Automatic Detection Method for Paper Feeding Size

Abstract

The present invention discloses an automatic detection method for paper feed size. A plurality of marking points are marked on the paperweight and arranged along a paperweight direction different from the paper feed direction. The paperweight direction is different from a paper feed direction, and the automatic detection method for paper feed size includes the following steps: during a paper passing between the paperweight and an image sensor, controlling the image sensor to continuously sense the plurality of marking points of the paperweight to obtain a scanned image including a plurality of consecutive column images; determining a first side length of the paper based on a covering range of the plurality of marking points covered by the paper among the plurality of column images; and determining a paper size of the paper based on the first side length. The present invention senses a plurality of consecutive column images that can be combined into a scanned image during the paper passing between the paperweight and the image sensor, determines the side length of the paper based on the range of the plurality of marking points covered by the paper, and determines the paper size based on the side length. Thereby, the present invention can effectively detect the paper feed size without an additional sensor.

Description

Technical Field

[0001] The present invention relates to the automatic detection of sizes, and particularly to a method for automatically detecting the paper feed size. Background Art

[0002] In existing methods for automatically detecting the paper feed size, a paper feed size sensor is provided in a paper feeding device to sense the size of the fed paper.

[0003] The above method requires the setting of an additional paper feed size sensor, which increases the hardware cost and maintenance cost. Moreover, in the above method, the paper feed size sensor must be installed in the paper feed path to correctly sense the paper feed size, which occupies the available space of the paper feed path and increases the difficulty of hardware installation and planning.

[0004] Therefore, the existing technology for automatically detecting the paper feed size has the above problems, and there is an urgent need for a more effective solution to be proposed. Summary of the Invention

[0005] The present invention provides a method for automatically detecting the paper feed size, which can calculate the paper feed size through image analysis without the need for an additional paper feed size sensor.

[0006] In one embodiment, a method for automatically detecting the paper feed size, where a plurality of marking points are marked on a paperweight along a paperweight direction, and the paperweight direction is different from a paper feed direction. The method for automatically detecting the paper feed size includes:

[0007] Step a) During the passage of a piece of paper between the paperweight and an image sensor, controlling the image sensor to continuously sense the plurality of marking points of the paperweight to obtain a scanned image including a plurality of consecutive column images;

[0008] Step b) Determining a first side length of the paper based on a covering range of the plurality of marking points covered by the paper in the plurality of column images; and

[0009] Step c) Determining a paper size of the paper based on the first side length.

[0010] In one embodiment, step a) includes:

[0011] Step a1) When detecting that a paper feed sensor is triggered, controlling the image sensor to start sensing; and

[0012] Step a2) When detecting that a paper output sensor is triggered, controlling the image sensor to stop sensing.

[0013] In one embodiment, step a) includes:

[0014] Step a3): When it is determined that a sensing condition is satisfied, control the image sensor to start sensing; and

[0015] Step a4): When it is detected that all the marked points in the column image are out of the cover, control the image sensor to stop sensing.

[0016] In one embodiment, before step c), it further includes:

[0017] Step d): Determine a second side length of the paper based on a motor step number corresponding to the cover range;

[0018] Wherein, step c) includes:

[0019] Step c1): Select one of multiple preset sizes as the paper size of the paper based on the first side length and the second side length.

[0020] In one embodiment, step b) includes:

[0021] Step b1): During the sensing process, when the multiple marked points start to be covered and one side of the cover range is scanned, perform an immediate side length calculation process on at least one column image covering the endpoints of the side to determine the first side length of the paper.

[0022] In one embodiment, the immediate side length calculation process includes:

[0023] Step e1): Identify a number of marks of the multiple marked points between the endpoints of the side; and

[0024] Step e2): Calculate the connection length of the multiple marked points based on a mark spacing and the number of marks as the first side length.

[0025] In one embodiment, the immediate side length calculation process includes:

[0026] Step f1): Perform a coordinate positioning on the endpoints of the side to obtain the coordinates of the multiple marked points; and

[0027] Step f2): Calculate the distance between the coordinates of the endpoints as the first side length;

[0028] Wherein, the coordinate positioning includes determining a first axis coordinate corresponding to the paperweight direction based on a number of marks and a mark spacing of the multiple marked points between the endpoints.

[0029] In one embodiment, step b) includes:

[0030] Step b2): After the sensing ends, perform a post-scan side length calculation process on the cover range of the scanned image to determine the first side length of the paper.

[0031] In one embodiment, the post-scanning side length calculation process includes:

[0032] Step g1) identifying a number of markers among a plurality of marker points between the top edge or the bottom edge of the covered range; and step g2) calculating the length of the line connecting the plurality of end points based on a marker spacing and the number of markers as the first side length.

[0033] In one embodiment, the automatic detection method for the paper feed size further includes: h1) performing a coordinate positioning on a plurality of end points of the top edge or the bottom edge of the covered range to obtain the coordinates of the plurality of end points; and

[0034] Step h2) calculating the distance between the plurality of end points based on the coordinates as the first side length;

[0035] Wherein, the coordinate positioning includes determining a first axis coordinate corresponding to the paperweight direction based on a number of markers and a marker spacing among the plurality of marker points between the plurality of end points.

[0036] In one embodiment, the step d) includes:

[0037] Step d1) obtaining the motor step number of a motor of the paper feeding device during the period when the plurality of marker points are covered by the paper; and step d2) calculating the second side length based on the motor step number and a conversion ratio.

[0038] In one embodiment, the step d) includes:

[0039] Step d3) performing a coordinate positioning on a plurality of end points of any side of the covered range to obtain the coordinates of the plurality of end points; and step d4) calculating the distance between the plurality of end points based on the coordinates as the second side length;

[0040] Wherein the coordinate positioning includes determining a second axis coordinate corresponding to the paper feeding direction based on the motor step number and a conversion ratio.

[0041] In one embodiment, the automatic detection method for the paper feed size further includes:

[0042] Step i1) performing a skew detection process on the covered range of the scanned image to determine a skew angle of the paper relative to the paper feeding direction or the paperweight direction; and

[0043] Step i2) rectifying the scanned image based on the skew angle.

[0044] In one embodiment, the skew detection process includes:

[0045] Step j1) performing a coordinate positioning on a plurality of end points of the covered range to obtain the coordinates of the plurality of end points; and

[0046] Step j2) Calculate the skew angle between the connection line of the multiple endpoints and the paper feeding direction or the paperweight direction based on the coordinates.

[0047] In one embodiment, the skew detection process includes:

[0048] Step k1) Identify multiple endpoints on the top edge, bottom edge or side edge of the covered area;

[0049] Step k2) Calculate a first displacement of the multiple endpoints in the paper feeding direction and a second displacement in the paperweight direction; and step k3) Calculate the skew angle between the connection line of the multiple endpoints and the paper feeding direction or the paperweight direction based on the first displacement and the second displacement.

[0050] In one embodiment, the adjacent marking points in the paperweight direction have the same marking spacing, and the marking spacing is less than all the preset side length differences of multiple preset sizes.

[0051] In one embodiment, the multiple marking points form a dotted line.

[0052] In one embodiment, the length of the multiple marking points is greater than all the preset side lengths of multiple preset sizes.

[0053] In one embodiment, it further includes:

[0054] Step l1) Select one of multiple paper trays based on the paper size to convey a printing paper to a printing device, where the multiple paper trays respectively correspond to different preset sizes; and

[0055] Step l2) Control the printing device to print the scanned image on the printing paper.

[0056] The present invention can effectively detect the paper feeding size without an additional sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a structural diagram of an automatic scanning device according to an embodiment of the present invention;

[0058] Figure 2 It is a schematic installation diagram of a paperweight according to an embodiment of the present invention;

[0059] Figure 3 It is a schematic appearance diagram of a paperweight according to an embodiment of the present invention;

[0060] Figure 4 It is a schematic diagram of paper feeding and scanning according to an embodiment of the present invention;

[0061] Figure 5 It is a structural diagram of a processor according to an embodiment of the present invention;

[0062] Figure 6 Flow chart of the automatic detection method according to an embodiment of the present invention;

[0063] Figure 7 Flow chart of the automatic scanning according to an embodiment of the present invention;

[0064] Figure 8 Flow chart of the automatic detection method according to an embodiment of the present invention;

[0065] Figure 9 Flow chart of the size detection according to an embodiment of the present invention;

[0066] Figure 10 Flow chart of the real-time detection according to an embodiment of the present invention;

[0067] Figure 11 Flow chart of the post-scanning detection according to an embodiment of the present invention;

[0068] Figure 12 Schematic diagram of the appearance of multiple marker points according to an embodiment of the present invention;

[0069] Figure 13 Schematic diagram of the paper feeding and scanning according to an embodiment of the present invention;

[0070] Figure 14 Schematic diagram of multiple column images according to an embodiment of the present invention;

[0071] Figure 15 Schematic diagram of the image for the measurement-based size detection according to an embodiment of the present invention;

[0072] Figure 16 Schematic diagram of the image for the measurement-based skew detection according to an embodiment of the present invention;

[0073] Figure 17 Schematic diagram of the image for the coordinate-based size detection according to an embodiment of the present invention;

[0074] Figure 18 Schematic diagram of the image for the coordinate-based skew detection according to an embodiment of the present invention.

[0075] Wherein, reference numerals:

[0076] 1: Automatic scanning device;

[0077] 10: Processor;

[0078] 11: Image sensor;

[0079] 12: Paperweight;

[0080] 120: Marker;

[0081] 13: Paper feeding device;

[0082] 14: Memory;

[0083] 140: Preset size;

[0084] 141: Computer program;

[0085] 15: Paper sensor;

[0086] 150: Paper feed sensor;

[0087] 151: Paper output sensor;

[0088] 16: Human-machine interface;

[0089] 20: Printing device;

[0090] 21: Paper supply device;

[0091] 210: Paper cassette;

[0092] 30: Paper;

[0093] 40: Scanning control module;

[0094] 41: Size detection module;

[0095] 42: Skew detection module;

[0096] 43: Image correction module;

[0097] 44: Printing control module;

[0098] 50, 52 - 55: Marking lines;

[0099] 601 - 633: Column images;

[0100] 70 - 77: Endpoints;

[0101] A: Paper feed direction;

[0102] w1: Width;

[0103] h1: Length;

[0104] θ1: Skew angle;

[0105] dw1, dw2: Long side difference;

[0106] dh1, dh2: Short side difference;

[0107] X1 - X8: X-axis coordinate values;

[0108] Y1 - Y8: X-axis coordinate values;

[0109] S10 - S12: First automatic detection steps;

[0110] S20 - S23: Automatic scanning steps;

[0111] S30 - S34, S40 - S41: Detection steps;

[0112] S50 - S53: Dimension detection steps;

[0113] S60 - S65: Real - time detection steps;

[0114] S70 - S73: Detection steps after scanning. Detailed implementation manners

[0115] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the specific embodiments cited do not limit the present invention.

[0116] The present invention mainly provides an automatic scanning device and an automatic detection method for the paper feeding size thereof. A plurality of marking points are arranged on the paperweight, so that when the paper passes between the image sensor and the paperweight, some of the marking points are covered, and the paper size can be determined by performing image analysis on the covered range.

[0117] Please refer to Figure 1 , which is a structural diagram of the automatic scanning device according to an embodiment of the present invention. The automatic scanning device 1 of the present invention mainly includes an image sensor 11, an automatic paper feeding module, and a processor 10.

[0118] The automatic paper feeding module is used to feed in and feed out the paper, and may include a paperweight 12 and a paper feeding device 13. The paperweight 12 is used to flatten the paper to be scanned (its weight and the gap size between it and the image sensor 11 can be determined according to the supported paper size and paper thickness), so that the image sensor 11 can be flat against the paper for scanning, thereby improving the quality of the scanned image. The paper feeding device 13, such as a combination of a motor (such as a stepping motor), a gear set, and a paper feeding roller, is used to transport the paper to be scanned from a starting point (such as a feeding paper tray) to between the image sensor 11 and the paperweight 12 for scanning, and transport the scanned paper to a destination (such as a feeding - out paper tray).

[0119] The image sensor 11, such as a CCD image sensor, a CMOS image sensor, or other contact image sensors (CIS, Contact Image Sensor), obtains a corresponding scanned image by photographing the paper.

[0120] In an embodiment, the area of the sensing region of the image sensor 11 is smaller than the area of the paper.

[0121] In one embodiment, the width of the sensing area of the image sensor 11 is greater than the width of the paper (the minimum side length), and the length of the sensing area is less than the length of the paper (the maximum side length). Specifically, in order to obtain a complete scanned image, the image sensor 11 obtains a plurality of column images by scanning different columns of the paper, and then stitches the plurality of column images into a complete scanned image.

[0122] The processor 10, such as an MCU, CPU, SoC, DSP, FPGA or other programmable processor, is electrically connected to the image sensor 11 and the automatic paper feeding module, and is used to control the automatic scanning device. In the present invention, the processor 10 can perform paper size detection on the image captured by the image sensor 11 to determine the paper size of the fed paper.

[0123] In one embodiment, the automatic scanning device 1 may include a memory 14 electrically connected to the processor 10, such as a RAM, ROM, EEPROM, flash memory, other memory, or any combination thereof, for storing data.

[0124] In one embodiment, the memory 14 may pre-store a plurality of preset sizes 140. The foregoing plurality of preset sizes 140 are the paper sizes supported by the automatic scanning device 1, such as recognizable paper sizes and / or scannable paper sizes.

[0125] In one embodiment, the automatic scanning device 1 may include a paper sensor 15 electrically connected to the processor 10, such as a photoelectric sensor or a shielding sensor, which is used to be disposed on the paper feeding path (such as at the start point and / or the end point of the paper feeding path) to sense whether the paper is fed in and / or fed out.

[0126] In one embodiment, the automatic scanning device 1 may include a human-machine interface 16 electrically connected to the processor 10, such as an indicator light, a buzzer, a button group, a display, a touch screen, or any combination thereof. The human-machine interface 22 is used to receive user operations and provide information.

[0127] In one embodiment, the automatic scanning device 1 may further include a network interface (not shown in the figure, such as Bluetooth, Wi-Fi, wired Ethernet, or other network interfaces). The network interface is used to connect to an external computer (such as a server or a user's computer device) through a network, so that the automatic scanning device 1 can accept the control of the external computer or perform data transmission, such as transmitting the scanned image to the external computer.

[0128] In one embodiment, the automatic scanning device 1 has copying and printing functions, and may include a paper feeding device 20 and a printing device 21 electrically connected to the processor 10. The paper feeding device 20 may include one or more paper trays 210, and each paper tray 210 is respectively used to provide printing paper conforming to different preset sizes 140 to the printing device 20 for printing. The printing device 20, such as an inkjet printing module or a laser toner printing module, etc., is used to print on the printing paper.

[0129] In one embodiment, when copying, the automatic scanning device 1 can select the paper tray 210 corresponding to the size to provide printing paper based on the paper size detected during scanning, and print the scanned image proportionally on the printing paper through the printing device 20.

[0130] Please refer to Figures 2 to 4 , Figure 2 , which is a schematic installation diagram of a paperweight according to an embodiment of the present invention, Figure 3 , which is a schematic external view of a paperweight according to an embodiment of the present invention, Figure 4 , which is a schematic diagram of paper feeding and scanning according to an embodiment of the present invention.

[0131] As Figure 2 shown, the automatic paper feeding device (including the paperweight 12) can be arranged in a copier or other devices with paper feeding requirements.

[0132] In this embodiment, the paperweight 12 can be arranged above the image sensor 11, and a plurality of marking points 120 ( Figure 3 taking equally spaced dotted lines as an example) are arranged along the direction of the paperweight. The aforementioned paperweight direction is different from the paper feeding direction ( Figure 4 taking the paperweight direction perpendicular to the paper feeding direction as an example).

[0133] As Figure 4 shown, the image sensor 11 can perform image sensing on the plurality of marking points 120 of the paperweight 12 from bottom to top, but this is not limited thereto, and the orientations of the image sensor 11 and the paperweight 12 can be arbitrarily changed according to requirements. When the paper 30 passes between the image sensor 11 and the paperweight 12, some of the marking points 120 will be covered, so that in the captured column images and the scanned image including these column images (such as Figures 15 - 18 ), the ranges where the plurality of marking points 120 are covered at different scanning timings can be clearly identified. The present invention detects the paper size of the paper 30 by analyzing the above-mentioned covered ranges.

[0134] Please refer to Figure 12 , which is a schematic external view of a plurality of marking points according to an embodiment of the present invention. The plurality of marking points 120 arranged on the paperweight 12 can form one or more parallel marking lines (such as straight lines or dotted lines). And when there are multiple marking lines at the same time, the types of these marking lines can be the same or different.

[0135] Figure 12 Four types of marking lines 50, 52 - 55 are shown, which can provide different recognition accuracies respectively.

[0136] The marking line 50 is an equidistant dotted line, and each marking point is a single point. Any two adjacent marking points in the direction of the paperweight have the same marking interval.

[0137] The marking line 52 is an equidistant dotted line, but each marking point is a line segment. Any two adjacent marking points in the direction of the paperweight have the same line segment length. The marking line 53 is an equidistant dotted line similar to the marking line 50, but the marking interval of the marking line 53 (such as 0.5 mm) is smaller than the marking interval of the marking line 50 (such as 1 mm), and can provide higher accuracy.

[0138] The marking line 54 is a non - equidistant dotted line, and each marking point is a single point, but has two different marking intervals (such as 1 mm and 2 mm).

[0139] The marking line 55 is an equidistant dotted line, but includes two different types of marking points (single points and line segments respectively).

[0140] In one embodiment, the foregoing marking interval and line segment length can be adjusted based on the preset size to be recognized and the required accuracy.

[0141] In one embodiment, various preset sizes include multiple preset side lengths (such as preset length and preset width), and the smallest marking interval is less than the difference between all preset side lengths of all preset sizes.

[0142] For example, if the preset sizes are A4 (210 mm * 297 mm) and B4 (250 mm * 353 mm), the marking interval is at least less than the difference of 40 mm between the smallest side lengths of the two sizes so as to be able to distinguish between the two lengths of 210 mm and 250 mm by the difference in the number of covered marking points.

[0143] In one embodiment, the marking interval can be directly set to less than 5 mm (such as 1 mm) to provide extremely high detection accuracy.

[0144] In one embodiment, the length of the marking line composed of multiple marking points can be greater than all preset side lengths of all preset sizes, so as to avoid the scanning paper completely covering the marking line and making it impossible to detect the covered range.

[0145] It is worth mentioning that the foregoing four marking lines 50, 52 - 55 are only used to illustrate some embodiments of the present invention and do not limit the available types of marking lines. The present invention can also be implemented by other types of marking lines, such as different marking point configurations, different marking interval configurations, different marking length configurations, or any combination of the above.

[0146] Please refer to Figure 5 which is an architecture diagram of a processor according to an embodiment of the present invention. In one embodiment, the processor 10 may include modules 40-44, and these modules 40-44 are respectively configured to implement different functions.

[0147] The scan control module 40 is used to control the image sensor 11 to perform image sensing.

[0148] The size detection module 41 is used to detect the size of the paper to be scanned.

[0149] The skew detection module 42 is used to detect the skew angle of the paper to be scanned.

[0150] The image correction module 43 is used to correct the scanned image based on the skew angle.

[0151] The print control module 44 is used to control the paper feeding device 21 and the printing device 20 to perform printing.

[0152] The foregoing modules 40-44 are interconnected (which may be electrically connected and information-connected), and may be hardware modules (such as electronic circuit modules, integrated circuit modules, SoC, etc.), software modules (such as firmware, operating system, or application programs), or a mixture of software and hardware modules, without limitation.

[0153] It is worth mentioning that when the foregoing modules 40-44 are software modules (such as firmware, operating system, or application programs), the memory 14 may include a non-volatile computer-readable recording medium (not shown in the figure), and the foregoing non-volatile computer-readable recording medium stores a computer program 141. The computer program 141 records computer-executable program codes. After the processor 10 executes the foregoing program codes, the functions corresponding to the modules 40-44 can be implemented.

[0154] Please refer to Figure 6 which is a flowchart of an automatic detection method according to an embodiment of the present invention. The automatic detection methods of the embodiments of the present invention can be implemented by the automatic scanning device 1 of any embodiment.

[0155] After the paper to be scanned is fed in, the automatic detection method of the present invention starts to be executed.

[0156] Step S10: During the period when the paper fed in passes between the paper weight 12 and the image sensor 11, the processor 10 controls the image sensor 11 to continuously sense multiple marker points of the paper weight 12 through the scan control module 40, so as to obtain a plurality of consecutive column images. The foregoing plurality of column images can be combined into a scanned image of the paper.

[0157] Simultaneously with or after executing step S10, the processor 10 executes steps S11-S12.

[0158] Step S11: The processor 10 identifies, via the size detection module 41, the covering range of a plurality of marked points 120 covered by the fed paper among the plurality of column images, and determines the first side length of the paper based on the covering range.

[0159] In one embodiment, the processor 10 can identify the number of marks of a plurality of marked points 120 covered by multiple endpoints of the paper (such as the two endpoints of the top edge) in the paperweight direction, and estimate the first side length corresponding to the paper in the paperweight direction based on the mark spacing and the number of marks of the marked points 120.

[0160] In one embodiment, the processor 10 can perform positioning processing on the endpoints of the top edge or the bottom edge of the paper based on the positions of the plurality of marked points 120 covered by the paper to determine the coordinates of the two endpoints, and calculate the first side length of the top edge or the bottom edge based on the coordinates of the two endpoints.

[0161] Step S12: The processor 10 determines the paper size of the fed paper via the size detection module 41 based on the determined first side length.

[0162]

[0163] Table 1

[0164] For example, please refer to Table 1, which is a preset size table (the length unit is mm) of an embodiment of the present invention. In this embodiment, the automatic scanning device 1 can identify the above 6 preset sizes.

[0165] Since the above 6 preset sizes have different preset side lengths, when the automatic scanning device 1 detects the first side length of the fed paper, it can determine which preset size the fed paper belongs to.

[0166] For example, if the first side length is 210 mm, it is determined that the fed paper belongs to the preset size A4; if the first side length is 176 mm, it is determined that the fed paper belongs to the preset size B6; if the first side length is 215 mm, and there is no matching preset side length, the closest preset size Letter (219.5 mm) can be selected as the detection result, and so on.

[0167] Therefore, the present invention can effectively detect the paper feed size using an existing image sensor for scanning, without the need to additionally set up a paper size sensor.

[0168] Please refer to Figure 6 and Figure 7 refer to Figure 7 , which is a flowchart of automatic scanning of an embodiment of the present invention. Compared with Figure 6 the automatic detection method of Figure 7The automatic detection method further includes steps S20 - S23 for implementing automatic paper feeding detection.

[0169] Step S20: The processor 10 detects whether there is paper being fed in through the scanning control module 40.

[0170] In one embodiment, when the processor 10 determines that the preset sensing condition is satisfied, it controls the image sensor 11 to start sensing (i.e., start scanning the fed paper).

[0171] In one embodiment, the aforementioned sensing condition can be that the paper sensor 15 is triggered, a scanning command (or scanning operation) is received, the paper feeding device 13 is pushed by paper, etc., but is not limited thereto.

[0172] If paper feeding is detected, step S21 is executed; otherwise, step S20 is executed again to continuously detect.

[0173] Step S21: The processor 10 controls the paper feeding device 13 through the scanning control module 40 to continuously feed the paper so that the paper is first transported between the image sensor 11 and the paperweight 12 and then sent to the output paper tray. At the same time, it controls the image sensor 11 to capture the paper passing through the sensing area to obtain consecutive column images of consecutive blocks of the paper, and these column images can be stitched into a scanned image of the paper. The coordination between the shooting frequency of the image sensor 11 and the paper feeding speed of the paper feeding device 13 is prior art in the field of automatic paper feeding scanning technology and will not be elaborated here.

[0174] Step S22: The processor 10 detects through the scanning control module 40 whether the paper has been fed out, such as when the paper has completely passed through the image sensor 11 and reached the output paper tray.

[0175] In one embodiment, when the paper sensor 15 is triggered again, a completion command (or completion operation) is received, or no paper is captured in the column images, the processor 10 determines that the paper has been fed out.

[0176] In one embodiment, after starting the scan, the processor 10 immediately detects whether all the marking points of the continuously captured column images are covered, and determines that the paper has been fed out when all the marking points of the same column image are out of the cover (or all the marking points of several consecutive column images are out of the cover).

[0177] Please refer back to Figure 4 , in one embodiment, the paper sensor 15 includes a paper - in sensor 150 and a paper - out sensor 151. In the paper feeding path, the paper sequentially passes through the paper - in sensor 150, the image sensor 11, and the paper - out sensor 151. Thus, the processor 10 can determine the start of paper feeding when the paper - in sensor 150 is triggered, and determine the completion of paper feeding when the paper - out sensor 151 is triggered.

[0178] If it is detected that the paper feeding is completed, step S23 is executed; otherwise, continue scanning and execute step S22 again to continuously detect.

[0179] Step S23: The processor 10 controls the paper feeding device 13 to stop through the scanning control module 40, and at the same time controls the image sensor 11 to stop sensing.

[0180] Thus, the present invention can achieve automatic detection of paper feeding and feeding out.

[0181] Please refer to Figures 6 to 8 , Figure 8 which is a flowchart of the automatic detection method of an embodiment of the present invention. Compared with the automatic detection method of Figure 6 , in the automatic detection method of Figure 8 , two sets of side lengths of the paper are obtained to more accurately detect the corresponding predicted size (steps S30 - S34).

[0182] Steps S30 - S31 are first executed to obtain the first side length of the paper corresponding to the paper weight direction. Steps S30 - S31 are the same as or similar to the foregoing steps S10 - S11, and will not be elaborated herein.

[0183] Step S32: After the paper is scanned, the processor 10 determines the second side length of the paper corresponding to the paper feeding direction through the size detection module 41.

[0184] In one embodiment, the processor 10 can identify the covered range in the scanned image, and calculate the second side length based on the length of the covered range in the paper feeding direction.

[0185] In one embodiment, during the period when the paper covers multiple marking points 120 (during scanning), the processor 10 can obtain the number of motor steps of the stepping motor of the paper feeding device 13 (which can be obtained through an encoder), such as the number of motor steps during the period from when the paper enters the sensing area of the image sensor 11 to when it leaves the sensing area. Then, the processor 10 can calculate the second side length based on the number of motor steps and the conversion ratio, such as multiplying the number of motor steps by the conversion ratio (such as the actual distance of the conveyed paper corresponding to each step of the motor) to obtain the length of the covered range in the paper feeding direction, and calculate the second side length accordingly.

[0186] In one embodiment, after identifying multiple end points (such as two end points) on either side of the covered range, the processor 10 can perform coordinate positioning on the two end points to obtain the coordinates of these two marking points, and calculate the distance between the coordinates of these two marking points as the second side length.

[0187] In one embodiment, the foregoing coordinates may include a first axis coordinate corresponding to the direction of the paperweight, and a second axis coordinate corresponding to the paper feed direction. For example, taking the X-Y coordinate system as an example, the first axis may be set as the X axis, and the second axis may be set as the Y axis, but it is not limited thereto.

[0188] In one embodiment, the present invention may set the first axis as the Y axis and the second axis as the X axis.

[0189] In one embodiment, in the foregoing coordinate positioning, the present invention may calculate the first axis coordinate based on the number of marks of multiple mark points between multiple end points (i.e., the number of marks spanned by multiple end points) and a preset mark spacing. Taking 400 mark points and a mark spacing of 1 mm as an example, if the end point is located at the 5th mark point, its first axis coordinate may be 5, and if the end point is located at the 297th mark point, its first axis coordinate may be 297, and so on.

[0190] In one embodiment, in the foregoing coordinate positioning, the present invention may calculate the second axis coordinate based on the motor step number and a conversion ratio. Taking a conversion ratio of 0.5 mm / step as an example, if the end point is captured at the 10th step of the motor step number, its second axis coordinate may be 5 (10 * 0.5), and if the end point is captured at the 490th step of the motor step number, its second axis coordinate may be 245 (490 * 0.5), and so on.

[0191] Thus, the present invention can determine the coordinates of all end points of the covered area in the above manner. And, after obtaining the coordinate positions of all end points, the present invention may perform image processing (such as rotation, correction, adjustment of image parameters, etc.) on the region of interest of the scanned image. The foregoing region of interest is the range surrounded by all end points, that is, the range of the paper image.

[0192] Step S33: The processor 10 determines the paper size of the fed paper based on the determined first side length and second side length through the size detection module 41.

[0193] Step S34: The processor 10 sets the size of the scanned image to the detected paper size through the scan control module 40.

[0194] Thus, when subsequently opening or printing the scanned image, the correct paper size can be used to open or print the scanned image.

[0195] In one embodiment, the processor 10 may select the preset size that most conforms to the preset side length (such as the length error is less than 10%) from multiple preset sizes based on the first side length and the second side length as the paper size.

[0196] The present invention can detect more preset sizes by simultaneously determining the preset size corresponding to the scanned paper based on the first side length and the second side length.

[0197] Please also refer to Figures 6 to 9 , Figure 9 which is a flowchart of size detection for an embodiment of the present invention. Compared with the embodiments of Figure 6 and Figure 8 , in the embodiment of Figure 9 the steps S12 / S33 of the automatic detection method further include steps S50 - S53 for implementing multi - size detection.

[0198] Step S50: The processor 10 compares the obtained side lengths (the first side length and / or the second side length) with all the preset side lengths of all the supported preset sizes one by one through the size detection module 41.

[0199] Step S51: The processor 10 determines through the size detection module 41 whether the obtained side lengths conform to the preset side lengths of any preset size, and can further determine whether the obtained other side length (if any) conforms to the other preset side length of any preset size, so as to determine whether it conforms to any preset size.

[0200] If it conforms to any preset size, then execute step S52: The processor 10 determines through the size detection module 41 that the paper size is the conforming preset size.

[0201] If it does not conform to all the preset sizes, then execute step S53: The processor 10 controls the human - machine interface 16 to issue a size - unrecognizable warning through the size detection module 41 or select the closest preset size as the paper size.

[0202] In an embodiment, considering the paper production error, when there is no conforming preset size and the gap between each obtained side length and the corresponding preset side length is less than 10%, the processor 10 selects the closest preset size as the paper size. When the gap between each obtained side length and the corresponding preset side length is not less than 10%, the processor 10 directly issues a size - unrecognizable warning.

[0203]

[0204] Table 2

[0205] For example, please refer to Table 2, which is a preset size table (the length unit is mm) for an embodiment of the present invention. In this embodiment, the automatic scanning device 1 can recognize the above 12 preset sizes. And, between some preset sizes, there is a same set of preset side lengths. For example, the short side of A3 is the same as the long side of A4, and the short side of B4 is the same as the long side of B5. The above situation makes it impossible to correctly detect the corresponding preset size only by obtaining the first side length of the paper.

[0206] In response to this, the present invention adds the detection of a second dimension. Since the above 12 preset dimensions have different combinations of preset side lengths, when the automatic scanning device 1 detects the first side length and the second side length of the fed paper, it can determine which combination of preset side lengths the fed paper belongs to and determine the corresponding preset dimension.

[0207] For example, if the obtained side lengths are 148mm * 210mm, it is determined that the fed paper belongs to the preset size A5; if the obtained side lengths are 125mm * 176mm, it is determined that the fed paper belongs to the preset size B6; if the obtained side lengths are 255mm * 355mm, in the case of no matching preset side lengths, the closest preset size Legal (261mm * 356mm) can be selected as the detection result, and so on.

[0208] Please refer back to Figure 8 , Figure 8 The automatic detection method further provides a skew detection function (steps S40 - S41), which can detect the skew angle of the paper and automatically correct the scanned image accordingly.

[0209] Step S40: The processor 10 performs skew detection processing on the covered range of the scanned image through the skew detection module 42 to determine the skew angle of the paper relative to the paper feeding direction or the paperweight direction.

[0210] In one embodiment, the aforementioned skew detection processing includes: performing coordinate positioning based on the number of marked points between multiple endpoints (such as two, three, or four) of the covered range to obtain the coordinates of these endpoints; calculating the skew angle between the connection line of these endpoints and the paper feeding direction or the paperweight direction based on the coordinates of these endpoints.

[0211] In one embodiment, the aforementioned skew detection processing includes: identifying multiple endpoints (such as two endpoints) of the top edge, bottom edge, or side edge of the covered range; calculating the first displacement of the multiple endpoints in the paper feeding direction and the second displacement in the paperweight direction; calculating the skew angle between the connection line of two marked points and the paper feeding direction or the paperweight direction based on the first displacement and the second displacement through trigonometric functions. The aforementioned first displacement can be calculated based on the number of marked points and the marked spacing between multiple endpoints, and the aforementioned second displacement can be calculated based on the difference in the number of motor steps between multiple endpoints and the conversion ratio.

[0212] Step S41: The processor 10 rotates the scanned image based on the detected skew angle through the image correction module 43.

[0213] In one embodiment, the automatic detection method further provides a copying function, and can print out the scanned image in proportion. Specifically, after determining the paper size and righting the scanned image, the processor 10 can select one of the plurality of paper trays 210 (such as selecting a paper tray 210 that matches the size) through the print control module 44 to convey the printing paper to the printing device 20, and control the printing device 20 to print the scanned image on the printing paper in proportion according to the paper size.

[0214] Please refer to Figures 6 to 10 , Figure 10 which is a flowchart of real-time detection of an embodiment of the present invention. In the Figure 10 automatic detection method of, the size of the column images obtained by scanning is detected in real time to determine the first side length and the second side length of the paper (steps S60 - S64) for determining the corresponding preset size (such as Figure 9 ), and the skew angle of the paper can be determined in real time (step S65).

[0215] Step S60: The processor 10 controls the image sensor 11 to start sensing (scanning) through the scanning control module 40 to start obtaining column images.

[0216] Step S61: During the sensing process, the processor 10 determines whether the paper enters the sensing area (such as multiple marking points start to be covered) through the size detection module 41, and determines whether the first side (the side parallel or nearly parallel to the paperweight direction) of the paper (the covered area) is scanned completely (such as the number of covered marking points reaches the maximum)

[0217] If the paper enters the sensing area and the first side is scanned completely, step S62 is executed; otherwise, continue scanning and execute step S61 again to continue detection.

[0218] Step S62: The processor 10 performs real-time side length calculation processing on a column image (without skew) or multiple column images (with skew) covering the two end points of this first side through the size detection module 41 to determine the first side length of the paper. The specific calculation method of the first side length can be as described above, and will not be elaborated here.

[0219] Step S63: The processor 10 determines whether the paper exits the sensing area through the size detection module 41, such as all marking points are out of the cover of the paper.

[0220] If the paper exits the sensing area, step S64 is executed; otherwise, continue scanning and execute step S63 again to continue detection.

[0221] Step S64: After the sensing is completed, the processor 10 can obtain the corresponding motor step number through the scanning control module 40, and calculate the second side length of the paper based on this.

[0222] In one embodiment, skew detection may be further performed on the paper, such as performing step S65: The processor 10 locates multiple corners of the paper (such as two adjacent corners, three corners, or all four corners) through the skew detection module 42, and calculates the skew angle.

[0223] Please refer to Figures 13 to 18 , Figure 14 , which is a schematic diagram of multiple column images of an embodiment of the present invention, Figure 15 , which is a schematic diagram of an image of measurement-based size detection of an embodiment of the present invention, Figure 16 , which is a schematic diagram of an image of measurement-based skew detection of an embodiment of the present invention, Figure 17 , which is a schematic diagram of an image of coordinate-based size detection of an embodiment of the present invention, Figure 18 , which is a schematic diagram of an image of coordinate-based skew detection of an embodiment of the present invention.

[0224] As Figure 13 shown, the paper feeding direction is A, and there is a marking line 50 arranged along the paperweight direction on the paperweight 12. The marking line 50 is composed of multiple marking points.

[0225] As Figure 14 shown, during scanning, different parts of the paper 30 sequentially pass through the sensing area, and the image sensor 11 can continuously sense to sequentially obtain column images 601 - 633 taken at different time sequences.

[0226] For example, taking 30 steps of the motor stepping number as an example, at step 1, the column image 601 marking points (the marking points are not covered) are taken, at step 2, the column image 602 is taken (some marking points start to be covered), at step 3, the column image 603 is taken (some marking points are covered), …, at step 28, the column image 628 is taken (some marking points are covered), at step 29, the column image 629 is taken (the marking points are out of the cover), and at step 30, the column image 630 is taken (the marking points are not covered).

[0227] Since the scanned image is obtained through continuous sensing, multiple marking points of the marking line 50 will be presented in the form of vertical lines in the scanned image after continuous sensing, which makes the scanned image composed of the column images 601 - 633 be as Figures 15 - 18 shown.

[0228] Please also refer to Figure 14 and Figure 15 , when the column image 602 is taken, since some marking points are covered, it can be determined that the paper enters the sensing area, and the distance between two marking points at both ends of the first side of the covered range can be calculated to obtain the first side length w1.

[0229] When the column image 629 is captured, since all the marker points are out of the covering, it can be determined that the paper has left the sensing area. Then, the second side length h1 can be calculated based on the number of motor steps between the column image 602 and the column image 628.

[0230] Thus, the present invention can instantly detect the side lengths of the paper.

[0231] Please also refer to Figure 14 and Figure 16 Taking the case where the paper has a skew angle θ1 as an example, after obtaining the column image 602 (step 2) and the column image 603 (step 3), the two end points of the first side can be identified, and the vertical difference dh1 (through the difference in the number of motor steps) and the horizontal difference dw1 (through the number of markers between the two end points) of these two end points can be calculated. And after obtaining the column image 629 and the column image 630, the two end points of the second side can be identified, and the vertical difference dh2 and the horizontal difference dw2 of the two end points can be calculated.

[0232] Then, the skew angle θ1 can be calculated based on the vertical difference dh1 and the horizontal difference dw1 through trigonometric functions as follows.

[0233]

[0234] Alternatively, the skew angle θ1 can be calculated based on the vertical difference dh2 and the horizontal difference dw2 through trigonometric functions as follows.

[0235]

[0236] After obtaining the skew angle θ1, the first side length w1 and the second side length h1 can be calculated through the following formula.

[0237]

[0238] Please also refer to Figure 14 and Figure 17 Taking coordinate positioning as an example, during the scanning process, when the column images 602 and 628 are captured, the four end points 70 - 73 of the covering range can be identified in the column images 602 and 629, and coordinate positioning is performed on these four end points to obtain the corresponding coordinates (X1, Y1), (X2, Y2), (X3, Y3), (X4, Y4).

[0239] Then, the distance between the end point 70 and the end point 71 or the distance between the end point 72 and the end point 73 can be directly calculated based on the coordinates as the first side length, and the distance between the end point 70 and the end point 72 or the distance between the end point 71 and the end point 73 can be calculated based on the coordinates as the second side length.

[0240] Please also refer to Figure 14 and Figure 18, taking the case where the paper has a skew angle θ1 as an example, the four endpoints 74-77 closest to the covered range can be respectively identified in the column images 602, 603, 629, and 630, and coordinate positioning is performed on these four endpoints 74-77 to obtain the corresponding coordinates (X5, Y5), (X6, Y6), (X7, Y7), and (X8, Y8).

[0241] Next, the distance between endpoint 74 and endpoint 75 or the distance between endpoint 76 and endpoint 77 can be directly calculated based on the coordinates as the first side length, and the distance between endpoint 74 and endpoint 76 or the distance between endpoint 75 and endpoint 77 can be calculated based on the coordinates as the second side length. And the skew angle θ1 can be calculated according to the coordinates in combination with the foregoing trigonometric function operations.

[0242] Please refer to Figures 6 to 11 , Figure 11 , which is a flowchart of post-scan detection for an embodiment of the present invention. In the Figure 11 automatic detection method, after the scanning is completed and all column images are stitched into a scanned image, size detection is performed to determine the first side length and the second side length of the paper (steps S70-S24) for determining the corresponding preset size (such as Figure 9 ), and the skew angle of the paper can be determined (step S73).

[0243] Step S70: After the scanning is completed, the processor 10 sequentially combines a plurality of column images (such as Figure 14 ) into a scanned image (such as Figure 15 ) through the scan control module 40.

[0244] Step S71: The processor 10 identifies the covered area of the paper (i.e., the range of the shadow paper) by whether the scanned image is covered by a plurality of marker points through the size detection module 41.

[0245] Step S72: The processor 10 performs post-scan side length calculation processing on the covered range of the scanned image through the size detection module 41 to determine the first side length and the second side length of the paper.

[0246] In one embodiment, the processor 10 can calculate the connection length between two endpoints based on the number of markers between a plurality of endpoints on the top or bottom edge of the covered range as the first side length, or calculate the second side length based on the number of motor steps corresponding to a plurality of endpoints on the side edge of the covered range.

[0247] In one embodiment, the processor 10 can perform coordinate positioning on a plurality of endpoints on the top, side, or bottom edge of the covered range to obtain the coordinates of the plurality of endpoints, and use the distance between the coordinates of the plurality of endpoints as the first side length (top or bottom edge) or the second side length (side edge).

[0248] In one embodiment, skew detection may be further performed on the paper, such as performing step S73: the processor 10 calculates the skew angle of the covered area through the size detection module 41.

[0249] Please refer to Figure 13 and Figures 15 to 18 . As Figure 15 shown, the processor 10 can identify the four endpoints of the covered range in the scanned image (such as the four marked points closest to the four endpoints), and calculate the first side length w2 and the second side length h2 based on the number of marks spanned by the four endpoints and the motor step number.

[0250] As Figure 16 shown, taking the case where the paper has a skew angle θ1 as an example, the processor 10 can identify the four endpoints of the covered range in the scanned image, and calculate the vertical difference dh1 or dh2 and the horizontal difference dw1 or dw2 based on the number of marks spanned by the four endpoints and the motor step number, and calculate the skew angle θ1, the first side length w1 and the second side length h1 through trigonometric functions.

[0251] As Figure 17 shown, taking coordinate positioning as an example, after the scanning is completed, the processor 10 can identify the four endpoints 70-73 of the covered range in the scanned image, and position these marked points to obtain the corresponding coordinates (X1, Y1), (X2, Y2), (X3, Y3), (X4, Y4).

[0252] Next, the distance between endpoint 70 and endpoint 71 or the distance between endpoint 71 and endpoint 73 can be directly calculated based on the coordinates as the first side length, and the distance between endpoint 70 and endpoint 72 or the distance between endpoint 71 and endpoint 73 can be calculated based on the coordinates as the second side length.

[0253] As Figure 18 shown, taking the case where the paper has a skew angle θ1 as an example, the four endpoints 74-77 of the covered range can be identified in the scanned image, and coordinate positioning is performed on endpoints 74-77 to obtain the corresponding coordinates (X5, Y5), (X6, Y6), (X7, Y7), (X9, Y8).

[0254] Next, the distance between endpoint 74 and endpoint 75 or the distance between endpoint 75 and endpoint 76 can be directly calculated based on the coordinates as the first side length, and the distance between endpoint 74 and endpoint 76 or the distance between endpoint 75 and endpoint 77 can be calculated based on the coordinates as the second side length. Moreover, the skew angle θ1 can be calculated based on the coordinates in combination with the foregoing trigonometric operations.

[0255] Thereby, regardless of whether the paper is skewed, the present invention can accurately calculate the first side length and the second side length of the paper and accurately detect the paper size.

[0256] The above-described embodiments are merely preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art of this technology on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. An automatic detection method for paper feed size, characterized in that, A paperweight has multiple single points marked thereon along the direction of the paperweight, and this paperweight direction is different from a paper feeding direction. The automatic detection method for the paper size includes: Step a): During a sheet of paper passing between the paperweight and an image sensor, control the image sensor to continuously sense the multiple marked points of the paperweight to obtain a scanned image including a plurality of consecutive column images, wherein the distance between any two adjacent marked points among the multiple marked points is the same; Step b): Based on a covered range of the paper covering the multiple marked points among the multiple column images, determine a first side length of the paper, wherein the first side length is the side length of the side of the paper relative to the paperweight direction; and Step c): Based on the first side length, determine a paper size of the paper.

2. The automatic detection method for paper feed size according to claim 1, characterized in that, This step a) includes: Step a1): When detecting that a paper feeding sensor is triggered, control the image sensor to start sensing; and Step a2): When detecting that a paper discharging sensor is triggered, control the image sensor to stop sensing.

3. The automatic detection method for paper feed size according to claim 1, wherein This step a) includes: Step a3): When determining that a sensing condition is satisfied, control the image sensor to start sensing; and Step a4): When detecting that all the marked points of the column image are out of cover, control the image sensor to stop sensing.

4. The automatic detection method for paper feed size according to claim 1, wherein, Before this step c), it further includes: Step d): Based on a motor step number corresponding to the covered range, determine a second side length of the paper; Wherein, this step c) includes: Step c1): Based on the first side length and the second side length, select one of multiple preset sizes as the paper size of the paper.

5. The automatic detection method for paper feed size according to claim 4, wherein, This step b) includes: Step b1): During the sensing process, when the multiple marked points start to be covered and one side of the covered range is scanned, determine the first side length of the paper according to at least one column image covering the endpoints of this side.

6. The automatic detection method for paper feed size according to claim 5, wherein, This step b1) includes the following steps: Step e1): Identify a marked number of the multiple marked points between the endpoints of this side; and Step e2): Based on the marked distance and the marked number, calculate the connection length of the multiple endpoints as the first side length.

7. The automatic detection method for paper feed size according to claim 5, characterized in that, This step b1) includes the following steps: Step f1): Perform a coordinate positioning on the multiple endpoints of this side to obtain the coordinates of the multiple endpoints; and Step f2): Calculate the distance between the coordinates of the multiple endpoints as the first side length; Wherein, the coordinate positioning includes determining a first axis coordinate corresponding to the paperweight direction based on a marked number of the multiple marked points between the multiple endpoints and the marked distance.

8. The automatic detection method for paper feed size according to claim 4, characterized in that, This step b) includes: Step b2): After the sensing ends, perform a post-scanning side length calculation process on the covered range of the scanned image to determine the first side length of the paper.

9. The automatic detection method for paper feed size according to claim 8, wherein, This post-scanning side length calculation process includes: Step g1): Identify a marked number of the multiple marked points between the endpoints of the top side or the bottom side of the covered range; and Step g2): Based on the marked distance and the marked number, calculate the connection length of the multiple endpoints as the first side length.

10. The automatic detection method for paper feed size as described in claim 8, wherein, It further includes: Step h1) Perform a coordinate positioning on multiple endpoints of the top or bottom edge of the covered range to obtain the coordinates of the multiple endpoints; and Step h2) Calculate the distances between the multiple endpoints based on the coordinates as the first side length; wherein the coordinate positioning includes determining a first axis coordinate corresponding to the paperweight direction based on a number of markers and a marker spacing between the multiple markers among the multiple endpoints.

11. The automatic detection method for paper feeding size according to claim 4, characterized in that, Step d) includes: Step d1) Obtain the motor step number of a motor of a paper feeding device during the period when the multiple markers are covered by the paper; and Step d2) Calculate the second side length based on the motor step number and a conversion ratio.

12. The automatic detection method for paper feeding size according to claim 4, characterized in that Step d) includes: Step d3) Perform a coordinate positioning on multiple endpoints of any side of the covered range to obtain the coordinates of the multiple endpoints; and Step d4) Calculate the distances between the multiple endpoints based on the coordinates as the second side length; wherein the coordinate positioning includes determining a second axis coordinate corresponding to the paper feeding direction based on the motor step number and a conversion ratio.

13. The automatic detection method for paper feeding size as described in claim 1, characterized in that, It further includes: Step i1) Perform a skew detection process on the covered range of the scanned image to determine a skew angle of the paper relative to the paper feeding direction or the paperweight direction; and Step i2) Rectify the scanned image based on the skew angle.

14. The automatic detection method for paper feed size according to claim 13, wherein The skew detection process includes: Step j1) Perform a coordinate positioning on multiple endpoints of the covered range to obtain the coordinates of the multiple endpoints; and Step j2) Calculate the skew angle between the connection line of the multiple endpoints and the paper feeding direction or the paperweight direction based on the coordinates.

15. The automatic detection method for paper feed size according to claim 13, characterized in that, The skew detection process includes: Step k1) Identify multiple endpoints of the top edge, bottom edge or side edge of the covered range; Step k2) Calculate a first displacement of the multiple endpoints in the paper feeding direction and a second displacement in the paperweight direction; and Step k3) Calculate the skew angle between the connection line of the multiple endpoints and the paper feeding direction or the paperweight direction based on the first displacement and the second displacement.

16. The automatic detection method for paper feed size according to claim 1, wherein The markers adjacent in the paperweight direction have the same marker spacing, and the marker spacing is less than all preset side length differences of multiple preset sizes.

17. The automatic detection method for paper feed size according to claim 1, characterized in that, The multiple markers form a dotted line.

18. The automatic detection method for paper feed size according to claim 1, wherein, The length of the multiple markers is greater than all preset side lengths of multiple preset sizes.

19. The automatic paper feed size detection method according to claim 1, wherein It further includes: Step l1) Select one of multiple paper trays based on the paper size to convey a printing paper to a printing device, wherein the multiple paper trays respectively correspond to different preset sizes; and Step l2) Control the printing device to print the scanned image on the printing paper.

Images