JP2005080040A - Automatic document feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make one slide guide member perform only a guiding action with a very small sliding fraction value by making the other guide member bear the weight of a scanner when moving the scanner in reading a document. <P>SOLUTION: For moving the scanner 10 along the bottom surface of a platen 24, one end of the scanner is guided by a guide rod 21, and the other end is guided for motion by a guide rail 22 and an upper guide protrusion 19 so as not to cause blurring. In such a case, at a side of a front side protrusion 17, a driving belt 25 presses the scanner down with pressing force F to make friction against the guide rail 22 at the opposite side. In addition, even though a rear side protrusion 16 floats, an upper guide protrusion 19 enables the scanner to slide under the bottom surface of the platen. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus provided in combination with an image forming apparatus, and more particularly to an apparatus configured to maintain a constant distance between a platen and a reading unit of a scanning device.

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a multi-function machine in which a facsimile machine and a copying machine means are combined, an image reading device is combined with the upper part of the apparatus body. Two scanning functions, ie, a flatbed scanner function and an ADF (automatic document feeder) function, are provided, and one scanning device is used for the two functions. Then, the image information of the original read by the reading device is transmitted to the recording unit to create a recording sheet. In the image reading apparatus combined with the image forming apparatus, a full-rate carriage provided with a lamp and one mirror and a half-rate carriage provided with two mirrors are arranged in combination as the reading apparatus, and each of the two carriages is arranged. Many were used that were synchronized and driven at the speed set to. In the reading apparatus, when the carriage is moved at a high speed, the carriage is moved in a state of being lifted from the guide rail, and there is a problem that the movement of the carriage is not stable. Therefore, it has been proposed to provide means that can accurately slide the carriage relative to the guide when the carriage is moved at high speed and stabilize the scanning posture (see, for example, Patent Document 1).
JP 2000-184138 A

  In the conventional apparatus, since the drive belt is connected to both sides of the carriage, the carriage can be easily prevented from being lifted up by appropriately selecting a path over which the belt is routed. However, in addition to the reading apparatus using the two carriages, in recent years, compared to an example in which a number of mirrors and CCDs are integrally combined in one carriage and compared to an example using two conventional carriages, Increasingly, the configuration of the reader is simplified. In the reading device using the one carriage, a guide means is used so that one end of the scanning device is guided by a guide rod and the other end is slid on a guide rail. Further, in order to move the scanning device, a single driving belt is often used, so that the configuration of the guide means and the driving means for the scanning device can be simplified. However, in the reading apparatus using the one carriage, it is troublesome to maintain the posture of the carriage at the time of reading and to guarantee a stable traveling, and particularly when configured as an apparatus capable of scanning at high speed. There is a long-awaited development of new means for moving the scanning device in a light and stable state.

  The present invention provides a scanning device using a single carriage and having a drive belt connected to one end of the carriage so that the portion sliding on the guide rod bears the weight and frictional resistance of the carriage. An object of the present invention is to provide a device that can perform the reading operation according to the above in a stable state.

  The present invention relates to an image reading apparatus provided with a scanning device that is arranged on an upper part of an image recording apparatus and reads an original while conveying the original. According to a first aspect of the present invention, in order to guide the scanning device inside the reading frame of the image forming apparatus, a guide rod is provided on one side of the scanning device, and sliding guide means is provided on the other side. A driving belt is connected to a side end portion guided by the guide rod of the scanning device, and an image of a document is read while moving the scanning device at a constant speed in the sub-scanning direction by the driving belt. Further, the driving belt is disposed on the side where the driving belt is attached so as to apply a pressing action downward to the end portion of the scanning device.

According to a second aspect of the present invention, on the side where the drive belt is attached, the force that applies a downward pressing action to the end of the scanning device is such that the weights on both sides of the scanning device guided by the guide rod are substantially balanced. It is characterized by being set as the power of.
According to a third aspect of the present invention, a reaction force receiving member that slides on the lower surface of the platen is disposed on the upper side of the scanning device that is not connected to the belt, and the interval between the reading unit of the scanning device and the platen is made constant. It is configured to be maintainable.

  As described above, one end side of the scanning device is guided by the guide rod, and a force that pushes downward by the driving belt connected to the end portion on that side is applied, so that the other end of the scanning device is provided. Friction resistance hardly acts on the guide member. Therefore, it is not necessary to consider the frictional resistance at the other side of the scanning device, and it is possible to drive the scanning device in a stable state using only one drive belt. In addition, by applying an appropriate amount of pressing force to the scanning device by a driving belt, it is possible to easily perform an operation of adjusting the frictional force on the guide members that support both sides of the scanning device. Is possible.

  In the image reading apparatus, when the scanning device 10 is reciprocally moved, a configuration that can simplify the configuration of the guide unit and that can be configured with a guide unit with low friction will be described below. In the embodiment described below, it is possible to provide an image reading apparatus in combination with an image forming apparatus that creates recording paper using an electrophotographic method. In particular, since it is not the gist of the present invention, the configuration of the image reading apparatus will be mainly described.

  The configuration of the present invention will be described according to the illustrated example. The example shown in FIG. 1 relates to an image reading apparatus 1 having an ADF 2 and FBS type reading means, and a reading frame 20 is provided below the image reading apparatus corresponding to the document handling means. When platens 23 and 24 corresponding to each of the FBS function and the ADF function are provided at predetermined positions on the upper portion of the reading frame 20, when reading an original of a sheet using the ADF function, The scanning device 10 is stopped at the position of the platen 23 to perform reading. When reading an original such as a book or a sheet using the FBS function, the original is set on the platen 24, and the original is pressed and held by the original pressing plate that also serves as the discharge tray 9. . Then, reading the document while moving the scanning device along the lower surface of the platen 24 is the same as the conventional image reading device.

  In the image reading apparatus 1, the ADF 2 disposed on the upper portion of the reading frame 20 is provided integrally with an upper member that can be opened and closed using hinge means provided on the rear side of the upper portion of the reading frame 20. . The ADF 2 connects the document tray 3 and the discharge tray 9 via a substantially horizontal U-shaped conveyance path 6, as in the known ADF, and a platen 23 below the document conveyance path 6. The image of the conveyed document is read at a portion corresponding to. A pickup roller 4 and a paper separation device 5 are provided at the document insertion portion from the document tray 3 to impart a separation action to the document set on the document tray 2, and the document conveyance path 6 one by one. Feed the paper toward. In the sheet separating apparatus 5 shown in the figure, a feed roller 5a and a separating pad 5b are combined. In addition to this example, the sheet separating device may be configured such that the lower part of the fed document is returned toward the document tray by combining a feed roller and a retard roller.

  The originals separated one by one through the paper separating device 5 are conveyed in the original conveying path 6 at a constant speed by the conveying roller device 7 and are stopped at the lower part of the platen 23. An image is read by the scanning device 10. Then, the document that has been read is discharged from the discharge path 8 toward the discharge tray 9 by the discharge roller device 8a. The discharge tray 9 is configured using the upper surface of the FBS function document pressing plate, and the document pressing plate can be used as a discharge tray in the same manner as a conventionally known ADF or FBS combination device. Is done.

  In the inside of the reading frame 20 provided with the two types of platens 23 and 24, the scanning device 10 provided with one carriage moves in accordance with the two types of functions and moves in a fixed position. It is possible to cope with a mode in which scanning is performed in a stopped state. The scanning device 10 is provided so as to be movable in the horizontal direction of the figure, and a lamp 12 is arranged on the upper part of the moving frame 11, and an optical path is formed in the frame 11 by a plurality of mirrors 13. doing.

  When the original is read using the ADF function, the original that is conveyed at a constant speed in the original conveyance path 6 is irradiated by the lamp 12, and the optical path is formed through the optical path formed to a predetermined length. The image is formed on the CCD 15 by the lens 14 provided at the end of the optical signal, and the optical signal is output as a digital signal and transmitted to the connected image forming apparatus. When the FBS function is used, the scanning device 10 moves the document set on the platen 24 by a distance corresponding to the length of the document, reads the document image, and reads the image reading information. The digital signal is output.

  The image information obtained from the scanning device 10 is transmitted to an image forming apparatus provided in combination with the image reading device 1 and used for creating recording paper, and also using a function of a facsimile machine (FAX). It is also possible to transmit to a remote FAX. In addition, the image reading apparatus is connected to an information processing device such as a personal computer and used as information input means in the same manner as a conventional apparatus.

  In the image reading apparatus 1, as in the case of the conventional image reading apparatus, a reciprocating movement is provided in the reading frame. In order to move the scanning apparatus 10, a guide as shown in FIGS. Means can be used. In order to reciprocate the scanning device 10 inside the reading frame 20, a guide rod 21 is disposed on one side of the device, and a guide rail 22 is provided on the other side. Further, a driving belt 25 for driving the scanning device 10 is attached to the front side protrusion 17 side, and an upper guide protrusion 19 is provided on the upper part of the frame 11 on the rear side protrusion 16 side. The upper guide protrusion 19 is provided to slide on the lower surface of the platen 24.

  In the example of FIG. 3 for explaining the guide and driving means of the scanning device 10, the guide rod 21 for guiding in the moving direction of the scanning device 10 is arranged in parallel with the platen 24. Further, as described in FIG. 2, the guide rod 21 and the guide rail 22 are positioned in parallel with the platen. With respect to the guide means of the scanning device, the belt mounting portion 18 is spaced from the line H connecting the upper surfaces of the pulleys on both sides of the drive pulley 26 and the driven pulley 27 that drive the drive belt 25 in the drive system. It is provided so as to be positioned only h. The height (position) for attaching the belt mounting portion 18 can be arbitrarily set. If possible, the force applied to the reading frame 20 by the driving belt 25 can be easily made by the distance h. It should be adjustable. When the connecting portion for the scanning device 10 is positioned above the pulley that drives the driving belt 25, a predetermined value of tension is applied to the driving belt 25. Thus, a force F is applied to the scanning device frame so as to push it down in the clockwise direction in the drawing with the guide rod 21 as the center.

  When the guide means as shown in FIG. 2 is provided, the force that is pushed down by the drive belt 25 acts on the guide rail on the other rear side protrusion 16 side of the frame 11 of the scanning device 10. Therefore, the weight of the frame 11 is not borne for the load 22. Therefore, the frictional force between the guide rail 22 and the frame is close to zero, and a traction action is applied by the drive belt 25 that moves the scanning device, so that the guide rail 22 side is placed on the guide rail 22. The lower surface of the rear-side protrusion 16 is likely to be lifted without sliding. Therefore, an upper guide protrusion 19 is provided on the upper surface of the rear-side protrusion 16 in order to prevent the rear-side protrusion 16 from floating and causing troubles in the reading operation. By sliding the upper guide protrusion 19 on the lower surface of the platen 24, the traveling of the scanning device is stabilized and the distance from the platen can be accurately maintained.

  A guide rail 22 provided in parallel with the guide rod 21 and for guiding the other end of the scanning device 10 slides a slide portion provided on the lower surface of the rear-side protrusion 16. Can be formed in an arbitrary guide shape such as an arc shape or a horizontal plane. Further, the surface of the upper surface of the guide rail 22 and the lower surface of the rear-side protrusion 16 that contacts the guide rail are subjected to a process for reducing friction, such as a process of covering with a fluorine resin in advance. Actually, however, it is not expected that a large frictional resistance acts on the upper surface of the guide rail 22 because the lower surface of the rear-side projection 16 slides lightly. In addition, by providing a means for reducing friction such as applying an arbitrary lubricant, it is possible to satisfactorily guide the scanning device.

  With the configuration as described above, the guide means for the scanning device 10 can be performed only by the guide rod 21, and the guide rail 22 bears only an effect of light guiding. Therefore, the guide rod 21 that bears all of the pressure applied by the drive belt in addition to the weight of the scanning device and the sliding portion of the front-side protrusion 17 that slides on the guide rod 21 effectively reduce the frictional resistance. It is necessary to make it feasible. For example, the guide hole of the front-side protrusion 17 that slides on the guide rod 21 performs a guide action with low friction, such as a linear bearing, in addition to simply interposing a lubricant such as grease. It is advisable to provide a means for obtaining.

  In the above-described embodiment, in order to drive the scanning device, it is possible to use a conductive means conventionally used as a driving device for the scanning device, such as a timing belt or a wire. Further, as a means for applying a force to push down one end portion of the scanning device by the drive belt, it is conceivable to provide a tension adjusting means for the tension pulley so that the marrow can be adjusted. Further, as the upper guide protrusion provided on the upper portion of the guide rail 22 side, the reading portion can be positioned satisfactorily by sliding it on the lower surface of the platen. You may make it slide the said upper guide protrusion with respect to a frame member.

It is explanatory drawing which shows the structure of an image reading apparatus. It is explanatory drawing of the relationship between a scanning device and a guide member. It is explanatory drawing which shows the arrangement | positioning relationship of the member of FIG.

Explanation of symbols

1 image reader, 2 ADF, 3 document tray,
4 Pickup roller, 5 Paper handling device, 6 Document transport path,
7 transport roller device, 8 discharge path, 9 discharge tray, 10 scanning device, 11 moving frame, 12 lamp, 13 mirror, 14 lens,
15 CCD, 16 rear side protrusion, 17 front side protrusion,
18 belt mounting portion, 19 upper guide protrusion, 20 reading frame,
21 guide rod, 22 guide rail, 23/24 platen,
25 Drive belt, 26/27 Guide pulley.

Claims (3)

In an image reading apparatus provided on a top of an image recording apparatus and provided with a scanning device that reads a document while conveying it,
In order to guide the scanning device inside the reading frame of the image forming apparatus, a guide rod is provided on one side of the scanning device, and sliding guide means is provided on the other side.
A driving belt is connected to a side end portion guided by the guide rod of the scanning device, and an image of a document is read while moving the scanning device at a constant speed in the sub-scanning direction by the driving belt. ,
An image reading apparatus, wherein the image reading apparatus is disposed so as to apply a pressing action downward to an end of the scanning device on a side where the driving belt is attached.   On the side where the drive belt is attached, the force that applies a pressing action downward to the end of the scanning device is set as a force that substantially balances the weights on both sides of the scanning device guided by the guide rod. The image reading apparatus according to claim 1. A reaction force receiving member that slides on the lower surface of the platen is disposed on the upper side of the scanning device that is not connected to the belt,
The image reading apparatus according to claim 1, wherein an interval between the reading unit and the platen of the scanning device can be maintained constant.

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