JPH0573659B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a sheet conveying device suitable for use in an image forming apparatus such as a copying machine, an information recording device, a laser beam printer, and especially a document feeding device. Specifically, the present invention relates to a sheet conveying device equipped with an endless belt.

(b) Prior Art Conventionally, sheet conveyance devices of image forming apparatuses such as copying machines, especially sheet conveyance devices that convey document sheets, have been equipped with a full-width, endless document conveyance belt, and the conveyance force of the belt has been improved. In order to do this, the original sheet is often conveyed on the slack side of the belt, so a drive roller that drives the belt is provided on the entrance side of the original sheet, and on the exit side it is biased by a spring and moves its position to transport the belt. The structure includes a driven roller that applies tension to the shaft.

(c) Problems to be Solved by the Invention Incidentally, in the sheet conveying device having the above configuration, the position of the driven roller changes due to variations in the circumference of the document conveying belt or changes in belt tension at the time of starting the drive. . The paper ejection path formed by the guide, etc. whose position does not change, and the driven roller whose position changes is set in advance at large intervals in consideration of the change in the position of the driven roller. However, increasing the interval between the paper ejection paths may cause poor conveyance of document sheets with weak stiffness or curled document sheets. In order to minimize conveyance failures of original sheets, it is desirable to maintain the interval between the paper ejection paths at a constant value (approximately 2 mm).

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an apparatus that can maintain a constant interval between paper discharge paths even if the position of the driven roller changes.

(d) Means for solving the problem The present invention has been made in view of the above-mentioned circumstances, and includes a guide member that guides the sheet material in a swingable manner facing the roller whose arrangement position changes. A rotating body that follows changes in the roller is rotatably supported on the guide member, and a biasing member that biases the guide member so that the rotating body follows the roller is disposed. It is characterized in that the body and the guide member are integral and always follow changes in the arrangement position of the roller.

(E) Effect Based on the above configuration, when the roller whose arrangement position changes changes its position, the rotating body that engages with the roller and the guide member that arranges the rotating body are integrated by the biasing member. The rotating body always contacts the roller, and the interval of the paper discharge path formed by the position of the guide member and the roller is maintained at a predetermined distance.

(f) Examples Examples of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the sheet conveyance device U of this embodiment is arranged above the copying machine main body 1,
The present invention relates to a document conveying device that conveys and places a document sheet at a predetermined position on a platen 2 provided at the top of the copying machine main body 1.

By the way, the copying machine main body 1 has a photosensitive drum 3 approximately in the center that rotates in the direction of arrow A.
The platen 2 made of a transparent member is provided on the upper part, and below the platen 2, an illumination lamp 5, a plurality of reflecting mirrors 6, 7, 9, 10 are provided, and an imaging lens 11 is provided. has been done. The projected image of the document placed on the platen 2 is formed by the illumination lamp 5, the plurality of reflecting mirrors 6,
7, 9, 10, arrow A by the imaging lens 11
A slit is exposed onto the photosensitive drum 3 rotating in the direction shown in FIG. Further, a charger 1 is provided near the photosensitive drum 3.
2. A developing device 13, a transfer device 15, and a cleaning section 16 are provided, and before the original image is exposed to the slit, the photosensitive drum 3 is uniformly charged by the charger 12. When the image is subjected to slit exposure, an electrostatic latent image is formed on the photosensitive drum 3, and the electrostatic latent image is further visualized by the developing device 13. On the other hand, a paper feed tray 19 for storing transfer material 17, a paper feed roller 20, a registration roller 21, a conveying section 22, a fixing device 23, an ejection roller 25, and an ejection tray 26 are provided at the bottom of the copying machine main body 1.
The transfer material 17 is transferred to the paper feed roller 20 and the photosensitive drum 3.
Registration roller 21 rotating in synchronization with the image above
The image is transported to the drum 3 by the transfer unit 15, the image is transferred by the transfer device 15, and further transported to the fixing device 23 by the transport section 22. The transfer material 17 having the image transferred thereon has the image fixed thereon by a fixing device 23, and is discharged onto a discharge tray 26 by a discharge roller 25.

On the other hand, as shown in FIGS. 2 and 3, the sheet conveyance device U has an endless conveyance belt 31 facing the entire width of the upper surface of the platen 2, and a drive for winding and driving the conveyance belt 31. It includes a roller 32 and a driven roller 33 that is wound around the conveyor belt 31 and moves idly. The driving roller 32 has a front shaft portion 32a and a rear shaft portion 32b rotatably supported by the front side plate 35 and the rear side plate 36, respectively, and the driven roller 33 is rotatably supported by the front side plate 35 and the rear side plate 36. A front auxiliary side plate 37 and a rear auxiliary side plate 39 arranged to slide, respectively.
A front shaft portion 33a and a rear shaft portion 33b are rotatably supported, respectively. Further, each of the front and rear auxiliary side plates 37, 39 has a bent portion 3 at one side end.
7a, 39a are formed, and these bent portions 37a,
39a and protrusions 35a, 36a formed on the front and rear side plates 35, 36, belt tension springs 40, 41 are disposed, respectively. ), tip hooks 40a, 41a are formed at the tip, and center hooks 40b, 41b are formed at the center, and rear end hooks 40c, 41c for hooking/unhooking are further extended from the center hooks 40b, 41b. It is formed. The tip hooks 40a, 41a of the belt tension springs 40, 41 engage with the bent portions 37a, 39a, respectively, and the center hooks 40b, 41b engage with the protrusions 35a, 36a.
are engaged with each other to apply tension to the conveyor belt 31. Furthermore, the rear end hooks 40c, 41c are
When the belt tension springs 40, 41 are attached to and removed from the bent portions 37a, 39a and the projections 35a, 36a, a tool is used to facilitate the work.
Further, facing the drive roller 32, a paper feed section 43 equipped with a paper feed tray 42 is disposed, and further facing the driven roller 33, a paper discharge section 46 equipped with a paper discharge tray 45 is disposed. The paper feed tray 42 of the paper feed section 43 has a paper feed guide 47.
As shown in FIG. 6a, the paper feed guide 47 includes an upper paper feed guide 47a, a lower paper feed guide 47b, and a reference guide 47c that are integrally formed, and further includes a transparent member such as acrylic, It is made of polycarbonate, transparent ABS resin, etc., and guides the original sheet smoothly, and can detect the original sheet with an optical sensor without making a hole in the paper feed guide. That is, the conventional paper feed guide 47' has an upper paper feed guide 47 as shown in FIGS.
a', the lower paper feed guide 47b', and the reference guide 47c' are composed of separate members, and the original sheet P' may get into the gap between each member and damage the original sheet P'.
It is also necessary to provide a notch h for the sensor.
There was a problem that the original sheet P' got caught in the notch h and the original sheet P' was damaged, but these problems can be solved by this paper feeding guide. And the second
As shown in FIG. 3 and FIG.
Further, document stoppers 51, 51 are provided facing the drive roller 32, and the document stoppers 51, 51 are connected to a solenoid 52, and the operation of the solenoid 52 causes the document sheet to pass through. Or stop. Further, a transmission-type paper feed section sensor _S1 is provided facing the paper feed guide 47, and the paper feed section sensor _S1 detects the presence or absence of a document sheet. A skew roller pulley 53 is provided on the skew roller shaft 49, and a drive roller pulley 53 is provided on the rear shaft portion 32b of the drive roller 32.
5, and a diagonal belt _b1 is wound around both pulleys 53 and 55. Further, a timing belt pulley 57 is further provided on the rear shaft portion 32b of the drive roller 32, and a timing belt _b2 is wound between it and a pulley 60 disposed on the output shaft 59a of the motor 59. ing.

Note that reference numeral 61 in FIG. 3 indicates a presser roller, which is located inside the conveyor belt 31 and presses the conveyor belt 31 against the platen 2.

As shown in detail in FIG.
is provided, and projecting pieces 62a and 62b are formed at both end portions of the rocking plate 62, respectively.
The projecting pieces 62a, 62b are attached to the front and rear side plates 35, 3.
Rocking plate support shafts 63 and 65 provided in 6, respectively.
The paper discharge swing plate 62 is supported in a freely swingable manner. A plurality of swinging rollers 66 are rotatably disposed on the paper discharge swinging plate 62 in contact with the driven roller 33, and furthermore, the swinging plate support shaft 66 is rotatably disposed in contact with the driven roller 33.
Swing springs 67 and 69 are respectively disposed at the engagement portions between the protrusions 3 and 65 and the protrusions 62a and 62b, and one ends 67a and 69a of the swing springs 67 and 69 are engaged with the front and rear side plates 35 and 36, respectively. stop, and the other end 67
b, 69b are in contact with the paper discharge swing plate 62,
The paper discharge swinging plate 62 is biased so that the swinging rollers 66 always come into contact with the driven roller 33, and the movement of the swinging plate 62 and the driven roller 33 follows the movement of the driven roller 33. A proper paper discharge path 70 is always formed in between. Further, a paper ejection guide 71 that stands upwardly is provided close to the driven roller 33, and a paper ejection roller 72 is disposed at the upper end of the paper ejection guide 71. Furthermore, a paper discharge sensor _S2 is disposed at the lower end of the paper discharge guide 71 (see FIG. 3), and a paper discharge cover 73 is provided to cover the paper discharge section 46. .

On the other hand, as shown in detail in FIG. 6, the driving roller 32 has an endless conveyor belt 31 wound around it, and has shaft portions 32a and 32b at both ends thereof supported by front and rear side plates 35 and 36, respectively. There is. The front side plate 35 has an outer circumference shorter than the inner circumference of the endless conveyor belt, and the front and rear plates 35 and 36 are fixed by a stay 76 and connected together. has been done. A bent portion 35b is formed in the upper part of the front plate 35, and the bent portion 35b is removably attached to an exterior cover 75 attached to the copying machine body 1 with screws 77. A bent portion 35b is also formed at the upper part of the rear side plate 36, and is attached to the exterior cover 75 with screws 79, and the bent portion 36b is configured to be deformable by being further bent by a predetermined amount. has been done. Further, a stay bent portion 76a is formed on the side of the stay 76 where the rear plate 36 is attached. The driven roller 33 around which the endless conveyor belt 31 is wound is connected to the front and rear side plates 35 and 35 of the above-described configuration via the front and rear auxiliary side plates 37 and 39, respectively.
It is supported by 36.

Since the present embodiment has the above-described configuration, when the leading edge of the original sheet placed on the paper feed tray 42 is inserted into the paper feed guide 47, the paper feed section sensor S ₁
detects the original sheet. Then, motor 59
rotates, the conveyor belt 31 wound around the drive roller 32 rotates, the oblique feed roller 50 further rotates, and the document sheet is conveyed to the document stopper 51. At this time, the original sheet is conveyed and aligned along the reference guide 47c by the oblique feed roller 50, and when the motor 59 rotates by the preset number of clocks required for alignment of the original sheet, the solenoid 52 is activated and the original stopper is activated. 51 passes the original sheet. There, the original sheet is conveyed over the platen 2 by the diagonal feed roller 50 and the conveyor belt 31, and the leading edge of the original sheet passes through the platen 2 and enters the sheet discharge guide 71, where it is detected by the sheet discharge sensor _S2 . and the motor 59 rotates in the reverse direction. At this time, the conveying direction of the leading edge of the original sheet is changed by the inertia of the motor 59 at a position slightly advanced from the sheet discharge sensor _S2 , and the original sheet is conveyed backward toward the sheet feeding section 46. Then, the original sheet is reversely fed by a preset number of clocks corresponding to the distance from the sensor S ₂ to a predetermined position on the platen ₂ from the time when the leading edge of the original sheet passes through the discharge sensor S 2 . It is stopped and placed at a predetermined position. Therefore, the copying machine body 1
The copying operation is started, and as described above, the original image of the original sheet placed on the platen 2 is transferred to the transfer material 1.
7 and is ejected onto the ejection tray 26, thereby completing the copying process. Then, the motor 59 that receives the document sheet discharge signal rotates, the conveyor belt 31 rotates, and the document sheet on the platen 2 is conveyed toward the paper discharge tray 45 and disposed on the paper discharge swing plate 62. The sheet is held between the swinging rollers 66 . . . and the conveyor belt 31 and reaches the sheet discharge path 70. At this time, the paper discharge swinging plate 62 is urged by the swinging springs 67 and 69 so that the swinging roller 33 comes into contact with the driven roller 33, and follows the movement of the driven roller 33. A paper ejection path 70 is formed between the conveyor belt 31 wound around the roller 33 and a paper ejection path 70 that always maintains an appropriate distance, and the document sheet is not moved by the ejection rocker even though the position of the driven roller 33 changes. The sheet is guided by the moving plate 62 and passes through the sheet discharge path 70 properly. Further, the document sheet is guided to a paper ejection guide 71, and when it passes through the paper ejection guide 71, its passage is detected by the paper ejection sensor _S2 , and the document sheet is transferred onto the paper ejection tray 45 by the ejection roller 72. is discharged.

Then, the conveyance belt 31 that has repeatedly conveyed the document sheet described above is replaced as appropriate. Upon said exchange,
First, the protrusions 35a, 36 of the front and rear side plates 35, 36
a and the bent portions 37a, 3 of the front and rear auxiliary side plates 37, 39
The belt tension springs 40 and 41 respectively disposed between the conveyor belt 9a and the conveyor belt 31 are removed, and the tension on the conveyor belt 31 is released. At this time, a tool is hung on the rear end hooks 40c, 41c of the tension springs, and the tension springs 40, 41 can be easily removed without deformation or damage. Then, the screws 77 that fasten the bent portion 35b of the front side plate 35 and the exterior cover 75 are removed, and then, as shown in FIG. The bent portion 36b is deformed and opened to create a gap between the exterior cover 75 and the front plate 35. Then, the bent portion 76 of the stay 76
a comes into contact with the exterior cover 75 to prevent permanent deformation of the bent portion 36b of the rear side plate 36, preventing it from being deformed beyond a predetermined value. When a gap is created between the exterior cover 75 and the front side plate 35 through which the conveyor belt 31 can pass, the conveyor belt 31 wound around the drive roller 32 and the driven roller 33 passes through the gap.
is pulled out with the front plate 35 hidden inside. Further, a new conveyor belt 31 is inserted inside the front plate 35, inserted inward through the gap, and wound around the driving roller 32 and the driven roller 33. A tension spring 4 is provided between the front and rear side plates 35, 36 and the front and rear auxiliary side plates 37, 39.
0 and 41 are placed on the rear hooks 40c and 41c, respectively, and tension is applied to the conveyor belt 31, thereby completing the replacement of the conveyor belt 31.

(g) Effects of the Invention As explained above, according to the present invention, a guide member for guiding the sheet material is swingably provided facing the roller whose arrangement position changes, and a conveyor belt is connected to the guide member. a rotating body that contacts the roller, and a biasing member that urges the guide member so that the rotating body comes into contact with the roller, so that the rotating body and the guide member are integrated. Since the rotating body always follows changes in the position of the rollers, even if the position of the rollers around which the conveyor belt is changed changes, the rotating body always contacts the rollers, and furthermore, the guide member A path with a predetermined interval is maintained between the rotating body and the conveyor belt, and the sheet material is held between the rotating body and the conveyor belt, guided by the guide member, and conveyed without causing conveyance defects.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the paper discharge section of a sheet conveying device according to an embodiment of the present invention, FIG. 2 is a side view of a copying machine equipped with the sheet conveying device of the present invention, and FIG. 3 is a side view of the sheet conveying device of the present invention. 4 is a front view of a belt tension spring attached to the sheet conveying device, FIG. 5 is a front cross-sectional view of a paper feed guide attached to the sheet conveying device, and a shows a sheet according to the present invention. 6 is a side sectional view showing the arrangement of drive rollers of the sheet conveying device according to the present invention, and FIG. FIG. 7 is a side sectional view showing how the conveyor belt is attached to and detached from the drive roller. U... Sheet conveyance device, 31... Conveyance belt,
33...Roller whose arrangement position changes (driven roller), 62...Guiding member (sheet ejection rocking plate), 66...
Rotating body (oscillating roller), 67, 69... biasing member (oscillating spring).

Claims (1)

[Scope of Claims] 1. In a sheet conveying device which winds a conveyor belt for conveying a sheet material and is equipped with rollers whose arrangement position can be changed, the sheet material is A guide member for guiding the roller is swingably provided, a rotary body that follows changes in the roller is rotatably supported on the guide member, and the guide member is biased so that the rotary body follows the roller. A sheet conveying device characterized in that a biasing member is disposed so that the rotary body and the guide member are integrated and always follow changes in the disposed position of the roller.