JP4862845B2 - IC tag position detection device, IC tag position detection method, and IC tag label printer - Google Patents

Description

  The present invention relates to an IC tag position detection device, an IC tag position detection method, and an IC tag label printer, and more particularly to a technique for detecting the position of an IC tag.

  In recent years, IC tags having a short-range wireless communication function using RFID (Radio Frequency Identification) technology have been widely used. In particular, the use of IC tags is being promoted in various systems such as logistics in the supply chain, and is expected to spread in the future due to global standardization and revision of the domestic radio wave law. Many of the logistics system IC tags are expected to use label-type IC tags (IC tag labels) that are low in molding costs. In general, surface printing and IC tag labels are used and used for IC tag labels. An IC tag label printer capable of reading and writing is required. IC tag label printers have already been put into practical use.

  When printing on an IC tag label, paper labels in which a number of IC tag labels are arranged in a line at regular intervals are run in a certain direction, and printed on the surface of the IC tag by an IC tag label printer (hereinafter also referred to as a printer). The method of performing is adopted. Conventionally, when printing is performed in a printer, the position of the IC tag label is detected by the number of rotations of the servo or the end position of the label using a print mark attached to the end of the IC tag label and capable of sensor detection. It is controlled by.

  However, in the method of detecting the position of the IC tag label based on the number of rotations of the servo, the roller of the printer is worn as the number of times of printing increases, and the accuracy of the paper feed width per servo rotation is deteriorated. If an error occurs in the paper feed width, the exact IC tag label position cannot be specified unless the value of the paper feed width per servo rotation or servo rotation is adjusted. In addition, in the method of attaching a print mark that can be detected by the sensor to the end of the IC tag label and detecting the end position of the IC tag label by the sensor, if the print mark becomes dirty, the sensor cannot be detected accurately, and the device resistance to the dirt is increased. Weakness becomes a problem. In addition, the printing cost of the IC tag label increases due to the work of attaching the print mark in advance.

  Patent Document 1 describes a method of detecting the position of each IC tag using the wireless communication function of the IC tag. In the technique of the patent document, the intensity of the electromagnetic wave generated by the antenna of the IC tag is detected by an IC tag reader / writer, the IC tag is positioned in the XY direction based on the detected intensity, and the IC tag is detected at that position. And the IC tag reader / writer.

Patent Document 2 describes a positioning method when writing from a IC tag reader / writer to a plurality of IC tags mounted on a mount. In this patent document, a method is adopted in which the IC tag reader / writer is used to determine whether or not data can be read from the IC tag and to perform positioning at the time of writing while back-feeding the mount on which the IC tag is mounted. To do. When communication from the IC tag becomes possible, the back feed is stopped and desired information is written to the IC tag. Then, after transporting to a predetermined printing position by the mount, printing is performed on the IC tag label.
JP 2007-164426 A JP 2006-272844 A

  In Patent Documents 1 and 2, an electromagnetic wave from an IC tag reaches the IC tag reader / writer, or a position where communication is possible, or a position where the intensity of the electromagnetic wave is maximum, between the IC tag and the IC tag reader / writer. It is described that communication is performed. However, these patent documents do not describe a problem related to positioning of the print position of the IC tag. When issuing an IC tag label, not only the positioning of the IC tag label in writing by the IC tag reader / writer but also the accurate positioning of the printing position on the IC tag label is an important problem. IC tag label positioning based only on the intensity of electromagnetic waves using the technology described in the above-mentioned patent document does not provide the exact center position of the IC tag label, and the IC tag positioning enables accurate positioning of the print position on the IC tag label. No IC tag label printer having a function has been known.

  In view of the problem of positioning of the conventional IC tag label, the present invention can be suitably used when printing on an IC tag label, and an IC tag positioning method and apparatus capable of accurately positioning the print position of the IC tag, and An object of the present invention is to provide an IC tag label printer having such an IC tag positioning device.

In order to achieve the above object, the present invention provides a method for detecting the position of an IC tag having a short-range wireless communication function and being conveyed in a predetermined direction.
A first step of measuring a first signal intensity transmitted by the IC tag at a first servo position near the tip of the IC tag;
A second step of measuring a second signal intensity transmitted by the IC tag at a second servo position near the rear end of the IC tag;
Estimating a center position of the IC tag from the first and second servo positions;
A third step of measuring the central signal intensity transmitted by the IC tag, using the estimated center position of the IC tag as the servo position of the IC tag;
A fourth step of calculating a center signal strength at a center position of the IC tag based on the first and second servo positions and the first and second signal strengths;
The calculated center signal intensity is compared with the estimated center signal intensity, and it is determined whether or not to adopt the estimated center position of the IC tag as the determined center position based on the comparison result. And an IC tag position detection method characterized by comprising:

Further, the present invention provides a method for detecting a position of an IC tag having a short-range wireless communication function and being conveyed in a predetermined direction.
A first step of measuring a first signal intensity transmitted by the IC tag at an arbitrary servo position;
A second step of referring to a table associating the servo position of the IC tag and the signal intensity at the servo position, and estimating the position of the IC tag that transmits the first signal intensity as the first servo position;
A second servo position is selected in association with the estimated first servo position, and a second signal intensity transmitted from the IC tag at the second servo position is estimated with reference to the table. Steps,
A fourth step of measuring a second signal intensity transmitted by the IC tag at the second servo position;
The estimated first or second servo position is determined by comparing the measured second signal strength with the estimated second signal strength. And a fifth step of determining whether or not to employ the IC tag position detecting method.

Furthermore, the present invention provides an IC tag position detection device that detects the position of an IC tag having a short-range wireless communication function.
Servo means for conveying the IC tag in a predetermined direction and outputting the servo position of the IC tag;
A signal strength acquisition unit for measuring the signal strength transmitted by the IC tag;
The first and second servo positions measured by the signal intensity acquisition unit at the first servo position near the front end of the IC tag, the second servo position near the rear end of the IC tag, and the first and second servo positions, respectively. An arithmetic unit that calculates the signal strength of the center position of the IC tag based on the signal strength of 2;
Estimating means for estimating a center position of the IC tag based on the first servo position and the second servo position;
The signal intensity of the IC tag measured by the signal intensity acquisition unit at the center position estimated by the estimation means is compared with the signal intensity calculated by the arithmetic device, and the estimated center is based on the comparison result An IC tag position detection apparatus comprising: a determination unit that determines whether or not to determine a position as a center position of an IC tag.

Furthermore, the present invention provides an IC tag position detection device that detects the position of an IC tag having a short-range wireless communication function.
Servo means for conveying the IC tag in a predetermined direction and outputting the servo position of the IC tag;
A signal strength acquisition unit for measuring the signal strength transmitted by the IC tag;
A table reference means for referring to a table in which a servo position of an IC tag and a signal intensity at the servo position are associated with each other, wherein the table is obtained from a first signal intensity measured by the signal intensity acquisition unit at an arbitrary servo position. The position of the IC tag is estimated as the first servo position with reference to FIG. 2, the second servo position is selected in association with the estimated first servo position, and the IC tag transmits at the second servo position. Table reference means for estimating the second signal strength;
By comparing the second signal strength measured by the signal strength acquisition unit at the second servo position with the second signal strength estimated by the table reference means, the estimated first servo There is provided an IC tag position detection apparatus comprising: a determination unit that determines whether or not to adopt a position as a confirmed first servo position.

  Furthermore, the present invention provides an IC tag label printer comprising the IC tag position detection device.

  According to the IC tag position detection device, IC tag position detection method, and IC tag label printer of the present invention, by detecting the position of each IC tag, or by detecting the position of the IC tag at regular intervals, The influence of the error of the IC tag label position caused by the abrasion of the roller in the prior art can be suppressed, and the position of the IC tag label can be specified without being affected by the dirt of the IC tag label.

  In addition, according to the IC tag label printer of the present invention, since the IC tag label can be accurately positioned, printing can be performed at an accurate position, and the cost of issuing the IC tag label can be reduced.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic block diagram showing a state of printing on an IC tag label by an IC tag label printer (printer) according to the first embodiment of the present invention. The printer 10 controls an IC tag reader / writer 14 that communicates with the IC tag label 11 via the antenna 13, a roll 15 that transports the mount 12 on which the IC tag labels 11 are arranged at regular intervals, and the rotation of the roll 15. It has a servo 16 and an IC tag label position controller 17 that detects the position of the IC tag label via the IC tag reader / writer 14 and controls the position of the IC tag label via the servo 16.

  The mount 12 is arranged so that the IC tag label 11 always passes through a predetermined position in the printer 10. The center of the antenna 13 is arranged below the center of the IC tag label 11 passing therethrough in the vertical direction. Further, the vertical separation distance between the antenna 13 and the IC tag label 11 arranged on the mount 12 is kept constant. Note that the direction of the antenna 13, the transport direction of the mount 12, and the direction of the IC tag label 11 may or may not be parallel.

  FIG. 2 shows a functional block diagram of the IC tag label position control unit 17 of FIG. 1 together with the IC tag reader / writer 14 and the servo 16. The IC tag label position control unit 17 includes an IC tag reader / writer control unit 18, a signal strength acquisition unit 19, a label position conversion unit 20, a servo position acquisition unit 21, and a servo control unit 22. FIG. 3 shows a functional block diagram of the label position conversion unit 20 shown in FIG. 2 together with the signal strength acquisition unit 19 and the servo position acquisition unit 21. The label position conversion unit 20 includes an IC tag center position specifying function 23, an IC tag label position management function 24, and a servo position management function 25.

  2, the IC tag reader / writer control unit 18 has a function of controlling the IC tag reader / writer 14 and executing communication with the IC tag label 11 at a predetermined timing. The signal strength acquisition unit 19 has a function of measuring the signal strength position of the wireless signal transmitted from the IC tag from the wireless signal of the IC tag reader / writer 14. The label position conversion unit 20 has a function of calculating the position of the IC tag label from the signal intensity and managing the servo position based on the calculation result. The servo position acquisition unit 21 acquires the current servo position from the servo control unit 22 and gives the current servo position to the label position conversion unit, and also controls the servo control unit 22 based on an instruction from the label position conversion unit 20 to control the servo. 16 is operated to control the position of the IC tag label.

  FIG. 3 is a functional block diagram of the label position conversion unit 20. The label position conversion unit 20 has a function 23 for specifying the center position of the IC tag, a position management function 24 for the IC tag label, and a servo position management function 25. The IC tag center position specifying function 23 transmits / receives data to / from the signal intensity acquisition unit 19 and determines the center position of the IC tag label 11 from the signal intensity acquired from the IC tag reader / writer 14 and the servo position. Next, the average signal strength at the central position is managed. The IC tag label position specifying function 24 manages a corresponding list of servo positions at the center position determined for each IC tag label. The servo position management function 25 transmits / receives data to / from the servo position acquisition unit 21, manages the servo position (rotation speed) with an eigenvalue, and controls the servo operation.

  The IC tag center position specifying function 23 receives the signal intensity at the point where the IC tag reader / writer in the IC tag label can communicate with the specific IC tag for the first time, the signal intensity immediately before communication is disabled from the signal intensity acquisition unit 19. To get. Then, the center position of the IC tag is identified by comparing the center signal intensity at the center position of the IC tag obtained from the calculation formula inversely proportional to the cube of the distance with the actually measured signal intensity, and the relative position to the antenna. Detect by setting the positional relationship. The center signal strength of the IC tag label is the average signal strength Ave. S is held inside. The signal strength when determining the center position of the IC tag label is the average signal strength Ave. of the plurality of IC tag labels in addition to the element of the average signal strength that is the theoretical value calculated from the calculation formula. S. For example, the center position of the first IC tag label is specified by a theoretical value, and the second and subsequent IC tag center positions are specified by elements of a theoretical value and an actual measurement value.

  FIG. 4 is a flowchart showing processing of the IC tag label printer of FIG. The IC tag label position controller 17 slides the IC tag label via the servo 16 (step A1), and determines the servo position (L1) and signal strength (S1) at which the signal can be read via the IC tag reader / writer 14. Obtain and store (step A2). Next, the servo 16 is rotated at a constant value to try to acquire the signal intensity (step A3). If the signal intensity can be acquired (step A4), the process returns to step A3, the servo 16 is rotated again by a constant value, and the processes of steps A3 and A4 are repeated as long as the signal intensity can be acquired. In step A4, the repetition of the rotation operation is stopped at the point where the signal intensity cannot be acquired, and the servo position (L2) and the signal intensity (S2) at which the signal intensity was finally acquired are acquired (step A5).

  Next, the servo position (L ') corresponding to the middle of L1 and L2 is determined from the values of S1 and S2 (step A6). Next, the signal strength at the servo position L ′ corresponding to the intermediate position between the servo positions L1 and L2 is calculated from the values of the signal strengths S1 and S2 (step A7). The calculation uses the relationship that the signal strength is inversely proportional to the cube of the distance from the antenna. This relationship may be held in a table. Next, the signal strength (S3) at the servo position L 'is acquired by the IC tag reader / writer (step A8). It is checked whether or not the values of S ′ and S3 match within an assumed error range (step A9). If they match, the process proceeds to step A10, and when the servo position is at L ′, IC It is determined that the center position of the IC tag label 11 is at the center position of the antenna 13 in the tag label printer 10, and the corresponding IC tag position in the IC tag label printer is determined (step A10). In step A9, if they do not match within the assumed error range, the process returns to step A3, and steps A3 to A9 are repeated.

  In this embodiment, the RFID tag function is used to detect the position of an IC tag label that has been detected only by the rotation of a conventional sensor or servo, thereby causing contamination of the IC tag label, misalignment of mark printing, and roller wear on the servo surface. Since the recognition error of the IC tag position that occurs can be complemented, it is possible to provide an IC tag label printer that can issue a large number of IC tags with high accuracy. Further, although the position of the IC tag label is specified by the rotation of the servo, the center position is corrected for each IC tag, so that errors due to servo wear can be suppressed. Furthermore, by eliminating the need for a sensor for identifying the position of the IC tag label and the mark on the IC tag label, it is possible to provide an IC tag label printer that realizes a reduction in device scale and cost.

  In particular, the present embodiment employs a mechanism for specifying the center position of the IC tag label by calculation regardless of the type of the set IC tag label. Therefore, even if the type of the IC tag label set in the IC tag label printer is unknown, there is an advantage that the center position of the IC tag label can be determined.

  An IC tag label printer according to a second embodiment of the present invention will be described. The configuration of the IC tag label printer of this embodiment is the same as that of the IC tag label printer of the first embodiment shown in FIGS. A label position conversion unit 30 is used instead of the label position conversion unit 20. FIG. 5 is a functional block diagram of the label position conversion unit 30. The label position conversion unit 30 includes an IC tag position specifying function 31, an IC tag label position management function 32, a servo position management function 33, a table data collation function 34, and a table data management function 35.

  The IC tag position specifying function 31 determines the position of the IC tag label from the comparison result of the signal intensity and the servo position. The IC tag label position management function 32 manages a correspondence list between the current position and the servo position for each IC tag label. The servo position management function 33 manages the servo position (rotation speed) with an eigenvalue. The table data collation function 34 collates the servo position corresponding to the signal strength. The table data management function 35 performs a process of reading a table of the set IC tag label type, and stores a table in which the relationship between the signal intensity and the servo position, which differs for each IC tag label type, is stored.

  The label position conversion unit 30 calculates the relative positional relationship between the IC tag reader / writer 14 and the IC tag label 11 from the signal intensity acquired from the IC tag reader / writer 14, and manages the position of the IC tag label in the IC tag label printer 10. In addition, it has a function of referring to, collating and calculating table data, and a function of transmitting / receiving data to / from the signal strength acquisition unit 19 and servo position acquisition unit 21. The table data includes data in which the signal intensity read by the IC tag reader / writer is associated with the relative positions of the IC tag reader / writer 14 and the IC tag label 11. In this embodiment, for each type of IC tag label corresponding to the IC tag label printer 10, table data having the signal intensity when read by the IC tag reader / writer 14 of the IC tag label printer and the read servo position value are prepared in advance. To do. Thereafter, the type of the IC tag label set in the IC tag label printer is set, and the position of the IC tag label is specified by comparing the signal intensity when the IC tag label is read with the value in the table.

  The processing in the IC tag label printer of the second embodiment will be described in detail with reference to the flowchart of FIG. First, the type of the IC tag label set in the IC tag label printer is set in the IC tag label printer (step A11). Next, the table data designated by the type of the IC tag level is read (step A12). Next, the signal strength (S1) is acquired from the IC tag reader / writer 14 at an arbitrary IC tag label position, and collated with the signal strength in the already read table data (step A13). If the matching signal strength does not exist in the table data as a result of the collation, the process returns to step A13, and the signal strength (S1) is reacquired at an arbitrary IC tag label position. Steps A13 and A14 are repeated until corresponding data is found. If only one matching signal strength is found as a result of the collation in step A14, the process proceeds to step A15, and if there are a plurality of signal intensities, the process proceeds to step A17. This is because if the matching signal strength is one, the IC tag position can be determined as it is, but if there are two or more matching signal strengths, the servo position cannot be determined as it is. This is because it is necessary to further check the signal strength.

  In step A17, the servo is operated so that the servo position (L2) is a predetermined distance away from each servo position (L1) corresponding to a plurality of signal intensities existing in the table data. At the servo position, the signal strength (S2) is acquired using an IC tag reader / writer. Next, the acquired signal strength is compared with the signal strength at the servo position in the table data corresponding to the servo position (L2). It is determined whether or not only one of the signal intensities found in step A14 can be specified as the signal intensity that satisfies the relationship between L1 and S1 and L2 and S2 (step A18). If only one signal intensity can be specified, the process proceeds to step A19, where it is determined that the IC tag reader / writer and the IC tag label are in the relative positions in the table data obtained by comparing L1 and L2. Thus, the corresponding IC tag label position in the IC tag label printer is specified. If it is determined in step A18 that there are a plurality of locations in the table where the relationship between L1 and S1 and L2 and S2 is established, the process returns to step A17, and the servo position (LX) separated by a certain distance is changed. The signal strength (SX) is obtained again by the IC tag reader / writer, and the elements (LX, SX) to be collated are added and collated with the signal strength in the table.

  In step A15, the signal strength (S2) is acquired by the IC tag reader / writer at an arbitrary servo position (L2) different from the corresponding servo position (L1). Next, the acquired signal strength is compared with the signal strength at the servo position in the table corresponding to the servo position (L2) (step A16). As a result of the collation, when the locations where the relationship between L1 and S1 and L2 and S2 are established can be specified in the table data, the IC tag reader / writer and the IC tag label in the collated table data are respectively identified as L1 and L2. And determine the corresponding IC tag label position in the IC tag label printer (step A19). If they do not match as a result of the collation, the process returns to step A13 and the processing from step A13 is repeated.

  In this embodiment, the RFID tag function is used to detect the position of an IC tag label that has been detected only by the rotation of a conventional sensor or servo, thereby causing contamination of the IC tag label, misalignment of mark printing, and roller wear on the servo surface. Since the recognition error of the IC tag position that occurs can be complemented, it is possible to provide an IC tag label printer that can issue a large number of IC tags with high accuracy. Further, by eliminating the need for a sensor for identifying the position of the IC tag label and the mark on the IC tag label, it is possible to provide an IC tag label printer that realizes a reduction in device scale and cost.

  In the present embodiment, in particular, the use of table data does not require calculation of the signal intensity, so there is also an advantage that the servo position is detected at high speed.

  An IC tag label printer according to a third embodiment of the present invention will be described. The IC tag label printer of this embodiment is employed in an environment in which an IC tag reader / writer can simultaneously read two or more consecutive IC tags in the IC tag label with one antenna in the IC tag label printer.

  The configuration of the IC tag label printer of this embodiment is the same as that of the IC tag label printer of the first embodiment shown in FIGS. In the present embodiment, a label position conversion unit 40 is used instead of the label position conversion unit 20. FIG. 7 is a functional block diagram of the label position conversion unit 40. The label position conversion unit 40 has an IC tag position specifying function 41, an IC tag label position management function 42, a servo position management function 43, a table data collation function 44, and a tail data management function 45. This configuration itself is the same as that of the second embodiment.

  In the present embodiment, for each type of IC tag corresponding to the IC tag label printer, a table having the signal intensity when read by the IC tag reader / writer in the IC tag label printer and the value of the read position is prepared in advance. Next, the type of the IC tag set in the IC tag label printer is set, the position of each IC tag is specified from the signal intensity at a plurality of IC tag label positions, and the relative positional relationship with the antenna can be detected.

  FIG. 8 is a flowchart showing processing of the IC tag label printer of the third embodiment. Steps A21 and A22 are the same as steps A11 and A12, respectively. In step A23, the IC tag reader / writer acquires the signal intensity from the label position where two IC tags (IC tag A and IC tag B) can be read, and the signal intensity is set to A-S1 and B-S1 (step A23). ). Next, the signal intensities of two other IC tags (IC tag A and IC tag B) are measured at positions different from the previous time, and the signal intensities are set as A-SX and B-SX (step A24). From the table data, the servo position corresponding to each signal intensity is extracted from the table data (step A25). If there are multiple servo positions, all are taken out.

  It is determined whether there exists a combination in which the difference between the servo positions of the signal strength A-S1 and the signal strength A-SX and the difference of the servo positions of the signal strength B-S1 and the signal strength B-SX are equal (step). A26). If there is no equal combination, the process returns to step A24, and the signal strengths A-SX and B-SX of two other IC tags are acquired again, and steps A24 to A26 are repeated. If there is a combination in which both differences are equal in step A26, the process proceeds to step A27, and it is determined whether or not the existing combination is the only combination in the table data (step A27). That is, it is determined whether or not the existing combination is unique. If it is determined that the combination is a unique combination, the process proceeds to step A28, and the relative position between each IC tag reader / writer and the IC tag label is determined to be the servo position obtained from the table data. If it is determined in step A27 that the combination is not unique, the process returns to step A24, and steps A24 to A27 are repeated. That is, A-SX and B-SX are acquired at the label position where any two IC tags (IC tag A and IC tag B) can be read, and the number of elements is increased, so that the relative position between the only IC tag reader / writer and the IC tag label. Repeat until can be identified.

  In this embodiment, the RFID tag function is used to detect the position of an IC tag label that has been detected only by the rotation of a conventional sensor or servo, thereby causing contamination of the IC tag label, misalignment of mark printing, and roller wear on the servo surface. Therefore, it is possible to provide an IC tag label printer that can issue a large number of IC tags with high accuracy. Further, by eliminating the need for a sensor for identifying the position of the IC tag label and the mark on the IC tag label, it is possible to provide an IC tag label printer that realizes a reduction in device scale and cost.

  In the present embodiment, in particular, the use of table data does not require calculation of the signal intensity, so there is also an advantage that the servo position is detected at high speed. If two servo positions can be detected at the same time, it is possible to print on both tags simultaneously.

  FIG. 9 shows a state of printing by the IC tag label printer according to the fourth embodiment of the present invention. In the present embodiment, the IC tag label printer 100 includes two antennas 13 and two IC tag readers / writers 14 that acquire signals from the antennas. The IC tag label position control unit 50 detects the position of the IC tag using two IC tag readers / writers.

  FIG. 10 is a flowchart showing processing in the present embodiment. First, the servo moves the IC tag level to a point where the IC tag reader / writer can acquire the signal strength of the IC tag (step A31). Next, the signal intensity (S1) acquired by the IC tag reader / writer and the servo position (L1) at that time are stored (step A32). At this time, if both IC tag readers / writers can acquire the signal strength of the IC tag at the same IC tag label position, the signal strength (S′1) acquired by the other IC tag reader / writer is also stored simultaneously. Next, the servo is rotated at a constant value, and acquisition of the signal intensity is attempted at the next servo position (step A33). Next, it is determined whether or not the signal intensity can be acquired (step A34).

  If the signal intensity can be acquired (step A34), the process returns to step A33, the servo 16 is rotated again by a constant value, and the processes of steps A33 and A34 are repeated as long as the signal intensity can be acquired. In step A34, the repetition of the rotation operation is stopped at the point where the signal intensity cannot be acquired, and the servo position (L2) and the signal intensity (S2) at which the signal intensity was finally acquired are stored (step A35). At this time, if the signal strength can be acquired by both IC tag readers / writers, the signal strength (S′2) of the other IC tag reader / writer is also stored.

  Next, the signal strength (SS) of the servo position (L ′) corresponding to the middle of L1 and L2 is calculated from the values of S1 and S2 based on the calculation formula that the signal strength is inversely proportional to the cube of the distance ( Step A36). At this time, if both values of S′1 and S′2 exist, the signal strength S ′S ′ is also calculated. The servo is moved to the servo position L 'which is the center position of the IC tag, and the signal strength (S3) is acquired by the IC tag reader / writer (step A37). Here, when S′1 and S′2 exist, S′3 is also acquired. If the values of SS and S3 match within the assumed error range (step A38), the process proceeds to step A39, and at the servo position of L ', the center position of the antenna 13 in the IC tag label printer 100 is reached. It is determined that the center position L3 of the IC tag label 11 exists, and the corresponding IC tag label position in the IC tag label printer is determined. If S′1 and S′2 exist, S′3 is also compared with S ′S ′ to determine whether or not they match. In step A38, if the signal strength does not match within the assumed error range, the process returns to step A33, and steps A33 to A38 are repeated.

  In the fourth embodiment, a plurality of IC tag readers / writers and antennas are installed in one IC tag label printer, and the signal strength of the two IC tags is used to increase the printing efficiency and further improve the measurement accuracy. There is a synergistic effect that can be done. In the present embodiment, the number of IC tag readers / writers may be set to N (N ≧ 2), or may be changed to a configuration in which IC tag readers / writers having different frequencies or IC tag labels are mixed.

  FIG. 11 shows processing of the IC tag label printer according to the fifth embodiment of the present invention. In the present embodiment, two IC tag reader / writers are applied to the second embodiment to change the processing. First, the type of the IC tag label set in the IC tag label printer is set in the IC tag label printer (step A41). Next, the table data designated by the type of the IC tag level is read (step A42). Next, the signal strength (S1, S′1) is acquired from the IC tag reader / writer 14 at an arbitrary IC tag label position, and collated with the signal strength in the already read table data (step A43). The number of data corresponding to S1 and S′1 obtained as a result of the collation is assumed to be X (X ≧ 0).

  If X = 0 or X ′ = 0 in step A44, the process returns to step A43 to acquire the signal intensity (S1, S′1) again at an arbitrary IC tag label position, and repeat steps A43 and A44. If X = 1 and X ′ = 1 in step A44, the process proceeds to step A45, and if X ≧ 2 or X ′ ≧ 2, the process proceeds to step A47.

  In step A47, the servo positions (L2, L′ 2) are separated from the servo positions (L1, L′ 1) corresponding to a plurality of signal intensities existing in the table data by a fixed distance (d). Activate the servo. At the servo position, the signal strength (S2, S′2) is acquired using an IC tag reader / writer. Next, the acquired signal strength is compared with the signal strength at the servo position in the table data corresponding to the servo position (L2, L'2). Of the plurality of signal intensities found in step A44, it is determined whether or not only one signal intensity satisfying the relationship of L1 and S1 and L2 and S2 can be specified (step A48). In this step, the measured signal intensity at the servo positions L1 and L′ 1 matches the signal intensity obtained from the table data, and the signal measured at the servo positions L2 (L1 + d) and L′ 2 (L′ 1 + d). The determination is made when the intensity matches the signal intensity obtained from the table data. As a result of the determination, if all match, the process proceeds to step A49, where the servo positions L1, L'1, L2, L'2 of the collated table data are determined as the IC tag positions. Steps A47 and A48 are repeated until the determination results in step A48 match.

  In step A45, an arbitrary servo position (L2, L'2) different from the servo position (L1, L'1) of the corresponding data is designated, and the signal strength (S2, S'2) is assigned to both IC tag reader / writers. The obtained signal strength is compared with the signal strength at the servo position in the table corresponding to the servo position (L2, L′ 2) (step A46). If the comparison results of L1 and S1, L′ 1 and S′1, L2 and S2, and L′ 2 and S′2 match, the process proceeds to step A49, and servo positions L1, L′ 1, L2, and L ′. 2 is determined as the IC tag position. Steps A45 and A46 are repeated until the determination results in step A46 match.

  In the fifth embodiment, table data is prepared, and a plurality of IC tag readers / writers and antennas are installed in one IC tag label printer. By measuring the signal intensities of the two IC tags simultaneously and using the table data, there is a synergistic effect that the measurement efficiency can be further improved and the measurement accuracy can be further improved. In the present embodiment, the number of IC tag readers / writers may be set to N (N ≧ 2), or may be changed to a configuration in which IC tag readers / writers having different frequencies or IC tag labels are mixed.

  FIG. 12 is a flowchart showing processing of the IC tag label printer according to the sixth embodiment of the present invention. In the present embodiment, two IC tag reader / writers are applied to the third embodiment to change the processing.

  Steps A51 and A52 are the same as steps A21 and A22, respectively. In step A53, the two IC tag readers / writers acquire the signal intensity from the label position where any two to four IC tags (IC tags A to D) can be read, and the signal intensity is set to A-S1, B- S1, C-S1, and D-S1 are set (step A53). Next, the signal strength of another two to four IC tags (IC tags A to D) is measured at a position different from the previous time, and the signal strengths are A-SX, B-SX, C-SX, and D-SX. (Step A54). From the table data, the servo position corresponding to each signal intensity is extracted from the table data (step A55). If there are multiple servo positions, all are taken out.

  Servo position difference between signal intensity A-S1 and signal intensity A-SX, difference between servo position at signal intensity B-S1 and signal intensity B-SX, and servo position at signal intensity C-S1 and signal intensity C-SX It is determined whether or not there is a combination in which the difference between the two and the servo position difference between the signal intensity D-S1 and the signal intensity D-SX are all equal (step A56). If there is no equal combination, the process returns to step A54 to obtain again the signal strengths A-SX, B-SX, C-SX, D-SX of the other two to four IC tags, and from step A54 to step A56 Repeat until. If there is a combination in which all the differences are equal in step A56, the process proceeds to step A57, and it is determined whether or not the existing combination is the only combination in the table data (step A57). That is, it is determined whether or not the existing combination is unique. If it is determined that the combination is a unique combination, the process proceeds to step A58, and it is determined that the relative position between both IC tag readers / writers and the IC tag A and IC tag B is the IC tag position obtained from the table data. . If it is determined in step A57 that the combination is not unique, the process returns to step A54, and steps A54 to A57 are repeated. In other words, A-SX, B-SX, C-SX, D-SX is acquired at the label position where any two to four IC tags (IC tags A to D) can be read, and the number of elements is increased. Repeat until the relative position of the IC tag reader / writer and the IC tag label can be specified.

  In the sixth embodiment, table data is prepared, a plurality of IC tag readers / writers and antennas are installed in one IC tag label printer, and the signal strength of two IC tag labels is measured for each IC tag reader / writer. ing. By measuring the signal strength of four IC tags at the same time and using table data, the printing efficiency is increased. In addition, there is a synergistic effect that the measurement accuracy can be further improved. In the present embodiment, the number of IC tag readers / writers may be set to N (N ≧ 2), or may be changed to a configuration in which IC tag readers / writers having different frequencies or IC tag labels are mixed.

  In the above embodiment, an example of an IC tag label printer that measures the position of an IC tag label has been described. However, the IC tag label position detection method and apparatus of the present invention are not limited to the detection of the position of an IC tag label, and are mounted on a mount, for example. It can be used to detect the position of any IC tag.

  Although the present invention has been described based on the preferred embodiments, the IC tag position detection device, the IC tag position detection method, and the IC tag label printer of the present invention are limited only to the configuration of the above embodiments. Instead, various modifications and changes made from the configuration of the above embodiment are also included in the scope of the present invention.

1 is a schematic block diagram of an IC tag label printer according to a first embodiment of the present invention. The functional block diagram of the IC tag label position control part shown in FIG. The functional block diagram of the label position conversion part shown in FIG. The flowchart which shows the process of the IC tab label printer of FIG. The functional block diagram of the label position conversion part of the IC tag label printer which concerns on the 2nd Embodiment of this invention. 9 is a flowchart showing processing of the IC tag label printer of the second embodiment. The functional block diagram of the label position conversion part of the IC tag label printer which concerns on the 3rd Embodiment of this invention. 9 is a flowchart illustrating processing of an IC tag label printer according to a third embodiment. The typical block diagram of the IC tag label printer which concerns on the 4th Embodiment of this invention. 10 is a flowchart illustrating processing of an IC tag label printer according to a fourth embodiment. 10 is a flowchart showing processing of an IC tag label printer of a fifth embodiment. 10 is a flowchart showing processing of an IC tag label printer according to a sixth embodiment.

Explanation of symbols

10, 100: IC tag label printer 11: IC tag label 12: Mount 13: Antenna 14: IC tag reader / writer 15: Roll 16: Servo 17, 50: IC tag label position control unit 18: IC tag reader / writer control unit 19: Signal strength acquisition unit 20, 30, 40: Label position conversion unit 21: Servo position acquisition unit 22: Servo control unit 23: IC tag center position specifying function 24, 32, 42: IC tag label position management function 25, 33, 43: Servo position management function 31, 41: IC tag position specifying function 34, 44: Table data collation function 35, 45: Table data management function

Claims (14)

In a method of detecting a position of an IC tag having a short-range wireless communication function and being conveyed in a predetermined direction,
A first step of measuring a first signal intensity transmitted by the IC tag at a first servo position near the tip of the IC tag;
A second step of measuring a second signal intensity transmitted by the IC tag at a second servo position near the rear end of the IC tag;
Estimating a center position of the IC tag from the first and second servo positions;
A third step of measuring the central signal intensity transmitted by the IC tag, using the estimated center position of the IC tag as the servo position of the IC tag;
A fourth step of calculating a center signal strength at a center position of the IC tag based on the first and second servo positions and the first and second signal strengths;
The calculated center signal intensity is compared with the estimated center signal intensity, and it is determined whether or not to adopt the estimated center position of the IC tag as the determined center position based on the comparison result. And an IC tag position detecting method characterized by comprising:   When the determination result in the fifth step is negative, a sixth step of measuring a third signal intensity transmitted from the IC tag at a third servo position near the first or second servo position is further performed. 2. The IC tag position detection method according to claim 1, wherein the third to fifth steps are executed by employing the third signal strength instead of the first signal strength. In a method of detecting a position of an IC tag having a short-range wireless communication function and being conveyed in a predetermined direction,
A first step of measuring a first signal intensity transmitted by the IC tag at an arbitrary servo position;
A second step of referring to a table associating the servo position of the IC tag and the signal intensity at the servo position, and estimating the position of the IC tag that transmits the first signal intensity as the first servo position;
A second servo position is selected in association with the estimated first servo position, and a second signal intensity transmitted from the IC tag at the second servo position is estimated with reference to the table. Steps,
A fourth step of measuring a second signal intensity transmitted by the IC tag at the second servo position;
The estimated first or second servo position is determined by comparing the measured second signal strength with the estimated second signal strength. And a fifth step of determining whether or not to employ the IC tag position detecting method.   When two or more first servo positions of the IC tag that has transmitted the first signal strength are estimated in the second step, the estimated plurality of first tags are replaced with the third to fifth steps. Selecting a third servo position that is a predetermined distance away from each servo position, referring to the table, and estimating a third signal intensity transmitted by each IC tag at the third servo position; Measuring the third signal intensity transmitted by the IC tag at each of the three servo positions, comparing the plurality of estimated third signal intensities with the measured third signal intensity, The IC tag position according to claim 3, further comprising: selecting one from a plurality of third signal strengths and selecting one of the plurality of estimated first servo positions based on the selection. Detection method.   The IC tag position detection method according to claim 3 or 4, wherein the position of two IC tags among the plurality of IC tags arranged in the predetermined direction is simultaneously detected using one IC tag reader / writer.   6. The IC tag position detection method according to claim 5, wherein the positions of four IC tags among the plurality of IC tags arranged in the predetermined direction are simultaneously detected using two IC tag reader / writers.   The IC tag position detection method according to claim 3 or 4, wherein two IC tag reader / writers are used to simultaneously detect the positions of two IC tags among the plurality of IC tags arranged in the predetermined direction. In an IC tag position detecting device for detecting the position of an IC tag having a short-range wireless communication function,
Servo means for conveying the IC tag in a predetermined direction and outputting the servo position of the IC tag;
A signal strength acquisition unit for measuring the signal strength transmitted by the IC tag;
The first and second servo positions measured by the signal intensity acquisition unit at the first servo position near the front end of the IC tag, the second servo position near the rear end of the IC tag, and the first and second servo positions, respectively. An arithmetic unit that calculates the signal strength of the center position of the IC tag based on the signal strength of 2;
Estimating means for estimating a center position of the IC tag based on the first servo position and the second servo position;
The signal intensity of the IC tag measured by the signal intensity acquisition unit at the center position estimated by the estimation means is compared with the signal intensity calculated by the arithmetic device, and the estimated center is based on the comparison result An IC tag position detecting device comprising: determination means for determining whether or not to fix the position as the center position of the IC tag. In an IC tag position detecting device for detecting the position of an IC tag having a short-range wireless communication function,
Servo means for conveying the IC tag in a predetermined direction and outputting the servo position of the IC tag;
A signal strength acquisition unit for measuring the signal strength transmitted by the IC tag;
A table reference means for referring to a table in which a servo position of an IC tag and a signal intensity at the servo position are associated with each other, wherein the table is obtained from a first signal intensity measured by the signal intensity acquisition unit at an arbitrary servo position. The position of the IC tag is estimated as the first servo position with reference to FIG. 2, the second servo position is selected in association with the estimated first servo position, and the IC tag transmits at the second servo position. Table reference means for estimating the second signal strength;
By comparing the second signal strength measured by the signal strength acquisition unit at the second servo position with the second signal strength estimated by the table reference means, the estimated first servo An IC tag position detection apparatus comprising: a determination unit that determines whether or not to adopt a position as a confirmed first servo position. When the table reference means estimates two or more servo positions of the IC tag that has transmitted the first signal strength, a plurality of third servo positions respectively separated from the estimated plurality of first servo positions by a predetermined distance are obtained. Selecting, estimating the third signal strength transmitted by the IC tag at the selected third servo position,
The determination unit compares the third signal strength measured by the signal strength acquisition unit at the plurality of third servo positions with the third signal strength estimated by the table reference unit, and The IC tag position detection device according to claim 9, wherein one of the plurality of estimated first servo positions is selected, and the selected first servo position is determined as the first servo position.   An IC tag label printer comprising the IC tag position detection device according to any one of claims 8 to 10.   The IC tag label printer according to claim 11, wherein the position of two IC tags is simultaneously detected by using one IC tag reader / writer.   The IC tag label printer according to claim 12, wherein the positions of four IC tags are simultaneously detected using two IC tag readers / writers.   The IC tag label printer according to claim 11, wherein two IC tag reader / writers are used to simultaneously detect the positions of two IC tags.

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