JP2005089116A - Automatic manuscript feeder and image formation device using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic manuscript feeder in which a manuscript passed through a reading part is hardly rocked, jitter and color shift are hardly generated and conveyance of the manuscript is stabilized, and to provide an image formation device using the feeder. <P>SOLUTION: A reading belt 20 is laid on a reading belt driving roller 19, a reading belt pressurization roller 27 and a reading belt driven roller 44, the reading belt driven roller 44 is arranged on a scale 53 and the reading belt 20 is wrapped around to that position. An inclination is provided on the scale 53 in order to scoop up the manuscript. The manuscript P of which an image is read out on a slit glass 52 is passed on the scale 53 and at this time, a leading end of the manuscript P and the reading belt 20 rotated in the manuscript conveying direction are moved at the approximately same speed. Therefore, relative line speed of the both are approximately zero. Rocking and vibrating of the leading end of the manuscript are not generated when the leading end of the manuscript passed on the slit glass 52 is raised on the scale 53, generation of jitter and the color shift at color copying can be prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an automatic document feeder using a sheet-through method and an image forming apparatus using the automatic document feeder.

Conventional techniques using an endless belt for a reading unit for reading a document of an automatic document feeder are known, but the distribution and layout of the endless belt outside the reading unit are determined by the positions of the registration roller and the discharge roller. In particular, the inventor of the present application does not know any technique regarding the positional relationship with the scale or the positional relationship with the contact glass.
JP-A-8-30044 JP-A-6-22080 JP-A-11-59949

  By the way, when an endless belt is used in the reading unit of the automatic document feeder that scans and reads a document in order to realize a high-quality image, the endless belt exists only on the contact glass and is downstream in the document transport direction. If there is a fixed guide plate that is not distributed on the scale, the leading edge of the document that has passed through the reading section hits the fixed guide plate when it rises above the upper surface of the scale, and the document being read is impacted by that impact. Jitter occurs due to shaking, and color misregistration occurs during color copying.

  In addition, the endless belt is not provided with a driven roller or the like having a suitable pressure for paper conveyance at the opposite position, so the endless belt does not have a function of conveying a document. Therefore, the document conveyance becomes unstable only with the endless belt. easy.

  Further, in this type of apparatus, it is important to maintain and manage the gap between the endless belt and the contact glass and other opposing members. If the gap is smaller than the target value, the conveyance resistance increases during document conveyance, which may change the document conveyance speed, and if the gap is large, the exposure of the document being read increases between the conveyance belt and the contact glass. These all reduce the reading accuracy of the document and cause a reduction in image quality.

  The present invention has been made to solve such problems.

  An automatic document feeder according to claim 1 of the present invention is an automatic document feeder that performs reading while conveying a document, a document reading unit that reads a document on a reading member at a fixed position, and the document on the reading member. A document conveying unit configured to convey the document while being in contact; the document conveying unit is configured to hang an endless belt-like reading belt around a plurality of rollers, and one of the rollers is located upstream of the fixed position in the document conveying direction; The other one of the rollers is disposed downstream of the fixed position in the document transport direction, and a slope member having a slope that contacts the document transported downstream of the reading member in the document transport direction is disposed, and the reading is performed. The belt is arranged to the vicinity of the slope member.

  According to a second aspect of the present invention, in the automatic document feeder of the first aspect, the second document conveying means is disposed in the vicinity of the document conveying means downstream in the document conveying direction.

  According to a third aspect of the present invention, in the automatic document feeder of the second aspect, the document conveying means includes a pair of integrally formed frame members, and at least a roller on the upstream side in the document conveying direction closest to the fixed position And a roller, which is farthest from the fixed position and downstream in the document conveying direction, is assembled between the frame members.

  According to a fourth aspect of the present invention, in the automatic document feeder according to the third aspect, the frame member has an abutting portion capable of contacting the reading member and the slope member.

  According to a fifth aspect of the present invention, in the automatic document feeder of the fourth aspect, the abutting portion is provided on each of the pair of frame members.

  According to a sixth aspect of the present invention, the automatic document feeder according to any one of the first to fifth aspects is used.

  The present invention has an effect that the original that has passed through the reading section is less likely to be shaken, jitter and color misregistration are less likely to occur, and the conveyance of the original is stabilized.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  FIG. 1 is a view showing an embodiment of an automatic document feeder according to the present invention and an embodiment of an image forming apparatus using the same. In the figure, reference numeral 50 denotes a main body of an image forming apparatus such as a copy or printer, and a reading unit (or reading position) 51, a slit glass 52, a document scale 53, and a platen glass 54 are provided on the upper surface thereof. The automatic document feeder is mounted on the image forming apparatus 50. The document table 2, the pickup roller 7, the paper feeding belt 9, the reverse roller 10, the pull-out roller 12, the turn roller 14, the reading inlet roller 16, and the reading belt drive. A roller 19, a reading belt 20 including an endless belt, a reading outlet roller 21, a reading belt pressure roller 27, a paper discharge roller 28, a paper discharge tray 29, and a reading belt driven roller 44 are provided. In addition, a transport path is formed between each table, each belt, and each roller so that the document can be transported.

  FIG. 2 is a schematic diagram showing the reading belt 20 and its drive system. The reading belt 20 is wound around the reading belt driving roller 19, the reading belt pressure roller 27, and the reading belt driven roller 44. The reading belt driven roller 44 is disposed on the scale 53, and accordingly, the reading belt 20 is also arranged to this position. The scale 53 is inclined to scoop up the document whose image has been read on the slit glass 52.

  The operation of this embodiment will be described with reference to FIG. The original P whose image has been read on the slit glass 52 passes through the scale 53. At this time, the leading end portion of the original P and the reading belt 20 rotating in the original conveying direction move at substantially the same speed. Therefore, the relative linear velocity of both is almost zero. Since there is no fixed guide plate as in the prior art, the leading edge of the document that has passed over the slit glass 52 does not sway or shake when it rises on the scale 53. There is no occurrence of jitter due to the shaking of the original document, color misregistration at the time of color copying, and the like, and it is possible to prevent deterioration in image quality.

  Further, as shown in FIG. 4, a reading exit roller 21 is provided in the vicinity of the reading belt driven roller 44 which is the most downstream in the document conveying direction. The reading exit roller 21 is in contact with a driven roller 21a for generating an appropriate pressure for conveying the document. By arranging the reading exit roller 21 having a conveying force in the immediate vicinity of the reading belt 20 in which the conveying force of the document P is likely to be unstable, more stable conveying property is obtained when the document P passes the reading belt 20. It can be secured.

  Further, as shown in FIG. 5, a housing 101 for holding the reading belt driving roller 19 and the reading belt pressure roller 27 is provided. The housing 101 is a frame member. By assembling the housing 101 to a housing 101 formed of a frame in which rollers are integrally formed, the dimensions between the rollers and the dimensions of each roller and related parts can be easily maintained. In other words, variations in assembling that occur when the housing 101 is composed of a plurality of components and variations in dimensions due to the accumulation of the dimensions of each component are suppressed. 53, the gap between the platen glass 54 and other opposing members can be maintained as intended.

  FIG. 6 is a detailed view of the housing 101. A shape in which the reading belt driving roller 19 and the reading belt pressure roller 27 are held in the housing 101 formed integrally (one component) with a metal or resin material. The provided form is shown.

  As shown in FIG. 7, protrusions 102 are provided on the bottom of the housing 101, and these protrusions 102 are in contact with the slit glass 52 and the scale 53. FIG. 8 shows the housing 101 as viewed from the rear. A projection 102 is also provided at the rear bottom of the housing 101, and the housing 101 abuts against the slit glass 52 and the scale 53 by the projections 102 at both the front and rear ends. That is, in accordance with the shape of the slit glass 52 and the scale 53 constituting the reading unit, the protrusions 102 for abutment are provided at almost both ends in the longitudinal direction, and the gap between the reading belt 20 and the slit glass 52 and other opposing members is set. Image quality deterioration prevention is enhanced by making it more stable and easy to maintain as intended.

1 is a diagram showing an embodiment of an automatic document feeder according to the present invention and an embodiment of an image forming apparatus using the same. 1 is a schematic side view showing the reading belt of FIG. 1 and its drive system. Side view showing the operation of the drive system of FIG. Side view showing a reading exit roller provided in the vicinity of the reading belt driven roller A perspective view showing a housing for holding a reading belt driving roller and a reading belt pressure roller Perspective view showing the housing alone 5 and 6 are perspective views showing a state in which a reading belt driving roller and a reading belt pressure roller are held in the housing of FIGS. 5 is a perspective view showing the housing holding the reading belt driving roller and the reading belt pressure roller when viewed from the opposite side of FIG.

Explanation of symbols

2: Document table 7: Pickup roller 9: Paper feed belt 10: Reverse roller 12: Pull-out roller 14: Turn roller 16: Reading entrance roller 19: Reading belt drive roller 20: Reading belt 21: Reading exit roller 21a: Follow roller 27 : Reading belt pressure roller 28: paper discharge roller 29: paper discharge tray 44: reading belt driven roller 50: image forming apparatus main body 51: reading unit 52: slit glass 53: document scale 54: platen glass 101: housing 102: projection P: Manuscript

Claims (6)

An automatic document feeder that reads a document while conveying the document, and includes a document reading unit that reads a document on a reading member at a fixed position, and a document conveying unit that conveys the document while contacting the reading member. The means wraps an endless belt-like reading belt around a plurality of rollers, one of the rollers being upstream of the fixed position in the document transport direction, and the other of the rollers being the position of the document at the fixed position. A slope member disposed on the downstream side in the transport direction and having a slope with which a document conveyed on the downstream side in the document transport direction of the reading member comes into contact is arranged, and the reading belt is arranged near the slope member. Automatic document feeder. 2. The automatic document feeder according to claim 1, wherein a second document feeder is disposed in the vicinity of the document feeder in the downstream of the document feeding direction. 3. The automatic document feeder according to claim 2, wherein the document conveying means includes a pair of integrally formed frame members, at least a roller on the upstream side in the document conveying direction closest to the fixed position, and farthest from the fixed position. An automatic document feeder, wherein a roller downstream in the document transport direction is assembled between the frame members. 4. The automatic document feeder according to claim 3, wherein the frame member has an abutting portion capable of contacting the reading member and the slope member. 5. The automatic document feeder according to claim 4, wherein the abutting portion is provided on each of the pair of frame members. An image forming apparatus comprising the automatic document feeder according to claim 1.

Images