JP2005170614A - Document conveying device and image processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a document conveying device for preventing slip of a document conveying belt, and an image processing device provided with the document conveying device for securely reading an image. <P>SOLUTION: A typical structure of the document conveying device and image processing device to solve the problem is characterized by the document conveying device for conveying a document by a belt stretched on a pair of rollers provided on a frame is provided with a spring hooking part provided on the frame, a guide member for supporting one of the rollers, moving to the frame, and having the spring hooking part, a spring for applying tensile force on the belt by acting on the frame and the spring hooking part of the guide member, and a stopper member for regulating movement of the guide member in a direction for loosening the belt. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a document conveying device that feeds a stacked document onto a platen glass of an image reading device, and an image processing apparatus including such a document conveying device.

  The present invention relates to a document conveying device used in an image reading apparatus, but such an apparatus may further include an image forming apparatus. That is, in the present application, the image processing apparatus refers to an apparatus provided with an image reading apparatus or an image forming apparatus, and specifically refers to an apparatus provided with at least an image reading apparatus.

  The image processing apparatus includes a copying machine that reads an original to form an image on a sheet, a facsimile that reads an original and transmits / receives it to / from a remote location, a scanner that reads an original and sends it to a computer, etc., and information input from outside the sheet There is a printer that only forms an image on the printer, or a multi-function machine of these. Such an image processing apparatus is often provided with an ADF (automatic document feeder) which is a document feeder.

  When the ADF is incorporated in a copying machine, it saves the trouble of feeding and placing a document on the platen glass of the copying machine and removing it from the platen glass after completion of exposure. That is, the ADF separates the original bundle one by one from the original stack placed on the original placement table in order of pages, and feeds it to a predetermined exposure position on the platen glass. A series of operations for stacking and stacking can be performed automatically.

  FIG. 5 is a front cross-sectional view of a conventional ADF, and FIG. 6 is a partial cross-sectional view of a transport portion of the ADF, showing a state in which a part of the transport belt 564 is cut away. As shown in FIG. 5, the ADF 550 is attached so as to cover the upper surface of the platen glass 552 provided at the top of the copying machine main body 551. The bundle of documents placed on the document placing table 555 provided on the upper portion of the ADF 550 is separated and fed one by one by the feeding roller 557, the separation roller 558, and the pickup plate 540 of the feeding unit 556, and the conveying unit 561 is conveyed to the original exposure position on the platen glass 552. The document discharged from the platen glass is U-turned by the reversing unit 566 and discharged and stacked on the document receiving tray 568 by the discharge unit 567.

  The transport unit 561 has a wide endless transport belt 564 wound around a pair of driving rollers 562 and a driven roller 563. The lower running portion 564a of the conveyor belt 564 is pressed against the upper surface of the platen glass 552 by a plurality of pressing rollers 565, conveys the document to a predetermined exposure position, and discharges the exposed document from the platen glass 552. ing.

  As shown in FIG. 6, the drive roller 562 is rotatably supported by the frame 511, and the drive is transmitted through a timing belt pulley 569 attached to the end. The driven roller 563 is pivotally supported by a tensioner plate 512 (guide member) as a guide member, and is attached to the frame 511 so as to be movable in the document conveying direction (arrow A direction). A tension spring 513 is hung on the spring hooking portion 511 a provided on the frame 511 and the spring hooking portion 512 a provided on the tensioner plate 512, and tension is applied to the transport belt 564. As a result, the conveying belt 564 is always kept in tension.

  By the way, when the upper surface of the platen glass is conveyed from the left to the right by the conveying unit 561 having the above-described configuration, static electricity is generated due to sliding between the original and the platen glass 552 or the conveying belt 564 and the platen glass 552. Charging occurs on the upper surface of the glass. In particular, in a low humidity environment, this charging is likely to occur when transporting a color original or the like in which the toner occupies a relatively large proportion of the image surface.

  When the platen glass 552 is charged in this manner, the conveyance belt 564 and the platen glass 552 are easily adsorbed, and the frictional force increases, resulting in a great load on the driving of the conveyance belt 564. Further, when the conveying belt surface in contact with the platen glass 552 is adsorbed to the platen glass 552, the driving roller 562 pulls the driven roller 563 on the side not in contact with the platen glass 552, so that the driven roller 563 is a tension spring. The belt 564 moves toward the driving roller 562 against the urging force of 513, and the conveying belt 564 is loosened. As a result, the drive roller 562 slips with respect to the conveyor belt 564 that has lost its tension, and there is a problem in that the document cannot be reliably read.

  Therefore, conventionally, in order to prevent the driving roller 562 from slipping, the diameter of the driving roller 562 or the driven roller 563 is increased to increase the contact area with the conveying belt 564, thereby increasing the slip torque or the tension spring. Measures have been taken such as preventing the phenomenon that the conveyor belt 564 is loosened by increasing the belt tension by 513.

  However, if the diameters of the driving roller and the driven roller are increased in order to prevent the driving roller from slipping as described above, the conveying section, and thus the entire document conveying apparatus, is increased in size. In addition, when a resin molded product is used as an integral part of the transport frame to reduce the size and weight of the transport unit, reduce costs, and simplify the configuration, the tension of the tension spring is weak because the spring hook is weak. As a result, it was not possible to take measures to increase the tension of the belt by increasing the belt tension.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a document conveying device that prevents the document conveying belt from slipping, and an image processing device that includes this document conveying device and can reliably read an image. In particular, in a low humidity environment, the color original and the platen glass, which have a high proportion of the toner accumulation amount, generate glass charging due to rubbing during transportation and prevent slippage of the driving roller caused by overloading the transportation belt.

  In order to solve the above problems, a typical configuration of the document conveying device and the image processing device according to the present invention is a document conveying device that conveys a document by a belt stretched between a pair of rollers provided in a frame. A spring hanging portion provided on the frame; a guide member that supports one roller and is movable with respect to the frame and has a spring hanging portion; and acts on the frame and the spring hanging portion of the guide member. A spring for applying tension to the belt and a stopper member for restricting movement of the guide member in a direction in which the belt is loosened are provided.

  According to the present invention, by providing the stopper member that restricts the movement of the guide member in the direction in which the belt is loosened, with respect to the guide member that supports one of the belts that stretches the conveyor belt, the conveyor belt, the platen glass, It is possible to prevent shrinkage between the shafts caused by the conveyance resistance and to prevent slippage between the conveyance belt and the driving roller. Thus, the present invention can provide a document conveying device that can prevent the conveyance belt from slipping, and an image processing apparatus that includes this document conveying device and can reliably read a document.

  At this time, it is not necessary to increase the diameters of the driving roller and the driven roller, and the unit and the apparatus can be downsized. Also, since it is not necessary to increase the tension of the belt by increasing the tension of the spring, a resin molded product is sufficient for the spring hook, and the device configuration is simplified by using an integral resin molded product for the transport frame. , Weight reduction and cost reduction can be achieved.

  In addition, the position where the stopper member restricts the movement of the stopper member according to the position of the guide member can be adjusted, so that even if the belt length varies from device to device, the guide member is restricted at an appropriate position. Is possible.

  Embodiments of the present invention will be described below with reference to the drawings. First, the document conveying device will be described, and then the image processing device will be described.

[Document feeder]
FIG. 1 is a diagram illustrating a conveyance unit of the document conveyance device according to this embodiment, FIG. 2 is a front sectional view of the document conveyance device, and FIG. 3 is a side sectional view of the document conveyance device.

  The ADF 50 shown in FIG. 2 is attached so as to cover the upper surface of the platen glass 52 provided at the top of the copying machine main body 51. 3 is a view of the ADF 50 shown in FIG. 2 as viewed from the left side. In FIG. 3, since the user stands on the right side and uses the ADF 550, the left side of FIG. 3 is the back side and the right side is the front side. The back side of the ADF 50 is pivotally attached to the copying machine body 51 by a hinge 53, and the front side is detachably attached to the copying machine body by a magnetic catch 54, for example.

  A document placing table 55 is provided above the ADF 50. On the left side of the ADF 50, a feeding unit 56 that separates and feeds the documents one by one from the document stack placed on the document placing table 55 is provided. The feeding unit 56 includes a feeding roller 57, a separation roller 58, a pickup plate 40, and the like. The documents on the document table 55 are sandwiched between the pickup plate 40 and the feeding roller 57 that are lowered by a solenoid (not shown), and then separated one by one by the separation roller 58 as the feeding roller 57 rotates. Then, the document is conveyed to the original exposure position on the platen glass 52 by the conveyance unit 61. The document discharged from the platen glass 52 by the transport unit 61 is U-turned by the reversing unit 66 and is discharged from the discharge unit 67 onto the document receiving stand 68 above the transport unit 61 and stacked. .

[Transport section]
FIG. 1A is a perspective view of the transport unit 61 of the ADF 50, and is a view in which a part of the transport belt 64 is cut away. FIG. 1B is an enlarged view of the main part of the stretch structure part of the conveyor belt 64 by the driven roller 63.

  The transport unit 61 includes a driving roller 62 that is a pair of rollers, a wide endless transport belt 64 wound around a driven roller 63, and a frame 11 that supports them. A plurality of holes 14 are formed in the horizontal surface portion 11 c of the frame 11. The pressing rollers 65 that have entered the holes 14 press a lower running portion 64a of a conveyance belt 64 described later downward, that is, toward the platen glass 52. At both ends of the driven roller 63, flanges 84 that define the edge 64b of the conveyor belt 64 are attached. The frame 11 is provided with a pair of regulation guides 21 that prevent the transport belt 64 from being displaced.

  The driving roller 62 is pivotally supported via a bearing in an engagement hole portion 11d formed on the left end side of each of the front side plate 11a and the rear side plate 11b of the frame 11. A timing belt pulley 69 is press-fitted into the back end of the drive roller 62. A driving force is transmitted to the timing belt pulley 69 by a timing belt from a DC motor (not shown), and the conveyor belt 64 is rotated in the forward and reverse directions by this driving force.

  The conveyor belt 64 is an endless belt made of polyester canvas. The conveyor belt 64 is stretched between a driving roller 62 and a driven roller 63.

  The driven roller 63 is rotatably supported by a tensioner plate 12 serving as a guide member via a bearing. The tensioner plate 12 applies appropriate tension to the conveyor belt 64, and is provided at the right end of both the front side plate 11a and the rear side plate 11b of the frame 11 so as to be movable along the direction of arrow A shown in FIG. ing.

  The frame 11 is provided with a spring hook portion 11e, and the tensioner plate 12 is similarly provided with a spring hook portion 12a. By applying the tension spring 13 to the spring hooks 11e and 12a, the conveying belt 64 is always maintained in a state where a predetermined tension is applied.

  Further, a stopper member 201 that restricts the movement of the tensioner plate 12 in the direction in which the transport belt 64 is loosened is attached to the frame 11. The stopper member 201 includes an elongated hole 201a through which a fixing screw 202 for fixing the stopper member 201 can be inserted, and an inclined end surface 201b that contacts the tensioner plate 12 and is inclined with respect to the elongated hole 201a. It can be fixed after moving and adjusting the position. Further, on the side opposite to the stopper member 201 of the frame 11, a standing rib 11g that supports the end surface of the stopper member 201 is provided.

  As shown in FIG. 1 (b), the stopper member 201 is moved along the long hole 201a (that is, standing) in a state in which the tension spring 13 is applied to the spring hooks 11e and 12a and a predetermined tension is applied to the conveying belt 64. The stopper member 201 is fixed by the fixing screw 202 at a position where the inclined end surface 201b is in contact with the corner of the spring hook 12a of the tensioner plate 12. Accordingly, the shaft between the driving roller 62 and the driven roller 63 is fixed in a state where a predetermined tension is applied to the conveying belt 64.

  Therefore, even if a large conveyance resistance is generated between the platen glass 52 and the conveyance belt 64, the stopper member 201 is in contact with the tensioner plate 12 in the conveyance direction, and the stopper member 201 is fixed to the fixing screw 202 and the standing belt 202. Since it is fixed by the rib 11g, the movement of the tensioner plate 12 can be restricted. For this reason, there is no possibility that the distance between the shafts of the driving roller 62 and the driven roller 63 is reduced, and the slip torque between the driving roller 62 and the conveying belt 64 is not reduced, so that the conveying belt 64 does not slip. Therefore, it is possible to carry out stable document conveyance even in a situation where glass charging is easily performed such as color document conveyance in a low humidity environment. Further, it is possible to prevent a problem in document conveyance due to these.

  Further, since the belt length varies from machine to machine, it is assumed that the shafts of the driving roller 62 and the driven roller 63 are different, and the fixing position of the tensioner plate varies. On the other hand, as described above, since the position where the stopper member 201 restricts the movement of the tensioner plate 12 can be adjusted, the guide member can be restricted flexibly at an appropriate position.

  Further, by restricting the movement of the tensioner plate 12 in the direction in which the belt is loosened by the stopper member 201, the tension spring 13 does not require excessive tension. For this reason, a resin molded product is used as the frame 11, and the spring hook 11e, the standing rib 11g, the regulation guide 21, and the like can be molded integrally with the frame 11. Thereby, the structure of the conveyance part 61 can be simplified and cost reduction can be aimed at.

[Image processing device]
Next, a copying machine which is an example of an image processing apparatus in which the document conveying device is incorporated will be described with reference to FIG. FIG. 4 is an overall configuration diagram of the image processing apparatus according to the present embodiment. The copying machine 900 includes an ADF 50, a platen glass 52, a light source 907, a lens system 908, a sheet supply unit 909, an image forming unit 902, and the like.

  The sheet supply unit 909 includes cassettes 910 and 911 that are detachably attached to the main body 51 of the copying machine 900 and a deck 913 disposed on the pedestal 912, a pickup roller that feeds the sheets to the image forming unit 902, and the like have. The image forming unit 902 includes a cylindrical photosensitive drum 914, a developing device 915, a transfer charger 916, a separation charger 917, a cleaner 918, a primary charger 919, and the like disposed around the photosensitive drum 914. ing. A conveyance device 920, a fixing device 904, a discharge roller pair 905, and the like are disposed on the downstream side of the image forming unit 902.

  Next, the operation of the copying machine 900 will be described. When a sheet supply signal is output from the control device 930 in the copying machine 900 main body 51, the sheet P is supplied from the cassette 910, 911 or the deck 913. On the other hand, the light reflected from the light source 907 on the document D placed on the platen glass 52 is applied to the photosensitive drum 914 via the lens system 908. The photosensitive drum 914 is charged in advance by a primary charger 919, and an electrostatic latent image is formed by irradiation with light. Then, the electrostatic latent image is developed by a developing device 915 to form a toner image. The

  The sheet S fed from the sheet feeding unit 909 is corrected in skew by the registration roller 901, and further fed to the image forming unit 902 at a proper timing. In the image forming unit 902, the toner image on the photosensitive drum 914 is transferred to the sheet S that has been sent by the transfer charger 916. The sheet S to which the toner image has been transferred is charged to a polarity opposite to that of the transfer charger 916 by the separation charger 917 and separated from the photosensitive drum 914. The separated sheet S is conveyed to the fixing device 904 by the conveying device 920, and the transfer image is permanently fixed on the sheet S by the fixing device 904. The sheet S on which the image is fixed is discharged from the copying machine main body 51 by the discharge roller pair 905. In this way, an image is formed on the sheet S fed from the sheet feeding unit 909 and discharged.

  Examples of the sheet include plain paper, a thin resin sheet that is a substitute for plain paper, a postcard, a cardboard, a sealed letter, and a plastic thin plate (OHP).

  The present invention can be used for a document conveying device that feeds a stacked document onto a platen glass of an image reading device, and an image processing apparatus including such a document conveying device.

FIG. 3 is a diagram illustrating a conveyance unit of the document conveyance device according to the embodiment. FIG. 3 is a front sectional view of the document conveying device. FIG. 3 is a side sectional view of the document conveying device. 1 is an overall configuration diagram of an image processing apparatus according to an embodiment. It is front sectional drawing of the conventional ADF. It is a fragmentary sectional view of the conveyance part of ADF.

Explanation of symbols

11 ... Frame
11a: Front side plate
11b ... rear side plate
11c… Horizontal plane
11d ... engaging hole
11e ... Spring hook
11g ... standing rib
12… Tensioner plate
12a ... Spring hook
13… Tension spring
14… hole
21… Regulatory Guide
40… Pickup plate
50 ... ADF
51 ... Copier body
52… Platen glass
53… Hinge
54… Magnet catch
55… Original table
56… Feeding department
57… feed roller
58… Separation roller
61… Conveying section
62… Drive roller
63… driven roller
64… Conveyor belt
64a ... Downhill section
64b ...
65… Pressing roller
66… Reverse part
67… discharge section
68… Original tray
69… Timing belt pulley
84… Flange
201 Stopper member
201a ... slot
201b ... Inclined end face
202… Fixing screw
511… Frame
511a ... Spring hook
512… tensioner plate
512a ... Spring hook
513… Tension spring
540… Pickup plate
550 ... ADF
551 ... Copier body
552 Platen glass
555… manuscript table
556… Feeding department
557… feed roller
558… Separation roller
561 ... Conveying section
562… Driving roller
563… Followed roller
564… Conveyor belt
564a ... Downhill section
565… Pressing roller
566… Reverse part
567… discharge section
568… manuscript tray
569… Timing belt pulley
900… Copier
901… Registration roller
902 ... Image forming unit
904. Fixing device
905… discharge roller pair
907… Light source
908… Lens system
909 ... Sheet supply section
910, 911 ... cassette
912… Pedestal
913… deck
914 ... Photosensitive drum
915… Developer
916… Transfer charger
917… Separation charger
918… cleaner
919 ... Primary charger
920 ... Conveying device
930… Control device

Claims (5)

In a document conveying device that conveys a document by a belt stretched between a pair of rollers provided in a frame,
A spring hook provided on the frame;
A guide member that supports one roller and is movable with respect to the frame and has a spring hook;
A spring that acts on a spring hook portion of the frame and the guide member to apply tension to the belt;
An original conveying apparatus comprising a stopper member for restricting movement of the guide member in a direction in which the belt is loosened. 2. The document conveying apparatus according to claim 1, wherein the guide member supports a roller disposed downstream in the document conveying direction. 2. The document conveying apparatus according to claim 1, wherein the stopper member can be fixed by adjusting a position for restricting movement of the stopper member according to a position of the guide member. The stopper member is
An elongated hole through which a screw for fixing the stopper member can be inserted;
An end face that is in contact with the guide member and inclined with respect to the elongated hole;
2. The document conveying apparatus according to claim 1, wherein the position of the document conveying apparatus can be adjusted by moving along the elongated hole. An original conveying apparatus according to any one of claims 1 to 4,
A platen on which a document is conveyed by the document conveying device;
An image processing apparatus, comprising: an image reading unit that reads an image of a document through the platen.

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