JP2017107417A - Barcode reader and barcode reading method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a barcode reader and a barcode reading method which can read a barcode even when there are no beginning end and final end in one line in a main scanning direction.SOLUTION: A barcode reader includes: a character collation part 73 which extracts an element pattern from a starting end point to a read finishing point when only a start character is detected from line data and extracts an element pattern from a reading starting point to a final end point when only a stop character is detected from the line data; a tilt angle calculation part 74 which calculates a tilt angle of a barcode; a pattern collation part 75 which extracts an element pattern joined to the element pattern extracted from other line data by the character collation part 73 on the basis of a matching pattern and the tilt angle; and an element memory 72 storing element patterns by being joined.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a barcode reading apparatus and a barcode reading method for reading a barcode of a code 128 (JISX0504: 2003).

  When reading the barcode 128 of the code 128 described in the document or the like with a scanner of a copying machine or a multi-function device, depending on how the document is placed, the barcode is inclined obliquely with respect to the main scanning direction and may not be read. In view of this, a barcode recognition process that is resistant to noise has been proposed by cutting out from the input image a rectangular area having a start pattern and an end pattern corresponding to a tilted barcode (see, for example, Patent Document 1).

JP-A-6-309482

  However, the conventional technique has a problem that the barcode cannot be read when the inclination of the barcode is large and there is no start end and no end on one line in the main scanning direction. That is, as shown in FIG. 9A, when there is one line in the main scanning direction in which the inclination is small and the start and end can be read by scanning one line from the top in the main scanning direction, the start pattern In addition, it is possible to cut out a rectangular area where the end patterns are aligned and to read a barcode. On the other hand, as shown in FIG. 9B, the inclination of the bar code is large, and even if one line is scanned from the top in the main scanning direction, there is no one line in the main scanning direction in which the start end and the end exist. In this case, the start code (or the reverse order of the stop code) at the start can be read, but the end cannot be read, so the rectangular area cannot be cut out and the barcode cannot be read.

  If the inclination of the barcode is large, it is possible to read the barcode by rotating the input image. However, a memory for rotation is required, and the processing cost for the rotation processing is increased. .

  The present invention has been made in view of such a point, and the object of the present invention is to reduce the memory usage even when the inclination of the bar code is large and there is no start end and no end in one line in the main scanning direction. An object of the present invention is to provide a barcode reading apparatus and a barcode reading method capable of reading a barcode without requiring processing such as rotation, which is a lot of processing costs.

The barcode reading apparatus of the present invention is a barcode reading apparatus that reads the barcode of the code 128 written on the document, and scans the document in the sub-scanning direction by a line sensor arranged in the main scanning direction. The reading unit compares the line data read by the line sensor with the start character and stop character, and if only the start character is detected, the start point of the start character and the reading end point are specified. Then, an element pattern from the start point to the reading end point is extracted, and when only the stop character is detected, a reading start point and an end point of the stop character are specified and the reading is performed. start A character collation unit that extracts an element pattern from an edge to the end point; and an inclination angle calculation unit that calculates an inclination angle of the barcode based on the start point or the rear end point specified by the character collation unit; The character matching unit identifies a matching pattern from the line data from which the element pattern is extracted, collates other line data with the identified matching pattern based on the tilt angle, A pattern matching unit that extracts an element pattern to be connected to the extracted element pattern, an element pattern extracted by the character matching unit, and an element pattern extracted by the pattern matching unit are connected and recorded. And element memory that is to wherein there to and a decoding processing unit for executing a decoding process of the element pattern stored in the element memory.
Furthermore, in the barcode reading apparatus of the present invention, when only the start character is detected by the character verification unit, the pattern verification unit extracts the element pattern extracted by the character verification unit in other subsequent line data. The character matching unit extracts the reading start point connected to the element pattern extracted by the pattern matching unit in other subsequent line data. In particular, when an element pattern from the reading start point to the end point is extracted and only the stop character is detected by the character verification unit, the pattern verification unit In the line data, an element pattern connected to the reading start point of the element pattern extracted by the character collation unit is extracted, and the character collation unit further performs the subsequent line data by the pattern collation unit. The reading end point connected to the extracted element pattern may be specified, and an element pattern from the starting end point to the reading end point may be extracted.
Furthermore, in the barcode reading apparatus of the present invention, the inclination angle calculation unit calculates the inclination angle of the barcode based on the start point or the rear end point respectively identified by two lines having different sub-scanning directions. You may make it do.
In the barcode reading method of the present invention, a document on which a barcode of code 128 is written is scanned and read in a sub-scanning direction by a document reading unit having a line sensor arranged in the main scanning direction. A bar code reading method for reading the bar code based on the line data read by the method, wherein the character collating unit collates the line data read by the line sensor with the start character and the stop character, and only the start character is If detected, the start point of the start character and the reading end point are specified, and the element pattern from the starting point to the reading end point is extracted, and only the stop character is detected. In this case, a reading start point and an end point of the stop character are specified, and an element pattern from the reading start point to the end point is extracted, and an inclination angle calculation unit specifies the character verification unit. The barcode inclination angle is calculated based on the start point or the rear end point, and the pattern matching unit identifies the matching pattern from the line data from which the character matching unit has extracted the element pattern, and identifies the other line data. The matching pattern is collated based on the tilt angle, the element pattern connected to the element pattern extracted by the character collating unit is extracted from other line data, and the character reference is stored in the element memory. The element pattern extracted by the unit and the element pattern extracted by the pattern matching unit are concatenated and stored, and the decoding processing unit executes the decoding process of the element pattern stored in the element memory. And

  According to the present invention, even if the inclination of the bar code is large and there is no start and end in one line in the main scanning direction, if the start character and the stop character can be detected on different lines in the sub scanning direction, respectively. The bar code can be read without requiring processing such as rotation, which uses a large amount of memory and has a high processing cost.

It is a schematic model sectional drawing which shows the internal structure of embodiment of the barcode reader which concerns on this invention. It is a block diagram which shows schematic structure of the barcode reader shown in FIG. It is a flowchart explaining the barcode reading operation | movement by embodiment of the barcode reading apparatus based on this invention. It is a flowchart explaining the barcode reading operation | movement by embodiment of the barcode reading apparatus based on this invention. It is explanatory drawing explaining the barcode reading operation | movement by embodiment of the barcode reader which concerns on this invention. It is explanatory drawing explaining the barcode reading operation | movement by embodiment of the barcode reader which concerns on this invention. It is explanatory drawing explaining the barcode reading operation | movement by embodiment of the barcode reader which concerns on this invention. It is explanatory drawing explaining the barcode reading operation | movement by embodiment of the barcode reader which concerns on this invention. It is a figure which shows the example of barcode reading.

Next, embodiments of the present invention will be specifically described with reference to the drawings.
The barcode reading apparatus according to the present embodiment is an image forming apparatus 1 such as a copying machine or a multifunction machine using an electrophotographic system. Referring to FIG. 1, a document reading unit 2, a document feeding unit 3, A main body 4 and an operation unit 6 are provided. The document feeding unit 3 is disposed on the top of the document reading unit 2, and the document reading unit 2 is disposed on the top of the main body unit 4, and between the document reading unit 2 and the main body unit 4. A paper discharge space 40 is formed.

  The operation unit 6 is provided with a touch panel 61 and operation buttons 62. The user operates the operation unit 6 and inputs an instruction to perform various settings of the image forming apparatus 1 and execute various functions such as a scan operation and image formation. The touch panel 61 is configured to display the state of the image forming apparatus 1, display the image forming status and the number of copies, and perform various settings such as functions such as double-sided printing and black-and-white reversal, magnification setting, and density setting. The operation buttons 62 include a start button for instructing start of a scan operation and image formation, a stop button for instructing stop of the scan operation and image formation, and a reset button used when setting various settings of the image forming apparatus 1 to the default state. Etc. are provided.

  The document reading unit 2 includes a light source and a line sensor arranged in the main scanning direction, guides light from a light source such as an LED or a cold cathode tube lamp to the image surface of the document MS as a recording medium, and from the image surface. The scanner 21 guides the reflected light to a line sensor such as a CCD sensor, a platen glass 22, and a document reading slit 23. The scanner 21 is fixed to a toothed belt 26 spanned between the motor 24 and the pulley 25, and the image of the original MS on which the scanner 21 is placed on the platen glass 22 by driving the motor 24. It is configured to move along the plane and scan (scan) the image plane of the document MS in the sub-scanning direction. The platen glass 22 is an original table made of a transparent member such as glass. The document reading slit 23 is a slit formed in a direction orthogonal to the document transport direction by the document feeder 3.

  When reading the document MS placed on the platen glass 22, the document MS placed on the platen glass 22 is moved in one line in the main scanning direction while moving the scanner 21 along the platen glass 22 in the sub-scanning direction. Image data is acquired by scanning each time, and the acquired image data is output to the main body unit 4. When reading the document MS conveyed by the document feeding unit 3, the scanner 21 is moved to a position facing the document reading slit 23, and the document is conveyed by the document feeding unit 3 through the document reading slit 23. In synchronization with the operation, the document MS is read to acquire image data, and the acquired image data is output to the main unit 4.

  The document feeding unit 3 includes a document placement unit 31, a document discharge unit 32, and a document transport mechanism 33. The document MS placed on the document placement unit 31 is sequentially fed out one by one by the document transport mechanism 33 and is transported to a position facing the document reading slit 23, and is then discharged to the document discharge unit 32. The document feeding unit 3 is configured to be retractable and functions as a platen cover that opens and closes the platen glass 22. When the document feeding unit 3 is lifted upward and opened, the upper surface of the platen glass 22 is opened. be able to.

  The main body unit 4 includes a recording unit 5 that records on the recording paper P by an electrophotographic process, and includes a paper feed cassette 41, a paper feed roller 42, a paper transport path 43, transport rollers 44 and 45, and a discharge roller. 46. The transport rollers 44 and 45 and the discharge roller 46 function as a transport unit 47 that transports the recording paper P. The recording paper P stored in the paper feed cassette 41 is fed one by one to the paper transport path 43 by the paper feed roller 42 and transported to the recording unit 5 by the transport roller 44. The recording paper P on which recording has been performed by the recording unit 5 is discharged into the paper discharge space 40 by the transport roller 45 and the discharge roller 46.

  The recording unit 5 includes a photosensitive drum 51, a charger 52, an optical scanning unit 53, a developing unit 54, a transfer roller 55, a fixing unit 56, and a cleaning unit 57. In the image formation by the recording unit 5, first, the surface of the photosensitive drum 51 is uniformly charged by the charger 52, and based on the image data read by the document reading unit 2, the photosensitive drum 51 is read by the optical scanning unit 53. An electrostatic latent image is formed by scanning the surface. Next, the electrostatic latent image formed on the surface of the photosensitive drum 51 is developed by the developing unit 54 to form a toner image. The toner image formed on the surface of the photosensitive drum 51 is transferred to the recording paper P while the recording paper P fed from the paper feed cassette 41 passes through the nip portion between the photosensitive drum 51 and the transfer roller 55. The The toner image transferred to the recording paper P is thermally fixed to the recording paper P while passing through the fixing unit 56.

  FIG. 2 is a block diagram illustrating a schematic configuration of the image forming apparatus 1. The document reading unit 2, the document feeding unit 3, the conveyance unit 47 (conveyance rollers 44 and 45, the discharge roller 46), the recording unit 5, and the operation unit 6 are connected to the control unit 7 and controlled by the control unit 7. Is done. In addition, an image processing unit 8 and a storage unit 9 are connected to the control unit 7.

  The image processing unit 8 is a unit that performs predetermined image processing on the image data. For example, image improvement processing such as enlargement / reduction processing, gradation adjustment, and density adjustment is performed.

  The storage unit 9 is a storage unit such as a semiconductor memory or an HDD (Hard Disk Drive), and stores image data acquired by reading a document by the document reading unit 2.

  The control unit 7 is an information processing unit such as a microcomputer including a ROM (Read Only Memory) 7a, a RAM (Random Access Memory) 7b, and the like. The ROM 7a stores a control program for controlling the operation of the image forming apparatus 1. The control unit 7 reads out a control program stored in the ROM 7a and develops the control program in the RAM 7b, thereby controlling the entire apparatus according to predetermined instruction information input from the operation unit 6.

  The RAM 7 b of the control unit 7 functions as an input line memory 71 and an element memory 72. The input line memory 71 is storage means for storing image data (hereinafter referred to as line data) for at least one line in the main scanning direction read by the line sensor of the scanner 2, and is scanned by scanning in the sub scanning direction. It is updated sequentially. The element memory 72 is storage means for storing an element pattern of a barcode (hereinafter referred to as a barcode 128) of a code 128 (JISX0504: 2003). In the element memory 72, the element pattern may be stored as image data read by the line sensor of the scanner 2, or may be stored after binarization.

  The control unit 7 has a function of reading the barcode 128 included in the image data acquired by the document reading unit 2. The character verification unit 73, the inclination angle calculation unit 74, the pattern verification unit 75, and the decode processing unit 76. Function as.

  The bar code 128 includes a quiet zone (top), a start character, a data character, a symbol check character, a stop character, and a quiet zone (end). The bar and space constituting the barcode 128 are called elements. The start character, the data character, and the symbol check character represent 6 elements, and the stop character represents one character by 7 elements. The element pattern of the stop character is set in advance. The start character is selected from three preset element patterns.

The character collating unit 73 collates the line data with the element pattern of the start character and the stop character of the barcode 128 and detects the element pattern of the start character and the stop character from the line data taken into the input line memory 71. Also, the character collating unit 73 is configured to identify the boundary between the quiet zone (top) and the start character as the starting point P ₁ of the start character, end points of the stop character boundary between the stop character and quiet zone (end) P ₄ is specified.

The inclination angle calculation unit 74 calculates the inclination angle θ of the barcode 128 based on the start end point P ₁ or the end point P ₄ specified by the character verification unit 73 on the different lines in the sub-scanning direction.

  The pattern matching unit 75 specifies a matching pattern including a reading end (start) point and a reading end (start) point in the line data. Further, the pattern matching unit 75 executes matching processing for detecting the identified matching pattern from the subsequent line data based on the tilt angle θ.

  The decode processing unit 76 executes a process for decoding the element pattern stored in the element memory 72.

Next, a barcode reading operation in the image forming apparatus 1 will be described in detail with reference to FIGS.
Referring to FIG. 3, when reading of a document by the document reading unit 2 is started, the control unit 7 functions as a character collating unit 73 and takes line data into the input line memory 71 (step A1).

  The character collation unit 73 collates the line data fetched into the input line memory 71 with the element patterns of the start character and stop character, and detects the element pattern of the start character from the line data fetched into the input line memory 71. Whether or not an element pattern of a stop character is detected (steps A3 and A4).

  If the bar code 128 does not exist in the line data and neither the start character nor the stop character element pattern is detected from the line data (both No in steps A2 and A4), the character collating unit 73 returns to step A1. Then, the next line data is taken into the input line memory 71.

When the barcode 128 is not inclined with respect to the main scanning direction and both the start character and stop character element patterns are detected from the line data (when both of steps A2 and A3 are Yes), the character verification unit 73 together to identify the boundaries of the quiet zone (top) and the start character as the starting point P ₁ of the start character (step A5), to identify the boundary between the stop character and the quiet zone (end) as a termination point P ₄ of stop characters (step A6), and stores the starting point _{P 1} the entire element pattern between the end points _{P 4} in the element memory 72 (step A7). Next, the control unit 7 functions as the decoding processing unit 76, executes the decoding process of the element pattern stored in the element memory 72 (step A8), and ends the barcode reading operation.

  If the bar code 128 is tilted with respect to the main scanning direction, line data is sequentially taken in the sub-scanning direction, and the start character and stop character are collated in steps A2 to A4. Either of these will be detected.

First, as shown in FIG. 5, a case where only the element pattern of the start character is detected from the line data at the Xth line will be described.
When only the element pattern of the start character is detected from the line data of the Xth line (when step A2 is Yes and step A3 is No), the character verification unit 73 starts the start character start point in the line data of the Xth line. identifying the P ₁ (step A9).

  Next, the character collation unit 73 sets 1 to the variable n (step A10), and takes in the next line data, that is, the X + n-th line data into the input line memory 71 (step A11). Then, the character collating unit 73 collates the line data captured in the input line memory 71 with the element pattern of the stop character, and detects whether the stop character element pattern is detected from the line data captured in the input line memory 71. It is determined whether or not (step A12).

When the stop character is detected in step A12, the character collating unit 73 identifies the termination point P ₄ stop character (step A13), in step A7, the entire element pattern between start point of the end point P ₄ It is stored in the element memory 72.

  If no stop character is detected in step A12, the character collating unit 73 increments the variable n (step A14), and determines whether or not the variable n has reached a preset threshold line number N (step A15). ). If the variable n has not reached the threshold line number N in step A15, the character collation unit 73 returns to step A11 and takes the next line data, that is, the X + n-th line data into the input line memory 71, and the variable n Steps A11 to A15 are repeated until the threshold line number N is reached. Thereby, when the inclination of the barcode 128 with respect to the main scanning direction is not large, the start character and the stop character are detected from the line data between the X + 1 line and the X + N line, and the barcode 128 is read. Note that the processing in steps A11 to A15 is based on the premise that the start character is continuously detected. If no start character is detected, the process returns to step A1.

Referring to FIG. 4, if the variable n in step A15 has reached the number of threshold line N, the character collating unit 73 identifies the starting point P ₁ of the start character in the X + N line of line data (step A16).

Next, the control unit 7 functions as the slope angle calculation unit 74, a start point P ₁ in the specified X line of line data in step A9, the starting point P ₁ in the specified X + N-th line of the line data in step A16 Based on the above, the inclination angle θ of the barcode 128 is calculated (step A17).

Next, the control unit 7 functions as a pattern matching section 75, while specifying the read end point P ₂ in the X + N-th line of line data to identify a matching pattern comprising a read end point P ₂ (step A18). In X + N-th line of line data, one of the rear end of the detected elements are identified as the end point P ₂ reading. Matching patterns, a plurality of elements including a reading end point P ₂ is specified.

Then, pattern matching unit 75, the element pattern from the starting point P ₁ specified in step A16 to the reading end point P ₂ identified in step A18 is extracted as a partial element pattern, extracted partial element pattern element memory 72 (Step A19).

Next, the pattern matching unit 75 fetches the next line data into the input line memory 71 (step A20), collates the line data fetched into the input line memory 71 with the matching pattern specified in step A18, and matches the matching pattern. A matching process for detecting (reading end point P ₂ ) is executed (step A21), and it is determined whether or not a matching pattern is detected from the line data (step A22). In the matching process, a matching pattern existing in the corresponding location is detected based on the tilt angle θ calculated in step A17. Therefore, even if an element pattern similar to the matching pattern is included in the line data taken into the input line memory 71, it is not mistaken for the matching pattern.

  When the matching pattern is not detected in step A22, the pattern matching unit 75 sets the line data after the M line set in advance, that is, the line data before the matching pattern is detected as the Y line, the Y + M line. Is taken into the input line memory 71 (step A23). M is an integer of 0 or more and the threshold line number N or less.

Then, pattern matching unit 75, based on the inclination angle θ calculated in step A17, the Y + M-th line of line data, the points corresponding to the read end point P ₂ of the Y line as a read start point P ₃ Specify (step A24). The pattern matching unit 75, as shown in FIG. 6, as well as identifying the read end point P ₂ in the Y + M-th line of line data to identify a matching pattern comprising a read end point P ₂ (step A25).

Then, pattern matching unit 75, the element pattern from the read start point P ₃ specified in step A24 to the reading end point P ₂ identified in step A24 is extracted as a partial element pattern, the extracted partial element pattern, already The partial line pattern stored in the element memory 72 is connected and stored (step A26), the process returns to step A20, and the next line data is taken into the input line memory 71. In step A26, the read end point P ₂ of the partial element patterns stored previously, the reading start point P ₃ of the partial element pattern stored later is connected.

  When the matching pattern is not detected in step A22, the control unit 7 functions as the character collating unit 73, collates the line data captured in the input line memory 71 with the element pattern of the stop character, and captures the input pattern in the input line memory 71. It is determined from the line data whether or not an element pattern of the stop character is detected (step A27). If no stop character is detected in step A27, the control unit 7 functions as the pattern matching unit 75, returns to step A20, and fetches the next line data into the input line memory 71.

When the stop character is detected in step A27, the character collating unit 73, as shown in FIG. 6, the Z line of line data stop character is detected, from the read end point P ₂ specified in step A21 corresponding (step A28) as well as specifying the read start point _{P 3} to, identify the termination point _{P 4} stop character (step A29), termination point P specified in step A29 from the reading start point _{P 3} specified in step A28 The element patterns up to ₄ are extracted as partial element patterns, and the extracted partial element patterns are connected to the partial element patterns already stored in the element memory 72 and stored (step A30). In step A30, the read end point P ₂ of the partial element patterns stored previously, the reading start point P ₃ of the partial element pattern stored later is connected. As a result, all the element patterns between the start point P ₁ and the end point P ₄ of the barcode 128 of the element memory 72 are stored, and the control unit 7 functions as the decode processing unit 76, and step A 8 Thus, the decoding process of the element pattern stored in the element memory 72 is executed.

  As described above, the steps A11 to A30 have been described in the case where only the element pattern of the start character is detected from the line data at the Xth line as shown in FIG. 5. However, as shown in FIG. The same applies to the case where only the stop character element pattern is detected from the data, as described below.

Referring to FIG. 3, when only the stop character element pattern is detected from the line data of the X-th line (when step A2 is Yes and step A3 is No), the character verification unit 73 determines that the line data of the X-th line. identifying the termination point _{P 4} stop character in (step A9).

  Next, the character collation unit 73 sets 1 to the variable n (step A10), and takes in the next line data, that is, the X + n-th line data into the input line memory 71 (step A11). Then, the character collation unit 73 collates the line data captured in the input line memory 71 with the element pattern of the start character, and detects whether the element pattern of the start character is detected from the line data captured in the input line memory 71. It is determined whether or not (step A12).

If the start character is detected in step A12, the character collating unit 73 identifies the starting point _{P 1} of the start character (step A13), in step A7, all elements between the starting point _{P 1} of the termination point _{P 4} The pattern is stored in the element memory 72.

  If no start character is detected in step A12, the character collation unit 73 increments the variable n (step A14) and determines whether the variable n has reached a preset threshold line number N (step A15). ). If the variable n has not reached the threshold line number N in step A15, the character collation unit 73 returns to step A11 and takes the next line data, that is, the X + n-th line data into the input line memory 71, and the variable n Steps A11 to A15 are repeated until the threshold line number N is reached. Thereby, when the inclination of the barcode 128 with respect to the main scanning direction is not large, the start character and the stop character are detected from the line data between the X + 1 line and the X + N line, and the barcode 128 is read. Note that the processing in steps A11 to A15 is based on the premise that the stop character is continuously detected. If no stop character is detected, the process returns to step A1.

Referring to FIG. 4, if the variable n has reached the number of threshold line N in step A15, the character collating unit 73 identifies the termination point P ₄ stop character in X + N line of line data (step A16).

Next, the control unit 7 functions as the slope angle calculation unit 74, a termination point P ₄ at a particular X-line line data in step A9, termination point P ₄ in the specified X + N-th line of the line data in step A16 Based on the above, the inclination angle θ of the barcode 128 is calculated (step A17).

Next, the control unit 7 functions as a pattern matching section 75, while specifying the read start point P ₃ in the X + N-th line of line data to identify a matching pattern comprising a read start point P ₃ (step A18). In X + N-th line of line data, one of the starting end of the detected elements are identified as the starting point P ₃ read. Matching patterns, a plurality of elements including a read start point P ₃ is identified.

Then, pattern matching unit 75, a read start point P ₃ specified in step A18, the element pattern between the termination point P ₄ identified in step A16 is extracted as a partial element pattern, the extracted partial element pattern It is stored in the element memory 72 (step A19).

Next, the pattern matching unit 75 fetches the next line data into the input line memory 71 (step A20), collates the line data fetched into the input line memory 71 with the matching pattern specified in step A18, and matches the matching pattern. A matching process for detecting (reading start point P ₃ ) is executed (step A21), and it is determined whether a matching pattern is detected from the line data (step A22). In the matching process, a matching pattern existing in the corresponding location is detected based on the tilt angle θ calculated in step A17. Therefore, even if an element pattern similar to the matching pattern is included in the line data taken into the input line memory 71, it is not mistaken for the matching pattern.

  When the matching pattern is not detected in step A22, the pattern matching unit 75 sets the line data after the M line set in advance, that is, the line data before the matching pattern is detected as the Y line, the Y + M line. Is taken into the input line memory 71 (step A23). M is an integer of 0 or more and the threshold line number N or less.

Then, pattern matching unit 75, based on the inclination angle θ calculated in step A17, the Y + M-th line of line data, the points corresponding to the read start point P ₃ of the Y line as a read end point P ₂ Specify (step A24). Further, as shown in FIG. 8, the pattern matching unit 75 specifies the reading start point P ₃ in the line data of the Y + M line, and specifies a matching pattern including the reading start point P ₃ (step A25).

Then, pattern matching unit 75, the element pattern from the reading start point P ₃ identified to the reading end point P ₃ specified in step A24 is extracted as a partial element pattern in step A24, the extracted partial element pattern already elements The partial line pattern stored in the memory 72 is connected to the partial element pattern (step A26), the process returns to step A20, and the next line data is taken into the input line memory 71. In step A26, the read start point P ₃ of the partial element patterns stored previously, the reading end point P ₂ of the partial element pattern stored later is connected.

  When the matching pattern is not detected in step A22, the control unit 7 functions as the character collating unit 73, collates the line data captured in the input line memory 71 with the element pattern of the start character, and captures the input pattern in the input line memory 71. It is determined from the line data whether an element pattern of the start character is detected (step A27). If the start character is not detected in step A27, the control unit 7 functions as the pattern matching unit 75, returns to step A20, and takes the next line data into the input line memory 71.

If the start character is detected in step A27, the character collating unit 73, as shown in FIG. 8, the Z line of line data is started character is detected, corresponding to the read start point P ₃ specified in step A21 to with identifying the read end point _{P 2} (step A28), to identify the start point _{P 1} of the start character (step A29), the read end point _{P 2} identified from the beginning point _{P 1} specified in step A29 in step A28 The above element patterns are extracted as partial element patterns, and the extracted partial element patterns are connected to the partial element patterns already stored in the element memory 72 and stored (step A30). In step A30, the read start point P ₃ of the partial element patterns stored previously, the reading end point P ₂ of the partial element pattern stored later is connected. As a result, all the element patterns between the start point P ₁ and the end point P ₄ of the barcode 128 of the element memory 72 are stored, and the control unit 7 functions as the decode processing unit 76, and step A 8 Thus, the decoding process of the element pattern stored in the element memory 72 is executed.

As described above, according to the present embodiment, the image forming apparatus 1 functions as a barcode reading device that reads the barcode 128 written on the document, and the document is detected by the line sensor arranged in the main scanning direction. The original reading unit 2 that scans the MS in the sub-scanning direction and the line data read by the line sensor are compared with the start character and stop character. If only the start character is detected, the start end of the start character is detected. the point P _1, to identify the read end point P _2, extracts the element pattern from the starting point P ₁ to the reading end point P _2, when only the stop character is detected, the read start point P ₃ And the end point of the stop character ₄ and identified by the, the character collating unit 73 for extracting the element pattern from the read start point P ₃ to the end point P _4, based on the starting point P ₁ or rear end point P ₄ that is identified by the character collating unit 73 The inclination angle calculation unit 74 for calculating the inclination angle θ of the barcode 128 and the character matching unit 73 identify the matching pattern from the line data from which the element pattern is extracted, and the other line data and the identified matching pattern are used as the inclination angle. A pattern matching unit 75 for collating based on θ and extracting an element pattern connected to the element pattern extracted from the other line data by the character matching unit 73; and an element pattern extracted by the character matching unit 73 and pattern matching According to part 75 An element memory 72 connected to the extracted element pattern and a decoding processing unit 76 for executing a decoding process of the element pattern stored in the element memory 72.
With this configuration, even if the inclination of the barcode 128 is large and there is no start and end in one line in the main scanning direction, if a start character and a stop character can be detected in different lines in the sub-scanning direction, The barcode 128 can be read without requiring processing such as rotation, which uses a large amount of memory and has a high processing cost. Since the element pattern to be connected is extracted based on the matching pattern and the inclination angle θ, even if an element pattern similar to the matching pattern is included in the line data, the element to be connected is not mistaken for the matching pattern. The pattern can be extracted accurately.

Furthermore, according to the present embodiment, when only the start character is detected by the character matching unit 73, the pattern matching unit 75 reads the element pattern extracted by the character matching unit 73 in the other subsequent line data. extracts the element pattern which is connected to the end point P _2, the character collating unit 73, in other line data further subsequent, the read start point P ₃ which is connected to the element pattern extracted by the pattern matching unit 75 identify and extract the element pattern from the read start point P ₃ to the end point P _4, when only the stop character is detected by the character collating unit 73, the pattern matching unit 75, in other line data subsequent, Extracts the element pattern which is connected to the read start point P ₃ of the element pattern extracted by the character collating unit 73, the character collating unit 73, in other line data for further subsequent, extracted by pattern matching unit 75 It identifies the read end point P ₂ which is connected to the element pattern, and extracts the element pattern from the starting point P ₁ to the reading end point P _2.
With this configuration, the element pattern extraction process for extracting the element pattern can be performed for each line data, so that the capacity of the line memory for storing the line data can be suppressed.

Furthermore, according to the present embodiment, the inclination angle calculation unit 72 determines the inclination angle θ of the barcode 128 based on the start end point P ₁ or the rear end point P ₄ respectively identified by two lines different in the sub-scanning direction. Is calculated.
With this configuration, the inclination angle θ of the barcode 128 can be accurately calculated.

  Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Original reading part 3 Original feeding part 4 Main body part 5 Recording part 6 Operation part 7 Control part 8 Image processing part 9 Storage part 21 Scanner 22 Platen glass 23 Original reading slit 24 Motor 25 Pulley 26 Toothed belt 31 Document placing section 32 Document discharge section 33 Document transport mechanism 40 Paper discharge space 41 Paper feed cassette 42 Paper feed roller 43 Paper transport path 44, 45 Transport roller 46 Discharge roller 47 Transport section 51 Photosensitive drum 52 Charger 53 Optical scanning section 54 Developing section 55 Transfer roller 56 Fixing section 57 Cleaning section 61 Touch panel 62 Operation button 71 Input line memory 72 Element memory 73 Character collation section 74 Inclination angle calculation section 75 Pattern collation section 76 Decoding processing section

Claims (4)

A barcode reader for reading the barcode of code 128 written on a manuscript,
A document reading unit that scans a document in the sub-scanning direction by a line sensor arranged in the main scanning direction;
The line data read by the line sensor is compared with the start character and stop character, and when only the start character is detected, the start point of the start character and the reading end point are specified, An element pattern from a start point to the reading end point is extracted, and when only the stop character is detected, a reading start point and an end point of the stop character are specified, and A character verification unit that extracts element patterns up to the end point;
An inclination angle calculation unit that calculates an inclination angle of the barcode based on the start end point or the rear end point specified by the character verification unit;
The character collation unit identifies a matching pattern from the line data from which the element pattern is extracted, collates other line data with the identified matching pattern based on the tilt angle, and extracts from the other line data by the character collation unit A pattern matching unit that extracts an element pattern connected to the element pattern
An element memory in which the element pattern extracted by the character verification unit and the element pattern extracted by the pattern verification unit are connected and stored;
A barcode reading apparatus comprising: a decoding processing unit that performs decoding processing of an element pattern stored in the element memory. When only the start character is detected by the character collation unit, the pattern collation unit is connected to the reading end point of the element pattern extracted by the character collation unit in other subsequent line data. And the character matching unit identifies the reading start point connected to the element pattern extracted by the pattern matching unit in other subsequent line data, and the end point from the reading start point. Extract the element pattern up to the point,
When only the stop character is detected by the character verification unit, the pattern verification unit is connected to the reading start point of the element pattern extracted by the character verification unit in other subsequent line data. And the character matching unit identifies the reading end point connected to the element pattern extracted by the pattern matching unit in other subsequent line data, and ends the reading from the starting point. 2. The barcode reading apparatus according to claim 1, wherein an element pattern up to a point is extracted.   The inclination angle calculation unit calculates the inclination angle of the bar code based on the start point or the rear end point respectively specified by two different lines in the sub-scanning direction. The barcode reading apparatus described. The bar code of the barcode 128 is read by scanning in the sub-scanning direction by a document reading unit having a line sensor arranged in the main scanning direction, and the bar code based on the line data read by the line sensor. A barcode reading method for reading
The character verification unit compares the line data read by the line sensor with the start character and the stop character, and when only the start character is detected, the start point of the start character and the reading end point are specified. , Extracting an element pattern from the start point to the reading end point, and when only the stop character is detected, specifying a reading start point and an end point of the stop character, and Extract the element pattern up to the end point,
An inclination angle calculation unit calculates an inclination angle of the barcode based on the start point or the rear end point specified by the character verification unit,
The pattern matching unit identifies a matching pattern from the line data from which the character matching unit has extracted the element pattern, collates other line data with the identified matching pattern based on the tilt angle, Extract the element pattern connected to the element pattern extracted by the character verification unit,
In the element memory, the element pattern extracted by the character verification unit and the element pattern extracted by the pattern verification unit are connected and stored,
A barcode reading method characterized in that a decoding processing unit executes decoding processing of an element pattern stored in the element memory.

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