JPH04338770A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce the number of parts, and further, to attain easy assembling and reduction in producing cost by eliminating the need of providing a member for pressing a contact glass, separately. CONSTITUTION:Two upper and lower carrying pathes 90d and 90e are composed of the upper cover 100 and the lower cover 110 which are freely attached/ detached. The contact glass 11a is depressed by the upper cover 100 to be stopped/set to an upper part casing 44.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electrostatic copying machine or a facsimile machine.

0002

2. Description of the Related Art Conventionally, a document conveyed along the upper surface of a casing of an apparatus main body is illuminated through a transparent contact glass that contacts the document, and light reflected from the document is guided to a photoreceptor. There are image forming apparatuses such as electrostatic copying machines and facsimile machines that form an electrostatic latent image on a photoreceptor drum, visualize this electrostatic latent image as a toner image, and then transfer it to paper.

0003

SUMMARY OF THE INVENTION In order to popularize the above-mentioned image forming apparatus for home and personal use, it is preferable to reduce the size and weight as much as possible, and to reduce the manufacturing cost and selling price. However, simply downsizing the parts of a conventional image forming apparatus as they are does not reduce the number of parts, so the manufacturing cost cannot be reduced very much. Furthermore, if the overall size is made smaller, each part must be attached in a narrow space, which impairs the ease of assembly. Therefore, it takes time to assemble, which increases assembly costs and increases manufacturing costs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus that can reduce the number of parts to realize a smaller size of the apparatus and reduce manufacturing costs.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the image forming apparatus of the present invention allows a document to be conveyed along the upper surface of a casing of the main body of the device to pass through a transparent contact plate that contacts the document. In an image forming apparatus that illuminates the document and guides reflected light from the document to a photoreceptor, there is a two-stage upper and lower conveyance path consisting of a lower conveyance path along the top surface of the casing, and an upper conveyance path formed above the lower conveyance path. The document transport section includes a document transport section that transports the document while reversing the document through the path, and the document transport section includes a lower cover that forms the lower transport path between the upper surface of the casing and the upper surface of the lower cover. An upper cover forming an upper conveyance path is detachably attached to the casing, and the contact plate is fixed to the casing in a pressed state by either the upper cover or the lower cover. That is.

[0006]

[Operation] According to the image forming apparatus configured as described above, since the contact member is fixedly fixed by either the upper cover or the lower cover constituting the conveyance path, there is no need to separately fix the contact member. There is no need to provide any members. Further, by attaching and detaching both covers, the contact member can be easily attached and detached.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples will be explained in detail below with reference to the accompanying drawings showing examples. FIG. 1 is a perspective view of a copying machine as an image forming apparatus showing an embodiment of the present invention. Referring to the figure, in this copying machine, the casing of the apparatus main body 2 is composed of an upper casing 24 and a lower casing 25, and a document conveying section 9 is attached to the upper surface 24p of the upper casing 24. This document conveyance section 9 conveys the document inserted into the document insertion slot 90a from the front of the apparatus main body 2 through an upper conveyance path 90d formed between an upper cover 100 and a lower cover 110. After flipping at the rear, the top surface 24
The document is conveyed through the lower conveyance path 90e along the direction p, and is discharged toward the front of the apparatus main body 2 from the document discharge port 90b. on the other hand,
A paper feed port 26 for the paper p is formed at the lower part of the front surface of the apparatus main body 2. The paper fed from the paper feed port 26 is discharged to the rear of the apparatus main body 2.

Further, the above-mentioned upper cover 100 and lower cover 110 are integrally attached to the upper casing 245 by a pair of connecting members 105. A contact glass 11a serving as a transparent contact plate is disposed on the upper surface 24p of the upper casing 24 and contacts the document d conveyed along the upper surface 24p. upper cover 10
It is pressed and fixed by the rib 100d of 0 (Fig. 1
(see 5).

Furthermore, an accessory case 140 consisting of a rectangular parallelepiped container with an open top is removably attached to the top surface 24p. Further, U-shaped carrying handles 120 are provided on both end surfaces 24u of the upper casing 24.
is rotatably attached within a predetermined range around the stopper 123 as a shaft member for connecting the upper and lower casings. In addition, from one end surface 24u of the upper casing 24 into the device main body 2,
A plug 132 at the tip of a power line 131 for power supply is inserted.

FIG. 3 is a schematic sectional view showing the internal structure of the copying machine. Referring to the figure, the copying machine has an apparatus main body 2.
An optical system 3 is formed in the photoreceptor drum 42 for illuminating and scanning the original transported by the transport roller pair 91 of the original transport unit 9 and for guiding reflected light from the original to the photoreceptor drum 42. After the electrostatic latent image is visualized by the developing device 41, an image forming section 4 that transfers it to paper, and a fixing section 6 that fixes the toner image transferred to the paper in the middle are arranged, and the paper is fed. It is equipped with functional parts such as a paper transport section 5 that introduces the paper into the inside of the apparatus main body 2 from the paper port 26 and then discharges it from the paper discharge port 21 through the image forming section 4. A drive system 7 for driving the document transport section 9, image forming section 4, and paper transport section 5 (see FIG. 13).
, and functional components such as an electrical component 8 (see FIG. 13) including a control circuit for controlling these drives.

The optical system 3 includes a fluorescent lamp 31 for illuminating the original, a lens 32 for guiding light reflected from the original to the photosensitive drum 42, and the like, which are arranged inside a case 33. . The image forming section 4 includes a photosensitive drum 4
A charger 43, a developing device 41, a transfer charger 44, and a cleaner 45 are arranged in this order around the photoreceptor drum 42, and an original image is formed on the outer peripheral surface of the photosensitive drum 42, which is uniformly charged by the charger 43. After forming an image to form an electrostatic latent image, the electrostatic latent image is transferred to a developing device 4.
This is a conventionally known configuration in which a toner image is visualized by a toner imager 1, a toner image is transferred to paper by a transfer charger 44, and residual toner is collected by a cleaner 45. A developing device 41, a photosensitive drum 42, a transfer charger 44, and a cleaner 4 are components of the image forming section 4.
5 are each assembled into an image forming frame 46 (see FIG. 4) to form a unit. Further, the electrification charger 43 is held by the case 33 of the optical system 3. The image forming frame 46 is made of a resin molded product, and a cleaner 4 is attached to the image forming frame 46.
A toner collection container 47 for storing the toner collected by 5 is integrally formed.

Referring to FIGS. 3 and 4, toner collection container 47 has a rectangular tray-like planar shape, and is provided above paper transport section 5 on the downstream side in the transport direction. The upper surface of this toner collection container 47 is covered with a lid 47f. A plurality of vertically extending ribs 47d are provided on the inner periphery of the side wall 47k of the toner collection container 47, and the lid 47f is attached by screwing a screw 47e into a screw hole of the rib 47d. Further, a flange portion 47a is formed continuously with the lid 47f of the toner collection container 47 and extends to the left in the figure.

The developing device 41 includes a toner cartridge 41c that is removably inserted into a developing housing 41a made of resin, and a toner supply device that supplies toner dropped from the toner cartridge 41c into the inside of the developing housing 41a. roller 41d and developer housing 41a
an agitation roller 41e that agitates the toner supplied inside the
and a developing roller 4 that supplies toner to the photoreceptor drum 42.
1f. A large number of rib-shaped upper guides 41b are provided on the lower surface of the developing housing 41a and project in parallel to each other, and these upper guides 41b guide the upper surface side of the sheet being conveyed. The upper guide 41b is molded integrally with the developer housing 41a, and therefore, compared to the case where the upper guide is formed separately, the number of parts and assembly steps can be reduced, and manufacturing costs can be reduced.

The paper transport unit 5 includes a transport roller pair 51 consisting of a pair of upper rollers 51a and a lower roller 51b, which sandwich the paper whose leading end has been inserted from the paper feed port 26 and introduce it into the apparatus main body 2; The fixing unit 6 includes a registration stopper 52 that abuts the leading edge of the paper conveyed by the pair 51 to temporarily hold the paper on standby, and the fixing unit 6.

The upper roller 5 of the conveying roller pair 51
1a is rotatably supported by an upper guide 41b protruding from a developing housing 41a of the developing device 41. That is, the upper guide 41b also serves as a support member for the upper roller 51a. Further, the fixing unit 6 fixes the toner image transferred to the paper while sandwiching the paper and conveying it, and uses a heat roller 6 heated by a built-in heater.
1, and a pressure roller 62 that is pressed against and driven by the heat roller 61. The pressure roller 62 is provided so as to be freely movable in the vertical and horizontal directions while being biased upward by a spring (not shown), and its support shaft 62a is introduced into the groove 63a of the stay 63 that supports the heat roller 61. By doing so, the relative position with respect to the heat roller 61 is determined. The heat roller 61 is surrounded by a stay 63.
It is substantially covered by a housing 64 fixed by a housing 64, thereby suppressing heat dissipation. At the lower end of the housing 64, a guide portion 64a that guides the paper to the heat roller 61 is provided together with a lower guide member 65.

Further, the registration stopper 52 is rotatably provided around a fulcrum 52a, and is normally biased to rotate clockwise in FIG. 3 by a coil spring (not shown) to stop the paper. It has advanced into the conveyance path, and in this advanced state, the leading end of the paper is abutted against it and the paper is put on standby. When the document has moved to a predetermined position, the registration stopper 52 is rotated counterclockwise via a rotation mechanism interlocking with a pair of conveyance rollers 91, etc., and the document is moved out of the paper conveyance path, thereby making it standby. The printed paper is supplied to the image forming section 4.

As described above, the casing of the apparatus main body 2 is composed of an upper casing 24 and a lower casing 25 that are separable from each other, and includes the optical system 3, image forming section 4, and paper conveyance as the above-mentioned functional components. part 5, drive system 7,
and electrical equipment 8 are held by upper casing 24 and lower casing 25, respectively. FIG. 2, FIG. 5, which is an exploded perspective view of the upper and lower casings and the handle 120;
To explain in more detail with reference to FIG. 13, the case 33 of the optical system 3 is screwed to the upper casing 24, so that the entire optical system 3 is held by the upper casing 24. Further, the image forming frame 46 of the image forming section 4 is fixed to the upper casing 24 with screws. That is, in FIG. 2, the left end of the imaging frame 46 is fixed by a screw 47g to the mounting member 48 fixed to the upper casing 24 by a screw 48a, and the mounting portion at the right end of the imaging frame 46 is fixed to the mounting member 48 fixed to the upper casing 24 by a screw 48a. 47
h is fixed to the upper casing 24 by screws 47i. As a result, the developing device 41 of the image forming section 4
, a photosensitive drum 42, a transfer charger 44, and a cleaner 45 are held in the upper casing 24. Further, the remaining charger 43 of the image forming section 4 is indirectly held by the upper casing 24 via the case 33 of the optical system 3. Furthermore, the upper roller 51a of the transport roller pair 51 of the paper transport section 5 is indirectly held by the upper casing 24 via the developing housing 41a, and the lower roller 51b and the resist stopper 5
2 is held by a lower guide 25a, which will be described later, which is integrally molded with the lower casing 25, and is held by a heat roller 6 of the fixing unit 6.
1 and the housing 64 are held by the upper casing 24 via the stay 63, and the pressure roller 62 and the guide member 65 are held by the lower casing 25.

Referring to FIGS. 1 and 5, this handle 12
0 is a handheld portion 121 made of resin or the like, and this handheld portion 12.
1 is attached to the central part in the longitudinal direction, and a U-shaped plate-shaped frame 122 made of metal or the like. The frame 122 is
When attached to the device main body 2, the main body portion 122a extends in the longitudinal direction of the device main body 2, and the end surface 2 of the upper casing 24 is bent at right angles from both ends of the main body portion 122a.
4u, and consists of an extension part 122b along the extension part 12
A hole 122 through which a stopper 123 is inserted is provided at the tip of 2b.
A ring portion 122c having a diameter d is provided. The stopper 123 includes a grip portion 123a that can be turned by hand, and a grip portion 123a that can be turned by hand.
A support portion 123b that is fitted into the hole 122 of No. 0 and rotatably supports the handle 120, and a mounting member 28 to be described later.
It is provided with a threaded portion 123c for attachment to. The above-mentioned stopper 123 can be easily attached to and detached from the outside by turning the attachment member 28 by hand, so the user can
The handle can be easily attached and detached without using tools such as a screwdriver. Therefore, users who do not need the handle 120 can conveniently remove it.

Furthermore, since the handle 120 supports both ends of the device main body 2 in the longitudinal direction, when the device is carried by the handle 120, the moment of inertia of the device main body 2 swinging about the stopper 123 is reduced. can be made small and easy to carry. Furthermore, when the device is lifted by gripping the handle 120, the handheld portion 121 and the stopper 123 are positioned on a vertical line passing through the center of gravity of the device main body 2 and above the center of gravity, so that the device can be held up. The device main body 2 can be lifted without rotating while the main body 2 is placed on a desk surface or the like. Further, since the hand-held portion 121 of the handle 120 is arranged at the center in the longitudinal direction of the handle 120, the device main body 2 can be stably held by the handle 120.

Further, a stopper 24 is integrally formed with a cylindrical seat 24v, which will be described later, of the upper casing 24, in the vicinity of the ring portion 122c of the extending portion 122b of the frame 122.
A protruding piece 124 that engages with 5 is provided. This protrusion 1
24 is engaged with the stopper 245, the handle 1
20 is positioned at a predetermined rotational position on the front side of the copying machine (see FIG. 11), and in this state, the handheld portion 121 and the main body portion 122a of the frame 122 are
It is set at just the right height to assist in transporting documents. Note that in order to position the handle 120 at the predetermined rotational position, the friction force between the ring portion 122c and the end surface 123d of the grip portion 123a, or the friction force between the ring portion 122c and the cylinder described later, without using the stopper 245 or the like. Receiver seat 2
A frictional force of 4V between the seat surface 247 and the seat surface 247 may be used (see FIG. 9). Also, with reference to FIG. 12, the handle 12
0 is tilted toward the front of the copying machine and held by the stopper 245, a mark 121a consisting of, for example, a line, indicating the setting position of the original according to the original size, is placed at a position where the user can see it, and the mark 121a corresponds to each mark 121a. A display section 121b indicating the original document size is attached.

Referring to FIGS. 2 and 5, lower casing 25 is made of a resin molded product and has a shallow container shape with an open top. A large number of rib-shaped lower guides 25a and 25k are integrally formed on the inner bottom portion 252 to guide the lower surface side of the sheet being conveyed. Lower guide 2
The end portion 5k forms an inclined portion 251 that is inclined downward in the direction opposite to the paper conveyance direction. This inclined part 2
Reference numeral 51 is for facilitating the introduction of paper placed on a desk or the like into the paper feed port 26. That is, referring to FIGS. 1 and 3, the paper feed port 26 is located at the bottom of the main body 2 of the apparatus, and the inclined portion 251 is provided. Even if the paper is not used, the paper can be introduced into the main body 2 of the apparatus while using the desk surface as a conveyance guide. Further, the lower guide 25k is provided with a recess 25m for attaching a transfer charger 44, which is one of the components of the image forming section 4 described above. Furthermore, the lower casing 25 includes, continuously from the peripheral side wall thereof,
A rib-shaped upright piece 25f extending to both ends of the transfer charger 44 is formed, and the lower casing 25 has a monocoque structure with the upright piece 25f and the lower guides 25a, 25k, etc., ensuring desired rigidity. . Furthermore, a pair of substantially L-shaped plate-shaped mounting members 28 are attached to both ends of the inner bottom portion 252 of the lower casing 25 in the longitudinal direction with screws 28d. This attachment member 28 is for attaching a stopper 123, which will be described later, as a shaft member for vertical positioning of the upper and lower casings. A protrusion 28a is formed on opposing surfaces of both mounting members 28, and a screw hole 28b is formed passing through this protrusion 28a in the longitudinal direction. Furthermore, one of the mounting members 28 is provided with a window 28c through which the plug 132 is inserted.

The upper casing 24 is an integrally molded resin product, and as shown in FIGS. 5 and 6, has cutouts 24a on both front and rear sides for forming a paper feed port 26 and a paper discharge port 21. is formed, and one end surface 24
An opening 24b is formed in u for inserting and removing the toner cartridge 41c. Upper casing 24
A cylindrical seat 24v is formed protruding from both end surfaces 24u around a through hole 246 through which the stopper 123 is inserted. Further, one end surface 24u is provided with a window 24w through which the plug 132 of the power supply line 131 is inserted. Further, a slit 24c for illuminating and scanning the original is formed on the upper surface 24p, and a contact glass 1 is formed by ridges 24m formed at both ends of this slit 24c.
1a is supported. Further, the upper surface 24p is provided with holes for attaching various parts of the document transport section 9 and an accessory case 140, which will be described in detail later. Further, inside the upper casing 24, a toner cartridge 41c is provided.
A pair of band-shaped guide portions 24d are formed to hang down to guide the introduction of the material. The guide portion 24d is integrally molded at the same time as the upper casing 24, and is formed along almost the entire length of the toner cartridge 41c (see FIG. 13). Further, since the cover 24g covering the opening 24b of the upper casing 24 can be removed and the toner cartridge 41c inserted or removed through the opening 24b, the replacement work can be easily performed without opening the inside of the apparatus main body 2. can be done. Moreover, since the guide portion 24d that guides the insertion and removal of the toner cartridge 41c is integrally molded on the upper casing 24, there is no need to separately form the guide, and the number of parts and assembly steps can be reduced accordingly. It will help reduce costs. The upper casing 24 has a monocoque structure including the guide 24d and the like, thereby ensuring desired rigidity.

Next, how the above-mentioned upper casing 24 and lower casing 25 are positioned will be explained. Positioning of both casings in the front-rear direction and the left-right direction is performed by boss portions 24n provided at the four corners of the upper casing 24 and extending downward, and recesses 25n provided in the lower casing 25 into which the boss portions 24n are fitted. It is being said. Furthermore, in the recessed portion 25n, there is a
2, a compression coil spring 27 is provided as an elastic member. This compression coil spring 27 is connected to the boss portion 24
n and the bottom surface of the recess 25n to bias the boss 24n in the detachment direction (upward) (see FIG. 8).
. Since the above-mentioned positioning is performed by fitting the boss portion 24n and the recessed portion 25n, positioning is very easy. Note that when the stopper 123 is removed, the compression coil spring 27 lifts the upper casing 24, so that the upper and lower casings can be easily separated.

The vertical positioning of both casings is performed by a stopper 123 serving as a shaft member. Referring to FIG. 9 showing the installation state of the upper and lower casings, the stopper 12
3 is fitted into the through hole 246 of the upper casing 24 and fixed to the mounting member 28 of the lower casing 15, thereby connecting the upper casing 24 and the lower casing 2.
5 can be restricted from relative movement in the vertical direction. In addition, with the stopper 123 fixed to the mounting member 28, the ring portions at both ends of the handle 120 are placed between the end surface 123d of the grip portion 123a on the threaded portion 123c side and the seat surface 247 of the cylindrical seat 24v. 122a is slidably held, and thereby the handle 120 is rotatably supported by the stopper 123. In this way, the stopper 123 as a member for vertical positioning of the upper and lower casings is also used as a fulcrum for rotation of the handle 120, so the number of parts can be reduced, thereby reducing manufacturing costs. can be reduced. Also, just by removing the stopper 123,
Since both casings can be easily separated, maintenance work on the device is much easier compared to loosening many screws and the like using a screwdriver. Furthermore, since the stopper 123 is fixed by screwing into the mounting member 28, reliable positioning can be achieved.

Note that the inner upper surface 248 of the upper casing 24
A hanging piece 23a hangs down from the hanging piece 2.
A stay 23b extending downward and having an L-shaped cross section is attached to the lower end of the stay 3a with a screw 23c. A plug connection portion 23d connected to a power transformer or the like is attached to the stay 23b. Plug 1 above
32 is a window portion 24w of the end surface 24u of the upper casing 24.
, and the window portion 28c of the mounting member 28, and is connected to the plug connection portion 23d. In this way, plug 13
2 is inserted through the window 24w of the upper casing 24 and also through the window 28c of the mounting member 28 on the lower casing 25 side, so when this plug 132 is connected to the plug connection part 23d, both casings cannot be separated. That is, the two casings can only be separated when the plug 132 is removed. Therefore, there is no need to provide a separate safety switch. In addition, since the plug 132 of the power line 131 is placed directly below the stopper 123 that is the center of rotation of the handle 120,
The power line 131 and the plug 132 do not interfere with the rotation of the handle 120.

Upper casing 24 and lower casing 25
It is preferable that the abutting portions are combined in an interlocking manner as shown in FIG. This is because it is possible to prevent light from entering the apparatus main body 2 from the abutting portion of the two, and to effectively prevent the photosensitive drum 42 from being deteriorated by the intruding light. Further, the paper feed port 26 and the paper discharge port 21 are formed at the boundary between the two casings by the notch 24a of the upper casing 24 and the notch 25g of the lower casing 25. As shown in FIG. 3, since it is located below the horizontal plane including the rotational axis r of the photoreceptor drum 42, external light, dust, etc. from the openings such as the paper feed port 26 and the paper discharge port 21, etc. However, it is difficult to reach the photoreceptor drum 42. Therefore, it is possible to prevent the photoreceptor drum 42 from suffering optical fatigue and the like, resulting in a decrease in durability, and from causing scratches on the surface of the photoreceptor drum 42 due to dust.

Furthermore, as shown in FIG. 2, the bosses 24n at the four corners of the upper casing 24 are located at the lowest part of the upper casing 24 with the functional parts attached, so that they are separated from the lower casing 25. The upper casing 24 can be supported by the boss portion 24n when placed on a flat surface such as the top surface of a desk. In this way, since the boss portion 24n can be used as a leg portion, the upper casing 24, which has been removed during jam removal or the like, can be placed on the top surface of a desk or the like as it is. Therefore, jam removal and the like can be easily performed, and functional components are not inadvertently damaged when the upper casing 24 is removed. Further, there is no need for a special stand or the like on which the removed upper casing 24 is placed.

FIG. 1, FIG. 2, and FIG. 14 which is an exploded perspective view.
Referring to FIG.
The lower cover 110 and the lower cover 1 that substantially cover the upper part of the
The upper cover 100 covers the rear upper part of the main body 10. The document insertion port 90a and the upper conveyance path 90d are formed between the upper cover 100 and the lower cover 110, and the document discharge port 90b and the lower conveyance path are formed between the upper surface 24p of the upper casing 24 and the lower cover 110. 90e is formed. The upper cover 100 and the lower cover 110 serve as document guides that guide the document in a predetermined direction.

Each transport roller pair 99 includes a lower roller 99b driven by the drive system 7, and an upper roller 99a rotated by the lower roller 99b. Each upper roller 99
a are arranged at predetermined intervals along the axial direction of the shaft 99c, and are rotatably supported by the lower cover 110 by the shaft 99c. The lower rollers 99b are arranged at predetermined intervals along the axial direction of the shaft 99d, and are rotatably supported by the upper casing 24 by the shaft 99d. These upper rollers 99a and lower rollers 99b are connected to the upper casing 2.
They are located above and below with the No. 4 slit 24s in between, and their circumferential surfaces are in contact with each other. The slits 24s are arranged in a row on the rear upper surface 24p of the upper casing 24 along the longitudinal direction of the upper casing 24 at predetermined intervals.

Each transport roller pair 91 includes a lower roller 91b driven by the drive system 7, and an upper roller 91a rotated by the lower roller 91b. The upper rollers 91a are arranged at predetermined intervals along the axial direction of the shaft 94, and are rotatably supported by the lower cover 110 by the shaft 94. The lower rollers 91b are arranged at predetermined intervals along the axial direction of the shaft 96, and are rotatably supported by the upper casing 24 by the shaft 96. These upper roller 91a and lower roller 91b are located above and below with the slit 24t of the upper casing 24 in between, and have their circumferential surfaces in contact with each other. The slits 24t are arranged in a line on the front upper surface 24p of the upper casing 24 along the longitudinal direction of the upper casing 24 at predetermined intervals.

The forward feed roller 92 is a long white roller that slides into contact with the contact glass 11a on the rear side of the apparatus main body 2 (upstream side in the document conveyance direction) than the conveyance roller pair 91, and is rotated downward by a shaft 97. It is rotatably supported by the cover 110. The forward feed roller 92 presses the document d downward so that the document d is conveyed reliably along the contact glass 11a. A transmission roller 98 that rotates integrally with the shaft 97 is attached to both ends of the shaft 97 . Further, a transmission roller 95 that rotates integrally with the shaft 94 is attached to both ends of the shaft 94 of the upper roller 91a of the transport roller pair 91, and between this transmission roller 95 and the transmission roller 98, , an endless belt 93 is wrapped around it. As a result, the forward feed roller 92 rotates following the roller 91a of the conveying roller pair 91 via the respective transmission rollers 95 and 98 and the belt 93.

The upper cover 100 and the lower cover 110 are detachably attached to the upper surface 24u of the upper casing 24 by a pair of connecting members 105 made of resin. The upper cover 100 is long in the direction orthogonal to the conveyance direction, and includes an upper surface portion 100a substantially parallel to the upper surface 24p of the upper casing 24, a rear surface portion 100j provided continuously to the upper surface portion 100a, and a pair of approximately trapezoidal shapes. side part 10 of
It is equipped with 0c. A slit 24 of the upper surface 24p of the upper casing 24 is provided at the lower end of the front side of each side surface portion 100c.
On both sides of c and the rotational axis r of the photoreceptor drum 42
A pair of recesses 241 and 242 provided on a vertical surface including
A protrusion 100g inserted into each is provided (see FIG. 15). A notch 1 is provided at the lower end of the rear surface portion 100j to form an opening 90c between the upper surface 24p of the upper casing 24 and the upper surface 24p of the upper casing 24 for inserting a document from the rear side of the apparatus main body 2.
00h is provided (see FIG. 16). Further, the inner circumferential surface of the rear surface portion 100j is connected to the upper roller 99 of the conveying roller pair 99.
A curved guide surface 100k substantially along the circumferential surface of a is formed (see FIG. 2). This guide surface 100k serves as a guide surface for a document d inserted from the front of the apparatus main body 2 through the document insertion opening 90a.
The leading end of the document d is guided to the contact area between the upper roller 99a and the lower roller 99b so that the leading end of the document d can be satisfactorily held by the transport roller pair 99.

At both ends of the upper surface portion 100a in the longitudinal direction,
A pair of through holes 100b through which the connecting member 105 is inserted.
However, a boss portion 100e protrudes below the upper surface portion 100a.
(See FIG. 19). Further, below the upper surface portion 100a, a pair of ribs 100d parallel to each side surface portion 100c are provided at a constant distance from each side surface portion 100c. As shown in FIG. 15, the height of these ribs 100d is such that when the upper cover 100 is attached to the upper surface 24p of the upper casing 24, the ribs 100d press down both longitudinal ends of the contact glass 11a from above. It is set up so that you can

The lower cover 110 includes an upper surface portion 110m approximately parallel to the upper surface 24p of the upper casing 24, and a pair of approximately trapezoidal side portions 100a. Upper surface part 110
A protrusion 110j as a mark for positioning the document is provided on the upper surface of the document m, along the conveyance direction and at a position corresponding to various document sizes, and this protrusion 110j
Display 110 indicating which document size corresponds to
K is attached. As described above, since the positioning protrusion 110j is provided on the upper surface portion 110m of the lower cover 110, the document can be easily positioned. Further, since positioning is performed using both the protrusion 110j of the lower cover 110 and the mark 121a provided on the hand-held portion 121 of the handle 120 described above, the document can be positioned very accurately.

[0035] A notch 110b and a notch 110c that are open downward are provided in the front part of the side surface portion 110a.
A rearwardly open notch 110d is provided at the rear end. A portion of the shaft 94 between the upper roller 91a and the transmission roller 95 is loosely fitted into the notch 110b. Notch 110c
In this case, a portion of the shaft 97 between the forward feed roller 92 and the transmission roller 98 is loosely fitted. The shaft 99c of the upper roller 99a of the transport roller pair 99 is loosely fitted into the notch 110g. In addition,
At least one pair of plate-shaped hanging pieces 110g for shaft support as shown in FIG. 17 are provided on the upper surface portion 110m of the lower cover 110. This hanging piece 110g includes a pair of elastically deformable protrusions 110n, a cut groove portion 110h formed between the protrusion pieces 110n and opened downward, and a cut groove portion 110h that is open downward.
A shaft support portion 110i is formed continuously at the inner part of the shaft 10h and is a concave portion capable of supporting the shaft 94. axis 94
is introduced into the shaft support portion 110i through the cut groove portion 110h with the width of the cut groove portion 110h once expanded by elastically deforming both protruding pieces 110n (indicated by the two-dot chain line in FIG. 17). After that, both protruding pieces 110h are returned to their original state (Fig. 17
(shown by a solid line), the shaft support portion 1 of the shaft 94
Prevents falling off from 10h. Although not shown, the shaft 97 of the forward feed roller 92 and the conveyance roller pair 99
The shaft 99c of the upper roller 99a is also supported by the lower cover 110 with a similar structure.

Further, a stay portion 110e that abuts the upper surface 24p of the upper casing 24 projects outward from the lower portion of the rear side of each side surface portion 110a. This stay part 1
10e is provided with a groove portion 110f that is open toward the outside. Next, positioning of the upper cover 100 and the lower cover 110 with respect to the upper casing 24 will be described with reference to FIGS. 14 and 18 to 22. First, Figure 19
With reference to , upper cover 100 is positioned with respect to upper casing 24 in the front-rear direction and left-right direction by fitting boss portion 100e of upper cover 100 into through hole 24r of upper casing 24. Also,
The vertical positioning of the upper cover 100 with respect to the upper casing 24 is performed by abutting the lower end surface of the boss portion 100e against the stepped portion 24q within the through hole 24r.

The positioning of the lower cover 110 with respect to the upper casing 24 in the longitudinal and lateral directions is performed by defining the relative positional relationship with the upper cover 100 positioned with respect to the upper casing 24 as described above. It is being said. That is, as shown in FIG. 18, by fitting the groove portion 110f of the stay portion 110e of the lower cover 110 with the outer peripheral surface of the boss portion 100e, the upper cover 10
0 and the lower cover 110 are positioned relative to each other in the front-rear direction E and the left-right direction F. On the other hand, with reference to FIGS. 18 and 19, a pair of presser ribs 100f extending halfway in the vertical direction are provided on the outer peripheral portion of the boss portion 100e, and the presser ribs 100f and the upper surface 24p of the upper casing 24 The stay portion 110e of the lower cover 110 is sandwiched between the lower cover 110 and the upper casing 24, thereby positioning the lower cover 110 in the vertical direction with respect to the upper casing 24. In this way, the upper cover 100 is positioned with respect to the upper casing 24 by fitting the boss portion 100e of the upper cover 100 into the through hole 24r of the upper casing 24, and the lower cover 110 is positioned with respect to the upper casing 24. This is done by positioning the cover 110 with respect to the boss portion 100e. That is, the upper casing 24 of the upper cover 100 and the lower cover 110
Since positioning is performed based on the fit between the boss portion 100e and the through hole 24r, positioning is very easy.

The upper cover 100 and lower cover 110 positioned as described above are attached to the upper casing 24 by the connecting member 105, as shown in FIG. With reference to FIGS. 19 and 20, connecting member 105
From above to below, there is a head 105d formed with a pair of parallel side walls so that the connecting member 105 can be rotated by pinching with fingers, a body 105c made of a cylinder, and a reduced diameter part 105b.
, and a substantially triangular arrowhead portion 105a. The head 105d has an insertion hole 105 for preventing fingers from slipping.
e is provided. Note that a tool such as a screwdriver may be inserted into the insertion hole 105e, so that the connecting member 105 can be turned by using the above-mentioned tool instead of by hand.

On the other hand, the through hole 24r of the upper casing 24
A step portion 24y is provided below the inner step portion 24q, against which the lower end surface 105f of the body portion 105c is abutted;
A pair of grooves 24z extending vertically through which the arrowhead portion 105a can be inserted is provided below the step portion 24y (see FIG. 21). In addition, the inner upper surface 2 of the upper casing 24
48, a cam surface 29 that engages with the arrowhead portion 105a of the connecting member 105 is formed around the through hole 24r. The height (degree of downward protrusion) of this cam surface 29 is shown in FIG.
In the range G between the pair of grooves 24z shown in FIG.
It is shown in the figure below. That is, a holding portion 29c of a constant height is formed in the center of the range G, and an inclined portion 29a is formed from the holding portion 29c toward the groove portion 24z. Further, the holding portion 29c is lower than the highest portion of the inclined portion 29a, and the highest portion constitutes a ridge portion 29b. The ridge portion 29b prevents the arrowhead portion 105a engaged with the holding portion 29c from moving toward the slope portion 29a. The arrowhead portion 105a of the connecting member 105 is
The upper casing 2 is inserted through the groove 24z of the through hole 24r.
4 protrudes below the upper surface portion 24u (in FIG. 19,
), then rotate the connecting member 105 at approximately 90°.
By rotating the arrowhead portion 105a, the cam surface 29
The holding part 29 passes through the inclined part 29a and the ridge part 29b of
Move to c (see Figure 20).

Note that the reduced diameter portion 105 of the connecting member 105
The length b is set such that a downward pressing force is applied by the cam surface 29 to the arrowhead portion 105a when the arrowhead portion 105a is located in the middle of the inclined portion 29a. On the other hand, the lower end surface 105f of the body portion 105c is restricted from moving downward by coming into contact with the stepped portion 24y. An elongation force is generated that causes elongation. On the other hand, the reduced diameter portion 105b expands and contracts in response to the stretching force generated according to the engagement position between the arrowhead portion 105a and the cam surface 29. Further, since an elastic pressing force is generated between the arrowhead portion 105a and the cam surface 29 depending on the amount of expansion of the reduced diameter portion 105b, engagement between the arrowhead portion 105a and the holding portion 29c of the cam surface 29 is prevented. It has become even more reliable.

[0041] Furthermore, a pair of upper cover 100 and lower cover 110 constituting the conveyance path of the original are attached to the upper casing 2.
Since the covers 100 and 4 are removably attached by a pair of connecting members 105, both the covers 100 and
By removing 110, the upper and lower conveyance paths can be completely opened at once. Therefore, it is easy to take out the document jammed in the conveyance path, and it is easy to clear the jam. Further, the document will not be damaged when taken out. Furthermore, both covers 1 are connected by a pair of connecting members 105.
00 and 110 are positioned relative to the upper casing 24, positioning is easy.

Moreover, since the connecting member 105 is made of resin and uses its elastic force to attach the upper cover 100 and the lower cover 110 to the upper casing 24, it is not necessary to provide a separate spring member. The structure can be simplified, and the manufacturing cost can be reduced by reducing the number of parts. Next, the operation of the document transport section 9 will be explained. First, the document d is inserted from the front of the apparatus main body 2 through the document insertion opening 90a between the upper cover 100 and the lower cover 110, and is conveyed along the upper conveyance path 90d. Then, the document d is placed on the curved guide surface 100 of the upper cover 100.
k, the leading edge of the document d is bent along the upper roller 99a of the transport roller pair 99, and the leading edge of the document d is
9 until it faces the contact area between the upper roller 99a and the lower roller 99b, and set the document d (see FIG. 23).
. In this state, by turning on a copy start switch (not shown), the document d is sandwiched and reversed by a pair of transport rollers 99 and transported to the forward feed roller 92 side on the lower transport path 90e (see FIG. 24). Furthermore, the document d is moved by the forward feed roller 92 and the conveyance roller pair 91.
The document is conveyed along the contact glass 11a and discharged from the document discharge port 90b (see FIG. 25). For thick documents that are difficult to invert, open the opening 9 as shown in FIG.
It can be introduced from the rear side of the apparatus main body 2 through 0c, and thick originals can be easily copied.

[0043] Referring to Fig. 14, the document conveying section 9 is located on one side of the upper surface 24p of the upper casing 24, and the above-mentioned accessory case 140 is removably attached to the upper surface 24p. . A pair of protrusions 141 and 142 are provided at the bottom of the accessory case 140, and these protrusions 141 and 142 are connected to the upper surface 2 of the upper casing 24.
The accessory case 140 can be positioned with respect to the upper casing 24 by fitting into the pair of recesses 243 and 244 of 4p. This accessory case 140 can conveniently store small items such as clips. Further, since the accessory case 140 is provided on the upper surface of the device main body 2, the stored accessories can be checked at a glance, which is more convenient.

By removing the accessory case 140, upper cover 100, and lower cover 110, the upper surface 24p of the upper casing 24 becomes substantially flat, as shown in FIG. On the other hand, the upper surface 24p of the upper casing 24
A pair of recesses 241 and 242 are provided on a vertical plane including the rotational axis r of the photoreceptor drum 42 at positions on both sides of the contact glass 11a. LE used as image forming means
When attaching an attachment such as a D unit to the upper surface 24p, if the recesses 241 and 242 are used for positioning the attachment, the upper surface 24p
Coupled with the fact that p is substantially flat, the attachment can be attached to the photoreceptor drum 42 and the like in an accurately positioned state.

The drive system 7 is fixed to a drive system arrangement portion 24h formed inside the upper casing 24, as shown in FIG. This drive system 7 drives, in addition to the photosensitive drum 42, a toner supply roller 41d, stirring roller 41e, and developing roller 41f of the developing device 41, an upper roller 51a of the paper conveying section 5, a heat roller 61 of the fixing section 6, etc. These driven parts are each driven by a motor 71 via a gear mechanism 72. Also,
An electrical component 8 having a circuit board and the like for controlling these drives is also attached to the upper casing 24. By arranging the drive system 7 and the electrical components 8 together on the upper casing 24 side in this manner, the wiring for the drive system 7 and the wiring between the electrical components can be easily and efficiently performed. That is, when the drive system 7 and the electrical components 8 are arranged separately on the upper casing 24 side and the lower casing 25 side, both casings 2
It is necessary to perform crossover wiring between 4 and 25, and
Since the wiring work cannot be done in a concentrated manner, the work is time-consuming, but if these are placed together on the upper casing 24 side, both casings 24, 25
There is no need for crossover wiring between the two casings, and the wiring work can be concentrated on one side of the casing.
The work can be done easily and efficiently.

As described above, according to this embodiment, the rib 10 of the upper cover 100 of the pair of removable upper cover 100 and lower cover 110 constituting the document transport path
Since the contact glass 11a is held down by 0d, there is no need to provide a separate holding member.
Manufacturing costs can be reduced by reducing the number of parts. Also,
Since the contact glass 11a can be easily attached and detached by attaching and detaching the upper cover 100, assembly costs can be reduced, and manufacturing costs can be further reduced.

Furthermore, since the reinforcing frame for attaching functional parts is eliminated, the number of parts is reduced accordingly, making it possible to achieve a reduction in size and weight, and further reduce manufacturing costs. Furthermore, the number of man-hours required for assembling the reinforcing frame is also eliminated, making it possible to further reduce manufacturing costs. Furthermore, in conventional copying machines with reinforced frames, there was a risk of damage such as cracking or plastic deformation at the joint between the casing and the reinforcing frame due to differences in material and strength between the two. In the embodiment, there is no such possibility.

If the reinforcing frame is simply abolished in a conventional copying machine equipped with a reinforcing frame, there is a concern that external forces will affect the functional parts due to a decrease in the rigidity of the main body of the device. In the example, since each functional component is held by the casings 24 and 25 which have a monocoque structure and ensure rigidity, it is possible to suppress the influence of external forces acting on the device main body 2 on the functional components. In particular, since important functional parts such as the image forming section 4 are attached to the casings 24 and 25 without significantly changing their form, the inherent rigidity of the functional parts themselves can be fully utilized. As a result, it can strongly withstand even excessive external forces. Therefore, even if the copying machine is handled roughly by a general user who is not familiar with the internal structure of the copying machine and tends to handle it roughly, it can exhibit excellent durability. As described above, it is possible to realize a copying machine that is small and lightweight, reduces manufacturing costs, and has sufficient durability against rough handling, and is therefore suitable for widespread use for home and personal use. Can be done.

Note that in the above embodiment, the upper cover 1
Although the contact glass 11a is held down by the contact glass 11a, the contact glass 11a can be held down by ribs formed on the lower cover 110 instead. Also,
In place of the protrusion 110j on the upper surface 110m of the lower cover 110, a groove can be used. Furthermore, various accessory cases 140 may be provided and replaced according to the user's preference. In addition, various design changes can be made without changing the gist of the invention.

[0050]

As described above, according to the image forming apparatus of the present invention, the contact plate is pressed and fixed by either one of the pair of covers constituting the document conveyance path. Since there is no need to provide a holding member on the holder, the number of parts can be reduced and manufacturing costs can be reduced. Furthermore, since the contact plate can be easily attached and detached by attaching and detaching the cover, it is easy to assemble and can further reduce manufacturing costs.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a copying machine as an image forming apparatus of the present invention.

FIG. 2 is an exploded sectional view of the copying machine.

FIG. 3 is a schematic cross-sectional view showing the internal configuration of the copying machine.

FIG. 4 is a plan view showing an image forming section frame and a toner collection container.

FIG. 5 is an exploded perspective view showing the upper and lower casings and the handle.

FIG. 6 is a perspective view of the upper casing.

FIG. 7 is a schematic cross-sectional view showing the state of the connecting portions of the upper and lower casings before they are connected.

FIG. 8 is a schematic cross-sectional view showing the state of the connecting portions of the upper and lower casings after they are connected.

FIG. 9 is a schematic vertical cross-sectional view showing how the upper and lower casings are attached.

FIG. 10 is an enlarged sectional view showing a state in which the upper casing and the lower casing are brought into contact with each other.

FIG. 11 is a side view of the main body of the apparatus showing a state in which a document is introduced.

FIG. 12 is an enlarged perspective view of the main part of the handle.

FIG. 13 is a bottom view showing how the functional components are held by the upper casing.

FIG. 14 is an exploded perspective view showing the document transport section, the accessory case, and the upper casing.

FIG. 15 is a partially sectional front view showing how the upper cover is attached to the upper casing.

FIG. 16 is a perspective view of the upper cover.

FIG. 17 is a schematic cross-sectional view of the lower cover.

FIG. 18 is a partially sectional plan view showing a state of engagement between the upper cover and the lower cover.

FIG. 19 is a sectional view showing a state before the upper cover and the lower cover are connected by a connecting member.

FIG. 20 is a sectional view showing a state in which the upper cover and the lower cover are connected by a connecting member.

FIG. 21 is a bottom view of the upper surface of the upper casing showing the cam surface.

FIG. 22 is a diagram showing the relationship between the circumferential position of the cam surface and the height of the cam surface.

FIG. 23 is a schematic cross-sectional view of the document transport section showing the document set state.

FIG. 24 is a schematic cross-sectional view of the document transport section showing a state in which the document is being transported.

FIG. 25 is a schematic cross-sectional view of the document transport section showing a state in which the document is ejected.

FIG. 26 is a schematic cross-sectional view of the document transport section showing a state in which a thick document is introduced.

[Explanation of symbols]

2 Apparatus main body 9 Original transport section 11a Contact glass (contact plate) 24
Upper casing 24p Upper surface 90d Upper transport path 90e Lower transport path d Original

Claims (1)

[Claims] 1. An image forming apparatus in which a document conveyed along the upper surface of a casing of an apparatus main body is illuminated through a transparent contact plate in contact with the document, and reflected light from the document is guided to a photoreceptor. The document transport unit is provided with a document transport unit that transports the original while inverting it through a two-tiered transport path consisting of a lower transport path along the top surface of the casing and an upper transport path formed above the lower transport path. teeth,
A lower cover forming the lower conveyance path between the upper surface of the casing and an upper cover forming the upper conveyance path between the upper surface of the lower cover are detachably attached to the casing. An image forming apparatus characterized in that the contact plate is fixed to the casing in a pressed state by either the cover or the lower cover.