JP2012070126A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader which has a cleaning mechanism reinforced in terms of strength and is capable of efficiently storing paper powder removed by the cleaning member.SOLUTION: The image reader optically reads the image of an original carried in the direction of an arrow d along reading glass 41 by a contact type reading sensor 40. The cleaning mechanism includes a cleaning brush 54 arranged so as to be rotated facing the reading glass 41, and a paper powder accumulation part 61 formed by a casing 60 covering the lower side of the cleaning brush 54, an opening 60a is formed at a part of the casing 60 (paper powder accumulation part 61), and a lid member 62 is detachably provided in the opening 60a.

Description

  The present invention relates to an image reading apparatus, and more particularly to an image reading apparatus that optically reads an image of a document conveyed one by one during conveyance.

  As an image reading apparatus for optically reading an image of a document, there are a platen set method for reading an image of a document placed on a platen glass and a sheet-through method for reading an image of a document conveyed one by one during conveyance. , Each alone or in combination. The sheet-through method has advantages in reducing the size of the apparatus, reducing the cost, increasing the speed of reading, and, in turn, the productivity of printing on a copying machine.

  By the way, in the sheet-through method, since the original is conveyed one by one along the transparent member (in the short side direction of the long reading glass) at the reading position, dust, paper dust, etc. The foreign matter adheres to the reading glass, and the portion shielded by the foreign matter appears as streak noise in the read image.

  Therefore, conventionally, a configuration has been adopted in which a brush-like cleaning member is rotatably provided facing the reading glass, and paper dust is removed from the reading glass by rotating the cleaning member between the original to be fed. It had been. In patent document 1, it is comprised so that the paper dust collect | recovered by the cleaning member may fall by the dead weight from the cleaning member, and may accumulate in an accommodating part.

  However, in the cleaning mechanism, paper dust accumulates in the storage unit as the number of sheets to be passed increases. Usually, the capacity of the storage unit is smaller than the life of the apparatus, so it is necessary to periodically remove paper dust from the storage unit. There is. In order to remove paper dust from the storage unit, a tray having a width larger than the width of the maximum size document to be conveyed is detachably provided, or a long opening larger than this width is formed in the casing to cover the opening. It is necessary to provide a detachable lid member.

  However, detachably providing a tray having a width equal to or greater than the width of the document requires a configuration for retracting a member that obstructs the attachment / detachment of the tray, and also requires a receiving member for holding a large tray. The whole device becomes large, leading to an increase in cost. Also, providing an opening that is longer than the width of the document greatly reduces the strength of the casing and makes handling of the unit troublesome in order to prevent breakage accidents.

JP 2004-48184 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image reading apparatus that includes a cleaning mechanism that is reinforced in strength and that can efficiently accommodate paper dust removed by a cleaning member.

An image reading apparatus according to one aspect of the present invention is
Reading means for optically reading an image of a document conveyed one by one at a reading position during conveyance;
A transparent member disposed between the document conveyed at the reading position and the reading unit;
A cleaning member that is rotatably arranged to rub against the document conveying side of the transparent member and is elastically deformable;
A paper dust reservoir covering the lower side of the cleaning member;
With
An opening is formed in a part of the paper dust reservoir, and a lid member is detachably provided in the opening;
It is characterized by.

  When paper dust removed from the transparent member by the cleaning member is deposited on the transparent member and accumulated in the paper dust reservoir, the paper dust is concentrated in a part of the direction perpendicular to the document conveying direction. To do. The position where the accumulation is concentrated is generally the substantially central portion in the direction orthogonal to the document conveyance direction corresponding to the document separation roller.

  In the image reading apparatus, the paper dust removed from the transparent member by the cleaning member falls and is stored in the pool portion, and most of the paper dust is collected in a part of the direction orthogonal to the document conveying direction. Then, by providing an opening that is detachably covered by the lid member only in this part, most of the paper dust can be removed from the reservoir by opening the lid member. Since the opening is provided only in a part, paper dust can be efficiently accommodated while eliminating the reduction in the strength of the casing forming the reservoir as much as possible.

  According to the present invention, the cleaning mechanism is reinforced in strength and can efficiently accommodate paper dust removed by the cleaning member.

It is a schematic block diagram which shows the principal part of the image reader which is one Example. It is sectional drawing which shows the cleaning mechanism in the said image reading apparatus. It is sectional drawing which shows the state which opened the said cleaning mechanism. (A) is explanatory drawing for showing the position of the opening part provided in the casing in the document width direction, and (B) is a graph showing the streak noise occurrence frequency in the document width direction. It is sectional drawing which shows the other example of the said cleaning mechanism.

  Embodiments of an image reading apparatus according to the present invention will be described below with reference to the accompanying drawings.

(Schematic configuration of image reading apparatus, see FIG. 1)
As shown in FIG. 1, the image reading device includes a platen set method for reading an image of a document placed on the platen glass 10, and a sheet-through method for reading an image of a document conveyed by an automatic document conveying device 20. And a reading optical system 30 and a close contact type reading sensor 40.

  The reading optical system 30 is known per se, and includes a lamp 33, mirrors 34, 35, and 36, and an imaging lens and an image sensor (CCD) (not shown). In order to read a document image by the platen set method, the lamp 33 and the mirror 34 are mounted on the first slider 31, and the mirrors 35 and 36 are mounted on the second slider 32, respectively, and are movable in the direction of arrow Z. Reading the image on the first surface of the document by the sheet-through method is performed in a state where the optical system 30 is stationary at the reading position A shown in FIG.

  Reading of the image on the second surface of the document by the sheet-through method is performed at the reading position B by the contact-type reading sensor 40. The reading sensor 40 is a well-known sensor incorporating a contact type CCD. In both reading positions A and B, reading glasses 37 and 41 are arranged along the document transport path.

  The automatic document feeder 20 includes a document placing tray 21, a pickup roller 22, a separating roller pair 23, a registration roller pair 24, and conveying roller pairs 25, 26, 27, and 28, and a path indicated by a one-dot chain line. A document is conveyed one by one along. The original is placed on the tray 21 with the first side facing up, fed from the uppermost layer by the pickup roller 22, and fed one by one by the separation roller pair 23, and passes through the registration roller pair 24. First, the reading roller A is conveyed by the conveying roller 25, and the image on the first surface is read by the optical system 30.

  Next, the original is conveyed at the reading position B by the conveying roller pair 26, and in the double-sided reading mode, the image on the second side is read by the reading sensor 40. At this time, the document is conveyed between the reading glass 41 of the reading sensor 40 and a conveyance guide member described in detail below. Thereafter, the original is discharged to a discharge tray (not shown) by the pair of conveying rollers 27 and 28.

  The close contact type reading sensor 40 has a shallow depth of focus, brings the document close to the reading glass 41 at the reading position B, is in non-contact with the reading glass 41 as much as possible, and within the range of the depth of focus, and The distance between the two surfaces and the reading glass 41 needs to be kept constant and transported.

  Therefore, in this embodiment, as shown in FIG. 2, guide plates 51 and 52 that function as conveyance guide members for the reading sensor 40 and a shaft member 53 having a semicircular cross section are attached to the casing 60. The casing 60 is attached to the cover member 65. The shaft member 53 has an arc-shaped outer peripheral surface painted in white, is used for shading correction at the time of image reading, and functions as a reading background portion. A cleaning brush 54 projects from the shaft member 53, and the shaft member 53 rotates in the clockwise direction in FIG.

(See cleaning mechanism, Figs. 2-4)
Hereinafter, a cleaning mechanism for the paper dust that has been read from the document conveyed at the reading position B in the direction of the arrow d and adhered to the reading glass 41 will be described. Specifically, the cleaning brush 54 is attached to the outer peripheral flat surface of the shaft member 53, and is synchronized with the shaft member 53 mounted on the casing 60 being rotated in the direction of arrow C by a driving means (not shown). Rotate. The cleaning brush 54 is, for example, a bundle of about 2D (denier) polyimide resin.

  The cleaning brush 54 is used once in the direction of arrow C while the document is conveyed one by one (while the trailing edge of the preceding document has passed the reading position B and the leading edge of the next document reaches the reading position B). The brush 54 is rotatively driven and rubbed while elastically deforming the surface of the reading glass 41 to take in paper dust adhered to the surface of the reading glass 41.

  The guide plate 52 also constitutes a part of the casing 60, and the casing 60 surrounds other than the upper part of the cleaning mechanism and forms a paper dust reservoir 61. When the brush 54 comes into contact with the tip of the guide plate 52, the paper powder taken in by the brush 54 is discharged, and the discharged paper powder falls freely and is stored in the reservoir 61.

  The cover member 65 is installed so as to be swingable about a support shaft 70 provided in the apparatus main body, and as shown in FIG. It can be opened. In this open state, the reading glass 41 can be cleaned with a waste cloth or the like. However, when a plurality of originals are conveyed continuously and an image is read, the reading glass 41 needs to be cleaned before the conveyance of all the originals is completed. The cleaning brush 54 is installed to clean the reading glass 41 between the original to be passed, and the paper dust removed from the reading glass 41 by the brush 54 is accumulated in the accumulation portion 61.

  As the number of passing sheets increases, paper dust accumulates in the accumulation portion 61, and eventually the accumulation portion 61 becomes full, that is, the accumulated paper dust comes into contact with the end of the rotating brush 54. . In this case, the paper dust accommodated in the pool portion 61 is reattached to the brush 54 and the reading glass 41 is soiled. Therefore, it is necessary to periodically take out paper dust from the reservoir 61. Therefore, an opening 60 a is formed at the bottom of the casing 60 and is configured to be always covered with the lid member 62. One end 62 a of the lid member 62 is engaged with the notch 65 a of the cover member 65, and the other end 62 b is fixed to the casing 60 with a screw 63. The lid member 62 can easily open the opening 60a by removing the screw 63, and in this state, the paper powder accommodated in the reservoir 61 can be taken out.

  By the way, if the opening part 60a is formed in the casing 60, the intensity | strength of casing 60 itself will become weak. In the present embodiment, the casing 60 is reinforced as follows.

  The inventor has experimentally investigated the state in which the paper dust removed from the reading glass 41 by the cleaning brush 54 is accumulated in the paper dust collecting portion 61 by being picked up from the conveyed document. However, it has been found that the accumulation of paper dust is concentrated in a part of the direction orthogonal to the document transport direction d (hereinafter also referred to as the document width direction). The position is generally a substantially central portion in the document width direction substantially corresponding to the axial length W1 of the separation roller pair 23 (see FIG. 4A).

  FIG. 4B shows the frequency with which streak noise caused by paper dust adhering to the reading glass 41 is generated in the image read by the reading sensor 40 with respect to the document width direction. This corresponds to the amount of paper dust accumulated in the section 61. As apparent from FIG. 4B, the accumulated amount of paper dust is remarkably increased in the substantially central portion in the document width direction corresponding to the separating roller pair 23. Since a large amount of stress acts on the document from the separation roller 23, it is considered that a large amount of paper dust is generated in this portion. The amount of paper dust generated in other parts is very small.

  As shown in FIG. 4A, the separating roller pair 23 is composed of an upper roller 23a and a lower roller 23b. The separating portion has a width W1 and is located at the center in the document width direction. Accordingly, in the casing 60, the opening 60 a is formed with the width W 2 only in the central portion in the document width direction where the accumulated amount of paper dust is large, and is covered with the lid member 62. Paper dust can be removed from the reservoir 61. Since the opening 60a is provided only in a part in the document width direction, paper dust can be efficiently accommodated while eliminating the strength reduction of the casing 60 including the reservoir 61 as much as possible.

  Regarding the casing 60, the strength reduction can be suppressed by forming the opening 60 a in a part in the width direction, but the strength of the casing 60 can be reinforced by fixing the lid member 62 to the casing 60 with the screws 63. There may be only one screw stop, but if there are a plurality of screws, the strength is further reinforced. Further, as a measure for strengthening strength, if a rib is formed around the opening 60a, or if the casing 60 is formed of a metal material, a drawing process is performed around the opening 60a, or the opening 60a It may be possible to make the periphery thicker than the other parts of the casing 60.

  The reservoir 61 of the casing 60 preferably has a wall 61a as shown in FIG. The wall 61a has an arc shape that is slightly larger than the rotation trajectory of the outer peripheral portion of the cleaning brush 54, and is installed at two points E in FIG. That is, the wall portion 61a is disposed so as to sandwich a portion with a large amount of paper dust accumulation, and restricts the accumulated paper dust from moving in the document width direction. Thus, when the cover member 65 is opened as shown in FIG. 3, the paper dust accommodated in the accumulation portion 61 is prevented from moving and scattering in the document width direction.

(Other examples)
The image reading apparatus according to the present invention is not limited to the above embodiment, and can be changed within the scope of the gist thereof.

  For example, the image reading apparatus may have various forms. For example, a contact type reading sensor may be installed in place of the optical system 30. Further, the details of the automatic document feeder can adopt any configuration.

  As described above, the present invention is useful for an image reading apparatus, and is particularly excellent in that it has a cleaning mechanism reinforced in strength and can efficiently accommodate paper dust removed by a cleaning member. .

DESCRIPTION OF SYMBOLS 20 ... Automatic document feeder 23 ... Separation roller pair 40 ... Reading sensor 41 ... Reading glass 54 ... Cleaning brush 60 ... Casing 60a ... Opening 61 ... Paper dust storage part 62 ... Cover member 63 ... Screw B ... Reading position d ... Document Transport direction

Claims (7)

Reading means for optically reading an image of a document conveyed one by one at a reading position during conveyance;
A transparent member disposed between the document conveyed at the reading position and the reading unit;
A cleaning member that is rotatably arranged to rub against the document conveying side of the transparent member and is elastically deformable;
A paper dust reservoir covering the lower side of the cleaning member;
With
An opening is formed in a part of the paper dust reservoir, and a lid member is detachably provided in the opening;
An image reading apparatus.   The image reading apparatus according to claim 1, wherein the pool portion is disposed below a height at which the cleaning member contacts the transparent member.   The image reading apparatus according to claim 1, wherein the opening is located at a substantially central portion in a direction orthogonal to the document conveyance direction. Furthermore, a document separation roller provided in the document conveyance unit is provided,
The image reading apparatus according to claim 1, wherein the opening is opened substantially corresponding to the axial length of the original separating roller.   5. The paper dust reservoir portion includes a wall portion that restricts movement of the accumulated paper dust in a direction orthogonal to the document conveying direction. 6. Image reader.   The image reading apparatus according to claim 1, wherein the lid member is screwed to the paper dust reservoir.   The periphery of the opening is reinforced by forming a rib, by drawing, or by making it thicker than the periphery. An image reading apparatus according to claim 1.

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