JPH11184174A - Original reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original reader constituted so that failure such as a black strip caused by soil or dust at a reading time is prevented from occurring. SOLUTION: A cleaning member 20 is arranged on the back surface side of a carrying guide plate 15 so that the plate 15 and the cleaning member 20 can be integrally rotated by a rocking member. Then, a distance between the shaft supporting point 21 of the rocking member and the end surface of the cleaning member 10 is set to be equal to a distance between the point 21 and the front surface of a contact glass 25. After an original is passed through a gap between the plate 15 and the glass 5, the plate 15 and the cleaning member 20 arranged on the back surface side of the plate 15 are integrally rotated with the point 21 as a center and the cleaning member 20 is moved while being brought into slidable contact with the front surface of the glass 5. Thus, the soil is eliminated from the front surface of the glass 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an original reading apparatus such as a digital copying machine and a scanner, and more particularly to an apparatus capable of removing dust and the like on the surface of a contact glass.

[0002]

2. Description of the Related Art When reading a binary image with a digital copying machine or the like, as the reading sensitivity is increased, even minute dirt or dust on the contact glass is read, and the result is read. The image is formed as a document image, and dirt and the like appear as black dots on the image.
If the reading sensitivity is reduced to solve this problem, the reproducibility of a low-density original such as a pencil original deteriorates. In particular, in a document reading apparatus that has a means for reading the document image by condensing the reflected light on the image forming element by moving the document, minute dirt and dust on the contact glass may become black stripes on the image. Appear, causing deterioration of the copied image. FIG. 1 is a cross-sectional view showing an example of a conventional document reading apparatus of this type.

In this apparatus, a reading unit 1 is provided with a condenser lens 2 and C
A CD 3, a mirror 4, a contact glass 5, a lamp 6, and the like are provided. These mirror lens systems have fixed positions for reading while transporting the original. The document transport unit 10
Is provided with a document table 11, a paper feed roller 12, a conveyance belt 13, an intermediate roller 14, a conveyance guide plate 15, a paper discharge roller 16, a paper discharge table 17, and the like. It is called by the rollers 8, is conveyed through the conveyance belt 9 and the intermediate roller 10, and is irradiated with light by the lamp 6 of the reading device when passing through the narrow gap between the conveyance guide plate 15 and the contact glass 5. CC light
The document image is read by being guided to D3. The arrows in the figure indicate the document transport path. The document feeding speed is set to the same speed in synchronization with the linear speed of image formation in the reading unit 1. The original is discharged onto the discharge tray 17 after being read and stacked.

[0004] The above-mentioned stains are mainly caused by the stains (paper dust, correction liquid, etc.) adhering to the original document moving onto the contact glass 5 and adhering thereto. This occurs when the sent original is pressed against the contact glass 5 by the transport guide plate 15. In other words, the gap between the transport guide plate 15 and the contact crow 5 is narrow so that the original does not flutter, and the original is turned to discharge the paper. Therefore, the contact glass 5 tends to be rubbed with dirt.

Therefore, according to the technique disclosed in Japanese Patent Application Laid-Open No. H6-164863, for example, a reference reflection plate and a contact glass 5 arranged at the same position as the conveyance guide plate 15 in the example of FIG.
The cleaning member passes through the gap for each sheet passing to remove dirt. However, there is no problem if the gap on the contact glass 5 is wide, but if the gap is narrow, it is very difficult to pass the cleaning member, and it is difficult to apply to the document reading apparatus having the configuration shown in FIG. There is. Although a method of ventilating the contact glass 5 to prevent dirt from adhering is also known, there is a problem that it is difficult to remove rubbed dirt and the like.

[0006] On the other hand, there is a method in which an original image is separated from other isolated points by software at the time of reading the original so that the image due to dirt or dust is removed from the read image as much as possible. However, even with this method, it is not possible to completely eliminate black spots and black streaks on the image.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a document reading apparatus capable of preventing the occurrence of a reading trouble caused by dirt or dust in the related art.

[0008]

According to a first aspect of the present invention, there is provided an original reading apparatus, comprising: a contact glass for exposing an original; A document reading device that includes a conveyance guide plate for conveying the document while maintaining a predetermined gap, and a conveyance roller that conveys the document, and for cleaning the contact glass in a document reading device that reads a document image while conveying the document. A cleaning member is provided on the rear surface of the transport guide plate, and a driving member for rotating the cleaning member from the rear surface of the transport guide plate toward the contact glass is provided.

According to a second aspect of the present invention, the transport guide plate and the cleaning member are rotatably supported integrally with each other, and the distance from the pivot to the end face of the cleaning member is set to be equal to the distance from the pivot to the contact. The distance to the glass is equal to the distance, and the distance from the pivot point to the end face of the transport guide plate is shorter than the distance from the pivot point to the contact glass.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In the following, portions common to the related art will be denoted by the same reference numerals, and redundant description will be omitted. FIG. 2 is a sectional view showing an embodiment of the present invention. In the document reading apparatus of the present embodiment, in order to clean the surface of the contact glass 5, a cleaning member 20 is disposed on the rear side of the transport guide plate 15, and the transport guide plate 15 and the cleaning member 20 are driven by a driving member (not shown). It can be rotated integrally. In the figure, reference numeral 21 denotes a shaft fulcrum of the driving member.

Here, the distance from the pivot point 21 to the end face of the cleaning member 20 is equal to the distance from the pivot point 21 to the surface of the contact glass 5, while the distance from the pivot point 21 to the end face of the conveyance guide plate 15 is set. Is shorter than the distance from the pivot point 21 to the surface of the contact glass 5.

The operation of the present embodiment will be described below with reference to FIG. After the document passes between the conveyance guide plate 15 and the contact glass 5, the conveyance guide plate 15 and the cleaning member 20 on the rear side thereof rotate integrally about the pivot point 21, and the cleaning member 20 is moved to the contact glass 5 side. And rotates while sliding on the surface of the contact glass 5 to wipe off dirt and the like from the surface of the contact glass 5. At this time, as described above, the shaft fulcrum 21
Is shorter than the distance from the fulcrum 21 to the surface of the contact glass 5, the end surface of the transfer guide plate 15 does not touch the surface of the contact glass 5 and becomes dirty.

A time interval for performing this cleaning is set in advance, and the surface of the contact glass 5 is cleaned at regular time intervals.
It is preferable to keep the degree of contamination on the surface of the sheet at a certain level or less.However, when documents are sent continuously, the interval between the documents is short, so that this cleaning operation should not be performed. It is preferable that the cleaning operation is performed after the reading of the document set on the document table 11 at a time is completed.

The cleaning member 20 may be a fibrous cleaning material or a blade-shaped cleaning means, and any cleaning can be performed.

[0015]

As described above, in the original reading apparatus according to the present invention, the cleaning member disposed on the rear surface of the transport guide plate for cleaning the contact glass is moved from the rear surface of the transport guide plate to the contact glass side. Because it is rotated integrally, it can be applied even if the gap between the conveyance guide plate and the contact glass is narrow, and it is possible to reliably remove the dirt on the contact glass that causes black spots and black stripes on the image. effective.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a document reading apparatus of a type having means for reading a document image by moving a document.

FIG. 2 is a cross-sectional view illustrating an embodiment of a document reading apparatus according to the present invention.

FIG. 3 is a cross-sectional view showing a state of the document reading apparatus according to the embodiment of the present invention at the time of cleaning.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reading part 2 Condensing lens 3 CCD 4 Mirror 5 Contact glass 6 Lamp 10 Document conveyance part 11 Document stand 12 Feed roller 13 Transport belt 14 Intermediate roller 15 Transport guide plate 16 Discharge roller 17 Discharge table 20 Cleaning member 21 Shaking Shaft fulcrum of moving member

Claims (2)

[Claims] A contact glass for exposing the original, a transport guide plate for transporting the original with a predetermined gap with respect to the contact glass, and a transport roller for transporting the original; In a document reading apparatus that reads a document image while transporting the document, a cleaning member disposed on the rear surface of the transport guide plate to clean the contact glass, and the cleaning member is moved from the rear surface of the transport guide plate to the contact glass side. A document reading device, comprising: a driving member configured to rotate integrally with the transport guide plate. 2. The cleaning apparatus according to claim 1, wherein the transport guide plate and the cleaning member are integrally rotatably supported, and a distance from the pivot point to an end face of the cleaning member is equal to a distance from the pivot point to the contact glass. 2. The document reading apparatus according to claim 1, wherein a distance from the pivot point to the end face of the transport guide plate is shorter than a distance from the pivot point to the contact glass.