JP6869035B2 - Image reader - Google Patents

Description

The present invention relates to an image reading equipment, in particular, clogging document in the transport path by the tilt of the document, and a technique for suppressing the breakage of the document.

In a so-called sheet feed type image reading device in which a scanning sensor is fixed to scan a document, the device can be made smaller than other methods that require fixing the entire document. However, in this configuration, since the document is conveyed by using a mechanism such as a roller, the document tends to be tilted with respect to the image reading line. In particular, in the case of an image reading device compatible with a large-sized document, it is not possible to place the document on a flat table, and it is difficult to perform alignment using abutting. If the user manually inserts the document into the image reading device under such conditions, a slight inclination occurs with respect to the transport direction of the document.

If the document is inserted at an angle, the edge of the document may hit the wall of the transport path during the transfer process and be clogged or torn in the image reading device depending on the size and insertion position of the document. Therefore, conventionally, a technique for automatically detecting the inclination and position of a fed document and stopping the transfer before the end of the document hits the wall of the transfer path has been disclosed.

For example, Patent Document 1 includes a detection unit that detects the position of the tip portion of a document transported on a transport path and a detection unit that detects the skew amount of the document, and is predetermined based on the change in the tip position and the skew amount. A device having a configuration for stopping the transfer of printed matter before exceeding the transfer area is disclosed.

Japanese Unexamined Patent Publication No. 2012-206858

However, in the above-mentioned conventional example, if skew is detected in the process of transporting the document during image scanning and the image scanning is stopped, the image scanning time required up to that point is wasted and the document extraction process is difficult. There is a problem that the manuscript may be damaged. Further, when the image reading device is connected to or combined with the recording device to form a multifunction printer that performs a copying operation, if the image reading is stopped due to a paper jam of the document to be read in the copying operation, the printing operation is also performed. It will stop and the printed matter will be ejected in the middle of printing.

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

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

That is, the transport means for transporting the document in the first direction and the line sensor in which a plurality of reading elements are arranged in the second direction intersecting the first direction are provided, and the document is transported by the transport means. However, it is an image reading device that reads a document with the line sensor, and prescans the tip of the document with the line sensor while transporting the tip of the document, and the end of the document in the second direction. The first acquisition means for acquiring the first information regarding the position, the second acquisition means for acquiring the second information regarding the length of the document in the first direction, and the first information can be conveyed in the first direction of the document. A calculation means for calculating the transportable length, and if the transportable length is larger than the length in the first direction of the document, the document is started to be read, and if the transportable length is smaller than the length in the first direction of the document, the document is read. It is provided with a control means for notifying the user to decide whether to perform or interrupt.

Therefore, according to the present invention, the transportable length of a document is calculated from the inclination of the document, and the execution of image reading from the document is controlled from the comparison between the transportable length and the length of the document. Therefore, for example, the document is tilted. This has the effect of preventing the situation in which the document is damaged in advance.

It is a perspective view which shows the appearance structure of the image reading apparatus which is a typical example of this invention. It is a figure which showed the internal structure of a scanner. It is a block diagram which shows the control structure of a scanner. It is a flowchart which shows the acceptance process of the setting of the manuscript information by the user according to Example 1. FIG. It is a figure which shows an example of the screen displayed on the LCD of the operation part at the time of setting the document information. FIG. 5 is a flowchart showing a process of feeding a document inserted into a document feeding port by a user according to the first embodiment and starting image scanning. It is a flowchart which shows the detail of a paper feed operation. It is a flowchart which shows the detail of a prescan. It is a top transmission view of the scanner explaining the width and inclination in the main scanning direction obtained by prescanning a document. It is a flowchart which shows the detail of the calculation process of the transportable length of a document. FIG. 5 is a flowchart showing a process of feeding a document inserted into a document feeding port by a user according to the second embodiment and starting image scanning. It is a flowchart which shows the detail of the process of estimating the length in a transport direction based on the information of the width of a document obtained by prescan. FIG. 5 is a flowchart showing a process of feeding a document inserted into a document feeding port by a user according to the third embodiment and starting image scanning. It is a figure which shows the example of the warning message displayed on the LCD.

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

FIG. 1 is a perspective view showing an external configuration of a sheet feed type image reader (hereinafter, scanner) that optically reads an image of a document, which is a typical embodiment of the present invention.

As shown in FIG. 1, the scanner 100 has a document feeding port 101 and a document feeding table 102 on the front side of the main body. The user places the tip of the document on the original paper feed tray 102 so that the central portion of the original is located at the center of the original paper feed port 101, and slides the original on the original paper feed port 101. insert. The width of the document feeding port 101 is designed so that the width in the main scanning direction of the document that can be read by the scanner 100 can be tolerated to some extent, such as misalignment and inclination at the time of insertion. The configuration of the paper feed path of the original will be described in detail with reference to FIG.

The scanner 100 is provided with an operation panel 103 composed of physical keys, an LCD panel, and the like on the upper surface of the main body, and can set scanning conditions and input the document size. Further, an upper cover 104 is provided on the upper surface of the scanner 100, and by opening the upper cover 104, access to the reading unit and the like is possible, and maintenance of the main body can be performed.

FIG. 2 is a diagram showing the internal configuration of the scanner 100. In FIG. 2, (a) is a cross-sectional view taken along the transport direction of the document, and (b) is a top view of the scanner 100.

In FIG. 2A, the left side is the upstream side of the original paper feeding and the right side is the downstream side, and the original material is conveyed in the y-axis direction. The document 201 fed by the user along the document paper feed tray 102 is ejected from the back surface of the main body through a substantially flat transport path. The document detection sensor 202 detects the insertion of the document 201, and when the insertion of the document 201 is detected, the upstream transfer roller 203 is rotated to draw the document 201 into the transfer path. The end detection sensor 204 is used to detect the tip of the document 201 drawn into the transport path by the rotation of the upstream transport 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 rear end of the document 201, and the like. Inside the transport path, the document 201 passes between the glass plate 205 and the document pressing plate 206. The document pressing plate 206 functions to press the document 201 against the glass plate 205 with a predetermined pressure.

The contact image sensor (hereinafter, CIS) 207 arranges a plurality of reading elements in the main scanning direction (x direction in FIG. 2B in the direction perpendicular to the y direction), and the arranged reading elements arrange one line at a time. It is a line sensor that optically reads an image. The reading surface of the CIS 207 faces the glass plate 205, and the reading focal position is designed to be located on the contact surface between the document 201 and the glass plate 205. The downstream transfer roller 208 is configured to follow the upstream transfer roller 203 by a belt (not shown), and ejects the document that has passed through the area pressed against the glass plate 205 by the document pressing plate 206 to the downstream side. Have a role. The image reading control unit 209 is composed of each detection sensor, a motor for rotating the transport roller (not shown), a circuit board for controlling CIS207, 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 is composed of an LCD 307 and an operation key 308. Information on the document for image reading, scanner settings, and the like are displayed on the LCD 307 by output from the CPU 301, and the user can change the settings while checking the information displayed on the LCD 307 by operating the operation keys 308.

The transfer motor 309 is controlled from the CPU 301 via the motor driver 303 to rotate the upstream transfer roller 203 and the downstream transfer roller 208. The output from the document detection sensor 202 and the end detection sensor 204 is input to the CPU 301, and the CPU 301 determines the drive timing of the CIS 207 based on the changes in the output signals of these sensors and the state of the transfer motor 309. Determine and control.

CIS207 outputs the read image as an analog signal to the image reading control unit 209. The analog signal output from CIS207 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 a necessary voltage for each unit to supply electric power.

Next, some examples of processing when feeding a document for scanning an image of the document using the scanner having the above configuration will be described.

Here, the operation related to the document feeding of the scanner 100 will be described with reference to FIGS. 4 to 10.

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

FIG. 4 is a flowchart showing a process of accepting the setting of manuscript information by the user.

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

After the power is input, the scanner 100 stands by in a state where it can accept changes in setting information by the user (S401). The LCD 307 of the operation panel 103 displays the setting information preset in the scanner 100 (for example, the size of the document, the resolution at the time of reading, the mode such as color and monochrome).

FIG. 5A shows an example of the read setting displayed on the LCD 307. As can be seen from FIG. 5A, default setting values are preset for each of the setting items. The user changes the preset information according to the document 201 for reading the image and the purpose of the read image. The change can be made by operating the up / down / left / right direction keys and the enter key included in the operation key 308.

For example, when you want to change the size information of the document 201, select the document size item and press the enter key to switch the LCD screen, and as shown in FIG. 5 (b), "standard size" and "user input". -You will be able to select either "Automatic". When the user selects "standard size", the screen is switched again, and as shown in FIG. 5 (c), the options such as ISO standard A4 portrait, A4 landscape, A3 portrait, A3 landscape, A2 portrait, etc. are available. It is displayed and can be selected by the user. When the user selects "user input", the screen is switched again, and as shown in FIG. 5D, the length in the main scanning direction (x-axis) and the length in the sub-scanning direction (y-axis) of the document are shown. ) Input screen is displayed.

Numerical values and units can be selected for inputting the length information, and "mm", "inch", or the like can be selected as the unit. As shown in FIG. 5B, when the user selects "automatic" in selecting the document size, the size of the document 201 is automatically determined based on the information obtained by scanning the scanner 100. When the user selects any of these settings and the enter key is pressed at the end, the CPU 301 saves the setting information in a predetermined area of the memory 302 as if 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 the information that can be set by the user is updated on the setting screen including other setting information.

Subsequently, the automatic execution determination process of the reading operation started by the user inserting the document 201 into the document feeding port 101 of the scanner 100 will be described with reference to FIGS. 6 to 10.

FIG. 6 is a flowchart showing a process from feeding the document 201 inserted into the document feeding port 101 by the user to starting image scanning.

After the power is input, the scanner 100 drives the document detection sensor 202 and waits for the document 201 to be inserted (S601). When the user inserts the document 201 to be read into the document feeding port 101 of the scanner 100 centered, the tip of the document 201 crosses the optical path of the document detection sensor 202. The document detection sensor 202 is a reflective sensor, and is designed so that the light emitted from the sensor is reflected on the facing surface and does not enter the light receiving surface of the sensor again in the absence of the document 201.

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. When 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, it determines that the document 201 has been inserted and starts a paper feeding operation (S602).

The details of the paper feeding operation in S602 of FIG. 6 will be described with reference to FIG. 7.

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

In the paper feeding operation, the CPU 301 first outputs a drive signal to the motor driver 303 to rotate the transport motor 309, and the kinetic energy of the drive signal rotates the upstream transport roller 203 (S701). When the user inserts the tip of the document 201 to the nip position of the upstream transport roller 203, the upstream transport roller 203 pulls in the document 201 and transports the tip of the document to the internal transport path. Similar to the document detection sensor 202, the end detection sensor 204, which is a reflection type optical sensor, is arranged in the center of the main scanning direction (x-axis direction) in the vicinity of the transport roller 203 on the upstream side of the internal transport path. Using this, it is examined whether or not the tip end portion of the document 201 has passed the detection range of the end portion detection sensor 204 (S702).

When the CPU 301 detects a change in the output level of the end detection sensor 204, the transfer motor is set so that the tip of the document 201 is positioned at the start position for the next prescan based on the state of the transfer motor 309 at that time. Adjust the rotation of 309. Then, the rotation of the transfer motor 309 is temporarily stopped (S703). On the other hand, when the document 201 is not sufficiently inserted by the user, the transfer motor 309 is continuously rotated until the time-out time, and when the time-out (S704) is finally detected, the transfer motor 309 is rotated. Stop (S705). After that, an error is displayed on the LCD 307 of the operation panel 103 as an insertion failure of the document 201, and the user is urged to insert the document again.

The explanation will be continued by returning to FIG. 6 again. When the document 201 is normally drawn into the transport path by the paper feeding operation (S602), a prescan operation for reading the information in the tip region of the document 201 is subsequently performed (S603).

Details of the prescan in S603 of FIG. 6 will be described with reference to FIG.

FIG. 8 is a flowchart showing the details of the prescan.

In the prescan, first, the rotation of the transfer motor 309 is started in order to start the transfer of the document 201 waiting at the scanning start position (S801). Next, after rotating the transfer motor 309 by a predetermined amount, image reading by CIS207 is started (S802). Since the main purpose of the pre-scan operation is to detect the position of the edge of the document, the lighting of the LED, which is the light source of CIS207, is limited to one of red (Red), green (Green), and blue (Blue). To do.

The LED is turned on based on the control information of the transfer 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 digital signals and stores the digital signals in the memory 302.

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

The explanation will be continued by returning to FIG. 6 again.

When the prescan (S603) is completed, the image data of the tip 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 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, the information on the edge position of the document 201 analyzed and detected in each line is referred to as the document edge position information.

Here, the details of the process of calculating the transportable length of the document 201 in S604 of FIG. 6 will be described with reference to FIGS. 9 to 10.

FIG. 9 is a top transparent view of the scanner 100 for explaining the width and inclination in the main scanning direction obtained by the scanner 100 prescanning 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 the details of the process of calculating the transportable length of the document 201.

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

When the detection of the end positions for all the target regions is completed, it is determined whether or not all the detected end positions are within the transportable region in the main scanning direction (S1002). This determination is performed by comparison with a predetermined threshold value, and if the end position exceeds the threshold value on any of the lines, it is determined that the document 201 has a paper feed error (ERROR), and error processing is performed. In this case, the original document 201 is once ejected to the outside of the scanner 100, and the user inserts the original document into the original document feeding port 101 again.

On the other hand, when it is determined that all the end positions of the document 201 are within the threshold value, the amount of change in the left and right end positions with respect to the y direction in the x 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 the scanner 100 is conveyed by 1 inch is 600 lines. When the 600 line is Δy, the amount of change in the end position detected during this period in the x-axis direction is Δx. This value is moved averaged within the range in which the value was read. If the amount of change in the end position around the unit transport amount (Δy) is calculated, the inclination of the original is calculated based on the value (S1004). The inclination (θ) of the document 201 with respect to the y-axis direction is obtained by the equation (1). That is,
θ = arctan (Δx / Δy) …… (1)
Is. Here, for Δx, the larger value of the left and right sides of the document 201 is used.

Subsequently, the width of the original is calculated using the obtained original inclination (θ) (S1005). Assuming that the difference in the x-direction of the left and right document edge position information on a predetermined line is Wd, the width (Wa) of the document 201 in the actual main scanning direction is calculated by the equation (2) using the calculated inclination θ. Desired. That is,
Wa = Wd × sinθ …… (2)
Is. When the original size is set to "automatic" or the width is set to "automatic" in the "automatic" setting of the original information performed by the operation of the operation panel 103 by the user before inserting the original 201, the above processing is performed. The calculated width (Wa) value is applied.

Subsequently, in calculating the length in the sub-scanning direction (y direction) that can be conveyed until 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, either the left or right end. The unit determines whether to perform the calculation (S1006). When the left and right ends of the document 201 are parallel to each other, it is one of the ends that may exceed the transportable area in the main scanning direction due to the inclination of the document 201. If the amount of change Δx around the unit transport amount at the left end of the document 201 is less than 0 (minus), the left end is the calculation target, and if the amount of change Δx around the unit transport amount at the right end of the document 201 is greater than 0, 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 right end is calculated.

When the end of the object for which the transportable length is to be calculated is determined, the transportable length of the document 201 is calculated (S1007).

Assuming that the edge detection position of the document 201 is Xd and the main scanning direction threshold of the document transportable area is Xe, the length Lf in the sub-scanning direction in which the edge position of the document 201 does not exceed the transportable area is
When Δx> 0 on the right edge side of the paper
Lf = Δy × (Xe−Xd) / Δx …… (3)
When Δx <0 on the left edge side of the paper
Lf = Δy × (Xd-Xe) / Δx …… (4)
Can be obtained by.

Further, at both ends of the paper, when 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 document 201 is small) or the distance between Xe and Xd is large (the size of the document 201 is small), the value of Lf is high. You can see that it gets bigger.

The explanation will be continued by returning to FIG. 6 again.

When the transportable length of the document 201 is calculated, the information regarding the length of the document 201 preset by the user is analyzed to acquire the length of the document 201 (S605). The user inputs the settings related to the document 201 by the operation panel 103 before inserting the document 201, 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 a fixed form is specified for the size of the document 201 by the operation of the operation panel 103, the length information in the y-axis direction is acquired from the set fixed form size, and the value is set to Ls. When the document size is set by the user, 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 y-axis length Ls of the document size set by the user are obtained, the CPU 301 compares the two values. Thereby, it is determined whether or not all the areas of the original document 201 can be read in the current state of the original document 201 (S606). Here, when Lf> Ls, it is determined that the entire area of the document can be read because the transportable distance is larger than the actual length of the document 201. On the other hand, when 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 scanning. ..

When it is determined by the CPU 301 that the image can be read (Lf> Ls), the scanner 100 automatically starts scanning the 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 contents of the display indicate that the reading may be interrupted in the middle of reading in the current mounting state of the document 201, and the user is allowed to select either execution of scanning or reloading of the document 201. The scanner 100 waits until the user makes one of the selections (S609). Here, when the user presses the read execution (“OK” key), the scanner 100 starts reading the original. When the user chooses to reattach the document 201, the upstream transport roller 203 rotates the document 201 in the direction opposite to the normal transport direction, and the document 201 is ejected to the outside of the scanner 100 (S610). When the original document 201 is ejected, the user inserts the original document 201 into the original document feeding port 101 again, and the scanning start determination is executed according to the above-described processing.

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

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

Further, since the allowable tilt amount changes depending on the width of the document, when scanning a small size document, the allowable tilt amount is relaxed and the document does not have to be strictly inserted into the device, which is convenient for the user. Is improved.

Further, many of the seed feed type scanners insert the original by aligning the center position of the document with the center of the conveying area in the main scanning direction, but in this embodiment, the actually inserted position and the conveying direction of the original are used. The possibility of scanning the original is determined based on the length information. Therefore, there is an advantage that it is not always necessary to insert the document at the center position.

In the above-described embodiment, the calculation method for obtaining the width of the document, the inclination with respect to the transport direction, and the like has been described with reference to FIGS. 9 to 10, but the present invention is not limited thereto, and other methods may be used. A calculation method or a detection method may be applied. For example, it is also possible to use information on which pixel position of the CIS 207 first detects the edge position of the document 201 after the edge detection sensor 204 detects the tip position of the document 201 during prescan. It is possible to calculate the inclination of the document 201.

In this embodiment, the operation when the user selects the size information of the document 201 to "automatic" in the document information setting operation in the first embodiment (that is, when the input of the size information can be omitted) is described in FIGS. 11 to 12. Will be described with reference to.

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 process steps already described with reference to FIG. 6 are assigned the same step reference numbers, the description thereof will be omitted, and only the processes specific to this embodiment will be described here. ..

The width Wa of the document 201 and the inclination θ are obtained by prescanning the document 201 inserted in the scanner 100, and the process (S601 to S604) until the transferable length Lf is calculated is executed to obtain the width Wa of the document 201. And the transportable length Lf is acquired. After that, the CPU 301 estimates the length of the document 201 in the transport direction in order to determine whether or not the reading can be executed (S605').

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

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

The CPU 301 refers to the document size table held in the memory 302 (S1201). The document size table is for determining which of the standard document sizes (for example, ISO A column, B column, etc.) supported by the scanner 100 corresponds to the size of the inserted document 201. .. The table contains a threshold value set to a few percent before and after the paper width of each size, and length information in the transport 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 prescan (S1202). Based on this comparison, when it is determined that the width Wa of the document 201 is within a certain paper size threshold value, the CPU 301 determines that the attached document 201 is a paper size having that threshold value (S1203). Then, the length in the transport direction is set to the paper length Lt held in the corresponding table (S1204).

Here, the description will be continued by returning to FIG.

When the original length Lt for determination is determined, it is determined whether or not to automatically start reading the original 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, when Lf> Lt, since the length that can be conveyed is larger than the length of the document 201, it is determined that the document 201 can be read, and scanning 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 any end of the document 201 in the x-axis direction is in the main scanning direction of the scanner 100 during scanning. It is judged that there is a possibility of going out of the transportable area of. Then, a warning message is displayed (S608). Subsequent processing (S609 to S610) is as described with reference to FIG.

The automatic start determination process of the scanning operation in the document size automatic detection mode has been described above.

By the way, the information held in the memory 302 for specifying the document size is set with a numerical value having a sufficient margin for scanning the image without damaging the document as much as possible. Specifically, even if the standard size is the same, the original can be inserted into the scanner in both the vertical and horizontal directions, but with the table information so that the standard paper size with worse conditions is selected. The order of comparison is set.

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

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

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

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

FIG. 13 is a flowchart showing an operation related to document feeding of the scanner 100 according to the third embodiment. Note that, in FIG. 13, the same process steps already described with reference to FIG. 6 are assigned the same step reference numbers, the description thereof will be omitted, and only the processes specific to this embodiment will be described here. ..

Here, as in 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 in the scanner 100 is prescanned to obtain the width Wa and the inclination θ of the document 201, and the process (S601 to S604) until the transferable length Lf is calculated is executed to execute the process (S601 to S604) of the document 201. The width Wa and the transportable length Lf are acquired.

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

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

As shown in FIG. 14, as a warning message, the fact that the document is tilted and the transportable length Lf are displayed on the screen of the LCD, and a button for instructing the interruption of reading is displayed. At the same time as the warning message is displayed, the timer is started inside the CPU 301. Then, it is determined whether or not the instruction to interrupt reading is selected (S606 "), and whether or not the timer value is timed out by comparing with a predetermined threshold value (S606" ").

If there is no operation of the operation panel 103 by the user before the timer value reaches the threshold value, a time-out occurs and scanning of the document 201 is automatically started (S607). On the other hand, the user confirms the readable length displayed on the LCD 307, and if the displayed length is shorter than the actual length of the original document, the operation panel 103 is operated to select the reading interruption. If the scanning interruption is selected before the timer times out, the scanner 100 ejects the document 201 and instructs the document to be inserted again (S610).

Therefore, according to the above-described embodiment, 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 scanning simply by checking the display on the LCD. Further, when the readable length displayed on the LCD is shorter than the actual length of the original document, it is possible to interrupt the reading before starting the scanning. According to this embodiment, the size of the document used by the user does not have 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 above-described embodiment, the CPU displays the transportable length of the document on the LCD, but the display method is not limited to this. For example, the length of the document detected in the pre-scan in the main scanning direction is close to one of the standard sizes stored in the memory, and the calculated transportable length of the document is the sub-scanning length of the standard size. It may be longer than that. In such a case, the CPU may display on the LCD side by side that the transportable length and its standard size are readable (for example, "A1 vertical or higher"). As a result, the user who handles a standard-sized document does not need to know the length of the scanned document, which facilitates confirmation.

In the above-described embodiment, a sheet-feed type single-function scanner has been described as an example, but the scope of application of the present invention is not limited to this, and a printer equipped with a sheet-feed type scanner (multi-function printer). ) Etc. can also be applied.

100 scanner, 101 document paper feed port, 102 paper feed tray, 103 operation panel,
104 top cover, 201 manuscript, 202 manuscript detection sensor,
203 upstream transfer roller, 204 end detection sensor, 205 glass plate,
206 manuscript pressing plate, 207 contact image sensor (CIS),
208 Downstream transport roller, 209 image reading control unit, 301 CPU,
302 memory, 303 motor driver, 304 I / F section, 305 A / D converter,
306 power supply, 307 LCD, 308 operation keys, 309 conveyor motor

Claims (9)

A transport means for transporting the document in the first direction and
A line sensor in which a plurality of reading elements are arranged in a second direction intersecting the first direction is provided.
An image reading device that reads a document with the line sensor while transporting the document with the transporting means.
A first acquisition means for prescanning the tip of the document by the line sensor while transporting the tip of the document to acquire first information regarding the position of the edge of the document in the second direction.
A second acquisition means for acquiring the second information regarding the length of the manuscript in the first direction, and
A calculation means for calculating the transportable length of the document in the first direction from the first information, and
If the transportable length is larger than the length of the document in the first direction, the scanning of the document is started, and if the transportable length is smaller than the length of the document in the first direction, scanning is performed. An image reading device including a control means for notifying a user to determine whether to interrupt. The first acquisition means detects the positions of both ends of the document in the second direction from the image obtained by the prescan, and detects the positions of both ends of the document.
From the length of the document in the second direction based on the positions of both ends and the amount of change in the positions of both ends in the first direction, the inclination of the document from the first direction is determined by the document. Calculated as the slope of
The image reading apparatus according to claim 1, wherein the width of the original document is calculated based on the calculated length and inclination of the original document in the second direction. The image reading device according to claim 1 or 2, wherein the second acquisition means includes an input means for allowing the user to input the length of the document in the first direction. The second acquisition means acquires the width of the manuscript from the first information, and estimates the length of the manuscript in the first direction by referring to a table stored in advance using the width of the manuscript. The image reading device according to claim 1 or 2, wherein the image reading device has an estimation means for the method. The transportable length means that when the document is transported in the first direction, one of both ends of the document does not hit the end of the document transport path in the second direction. The image reading device according to any one of claims 1 to 4, wherein the image reading device is characterized by having a length. The image reading device according to any one of claims 1 to 5, wherein the control means ejects the original from the original transport path when the user instructs to interrupt the reading. .. Claims 1 to 6 are characterized in that the control means starts scanning the original if the user does not give an instruction to perform scanning or interrupting within a predetermined threshold time. The image reading device according to any one of the above. The image reading device according to any one of claims 1 to 7 , wherein the line sensor is a contact image sensor. The image reading apparatus according to any one of claims 1 to 8, wherein after the prescan, the original is conveyed in the reverse direction of the first direction to return the original to the starting position.

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