JP2018037984A - Image reading apparatus, image forming apparatus, and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading apparatus which shortens time until reading of a document is started.SOLUTION: The image reading apparatus, in response to detection of an open state of a document cover, detects the size of a document on a document platen from a reading result of a reading unit capable of reading an image of the document placed on the document platen. After the size of the document is detected, the reading unit is moved to a reading standby position.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an image reading apparatus that reads a document image, an image forming apparatus, and a control method.

  2. Description of the Related Art Conventionally, an original reading apparatus is generally used that has a function of automatically detecting the original size and the presence / absence of an original. Conventionally, as a document size detection method, there is a method in which a document reading CCD (Charge Coupled Device) is used for size detection in the main scanning direction.

  As a method of using the CCD for detecting the size of the document, light is irradiated from the light source toward the document from the lower side of the document placing table, and the reflected light is read by the CCD to detect the size of the document in the main scanning direction. In this method, for example, in both the state before the document cover is completely closed and the state in which the document cover is completely closed, the document is irradiated with light from the light source, and the reflected light is read by the CCD. In the data read in this way, an area corresponding to white data is determined as a document area, and a black area is determined as an area outside the document. There is a technique for improving the size detection accuracy of a document by comparing two read data of a state before the document cover is completely closed and a state where the document cover is completely closed (Patent Document 1).

JP 9-191370 A

  However, when reading a document image while scanning the reading sensor, in order to keep the scanning speed at the time of reading constant, it is necessary to provide a scanning start position at a position upstream in the scanning direction from a position at which reading on the document is started. . The conventional reading sensor detects the size after receiving an instruction to start reading by the user if the document cover remains open. Therefore, when reading an image after moving to the scanning start position after size detection, it takes time until the reading of the image is actually started after receiving a reading start instruction from the user.

  An object of the present invention is to solve such conventional problems. In view of the above, it is an object of the present invention to provide an image reading apparatus, an image forming apparatus, and a control method that reduce the time required to start reading a document.

  In order to solve the above-described problems, an image reading apparatus according to the present invention includes a reading unit that can read an image of a document placed on a platen and an open / close detection unit that detects an open / closed state of a document cover that covers the platen. And detecting means for detecting the size of the original on the original table from the reading result of the reading means in response to detection of the open state of the original cover by the open / close detecting means, and the original by the detecting means. The reading unit can be moved to a size detection position for detecting the size of the image and a reading standby position, and after the size is detected by the detection unit, the reading unit is moved from the size detection position to the reading standby position. And moving means for moving to.

  According to the present invention, it is possible to shorten the time required to start reading a document.

It is a block diagram which shows the internal structure of an image reading apparatus. 1 is a schematic perspective view showing an image forming apparatus. It is a top view of an image reading apparatus. FIG. 6 is a diagram illustrating the position of a reading unit in the case of document size detection. FIG. 6 is a diagram illustrating a document size detection position. It is a figure which shows the table for determining original size. 6 is a flowchart showing processing of reading start control.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the present invention according to the claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the present invention. . The same constituent elements are denoted by the same reference numerals, and the description thereof is omitted.

[First Embodiment]
FIG. 1 is a block diagram showing the internal configuration of the image reading apparatus according to this embodiment. The image reading apparatus 10 includes a CPU 101, a RAM 102, a ROM 103, a communication interface (I / F) 104, a panel operation unit 105, a print control unit 106, an image reading unit 107, a document cover open / close sensor 108, And a scan motor 109.

  The CPU 101 controls the entire image reading apparatus 10 in an integrated manner. The RAM 102 is a general-purpose RAM, and is used as a work area for the CPU 101 and a temporary storage area for data. The ROM 103 is a general-purpose ROM, stores a firmware program for driving the image reading device 10 and a boot program for controlling the firmware program, and is read by the CPU 101 into the RAM 102 and executed. The communication I / F 104 is connected to an external computer terminal device or the like via a wired or wireless network medium, and transmits data, jobs, and the like. The panel operation unit 105 includes a panel, input keys, and the like, and accepts various setting operations of the image reading apparatus 10 by the user and displays a user interface screen and the like.

  The print control unit 106 supplies image data received from the outside or image data obtained by reading an original with the image reading unit 107 to the printing unit. The printing unit corresponds to the apparatus main body 200 of the image forming apparatus 20 in FIG. 2, and performs recording on a recording medium by a recording method such as an inkjet recording method or an electrophotographic method. The image reading unit 107 is a line type image sensor including a reading sensor and a light source such as an LED. The image reading unit 107 optically reads a document placed on the document table to acquire image data, detects the length of the document in the main scanning direction (line direction), and scans the document on the document table. Detect the presence or absence.

  Document cover opening / closing sensor 108 includes a flag mechanism that moves up and down in conjunction with the document cover when the document cover is opened and closed, and an angle detection sensor for detecting the opening / closing angle of the document cover. The document cover open / close sensor 108 is used to detect that the document cover has been opened or to detect that the document cover has reached the document detection angle when the document cover is closed. The scan motor 109 scans the image reading unit 107 in the sub scanning direction orthogonal to the main scanning direction. The system bus 100 connects the above blocks so that they can communicate with each other.

  FIG. 2 is a schematic perspective view showing the image forming apparatus 20 provided with the image reading apparatus 10. The image forming apparatus 20 includes an apparatus main body 200 and a document reading device (reader) 201 installed on the upper portion of the apparatus main body 200. The automatic document reading apparatus includes a reader 201 and an automatic document feeder (ADF) 202 installed on the reader 201. The reader 201 corresponds to the image reading apparatus 10 in FIG.

  In the present embodiment, the apparatus main body 200 is configured as a printer that performs printing on a sheet by an electrophotographic method, and forms an image on the sheet based on the image data sent from the reader 201. The printing method on paper in the apparatus main body 200 is not limited to the electrophotographic method, and may be another method such as an ink jet recording method. The image forming apparatus 20 may be a so-called MFP (Multi Functional Peripheral) in which a plurality of functions such as a FAX function and a box function are integrated, as well as a scanning and printing function.

  The ADF 202 includes a document tray 203 and a document detection sensor 204. The document detection sensor 204 detects whether a document bundle is placed on the document tray 203. In addition, the ADF 202 is configured so that a user can perform an opening / closing operation by a hinge 205. The ADF 202 is a document cover that covers the document table glass 206. When the automatic document reader detects that a document bundle is placed on the document tray 203, the ADF 102 separates the documents from the document bundle one by one and supplies them to the reader 201 for reading. When the document bundle is not placed, the reader 201 reads the document on the document table glass 206.

  The apparatus main body 200 includes an operation unit 207. The operation unit 207 includes a display unit (panel) and input keys. The user operates the image forming apparatus 20 and corresponds to the panel operation unit 105 in FIG. The operation unit 207 is provided with a start key for accepting an instruction to start copying or scanning by the user, for example. In addition, as a configuration for receiving an instruction to start copying or scanning, there is a case of a touch display using a panel.

  FIG. 3 is a schematic plan view of the image reading apparatus 10 in the present embodiment. In the platen glass 206 (the part opposite to the side on which the document is placed), a reading unit 301 for optically reading the document, a driving device 302 for driving the reading unit 301, and the presence and size of the document on the platen glass 206 Document size sensors 303a and 303b for detecting the above are arranged.

  The reading unit 301 is a light source 301a (LED or the like) for irradiating light on a document placed on a contact glass, and is arranged along the main scanning direction X. The light source 301a irradiates the original with light, and the image sensor 301b, which is a photoelectric conversion element, detects the light reflected from the original, thereby reading the original image. The photoelectric conversion element converts the detected light into an electric signal. The reading unit 301 is not limited to such a structure, and various conventionally known structures can be employed.

  Further, the driving device 302 moves the reading unit 301 along a sub-scanning direction Y orthogonal to the main scanning direction X, and includes a motor 302a, a belt 302b, and a guide rail 302c. The guide rail 302c is disposed along the sub-scanning direction Y. The reading unit 301 can move along the guide rail 302c via the belt 302b by driving the motor 302a of the driving device 302. With this configuration, the reading unit 301 can reciprocate along the sub-scanning direction Y.

  Document size sensors 303a and 303b detect the presence and size of the document on the document table glass 206. The document size sensors 303a and 303b detect the presence or absence of a document from the result of receiving external light, or detect light reflected from the document by a light source from an LED or the like by an image sensor such as a CCD. The presence or absence of a document on the glass 206 is detected. A plurality of document size sensors 303a and 303b are arranged side by side in the sub-scanning direction Y (the moving direction of the reading unit 301), and the size of the document is detected from the position of the sensor that detected the presence of the document.

  FIG. 4 is a diagram showing the position of the reading unit 301 in the case of document size detection in the present embodiment. When detecting the size of the document, the CPU 101 moves the reading unit 301 to the size detection position 403 on the reading area on the platen glass 206 to detect the document size. Move to standby position 401. The reading standby position 401 is located upstream of the size detection position 403 in the scanning direction when the reading unit 301 reads an original on the original platen glass 206 and is located outside the reading area on the original platen glass 206. With such an arrangement, when the CPU 101 starts moving the reading unit 301 for reading a document, the moving speed of the reading unit 301 can be made constant when the reading unit 301 reaches the reading area. . When the document cover is closed and no processing is required, the reading unit 301 waits for execution of a job at a standby position 402 (home position) when the document cover is closed.

  The method for determining the document size will be described with reference to the diagram showing the document size detection position in FIG. 5 and the diagram showing the size detection table in FIG. As in the table shown in FIG. 6, there are a plurality of document size candidates for combinations of detection states of the sensors 303a and 303b. Therefore, in order to determine the document size, the final document size is determined by detecting the size in the main scanning direction X using the image sensor 301 b mounted on the reading unit 301. The size detection method in the main scanning direction X includes a method in which the light source is turned off and detected from the result of receiving external light, or an open state before the document cover is completely closed by turning on the light source and opening and closing the document cover (ADF 202). There is a method of comparing the luminance difference between the luminance of the reflected light and the luminance of the reflected light in the closed state after being almost closed.

  In the present embodiment, when the open state of the document cover (ADF 202) is detected, the document size is detected from the result of receiving external light. In this case, the CPU 101 places the original on the portion that did not receive the extraneous light from the combination of the detection states of the image sensor 301b and the sensors 303a and 303b of the reading unit 301 moved to the size detection position 403 with the light source turned off. The size of the document can be detected as the area that has been set.

  For example, when the document cover (ADF 202) is in the open state, the image sensor 301b and the sensors 303a and 303b do not receive light at the portion where the document is placed because the external light is blocked by the document. However, for the part where the document is not placed, when the document cover is in the open state, there is no medium that blocks the extraneous light, so the image sensor 301b and the sensors 303a and 303b receive the extraneous light. Therefore, there is a difference in luminance of external light received by the image sensor 301b and the sensors 303a and 303b between the portion where the document is placed and the portion where the document is not placed.

  As described above, the position of the edge of the document is specified by detecting the extraneous light in the opened state of the document cover. In the present embodiment, for example, among the plurality of image sensors 301b, a plurality of image sensors 301b used for specifying the position of the edge of the document are determined in advance, for example, at four locations A to D in FIG. deep. Then, the document size in the main scanning direction X is determined according to the position at which the sensor detects extraneous light at the four locations.

  Here, it is assumed that the sensors 303a and 303b are both ON when the document cover is open. A position where no extraneous light is detected in the main scanning direction is A. In this case, the document size is determined as “STMT-R A5-R” from the table of FIG. If the positions where no extraneous light is detected in the main scanning direction are A and B, the document size is determined as “STMT A5”. If the position where no extraneous light is detected in the main scanning direction is A, B, or C, the document size is determined as “LTR B5”. If the positions where no extraneous light is detected in the main scanning direction are A, B, C, and D, the document size is determined as “A4”.

  Further, it is assumed that the sensor 303a is OFF and the sensor 303b is ON when the document cover is open. If the positions where no extraneous light is detected in the main scanning direction are A and B, the document size is determined as “LTR-R A4-R”.

  Further, it is assumed that both the sensors 303a and 303b are OFF when the document cover is open. If the positions where no extraneous light is detected in the main scanning direction are A and B, the document size is determined as “LGL”. If the positions where no extraneous light is detected in the main scanning direction are A, B, and C, the document size is determined as “LDR B4”. If the positions where no extraneous light is detected in the main scanning direction are A, B, C, and D, the document size is determined as “A3”.

  FIG. 7 is a flowchart showing a reading control process in the present embodiment. Each process in FIG. 7 is realized, for example, by the CPU 101 reading out a program stored in the ROM 103 to the RAM 102 and executing it.

  In step S <b> 701, the CPU 101 determines whether the document cover is open or closed by the document cover open / close sensor 108. If it is determined that the document is in the open state, in step S702, the CPU 101 moves the reading unit 301 to the document size detection position 403 in FIG. If it is determined that the document cover is in the closed state, the process in S701 is repeated until it is determined that the document cover is in the open state.

  In step S <b> 703, the CPU 101 determines whether the document is placed on the document table glass 206 by the reading unit 301 at the document size detection position 403. Here, it is determined that there is a document if there is a portion that does not receive extraneous light at the detection position of the sensor. If it is determined that a document is placed on the platen glass 206, the process proceeds to S704. If it is determined that a document is not placed, the processing from S703 is repeated.

  In step S704, the CPU 101 performs document size determination processing based on the detection result of the amount of external light read by the image sensor 301b. That is, the CPU 101 determines the document size by referring to the table in FIG. 6 based on the combination of the detection states of the sensors 303a and 303b and the detection state of the image sensor 301b at the document size detection positions A to D in FIG. .

  In this embodiment, when it is detected that the document cover is in the open state, the document size is determined regardless of whether there is a reading start instruction from the user. Thus, the document size can be determined and the reading unit 301 can be moved to the reading standby position without receiving a reading start instruction from the user. Therefore, the original image can be read immediately after receiving the reading start instruction from the user, and the time until the reading of the original can be shortened compared to the conventional case.

  In step S <b> 705, the CPU 101 determines whether the document size has been determined. If it is determined that the document size has been determined, the process proceeds to S706. If it is determined that the document size has not been determined, the process proceeds to S711.

  In step S706, the CPU 101 stores the determined document size in a storage unit such as the RAM 102. In step S707, the CPU 101 moves the reading unit 301 to the reading standby position 401 in FIG. In step S <b> 708, the CPU 101 determines whether there is a change in the determined document size. In S708, for example, when an opening / closing operation of the document cover is detected, the CPU 101 may determine that there is a change in the document size.

  On the other hand, if it is determined in S705 that the document size has not been determined, in S711, the CPU 101 determines that the document size is indefinite, and in S712, moves the reading unit 301 to the reading standby position 401 in FIG. For example, the processing of S711 is performed when the document size cannot be determined from the detection result of the image sensor 301b of the reading unit 301.

  In step S <b> 713, the CPU 101 causes the panel operation unit 105 to display a user interface screen for allowing the user to input a document size. In step S714, the CPU 101 determines whether or not the document size has been input. If it is determined that the document size has been input, the process advances to step S708. On the other hand, if it is determined that the document size has not been input, the process of S714 is repeated.

  If it is determined in S708 that there is no change in the determined document size, in S709, the CPU 101 determines whether or not a reading instruction is given by pressing a copy start key or a scan key. On the other hand, if it is determined in S708 that there is a change in the determined document size, in S715, the CPU 101 moves the reading unit 301 to the document size detection position 403 in FIG. 4 again, and repeats the processing from S703. .

  If it is determined in step S709 that an instruction to start reading has been issued, in step S710, the CPU 101 drives the reading unit 301 to start a document reading process, and then ends the process in FIG. On the other hand, if it is determined in S709 that the instruction to start reading has not been given, the processing from S708 is repeated, and the document placement state is continuously monitored. After the processing in FIG. 7, functions that can be executed by the image forming apparatus 20 such as printing and FAX transmission are executed based on the read data obtained by reading the document by the reading unit 301.

  As described above, according to the present embodiment, when a document is placed with the document cover opened, the document size is detected, and immediately after the detection of the document size is completed, the reading unit 301 waits for reading in FIG. Move to position 401. As a result, it is possible to shorten the time from when the user gives an instruction to start reading to when the image reading process starts. Furthermore, when the document cover (ADF 202) is in the open state, the document size is detected based on the amount of received light, so that the document size can be determined before the document cover is closed, and more quickly. The reading unit 301 can be moved to the reading standby position 401.

  The present invention is not limited to this embodiment, and various improvements and modifications can be made without departing from the scope of the present invention. Further, the flowchart described above is merely an example, and the document size specifying process may be realized by another flowchart as long as a result equivalent to the process of the flowchart can be obtained.

  10 Image reading device: 101 CPU: 102 RAM: 103 ROM

Claims (10)

Reading means capable of reading an image of a document placed on a document table;
Open / close detection means for detecting the open / closed state of the document cover covering the document table;
Detecting means for detecting the size of the original on the original table from the reading result of the reading means in response to detection of the open state of the original cover by the open / close detection means;
The reading means can be moved between a size detection position for detecting the size of the original by the detection means and a reading standby position, and after the detection of the size by the detection means, the reading means detects the size. Moving means for moving from a position to the reading standby position;
An image reading apparatus comprising: A receiving unit for receiving an instruction to read the document;
The moving unit moves the reading unit to the reading standby position before receiving the reading instruction by the receiving unit, and moves the reading unit from the reading standby position when the reading unit receives the reading instruction. To read the original,
The image reading apparatus according to claim 1. The moving means moves the reading means to the size detection position on the reading area on the document table when the open / close detection means detects the open state of the document cover.
The detection means starts detecting the size of the document from the reading result of the reading means at the size detection position;
The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus.   The detection unit detects the size of the document based on a detection result of a sensor arranged side by side in a moving direction of the reading unit and a detection result of an image sensor of the reading unit. The image reading apparatus according to any one of claims 1 to 3.   The image reading apparatus according to claim 4, wherein the detection unit detects the size of the document based on a change in a detection result of the image sensor depending on the presence or absence of the document.   The image reading apparatus according to claim 1, wherein the detection unit detects the size of the document based on the amount of external light detected by the reading unit.   The image reading apparatus according to claim 1, wherein the reading standby position is outside a reading area on the document table.   The image reading apparatus according to claim 1, wherein the reading unit is a line-type image sensor. An image reading apparatus according to any one of claims 1 to 8,
Recording means for performing recording on a recording medium based on the data read from the original;
An image forming apparatus comprising: A control method executed in an image reading apparatus,
An open / close detection process for detecting an open / closed state of a document cover covering the document table;
The size of the original on the original table is determined from the reading result of the reading means capable of reading the image of the original placed on the original table in response to the detection of the open state of the original cover in the opening / closing detection step. A detection step for detecting
The reading means can be moved between a size detection position for detecting the size of the document in the detection step and a reading standby position, and after the size is detected in the detection step, the reading means detects the size. A movement step of moving from a position to the reading standby position;
A control method characterized by comprising:

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