the paper feed tray TR1.

  A pair of left and right recording unit fixing portions 38 and 39 extending upward are formed at the rear end portion of the bottom wall 32 as an example of the first unit fixing portion. In the left recording unit fixing portion 38 as an example of the first supported portion, as an example of the first positioned member, a left positioning shaft 38a is disposed corresponding to the left positioning groove 6a and protrudes to the left. Is formed. Left and right screw holes 38b and 38c arranged corresponding to the screw passage holes 6b and 6c are formed on both the upper and lower sides of the left positioning shaft 38a as an example of a first fixed portion. In FIG. 9, a pair of upper and lower rear screw holes 38 d are formed on the rear surface of the recording unit fixing portion 38 as an example of an exterior fixing portion.

  The right recording unit fixing part 39 as an example of the second supported part is configured in the same manner as the left recording unit fixing part 38. Therefore, as shown in FIG. 11, a right positioning shaft 39a corresponding to the right positioning groove 7a is formed in the right recording unit fixing portion 39 as an example of the second positioning member. As an example, right screw holes 39b and 39c corresponding to the screw passage holes 7b and 7c are formed. As shown in FIG. 9, a pair of upper and lower rear screw holes 39d are formed on the rear surface of the right recording unit fixing portion 39 as an example of an exterior fixing portion.

6 and 7, the registration roll Rr is supported between the recording unit fixing portions 38 and 39 in the vicinity of the positioning shafts 38a and 39a. At the left end of the registration roll Rr, a registration roll gear 41 having a built-in clutch that controls transmission and disconnection of rotation is supported as an example of a transmitted gear to which driving is transmitted. The paper feed roll Rp is supported below the front side of the registration roll Rr, and a paper feed roll gear 42 as an example of a transmitted gear is supported at the left end of the paper feed roll Rp.
In FIG. 8, the registration roll gear 41 according to the first embodiment is supported so as to be able to transmit rotation via an intermediate gear 43 as an example of an intermediate transmission member rotatably supported by the left positioning shaft 38a. The intermediate gear 43 meshes with a gear 44 as an example of a first rotation transmission member to which driving is transmitted from the drive motor 17 of the image recording unit 1, is rotatably supported by the medium transport unit 31, and is connected to the registration roll gear 41. It meshes with a gear 45 as an example of a meshing second rotation transmission member. When the drive motor 17 is driven, the registration roll gear 41 is configured to be rotatable via the gears 43 to 45.

A pair of left and right vertical guide members 46 and 47 extending upward are supported on the front surfaces of the exterior fixing portions 33 and 34 as an example of a vertical guide member. The lower ends of the vertical guide members 46 and 47 of the first embodiment are supported on the upper surface of the bottom surface 32. Upper screw holes 46a and 47a are formed at upper ends of the vertical guide members 46 and 47 as an example of an exterior fixing portion.
A horizontal guide member 48 extending in the left-right direction and connecting the vertical guide members 46 and 47 is supported as an example of a third supported portion below the upper screw holes 46a and 47a. A front screw through hole 48a is formed at the center in the left-right direction of the horizontal guide member 48 as an example of the third fixed portion, corresponding to the front screw hole 14 of the image recording unit 1. Further, on the upper surface of the lateral guide member 48, a front positioning surface 48b that is in contact with the front positioning piece 13 is formed as an example of a third positioned portion.

Above the bottom wall 32, an upper wall TR1c of the paper feed tray TR1 is disposed, and a front end of the upper wall TR1c is supported by vertical guide members 46 and 47.
A space surrounded by the bottom wall 32, the exterior fixing portions 33 and 34, the vertical guide members 46 and 47, and the horizontal guide member 48 constitutes a replenishing port TR1d of the paper feed tray TR1.
Further, in the medium transport unit 31 according to the first embodiment, the vertical guide members 46 and 47 and the horizontal guide member 48 are used for signal transmission and power supply wiring extending to the substrates 21 to 26, so-called harnesses, avoiding the replenishment port TR1d. Wiring guide members that are guided for routing, so-called harness guides 46 to 48 are configured.

(Description of fixing unit)
In FIG. 7, the fixing unit 51 as an example of the third unit of the first embodiment includes a fixing left wall 52 and a fixing right wall 53. Between the fixing left wall 52 and the fixing right wall 53, the fixing device F and the discharge roll R1 are supported.
In FIG. 7, a fixing connecting member 56 extending in the front-rear direction is supported at the lower end of the fixing left wall 52 as an example of a fixing supported member. 5 and 7, at the rear end of the fixing connecting member 56, as an example of a fixing portion to be fixed, a positioned fixing portion 56a bent downward is formed corresponding to the positioning fixing portion 8a. Has been. In FIG. 5, the fixing fixing portion 56a is formed with a rear positioning hole 56b that can be penetrated in a state where the positioning fixing portions 8a and 9a are fitted.

5 and 7, the front end of the fixing connecting member 56 is formed in a bifurcated shape as an example of a positioning target portion for fixing, and is positioned in the vertical direction with the fixing positioning portion 8c interposed therebetween. A portion 56c is formed.
The right fixing connecting member 56 corresponding to the right fixing unit support portion 9 is also formed at the lower end of the fixing right wall 53 in the same manner as the left fixing connecting member 56.

(Description of exterior member)
10 and 11, the printer U according to the first embodiment includes, as an example of an exterior member, a top cover 61 that covers the top, a front cover 62 that covers the front surface, and a rear cover 63 that covers the rear surface.
In FIG. 11, the discharge tray TRh is formed on the front surface of the top cover 61, and vertical guide members 46 and 47 are provided at the front end as an example of a fixed portion for exterior that fixes the exterior member to the unit. A pair of left and right upper fixed pieces 61a formed corresponding to the above and extending downward are formed. Each upper fixed piece 61a is formed with a screw through hole 61b corresponding to the upper screw holes 46a, 47a of the upper end portions of the vertical guide members 46, 47.

In FIG. 11, at the rear end portion of the top cover 61, a pair of left and right cover fixed portions 61c is formed as an example of a fixed portion between the covers for fixing the exterior members, and the fixed portion 61c between the covers. A screw hole (not shown) is formed in.
In FIG. 11, a pair of left and right semicircular positioning recesses 61 d are formed at the front end of the top cover 61 as an example of a positioning part between exteriors. On the inner side in the left-right direction of the positioning recess 61d, three fixing ports 61e that are formed in a quadrangular hole shape and spaced apart in the left-right direction are formed as an example of the fixing part between the exteriors.

The front cover 62 has an opening 62a corresponding to the replenishing port TR1d. A pair of left and right screw passage holes 62b are formed at positions corresponding to the lower fixing screw holes 33a and 34a of the medium transport unit 31 as an example of a fixed portion for exterior use at the lower portions on both the left and right sides of the opening 62a. In FIG. 11, a pair of left and right positioning projections 62 c configured by cylindrical projections project forward from the upper end portion of the front cover 62 at a position corresponding to the positioning recess 61 d as an example of a positioned portion between the exteriors. Is formed. Further, on the inner side in the left-right direction of the positioning protrusion 62c, as an example of a fixed portion between the exteriors, a fixing claw 62d formed in a claw shape is formed at a position corresponding to the fixing port 61e.
The replenishing port cover U2 is rotatably supported by the front cover 62.

  The rear cover 63 is formed with an opening / closing door opening 63a at the center. On the left and right sides of the opening 63a, four rear screw passage holes 63b are formed at positions corresponding to the four rear screw holes 38d as an example of the exterior fixed portion. Further, as an example of the exterior fixing part, an inter-cover fixing part 63c is formed at the upper end of the rear cover 63 so as to face the rear surface of the inter-cover fixed part 61c. A screw through hole 63d is formed corresponding to the screw hole of the fixed portion 61c.

  An opening / closing door 64 as an example of an opening / closing member is supported in the opening 63 a of the rear cover 63. The open / close door 64 has a lower end portion rotatably supported by the exterior fixing portions 33 and 34 of the medium transport unit 31, and a guide member 66 on the rear side of the secondary transfer roll T <b> 2 b and the medium transport path SH on the inner surface. Is supported.

(Description of fixing each unit and member)
(Fixing of image recording unit and medium transport unit)
When the image recording unit 1 is supported by the medium conveyance unit 31, as shown in FIGS. 3, 6, 7, 8, and 11, the positioning grooves 6a and 7a are fitted into the positioning shafts 38a and 39a. In addition to being positioned, the image recording unit 1 is supported rotatably about the positioning shafts 38a and 39a. Then, the front side of the image recording unit 1 is positioned by rotating until the front positioning piece 13 of the image recording unit 1 contacts the front positioning surface 48b. In this state, the left rear end of the image recording unit 1 is fixed from the left by screws that pass through the left screw passage holes 6b and 6c and fit into the screw holes 38b and 38c. Similarly, the right rear end of the image recording unit 1 is fixed from the right by a screw that passes through the right screw passage holes 7b and 7c and fits into the screw holes 39b and 39c, and passes through the front screw through hole 48a. The front end of the image recording unit 1 is fixed from the front by a screw fitted in the front screw hole 14. That is, in the first embodiment, the left and right fixing parts 6 and 7 and the front fixing part 13 + 14 as the third support part have a fastening structure that is fastened to the image recording unit 1 from the horizontal direction. As a result, the image recording unit 1 according to the first exemplary embodiment is fixed to the medium transport unit 31 in a state where the recording unit fixing units 38 and 39 and the lateral guide member 48 are positioned at three positions.

Therefore, the image recording unit 1 is supported to the medium transport unit 31 so as not to be detachable for a user who uses the medium (recording sheet S). “Users who use media” means “persons who print data at offices, stores, airport / hotel lounges, homes, etc. It does not include service personnel to repair, or workers to inspect and repair at warehouses and factories. " Therefore, a non-user such as a serviceman or a worker can attach and detach the image recording unit from the medium transport unit using a tool or the like.
The recording unit fixing portions 38 and 39 and the lateral guide member 48 constitute the recording unit supported portion 39 + 39 + 48 of the first embodiment.

(Fixing of image recording unit and fixing unit)
When the fixing unit 51 is supported by the image recording unit 1, in FIG. 5 and FIG. 7, the bifurcated positioned portion 56 c of the fixing unit 51 is inclined surface 8 d of the image recording unit 1 as shown in FIG. 5A. 9d and the positioning lower surfaces 8e and 9e, the positioned portion 56c is fitted into the fixing positioning portions 8c and 9c. Accordingly, the fixing unit 51 is supported by the image recording unit 1 so as to be movable in the front-rear direction by fitting the positioned portion 56b and the fixing positioning portions 8c and 9c. When the fixing unit 51 is moved until the positioning fixing portions 8a and 9a are fitted in the rear positioning holes 56b of the positioning fixed portion 56a of the fixing unit 51, the fixing unit 51 is positioned. The fixing unit 51 is fixed to the image recording unit 1 by being fixed with screws that fit into the screw holes 8 b and 9 c of the fixing unit support portions 8 and 9.

(Fixing the exterior cover)
10 and 11, the top cover 61 is fixed by screws whose front end portions pass through the screw through holes 61b of the upper fixing pieces 61a and fit into the upper screw holes 46a and 47a of the vertical guide members 46 and 47, respectively. Has been. The rear end of the top cover 61 is fixed to the rear cover 63 by a screw that passes through the screw through-hole 63d of the inter-cover fixing portion 63c of the rear cover 63 and fits into a screw hole (not shown) of the inter-cover fixing portion 61c.
The front cover 62 is positioned with the upper edge thereof being inserted inside the front edge of the top cover 61 and the positioning projection 62c is fitted into the positioning recess 61d, and the fixing claw 62d is inserted into the fixing opening 61e of the top cover 61. Get caught. Accordingly, the front end of the top cover 61 is fixed to the front cover 62. The lower portion of the front cover 62 passes through the screw passage hole 62b and is fixed to the medium transport unit 31 by screws that fit into the lower fixing screw holes 33a and 34a of the medium transport unit 31.

The rear cover 63 passes through the rear screw passage hole 63b and is fixed by a screw that fits into the rear screw hole 38d of the medium transport unit 31.
Accordingly, the top cover 61, the front cover 62, and the rear cover 63 are not fixed to the image recording unit 1 or the fixing unit 51 but are fixed to the medium transport unit 31. Note that the side covers of the first embodiment (not shown) on both the left and right sides are supported by the covers 61 to 63 or the bottom wall 32.

(Operation of Example 1)
In the printer U according to the first embodiment having the above-described configuration, the image recording unit 1 is fixed to the medium transport unit 31 while being directly positioned, and the fixing unit 51 is positioned with respect to the image recording unit 1. It is fixed. That is, it can be considered that the medium transport unit 31 and the fixing unit 51 are fixed while being positioned with respect to the image recording unit 1. Therefore, the printer U according to the first embodiment has a configuration without a frame, that is, a so-called frameless configuration, unlike a conventional frame having a so-called frame. Therefore, compared with the conventional printer that is not positioned directly between the units and positioned via the frame, accumulated errors such as manufacturing errors and mounting errors of each member that are generated via the frame are reduced. . Therefore, the positional deviation between the images of the respective colors at the time of image formation, the positional deviation between the image and the recording sheet S, and the like are reduced, and the image quality is improved. Further, the frame is omitted, and the size, weight, and cost are reduced compared to the conventional configuration having the frame.

Further, in the printer U of the embodiment, the image recording unit 1 is fixed to the medium transport unit 31 at three locations, that is, the center in the left-right direction at the front end, the left rear end, and the right rear end. In the first embodiment, more precisely, the left and right screw passage holes 6b, 6c, 7b, and 7c are fixed at four locations, but the positions of the screw passage holes 6b and 6c and the screw passage holes 7b and 7c are close to each other. Therefore, it can be seen as two places in a pseudo manner when viewed from the entire image recording unit 1.
Accordingly, when the image recording unit 1 is fixed at four locations, if the medium transport unit 31 is distorted, the fixed image recording unit 1 is distorted, and the positions of the Y, M, C, and K images are shifted. The image transferred to the recording sheet S in the secondary transfer area Q5 may be displaced, but in the first embodiment, the image recording unit is fixed at three positions and the medium transport unit 31 is distorted. 1 is less susceptible to distortion. Therefore, compared to the case of fixing at four or more locations, the adverse effects of distortion such as the occurrence of image shift are less likely to occur.

  In particular, the image recording unit 1 of Example 1 has an intermediate transfer belt B that is an endless belt-like member. If the image recording unit 1 is distorted, the intermediate transfer belt B may be offset or meandered. However, the image recording unit 1 according to the first embodiment is less susceptible to the distortion of the medium transport unit 31 than the conventional configuration, and the deviation of the intermediate transfer belt B is reduced.

FIG. 12 is an explanatory diagram of the influence of the distortion of the image recording unit. FIG. 12A is an explanatory diagram in the case of Example 1 in which the image recording area is arranged on the two-point support side on the carry-out side, and FIG. It is explanatory drawing in the conventional case where the image recording area | region is arrange | positioned in the position away from the point support side and the carrying-out port.
Further, in the first embodiment, the image recording unit 1 is located on the left and right sides of the medium transport unit 31 on the rear side, which is the side of the exit Rr1 from which the recording sheet S is transported from the medium transport unit 31 to the image recording unit 1. It is fixed at two places. That is, in the first embodiment, the image recording unit 1 supported by the medium conveyance unit 31 at three points is supported at the rear side at two points.
In FIG. 12A, in the printer U of Example 1 in which the transfer area Q5, which is an image recording area, is disposed on the side of the carry-out port Rr1, when the medium transport unit 31 is distorted due to unevenness of the surface on which the printer U is installed As shown in FIG. 12A, the transfer region Q5 side is distorted in conjunction with the distortion of the carry-out port Rr1, and the distortion between the recording sheet S conveyed from the carry-out port Rr1 and the image transferred in the transfer region Q5 is relatively Less.

  On the other hand, in the conventional configuration in which the image recording area 03 is provided at a position away from the two-point support portion 01 and the one-point support portion 02 in FIG. 12B, the lower unit is distorted as shown by the broken line in FIG. In the case of the influence, the distortion occurs in conjunction with the support portions 01 and 02, but the distortion does not match in the image recording area 03, and a deviation occurs. Therefore, the distortion is different along the conveyance path 04 indicated by the alternate long and short dash line, and the recording sheet S is easily inclined until the conveyed recording sheet S is conveyed to the image recording area 03. That is, there is a risk that a deviation between the inclined recording sheet S and the image tends to occur. Even if a configuration in which the skew of the recording sheet S is corrected by a registration roll or the like on the upstream side of the image recording area 03 is used, the skew cannot be completely corrected or a distortion shift from the registration roll to the image recording area 03. There is a possibility that skew occurs after the skew correction and transfer, and the image and the recording sheet S are misaligned. On the other hand, in the first embodiment, as compared with the conventional configuration, the deviation between the distortion of the carry-out port Rr1 and the distortion of the transfer region Q5 is relatively small, the positional deviation of the image is small, and the image quality is improved. Yes.

  In the image recording unit 1 of the first embodiment, not only the photoreceptors Py to Pk and the intermediate transfer belt B but also the LED heads LHy to LHk are supported on the left and right end walls 3 and 4. Similar behavior to strain. Therefore, relative positional deviation is reduced compared to a configuration in which the latent image forming apparatus is provided outside the image recording unit, and deterioration in image quality is reduced.

  Further, in the first embodiment, the image recording unit 1 is screwed from the horizontal direction instead of the vertical direction, and is fastened from the direction in which the image recording unit 1 is not easily twisted. That is, as shown in FIG. 12A, when the left fixing portion 6 and the right fixing portion 7 are distorted in the vertical direction along with the distortion of the medium transport unit 31 due to the unevenness of the installation surface of the printer U, the front screw It is possible to cause a distortion amount similar to the distortion amount rotating around the hole 14 to be distorted on the left fixing portion 6 or the right fixing portion 7 side of the image recording unit 1 also on the front fixing portion 13 + 14 side. In particular, the direction of the center of rotation when the image recording unit 1 is tilted and the direction of the tip of a fastening member such as a screw are aligned in the same direction and can rotate about the screw. If the front end of the fastening member such as a screw is downward, the front fixing portion 13 + 14 side of the image recording unit obstructs the inclination of the image recording unit 1, but in the first embodiment, it is fixed from the horizontal direction. And is not easily disturbed. Therefore, in the image recording unit 1 according to the first embodiment, the twist hardly occurs, and the deviation between the medium S and the image recorded on the medium S can be reduced.

  In the printer U of the first embodiment, the fixing unit 51 is supported above the transfer region Q5, and the fixing region Q6 is also positioned and fixed on the side of the carry-out port Rr1. Therefore, when the medium transport unit 31 is distorted, the fixing unit 51 is also easily distorted, and the relative displacement between the fixing region Q6 and the recording sheet S is suppressed, and fixing failure or inclined recording is performed. Occurrence of a paper jam or the like of the sheet S is reduced compared to the conventional configuration.

Further, in the printer U according to the first embodiment, the top cover 61, the front cover 62, the rear cover 63, the opening / closing door 64, and the like, which are exterior covers, are not fixed to the image recording unit 1 and the fixing unit 51, and are not attached to the medium transport unit 31. Fixedly supported. In the structure using the conventional frame, the exterior cover is attached to the frame, and even if external force is applied, the external force does not directly act on the image recording unit. However, in the structure using no frame as in the present invention, the exterior cover If the covers 61 to 64 are attached to the image recording unit 1, the external force may act directly and the image recording member may be displaced. Therefore, in the first embodiment, the exterior covers 62 to 64 are attached to the medium transport unit 31, and the top cover 61 includes the inter-cover fixing portion 63c and the inter-cover fixed portion 61c, the positioning protrusion 62c and the positioning concave portion 61d, and the fixing. It is fixed to the other exterior covers 62 and 63 by the opening 61e and the fixing claw 62d.
Therefore, in the first embodiment, the exterior covers 61 to 64 are fixed to the image recording unit 1 without being fixed to the plurality of exterior covers 61 to 64, and the rigidity of the entire exterior cover is ensured. Therefore, even if the structure has no frame, that is, the so-called frameless, it is possible to prevent the impact and distortion on the exterior member from being transmitted to the image recording unit 1. Therefore, compared with the case where the exterior covers 61 to 64 are attached to the image recording unit 1, in Example 1, the external force received by the exterior covers 61 to 64 is reduced from adversely affecting the image recording unit 1. Occurrence of distortion of the image recording unit 1 and deviation of the intermediate transfer belt B is reduced.

FIG. 13 is an explanatory diagram for explaining the relationship between the fixing direction of the image recording unit of Example 1 and the allowable distortion.
In the printer U according to the first embodiment, the image recording unit 1 is supported so as to be rotatable with respect to the rotation direction indicated by the arrow Ya in FIG. Yes. Therefore, it is easier to position the image recording unit on the third support portion than in the case where rotation is impossible.
The image recording unit 1 is fixed from the left or the right on the rear end side, and is fixed from the front on the front end side. Therefore, compared to a configuration in which screws are fastened from above or below, it is easier to insert a tool such as a screwdriver when fastening screws, and the assembly workability is improved. Further, there is no need to form a passage or a mouth for inserting a driver or the like, and a space for securing the passage or the like is unnecessary, which contributes to downsizing. Further, as compared with the case where the screws are fixed from above, it is possible to prevent the positional deviation due to the deformation of the horizontal guide member 48 supported by the vertical guide members 46 and 47 from the front side.

  The image recording unit 1 is fixed from the left or right side at the rear end side, which is the two-point support side, and is different from the left side or right side at the front end side, which is the one-point support side. It is fixed at the center in the left-right direction from a certain front. Therefore, on the one-point support side, distortion in the rotation direction indicated by the arrow Yb in FIG. 13 is allowed on both the left and right sides of the front side of the image recording unit 1 as compared to the configuration fixed from the left and right rather than from the front. Has been. Therefore, the deviation and meandering of the intermediate transfer belt can be reduced. That is, when the front end of the image recording unit 1 is fixed from the left or right side, the left or right side of the image recording unit 1 is constrained, and the distortion indicated by the arrow Yb is not allowed on the right or left side. Then, the image recording unit 1 is distorted following the distortion of the medium transport unit, and the offset and meandering of the intermediate transfer belt B cannot be reduced.

  In the image recording unit 1 of the first embodiment, the intermediate gear 43 is supported on the positioning shaft 38a fixed by the screw holes 38b and 38c on the upper and lower sides with screws, and the rotation center of the image recording unit 1 is It is common. In general, when gears mesh with each other and rotate, a reaction force (drive reaction force) at the time of meshing causes a force in a direction in which the gears are separated. If the intermediate gear 43 is disposed at a position different from the positioning shaft 38a, when a reaction force is applied, the image recording unit 1 receives a force in a direction away from the medium transport unit 31, that is, a lifting direction, and image recording is performed. There is a possibility that the unit 1 is distorted or the position of the transfer region Q5 is displaced. On the other hand, in the first embodiment, the intermediate gear 43 is supported by the positioning shafts 38a and 39a and is fixed by the screw holes 38b and 38c in the vicinity even if a reaction force at the time of meshing acts. It is less susceptible to adverse effects such as.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is performed within the range of the summary of this invention described in the claim. It is possible. Modification examples (H01) to (H09) of the present invention are exemplified below.
(H01) In the above-described embodiment, the printer as an example of the image forming apparatus is illustrated. However, the present invention is not limited to this. For example, the printer is configured by a copier, a FAX, or a multifunction machine having a plurality or all of these functions. It is also possible. Further, the image forming apparatus is not limited to the electrophotographic image forming apparatus, and can be applied to other image recording systems such as an ink jet recording system and a thermal transfer system image forming apparatus.
(H02) In the above embodiment, the printer U has exemplified the configuration in which four color developers are used. However, the present invention is not limited to this. For example, a single color image forming apparatus, 5 colors or more, or 3 colors or less. The present invention can also be applied to a multicolor image forming apparatus.

(H03) In the above-described embodiment, the image recording unit 1 is preferably configured to be rotatable around the positioning shafts 38a and 39a. However, the present invention is not limited to this configuration. It is also possible to adopt a configuration that is supported from below. Further, the positioning shafts 38a and 39a are not limited to the exemplified configuration, and can be shared with the rotation shaft of the registration roll Rr, for example. In this case, the positioning accuracy of the image recording unit 1 with respect to the registration roll Rr is further improved, and the deviation between the conveyed recording sheet S and the secondary transfer region Q5 is further reduced. However, a registration roll gear 41, a registration sensor (not shown), and the like are arranged in the vicinity of the rotation axis of the registration roll Rr. There is a possibility that the printer U will be enlarged. Therefore, if it can be shared with the positioning shafts 38a and 39a due to the allowable size of the printer U and the components such as the gear 41, it is desirable to make it common.

(H04) In the above-described embodiment, it is desirable to support the fixing unit 51 above the image recording unit 1. However, the present invention is not limited to this configuration, and the fixing unit 51 is included in the image recording unit 1 or the fixing unit 51 is used as a medium. It is also possible to adopt a configuration that supports the transport unit 31.
(H05) In the above embodiment, the exterior covers 61 to 64 are preferably not fixed to the image recording unit 1 or the fixing unit. However, the present invention is not limited to this configuration, and can be fixed to the image recording unit 1 or the like. .

(H06) In the embodiment, the front fixing direction of the image recording unit 1 is preferably fixed from the front or in the vertical direction perpendicular to the left-right direction, for example, from above with the front positioning piece 13. However, it is possible to fix from the left or the right.
(H07) In the above-described embodiment, the configuration in which the registration roll Rr is provided in the medium transport unit 31 is illustrated. However, the configuration is not limited to this configuration. For example, the registration roll Rr can be incorporated in the image recording unit 1. In this case, the exit of the recording sheet S from the transport member on the upstream side of the registration roll Rr becomes the exit from the medium transport unit 31 to the image recording unit 1. Similarly, the secondary transfer roll T2b can be incorporated in the image recording unit 1.

(H08) In the above-described embodiment, it is desirable that the intermediate gear 44 be rotatably supported by the positioning shaft 38a. However, the configuration is not limited to this configuration, and a configuration in which the intermediate gear 44 is supported at a place other than the positioning shaft 38a is also possible.
(H09) In the above embodiment, each unit 1, 31, 51 is fixed as a fastening method and a fastening mechanism is exemplified by screwing, but is not limited to this configuration, for example, a fixing method such as so-called snap fitting or riveting, It is also possible to employ a fastening mechanism.

1 ... Image recording unit,
6 ... 1st support part,
6 + 7 + 13 + 14 ... recording unit support,
6a, 7a ... positioning members,
7 ... second support part,
8, 9 ... fixing unit support,
13 + 14 ... third support,
31 ... Medium transport unit,
44 ... 1st rotation transmission member,
45. Second rotation transmission member,
46: Intermediate transmission member,
51. Fixing unit,
61, 62, 63, 64 ... exterior members,
B ... Intermediate transfer member,
F: Fixing device,
Py, Pm, Pc, Pk ... image carrier,
Q5 ... Image recording area,
Rr: timing adjusting member, medium conveying member,
Rr1 ... unloading port,
S ... medium,
T1y, T1m, T1c, T1k ... primary transfer unit,
T2 ... secondary transfer device,
U: Image forming apparatus,
UY to UK + B: Image recording apparatus.

Claims (2)

A medium conveying unit having a medium conveying member for conveying a medium on which an image is recorded, and a carry-out port from which the medium is carried out;
An image recording unit having an image recording apparatus for recording an image on a medium transported from the medium transport unit in an image recording area disposed on the transport outlet side;
A first support portion and a second support portion which are arranged on the carry-out port side in the image recording unit and arranged at positions separated in the width direction of the medium to be conveyed; and the carry-out port in the image recording unit; And a third support portion disposed on the opposite side, and at least the first support portion and the second support portion are supported on the carry-out side of the medium transport unit, and the medium A recording unit support for the image recording unit to be detachably supported with respect to the medium transport unit for a user using
A drive source supported by the image recording unit and driving the image recording apparatus;
A member for transmitting the drive of the drive source to the medium transport member;
A low-voltage power supply board for supplying power to the drive source, and a high-voltage power supply board for supplying power to the image recording apparatus, and a power supply circuit supported by the image recording unit;
A wiring guide member that is provided in the medium transport unit and guides wiring electrically connected to the power supply circuit;
An image forming apparatus comprising: An image holding body that rotates while holding an image on the surface, and an endless belt-like body. The image on the surface of the image holding body is transferred, and the image transferred from the image holding body in the image forming area is transferred to the medium. The image recording unit comprising: an intermediate transfer member to be transferred; and a primary transfer unit that transfers an image on the surface of the image carrier to the intermediate transfer member;
A fixing unit having a fixing device for fixing the image transferred to the medium;
A fixing unit support provided on the image recording area side of the image recording unit and supporting the fixing unit;
The image forming apparatus according to claim 1, further comprising:

Images