JPH06253148A - Picture reader - Google Patents

Abstract

PURPOSE:To correct the read density of an original automatically so that the read density is the same for a read mode not using an ADF and a read mode using the ADF. CONSTITUTION:When a service man or the user designates the density recognition at the delivery of the picture reader or the like and a chart used to recognize the read density is read respectively in a 1st read mode not using an ADF and a 2nd read mode using the ADF, the picture reader recognizes the density of specific data and stores the result to a memory. Then different picture processing is applied to read picture data in response to the difference of each stored density from the 1st and 2nd read modes to make the read density same to each other.

Description

Detailed Description of the Invention

[0001]

This invention relates to an image scanner,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus such as a facsimile apparatus and a scanner section of a digital copying machine, and more particularly to an image reading apparatus including an image reading apparatus main body and an automatic document feeder.

[0002]

2. Description of the Related Art An image reading apparatus equipped with an automatic document feeder (hereinafter abbreviated as "ADF") generally has a reading body (a light source and a first light source) for reading a document set on a document glass of an image reading apparatus body. The first reading mode in which a mirror or the like) is moved to read, and the reading traveling body is stopped at a predetermined position and the original set in the ADF is fed to the original glass of the image reading apparatus and is read while being conveyed. 2 reading modes. In the past, the same image processing was performed on the image data read in any of the reading modes and the image data was output.

[0003]

However, in such an image reading apparatus, even when the original is read in the first reading mode and the original is read in the second reading mode, even if the same original is read. There is a problem that the read density is different.

This is because in the first reading mode, the original is brought into close contact with the original glass for reading, but in the second reading mode the original is read while being conveyed on the original glass.
Since the original is being read in a slightly floating state without completely touching the original glass by the conveyance path of the original, it is considered that a difference in reading density occurs.

Further, in the first reading mode, reading is performed while moving the reading traveling body, but in the second reading mode, since the reading traveling body is stopped and the document is moved and read, flare light is emitted near the reading. In the case where it is easily affected by the above, the concentration will be different.

Since such a read density difference varies depending on the combination of the image reading apparatus main body and the ADF, it cannot be corrected in advance. Therefore, when the user wants to make the reading density the same in any reading mode, he must first confirm the density in both reading modes and set the density in each reading mode. Alternatively, when reading a document using the ADF, it has been attempted to change the position of the light source by a command so that the reading densities in both reading modes become the same, but it is not possible to make the readings match completely. could not.

The present invention has been made in view of the above points, and can be automatically corrected at the time of image processing so that the reading density of the original becomes the same in both the first reading mode and the second reading mode. The purpose is to do so.

[0008]

To achieve the above object, the present invention comprises an image reading apparatus main body and an ADF, and moves a traveling body for reading an original set on an original glass of the image reading apparatus main body. And a first reading mode for reading,
An image reading apparatus having a second reading mode in which the reading traveling body is stopped at a predetermined position and a document set in the ADF is read while being fed onto the document glass of the image reading apparatus body and conveyed. And means for reading the chart for recognizing the read density in the first reading mode and recognizing and storing the density of the specific data in the state where the density recognition is instructed by the means. Means for recognizing and storing the density of the specific data by reading the chart in the second reading mode, and for performing subsequent document reading in the first reading mode by each of the stored densities. Image processing means for performing different image processing on the image data read in the second reading mode is provided.

The image processing means performs the document reading in the first
It is preferable that the image processing is performed by using a different ngamma correction curve when the reading mode is performed and when the reading mode is performed in the second reading mode.

[0010]

According to the image reading apparatus of the present invention, the service person or the user designates the density recognition at the time of delivery of the apparatus, and the chart for recognizing the read density is first set in the image reading apparatus and the above-mentioned chart is set. When the image is read in the first reading mode, the image reading device recognizes the density of the specific data and stores it in the memory. Next, when the chart is set in the ADF and read in the second reading mode, the image reading device recognizes the density of the specific data and stores it in the memory.

Accordingly, when the original is read thereafter, depending on the difference between the densities stored in the memory depending on the difference between the first reading mode and the second reading mode. By performing different image processing on the read image data, the read density can be automatically made the same. The different image processing can be performed using different ngamma correction curves.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 3 is a perspective view showing an external appearance example of the entire image reading apparatus embodying the present invention.

This image reading apparatus comprises an image reading apparatus main body 1
0 and an automatic paper feeder (ADF) 11
Reference numeral 1 is mounted on the image reading apparatus main body 10 so as to be openable and closable around a support shaft (not shown) provided on the paper exit side (left side in the drawing). Reference numeral 12 denotes a paper discharge tray for discharging the read document.

Inside the image reading apparatus, as shown in FIG. 4, a document glass 13 is provided on the upper surface of the main body of the image reading apparatus. A guide shaft and a guide rail are provided in parallel with the original glass 13 along a not-shown document conveyance direction (left-right direction in the figure), and the guide shaft and guide rail are two carriages for reading. Is movably supported.

On one of the carriages, the original glass 1
The light source 14 for irradiating the slit light toward the reading position A on 3 and the first mirror 15 are mounted, and the second carriage 16 and the third mirror 17 are mounted on the other carriage. Further, at a position facing the reflecting surface of the third mirror 17, a lens 18 for converging reflected light from the third mirror 17 to form an image and a photoelectric conversion element 19 such as a CCD sensor for reading the image are arranged. .

On the other hand, in the ADF 11, the document placing surface 20 is placed.
The paper feed rollers 21 and 21 are provided along with the above, and the original glass 13 of the apparatus body 10 is viewed from the upper surface of the original placing surface 20.
A conveyance path 22 reaching the paper ejection tray 12 via the upper reading position A is provided, and a pair of upper and lower separation rollers 23a and a feed roller 23b are provided in the conveyance path 22, and a conveyance roller 24 is provided in the front in the conveyance direction. ing. Further, a conveyance roller 25 is provided on the front side of the reading position A, and a conveyance roller pair 26 and a paper discharge roller pair 27 are provided forward of the reading position A in the conveyance direction.

Further, near the reading position A of the image reading apparatus main body 10, as shown in FIG.
Sheet-shaped white member (white reference plate) 3 attached to the upper surface of the
1 and its sheet-like black member 32 covering the white member 31
A pressing plate 33 made up of and is provided, and a sensor 34 for detecting the presence or absence of a document in the transport path 22 is provided in front of the transport roller 25.
Is provided.

In this image reading apparatus, the original is directly set on the original glass 13 of the image reading apparatus main body 10 and is pressed by the ADF 11, and the two carriages are connected to each other as shown in FIG.
The first reading mode in which the document is read while moving it to the right side of the document, and the first document is set on the document placement surface 20 of the ADF 11 and sequentially fed to the reading position A one by one to perform the reading while being conveyed. The two reading modes can be arbitrarily selected.

FIG. 6 is a block diagram showing the configuration of the control system of the image reading apparatus, which constitutes C which constitutes a microcomputer.
The PU 35, the ROM 36, and the RAM 37, the interface unit 38, the two carriages in the image reading apparatus body 10 described above are moved, and the paper feed roller 21 in the ADF 11 is moved.
And a motor drive circuit 39 for driving a motor 40 (may be a plurality of motors) for rotating the transport roller 24 and the like,
A light source lighting device 41 for lighting the light source 14, various sensor processing units 45 for processing signals from various sensors, and the like are connected by a bus line 46.

The interface inputs the processed image data from the image processing unit that processes the image data read by the image reading unit 43 including the photoelectric conversion element 19 described above, and outputs it to the host computer. Although the image processing unit 42 is illustrated as an independent unit for performing the processing according to the present invention, in reality, the CPU 35, the ROM 36,
And the function of the microcomputer by the RAM 37 and the like.

When the ADF 11 is used (second reading mode), the original is placed on the original placing surface 20 of the ADF 11, and the host computer sends a reading start command to the CPU 35 via the interface 38. . CP
The U 37 sends a signal to the motor drive circuit 39 based on the data of the ROM 38 to drive the motor 40, and
A signal is sent to the light source lighting device 41 to turn on the light source 14.

4 is driven by the motor 40.
Documents are fed one by one to the conveyance path 22 by the paper feed roller 21, the separation roller 23a, and the feed roller 23b shown in FIG. Discharge onto 12. During this time,
Each carriage in the image reading apparatus main body 10 is shown in FIGS.
In the reading position A, the image reading unit 43 including the photoelectric conversion element 19 reads the image of the document being conveyed.

That is, the light from the light source 14 is applied to the original at the reading position A, and the reflected light is made incident on the lens 18 through the first mirror 15, the second mirror 16 and the third mirror 17 in order, and from there. Light is focused on the photoelectric conversion element 19 of the image reading section 43 to read the image on the document.

On the other hand, when the ADF 11 is not used (first reading mode), the user rotates the ADF 11 upward about the support shaft, places the original on the original glass 13, and sets the light source 14 and The carriage on which the first mirror 15 is mounted and the carriage on which the second mirror 16 and the third mirror 17 are mounted are moved and scanned to the right in FIG. 4 at a speed of 2: 1 to read an image on a fixed original. . After reading, C
Conveying rollers 25, 26, 27 according to a command from the PU 37
To discharge the original on the original glass 13 to the paper output tray 12
Discharge on top.

Next, the operation according to the present invention when using the image reading apparatus thus constructed will be described. When the ADF 11 is shipped from the factory, a chart for allowing the image reading apparatus main body 10 to recognize the read density, for example, a sheet with one black or gray line on a white background is included.

The user uses the ADF on the image reading apparatus body 10.
After the apparatus 11 is installed and installed, the image reading apparatus is instructed to recognize the read density by operating a key on an operation panel (not shown) or by issuing a command from the host computer.
Then, the chart is set on the original glass of the image reading apparatus main body 10 and read in the first reading mode,
Then, by simply setting the chart in the ADF 11 and reading the chart in the second reading mode, each reading density is recognized and stored.

The processing on the side of the image reading apparatus at that time will be described with reference to the flowchart of FIG. When this process starts, a command for instructing density recognition is waited, and when it is accepted, it is determined whether or not the above-mentioned chart is set in the image reading device body 10, and when it is set, only the image reading device body 10 is set. The chart is read (in the first reading mode without using the ADF 11), the density Mb of the black (or gray) data therein is recognized, and the chart is written in the memory. The memory may be the RAM 37 shown in FIG. 6 as long as it is backed up by a battery, or a nonvolatile memory may be provided and stored in it.

If the chart is not set in the image reading apparatus main body 10, it is judged whether or not the chart is set in the ADF 11, and when the chart is set, the chart is sent by the ADF 11 and the chart is read in the second reading mode. The density Ma of the black (or gray) data inside is recognized, and it is written in the memory. Then, the concentration Ma
If the writing of Mb and Mb is not completed, the process is delayed by the time required to exchange the charts, and the process returns to the step of determining which of the image reading device and the ADF the chat is set again. If the writing of the densities Ma and Mb is completed, the process is ended.

Next, different image processing is performed by the image processing unit 42 shown in FIG. 6 on the image data read when the original is read in the first reading mode and when the original is read in the second reading mode. A process for making the read densities the same will be described with reference to the flowchart of FIG. 2 and the gamma curve diagram of FIG.

When the process of FIG. 2 is started, a command for reading the original is waited for, and when it is accepted,
It is determined whether or not a document is set on the image reading apparatus main body 10, and when set, only the image reading apparatus main body 10 (first
(In reading mode), the original is read, the normal gamma curve γb shown in FIG. 7 is selected, and the read image data D
Image processing is performed on b using the gamma curve γb, and the image data is output to the host computer via the interface 38 of FIG.

The document is AD instead of the image reading apparatus main body 10.
When it is set to F11, the image reading apparatus main body 10 moves to the second position while sequentially feeding the original document by the ADF 11.
Read the original in the reading mode. Then, according to the ratio Mb / Ma of the concentrations Ma and Mb previously stored in the memory,
The normal comma curve shown in FIG. 7 is corrected to determine gamma curve γa = gamma curve γb × Mb / Ma, and image processing is performed on the read image data Da using the gamma curve γa. Output image data.

The above processing is repeated until the reading of all the originals is completed, and then the processing is completed. In this way, by giving different gamma curves to the image processing for the image data read in the case of reading a document using the ADF and in the case of not reading the document, the reading density difference is almost eliminated or at least considerably reduced. can do.

In the embodiment described above, the second one using ADF
Although the gamma curve in the reading mode of No. 1 is corrected, the gamma curve in the first reading mode in which the ADF is not used may be corrected. Further, it goes without saying that a service person may perform the initial setting operation for causing the image reading apparatus to recognize the read density of each mode, instead of the user.

[0034]

As described above, when the image reading apparatus of the present invention is used, a service person or a user designates density recognition at the time of delivery of the apparatus, and a chart for recognizing the read density is displayed. The image reading apparatus can recognize the density of the specific data on the chart and store it in the memory simply by causing the image reading apparatus to read in the first reading mode that does not use the ADF and the second reading mode that uses the ADF. .

Then, when the original is read, the read image is read according to the difference in each density stored in the memory between the first read mode and the second read mode. By performing different image processing on the data, the read densities can be automatically made the same. The different image processing can be performed by correcting the gamma curve. Therefore, when it is desired to output the image data with the same density in the reading when the ADF is used and when the ADF is not used, it becomes unnecessary for the person to set the reading density each time.

[Brief description of drawings]

FIG. 1 is a process flow chart at the time of reading density recognition by the image reading apparatus shown in FIGS. 3 to 6;

FIG. 2 is a flowchart of the process of reading the document.

FIG. 3 is an external perspective view of an image reading apparatus showing an embodiment of the present invention.

FIG. 4 is a vertical sectional view showing a schematic configuration of the inside of the same.

FIG. 5 is a cross-sectional view showing an enlarged main part of the same.

FIG. 6 is a block diagram of its control system.

7 is a diagram showing an example of a gamma curve used in the image processing unit of FIG.

[Explanation of symbols]

10: Image reading device main body 11: Automatic paper feeding device (AD
F) 12: Paper ejection tray 13: Original glass 1
4: Light source 15: First mirror 16: Second mirror
17: Third mirror 18: Lens 19: Photoelectric conversion element (CCD) 35: CPU 36: ROM
37: RAM 38: Interface part 3
9: Motor drive circuit 40: Motor 41: Light source lighting device 42: Image processing unit 43: Image reading unit

Claims (2)

[Claims] 1. A first reading mode comprising an image reading apparatus main body and an automatic document feeder, and reading a document set on a document glass of the image reading apparatus main body by moving a reading traveling body, An image reading apparatus having a second reading mode in which a reading traveling body is stopped at a predetermined position and a document set in the automatic document feeder is read while being fed and conveyed on a document glass of the image reading apparatus body. A means for instructing density recognition, and in a state in which the density recognition is instructed by the means, a chart for recognizing read density is read in the first reading mode, and the density of the specific data is recognized and stored. Means for recognizing and storing the density of the specific data by reading the chart in the second reading mode, and And an image processing unit for performing different image processing on the image data read when the original reading is performed in the first reading mode and when the original reading is performed in the second reading mode. . 2. The image reading apparatus according to claim 1,
Image reading means characterized in that the image processing means performs image processing using different ngamma correction curves depending on whether the original reading is performed in the first reading mode or the second reading mode. apparatus.