# US 2019/0174019 A1 · Image reading apparatus and image reading method

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- Number: US 2019/0174019 A1
- Document ID: US20190174019A1
- Status: Published application
- Kind: A1
- Application number: 16/200,454
- Filed: 2018-11-26
- Published: 2019-06-06
- Earliest claimed: 2017-12-05
- Assignees: Canon Kabushiki Kaisha
- Applicants: Canon Kabushiki Kaisha
- Inventors: Kenji Ooki
- Web page: https://patentgrep.com/patent/US20190174019A1

## CPC

- H04N 1/00681: {Detecting the presence, position or size of a sheet or correcting its position before scanning (H04N1/047 takes precedence; mode signalling H04N1/333; skew detection or correction in image signals H04N1/3878)}
- H04N 1/00031: {Testing, i.e. determining the result of a trial (H04N1/00029 takes precedence; using test signals for transmission mode changing H04N2201/33371)}
- H04N 1/00034: {Measuring, i.e. determining a quantity by comparison with a standard (H04N1/00031 takes precedence)}
- H04N 1/00039: {Analysis, i.e. separating and studying components of a greater whole}
- H04N 1/00087: {Setting or calibrating (picture signal circuits H04N1/40)}
- H04N 1/00588: {to the scanning position (H04N1/00572, H04N1/00594 take precedence)}
- H04N 1/401: Compensating positionally unequal response of the pick-up or reproducing head (H04N1/403 takes precedence)
- H04N 1/4076: {dependent on references outside the picture}
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

Provided is an image reading apparatus configured to avoid unnecessarily performing shading correction processing. The image reading apparatus detects whether or not an original is placed on an original tray when detecting an open state of an ADF and then detecting a closed state thereof. In a case where the original is placed on the original tray, the image reading apparatus performs shading correction for flow reading, and in a case where no original is placed on the original tray, the image reading apparatus performs shading correction for platen cover reading.

## Claims

### Claim 1

An image reading apparatus, comprising:
an original table on which an original is to be placed;
a document feeder configured to convey the original, the document feeder including:
an original tray on which the original is to be placed;
a first sensor configured to detect that the original is placed on the original tray;
a conveyor configured to convey the original placed on the original tray; and
a sheet discharge tray to which the original is to be discharged;
a reference member;
a second sensor configured to detect an open state and a closed state of the document feeder;
a reading unit configured to read one of the original placed on the original table and the original to be conveyed by the document feeder,
the reading unit being configured to read the original placed on the original table under a state in which the reading unit is moving a reading position in a first mode, and to read the original to be conveyed by the conveyor to a predetermined reading position in a second mode;
an image processor configured to perform shading correction on image data output from the reading unit in the first mode with use of first shading correction data, and to perform shading correction on image data output from the reading unit in the second mode with use of second shading correction data; and
a processor configured to generate one of the first shading correction data for the first mode and the second shading correction data for the second mode based on a result of reading the reference member by the reading unit,
wherein, in a case where the first sensor detects that no original is placed on the original tray and the second sensor detects that the original table is changed from the open state, the processor generates the first shading correction data, and
wherein, in a case where the first sensor detects that the original is placed on the original tray and the second sensor detects that the original table is changed from the open state, the processor is prevented from generating the first shading correction data.

### Claim 2 (depends on 1)

The image reading apparatus according to claim 1, wherein the reference member is arranged between the predetermined reading position and a region of the original table in which the original is to be placed, in a movement direction of the reading position.

### Claim 3 (depends on 1)

The image reading apparatus according to claim 1, wherein, in a case where the first sensor detects that the original is placed on the original tray, the processor generates the second shading correction data.

### Claim 4

An image reading apparatus, comprising:
an original table on which an original is to be placed;
a first sensor configured to detect presence or absence of the original to be placed on the original tray;
a reading unit configured to read an image from the original;
a reference member to be used for shading correction;
a conveyor configured to convey the original from the original tray to a reading position to be used by the reading unit;
an original table on which an original from which an image is read under a state in which the reading unit is being moved is to be placed;
a platen cover freely openable and closable with respect to the original table;
a second sensor configured to detect one of an open state and a closed state of the platen cover;
a shading corrector configured to generate, in accordance with a result of reading the reference member by the reading unit, first shading correction data to perform shading correction in a case where the reading unit reads the original conveyed from the original tray, and to generate second shading correction data to perform shading correction in a case where the reading unit reads the original placed on the original table; and
a controller configured to, in a case where the first sensor detects that the original is placed on the original tray:
cause the shading corrector to generate the first shading correction data to perform the shading correction regardless of a detection result of the second sensor; and
move the reading unit to a position for reading the original conveyed from the original tray to cause the reading unit to read the image of the original.

### Claim 5 (depends on 4)

The image reading apparatus according to claim 4, wherein the controller is configured to, in a case where the second sensor detects the open state of the platen cover and then detects the closed state of the platen cover:
cause, in a case where the first sensor detects that the original is placed on the original tray, the shading corrector to generate the first shading correction data to perform the shading correction, and move the reading unit to the position for reading the original conveyed from the original tray; and
cause, in a case where the first sensor detects that no original is placed on the original tray, the shading corrector to generate the second shading correction data to perform the shading correction, and move the reading unit to a position for reading the original placed on the original table.

### Claim 6 (depends on 5)

The image reading apparatus according to claim 5, wherein, in a case where a predetermined time period elapses until detection of the closed state after the second sensor detects the open state of the platen cover, the controller moves the reading unit to a standby position.

### Claim 7 (depends on 4)

The image reading apparatus according to claim 4, wherein the controller is configured to, in a case where an instruction to start reading is issued when the second sensor detects the closed state of the platen cover, and the first sensor detects that the original is placed on the original tray:
cause the shading corrector to generate the first shading correction data to perform the shading correction; and
move the reading unit to the position for reading the original conveyed from the original tray.

### Claim 8 (depends on 7)

The image reading apparatus according to claim 7, wherein, in a case where the instruction to start reading is issued when the second sensor detects the closed state of the platen cover, and the reading unit is located at a position at which the image is readable at the reading position, and further the shading correction is already performed by the shading corrector with use of the first shading correction data, the controller prevents the shading corrector from performing the shading correction.

### Claim 9 (depends on 4)

The image reading apparatus according to claim 4, wherein the controller is configured to, in a case where an instruction to start reading is issued and the second sensor detects the closed state of the platen cover, and the first sensor detects that no original is placed on the original tray:
cause the shading corrector to generate the second shading correction data to perform the shading correction; and
move the reading unit to a position for reading the original placed on the original table.

### Claim 10 (depends on 4)

The image reading apparatus according to claim 4,
wherein the reading unit is fixed at a first position for reading the original conveyed from the original tray when the image is read from the original conveyed by the conveyor,
wherein the reading unit is configured to read the original under a state in which the reading unit is being moved from a second position for reading the original placed on the original table when the image is read from the original placed on the original table,
wherein the reading unit is arranged at a standby position when the reading unit is prevented from reading the image,
wherein the controller is configured to, in a case where the second sensor detects the closed state of the platen cover and further the first sensor detects that the original is placed on the original tray, when the reading unit is located at the standby position, cause the reading unit to read the reference member under a state in which the reading unit is being moved from the standby position to the first position, and
wherein the shading corrector is configured to perform the shading correction for allowing the reading unit to read the original conveyed by the conveyor, in accordance with a result obtained by the reading unit reading the reference member under a state in which the reading unit is being moved from the standby position to the first position.

### Claim 11 (depends on 10)

The image reading apparatus according to claim 10, wherein the controller is configured to cause the reading unit to wait at the first position after movement of the reading unit is completed.

### Claim 12 (depends on 10)

The image reading apparatus according to claim 10, wherein, in a case where the second sensor detects the closed state of the platen cover and further the first sensor detects that the original is placed on the original tray, when the reading unit is located at the first position, the controller causes the reading unit to stay still at the first position.

### Claim 13 (depends on 10)

The image reading apparatus according to claim 10,
wherein the controller is configured to, in a case where the second sensor detects the closed state of the platen cover and further the first sensor detects that no original is placed on the original tray, cause the reading unit to read the reference member under a state in which the reading unit is being moved from the standby position to the second position, and
wherein the shading corrector is configured to perform the shading correction for allowing the reading unit to read the original placed on the original table, in accordance with a result obtained by the reading unit reading the reference member under a state in which the reading unit is being moved from the standby position to the second position.

### Claim 14 (depends on 13)

The image reading apparatus according to claim 13, wherein the controller is configured to cause the reading unit to wait at the second position after movement of the reading unit is completed.

### Claim 15

An image reading method to be executed by an apparatus including:
an original tray on which an original is to be placed;
a first sensor configured to detect presence or absence of the original placed on the original tray;
a reading unit configured to read an image from the original;
a reference white plate to be used for shading correction of the reading unit;
a conveyor configured to convey the original from the original tray to a reading position to be used by the reading unit;
an original table on which an original from which an image is read under a state in which the reading unit is being moved is to be placed;
a platen cover freely openable and closable with respect to the original table;
a second sensor configured to detect one of an open state and a closed state of the platen cover; and
a shading corrector configured to generate, in accordance with a result of reading the reference white plate by the reading unit, first shading correction data to perform shading correction when the reading unit reads the original conveyed from the original tray, and to generate second shading correction data to perform shading correction when the reading unit reads the original placed on the original table,
the image reading method comprising:
generating, by the shading corrector, the first shading correction data to perform the shading correction regardless of a detection result of the second sensor in a case where the first sensor detects that the original is placed on the original tray; and
moving the reading unit to a position for reading the original conveyed from the original tray to cause the reading unit to read the image of the original.