Image reading apparatus and information processing method

Abstract

To provide an image reading device and an information processing method capable of determining a paper size of a document with a simpler configuration.SOLUTION: An image reading device 1 includes a document placement table on which a document is placed, a cover provided so as to be openable and closable with respect to the document placement table, an image sensor 11 that acquires an image on the document placement table, an AnalogFrontEnd (AFE) 12 that is an adjustment unit that executes predetermined gain adjustment on brightness indicating brightness of the image acquired by the image sensor 11, and a control unit (Soc13) that determines a paper size of the document placed on the document placement table based on a first gain adjustment value related to the gain adjustment executed on the brightness of the image acquired when the cover is in a first state and a second gain adjustment value related to the gain adjustment executed on the brightness of the image acquired when the cover is in a second state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an image reading device and an information processing method. [Background technology]

[0002] Conventionally, image reading devices that detect the paper size of a document placed on a document table have been known. For example, Patent Document 1 discloses an image reading device that reads the output value of an image sensor multiple times when a document holder is closed, and determines the paper size of the document based on the difference between the output values. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-34461 Summary of the Invention [Problem to be solved by the invention]

[0004] The image reading device disclosed in Patent Document 1 needs to acquire output values ​​when the closing operation is being performed in order to determine the paper size of the document. However, in order to acquire output values ​​multiple times within the limited time of the closing operation and perform calculations and judgments based on the output values, an image signal processing circuit (ASIC: Application Specific Integrated Circuit) that operates at high speed is required.

[0005] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide an image reading device and an information processing method that are capable of determining the paper size of a document with a simpler configuration. [Means for solving the problem]

[0006] An image reading device according to one embodiment of the present disclosure includes a document tray on which a document is placed, a cover that can be opened and closed relative to the document tray, an image sensor that acquires an image on the document tray, a gain adjustment unit that performs a predetermined gain adjustment on a brightness that indicates the brightness of the image acquired by the image sensor, and a control unit that determines the paper size of the document placed on the document tray based on a first gain adjustment value related to the gain adjustment performed on the brightness of the image acquired when the cover is in a first state and a second gain adjustment value related to the gain adjustment performed on the brightness of the image acquired when the cover is in a second state.

[0007] An information processing method according to one embodiment of the present disclosure is an information processing method performed by an image reading device that includes a document tray on which a document is placed, a cover that can be opened and closed relative to the document tray, and an image sensor that acquires an image on the document tray, and the method performs a predetermined gain adjustment on a brightness that indicates the brightness of the image acquired by the image sensor, and determines the paper size of the document placed on the document tray based on a first gain adjustment value related to the gain adjustment performed on the brightness of the image acquired when the cover is in a first state, and a second gain adjustment value related to the gain adjustment performed on the brightness of the image acquired when the cover is in a second state. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide an image reading device and an information processing method that are capable of determining the paper size of a document with a simpler configuration. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a functional block diagram illustrating a schematic configuration of an image reading apparatus according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the arrangement of components of a document table of the image reading device in a plan view. [Figure 3]FIG. 10 is a diagram illustrating an example of a paper size determination table. [Figure 4] FIG. 2 is a diagram illustrating an area of ​​a platen glass. [Figure 5] 10 is a flowchart showing an example of a paper size determination process executed by the image reading apparatus of FIG. [Figure 6] 10 is a diagram showing the positional relationship between the cover and the document placing table in an open state as viewed from the side. FIG. [Figure 7] 10 is a diagram showing the positional relationship between the cover and the document placing table in a first state as seen from the side. FIG. [Figure 8] FIG. 10 is a diagram schematically illustrating the brightness of an image when a reference white plate is scanned. [Figure 9] FIG. 10 is a diagram schematically illustrating the brightness of an image when the offset value is lowered. [Figure 10] 4A and 4B are diagrams showing, in a side view, a schematic diagram illustrating the relationship between the lower surface of the cover and the upper surface of the document placing table in a first state and a second state. [Figure 11] 10 is a flowchart showing an example of a process for obtaining a gain adjustment value executed by the image reading apparatus of FIG. 1. [Figure 12] FIG. 2 is a conceptual diagram showing an image acquired by reading a document using an image sensor. [Figure 13] FIG. 10 is a diagram schematically showing a brightness gain value in the first document reading. [Figure 14] FIG. 10 is a diagram schematically showing a brightness gain value in the second document reading. [Figure 15] FIG. 10 is a diagram schematically showing a brightness gain value in the third document reading. [Figure 16] FIG. 10 is a diagram schematically showing a brightness gain value in the fourth document reading. [Figure 17] FIG. 10 is a diagram schematically showing a brightness gain value in the fifth document reading. [Figure 18] 10 is a flowchart showing an example of a paper size determination process executed by the image reading apparatus of FIG. [Figure 19] 10 is a table showing the determination results of whether or not an original is placed on the original placement plate. [Figure 20] 10 is a graph showing the relationship between the number of readings and the gain adjustment value. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present disclosure will be described with reference to the drawings. The embodiment described below is merely an example of the present disclosure, and the present disclosure is not limited to the embodiment. Even if it is not the embodiment described below, various modifications can be made depending on the design, etc., as long as they do not deviate from the technical idea of ​​the present disclosure.

[0011] [Image reader] FIG. 1 is a functional block diagram showing a schematic configuration of an image reading device 1 according to one embodiment. The image reading device 1 is connected to an image forming device 2. The image forming device 2 is a multifunction device having multiple functions, such as a copy function, a scanner function, a facsimile function, and a printer function. The image reading device 1 reads an image of a document. For example, the image reading device 1 scans and reads a document placed on a document placing table of a document reading unit. The image reading device 1 may read an image of the document while the document is being transported by a document feeder. The image forming device 2 forms an image of the document read by the image reading device 1. The image reading device 1 may be configured as a part of the image forming device 2.

[0012] FIG. 2 is a schematic diagram showing the arrangement of each component of document table 40 of image reading device 1 in a plan view. The document table is a table on which a document is placed. In image reading device 1, a cover is provided above document table 40 (the front side of the paper in FIG. 2). The cover is provided so as to be able to open and close relative to document table 40. The cover is attached to document table 40 via a hinge, for example. In this example, the hinge is attached to the top side of FIG. 2. Therefore, in this example, the cover can be opened and closed around the top side of document table 40 shown in FIG. 2 as a rotation axis.

[0013] The cover is used to press down on the document from above when reading the document placed on document table 40, for example. That is, when reading a document with image reading device 1, the cover is closed and the top side of document table 40 is covered with the cover. When the cover is opened, the top side of document table 40 is not covered with the cover, and a document can be placed on document table 40 or a document placed on document table 40 can be removed.

[0014] Fig. 2 shows a plan view of document placing table 40 with the cover open. In this embodiment, the up-down direction in Fig. 2 is also referred to as the main scanning direction, and the left-right direction in Fig. 2 is also referred to as the sub-scanning direction. In Fig. 2, components that are visible to the user with the cover open are shown with solid lines, and components that are not visible because they are located inside image reading device 1, for example, are shown with dashed lines.

[0015] In the document placement table 40, a document glass 41 is provided in an area where the document is read. The user places the document on the document glass 41 and causes the image reading device 1 to read the image of the document. In this embodiment, the user places the document on the document glass 41 so that the edge of the document is aligned with the upper left corner of the document glass 41.

[0016] As shown in FIG. 1, the image reading device 1 includes an image sensor 11, an AFE (Analog Front End) 12, an SoC (System on a Chip) 13, a motor 14, a motor drive circuit 15, a cover open / close detection switch 16, a sub-scanning position sensor 17, a reference position sensor 18, a detection circuit 19, a memory unit 20, a network circuit 21, and an external memory circuit 22.

[0017] The image sensor 11 is a device that converts received light into an electrical signal and reads out the converted signal to acquire an image. The image sensor 11 acquires an image on the document table 40. The image sensor 11 has a light-emitting unit such as an LED (Light Emitting Diode), and acquires an image by emitting light from the light-emitting unit and receiving reflected light of the irradiated light. The image sensor 11 is housed in a carriage case 42 shown in FIG. 2. The image sensor 11 is arranged to extend over the entire document table glass 41 in the main scanning direction.

[0018] The AFE 12 converts the analog image data acquired by the image sensor 11 into digital image data. The AFE 12 provides the converted digital image data to the SoC 13.

[0019] In this embodiment, the AFE 12 functions as a gain adjustment unit having a gain adjustment function. Specifically, the AFE 12 performs a predetermined gain adjustment on the brightness of the image acquired by the image sensor 11. Specifically, the AFE 12 performs the gain adjustment by amplifying the brightness of the image acquired by the image sensor 11 to a gain adjustment target value.

[0020] SoC13 functions as a control unit that controls the entire image reading device 1. SoC13 executes various processes by controlling the entire image reading device 1. For example, SoC13 executes a paper size determination process that determines the paper size of the document placed on the document placing table 40. Details of the paper size determination process executed in this embodiment will be described later. SoC13 also executes an image reading process that reads an image of the document placed on the document placing table 40. The image reading process may be executed by a known method, and therefore a detailed description thereof will be omitted here.

[0021] In this embodiment, as shown in FIG. 1, the SoC 13 includes, as functional units, an image signal processing unit 31, a reading device control unit 32, a main control unit 33, and an image forming device control unit .

[0022] The image signal processing unit 31 processes image data acquired from the AFE 12. The reading device control unit 32 controls the image reading device 1. In this embodiment, the reading device control unit 32 particularly controls the motor drive circuit 15 and the detection circuit 19, which are related to image reading. The main control unit 33 performs overall control, including the image signal processing unit 31, the reading device control unit 32, and the image forming device control unit 34. In this embodiment, the main control unit 33 performs paper size determination processing. The image forming device control unit 34 controls the image formation processing by the image forming device 2. The image forming device control unit 34 controls the image forming device 2 using a known method.

[0023] The motor 14 moves the image sensor 11. Specifically, when the motor 14 rotates, the belt 45 operates via a gear 43 and a pulley 44, causing the carriage case 42 connected to the belt 45 to move in the sub-scanning direction along a rail 46. As a result, the image sensor 11 housed in the carriage case 42 also moves in the sub-scanning direction. The motor 14 is driven by a motor drive circuit 15 under the control of the SoC 13.

[0024] The cover open / close detection switch 16 detects whether a cover provided on the image reading device 1 is open or closed. The cover open / close detection switch 16 is disposed in a position on the document placing table 40 where it can detect whether the cover is open or closed. The cover open / close detection switch 16 is disposed, for example, near the rotation axis of the cover. In the example shown in FIG. 2, the cover open / close detection switch 16 is disposed between the document placing glass 41 and the upper side of the document placing table 40.

[0025] The cover open / close detection switch 16 is, for example, a mechanical switch. For example, when the cover is open, at least a part of the switch protrudes above the image reading device 1 from the placement surface formed by the document placement table 40, and when the cover is closed to a certain extent or more, the protruding part of the switch is pressed down on the image reading device 1, thereby detecting that the cover is closed. However, the cover open / close detection switch 16 does not have to be a mechanical switch. The cover open / close detection switch 16 may have any configuration that can detect whether the cover is open or closed.

[0026] The sub-scanning position sensor 17 determines whether or not a document is placed at the position where the sub-scanning position sensor 17 is located on the document platen glass 41. The sub-scanning position sensor 17 is configured, for example, by a known reflective photoelectric sensor. The sub-scanning position sensor 17 configured by a reflective photoelectric sensor determines whether or not a document is placed based on the received light intensity of reflected light. The specific location of the sub-scanning position sensor 17 will be described later.

[0027] The reference position sensor 18 determines whether the image sensor 11 is at a reference position P (see FIG. 2) in the image reading device 1. The reference position P is a reference position for determining the position of the image sensor 11 in the image reading device 1, and in the example shown in FIG. 2, the reference position P is located on the left side of the platen glass 41 in a plan view of the platen 40.

[0028] The reference position sensor 18 is configured by, for example, a transmission-type photoelectric sensor. In this embodiment, as shown in FIG. 2 , the reference position sensor 18 is located to the left of the reference position P in a plan view of the document placing table 40. A light-shielding plate 47 that protrudes leftward in a plan view of the document placing table 40 is provided on the carriage case 42 that houses the image sensor 11. When the carriage case 42 is located at the reference position P, the light-shielding plate 47 blocks light emitted from the light source of the transmission-type photoelectric sensor, and the light-receiving portion of the transmission-type photoelectric sensor does not receive light from the light source. This allows the reference position sensor 18 to detect that the image sensor 11 is located at the reference position P.

[0029] The detection circuit 19 provides the SoC 113 with the detection results of the cover open / close detection switch 16, the sub-scanning position sensor 17, and the reference position sensor 18 based on signals from the cover open / close detection switch 16, the sub-scanning position sensor 17, and the reference position sensor 18.

[0030] The storage unit 20 is a storage medium capable of storing programs and data. The storage unit 20 can be configured, for example, with a semiconductor memory or a magnetic memory. The storage unit 20 stores, for example, programs for operating the SoC 13. As shown in FIG. 2, the storage unit 20 includes, for example, a nonvolatile memory 20a and a volatile memory 20b.

[0031] The network circuit 21 executes information communication with external devices via a network. The external memory circuit 22 records information in an external storage device and reads information from the external storage device.

[0032] [Paper size judgment table] The storage unit 20 stores a paper size determination table used in the paper size determination process. FIG. 3 is a diagram showing an example of the paper size determination table. Each row of the paper size determination table indicates whether or not a document is placed in areas 1 to 6 and the sub-scanning position sensor 17. Specifically, a check mark indicates that it has been determined that a document is placed, and an X indicates that it has been determined that a document is not placed. Each column of the paper size determination table indicates a pattern regarding whether or not a document is placed in areas 1 to 6 and the sub-scanning position sensor 17 when paper of each size is placed on the document placement table 40.

[0033] Here, regions 1 to 6 will be described with reference to FIG. 4. Regions 1 to 6 are regions obtained by dividing the platen glass 41 in the main scanning direction for the purpose of paper size determination processing. FIG. 4 is a diagram illustrating the regions of the platen glass 41. In FIG. 4, the dashed and dashed lines indicate the outline of the manuscript paper when the manuscript is placed aligned with the upper left corner S of the platen glass 41. The numbers written to the right and below the upper left corner S indicate the distance (mm) from the upper left corner S in the main scanning direction and the sub-scanning direction at which the outline of the manuscript paper is located, respectively. The combination of letters and numbers indicates the paper size of the manuscript at which the outline is located at each distance. For example, when a B4-sized manuscript is placed on the platen glass 41, as shown in FIG. 4, the outline of the manuscript paper is located 364 mm from the upper left corner S in the sub-scanning direction and 257.5 mm from the upper left corner S in the main scanning direction.

[0034] It should be noted that document paper sizes with "R" at the end are the same size as those without "R", but are placed in different directions on the document glass 41. For example, A5 size and A5R size are the same paper size, but are placed in different directions vertically and horizontally on the document glass 41. In this embodiment, the image reading device 1 identifies two sizes that are the same paper size but different directions as different paper size categories.

[0035] 4, areas 1 to 6 are provided at positions 148.5 mm or less from the upper left edge S in the main scanning direction. As a result, even when an A5-sized original document, which is the smallest paper size that can be determined by image reading device 1 of this embodiment, is placed on platen glass 41, image reading device 1 can detect that an original document has been placed on platen glass 41 in at least one of areas 1 to 6. Areas 1 to 6 are located at different positions in the main scanning direction.

[0036] Area 1 is set at a position 148.5 mm or less in the main scanning direction from the upper left corner S. Since the length in the short direction of an A5-sized document, which is the smallest paper size that can be determined by image reading device 1 of this embodiment, is 148.5 mm, by setting area 1 at a position 148.5 mm or less from the upper left corner S, area 1 can detect that a document has been placed on document table glass 41, regardless of the size of the document placed on document table glass 41.

[0037] Area 2 is set at a position between 182 mm and 210 mm inclusive in the main scanning direction from the upper left corner S. As a result, as shown in the table in Fig. 3, when an A5R or B5R size document is placed on platen glass 41, area 2 does not detect that the document has been placed, but when a document of any other paper size is placed on platen glass 41, area 2 detects that the document has been placed.

[0038] Area 3 is set at a position between 210 mm and 257.5 mm inclusive in the main scanning direction from the upper left corner S. As a result, as shown in the table in Fig. 3, when an original of A5 size, A4R size, A5R size, or B5R size is placed on platen glass 41, area 3 does not detect that an original has been placed, but when an original of any other paper size is placed on platen glass 41, area 3 detects that an original has been placed.

[0039] Area 4 is set at a position between 257.5 mm and 270 mm inclusive in the main scanning direction from the upper left corner S. As a result, as shown in the table in Fig. 3, when a document of B4 size, B5 size, A5 size, A4R size, A5R size, or B5R size is placed on platen glass 41, area 4 does not detect that a document has been placed, but when a document of any other paper size is placed on platen glass 41, area 4 detects that a document has been placed.

[0040] Area 5 is set at a position between 270 mm and 297 mm inclusive in the main scanning direction from the upper left corner S. As a result, as shown in the table in Fig. 3, when an original of 8K size, 16K size, B4 size, B5 size, A5 size, A4R size, A5R size, or B5R size is placed on platen glass 41, area 5 does not detect that an original has been placed, but when an original of any other paper size is placed on platen glass 41, area 5 detects that an original has been placed.

[0041] Area 6 is set at a position 297 mm or more from the upper left end S in the main scanning direction. Since the length in the short direction of an A3-sized document, which is the largest document size that can be determined by image reading device 1 of this embodiment, is 297 mm, by setting area 6 at a position 297 mm or more from the upper left end S, no matter what size document is placed on document table glass 41, the presence of a document will not be detected in area 6.

[0042] The sub-scanning position sensor 17 is disposed at a position 148.5 mm or less from the upper left corner S in the main scanning direction and at a position 210 mm to 257.5 mm from the upper left corner S in the sub-scanning direction. This allows for the identification of paper sizes that cannot be detected solely by detection using areas 1 to 6. For example, as shown in FIG. 3 , when A3-sized and A4-sized documents are placed on the platen glass 41, the placement of the documents is detected in areas 1 to 5, but not in area 6. However, when the sub-scanning position sensor 17 detects the placement of a document, it is determined that the document is A3 size, and when the sub-scanning position sensor 17 does not detect the placement of a document, it is determined that the document is A4 size. Therefore, the sub-scanning position sensor 17 is disposed at a position different from areas 1 to 6 in the main scanning direction so that it can identify paper sizes that cannot be detected solely by detection using areas 1 to 6.

[0043] [Paper size determination process] 5 is a flowchart showing an example of a paper size determination process executed by image reading device 1. When a user wants image forming device 2 to form an image, the user opens the cover of document table 40 of image reading device 1 and places a document on document table 40. Then, the user closes the cover of document table 40 and performs an operation input to form an image. During this process, image reading device 1 executes the paper size determination process. Image reading device 1 starts the flow of FIG. 5 when, for example, the cover changes from a closed state to an open state. The change of the cover from a closed state to an open state can be detected, for example, by cover open / close detection switch 16.

[0044] 5, the SoC 13 of the image reading device 1 saves the gain setting value in the storage unit 20 (step S11). As will be described later, the image reading device 1 performs gain adjustment in the paper size determination process, and therefore, before the gain adjustment is performed, the current gain setting value set for the image reading device 1 is stored at least temporarily in the storage unit 20. Note that if the gain setting value has already been stored, step S11 does not need to be executed.

[0045] The SoC 13 of the image reading device 1 determines whether the cover has changed from an open state to a closed state (step S12). Specifically, the SoC 13 determines whether the cover has entered a first state, which occurs in the process of changing from an open state to a closed state. In this embodiment, the first state is a state in which the cover open / close detection switch 16 begins to be pressed.

[0046] For example, a user places an original R on the document tray 40 with the cover 50 in the open state shown in FIG. 6 . The user closes the cover 50 to cause the image forming apparatus 2 to form an image. As a result, the cover 50 rotates about the rotation shaft 52, approaching the document tray 40. At this time, the cover open / close detection switch 16 protrudes upward from the document tray 40 as shown in FIG. 6 . Therefore, while the cover 50 is being closed, the cover 50 comes into contact with the cover open / close detection switch 16 and pushes the cover open / close detection switch 16 downward (toward the document tray 40), as shown in FIG. 7 . When the cover open / close detection switch 16 is pushed down, the SoC 13 can detect that the cover 50 is being closed. In this embodiment, the state when the cover open / close detection switch 16 comes into contact with the cover open / close detection switch 16 and begins to be pushed down, that is, when the SoC 13 detects that the cover open / close detection switch 16 has been pushed down, as shown in FIG. 7 , is the first state. Therefore, in step S12, the SoC 13 does not determine whether the cover is completely closed, but detects whether the cover 50 is being closed.

[0047] If it is determined that the cover has not changed from the open state to the closed state (No in step S12), the SoC 13 determines whether or not there is a document reading job (step S23). Whether or not there is a document reading job can be determined based on whether or not a predetermined operation input by the user has been accepted.

[0048] If the SoC 13 determines that there is no document reading job (No in step S23), the process proceeds to step S12.

[0049] On the other hand, if the SoC 13 determines that there is a document reading job (Yes in step S23), it executes the document reading job (step S24). The execution process of the document reading job may be a known process, and therefore a detailed description thereof will be omitted here.

[0050] After executing the document reading job, the SoC 13 restores the gain setting value stored in the storage unit 20 in step S11 (step S22). This restores the gain setting value of the image reading device 1. Then, this flow ends.

[0051] On the other hand, if SoC 13 determines that the cover has changed from the open state to the closed state (Yes in step S12), it acquires the detection state of the sub-scanning position sensor 17 (step S13). That is, SoC 13 acquires information on the determination result by the sub-scanning position sensor 17 regarding whether or not a document is placed. SoC 13 may store the acquired information on the determination result in, for example, the storage unit 20.

[0052] The SoC 13 decreases the offset value (step S14). Here, the offset value is a black reference value that indicates the brightness of black when the image sensor 11 normally captures an image. The normal state is, for example, when the paper size determination process described in this embodiment is not executed.

[0053] The image reading device 1 normally scans using a reference white plate. The reference white plate is provided, for example, as part of the document table 40. The image reading device 1 acquires an image of the reference white plate using the image sensor 11. FIG. 8 is a diagram schematically illustrating the brightness of an image obtained by scanning the reference white plate. In FIG. 8, the vertical axis represents brightness, and the horizontal axis represents position in the main scanning direction. For example, on the horizontal axis of FIG. 8, the left side represents the starting point of the main scanning direction (the upper side of FIG. 2), and the right side represents the end point of the main scanning direction (the lower side of FIG. 2). FIG. 8 shows brightness data of an image for one scanning cycle. During scanning, the image sensor 11 illuminates the light-emitting unit to irradiate light onto the reference white plate and acquires an image of the reference white plate. As shown in FIG. 8, the brightness at the position where the reference white plate is present (i.e., the position where reflected light from the reference white plate is received) in the image is L1, and the brightness at the position where the reference white plate is not present is L2 (L1>L2). When an original is read in this state, the SoC 13 recognizes that areas with a lightness of L1 in the image obtained by reading the original are white, and areas with a lightness of L2 are black. In other words, the lightness L2 is the black reference value.

[0054] FIG. 9 is a diagram schematically showing the brightness of an image when the offset value is decreased. That is, FIG. 9 shows an example when SoC 13 performs a process of decreasing the offset value in step S14. The vertical axis and the horizontal axis in FIG. 9 are the same as those in FIG. 8. As shown in FIG. 9, when SoC 13 decreases the offset value, the brightness L3 becomes the black reference value (L3 < L2). That is, in a state where the offset value is decreased, a portion with brightness L3 is recognized as black. Thus, by decreasing the offset value, the brightness recognized as black becomes lower than that in a state where the offset value is not decreased. Thereby, in the gain adjustment executed in step S16 described later, gain adjustment can be executed even for black. That is, when the offset value is not decreased, since the gain output value remains constant even if the gain is increased for the black reference value, gain adjustment cannot be executed. However, by decreasing the offset value, the brightness L2 when a black image is read becomes higher than the brightness L3 of the black reference value, so that gain adjustment can be executed.

[0055] Referring again to FIG. 5, SoC 13 executes multiple scans of the document in order to obtain a first gain adjustment value and a second gain adjustment value that are necessary for determining the paper size of the document. To execute multiple scans of the document, SoC 13 sets the number of scans N to 1 (step S15).

[0056] Here, the first gain adjustment value is a gain adjustment value related to the gain adjustment performed on the brightness of an image captured when the cover 50 is in the first state, and the second gain adjustment value is a gain adjustment value related to the gain adjustment performed on the brightness of an image captured when the cover 50 is in the second state. In this embodiment, the second state is a state from the first state, in which the cover open / close detection switch 16 begins to be pressed, until the cover 50 is fully closed. Therefore, in the second state, the cover 50 is closer to the document tray 40 than in the first state shown in FIG. 7 . The first and second states differ in the distance or orientation of the cover 50 relative to the document tray 40. When a user places a document on the document tray 40 and closes the cover of the document tray 40, the second state usually appears during the user's continuous operations after the first state.

[0057] The second state does not necessarily have to be constituted by only one specific state of the cover 50 between the first state and the closed state. That is, the second state may include multiple states of the cover 50 between the first state and the closed state. In this embodiment, the second state includes multiple states of the cover 50 between the first state and the closed state. The multiple states, for example, each differ in the distance or orientation of the cover 50 relative to the document tray 40. In this embodiment, the second state includes four states of the cover 50 that occur every 100 ms after the cover 50 enters the first state. In other words, the second state includes states 100 ms, 200 ms, 300 ms, and 400 ms after the cover 50 enters the first state.

[0058] FIG. 10 is a diagram showing, in a side view, a schematic diagram illustrating the relationship between the underside of the cover 50 (the surface facing the document platform 40 when the cover 50 is closed) and the upper surface of the document platform 40 in the first and second states. In FIG. 10, the dashed-dotted line indicates the underside of the cover 50 in the first and second states, and the dashed line indicates the upper surface of the document platform 40. When the user is closing the cover 50, it is considered that the cover 50 gradually approaches the document platform 40 as 100 ms, 200 ms, 300 ms, and 400 ms pass from the first state. Therefore, the second state includes the state of the cover 50 when it is gradually approaching the document platform 40. In this embodiment, the second state includes four states 100 ms, 200 ms, 300 ms, and 400 ms after the first state, so the image reading device 1 performs document reading (image acquisition) five times in total, including one time when the cover 50 is in the first state and four times when the cover 50 is in the second state. Note that the time interval in the second state is set to 100 ms here, but it does not necessarily have to be 100 ms and can be any appropriate interval.

[0059] 5 again, SoC13 performs the Nth document reading and acquires the gain adjustment value for the Nth document reading (step S16). Specific processing of step S16 will be described later. SoC13 may store the gain adjustment value acquired in the Nth document reading in storage unit 20.

[0060] Next, the SoC 13 increments the number of reads N (step S17).

[0061] Then, the SoC 13 determines whether the incremented number of readings N is greater than 5 (step S18). Here, the reference number of times "5" is the total number of times the document is read, including the first state and the second state. Therefore, the reference number of times is not limited to "5" and may be set appropriately according to, for example, the number of states included in the second state.

[0062] If SoC13 determines that the number of readings N after the increment is 5 or less (No in step S18), it waits for a predetermined time (step S19). The predetermined time here is the time until the second state in which the next document reading is performed. Therefore, in this example, the predetermined time is 100 ms. Note that the predetermined time may be set appropriately depending on the time interval in the second state, etc. After waiting for the predetermined time, SoC13 proceeds to step S16 and performs the Nth document reading after the increment.

[0063] If SoC13 determines that the number of readings N after the increment is greater than 5 (Yes in step S18), it determines the paper size of the document placed on document platen 40 based on the first gain adjustment value and the second gain adjustment value (step S20). Here, the gain adjustment values ​​are obtained in five document readings as the first gain adjustment value and the second gain adjustment value, so SoC13 determines the paper size of the document placed on document platen 40 based on the gain adjustment values ​​obtained in five document readings. Specific processing in step S20 will be described later.

[0064] After determining the paper size, the SoC 13 restores the offset value that was decreased in step S14 (step S21).

[0065] Also, the SoC 13 restores the gain setting value stored in the storage unit 20 in step S11 (step S22), thereby restoring the gain setting value of the image reading device 1. Then, this flow ends.

[0066] Fig. 11 is a flowchart showing an example of a process for obtaining gain adjustment values ​​executed by the image reading device 1 in Fig. 1. Specifically, Fig. 11 is a flowchart showing details of step S16 in Fig. 5. In obtaining the gain adjustment values, the SoC 13 of the image reading device 1 obtains gain adjustment values ​​for six areas from area 1 to area 6 during the Nth document reading.

[0067] First, the SoC 13 sets the region M to 1 (step S31).

[0068] Then, the SoC 13 sets the region M as the gain adjustment region (step S32). That is, since M=1 here, the SoC 13 sets the region 1 as the gain adjustment region.

[0069] The SoC 13 causes the light emitting unit (LED) of the image sensor 11 to emit light, and executes document reading by the image sensor 11 (step S33). As a result, the AFE 12 acquires a brightness gain value.

[0070] The AFE 12 performs gain adjustment for region M, which is a gain adjustment region of the read document (step S34). Specifically, the AFE 12 amplifies the brightness of the image acquired by the image sensor 11 to a target value. For example, the AFE 12 amplifies the maximum brightness in region M to the gain adjustment target value. The gain adjustment target value can be set as appropriate. For example, if the brightness is expressed in 256 gradations, the gain adjustment target value can be set to 250. However, the gain adjustment target value is not limited to this and can be set as appropriate. The gain adjustment target value is, for example, determined in advance and stored in the storage unit 20.

[0071] Based on the gain adjustment performed in step S34, SoC13 calculates the gain adjustment value G NM (Step S35). NM is an index relating to the gain adjustment target value for the gain value. In this embodiment, the gain adjustment target value is T The black reference value is G S The brightness gain value of the image acquired by the image sensor 11 is G A Then, the gain adjustment value G NM is the formula G NM =G T / (G A -G S ) is expressed by the following formula. SoC13 calculates the gain adjustment value G NM The formula for calculating the gain adjustment value is not limited to this, and may be determined as appropriate. The SoC 13 calculates the calculated gain adjustment value GNM is stored in the storage unit 20, for example.

[0072] Next, the SoC 13 increments the region M (step S36).

[0073] Then, the SoC 13 determines whether the incremented region M is greater than 6 (step S37). Here, the reference number "6" for the determination is the number of regions. In this embodiment, there are six regions, from region 1 to region 6, so the reference number for the determination is "6". Therefore, the reference number is not limited to "6" and may be set appropriately according to the number of regions.

[0074] If the SoC 13 determines that the incremented region M is 6 or less (No in step S37), the SoC 13 proceeds to step S32 and executes the processes of steps S32 to S36 for the incremented region M. As a result, step S34 is executed again, and the AFE 12 executes gain adjustment for multiple regions.

[0075] On the other hand, if the SoC 13 determines that the incremented region M is greater than 6 (Yes in step S37), it ends this flow and proceeds to step S17 in FIG.

[0076] Here, a specific example will be given of the process of acquiring the gain adjustment value described with reference to Fig. 11. In this example, it is assumed that a user places an A5 size document on document table 40.

[0077] 12 is an image diagram showing an image acquired by document reading by image sensor 11. The horizontal direction in FIG. 12 is the main scanning direction. When a user places an A5-sized document on document table 40 with the document aligned with the upper left corner S in FIG. 4, as can be seen from FIG. 4, the document exists in areas 1 and 2, but does not exist in areas 3 to 6.

[0078] 12 shows images acquired in the first through fifth document readings, arranged vertically. The top image is an image acquired in the first document reading, and is therefore an image acquired when the cover 50 is in the first state. The second image from the top is an image acquired in the second document reading, and is therefore an image acquired when the cover 50 is in the second state 100 ms after it has been in the first state. The third image from the top is an image acquired in the third document reading, and is therefore an image acquired when the cover 50 is in the second state 200 ms after it has been in the first state. The fourth image from the top is an image acquired in the fourth document reading, and is therefore an image acquired when the cover 50 is in the second state 300 ms after it has been in the first state. The fifth image from the top is an image of an image acquired during the fifth document reading, and therefore is an image of an image acquired when the cover 50 is in the second state 400 ms after the first state.

[0079] When an A5-sized document is placed on the document tray 40, as shown in FIG. 12, the document is present in areas 1 and 2, and therefore the images acquired by the image sensor 11 during the first to fifth document readings are images of the document. Therefore, the images acquired during the first to fifth document readings are essentially unchanged. On the other hand, since the document is not present in areas 3 to 6, the images acquired by the image sensor 11 do not include the document. In this case, during the first document reading, the cover 50 is in the first state, and the distance between the cover 50 and the document tray 40 is greater than during the second and subsequent document readings. Therefore, the image acquired becomes a black image, as shown in FIG. 12, for example. On the other hand, as the number of document readings approaches the fifth reading, the distance between the cover 50 and the document tray 40 decreases. At this time, because a white plate 51 (see FIGS. 6 and 7) is attached to the underside of the cover 50, the image acquired by the image sensor 11 decreases to a white image as shown in FIG. 12 as the distance between the cover 50 and the document tray 40 decreases.

[0080] In this way, while the image basically does not change in areas where a document is placed (areas 1 and 2 in this example) with the number of times the document is read, the brightness of the image changes in areas where no document is placed (areas 3 to 6 in this example). In the process of obtaining the gain adjustment value, the image reading device 1 quantifies this change as the gain adjustment value.

[0081] 13 to 17 are diagrams each showing a lightness gain value in the first to fifth document readings, respectively. In FIGS. 13 to 17, the vertical axis indicates the lightness gain value, and the horizontal axis indicates the position in the main scanning direction. Here, the gain adjustment target value G T is 250, and the black reference value G S is set to 0. Here, the gain adjustment values ​​for region 2 and region 3 will be described as an example.

[0082] In the first document reading (number of readings N=1), the brightness gain values ​​shown in FIG. 13 are obtained. A is 200. In this case, in step S35 of FIG. 11, the gain adjustment value G 12 is calculated as 250 / (200-0) to be 1.25. The gain value G A In this case, the gain adjustment value G 13 is calculated as 250 / (40-0), which is 6.25.

[0083] In the second document reading (number of readings N=2), the brightness gain values ​​shown in FIG. 14 are obtained. A is 198. In this case, in step S35 of FIG. 11, the gain adjustment value G 22 is calculated as 250 / (198-0) to be 1.26. The gain value G A is 80. In this case, in step S35 of FIG. 11, the gain adjustment value G 23 is calculated as 250 / (80-0), which is 3.13.

[0084] In the third document reading (number of readings N=3), the brightness gain values ​​shown in FIG. 15 are obtained. A is 199. In this case, in step S35 of FIG. 11, the gain adjustment value G 32 is calculated as 250 / (199-0) to be 1.26. A is 120. In this case, in step S35 of FIG. 11, the gain adjustment value G 33 is calculated as 250 / (120-0), which is 2.08.

[0085] In the fourth document reading (number of readings N=4), the brightness gain values ​​shown in FIG. 16 are obtained. A is 201. In this case, in step S35 of FIG. 11, the gain adjustment value G 42 is calculated as 250 / (201-0) to be 1.24. The gain value G A is 180. In this case, in step S35 of FIG. 11, the gain adjustment value G 43 is calculated as 250 / (180-0), which is 1.39.

[0086] In the fifth document reading (number of readings N=5), the brightness gain values ​​shown in FIG. 17 are obtained. A is 200. In this case, in step S35 of FIG. 11, the gain adjustment value G 52 is calculated as 250 / (200-0) to be 1.25. The gain value G A is 190. In this case, in step S35 of FIG. 11, the gain adjustment value G 53 is calculated as 250 / (190-0), which is 1.32.

[0087] 18 is a flowchart showing an example of a paper size determination process executed by the image reading device 1 of FIG. 1. Specifically, FIG. 18 is a flowchart showing the details of step S20 of FIG. 5. In determining the paper size, the SoC 13 of the image reading device 1 uses the gain adjustment value G calculated in the flow shown in FIG. NMand the paper size determination table shown in FIG.

[0088] The SoC 13 determines the paper size based on the change from the first gain adjustment value to the second gain adjustment value. In this embodiment, multiple gain adjustment values ​​are acquired as the second gain adjustment value, so the SoC 13 determines the paper size based on the change in the gain adjustment value, including the multiple gain adjustment values. In addition, in this embodiment, a gain adjustment value is acquired for each of the multiple regions, so the SoC 13 determines the paper size of the document placed on the document table 40 based on the first gain adjustment value and the second gain adjustment value related to the gain adjustment performed for each of the multiple regions.

[0089] Specifically, the SoC 13 sets the region M to 6 (step S41).

[0090] Next, SoC13 uses the fluctuation rate R M (Step S42). Here, the fluctuation rate R M is the maximum gain adjustment value MaxG in region M M Minimum gain adjustment value MinG for M That is, R M =MinG M / MaxG M The SoC13 is expressed as N gain adjustment values ​​G in the region M calculated by the flow shown in FIG. NM MaxG M and minimum gain adjustment value MinG M The SoC13 selects the maximum gain adjustment value MaxG M and minimum gain adjustment value MinG M From R M =MinG M / MaxG M Using the formula, the rate of change R M SoC13 calculates the calculated fluctuation rate R M is stored in the storage unit 20, for example.

[0091] The SoC 13 also determines whether the area M currently being processed is the area 6 (step S43).

[0092] If SoC13 determines that the area M currently being processed is area 6 (Yes in step S43), it determines that no document is placed in area M (i.e., area 6) (step S46). As described with reference to FIG. 4, area 6 is an area where no document is placed, regardless of the paper size of the document placed on platen glass 41. SoC13 stores the determination result in step S46 in, for example, storage unit 20.

[0093] In this case, the SoC 13 decrements the region M (step S47).

[0094] Then, the SoC 13 determines whether the decremented area M is smaller than 1 (step S48). That is, the SoC 13 determines whether M<1 is satisfied.

[0095] If the SoC 13 determines that the area M after the decrement is equal to or greater than 1 (No in step S48), the SoC 13 proceeds to step S42 and executes the processes of steps S42 to S48 on the area M after the decrement.

[0096] In step S43, when it is determined that the region M currently being processed is not region 6 (No in step S43), the SoC13 calculates the fluctuation rate R M is smaller than the fluctuation rate R6 of region 6, or the fluctuation rate R Mis smaller than the threshold value T (step S44). In the first condition, for example, when SoC13 is executing processing for area 3, it is determined whether the fluctuation rate R3 of area 3 is smaller than the fluctuation rate R6 of area 6. In the second condition, for example, when SoC13 is executing processing for area 3, it is determined whether the fluctuation rate R3 of area 3 is smaller than the threshold value T. The threshold value T can be predetermined as an appropriate value that can determine whether a document is placed in area M. Here, the threshold value T is assumed to be 0.7.

[0097] If it is determined that either the first condition or the second condition is satisfied (Yes in step S44), the SoC 13 proceeds to step S46 and determines that no document is placed in the area M. The determination result in step S46 is stored in the storage unit 20, for example.

[0098] Here, in the area where the document is placed, the image acquired by the image sensor 11 is an image obtained by reading the document, and therefore the brightness does not change substantially even when the document is read multiple times. Therefore, the maximum gain adjustment value MaxG in the area M where the document is placed is M The first gain adjustment value MinG for M The ratio of the two, i.e., the fluctuation rate R M is a value close to 1. In contrast, as described above, region 6 is an area where no document is placed, regardless of the paper size of the document placed on platen glass 41, and therefore, as described with reference to FIG. 12, in region 6, the brightness of the image acquired by image sensor 11 changes significantly compared to an area where a document is placed. Therefore, the ratio of the initial gain adjustment value MinG6 to the maximum gain adjustment value MaxG6 in region 6, i.e., the fluctuation rate R6, is smaller compared to an area where a document is placed. Therefore, if the fluctuation rate R of region M is M is smaller than the fluctuation rate R6 of area 6, it can be considered that no document is placed in area M. Therefore, when the first condition is satisfied, SoC13 can determine that no document is placed in area M.

[0099] On the other hand, even in an area where no document is placed, the fluctuation rate R of the area M does not necessarily M is not necessarily smaller than the fluctuation rate R6 of region 6. Therefore, the fluctuation rate R M Even if the fluctuation rate R6 of the area 6 is equal to or greater than the fluctuation rate R6 of the area 6, if the fluctuation rate R6 is smaller than the threshold value T, the SoC 13 determines that no document is placed in the area M.

[0100] On the other hand, if it is determined that neither the first condition nor the second condition is satisfied (No in step S44), the SoC 13 determines that a document is placed in the region M (step S45). M is greater than or equal to the fluctuation rate R6 of region 6 and the fluctuation rate R of region M M is equal to or greater than the threshold value T. The determination result in step S45 is stored in the storage unit 20, for example.

[0101] In this case, SoC13 may determine that a document is placed in areas that have not yet been processed. For example, suppose that processing is performed while decrementing sequentially from area 6, and it is determined that a document is placed in area 2. In this case, SoC13 may also determine that a document is placed in area 1, which has not yet been processed.

[0102] If SoC 13 determines in step S45 that a document is placed in area M, or if it determines in step S48 that area M after decrement is smaller than 1 (Yes in step S48), it determines the size of the paper placed on document tray 40 based on the determination results in steps S45 and S46 (step S49). At this time, SoC 13 determines the paper size by referring to the detection state of sub-scanning position sensor 17 acquired in step S13 of FIG. 5 and the paper size determination table shown in FIG. 3. For example, if SoC 13 determines that a document is placed in areas 1 and 2, but determines that no document is placed in areas 3 to 6 or sub-scanning position sensor 17, SoC 13 determines the paper size to be A5 size, as shown in the paper size determination table of FIG. 3. The paper size determined in this manner is used as the determination result in step S20 of FIG. 5.

[0103] Here, a specific example will be given of the paper size determination process described with reference to Fig. 18. In this example, the gain values ​​shown in Figs. 13 to 17 will be used again.

[0104] 19 is a table showing the results of determination as to whether or not a document is placed on document table 40 for each region. The table shown in FIG. 19 shows the gain adjustment values ​​G for regions 1 to 6 when the number of reads N is 1 to 5. NM For example, the adjustment value G of the area 1 when the number of readings N=1 is 11 is 1.23, and the adjustment value G of the area 5 when the number of readings N=3 35 is 2.15.

[0105] The table shown in FIG. 19 further includes a maximum gain adjustment value MaxG for each region. M , minimum gain adjustment value MinG M and volatility R MSpecifically, the fluctuation rate R1 of region 1 is 0.98, the fluctuation rate R2 of region 2 is 0.98, the fluctuation rate R3 of region 3 is 0.21, the fluctuation rate R4 of region 4 is 0.22, the fluctuation rate R5 of region 5 is 0.22, and the fluctuation rate R6 of region 6 is 0.22. SoC13 calculates these fluctuation rates R M Using these, it is determined whether or not a document is placed in each area. For example, the fluctuation rates R4 and R5 of areas 4 and 5 are 0.22, which is smaller than the threshold value T=0.7. Therefore, in step S44, SoC13 determines that the second condition is met, and determines that no document is placed in areas 4 and 5. For example, the fluctuation rate R3 of area 3 is 0.21, which is smaller than the fluctuation rate R6 of area 6=0.22. Therefore, in step S44, SoC13 determines that the second condition is met, and determines that no document is placed in area 3. For example, the fluctuation rate R2 of area 2 is 0.98, which is greater than the fluctuation rate R6 of area 6=0.22 and greater than the threshold value T=0.7. Therefore, in step S44, SoC13 determines that the first and second conditions are not met, and determines that a document is placed in area 2. Since the SoC 13 has determined that a document has been placed in the area 2, it similarly determines that a document has been placed in the area 1 as well.

[0106] In the table shown in Fig. 19, the "Document Presence Determination" column indicates the determination result of whether or not a document is placed in each area. In step S49 of Fig. 18, SoC 13 uses the determination result shown in the "Document Presence Determination" column to refer to the paper size determination table of Fig. 3 and determine the size of the paper placed on document tray 40.

[0107] 20 is a graph showing the relationship between the number of readings and the gain adjustment value. Specifically, FIG. 20 shows the relationship between the number of readings and the gain adjustment value G NM In Fig. 20, the vertical axis represents the gain adjustment value G NM The horizontal axis represents the number of reads N. In FIG. 20, the gain adjustment values ​​G NMAs can be seen from FIG. 20, in the areas 1 and 2 where the document is placed, the gain adjustment value G NM On the other hand, in areas 3 and 6 where no document is placed, the gain adjustment value G NM This is because the cover 50 is closed as the number of readings N increases, and the distance between the cover 50 and the document table 40 becomes shorter. In this way, in the area where no document is placed, the gain adjustment value G NM In the area where the document is placed, the change in gain adjustment value G NM Therefore, the SoC 13 can determine the paper size based on the change in the gain adjustment value.

[0108] In this way, the image reading device 1 according to this embodiment can determine the paper size of the document placed on the document tray 40 based on the first gain adjustment value and the second gain adjustment value. That is, the image reading device 1 can determine the paper size of the document by performing the processing described in the above embodiment using the gain adjustment function of the AFE 12. Therefore, there is no need to use an ASIC that performs dedicated image processing on the digital data output from the AFE to determine the paper size. This allows the document paper size to be determined with a simpler configuration. Furthermore, because the image reading device 1 according to this embodiment does not require a high-speed ASIC, it can determine the document paper size using a less expensive circuit.

[0109] In the above embodiment, the first state is a state in which the cover open / close detection switch 16 begins to be pressed, and the second state is a state from the first state in which the cover open / close detection switch 16 begins to be pressed until the cover 50 is completely closed. However, the first state and the second state are not limited to this. For example, the first state and the second state may each be a state at a different timing from the first state in which the cover open / close detection switch 16 begins to be pressed until the cover 50 is completely closed. In other words, the first state does not necessarily have to be a state in which the cover open / close detection switch 16 begins to be pressed. Even in such a case, the paper size determination process described in the above embodiment can be similarly applied, and the paper size can be determined using the gain adjustment values ​​in the first state and the second state.

[0110] In the above embodiment, the SoC 13 may change the reading cycle (line cycle) of the image sensor 11 when performing the paper size determination process. That is, the SoC 13 can change the line cycle when reading a document and when performing the paper size determination process. This allows the paper size determination process to be performed at higher speed.

[0111] Although the present disclosure has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various modifications and alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included in the scope of the present disclosure. For example, functions included in each functional unit or step can be rearranged so as not to be logically inconsistent, and multiple functional units or steps can be combined or divided into one. [Explanation of symbols]

[0112] 1. Image reader 2. Image forming device 11 Image sensor 12 AFE (gain adjustment unit) 13 SoC (control unit) 14 Motor 15 Motor drive circuit 16 Cover open / close detection switch 17 Sub-scanning position sensor 18 Reference position sensor 19 Detection circuit 20 Memory section 20a Non-volatile memory 20b Volatile Memory 21 Network Circuit 22 External memory circuit 31 Image signal processing unit 32 Reader control unit 33 Main control unit 34 Image forming device control unit 40 Document stand 41 Document glass 42 Carriage Case 43 Gear 44 Pulley 45 Belt 46 Rail 47 Shade 50 Cover 51 White board 52 Rotation axis P reference position R manuscript S Upper left corner

Claims

1. a document placement table on which a document is placed; a cover provided so as to be openable and closable relative to the document table; an image sensor for capturing an image on the document table; a gain adjustment unit that performs a predetermined gain adjustment on the brightness of the image acquired by the image sensor; a control unit that determines a paper size of the document placed on the document placing platen based on a first gain adjustment value related to the gain adjustment performed on the brightness of the image acquired when the cover is in a first state and a second gain adjustment value related to the gain adjustment performed on the brightness of the image acquired when the cover is in a second state; An image reading device comprising:

2. The image reading device according to claim 1 , wherein the control unit determines the paper size based on a change from the first gain adjustment value to the second gain adjustment value.

3. the gain adjustment unit performs the gain adjustment for each of the brightnesses in a plurality of predetermined regions set in the image sensor; the control unit determines a paper size of the document placed on the document placing table based on the first gain adjustment value and the second gain adjustment value related to the gain adjustment executed for each of the plurality of predetermined areas.

2. The image reading device according to claim 1.

4. The image reading device according to claim 1 , wherein the first state and the second state differ in a distance or an orientation of the cover relative to the document table.

5. An information processing method executed by an image reading device including a document table on which a document is placed, a cover provided so as to be able to open and close the document table, and an image sensor that acquires an image on the document table, performing a predetermined gain adjustment on a brightness indicating the brightness of the image acquired by the image sensor; determining a paper size of the document placed on the document placing table based on a first gain adjustment value related to the gain adjustment performed on the brightness of the image acquired when the cover is in a first state and a second gain adjustment value related to the gain adjustment performed on the brightness of the image acquired when the cover is in a second state; Information processing methods.

Images