JPH04346361A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce production cost by reducing the number of parts and the man-hour for assembly of a paper feeding guide, and suppress to produce faulty feeding of paper by maintaining an accuracy of relative position between a paper feeding tray and the feeding guide. CONSTITUTION:A lower guide 25a for guiding the feeding of a paper on its lower side is formed integrally on the bottom of a lower casing 25. A paper feeding tray 22 is fitted closely into the lower casing 25 to maintain an accuracy of relative position between the paper feeding tray and the lower guide 25a.

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 an electrostatic printer.

0002

[Prior Art] Conventionally, extremely small image forming apparatuses such as electrostatic copiers and printers have been used to visualize an electrostatic latent image formed on a photoreceptor drum into a toner image and then transfer it to paper. A so-called portable type device has been provided (for example, see Japanese Patent Publication No. 2-17453).

This type of image forming apparatus includes an image forming section that visualizes an electrostatic latent image corresponding to a document image formed on a photoreceptor into a toner image, and then transfers the toner image onto paper; It includes a fixing section that fixes images, a paper transport section that introduces paper into the apparatus main body, supplies it to the image forming section, and then discharges it from the apparatus main body, a drive system that drives these, and a control circuit and other electrical equipment. It is equipped with functional parts such as products. and,
Each of these functional parts is attached to a metal reinforcing frame, which is arranged inside a box-shaped casing made of a resin molded product, and is made of a pair of side plates, a stay connecting the side plates, and the like.

[0004] Furthermore, a paper feed tray is provided upstream of the paper transport section to assist manual paper feeding.
This paper feed tray is attached to the reinforcing frame.

[0005]

SUMMARY OF THE INVENTION In order to popularize the image forming apparatus having the above structure for home and personal use, it is desirable to reduce the size and weight as much as possible, and to reduce the manufacturing cost and selling price. However, in the above-mentioned image forming apparatus, it is necessary to arrange a large number of paper conveyance guides along the paper conveyance path, which increases the number of parts and the number of assembly steps, resulting in high manufacturing costs. There was a problem with it sticking.

Furthermore, since both the conveyance guide and the paper feed tray are attached to the reinforcing frame by screws or the like, it is difficult to ensure relative positional accuracy between the two.
There was a problem that transportation defects were likely to occur. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus that can reduce the number of parts and is less likely to cause sheet conveyance defects.

[0007]

[Means for Solving the Problems] The image forming apparatus of the present invention for achieving the above object has the following features: (1) Developing an electrostatic latent image formed on a photoreceptor into a toner image and then transferring it to paper; an image forming section, (1) a fixing section that fixes the toner image transferred to the paper, and which introduces the paper into the apparatus main body and discharges the paper from the apparatus main body through the image forming section; (2) a paper transport section that drives these. It is equipped with at least a drive system and (1) electrical components, and these (2) to (4) functional components are arranged in a casing made of a resin molded product, and a paper feed tray is provided on the upstream side of the paper transport section. The image forming apparatus is characterized in that a lower guide for guiding conveyance of the lower surface of the paper is integrally formed on the bottom of the casing, and the paper feed tray is fitted and attached to the casing. That is.

[0008]

[Operation] According to the image forming apparatus configured as described above, the lower guide that guides the conveyance of the lower surface side of the paper is integrally molded in the casing, so there is no need to form this lower guide independently, and the lower guide The man-hours required for assembly are also eliminated. Furthermore, since the paper feed tray is fitted and attached to the casing in which the lower guide is integrally molded, relative positional accuracy between the lower guide and the paper feed tray can be easily ensured.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples will be explained in detail below with reference to the accompanying drawings showing examples. FIG. 2 is a perspective view of a copying machine as an image forming apparatus showing an embodiment of the present invention, and FIG. 3 is a schematic sectional view showing its internal configuration. The above-mentioned copying machine is a so-called moving table type that illuminates and scans a document placed on the document table 1 by moving the document table 1 made of a transparent glass plate in the left-right direction in FIG. A document presser 11 for holding down a placed document is provided above the document table 1 so as to be rotatable and openable. The copying machine includes an optical system 3 for illuminating and scanning a document moved by a document table 1, and a photosensitive drum 42, inside a device main body 2.
After the electrostatic latent image formed on the paper is visualized by the developing device 41, an image forming section 4 is arranged to transfer the toner image onto a sheet of paper, and a fixing section 6 is disposed in the middle to fix the toner image transferred to the paper. is introduced into the apparatus main body 2 from the paper feed port 26, and then the image forming section 4
A paper transport section 5 that discharges the paper from the paper discharge port 21 through the paper, a drive system 7 (see FIG. 9) for driving the document table 1, the image forming section 4, and the paper transport section 5, and a control circuit that controls these drives. It is equipped with functional parts such as electrical equipment 8 (see FIG. 9).

The optical system 3 includes a fluorescent lamp 31 for illuminating the original, a lens 32 that guides reflected light 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. This toner collection container 47 has a rectangular tray-like planar shape, and is provided above the paper transport section 5 on the downstream side in the transport direction.

The toner collection container 47 has an inclined side surface 47c continuous with a horizontal bottom 47b.
A flange portion 47a extending toward the paper discharge port 21 is formed continuously from the upper end of the side surface portion 47c, and the slanted side surface portion 47c and the flange portion 47a are configured as a hand insertion guide. This hand insertion guide guides the insertion of the hand into the apparatus main body 2 to a position that allows taking out small-sized paper such as a business card size that has passed through the fixing section 6, and mainly uses the side surface portion 47c to This restricts insertion of the finger and prevents the finger from coming into contact with the fixing unit 6. In addition, the above-mentioned collar part 47
When the sheet a is introduced into the paper ejection port 21, it is brought into close contact with the upper edge of the paper ejection port 21, and is designed to prevent the paper from getting caught on the upper edge. In this way, since a part of the toner collection container 47 is configured as a hand insertion guide, there is no need to separately arrange a hand insertion guide, and the number of parts and assembly man-hours can be reduced accordingly.
Manufacturing costs can be reduced.

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 section 5 has a paper feed tray 22 at its leading end.
a pair of conveyance rollers 51 that sandwich the paper received by the paper and introduce it into the inside of 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 paper and temporarily puts the paper on standby, and the fixing unit 6. The upper roller 51a of the conveying roller pair 51 is connected to the developing housing 41 of the developing device 41.
It is rotatably supported by an upper guide 41b protruding from a. That is, the upper guide 41b also serves as a support member for the upper roller 51a. In addition, the fixing section 6
The device fixes the toner image transferred to the paper while sandwiching the paper and conveying it, and includes a heat roller 61 heated by a built-in heater, and a pressure roller that is in pressure contact with the heat roller 61 and driven. 62. The pressure roller 62
is biased upward by a spring (not shown),
It is provided to be movable vertically and horizontally, and its relative position with respect to the heat roller 61 is determined by introducing its support shaft 62a into the groove 63a of the stay 63 that supports the heat roller 61. Further, the registration stopper 52 is rotatably provided around a fulcrum 52a, and is normally biased to rotate clockwise in FIG. The leading edge of the paper is brought into contact with the paper in this advanced state, and the paper is put on standby. Then, when the document table 1 has moved to a predetermined position, the registration stopper 52 is rotated counterclockwise via a link mechanism operated by the document table 1, for example, to retreat from the paper conveyance path, thereby making it standby. The paper thus prepared is supplied to the image forming section 4.

The casing of the apparatus main body 2 is composed of an upper casing 24 and a lower casing 25 that are separably screwed to each other, and include the optical system 3, image forming section 4, and paper conveying section as the above-mentioned functional components. 5, a drive system 7, and an electrical component 8 are held by an upper casing 24 and a lower casing 25, respectively. In further detail with reference to FIGS. 1, 9 and 10, the optical system 3
The case 33 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 screwed to the upper casing 24, and thereby the developing device 41, the photosensitive drum 42, the transfer charger 44, and the cleaner 45 of the image forming section 4 are fixed to the upper casing 24 with screws. is 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 52
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 61 of the fixing unit 6.
is held by the upper casing 24 via a stay 63, and the pressure roller 62 is held by the lower casing 25.

The lower casing 25 is made of a resin molded product, and as shown in FIGS. 5 and 10,
A large number of rib-shaped lower guides 25a are integrally molded on the inner bottom of the guide 25a to guide the lower surface side of the sheet being conveyed. Further, an opening 25b is provided at the bottom of the lower casing 25, and the support member 25 is provided in the opening 25b.
d has been introduced. The support member 25d is made of a resin molded product, and has a large number of integrally molded rib-shaped lower guides 25e arranged side by side on the upper surface side to guide the lower surface side of the sheet being conveyed. In this way, the lower casing 25 is formed with the lower guides 25a and 25e that guide the conveyance of the lower surface of the paper, so there is no need to separately form these, and the number of parts can be reduced accordingly. This also eliminates the need for man-hours for assembling the lower guide to the lower casing 25. In addition, the support member 25d
is provided so as to be rotatable about a fulcrum 25c, and by rotating clockwise in FIG. 3 about this fulcrum 25c, the bottom of the lower casing 25 can be opened. Therefore, it is possible to open a part of the paper conveyance path, and as a result, jam removal and the like can be easily performed. Further, the lower casing 25 is formed with a rib-shaped upright piece 25f along the peripheral edge of the opening 25b, and the lower casing 25 has a monocoque structure with this upright piece 25f and the lower guide 25a. , ensuring the desired rigidity. Note that cutouts 25g for forming a paper feed port 26 and a paper discharge port 21 are formed on both sides of the lower casing 25.

The upper casing 24 is made of resin and is integrally molded, and has cutouts 2 on both sides for forming a paper feed port 26 and a paper discharge port 21, as shown in FIG.
4a is formed, and an opening 24b for inserting and removing the toner cartridge 41c is formed on one side that intersects the both sides. In addition, a slit 24c for illuminating and scanning the original is formed on the upper surface, and a groove 24i for attaching a slider S (see FIG. 7) that movably supports one end of the original table 1; Projections 24j for supporting the other end of the document table 1 are formed, respectively. Further, inside the upper casing 24, a pair of band-shaped guide portions 24d are formed to hang down and guide the introduction of the toner cartridge 41c. The guide portion 24d is integrally molded at the same time as the upper casing 24, and is formed integrally with the toner cartridge 4.
It is formed along almost the entire length of 1c (see FIG. 9). Further, a lid portion 24e that covers the upper opening of the toner collection container 47 is formed at a location corresponding to the toner collection container 47. This lid portion 24e is connected to the ceiling surface of the upper casing 24 and a frame-shaped hanging piece 24 extending downward from the ceiling surface.
f, and the hanging piece 24
f in close contact with the upper opening edge of the toner collection container 47,
The toner collection container 47 is closed, thereby preventing the toner collected in the toner collection container 47 from scattering. Note that the toner collection container 47 and the upper casing 2
The lid portion 24e of No. 4 is connected to the lid portion 24e of No. 4 so as to be in close contact with each other by screws (not shown). As described above, since the lid part 24e is integrally molded on the upper casing 24, there is no need to form a separate lid on the toner collection container 47, which reduces the number of parts and reduces the number of assembly steps. be able to. Further, since the toner cartridge 41c can be inserted and removed through the opening of the upper casing 24, the replacement work can be easily performed without opening the inside of the apparatus main body 2. Moreover, the guide portion 24d guides the insertion and removal of the toner cartridge 41c.
Since it is integrally molded into 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, which is useful for cost reduction. The upper casing 24 is
The guide 24b, the hanging piece 24f, etc. form a monocoque structure, thereby ensuring desired rigidity.

Further, the upper casing 24 is integrated with the lower casing 25 by screwing them at connecting portions 24k and 25h formed at at least four corners of each. In this way, the upper casing 24
are screwed to the lower casing 25 at least at the four corners, so even if each of the casings 24, 25 is warped, this can be corrected and both can be accurately positioned. That is, the upper casing 24
When the upper and lower casings 24 and 25 are pivoted to be rotatably opened and closed to form a so-called clamshell type, if the upper and lower casings 24 and 25 are warped, accurate positioning of both becomes difficult. Although local stress is generated in the pivot portion and durability becomes a problem, such a problem can be avoided by using the above-mentioned screw fastening method.

The opening 24b for inserting and removing the toner cartridge 41c is closed by a cover 24g fitted to the opening 24b. Further, it is preferable that the abutting portions of the upper casing 24 and the lower casing 25 be combined in a zigzag 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.

The paper feed tray 22 is connected to the lower casing 2.
5, and can be placed along the upper casing 24 by being rotated upright when not in use. The fitting of the paper feed tray 22 to the lower casing 25 is achieved through holes 25i formed by exposing pins 22p (see FIG. 11) protruding from both sides of the paper feed tray 22 to the notches 25g of the lower casing 25. (See FIG. 5). Here,
Since the lower casing 25 is integrally molded with a lower guide 25a that guides conveyance of the lower side of the paper, relative positional accuracy between the lower guide 25a and the paper feed tray 22 can be easily ensured. . Therefore, it is possible to effectively prevent paper conveyance failure from occurring. Note that the paper feed tray 22 is formed with a large number of reinforcing ribs 22g, thereby ensuring desired strength and receiving paper.

The paper feed tray 22 is provided with a width guide 9 for guiding the insertion of paper into the apparatus main body 2, as shown in FIGS. 10 and 11. This width guide 9 has a pair of cursors 91a for positioning the paper in the width direction.
, 91b and both cursors 91a, 91b to paper feed tray 2.
A pair of rack gears 92a and 92b and a pinion gear 93 are provided, which are interlocked with each other in opposite directions with the two centers interposed therebetween. The cursors 91a, 91b and rack gears 92a, 92b are made of resin, and one cursor 91a and rack gear 92a, and the other cursor 9
1b and rack gear 92b are each integrally molded. The cursors 91a and 91b are the rack gear 92a.
, 92b, and each has a groove 91c for introducing the widthwise end of the sheet. Further, one rack gear 92a is connected to the paper feed tray 22
It is introduced into a first guide groove 22a formed on the upper surface side and its movement is guided, and the other rack gear 92b
is introduced into a second guide groove 22b formed parallel to the first guide groove 22a, and its movement is guided. Then, the first guide groove 22a and the second guide groove 22
At positions facing each other across the center of the paper feed tray 22, there are a first rack presser 22c and a second rack presser 22c for preventing the rack gears 92a and 92b installed in each of them from lifting up.
A rack retainer 22d is formed. These rack pressers 22c and 22d are slidably pressed against the upper surfaces of the rack gears 92a and 92b while protruding into the guide grooves 22a and 22b. , corresponding guide groove 22
a, 22b, the range is set such that it can be introduced from above. Note that both ends of each guide groove 22a, 22b are closed. And each rack gear 92a, 92b
are installed in each guide groove 22 with their tooth surfaces facing each other.
a, 22b, and the respective paper feed trays 22
It is meshed with a pinion gear 93 at the center. This pinion gear 93 is supported by a support pin 22e projecting from the paper feed tray 22. As shown in FIG. 12, this support pin 22e is divided at the upper end so that it can be contracted in the radial direction, and a pinion gear 9 is provided at the top.
A flange portion 22f is formed to prevent the pinion gear 93 from being pulled out, and the pinion gear 93 can be rotatably supported by simply inserting the pinion gear 93 while contracting the upper end side.

[0021] Therefore, each rack gear 92a, 92b
the rack presser 22 against the guide grooves 22a, 22b.
The width guide 9 can be easily inserted into the paper feed tray 22 by simply inserting the pinion gear 93 into the support pin 22e while moving it to the rack presser 22c and 22d sides after introducing it from the side where the racks 22c and 22d are not formed. It can be assembled into Moreover, since the cursors 91a, 91b and the rack gears 92a, 92b are integrally molded, the number of parts can be reduced.

The pinion gear 93 may be prevented from coming off the support pin 22e by a snap ring or the like. On the other hand, like the paper feed tray 22, the paper ejection tray 23 that receives paper ejected from the paper ejection port 21 is rotatably fitted to the lower casing 25, and can be rotated upright when not in use. By doing so, it can be kept along the upper casing 24.

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 each have a gear mechanism 7.
It is driven by a motor 71 via 2. Further, 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 way, 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 distributed and arranged on the upper casing 24 side and the lower casing 25 side, it is necessary to perform crossover wiring between both casings 24 and 25. , wiring work cannot be done in a concentrated manner, which takes time and effort; however, if these are placed together on the upper casing 24 side, there is no need for crossover wiring between the two casings 24 and 25. In addition, since the wiring work can be performed intensively, the work can be performed easily and efficiently.

According to the above embodiment, 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 to reduce manufacturing costs. can. Further, 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, important functional parts such as the image forming section 4 are attached to the casings 24 and 25 without significantly changing their form, so that 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 mentioned above, miniaturization and weight reduction,
Since manufacturing costs can be reduced and durability is sufficient to withstand rough handling, a copying machine suitable for widespread use at home and for personal use can be realized.

It should be noted that the present invention can of course be applied and practiced not only to the above-mentioned moving table type copying machine but also to a type of copying machine in which a document is moved by a conveyance roller. Furthermore, the present invention can be applied not only to copying machines but also to electrostatic printers and the like.

[0027]

[Effects of the Invention] As described above, according to the image forming apparatus of the present invention, the lower guide that guides the conveyance of the lower side of the paper is integrally molded in the casing, so it is not necessary to form this lower guide independently. Therefore, the number of parts can be reduced accordingly, and the number of man-hours for assembling the lower guide is also eliminated, making it possible to reduce manufacturing costs.

Furthermore, since the paper feed tray is fitted and attached to the casing in which the lower guide is integrally molded,
As a result of being able to easily ensure relative positional accuracy between the lower guide and the paper feed tray, paper conveyance defects are less likely to occur.

[Brief explanation of drawings]

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

FIG. 2 is a perspective 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 a perspective view showing the lower casing.

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

FIG. 7 is a partially omitted cross-sectional view showing the upper casing and the document table.

FIG. 8 is an enlarged cross-sectional view showing a butted state of the upper casing and the lower casing.

FIG. 9 is a bottom view showing how the functional components are held by the upper casing.

FIG. 10 is a plan view showing how the functional components are held by the lower casing.

FIG. 11 is a partially cutaway perspective view showing a paper feed tray and a width guide.

FIG. 12 is a sectional view of a main part of the paper feed tray.

[Explanation of symbols]

1 Manuscript table 2　　　　　　　　Device body 3. Optical system 4 Imaging section 5 Paper transport section 6 Fusing part 7 Drive system 8 Electrical components 22 Paper feed tray 23 Paper output tray 24 Upper casing 25 Lower casing 25a Lower guide 25e Lower guide

Claims (1)

[Claims] Claim 1: ■ An image forming unit that visualizes an electrostatic latent image formed on a photoreceptor into a toner image and then transfers it to paper;
A paper transport section that includes a fixing section that fixes the toner image transferred to the paper, introduces the paper into the apparatus main body, and discharges the paper from the apparatus main body through the image forming section, ■ A drive system that drives these, and ■ Electrical equipment. In an image forming apparatus, the functional parts (1 to 2) are arranged in a casing made of a resin molded product, and a paper feed tray is provided on the upstream side of the paper transport section. An image forming apparatus characterized in that a lower guide for guiding conveyance of the lower surface of the paper is integrally formed on the bottom of the casing, and the paper feed tray is fitted and attached to the casing.