JPH09298650A - Image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To read uniform and stable images at all times by using a specified white reference board for shading correction and reading shading data at the time of reading the images of an original by plural read optical systems. SOLUTION: When a common switch 33 is selected in a state where a book mode switch 31 is operated, a switching part 43 selects a sheet read optical system control part 41 and the shading data are read from the white reference board of a sheet read optical system. When the read of the shading data is ended, the switching part 43 switches to a book read optical system control part 42 and makes the image of a book be read by a book read optical system. The read image data are shading corrected by the shading data read by the white reference board of the sheet read optical system and the uniform and stable images are read at all times.

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, such as a digital copying machine or a facsimile apparatus, which can directly read not only a sheet-shaped original but also a required page from a book. .

[0002]

2. Description of the Related Art For example, it is demanded that a facsimile machine not only reads and sends one sheet-like document such as a document or drawing, but also reads and sends a necessary page directly from a book. For example, a book facsimile apparatus as disclosed in Japanese Patent Laid-Open No. 5-19563 has been developed. The reading optical system of such a book facsimile apparatus has a sheet reading optical system 1 and a book reading optical system 2 as shown in the configuration diagram of FIG. 3, for example. The sheet reading optical system 1 is a white reference plate 11 for shading correction provided on the upper surface of the apparatus.
A contact glass 12 and a light source 13 for irradiating the sheet-shaped document 3 placed on the contact glass 12 with light.
And a first mirror 14 that reflects the reflected light from the original 3.
It is composed of a second mirror 15, a third mirror 16, a lens 17 and an optical element 18 such as a CCD. This sheet
The first mirror 14 of the reading optical system 1 can rotate in the vertical direction. The book reading optical system 2 includes a white reference plate 21 for shading correction provided at the bottom of the device,
The contact glass 22 provided at a position facing the book surface 41 of the book 4 placed at the bottom of the device, the light source 23 for irradiating the book surface 41 with light, the mirror 24, and the second mirror-1.
5, the third mirror 16, the lens 17 and the optical element 18
It is composed of The sheet reading optical system 1 and the book reading optical system 2 are sub-scanned by the feed rod 5 except for the sheet reading white reference plate 11 and the contact glass 12 and the book reading white reference plate 21 as indicated by arrow A. It is attached to a moving table 6 that moves in the direction.

When the sheet-shaped original 3 placed on the contact glass 12 is read, the first mirror-1 is used.
4 is rotated upward as shown by the chain line in FIG. 4, and the sheet reading optical system 1 reads the image of the sheet-shaped document 3. Also,
When reading the book surface 41 of the book 4, the first mirror-14
Is rotated downward to secure the optical path between the mirror 24 and the second mirror 15 of the book reading optical system 2, and the book reading optical system 2 reads the image on the book surface 41. As described above, when the image of the sheet-shaped document 3 is read, the shading data is read using the white reference plate 11 of the sheet reading optical system 1, and when the image of the book 4 is read, the book reading is performed. Optical system 2
The shading data is read using the white reference plate 21.

[0004]

As described above, when the shading data is read by using the different white reference plate 11 and white reference plate 21 when the image is read, the white reference plate is white when it is used for a long period of time. The stains on the surfaces of the reference plate 11 and the white reference plate 21 are different from each other, and the shading data is different between when the sheet-shaped document 3 is read and when the book 4 is read. In particular, when the white reference plate 21 is arranged, for example, facing upward, foreign matters such as dust are likely to be accumulated and easily stained. Therefore, when the book 4 is read, an abnormal image having band-shaped streaks in the sub-scanning direction is likely to occur.

The present invention has been made in order to improve such disadvantages, and an object thereof is to obtain an image reading apparatus capable of stably reading a normal image.

[0006]

An image reading apparatus according to the present invention is an image reading apparatus having a plurality of reading optical systems having a white reference plate for shading correction, and when reading an image of a document with each reading optical system. It is characterized in that the shading data is read by using a specific white reference plate for shading correction.

It is desirable to be able to arbitrarily select whether to use the above-mentioned white reference plate for shading correction or the white reference plate for shading correction of each reading optical system.

Further, when the shading data is read by using a specific white reference plate for shading correction, the gain adjustment is preferably performed by the data read by the reading optical system actually used. .

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A sheet mode for selecting a sheet reading optical system is provided in an operating portion of a book facsimile apparatus of the present invention.
Mode switch and book mode for selecting the book reading optical system
Mode switch and book reading optical system
Shading data using the white reference plate of the reading optical system
There is a common switch that selects reading the data, an independent switch that selects reading the shading data using the white reference plate of the book reading optical system when the book reading optical system is selected, and a reading start switch. Have.

The reading optical system control unit has a sheet reading optical system control unit, a book reading optical system control unit, and a switching unit. The switching section selects the book reading optical system, and when the sheet reading optical system is selected to read the shading data using the white reference plate, the sheet is read after the shading data is read. The reading optical system is switched to the book reading optical system.

When the common switch is selected while the book mode switch is operated to read the image of the book, the switching section selects the sheet reading optical system control section, and the sheet reading optical system is operated. , The shading data is read from the white reference plate of the sheet reading optical system. When the reading of the shading data is completed, the switching section deselects the sheet reading optical system control section and selects the book reading optical system control section so that the book reading optical system reads the image of the book. The read image data is subjected to shading correction by the shading data read from the white reference plate of the sheet reading optical system, and a uniform and stable image is always read.

[0012] Further, when reading the image of the book,
Read the shading data from the white reference plate of the reading optical system, read the shading data from the white reference plate of the book reading optical system, or operate it by freely selecting it with the common switch and the independent switch. Improve sex.

Further, gain correction coefficients corresponding to the sheet reading optical system and the book reading optical system are provided,
When reading the image of a book, if the shading data is read using the sheet reading optical system, automatic gain adjustment (AGC) is performed using the correction coefficient of the book reading optical system to obtain a high quality image. obtain.

[0014]

1 is a block diagram showing the configuration of an embodiment of the present invention. The reading optical system of the book facsimile apparatus of this embodiment has exactly the same configuration as that shown in the configuration diagram of FIG. A sheet mode switch 31 for selecting the sheet reading optical system 1 is provided in the operation unit 30 of the book facsimile machine.
And a book mode switch 32 for selecting the book reading optical system 2 and the white reference plate 11 of the sheet reading optical system 1 when the book reading optical system 2 is selected to read the shading data. Common switch 33 for selecting that,
When the book reading optical system 2 is selected, an independent switch 34 and a reading start switch 35 are provided for selecting to read the shading data using the white reference plate 21 of the book reading optical system 2.

The reading optical system control unit 40 controls the sheet reading optical system control unit 41 for controlling the sheet reading optical system 1 and the book reading optical system 1 and a solenoid for rotating the first mirror 14. A book reading optical system control unit 42 and a switching unit 43 for controlling the operation of the mirror rotation unit 44 including the above. The switching unit 43 selects the book reading optical system 2 and reads the shading data when the sheet reading optical system 1 selects the white reference plate 11 to read the shading data. After that, the sheet reading optical system 1 is switched to the book reading optical system 2.

The reading control unit 50 controls the operation of the sub-scanning drive unit 51 that drives the movable table 6 and starts the operation of the image processing unit 60 by the reading start signal from the reading start switch 35. The image processing unit 60 includes a gain adjustment unit 61, an offset adjustment unit 62, an A / D conversion unit 63, a shading correction unit 64, a memory 65, and an image recognition unit 66. Then, the gain of the image signal read by the optical element 18 is adjusted by the gain adjusting unit 61, and then the offset adjustment, A
The / D conversion is performed, and the shading correction unit 64 performs shading correction.

The operation of reading the sheet-shaped original 3 and the book surface 41 of the book 4 by the book facsimile apparatus configured as described above will be described with reference to the flowchart of FIG.

When the sheet mode switch 31 of the operating section 30 is operated to read the sheet-like document 3, the sheet reading optical system control section 41 is selected (steps S1 and S).
2). In this state, when the reading start switch 35 is pushed down and a reading command is sent from the reading control section 50, the sheet reading optical system control section 41 turns on the light source 13 of the sheet reading optical system 1 (steps S3 and S4). ). Further, the reading control unit 50 drives the sub-scanning driving unit 51 to move the movable table 6 in the sub-scanning direction and causes the reading processing unit 60 to start the reading process. In the reading process, the sheet reading optical system 1 sends the white reference plate 11 to the reading image processing unit 60 before reading the image of the original 3. The image processing unit 60 performs gain adjustment and the like on the signal sent from the optical element 18 and then stores it in the memory 65 as shading data, reads the image of the original 3 and performs processing such as shading correction and image information. (Step S5). When the reading control unit 50 detects that the reading of all the images of the original 3 to be transmitted is completed (step S6), the sheet reading optical system control unit 41.
Turns off the light source 13 and finishes the reading process of the document 3 (step S7).

Further, in order to read the book 4, the operation unit 30
If the common switch 33 is selected while the book mode switch 32 is operated and the book reading optical system control unit 42 is selected (steps S1 and S8), the switching unit 43 changes the sheet reading optical system control unit. 41 is selected (step S
9). When the reading start switch 35 is pushed down in this state, the reading control unit 50 sends a reading command to the sheet reading optical system control unit 41 (step S10). The sheet reading optical system control unit 41 receives the reading command, and then the sheet reading optical system 1
The light source 13 is turned on (step S11). The reading control unit 50 drives the sub-scanning drive unit 51 to move the movable table 6 to a position corresponding to the white reference plate 11. The sheet reading optical system 1 sends the white reference plate 11 to the image reading section 60.
The image processing unit 60 performs gain adjustment and the like on the signal sent from the optical element 18, and then stores it in the memory 65 as shading data (step S12). Read control unit 50
When the reading of the shading data is completed, the switching unit 43 is notified that the reading of the shading data is completed. When the switching unit 43 is notified that the reading of the shading data is completed, the switching unit 43 deselects the sheet reading optical system control unit 41 and selects the book reading optical system control unit 42 (step S1).
3). By switching this selection, the sheet reading optical system control unit 41 turns off the light source 13, and the book reading optical system control unit 4
2 turns on the light source 23. Further, the book reading optical system controller 42 drives the mirror rotating means 44 to drive the first mirror-1.
4 is rotated to form an optical path between the mirror 24 of the book reading optical system 2 and the second mirror 15 (step S14).
In this state, the reading control unit 50 drives the sub-scanning driving unit 51 to move the moving table 6, and the book reading optical system 2 reads the image on the book surface 41 of the book 4. Shade of reading processing unit 60
The shading correction unit 64 performs shading correction on the read image using the shading data stored in the memory 65,
The image recognition unit 66 recognizes it as image information (step S
15). When the reading control unit 50 detects that the reading of all the images of the original 3 to be transmitted is completed (step S1
6), the book reading optical system controller 42 turns off the light source 23, drives the mirror rotating means 44 to rotate the first mirror 14 to the initial position, and finishes the reading process of the book 4 (step S17). ).

In this way, even when the image of the book 4 is read, the white reference plate 11 of the sheet reading optical system 1 is used to read the shading data, so that the image is always uniform and stable. Can be read.

Further, in order to read the book 4, the operation unit 30
When the single switch 34 is selected while the book mode switch 32 of FIG. 3 is operated, the book reading optical system control section 42 is immediately selected (steps S1, S8, S1).
8). When the reading start switch 35 is pushed down in this state, the reading control unit 50 sends a reading command to the book reading optical system control unit 42 (step S19). When the reading command is sent, the book reading optical system control unit 42 turns on the light source 23 (step S20), drives the mirror rotating means 44 to rotate the first mirror 14, and rotates the mirror of the book reading optical system 2. -2
4 to form an optical path with the second mirror 15 (step S21). In this state, the reading control unit 50 is operated by the sub-scanning drive unit 5.
1 is driven to move the movable table 6 in the sub-scanning direction, and the reading processing unit 60 is caused to start the reading processing. When the reading process is started, the book reading optical system 2 reads the white reference plate 21 before reading the image on the book surface 41 of the book 4, and the image processing unit 6 reads.
Send to 0. The image processing unit 60 performs gain adjustment and the like on the signal sent from the optical element 18 and then stores the data as shading data in the memory 65, reads the image of the book surface 41 and performs processing such as shading correction. It is recognized as information (step S22). When the reading control unit 50 detects that all the images on the book surface 41 have been read (step S23), the book reading optical system control unit 42 turns off the light source 23 and drives the mirror rotation unit 44. The first mirror 14 is rotated to the initial position and the reading process of the book 4 is completed (step S17).

In this way, when reading the image of the book 4, the white reference plate 1 for reading the shading data by selecting the common switch 33 and the independent switch 34.
1, 21 can be arbitrarily selected.

When the image of the book 4 is read as described above, the sheet reading optical system 1 is used to shade the data.
When reading data, the sheet reading optical system 1 and the book reading optical system 2 have different light sources 13 and 23 and different optical path lengths. Therefore, when the sheet reading optical system 1 and the book reading optical system 2 have different light amounts, the gain adjusting unit 61 of the reading processing unit 60 adjusts the gain with the same correction coefficient.
The image with the smaller light amount becomes a dark image as a whole, and the image quality is deteriorated. Therefore, the gain adjusting section 61 is provided with correction coefficients corresponding to the sheet reading optical system 1 and the book reading optical system 2, respectively, and when the image of the book 4 is read, the sheet reading optical system 1 is used. When reading the reading data, it is preferable to use the correction coefficient of the book reading optical system 2 to perform automatic gain adjustment (AGC).

[0024]

As described above, according to the present invention, when the image of the original is read by a plurality of reading optical systems, a specific shape is read.
Shading data using white reference plate for shading correction
Since the data is read, a uniform and stable image can always be read.

Further, whether the shading data is read by using a specific white reference plate for shading correction or whether the white reference plate for shading correction of each reading optical system is read by the shading data. Since it is possible to select, when the white reference plate for shading correction of a certain reading optical system becomes dirty, it is possible to immediately switch to the white reference plate for shading correction and obtain a high quality image. It is possible to improve operability.

Furthermore, when a gain correction coefficient corresponding to each reading optical system is provided and the shading data is read by using a specific white reference plate for shading correction, the image is actually read. A high-quality image can be obtained by performing automatic gain adjustment (AGC) using the correction coefficient of the reading optical system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment.

FIG. 3 is a configuration diagram of a reading optical system of the book facsimile apparatus.

[Explanation of symbols]

 1 sheet reading optical system 11 white reference plate 2 book reading optical system 21 white reference plate 3 original 4 book 31 sheet mode switch 32 book mode switch 33 common switch 34 independent switch 41 sheet reading optical system control Section 42 book reading optical system control section 43 switching section 50 reading control section 60 image processing section

Claims (3)

[Claims] 1. An image reading apparatus having a plurality of reading optical systems having a white reference plate for shading correction, wherein a specific white reference plate for shading correction is used when an image of a document is read by each reading optical system. An image reading apparatus characterized by reading the shading data. 2. The image reading apparatus according to claim 1, wherein it is possible to arbitrarily select whether to use the specific white reference plate for shading correction or the white reference plate for shading correction of each reading optical system. . 3. When the shading data is read by using the specific white reference plate for shading correction, the gain adjustment is performed by the correction coefficient of the reading optical system actually used. 2. The image reading device described in 2.