JP2775734B2 - Barcode identification method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of synthesizing barcode information when the one-dimensional image sensor is tilted by a certain degree or more with respect to a barcode, and the barcode information is fragmented. The present invention has a feature in a method of identifying a code, particularly in a preprocessing method executed in a preceding stage of the synthesis. In the present specification, the one-dimensional image sensor is referred to as a “line sensor”. [Prior Art] As a means for optically identifying a barcode, a pen-type identification device and a stationary identification device using a laser beam have been conventionally known. Further, cylindrical products such as irregular shaped bags and cans are known. In order to improve the operability in the case of the above, a so-called one-touch type identification device which operates a one-touch scanner incorporating a line sensor by hand has recently become the mainstream of the POS system. When a barcode is identified using the one-touch identification device as described above, if the scanner is operated with a tilt angle larger than a certain value with respect to the barcode, the line sensor also tilts at the same angle, so that part of the barcode is It may be out of the field of view of the line sensor. When scanning the line sensor in such a state, the barcode information obtained by the scanning becomes fragmented and the entire barcode cannot be identified, so that an alarm is issued to the operator or no response is made. Then, a re-operation is commanded. In order to minimize the hassle of re-operation, the height of the barcode has been set to be larger than a certain height,
In the case of a stationary type identification device, it can be operated in multiple directions at a time (for example, 4 directions).
(Direction) for reading. [Problems to be Solved by the Invention] Since the barcode is printed on a medium such as a price tag, the size of the medium cannot be reduced to a certain size or less according to the above-described conventional technology. There were problems such as necessity. Further, in the stationary identification device, it is necessary to operate in multiple directions at a time, and there is a problem that both hardware and software are complicated. In order to solve the above-mentioned problems, a method of combining fragmented barcode information by combining and identifying it is disclosed in Japanese Patent Application Laid-Open No. Sho 56-103768. A problem in synthesizing fragmentary barcode information is determining whether or not all pieces of read fragmentary barcode information include information on the entire barcode. Regarding the basic idea of the determination, in the above publication, the length of each piece of barcode information is, for example,
When l ₀ , l ₁ , l ₂ , l ₃ , the total length of the bar code is l, and the relative inclination angle between the scanning line and the bar code is θ, l
= Cos θ · (l ₀ + l ₁ + l ₂ + l ₃ ). However, according to such a method, it is necessary to perform a process of detecting the lengths l ₀ to l ₃ and the inclination angle θ of each bar code information before combining the bar code information. In the case of a stationary bar code identification device as disclosed in the above publication, a bar code in a stationary state is read at a constant scanning cycle, so that the interval between scanning lines (△ l). Becomes constant. Therefore, the above processing can be performed by a relatively simple calculation. On the other hand, in a type in which the scanner is manually operated, such as a one-touch identification device, the movement speed of the scanner and the line sensor incorporated therein is substantially constant during one operation (therefore, the above-mentioned interval ( There is no problem because Δl) is considered to be constant), but in the next operation, the speed is not necessarily the same as the previous speed.
Further, when the operator changes, it becomes even less constant. For this reason, in the case of the one-touch type, the method shown in the above-mentioned publication cannot be adopted. Therefore, according to the present invention, when the inclination of the line sensor with respect to the bar code is greater than a certain value and the bar code information becomes fragmented, the moving speed of the line sensor may be different between the previous operation and the next operation. Or, even if there is a difference due to the change of the operator, the pre-processing for acquiring the barcode information necessary for the composition without falling off without being affected by the difference is performed, and then the composition is performed. An object of the present invention is to provide a barcode identification method. Means for Solving the Problems In order to achieve the above object, in the method of the present invention, a barcode identification device provided with a line sensor is moved relatively to a barcode, and an image of the barcode is displayed. Is optically imaged on the line sensor, and a bar code is identified based on bar code information obtained by electrically scanning the line sensor. By comparing the amount of movement of the position of one end point and the amount of movement of the other end point on each line sensor with the bar code information obtained after the predetermined period, the magnitude relationship between the amount of movement of both end points is In some cases, the barcode information is stored as first barcode information, and the amount of movement of one end point of the barcode information obtained thereafter on the line sensor is compared with the amount of movement of the other end point. , End point shift When the amounts are equal to each other, the barcode information repeatedly obtained in each of the predetermined periods is stored as second barcode information, and further, the barcode information obtained through the predetermined period is stored on a line sensor. If the magnitude relation of the movement amounts of the two end points is opposite to the magnitude relation described above, the bar code information is
And the barcode is identified based on the first to third series of barcode information stored above. Next, the contents of the above-described invention will be specifically described with reference to the accompanying drawings. FIG. 1 is an explanatory diagram of terms in the present invention. In the present invention, the left end of the bar code 1 is represented by L, and the right end is represented by R. The line denoted by reference numeral 2 represents a scanning line of the line sensor. The inclination angle θ of the scanning line 2 may be inclined to the left (negative inclination angle) or inclined to the right (positive inclination angle) as shown in the figure. Note that when the inclination angle θ is small and the scanning line 2 reaches from the left end L to the right end R of the barcode 1 (that is, when both ends are within the field of view of the line sensor at both ends), it is not necessary to combine the barcode information. Therefore, it is not an object of the present invention. The inclination angle θ of the scanning line 2, its moving speed and the scanning cycle are
It is assumed that it is substantially constant during one operation of the line sensor. It should be noted that there is a case where one of the barcode 1 and the line sensor is stationary and the other moves, and a case where both move relatively. The present invention is applied to both cases. Also, if the scanning line interval becomes too wide due to, for example, the moving speed of the line sensor being manually operated relatively high with respect to the scanning cycle, the barcode information between the preceding barcode information and the following barcode information will be lost. There is no overlapping part, and the barcode information necessary for the composition is omitted. Therefore, in the present invention, the relationship between the relative movement speed of the line sensor with respect to the bar code and the scanning cycle of the line sensor is such that there is an overlap between the preceding bar code information and the following bar code information. It is assumed that Under the above assumption, when the inclination angle θ of the scanning line 2 is negative, the scanning line 2 extends from the upper left corner to the lower right corner of the barcode 1 as shown by a representative example of X, Y, Z. The bar code information moves at a fixed interval in parallel with the scanning direction and is scanned by X and Y scanning lines and Y and Z scanning lines. When the tilt angle θ is positive, the parallel movement is performed from the upper right corner to the lower left corner. In the figure, the intersection between the scanning line 2 and the left end L of the barcode 1 and the intersection with the right end R are denoted by reference character a, respectively.
The intersection of the upper edge and the lower edge is indicated by the symbol b.
Points a and b both indicate the end points of the barcode information detected by the line sensor. Now, the positions of the scanning lines 2 are each X by the two scans.
X and y represent the amount of movement between points a and b when moving a certain distance from X to Y 'or from Y to Y' or from Z to Z '. If the inclination angle θ is less than 45 °, x <y Therefore, the positional relationship between the barcode 1 and the scanning line 2 can be known by calculating and comparing the amount of movement of the position of each end point on the line sensor. In the following description, an endpoint having a relatively small amount of movement, such as an intersection a with the left end L or the right end R of the bar code 1, is a fixed end, and an intersection with the upper end or the lower end of the bar code 1. An end point having a relatively large movement amount, such as b, is referred to as a movement end point. Note that the inclination angle θ of the scanning line 2 is set to less than 45 °
In the case of ゜, since the movement amounts (x, y) are equal, it is not possible to determine the magnitude of the movement amount, and it is practically impossible to exceed 45 °. When the positional relationship between the barcode 1 and the scanning line 2 is specifically analyzed, there are the states shown in FIGS. 2A and 2B. (A) The figure shows the case where the tilt angle θ is negative, and the initial state.
In B _1, L is a fixed end points a, R movement end point (L = a,
R = b). In the state B _1, the typical bar code information of the bar code information obtained by at least two scans in order to obtain bar code information of the vicinity of the left end of the bar code 1 (in the figure indicated by bold lines. Hereinafter the same) The barcode information and the position information of both end points on the line sensor are read and stored for identification. As described above, one end point is a fixed end point and the other end point is a moving end point
B ₁ is referred to as a first transition state. Next, the state B ₂ from the state _{B 1 (L = b, R} = b) if a transition to, for obtaining bar code information of the central portion, by reading the position information on the line sensor of the bar code information and end points Remember. As indicated above, the state B ₂ both endpoints is moving end point is referred to as a second transition state. Further, when the state transits to the state B ₃ (L = b, R = a), in order to obtain barcode information near the right end of the barcode 1, the barcode information and the position information of both end points are read and stored. As indicated above, the first transition state opposite, referred the one end point is moving end point, a state B ₃ where the other endpoint is fixed endpoints and third transition state. Although the bar code information obtained in the third transition state B ₁ .about.B ₃ from the first is a fragmentary, cross and partially overlap, all the information from the left edge L of the bar code 1 to the right R It is included. (B) drawing a case where the inclination angle θ is positive, the sequential state changes from C ₁ to C _3. In this case, except that the direction of the inclination is different, it is the same as the case of FIG. 7B, so that it is only shown in the figure and the description is omitted. FIG. 3 shows the transition of the state (a or b) of both end points at the left end L and the right end R. S ₀ is the initial state,
S ₁ means the state in which the barcode 1 has appeared, and the state of the end points of L and R transits from the state of S ₁ according to the above case,
After passing through the first transition state B ₁ , C ₁ , the second transition state B ₂ , C ₂ and the third transition state B ₃ , C ₃ , synthesis is performed and decoding is performed. A series of processes that sequentially go through the first, second, and third transition states described above is referred to as pre-processing. Figure 4 is illustrates a concept of A Method for the synthesis of the read barcode information by scanning between the bar code 1 over the first transition state B ₁ to the third transition state B _3, X to
It indicates the position information of the read bar code information and its end points at the Z position (position information P ₀ to P ₅ on the line sensor).
Each of these barcode information and position information is stored in the storage device. In this case, the position information P ₁ of the X position is consistent with the position information P ₁ of the Y position shifted in a direction perpendicular, X
From P ₁ barcode information and Y position of the P ₀ position to P ₁
Simply combining the bar code information to P _3, the bar code information distance S as shown is lost. For this reason, the bar code information at the Y position is between P ₂ ′ (ie, the position information at the intersection of the line drawn from P _{1 at the} X position in the bar direction and the scanning line at the Y position) to P _3. and a bar code information, the need for combining the bar code information from P ₀ to P _1. Thus in the synthesis of the bar code information, the distance d on the line sensor between P ₁ and P ₂ 'in the Y position is required. This distance d is obtained as follows. That is, as shown in FIG. 5, among the plurality of scan lines in the first transition state of the aforementioned (B ₁ or C _1), the left end of the bar code information obtained by the scanning lines X ₀ the preceding (in C ₁ Indicates the position information on the line sensor at the end point (the right end point)
Assuming that the position information on the line sensor of the fixed end point a of the bar code information obtained by L ₁ and the subsequent scanning line X one cycle later is L ₂ , the distance d on both line sensors is:
L ₂ a -L _1. Now, assuming that the scanning lines at the X position and the Y position in FIG. 4 have a difference of one period, the distance d on the Y position can be obtained from L ₂ −L ₁ as described above (however, When the scanning line is thinned out, it becomes a multiple of d.). Position Y
The same applies to the distance d between P ₃ and P ₄ ′ in P and Z, so that the bar code information between P ₀ and P ₁ , P ₂ ′ and P ₃ , and P ₄ ′ and P ₅ is eventually connected. Thus, the barcode information can be combined with the complete barcode information, and the combined barcode information can be identified. Even if the moving speed of the line sensor changes from the previous operation when the next operation or the operator changes, the distance d is calculated for each operation. It is not affected by a change in the moving speed of the line sensor. The above description is based on the assumption that the moving speed of the line sensor is constant during one operation, and P ₁ and P ₂ ′ on the Y position
Both the distance between them and the distance between P ₃ and P ₄ ′ on the Z position are d = L ₂
Although a is -L _1, if the moving speed there is some variation, the above distance d determined at L ₂ -L ₁ is an approximation. [Embodiment] FIG. 6 is a block diagram of a bar code identification device having a one-touch scanner 3 and a pre-processing unit 4 for implementing a bar code identification method according to the present invention. It has a line sensor. The fragmentary barcode information read by the one-touch scanner 3 and the preprocessing unit 4 is combined in a combining unit 5, the combined barcode information is identified in a decoding unit 6, and further in a format check unit 7. It is checked whether a predetermined condition is satisfied. When a predetermined condition is satisfied, the data is sent to a required host device via the interface unit 8. In addition, for example, when the composition is not possible or the predetermined condition is not satisfied even if the composition is possible, for example, when the deformation of the medium is remarkable, the decoding unit 6 and the format check unit 7 check it, and start again from the composition. Do. FIG. 7 is a block diagram of a microcomputer for executing the functions shown in the above block diagram. Reference numeral 3 denotes a one-touch scanner, 14 denotes a CPU, 9 denotes a ROM, 10 denotes a RAM, and 11 denotes an interface. From the one-touch scanner 3, bar code information / position information 12 and a synchronization signal 13 are input to the CPU. The contents of the ROM 9 are a preprocessing algorithm, a synthesis algorithm, a barcode decoder, a format check, an interface control, and the like. The contents of the RAM 10 are an execution buffer for various programs, a read data register, and the like. FIG. 8 shows a model of the data register of the RAM 10, in which barcode information obtained by each scan from the first line to the n-th line (n is a positive integer) is stored. Generally, "LxAdd Reg" stores the position information of the leftmost black (bar) on the xth line, and "RxAdd Reg" stores the position information of the rightmost black (bar) on the xth line. Bxy stores the length of the y-th black (bar) on the x-th line, and Wxy stores the length of the y-th white (space) on the x-th line. FIG. 9 shows an example of a flowchart for barcode synthesis. First, the case of FIG. 2A (the same as the case of S ₁ → B ₁ → B ₂ → B ₃ → synthesis → decode in FIG. ₃ ) will be described in order. When a bar appears after the flow is started and initialized, the position information of the bar at the left end L and the right end R of the bar code information is stored in a predetermined position of the first line of the data register (step). In the following, the second
Similar processing is performed for the lines below the line (same as above). However, if the scanning cycle is short, unnecessary thinning may be performed (same as above) and unnecessary information may be discarded. Next, it is determined whether or not L is a fixed end point by comparing the bar code information obtained by the first scan with the movement amount of the L and R position information of the bar code information obtained after a predetermined period. (Same as above) If it is a fixed end point, the processing of L = a is performed and the flag of LF = 1 is set, indicating that the scanning has started from the left end of the bar code. Next, it is determined whether or not R is the moving end point (same as above). If R is the moving end point, processing of R = b is performed. As a result, the above-described first transition state is determined, and the barcode information at this time is read (same). The processing from the step to the step is repeated until the flag of RF = 1 (same) is set (that is, until the scanning reaches the right end of the bar code). If it is determined that L is not a fixed end point (is a moving end point) in the middle of the above-described repetition routine (same), processing of L = b (same) is performed, and it is further determined whether or not R is a moving end point. (Same) If R is the moving end point, the processing of R = b is performed. That is, it is determined that the state is the second transition state. Then, the barcode information at this time is read (same as above). Processing from step to RF is 1 (same as above)
Repeat until. Further, if it is determined that R is not a moving end point (is a fixed end point) during the above-mentioned repetition routine (same), then R =
The process (a) is performed. That is, it is determined that the state is the third transition state. Then, a flag of RF = 1 is set,
Indicates that scanning has been performed to the right end of the barcode. Next, the barcode information is read (same as above). Then, after determining whether or not LF = 1 (same as above), if LF = 1, then the position information of L and R is cleared, and LF = 0 and RF =
It returns to the initial state of 0 (the same), and shifts to the combining process (the same). When the synthesis is completed, decoding is performed (same as above), and then the process ends. If LF is not 1 in the step, the process returns to the step. When it is determined in step S that R is not the moving end point (is a fixed end point), the process of R = a (RF = 1) is performed (same), and the barcode information at that time is read (same). In this case, since it is not necessary to combine the barcode information, the position information of L and R is cleared and LF
After returning to the initial state of = 0 and RF = 0, the process proceeds to decoding. In the case of FIG. 2B, the algorithm is substantially the same, and a description thereof will be omitted. The distance d (see FIG. 5) required for the composition is
It is obtained by calculating the difference between the position information of the fixed end point a of the barcode information read by two scans in the first transition state. [Effect of the Invention] As described above, according to the present invention, when the line sensor and the barcode are relatively moved to read and identify the barcode information, the inclination angle of the line sensor is larger than a certain value. Even if the bar code information becomes fragmented, the relationship between the bar code and the scanning line is sequentially changed to three modes without using the relative inclination angle between the bar code and the scanning line and the numerical value of the interval between the scanning lines. During the transition to, the pre-processing of storing the first to third barcode information allows the information necessary for the synthesizing process to be reliably obtained without any omission, and the movement speed of the line sensor differs for each operation. Is not affected. This has the effect that the barcode can be accurately identified.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of the relationship between bar codes and scanning lines, FIGS. 2A and 2B are analysis diagrams of the relationship between bar codes and scanning lines, and FIG. Is a transition diagram of the state of both end points, FIG. 4 is a principle diagram of image information composition, FIG. 5 is a principle diagram of barcode information composition, FIG. 6 is a block diagram of a barcode identification device according to the embodiment, FIG. FIG. 7 is a block diagram of an embodiment of a microcomputer, FIG. 8 is an explanatory diagram of a data register, and FIG. 9 is a flowchart of preprocessing. 1 ... Barcode, 2 ... Scanning line, 3 ... One-touch scanner, 4 ... Preprocessing unit, 5 ... Synthesis unit.

Claims (1)

(57) [Claims] A bar code identification device having a line sensor was moved relative to the bar code, an image of the bar code was optically formed on the line sensor, and the line sensor was electrically scanned. A method of identifying a barcode based on barcode information, wherein the barcode information obtained first and the barcode information obtained after a predetermined period have the position of one end point on each line sensor. Compare the movement amount with the movement amount of the other end point,
When there is a magnitude relationship between the movement amounts of both end points, the barcode information is stored as first barcode information, and thereafter, the movement amount of one end point on the line sensor of the obtained barcode information And comparing the movement amounts of the other end points with each other, and when the movement amounts of the both end points are equal to each other, the barcode information repeatedly obtained at the predetermined cycle is stored as second barcode information, respectively. If the magnitude relationship between the movement amounts of the bar code information obtained by extending the predetermined period on the line sensor is opposite to the magnitude relationship described above, the bar code information is stored as third bar code information. A barcode identification method for identifying a barcode based on the first to third series of barcode information stored above.