JP3315528B2 - Document feeder in image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In an image forming apparatus, as one of means for transporting a sheet document to an exposure position, a document wound around at least two belt wheels including a driving belt wheel and fed from a document feeder is fed. There is a method of attaching a document feeder having an endless belt for transporting a document to a predetermined exposure position of the image forming apparatus main body and transporting the document. According to this method, the document is stopped at a predetermined position and the document is exposed by the scanner of the main body, so that the risk of occurrence of jitter is reduced, and a mechanism for moving the document table is not required. Can be used for

In this type of document feeder, there are two methods of supporting the endless belt: a method of attaching the endless belt directly to the frame of the document feeder; There is a way to attach. In the former case, the configuration is simple, and it is possible to manufacture at low cost. On the other hand, in the latter case, the endless belt can be easily replaced.

[0004]

Since the endless belt is in constant contact with the contact glass or the original, the endless belt is conveyed.
When used for a long period of time, a sufficient conveying force cannot be obtained due to wear or dirt on the endless belt, and image quality deteriorates due to dirt on the endless belt. Therefore, it is necessary to replace the endless belt within a certain period. Although it is possible to make the support housing of the endless belt a separate housing from the frame of the document feeder and to rotate or bend a part of this housing, belt replacement can be relatively easily performed. In this case, there is a problem that the structure of the belt housing becomes complicated. Further, when an endless belt is used, it is necessary to add a member or the like for restricting the movement of the belt in the thrust direction. Therefore, there is a problem that the structure is further complicated and the number of parts is increased. Therefore, the assembling process is complicated, and it takes a long time to assemble, and the cost increases in terms of both the component configuration and the assembling process. Although the method of directly attaching the belt to the frame of the document feeder reduces the number of parts and reduces the cost, it requires a great deal of labor for belt replacement, and also requires the endless belt regulating member or the endless belt. A problem that the assembling process does not lead to the shortening of the assembling time as expected because the pressurizing member for securely pressing the document against the contact glass and the driving roller for driving the endless belt are attached. There is.

The present invention has been made in view of the above-mentioned conventional problems, and provides an original feeder in an inexpensive image forming apparatus in which the endless belt can be easily replaced, the number of parts and the number of assembly steps are reduced, and the structure is simple and inexpensive. It is intended to be.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an image forming apparatus which wraps a document wound around at least two belt wheels including a drive belt wheel and is fed from a document feeder. An endless belt that is conveyed to a predetermined exposure position of the main body; the endless belt is supported by a supporting housing via a belt wheel; and the endless belt is detached by turning or bending a part of the supporting housing. In an original feeding device in a possible image forming apparatus, an endless belt restricting member for restricting a belt shift in which the endless belt moves in a thrust direction of the belt wheel, and a lower running side of the endless belt is used as a main body of the image forming apparatus. A movable pressing member that presses against the contact glass, a guide means for guiding the pressing member in a substantially vertical direction, and a restriction for restricting the pressing member in a thrust direction. And a timber, said endless belt regulating member is characterized by being formed by integrally molding said guide means and said regulating member with said support casing.

[0007]

According to the present invention, at least one upper end of the guide means is removably opened by attaching and detaching the pressing member, and the guide means is deformed by a load exceeding a certain level due to the elasticity of the guide means itself. It is effective if a stop member which can be released by pressing is provided, and the attachment and detachment of the pressing member is regulated by the stop member.

Further, the present invention is a drive belt wheel in which one of the belt wheels is integrally provided with a drive force transmitting means for transmitting a drive force for driving an endless belt by rotational force. A bearing member that can move in the thrust direction is inserted into the wheel shaft, and a cutout engaging portion that guides the drive belt wheel to a mounting position and engages with the bearing member is formed in the support housing. It is effective if the drive belt wheel is attached to the attachment position via the notch of the notch engaging portion.

[0010]

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an overall schematic diagram showing an ARDF according to the present invention. In FIG. 1, an ARDF denoted by reference numeral 1 is mounted on a copier body 2 via a hinge (not shown) on a contact glass 3 so as to be openable and closable. The ARDF 1 includes a transport belt mechanism 4 having a transport belt having a size to cover the contact glass 3, a document feed mechanism 5 disposed on one side of the transport belt mechanism 4, in this example, on the left side of the drawing. It has a reversing / discharging mechanism 6 disposed on the right side of the drawing, which is the other side of the transport belt mechanism 4. A document table 7 is provided at an upper center position of the ARDF 1, and a document discharge section 8 is provided below the document table 7. In addition,
Since the document feeding mechanism 5 and the reversing / discharging mechanism 6 are not the gist of the present invention, detailed description thereof will be omitted.

As shown in FIGS. 1 and 2, the transport belt mechanism 4 of the ARDF 1 has a driving roller 1 as a belt wheel.
1 and an endless transport belt 10 wound around a driven roller 12, and a support frame 13 as a support housing that supports the transport belt via the drive roller 11 and the driven roller 12. The support frame 13 is composed of a main frame 14 and a sub-frame 15. The main frame 14 is composed of a bottom plate 14a, a front plate 14b, a rear plate 14c, and left and right side plates 14d, 14e. It is composed of a plate 15b, a rear plate 15c, and left and right side plates 15d and 15e. The sub-frame 15 is rotatably attached to the main frame 14 via a shaft 16, and the sub-frame 15 is rotated clockwise with respect to the main frame 14 as shown in FIG. The belt 10 can be detached from the support frame 13. At this time, as shown in FIG. 4, an appropriate number of substantially fan-shaped guide pieces 17 are provided on the right side plate 14 e of the main frame 14 near the rotating portion of the shaft 16, and the transport belt 10 is mounted on the support frame 13. In this case, the belt can be smoothly inserted without being caught by the roundness of the guide piece 17 shown by the solid line in FIG. Also,
The rear plate 14c of the main frame 14 is formed with a fence 18 against which the transport belt 10 inserted on the right end side abuts, so that the positioning of the transport belt 10 to be mounted can be reliably performed.

The support frame 13 is provided with an L-shaped regulating plate 19 as an endless belt regulating member for preventing the conveyor belt 10 from shifting, that is, preventing the conveyor belt 10 from shifting in the thrust direction of the driving roller 11. Is provided. In the case of this embodiment, the front plate 15b of the sub-frame 15
And a regulating plate 19 is provided on the rear plate 15c so as to face each other, and the main frame 14 has the same direction as that provided on the rear plate 15c of the subframe 15 only on the rear plate 14c near the opposite end of the subframe 15. Is provided. When the transport belt 10 is mounted, the regulating plate 19 inserts the transport belt 10 into the regulating plate 19 before returning the sub-frame 15 to the normal position.

The ARDF 1 having the above-described structure includes a support frame 1.
The main frame 14 and the sub-frame 15 are both molded products.
In both cases, the regulating plate 19 is integrally formed. Therefore, the step of attaching the regulating plate 19 to the support frame 13 is unnecessary, and the accuracy of the tolerance of the support frame 13 such as flatness is improved. The guide piece 17 and the fence 18 are also integrally formed with the main frame.

The transport belt 1 is mounted on the support frame 13.
An appropriate number of movable pressing rollers 20 as a pressing member for pressing 0 to the contact glass 3 are provided. In this embodiment, the movable pressing rollers 20
And one for each sub-frame 15.
The main frame 14 and the sub-frame 15 have a notch 22 formed in a frame bottom plate for guiding a shaft 21 of a holding roller 20, which will be described later, and a holding plate 20 for contacting the holding roller 20 with the transport belt 10. A shaft regulating plate 29 as a regulating member for regulating the pressing roller 20 in the thrust direction is provided. In FIG. 1, reference numeral 23 denotes a pressing and fixing roller, and only the pressing and fixing roller 23 is a position fixing roller. The thrust direction of these pressing rollers is a direction orthogonal to the traveling direction of the conveyor belt 10.

The guide means of the holding roller 20 is shown in FIG.
As shown in FIG. 5, a pair of guide claws 24 erected in the vertical direction at a predetermined interval on the front side of the support frame 13 and a guide plate 26 erected on the back side of the support frame 13 are formed. And a guide hole 27 extending in the vertical direction. The guide claw 24 can be deformed when a certain load or more is applied due to its own elasticity. A claw portion 25 is formed at the tip of the guide claw 24 as a stop member for preventing the roller shaft 21 from coming off. As shown in FIG. 6, the shaft restricting plate 29 has a slight gap between both end surfaces of the shaft 21 of the holding roller 20, or is located at the position of the front plates 14b, 15b and the rear plates 14c, 15c of the frame that lightly contact. Is formed. Then, the guide claw 24, the guide hole 27
The guide plate 26 and the shaft restricting plate 29 on which the main frame 14 and the sub-frame 1
5 and are integrally formed.

The ARDF 1 having the above-described structure includes a holding roller 20.
When the support roller 13 is mounted on the support frame 13, the back side of the shaft 21 of the holding roller 20 is inserted into the guide hole 27, and as shown in FIG. The work of mounting the holding roller 20 is completed by expanding the claw portion 25 of the claw 24 by elastic deformation and mounting the claw portion 24 between the guide claws 24. Since this mounting operation is very simple, and the guide pawl 24, the guide plate 26 having the guide hole 27 formed therein, and the shaft regulating plate 29 are molded integrally with the main frame 14 and the sub-frame 15, these members can be used. No assembly work is required.

Further, once the holding roller 20 is mounted, the roller is not easily removed by the claw portion 25.

Thus, the holding roller 20 is provided with the guide claw 24.
And the guide hole 27 so as to be movable in the vertical direction.
0 can be held down. When the pressing force of the pressing roller 20 is insufficient only with the weight of the pressing roller 20, the pressing force of the pressing roller 20 may be urged by a spring 28 as shown in FIG. .

As shown in FIG. 9, the drive roller 11 is supported by a front plate 14b and a rear plate 14c on the left end side of the main frame 14. In this case, a drive gear 31 is integrally attached to the end of the shaft 11a of the drive roller 11 on the rear plate 14c side, and then a bearing 30 is attached movably in the thrust direction. The rear plate 14c of the main frame 14 has a recess 32 formed on the outer surface thereof so that the bearing 30 can be fitted to the rear plate 14c.
Further, a notch 33 is formed in the rear plate 14c so as to communicate with a hole for supporting the shaft 11a of the drive roller 11 and to have a width through which the shaft 11a can pass. This recess 32 and notch 3
3 constitutes the notch engaging portion of the present example.

When the driving roller 11 is mounted on the main frame 14 in the ARDF 1 having the above-described structure, first, the shaft 11a on the front side of the bearing 30 is passed through the notch 33,
Next, the front end of the shaft 11a is inserted into the support hole 34 of the front plate 14b.
Through. Then, the bearing 30 is fitted into the concave portion 32, and at this time, the front end side protruding from the support hole 34 of the front plate 14b has E
If a ring (not shown) is attached, as shown in FIG. 10, the bearing 30 is sandwiched between the drive gear 31 and the rear plate 14c of the main frame 14, so that the drive roller 11 is mounted at the correct position without rattling. be able to.

[0023]

According to the first aspect of the present invention, the endless belt restricting member for restricting the shift of the endless belt in the thrust direction, and the endless belt for reliably pressing the original against the exposure surface such as the contact glass. A guide means for guiding a pressing member movable in a vertical direction or a substantially vertical direction, and a member for restricting the pressing member in the thrust direction are integrally formed with the support housing, thereby restricting the endless belt in the thrust direction. It is not necessary to separately provide members, so that the number of components and the number of assembling steps can be reduced, and the accuracy of tolerances such as flatness of the support housing is improved.

[0024]

According to the second aspect of the present invention, at least one upper end of the guide means is removably opened by attaching the pressing member to the guide means, and the upper end of the guide means is subjected to a certain load or more by the elasticity of the guide means itself. By providing a stop member that is deformable and releasable, and the attachment and detachment of the pressing member is regulated by the stop member, the assembly is completed by simply inserting the pressing member with one touch, and significant This improves the assemblability and reduces costs.

According to the third aspect of the present invention, one of the belt pulleys is a drive belt pulley integrally provided with a driving force transmitting means for transmitting a driving force for driving the endless belt by rotational force. A bearing member that can move in the thrust direction is inserted into the shaft of the drive belt wheel, and a notch engaging portion that guides the drive belt wheel to the mounting position and engages with the bearing member is formed in the support housing, Since the bearing member is mounted at the mounting position via the notch of the notch engaging portion, the assemblability of the drive belt wheel to the support housing is greatly improved, and the number of parts for mounting the drive belt wheel is reduced. Can be.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram showing an ARDF according to the present invention.

FIG. 2 is a perspective view showing the entire ARDF support housing.

FIG. 3 is an explanatory diagram showing a movement of a support frame when a transport belt is attached / detached.

FIG. 4 is a perspective view showing a sub-frame side end of the main frame.

FIG. 5 is a perspective view showing a guide means and a shaft restricting means of a pressing roller.

FIG. 6 is a cross-sectional view showing a shaft regulating unit of a holding roller.

FIG. 7 is a cross-sectional view showing a guide means of a holding roller.

FIG. 8 is a cross-sectional view showing an example in which a pressing roller is provided with a pressing roller.

FIG. 9 is a perspective view illustrating a mounting portion of a driving roller.

FIG. 10 is a cross-sectional view showing a state where a driving roller is attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ARDF 4 Conveyor belt mechanism 10 Conveyor belt 11 Drive roller 12 Follower roller 13 Support frame 14 Main frame 15 Subframe 19 Restriction plate 20 Press roller 24 Guide claw 25 Claw portion 27 Guide hole 29 Shaft restriction plate 30 Bearing 31 Drive gear 32 Recess 33 Notch

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masahiro Minato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-5-88484 (JP, A) JP-A Heihei 3-167563 (JP, A) JP-A-5-139552 (JP, A) JP-A-2-188333 (JP, A) JP-A-3-100238 (JP, U) JP-A-2-3539 (JP, A) Y2) Jiko 62-25484 (JP, Y2) (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 5/02 G03G 15/00 107

Claims (3)

(57) [Claims] An endless belt that is wound around at least two belt wheels including a driving belt wheel and that conveys a document fed from a document feeder to a predetermined exposure position of an image forming apparatus main body; An endless belt is supported by a support case via a belt wheel, and a part of the support case is rotated or bent, so that the endless belt is detachable. An endless belt restricting member for restricting the belt from moving in the thrust direction of the belt wheel,
A movable pressing member for pressing the lower running side of the endless belt against the contact glass of the image forming apparatus main body, guide means for guiding the pressing member in a substantially vertical direction, and moving the pressing member in the thrust direction. A document feeder, comprising a regulating member for regulating the endless belt, the endless belt regulating member, the guide means, and the regulating member are integrally formed with the support housing. 2. The document feeder in the image forming apparatus according to claim 1, wherein at least one upper end of said guide means is removably opened by attaching said pressing member, and said guide means itself is provided at said upper end. A document feeder, wherein a stop member is provided which can be deformed and released by a certain load or more due to the elasticity of the pressurizing member, and the mounting and dismounting of the pressing member is regulated by the stop member. 3. A document feeding device according to claim 1, wherein a driving force transmitting means for transmitting a driving force for driving one of said belt wheels by a rotational force is integrally mounted. A bearing member movable in a thrust direction is inserted into a shaft of the drive belt wheel, and the drive belt wheel is guided to an attachment position in the support housing; A document feeder, wherein a notch engaging portion that engages with the drive belt wheel is formed, and the drive belt wheel is mounted at a mounting position via a notch in the notch engaging portion.