JP2019169866A - Image reading device - Google Patents

Abstract

To provide an image reading device capable of detecting double feed of different type of scripts, respectively.SOLUTION: According to setting operation received by the operation part of an operation panel, setting is made whether double feed is not detected, double feed is detected using a double feed threshold level (double feed detection level) by permanent setting, or double feed is detected using a double feed threshold level by temporary setting (S13). According to the setting, double feed of script is not detected (S13: YES), or double feed is detected using a double feed threshold level by permanent setting, or using a double feed threshold level by temporary setting (S13: NO).SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image reading apparatus that reads an image of a document.

  2. Description of the Related Art Conventionally, in an image reading apparatus that reads an image of an original by an ADF (Auto Document Feeder) method, a multi-feed sensor is used to detect a so-called multi-feed in which a plurality of originals are conveyed without being separated one by one. Is provided. In Patent Document 1, when a card or cardboard is conveyed, in order to prevent erroneous detection of double feeding by the double feeding sensor, when it is determined that a sound jam has occurred at a predetermined timing, the double feeding sensor It is described that even if it is determined that double feeding has occurred, paper transport is performed assuming that double feeding has not occurred.

JP 2014-43351 A

  However, in the known configuration, when a card or cardboard is really double-fed, the double-fed cannot be detected.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image reading apparatus capable of detecting double feeding of different types of documents.

  In order to achieve the above object, an image reading apparatus according to the present invention includes a conveyance unit that conveys a document, a reading unit that reads an image of a document conveyed by the conveyance unit, an operation unit, a storage unit, and a control unit. And the storage unit stores a value indicating a first determination level used for detecting double feeding in which the originals are conveyed in a superimposed manner, and a value indicating a second determination level different from the first determination level. The control unit does not detect double feed according to the setting operation accepted by the operation unit, detects double feed using the first determination level, or uses the second determination level to perform double feed detection. Executes the setting process to set whether to detect the feed, and when the document is transported by the transport unit, if the setting by the setting process is set not to detect the double feed, the setting is not detected. Setting by processing detects double feed using the first judgment level In the case of setting, the first judgment level is used to detect double feed, and the setting by the setting process is set to detect double feed using the second judgment level. Perform detection.

  According to this configuration, according to the setting operation accepted by the operation unit, whether or not double feed is detected, double feed is detected using the first determination level, or using the second determination level. Whether to detect double feed is set. Then, according to the setting, detection of double feeding of the document conveyed by the conveyance unit is not performed, or detection of double feeding is performed using the first determination level or the second determination level. Accordingly, it is possible to detect double feeding of the first type of document at the first determination level suitable for the document, and it is possible to detect double feeding of the second type of document different from the first type for the document. Detection can be performed at the second determination level.

  According to the present invention, it is possible to detect double feeding of different types of documents.

1 is a cross-sectional view of an image reading apparatus according to an embodiment of the present invention. 2 is a block diagram illustrating an electrical configuration of the image reading apparatus. FIG. It is a screen transition diagram for demonstrating double feed detection setting. It is a figure which shows an example of a double feed detection table. 6 is a flowchart illustrating a flow of scan job processing. It is a flowchart which shows the flow of a double feed detection setting process. It is a flowchart which shows the flow of a double feed threshold value change process. It is a flowchart which shows the flow of a double feed threshold value registration process. It is a screen transition diagram for demonstrating shortcut registration. It is a screen transition diagram for demonstrating additional registration of a double feed detection setting.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Mechanical configuration>
An image reading apparatus 1 shown in FIG. 1 is an electronic device that reads an image of a document by an ADF (Auto Document Feeder) method. The image reading apparatus 1 includes a housing 2, a supply tray 3, and a discharge tray 4. The supply tray 3 is provided on one side with respect to the housing 2, and the discharge tray 4 is provided on the opposite side of the supply tray 3 with respect to the housing 2. In the image reading apparatus 1, one side on which the supply tray 3 is provided with respect to the housing 2 is the rear side, and the opposite side is the front side. The supply tray 3 extends rearward and upward from the housing 2 in the use state. The discharge tray 4 extends forward from the housing 2 when in use.

  The housing 2 is formed with a support surface 11 that extends forward and downward from the vicinity of the front end of the supply tray 2 in use. The front end of the support surface 11 forms the lower end of the insertion port 12 that communicates the inside and outside of the housing 2. Further, the housing 2 is formed with a discharge port 13 communicating with the inside and outside of the housing 2 at a position above the rear end of the discharge tray 4.

  In the housing 2, a conveyance path 14 is provided that extends in a slanting direction from the insertion port 12 toward the discharge port 13. In the housing 2, a supply roller 15, a separation piece 16, a conveyance roller 17, and a discharge roller 18 are provided in order from the insertion port 12 side along the conveyance path 14. The supply roller 15 is disposed so that its peripheral surface is in contact with a virtual plane extending forward along the support surface 11 from below. The separation piece 16 is disposed so as to contact the peripheral surface of the supply roller 15 from the front upper side. The transport roller 17 is disposed at a position separated from the supply roller 15. The conveyance roller 17 includes a pair of an upper conveyance roller 21 and a lower conveyance roller 22. The upper transport roller 21 and the lower transport roller 22 form a nip when their peripheral surfaces abut on the transport path 14. The discharge roller 18 includes a pair of an upper discharge roller 23 and a lower discharge roller 24. The upper discharge roller 23 and the lower discharge roller 24 form a nip when their peripheral surfaces abut on the conveyance path 14, and the nip portion is exposed to the outside of the housing 2 from the discharge port 13.

  A first CIS (Contact Image Sensor) 25 and a second CIS 26 (each example of a reading unit) are provided between the transport roller 17 and the discharge roller 18. The first CIS 25 is disposed below the conveyance path 14. The second CIS 26 is disposed on the upper side of the transport path 14 and at a position shifted to the front side with respect to the first CIS 25. The first CIS 25 and the second CIS 26 include an image sensor in which a plurality of light receiving elements are arranged in the width direction of the image reading device 1, a light source that emits light toward the conveyance path 14, and a light emitted from the light source and reflected by an irradiated object. And a rod lens array that forms an image on each light receiving element of the image sensor. The image sensor outputs an analog signal corresponding to light reception in each light receiving element.

  When executing a scan job for reading an image of an original, for example, the original is gripped by a user's finger, and the leading end of the original slides on the support surface 11 of the casing 2 from the insertion port 12 into the casing 2. Plugged into. After the document is inserted into the housing 2 until the leading edge of the document comes into contact with the peripheral surface of the supply roller 15, when the user's finger is released from the document, the document is supported on the supply tray 3 and the support surface 11. When there are a plurality of documents, the documents are supported on the supply tray 3 and the support surface 11 in a stacked state. Depending on the size of the document, the document is supported only by the support surface 11 without reaching the supply tray 3.

  In response to an instruction to start scanning by the user, rotation of the supply roller 15, the transport roller 17, and the discharge roller 18 is started. By the rotation of the supply roller 15, a conveyance force is applied from the supply roller 15 to the document in contact with the supply roller 15, and the leading end of the document passes between the supply roller 15 and the separation piece 16. When a plurality of documents are stacked, the lowermost document passes between the supply roller 15 and the separation piece 16, so that the document is separated from the other documents. Thereafter, when the document reaches the transport roller 17, a transport force is applied to the document from the transport roller 17, and the document is further transported toward the discharge roller 18. Then, when the document passes between the first CIS 25 and the second CIS 26, light is irradiated from the first CIS 25 to the lower surface of the document, and an image on the lower surface of the document is read by the first CIS 25. Further, when images on both sides of the document are read, light is irradiated from the second CIS 26 to the upper surface of the document, and the image on the upper surface of the document is read by the second CIS 26. When the document reaches the discharge roller 18, a conveyance force is applied to the document from the discharge roller 18, and the document is discharged onto the discharge tray 4 by the conveyance force.

  A document sensor 31 and a double feed sensor 32 are provided in the housing 2. The document sensor 31 includes, for example, an actuator that rotates when the document supported on the supply tray 3 and the support surface 11 comes in contact with it, and an optical sensor that detects the rotation of the actuator. The double feed sensor 32 employs a configuration including an ultrasonic wave oscillation unit 33 that oscillates an ultrasonic wave and an ultrasonic wave reception unit 34 that receives the ultrasonic wave.

<Electrical configuration>
As shown in FIG. 2, the image reading apparatus 1 includes an ASIC (Application Specific Integrated Circuit) 41, a ROM (Read Only Memory) 42, and a RAM (Random Access Memory) 43.

  The ASIC 41 includes a CPU 44 (an example of a control unit). The ROM 42 (an example of a storage unit) includes a rewritable nonvolatile memory such as a flash memory. The ROM 42 stores programs executed by the CPU 44 and various data. The RAM 43 is a volatile memory such as a DRAM (Dynamic Random Access Memory), and is used as a work area when the CPU 44 executes a program.

  AFE (Analog Front End) 45 and 46 are provided in association with the first CIS 25 and the second CIS 26, respectively. The analog signal output from the image sensor of the first CIS 15 is amplified by the AFE 45 and converted into image data that is a digital signal. In addition, the analog signal output from the image sensor of the second CIS 26 is amplified by the AFE 46 and converted into image data that is a digital signal. Image data is input from the AFEs 45 and 46 to the ASIC 41.

  A detection signal from the document sensor 31 is input to the ASIC 41. The rotation position of the actuator of the document sensor 31 differs depending on whether or not the document is supported on the supply tray 3 and the support surface 11, and the level of the detection signal output from the optical sensor of the document sensor 31, that is, the optical sensor. The voltages output from the included light receiving elements are different. Therefore, the CPU 44 of the ASIC 41 can determine whether or not a document is supported on the supply tray 3 and the support surface 11 from the level of the detection signal of the document sensor 31.

  A detection signal of the double feed sensor 32 is input to the ASIC 41. When a document is present between the ultrasonic wave oscillating unit 33 and the ultrasonic wave receiving unit 34 of the double feed sensor 32, the ultrasonic wave reception from the ultrasonic wave oscillating unit 33 is performed according to the thickness of the document, the presence or absence of double feed, and the like. Since the ultrasonic waves that reach the unit 34 are attenuated, the voltage (analog signal) output from the ultrasonic receiver 34 changes. In the ASIC 41, a double feed sensor signal value (digital value) is acquired by A / D conversion of a detection signal input from the double feed sensor 32, that is, an analog signal output from the ultrasonic receiver 34. Since the double feed sensor signal value changes according to the thickness of the document, the presence or absence of double feed, etc., the CPU 44 of the ASIC 41 can detect double feed from the double feed sensor signal value.

  A network interface 47 and a USB interface 48 are connected to the ASIC 41. The network interface 47 is an interface for data communication with an external device such as a PC (Personal Computer) via a LAN (Local Area Network). The communication method may be a wireless communication method or a wired communication method. The USB interface 48 is an interface for data communication with a USB device.

  The image reading apparatus 1 includes an operation panel 51. The operation panel 51 is disposed at a position where the user can visually recognize and operate, for example, on the upper surface of the housing 2. The operation panel 51 includes a touch panel, and is configured by superimposing an operation unit 53 such as a pressure-sensitive or capacitive transparent film switch on a display unit 52 such as a liquid crystal display. The display unit 52 displays various information and images such as operation keys. When the user performs a touch operation on the operation key displayed on the display unit 52, the touch operation of the operation key is received by the operation unit 53, and a signal corresponding to the touch operation is input from the operation unit 53 to the ASIC 41.

  In addition, the display part 52 and the operation part 53 may be provided separately independently, without comprising a touch panel.

  Further, the image reading apparatus 1 includes a conveyance motor 54 as a rotational drive source for the supply roller 15, the conveyance roller 17, and the discharge roller 18. The supply roller 15, the conveyance roller 17, the discharge roller 18, the conveyance motor 54, and the like constitute an example of a conveyance unit that conveys the document.

  The CPU 44 of the ASIC 41 executes a program stored in the ROM 22, and based on information acquired from a signal or the like input to the ASIC 41, the first CIS 25, the second CIS 26, the network interface 47, the USB interface 48, and the display unit Each unit such as 53 and the conveyance motor 54 is controlled.

<Double feed detection level setting>
In the image reading apparatus 1, it is possible to set whether or not to detect double feeding of a document when executing a scan job by operating the operation unit 53 of the operation panel 51. The double feed detection threshold used for double feed detection can be changed.

  When the power of the image reading apparatus 1 is turned on and the function for the image reading apparatus 1 is ready for execution, a standby screen is displayed on the display unit 52 of the display panel 51. Further, after the display screen is switched by the user operating the display unit 52 of the display panel 51, or after the scan job for reading the images of all the originals supported on the supply tray 3 and the support surface 11 is completed, a predetermined time is elapsed. For example, when one minute has elapsed, a standby screen is displayed on the display unit 52 of the display panel 51.

  For example, as shown in FIG. 3, three job selection keys 61, 62, and 63 are displayed on the standby screen. The scan job includes a “Scan To USB” job in which image data is transmitted from the USB interface 48 to the USB device after reading the document image, and image data is transmitted from the network interface 47 to the server via the Internet after the document image is read. And a “Scan To Network” job that transmits image data from the network interface 47 to a LAN-connected device after reading the image of the document. The job selection key 61 is a key that is touch-operated when the user selects a “Scan To USB” job. The job selection key 62 is a key that is touch-operated when the user selects a “Scan To FTP” job. The job selection key 63 is a key that is touch-operated when the user selects a “Scan To Network” job.

  In addition, on the standby screen, a permanent setting key 64 that is touch-operated when confirming or changing the permanent setting status of the double feed detection is displayed. In the permanent setting, ON / OFF of double feed detection can be set. When the permanent setting key 64 is touched, a double feed detection setting menu 67 is displayed on the display unit 52. By touching one of the arbitrary multifeed detection settings from the multifeed detection setting menu 67, the multifeed detection setting can be changed as a permanent setting. As an initial setting, the double feed detection setting of the image reading apparatus 1 in the present embodiment is set to “ON”. Once the permanent setting is changed by a user operation, the changed setting is retained until the user operation is performed again.

The double feed detection setting menu 67 is displayed according to the contents of the double feed detection table stored in the ROM 42. In the double feed detection table, a double feed threshold used for double feed detection is stored in association with the double feed detection setting. Further, for the double feed detection setting in which the name is registered, the name is stored in association with the double feed detection setting. In the double feed detection setting menu 67, the registered name is also displayed for the double feed detection setting in which the name is registered.

  FIG. 4 shows an example of a double feed detection table corresponding to FIG. In the double feed detection table of FIG. 4, “OFF” setting, “ON” setting, “ON1” setting, “ON2” setting, and “ON3” setting are stored in association with the name and the double feed threshold value, respectively. The “OFF” setting is a setting for turning off double feed detection. The “ON” setting, the “ON1” setting, the “ON2” setting, and the “ON3” setting are settings for turning on the multifeed detection, and the multifeed thresholds are different from each other. In the “ON” setting, a double feed threshold “500” is stored. The double feed detection level is a standard setting, and is registered from the time of factory shipment. The double feed threshold value in this double feed detection table can be changed. In the “ON1” setting, the double feed threshold “300” and the registered name “card” are stored, and among the “ON” setting, the “ON1” setting, the “ON2” setting, and the “ON3” setting, the double feed detection level is set. This is the lowest setting. That is, it is suitable as double feed detection used when a thick original like a card is conveyed. In the “ON2” setting, the double feed threshold “400” and the registered name “thick paper” are stored, the double feed detection level is lower than the “ON” setting, and the double feed detection level is higher than the “ON3” setting. is there. For example, it is suitable as double feed detection used when a document such as a thick paper having a thickness larger than that of a plain paper but thinner than a card is conveyed. The “ON3” setting is a setting in which the double feed threshold “550” and the registered name “thin paper” are stored, and the double feed detection level is higher than the “ON” setting. For example, it is suitable as double feed detection used when a document such as thin paper having a thickness smaller than that of plain paper is conveyed. In the double feed detection, when the double feed sensor signal value acquired from the detection signal of the double feed sensor 32 at the time of reading the image of the document is equal to or less than the double feed threshold value, it is determined that the document is double fed to the CPU 44 of the ASIC 41. . Therefore, it can be said that the higher the multifeed threshold, the higher the multifeed detection level, and the lower the multifeed threshold, the lower the multifeed detection level.

  Furthermore, a shortcut key 65 is displayed on the standby screen. The shortcut key 65 will be described later.

  When any of the job selection keys 61 to 63 is touched, the display screen of the display unit 52 is switched from the standby screen to the execution instruction screen. On the execution instruction screen, various settings related to the scan job corresponding to the touch-operated job selection keys 61 to 63, for example, settings such as the image data file format and scan resolution are displayed.

  A detailed setting key 66 is displayed on the execution instruction screen. The user can change various settings related to the scan job by touching the detailed setting key 66. That is, when the detailed setting key 66 is touched, the display screen of the display unit 52 is switched from the execution instruction screen to the detailed setting screen, and various settings relating to the scan job can be changed on the detailed setting screen.

  On the detailed setting screen, it is possible to change the double feed detection setting related to double feed detection from the permanent setting. For example, when a double feed detection setting menu display key displayed on the detailed setting screen is touched, a double feed detection setting menu 67 is popped up on the detailed setting screen. In the double feed detection setting menu 67, a plurality of selectable double feed detection settings are displayed in a list format in a state where the double feed detection setting currently set by the permanent setting is selected. By touching one of the arbitrary double feed detection settings from the double feed detection setting menu 67, the double feed detection setting can be changed to the double feed detection setting touched as a temporary setting. The temporary setting is set as double feed detection for a scan job to start scanning from now. Therefore, when the scan job process is completed, the double feed detection setting set in the temporary setting is reset. If the double feed detection is set to OFF in the permanent setting, the double feed detection setting cannot be changed in the temporary setting.

  In addition, a start key 68 and a shortcut registration key 69 are displayed on the execution instruction screen. The start operation of the scan key is instructed by a touch operation of the start key 68. When the scan job is started, “Scanning” indicating that the scan job is being executed is displayed on the display unit 52 of the operation panel 51. The shortcut registration key 69 will be described later.

<Scan job processing>
When a standby screen is displayed on the display unit 52 of the operation panel 51 and any of the job selection keys 61 to 63 is touched on the standby screen, the CPU 44 of the ASIC 41 executes the scan job process shown in FIG. .

  In the scan job process, the CPU 44 determines whether or not a document is set, that is, whether or not the document is supported on the supply tray 3 and the support surface 11 (S11). Until the original is set, the scan job processing does not proceed to the subsequent steps, and the CPU 44 repeatedly determines whether or not the original is set.

  When the document is set and the document is supported on the supply tray 3 and the support surface 11 (S11: YES), the CPU 44 determines whether or not the start key 68 is touched on the execution instruction screen displayed on the display unit 52. That is, it is determined whether or not the start of the scan job is instructed (S12). Until the start of the scan job is instructed, the scan job processing does not proceed to the subsequent steps, and the CPU 44 repeatedly determines whether or not the start of the scan job is instructed.

  When the start of the scan job is instructed by touching the start key 68 on the execution instruction screen (S12: YES), the CPU 44 sets whether or not to perform double feed detection, and also performs double feed detection. Then, a double feed detection setting process for setting a double feed threshold used for the double feed detection is executed (S13). Details of the double feed detection setting process will be described later.

  After completion of the double feed detection setting process, the CPU 44 determines whether or not double feed detection is set to OFF in the double feed detection setting process (S14). When the double feed detection is set to OFF (S14: YES), the CPU 44 controls the first CIS 25, the second CIS 26, the transport motor 54, and the like until there is no document supported on the supply tray 3 and the support surface 11. Then, scanning (image reading) of the stacked number of originals is executed (S15), and the scan job processing is ended.

  When the double feed detection is set to ON (S14: NO), the CPU 44 turns on the double feed sensor 32 (S16). When the double feed sensor 32 is turned on, an ultrasonic wave is oscillated from the ultrasonic wave oscillating unit 33 of the double feed sensor 32, and the ultrasonic wave is received by the ultrasonic wave receiving unit 34, and analog corresponding to the strength of the received ultrasonic wave. A signal is output from the ultrasonic receiver 34. In the ASIC 41, the double feed sensor signal value is acquired at a constant period by A / D conversion of the analog signal output from the ultrasonic wave receiver 34.

  After the double feed sensor 32 is turned on, the CPU 44 controls the transport motor 54 and the like to start transporting one original (S17). Further, the CPU 44 controls the first CIS 25 and the second CIS 26 to read an image on at least one side of the conveyed document.

  Whenever the double feed sensor signal value is acquired, the CPU 44 determines whether or not the double feed sensor signal value is equal to or less than the double feed threshold value (S18). If the double feed sensor signal value is larger than the double feed threshold value (S18: NO), the CPU 44 determines whether or not scanning of one original has been completed (S19). Until the scanning of one original is completed, the CPU 44 determines whether or not the double feed sensor signal value is equal to or lower than the double feed threshold (S18), and when the scanning of one original is completed (S19: YES). Then, it is determined from the detection signal of the document sensor 31 whether or not there is a document on the supply tray 3 and the support surface 11 (S20).

  When there is a document on the supply tray 3 and the support surface 11 (S21), the CPU 44 starts conveying the next one document (S17), and executes the processing from step S17 described above. When there are no more documents on the supply tray 3 and the support surface 11 (S21: NO), the CPU 44 turns off the double feed sensor 32 and ends this scan job processing. Thus, one scan job is completed.

  If the CPU 44 determines that the double feed sensor signal value is equal to or lower than the double feed threshold value during document conveyance (S18: YES), the CPU 44 stops conveyance of the document (S22). Then, the CPU 44 displays a level change confirmation message, for example, a character “The double feed has been detected. Reading of the document is terminated. Do you want to change the double feed detection level?” On the display unit 51 of the display panel 51. (S23). Further, the CPU 44 displays a “YES” key and a “NO” key on the display unit 52 together with the message. The user confirms double feeding of the conveyed document, and touches the “YES” key and the “NO” key. When the double feed is actually confirmed, “NO” is selected, and when the double feed is not actually generated, “YES” is selected.

  When the “NO” key is touched by the user (S24), the CPU 44 determines not to change the double feed detection level (S25: NO), and displays the characters “End because double feed has occurred”. This is displayed on the section 52 (S26: error display), and this scan job processing is terminated. On the other hand, when the “YES” key is touched by the user (S24), the CPU 44 determines to change the double feed detection level (S25: YES), and executes the double feed threshold value changing process (S27). This scan job processing is terminated. The double feed threshold value changing process will be described later. The user can execute scan job processing while performing double-feed detection using the double-feed detection level after the change by setting the original again and executing scan job processing.

  When the scan job processing ends, the CPU 44 displays an execution instruction screen on the display unit 52 of the display panel 51. At this time, the temporary setting for double feed detection is reset.

<Double feed detection setting process>
The flow of the double feed detection setting process executed in step S13 of FIG. 5 is shown in FIG.

  In the double feed detection setting process, the CPU 44 of the ASIC 41 determines whether or not double feed detection is set to ON in the permanent setting (S131). When the double feed detection is set to OFF (S131: NO), the CPU 44 turns off the double feed detection in the scan job (S132), that is, determines that the double feed detection is not performed, and determines the double feed detection. The transmission detection setting process ends.

  When the double feed detection is set to ON (S131: YES), the CPU 44 displays on the display unit 52 of the operation panel 51 whether or not there is an instruction to change the double feed detection setting from the permanent setting. From the double feed detection menu 67, it is determined whether or not a change in the double feed detection level is instructed as a temporary setting (S133).

  When an instruction to change the double feed detection level is given (S133: YES), that is, “ON” setting, “ON1” setting, “ON2” setting or “ON3” setting is set temporarily from the double feed detection menu 67. In this case, the CPU 44 determines the double feed threshold corresponding to the temporarily set “ON” setting, “ON1” setting, “ON2” setting, or “ON3” setting as the double feed threshold used for double feed detection. (S134), the double feed detection setting process is terminated. On the other hand, when the change of the double feed detection level is not instructed (S133: NO), the CPU 44 corresponds to the permanent setting of “ON” setting, “ON1” setting, “ON2” setting or “ON3” setting. The double feed threshold to be used is determined as the double feed threshold used for double feed detection (S134), and the double feed detection setting process is terminated.

<Multifeed threshold change processing>
The flow of the double feed threshold value changing process executed in step S27 of FIG. 5 is shown in FIG.

  In the double feed threshold value changing process, the CPU 44 of the ASIC 41 acquires a double feed sensor signal value that has fallen below the double feed threshold value (S271). Then, a replacement / new registration confirmation message such as “Do you want to replace the double feed detection level? Do you want to newly register the double feed detection level?” Is displayed on the display unit 52 of the operation panel 51 (S272). Further, the CPU 44 displays a “replacement” key and a “new registration” key on the display unit 52 together with the message.

  Thereafter, when the user performs a touch operation on the “Replace” key (S273), the CPU 44 determines replacement of the double feed detection level (S274: YES), and associates it with the double feed detection setting set at that time. Then, the double feed threshold value stored in the double feed detection table is replaced with the double feed sensor signal value (S275), and the double feed threshold value changing process is ended.

  On the other hand, when the “new registration” key is touched by the user (S273), the CPU 44 determines the new registration of the double feed detection level (S274: NO), and performs the double feed threshold value registration process described below. This is executed (S276), and the double feed threshold value changing process is terminated.

<Multifeed threshold registration process>
The flow of the double feed threshold value registration process is shown in FIG.

  In the double feed threshold value registration process, the CPU 44 of the ASIC 41 causes the display unit 52 of the operation panel 51 to display a double feed threshold value registration screen. On the double feed threshold value registration screen, for example, a display name input box for inputting a name (display name) of the double feed detection setting is displayed. A QWERTY keyboard and an “OK” key are displayed below the display name input box. Is displayed. When the user touches the keyboard, the name can be input in the display name input box. After an arbitrary name is entered in the display name input box (S2761), when the “OK” key is touched, the CPU 44 newly registers the double feed detection setting in the double feed detection table stored in the ROM. Then, the double feed sensor signal value is stored as a double feed threshold value in association with the newly registered double feed detection setting (S2762). Then, the CPU 44 ends the double feed threshold value registration process.

<Shortcut function>
As shown in FIG. 9, when the shortcut registration key 69 is touched on the execution instruction screen displayed on the display unit 52 of the operation panel 51, the display screen of the display unit 52 changes from the execution instruction screen to the shortcut menu screen. Switch. A shortcut menu 71 is displayed on the shortcut menu screen. The shortcut menu 71 includes a “+” button for instructing new registration of a shortcut in addition to a shortcut name of a shortcut already registered.

  When the “+” button is touched, a shortcut name input box 72 for inputting a shortcut name is displayed, and a QWERTY keyboard 73 and an “OK” key 74 are displayed below the display name input box 72. The When the user touches the keyboard 73, a shortcut name can be input to the shortcut name input box 72. When an “OK” key 74 is touched after an arbitrary name is entered in the shortcut name input box 72, the touched “+” button is input to the shortcut name input box 72 at the location where the “+” button is displayed. The shortcut name is displayed, and various settings relating to the scan job such as the double feed detection setting at that time are stored in the ROM 42 in association with the shortcut name.

  When a shortcut name is touched on the shortcut menu screen, a scan job is executed according to various settings stored in the ROM 42 in association with the shortcut name. The shortcut menu screen is also displayed on the display unit 52 by touching the shortcut key 65 on the standby screen. Once, various settings associated with the shortcut name are registered with temporary settings for double feed detection. Therefore, by registering the shortcut, it is possible to perform double feed detection by the double feed detection setting according to the temporary setting without having to change the temporary setting every time.

<Effect>
As described above, in accordance with the setting operation accepted by the operation unit 53 of the operation panel 51, detection of double feed is not performed, or multiple feed thresholds are used among multiple feed thresholds. Whether to detect is set. Then, according to the setting, the document double feed is not detected, or the double feed is detected using the set double feed threshold. Thereby, it is possible to detect double feeding of different types of documents at a double feed detection level suitable for the document. Since the double feed threshold can be set by the permanent setting and the temporary setting, the double feed detection setting corresponding to the type of document that is read frequently is set in the permanent setting, and the document type that is read less frequently is set. By setting the corresponding double feed detection setting as a temporary setting when that type of document is read, it is possible to perform double feed detection with an appropriate double feed threshold according to the usage frequency. Since the double feed detection menu at the time of temporary setting is included in the menu screen for performing various settings of the scan job, the operability for changing the double feed threshold is improved.

  Even when the multifeed threshold is changed by the temporary setting, when the scan job is completed, the multifeed threshold is returned to the multifeed threshold by the permanent setting. Accordingly, it is possible to suppress the double feed detection using the double feed threshold value by the temporary setting in the next and subsequent scan jobs without being noticed by the user.

  When a double feed of a document is detected, a “YES” key and a “NO” key are displayed together with a level change confirmation message on the display unit 52 of the operation panel 51. When the “YES” key is touched, When the double feed threshold value changing process is executed, the double feed threshold value associated with the double feed detection setting is replaced with the double feed sensor signal value acquired during the scan job, or the double feed sensor signal value is replaced with a new double feed sensor signal value. It is registered in the ROM 42 in association with the transmission detection setting. As a result, double feed detection at an appropriate double feed detection level desired by the user is possible, and the accuracy of document double feed detection can be further increased.

  In addition, not only when the double feed of the document is detected, but also when the scan job is executed a predetermined number of times, for example, the double feed corresponding to the double feed detection setting in the scan job executed last is executed. The threshold value may be automatically updated to the lowest value of the double feed sensor signal value acquired during the execution of the scan job. Thereby, the fall of the precision of the double feed detection by aged deterioration can be suppressed.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  The double feed detection registration process may be registered by the user at an arbitrary timing. For example, an item of “double feed level setting (automatic)” may be provided in the double feed detection setting menu 67 displayed on the display unit 52 of the operation panel 51 by operating the standby screen (see FIG. 10). When this item is touched, for example, “Set one measurement document. Press the“ Start ”key. Is displayed on the display unit 52. According to this display, when the user sets a measurement document on the image reading apparatus 1 and touches a start key displayed on the display unit 52, the measurement document is conveyed on the conveyance path. During this conveyance, the double feed sensor 32 is turned on, and the ASIC 41 acquires the double feed sensor signal value. When conveyance of the measurement document is completed, a registration screen is displayed on the display unit 52. For example, a display name input box 81 for inputting a name (display name) of the double feed detection setting is displayed on the registration screen. A QWERTY keyboard 82 and an “OK” key are displayed below the display name input box 81. 83 is displayed. A name can be input to the display name input box 81 by the user touching the keyboard 82. When an “OK” key 83 is touched after an arbitrary name is entered in the display name input box 81, a double feed detection setting is newly registered in the double feed detection table stored in the ROM 42, and The lowest value of the multifeed sensor signal values acquired when the measurement document is conveyed in association with the newly registered multifeed detection setting is stored as a multifeed threshold. Then, the newly registered double feed detection setting is added to the double feed detection setting menu 67.

  This enables new registration of the double feed detection setting even when the double feed of the document is not detected, and a double feed threshold larger than the double feed threshold currently stored in the double feed detection table can be added.

  As the permanent setting, the double feed detection level can be selected from the standard setting “ON” setting and “OFF” setting. As the temporary setting, the “ON” setting can be selected from different multifeed threshold values. It may be possible to select from. In addition, a plurality of multifeed detection settings having different multifeed threshold values may be stored in the multifeed detection table at the time of factory shipment.

  The level change confirmation display in S23 may be displayed in two stages. For example, “Multiple feed detected. Do you want to stop scanning?” Is displayed, and if YES is selected by the operation unit, an error display of S26 is displayed. Do you want to change the detection level? " And if YES is selected by the operation part, you may perform the double feed threshold value change process of S27. Here, when NO (do not change the double feed detection level) is selected, the stopped reading process may be resumed. Further, after the double feed threshold value changing process of S27, the continuation of the stopped document may be read with the changed double feed threshold value. When a new threshold value is registered in the double feed threshold value changing process, double feed detection in the subsequent document reading may be performed according to the newly registered double feed detection setting.

  Further, even if the permanent setting is off, the temporary setting may be performed. Further, the double feed detection may be set off from the temporary setting. Further, when the permanent setting is changed to off after the shortcut key including the predetermined temporary setting is registered, the temporary setting registered for the shortcut may be switched off.

  In the above-described embodiment, the case where the CPU 44 executes each process has been described. However, the ASIC 41 may include a plurality of CPUs, and the plurality of CPUs may cooperate to execute each process.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

1: Image reading device 25: First CIS
26: Second CIS
32: Double feed sensor 42: ROM
44: CPU
52: Display unit 53: Operation unit

Claims (7)

A transport section for transporting a document;
A reading unit that reads an image of a document conveyed by the conveyance unit;
An operation unit;
A storage unit;
A control unit,
The storage unit stores a value indicating a first determination level used for detecting double feeding in which documents are conveyed while being overlapped, and a value indicating a second determination level different from the first determination level,
The controller is
According to the setting operation accepted by the operation unit, double feed is not detected, double feed is detected using the first determination level, or double feed is detected using the second determination level. Execute the setting process to set whether to perform detection,
When the document is transported by the transport unit, when the setting by the setting process is a setting for not detecting the double feed, the setting by the setting process uses the first determination level. In the case of setting to detect double feed, the first judgment level is used to detect double feed, and when the setting by the setting process is set to detect double feed using the second determination level, An image reading apparatus that detects double feeding using a second determination level. The image reading apparatus according to claim 1,
The control unit, in the setting process,
As a setting relating to the image reading apparatus, a first setting relating to double feed detection is performed, and as a setting relating to reading by the reading unit, a second setting relating to detection of double feeding is performed,
When different judgment levels are set according to the first setting and the second setting, double feed is detected according to the contents of the second setting,
An image reading apparatus that, when detecting double feed according to the content of the second setting, sets the content of setting related to detection of double feed to the content of the first setting after the reading by the reading unit is completed. The image reading apparatus according to claim 2,
The control unit, in the setting process,
An image reading apparatus that prohibits the second setting when the content of the first setting is a setting that does not detect double feeding. The image reading apparatus according to claim 2, wherein
The controller is
When the second setting is performed, according to a shortcut registration operation accepted by the operation unit, the content of the second setting is associated with a shortcut key and stored in the storage unit,
When the screen including the shortcut key is displayed, and the shortcut key is selected by a selection operation accepted by the operation unit, the second setting associated with the shortcut key from the storage unit Accordingly, an image reading device that detects double feeding. The image reading apparatus according to any one of claims 1 to 4,
The controller is
An image reading apparatus that stores a value indicating a determination level used for detecting double feeding in the storage unit in a new or overwritten manner in response to a determination level registration operation accepted by the operation unit. The image reading apparatus according to claim 5,
The controller is
When double feed is detected by detecting double feed using the first judgment level, and the judgment level registration operation is accepted by the operation unit, the measured value when the double feed is detected is displayed. An image reading apparatus that stores a value indicating the first determination level in the storage unit by overwriting based on the first determination level. The image reading apparatus according to any one of claims 1 to 6,
An ultrasonic sensor that receives the ultrasonic wave that has passed through the document conveyed by the conveying unit and outputs a signal having a level corresponding to the intensity of the received ultrasonic wave;
The controller is
At the time of conveying the first type of document by the conveying unit, it is determined that the first type of document has detected double feeding if the level of the signal output from the ultrasonic sensor is equal to or lower than the first determination level. When the second type document is conveyed by the conveyance unit, the second type document has detected double feed when the level of the signal output from the ultrasonic sensor is equal to or lower than the second determination level. An image reading apparatus that determines that

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