JP2018117294A - Image reading device and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent document jamming due to inclined insertion of the document while reducing user's return time, in a sheet feed system reading device.SOLUTION: In an image reading device for reading the image of a document by using a line sensor where multiple reading elements are arranged in a second direction different from the first direction, and having a predetermined readable length in the second direction, while transporting the inserted document inward in the first direction, following control is performed. Based on the information obtained by pre-scanning the tip of the document in the first direction by means of the line sensor, width and inclination of the document are acquired. Next, based on the width and inclination of the document thus acquired and the width of the internal transfer path of the image reading device, transportable length of the document in the first direction is calculated. The transportable length thus calculated and the length of the document in the first direction are then compared, and execution of image reading of the document is controlled based on the comparison results.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an image reading apparatus and a control method thereof, and more particularly, to a technique for suppressing document jamming in a conveyance path due to document inclination and document damage.

  In a so-called sheet feed type image reading apparatus that scans an original while fixing a reading sensor, the apparatus can be made smaller than other systems that require fixing the entire original. However, in this configuration, since the document is conveyed using a mechanism such as a roller, the document is easily inclined with respect to the image reading line. In particular, in the case of an image reading apparatus corresponding to a large-size document, a configuration in which the document is placed on one flat table cannot be taken, and alignment using abutment is difficult to perform. When the user manually inserts the document into the image reading device under such conditions, a slight inclination occurs with respect to the document conveyance direction.

  If the document is inserted with an inclination, depending on the size and insertion position of the document, the end of the document may hit the wall of the conveyance path during the conveyance process and may be clogged or torn in the image reading apparatus. For this reason, there has been disclosed a technique for automatically detecting the tilt and position of a fed document and stopping conveyance before the end of the document hits the wall of the conveyance path.

  For example, Patent Document 1 includes a detection unit that detects the position of the leading edge of a document that is conveyed on the conveyance path and a detection unit that detects the skew amount of the document. An apparatus configured to stop the conveyance of printed matter before the conveyance area is exceeded is disclosed.

JP 2012-206858 A

  However, in the above-described conventional example, if skew feeding is detected during the document conveyance process during image reading and the image reading is stopped, the image reading time required up to that time is wasted and the document extraction process is difficult. There is a problem that the manuscript may be damaged. Further, when the image reading apparatus is connected to or coupled to the recording apparatus to constitute a multi-function printer that performs a copying operation, if the image reading is stopped due to a paper jam of an original that reads an image during the copying operation, a printing operation is also performed. It stops and the printed matter is discharged at a stage during printing.

  The present invention has been made in view of the above conventional example, and provides an image reading apparatus capable of highly reliable reading and a control method thereof without causing interruption of image reading during the conveyance due to the inclination of the document. The purpose is to do.

  In order to achieve the above object, the image reading apparatus of the present invention has the following configuration.

  That is, an image reading apparatus that reads an image of an original using a line sensor that extends in a second direction different from the first direction while conveying the original in the first direction, the line sensor Pre-scans the leading edge of the document with respect to the first direction to acquire information about the width of the document and the tilt of the document, and based on the acquired information, the document Calculating means for calculating the transportable length in the first direction, second acquisition means for acquiring information on the length of the document in the first direction, and the transportable length and the length of the document. Control means for controlling execution of image reading of the document based on the comparison.

  The image reading apparatus is an image reading apparatus that reads an image of the document using a line sensor while conveying the document, and the means for pre-scanning the leading edge of the document by the line sensor; And means for notifying the user without executing the image reading when it is determined that the image reading of the document cannot be normally performed to the end based on the information obtained by the pre-scan. good.

  According to another aspect of the present invention, there is provided a control method of an image reading apparatus that reads an image of an original using a line sensor while conveying the original, and the prescan of the leading edge of the original is performed by the line sensor. And when it is determined that the image reading of the document cannot be normally performed to the end based on the information obtained by the pre-scan, the user is notified without executing the image reading. A control method is provided.

  Therefore, according to the present invention, the transportable length of the document is calculated from the inclination of the document, and execution of image reading from the document is controlled by comparing the transportable length with the length of the document. Therefore, it is possible to prevent the situation in which the original is damaged.

1 is a perspective view showing an external configuration of an image reading apparatus that is a typical embodiment of the present invention. It is the figure which showed the internal structure of the scanner. It is a block diagram which shows the control structure of a scanner. 6 is a flowchart illustrating processing for accepting setting of document information by a user according to the first embodiment. FIG. 6 is a diagram illustrating an example of a screen displayed on the LCD of the operation unit when setting document information. 6 is a flowchart showing processing from when a user according to the first embodiment feeds a document inserted into a document feed slot to start image reading. 10 is a flowchart illustrating details of a sheet feeding operation. It is a flowchart which shows the detail of a prescan. FIG. 5 is a top transparent view of the scanner for explaining the width and inclination in the main scanning direction obtained by prescanning a document. 6 is a flowchart illustrating details of a process for calculating a document transportable length. 12 is a flowchart illustrating processing from when a user according to a second embodiment feeds a document inserted into a document feeding port to start image reading. 6 is a flowchart showing details of processing for estimating the length in the transport direction based on document width information obtained by pre-scanning. 10 is a flowchart illustrating processing from when a user according to a third embodiment feeds a document inserted into a document feeding port to start image reading. It is a figure which shows the example of the warning message displayed on LCD.

  Hereinafter, preferred embodiments of the present invention will be described more specifically and in detail with reference to the accompanying drawings. In the following description, the same components are referred to with the same reference numerals throughout the drawings. Therefore, the components once described are referred to using the same reference numerals, and the description thereof will not be repeated.

  FIG. 1 is a perspective view showing an external configuration of a sheet feed type image reading apparatus (hereinafter referred to as a scanner) that optically reads an image of an original, which is a typical embodiment of the present invention.

  As shown in FIG. 1, the scanner 100 has a document feed port 101 and a document feed table 102 on the front side of the main body. The user places the leading end of the document on the document feeding table 102 so that the center of the document is positioned at the center of the document feeding port 101, and slides the document on the document feeding port 101 so as to slide on the table. insert. The width of the document feed port 101 is designed to allow a certain amount of positional deviation or inclination at the time of insertion with respect to the width in the main scanning direction of the document that can be read by the scanner 100. The configuration of the document feed path will be described in detail with reference to FIG.

  The scanner 100 includes an operation panel 103 including a physical key, an LCD panel, and the like on the upper surface of the main body, and can set a reading condition and input a document size. Further, an upper cover 104 is provided on the upper surface of the scanner 100, and opening to the upper side enables access to the reading unit and the like so that the main body can be maintained.

  FIG. 2 is a diagram showing the internal configuration of the scanner 100. 2A is a cross-sectional view taken along the document conveyance direction, and FIG. 2B is a top view of the scanner 100.

  In FIG. 2A, the left side is the upstream side of document feeding and the right side is the downstream side, and the document is conveyed in the y-axis direction. The document 201 fed by the user along the document feed tray 102 is discharged from the back of the main body through a substantially flat conveyance path. The document detection sensor 202 detects the insertion of the document 201. When the document 201 is detected, the upstream detection roller 203 is rotated to draw the document 201 into the transport path. The edge detection sensor 204 is used to detect the leading edge of the document 201 drawn into the conveyance path by the rotation of the upstream conveyance roller 203. The detection result of the edge detection sensor 204 is used for determining the reading start position of the document 201, detecting the position of the trailing edge of the document 201, and the like. Inside the conveyance path, the original 201 passes between the glass plate 205 and the original pressing plate 206. The document pressing plate 206 functions to press the document 201 against the glass plate 205 with a predetermined pressure.

  A contact image sensor (hereinafter referred to as CIS) 207 has a plurality of reading elements arranged in the main scanning direction (the x direction in FIG. 2B perpendicular to the y direction), and one line at a time by the arranged reading elements. It is a line sensor that optically reads an image. The reading surface of the CIS 207 is opposed to the glass plate 205, and the reading focal position is designed to be located on the contact surface between the original 201 and the glass plate 205. The downstream side conveyance roller 208 is configured to be driven by the upstream side conveyance roller 203 by a belt (not shown), and discharges the document that has passed through the pressing region of the document pressing plate 206 against the glass plate 205 to the downstream side. Have a role. The image reading control unit 209 includes a detection circuit and a motor (not shown) for rotating the conveyance rollers, a circuit board for controlling the CIS 207, and the like.

  FIG. 3 is a block diagram showing a control configuration of the scanner 100.

  As shown in FIG. 3, the image reading control unit 209 includes a CPU 301, a memory 302, a motor driver 303, an I / F unit 304, an A / D conversion unit 305, and a power supply unit 306. The operation panel 103 includes an LCD 307 and operation keys 308. The LCD 307 displays information on a document to be scanned, scanner settings, and the like by output from the CPU 301, and the user can change settings while confirming information displayed on the LCD 307 by operating the operation keys 308.

  The transport motor 309 is controlled by the CPU 301 via the motor driver 303 and rotates the upstream transport roller 203 and the downstream transport roller 208. The outputs from the document detection sensor 202 and the edge detection sensor 204 are input to the CPU 301. The CPU 301 determines the drive timing of the CIS 207 based on the change in the output signals of these sensors and the state of the transport motor 309. Decide and control.

  The CIS 207 outputs the read image to the image reading control unit 209 as an analog signal. The analog signal output from the CIS 207 is converted into a digital signal by the A / D conversion unit 305 and input to the CPU 301. The CPU 301 can process the data converted into a digital signal by the A / D conversion unit 305 and transmit it as image data to an external device connected by an interface such as USB or LAN via the I / F unit 304. . The power supply unit 306 generates power necessary for each unit and supplies power.

  Next, several embodiments will be described with respect to processing when feeding a document for reading an image of the document using the scanner having the above-described configuration.

  Here, an operation related to document feeding of the scanner 100 will be described with reference to FIGS.

  First, with reference to FIGS. 4 to 5, a procedure for accepting a change in document information setting by the user will be described.

  FIG. 4 is a flowchart showing processing for accepting document information setting by the user.

  FIG. 5 is a diagram showing an example of a screen displayed on the LCD of the operation unit when setting document information.

  After the power is input, the scanner 100 waits in a state where it can accept the change of the setting information by the user (S401). On the LCD 307 of the operation panel 103, setting information preset in the scanner 100 (for example, the size of the original, the resolution at the time of reading, the mode of color, monochrome, etc.) is displayed.

  FIG. 5A shows an example of reading settings displayed on the LCD 307. As can be seen from FIG. 5A, default setting values are preset for each setting item. The user changes the preset information in accordance with the original 201 on which the image is read and the use of the read image. The change can be performed by operating the up / down / left / right direction keys and the enter key included in the operation keys 308.

  For example, to change the size information of the original 201, selecting the original size item and pressing the enter key switches the LCD screen. As shown in FIG. 5B, "standard size" and "user input"・ You can select either “Auto”. When the user selects “standard size”, the screen is switched again, and ISO standard A4 vertical, A4 horizontal, A3 vertical, A3 horizontal, A2 vertical... Displayed and selectable by the user. When the user selects “user input”, the screen is switched again, and as shown in FIG. 5D, the length of the original in the main scanning direction (x axis) and the length in the sub scanning direction (y axis) ) Input screen is displayed.

  For the input of the length information, a numerical value and a unit can be selected, and “mm”, “inch” or the like can be selected as the unit. As shown in FIG. 5B, when the user selects “automatic” in the document size selection, the size of the document 201 is automatically determined based on information obtained by reading the scanner 100. When the user selects one of these settings and finally presses the enter key, the CPU 301 saves the setting information in a predetermined area of the memory 302, assuming that the setting information has been changed (S402).

  Similarly, the setting information on the memory 302 is overwritten and saved in the memory 302 every time information that can be set by the user on the setting screen including other setting information is updated.

  Next, the automatic execution determination process of the reading operation started when the user inserts the document 201 into the document feeding port 101 of the scanner 100 will be described with reference to FIGS.

  FIG. 6 is a flowchart showing the processing from when the user feeds the document 201 inserted into the document feed port 101 to start image reading.

  After input of power, the scanner 100 drives the document detection sensor 202 and waits for the document 201 to be inserted (S601). When the user inserts the original 201 to be read into the original feed port 101 of the scanner 100 in the center, the leading end of the original 201 crosses the optical path of the original detection sensor 202. The document detection sensor 202 is a reflection type sensor, and the light emitted from the sensor is designed to be reflected on the opposite surface and not incident on the light receiving surface of the sensor again when the document 201 is not present.

  When the document 201 crosses the optical path of the document detection sensor 202, the irradiated light is reflected by the document 201, and a part of the light enters the light receiving element of the document detection sensor 202. If the light incident on the document detection sensor 202 exceeds a certain value, the output of the document detection sensor 202 changes. When the CPU 301 detects a change in the output of the document detection sensor 202, the CPU 301 determines that the document 201 has been inserted, and starts a paper feeding operation (S602).

  Details of the sheet feeding operation in S602 of FIG. 6 will be described with reference to FIG.

  FIG. 7 is a flowchart showing details of the sheet feeding operation.

  In the paper feeding operation, first, the CPU 301 outputs a drive signal to the motor driver 303 to rotate the transport motor 309, and the upstream transport roller 203 is rotated by the kinetic energy (S701). When the user inserts the leading edge of the original 201 to the nip position of the upstream conveying roller 203, the upstream conveying roller 203 pulls the original 201 and conveys the leading edge of the original to the internal conveying path. Similar to the document detection sensor 202, an end detection sensor 204, which is a reflective optical sensor, is disposed in the center of the main scanning direction (x-axis direction) in the vicinity of the upstream conveyance roller 203 in the internal conveyance path. Using this, it is checked whether or not the leading edge of the document 201 has passed the detection area of the edge detection sensor 204 (S702).

  When the CPU 301 detects a change in the output level of the edge detection sensor 204, based on the state of the conveyance motor 309 at that time, the conveyance motor so that the leading edge of the document 201 is positioned at the start position for performing the next pre-scan. Adjust the rotation of 309. Then, the rotation of the transport motor 309 is temporarily stopped (S703). On the other hand, when the user does not insert the original 201 sufficiently, the conveyance motor 309 is continuously rotated until the timeout time, and when the timeout (S704) is finally detected, the conveyance motor 309 is rotated. Stop (S705). After that, an error is displayed on the LCD 307 of the operation panel 103 as a defective insertion of the document 201, and the user is prompted to insert the document again.

  Returning to FIG. 6 again, the description will be continued. When the original 201 is normally drawn into the conveyance path by the paper feeding operation (S602), a pre-scan operation for reading information on the leading end area of the original 201 is subsequently performed (S603).

  Details of the pre-scan in S603 of FIG. 6 will be described with reference to FIG.

  FIG. 8 is a flowchart showing details of the pre-scan.

  In the pre-scan, first, rotation of the carry motor 309 is started in order to start carrying of the original 201 waiting at the reading start position (S801). Next, after the conveyance motor 309 is rotated by a predetermined amount, image reading by the CIS 207 is started (S802). Since the pre-scan operation is mainly intended to detect the edge position of the document, the lighting of the LED as the light source of the CIS 207 is limited to only one of red (Red), green (Green), and blue (Blue). To do.

  The LED is turned on based on the control information of the transport motor 309, and the reflected light is exposed to the line sensor arranged in the CIS 207. As a result, analog signals that change according to the amount of light received by the line sensor are sequentially input to the A / D conversion unit 305 of the image reading control unit, converted into digital signals, and input to the CPU 301. The CPU 301 sequentially processes the digital signals and stores the digital signals in the memory 302.

  While reading the image, the original 201 is conveyed, and when reading of a predetermined length in the sub-scanning direction is completed (S803), the rotation of the conveyance motor 309 is stopped (S804). Thereafter, the document motor 201 is reversely conveyed upstream by rotating the conveyance motor 309 in the reverse direction (S805). The CPU 301 calculates the rotation speed of the conveyance motor 309 so that the leading edge of the document 201 returns to the reading start position, and stops the rotation of the conveyance motor 309 when the leading edge of the document 201 reaches the reading start position (S806).

  Returning to FIG. 6 again, the description will be continued.

  When the pre-scan (S603) is completed, the image data of the front end portion of the document 201 read by the CIS 207 and stored in the memory 302 is analyzed by the CPU 301. The image data of the document 201 stored in the memory 302 is sequentially read out by the CPU 301, the end position in the main scanning direction (x direction) is detected through a predetermined algorithm, and the document 201 is conveyed based on the information. The possible length is calculated (S604). In this embodiment, information on the edge position of the document 201 analyzed and detected in each line is referred to as document edge position information.

  Details of the process for calculating the transportable length of the document 201 in S604 of FIG. 6 will be described with reference to FIGS.

  FIG. 9 is a transparent top view of the scanner 100 for explaining the width and inclination in the main scanning direction obtained by the scanner 100 pre-scanning the document 201.

  As shown in FIG. 9, the document 201 is inserted with a predetermined inclination (θ) with respect to the sub-scanning direction (y-axis direction) of the scanner 100. The reference in the x-axis direction is on the left side of the figure.

  FIG. 10 is a flowchart showing details of a process for calculating the transportable length of the document 201.

  First, by analyzing the image data of the document 201 stored in the memory 302 by the pre-scan, the left and right end positions of the document 201 with respect to the x axis are detected (S1001). Edge position detection is performed for all lines in a predetermined range of the leading edge of the document read by prescanning.

  When the end position detection is completed for all the target areas, it is determined whether all the detected end positions are within the transportable area in the main scanning direction (S1002). This determination is performed by comparison with a predetermined threshold value. If the end position of any line exceeds the threshold value, it is determined that the document 201 has a paper feed error (ERROR), and error processing is performed. In this case, the document 201 is once discharged out of the scanner 100 and the user inserts the document into the document feed port 101 again.

On the other hand, when it is determined that the end positions of the document 201 are all within the threshold, the amount of change in the x direction of the left and right end positions with respect to the y direction is obtained (S1003). The position is detected in the reading resolution unit of the scanner 100 in both the x-axis and y-axis directions. For example, when the reading resolution of the scanner 100 is 600 dpi, the number of lines obtained when transported for 1 inch is 600 lines. When 600 lines is Δy, the amount of change in the x-axis direction of the end position detected during this time is Δx. This value is moving averaged over the range in which the value was read. If the end position change amount around the unit transport amount (Δy) is calculated, the inclination of the document is calculated based on the calculated value (S1004). The inclination (θ) of the original 201 with respect to the y-axis direction can be obtained by Expression (1). That is,
θ = arctan (Δx / Δy) (1)
It is. Here, for Δx, the larger value of the left and right sides of the original 201 is used.

Subsequently, the width of the original is calculated using the obtained original inclination (θ) (S1005). When the difference in the x direction between the left and right document edge position information in a predetermined line is Wd, the actual width (Wa) of the document 201 in the main scanning direction is calculated by the equation (2) using the calculated inclination θ. Desired. That is,
Wa = Wd × sin θ (2)
It is. When the document size is set to “automatic” or “user setting” and the width is set to “automatic” in the document information setting performed by the user operating the operation panel 103 before the document 201 is inserted, the above processing is performed. The calculated width (Wa) value is applied.

  Subsequently, the left or right end of the document 201 is calculated when calculating the length in the sub-scanning direction (y direction) before the left and right end positions of the document 201 exceed the document transportable area set in the main scanning direction of the scanner 100. It is determined whether or not the calculation is to be performed in the unit (S1006). When the left and right edges of the document 201 are parallel to each other, it is possible that the edge of the document 201 exceeds the transportable area in the main scanning direction due to the inclination of the document 201. When the change amount Δx around the unit conveyance amount at the left end portion of the document 201 is less than 0 (minus), the left end portion is a calculation target, and when the change amount Δx around the unit conveyance amount at the right end portion of the document 201 is greater than zero. The right end is the calculation target. Here, when Δx is 0 at both the left and right ends, that is, when there is no inclination, either the left or the right or both are set as calculation targets.

  When the end of the target for calculating the transportable length is determined, the transportable length of the document 201 is calculated (S1007).

When the edge detection position of the document 201 is Xd and the main scanning direction threshold value of the document transportable area is Xe, the length Lf in the sub-scanning direction in which the edge position of the document 201 can be transported without exceeding the transportable area is
On the right edge of the paper, if Δx> 0,
Lf = Δy × (Xe−Xd) / Δx (3)
If Δx <0 on the left edge of the paper,
Lf = Δy × (Xd−Xe) / Δx (4)
It can ask for.

  At both ends of the paper, if Δx = 0, Lf is set to the maximum length that the scanner 100 can handle. According to the calculation using the equations (3) to (4), when Δx is small (the inclination of the original 201 is small) or the distance between Xe and Xd is large (the size of the original 201 is small), the value of Lf is You can see it grows.

  Returning to FIG. 6 again, the description will be continued.

  When the transportable length of the document 201 is calculated, information on the length of the document 201 preset by the user is analyzed to obtain the length of the document 201 (S605). The user inputs settings related to the document 201 through the operation panel 103 before the document 201 is inserted, and the settings are held in the memory 302 in the image reading control unit 209. The CPU 301 refers to the size information of the document 201 from the memory 302. At this time, if the standard size is specified for the size of the document 201 by operating the operation panel 103, length information in the y-axis direction is acquired from the set standard size, and the value is set to Ls. When the document size setting is user input, the value of the y-axis length (displayed as “vertical” on the panel) input by the user is set to Ls.

  When both the transportable length Lf obtained by the prescan and the length Ls in the y-axis direction of the document size set by the user are obtained, the CPU 301 compares the two values. Thus, it is determined whether or not all areas of the original 201 can be read in the current state of the original 201 (S606). Here, when Lf> Ls, since the distance that can be conveyed is larger than the actual length of the original 201, it is determined that the entire area of the original can be read. On the other hand, if Lf <Ls, it is determined that any end of the document 201 in the x-axis direction may exceed the transportable area in the main scanning direction of the scanner 100 during reading. .

  When the CPU 301 determines that reading is possible (Lf> Ls), the scanner 100 automatically starts reading an image of the document 201 (S607). The read data is converted into a predetermined output format by the CPU 301 and output to the outside of the scanner 100 via the I / F unit 304 or the like.

  On the other hand, when Lf <Ls, the CPU 301 displays a warning message on the LCD 307 (S608). The content of the display indicates that there is a possibility that the reading may be interrupted in the middle of reading in the current attachment state of the original 201, and the user selects either execution of reading or reattachment of the original 201. The scanner 100 waits until the user makes any selection (S609). Here, when the user presses read execution (“OK” key), the scanner 100 starts reading the document. When the user selects reattachment of the original 201, the upstream conveyance roller 203 is rotated in the direction opposite to the normal conveyance direction of the original 201, and the original 201 is discharged out of the scanner 100 (S610). When the document 201 is discharged, the user inserts the document 201 into the document feed port 101 again, and the reading start determination is executed according to the above-described processing.

  The above is the document feeding procedure to the scanner 100.

  Therefore, according to the embodiment described above, the scanner calculates the document transportable length from the detection result of the end position of the document in the main scanning direction, and the calculated result and the length of the document input by the user in the document transport direction. Compare the information about the length. Then, only when it is determined that the end portion of the document does not exceed the predetermined conveyance area during the reading operation, reading of the document is automatically started. Accordingly, it is possible to reduce the situation in which the end of the document exceeds the transportable area while the scanner is reading the document and the reading operation must be stopped.

  Further, since the allowable amount of inclination varies depending on the width of the original, when reading a small-size original, the allowable amount of inclination is relaxed, and it is not necessary to insert the original into the apparatus strictly. Will improve.

  Furthermore, many of the seed feed type scanners are inserted so that the center position of the document is aligned with the center of the transport area in the main scanning direction. In this embodiment, however, the actual insertion position and the transport direction of the document are The possibility of document reading is determined based on the length information. For this reason, there is an advantage that it is not always necessary to insert a document in accordance with the center position.

  In the embodiment described above, the calculation method for obtaining the document width and the inclination with respect to the conveyance direction has been described with reference to FIGS. 9 to 10. However, the present invention is not limited to this, and other A calculation method and a detection method may be applied. For example, information indicating which pixel position of the CIS 207 first detected the edge position of the document 201 after the edge detection sensor 204 detects the leading edge position of the document 201 during pre-scanning may be used. It is possible to calculate the inclination of the document 201.

  In this embodiment, the operation when the user selects “automatic” as the size information of the original 201 in the original information setting operation in the first embodiment (that is, when the input of the size information can be omitted) is shown in FIGS. Will be described with reference to FIG.

  FIG. 11 is a flowchart showing an automatic start determination operation of the reading operation after inserting the document 201 according to the second embodiment. In FIG. 11, the same processing steps as those already described with reference to FIG. 6 are denoted by the same step reference numbers, and the description thereof is omitted. Here, only processing unique to this embodiment will be described. .

  The document 201 inserted in the scanner 100 is pre-scanned to obtain the width Wa and the inclination θ of the document 201, and processing (S601 to S604) until the transportable length Lf is calculated is executed. And the transportable length Lf are acquired. Thereafter, the CPU 301 estimates the length of the original 201 in the conveyance direction to determine whether or not to perform reading (S605 ').

  Here, the details of the process of estimating the length of the document 201 in the conveyance direction performed in S605 'of FIG. 11 will be described with reference to FIG.

  FIG. 12 is a flowchart showing details of processing for estimating the length in the transport direction based on the width information of the document 201 obtained by prescanning.

  The CPU 301 refers to the document size table held in the memory 302 (S1201). The document size table is used to determine whether the size of the inserted document 201 corresponds to a fixed document size (for example, ISO A column or B column) supported by the scanner 100. . The table includes threshold values set to several percent before and after the paper width of each size and length information in the conveying direction corresponding to the threshold value.

  The CPU 301 compares the threshold values of these tables held in the memory 302 with the width Wa of the document 201 calculated by pre-scanning (S1202). If it is determined by this comparison that the width Wa of the original 201 is within a certain paper size threshold, the CPU 301 determines that the attached original 201 has a paper size having the threshold (S1203). Then, the length in the transport direction is set to the paper length Lt held in the corresponding table (S1204).

  Here, it returns to FIG. 11 again and continues description.

  When the document length Lt for determination is determined, it is determined whether to automatically start reading the document based on the length information and the calculated transportable length Lf (S606 '). Here, the CPU 301 compares the calculated transportable length Lf with the document length Lt obtained by referring to the table. Here, if Lf> Lt, since the length that can be conveyed is larger than the length of the original 201, it is determined that the original 201 can be read, and reading is automatically started (S607).

  On the other hand, when Lf <Lt, the length that can be conveyed is smaller than the length of the document 201, so that either end of the document 201 in the x-axis direction during scanning is in the main scanning direction of the scanner 100. It is determined that there is a possibility of going out of the transportable area. Then, a warning message is displayed (S608). The subsequent processing (S609 to S610) is as described with reference to FIG.

  The automatic start determination process for the reading operation in the original document size automatic detection mode has been described above.

  The information held in the memory 302 for specifying the document size is set to a value with a sufficient margin for reading an image without damaging the document as much as possible. Specifically, even if the same standard size is used, it is possible to insert a document in both the vertical and horizontal directions with respect to the scanner. The order of comparison is set.

  As an example, a case where an ISO A1 size document is used will be described.

  When the user inserts the A1 size original 201 into the scanner 100 in the vertical direction, the CPU 301 calculates that the width is about 594 mm by pre-scanning. Since the memory 302 holds a size estimation table assuming that a document is inserted in the vertical direction, it is determined as an ISO A1 size as a result, and the length Lt in the transport direction is held in the table. A length of 841 mm is set. On the other hand, when the user inserts an ISO A1 size original 201 in the horizontal direction with respect to the scanner 100, the CPU 301 calculates that the width is about 841 mm by pre-scanning. However, the memory 302 similarly holds only a size estimation table that assumes a case where a document is inserted in the vertical direction, and as a result, it is determined to be an ISO A0 size. As a result, the document length Lt for size determination is set to 841 mm, which is the vertical length of ISO A0 size. In this way, the determination is made with a size (A0) different from the original size (A1) of the original 201, but the end of the original 201 exceeds the transportable area of the scanner 100 during the reading. The situation where reading is interrupted can be avoided.

  In this embodiment, since it operates as described above, it is possible to omit the trouble of setting the length information of the document by operating the operation panel every time the user sets the document. The document size automatic detection mode contributes to the improvement of user convenience, especially for users who frequently use a standard size document.

  Similar to the second embodiment, this embodiment will be described with reference to FIGS. 13 to 14 when the document size is selected as “automatic” in the input of document information.

  FIG. 13 is a flowchart showing an operation related to document feeding of the scanner 100 according to the third embodiment. In FIG. 13, the same processing steps as those already described with reference to FIG. 6 are denoted by the same step reference numerals, and the description thereof will be omitted. Here, only processing unique to this embodiment will be described. .

  Here, similarly to the second embodiment, the document size information is set to “automatic”, and the document 201 is inserted into the scanner 100. Then, the document 201 inserted into the scanner 100 is pre-scanned to obtain the width Wa and the inclination θ of the document 201, and processing (S601 to S604) until the transportable length Lf is calculated is executed. The width Wa and the transportable length Lf are acquired.

  After that, the CPU 301 estimates the document size by referring to the document size estimation table stored in the memory 302 based on the information on the length Wa of the document 201 in the main scanning direction, and conveys it to the user via the LCD 307. The possible length is displayed (S605 ″).

  FIG. 14 is a diagram illustrating an example of a warning message displayed on the LCD 307.

  As shown in FIG. 14, the warning message displays that the document is tilted, the transportable length Lf, and a button for instructing to interrupt reading. The timer is started inside the CPU 301 simultaneously with the display of the warning message. Then, it is determined whether or not the reading interruption instruction is selected (S606 ″), and it is determined whether or not the timer value is timed out by comparing with a predetermined threshold (S606 ′ ″).

  If the user does not operate the operation panel 103 before the timer value reaches the threshold value, a time-out occurs and reading of the document 201 is automatically started (S607). On the other hand, the user confirms the readable length displayed on the LCD 307, and when the displayed length is shorter than the actual length of the original, the operation panel 103 is operated to select reading interruption. If reading interruption is selected before the timer times out, the scanner 100 discharges the original 201 and instructs to insert the original again (S610).

  Therefore, according to the embodiment described above, the scanner automatically detects the length of the inserted document in the main scanning direction, and displays the readable length on the LCD to notify the user. As a result, the user does not need to set the size of the document in advance, and can automatically start reading only by confirming the display on the LCD. Further, when the readable length displayed on the LCD is shorter than the actual length of the original, it is possible to interrupt the reading before starting the reading. According to this embodiment, the size of the document used by the user does not need to be a fixed size, and there is an advantage that it can be applied to a document that is particularly long in the transport direction.

  In the embodiment described above, the CPU displays the document transportable length on the LCD, but the display method is not limited to this. For example, the length in the main scanning direction of the document detected in the pre-scan is close to one of the standard sizes stored in the memory, and the calculated transportable length of the document is the length in the sub-scanning direction of the standard size It may be longer than this. In such a case, the CPU may display on the LCD side by side that the transportable length and the standard size are readable (for example, “A1 length or more”). This eliminates the need for a user handling a standard-size document to know the length of the read document, and facilitates confirmation.

  In the embodiment described above, the sheet feed type single function scanner has been described as an example. However, the scope of application of the present invention is not limited to this, and a printer (multifunction printer) equipped with a sheet feed type scanner is described. ) And the like.

100 scanner, 101 document feeder, 102 document feeder, 103 operation panel,
104 upper cover, 201 document, 202 document detection sensor,
203 upstream conveying roller, 204 edge detection sensor, 205 glass plate,
206 Document pressing plate, 207 Contact image sensor (CIS),
208 downstream conveyance roller, 209 image reading control unit, 301 CPU,
302 memory, 303 motor driver, 304 I / F unit, 305 A / D conversion unit,
306 Power supply unit, 307 LCD, 308 operation keys, 309 transport motor

Claims (11)

An image reading apparatus that reads an image of the document using a line sensor that extends in a second direction different from the first direction while conveying the document in the first direction,
First acquisition means for pre-scanning the leading edge of the document in the first direction by the line sensor to acquire information on the width of the document and the inclination of the document;
Calculation means for calculating a transportable length in the first direction of the document based on the acquired information;
Second acquisition means for acquiring information relating to the length of the document relating to the first direction;
An image reading apparatus comprising: control means for controlling execution of image reading of the document based on a comparison between the transportable length and the length of the document. The first acquisition means includes
Based on the information obtained by performing the pre-scan, detect the positions of both ends of the second direction in the first direction,
Calculating the length of the document in the second direction based on the positions of the both ends;
From the amount of change in the first direction of the positions of the both ends, the inclination of the original from the first direction is calculated as the inclination of the original.
The image reading apparatus according to claim 1, wherein the width of the document is calculated based on the calculated length of the document in the second direction and the inclination of the document.   The transportable length means that when the document is transported in the first direction, either of both end portions of the document can be transported without hitting the end of the document transport path in the second direction. The image reading apparatus according to claim 1, wherein the image reading apparatus has a length.   4. The image reading apparatus according to claim 1, wherein the second acquisition unit includes an input unit that allows a user to input a length of the document in the first direction. 5.   2. The second acquisition unit includes an estimation unit that estimates a length of the original in the first direction by referring to a table stored in advance using the width of the original. 4. The image reading device according to any one of items 1 to 3.   As a result of the comparison, when the transportable length is larger than the length of the original in the first direction, image reading of the original is started, and the transportable length is smaller than the length of the original in the first direction. 6. The image reading apparatus according to claim 1, further comprising a notification unit configured to notify the user whether to perform image reading or to interrupt the image reading.   The image reading apparatus according to claim 6, wherein the control unit discharges the document from a document transport path when the user instructs to interrupt the image reading.   The control unit discharges the document from the conveyance path when the user does not give an instruction to perform image reading or interruption within a predetermined threshold time. The image reading apparatus according to claim 7.   The image reading apparatus according to claim 1, wherein the line sensor is a contact image sensor. An image reading apparatus that reads an image of the document using a line sensor while conveying the document,
Means for pre-scanning the leading edge of the document by the line sensor;
And a means for notifying the user without executing the image reading when it is determined that the image reading of the document cannot be normally performed to the end based on the information obtained by the pre-scan. An image reading apparatus. A method of controlling an image reading apparatus that reads an image of the original using a line sensor while conveying the original,
Pre-scanning the leading edge of the document by the line sensor,
A control method comprising: notifying the user without executing the image reading when it is determined that the image reading of the document cannot be normally performed to the end based on the information obtained by the pre-scanning.

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