JP2002190912A - Image reader and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader which improves the stop accuracy of an image reader and suppresses the image quality from deteriorating during reading of a manuscript. SOLUTION: A CPU 304a turns on a lamp 107 (S42), reads the stores an output signal from a CCD 117 (S43), while moving a first optical table 109 and a second optical table 112 located at a home position, and determines whether data below a threshold exists in the read data (S44). If the read data below the threshold continues over a specified number of pixels (S45), the CPU decides a read position mark to be present and set s a manuscript read position (S46) and saves it in a backup RAM 303 (S47). If no read data below the threshold exists, it determines that no read position mark to be present on a manuscript guide plate 104 (S49) and changes the detection and setting method of the manuscript read position.

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 mounted on a copying machine, a scanner, or the like, for reading image information of an original, and a control method therefor. The present invention also relates to an image reading apparatus that reads image information based on the amount of light from a subject image and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, when a document in an ADF is copied using a digital copying machine having a document feeder (hereinafter, referred to as an ADF (Auto Document Feeder)) such as a two-sided automatic document feeder, an ADF is used. The image reading device provided below is set at a set position by a motor,
After moving almost immediately below the transport roller inside and stopping it,
By emitting light from the lamp unit, transporting the document between the transport roller and the glass plate, scanning the document, detecting the reflected light with an image reading device, and processing the read image data with the printer unit An image was being formed.

However, in such a digital copying machine, the motor is stopped when a predetermined pulse count has elapsed after the position sensor detects the image reading device, and the reading position of the image reading device is set. Variations in the mounting position of the ADF and variations in the relative position between the reading position of the ADF and the image reading device deteriorate the stopping accuracy of the image reading device (approximately ± 2 mm), and lower the image quality of the image reading device when reading. There was a problem of doing it.

[0004] In view of such a situation, Patent Publication No. 299
No. 3810, the reflected light is read while moving the cylindrical transport roller in the sub-scanning direction, and the maximum projection position where the reflected light from the transport roller is considered to be the largest is determined to determine the read position. Techniques for doing so have been proposed.

[0005]

However, in the above-mentioned Japanese Patent Publication No. 2993810, for example, in a digital copying machine in which a circular portion of a transport roller such as a document transport device having a guide plate cannot be used, a similar reading operation is performed. There has been a problem that an optimum reading position may not be obtained even if the position is adjusted. In addition, due to the influence of the surface shape of the transport roller and the like, the reflected light from the transport roller is not always maximized at the maximum projection position of the transport roller, and there is a problem that an optimal reading position may not be obtained. Further, when the digital copying machine can mount a plurality of types of ADFs, the configuration of the document reading position in each ADF is different.
There has been a problem that an optimum reading position may not be obtained even if the same reading position setting adjustment is performed uniformly.

An object of the present invention is to provide an A
Regardless of the variation of the DF mounting position or the difference of the ADF configuration, the stopping accuracy of the image reading device is improved,
An object of the present invention is to provide an image reading apparatus capable of suppressing a decrease in image quality when reading a document.

Another object of the present invention is to improve the stopping accuracy of the image reading apparatus and suppress the deterioration of image quality when reading an original, irrespective of the variation in the mounting position of the ADF or the difference in the configuration of the ADF. An object of the present invention is to provide a method for controlling a document reading apparatus to obtain the same.

[0008]

According to a first aspect of the present invention, there is provided an image reading apparatus for reading an image of a document conveyed and moved by a document conveying device, a light source for emitting light to a subject image, A light amount detection unit for detecting the light amount of the light from the image; a light amount detection result by the light amount detection unit; and a first threshold value, and a light amount detection value in a light amount detection section reaching the first threshold value And an adjusting means for setting a document reading position according to the image reading apparatus.

According to a second aspect of the present invention, in the image reading device according to the first aspect, the adjusting means is configured to detect the light quantity when the light quantity detecting means detects a light quantity less than the first threshold value. The document reading position is set according to the detected light amount in the light amount detection section below the threshold value of 1.

According to a third aspect of the present invention, in the image reading apparatus according to the first aspect, the adjusting means is configured to detect the light quantity when the light quantity detecting means detects a light quantity exceeding the first threshold value. The document reading position is set according to the detected light amount in the light amount detection section exceeding the threshold value of 1.

[0011] The invention according to claim 4 is the invention according to claims 1 to 3.
In the image reading device according to any one of the above, when the detection value of the light amount in the section where the first threshold value is reached is continued for a predetermined number of pixels, the adjustment unit may set the document conveyance device to the position of the document reading position. It is characterized by recognizing that the document is a document conveying device having an instruction, and setting the original reading position according to the instruction of the original reading position.

[0012] The invention according to claim 5 is the invention according to claims 1 to 3.
In the image reading device according to any one of the above, when the detection value of the light amount in the section where the first threshold value is reached is not continuous for a predetermined number of pixels, the adjusting unit may be configured to perform the adjustment based on the light amount from the subject image. Setting a second threshold value;
The document reading position is set on the basis of the threshold value.

According to a sixth aspect of the present invention, in the image reading apparatus according to the fifth aspect, the light amount reaching the second threshold is detected at a plurality of positions by the light amount detection means. When the interval between at least two detection points is larger than a predetermined value, the adjusting means sets the document reading position at the center position of the two detection points.

The invention described in claim 7 is the first to third aspects of the present invention.
The image reading device according to any one of the above, further comprising: a signal analysis unit that receives a connection signal from the document feeder to the image reading device, analyzes a form of the connection signal, and identifies a type of the document feeder. Wherein the adjusting means determines the presence or absence of an instruction for a document reading position in the document feeder according to the form of the connection signal identified by the signal analyzing means, and sets the document reading position. .

[0015] The invention described in claim 8 is the invention according to claims 1 to 3.
The image reading apparatus according to any one of claims 1 to 3, further comprising a communication unit that reads information that specifies a type of the document transport device stored in a memory included in the document transport device, wherein the adjusting unit is configured such that the communication unit reads the information from the memory. It is characterized in that the presence or absence of an instruction for a document reading position in the document feeder is determined based on the read information, and the document reading position is set.

The invention according to claim 9 is the invention according to claims 1 to 8
In the document reading device according to any one of the above, the adjustment unit adjusts the image reading device to move the image reading device to the document reading position and start reading an image.

According to a tenth aspect of the present invention, there is provided a method for controlling an image reading apparatus for reading an image of a document conveyed and moved by a document conveying device. Comparing the detection result of the light amount of the light from the first light source with a first threshold value, and setting the document reading position of the image reading device according to the detected light amount value in the light amount detection section reaching the first threshold value It is a control method of a reading device.

According to an eleventh aspect of the present invention, in the control method of the image reading apparatus according to the tenth aspect, when the light amount detecting means detects a light amount less than the first threshold value, the first light amount is detected. The document reading position is set according to a detected value of the light amount in a light amount detection section below the threshold value.

According to a twelfth aspect of the present invention, in the control method of the image reading device according to the tenth aspect, when the light amount detecting means detects a light amount exceeding the first threshold, the first light amount is detected. The document reading position is set according to the detected value of the light amount in the detection section of the light amount exceeding the threshold value.

According to a thirteenth aspect of the present invention, in the control method of the image reading apparatus according to any one of the tenth to twelfth aspects, the detected value of the amount of light in the section in which the first threshold value is reached is a predetermined number of pixels In the case where the originals are continuous, the original transporting device recognizes that the original transporting device is an original transporting device in which an instruction of the original reading position is written, and sets the original reading position according to the original reading position.

According to a fourteenth aspect of the present invention, in the control method of the image reading apparatus according to any one of the tenth to twelfth aspects, the detected value of the light amount in the section in which the first threshold value is reached is a predetermined number of pixels. If not continuous, a second threshold is set based on the amount of light from the subject image,
The document reading position is set on the basis of the threshold value.

According to a fifteenth aspect of the present invention, in the control method of the image reading device according to the fourteenth aspect, the second method comprises:
Is detected at a plurality of locations, and when an interval between at least two of the plurality of detected locations is larger than a predetermined value, the document reading position is set at the center position of the two detected locations. It is characterized by setting.

According to a sixteenth aspect of the present invention, in the control method of the image reading apparatus according to any one of the tenth to twelfth aspects, a connection signal from the document feeder to the image reading apparatus is received, and It is characterized in that the form of the signal is analyzed to identify the type of the document feeder, the presence or absence of an instruction of the document reading position in the document feeder is determined according to the form of the connection signal, and the document reading position is set. .

According to a seventeenth aspect of the present invention, in the control method of the image reading device according to any one of the tenth to twelfth aspects, the information for specifying the type of the document feeder is read from a memory provided in the document feeder. The type of the document feeder is identified, the presence or absence of a document read position instruction in the document feeder is determined based on the information read from the memory, and the document read position is set.

According to an eighteenth aspect of the present invention, in the method for controlling an image reading apparatus according to any one of the tenth to seventeenth aspects, the image reading apparatus is moved to the document reading position to start reading an image. It is characterized by the following adjustment.

According to a nineteenth aspect of the present invention, there is provided a program for realizing the control method according to any one of the tenth to eighteenth aspects.

According to a twentieth aspect of the present invention, there is provided a computer-readable recording medium storing the program according to the nineteenth aspect.

[0028]

FIG. 1 is a sectional view showing a schematic configuration of an image reading apparatus (hereinafter, this apparatus) to which the present invention is applied. This apparatus comprises a scanner main body 105 and an ADF 101 detachably attached to the scanner main body 105.
And

The ADF 101 is for setting the original document 102.
Is transported to the original table glass 106 of the scanner main body 105 by the transport roller 103 and collected. At this time, the manuscript 10
2 is a transport roller 10 attached to the ADF 101
3 and the document glass table 106 of the scanner body 105, and the scanner body 105 optically scans the document in the course of the passage to read document information.

The scanner body 105 includes a lamp 107 for irradiating light to the original surface, and mirrors 108, 110, and 11 for guiding reflected light from the original 102 corresponding to the light emitted from the lamp 107 to the lens 116 and the CCD 117.
1, a wire 113, a motor 114, a position sensor 115, a first optical bench 109, and a second optical bench 112. The lamp 107 and the mirror 108 are mounted on a first optical bench 109, and the mirror 110 and the mirror 111 are mounted on a second optical bench 112.

The first optical table 109 and the second optical table 112 are
The motor 113 is coupled to the motor 114 by a wire 113, and the movement of the motor 114 is controlled in parallel with the platen glass 118 by the rotation of the motor 114. The position sensor 115 is a sensor for detecting the home position position of the first optical bench 109. By rotating the motor 114 forward or backward based on the position of the position sensor 115,
The first optical table 109 and the second optical table 112 are moved, and the original on the original table glass 106 is optically scanned. Motor 1
Reference numeral 14 denotes a stepping motor.

The reflected light from the original is transmitted to mirrors 108 and 11
The lens 11 is guided to the lens 116 through the
The light is condensed on the CCD 117 by 6. And CCD
Reference numeral 117 photoelectrically converts the reflected light reflecting the document information, and outputs the reflected light as an electronic image signal.

FIG. 2 is a view showing the document guide plate 104 on which a document reading position is described. The original guide plate 104 of the ADF 101 is marked such as a reading position mark 201. Thereby, the motor 11
4 can prevent erroneous detection of the reading position mark 201 due to the variation in the stop accuracy. Here, the document guide plate 104
In general, white is used in order to prevent the document from fogging when reading a document, and a black reading position mark 201 indicating a regular reading position is placed here. This reading position mark 2
01, the first optical bench 109 and the second optical bench 1
12 is the position sensor 11 of the document guide plate 104
The normal reading position is shown when the document is moved from the side 5 to the upstream of the document transport unit and scans the document. By configuring the document guide plate 104 in this manner, it is possible to prevent erroneous detection of the reading position mark 201 due to variation in the stopping accuracy of the motor 114.

Here, the reading position mark 201 has a predetermined width n [mm] in order to easily distinguish it from dust and the like.
It is desirable that the width of the reading position mark 201 in the sub-scanning direction be larger than the stop precision width of the motor 114.

The image reading apparatus thus configured stops the first optical table 109 at the document reading position,
ADF original reading mode in which original information is read while the original is conveyed by the ADF 101, and the original is fixedly placed on the original platen glass 118 and the first optical base 109 and the second optical base 112 are moved in the sub scanning direction. Original platen glass original reading mode for reading original information while scanning
The document information can be read in one of two modes.

FIG. 3 is a schematic diagram showing the configuration of the scanner controller 304 for controlling the present apparatus. The scanner controller 304 includes a CPU 304a and a ROM 304b.
And a RAM 304c. The CPU 304a executes a program corresponding to a flowchart shown in FIG. 4 or FIG. The ROM 304b is provided in FIG.
Various programs such as the program corresponding to the flowchart shown in FIG. The RAM 304c is a CPU 304
a temporarily stores input / output data and the like when executing various programs.

The scanner controller 304 stores the original 10
Roller 103 for transporting document 2, lamp 107 for irradiating light to the document surface, first optical table 109 and second optical table 112
And a motor 11 for scanning the original by moving
4. CCD 117 for photoelectrically converting reflected light from the document surface;
A / D conversion circuit 301 for A / D converting the output signal of CCD 117, encoder 3 connected to motor 114
02, a position sensor 115 for positioning the first optical table 109 at the home position, and a backup RAM 303 for setting a normal document reading position in the ADF document reading mode.

The scanner controller 304 configured as described above can recognize how many pulses the first optical base 109 and the second optical base 112 have moved based on the output from the encoder 302. That is, the scanner controller 403 determines the first optical base 109 and the second optical base 11 based on the encoder pulse from the encoder 302 and the output signal from the position sensor 115.
Grab the position of 2. Then, based on the output signal of the CCD 117 digitized by the A / D conversion circuit 301, the reading position is adjusted by means described later, and the set position is stored in the backup RAM 303.

The operation of detecting and setting the document reading position is performed, for example, by setting the ADF 101 to the scanner body 1.
05 may be performed when the operator instructs the ADF document reading mode to perform the reading operation in the ADF document reading mode, or when the power is turned on to the device. It is good. Further, for example, by operating a predetermined key, it is also possible to execute the operation of detecting and setting the document reading position at an arbitrary timing. The operation of detecting and setting the document reading position by operating the predetermined key is performed by, for example, the ADF and the 101 scanner body 1.
This is particularly effective when there is a possibility that the ADF 101 and the scanner main body 105 may easily be misaligned when the connection mechanism with the ADF 101 touches the ADF 101 with a hand.

In any case, each time an original is read, it is not necessary to perform the operation of detecting and setting the original reading position each time prior to the reading operation of each original, so that the original is quickly read. It is possible. The detection and setting timing of this document reading position
It is desirable that the operator can arbitrarily select.

Next, detection and setting processing of a document reading position will be described. FIG. 4 shows detection of a document reading position,
It is a flowchart which shows an example of a setting process. The CPU 304a in the scanner controller 304
First, the motor 114 is driven and controlled in accordance with the program stored in the first optical table 109 and the second optical table 112 in the direction of the platen glass 106 by a preset number of pulses from the home position according to the program stored in the program 4b. Move and stop (S41). The movement amount at this time is the first
The optical table 109 and the second optical table 112 are
3 is set so as to be located almost directly below the center position.

Next, the CPU 304a turns on the lamp 107 to drive the motor 114 (S42). Then, while moving the first optical bench 109 and the second optical bench 112 within a predetermined range in the sub-scanning direction with the center as the center,
The signal output from the CCD 117 and converted into a digital signal by the A / D conversion circuit 301 is read, and the position indicating the maximum value of the digital signal value in the range and the maximum value are stored (S43). In the present embodiment, the position indicating the maximum value and the maximum value are stored as a digital signal in the A / D conversion circuit 301, but may be processed as an analog signal. This is because it suffices to detect the amount of the reflected light of the subject image and compare it with a threshold described below based on the detection result.

Next, the scanner controller 304 compares a preset threshold value for judging the presence of the reading position mark with data corresponding to the luminance level of the read subject image. It is determined whether there is data (S44). If there is no read data equal to or smaller than the threshold, the CPU 304a determines that there is no read position mark on the document guide plate 104 (S4).
9). The CPU 304a determines that the type of the ADF mounted on the apparatus is different from the ADF shown in FIG. 1, and detects and sets the reading position according to a procedure shown in FIG.

If there is read data equal to or less than the threshold value in S4, the CPU 30 of the scanner controller 304
4a indicates that data equal to or less than the threshold value is a predetermined number of pixels, for example, n [m
[m] It is calculated whether the number of pixels is continuous (S45). If the data equal to or smaller than the threshold value is continuous for n [mm] pixels, the CPU 304a of the scanner controller 304 determines that there is a reading position mark and sets the document reading position (S46).
The set document reading position is stored in the backup RAM 303.
(S47), and the document reading position detection and setting operations are completed.

FIG. 5 shows that the CPU 304a
FIG. 9 is a diagram showing a reading result of a digital signal value read by the digital camera. A state in which the luminance level of the read data drops below the threshold is shown (YES in S44). S
At 45, when such a drop in read data equal to or less than the threshold value is continuous for n [mm] pixels, the CPU 304 a of the scanner controller 304 uses the black portion of the read position mark 201 on the document guide plate 104,
That is, it is determined that the reading position mark 201 is present, and FIG.
S46 and S47 are performed.

On the other hand, if it is determined in step S45 that the data equal to or smaller than the threshold value is not continuous for n [mm] pixels, the CPU 304a
Determines that the read data has fallen below the threshold value due to a noise component such as dust, and moves the first optical table 109 and the second optical table 112 to the upstream side of the document conveying section for n pulses of the motor 114. Subsequently, the presence or absence of the reading position mark is determined by the same procedure (S48). As described above, the reading position mark is detected toward the upstream side of the document conveying section until it is determined that there is no reading position mark on the document guide plate 104 (S49).

This embodiment can also be configured using an image reading apparatus equipped with an ADF having a different configuration from the ADF 101 in the above-described embodiment. FIG. 6 is a diagram illustrating a configuration of an image reading apparatus equipped with an ADF 601 having a different image reading unit structure from the ADF 101 illustrated in FIG. In the ADF 101 shown in FIG. 1, when the document 102 passes through the image reading position,
Pass between the document guide plate 104 and the document table glass 106. However, in the ADF 601 shown in FIG.
The original 602 is transported by the transport roller 603 and the platen glass 10.
Pass between 6.

In the process of detecting and setting the document reading position shown in FIG.
The U304a determines that there is no reading position mark on the document guide plate 104 (S49).
When it is determined that an ADF of a type different from that of F101, for example, the ADF 601 as shown in FIG. 6 described above is mounted, the process of detecting and setting the document reading position is performed as follows.

FIG. 7 is a flow chart showing an example of processing for detecting and setting a document reading position in the apparatus constructed as shown in FIG. Scanner controller 30
4 first controls the drive of the motor 114 in accordance with the program stored in the ROM 304b,
The first optical table 10 is moved in the direction of the platen glass 106 by a predetermined number of pulses from the home position.
9. The second optical bench 112 is moved and stopped (S1). The amount of movement at this time depends on the first optical bench 109 and the second optical bench 112.
Is set almost immediately below the center position of the transport roller 103.

Next, the CP of the scanner controller 304
U304a turns on the lamp 107 and sets the motor 1
14 is driven (S2). The first optical bench 109 and the second optical bench 1 are located within a predetermined range in the sub-scanning direction with the center as the center.
12 is output from the CCD 117 while moving
A signal corresponding to the luminance level of the subject image converted into a digital signal by the / D conversion circuit 301 is read (S3). Then, the position indicating the maximum value of the digital signal value in the range and the maximum value are detected and stored in the RAM 304b (S4). FIG. 8 shows an example of a read signal in the sub-scanning direction read in S3.

Here, the CPU 304a determines whether or not the maximum value detected in S4 is larger than a predetermined value (S5). When the maximum value is larger than the predetermined value, the process proceeds to S7. On the other hand, if the maximum value is smaller than the predetermined value, the CPU 30
4a determines that there is an error, displays an error message on a display in an operation unit (not shown), and terminates the operation (S6). The reason why the error message is displayed is that ADF60
The transport roller 103 does not exist within a predetermined range with respect to the scanner main body 105 due to a defect in the positional relationship between the scanner main body 1 and the scanner main body 105 or the like.
A situation such as a floating state can be assumed.

Next, the CPU 304a multiplies the detected maximum value by a predetermined coefficient and sets the calculated value as a threshold value.
(S7). Next, the CPU 3 of the scanner controller 304
04a drives and controls the motor 114, and the first optical table 1
09, the second optical bench 112 is stored in the RAM 304 in S4.
It moves to the position indicating the maximum value of the digital signal value stored in b (S8). Next, the CPU 304a turns on the lamp 107, and drives the first optical
While moving the optical table 112 in the sub-scanning direction, the CCD 11
7 and is read by the A / D conversion circuit 301 and converted into a digital signal (S9). Then, the read data is compared with the threshold calculated in S7,
Sub-scanning positions (two locations) where the read value is below the threshold are detected and stored in the backup RAM 303 (S10). In this study, it has been confirmed that similar image quality can be obtained at a position where a read signal level equal to or higher than a predetermined threshold can be detected.

Next, the CPU 304a determines whether or not the interval between the two sub-scanning positions where the read value stored in the backup RAM 303 is less than the threshold value in S10 is larger than a predetermined value (S11). When the interval between the two locations stored in the backup RAM 303 is larger than the predetermined value, the center of the two sub-scanning positions where the read value is below the threshold value is stored in the backup RAM 303 as the read position (S12). On the other hand, if the two sub-scanning positions where the read values are below the threshold are smaller than the predetermined value, the CPU 3
In step 04a, an error is determined, an error message is displayed on a display unit in an operation unit (not shown), and the detection of the document reading position and the setting operation are completed (S13). This is the above 2
This is because a predetermined value can be derived from the shape of the transport roller 103 for the distance between the sub-scanning positions.

As described above, in the present embodiment, a fixed threshold value is provided for the CCD data read by the scanner controller 304, and the document reading position is detected and set based on the threshold value, so that the ADF mounting position is set. Optical table 10 irrespective of the variation of the position and the variation of the relative position between the reading position of the ADF and the image reading device.
9. Since the second optical bench 112 is stopped at an appropriate position,
It is possible to suppress a decrease in image quality during image reading. Also, according to the present embodiment, the scanner controller 304
By detecting and setting the document reading position based on the maximum value of the read CCD data, the first optical base 109 and the second optical base 11 are located at appropriate positions according to the type of the ADF.
2 is stopped, it is possible to suppress a decrease in image quality when reading an image even in an image reading apparatus equipped with a plurality of types of ADFs.

In the above-described embodiment, the original guide plate 104 shown in FIG. 2 uses white to prevent the document from flanking when reading the original, and a black reading position mark 201 indicating a regular reading position is used here. , But is not limited to this. That is, when the document guide plate 104 is in a color other than the color, for example, black, the reading position mark 201 is configured with a color other than the same color (in this case, black). This is because it is sufficient that the reading position mark 201 can be identified as the amount of reflected light with respect to the document guide plate 104. For example, when the document guide plate 104 is black and the reading position mark 201 is white, the following is performed. That is, referring to FIG. 4, CPU 304a turns on lamp 107 (S
42), the first optical bench 10 at the home position
9. While moving the second optical bench 112, the CCD 117
Is read and stored (S43), and it is determined whether or not the read data includes data equal to or greater than a threshold (S44). If the read data equal to or larger than the threshold value is continuous for a predetermined number of pixels (S45), it is determined that there is a read position mark, and a document read position is set (S46). (S47). If there is no read data equal to or greater than the threshold value, it is determined that there is no reading position mark on the document guide plate 104 (S49), and the method of detecting and setting the document reading position is changed.

(Second Embodiment) In the first embodiment, light is emitted from the light source provided in the original reading device to the transport roller while moving the original reading device forward and backward, and reflected from the transport roller at each moving position. The amount of light is detected, and the method of adjusting the reading position is selected according to the detected amount of reflected light. However, the type of the connected ADF can be specified based on a control signal for connecting the ADF and the image reading device. The same effect as in the above-described first embodiment can be obtained by setting the reading position and adjusting the reading position according to the output result of the signal.

(Third Embodiment) In the second embodiment,
One of the control signals for connecting the ADF and the image reading device
The type of ADF mounted is determined based on the signal output of the bit, and the reading position is adjusted.
The information of the mounted ADF is stored in advance in a memory such as a ROM in the DF, and is stored in the CPU 3 of the scanner controller 304 by communication means such as serial communication.
The same effect can be obtained by recognizing the type of the ADF by reading by 04a and selecting a reading position adjustment method.

[0058]

As described above, according to the present invention,
The image reading device can be stopped in accordance with a variation in the mounting position of the ADF, a difference in the configuration of the ADF, and the like, and a decrease in image quality when reading the document can be suppressed.

According to another aspect of the present invention, in an image reading apparatus in which a plurality of ADFs can be mounted, a document reading position can be adjusted according to each ADF, and image quality degradation during document reading can be suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image reading apparatus to which the present invention has been applied.

FIG. 2 is a diagram illustrating a document guide plate on which a document reading position is described.

FIG. 3 is a schematic diagram illustrating a configuration of a scanner controller that controls the present apparatus.

FIG. 4 is a flowchart illustrating an example of a document reading position detection and setting process.

FIG. 5 is a diagram showing a reading result of a digital signal value.

FIG. 6 is a diagram illustrating a configuration of an image reading device.

FIG. 7 is a flowchart illustrating an example of a document reading position detection and setting process.

FIG. 8 is a diagram illustrating an example of a read signal in a sub-scanning direction.

[Explanation of symbols]

 101 ADF 102 Document 103 Conveyance roller 104 Document guide plate 105 Scanner body 106 Document table glass 107 Lamp 108, 110, 111 Mirror 109 First optical table 112 Second optical table 113 Wire 114 Motor 116 Lens 117 CCD 301 A / D conversion circuit 302 Encoder 303 Backup ROM 304 Scanner controller

Continued on the front page F term (reference) 2H076 AA58 BA24 BA63 BA87 BA95 BB06 2H108 AA01 CB01 DA06 FA29 5B047 BA02 BC12 BC16 BC18 CA08 CB09 5C072 AA01 CA02 CA14 EA05 LA02 NA01 NA08 RA04

Claims (20)

[Claims] An image reading apparatus for reading an image of a document conveyed and moved by a document conveying device, comprising: a light source that emits light to a subject image; and a light amount detection unit that detects a light amount of light from the subject image. Adjusting means for comparing the detection result of the light quantity by the light quantity detection means with a first threshold value and setting the document reading position in accordance with the detected light quantity value in the light quantity detection section reaching the first threshold value; An image reading device, comprising: 2. The image reading device according to claim 1, wherein the adjusting unit detects a light amount lower than the first threshold when the light amount detecting unit detects the light amount lower than the first threshold. An image reading apparatus, wherein a document reading position is set according to a detection value of a light amount in a detection section. 3. The image reading device according to claim 1, wherein the adjusting unit detects the light amount exceeding the first threshold when the light amount detecting unit detects the light amount exceeding the first threshold. An image reading apparatus, wherein a document reading position is set according to a detection value of a light amount in a detection section. 4. The image reading device according to claim 1, wherein the adjusting unit is configured to detect the light amount in a section where the first threshold is reached for a predetermined number of pixels. An image reading apparatus for recognizing that the document transport device is a document transport device on which an instruction for a document reading position is written, and setting a document reading position in accordance with the instruction for the document reading position. . 5. The image reading apparatus according to claim 1, wherein the adjustment unit is configured to determine that a light amount detection value in a section where the first threshold value is reached is not continuous for a predetermined number of pixels. Setting a second threshold based on the amount of light from the subject image;
An image reading apparatus for setting a document reading position based on the second threshold value. 6. The image reading device according to claim 5, wherein the light amount reaching the second threshold is detected at a plurality of places by the light amount detection means, and at least two of the plurality of places are detected. An image reading apparatus, wherein when the interval is larger than a predetermined value, the adjusting means sets a document reading position at a center position between the two detected points. 7. The image reading device according to claim 1, wherein a connection signal from the document feeding device to the image reading device is received, and a form of the connection signal is analyzed to form the document reading device. Further comprising signal analysis means for identifying the type of the document, wherein the adjustment means determines the presence or absence of an instruction for a document reading position in the document conveyance device according to the form of the connection signal identified by the signal analysis means, An image reading device for setting a reading position. 8. The image reading device according to claim 1, further comprising a communication unit that reads information that specifies a type of the document transport device stored in a memory included in the document transport device, wherein the adjustment is performed. The image reading device sets the document reading position by determining whether or not there is an instruction of a document reading position in the document conveying device based on information read from the memory by the communication unit. 9. The original reading apparatus according to claim 1, wherein the adjusting unit adjusts the image reading apparatus to move the image reading apparatus to the original reading position and start reading an image. An original reading device. 10. A method for controlling an image reading device that reads an image of a document conveyed and moved by a document conveying device, comprising: emitting light from a light source for a subject image; and detecting a light amount of the light from the subject image. Comparing the result with a first threshold value;
A document reading position of the image reading device is set according to a detected value of a light amount in a light amount detection section that reaches a threshold value. 11. The control method for an image reading device according to claim 10, wherein when the light amount detection unit detects a light amount below the first threshold, a detection section of the light amount below the first threshold. A document reading position is set in accordance with a detection value of a light amount in the image reading apparatus. 12. The control method for an image reading apparatus according to claim 10, wherein when the light amount detection unit detects a light amount exceeding the first threshold value, a detection section of the light amount exceeding the first threshold value. A document reading position is set in accordance with a detection value of a light amount in the image reading apparatus. 13. The method for controlling an image reading device according to claim 10, wherein the detection value of the light amount in the section where the first threshold value is reached is continued for a predetermined number of pixels. A method for controlling an image reading apparatus, comprising: recognizing that a document transport device is a document transport device in which an instruction of a document reading position is written, and setting a document reading position according to the document reading position. 14. The control method of the image reading device according to claim 10, wherein the light amount detection value in the section where the first threshold value is reached is not continuous for a predetermined number of pixels. A control method for an image reading apparatus, comprising: setting a second threshold based on a light amount from a subject image, and setting a document reading position based on the second threshold. 15. The control method for an image reading device according to claim 14, wherein a light amount reaching the second threshold is detected at a plurality of locations, and an interval between at least two of the plurality of locations is detected. A document reading position is set at a center position between the two detected positions when the value of the original is larger than a predetermined value. 16. The control method for an image reading device according to claim 10, wherein a connection signal from said document feeder to said image reading device is received, and a form of said connection signal is analyzed. Identify the type of the document feeder, determine the presence or absence of an instruction of the document reading position in the document feeder according to the form of the connection signal,
A method for controlling an image reading device, comprising setting a document reading position. 17. The method of controlling an image reading apparatus according to claim 10, wherein information for identifying a type of the document transport device is read from a memory provided in the document transport device, and the type of the document transport device is read. A document reading position in the document feeder is determined based on information read from the memory, and the document reading position is set. 18. The method for controlling an image reading device according to claim 10, wherein the image reading device is moved to the document reading position and adjusted so as to start reading an image. Control method of an image reading apparatus. 19. A program for realizing the control method according to claim 10. Description: 20. A computer-readable recording medium storing the program according to claim 19.