JP5630336B2 - Optical information reader - Google Patents

Description

  The present invention relates to an optical information reading apparatus having a double reading prevention function.

  Conventionally, an optical information reading device has been provided with a double reading prevention function in order to prevent double reading of the same barcode, and the optical information reading device having this double reading prevention function is provided. As an apparatus, a bar code hand scanner shown in Patent Document 1 below is known. This bar code hand scanner includes an accelerometer for detecting the movement state of the bar code hand scanner.

  In the barcode hand scanner, when the barcode is read and the barcode data is obtained, the change in acceleration starting before the barcode is read changes from the first predetermined value or more to the second predetermined value or less. If this acceleration determination is Yes, it is assumed that the operator is moving the barcode hand scanner in order to read the same product twice. Is sent to the host device. In addition, when the acceleration determination is No and the obtained barcode data does not match the data sent immediately before or when it reaches the specified time even if it matches, the obtained barcode data is sent to the host device. Send it out. On the other hand, when the acceleration determination is No, and the obtained barcode data matches the data sent immediately before and the specified time has not been reached, the barcode is obtained with a double reading prevention function. Data is discarded.

Japanese Patent Application No. 08-147403

  By the way, in the configuration as disclosed in Patent Document 1, the reading prevention function can be canceled by detecting the acceleration of the apparatus main body. However, the use condition such as the stationary type in which the apparatus main body is fixed is used. Then, since only the reading object moves, there is a problem that the reading preventing function cannot be properly canceled even if the acceleration of the apparatus main body is detected.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical information reader capable of suitably canceling the double reading prevention function.

In order to achieve the above object, in the optical information reading device according to claim 1, an image pickup unit that picks up an information code and an information code included in a picked-up image picked up by the image pickup unit are decoded. An optical information reading apparatus comprising: a decoding unit that performs a predetermined process using a decoding result obtained by the decoding unit; and the imaging region of the captured image is divided into a plurality of divided regions. Position detection means for detecting a code position of the information code with respect to the imaging area based on the fact that the information code is located in any of the plurality of divided areas; and The decoding result when the process is executed is overwritten and stored as the previous decoding result, and the code corresponding to the decoding result is stored. Storage means for overwriting and storing the position as the previous detection position; determination means for determining whether or not a decoding result by the decoding means matches the previous decoding result stored in the storage means; and the storage and a position change detecting means for detecting a change of the detected code position by the position detecting means as a reference the previously detected position is stored in the means, the control means, the last decoded by said determining means For the information code determined not to match the result, the predetermined process using the decoding result of the information code is executed, and for the information code determined to match the previous decoding result by the determining means, After the change in the code position in the direction toward the outer edge of the imaging area is detected by the position change detection means, the direction change is different from this direction. That the change of the code position of the direction is detected, and executes the predetermined processing using the decoded result of the information code.

  According to a second aspect of the present invention, in the optical information reading apparatus according to the first aspect, the plurality of divided areas are divided into weights that gradually decrease from the center of the imaging area toward the outer edge of the imaging area. The position change detecting means corresponds to the code position detected by the position detecting means on the basis of the weighting of the divided area corresponding to the previous detected position as the code position change. A first change that lowers the weight of the divided area to be detected and a second change that increases the weight of the divided area, and the control means matches the previous decoding result by the determination means. If it is determined, the second change of the information code is detected after the first change is detected by the position change detecting means. , And executes the predetermined processing using the decoded result of the information code.

  According to a third aspect of the present invention, in the optical information reading apparatus according to the second aspect, the storage unit is configured such that the previous detection position coincides with the highest weighted code position detected by the position detection unit. It is characterized by being overwritten and stored.

  According to a fourth aspect of the present invention, in the optical information reading apparatus according to the first aspect, each time the previous decoding result is stored in the storage unit, the plurality of divided areas correspond to the previous decoding result. A weight that gradually decreases toward the outer edge of the imaging region with respect to the previous detection position is given to each divided region, and the position change detection unit corresponds to the previous detection position as a change in the code position. A first change in which the weighting of the divided area corresponding to the code position detected by the position detection unit becomes lower and a second change in which the weight of the divided area becomes higher with the weight of the divided area as a reference. When the determination unit determines that the control unit matches the previous decoding result, the control unit When the second change is detected after the first change is detected by the position deviation detection means, and executes the predetermined processing using the decoded result of the information code.

  According to a fifth aspect of the present invention, in the optical information reading device according to any one of the second to fourth aspects, the time duration when the detection of the first change is continued by the position change detecting means is measured. A timing unit, and when the determination unit determines that the determination result matches the previous decoding result, the information code has the duration time measured by the timing unit equal to or longer than a predetermined time and thereafter When the second change is detected by the position change detecting means, the predetermined process using the decoding result of the information code is executed.

  The invention of claim 6 is the optical information reader according to any one of claims 2 to 4, wherein the position change detecting means is based on the weighting of the divided area corresponding to the previous detection position. The first change is detected when the weighting of the divided region corresponding to the code position detected by the position detecting unit becomes lower than the first difference.

  A seventh aspect of the present invention is the optical information reading device according to any one of the second to fourth and sixth aspects, wherein the position change detecting means is based on the weighting of the divided area corresponding to the previous detected position. The second change is detected when the weight of the divided region corresponding to the code position detected by the position detecting unit becomes higher than the second difference.

  According to an eighth aspect of the present invention, in the optical information reading apparatus according to any one of the second to sixth aspects, the weighting is digitized.

  In the first aspect of the invention, the code position of the information code with respect to the captured image is detected by the position detecting means based on the information code being located in any of the plurality of divided regions. Further, the decoding result when the predetermined processing is executed by the control means is overwritten and stored in the storage means as the previous decoding result, and the code position corresponding to the decoding result is overwritten and stored as the previous detection position. Is done. For the information code that is determined not to match the previous decoding result by the determination unit, a predetermined process using the decoding result of the information code is executed by the control unit, and the determination unit determines that it matches the previous decoding result. If the change in the code position in a direction different from this direction is detected after the change in the code position in the direction toward the outer edge of the imaging region is detected by the position change detection means, the information code is decoded. A predetermined process using the result is executed by the control means.

  As a result, the decoding result by the decoding unit coincides with the previous decoding result stored in the storage unit, and after the change of the code position in the direction toward the outer edge of the imaging region is detected by the position change detection unit, If a change in the code position is detected, that is, the user moves the information code relative to the field of view again after moving the information code in the direction to remove it from the field of view of the imaging area in order to read the same information code twice In the case of the movement, the control unit executes a predetermined process using the decoding result of the information code without exhibiting the double reading prevention function. On the other hand, the decoding result by the decoding unit coincides with the previous decoding result stored in the storage unit, and the position change detecting unit detects the change in the code position in the direction toward the outer edge of the imaging region, and the direction in the direction different from this direction is detected. When the code position change is not detected, the double reading prevention function is exhibited, and the predetermined processing using the decoding result of the information code is not executed by the control means.

In addition, since the imaging area of the captured image is divided into a plurality of divided areas and the information code is located in any of the plurality of divided areas, the code position of the information code with respect to the imaging area is detected. Thus, the code position can be detected without performing complicated arithmetic processing. In particular, since the relative position of the information code with respect to the imaging region is detected, it can be employed not only in a portable optical information reader but also in a stationary optical information reader.
Therefore, in the portable or stationary optical information reader, the double reading prevention function can be preferably canceled.

  In the invention of claim 2, weights that gradually decrease from the center of the imaging region toward the outer edge of the imaging region are assigned to the plurality of divided regions, respectively. For an information code determined by the determining means to match the previous decoding result, when the second change is detected after the first change is detected by the position change detecting means, the information code is decoded. A predetermined process using the result is executed by the control means.

  As described above, since weighting is applied to each of the plurality of divided regions and the change in the code position is detected by the change in the weighting, the arithmetic processing for detecting the change in the code position can be easily performed. In particular, since the weighting is given on the basis of the center of the imaging area, it is possible to easily perform the arithmetic processing for giving the weighting.

  In the invention of claim 3, the previous detection position is overwritten and stored in the storage means so as to coincide with the highest weighted code position detected by the position detection means. In this way, the previously detected position is set to be equal to the highest weighted code position, that is, the code position that the user is aware of as the center of the imaging area, so the user's reading work is taken into consideration. Thus, the previous detection position is set, and the operability regarding the cancellation of the double reading prevention function can be improved.

  According to the invention of claim 4, each time the previous decoding result is stored in the storage means, the plurality of divided areas are gradually lowered toward the outer edge of the imaging area around the previous detection position corresponding to the previous decoding result. Are given to each divided region. For an information code determined by the determining means to match the previous decoding result, when the second change is detected after the first change is detected by the position change detecting means, the information code is decoded. A predetermined process using the result is executed by the control means.

  As described above, since weighting is applied to each of the plurality of divided regions and the change in the code position is detected by the change in the weighting, the arithmetic processing for detecting the change in the code position can be easily performed. In particular, since weighting is given each time based on the previous detection position, weighting is given in consideration of the user's reading work, and the operability related to the release of the double reading prevention function can be improved. .

  In the invention of claim 5, when it is determined by the determining means that the result matches the previous decoding result, the duration time counted by the time measuring means becomes equal to or longer than a predetermined time for this information code, and then the second change by the position change detecting means is performed. When the change is detected, a predetermined process using the decoding result of the information code is executed by the control means.

  As a result, the double reading prevention function is not released only by temporarily changing the weighting detected by the position change detecting means due to camera shake or the like from the first change to the second change. By appropriately setting the time, it is possible to prevent the unnecessary double reading prevention function from being canceled.

  In the invention of claim 6, when the weight of the divided area corresponding to the code position detected by the position detecting means becomes lower than the first difference on the basis of the weight of the divided area corresponding to the previously detected position, The first change is detected by the position change detecting means.

  As a result, even if the weight detected by the position change detection means due to camera shake or the like is simply lower than the weight of the divided region corresponding to the previous detection position, it is read twice as long as it does not become lower than the first difference. Since the prevention function is not released, it is possible to prevent the unnecessary double reading prevention function from being canceled by appropriately setting the first difference.

  In the invention of claim 7, when the weight of the divided area corresponding to the code position detected by the position detecting means becomes higher than the second difference with reference to the weight of the divided area corresponding to the previously detected position, The second change is detected by the position change detecting means.

  As a result, after the first change is detected, even if the weight detected by the position change detection means due to camera shake or the like is simply higher than the weight of the divided region corresponding to the previous detection position, the second difference is exceeded. Since the double reading prevention function is not released unless the value becomes high, the unnecessary double reading prevention function can be prevented from being released by appropriately setting the second difference.

  In the invention of claim 8, since the weighting is digitized, it is possible to easily perform arithmetic processing for assigning weighting or detecting a change in weighting.

1 is a block diagram illustrating an electrical configuration of an optical information reading device according to a first embodiment. FIG. 2A is an explanatory diagram illustrating an imaging region divided into a plurality of divided regions, and FIG. 2B is an explanatory diagram illustrating a change in the code position of a decoded barcode. 3 is a flowchart illustrating the flow of a reading process performed in the first embodiment. It is a flowchart which shows the subroutine of the double reading cancellation | release determination process of FIG. It is a timing chart which illustrates change of the code position point of the information code decoded in a 1st embodiment. It is explanatory drawing which illustrates the imaging area divided into the some division area in the modification of 1st Embodiment. It is a flowchart which shows the subroutine of double reading cancellation | release determination processing in 2nd Embodiment. It is a timing chart which illustrates change of a code position point of an information code decoded in a 2nd embodiment. It is a flowchart which shows the subroutine of double reading cancellation | release determination processing in 3rd Embodiment. It is a timing chart which illustrates change of the code position point of the information code decoded in a 3rd embodiment. It is a flowchart which shows the subroutine of double reading cancellation | release determination processing in 4th Embodiment. It is a timing chart which illustrates change of the code position point of the information code decoded in a 4th embodiment.

[First Embodiment]
Hereinafter, an optical information reading apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an electrical configuration of an optical information reading apparatus 10 according to the first embodiment.

  As shown in FIG. 1, the optical information reader 10 is configured as an apparatus that optically reads an information code such as a one-dimensional code or a two-dimensional code attached to an article. The optical information reading apparatus 10 includes a circuit unit 20 housed in a case (not shown). The circuit unit 20 mainly includes an illumination light source 21, a light receiving sensor 28, an imaging lens 27, and the like. And a microcomputer (hereinafter referred to as “microcomputer”) system such as a memory 35, a control circuit 40, and a trigger switch 42.

  The optical system is divided into a light projecting optical system and a light receiving optical system. The illumination light source 21 constituting the light projecting optical system functions as an illumination light source capable of emitting the illumination light Lf, and includes, for example, a red LED and a lens provided on the emission side of the LED. In addition, in FIG. 1, the example which irradiates the illumination light Lf toward the articles | goods R to which barcode B was attached | subjected is shown notionally.

  The light receiving optical system includes a light receiving sensor 28, an imaging lens 27, a reflecting mirror (not shown), and the like. The light receiving sensor 28 is configured to receive the reflected light Lr irradiated and reflected on the barcode B or the like. For example, a light receiving element which is a solid-state imaging element such as a C-MOS or a CCD is two-dimensionally arranged. An area sensor corresponds to this. The light receiving sensor 28 is mounted on a printed wiring board (not shown) so as to be able to receive incident light incident through the imaging lens 27. The light receiving sensor 28 may correspond to “imaging means” recited in the claims.

  The imaging lens 27 functions as an imaging optical system capable of condensing incident light incident from the outside via a reading port (not shown) and forming an image on the light receiving surface 28a of the light receiving sensor 28. . In the present embodiment, after the illumination light Lf emitted from the illumination light source 21 is reflected by the barcode B, the reflected light Lr is condensed by the imaging lens 27 and a code image is formed on the light receiving surface 28 a of the light receiving sensor 28. The image is formed.

  The microcomputer system includes an amplification circuit 31, an A / D conversion circuit 33, a memory 35, an address generation circuit 36, a synchronization signal generation circuit 38, a control circuit 40, a trigger switch 42, a light emitting unit 43, a buzzer 44, a vibrator 45, and a liquid crystal display. 46, a communication interface 48, and the like.

  The image signal (analog signal) output from the light receiving sensor 28 of the optical system is amplified by a predetermined gain by being input to the amplifier circuit 31, and then input from the analog signal when input to the A / D conversion circuit 33. Converted into a digital signal. When the digitized image signal, that is, image data (image information) is generated and input to the memory 35, it is stored in a predetermined code image information storage area. The synchronization signal generation circuit 38 is configured to generate a synchronization signal for the light receiving sensor 28 and the address generation circuit 36, and the address generation circuit 36 is based on the synchronization signal supplied from the synchronization signal generation circuit 38. Thus, the storage address of the image data stored in the memory 35 can be generated.

  The memory 35 is a semiconductor memory device, and corresponds to, for example, a RAM (DRAM, SRAM, etc.) or a ROM (EPROM, EEPROM, etc.). In addition to the above-described code image information storage area, the RAM of the memory 35 is configured to be able to secure a work area and a reading condition table used by the control circuit 40 in each processing such as arithmetic operation and logical operation. Yes. The ROM stores in advance a predetermined program that can execute reading processing, analysis processing, and the like, which will be described later, and a system program that can control each piece of hardware such as the illumination light source 21 and the light receiving sensor 23.

  The control circuit 40 is configured by a microcomputer capable of controlling the entire optical information reading apparatus 10, has a CPU, a system bus, an input / output interface, and the like, and has an information processing function. Is configured. In the present embodiment, a trigger switch 42, a light emitting unit 43, a buzzer 44, a vibrator 45, a liquid crystal display 46, a communication interface 48, and the like are connected to the control circuit 40.

  Thereby, for example, the control circuit 40 can turn on / off the light emitting unit 43 that functions as an indicator for notifying information related to monitoring and management of the trigger switch 42 and reading of the barcode B, and a buzzer that can generate a beep sound and an alarm sound. Communication that enables ON / OFF of ringing 44, drive control of the vibrator 45 capable of generating vibration that can be transmitted to the user of the optical information reader 10, display control of the liquid crystal display 46, and serial communication with an external device Communication control of the interface 48 is enabled.

  Next, a reading process executed by the control circuit 40 of the optical information reading apparatus 10 in the first embodiment will be described with reference to FIGS. 2A is an explanatory diagram illustrating the imaging region S divided into a plurality of divided regions, and FIG. 2B is an explanatory diagram illustrating a change in the code position of the decoded barcode. . FIG. 3 is a flowchart illustrating the flow of the reading process performed in the first embodiment. FIG. 4 is a flowchart showing a subroutine of the double reading cancellation determination process of FIG. FIG. 5 is a timing chart illustrating the change of the code position point of the decoded information code.

  In the optical information reading apparatus 10 according to the present embodiment, a double reading prevention function for preventing double reading that reads the same barcode is employed. In the reading process executed by the control circuit 40, when the same decoding result as the previous decoding result is obtained in order to suitably cancel the double reading prevention function, the imaging region of the captured image is obtained. In accordance with the change in the position of the information code in S, a determination is made as to whether or not to transfer this decoding result to a predetermined arithmetic unit or the like.

  Specifically, the imaging region S of the captured image is divided into a plurality of divided regions, and weights that gradually decrease from the center of the imaging region S toward the outer edge are given in advance for each divided region. In this embodiment, as illustrated in FIG. 2A, as weighting, for example, a point consisting of a numerical value of 1 to 4 (hereinafter referred to as a code position point) is captured from the center of the imaging region S. It is given to each divided region formed in a square shape so as to gradually decrease toward the outer edge of the region S. Then, by setting the code position point of the code position that the information code occupies in the imaging area S to be equal to the code position point assigned to the divided area where the center of the information code is located, the code of the information code The position is detected according to the code position point, and the change of the code position is detected according to the difference of the code position point.

  Then, the code position point of the information code that has been successfully decoded is stored as a reference position point (described later), and the code position point of the information code that matches the previous decoding result has undergone a predetermined change with respect to the reference position point. In this case, assuming that the user is performing an operation for causing the same information code to be read twice, the above-described double reading prevention function is canceled.

Hereinafter, the reading process in which the above-described double reading prevention function cancellation determination is made will be described in detail with reference to the flowchart shown in FIG.
When the optical information reader 10 is turned on and is in a reading state in which an information code can be read, first, in step S101, a double reading prevention canceling process is performed, and double reading prevention is set as described later. It becomes a released state.

  Next, imaging processing is performed in step S103, and when an information code exists within the imageable range, a captured image including this information code is captured. Subsequently, a decoding process is performed in step S105, and a known decoding process is performed on the information code included in the captured image captured in step S103. If a decoding result is obtained by this decoding process and reading is successful, it is determined Yes in step S107. If it is in a state in which the double reading prevention is canceled, it is determined No in step S109, the double reading prevention setting process is performed in step S111, and the double reading prevention is set. Note that the control circuit 40 that executes step S105 may correspond to an example of a “decoding unit” recited in the claims.

  As described above, when reading prevention is set twice because of successful decoding, a setting process for setting the previous decoding result and the reference point is performed in step S113. In this process, the decoding result decoded in step S105 is set as the previous decoding result and stored in an overwritten state in the memory 35, and the code position point corresponding to this decoding result is set as the reference position point Po and stored in the memory 35. Is stored in an overwritten state. The memory 35 may correspond to an example of the “storage unit” described in the claims, and the previous decoding result and the reference position point Po are the “previous decoding result” and the “previous time” described in the claims. It may correspond to an example of “detection position”.

  Subsequently, when a flag F, which will be described later, is set to 0 in step S115, a data transfer process is performed in step S117, and the decoding result obtained in step S105 is assumed to be valid data. The data is transferred to a calculation unit or a host system that executes processing. When the decoding result is transferred in this way, the processing from step S103 is performed again in a state where reading prevention is set twice.

  Then, a captured image including the information code is captured again in step S103, the information code included in the captured image is decoded in step S105, and if this decoding is successful, Yes is determined in step S107. . At this stage, since reading prevention is set twice, it is determined Yes in step S109, and in step S119, the decoding result decoded in step S105 and the previous decoding stored in the memory 35 are determined. A determination is made as to whether the results match.

  Here, if the decoding result decoded in step S105 does not match the previous decoding result, it is determined No in step S119, and the processing from step S111 onward is performed. As a result, the decoding result decoded in step S105, that is, the latest decoding result is set as the previous decoding result and stored in an overwritten state in the memory 35, and the reference position point Po corresponds to the code position corresponding to this decoding result. It is set to be equal to the point and stored in the memory 35 in an overwritten state.

  On the other hand, if the decoding result decoded in step S105 matches the previous decoding result, it is determined Yes in step S119, a point acquisition process is performed in step S121, and the decoding is performed in step S105. The code position point P of the code position corresponding to the decoded result is obtained. Note that the control circuit 40 that executes step S119 may correspond to an example of the “determination unit” recited in the claims.

  When the code position point P is acquired in this way, a reading cancellation determination process is performed twice in step S200. In this subroutine, first, in step S201 of FIG. 4, it is determined whether or not the flag F is set to 1. If the flag F is not set to 1, it is determined No. Next, in step S203, whether or not a first change in which the code position point P acquired in step S121 is smaller (lower) than the reference position point Po set in step S113 is detected. Determined. Here, if the code position point P is equal to or greater than the reference position point Po, it is determined No in step S203 because the first change is not detected, and the double reading cancellation determination processing subroutine is terminated.

  On the other hand, if the code position point P is smaller than the reference position point Po, that is, if the code position changes in the direction toward the outer edge of the imaging region S, the first change is detected in step S203. It is determined Yes and the flag F is set to F = 1 in step S205. This flag F is a flag for indicating a change in the code position. When it is detected that the information code that has been successfully decoded moves relatively in the direction toward the outer edge of the imaging region S (the first change is detected). F = 1.

  Here, a case where the flag F is set to F = 1 will be described with reference to FIG. The code position of the bar code that has been successfully decoded and transferred is indicated by symbol B1, and when the next image is captured, the bar code is relatively moved in the direction toward the outer edge of the imaging region S, and is indicated by symbol B2. It is assumed that the code position has been changed. In the case shown in FIG. 2B, the reference position point Po is set to “3” and the code position point P is set to “1”, so that the code position point P is smaller than the reference position point Po. Therefore, the flag F is set to F = 1 on the assumption that the first change in which the information code that has been successfully decoded is relatively moved in the direction toward the outer edge of the imaging region S is detected.

  Then, in the state where the flag F is set to F = 1, the process from step S103 is performed again, and it is determined Yes in steps S109 and S119, so that the latest captured image is determined in step S121. When the code position point P is acquired and the reading cancellation determination process is performed twice in step S200, it is determined Yes in step S201. Next, in step S207, it is determined whether or not a second change in which the code position point P is equal to the reference position point Po is detected, and the code position point P is kept smaller than the reference position point Po. In the case where the second change is not detected, it is determined No in step S207, and the twice reading cancellation determination processing subroutine is completed.

  On the other hand, when the code position point P becomes higher and becomes equal to the reference position point Po according to the relative movement of the information code, it is determined Yes in step S207 because the second change is detected, and twice in step S209. A reading prevention cancellation process is performed. Thus, when the code position point P becomes equal to the reference position point Po, after detecting the change of the code position in the direction toward the outer edge of the imaging region S (first change), a direction different from this direction, specifically Specifically, it can be determined that a change (second change) in the code position in the direction toward the center of the imaging region S has been detected. In order to allow the user to read the same information code twice, such a change in the code position is performed by relatively moving the information code in the direction of removing it from the field of view of the imaging region S and then moving it relative to the inside of the field of view again. It is assumed that Therefore, in this case, reading prevention is canceled in step S209. Note that the control circuit 40 that executes steps S203 and S207 may correspond to an example of “position change detection means” described in the claims.

Here, the change of the code position point P described above will be described with reference to the timing chart shown in FIG.
As illustrated in FIG. 5, the code position point P of the information code that has been successfully decoded is set as “3” as the reference position point Po, and after the decoding result is transferred, the code position acquired in step S121 When the point is “1” (see time t _{1 in} FIG. 5), that is, when the information code is relatively moved in the direction toward the outer edge of the imaging region S by the user, the flag F is set to F in step S205. = 1 is set. When the code position point obtained after the flag F is set to F = 1 at step S121 is "3" (see time t ₂ in FIG. 5), i.e. the information code imaging region by the user In the case of relative movement in the direction toward the center of S, reading prevention is canceled in step S209.

  As described above, when the double reading prevention is canceled in step S209 and the double reading cancellation determination processing subroutine ends, when the newly imaged information code is successfully decoded (Yes in S107), the process proceeds to step S109. No, and the decoding process is not compared with the previous decoding result, and the processes after step S111 are performed. In addition, when reading prevention is canceled twice in step S209, the code position point P becomes equal to the reference position point Po by performing the processing after step S111 without performing new imaging thereafter. The decoding result may be transferred in step S117.

  On the other hand, when the decoding in step S105 has failed (No in S107), and when reading prevention is set twice (Yes in S127), the information code is captured in the captured image captured in step S103. If the decoding has failed, it is determined No in step S129. In this case, it is determined that the user has imaged a state in which no information code exists in order to cancel the double reading prevention, and the double reading prevention is canceled in step S131.

  As described above, in the optical information reading device 10 according to the present embodiment, the code position of the information code with respect to the imaging region P is the code position based on the information code being located in any of the plurality of divided regions. Detected using point P. Further, the decoding result is overwritten and stored in the memory 35 as the previous decoding result, and the code position corresponding to the decoding result is overwritten and stored as the reference position point Po. For the information code determined not to match the previous decoding result, the decoding result of the information code is transferred, and for the information code determined to match the previous decoding result, the information code in the direction toward the outer edge of the imaging region S is transferred. If a change (second change) in which the code position point P becomes equal to the reference position point Po is detected after detection of the change in the code position (first change), the reading prevention is canceled twice and this information is released. The decoding result of the code is transferred.

  Thus, when the decoding result matches the previous decoding result stored in the memory 35 and the second change is detected after the first change is detected, that is, the user reads the same information code twice. Therefore, when the information code is relatively moved in the direction of removing it from the field of view of the imaging area and then moved inward relative to the field of view again, the decoding result of this information code is not exhibited without performing the reading prevention function twice. Is transferred. On the other hand, when the decoding result matches the previous decoding result stored in the memory 35 and the second change after the detection of the first change and the detection of the first change is not detected, the double reading prevention function Therefore, the decoding result of the information code is not transferred.

Further, based on the fact that the imaging area S of the captured image is divided into a plurality of divided areas and the information code is located in any of the plurality of divided areas, the code position of the information code with respect to the imaging area S is detected. Therefore, the code position can be detected without performing complicated calculation processing. In particular, since the relative position of the information code with respect to the imaging region S is detected, it can be adopted not only for a portable optical information reader but also for a stationary optical information reader.
Therefore, in the portable or stationary optical information reader, the double reading prevention function can be preferably canceled.

  Further, in the plurality of divided regions in the imaging region S, points each having a numerical value of 1 to 4 as weights gradually decreasing from the center of the imaging region S toward the outer edge of the imaging region S are provided for each divided region. Each is given. For the information code determined to match the previous decoding result, when the second change is detected after the first change is detected, the decoding result of the information code is transferred.

  In this way, weighting is applied to each of the plurality of divided regions, and the change in the code position is detected by the change in the weighting. Therefore, the arithmetic processing for detecting the change in the code position can be easily performed. In particular, since the weighting is given on the basis of the center of the imaging region S, the arithmetic processing for giving the weighting can be easily performed.

  In particular, since the weighting is quantified using the code position point P, it is possible to easily perform arithmetic processing for applying weighting and detecting a change in weighting.

  In addition, since the change in the code position is detected using the code position point P as described above, as shown in FIG. 2B, a pattern that is difficult to distinguish from the information code in the imaging region S (FIG. 2B ), The double reading prevention function can be preferably canceled without being affected by this.

FIG. 6 is an explanatory diagram illustrating the imaging region S divided into a plurality of divided regions in the modification of the first embodiment.
As a modified example of the first embodiment, every time the previous decoding result is stored in the memory 35 in the above-described step S113 in the above-described step S113, the imaging region S is centered on the code position corresponding to the previous decoding result. As the weighting that gradually decreases toward the outer edge, the code position point P may be given to each divided region each time.

  For example, as illustrated in FIG. 6, the code position point P is directed toward the outer edge of the imaging region S around the information code (indicated by reference numeral B <b> 1 in FIG. 6) whose previous decoding result is stored in the memory 35. It is given to each divided region so as to be gradually lowered.

  As described above, even if the code position point P (weighting) is given to each of the plurality of divided regions and the change of the code position is detected by the change of the code position point P, the calculation process for detecting the change of the code position Can be easily implemented. In particular, since the code position point P is assigned to each divided area each time based on the code position corresponding to the previous decoding result, the code position point P (weighting) is given in consideration of the reading operation of the user. As a result, the operability related to the release of the double reading prevention function can be improved.

[Second Embodiment]
Next, an optical information reading apparatus 10 according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a flowchart showing a subroutine of the double reading cancellation determination process in the second embodiment. FIG. 8 is a timing chart illustrating the change of the code position point of the information code decoded in the second embodiment.

  In the optical information reading apparatus 10 according to the second embodiment, FIG. 4 shows a subroutine of the double reading cancellation determination process described above in order to update the reference position point Po every time in consideration of the reading operation of the user. The main difference from the optical information reading apparatus according to the first embodiment is that arithmetic processing is performed based on the flowchart shown in FIG. 7 instead of the flowchart. Therefore, substantially the same components as those of the optical information reading apparatus of the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  The characteristic part in the reading process of the second embodiment differs from the first embodiment in that the reference position point Po is updated even after the previous decoding result is stored in the memory 35 and is the highest detected thereafter. It is set to coincide with the code position point P.

Hereinafter, the double reading cancellation determination subroutine in the second embodiment will be described with reference to the flowchart of FIG.
Similar to the reading process in the first embodiment, when the decoding result of the information code that has been set to prevent reading twice and has been successfully decoded matches the previous decoding result stored in the memory 35 (in S109 and S119). Yes), the code position point P for the latest captured image is acquired in step S121, and the reading cancellation determination process is performed twice in step S200. In the subroutine in this embodiment, first, in step S201 of FIG. 7, it is determined whether or not the flag F is set to F = 1. If the flag F is not set to F = 1, No is set. Determined.

  Next, in step S203, it is determined whether or not the first change in which the code position point P acquired in step S121 is smaller (lower) than the reference position point Po is detected. Here, if the code position point P is equal to or greater than the reference position point Po, it is determined No in step S203 because the first change is not detected.

  Subsequently, in step S211, a reference position point resetting process is performed. In this process, the reference position point Po is reset so as to be equal to the code position point P acquired in step S121. When the reference position point Po is reset in this manner, the twice reading cancellation determination processing subroutine ends. As in the first embodiment, when the processing from step S103 is performed and the code position point P for the latest captured image is acquired in step S121, the double reading cancellation determination is performed again in step S200. Processing is done.

  Then, the process of resetting the reference position point Po in step S211 until the first change in which the code position point P acquired in step S121 becomes smaller (lower) than the reference position point Po is detected. Is repeated. That is, when the code position point P is equal to or greater than the reference position point Po, the reference position point Po is reset so as to be equal to the code position point P. Therefore, the code position point P is more than the previous code position point P. The process of resetting the reference position point Po is repeated until it becomes lower (until the rise of the code position point P stops).

  Then, after the decoding result is transferred, when the relative movement of the information code toward the center of the imaging area S stops by the user and the code position changes in the direction toward the outer edge of the imaging area S, the code position point acquired in step S121 Since P is smaller than the reference position point Po, it is determined that the first change has been detected, Yes is determined in step S203, and the flag F is set to F = 1 in step S205.

  In this manner, with the flag F set to F = 1, the processing from step S103 is performed again, and when the determination is Yes in steps S109 and S119, the code position for the latest captured image in step S121. When the point P is acquired and the reading cancellation determination process is performed twice in step S200, it is determined Yes in step S201. When the second change in which the code position point P becomes equal to the reference position point Po is detected, Yes is determined in step S207, and the double reading prevention is canceled in step S209. The subroutine for the release determination process ends.

Here, the change of the code position point P described above will be described with reference to the timing chart shown in FIG.
As illustrated in FIG. 8, even after the code position point P of the information code to which the decoding result has been transferred is set as “3” as the reference position point Po, the information code is directed toward the center of the imaging region S by the user. When code position points P obtained in step S121 by the relative movement direction is "4" (see time t ₁ in FIG. 8), setting code position point P ( "4") as the reference position point Po Is done.

When the code position point obtained in step S121 becomes "1" (see time t ₂ in FIG. 8), i.e. the information code stops the relative movement of the information code toward the center of the imaging area S by the user Is relatively moved in the direction toward the outer edge of the imaging region S, the flag F is set to F = 1 in step S205. Then, (see time t ₃ in FIG. 8) If code position point obtained after the flag F is set to F = 1 at step S121 is "4", namely the by the user for reading twice When the information code is relatively moved again in the direction toward the center of the imaging region S, reading prevention is canceled twice in step S209.

  As described above, in the optical information reading apparatus 10 according to the present embodiment, when the previous decoding result is stored in the memory 35, the reference position point Po is the highest code position point acquired (detected) thereafter. Set to match P.

  Thus, since the reference position point Po is set to be equal to the highest code position point P, that is, the code position that the user is aware of as the center of the imaging region S, the user's reading operation is performed. The reference position point Po is set in consideration of the above, and the operability related to the release of the double reading prevention function can be improved.

[Third Embodiment]
Next, an optical information reading apparatus 10 according to a third embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a flowchart showing a subroutine of the double reading cancellation determination process in the third embodiment. FIG. 10 is a timing chart illustrating the change of the code position point of the information code decoded in the third embodiment.

  In the optical information reading apparatus 10 according to the third embodiment, the reading prevention function is not canceled by a temporary change of the code position point. Therefore, instead of the flowchart shown in FIG. The main difference from the optical information reading apparatus according to the first embodiment is that arithmetic processing is performed based on the flowchart shown in FIG. Therefore, substantially the same components as those of the optical information reading apparatus of the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  The characteristic part in the reading process of the third embodiment is different from the first embodiment, and when it is determined that it matches the previous decoding result, the detection of the first change continues for a predetermined time for this information code. Then, when the second change is detected, reading prevention is canceled twice.

Hereinafter, a subroutine of the double reading cancellation determination process in the third embodiment will be described with reference to the flowchart of FIG.
Similar to the reading process in the first embodiment, when the decoding result of the information code that has been set to prevent reading twice and has been successfully decoded matches the previous decoding result stored in the memory 35 (in S109 and S119). Yes), the code position point P for the latest captured image is acquired in step S121, and the reading cancellation determination process is performed twice in step S200. In the subroutine in the present embodiment, first, in step S201 of FIG. 9, it is determined whether or not the flag F is set to F = 1. If the flag F is not set to F = 1, No is set. Determined.

  At this time, if a first change is detected in which the code position point P acquired in step S121 becomes smaller (lower) than the reference position point Po, it is determined Yes in step S203, and the process proceeds to step S213. The time measurement process is performed, and the time measurement of the duration T after the first change is first detected is started. Then, until the duration time T becomes equal to or longer than the predetermined time To, it is determined No in step S215, and the twice-reading cancellation determination processing subroutine ends. Here, the predetermined time To is a time set in order not to cancel the reading prevention function twice by a temporary change of the code position point, and is set to 1 second, for example.

  Then, when the first change is continuously detected (Yes in S203) and the elapsed time T during which the first change continues is equal to or longer than the predetermined time To, it is determined Yes in Step S215, and the process proceeds to Step S205. Thus, the flag F is set to F = 1, and the twice reading cancellation determination processing subroutine is completed. In this manner, with the flag F set to F = 1, the processing from step S103 is performed again, and when the determination is Yes in steps S109 and S119, the code position for the latest captured image in step S121. When the point P is acquired and the reading cancellation determination process is performed twice in step S200, it is determined Yes in step S201. When the second change in which the code position point P becomes equal to the reference position point Po is detected, Yes is determined in step S207, and the double reading prevention is canceled in step S209. The subroutine for the release determination process ends.

  On the other hand, if the code position point P becomes greater than the reference position point Po before the elapsed time T for which the first change continues becomes equal to or greater than the predetermined time To, the elapsed time T is set to 0 in step S217, The subroutine of the reading cancellation determination process ends.

Here, the change in the code position point P described above will be described with reference to the timing chart shown in FIG.
As illustrated in FIG. 10, the code position point P acquired in step S121 after the code position point P of the information code to which the decoding result has been transferred is set as “3” as the reference position point Po is the reference position point. is smaller than Po (lower) first changes be detected (see time t ₁ in FIG. 10), if the detection of the first change does not continue, the first after the detection of the first change Even if a change of 2 is detected, the decoding result is not transferred.

Then, (see time t ₂ in FIG. 10) after the first change is detected, the elapsed time T becomes equal to or larger than the predetermined time To (see time t ₃ in FIG. 10), detecting a predetermined time of the first change When continuing (Yes in S215), the flag F is set to F = 1 in Step S205. Then, (see time t ₄ in FIG. 10) If code position point obtained after the flag F is set to F = 1 at step S121 is "3", ie the by the user for reading twice When the information code is relatively moved again in the direction toward the center of the imaging region S, reading prevention is canceled twice in step S209.

  As described above, in the optical information reading apparatus 10 according to the present embodiment, the duration T after the first change is first detected becomes equal to or longer than the predetermined time To, and then the second change is detected. Then, reading prevention is canceled twice and the decoding result is transferred.

  As a result, the code reading point P (weighting) detected by hand shake or the like temporarily changes from the first change to the second change, so that the double reading prevention function is not canceled. By appropriately setting the predetermined time To, it is possible to prevent the unnecessary double reading prevention function from being released.

[Fourth Embodiment]
Next, an optical information reading apparatus 10 according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a flowchart illustrating a subroutine of the double reading cancellation determination process in the fourth embodiment. FIG. 12 is a timing chart illustrating the change of the code position point of the information code decoded in the fourth embodiment.

  In the optical information reading apparatus 10 according to the fourth embodiment, the reading prevention function is not canceled by a temporary change of the code position point. Therefore, instead of the flowchart shown in FIG. The main difference from the optical information reading apparatus according to the first embodiment is that arithmetic processing is performed based on the flowchart shown in FIG. Therefore, substantially the same components as those of the optical information reading apparatus of the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  The characteristic part in the reading process of the fourth embodiment differs from the first embodiment in that the code position point P acquired in step S121 is relative to the reference position point Po set in step S113. The first change is detected when it becomes smaller than a first difference which will be described later, and the second change is detected when it becomes larger than a second difference which will be described later.

Hereinafter, the double reading cancellation determination subroutine in the fourth embodiment will be described with reference to the flowchart of FIG.
Similar to the reading process in the first embodiment, when the decoding result of the information code that has been set to prevent reading twice and has been successfully decoded matches the previous decoding result stored in the memory 35 (in S109 and S119). Yes), the code position point P for the latest captured image is acquired in step S121, and the reading cancellation determination process is performed twice in step S200. In the subroutine in the present embodiment, first, threshold setting processing is performed in step S219 of FIG. In this process, based on the set reference position point Po at step S113, setting the first and threshold P ₁ which is subtracted by the first differential, the second threshold value P _2, which is subtracted by the second difference Is done. In the present embodiment, for example, the first difference is set to a value exceeding 1 and less than 2, and the second difference is set to a value exceeding 0 and less than 1.

When the first threshold value P ₁ and the second threshold value P ₂ is set as described above, in step S201, the flag F is determined for whether it is set to F = 1, the flag F is set to F = 1 If not, it is determined No.

Subsequently, in step S203a, (lower) is smaller than the code position point P is the first threshold value P ₁ acquired in Step S121 the first change is determined whether the detected. Here, code position point P is if the first threshold P ₁ or more, the first change is determined as No at step S203 as not detected, subroutine cancel determination processing is finished reading twice.

On the other hand, if the code position point P is smaller than the first threshold value _{P 1,} at step S203a as the first change is detected is determined as Yes, the flag F is in F = 1 at step S205 Once set, the twice-reading cancellation processing subroutine ends.

With such flag F is determined as Yes at step S201 since it is set to F = 1, at step S207a, code position points P obtained in step S121 is higher than the second threshold value _{P 2} It is determined whether or not a second change that becomes larger (higher) is detected. Here, code position point P is if the second threshold value P ₂ or less, the second variation is determined as No at step S207a as not detected, subroutine cancel determination processing is finished reading twice.

On the other hand, code position point P is in the case larger than the second threshold value P _2, at step S207a as the second change is detected is determined as Yes, twice-read prevention is released at step S209 This completes the twice-reading release determination subroutine.

Here, the change of the code position point P described above will be described with reference to the timing chart shown in FIG.
As illustrated in FIG. 12, the code position point P acquired in step S121 after the code position point P of the information code to which the decoding result has been transferred is set as “3” as the reference position point Po is the reference position point. Even if it becomes smaller than Po (see time t _{1 in} FIG. 12), if it does not become smaller than the first threshold value P ₁ , the first change is not detected and reading prevention is not canceled twice. .

Then, (see time t ₂ in FIG. 12) after the code position point P is first change smaller than the first threshold value P ₁ has been detected, the obtained code position point P rises in Step S121 also (see time t ₃ in FIG. 12), if not greater than the second threshold value P ₂ will not be the second change is prevented read twice without being detected is released. Then, after the detection of the first change, (see time _{t 4} in FIG. 12) code position point P becomes larger than the second threshold value _{P 2,} the second change is detected (Yes in S207a), a step In S209, reading prevention is canceled twice.

As described above, in the optical information reading apparatus 10 according to the present embodiment, based on the set reference position point Po at step S113, the first threshold value P ₁ is set, acquired in step S121 code position point P is, when the lower beyond the first threshold value P ₁ (if the reference to the reference position point Po is lower than the first difference), the first change is detected.

As a result, even if the code position point P acquired in step S121 due to camera shake or the like simply becomes lower than the reference position point Po, as long as the code position point P does not exceed the first threshold value P ₁ (the first difference), Since the double reading prevention function is not released, unnecessary setting of the double reading prevention function can be prevented by appropriately setting the first threshold value P ₁ (the first difference).

With reference to the set reference position point Po at step S113, the second threshold value P ₂ is set, if the code position points P obtained in step S121 becomes higher than the second threshold value P ₂ The second change is detected (when it becomes higher than the second difference with reference to the reference position point Po).

Thus, even after the first change is detected, even if the code position point P acquired in step S121 due to camera shake or the like is simply higher than the reference position point Po, the second threshold value P ₂ (the second difference described above) ) Is not canceled unless the value exceeds 2), an unnecessary double reading prevention function is prevented from being canceled by appropriately setting the second threshold value P ₂ (the second difference). be able to.

In the present embodiment has been set the first both threshold P ₁ and the second threshold value P ₂ in step S219, not limited to this, only either one may be set. For example, in the case where only the first threshold value P ₁ is set, the determination processing in step S207 described above in place of step S207a definitive determination process is performed. Further, when only the second threshold value P ₂ is set, the determination processing in step S203 described above in place of step S203a definitive determination process is performed.

In addition, this invention is not limited to said each embodiment, You may actualize as follows.
(1) Each divided region of the imaging region S is not limited to being given a point composed of any numerical value of 1 to 4 as a weight, but includes points composed of a plurality of types of numerical values having a maximum value of 5 or more. It may be granted. In addition, the weighting is not limited to the numerical value as described above, and, for example, four levels of weighting using A to D or multiple levels of weighting may be performed.

(2) The imaging region S is not limited to a plurality of divided regions formed in a square shape, and, for example, a plurality of divided regions formed in a rectangular shape or a plurality of shapes formed in a plurality of types of shapes. You may comprise from the following divided area.

(3) In the state where reading prevention is canceled twice, the process of transferring the decoding result is not limited, and a predetermined process using the decoding result may be executed by the control circuit 40 or the like.

(4) In step S207, when the code position point P acquired in step S121 is equal to the reference position point Po, the code position point P is not less than the reference position point Po. In this case, the second change may be detected.

DESCRIPTION OF SYMBOLS 10 ... Optical information reader 35 ... Memory (memory | storage means)
40... Control circuit (control means, decode means, determination means, position change detection means)
P: Code position point Po: Reference position point P ₁ : First threshold value P ₂ ... Second threshold value S: Imaging region T: Duration To: Predetermined time

Claims (8)

An imaging means for imaging the information code;
Decoding means for decoding an information code included in a captured image captured by the imaging means;
Control means for executing a predetermined process using a result of decoding by the decoding means;
An optical information reader comprising:
The imaging area of the captured image is divided into a plurality of divided areas,
Position detecting means for detecting a code position of the information code with respect to the imaging region based on the information code being located in any of the plurality of divided regions;
The decoding result when the predetermined processing is executed by the control means is overwritten and stored as a previous decoding result, and the code position corresponding to the decoding result is overwritten and stored as the previous detection position Means,
Determining means for determining whether or not a decoding result by the decoding means matches the previous decoding result stored in the storage means;
A position change detection means for detecting a change of the detected code position by the position detecting means as a reference the previously detected position is stored in the storage means,
With
The control means includes
For the information code determined not to match the previous decoding result by the determination means, the predetermined processing using the decoding result of the information code is executed,
For the information code determined by the determining means to match the previous decoding result, the position change detecting means moves to a direction different from this direction after detecting the change in the code position in the direction toward the outer edge of the imaging region. When the change in the code position is detected, the predetermined processing using the decoding result of the information code is executed. Each of the plurality of divided areas is given a weight that gradually decreases from the center of the imaging area toward the outer edge of the imaging area for each of the divided areas.
The position change detecting means is configured to reduce the weight of the divided area corresponding to the code position detected by the position detecting means with reference to the weight of the divided area corresponding to the previous detected position as the code position change. And a second change in which the weighting of the divided region is increased.
The control means includes
When it is determined by the determining means that the result matches the previous decoding result, for this information code, when the second change is detected after the first change is detected by the position change detecting means, The optical information reading apparatus according to claim 1, wherein the predetermined process using a decoding result of an information code is executed.   3. The optical recording apparatus according to claim 2, wherein the previous detection position is overwritten and stored in the storage means so as to coincide with the highest weighted code position detected by the position detection means. Information reader. Each time the previous decoding result is stored in the storage unit, the plurality of divided areas are weighted gradually lowering toward the outer edge of the imaging area around the previous detection position corresponding to the previous decoding result. Is assigned to each divided area,
The position change detecting means is configured to reduce the weight of the divided area corresponding to the code position detected by the position detecting means with reference to the weight of the divided area corresponding to the previous detected position as the code position change. And a second change in which the weighting of the divided region is increased.
The control means includes
When it is determined by the determining means that the result matches the previous decoding result, for this information code, when the second change is detected after the first change is detected by the position change detecting means, The optical information reading apparatus according to claim 1, wherein the predetermined process using a decoding result of an information code is executed. A time measuring means for measuring a duration when the detection of the first change is continued by the position change detecting means;
The control means includes
When it is determined by the determination means that the result matches the previous decoding result, for the information code, the duration time measured by the time measurement means becomes equal to or longer than a predetermined time, and then the second change is detected by the position change detection means. 5. The optical information reading apparatus according to claim 2, wherein the predetermined process using the decoding result of the information code is executed when the information code is detected.   The position change detection means uses the weight of the divided area corresponding to the previous detection position as a reference, and the weight of the divided area corresponding to the code position detected by the position detection means is lower than a first difference. The optical information reader according to any one of claims 2 to 4, wherein the first change is detected.   The position change detecting means uses the weight of the divided area corresponding to the previous detected position as a reference, and the weight of the divided area corresponding to the code position detected by the position detecting means is higher than a second difference. The optical information reading device according to any one of claims 2 to 4 and 6, wherein the second change is detected.   The optical information reading apparatus according to claim 2, wherein the weight is digitized.

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