JP4403975B2 - Optical information reader - Google Patents

Description

  The present invention provides an optical information reading device comprising marker light irradiating means for irradiating a plurality of marker lights for indicating a reading position or a reading range with respect to a reading target on which an information code such as a barcode or a two-dimensional code is written. Relates to the device.

  In recent years, handy type optical information readers for reading information codes such as bar codes and two-dimensional codes have been provided that can be read from a position away from the reading object for ease of use. 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, and the like are provided in a main body case configured to be handheld. When the user operates the trigger switch with the reading port at the tip of the main body case facing the reading target, the illumination device irradiates the reading target (barcode) with illumination light, and the reflected light is The light is incident from the reading port and imaged by the light receiving sensor through the imaging lens. In such a handy type optical information reader, a battery (secondary battery) is generally used as a driving power source.

  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 ( A device including marker light irradiation means for irradiating marker light for indicating the visual field of the light receiving sensor and its center position is considered (for example, see Patent Document 1). This marker light irradiating means irradiates three spot lights, that is, the central portion of the reading 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 kind of optical information reading apparatus, there is a certain range in the reading distance (distance from the apparatus 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. . Therefore, in Patent Document 1 described above, in order to visually inform the user of the optimum reading depth (distance) of the information code, the marker light consisting of three spot lights is clearly displayed on the reading target surface at the optimum reading distance. And is configured to be blurred when it is out of an appropriate distance range.
JP-A-11-250172

  However, in the conventional optical information reader described above, the marker range can tell the user the range of the distance from the appropriate device to the reading target, but it is in a position outside the appropriate distance range. However, when the trigger switch is turned on, a reading operation (imaging (exposure), image data fetching, decoding processing) is always executed. For example, when you want to read a relatively large (horizontal) barcode, the user turns the trigger switch on with the main body case far away from the appropriate distance range so that the entire barcode can be viewed. May end up.

  In such a case, for example, the reading cannot be performed satisfactorily due to insufficient light quantity, and after the decoding process is performed, the user is notified that the decoding has failed, and the reading operation is prompted again. In this case, useless decoding processing is performed, so that power consumption increases, and a battery-driven product causes a problem that continuous use time is shortened.

  The present invention has been made in view of the above circumstances, and its purpose is to enable reading of an information code from a position distant from the reading target, and the distance from the apparatus to the reading target is within a range where reading can be satisfactorily performed. It is an object of the present invention to provide an optical information reading apparatus that can automatically determine whether or not it is present and can suppress wasteful power consumption.

In order to achieve the above object, an optical information reading apparatus according to claim 1 of the present invention is capable of reading an information code from a position away from a reading object, and sets a reading position or reading range with respect to the reading object. Marker light irradiating means for irradiating marker light for indicating is configured such that the marker light draws a clear pattern on the reading target within a range where the distance to the reading target can be satisfactorily read, and blurs when the marker light deviates from the range. In addition, a marker light image capturing operation execution unit that captures an image in a state in which the marker light is irradiated to the reading target by the imaging unit, and the blur of the marker light from the image captured by the marker light image capturing operation execution unit determining includes a blur determination unit, after the capture operation of the marker light image by the marker light image capture operation execution means, to stop the irradiation of the marker light condition The information code image capturing operation is configured to be continuously executed, and when the blur determination unit determines blur, processing of the captured information code image is stopped. Ru der those having the characteristics where that is configured to.
An optical information reader according to a second aspect of the present invention is capable of reading an information code from a position distant from a reading object, and irradiates the reading object with marker light for indicating a reading position or a reading range. The marker light irradiating means is configured so that the marker light draws a clear pattern on the reading object within a range where the distance to the reading object can be satisfactorily read, and blurs when the marker light deviates from the reading object. Marker light image capturing operation execution means for capturing an image in an irradiated state by an imaging means, and blur determination means for determining blur of the marker light from an image photographed by the marker light image capturing operation execution means After the marker light image capturing operation by the marker light image capturing operation executing means, the image of the information code is captured with the marker light irradiation stopped. When the blur is determined by the blur determining means, the information code image capturing operation is interrupted and the marker light image capturing operation is performed again. It is characterized in that it is configured to execute.

According to the present invention , when the distance from the apparatus to the reading target is within a range where the reading can be satisfactorily performed, the marker light irradiated by the marker light irradiation unit draws a clear pattern on the reading target. On the other hand, when the distance to the reading target is out of the range where reading can be performed satisfactorily, the reading target is irradiated with the marker light blurred. Therefore, first, the user can know whether or not the reading distance is appropriate by visually recognizing the marker light applied to the reading target. Then, the marker light image capturing operation executing means captures an image in a state where the marker light is irradiated to the reading object, and the blur determining means determines the blur of the marker light in the image. It is possible to automatically determine whether the distance up to is within a range where reading can be satisfactorily performed.
In the optical information reading apparatus of the present invention, as the image capturing operation, the marker light image is first captured by the marker light image capturing operation executing means, and then the information code image is stopped in a state where the irradiation of the marker light is stopped. The capturing operation can be performed in two stages, that is, in a so-called two stages, whereby the marker light image can be captured and the information code can be reliably read. Then, when the blur is determined by the blur determination unit, the processing of the image of the information code that has been captured next is stopped, or the image code capture operation of the information code is interrupted, and the marker light is again detected. By configuring the image capturing operation to be performed, it is possible to avoid unnecessary processing when the reading distance is not appropriate, and power consumption can be reduced correspondingly.
According to a third aspect of the present invention, there is provided an optical information reading apparatus capable of reading an information code from a position distant from a reading object, and emitting a marker light for indicating a reading position or a reading range with respect to the reading object. The marker light irradiating means for irradiating is configured so that the marker light draws a clear pattern on the reading target within a range where the distance to the reading target can be satisfactorily read, and blurs when the marker light is out of the range. Marker light image capturing operation execution means for capturing an image in a light-irradiated state by an imaging means; blur determination means for determining blur of the marker light from an image photographed by the marker light image capturing operation execution means; And the marker light image captured by the marker light image capturing operation executing means when the blur amount determined by the blur determining means is less than or equal to a predetermined value. From having characterized in that is configured to run together reading processing of the information code.
According to this, it is possible to perform both the determination of whether or not the reading distance is appropriate and the reading of the information code by one image capture, which is efficient. At this time, when reading a one-dimensional code such as a barcode, it is sufficient to read at a portion where there is no marker light (horizontal scanning line). Even when reading a two-dimensional code, error correction ( By using a (data restoration) function or the like, reading can be performed at an error correction level.

At this time, a range that allows good reading described above, can be set in the vicinity best focus of the imaging lenses constituting the imaging means (the invention of claim 4). Thereby, when it exists in the suitable reading distance, the information code of reading object can be read reliably. In the present invention, the marker light includes linear light, and the blur determination unit determines blur based on detecting the thickness of the linear portion of the marker light from the captured image. (Invention of claim 5 ). This makes it possible to determine the blur with a simple configuration and processing. Various other methods for determining blur are conceivable. For example, when a color sensor is used as the light receiving sensor, a method of detecting a blur of the color of the marker light is also possible.

In the present invention, the marker light irradiating means has a diaphragm in a configuration in which the marker light draws a clear pattern on the reading target within a range where the distance to the reading target can be satisfactorily read and falls out of the range. In some cases, it can be realized by the size of the diaphragm (invention of claim 6 ). Or it is also possible to implement | achieve by the shape of the lens with which marker light irradiation means is provided (invention of Claim 7 ).

  Hereinafter, several embodiments in which the present invention is applied to a hand-held (gun type) two-dimensional code reader will be described with reference to the drawings.

<1> First Embodiment A first embodiment of the present invention will be described with reference to FIGS. First, the overall configuration of a two-dimensional code reading apparatus as an optical information reading apparatus according to the present embodiment will be described with reference to FIGS. As shown in FIG. 2, the main body case 1 of the two-dimensional code reader is operated by the user gripping with one hand near the rear side of the lower surface side of the main part 1 a that is rounded and thin and has a substantially rectangular box shape. And a grip portion 1b capable of being integrated. A reading port 1c having a rectangular shape and translucency is provided at the front end surface portion of the main body case 1 (main portion 1a). A trigger switch 2 for reading instructions is provided at the upper end of the grip portion 1b.

  A two-dimensional code such as a QR code, which is an information code recorded on a reading target R (see FIG. 3) such as a label attached to a product or a catalog, is provided on the front end portion in the main body case 1 (main portion 1a). A reading mechanism for reading Q (for convenience, see FIG. 9) is provided. As shown in FIG. 3, this reading mechanism includes, for example, a light receiving sensor 3 composed of a CCD area sensor, an imaging lens 4 constituting an imaging optical system, an illumination unit 5 (not shown in FIG. 2), and marker light described later. It is comprised from the marker light irradiation part 6 etc. as an irradiation means.

  Among them, the light receiving sensor 3 is disposed in the central portion of the main body case 1 (main portion 1a) so as to face the reading port 1c, and the imaging lens 4 is disposed in front thereof. Although detailed illustration and description are omitted, the imaging lens 4 is configured by arranging a plurality of lenses in a lens barrel. Although not shown in detail, the illumination unit 5 includes an LED that serves as an illumination light source and an illumination lens that is disposed in front of the LED and collects and diffuses light. 2), a plurality of sets are arranged toward the reading port 1c. As a result, the illumination unit 5 irradiates illumination light to the two-dimensional code Q written on the reading object R through the reading port 1c, and the reflected light from the two-dimensional code Q is incident through the reading port 1c. 4 forms an image on the light receiving sensor 3, and thus an imaging means for capturing an image of the two-dimensional code Q is configured.

  At this time, as shown in FIG. 1, from the device (reading port 1 c) to the reading object R that can read the information code satisfactorily due to the optical characteristics of the reading mechanism (mainly the focal length of the imaging lens 4). The distance (focus position) is determined in advance. In this case, the readable range A has a width of about 200 mm as a whole in the vicinity (front and back) of the best focus of the imaging lens 4, for example. Accordingly, the user needs to perform a reading operation in a state where the reading object R is located in the readable range A, and QR code Q decoding processing is performed at distances (ranges B and C) that deviate from the perspective direction. There are circumstances that cannot be performed correctly.

  As shown in FIG. 4A, the marker light irradiation unit 6 includes a laser diode 7 serving as a light source, and is positioned in front of the laser diode 7 so as to have a collimating lens 8 and a pattern of the marker light M. Are sequentially provided, and a diaphragm 10 is formed. The marker light irradiating unit 6 is located above the imaging lens 4 and is disposed slightly diagonally downward toward the reading port 1c. The reading position (reading range) with respect to the reading target R. The marker light M for indicating is emitted.

  In this case, the marker light irradiating unit 6 is located above the imaging lens 4 and is disposed horizontally and obliquely downward toward the reading port 1c. As shown in FIGS. The target light R is irradiated with marker light M for indicating a reading position (reading range). In the present embodiment, the marker light M is L-shaped light corresponding to four corners of a slightly oblong rectangle that is slightly smaller than the field of view F of the light receiving sensor 3 and a cross-shaped light indicating the center. It consists of light. That is, the marker light M is composed of a combination of linear lights.

  At this time, as shown in FIG. 1, the marker light M irradiated to the reading target R by the marker light irradiation unit 6 is within a readable range A where the distance to the reading target R can be read satisfactorily. A clear pattern is drawn on the reading object R, and it is configured to be blurred in the ranges B and C that are far away from the range. In the present embodiment, as shown in FIG. 5, the best focus position of the marker light irradiation unit 6 and the best focus position of the imaging lens 4 are substantially matched, and as shown in FIG. By making the aperture diameter of the diaphragm 10 relatively large (for example, 2 mm in diameter), the imaging and blurring of the marker light M are realized. In this case, as shown in FIG. 4B, in the conventional marker light irradiation unit, the aperture diameter of the diaphragm 25 is relatively small (for example, a diameter of 1 mm or less).

  In the present embodiment, the marker light irradiation unit 6 always irradiates (lights up) the marker light M except when the light receiving sensor 3 captures (captures) an image of the two-dimensional code Q when the apparatus is turned on, for example. It is supposed to be. Alternatively, the trigger switch 2 is configured to be capable of two-stage pressing operation, and the irradiation operation of the marker light M is executed by the first-stage pressing operation (so-called half-pressed state). The image capturing operation according to 3 may be executed.

  As shown in FIG. 2, a circuit board 23 on which the circuits shown in FIG. 3 are mounted is provided on the rear side in the main body case 1 (main part 1a). Further, as shown only in FIG. 3, an operation switch 24 for the user to give various input instructions, a notification LED 11, and a liquid crystal display 12 are provided on the outer surface portion (upper surface portion of the main portion 1 a) of the body case 1. Etc. are provided. In the main body case 1, a buzzer 13 for performing error notification and the like, a communication interface 14 for performing communication with the outside, a secondary battery 15 serving as a driving power source, and the like are also provided.

  FIG. 3 schematically shows the electrical configuration of the two-dimensional code reader according to the present embodiment. The circuit board 23 is mainly composed of a microcomputer, and is a control circuit that performs overall control, decoding processing, and the like. 16 is provided. Signals from the trigger switch 2 and the operation switch 24 are input to the control circuit 16, and the control circuit 16 controls the light receiving sensor 3, the illumination unit 5, and the marker light irradiation unit 6. As a result, the operation of taking in the image of the two-dimensional code Q written in the reading object R is executed. The control circuit 16 controls the LED 11, the buzzer 13, and the liquid crystal display 12, and executes data communication with the outside (such as a management computer) via the communication interface 14.

  Further, an amplification circuit 17, an A / D conversion circuit 18, a memory 19, a specific ratio detection circuit 20, a synchronization signal generation circuit 21, an address generation circuit 22 and the like are mounted on the circuit board 23, which are also the control circuit 16 It is controlled by. Thus, the image pickup signal from the light receiving sensor 3 is amplified by the amplifier circuit 17, converted into a digital signal by the A / D conversion circuit 18, and stored in the memory 19 as image data. At this time, a specific pattern in the image data is detected by the specific ratio detection circuit 20. A synchronization signal is supplied from the synchronization signal generation circuit 21 to the light receiving sensor 3, the specific ratio detection circuit 20, and the address generation circuit 22.

  As will be described later in the description of the operation, in this embodiment, the control circuit 16 receives an image in a state in which the marker light M is irradiated on the reading object R mainly by the software configuration (execution of the program). A marker light image capturing operation to be photographed by the sensor 3 is executed, and blur (amount of blur) of the marker light M is determined from the photographed image. Therefore, the control circuit 16 functions as a marker light image capturing operation execution means and a blur determination means according to the present invention.

  In this case, in this embodiment, irradiation (lighting) of the marker light M is continuously performed by the marker light irradiation unit 6 in a normal state, and when the trigger switch 2 is turned on in this state, the light receiving sensor 3 Thus, an image is captured in a state where the marker light M is irradiated to the reading object R (the illumination unit 5 is turned off), and the illumination unit is continuously stopped in a state where irradiation of the marker light M is temporarily stopped. 5 is turned on (lights up), and the light receiving sensor 3 captures the image of the two-dimensional code Q (exposure in the light receiving sensor 3, capture of image data (digital image data from the A / D conversion circuit 18 into the image memory 19) Writing) and two-dimensional code Q decoding processing are performed continuously. That is, a two-stage image capturing operation is executed.

  As will be described later in the description of the operation, when the marker light image is captured by the first stage image capturing operation, the control circuit 16 detects the marker light M in the imaging field of view F and the marker light. The thickness of the line M is obtained and compared with a preset threshold value (for example, 2 mm). When the thickness of the marker light M is larger than the threshold, it is determined that the marker light M is blurred. When the thickness of the marker light M is equal to or smaller than the threshold, the marker light M is not blurred. It is determined.

  In this embodiment, when it is determined that the marker light M is not blurred, the control circuit 16 assumes that the distance to the reading target R is within the readable range A in which reading can be performed satisfactorily. The image capturing operation of the two-dimensional code Q is executed (continued) as it is. On the other hand, if it is determined that the marker light M is blurred, it is assumed that the distance to the reading object R is in the range B or C of the distance inappropriate for reading the two-dimensional code Q. The two-dimensional code Q image capturing operation is stopped (interrupted), and the first-stage marker light image capturing operation is performed again.

  Next, the operation of the two-dimensional code reader according to the present embodiment configured as described above will be described with reference to FIGS. When the user reads the two-dimensional code Q written on the reading object R, the main body case 1 is separated from the reading object R by an appropriate distance, and the reading port 1c faces the reading object R. . At this time, since the marker light M is emitted from the marker light irradiation unit 6, the user applies the marker light M to the reading target R and arranges the two-dimensional code Q at the position of the central portion of the marker light M as much as possible. As described above, the body case 1 (reading port 1c) is aligned. In addition, by visually recognizing the marker light M irradiated on the reading object R, the user performs alignment for the distance so that the marker light M is drawn as clearly as possible (does not blur), and the alignment state Then, the trigger switch 2 is turned on.

  The flowchart in FIG. 6 shows an outline of a processing procedure for reading the two-dimensional code Q executed by the control circuit 16 when the trigger switch 2 is turned on. The time chart of FIG. 7 shows the relationship between the on / off control of the marker light M (marker light irradiation unit 6) and the reading process at that time, and FIG. When it is determined that the marker light M is not blurred by the image capturing operation of FIG. 7, FIG. 7B shows a case where it is determined that the marker light M is blurred by the first-stage image capturing operation.

  As shown in the flowchart of FIG. 6, when the trigger switch 2 is turned on, first, the first stage image capturing operation (exposure) by the light receiving sensor 3 is started in step S1. At this time, as shown in FIG. 7, since the marker light M is irradiated to the reading object R and the illumination light is off, the light receiving sensor 3 has an image in which the marker light M is reflected on the reading object R. Will be taken in. In step S <b> 2, the marker light image data is captured, and the blur of the marker light M is determined from the captured marker light image data.

  At this time, although not shown in detail in FIG. 6, as shown in FIG. 7, the second stage image capturing operation (exposure) by the light receiving sensor 3 simultaneously with the start of blur determination processing (end of image data capturing). Is started. At this time (only during exposure), as shown in FIG. 7, since the marker light M is turned off and the illumination light is turned on by the illumination unit 5, the illumination light is irradiated onto the reading object R and the reflected light ( The image of the two-dimensional code Q) is captured by the light receiving sensor 3.

  In step S3, it is determined whether or not the marker light M is blurred. If it is determined that the marker light M is not blurred (No in step S3), the distance to the reading object R is within the readable range A where the reading can be satisfactorily performed, so the process proceeds to step S4, and FIG. As shown in a), the second-stage image capture process (image data capture and decoding) is executed as it is. In step S5, it is determined whether or not the decoding is successful. If the decoding is successful (Yes), the process ends. If the decoding fails (No in step S5), the process returns to step S1 and the first-stage image capture operation is executed again.

  On the other hand, when the distance to the reading object R is a distance inappropriate for reading the two-dimensional code Q (too far or too close), the marker light M is blurred in the first stage image capturing operation. (Yes in step S3). In this case, as shown in FIG. 7B, the second-stage image capture process (image data capture and decoding) is interrupted (stopped), and the process returns to step S1 to perform the first-stage image capture operation. The (marker light image capturing operation) is executed again, and the process of determining the blur of the marker light M is repeated.

  As described above, according to the present embodiment, the marker light irradiation unit 6 causes the marker light M to draw a clear pattern on the reading target R in the range A where the distance to the reading target R can be satisfactorily read. It is configured so as to be blurred when it deviates, and it is automatically determined whether or not the distance to the reading target R is within the readable range A using the marker light image. Then, when it is determined that the marker light M is blurred, that is, when the distance to the reading target R is out of the readable range A, the process of capturing the image of the two-dimensional code Q is stopped.

  As a result, unlike the conventional case where reading processing is always performed when the trigger switch is operated, it is possible to prevent unnecessary decoding processing and the like from being executed and to reduce unnecessary power consumption. In addition, since the determination is performed using the marker light irradiation unit 6 originally provided for alignment of the two-dimensional code Q at the time of reading, a simple configuration can be achieved without using a separate distance sensor or the like. be able to. Furthermore, it is a matter of course that the user can easily know whether the reading distance is within an appropriate reading distance by visually recognizing the marker light M applied to the reading object R.

<2> Second to Sixth Embodiments and Other Embodiments FIGS. 8 and 9 show a second embodiment of the present invention. Each embodiment described below is similar to the first embodiment in that the present invention is applied to a gun-type two-dimensional code reader as an optical information reader, and therefore the first embodiment described above. The same reference numerals are given to the same parts, and new illustrations and detailed explanations are omitted, and hereinafter, different points will be mainly described.

  The second embodiment is different from the first embodiment in that instead of executing a two-stage image capturing operation by the light receiving sensor 3, a single image capturing operation is performed and the captured image data is obtained. Based on the above, the blur of the marker light M is determined, and when it is determined that the marker light is not blurred by M (when the blur amount is equal to or less than a predetermined value), from the captured image data, The dimension code Q is read (decoded) at the same time.

  Here, as is well known, the QR code, which is the two-dimensional code Q, has an error correction (data restoration) function using a Reed-Solomon code, and a maximum of 30% of the area is dirty or damaged. However, reading is possible. In this embodiment, such an error correction function is used. In the captured image, for example, as shown in FIG. 9, a part of the marker light M overlaps the image of the two-dimensional code Q, Even if a part of the data of the two-dimensional code Q cannot be read correctly, it can be decoded as long as the data can be restored by the error correction function (area).

  The time chart of FIG. 8 shows the relationship between the on / off control of the marker light M (marker light irradiation unit 6) when the trigger switch 2 is turned on and the reading process executed by the control circuit 16 in this embodiment. It shows. Also at this time, the user places the marker case M on the reading object R in a state where the main body case 1 is separated from the reading object R by an appropriate (arbitrary) distance, and the two-dimensional code Q is arranged at the center thereof. Then, the trigger switch 2 is turned on.

  Then, an image capturing operation (exposure) by the light receiving sensor 3 is executed. At this time, the marker light M is irradiated to the reading object R, and the illumination light is turned on. Therefore, the light receiving sensor 3 captures an image in which the marker light M is reflected in the image of the two-dimensional code Q written on the reading object R as shown in FIG. Then, image data is taken in, and then the marker light M in the field of view F is detected first, and the thickness of the line of the marker light M is obtained to determine blur. At this time, the marker light M can be detected by the L-shaped portion of the corner portion of the marker light M.

  Here, when it is determined that the marker light M is not blurred, the decoding process of the two-dimensional code Q using the error correction function is continued. If the decoding is successful, the process is terminated, and for example, the next image capturing operation is executed. On the other hand, although not shown, if it is determined that the marker light M is blurred, the decoding process is stopped, the image capturing operation is performed again, and the above-described process is repeated.

  According to the second embodiment, as in the first embodiment, the two-dimensional code Q can be read from a position away from the reading object R, and the device to the reading object R can be read. It is possible to automatically determine whether or not the distance is within the range A in which reading can be performed satisfactorily, and as a result, it is possible to suppress the wasteful power consumption. In addition to that, it is possible to perform both the determination of the blur of the marker light M and the reading (decoding) of the two-dimensional code Q by an image capture once, and an efficient operation can be performed. When the dimension code Q is read continuously, the processing time can be shortened.

  FIG. 10 shows a third embodiment of the present invention. When it is determined that the marker light M is blurred by the first stage image capturing operation, the marker light M (marker light irradiation unit 6) is shown. 5 is a time chart showing the relationship between on / off control and reading processing. The third embodiment differs from the first embodiment in that the second stage image capture process (when the marker light M is determined to be blurred in the first stage image capture operation) The configuration is such that the capture (decoding of image data) is interrupted, and the operation immediately proceeds to the capture (exposure) of the marker light image again (first stage). Thereby, processing time can be shortened more.

  FIGS. 11 to 13 sequentially show fourth to sixth embodiments of the present invention, and the configuration of the marker light irradiation unit as the marker light irradiation means is the marker light irradiation unit 6 of the first embodiment. Is different. That is, the marker light irradiation unit 31 according to the fourth embodiment of the present invention shown in FIG. 11 includes a laser diode 7 serving as a light source, a condensing lens 32, a cylindrical lens 33 that forms a pattern of the marker light M, and an aperture 10. They are arranged in order. Also in this case, by making the aperture diameter of the diaphragm 10 relatively large (for example, 2 mm in diameter), the marker light M irradiated to the reading target R by the marker light irradiation unit 31 is In the readable range A where the distance can be read satisfactorily, a clear pattern is drawn on the reading target R, and the ranges B and C far from the range are blurred.

  The marker light irradiation unit 34 according to the fifth embodiment of the present invention shown in FIG. 12 includes a laser diode 7 serving as a light source, a collimating lens 35, and a follower 36 for forming a pattern of the marker light M in order, and has a diaphragm. It is configured without. Further, the marker light irradiation unit 37 according to the sixth embodiment of the present invention shown in FIG. 13 includes a laser diode 7 serving as a light source, a condensing lens 38, and a cylindrical lens 39 that forms a pattern of the marker light M in order. After all it is configured without an aperture. In these configurations, the imaging of the marker light M and the blur are realized by the shapes of the lenses 35, 38, and 39.

  In the above-described embodiment, the blur of the marker light M is determined based on detecting the thickness of the linear portion of the marker light M, but various methods are used for the blur determination. For example, a color sensor is used as the light receiving sensor, the marker light M is irradiated with a specific color (for example, red), and the degree of blur (blur) is detected based on detection of the color blur of the marker light. A method of determining the amount) is also possible. As the pattern (shape) of the marker light M, there are various modifications such as a light radiating three point-like lights on the central part and the right and left sides thereof, and a square frame-like light indicating the field of view of the reading mechanism. Conceivable.

  In the above-described embodiment, when the blur of the marker light M is determined, the processing for capturing (decoding) the image of the two-dimensional code Q is stopped and the marker light image is captured again. Using the result of the blur determination, it is possible to control the shutter speed (exposure time) of the light receiving sensor, or to adjust the intensity of the illumination light when the intensity of the illumination light is variable. In this case, instead of simply determining whether or not the marker light M is blurred, the degree of blur (the amount of blur) may be determined in a plurality of stages, and finer control is possible. When the blur of the marker light M is determined, the user may be notified by buzzer or display when the blur is determined.

  Further, in each of the above embodiments, the optical information reading apparatus of the present invention is applied to reading a two-dimensional code Q as an information code, particularly a QR code, but may be applied to reading other types of two-dimensional codes. It can also be applied to reading one-dimensional codes such as bar codes. For example, when a blurring determination of the marker light M and reading of the information code are performed with respect to the barcode by reading the image once, the barcode is read (decoded) along a portion where the marker light M does not exist (horizontal scanning line). Can be carried out in the same manner.

  In addition, for example, the optical information reader according to the present invention is not limited to a gun type, but is a handy type or one that is fixedly incorporated in an FA system or the like (the position on the reading target side varies). The present invention is not limited to the above-described embodiments, and various modifications can be made to the overall hardware configuration, particularly the configuration of the marker light irradiation means. It can be implemented with appropriate modifications within the range.

The 1st Example of this invention is a figure which shows a mode that a marker light image blurs with the change of the distance to reading object. Longitudinal side view schematically showing the configuration of the two-dimensional code reader Block diagram schematically showing the electrical configuration of the two-dimensional code reader Enlarged vertical side view showing the configuration of the marker light irradiating unit together with the conventional (b) The figure which shows a mode that the best focus position of a marker light irradiation part and the best focus position of an imaging lens correspond Flow chart showing processing procedure for reading two-dimensional code It is a time chart which shows the relationship between the on / off control of the marker light and the reading process, and when (a) is determined that the marker light is not blurred, (b) is determined that the marker light is blurred. Figure showing the case The time chart which shows the 2nd Example of this invention and shows the relationship between on / off control of marker light and reading processing. Diagram showing an image of marker light reflected in a two-dimensional code image FIG. 8 equivalent view showing a third embodiment of the present invention. The expanded vertical side view which shows the 4th Example of this invention and shows the structure of a marker light irradiation part. FIG. 11 equivalent view showing a fifth embodiment of the present invention. FIG. 11 equivalent view showing the sixth embodiment of the present invention.

Explanation of symbols

  In the drawings, 1 is a body case, 1c is a reading port, 2 is a trigger switch, 3 is a light receiving sensor, 4 is an imaging lens, 5 is an illumination unit, 6, 31, 34 and 37 are marker light irradiation units (marker light irradiation). Means) 10 is a diaphragm, 16 is a control circuit (marker light image capturing operation execution means, blur determination means), 19 is a memory, R is a reading target, Q is a two-dimensional code (information code), M is marker light. Show.

Claims (7)

An image pickup unit that includes an imaging lens and a light receiving sensor, and that captures an image of an information code written on a reading target; a marker light irradiation unit that irradiates a marker light for indicating a reading position or a reading range with respect to the reading target; An optical information reader comprising:
The marker light irradiating means is configured so that the marker light draws a clear pattern on the reading target within a range where the distance to the reading target can be satisfactorily read, and blurs when the marker light deviates from the range.
Marker light image capturing operation executing means for capturing an image in a state in which marker light is irradiated on the reading object by the imaging means;
A blur determination unit that determines blur of the marker light from an image photographed by the marker light image capturing operation execution unit ;
After the marker light image capturing operation by the marker light image capturing operation executing means, the information code image capturing operation is continuously executed in a state where irradiation of the marker light is stopped. With
An optical information reading apparatus configured to stop processing of the captured image of the information code when blur is determined by the blur determination unit. An image pickup unit that includes an imaging lens and a light receiving sensor, and that captures an image of an information code written on a reading target; a marker light irradiation unit that irradiates a marker light for indicating a reading position or a reading range with respect to the reading target; An optical information reader comprising:
The marker light irradiating means is configured so that the marker light draws a clear pattern on the reading target within a range where the distance to the reading target can be satisfactorily read, and blurs when the marker light deviates from the range.
Marker light image capturing operation executing means for capturing an image in a state in which marker light is irradiated on the reading object by the imaging means;
A blur determination unit that determines blur of the marker light from an image photographed by the marker light image capturing operation execution unit;
After the marker light image capturing operation by the marker light image capturing operation executing means, the information code image capturing operation is continuously executed in a state where irradiation of the marker light is stopped. With
An optical information reader configured to interrupt the image code capturing operation of the information code and execute the marker light image capturing operation again when blur is determined by the blur determining means . An image pickup unit that includes an imaging lens and a light receiving sensor, and that captures an image of an information code written on a reading target; a marker light irradiation unit that irradiates a marker light for indicating a reading position or a reading range with respect to the reading target; An optical information reader comprising:
The marker light irradiating means is configured so that the marker light draws a clear pattern on the reading target within a range where the distance to the reading target can be satisfactorily read, and blurs when the marker light deviates from the range.
Marker light image capturing operation executing means for capturing an image in a state in which marker light is irradiated on the reading object by the imaging means;
A blur determination unit that determines blur of the marker light from an image photographed by the marker light image capturing operation execution unit;
When the amount of blur determined by the blur determination unit is equal to or less than a predetermined value, the information code reading process is also executed from the marker light image captured by the marker light image capturing operation execution unit. An optical information reading apparatus, comprising: 4. The optical information reading apparatus according to claim 1 , wherein a range in which the reading can be favorably performed is in the vicinity of a best focus of the imaging lens . The marker light is configured to include linear light,
5. The optical information reader according to claim 1, wherein the blur determination unit determines blur based on detecting a thickness of a linear portion of the marker light from a captured image. . The marker light irradiation means is configured to include a diaphragm,
6. The optical information reading apparatus according to claim 1, wherein imaging and blurring of the marker light are realized depending on a size of the diaphragm . The marker light irradiation means includes a lens, and
6. The optical information reading apparatus according to claim 1, wherein the marker light is imaged and blurred by the shape of the lens .

Images