JP3836084B2 - Image reading device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image reading apparatus such as a digital copying machine, an image scanner, and a facsimile using a CCD sensor (charge coupled device) as a reading element, and in particular, reads an image of a document while moving the document at a constant speed. The present invention relates to an image reading apparatus capable of performing continuous reading.
[0002]
[Prior art]
Conventionally, digital copiers, image scanners, facsimile machines, and the like use digital reading devices that read an image of a document by a reading sensor. In this digital reading apparatus, a CCD sensor (charge coupled device) is used as a reading sensor, and the density of an original image is converted into an electric signal level.
[0003]
Further, in this image reading apparatus, as a reading optical system that scans by moving the light source parallel to the document surface at a constant scanning speed and forms an image of the reflected light from the document surface on the CCD unit by the imaging lens, The original placed on the platen glass is slit-irradiated by a light source, the reflected light is reflected by the first mirror in parallel to the original surface, and reflected in the opposite direction through the second and third mirrors orthogonal to each other, In general, an image forming lens is used to form an image on a CCD sensor.
[0004]
In addition, an automatic document feeder is attached to such an image reading apparatus, and an apparatus for performing “flowing reading” in which an image of a document is read while moving the document on a flow reading contact glass at a constant speed has been developed. In this case, in the reading optical system, the light source and the first to third mirrors move to a predetermined position in the image reading apparatus and are fixed, and under this state, the automatic document feeder performs the flow reading contact. The document is moved on the glass at a constant speed, and an image of the document is read by reading a predetermined position of the flow reading contact glass using the light source and the first to third mirrors.
[0005]
Here, when performing the above-described flow reading, if dust or dust adheres to the flow reading position on the flow reading contact glass, the reading optical system (image reading unit) causes the dust or dust to move. Therefore, black stripes (vertical stripes appearing in the document advancing direction) are generated in the read image. Therefore, a conventional image reading apparatus has been disclosed which has a dust detection function for detecting dust on the contact glass. The image reading apparatus is configured to detect dust on the contact glass outside the document reading period. It is difficult to avoid dust by performing dust detection processing based on the result of the dust detection processing, dust correction processing based on the result of dust detection processing, and dust avoidance processing for changing the reading position to a position where there is no dust on the contact glass. In this case, the flow reading itself is prohibited, and switching to original reading by normal optical scanning is performed (for example, see Patent Document 1).
[0006]
[Patent Document 1]
JP-A-2002-354213 (pages 8-12 and 1-9)
[0007]
[Problems to be solved by the invention]
However, in the above-described conventional image reading apparatus, it is possible to avoid black streaks in the read image by performing dust detection, dust correction, and dust avoidance processing. It can be said that it is necessary to clean the dust and dirt adhering to the top. Here, the cleaning of the flow-reading contact glass is usually performed under an indoor illumination light. However, in the conventional image reading apparatus, dirt such as dust and dust is visually observed under the indoor illumination light. Therefore, it is difficult to clearly distinguish these stains, and it is difficult to perform proper cleaning. In addition to the person who is familiar with the cleaning work (for example, a service person), the person who is not familiar with the cleaning work (for example, a user) may perform the above cleaning. There was a problem that the cleaning effect was difficult to understand.
[0008]
The present invention solves the above-mentioned problems, and when cleaning the flow-reading contact glass, it is possible to easily visually check for dirt, dust, etc. adhering to the contact glass, and to clean the contact glass. An object of the present invention is to provide an image reading apparatus that can be appropriately performed.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an automatic document conveying device for performing a flow reading of a document, a flow reading contact glass for conveying a document fed into the automatic document conveying device, and a light source. In an image reading apparatus provided with an image reading means for reading an image of a document based on irradiation light irradiated and reflected by the document, a light source is adjacent to the flow reading contact glass when cleaning the flow reading contact glass. The irradiation light shielding member is moved and stopped below, and the irradiation light shielding member is irradiated with the light source.
[0010]
According to this configuration, when cleaning the reading contact glass, the light emitted from the light source stopped at a predetermined position functions as indirect light for illuminating the reading contact glass. It is possible to easily identify (or recognize) dirt such as dust and dirt adhering to the flow reading contact glass, which causes black streaks without causing pain, so that the visual flow reading contact can be identified. The glass can be appropriately cleaned and the cleaning effect can be easily determined.
[0011]
Here, in the present invention, the document size indicating member serving as an index of the size of another document placed on the document table glass provided on the upper surface of the image reading apparatus main body also serves as the irradiation light shielding member. Can be.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram illustrating the overall configuration of an image reading apparatus including an automatic document feeder according to an embodiment of the present invention.
[0013]
In FIG. 1, an image reading device 50 includes an image reading device main body 1, an original table glass 2 provided on the upper surface of the image reading device main body 1, a flow reading contact glass 17, and an upper surface of the original table glass 2. A document size indicating member 18 provided to be adjacent to the document table glass 2 and the flow-reading contact glass 17 is provided while partially covering the document glass. The document size instruction member 18 serves as an index of the size of the document 3 placed on the document table glass 2. The image reading apparatus main body 1 includes a light source 4 that illuminates the original by irradiating the original 3 placed on the original table glass 2, and a first light that reflects the irradiation light reflected by the original 3 in a 90-degree direction. The first optical system unit 6 composed of the mirror 5, the second mirror 7 that reflects the light reflected by the first mirror 5 in the 90-degree direction, and the light reflected by the second mirror 7 is further reflected in the 90-degree direction. And a second optical system unit 9 including a third mirror 8.
[0014]
In addition, an image forming lens 10 and a CCD unit 11 ′ equipped with a CCD sensor 11 are provided inside the image reading apparatus main body 1, and reflected light from the document 3 reflected by the third mirror 8 is reflected. Then, the light is converged by the imaging lens 10 provided facing the CCD sensor 11, enters the CCD sensor 11 through the imaging lens 10, and forms an image on the CCD sensor 11. Then, the light of the image scanned on the document 3 is converted into an electric signal by the CCD sensor 11, and the density of the document image is converted into the level of the electric signal level. In the present embodiment, the first optical system unit 6, the second optical system unit 9, the imaging lens 10, and the CCD unit 11 ′ are irradiated by the light source 4 and reflected by the document 3, An image reading unit for reading a document image is configured.
[0015]
In the above configuration, the imaging lens 10 and the CCD sensor 11 are fixed to the image reading apparatus main body 1, but the original-side optical path length does not change even when the light source 4 moves in the scanning direction. In addition, the first optical unit 6 composed of the light source 4 and the first mirror 5 and the second optical unit 9 composed of the second mirror 7 and the third mirror 8 can each move at a constant speed. It is provided to become. The first and second optical units 6 and 9 are moved and stopped by driving means (not shown).
[0016]
Further, the image reading apparatus 50 of the present embodiment includes an automatic document conveying device 12 for performing the flow reading of the document. The automatic document conveying device 12 includes the document feeding tray 13 and the document feeding paper. A paper feeding section 15 for feeding the original 14 loaded on the tray 13, a paper conveying path 16 for conveying the fed original 14, and a paper discharge conveying path for discharging the original 14. 19 and a document discharge tray 20 on which the discharged document 14 is stacked.
[0017]
When the document 14 is scanned, the document 14 loaded on the document feeding tray 13 of the automatic document feeder 12 is fed into the automatic document feeder 12 by the paper feeder 15 and is transported to the document. 16 is conveyed to the contact glass 17 for flow reading. At this time, the first optical unit 6 and the second optical unit 9 are moved at a constant speed in the directions of the arrows 21 and 22 in the drawing at a predetermined timing by driving means (not shown), respectively, The document 14 passing on the contact glass 17 is stopped at a position where it can be read, and reading of the image of the document 14 is started. Also in this case, the image of the document 14 is read by the same image reading unit as that in the case of performing the normal image reading described above. That is, the irradiation light irradiated by the light source 4 and reflected by the original 14 is further reflected by the first to third mirrors 5, 7, and 8, and the imaging lens 10 provided facing the CCD sensor 11 is provided. Then, the light enters the CCD sensor 11 and forms an image on the CCD sensor 11. Then, the light of the image scanned on the original 14 is converted into an electric signal by the CCD sensor 11, and the density of the original image is converted into the electric signal level. That is, based on the irradiation light irradiated by the light source 4 and reflected by the document 14, the image reading constituted by the first optical system unit 6, the second optical system unit 9, the imaging lens 10, and the CCD unit 11 ′. The unit is configured to read the image of the document 14.
[0018]
The document 14 that has passed through the flow-reading contact glass 17 and whose image has been read is discharged out of the automatic document feeder 12 via the document delivery transport path 19 and placed on the document delivery tray 20. Loaded.
[0019]
Next, with reference to drawings, the operation | movement procedure in the dust confirmation mode in embodiment of this invention is demonstrated. FIG. 2 is a flowchart illustrating a procedure for cleaning the flow reading contact glass in the image reading apparatus including the automatic document feeder according to the embodiment of the present invention. FIG. 3 is a flow chart of the flow reading contact glass. It is a schematic diagram for demonstrating the movement of an optical unit at the time of cleaning, and the mode of the light irradiation by a light source.
[0020]
In the procedure shown in FIG. 2, first, black streaks are generated in the read image (output image) due to adhesion of dirt such as dust and dust at the flow reading position on the flow reading contact glass 17 (step S1). Next, the automatic document feeder 12 is opened in order to remove the dirt associated with the black streaks (step S2). Next, an operation unit (not shown) formed in the image reading apparatus main body 1 is operated to select the “dust check mode” (step S3). At this time, by selecting the “dust check mode”, the first optical unit 6 and the second optical unit 9 including the light source 4 are respectively moved to the home position (that is, the position A in FIG. ) At a constant speed in the direction of arrows 23 and 24, and stops at a predetermined position, that is, below the document size instruction member 18 (position B in FIG. 3) (step S4). At this time, as shown in FIG. 3, the light source 4 moves below the document size instruction member 18 and stops. After the first optical unit 6 and the second optical unit 9 are stopped at the predetermined positions, when a “dust check mode start button” provided on the operation unit (not shown) is selected (step S5), control means ( As a result, the light source 4 constituting the first light source unit 6 is turned on, and irradiation of the document size instruction member 18 is started (step S6).
[0021]
Here, in this embodiment, as described above, the first optical unit 6 is stopped at a predetermined position, that is, below the document size instruction member 18 (position B in FIG. 3). In this case, the light source 4 is irradiated to the document size instruction member 18. At this time, as shown in FIG. 3, the irradiation light 25 to the document size instruction member 18 directly irradiates the contact glass 17 for flow reading. Instead, the document size indicating member 18 reflects the irradiation light 25 downwardly from the flow reading contact glass 17. That is, the irradiation light 25 functions as indirect light (a wavy arrow in the drawing) for illuminating the reading contact glass 17 from the inside of the image forming apparatus main body 1 by the reflection. Therefore, the irradiation light 25 generated from the light source 4 is shielded by the document size instruction member 18 and directly irradiated to the flow-reading contact glass 17 because the document size instruction member 18 also functions as an irradiation light shielding member. However, since the reflection contact glass 17 functions as indirect light that illuminates the image forming apparatus main body 1 from the inside by the reflection, the indirect light does not hurt the eyes due to the strong irradiation light from the light source 4. It is possible to easily determine (or recognize) dirt 26 such as dust or dust adhering to the flow-reading contact glass 17 that is a cause of occurrence. Cleaning (step 7) can be performed, and the cleaning effect can be easily determined.
[0022]
In this sense, the predetermined position where the first optical unit 6 and the second optical unit 9 are stopped in step S4 is clearly distinguished from dirt such as dust and dirt adhering to the contact glass 17 for flow reading. And it can be said that it is the optimal position for performing the appropriate cleaning of the said contact glass 17 for flow reading.
[0023]
When the “dust check mode stop button” provided on the operation unit (not shown) is selected after the cleaning of the flow reading contact glass 17 in step 7 (step S8), the light source 4 is controlled by the control means (not shown). After the irradiation, the first optical unit 6 and the second optical unit 9 are reversed from the predetermined positions (that is, positions B in FIG. 3) by arrows 23 and 24 by driving means (not shown). And at the above-mentioned home position (position A in FIG. 3) (step S9), the cleaning of the flow-reading contact glass 17 is completed.
[0024]
In addition, this invention is not limited to the said embodiment, Based on the meaning of this invention, it is possible to change suitably the structure of each part, a shape, etc., and excludes them from the scope of the present invention. is not.
[0025]
For example, in the above-described embodiment, the original plate glass 2 provided on the upper surface of the image reading apparatus main body 1 and the original size indication member 18 provided adjacent to the flow reading contact glass 17 are used as the irradiation light shielding member. However, as shown in FIG. 4, the irradiation light shielding member 27 may be provided adjacent to the reading contact glass 17 separately from the document size instruction member 18. In this case, the same effect as that of the first embodiment can be obtained. Since the other configuration shown in FIG. 4 is the same as that of the above embodiment, the same members as those of the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted here.
[0026]
【The invention's effect】
As described above, according to the present invention, when cleaning the flow-reading contact glass, from the light source stopped at a predetermined position toward the original size indicating member functioning as the irradiation light shielding member. By irradiating, the irradiated light functions as indirect light that illuminates the reading contact glass. Therefore, it is possible to easily determine (or recognize) dirt such as dust and dust adhering to the flow-reading contact glass that causes black streaks due to the indirect light without damaging the eyes by the strong irradiation light from the light source. ), It is possible to perform appropriate cleaning of the contact glass for flow-reading by visual observation and to easily determine the cleaning effect.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an overall configuration of an image reading apparatus including an automatic document feeder according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a procedure for cleaning a flow reading contact glass in an image reading apparatus provided with an automatic document feeder according to an embodiment of the present invention.
FIG. 3 is a schematic diagram for explaining the movement of the optical unit and the state of light irradiation by the light source when cleaning the flow-reading contact glass.
FIG. 4 is a schematic diagram illustrating a modified example of the irradiation light shielding member in the image reading apparatus including the automatic document feeder according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image reading apparatus main body 2 Manuscript table glass 4 Light source 5 1st mirror 7 2nd mirror 8 3rd mirror 10 Imaging lens 11 CCD sensor 12 Automatic document conveying apparatus 13 Document feeding tray 15 Paper feeding part 16 Document conveying path 17 Contact glass 18 for flow reading Document size instruction member 19 Document discharge path 20 Document discharge tray 25 Irradiation light 26 Dirt 27 Irradiation light shielding member

Claims (2)

An automatic document conveying device for performing a flow reading of a document, a flow reading contact glass for conveying a document fed into the automatic document conveying device, and an irradiation light irradiated by a light source and reflected by the document In an image reading apparatus comprising image reading means for reading an image of the document based on
When cleaning the flow-reading contact glass, the light source is moved and stopped below the irradiation light shielding member provided adjacent to the flow-reading contact glass, with respect to the irradiation light shielding member. And irradiating the light source. The document size instruction member serving as an index of the size of another document placed on a document glass provided on the upper surface of the image reading apparatus main body also serves as the irradiation light shielding member. The image reading apparatus according to 1.

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