JP2003140404A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive image reader without adding a new part for the purpose of cleaning while keeping stable image quality by automatically removing dirt and dust dropping and adhering to the surface of a document glass without performing special operation by an operator when an automatic document feeder is opened/ closed. SOLUTION: This image reader is provided with a driving control part for eliminating dirt and dust by operating a carrying belt 120 in the ADF 101 for a specified time when a document detection sensor 302 detects that the document S does not exist on a platen glass 116.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus, and more particularly to an image reading apparatus equipped with an automatic document feeder for automatically feeding a document onto a document table.

[0002]

2. Description of the Related Art In a conventional image reading apparatus equipped with an automatic document feeder of this type, an automatic document feeder is used when one wants to copy a book or magazine spread or a document with cut and paste. It is necessary to open and place the original directly on the platen glass. Therefore, depending on the usage environment, dust and dirt in the room may adhere to the platen glass when opening and closing.

In recent years, since high-resolution, high-gradation and high-quality reading is possible, even if the above-mentioned fine dust or dust adheres to the platen glass, it can be identified on the read image. It started to come. In particular, in a flow-reading type image reading apparatus that reads a document on a platen glass with respect to the reading unit, streak-shaped noise is generated in a straight line in the document conveyance direction, and therefore, the reading is performed. The image is remarkably deteriorated.

As to the dust on the surface of the platen glass, conventionally, as disclosed in Japanese Patent Laid-Open No. 5-188687, ventilation holes are provided in the conveyor belt of the automatic document feeder to sandwich the conveyor belt. It has been proposed to clean the surface of the platen glass by sucking dust while the ventilation hole passes over the platen glass by means of a suction device having a suction port facing the platen glass.

Further, as disclosed in Japanese Patent Laid-Open No. 11-46286, a pattern plate having a specific pattern recorded thereon, which is arranged at a position facing the reading position of the platen glass, is read and collated with a predetermined pattern. However, it is also proposed to detect dust based on the difference and prompt the operator to clean.

[0006]

However, in the conventional example for sucking dust as described above, a new fan motor is required for cleaning the platen glass, and there is a concern that the read image quality such as reading blur may deteriorate. The cost will also increase. Further, in the case of the conventional example in which dust is detected, a pattern plate is required for dust identification, and further cleaning by an operator is required after detection.

The present invention solves the above problem, and automatically removes dust and dirt that drops and adheres to the surface of the platen glass when the automatic document feeder is opened and closed, without any special operation by the operator. Accordingly, it is an object of the present invention to provide an inexpensive image reading apparatus without adding a new component for cleaning while maintaining stable image quality.

[0008]

In order to achieve the above object, according to the present invention, an original placing table and a conveying means which is arranged so as to face the original placing table and conveys an original on the original placing table. An image reading apparatus including an automatic document feeder including a document reading unit and a reading unit that reads a document on the document placing table, and a document detecting unit that detects the presence or absence of the document on the document placing table is provided. It is characterized by further comprising drive control means for operating the conveying means in the automatic document feeder for a predetermined time when the detecting means detects that there is no original on the original placing table.

Further, whether the automatic document feeder is arranged on the document placing table so that it can be separated from the document placing table, and whether the automatic document feeding device is in a state of being separated from the document placing table or in a state in which the document can be conveyed. In the case where there is no document on the document table when the automatic document feeder is set in a document transportable state on the document table from the separated state, The drive control means operates the conveying means of the automatic document feeder for a predetermined time.

In another aspect of the invention, a flow reading original table, an automatic document feeder having a conveying means for conveying a document to the flow reading original table, and an image reading section on the flow reading original table are opposed to each other. An image reading apparatus having a flow reading function for reading a document while moving the document relative to the image reading unit, the counter member being disposed at a position and driven simultaneously with the conveying means. It is characterized by further comprising drive control means for operating the facing member for a predetermined time when there is no original.

Further, the automatic document feeder is arranged on the flow reading document table so as to be separated from the flow reading document table, and the automatic document feeding device can be separated from the flow reading document table or can convey the document. When the automatic document feeder is set from the separated state to the state in which the document can be conveyed on the flow reading original table, the drive control means keeps the facing member for a predetermined time. It is characterized by operating.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions of the components described in this embodiment,
Unless otherwise specified, the material, the shape, the relative arrangement, and the like are not intended to limit the scope of the present invention thereto.

(First Embodiment) The first embodiment will be described with reference to FIGS.

FIG. 1 is a sectional view of an image reading apparatus showing a first embodiment of the present invention. This image reading apparatus is applied to the scanner unit 102 of the image forming apparatus 100. That is, the image forming apparatus 100 includes the scanner unit 10.
2 and the printer unit P, the image read by the scanner unit 102 is output to the recording material by the printer unit P.

The scanner section 102 is provided with a platen glass 116 as a document placing table, and an automatic document feed provided with a conveyor belt 120 as a conveying means which is arranged so as to face the platen glass 116 and conveys the document on the platen glass 116. An apparatus (hereinafter referred to as ADF) 101, a reading scanning system 201 as a reading unit for reading a document on the platen glass 116, and a document detection sensor 302 as a document detection unit for detecting the presence or absence of the document S on the platen glass 116. It is equipped with it.

When the document detection sensor 302 detects that there is no document on the platen glass 116, the ADF
A drive control unit 300 is provided as drive control means for operating the conveyor belt 120 in 101 for a predetermined time.

The ADF 101 is the platen glass 1
16 is provided so that the ADF 101 can be separated from the platen glass 116, and an open / close detection sensor 301 as a separated state detection unit that detects whether the ADF 101 is separated from the platen glass 116 or a document can be conveyed. When the document is set to the
When there is no document on the platen glass 116, the drive control unit 300 causes the transport belt 12 of the ADF 101 to move.
0 is operated for a predetermined time.

The reading / scanning system 201 uses the CCD to scan the image of the original document.
A reading sensor 115 such as a photoelectric conversion device reads the original, and a first illuminating lamp 110 that illuminates the original and a first scanning body 211 that includes a first mirror 111 that returns the image light of the original, and an image from the first mirror 111. The second scanning body 21 having the second and third mirrors 112 and 113 for returning light
2 and a lens 114 for focusing the image light from the second scanning body 212 on a reading sensor 115 such as a CCD. The original on the platen glass 116 is the first scanning body 12
1 is moved in the sub-scanning direction of the original to read the entire area of the original, and the second scanning body 212 is configured to move at half the speed of the first scanning body 211.

In FIG. 2, the document S fed from the ADF 101 is conveyed to a predetermined position on the platen glass 116 by the conveyance belt 120 and then stopped, and the reading scanning system 2
The operation of the optical system when the document S is read by moving 01 is shown.

The first and second scanning members 211 and 212 are driven by a motor (not shown), scan the range indicated by arrow 118, and read the document S fed on the platen glass 116.

In the case of a three-dimensional object such as a book or an original such as a cut original that cannot be conveyed by the ADF 101, the operator directly sets the original S on the platen glass 116 by opening the ADF 101, as shown in FIG. Then ADF10
Close 1 At this time, the open / close detection sensor 301
The opening / closing of the DF 101 is detected, and the document detection sensor 302 detects the presence or absence of the document S on the platen glass 116 and the size thereof. Then, the document S is read by the same operation as when the document S is conveyed by the ADF 101.

Next, the feeding of the document S by the ADF 101 will be described.

In FIG. 1, 103 is a document stacking tray for stacking a plurality of documents, and 105 is a paper feed roller. The document S fed from the document stacking tray 103 by the paper feed roller 105 is separated by the separation roller 119 one by one and introduced into the paper path. The original S introduced into the paper path is sequentially conveyed in the paper path by each roller, passes through the registration rollers 106 and 107, and then stops reading the original on the platen glass 116. Original S read thereafter
Is discharged from the paper discharge port 109 and is stacked on a paper discharge tray unit (not shown).

Normally, when the ADF 101 is mainly used, since the ADF 101 is closed, it is unlikely that dust or dust D flying in the room will be deposited on the reading portion of the platen glass 116, but a book or the like will be used. When reading the document S that cannot be conveyed by the ADF 101, the operator needs to open the ADF 101 and set the document S on the platen glass 116. Therefore, while the ADF 101 is open, the dust D remains on the platen glass 116. Is more likely to occur. Also,
If the ADF 101 is left open, the possibility increases.

Therefore, in the present invention, the ADF is set by the operator.
Opening / closing detection sensor 30 that 101 is closed
1 (step 1 in FIG. 7), when the document detection sensor 302 does not detect the document S on the platen glass 116 in step 2 in FIG. 7 (state in FIG. 4), the platen glass 116 is detected. The conveyor belt 120 of the opposing ADF 101 is operated by a drive unit (not shown) (step 4 in FIG. 7). Then, the driving is stopped after a predetermined time has passed (step 5 in FIG. 7). As a result of this operation, as shown in FIG. 5, if dust or dirt D is on the platen glass 116, it is removed from the reading area of the platen glass 116 by the conveyor belt 120.

If the document detection sensor 302 recognizes that the document S is on the platen glass 116 in step 2 of FIG. 7, this operation is not performed and the process ends (step 3 of FIG. 7). It is also possible to prevent the document S from being unintentionally discharged when the operator tries to read an image by setting the document S directly on the platen glass 116.

Actually, the original S is set on the platen glass without using the ADF 101, the original S is read and then the ADF 101 is closed and the ADF 101 is closed.
Is left open, and the operator
ADF101 trying to read an image using
When is closed, the idling operation of the conveyor belt 120 is performed.

As described above, as shown in the flow chart of FIG. 7, by driving the conveyor belt 120 at the time of detecting the change in the open-closed state of the ADF 101, it is possible to reduce unnecessary rotation of the conveyor belt 120 and to convey the conveyor belt 120. Belt 1
It is efficient because dirt, driving sound and power consumption of 20 can be suppressed.

When there is a high possibility that dust or dust D is present on the platen glass 116, the dust D discharge operation by the conveyor belt 120 is always performed before image reading, so the image quality of the read image is stabilized. It becomes possible to keep it.

Further, in the present embodiment, the AD in the reading unit is
Although a belt is used as the transporting means of F101, the same effect can be obtained when another transporting means for transporting the document S to a position facing the image reading portion of the platen glass 116, for example, a roller is used. can get.

As a matter of course, if the operation of driving the conveying means at the time of detecting the absence of the document is performed at a predetermined interval, for example, every fixed time or every time the image reading operation is performed a predetermined number of times, the ADF 101 It can also be implemented in an image reading apparatus that does not have the open / close detection sensor 301.

Further, as shown in FIG. 6, the optical system is moved to a predetermined reading position and then fixed, and the original S fed from the ADF 101 is conveyed on the platen glass 116 by the conveying belt 120 at a predetermined speed. The present invention can also be applied to a flow-reading image reading device that reads the document S while performing the scanning. In such a flow-reading image reading apparatus, the platen glass 11
If there is a minute dust or dust D at the reading position on 6, the read image will have streak-like noise in the document conveyance direction. Therefore, by performing the above operation, the image quality of the read image is stabilized. It becomes possible to keep.

(Second Embodiment) FIGS. 8 to 10 show
A second embodiment is shown. In the following description, the points that are different from the first embodiment will be mainly described, and the same components will be assigned the same reference numerals and description thereof will be omitted.

FIG. 8 is a sectional view of the image reading apparatus according to the second embodiment. That is, this image reading apparatus includes a flow-reading platen glass 830, an ADF 801 having conveyance rollers 806 and 807 as conveyance means for conveying a document to the flow-reading platen glass 830, and the flow-reading platen glass 830. And a platen roller 831 as a facing member that is arranged at a position facing the image reading unit and is driven simultaneously with the transport rollers 806 and 807. It has a flow reading function of reading the original S while moving S relatively.

Further, a platen glass 816 as a document placing table is disposed adjacent to the non-scanning platen glass 830, and a book or the like that cannot be read can be read. When reading an original on the platen glass 816, the reading scanning system 201 is moved to perform reading scanning.

Platen glass 830 for flow reading
A drive control unit 8 as a drive control unit that operates the platen roller 831 for a predetermined time when there is no document on the upper side.
Have 50.

In this embodiment, the ADF 801 is arranged on the flow-reading platen glass 830 so as to be separated from the flow-reading platen glass 830.
An open / close detection sensor 832 is provided as a separated state detection unit that detects whether 01 is a separated state or a document transportable state from the flow-reading platen glass 830.
1 is set from the separated state to the original transportable state on the flow reading platen glass 830, the drive control unit 85
When 0, the platen roller 831 of the ADF 801 is operated for a predetermined time.

FIG. 8 shows a reading scanning system 201 for reading a document S fed from the ADF 801 by a flow reading method.
, The reading scanning system 201 is moved to a predetermined reading position and then stopped, and the document S fed from the ADF 801 is conveyed on the flow reading platen glass 830 at a predetermined speed. Read the image of S.

At this time, the flown reading platen glass 83
The platen roller 831 is provided at a position facing the position of the image reading unit of 0 to prevent the influence of the transmitted light of the document S due to the exposure of the illumination lamp 110 and the floating of the document S, and prevent the document S from being conveyed. I try not to. The facing member may be the belt as in the first embodiment.

Further, when reading one original S placed on the platen glass 816, as shown in FIG.
The first and second scanning bodies 211 and 212 of the reading scanning system 201 are driven by a motor (not shown) to scan the range indicated by an arrow 818.

In the present embodiment, especially dust and dirt D
If a sheet adheres to the scanned platen glass 830, streak noise will appear in the scanned image.
When the opening / closing detection sensor 832 detects that the DF 801 is closed from the open state by the operator, the platen roller 831 is operated for a predetermined time by a drive unit (not shown). Then, as shown in FIG. 10, dust and dust D on the flow-reading platen glass 830 are removed from the reading unit.

In this embodiment, since the operator does not set the original directly on the flow-reading platen glass 830, the original detecting means is not required and the ADF 801 is opened.
Each time the closing operation is performed, the platen glass 8 for the flow reading
Dust and dust D on 30 are removed from the reading unit, and the same effect as in the first embodiment can be obtained. In addition, the automatic document feeder 801 can be made small, lightweight and low cost.

Further, if the operation of driving the platen roller 831 during the opening-closing operation of the ADF 801 is performed at a predetermined interval, for example, every time a predetermined time or a predetermined number of times of image reading operation is performed, the opening / closing detection of the ADF 101 is detected. It can also be implemented in an image reading device without the sensor 301.

[0044]

As described above, when the original detecting means detects that there is no original on the original placing table, the drive control means for operating the conveying means in the automatic original feeding device for a predetermined time is provided. Therefore, it is possible to effectively remove dust and dirt on the document mounting table, which may be a major cause of deterioration of the read image, with a simple configuration without adding special parts, and the read image quality can be improved. Can be stabilized.

Further, when the automatic document feeder is set in the state where the original can be transported from the separated state onto the document placing table, and there is no document on the document placing table, the feeding means of the automatic document feeding device is set to a predetermined value. Since it is configured to operate for a time,
It is possible to remove dust and the like more effectively.

Further, since there is a drive control means for operating the facing member facing the flow reading original plate for a predetermined time when there is no original on the flow reading original plate, it may be a major factor of deterioration of the read image. It is possible to effectively remove dust and dirt on the flow reading original table with a simple configuration without adding special parts, and the quality of the read image can be stabilized.

Further, when the automatic document feeder is set from the separated state to the original reading possible state on the original reading platen, the drive control means operates the facing member for a predetermined time to more effectively remove dust and the like. Can be removed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an image reading device according to a first embodiment.

2 is an explanatory diagram of an operation of an optical system of the image reading apparatus in FIG.

3 is an explanatory diagram of a detection sensor of the image reading apparatus in FIG.

FIG. 4 is a diagram showing a cleaning operation on a platen glass of the image reading apparatus of FIG.

5 is a diagram showing a cleaning operation on the platen glass of the image reading apparatus of FIG.

FIG. 6 is a diagram showing a flow reading operation on a platen glass of the image reading apparatus of FIG.

FIG. 7 is a flowchart of a cleaning operation of the image reading apparatus in FIG.

FIG. 8 is an explanatory diagram of an operation of an optical system at the time of flow reading of the image reading apparatus according to the second embodiment.

9 is an explanatory diagram of an operation of an optical system of the image reading apparatus in FIG.

FIG. 10 is a diagram showing a cleaning operation on the platen glass of the image reading apparatus of FIG.

[Explanation of symbols]

101,801 ADF (Automatic Document Feeder) 102 Scanner (image reading device) 103 document tray 105 paper feed roller 106,107 registration rollers 109 paper exit 110 Original illumination lamp 111-113 1st-3rd mirror 115 CCD 116,816 Platen glass 119 Separation roller 120 Conveyor belt (conveying means) 300 Drive control unit (drive control means) 301 Open / close detection sensor (separation state detection means) 302 original detection sensor (original detection means) 830 Platen glass for non-stop reading 831 Platen roller (opposing member) 832 Open / close detection sensor (separation state detection means) 850 Drive control unit (drive control means)

Claims (4)

[Claims] 1. An automatic document feeder including an original placing table, a conveying unit which is arranged so as to face the original placing table and conveys an original on the original placing table, and an original on the original placing table is read. In an image reading apparatus including a reading unit, a document detecting unit that detects the presence or absence of a document on the document placing table is provided, and when the document detecting unit detects that there is no document on the document placing table, An image reading apparatus having drive control means for operating the conveying means in the automatic document feeder for a predetermined time. 2. The automatic document feeder is arranged on the document table so as to be separated from the document table, and whether the automatic document feeder is separated from the document table or is in a document transportable state. When the automatic document feeder is set to a document transportable state on the document table from the separated state, when there is no document on the document table, The image reading apparatus according to claim 1, wherein the drive control unit operates the conveying unit of the automatic document feeder for a predetermined time. 3. A flow reading original table, an automatic document feeder having a conveying means for conveying a document to the flow reading original table, and an automatic document feeding device arranged on the flow reading original table at a position facing an image reading section. An image reading apparatus having a flow reading function for reading a document while moving the document relative to the image reading unit, the facing member being driven at the same time as a conveying unit, wherein no document is present on the flow reading document table. 2. An image reading apparatus comprising drive control means for operating the facing member for a predetermined time. 4. The automatic document feeder is arranged on the non-scanning document platen so as to be separated from the non-scanning document platen, and the automatic document feeder can be separated from the non-scanning document platen or can convey the document. When the automatic document feeder is set from the separated state to the state in which the original can be conveyed on the flow reading original table, the drive control means keeps the facing member for a predetermined time. The image reading apparatus according to claim 3, wherein the image reading apparatus is operated.