JPH0613263U - Reader - Google Patents

Abstract

(57) [Abstract] [Purpose] To make it easy to position the rear roller with respect to the reading unit, and to reduce the document width limit as much as possible. A reading device according to the present invention is disposed at an end portion of a back roller 60, and abuts on an outer surface 41a of a cover glass 41 of a contact type image sensor 40 so that a predetermined distance is provided between the outer surface 41a and the outer surface 41a. Abutment portion 6 that secures the gap t of
2, 62, a drive motor 54 for rotating the contact portions 62, 62, a drive gear 53, a reduction gear train 50, and a driven gear 65.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a reading device having a back roller at a portion facing a reading unit with a document feeding area interposed therebetween.

[0002]

[Prior art]

 Generally, in a reading device which is designed to read a written image of a document being conveyed, a back roller is disposed at a portion facing the reading unit with a document feeding area interposed therebetween, and the back roller is used to scan a document in a predetermined manner. By guiding within a distance, for example, within the depth of field of the reading unit, the resolution of the document by the reading unit is set to be in a practical range.

[0003]

[Problems to be solved by the device]

 By the way, in this type of reading device, a large diameter portion is formed at both ends of the back roller, and the large diameter portion is brought into contact with the reading unit to easily position the peripheral surface of the back roller. I have to.

However, when the width of the document is such that it abuts against the large diameter portion, the document cannot be read because the large diameter portion prevents the document from being conveyed downstream. Although the large-diameter portion is usually disposed on the outermost side of the back roller, it significantly limits the width of the original that can be read.

In view of the above situation, an object of the present invention is to provide a reading device in which the position of the back roller with respect to the reading unit can be easily determined and the limitation of the document width can be made as small as possible. To do.

[0006]

A reading device according to the present invention is a reading device having a back roller at a portion facing a reading unit with a document feeding area interposed therebetween, and the reading device is disposed at an end of the back roller. It is provided with a large-diameter portion that secures a predetermined gap with the reading unit by abutting on the reading unit, and a drive unit that rotates the large-diameter portion.

[0007]

[Action]

 According to the above configuration, even when the original comes into contact with the large diameter portion, the original can be conveyed downstream by the rotation.

[0008]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment.

FIG. 1 conceptually shows a reading device according to the present invention. The reading apparatus illustrated here is applied to an image reading unit such as a facsimile machine, and as shown in FIG. 3, it is provided at a portion located between the conveyance roller pair 10 and the discharge roller pair 20 in the original conveyance area 1. A frame 30 is provided.

The frame 30 includes a bottom wall 31 having a rectangular plate shape, and a pair of bottom walls 31 standing upright from both sides of the bottom wall 31 and having notches 32 a and 33 a formed at respective portions facing each other from their respective leading edges. Not shown, with the bottom wall 31 disposed at the lower part of the document transport area 1 and the pair of side walls 32, 33 facing upward, respectively. It is held in the housing.

As is apparent from FIG. 1, a reading unit 40 is arranged on the frame 30 between the pair of side walls 32 and 33. As shown in FIG. 3, the reading unit 40 includes a box-shaped body 42, one side of which is covered with a cover glass 41, in which a light source 43, a rod lens array 44, and a photoelectric conversion element 45 are arranged. Type image sensor, which has a length longer than the maximum width of the original to be read, for example, a width of the B4 size original, and the outer surface 41a of the cover glass 41 is located in the original conveyance area. It is held on the bottom wall 31 of the frame 30 via the bracket 46 in a manner facing the first side. In this image sensor 40, the original reading surface is formed on the outer surface 41a of the cover glass 41, and the original reading position α is formed in the center of the cover glass 41.

Further, as shown in FIG. 1, the frame 30 includes a reduction gear train (driving means) 50 on one side wall 32. The reduction gear train 50 is fixed to the large gear 52 rotatably provided at the tip of the reduction shaft 51 and concentrically with the end face of the large gear 52, and is driven via a drive gear (driving means) 53. A small gear 55 connected to a motor (driving means) 54, and is arranged on the outer surface of the side wall 32 via the reduction shaft 51.

On the other hand, the reading device is provided with a back roller 60 at a position located above the document transport area 1 and between the transport roller pair 10 and the discharge roller pair 20. The back roller 60 is a columnar regulating portion 61 which is formed to be slightly shorter than the cover glass 41 of the image sensor 40 and longer than the width of the B4 size document, and is concentric with both end portions of the regulating portion 61. It is arranged above, and its radius is longer than that of the restriction portion 61, and specifically, the radius is formed to be longer than that of the restriction portion 61 only at a distance t corresponding to the depth of field of the image sensor 40. A pair of columnar contact portions (large diameter portions) 62, 62, and concentric projections outward from the center of the end faces of the contact portions 62, 62, respectively, are provided on the side wall 32 of the frame 30. , 33 has a pair of shaft portions 63, 64 formed to have a diameter slightly smaller than the widths of the notches 32a, 33a formed therein, and is integrally formed of a highly slidable resin such as silicon rubber. ing.

Further, the back roller 60 is provided with a driven gear (driving means) 65 at one end thereof. The driven gear 65 is configured to mesh with the large gear 52 of the reduction gear train 50, and is concentrically fixed to the end surface of one shaft portion 63.

The rear roller 60 configured as described above arranges the pair of shaft portions 63 and 64 in the notches 32a and 33a formed in the side walls 32 and 33, respectively, and also drives the driven gear 65. Is engaged with the large gear 52, and is held by the frame 30 in a state of being biased in a direction approaching the image sensor 40 by biasing means such as a coil spring (not shown). At this time, since the abutting portions 62, 62 of the back roller 60 are pressed against the outer surface 41a of the cover glass 41, the outer surface 41a of the cover glass 41 and the back roller 60 in the document transport area 1 are pressed. A space t corresponding to the depth of field of the image sensor 40 is secured between the peripheral surface 61a of the restriction portion 61 and the peripheral surface 61a.

In this state, when a start switch (not shown) is turned on to read the document P, for example, the B4 size document P1, the drive rollers 11 and 21 of the transport roller pair 10 and the discharge roller pair 20 are driven, respectively. The document P1 is started to be conveyed in cooperation with the pinch rollers 12 and 22 which are pressed against the drive rollers 11 and 21.

Further, the image sensor 40 is driven and the reading operation thereof is started, and at the same time, the drive motor 54 is driven, and the back roller 60 is driven via the drive gear 53, the reduction gear train 50 and the driven gear 65. The rotation of is started.

The original P1 conveyed by the pair of conveying rollers 10 passes through a gap t defined between the outer surface 41a of the cover glass 41 and the peripheral surface 61a of the regulating portion 61 of the rear roller 60, and Further, it is conveyed downstream by the pair of discharge rollers 20. During this time, the image sensor 40 sequentially reads the document P1 at the reading position α and obtains image data corresponding to the written image.

At this time, according to this reading device, as shown in FIG. 1, the original P1 is removed from the outer surface 41a of the cover glass 41 of the image sensor 40 by the peripheral surface 61a of the regulating portion 61 of the rear roller 60. Since the document is guided within the preset distance t, the resolution at the time of reading the original by the image sensor 40 is in the practical range, and the original P1 can be read accurately.

On the other hand, if the original P2 has a width exceeding the B4 size, such as an output sheet of a computer, both ends of the original P2 abut on the abutting portions 62, 62 of the back roller 60, respectively. Become.

However, according to the reading device, the back roller 60 is rotationally driven by the driving of the drive motor 54, and as shown in FIG. 2, the original P2 that abuts on the abutting portions 62, 62 is moved. The original P2 can be read at the reading position .alpha. Of the image sensor 40 because it can be sequentially conveyed downstream by the rotational force. In this case, the original P2 conveyed by the abutting portions 62, 62 is brought into close contact with the outer surface 41a of the cover glass 41, that is, the conveyed original P2 is transferred from the outer surface 41a of the cover glass 41 in advance. Since the guide is carried out within the set distance t, the resolution at the time of reading the original by the image sensor 40 is in the practical range, and the original P2 can be accurately read.

In the above embodiment, the back roller 60 in which the restricting portion 61, the contact portions 62 and 62, and the shaft portions 63 and 64 are integrally formed is illustrated, but the back roller 60 and the large diameter portion 62 are illustrated. , 62 need not necessarily be integrated. Further, when the back roller 60 and the large-diameter portions 62 and 62 are separately configured, it is not always necessary to rotate the back roller 60.

[0023]

[Effect of device]

 As described above, according to the reading device of the present invention, even when a document comes into contact with a large diameter portion, the document can be conveyed downstream by its rotation, so that the reading of the rear roller is possible. The positioning with respect to the unit can be easily performed, and the limitation of the document width can be made as small as possible.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a main part of a reading device according to the present invention.

FIG. 2 is a conceptual diagram showing an operation of the reading device shown in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

[Explanation of symbols]

 Document transport area 1 Reading unit 40 Back roller 60 Large diameter portion 62 Driving means 50, 53, 54, 65

Claims (1)

[Scope of utility model registration request] 1. A reading device having a back roller at a portion facing the reading unit with a document transport area interposed therebetween, the reading unit being disposed at an end of the back roller and contacting the reading unit. A reading device comprising a large-diameter portion that secures a predetermined gap between the large-diameter portion and a driving unit that rotates the large-diameter portion.