JP4175358B2 - Optical information reader - Google Patents

Description

  The present invention relates to an optical information reading apparatus capable of reading a dynamic information code composed of a plurality of element codes displayed individually on a display screen of an information code display apparatus.

  Conventionally, as a dynamic information code composed of a plurality of element codes displayed individually on the display screen of an information code display device, for example, there is one disclosed in Patent Document 1 below, and a more specific example There is what is called “active code” disclosed in Non-Patent Document 1 below.

This active code displays, for example, a mobile phone or a PDA (Personal Digital Assistance) with a display screen capable of performing dynamic display in which displayed information changes with time. The information code displayed on the display screen used as a device is sequentially switched and displayed at intervals of about 0.1 seconds. As shown in FIG. 13, if the code is a one-dimensional code such as a barcode, the entire code is displayed. 100 is divided into a plurality of element codes 101 to 104, and the divided element codes 101 to 104 can be displayed individually and sequentially on the screen 201 of the information code display device 200. Also in the case of a two-dimensional code such as a QR code, it is divided into a plurality of QR codes so that they can be displayed individually one after another.
JP 2003-317051 A Codex Co., Ltd., “What is ACD?”, [Online], [Search September 30, 2005], Internet <URL: http://www.code-x.jp/whatacd.html>

  However, as disclosed in Patent Document 1 and Non-Patent Document 1, a dynamic information code taking such an active code as an example, at first glance, is a normal information code printed on a display medium such as paper ( (It is referred to as “Static Information Code” below). However, it is necessary to grasp the order of the information codes to be sequentially switched and the total number of codes on the barcode reader (optical information reader) side. Is added to each divided code (element code). The check character (check digit) added to the information code is also generated by a calculation method different from that of the static information code. For this reason, even if such a dynamic information code is read by a bar code reader capable of reading a static information code, it is subjected to error processing by a check character.

  On the other hand, a barcode reader that can read such a dynamic information code exclusively reads a static information code without the additional information because the reading process is performed on the assumption that such additional information exists. In addition, since the check character generation method is different, even if each divided code (element code) is read, it becomes a target of error processing. That is, there is a problem that a static information code cannot be read by a barcode reader dedicated to a dynamic information code.

  Further, even though there is a dynamic information code and both the readable bar code reader of static information code, whether previously read which type information code on set by the operator, you need to start the read operations It is thought that there is. Therefore, if the type of information code to be read, such as whether it is a dynamic information code or a static information code, does not match the setting state of the barcode reader, the information code to be read is read. In addition, there is a problem that the setting operation and the confirmation thereof are compulsory before the reading operation, and the operation is complicated and confused during the reading operation.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical that can read both static information codes and dynamic information codes without performing complicated setting work. It is to provide an information reading apparatus.

  In order to achieve the above object, in the optical information reading device according to claim 1, the first reading mode capable of reading the static information code printed on the display medium, and the information code display device are provided. A second reading mode capable of reading a dynamic information code composed of a plurality of element codes that are sequentially displayed individually on a display screen, wherein the static information code or the element code is An image information acquisition unit capable of acquiring the included image information, a code type determination unit capable of determining whether the element information is included in the image information based on the image information, and the code type determination unit Reading mode switching means for switching to a second reading mode in which the dynamic information code can be read when it is determined that the element information is included in the image information. And technical features of the door.

  The “information code” is not limited to a one-dimensional code (EAN / UPC, interleaved 2 of 5, coder bar, code 39/128, standard 2 of 5, RSS, etc.), and a two-dimensional code (QR code, PDF417). , Data matrix, maxi code, RSS composite, etc.). The “static information code” is a static display of these information codes by printing them on paper, etching them on a metal plate, or marking them with laser light. The “general information code” is obtained by dividing these information codes into a plurality of element codes and dynamically displaying them on a screen such as a liquid crystal display device while sequentially switching the display.

  Further, in the optical information reading device according to claim 2, wherein the code type determining means is the static information code or the static information code based on the image information. A decoding unit capable of generating code information obtained by decoding the element code; and an operation unit performing predetermined calculation processing on the code information. The code information decodes the element code from the calculation result. The dynamic information code is included in the image information, and the dynamic information code is included in the image information when the code information is not a result of decoding the element code. It is a technical feature to determine that it is not.

  Furthermore, in the optical information reading device according to claim 3, the code type determination means is included in the image information based on the image information. Light intensity information generating means capable of generating information relating to light intensity, and based on the information relating to the light intensity, the image information indicates variations in brightness due to a backlight that illuminates the display screen of the information code display device from its back surface. Brightness determination means for determining whether or not the image information includes a variation in brightness and darkness due to the backlight based on a determination result by the brightness determination means. When it is determined that an information code is included, and the image information does not include variations in brightness due to the backlight, the image information includes And technical features determining that does not contain the information code.

  Further, in the optical information reading device according to claim 4, the code type determination unit is configured such that the code type determination unit is based on the image information. Pixel partition frame determination means capable of determining whether or not the image information includes a partition frame between pixels constituting the display screen, and the image information is determined by the pixel partition frame determination means based on a determination result by the pixel partition frame determination means; If the image information includes the partition frame between the pixels, it is determined that the dynamic information code is included in the image information, and the image information does not include the partition frame between the pixels. It is a technical feature to determine that the dynamic information code is not included.

  Furthermore, in the optical information reading device according to claim 5, the code type determination unit is acquired at an arbitrary time t0 by the image information acquisition unit in the optical information reading device according to claim 1. Reference image information holding means capable of holding image information as reference image information, and the static information code or the element code included in the image information acquired at time t1 after arbitrary time t0 by the image information acquisition means; When the code image comparison means for comparing the static information code or the element code included in the reference image information and the images of the two codes differ by the code image comparison means, from the arbitrary time t0 to the time t1 Is a time interval at which the element code displayed on the display screen of the information code display device is switched to the next element code. Switching interval determination means capable of determining whether or not the time is approximately equal, and the time Δt is substantially equivalent to the time interval at which the element code is switched based on the determination result by the switching interval determination means , If it is determined that the dynamic information code is included in the image information acquired at the later time t1, and the time Δt is not substantially equal to the time interval at which the element code is switched, the later time It is a technical feature that it is determined that the dynamic information code is not included in the image information acquired at t1.

  Further, in the optical information reading device according to claim 6, wherein the reading mode switching means is the second reading device in the optical information reading device according to any one of claims 1 to 5. In the mode, when the code type determination unit determines that the dynamic information code is not included in the image information, the mode is switched from the second reading mode to the first reading mode. Characteristic.

  Furthermore, in the optical information reading device according to claim 7, wherein the reading mode switching means is the second reading device, the optical information reading device according to any one of claims 1 to 5. In the mode, when the reading of the element code cannot be completed within a predetermined time or within a predetermined number of times, the mode is switched from the second reading mode to the first reading mode.

  Furthermore, in the optical information reading device according to claim 8 according to the claims, in the optical information reading device according to any one of claims 1 to 7, the element code in the second reading mode is changed. A reading condition table capable of holding a reading condition, and the second reading mode reads the element code when reading the element code based on the reading condition held in the reading condition table; If it is completed within a predetermined time or a predetermined number of times, a time setting value corresponding to the predetermined time or a frequency setting value corresponding to the predetermined number of times is held in the reading condition table as the reading condition, and the element If the code reading cannot be completed within a predetermined time or within a predetermined number of times, the time set value corresponding to the predetermined time or the predetermined number of times The number setting value corrected to moderate condition value, the time set value or set value of the number of the corrected, and technical features to hold the reading condition table as the reading condition.

  In the first aspect of the present invention, the image information acquisition means acquires image information including a static information code or an element code, and the code type determination means adds the dynamic information code element to the image information based on the image information. Determine if a code is included. When the code type determination unit determines that the element information is included in the image information, the reading mode switching unit switches to the second reading mode in which the dynamic information code can be read. Thus, even in the first reading mode in which the static information code can be read, if the acquired image information includes the element code of the dynamic information code, the reading mode switching unit causes the first information mode to be read. The reading mode is automatically switched to the second reading mode in which the dynamic information code can be read. Therefore, both the static information code and the dynamic information code can be read without performing complicated setting work.

  In the invention of claim 2, the code type determining means generates code information obtained by decoding the static information code or the element code based on the image information by the decoding means, and the code means determines a predetermined information for the code information. Perform arithmetic processing. Then, the code type determining means determines that the dynamic information code is included in the image information when the code information is obtained by decoding the element code, and the code information decodes the element code. If not, it is determined that the dynamic information code is not included in the image information. Accordingly, the code type determination unit can easily determine whether or not the image information includes the element code of the dynamic information code by the predetermined calculation process.

  In the invention of claim 3, the code type determining means generates information on the light intensity included in the image information based on the image information by the light intensity information generating means, and the light intensity information generating means relates to the light intensity. Based on the information, it is determined whether or not the image information includes light and dark variations due to the backlight that illuminates the display screen of the information code display device from its back surface. Then, the code type determination means determines from the determination result that the image information includes a dynamic information code when the image information includes variations in brightness due to the backlight, and the image information is stored in the backlight. If there is no variation in brightness due to, it is determined that the dynamic information code is not included in the image information.

  In the case of a static information code, since it is printed on a display medium such as paper, generally there is little variation in light and dark, whereas in the case of a dynamic information code, it is displayed on the display screen of the information code display device. Therefore, the variation in brightness due to the backlight is larger than that of the static information code. For example, when the backlight is composed of an LED and a light guide plate that can disperse the light of the LED in a planar shape, there is a slight light and dark variation due to non-uniform dispersion of the light. The code type determination means can determine whether or not the element information of the dynamic information code is included in the image information based on such light and dark variations.

  In the invention of claim 4, the code type determination means determines whether or not the image information includes a partition frame between pixels constituting the display screen of the information code display device based on the image information by the pixel partition frame determination means. From this determination result, the code type determination means determines that the dynamic information code is included in the image information when the image information includes a partition frame between the pixels, and the image information is the pixel When the partition frame is not included, it is determined that the dynamic information code is not included in the image information.

  In the case of a static information code, the background of the static information code is a display medium such as paper on which the static information code is printed. The background of the element code constituting the target information code is the display screen of the information code display device on which the element code is displayed. As a result, in the case of static information codes, the background is almost uniform in color with the color of the display medium such as paper, whereas in the case of dynamic information codes, the background constitutes the display screen. Since there are two or more colors of the color of the pixel to be processed and the color of the partition frame between the pixels (generally black), a difference in brightness occurs between the pixel and the partition frame between the pixels. For this reason, the code type determination means can determine whether or not the element information of the dynamic information code is included in the image information based on the brightness difference between the partition frames.

  In the invention of claim 5, the code type determination means includes a static information code or an element code included in the image information acquired at the time t1 after the arbitrary time t0 by the image information acquisition means by the code image comparison means, When the static information code or the element code included in the reference image information is compared and the images of the two codes are different, the time Δt from the arbitrary time t0 to the time t1 is displayed on the display screen of the information code display device. The switching interval determining means determines whether or not the element code is substantially equal to the time interval for switching to the next element code. Based on the determination result, the code type determination unit includes the dynamic information code in the image information acquired at the later time t1 when the time Δt is substantially equal to the time interval at which the element code is switched. If the time Δt is not substantially equal to the time interval at which the element code is switched, it is determined that the dynamic information code is not included in the image information acquired at the later time t1.

  In the case of a static information code, since it is printed on a display medium such as paper and fixed to the display medium, it is unlikely that other different static information codes are read one after another in a short time. On the other hand, in the case of a dynamic information code, the element code constituting the dynamic information code is displayed on the display screen of the information code display device, and the element code is sequentially displayed individually. The element codes are read one after another in a short period of time. Therefore, the code image of the static information code or element code at the arbitrary time t0 is different from the code image of the static information code or element code at the subsequent time t1, and the time Δt from the arbitrary time t0 to the time t1 is By determining whether or not the element code displayed on the display screen of the information code display device is approximately equal to the time interval at which the element code is switched to the next element code, the code type determination means can add the dynamic information code to the image information. It is possible to determine whether or not the element code is included.

  In the invention of claim 6, the reading mode switching means, in the second reading mode, when the code type determining means determines that the dynamic information code is not included in the image information, the second mode The reading mode is switched to the first reading mode. Thus, when the static information code is read once after switching to the second reading mode, the reading mode switching means switches the second reading mode to the first reading mode in which the static information code can be read. It is automatically switched. Therefore, both the static information code and the dynamic information code can be read without performing complicated setting work.

  In the seventh aspect of the invention, the reading mode switching means switches from the second reading mode to the second reading mode when the reading of the element code cannot be completed within a predetermined time or within a predetermined number of times. Although the mode is switched to the first reading mode, if it can be completed within a predetermined time or a predetermined number of times, the second reading mode cannot be switched to the first reading mode. As a result, after a switch to the second reading mode, if a code other than the element code is read due to erroneous reading or the like, it does not immediately switch to the first reading mode but waits for a predetermined time or a predetermined number of times. During this time, when a code other than the element code is continuously read, the second reading mode is automatically switched to the first reading mode. Therefore, useless mode switching due to such a reading error can be prevented.

  In the invention of claim 8, there is provided a reading condition table capable of holding element code reading conditions in the second reading mode, and the second reading mode is based on the reading conditions held in the reading condition table. When reading a code, if reading of an element code can be completed within a predetermined time or a predetermined number of times, a time setting value corresponding to the predetermined time or a frequency setting value corresponding to the predetermined number of times is set as a reading condition. If the reading of the element code cannot be completed within a predetermined time or a predetermined number of times, a time setting value corresponding to the predetermined time or a frequency setting value corresponding to the predetermined number of times is stored. It is corrected to a gentle condition value, and the corrected time setting value or frequency setting value is held in the reading condition table as a reading condition. As a result, the reading condition table holds the time setting value when reading of the element code can be completed within a predetermined time, and the number of times setting value when reading of the element code can be completed within the predetermined number of times. In the second reading mode, the element code can be read based on the held time setting value and the number of times setting value. Therefore, in the second reading mode, the element code can be read based on the time setting value and the number of times setting value at which the element code can be read.

  Hereinafter, an embodiment in which an optical information reading device of the present invention is applied to a barcode reader will be described with reference to the drawings. First, a configuration outline of the barcode reader 20 according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the barcode reader 20 mainly includes an optical system such as an illumination light source 21, a light receiving sensor 23, a filter 25, and an imaging lens 27, a memory 35, a control circuit 40, an operation switch 42, and a liquid crystal display. And a power supply system such as a power switch 41 and a battery 49. These are mounted on a printed wiring board (not shown) or housed in a housing (not shown).

  The optical system includes an illumination light source 21, a light receiving sensor 23, a filter 25, an imaging lens 27, and the like. The illumination light source 21 functions as an illumination light source capable of emitting illumination light Lf, and includes, for example, a red LED and a diffusion lens, a condensing lens, and the like provided on the emission side of the LED. In the present embodiment, illumination light sources 21 are provided on both sides of the light receiving sensor 23, and configured to irradiate the illumination light Lf toward the reading object R through a reading port of a housing (not shown). . The reading object R is affixed with a normal barcode as a static information code printed on paper, a label or the like, or active as a dynamic information code on the screen of a mobile phone (information code display device). The element code of the code is displayed.

  Note that the symbol Q shown in FIG. 1 indicates an information code and is a concept including both a normal barcode (static information code) and an active code (dynamic information code) element code. The active code is the same as that described with reference to FIG. 13 in the “Background Art” column.

  The light receiving sensor 23 is configured to receive the reflected light Lr irradiated and reflected on the reading object R and the information code Q. For example, the light receiving sensor 22 is a solid-state image pickup device such as a C-MOS or CCD. An area sensor arranged in two dimensions corresponds to this. The light receiving surface 23a of the light receiving sensor 23 is positioned so as to be externally visible through the reading port from the outside of the housing. The light receiving sensor 23 can receive incident light incident through the imaging lens 27 on the light receiving surface 23a. It is mounted on a printed wiring board (not shown).

  The filter 25 is an optical low-pass filter that allows passage of light that is less than or equal to the wavelength of the reflected light Lr, and that can block passage of light that exceeds the wavelength, and is provided between the reading port of the housing and the imaging lens 27. Is provided. Thereby, unnecessary light exceeding the wavelength equivalent of the reflected light Lr is prevented from entering the light receiving sensor 23.

  The imaging lens 27 functions as an imaging optical system capable of condensing incident light incident from the outside via a reading port and forming an image on the light receiving surface 23a of the light receiving sensor 23. And a plurality of condensing lenses housed in the lens barrel. In the present embodiment, the illumination light Lf emitted from the illumination light source 21 is reflected by the information code Q, and the reflected light Lr incident on the reading port is collected, whereby the information code Q is reflected on the light receiving surface 23a of the light receiving sensor 23. An image can be formed.

  Next, a configuration outline of the microcomputer system will be described. 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, an operation switch 42, an LED 43, a buzzer 44, a liquid crystal display 46, and a communication interface 48. Etc. As the name suggests, this microcomputer system is composed mainly of a control circuit 40 and a memory 35 that can function as a microcomputer (information processing apparatus). The microcomputer system captures the image signal of the information code Q imaged by the optical system described above. It can perform signal processing in terms of hardware and software. The control circuit 40 also performs control related to the entire system of the barcode reader 20.

  An image signal (analog signal) output from the light receiving sensor 23 of the optical system is input to the amplification circuit 31 and amplified by a predetermined gain, and then input to the A / D conversion circuit 33. Converted into a digital signal. When the digitized image signal, that is, image data (image information) is input to the memory 35, it is stored in the image data storage area. The synchronization signal generation circuit 38 is configured to generate a synchronization signal for the light receiving sensor 23 and the address generation circuit 36. 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 image data storage area, the RAM of the memory 35 is configured to be able to secure a work area and a reading condition table that are used by the control circuit 40 in each processing such as arithmetic operation and logical operation. . The ROM stores in advance a predetermined program that can execute a reading process and the like that will be described later, and a system program that can control each piece of hardware such as the illumination light source 21 and the light receiving sensor 23.

  The control circuit 40 is a microcomputer that can control the entire barcode reader 20 and includes a CPU, a system bus, an input / output interface, and the like. The control circuit 40 can constitute an information processing apparatus together with the memory 35 and has an information processing function. The control circuit 40 is configured to be connectable to various input / output devices (peripheral devices) via a built-in input / output interface. In the present embodiment, the power switch 41, the operation switch 42, the LED 43, A buzzer 44, a liquid crystal display 46, a communication interface 48, and the like are connected.

  Thereby, for example, monitoring and management of the power switch 41 and the operation switch 42, turning on / off the LED 43 functioning as an indicator, turning on / off the buzzer 44 capable of generating a beep sound and an alarm sound, and further reading the information code Screen control of the liquid crystal display 46 capable of displaying the code content by Q, communication control of the communication interface 48 enabling serial communication with an external device, and the like are enabled. The external devices connected to the communication interface 48 include a host computer HST corresponding to the host system of the barcode reader 20 and the like.

  The power supply system includes a power switch 41, a battery 49, and the like. When the power switch 41 managed by the control circuit 40 is turned on and off, the conduction of the drive voltage supplied from the battery 49 to each device and each circuit described above is established. Or shut off is controlled. The battery 49 is a secondary battery that can generate a predetermined DC voltage, and corresponds to, for example, a lithium ion battery. Further, the battery 49 may be configured to receive power supply from an external device such as the host computer HST connected via the communication interface 48 without using the battery 49. In this case, the battery 49 is unnecessary.

  By configuring the barcode reader 20 in this manner, for example, when the power switch 41 is turned on and a predetermined self-diagnosis process or the like is normally completed and the information code Q can be read, the illumination light Lf is emitted. The input of the operation switch 42 (for example, a trigger switch) is given. As a result, when the operator presses the trigger switch to turn it on, the control circuit 40 outputs a light emission signal to the illumination light source 21 based on the synchronization signal, so that the illumination light source 21 that has received the light emission signal turns on the LED. Light is emitted to irradiate illumination light Lf. Then, the illumination light Lf irradiated to the information code Q is reflected, and the reflected light Lr enters the imaging lens 27 through the reading port and the filter 25, so that the imaging lens is formed on the light receiving surface 23a of the light receiving sensor 23. 27, an image of the information code Q is formed. Thereby, the light receiving element 22 is exposed, so that the image data can be acquired by the image signal by the image information acquiring process of the reading process by the control circuit 40.

  An outline of such an operation is a basic reading operation of the information code Q by the bar code reader 20, but as described in the section [Problems to be solved by the invention], a normal bar code (static The information code) and the active code (dynamic information code) element code are substantially the same in appearance, but the calculation method of the check character (check digit) added to the information code Q differs between the two codes. . For this reason, an active bar code reader cannot read an active code, and a bar code reader dedicated to an active code cannot read a normal bar code.

  Therefore, in the barcode reader 20 according to the present embodiment, both normal barcodes and active codes can be read by the reading process described below with reference to FIGS.

  Next, the outline of the reading process by the barcode reader 20 will be described with reference to FIG. The flowchart shown in FIG. 2 conceptually shows an example of the reading process by the barcode reader 20 according to the present invention, and the implementation of this is the reading process shown in FIG. 3, for example.

  As shown in FIG. 2, in the reading process by the barcode reader 20, first, the image information acquisition process in step S10 is performed. This process acquires image data (image information) including an element code of a normal barcode or active code from the image data storage area of the memory 35. The “image information acquisition means” recited in the claims It can correspond to.

  In the subsequent step S20, a code type determination process is performed. This process determines whether or not an element code of an active code is included in the image data based on the image data acquired in step S10. “Code type determination unit” described in the claims It can correspond to. The code type determination process has various variations as will be described later with reference to FIGS.

  In the next step S30, a reading mode switching process is performed. If it is determined in step S20 that the image data includes a normal barcode, this processing is switched to a normal label reading mode in which the normal barcode can be read. In step S20, the element code is added to the image data. If it is determined that the active code is included, the active code reading mode is switched to the active code reading mode. This step S30 can correspond to “reading mode switching means” described in the claims.

  In subsequent steps S40 and S50, output processing is performed. That is, when the mode is switched to the normal label reading mode in step S30, the read image data is adapted to a predetermined format as normal barcode data, and is output to the outside via the communication interface 48.

  On the other hand, when the mode is switched to the active code reading mode in step S30, the read image data is adapted to a predetermined format as element code data of the active code, and is output to the outside via the communication interface 48. In the case of the present embodiment, any external output destination is a host computer HST or the like in which an application program capable of processing these data is mounted.

  When the output process in step S40 is completed, that is, in the case of a normal bar code label, when the data output to the host computer HST is completed, the reading process is completed in preparation for the information code Q to be read next. On the other hand, when the output process in step S50 is completed (in the case of an active code), the process proceeds to step S60.

  That is, in the case of an active code, the reading of the active code is not completed unless all the element codes constituting it are read and output to the host computer HST. Therefore, in the output completion determination process in step S60, the active code is Processing is performed to determine whether or not all constituent element codes have been output.

  If all the element codes have not been output (S60; No), in preparation for reading the remaining element codes, the process proceeds to step S10 again and all the element codes have been output. (S60; Yes), the reading process is completed in preparation for the information code Q to be read next.

  As described above, the reading process by the barcode reader 20 according to the present embodiment can be grasped as the concept of the process flow as shown in the flowchart of FIG. 2. As an example implemented in the code reader 20, the reading process shown in FIG. 3 will be described.

  As shown in FIG. 3, in the reading process implemented in the barcode reader 20, first, image information acquisition processing is performed in step S101. This process corresponds to the above-described image information acquisition process S10 (FIG. 2). Image data detected by the light receiving sensor 23 and converted into digital data by the A / D conversion circuit 33 is converted into image data in the memory 35. Obtain from the accumulation area.

  In the next step S103, a code type determination process is performed. This process corresponds to the above-described code type determination process S20 (FIG. 2). Here, the character check process shown in FIG. 4 corresponds to this, and will be described with reference to FIG.

  As shown in FIG. 4, in the character check process (code type determination process), first, the decoding process is performed in step S201. This process decodes the image data acquired in step S101 into code data (code information), and can correspond to “decoding means” recited in the claims. For example, in the case of the barcode with the code 128 shown in FIG. 5A, the data character located between the start character and the stop character is decoded. The active code substantially conforms to the code set C of the code 128.

  In the subsequent step S203, the “modulus 103 + 1” calculation process is performed. That is, in the case of the code 128, as shown in FIGS. 5 (A) and 5 (B), a check character (check digit) is set for the data character located immediately before the stop character. By processing, it is possible to detect whether or not there is a data error in these data characters.

  In the case of an element code constituting an active code, the check character is set with a value obtained by adding 1 to the sum of all data characters divided by 103, that is, a value calculated by the modulus 103 + 1. Therefore, by performing such calculation processing in step S203, whether or not the obtained calculation result matches the value set in the check character, that is, whether or not the calculation processing does not cause an error. It is possible to determine whether the code data is an active code element code. This process can correspond to the “calculation means” described in the claims.

  In the next step S205, processing for determining whether or not there is an operation error in step S203 is performed. If it is determined by this process that there is no error (S205; Yes), the code data decoded in step S201 is determined to be an element code of the active code. An element code flag that clearly indicates this is set (ADC flag setting process).

  On the other hand, if it is determined in step S205 that there is an operation error (S205; No), the code data decoded in step S201 is determined not to be an element code of the active code, so the process proceeds to the subsequent step S207. Then, the “modulus 103 etc.” calculation process, which is a check digit calculation method used for the normal code 128, is performed.

  In step S207, the “modulus 103 etc.” calculation process is performed. In the case of a barcode according to code set C of code 128, the check character is set with a value obtained as a remainder obtained by dividing the sum of all data characters by 103, that is, a value calculated by modulus 103. In the case of other barcodes (code 39, interleaved 2 of 5, coder bar, standard 2 of 5, RSS, etc.), values obtained by the arithmetic processing defined in the respective code specifications are set. Yes. For this reason, whether or not the obtained calculation result matches the value set in the check character by performing the calculation process according to each code specification in step S207, that is, the calculation process does not cause an error. Whether or not the code data is a normal barcode can be determined.

  In the next step S209, processing for determining whether or not there is an operation error in step S207 is performed. If it is determined that there is no error (S209; Yes) by this process, the code data decoded in step S201 is determined to be normal bar code data, so the process proceeds to step S215. A bar code flag that clearly indicates that fact is set (NRM flag setting process).

  On the other hand, if it is determined in step S209 that there is an operation error (S209; No), it is determined that the code data decoded in step S201 is neither an active code element code nor a normal barcode. That is, since it is determined that there is a data error in any of the data characters, the data error is determined, and in the subsequent step S217, a bar code flag that clearly indicates that is set (ERR flag setting process).

  When the flag setting process is completed in any one of steps S213, S215, and S217, the character check process is completed. Therefore, the process returns to step S105 of the reading process by returning to FIG.

  Referring to FIG. 3 again, in step S105, processing for determining whether or not the code is an active code is performed. This process corresponds to the above-described reading mode switching process S30 (FIG. 2), and the mode is switched by referring to the flag set by the character check process (FIG. 4) in step S103.

  For example, when the ADC flag is set (S105; Yes), the element information of the active code is included in the image information acquired in step S101. Therefore, “active code reading mode” Then, the process proceeds to the subsequent step S107, and the code data is output to the host computer HST in accordance with a predetermined format as an element code of the active code (element code data output process). This element code data output process corresponds to the above-described output process S50 (FIG. 2).

On the other hand, by referring to such a flag, when the NRM flag or the ERR flag is set and the ADC flag is not set (S105; No), the processing is performed in step S110 as “normal label reading mode”. Then, the normal code data or the corresponding error code is output to the host computer HST (code data output processing). This bar code data output process corresponds to the above-described output process S40 (FIG. 2).

  An example of the output format of the element code to be output to the host computer HST is as shown in FIG. 5B. The order data part SQN, total data part SUM, type data part ID, transmission data part DAT, digit number adjustment It consists of a part PAD and a check character CHK. Here, the output format of the element code will be briefly described with reference to FIG. FIG. 5B illustrates an active code when the total number of element codes is “5”.

  As shown in FIG. 5 (B), the order data portion SQN indicates what number the element code corresponds to by a two-digit numerical value of 00 to 99. The first element code is “00”, “01” is set for the next element code, “02” is set for the next element code, and so on. When the total number of element codes is 100, the order data portion SQN is “99”.

  The total number data part SUM indicates the total number of element codes obtained by dividing the active code, and the order data part SQN is set to an element code of “00”. The number of setting positions is set after the order data portion SQN and excluding the first element code. Therefore, for example, when the total number of element codes is 5, 5-1 = 4 is set.

  The type data part ID represents the type of the active code by a 6-digit numerical value, and the order data part SQN is set to an element code of “00”. The setting position is next to the total number data portion SUM, and when the total number of digits in the output data portion is an even number, a value of 000000 to 499999 is set, and when the total number of digits in the output data portion is an odd number , 500,000 to 999999 are set.

  The transmission data portion DAT is actual data output to the host computer HST, and is set in all element codes. As for the setting position, the element code whose order data part SQN is “00” is set after the identification data part ID, and the other element codes are set after the order data part SQN.

  The digit number adjustment unit PAD cannot display the code 128 because the total number of digits in the output data part is odd when the first digit of the type data part ID is 5 to 9. In such a case, “0” is added to the last element code in order to make the total number of digits of the entire active code an even number. For this reason, the digit number adjusting unit PAD is set to the last element code.

  The check digit CHK is calculated as a check digit from all digits of the type data part ID + transmission data part DAT + digit number adjusting part PAD by a predetermined calculation and set as a total check digit of the active code. For this reason, the check digit CHK is set to the last element code. Each element code is appended with data that is not output to the host computer HST, such as S (start code), C (check digit), and E (stop code) enclosed in a broken line frame in FIG. ing.

  Returning to FIG. 3 again, when an element code is output to the host computer HST in such an output format in step S107, an active code reading setting process is performed in the subsequent step S109. In this process, for example, element code reading conditions are set in the active code reading mode. This reading condition is held in a reading condition table secured in the memory 35. For example, the number of retries (number setting value), timeout time (time setting value), etc., when reading of the element code of the active code fails Is set. Further, in the process in step 109, for example, the operator is notified that the buzzer 44 has been sounded and the mode has been shifted to the “active code reading mode”, that is, the normal barcode cannot be read.

  In the next step S111, a process for determining whether or not all the element codes constituting the active code have been output to the host computer HST is performed. In this process, as described with reference to FIG. 5B, the total number data part SUM is set in the first element code (the element code whose order data part SQN is “00”). It is determined whether all element codes have been output to the host computer HST by referring to the values.

  If it is determined that all element codes have been output to the host computer HST (S111; Yes), the process proceeds to step S121, the “active code reading mode” is canceled, and the reading process is terminated. On the other hand, when it is determined that all element codes have not been output to the host computer HST (S111; No), the process proceeds to the next step S113 to acquire image information. Note that the image information acquisition process in step S113 is the same as the image information acquisition process in step S101 described above, and a description thereof will be omitted here. The image information acquisition process in step S111 corresponds to the above-described image information acquisition process S10 (FIG. 2).

  When image data is acquired in step S113, code type determination processing is performed in subsequent step S115. Since this process is also the same as the code type determination process in step S103 described above, a description thereof will be omitted. The code type determination process in step S115 corresponds to the above-described code type determination process S20 (FIG. 2).

  In the subsequent step S117, a process for determining whether or not the code data decoded in step S113 has already been output to the host computer HST is performed. That is, if the image data acquired by the image information acquisition process in step S111 is duplicated (S117; Yes), such data is wasted even if output to the host computer HST. A process of clearing the element data is performed in S123. Then, after step S123, the process proceeds to step S113, and the next image data is acquired.

  On the other hand, if it is not such a duplicate (S117; No), in the subsequent step S119, the code data is output as an active code element code to the host computer HST according to a predetermined format (element code data output processing). . The element code data output process is the same as the element code data output process in step S107 described above, and a description thereof will be omitted. The element code data output process in step S119 corresponds to the above-described output process S50 (FIG. 2).

  When the output process of the element code data in step S119 is completed, the process proceeds to step S111, and a process for determining again whether all of the element codes constituting the active code have been output to the host computer HST is performed. . Then, while repeatedly executing such a loop, it is determined that all element codes have been output to the host computer HST (S111; Yes), and the reading process is terminated.

  Thus, according to the barcode reader 20 according to the present embodiment, the image data acquisition process S10 (S101) acquires the image data including the element code of the normal barcode or active code, and the code type determination process S20 ( Through S103), it is determined based on the image data whether or not the element code of the active code is included in the image data. If it is determined in the code type determination process S20 (S103) that the element data is included in the image data, the active code reading mode is switched to the readable active code reading mode in the reading mode switching process S30 (S105). Thus, even in the normal label reading mode in which a normal barcode can be read, if the acquired image data includes an element code of an active code, the normal label is read by the reading mode switching process S30 (S105). The reading mode is automatically switched to an active code reading mode capable of reading an active code. Therefore, both a normal bar code and an active code can be read without performing complicated setting work.

  In the barcode reader 20 according to the present embodiment, the code type determination process S20 (S103) decodes the normal barcode or active code element code based on the image data by the decoding process S201 based on the character check process. Code data is generated, and the processing of the modulus 103 + 1 according to the code 128 that can calculate the calculation result that can determine whether or not the code data is obtained by decoding the element code is performed by the “modulus 103 + 1” calculation processing S203. Implement on code data. From this calculation result, if the code data is obtained by decoding the element code (S205; Yes), it is determined that the active code is included in the image data, and the code data is not obtained by decoding the element code. In the case (S205; No), it is determined that the active code is not included in the image data. As a result, the code type determination process S20 (S103) can easily determine whether or not the image data includes the element code of the active code by the “modulus 103 + 1” calculation process.

  In the reading process shown in FIG. 3, the active code element data is individually output to the host computer HST (S107, S119). For example, these element codes are stored in an output buffer secured in the memory 35. Then, after all of the element codes constituting the active code have been prepared, processing may be performed so as to output to the host computer HST.

  Specifically, for example, as in the modification example (part 1) shown in FIG. 6, the element code data output process in step S107 and the element code data output process in step S119 are respectively performed as element code data storage processes (S107 ′, S119 ′) and an element code data output process in step S120 is newly provided before step S121. Also, the determination process in step S111 is changed to one that can determine whether or not all element codes have been accumulated (S111 ').

  In S107 ′ and S119 ′, a process of storing the code data decoded and generated by the character check process (FIG. 4) of the code type determination process as an active code element code in an output buffer secured in the memory 35 is performed. Is called. In this process, based on the element code order data portion SQN described with reference to FIG. 5B, the number of accumulated element codes is determined, and the accumulated element codes are determined. For example, it is managed by a flag. The total number of element codes can be known by referring to the total number data part SUM set to the element code whose order data part SQN is “00”.

  Whether or not all the element codes constituting the active code have been prepared by determining whether or not the flag has been set for the total number of element codes, that is, whether or not all the element codes have been accumulated in step S111 ′. I know if it's not. If it is determined in step S111 'that all element codes have been accumulated (S111'; Yes), the element codes accumulated in the output buffer in step S120 are collectively output to the host computer HST. On the other hand, if it is not determined in step S111 'that all the element codes have been accumulated (S111'; No), the process proceeds to step S113, and image information is acquired to obtain the remaining element codes.

  In this way, the element data of the active code is not individually output to the host computer HST, but is output to the host computer HST after all the element codes are prepared, whereby the barcode reader 20 and the host computer HST Since the number of communications in between decreases, the burden of communication processing of the host computer HST can be reduced. In addition, since the number of communications is reduced, the amount of data due to redundant data added to each transmission data can also be reduced, so that overall communication traffic can be reduced.

Next, a variation example of the code type determination process will be described with reference to FIGS.
As shown in FIG. 7, in the pixel partition frame determination process which is an example of the code type determination process, first, image data analysis processing is performed in step S301. This image data analysis process (S301) is performed based on the image data converted into digital data from the A / D conversion circuit 33 described above. In the “pixel partition frame determination means” described in the claims, It can be equivalent.

  For example, for example, the waveform shown in the upper part of FIG. 8A is obtained as a waveform when an active code displayed on the screen of a color liquid crystal display device is read. The waveform shown in FIG. 8 (A) is a voltage value based on the intensity of light incident on the light receiving sensor 23 on the horizontal axis in the barcode scanning direction, and the waveform existing inside the broken line X is enlarged. Things are shown in the lower part of the figure. On the other hand, a waveform as shown in the upper part of FIG. 8B is obtained as a waveform when a normal bar code printed on paper is read, and the waveform existing inside the broken line Y is enlarged. It is shown in the lower part of the figure.

  Here, in the case of the active code displayed on the screen of the color liquid crystal display device, it can be seen that a waveform with an amplitude having a narrow interval is generated in the ellipse x (lower part of FIG. 8A). On the other hand, in the case of a normal barcode printed on paper, it can be seen that the waveform in the ellipse y corresponding to the ellipse x is relatively flat (lower part of FIG. 8B). In the case of a waveform obtained by reading an active code (FIG. 8A), such a waveform difference is caused by the color of the pixel (red, green, blue) constituting the display screen and the pixel of the active code background. Since there are two or more colors, such as the color of the partition frame between them (generally black), a difference in brightness occurs between the pixels and the partition frame between the pixels, whereas in the case of a barcode printed on paper ( (B) in FIG. 8 is caused by the fact that the background is the color of paper itself (generally white) as a display medium and the brightness is almost uniform.

  Accordingly, in step S301, it is possible to determine whether or not the image data includes a partition frame between the pixels by analyzing the image data based on the image signal detected by the light receiving sensor 23 for such a brightness difference. Yes. That is, when the fine black range due to the partition frame between the pixels is scattered, the liquid crystal screen is reflected in the background of the information code Q. Therefore, the information code Q displayed in such a background is active. There is a high possibility that the code is an element code.

  Therefore, when it is determined in step S303 that there is a partition frame between pixels (S303; Yes), it is determined that there is a high possibility that the analyzed image data includes the element code of the active code. Therefore, the process proceeds to step S311 to set an element code flag that clearly indicates that fact (ADC flag setting process). On the other hand, when it is determined that there is no partition frame between such pixels (S303; No), it is determined that there is a high possibility that the analyzed image data includes a normal barcode. Therefore, the process proceeds to step S313, and a bar code flag that clearly indicates that is set (NMR flag setting process).

  In step S320, the image data is decoded. This decoding process is to decode the image data into code data (code information), and step S201 by the character check process described with reference to FIG. 4 is similarly performed.

  As described above, in the pixel partition frame determination process shown in FIG. 7, it is determined whether the code is a normal barcode or an active code element code based on the brightness of the background on which the information code Q is displayed. This is particularly effective when the display screen 201 of the display device 200 is composed of a color liquid crystal device.

  Based on the lightness of the background on which the information code Q is displayed, it is determined whether the information code Q is a normal bar code or an active code element code. An example of the type determination process. This brightness / darkness determination process is particularly effective when, for example, the display screen 201 of the information code display device 200 is illuminated by a backlight using a light guide plate from the back surface thereof.

  That is, as shown in FIG. 9, in the light / dark determination process, first, the light intensity detection process is performed in step S401. Similarly to the image data analysis process (S301) described above, this process also analyzes the image data based on the image signal from the light receiving sensor 23 to detect the light intensity and generate numerical data. The light intensity detection process (S401) can correspond to “light intensity information generation means” recited in the claims.

  In the next step S403, a process for detecting a variation in brightness of the background including the information code Q from the intensity of light detected in step S401 is performed. For example, in this process, the variation in light and dark is analyzed from the magnitude relation of the numerical difference based on the intensity of light digitized in step S401, and a variation greater than a predetermined threshold is detected. This brightness / darkness variation detection process (S403) can correspond to “lightness / darkness determination means” recited in the claims.

  In the case of a normal barcode, since it is printed on a display medium such as paper, generally there is little variation in light and darkness, whereas in the case of an element code constituting an active code, there is variation in light and darkness due to the backlight. Exists. For example, when the backlight is composed of an LED and a light guide plate that can disperse the light of the LED in a planar shape, a slight variation in brightness and darkness occurs due to uneven dispersion of the light. Therefore, if there is a light / dark variation greater than or equal to a predetermined threshold, the image data is likely to contain an active code element code.

  Therefore, if it is determined in step S405 that there is a variation in light and dark (S405; Yes), it is determined that there is a high possibility that the element code of the active code is included in the image data. The process proceeds to S411, and an element code flag that clearly indicates that is set (ADC flag setting process). On the other hand, if it is determined that there is no such variation in brightness (S405; No), it is determined that there is a high possibility that the image data includes a normal barcode. The process proceeds to S413, and a bar code flag indicating that fact is set (NMR flag setting process).

  Thereafter, the image data is decoded in step S420. This decoding process is to decode the image data into code data (code information), and step S201 by the character check process described with reference to FIG. 4 is similarly performed.

  In this way, in the light / dark determination process shown in FIG. 9, based on the intensity (lightness) of the light from the background backlight on which the information code Q is displayed, it is determined whether the code is a normal bar code or an active code element code. Therefore, when the display screen 201 of the information code display device 200 is illuminated by the backlight from the back surface thereof, particularly in the case of illumination by the LED, it is effective.

  Even when the backlight is EL illumination, if the switching frequency for controlling the lighting is later than or close to the exposure timing of the light receiving sensor 23, the background of the information code Q becomes dark. In the case of variation, it is possible to determine whether the code is an active code by detecting the brightness of the entire background.

  Next, as an example of the code type determination process, an example of the image switching time determination process will be described with reference to FIG. As shown in FIG. 10, in the image switching time determination process, first, a process for determining whether or not there is reference image data is performed in step S501. If there is no reference image data (S501; No), the following step is performed. In step S503, image data is acquired by image information acquisition processing, and in step S505, an image of the information code Q included in the image data, that is, a code image is registered in a predetermined area of the memory 35 as reference image data. Is done. If reference image data has already been registered and exists (S501; Yes), steps S503 and S505 are skipped and the process proceeds to step S507. The reference image data registration process (S505) and the predetermined area of the memory 35 can correspond to “reference image information holding unit” recited in the claims.

  The image information acquisition process in step S503 is substantially the same as the image information acquisition process in step S10 described with reference to FIG. 2, but in the image information acquisition process in step S503, the time t0 when the image data is acquired. Is recorded. This time t0 is based on time data measured by a clock device built in the control circuit 40.

  Next, an image information acquisition process is performed in step S507. In this process, image data including a code image at a time t1 different from the above-described reference image data is acquired. Similar to step S503, image data is acquired, and the acquisition time t1 is also acquired. .

  In the subsequent step S509, the code image based on the image data acquired in step S507 is compared with the code image based on the reference image data, and processing for determining whether or not the code image has changed between time t0 and time t1 is performed. Is called. If there is a change (S509; Yes), the process proceeds to the elapsed time calculation process in step S511 to calculate the elapsed time Δt (Δt = t0−t1), and if there is no change ( S509; No), the process proceeds to step S507, and the image information acquisition process is performed again. That is, the image data is repeatedly acquired in step S507 until the code image of the image data acquired in step S507 changes as compared with the code image of the reference image data. The comparison processing (S509) can correspond to “code image comparison means” recited in the claims.

  Processing is performed in step S513 to determine whether or not the elapsed time Δt calculated in step S511 is substantially equal to the time interval for switching the active code element code. That is, when the elapsed time Δt in step S511 is substantially equal to the element code display switching time (for example, 0.1 second), the code image can correspond to the element code of the active code, but such an element. It is unlikely that normal bar codes will be read one after another by a reading operation by an operator in a short time corresponding to the code display switching time.

  For this reason, when it is determined in step S513 that the elapsed time Δt is substantially equal to the element code display switching time (S513; Yes), the code image included in the image data is an active code element. Since it is determined that there is a high possibility of being a code, the process proceeds to step S515, and an element code flag that clearly indicates that is set (ADC flag setting process). On the other hand, when it is not determined that the elapsed time Δt is substantially equal to the element code display switching time (S513; No), the code image included in the image data is highly likely to include a normal barcode. Therefore, the process proceeds to step S517, and a bar code flag indicating that fact is set (NMR flag setting process). The determination process (S513) and the elapsed time calculation process (S511) can correspond to “switching interval determination means” described in the claims.

  Thereafter, the image data is decoded in step S520. This decoding process is to decode the image data into code data (code information), and step S201 by the character check process described with reference to FIG. 4 is similarly performed.

  As described above, in the image switching time determination process shown in FIG. 10, when the time Δt from the arbitrary time t0 to the time t1 is substantially the same as the time interval at which the element code is switched (S513; Yes), the time is acquired at the time t1. When it is determined that the element code of the active code is included in the image information and such a time Δt is not substantially equal to the time interval at which the element code is switched, the element of the active code is included in the image data acquired at time t1. Determine that no code is included. That is, whether the code is an active code or a normal bar code is determined based on the time required for the code image to change.

  Here, modified examples (No. 2 and No. 3) of the reading process shown in FIG. 3 will be described with reference to FIG. In FIG. 11, in each of the partial diagrams, a part of the flowchart shown in FIG. 3 is extracted to illustrate the difference in the processing flow.

  First, a modification example (No. 2) shown in FIG. As shown in FIG. 11A, in this modified example (part 2), there is an active code between the code type determination process in step S115 and the process for determining whether or not the element code has been output in step S117. A process for determining whether or not is present as step S120.

  That is, in the reading process described with reference to FIG. 3, in the active code reading mode, it is assumed that the image data acquired in the image information acquisition process (S113) includes an element code constituting the active code. Each treatment was performed. However, since the image data may include a code image other than the element code, in the present modification, the image data acquired by the image information acquisition process (S113) is also the element code in the active code reading mode. It was decided to judge whether or not.

  If it is determined in step S131 for determining whether or not it is an active code, it is not an active code, that is, it is not data of an element code constituting the active code (S131; No), an active code reading is performed in step S133. Processing to cancel the mode was performed, and the reading process was terminated. If it is determined that the data is an element code constituting an active code (S131; Yes), the process proceeds to the subsequent step S117 and the same determination process as in FIG. 3 is performed.

  As a result, when a normal barcode is read once after switching to the active code reading mode, it is automatically changed from the active code reading mode to the normal label mode in which the normal barcode can be read by the determination processing in step S131. Since it is switched, both a normal bar code and an active code can be read without performing complicated setting work.

  Next, a modification example (No. 3) shown in FIG. As shown in FIG. 11B, this modified example (part 3) is obtained by adding a retry function to the above-described modified example (part 2). That is, in the modified example (part 2) described with reference to FIG. 11A, whether or not the image data acquired in the image information acquisition process (S113) is an element code even in the active code reading mode. However, if it is determined that the code is not an active code even once, the active code reading mode is canceled. Therefore, the present modification (part 3) is configured to retry the image information acquisition process (S113) and the code type determination process (S115) until a predetermined time has elapsed even if it is determined that the code is not an active code. .

  Specifically, as shown in FIG. 11B, it is determined whether or not it is an active code between the code type determination process in step S115 and the process for determining whether or not the element code has been output in step S117. Before the process of canceling the active code reading mode (S147), the process of counting up the timer value (S143), and the time-up determination process of monitoring the timer value (S145). Intervened. If the time has not yet expired (S145; No), the process is set to shift immediately before the image information acquisition process (S113).

  Thereby, in the active code reading mode, when the reading of the element code cannot be completed within a predetermined time (S145; Yes), the active code reading mode is switched to the normal label reading mode. Can be completed within a predetermined time (S145; No, S141; Yes), the active code reading mode cannot be switched to the normal label reading mode. For this reason, if a code other than the element code is read due to erroneous reading after switching to the active code reading mode, the system immediately waits for a predetermined time without switching to the normal label reading mode. When a code other than the element code is read, the active code reading mode is automatically switched to the normal label reading mode. Therefore, useless mode switching due to such a reading error can be prevented.

  In the modified example (part 3) shown in FIG. 11 (B), the predetermined time is counted by the process of counting up the timer value (S143) and the time-up determination process (S145). Retry is allowed within a predetermined number of times by the counting process and the count-up judgment process for monitoring the count value. When the predetermined number of times is exceeded, the retry is prevented and the active code reading mode is canceled in step S147. The process may be configured to shift to the process.

  Next, the reading condition learning process executed in the active code reading mode will be described with reference to FIG. FIG. 12 (A) shows a basic flowchart of the processing, and FIG. 12 (B) shows a modified example. The reading condition learning process is sequentially executed after reading the element code of the active code. The “reading condition” is set by the active code reading setting process in S109 described with reference to FIG. "Element code reading conditions".

  As shown in FIG. 12A, in the reading condition learning process, first, in step S601, a process of determining whether or not the element code has been successfully read is performed. If it succeeds (S601; Yes), a process of storing (holding) the current reading conditions in the reading condition table is performed in step S603, and if not successful (failed) (S601; No). In step S605, a process for setting the current reading condition more gently than that is performed. When these processes are completed, the reading condition learning process ends.

  Here, “to set the current reading condition more gently than that” means that, for example, when the reading condition is set so that the read element code matches a plurality of times, the number of times setting value is decreased. This corresponds to this, and when the time required for reading is set as the reading condition, it corresponds to increasing the time set value. Further, when a threshold value of binary data based on image data is set as the reading condition, increasing or decreasing the threshold value corresponds to this.

  Thereby, the reading condition table stores (holds) a time setting value when reading of the element code can be completed within a predetermined time and a setting value of the number of times when reading of the element code can be completed within a predetermined number of times. Therefore, in the active code reading mode, the element code can be read based on the stored (held) time setting value and number of times setting value. Therefore, in the active code reading mode, the element code can be read based on the time setting value and the number of times setting value at which the element code can be read.

  Next, a modified example of the reading condition learning process will be described with reference to FIG. As shown in FIG. 12B, in this modification, after step S603 of the process described with reference to FIG. 12A, a process for strictly setting the reading conditions is added as step S607. That is, even if the element code of the active code is successfully read, the current reading condition is stored in the reading condition table (S603) and then the current reading condition is set more severely (S607). .

  Here, “to set the current reading condition more strictly” means, for example, that when the reading condition is set so that the read element code matches a plurality of times, the number of times setting value is increased. Corresponds to this, and when the time required for reading is set as a reading condition, it corresponds to reducing the time set value. Further, when a threshold value of binary data based on image data is set as the reading condition, increasing or decreasing the threshold value corresponds to this.

  As a result, in the reading condition learning process shown in FIG. 12A, once the reading condition is set gently, no more severe reading condition is set. In step S607, the reading condition is reset in a strict direction. For this reason, the reading condition relaxation process in step S605 and the read condition tensioning process in step S607 can be combined to enable optimal setting of the reading condition. Therefore, in the active code reading mode, the element code can be read under optimum reading conditions.

  In the above-described embodiment, the element codes constituting the active code are set so as to be read in order. However, as described with reference to FIG. Based on the part SQN, the number of accumulated element codes is grasped, and the accumulated element codes are managed by, for example, flags, so that each element code is skipped in the order, not in order. For example, it may be configured such that the reading can be performed in a manner such as second → fourth → fifth → third →. The total number of element codes can be known by referring to the total number data part SUM set to the element code whose order data part SQN is “00”. Thereby, an active code in which element codes are displayed at random can be read.

  Although not shown, the progress of reading the element code constituting the active code may be displayed on the liquid crystal display 46 by, for example, a bar length or a numerical value (0% to 100%). Thus, the operator can visually grasp the reading status of the element code in the active code reading mode. For example, the operator can change the reading direction of the barcode reader 20 even though the element code is being read. It is possible to suppress incentives for an operation that leads to a reading error such as changing or stopping the reading operation.

It is a block diagram which shows the structure of the barcode reader which concerns on embodiment of this invention. It is a flowchart which shows notionally the flow of the reading process by the barcode reader which concerns on embodiment of this invention. It is a flowchart which shows the specific example of the reading process mounted in the barcode reader which concerns on embodiment of this invention. It is a flowchart which shows a character check process as an example of the code classification determination process shown in FIG. FIG. 5A is an explanatory diagram showing a configuration example of a bar code by the code 128, and FIG. 5B is an example of an output format when an element code of an active code is output to the host computer. FIG. 4 is a flowchart illustrating a modification example (No. 1) of the reading process illustrated in FIG. 3. FIG. It is a flowchart which shows a pixel partition frame determination process as an example of the code classification determination process shown in FIG. 8A is a waveform diagram when a barcode displayed on the screen of a color liquid crystal display device is read, and FIG. 8B is a waveform diagram when a barcode printed on paper is read. is there. It is a flowchart which shows a light / dark determination process as an example of the code classification determination process shown in FIG. 4 is a flowchart illustrating an image switching time determination process as an example of a code type determination process illustrated in FIG. 3. FIG. 11A shows a modified example (No. 2) and FIG. 11B shows a modified example (No. 3) in an excerpt of the flowchart showing the modified example of the reading process shown in FIG. FIG. 12A is a flowchart showing the flow of the reading condition learning process executed in the active code reading mode in the reading process by the bar code reader according to the embodiment of the present invention, and FIG. This is a modification of the process shown in FIG. It is explanatory drawing which shows the example of an active code.

Explanation of symbols

20: Bar code reader (optical information reader)
DESCRIPTION OF SYMBOLS 21 ... Illumination light source 22 ... Light receiving element 23 ... Light receiving sensor 25 ... Filter 27 ... Imaging lens 35 ... Memory 46 ... Liquid crystal display device 48 ... Communication interface 100 ... The whole normal barcode 101-104 ... Element code 200 ... Information code display Apparatus 201 ... Display screen HST ... Host computer Lf ... Illumination light Lr ... Reflected light Q ... Information code R ... Reading object S10 ... Image information acquisition process (image information acquisition means)
S20: Code type determination process (code type determination means)
S30: Reading mode switching process (reading mode switching means)
S40, S50 ... Output processing S60 ... Output completion judgment processing S201 ... Decoding processing (decoding means)
S203 ... "modulus 103 + 1" calculation process (calculation means)
S301: Image data analysis processing (pixel partition frame determination processing)
S401: Light intensity detection processing (light intensity information generating means)
S403: Light / dark variation detection processing (light / dark determination means)
S503, S507 ... Image information acquisition process S505 ... Reference image data registration process (basic image information holding means)
S509: Determination means (code image comparison means)
S511: Elapsed time calculation process (switching interval determination means)
S513: Determination processing (switching interval determination means)
t0 Time (arbitrary time)
t1 Time (time after arbitrary time)
Δt Elapsed time (time from arbitrary time t0 to time t1)

Claims (8)

A first reading mode capable of reading a static information code printed on a display medium, and a first reading mode capable of reading a dynamic information code consisting of a plurality of element codes displayed individually on the display screen of the information code display device. An optical information reading device comprising two reading modes,
Image information acquisition means capable of acquiring image information including the static information code or the element code;
Code type determination means capable of determining whether or not the element code is included in the image information based on the image information;
Reading mode switching means for switching to a second reading mode in which the dynamic information code can be read when the code type determining means determines that the element code is included in the image information. An optical information reading device. The code type determination means includes
Decoding means capable of generating code information obtained by decoding the static information code or the element code based on the image information;
Arithmetic means for performing predetermined arithmetic processing on the code information;
From the calculation result,
If the code information is a decryption of the element code, it is determined that the dynamic information code is included in the image information,
2. The optical information reader according to claim 1, wherein if the code information is not a result of decoding the element code, it is determined that the dynamic information code is not included in the image information. The code type determination means includes
Based on the image information, light intensity information generating means capable of generating information on the intensity of light included in the image information;
Based on the information on the light intensity, light / dark judgment means for judging whether or not the image information includes a light / dark variation by a backlight that illuminates the display screen of the information code display device from the back surface thereof;
From the determination result by the brightness determination means,
When the image information includes light and dark variations due to the backlight, it is determined that the dynamic information code is included in the image information,
2. The optical information reading apparatus according to claim 1, wherein when the image information does not include variations in brightness due to the backlight, it is determined that the dynamic information code is not included in the image information. The code type determination means includes
Based on the image information, the pixel partition frame determining means capable of determining whether or not the image information includes a partition frame between pixels constituting the display screen of the information code display device, and the pixel partition frame From the judgment result by the judgment means,
When the image information includes a partition frame between the pixels, it is determined that the dynamic information code is included in the image information,
The optical information reading apparatus according to claim 1, wherein when the image information does not include a partition frame between the pixels, it is determined that the dynamic information code is not included in the image information. The code type determination means includes
Reference image information holding means capable of holding image information acquired at an arbitrary time t0 by the image information acquisition means as reference image information;
The static information code or the element code included in the image information acquired at time t1 after the arbitrary time t0 by the image information acquisition means, and the static information code or the element code included in the reference image information Code image comparison means for comparing
When the images of the two codes are different by the code image comparison means, the time Δt from the arbitrary time t0 to the time t1 indicates that the element code displayed on the display screen of the information code display device is the next element code. A switching interval determination means capable of determining whether or not the time interval is approximately equal to the switching time interval;
From the determination result by the switching interval determination means,
When the time Δt is approximately equal to the time interval at which the element code is switched, it is determined that the dynamic information code is included in the image information acquired at the later time t1,
When the time Δt is not substantially equal to a time interval at which the element code is switched, it is determined that the dynamic information code is not included in the image information acquired at the subsequent time t1. Item 3. The optical information reader according to Item 1.   In the second reading mode, when the code type determining unit determines that the dynamic information code is not included in the image information, the reading mode switching unit performs the second reading mode. The optical information reading device according to claim 1, wherein the optical information reading device is switched to the first reading mode.   In the second reading mode, when the reading of the element code cannot be completed within a predetermined time or within a predetermined number of times, the reading mode switching unit starts the first reading from the second reading mode. The optical information reading device according to claim 1, wherein the optical information reading device is switched to a mode. A reading condition table capable of holding reading conditions of the element code in the second reading mode;
In the second reading mode, when reading the element code based on the reading conditions held in the reading condition table,
When the reading of the element code can be completed within a predetermined time or a predetermined number of times, a time setting value corresponding to the predetermined time or a frequency setting value corresponding to the predetermined number of times is used as the reading condition. Hold on the table,
When the reading of the element code cannot be completed within a predetermined time or within a predetermined number of times, the time setting value corresponding to the predetermined time or the number setting value corresponding to the predetermined number of times is corrected to a moderate condition value. 8. The optical information reading apparatus according to claim 1, wherein the corrected time setting value or frequency setting value is held in the reading condition table as the reading condition.

Images