JP2013089069A - Optical information reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical information reader capable of notifying a proper reading distance in consideration of an imaging state of an information code.SOLUTION: For respective extracted modules constituting a specific pattern, a blurring degree of the specific pattern is calculated on the basis of luminance values of the respective modules, and a specific width value of the specific pattern is calculated on the basis of width values of the respective modules. Then, when it is determined that the specific pattern is imaged outside a reading proper distance range X on the basis of the blurring degree, control is performed so that first irradiation light L1 is radiated when it is determined that the specific pattern is imaged at a place farther than the reading proper distance range X, and second irradiation light L2 is radiated when it is determined that the specific pattern is not imaged at a place farther than the reading proper distance range on the basis of the specific width value.

Description

  The present invention relates to an optical information reader that optically reads an information code.

  In recent years, handy type optical information readers for optically reading information codes such as barcodes and two-dimensional codes have been put into practical use because of their ease of use. ing. This type of handy type optical information reader includes, for example, a light receiving sensor such as a CCD area sensor, an imaging optical unit having an imaging lens, an illumination device such as an LED, etc. in a main body case configured to be handheld. It is configured with. Then, when the user operates the trigger switch in a state where the reading port formed at the distal end portion of the main body case faces the reading target, the illumination light is irradiated to the reading target on which the information code is displayed by the lighting device. The reflected light enters from the reading port and is picked up by the light receiving sensor through the imaging lens.

  In this type of optical information reading apparatus, a laser diode or LED is used for alignment between the reading object (information code) and the apparatus (reading port), and the reading position with respect to the reading object. For example, an information symbol reading device shown in Patent Document 1 is known as including a marker light irradiating unit that irradiates a marker light to indicate (the visual field of the light receiving sensor and its center position). The marker light irradiating means employed in this information symbol reading device irradiates three spot lights, that is, the central portion of the reading visual field and the left and right end portions. The marker light is irradiated (lighted) only at the time of alignment, and is turned off when an image of the information code is taken.

  By the way, in this type of optical information reading device, a certain range of reading distance (distance from the device to the reading object) suitable for reading due to the relationship between the intensity of illumination light and the exposure time of the light receiving sensor. There is. For this reason, in the information symbol reader of Patent Document 1 described above, marker light consisting of three spot lights is read at an optimum reading distance in order to visually inform the user of the optimum reading depth (distance) of the information code. The image is clearly imaged on the object surface and is configured to be blurred when it is out of an appropriate distance range.

JP-A-11-250172

  By the way, when an information code is optically read, the readable reading distance changes according to the module size of each module constituting the information code. For this reason, in the configuration as disclosed in Patent Document 1 described above, the focal length is reported based on the shape of the projected image of the marker light, but the imaging state of the information code is not taken into account, so the information code module Depending on the size, an appropriate reading distance may not be notified. In this case, there is a problem that if the decoding fails because the imaged information code is blurred, the user is distrusted.

  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 reading apparatus capable of notifying an appropriate reading distance in consideration of an imaging state of an information code. There is.

  In order to achieve the above object, the optical information reader according to claim 1 is an information code (B, Q) comprising a plurality of light color modules and dark color modules, and the light color module and the dark color module are predetermined. Imaging means (28) for imaging an information code including a specific pattern (Cs, FP) arranged in this order, and the information based on the code image of the information code included in the captured image captured by the imaging means An optical information reading device (40) comprising: a decoding means (40) for decoding a code, the extraction means for extracting the specific pattern of the information code from the captured image; and the extraction means extracted by the extraction means A blur condition calculation means for calculating a blur condition (F) of the specific pattern based on the luminance value of each module constituting the specific pattern. 40) and width value calculating means (40) for calculating the width value in the arrangement direction of the specific pattern as the specific width value (H) based on the width value of each module constituting the specific pattern extracted by the extracting means. ) And first determination means (40) for determining whether or not the specific pattern has been imaged outside the proper reading distance range (X) based on the degree of blur calculated by the degree of blur calculation means, Based on the specific width value calculated by the width value calculating means, a second determination means (40) for determining whether or not the specific pattern has been imaged farther than the appropriate reading distance range; and the imaging means Illumination light indicating that the imaged information code is located outside the proper reading distance range with respect to the device, and indicates that the information code is located far outside the proper reading distance range. Irradiating means (50, 51, 52) capable of irradiating either one irradiation light (L1) and second irradiation light (L2) indicating that the reading appropriate distance range is located in the vicinity; When it is determined by the first determination unit that the specific pattern has been imaged outside the proper reading distance range based on the blur condition, the specific pattern is determined based on the specific width value by the second determination unit. The first irradiation light is emitted when it is determined that the image is taken farther than the proper reading distance range, and the second irradiation is determined when it is determined that the specific pattern is not taken farther than the proper reading distance range. And a control means (40) for controlling the irradiating means so as to be irradiated with light.

  According to a second aspect of the present invention, in the optical information reading device according to the first aspect, the irradiating unit is configured such that a light emission state of the first irradiation light is different from a light emission state of the second irradiation light. It is characterized by being.

  According to a third aspect of the present invention, in the optical information reading device according to the first or second aspect, is the captured image captured by the imaging unit partially included without including all of the code image? A third determination unit (40) for determining whether or not, and a third irradiation to a plurality of locations corresponding to outer edges (Se, S1 to S4) of the imaging area (S) imaged as the captured image by the imaging unit Outer edge irradiating means (50, 51 to 54) capable of irradiating light (L1 to L4), and the control means includes a part without including all of the code image by the third determining means. A portion corresponding to the outer edge of the imaging area, where the portion of the code image is located in the information code obtained from the position occupied in the captured image, or the information code Vs. The portion located closer than the other portions Te, wherein said third illumination light to control the outer irradiation means is irradiated.

  According to a fourth aspect of the present invention, in the optical information reading apparatus according to the third aspect, the outer edge irradiating means is configured such that the light emission state of the third irradiation light is the light emission state of the first irradiation light and the second irradiation light. It is characterized by being different from the light emission state.

The optical information reader according to any one of claims 1 to 4, wherein the information code is a QR code (Q), and the specific pattern is the QR code. It is a position detection pattern (FP) for detecting the position of the code.
In addition, the code | symbol in each said parenthesis shows the correspondence with the specific means as described in embodiment mentioned later.

  In the invention of claim 1, for each module constituting the specific pattern extracted by the extracting means, the degree of blur of the specific pattern is calculated by the degree of blur calculation means based on the luminance value of each module, Based on the module width value, the specific width value of the specific pattern is calculated by the width value calculating means. Then, when it is determined by the first determination unit that the specific pattern is captured outside the range of the appropriate reading distance based on the blur condition, the specific pattern is read based on the specific width value by the second determination unit. The first irradiation light is emitted when it is determined that the image is taken farther than the appropriate distance range, and the second irradiation light is emitted when it is determined that the specific pattern is not imaged farther than the reading appropriate distance range. The irradiation means is controlled by the control means so as to be irradiated.

  As a result, when the information code having the specific pattern is imaged farther than the appropriate reading distance range, the first determination means determines that the specific pattern has been imaged outside the appropriate reading distance range and the second determination. It is determined by the means that the specific pattern has been imaged farther than the appropriate reading distance range, and the first irradiation light is emitted. The information code is imaged farther than the appropriate reading distance range for the user who has seen the first irradiation light irradiated in this manner, and the optical information reader is brought closer to the information code. It can be notified that it is necessary.

When the information code having the specific pattern is imaged in the vicinity of the proper reading distance range, the first determining means determines that the specific pattern is imaged outside the proper reading distance range, and the second determining means. Thus, it is determined that the specific pattern is not imaged farther than the appropriate reading distance range, and the second irradiation light is emitted. The information code is imaged in the vicinity of the appropriate reading distance range for the user who has seen the second irradiation light irradiated in this manner, and the optical information reading device is moved away from the information code. It can be notified that it is necessary.
Therefore, an appropriate reading distance can be notified in consideration of the imaging state of the information code.

  In the invention of claim 2, since the irradiation means is configured so that the light emission state of the first irradiation light and the light emission state of the second irradiation light are different, the first irradiation light and the second irradiation light can be easily obtained. Since it becomes easy to distinguish, the user can easily grasp the appropriate reading distance only by looking at either the first irradiation light or the second irradiation light.

  In the third aspect of the invention, when the third determination unit determines that the code image captured by the imaging unit includes a part of the code image without including all of the code image, it corresponds to the outer edge of the imaging area. The third irradiation is applied to a location that is located within an information code that is obtained from a position that a part of the code image occupies in the captured image, or that is located closer to the information code than other locations. The outer edge irradiation means is controlled by the control means so that light is irradiated.

  As a result, the position where the third irradiation light is irradiated is on the outer edge of the imaging area and indicates the inside or the vicinity of the information code where a part is imaged, so that the imaging direction of the imaging means is directed to the irradiation position. Thus, all of the information code can be put in the imaging area. Therefore, by irradiating the third irradiation light as described above, not only that the captured image does not include the entire code image, but also that the information code is captured. The direction in which the imaging direction of the imaging means should be changed can be notified.

  In the invention of claim 4, since the outer edge irradiation means is configured such that the light emission state of the third irradiation light is different from the light emission state of the first irradiation light and the light emission state of the second irradiation light, the third irradiation light And the first irradiation light and the second irradiation light can be easily distinguished from each other, so that the user should change the appropriate reading distance or the imaging direction of the imaging means only by looking at one of the irradiation lights. Can be easily grasped.

  If the information code to be imaged is a QR code (registered trademark) as in the invention of claim 5, a position detection pattern for detecting the position of the QR code is adopted as the specific pattern. The specific width value can be calculated easily and accurately. Thereby, the imaging state of the information code is sufficiently considered, and an appropriate reading distance can be notified reliably.

It is a block diagram which shows the electric constitution of the optical information reader which concerns on this embodiment. It is explanatory drawing for demonstrating each irradiation state of the outer periphery irradiation apparatus with respect to an imaging area. It is explanatory drawing for demonstrating the relationship between a reading appropriate distance range and each irradiation state of an outer edge irradiation apparatus. It is a flowchart which illustrates the flow of the reading process performed by a control circuit. FIG. 5A is an explanatory diagram illustrating a state where a QR code is captured as a captured image, and FIG. 5B illustrates an imaging state of a QR code position detection pattern within the proper reading distance range and this position detection. It is explanatory drawing which shows the change of the luminance value in the arrangement direction of a pattern. FIG. 6A is an explanatory diagram showing an imaging state of a QR code position detection pattern imaged far from the appropriate reading distance range and a change in luminance value in the arrangement direction of the position detection pattern. FIG. 7B is an explanatory diagram illustrating an imaging state of a QR code position detection pattern imaged in the vicinity of a proper reading distance range and a change in luminance value in the arrangement direction of the position detection pattern. It is explanatory drawing which shows the positional relationship of QR Code and the outer edge area | region of an imaging area when a code image is partially included in image data. FIG. 8A is an explanatory diagram illustrating a state in which a barcode is captured as a captured image, and FIG. 8B illustrates an imaging state of the start character of the barcode in the proper reading distance range and the start character. It is explanatory drawing which shows the change of the luminance value in an arrangement direction. FIG. 9A is an explanatory diagram showing an imaging state of a bar code start character imaged farther than the proper reading distance range and a change in luminance value in the arrangement direction of the start character. These are explanatory drawings showing the imaging state of the start character of the barcode imaged in the vicinity of the proper reading distance range and the change in the luminance value in the arrangement direction of the start character.

  Hereinafter, an embodiment of an optical information reading device according to 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 present embodiment. FIG. 2 is an explanatory diagram for explaining each irradiation state of the outer edge irradiation device 50 with respect to the imaging area S. FIG.

  The optical information reader 10 shown in FIG. 1 has a plurality of white patterns (light color patterns) and black patterns (dark color patterns) such as one-dimensional codes and two-dimensional codes such as barcodes attached to articles. It is comprised as an apparatus which reads the information code which becomes. The optical information reading apparatus 10 includes a case 20 in which a circuit unit 20 is housed. The circuit unit 20 mainly includes an illumination light source 21, an outer edge irradiation device 50, a light receiving sensor 28, and 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 light projecting optical system includes an illumination light source 21 and an outer edge irradiation device 50. The illumination light source 21 is controlled by the control circuit 40 and functions as an illumination light source capable of emitting the illumination light Lf. For example, the illumination light source 21 includes 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 reading object R to which QR code Q 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 by the QR code Q or the like. For example, a light receiving element which is a solid-state imaging device such as a C-MOS or CCD is arranged two-dimensionally. 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 an example of an “imaging unit” recited in the claims.

  The imaging lens 27 functions as an imaging optical system capable of condensing incident light incident from the outside through the reading port 13 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 QR code Q, 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 outer edge irradiation device 50 irradiates a plurality of locations in the outer edge region Se corresponding to the vicinity of the outer edge of the imaging area S regardless of the distance from the imaging area (reading visual field) S captured as a captured image by the light receiving sensor 28. It is configured to be able to irradiate light. Specifically, the outer edge irradiation device 50 includes four light sources 51 to 54 controlled by the control circuit 40. As shown in FIG. 2, the outer edge region Se is moved to the lower region S1 by the light source 51. The irradiation light L1 is irradiated to the upper region S2 by the light source 52, the irradiation light L3 is irradiated to the left region S3 by the light source 53, and the right region S4 is irradiated by the light source 54 to the right region S4. The irradiation light L4 is configured to be irradiated.

  In particular, the light source 51 is configured to be able to irradiate either the green irradiation light L1 or the blue irradiation light L1 with respect to the lower region S1, and the light source 52 is yellowish green with respect to the upper region S2. It is configured to be able to irradiate either the irradiation light L2 or the blue irradiation light L2. The light source 53 is configured to be able to irradiate the left region S3 with the blue irradiation light L3, and the light source 54 is configured to be able to irradiate the right region S4 with the blue irradiation light L4.

  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 liquid crystal display 46, a communication interface 48, and the like. It is composed of

  The image signal (analog signal) output from the light receiving sensor 28 of the optical system is input to the amplification circuit 31 and amplified with a predetermined gain, and then input to the A / D conversion circuit 33. Converted. 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. In addition, the ROM stores in advance a predetermined program that can execute a reading process and an analysis process, which will be described later, and a system program that can control each hardware such as the illumination light source 21, the outer edge irradiation device 50, and the light receiving sensor 28. ing.

  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. The control circuit 40 is configured to be connectable to various input / output devices (peripheral devices) via a built-in input / output interface. In this embodiment, the control circuit 40 includes a trigger switch 42, light emission. The unit 43, the buzzer 44, the vibrator 45, the communication interface 48, and the like are connected. Thereby, for example, monitoring and management of the trigger switch 42, lighting and non-lighting of the light emitting unit 43, on / off of the sound of the buzzer 44 capable of generating a beep sound and an alarm sound, and transmission to the user of the optical information reading device 10 The control circuit 40 performs drive control of the vibrator 45 that can generate possible vibrations, communication control of the communication interface 48 that enables communication with an external device, and the like.

  Next, a reading process executed by the control circuit 40 of the optical information reading apparatus 10 configured as described above will be described with reference to the drawings. FIG. 3 is an explanatory diagram for explaining the relationship between the proper reading distance range X and each irradiation state of the outer edge irradiation device 50. FIG. 4 is a flowchart illustrating the flow of the reading process executed by the control circuit 40. FIG. 5A is an explanatory diagram showing a state where the QR code Q is captured as a captured image, and FIG. 5B is an imaging state of the position detection pattern FP of the QR code Q in the proper reading distance range X. It is explanatory drawing which shows the change of the luminance value in the sequence direction of this position detection pattern FP. FIG. 6A is an explanatory diagram showing an imaging state of the position detection pattern FP of the QR code Q imaged far from the proper reading distance range X and a change in luminance value in the arrangement direction of the position detection pattern FP. FIG. 6B is an explanatory diagram showing an imaging state of the position detection pattern FP of the QR code Q captured in the vicinity of the proper reading distance range X and a change in luminance value in the arrangement direction of the position detection pattern FP. is there. FIG. 7 is an explanatory diagram showing a positional relationship between the QR code Q and the outer edge region Se of the imaging area S when a part of the code image is included in the image data.

  In the configuration of the optical information reading apparatus typified by this embodiment, the reading distance (distance from the apparatus to the reading object) suitable for reading is some extent due to the relationship between the intensity of illumination light and the exposure time of the light receiving sensor. There is a range (read appropriate distance range X: see FIG. 3). Then, when the information code is optically read, the optimum illumination light intensity and the exposure time of the light receiving sensor change according to the module size of each module constituting the information code, so that the information code can be read according to the module size. The reading distance, that is, the reading appropriate distance range X changes.

  Therefore, in the reading process according to the present embodiment, an information code including a specific pattern in which the light color module and the dark color module are arranged in a predetermined order, for example, a QR code including a position detection pattern FP for detecting the position as the specific pattern. When Q is imaged, processing is performed as follows. That is, when it is determined that the position detection pattern FP has been imaged farther than the proper reading distance range X and when it is determined that the position detection pattern FP has been imaged nearer than the proper reading distance range X, the outer edge irradiation device 50 Change the irradiation state.

  Specifically, when it is determined that the position detection pattern FP has been imaged farther than the proper reading distance range X, the captured QR code Q is located far from the proper reading distance range X. As the first irradiation light to be notified, the green irradiation light L1 is emitted from the light source 51 of the outer edge irradiation device 50 to the lower region S1. Further, when it is determined that the position detection pattern FP has been imaged in the vicinity of the proper reading distance range X, a notification is made that the picked-up QR code Q is outside the proper reading distance range X and is positioned in the vicinity. As the second irradiation light, yellow-green irradiation light L2 is emitted from the light source 52 of the outer edge irradiation device 50 to the upper region S2. Thereby, the user can see whether the imaged QR code Q is imaged farther than the appropriate reading distance range X or the imaged in the vicinity by viewing the irradiation state by the outer edge irradiation device 50. The user can be notified.

  Hereinafter, the reading process according to the present embodiment will be described in detail with reference to the flowchart shown in FIG. In the following description, first, a case where the QR code Q having the position detection pattern FP is to be read will be described. Here, when the light and dark information is scanned so that the position detection pattern FP crosses or crosses the position detection pattern FP, the continuous ratio of the same color modules is 1: 1 in the order of dark, bright, dark, bright, and dark. : 3: 1: 1. Note that the control circuit 40 that executes the reading process may correspond to an example of a “control unit” recited in the claims.

  In the present embodiment, the optical information reading apparatus 10 is turned on, the reading process shown in FIG. 4 is started, and the user performs a predetermined operation, for example, an operation of turning on the trigger switch 42, so that step S101 is performed. When it is determined Yes in the determination process shown in FIG. 8, the code imaging process shown in step S103 is performed. In this process, first, the control circuit 40 outputs a light emission signal to the illumination light source 21 based on the synchronization signal, and the illumination light source 21 that has received the light emission signal emits the LED to emit the illumination light Lf. Then, the illumination light Lf applied to the QR code Q is reflected, and the reflected light Lr enters the imaging lens 27 through the reading port 13. An image of the QR code Q, that is, a code image is formed on the light receiving surface 28 a of the light receiving sensor 28 by the imaging lens 27. Thereby, each light receiving element constituting the light receiving sensor 28 is exposed, and a light receiving signal corresponding to the image including the QR code Q is output from each light receiving element. These received light signals constitute, for example, image data including a code image of QR code Q as illustrated in FIG. 5A, and the image data thus generated is temporarily stored in the memory 35. Is remembered.

  Next, the specific pattern extraction process shown in step S105 is performed. In this process, a process for extracting any one of the three position detection patterns FP of the QR code Q is performed on the image data generated in step S103. At this time, when the position detection pattern FP is not included in the image data captured by the code imaging process, it is determined No in step S107, and the above-described code imaging process is performed again. The control circuit 40 that executes the determination process shown in step S105 may correspond to an example of an “extraction unit” recited in the claims.

When the position detection pattern FP is included in the image data captured by the code imaging process (Yes in S107), the blur condition calculation process shown in step S109 is performed. In this process, the brightness value of each module constituting the position detection pattern FP extracted in the specific pattern extraction process and the surrounding margin, specifically, the widest width among the modules constituting the position detection pattern FP. The brightness value WB of the dark color module (see M3 in FIG. 5B) with the largest value, the brightness value NS of the light color module (see M2 in FIG. 5B) with the smallest width value, and the smallest width value Based on the brightness value NB of the dark color module (see M4 in FIG. 5B) and the brightness value WS of the margin, the blur condition F of the position detection pattern FP is calculated by the following equation (1). .
F = (WS-WB) / (NS-NB) (1)

  The brightness value of a wide module is less affected by blur, and the brightness value of a narrow module is more susceptible to blur, so the brightness difference between light and dark of a wide module and the brightness difference of a narrow module Therefore, the degree of blur F can be calculated by the above equation (1). As the brightness value WS, the brightness value of the light color module having the largest width value among the modules constituting the position detection pattern FP may be adopted instead of the brightness value of the margin.

  In the present embodiment, the brightness value is indicated by 0 to 255, and the numerical value increases as it approaches white, that is, the lighter color degree increases, and the numerical value increases as it approaches black, that is, the darker degree increases. Lower. Therefore, for example, when the position detection pattern FP is imaged within the proper reading distance range X, when there is little blur, as illustrated in FIG. 5B, not only the luminance value WS but also the luminance value NS is also close to 255, and not only the brightness value WB but also the brightness value NB is close to 0. Therefore, the denominator and the numerator of Expression (1) are equal, and the degree of blur F approaches 1. On the other hand, when the influence of blur increases because the position detection pattern FP is captured outside the proper reading distance range X, the value of the blur condition F increases as the distance outside the proper reading distance range X increases. growing. Note that the control circuit 40 that executes the blur condition calculation process shown in step S109 may correspond to an example of the “blur condition calculation unit” recited in the claims.

  Next, the specific width value calculation process shown in step S111 is performed. In this process, the width value of the position detection pattern FP, which is the sum of the width values of all the modules M1 to M5 (see FIG. 5B) constituting the position detection pattern FP, is calculated as the specific width value H. The units of the width value and the specific width value H of each module M1 to M5 are values corresponding to the width value of one pixel of the captured image. For example, when the modules M1, M2, M4, and M5 are each composed of 3 (pixels) and the module M3 is composed of 9 pixels, the specific width value H is 21 (pixels). Further, the control circuit 40 that executes the specific width value calculation process shown in step S111 may correspond to an example of “width value calculation means” recited in the claims.

  Subsequently, in the determination process shown in step S113, it is determined whether or not the blur condition F calculated in the blur condition calculation process is equal to or less than a predetermined threshold value Fo. The predetermined threshold Fo is the degree of blur F calculated by the above equation (1) when the position detection pattern FP located at the farthest position or the nearest position in the proper reading distance range X is imaged. In this embodiment, for example, Fo = 2 is set. The control circuit 40 that executes the determination process shown in step S113 may correspond to an example of “first determination unit” recited in the claims.

  Here, since the position detection pattern FP is imaged within the proper reading distance range X, when the degree of blur F is equal to or less than the predetermined threshold Fo (Yes in S113), the extinguishing process shown in step S115 is performed. When any one of the light sources 51 to 54 of the outer edge irradiation device 50 is lit, the lit light source is turned off.

  Subsequently, a code image extraction process shown in step S117 is performed. In this process, a process for extracting a code image corresponding to the QR code Q is performed on the image data generated in step S103. At this time, if all the code images are included in the image data captured by the code imaging process, the determination at Step S119 is Yes and the decoding process shown at Step S121 is performed. In this process, a known decoding process is performed on the code image extracted as described above. When the decoding by the decoding process is successful and character data encoded as QR code Q is acquired (Yes in S123), the data transmission process shown in step S125 is performed, and the character acquired by the decoding process is performed. Data or the like is transmitted to a host system such as an external device via the communication interface 48. And the process from the determination process shown to step S101 is repeated again. The control circuit 40 that executes the specific width value calculation process shown in step S121 may correspond to an example of a “decoding unit” recited in the claims.

  In the determination process shown in step S113 described above, since the position detection pattern FP located farther than the proper reading distance range X is imaged, the imaged position detection pattern FP is illustrated in FIG. When the brightness difference (NS-NB) of the narrow module becomes smaller than the brightness difference (WS-WB) of the wide module and the blur condition F exceeds the predetermined threshold Fo, it is determined as No. Is done.

  As described above, when the blur condition F exceeds the predetermined threshold value Fo, whether or not the specific width value H calculated in the specific width value calculation process is equal to or less than the predetermined threshold value Ho in the determination process shown in step S127. Is determined. The predetermined threshold Ho is a value corresponding to the specific width value H calculated by the sum of the width values of the modules M1 to M5 when the position detection pattern FP located far from the proper reading distance range X is imaged. Is set to Specifically, the predetermined threshold value Ho is set as Ho = 7 (pixels) so that the width value of the unit modules constituting the position detection pattern FP corresponds to the width value of one pixel, for example. The control circuit 40 that executes the determination process shown in step S127 may correspond to an example of a “second determination unit” recited in the claims.

  As described above, as illustrated in FIG. 6A, when the position detection pattern FP located far from the proper reading distance range X is captured, the specific width value H is equal to or less than the predetermined threshold value Ho. (Yes in S127), the first irradiation light irradiation process shown in step S129 is performed. In this process, as the first irradiation light for notifying that the imaged QR code Q is located far from the proper reading distance range X, the irradiation light is emitted from the light source 51 of the outer edge irradiation device 50 to the lower region S1. L1 is irradiated (see FIGS. 2 and 3). Thereby, the user is notified that the captured QR code Q is located farther than the proper reading distance range X by viewing the irradiation light L1 irradiated to the lower region S1. be able to.

  On the other hand, in the determination process shown in step S113 described above, since the position detection pattern FP located in the vicinity of the proper reading distance range X is captured, the captured position detection pattern FP is illustrated in FIG. 6B. In addition, even when the brightness difference (NS-NB) of the narrow module becomes smaller than the brightness difference (WS-WB) of the wide module, and the blur condition F exceeds the predetermined threshold Fo, No is determined.

  Since the position detection pattern FP located in the vicinity of the proper reading distance range X is captured, when the specific width value H exceeds the predetermined threshold value Ho (No in S127), the second irradiation light irradiation shown in step S131 is performed. Processing is done. In this process, the irradiation light L2 from the light source 52 of the outer edge irradiation device 50 to the upper region S2 is used as the second irradiation light for notifying that the imaged QR code Q is located in the vicinity of the proper reading distance range X. Is irradiated (see FIGS. 2 and 3). Thereby, the user is notified that the captured QR code Q is located closer to the proper reading distance range X by viewing the irradiation light L2 irradiated on the upper region S2. Can do.

  As described above, when the irradiation light L1 is irradiated in the first irradiation light irradiation process or the irradiation light L2 is irradiated in the second irradiation light irradiation process, the code is maintained with the irradiation state maintained. Imaging processing is performed. For example, the user who viewed the irradiation light L1 in the state where the irradiation light L1 is irradiated because the QR code Q located far away from the appropriate reading distance range X is imaged is displayed by the user. When the QR code Q is imaged within the appropriate reading distance range X (Yes in S113) by bringing the optical information reading device 10 closer to the above, the irradiation of the irradiation light L1 is stopped by the extinguishing process. . The user who sees the stop of the irradiation of the irradiation light L1 can recognize that the QR code Q to be read is captured within the proper reading distance range X.

  In addition, since the QR code Q located outside the proper reading distance range X is imaged, the user who viewed the irradiation light L2 in the state of irradiation with the irradiation light L2 When the QR code Q is imaged within the proper reading distance range X by moving the optical information reader 10 away (Yes in S113), the irradiation of the irradiation light L2 is stopped by the extinguishing process. The user who sees the stop of the irradiation of the irradiation light L2 can recognize that the QR code Q to be read has been imaged within the proper reading distance range X.

  Further, in the determination process shown in step S119 described above, as illustrated in FIG. 7, all the code images of the image data captured by the code imaging process including the position detection pattern FP are included. If not, it is determined No and the code position calculation process shown in step S133 is performed. In this process, a position corresponding to a code image in which a part of the image data is included in the outer edge region Se of the imaging area S is calculated as a code position. The control circuit 40 that executes the determination process shown in step S119 can correspond to an example of “third determination unit” recited in the claims.

  Subsequently, a third irradiation light irradiation process shown in step S135 is performed. In this process, as the third irradiation light for notifying that the captured QR code Q is out of the imaging area S, the light source 51 to 54 is closest to the code position calculated as described above. Blue light is emitted from a light source that emits light. Specifically, as illustrated in FIG. 7, when the code position corresponds to the right region S4, the blue light L4 is emitted from the light source 54 to the right region S4.

  As a result, the user sees the blue irradiation light L4 irradiated to the right side region S4, so that the captured QR code Q is out of the imaging area S, and the irradiation light L4 is in the center of the imaging area S. By changing the orientation of the reading port 13 so as to be positioned, it is possible to notify the user that the QR code Q is entirely included in the imaging area S.

  In the third irradiation light irradiation process, when the code position corresponds to the lower region S1, the blue light L1 is irradiated from the light source 51 to the lower region S1, and the code position is set to the upper region S2. In the case of corresponding to the above, the blue irradiation light L2 is emitted from the light source 52 to the upper region S2. In the third irradiation light irradiation process, when the code position corresponds to the left region S3, the blue irradiation light L3 is irradiated from the light source 53 to the left region S3.

  In addition, when the code position is located at approximately the same distance with respect to two near each of the areas S1 to S4, the irradiation light may be simultaneously applied to both the areas. In this case, the user is notified that the QR code Q is all included in the imaging area S by changing the orientation of the reading port 13 so that the two irradiation lights are located in the center of the imaging area S. can do.

  Here, when the irradiation light L1 is irradiated to the lower region S1, if the emission color of the irradiation light L1 is blue, a state in which the captured QR code Q is out of the imaging area S is notified, and irradiation is performed. If the emission color of the light L1 is green, a state in which the captured QR code Q is located far from the proper reading distance range X is notified. Also, when the upper region S2 is irradiated with the irradiation light L2, if the emission color of the irradiation light L2 is blue, it is notified that the captured QR code Q is out of the imaging area S, and the irradiation light L2 If the emission color is yellow-green, a state in which the captured QR code Q is outside the proper reading distance range X and located in the vicinity is notified.

  As described above, when the third irradiation light is irradiated in the third irradiation light irradiation process, the code imaging process is performed while the irradiation state is maintained. Then, the user who sees the third irradiation light irradiated as described above changes the direction of the reading port 13 so that the third irradiation light is positioned in the center of the imaging area S, whereby the code imaging processing is performed. When all the code images are included in the image data picked up at (Yes in S119), the processes after the decoding process are performed.

  Next, a case where the barcode B of the CODE 39 having the start character Cs as a specific pattern is to be read will be described with reference to FIGS. FIG. 8A is an explanatory diagram illustrating a state in which the barcode B is captured as a captured image, and FIG. 8B illustrates an imaging state of the start character Cs of the barcode B in the proper reading distance range X. It is explanatory drawing which shows the change of the luminance value in the arrangement direction of this start character Cs. FIG. 9A is an explanatory diagram showing an imaging state of the start character Cs of the bar code B imaged far from the proper reading distance range X and a change in luminance value in the arrangement direction of the start character Cs. FIG. 9B is an explanatory diagram illustrating an imaging state of the start character Cs of the barcode B imaged in the vicinity of the proper reading distance range X and a change in luminance value in the arrangement direction of the start character Cs. In FIG. 8A, the symbol Ce indicates a stop character, the symbols Cd1 and Cd2 indicate predetermined data characters, the symbol Qz indicates a quiet zone, and the symbol G indicates a gap between characters. .

  As in the case of reading the QR code Q, when image data is generated in the code imaging process shown in step S103, a process for extracting the start character Cs of the barcode B is performed in the specific pattern extraction process. Made. Then, as shown in FIG. 8A, when the start character Cs is included in the image data captured by the code imaging process (Yes in S107), the blur condition calculation process shown in step S109 is performed. .

  In this process, the brightness value of each module constituting the start character Cs extracted in the specific pattern extraction process, specifically, the light color module having the largest width value among the modules constituting the start character Cs. The luminance value WS (see M2 in FIG. 8B), the luminance value WB of the dark color module (see M5 in FIG. 8B) with the largest width value, and the light color module with the smallest width value (see FIG. 8). Based on the brightness value NS of (M4 in (B)) and the brightness value NB of the dark color module having the smallest width value (see M3 in FIG. 8B), the blur condition F of the start character Cs is described above. Calculated by equation (1).

  Next, the specific width value calculation process shown in step S111 is performed, and the width value of the start character Cs, which is the sum of the width values of all the modules M1 to M7 constituting the start character Cs, is calculated as the specific width value H.

  Since the start character Cs is imaged within the proper reading distance range X, as can be seen from FIG. 8B, when the calculated blur degree F is equal to or less than the predetermined threshold Fo (S113). Yes), the process after the extinguishing process shown in step S115 is performed.

  On the other hand, since the start character Cs located farther than the appropriate reading distance range X is imaged, as shown in FIG. 9A, the imaged start character Cs has a brightness difference between light and dark ( The difference in brightness between dark and light (NS-NB) of a module having a narrower width than (WS-WB) becomes smaller, the degree of blur F exceeds a predetermined threshold Fo (No in S113), and the specific width value H is a predetermined threshold Ho. When the following occurs (Yes in S127), the first irradiation light irradiation process shown in step S129 is performed. Thereby, since irradiation light L1 is irradiated with respect to lower area | region S1 from the light source 51 of the outer edge irradiation apparatus 50 as said 1st irradiation light, irradiation light L1 with which a user irradiates with respect to lower area | region S1. The user can be informed that the imaged barcode B is located farther than the proper reading distance range X.

  Further, since the start character Cs located in the vicinity of the proper reading distance range X is imaged, as shown in FIG. 9B, the imaged start character Cs has a brightness difference between light and dark in a wide module ( The difference in brightness between dark and light (NS-NB) of a module having a narrower width than (WS-WB) becomes smaller, the degree of blur F exceeds a predetermined threshold Fo (No in S113), and the specific width value H is a predetermined threshold Ho. (No in S127), the second irradiation light irradiation process shown in step S131 is performed. Thereby, since the irradiation light L2 is irradiated to the upper region S2 from the light source 52 of the outer edge irradiation device 50 as the second irradiation light, the user sees the irradiation light L2 irradiated to the upper region S2. Thus, it is possible to notify the user that the imaged barcode B is located closer to the proper reading distance range X.

  Even when the start character Cs is captured within the proper reading distance range X, if the entire code image of the barcode B is not included (No in S119), the code position calculation process is performed. Thus, the code position is calculated. Then, the third irradiation light irradiation process is performed, and the third irradiation light for notifying that the imaged barcode B is out of the imaging area S is calculated as described above among the light sources 51 to 54. Blue light is emitted from a light source that emits irradiation light closest to the cord position. Thereby, the imaged barcode B is out of the imaging area S by viewing the blue third irradiation light irradiated by the user, and the third irradiation light is positioned at the center of the imaging area S. By changing the orientation of the reading port 13, it is possible to notify the user that the barcode B is entirely included in the imaging area S.

  As described above, in the optical information reading apparatus 10 according to the present embodiment, for each module constituting the extracted specific pattern (position detection pattern FP, start character Cs), based on the luminance value of each module. The blur condition F of the specific pattern is calculated, and the specific width value H of the specific pattern is calculated based on the width value of each module. When it is determined that the specific pattern is captured outside the proper reading distance range X based on the blur condition F, the specific pattern is farther than the proper reading distance range X based on the specific width value H. If it is determined that the image has been captured (Yes in S127), the first irradiation light is irradiated, and if it is determined that the specific pattern is not captured farther than the proper reading distance range X (No in S127), The control circuit 40 controls the light sources 51 to 54 of the outer edge irradiation device 50 so that the second irradiation light is irradiated.

  As a result, when the information code having the specific pattern is imaged farther than the proper reading distance range X, it is determined by the determination process shown in step S115 that the specific pattern has been imaged outside the proper reading distance range X. In the determination process shown in step S127, it is determined that the specific pattern has been imaged farther than the appropriate reading distance range X, and the first irradiation light is emitted. An information code is imaged farther than the appropriate reading distance range X with respect to the user who has seen the first irradiation light irradiated in this manner, and the optical information reading device 10 corresponds to the information code. It is possible to notify that it is necessary to bring

When the information code having the specific pattern is imaged in the vicinity of the proper reading distance range X, it is determined by the determination process shown in step S115 that the specific pattern has been imaged outside the proper reading distance range X. It is determined by the determination process shown in step S127 that the specific pattern has not been imaged farther than the appropriate reading distance range X, and the second irradiation light is emitted. For the user who has seen the second irradiation light irradiated in this way, an information code is imaged in the vicinity of the appropriate reading distance range X, and the optical information reading device is connected to the information code. It is possible to notify that it is necessary to keep away.
Therefore, an appropriate reading distance can be notified in consideration of the imaging state of the information code.

  The first irradiation light is green irradiation light L1 emitted from the light source 51 to the lower region S1, and the second irradiation light is yellowish green emitted from the light source 52 to the upper region S2. The outer edge irradiation device 50 is configured so that the light emission state of the first irradiation light and the light emission state of the second irradiation light are the irradiation light L2. For this reason, since it becomes easy to distinguish the first irradiation light and the second irradiation light, the user can easily set an appropriate reading distance only by looking at either the first irradiation light or the second irradiation light. I can grasp it.

  Furthermore, when it is determined by the determination process shown in step S119 that the captured image does not include all of the code image but is partially included, the outer edge region Se of the imaging area S The outer edge irradiation device 50 is controlled by the control circuit 40 so that the third irradiation light is irradiated to any one of the region S1, the upper region S2, the left region S3, and the right region S4.

  Thereby, all the information codes can be put in the imaging area S by directing the reading port 13 to the irradiation position of the third irradiation light. Therefore, by irradiating the third irradiation light as described above, not only that the captured image does not include the entire code image, but also that the information code is captured. The direction in which the direction of the reading port 13 (the imaging direction by the light receiving sensor 28) should be changed can be notified.

  In particular, the third irradiation light is blue irradiation light L1 to L4, the first irradiation light is green irradiation light L1, and the second irradiation light is yellow-green irradiation light L2. The outer edge irradiation device 50 is configured such that the emission state of the irradiation light is different from the emission state of the first irradiation light and the emission state of the second irradiation light. For this reason, since it becomes easy to distinguish the 3rd irradiation light, the 1st irradiation light, and the 2nd irradiation light, a user only looks at any one of each irradiation light, and proper reading distance or reading mouth 13 It is possible to easily grasp the direction to change the direction of the. Note that the emission colors (green, yellow-green, and blue) of the first to third irradiation lights described above are examples, and other easily-identified emission colors may be employed.

  Furthermore, if the information code to be imaged is a QR code Q, the position detection pattern FP for detecting the position of the QR code is adopted as the specific pattern, so that the blur condition F and the specific width value H can be easily and It is possible to calculate with high accuracy. Thereby, the imaging state of the information code is sufficiently considered, and an appropriate reading distance can be notified reliably.

  Furthermore, if the information code to be imaged is a bar code B, the start character Cs is adopted as the specific pattern. Therefore, even in this way, the blur condition F and the specific width value H can be calculated easily and accurately. be able to. Thereby, the imaging state of the information code is sufficiently considered, and an appropriate reading distance can be notified reliably.

Note that the present invention is not limited to the above-described embodiments and modifications, and may be embodied as follows.
(1) In the above step S105, not only the above-described QR code Q position detection pattern FP and bar code B start character Cs are extracted, but also the information code in this information code is premised on reading other standard information codes. A specific pattern may be extracted. In this case, the degree of blur F and the specific width value H are calculated for the extracted specific pattern, and any one of the light sources 51 to 54 of the outer edge irradiation device 50 is selected according to the comparison result of the comparison with the predetermined threshold values Fo and Ho. By setting the irradiation state, an appropriate reading distance can be notified.

(2) The first irradiation light is not limited to being applied to the lower region S1 by the light source 51, but is applied to the outer edge region Se or the like of another imaging area S, whereby the second irradiation light and the third irradiation are performed. It may be irradiated so as to be distinguishable from light. Further, the second irradiation light is not limited to being irradiated to the upper region S2 by the light source 52, but is irradiated to the outer edge region Se or the like of the other imaging area S, so that the first irradiation light and the third irradiation light are combined. It may be irradiated in a distinguishable manner.

(3) In the outer edge irradiation device 50, the first irradiation light for notifying that the imaged information code is located far from the proper reading distance range X, and the imaged information code is downward from the imaging area S. The third irradiation light for notifying the detached state is not limited to being distinguished by changing the emission color (green and blue) of the light source 51. For example, a new light source dedicated to the first irradiation light is provided. The first irradiation light and the third irradiation light may be distinguished. Further, in the outer edge irradiation device 50, the second irradiation light for notifying that the imaged information code is located in the vicinity of the proper reading distance range X and the imaged information code deviate upward from the imaging area S. By changing the emission color (green and blue) of the light source 52, the third irradiation light that informs the state is not limited to being distinguished, for example, by newly providing a light source dedicated to the second irradiation light, The second irradiation light and the third irradiation light may be distinguished.

(4) In the optical information reading apparatus that can clearly indicate the reading field of view by the light receiving sensor 28 by marker light or the like, the determination process, the code position calculation process, and the third irradiation light irradiation process shown in step S119 may be abolished.

DESCRIPTION OF SYMBOLS 10 ... Optical information reader 28 ... Light receiving sensor (imaging means)
40. Control circuit (decoding means, extraction means, blur condition calculation means, width value calculation means, first determination means, second determination means, control means, third determination means)
50 ... Outer edge irradiation device (irradiation means, outer edge irradiation means)
51, 52 ... Light source (irradiation means, outer edge irradiation means)
53, 54 ... Light source (outer edge irradiation means)
B ... Bar code (information code)
Cs: Start character (specific pattern)
FP ... Position detection pattern (specific pattern)
L1 to L4 ... Irradiation light S ... Imaging area Se ... Outer edge region S1 ... Lower region S2 ... Upper region S3 ... Left region S4 ... Right region Q ... QR code (information code)
X ... Reading distance range

Claims (5)

Imaging means for imaging an information code comprising a plurality of light color modules and dark color modules and including a specific pattern in which the light color modules and the dark color modules are arranged in a predetermined order;
Decoding means for decoding the information code based on the code image of the information code included in the captured image captured by the imaging means;
An optical information reader comprising:
Extracting means for extracting the specific pattern of the information code from the captured image;
A blur condition calculating means for calculating a blur condition of the specific pattern based on a luminance value of each module constituting the specific pattern extracted by the extracting means;
A width value calculating means for calculating the width value in the arrangement direction of the specific pattern as the specific width value based on the width value of each module constituting the specific pattern extracted by the extracting means;
First determination means for determining whether or not the specific pattern has been imaged outside a proper reading distance range based on the blur condition calculated by the blur condition calculation means;
Based on the specific width value calculated by the width value calculating means, second determination means for determining whether or not the specific pattern has been imaged farther than the appropriate reading distance range;
Irradiation light indicating that the information code imaged by the imaging means is located outside the proper reading distance range with respect to the apparatus, and indicates that the information code is located far outside the proper reading distance range. Irradiating means capable of irradiating either the first irradiating light and the second irradiating light indicating that the reading appropriate distance range is located in the vicinity;
When it is determined by the first determination unit that the specific pattern has been imaged outside the proper reading distance range based on the degree of blur, the specific pattern is determined based on the specific width value by the second determination unit. When it is determined that an image is taken farther than the proper reading distance range, the first irradiation light is emitted, and when it is determined that the specific pattern is not taken farther than the proper reading distance range, the second is applied. Control means for controlling the irradiation means so that the irradiation light is irradiated;
An optical information reading apparatus comprising:   The optical information reading apparatus according to claim 1, wherein the irradiation unit is configured such that a light emission state of the first irradiation light is different from a light emission state of the second irradiation light. Third determination means for determining whether or not a part of the code image is included in the captured image captured by the imaging means;
An outer edge irradiating means capable of irradiating a third irradiation light to a plurality of locations corresponding to an outer edge of an imaging area captured as the captured image by the imaging means
The control means is a portion corresponding to an outer edge of the imaging area when the third determination means determines that a part of the code image is included without being included, and The third irradiation light may be irradiated to a location where a part is located in the information code obtained from a position occupied in the captured image or a location located closer to the information code than other locations. The optical information reader according to claim 1, wherein the outer edge irradiation unit is controlled.   The said outer edge irradiation means is comprised so that the light emission state of the said 3rd irradiation light may differ from the light emission state of the said 1st irradiation light, and the light emission state of the said 2nd irradiation light. Optical information reader. The information code is a QR code,
The optical information reading apparatus according to claim 1, wherein the specific pattern is a position detection pattern for detecting a position of the QR code.