JP2009159215A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a tilt of a density reference member with respect to shading correction. <P>SOLUTION: An image reader comprises a read means of reading a document being conveyed; the density reference member which has a reference density area disposed at a read position of the read means and given reference density for read unevenness detection and a phase adjustment area given a reference mark for fitting tilt detection at both ends in a read main scan direction and guides conveyance of the document when the document is being conveyed and is also configured to have the reference density area read by the read means during reference unevenness detection and the reference mark read by the read means during fitting tilt detection; and a control means of performing control to report or display read results of reference marks given to the density reference member at the both ends. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image reading apparatus having a function of reading both-side images while generating a document and generating image data, and more particularly to an image reading apparatus in consideration of shading correction.

2. Description of the Related Art Conventionally, image reading apparatuses capable of reading both sides of a document have been widely used.
Such a double-sided reading type image reading apparatus has one reading unit and a document reversing and conveying mechanism, and after reading the first surface of the document by conveying the document to the image reading position, There are some which read the image on the second surface by the reading means by reversing the front and back and transporting the document again to the image reading position.

  Further, such a double-sided reading type image reading apparatus has a first reading unit for reading the first side of the original and a second reading unit for reading the second side, and conveys the original once. Accordingly, there is a so-called double-sided simultaneous reading type image reading apparatus that can read images on both sides of a document simultaneously or in parallel.

  Here, although the double-sided simultaneous reading type image reading apparatus requires two reading units, since both sides can be read almost simultaneously with one original conveyance, high-speed reading and document conveyance are possible. Since the mechanism is simple, it has many advantages such as low failure and low cost.

  By the way, in the image reading, in order to correct the influence on the image data by the light source that illuminates the document or the reading optical system, and for the determination of the reference white level, the reading result of the density reference member having a predetermined white is used. The shading correction used is generally performed. That is, with reference to the white level obtained by reading the density reference member, the shading correction circuit corrects the level of the read signal and the decrease in the peripheral light amount of the optical system.

  By the way, in the above-described double-side reading type image reading apparatus, as the first reading means, a first reading means having a movable reading opening (such as a movable mirror), a fixed contact-type second reading means, Is often used.

Here, since the first reading means has a movable reading opening, the positional restriction for providing the density reference member is loose, and there is no problem in installing the density reference member.
However, since the reading opening of the contact-type second reading means is fixed, it is often difficult to provide the density reference member.

Therefore, in such a close-contact type reading means, there are many image reading apparatuses that deal with by using, as a density reference member, a guide plate or a roller at a position facing the reading sensor (reading position).
JP 2004-336100 A (Claim 1, FIG. 1)

  In the above Patent Document 1, the roller provided at the reading position is also used as a density reference member for shading correction. When a line sensor that reads one line by joining a plurality of sensors is used, a reference mark is attached to the roller at the joint position of the line sensor, so that the inclination at the time of joining the line sensors can be reduced. Is to be detected.

However, it is a case where one continuous line sensor is used, and the inclination between the line sensor and the roller cannot be detected.
For example, FIG. 7 is a side view (cross-sectional view) of a sensor 20B whose longitudinal direction is the vertical direction of the paper surface and a shading correction roller (density reference member) 29 whose longitudinal direction is the vertical direction of the paper surface corresponding to the sensor 20B. 7A shows a state where the sensor and the shading correction roller are in an appropriate positional relationship, and FIG. 7B shows a position where the sensor and the shading correction roller are out of the appropriate positional relationship. Shows the state.

In this case, the distance between the sensor and the roller changes from F1 to F1 ′ by shifting the sensor and the shading correction roller by δ.
As a result, the amount of light detected changes, and the shading correction becomes out of order in accordance with the change in the amount of light. For example, as shown in FIG. 7B, when the roller is displaced, the distance between the line sensor and the roller is increased, and thereby the detected light amount is reduced. Accordingly, the shading correction is excessively performed by the control unit that misunderstands that the amount of light has decreased.

Thus, there has been no method that can appropriately detect the inclination between the sensor of the contact-type reading unit and the shading correction roller.
The present invention has been made to solve the above-described problems, and relates to shading correction by a fixed reading unit when an image is read and an image data is generated while a document is being conveyed. It is an object of the present invention to provide an image reading apparatus capable of accurately correcting shading while maintaining an appropriate inclination of a density reference member and a sensor when a reading means for reading a document is used.

The present invention for solving the above problems is as described below.
(1) According to the first aspect of the present invention, in the image reading apparatus for detecting and correcting the reading unevenness of the reading means by reading the reference density, the reading means for reading the document being conveyed and the reading position of the reading means are arranged. And a reference density area to which a reference density for detecting uneven reading is attached, and phase adjustment areas to which reference marks for detection of attachment inclination are attached at both ends in the reading main scanning direction, and the original is being conveyed The density reference is configured to guide conveyance of the document and to read the reference density area by the reading unit when detecting the reading unevenness and to read the reference mark by the reading unit when detecting the mounting inclination. The member and the reading result of the reference marks on both ends of the density reference member are notified. There is an image reading apparatus characterized by and a control means for performing control to display.

  (2) The image reading apparatus according to claim 1, wherein the density reference member is a cylinder or a polygonal column whose longitudinal direction is a main scanning direction.

  (3) The image reading apparatus according to claim 1 or 2, wherein the density reference member includes a white area for shading correction as the reference density area. Device.

  (4) The invention according to claim 4 is characterized in that the density reference member includes a white area and a black area for shading correction as the reference density area. It is an image reading apparatus of description.

  (5) The invention according to claim 5 is characterized in that the density reference member has the reference marks at both ends in an effective image area at the time of reading as the phase adjustment area. An image reading apparatus according to claim 4.

  (6) In the invention according to claim 6, the density reference member includes a mark having any one of a triangle, an arrow shape, or a figure by at least two line segments that are not parallel to each other as the reference mark. The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus.

  (7) The invention according to claim 7 is an image reading apparatus that has a function of reading both sides of a document and detects a reading unevenness by reading a reference density on each of both sides, and at least one side of the document. The image reading apparatus according to claim 1, further comprising: the reading unit, the density reference member, and the control unit.

According to the present invention, the following effects can be obtained.
According to the present invention, in an image reading apparatus that detects and corrects reading unevenness of the reading unit by reading the reference density, a reference density region that is arranged at a reading position of the reading unit and is provided with a reference density for detecting uneven reading; A reference mark for detecting the mounting inclination is provided with a phase adjustment area attached to both ends of the main scanning direction for reading, and guides the conveyance of the original when the original is being conveyed, and reads the reading means when detecting uneven reading. The reference density area is read, and when the mounting inclination is detected, the density reference member configured to read the reference mark by the reading means is used, and the reference marks at both ends attached to the density reference member are read. By notifying or displaying the result, you can scan the image while conveying the document With regard to shading correction with a fixed reading means when generating data, it is possible to appropriately maintain the inclination between the density reference member and the sensor when using the close contact type reading means and perform accurate shading correction. .

  It should be noted that the density reference member is a cylinder or polygonal column whose longitudinal direction is the main scanning direction, so that the inclination of the column or polygonal column can be maintained appropriately, while the document is being conveyed. When the image is generated by reading the image, the shading correction by the fixed reading means is performed, and the inclination of the density reference member and the sensor is properly maintained when the contact type reading means is used, and the accurate shading correction is performed. It becomes possible.

  Further, since the density reference member includes a white area for shading correction as the reference density area, accurate white shading correction can be performed while maintaining an appropriate distance between the sensor and the density reference member.

  In addition, the density reference member includes a white area and a black area for shading correction as the reference density area, so that the distance between the sensor and the density reference member is appropriately maintained, and accurate white and black colors can be obtained. Shading correction is possible.

  Further, the density reference member has the reference marks at both ends in the effective image area at the time of reading as the phase adjustment area, so that it is possible to appropriately detect the inclination of the density reference member with respect to the sensor. Become.

  In addition, the density reference member includes a mark having any one of a triangle, an arrow shape, or a figure with at least two line segments that are not parallel to each other as a reference mark, so that the inclination of the density reference member with respect to the sensor can be increased. It becomes possible to detect appropriately and accurately.

  Further, the image reading apparatus has a function of reading both sides of a document and detects reading unevenness by reading a reference density on each of both sides, and the above invention is applied to reading at least one side of a document. As a result, a good shading correction becomes possible.

  The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described below in detail with reference to the drawings. It should be noted that even an image reading apparatus that reads the contents of a document as image information by a document reading unit (scanner), generates image data, and outputs the image data. Even in an image forming apparatus (copying apparatus) having a function of reading and copying contents as image information, the contents of a transmission object (original) are read as image information by an original reading means (scanner), and a communication line The embodiment of the present invention can be applied even to an image transmission apparatus (facsimile apparatus) having a function of transmitting via a network.

  In this embodiment, an image reading apparatus having a function of reading images on both sides at a time and generating image data on both sides while conveying a document, that is, reading a solid-state image sensor having a plurality of pixels in the main scanning direction. It has an element, and the original is moved in the sub-scanning direction with respect to the reading element, so that two-dimensional reading (sheet-through reading) in the main scanning direction and the sub-scanning direction is performed on both sides of the original. It is intended for an image reading apparatus or an image forming apparatus having a function.

<Mechanical configuration of image reader>
First, the mechanical configuration of the image reading apparatus of this embodiment will be described with reference to FIG. Here, an image reading apparatus having a function of reading images on both sides of a document while generating a document and generating image data on both sides is used as a specific example of this embodiment.

  Here, the document d placed on the document placement unit 11 of the automatic document feeding unit (ADF) 10 is sent out by the feed roller 12a, and separated and conveyed by the separation roller 12b. Then, the document d is further conveyed by the registration roller 12c under posture control and timing control. The document d is further transported around the platen roller 13 and is discharged onto a paper discharge tray 19 through transport rollers 14 and 15 as backup rollers. The conveyance rollers 14 and 15 are provided before and after the reading position of the second reading unit 20B.

  The image reading unit 20 includes a first reading unit 20A serving as a first reading unit having a movable reading opening for reading the first surface of the conveyed document, and a second surface of the conveyed document. The second reading unit 20B as a fixed and close contact type second reading means is configured.

  The first reading unit 20A and the second reading unit 20B respectively read the first side and the second side of the document conveyed at the same time, and any of them may be arranged on the upstream side. . Therefore, contrary to FIG. 2, there is no problem even if the second reading unit 20B is arranged on the upstream side.

  Here, in the first reading unit 20A, the original surface of the original d is irradiated by the light source 23, and the reflected light is CCD (photoelectric conversion means) via the imaging optical system 25 via the mirrors 24a, 24b and 24c. An image is formed on the light receiving surface of the reading element 26. That is, here, the light source 23, the mirrors 24a, 24b, 24c, the optical system having the imaging optical system 25 and the CCD 26, and the optical system driving means (not shown) constitute the first reading unit 20A. . Here, the light source 23 is a light source composed of a rod-shaped xenon lamp having a longitudinal direction in the main scanning direction.

  In FIG. 2, when the document d is placed on the platen glass 21 with the reading surface facing downward, the optical system scans along the platen glass 21 and reads an image on one side of the document. I do. The first reading unit 20A includes movable scanning units U1 and U2 that constitute a movable reading opening.

  When the document d is automatically fed by the ADF 10 and rotates around the platen roller 13, the first surface of the document is read with the light source 23 and the mirror 24 a moving under the second platen glass 22. Is called. The read image data of the document d is sent from the CCD 26 to an image processing unit (not shown). In this state, in the first reading unit 20A, the movable scanning units constituting the movable reading opening remain at the positions indicated by U1 'and U2'.

  The second reading unit 20B is in close contact with a document by a CIS (contact image sensor) composed of a linear light source 201 such as an LED (light emitting diode) or a xenon lamp and a line sensor 202 including a CCD or the like. Is a contact-type second reading unit that reads a second side of the document being conveyed.

  When the document d is automatically fed by the ADF 10 and rotates around the platen roller 13, the second reading unit 20B reads the second surface of the document d in parallel with this. The read image data of the document d is sent from the second reading unit 20B to an image processing unit (not shown).

In this way, the original d from which the images on the first side and the second side are read in parallel is stacked on the paper discharge tray 19.
Further, a first white reference member 27 as a first density reference member made of YUPO paper having a uniform white density is provided in the vicinity of the platen glass 21. Prior to the reading of the original, the amount of light in the main scanning direction at the first reading unit 20A is obtained from the image data obtained by reading the light source 23 and the mirror 24a under the first white reference member 27. Light amount distribution data representing a difference (light amount distribution) is collected, and first shading correction data for correcting the light amount distribution is generated.

  As the second white reference member 29 as the second density reference member, a conveyance roller is provided at the reading position of the second reading unit 20B as will be described later, and also serves as the second white reference member. Yes. That is, the second white reference member is disposed at the reading position of the second reading unit 20B, and operates as a backup roller that drives the document while keeping the document in close contact with the second reading unit 20B when the document is being conveyed. At the same time, when the document is not present, the surface is read by the second reading unit 20B (see FIG. 3A).

  That is, the second white reference member 29 is a cylinder having a longitudinal direction as a main scanning direction as shown in FIG. In addition, when the document is read, the second white reference member 29 does not rotate and can act as a guide plate that helps the document to pass. In this case, a polygonal column as shown in FIG. It may be.

  Further, when the surface of the second white reference member 29 is developed, it becomes as shown in FIG. That is, reference density areas (black correction area and white correction area) with reference density for reading unevenness (shading) detection, and reference marks M1 and M2 for attachment inclination detection are attached to both ends in the reading main scanning direction. And a phase adjustment region.

  The second white reference member 29 guides the conveyance when the document is conveyed, and also reads the reference density area by the second reading unit 20B when detecting uneven reading, and further detects the attachment inclination. The reference marks M1 and M2 are read by the second reading unit 20B. Here, the reference marks M1 and M2 are arranged at both ends in the effective image area in the reading main scanning direction.

  Further, as a reference mark of the second white reference member 29, a mark having any of a triangle, an arrow shape, or a figure by at least two line segments (/ \, / |, | \) that are not parallel to each other. It is desirable to provide.

  Thus, if there is no inclination between the second reading unit 20B and the second white reference member 29, the value A1 obtained by reading the reference mark M1 and the reference mark M2 are read as shown in FIG. The value B1 obtained in this way is equal to the value (width, number of dots).

  On the other hand, if there is an inclination between the second reading unit 20B and the second white reference member 29, it becomes as shown in FIG. 6 (2), and the value A2 obtained by reading the reference mark M1 and the reference mark M2 are obtained. The value B2 obtained by reading is not equal to the value (width, number of pixels).

  Then, in order to eliminate the inclination (deviation δ) of the second white reference member 29 shown in FIG. 7B, an adjustment mechanism such as a slide mechanism using a known actuator or screw is used. 29 is provided at at least one end.

<Electrical configuration of image reader>
FIG. 1 is a block diagram showing a detailed configuration in the image reading apparatus according to the first embodiment of the present invention. In FIG. 1, the periphery of the portion necessary for the description of the operation of the present embodiment is mainly described, and other portions known as the image reading apparatus are omitted.

  100 includes an image reading apparatus having a function of reading images on both sides at a time and generating image data on both sides while conveying an original, that is, a first reading unit 20A and a second reading unit 20B, and a sheet An image reading apparatus having a function of executing through-type reading on both sides of a document.

  Further, the image reading apparatus 100 collects light amount distribution data indicating a difference in light amount in the main scanning direction included in image data obtained by reading the first white reference member and the second white reference member, and the light amount distribution. It has a function of calculating shading correction data for making the light quantity distribution uniform on both sides based on the data, and executing shading correction on the image data on both sides of the document based on the shading correction data.

In the image reading apparatus 100, reference numeral 101 includes a CPU or the like, and is a control unit as a control unit that controls each unit.
The control unit 101 controls the second reading unit 20B to read the reference marks M1 and M2 at both ends attached to the second white reference member 29 during the density reference member inclination adjustment process, and the second white reference member. Control is performed to notify the external computer of the reading results of the reference marks M1 and M2 at both ends attached to 29 or display them on the display unit.

Reference numeral 111 denotes an electrical component of the first reading unit 20A, which corresponds to an image sensor, a drive circuit, or the like of the first reading unit 20A.
Reference numeral 112 denotes an electrical component of the second reading unit 20B, and corresponds to the light source 201, the image sensor 202, the drive circuit, and the like of the second reading unit 20B.

Reference numeral 121 denotes an A / D conversion unit that converts a read analog signal of the first reading unit 111 into digital data.
Reference numeral 122 denotes an AD converter that converts the analog signal read by the second reader 112 into digital data.

A first image processing unit 131 performs various image processing on the first image data read by the first reading unit 111 and generated by the AD conversion unit 121.
Reference numeral 132 denotes a second image processing unit when various image processing is performed on the second image data read by the second reading unit 112 and generated by the AD conversion unit 122.

Reference numeral 141 denotes a first data memory that stores first shading correction data for performing shading correction according to the reading characteristics of the first reading unit 111.
Reference numeral 142 denotes a first data memory in which second shading correction data for performing shading correction according to the reading characteristics of the first reading unit 112 is stored.

Reference numeral 151 denotes a first shading correction unit that performs shading correction on the first image data using the first shading correction data.
A second shading correction unit 152 performs shading correction on the second image data using the first shading correction data.

  An image memory 160 stores image data subjected to various image processing and shading correction. The image data is transferred to an external device based on the control of the control unit 101 via an interface (not shown) as a communication unit. Are output.

Reference numeral 170 denotes an operation unit that performs power on / off, reading start, input of various settings at the time of reading, and the like, and key data corresponding to the input key is sent to the control unit 101.
A display unit 180 of the image reading apparatus displays various states or various messages with characters, numerical codes, pictograms, and the like based on the control of the control unit 101. Alternatively, the display unit 180 displays or informs by flashing sound or light as necessary.

In this embodiment, the “first shading correction data” is generated from the read data of the first white reference member 27 by the first reading unit 20A.
In this embodiment, the “second shading correction data” is generated from the read data of the second white reference member 29 by the second reading unit 20B.

<Operational state of the first embodiment>
Hereinafter, the operation of the image reading apparatus of the first embodiment will be described in detail with reference to the flowchart of FIG. FIG. 4 is a flowchart showing the operation of the characterizing portion of this embodiment, and the operations that are common and known as an image reading apparatus are omitted.

  First, at the time of inspection by an inspector at the time of factory shipment or adjustment by a service person, when a predetermined key input is made on the operation unit 170 or when an instruction from an external computer (not shown) is given, The control unit 101 operates the image reading apparatus 100 in the “density reference member inclination adjustment processing mode” (start in FIG. 4).

  Here, the control unit 101 rotates the second white reference member 29 so that the reference marks M1 and M2 in the phase adjustment region are read by the second reading unit 20B (step S401 in FIG. 4).

  When the rotational driving of the second white reference member 29 is completed, the control unit 101 causes the second reading unit 112 to read the reference marks M1 and M2, and the widths of the reference marks M1 and M2 are increased as shown in FIG. It detects (step S401 in FIG. 4).

In this case, the image data obtained by reading is stored in the image memory 160, and predetermined image processing is executed to obtain the number of pixels having the width of the reference marks M1 and M2.
If the reference mark of the second white reference member 29 is any one of a triangle, an arrow, or a figure with at least two line segments (/ \, / |, | \) that are not parallel to each other, The inclination of the second white reference member 29 can be detected effectively.

  Then, the control unit 101 determines whether or not the number of pixels with the widths of the reference marks M1 and M2 is equal (step S403 in FIG. 4), and the number of pixels with the widths of the reference marks M1 and M2 is not equal (FIG. 4). 4, the control unit 101 displays the detected shift amount (difference) or the values of M1 and M2 on the display unit 180 or notifies the external computer.

  The inspector or service person who grasps the amount of deviation of M1 and M2 displayed on the display unit 180 or notified to the external computer adjusts the inclination of the second white reference member 29 through an adjustment mechanism (not shown), The adjustment is repeated so that the deviation amount of M2 becomes small (steps S405, S402, S403, S404, and S405 in FIG. 4).

  When the adjustment is performed as described above, the control unit 101 determines again whether or not the number of pixels having the widths of the reference marks M1 and M2 is equal (step S403 in FIG. 4), and the reference mark M1. , M2 are not equal (NO in step S403 in FIG. 4), the control unit 101 again displays the detected shift amount (difference) or the values of M1 and M2 on the display unit 180. Display or notify external computer.

  When the adjustment is performed as described above, the control unit 101 determines again whether or not the number of pixels having the widths of the reference marks M1 and M2 is equal (step S403 in FIG. 4), and the reference mark M1. , M2 are equal (YES in step S403 in FIG. 4), the control unit 101 displays on the display unit 180 that the inclination adjustment of the second white reference member 29 has been completed or externally. The computer is notified (step S406 in FIG. 4).

  In the above description, the inspector or service person operates the adjustment mechanism to perform the adjustment. However, by using an automatic adjustment mechanism such as a motor-driven ball screw or actuator, the adjustment is performed according to an instruction from the control unit 101. It is also possible to execute.

  After this, shading correction is executed using a white region or a black region of the second white reference member 29 based on an instruction from the control unit 101 by a known method. In this case, since the inclination of the second white reference member 29 is eliminated, accurate shading correction can be executed.

  That is, in this embodiment, in an image reading apparatus that detects and corrects (shading correction) the reading unevenness of the reading unit 20B by reading the reference density, it is arranged at the reading position of the reading unit 20B and is used for detecting the reference unevenness. , And reference adjustment areas M1 and M2 for detecting attachment inclinations are provided at both ends of the main scanning direction for reading and guiding the original when the original is being conveyed. A white reference member 29 configured to read the reference density region by the reading unit 20B when detecting uneven reading and to read the reference marks M1 and M2 by the reading unit 20B when detecting the mounting inclination is used. Reference marks M1, M2 on both ends of the white reference member 29 A white reference member when a contact-type reading unit is used for shading correction in a fixed reading unit when an image is generated while conveying an original by notifying or displaying the reading result. It is possible to maintain an appropriate inclination between the sensor 29 and the sensor and perform accurate shading correction.

  Note that the white reference member 29 is a cylinder or polygonal column whose longitudinal direction is the main scanning direction, so that the inclination of the column or polygonal column can be appropriately maintained, and the document is conveyed. When the image is read and image data is generated, the shading correction by the fixed reading unit 20B is performed, and the inclination of the density reference member and the sensor is appropriately maintained when the contact type reading unit is used, and accurate shading correction is performed. It becomes possible to do.

  Further, since the white reference member 29 includes a white region for shading correction as the reference density region, accurate white shading correction can be performed while maintaining an appropriate distance between the sensor and the density reference member.

  In addition, the white reference member 29 includes a white region and a black region for shading correction as the reference density region, so that the distance between the sensor and the density reference member is appropriately maintained, and the white and black colors are accurately detected. Shading correction becomes possible.

  Alternatively, the white reference member 29 has the reference marks M1 and M2 at both ends in the effective image area at the time of reading as the phase adjustment area, so that the inclination of the white reference member 29 with respect to the sensor of the second reading unit 20B. Can be detected appropriately.

  In addition, the white reference member 29 includes a mark having any one of a triangle, an arrow, or a figure formed by at least two line segments that are not parallel to each other as the reference mark. It becomes possible to detect the inclination with respect to the reading unit 20B appropriately and accurately.

  Further, the image reading apparatus has a function of reading both sides of a document and detects reading unevenness by reading a reference density on each of both sides, and the above invention is applied to reading at least one side of a document. As a result, a good shading correction becomes possible.

<Other embodiment (1)>
In the above embodiment, the image reading apparatus reads both sides of the document, but the present invention is not limited to this. For example, in the image reading apparatus shown in FIGS. 1 and 2, even if the image reading apparatus is a single-sided image reading apparatus including the second reading unit 20B (112) without including the first reading unit 20A (111), It is possible to effectively eliminate the inclination of the reference member 29.

<Other embodiment (2)>
Further, even if the image reading apparatus includes a fixed and close-contact type reading unit such as the second reading unit 20B on both sides of the document, good results can be obtained by applying the present embodiment to both sides. Can do.

<Other embodiment (3)>
The inclination correction of the second white reference member 29 in the above embodiment is preferably performed at the time of factory shipment or when parts are replaced. In addition, the control unit 101 monitors the number of image formations and executes a predetermined number of image formations. Each unit may be controlled so as to be executed periodically after.

<Other embodiment (4)>
The white reference member 29 described above includes the white area and the black area for shading correction as the reference density area, but it is sufficient to include the white area at the minimum. The black area includes not only so-called black but also gray. In other words, halftone shading correction can be performed by this black region.

<Other embodiment (5)>
In the above embodiment, the image reading apparatus has been described as a specific example. However, the above-described control and processing are also executed in the case of an image forming apparatus, a facsimile apparatus, and a composite apparatus including the image reading apparatus. The same excellent effect can be obtained.

<Other embodiment (6)>
It should be noted that the portion described as “close contact” in the above embodiment may be kept close without actually being in close contact, and such close state is also included in the description of the above embodiment.

1 is a functional block diagram illustrating an electrical configuration of an image reading apparatus according to an embodiment of the present invention. It is a block diagram which shows the mechanical structure of the image reading apparatus of embodiment of this invention. It is a block diagram which shows the principal part of the mechanical structure of the image reading apparatus of embodiment of this invention. It is a flowchart which shows the processing operation of the inclination cancellation | release of the density | concentration reference member of embodiment of this invention. It is explanatory drawing relevant to the process of the inclination cancellation of the density | concentration reference member of embodiment of this invention. It is explanatory drawing relevant to the process of the inclination cancellation of the density | concentration reference member of embodiment of this invention. It is explanatory drawing which shows the mode of the inclination of a density | concentration reference member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image reading apparatus 101 Control part 111 1st reading part 112 2nd reading part 121 AD conversion part 122 AD conversion part 131 1st image processing part 132 2nd image processing part 141 1st data memory 142 2nd data Memory 151 First shading correction unit 152 Second shading correction unit 160 Image memory 170 Operation unit 180 Display unit

Claims (7)

In the image reading apparatus that detects and corrects the reading unevenness of the reading means by reading the reference density,
A reading means for reading a document being conveyed;
A reference density region disposed at a reading position of the reading means and provided with a reference density for detecting uneven reading, and a phase adjustment region provided with reference marks for detecting a mounting inclination at both ends of the reading main scanning direction, When the original is being conveyed, the conveyance of the original is guided, and when the reading unevenness is detected, the reference density region is read by the reading means, and when the mounting inclination is detected, the reference mark is read by the reading means. A concentration reference member configured to be read; and
Control means for performing control for notifying or displaying the reading result of the reference marks at both ends attached to the density reference member;
An image reading apparatus comprising: The density reference member is a cylinder or a polygonal column having a longitudinal direction as a main scanning direction.
The image reading apparatus according to claim 1. The density reference member includes a white area for shading correction as the reference density area.
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. The density reference member includes a white area and a black area for shading correction as the reference density area.
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. The density reference member has the reference marks at both ends in an effective image area at the time of reading as the phase adjustment area.
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. The concentration reference member includes a mark having any one of a triangle, an arrow shape, or a figure by at least two line segments that are not parallel to each other as the reference mark.
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. An image reading apparatus having a function of reading both sides of a document and detecting reading unevenness by reading a reference density on each of both sides,
For reading at least one side of a document, the reading means, the density reference member, and the control means,
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus.

Images