Terminal device, control method, and program

Abstract

To provide a terminal device that improves a recognition rate of a code symbol and improves efficiency of the code symbol reading processing.SOLUTION: A handy terminal 10 includes: illumination (light source) 173 that can emit auxiliary light of a plurality of colors for reading a code symbol; and a CPU (control unit) 11 that controls irradiation of auxiliary light by the illumination 173. The CPU 11 switches auxiliary light of a plurality of colors in a predetermined order to irradiate the illumination 173 with auxiliary light, determines, if the code symbol is successfully read while the illumination is irradiated with auxiliary light, which color of the plurality of colors of auxiliary light was used to read the code symbol, and changes, on the basis of the determination result, the predetermined order for irradiating the illumination with auxiliary light next time.SELECTED DRAWING: Figure 6

Description

Technical Field

[0005]

[0001] The present invention relates to a terminal device, a control method, and a program.

Background Art

[0002] Conventionally, in the logistics industry, manufacturing industry, retail industry, etc., management of products has been carried out by reading code symbols such as barcodes and two-dimensional codes attached to products using a handheld terminal. Although these code symbols are sometimes colored not only black but also red, green, etc. according to the design of the product, when the code symbol and the background are the same color system, the contrast ratio is low, making it difficult to read the code symbol.

[0003] Therefore, for example, a barcode reading device has been disclosed that irradiates light simultaneously from at least two types of light sources, a first light source consisting of red light and a second light source consisting of white light, onto a barcode (code symbol), enabling even a barcode with a small contrast ratio to be read without stress (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the barcode reading device disclosed in Patent Document 1 above, when reading a barcode printed on, for example, a form, if the printed position of the barcode is misaligned such that the barcode overlaps the frame line of the form or approaches the frame line of the form and a necessary margin width (blank space; quiet zone) cannot be secured, the frame line interferes with the reading of the barcode and the recognition rate of the barcode decreases.

[0006] This invention has been made in view of these problems, and aims to improve the recognition rate of code symbols and to improve the efficiency of the reading process of said code symbols. [Means for solving the problem]

[0007] To solve the above problems, the terminal device according to the present invention To read code symbols The white auxiliary light and the color are different from each other. Multiple colored auxiliary lights and A light source capable of illuminating, A control unit that controls the irradiation of the auxiliary light by the light source, Equipped with, The control unit, If reading the code symbol based on the illumination of the white auxiliary light is unsuccessful, The aforementioned multiple colors of auxiliary light are switched in a predetermined order and irradiated onto the light source. The aforementioned Tinted with color If the code symbol is successfully read while the auxiliary light is irradiated, which of the multiple colors of the auxiliary light is selected? taste When the auxiliary light is shone, it is determined whether the code symbol can be read. Based on the results of the above determination, next to the aforementioned multiple colors To change the predetermined order when irradiating with auxiliary light, It is characterized by the following: [Effects of the Invention]

[0008] According to the present invention, the recognition rate of code symbols can be improved, and the processing of reading said code symbols can be made more efficient. [Brief explanation of the drawing]

[0009] [Figure 1] (a) is a front view of a handheld terminal according to an embodiment of the present invention. (b) is a rear view of the handheld terminal. [Figure 2] This is a diagram showing the functional configuration of a handheld terminal. [Figure 3] This diagram shows the schematic configuration of the scanner unit. [Figure 4] It is a diagram showing the configuration of the barcode. [Figure 5] (a) is a diagram showing a state where the barcode is appropriately printed within a predetermined frame of the slip. (b) is a diagram showing the barcode printed on the slip, and shows a state where the blank portion on the left side of the barcode overlaps with the vertical frame line of the slip. (c) is a diagram showing the barcode printed on the slip, and shows a state where the bars and spaces constituting the barcode overlap with the vertical frame line of the slip. [Figure 6] It is a flowchart showing the control procedure of the code symbol reading process. [Figure 7] It is a flowchart showing the control procedure of the code symbol reading process. [Figure 8] It is a table showing the lighting switching pattern in the initial state. [Figure 9] (a) is a diagram showing an image of the barcode as seen from the scanner unit when auxiliary light of a color different from the color of the frame line of the slip is lit. (b) is a diagram showing an image of the barcode as seen from the scanner unit when auxiliary light of the same color as the frame line of the slip is lit. [Figure 10] It is a sequence diagram showing the reading operation of the code symbol. [Figure 11] It is a diagram for explaining the method of automatically selecting the optimal color of the auxiliary light irradiated by illumination.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0011] FIG. 1(a) is a front external view of the handy terminal (terminal device) 10 of the present embodiment. FIG. 1(b) is a rear external view of the handy terminal 10. FIG. 2 is a block diagram showing the functional configuration of the handy terminal 10.

[0012] The handy terminal 10 is a portable information processing terminal that is used, for example, by an introducer such as a logistics company and is operated by a user such as a management person of the introducer to input information. The handy terminal 10 has a function of scanning code symbols (barcodes, two-dimensional codes).

[0013] As shown in FIGS. 1(a) and 1(b), the handy terminal 10 includes an operation unit 12, a display unit 14, an NFC unit 161, a scanner unit 17, a camera unit 18, and an LED (Light Emitting Diode) 191 on a housing 10a.

[0014] The operation unit 12 includes a touch panel 121 and a physical key unit 122. The touch panel 121 is a capacitive touch panel provided on the display panel of the display unit 14 on the front side of the housing 10a and receives touch input from the user. Note that the touch panel 121 may be another type of touch panel such as a resistive film type.

[0015] The physical key unit 122 has a physical trigger key 122a and a physical key group 122b. The physical trigger key 122a is provided on the front, left and right side surfaces, and the back surface of the housing 10a respectively, and is a trigger key as a physical key (hard key) that receives a scan execution input of the scanner unit 17 from the user. The physical key group 122b is provided on the front side of the housing 10a and is a plurality of physical keys that receive various inputs from the user. For example, it has a numeric keypad that receives input of numbers and characters, cursor keys that receive up, down, left, and right direction inputs, and various function keys that receive input of various functions.

[0016] The display unit 14 has an LCD (Liquid Crystal Display) display panel and performs various displays on the display panel.

[0017] The NFC unit 161 is located on the back of the housing 10a and is a communication unit that has an antenna (NFC antenna (coil antenna)) for the NFC wireless communication method, a modulation / demodulation circuit, a signal processing circuit, etc., and performs NFC wireless communication with the communication partner by inputting and outputting an electromagnetic field. The frequency of the radio waves (electromagnetic field) of the NFC unit 161 is assumed to be, for example, 13.56 [MHz], but is not limited to this. The NFC unit 161 may also be configured as a wireless communication unit for a communication method of another frequency.

[0018] The NFC unit 161 performs NFC wireless communication with a communication destination such as an employee ID card or other contactless IC (Integrated Circuit) card, and reads the information stored in the communication destination. The NFC unit 161 is positioned close to the camera unit 18, surrounding the camera unit 18 and the LED 191.

[0019] The scanner unit 17 is located on the top surface of the housing 10a and includes an aimer 171 (described later), an image sensor 172 (described later), and an illumination 173 (described later). The scanner unit captures images of a code symbol (barcode, 2D code) that is the subject and reads the code symbol. For example, the user directs the scanner unit 17 of the handheld terminal 10 so that the code symbol is within the aimer light, and the code symbol is captured and scanned by pressing a physical trigger key 122a or touching a virtual trigger key displayed on the display unit 14.

[0020] The camera unit 18 is located on the back of the housing 10a and is a digital camera unit that has an optical system and an image sensor, and captures images of a subject to generate image data. During preview, when real-time preview (live) image data is displayed on the display unit 14, the image data generated by the camera unit 18 is acquired as preview image data, and when the shutter is pressed by the user during preview, the image data of a still image for storage that is generated by the camera unit 18 as captured image data.

[0021] LED191 is a light-emitting unit located in close proximity to the camera unit 18 on the back of the housing 10a, and illuminates the subject of the camera unit 18.

[0022] Next, with reference to Figure 2, the internal functional configuration of the handheld terminal 10 will be described. The handheld terminal 10 comprises a CPU (Central Processing Unit) 11, an operation unit 12, a RAM (Random Access Memory) 13, a display unit 14, a storage unit 15, a wireless communication unit 16, a scanner unit 17, a camera unit 18, an output unit 19, and a battery 20. Each part of the handheld terminal 10 is connected via a bus 21.

[0023] The CPU (control unit) 11 controls each part of the handheld terminal 10. The CPU 11 reads a specified program from the system programs and application programs stored in the memory unit 15, loads it into the RAM 13, and performs various processes in cooperation with the loaded program.

[0024] As described above, the operation unit 12 has a touch panel 121 and a physical key unit 122, and accepts touch input from the user to the touch panel 121 and key input to the physical key unit 122, and outputs the operation information to the CPU 11.

[0025] RAM13 is a volatile memory that forms a work area for temporarily storing various data and programs.

[0026] The display unit 14 displays various information on the LCD display panel according to the display information instructed by the CPU 11. The display unit 14 may also be an EL (Electro-Luminescence) display or the like.

[0027] The memory unit 15 is a non-volatile memory such as flash memory that can read and write information. Various data and programs are stored in the memory unit 15.

[0028] The wireless communication unit 16 has antennas, modulation / demodulation circuits, signal processing circuits, etc., for various wireless communication methods, and is at least one wireless communication unit that performs wireless communication with a communication partner, and has the NFC unit 161 described above. The wireless communication methods of each wireless communication unit of the wireless communication unit 16 other than the NFC unit 161 are wireless LAN (Local Area Network) such as Wi-Fi (registered trademark), wireless WAN (Wide Area Network), etc. For example, the CPU 11 transmits and receives information with a communication partner such as a contactless IC card via NFC communication through the NFC unit 161 of the wireless communication unit 16.

[0029] The scanner unit 17, following the control of the CPU 11, captures an image of the code symbol as its subject, generates image data, and outputs it to the CPU 11. The CPU 11 decodes the image data of the code symbol captured by the scanner unit 17 to obtain the data contained in the code symbol. Alternatively, the scanner unit 17 may be a laser scanner that scans the code symbol by irradiating it with laser light and decodes the signal obtained from the input of the reflected light to obtain the data contained in the code symbol.

[0030] The camera unit 18, in accordance with the control of the CPU 11, captures an image of the subject and generates captured image data.

[0031] The output unit 19 has an LED 191 and sound output units such as an amplifier and a speaker, and controls the LED 191 to turn on / off and outputs sound from the sound output units according to the control of the CPU 11.

[0032] Battery 20 is a rechargeable battery (secondary battery) such as a lithium-ion battery, and supplies power to each part of the handheld terminal 10. Battery 20 also turns off the power supply to each part of the handheld terminal 10 (power off) according to the control of the CPU 11.

[0033] Next, the schematic configuration of the scanner unit 17 will be described with reference to Figure 3. Figure 3 is a diagram showing the schematic configuration of the scanner unit 17.

[0034] As shown in Figure 3, the scanner unit 17 includes an aimer 171, an image sensor 172, and an illumination 173.

[0035] Aimer 171 is a laser diode (LD) that emits a laser beam that serves as a measurement index for the distance between the image sensor 172 and the subject, which is a code symbol, and as a reference spot light for aligning the imaging direction of the image sensor 172 with the subject direction.

[0036] The image sensor 172 is a CMOS (Complementary Metal Oxide Semiconductor) image sensor, although it is not particularly limited to any specific type. The image sensor 172 captures (acquires) image data by converting the incident image of the subject, received through the optical system, into an electrical signal via photoelectric conversion.

[0037] The illumination 173 is composed of a light source, such as an LED (Light Emitting Diode), and emits illumination light (auxiliary light) to brightly illuminate the subject and the surrounding area. The illumination 173 in this embodiment is equipped with three LEDs: red, green, and blue.

[0038] Next, with reference to Figure 4, we will explain the structure of a barcode, which is a type of code symbol. Figure 4 is a diagram showing the structure of a barcode.

[0039] As shown in Figure 4, a barcode is composed of a combination of thin bars (narrow bars), thick bars (wide bars), and spaces between each bar, as well as margins (quiet zones) provided to the left of the leftmost bar and to the right of the rightmost bar. These margins are provided to stabilize barcode reading and require a width of at least 10 times the width of the narrow bars. Therefore, as shown in Figure 5(a), when printing barcode BC within a predetermined frame on a slip SL, for example, the printing position of barcode BC may be misaligned, and as shown in Figure 5(b), the left margin of barcode BC may overlap with the vertical frame line, resulting in insufficient margin. Alternatively, as shown in Figure 5(c), if the bars or spaces constituting barcode BC overlap with the vertical frame line, barcode BC may become unreadable. Therefore, in this embodiment, in the code symbol reading process described later (see Figures 6 and 7), by sequentially switching the color of the auxiliary light (illumination light) emitted by the illumination 173 while reading the code symbol, when the color of the auxiliary light becomes the same as the color of the border of the slip SL, the border appears to blend in with the background of the code symbol. This makes it possible to read the barcode BC even when the margins on both sides of the barcode BC overlap with the vertical border of the slip SL, or when the bars or spaces constituting the barcode BC overlap with the vertical border of the slip SL.

[0040] Next, the operation of the handheld terminal 10 will be explained with reference to Figures 6 and 7. Figures 6 and 7 are flowcharts showing the control procedure for the code symbol reading process by the handheld terminal 10.

[0041] As shown in Figure 6, when the code symbol reading process is started, the CPU 11 of the handheld terminal 10 first determines, via the operation unit 12, whether or not a predetermined termination operation has been performed to end the reading (scanning) of the code symbol (step S1).

[0042] If it is determined in step S1 that a predetermined termination operation has been performed (step S1; YES), the CPU 11 terminates the code symbol reading process.

[0043] Furthermore, if it is determined in step S1 that a predetermined termination operation has not been performed (step S1; NO), the CPU 11 determines whether or not the physical trigger key 122a has been pressed, or whether or not the virtual trigger key displayed on the display unit 14 as a soft key has been pressed (step S2).

[0044] In step S2, if it is determined that neither the physical trigger key 122a has been pressed nor the virtual trigger key displayed on the display unit 14 has been pressed (step S2; NO), the CPU 11 returns to the determination process in step S1 and repeatedly executes the subsequent processes.

[0045] Furthermore, in step S2, if it is determined that the physical trigger key 122a has been pressed, or that the virtual trigger key displayed on the display unit 14 as a soft key has been pressed (step S2; YES), the CPU 11 controls the illumination 173 to read the code symbol under the first illumination state (step S3). Here, in the initial state immediately after the code symbol reading process has started, that is, before the illumination switching pattern change process (step S19) described later is executed, in the first state, as shown in Figure 8, all three LEDs of the illumination 173—red (R), green (G), and blue (B)—are lit. In other words, white light, which is a combination of red, green, and blue light, is lit.

[0046] Next, the CPU 11 determines whether or not it succeeded in reading the code symbol in step S3 (step S4).

[0047] In step S4, if it is determined that the code symbol was successfully read in the process of step S3 (step S4; YES), the CPU 11 displays the result of reading the code symbol on the display unit 14 (step S17). Then, the CPU 11 returns to the determination process of step S1 and repeatedly executes the subsequent processes.

[0048] Furthermore, in step S4, if it is determined that the code symbol was not successfully read in the processing of step S3 (step S4; NO), the CPU 11 controls the illumination 173 to read the code symbol under the second illumination state (step S5). Here, in the initial state immediately after the code symbol reading process starts, as the second state, as shown in Figure 8, only the red (R) LED of the illumination 173 is lit.

[0049] For example, as shown in Figure 5(b), when the left margin of the barcode (bar color: black) BC overlaps with the vertical border of the slip (border color: red, background color: white) SL, and the barcode BC is read under the illumination of white light (first mode), as shown in Figure 9(a), the image seen by the scanner unit 17 will show the bars of the barcode BC as black, the border of the slip SL as gray (dashed line in the figure), and the background as white. In other words, the border of the slip SL remains visible in the image seen by the scanner unit 17, hindering the reading of the barcode BC, resulting in a failure to read the barcode BC. On the other hand, in the state shown in Figure 5(b) above, when the barcode BC is read under the illumination of red light (second mode), as shown in Figure 9(b), the image seen by the scanner unit 17 will show the bars of the barcode BC as black, and the border of the slip SL as white, blending in with the background. In other words, the border lines of the slip SL disappear from the image visible to the scanner unit 17, making it possible to read the barcode BC.

[0050] Next, the CPU 11 determines whether or not it succeeded in reading the code symbol in step S5 (step S6).

[0051] In step S6, if it is determined that the code symbol was successfully read in the process of step S5 (step S6; YES), the CPU 11 displays the result of reading the code symbol on the display unit 14 (step S18). Subsequently, the CPU 11 changes the lighting switching pattern for the illumination 173 (step S19). Then, the CPU 11 returns to the determination process of step S1 and repeatedly executes the subsequent processes. For example, if the illumination 173 was lit with red light in the second mode, the CPU 11 changes the red light to the first mode (first mode) of the lighting switching pattern the next time the illumination 173 is lit. In such cases, the CPU 11 sets the second and subsequent lighting patterns to colors whose frequency bands are furthest from the color of the light (auxiliary light) that was lit in the previous sequence, for example, blue light for the second (second mode) of the above lighting switching pattern, yellow light for the third (third mode), light blue light for the fourth (fourth mode), green light for the fifth (fifth mode), magenta light for the sixth (sixth mode), and white light for the seventh (seventh mode).

[0052] Furthermore, in step S6, if it is determined that the code symbol was not successfully read in the processing of step S5 (step S6; NO), the CPU 11 controls the illumination 173 to read the code symbol under the illumination of the third mode (step S7). Here, in the initial state immediately after the code symbol reading process starts, as the third mode, as shown in Figure 8, only the green (G) LED of the illumination 173 is lit.

[0053] Next, the CPU 11 determines whether or not it succeeded in reading the code symbol in step S7 (step S8).

[0054] In step S8, if it is determined that the code symbol was successfully read in the process of step S7 (step S8; YES), the CPU 11 displays the result of reading the code symbol on the display unit 14 (step S18). Subsequently, the CPU 11 changes the lighting switching pattern for the illumination 173 (step S19). Then, the CPU 11 returns to the determination process of step S1 and repeatedly executes the subsequent processes. For example, if the illumination 173 was lit with green light as the third mode, the CPU 11 changes the green light to the first mode (first mode) of the lighting switching pattern the next time the illumination 173 is lit. In such cases, the CPU 11 sets the second and subsequent lighting patterns to the color whose frequency band is furthest from the color of the light (auxiliary light) emitted in the previous sequence, for example, red light for the second (second mode) of the above lighting switching pattern, blue light for the third (third mode), yellow light for the fourth (fourth mode), light blue light for the fifth (fifth mode), magenta light for the sixth (sixth mode), and white light for the seventh (seventh mode).

[0055] Furthermore, in step S8, if it is determined that the code symbol was not successfully read in the processing of step S7 (step S8; NO), the CPU 11 controls the illumination 173 to read the code symbol under the illumination of the fourth mode (step S9). Here, in the initial state immediately after the code symbol reading process starts, as the fourth mode, as shown in Figure 8, only the blue (B) LED of the illumination 173 is lit.

[0056] Next, the CPU 11 determines whether or not it succeeded in reading the code symbol in step S9 (step S10).

[0057] In step S10, if it is determined that the code symbol was successfully read in the process of step S9 (step S10; YES), the CPU 11 displays the result of reading the code symbol on the display unit 14 (step S18). Subsequently, the CPU 11 changes the lighting switching pattern for the illumination 173 (step S19). Then, the CPU 11 returns to the determination process of step S1 and repeatedly executes the subsequent processes. For example, if the illumination 173 was lit with blue light in the fourth mode, the CPU 11 changes the blue light to the first mode (first mode) of the lighting switching pattern the next time the illumination 173 is lit. In such cases, the CPU 11 sets the second and subsequent lighting patterns to the color whose frequency band is furthest from the color of the light (auxiliary light) emitted in the previous sequence, for example, red light for the second (second mode) of the above lighting switching pattern, light blue light for the third (third mode), yellow light for the fourth (fourth mode), magenta light for the fifth (fifth mode), green light for the sixth (sixth mode), and white light for the seventh (seventh mode).

[0058] Furthermore, in step S10, if it is determined that the code symbol was not successfully read in the process of step S9 (step S10; NO), the CPU 11 controls the illumination 173 to read the code symbol under the fifth illumination state (step S11), as shown in Figure 7. Here, in the initial state immediately after the code symbol reading process starts, as the fifth state, as shown in Figure 8, only the red (R) and green (G) LEDs of the illumination 173 are lit. In other words, yellow light, which is the combination of the red and green lights, is lit.

[0059] Next, the CPU 11 determines whether or not it succeeded in reading the code symbol in step S11 (step S12).

[0060] In step S12, if it is determined that the code symbol was successfully read in the process of step S11 (step S12; YES), the CPU 11 displays the reading result of the code symbol on the display unit 14 (step S18). Subsequently, the CPU 11 changes the lighting switching pattern for the illumination 173 (step S19). Then, the CPU 11 returns to the determination process of step S1 and repeatedly executes the subsequent processes. For example, if the illumination 173 was lit with yellow light as the fifth mode, the CPU 11 changes the yellow light to the first mode (first mode) of the lighting switching pattern the next time the illumination 173 is lit. In such cases, the CPU 11 sets the second and subsequent lighting patterns to the color whose frequency band is furthest from the color of the light (auxiliary light) emitted in the previous sequence, for example, blue light for the second (second mode) of the above lighting switching pattern, red light for the third (third mode), light blue light for the fourth (fourth mode), magenta light for the fifth (fifth mode), green light for the sixth (sixth mode), and white light for the seventh (seventh mode).

[0061] Furthermore, in step S12, if it is determined that the code symbol was not successfully read in the processing of step S11 (step S12; NO), the CPU 11 controls the illumination 173 to read the code symbol under the illumination of the sixth mode (step S13). Here, in the initial state immediately after the code symbol reading process starts, as the sixth mode, as shown in Figure 8, only the green (G) and blue (B) LEDs of the illumination 173 are lit. In other words, a cyan light, which is the combination of green light and blue light, is lit.

[0062] Next, the CPU 11 determines whether or not it succeeded in reading the code symbol in step S13 (step S14).

[0063] In step S14, if it is determined that the code symbol was successfully read in the processing of step S13 (step S14; YES), the CPU 11 displays the result of reading the code symbol on the display unit 14 (step S18). Subsequently, the CPU 11 changes the lighting switching pattern for the illumination 173 (step S19). Then, the CPU 11 returns to the determination process of step S1 and repeatedly executes the subsequent processes. For example, if the illumination 173 was lit with a light blue light as the sixth mode, the CPU 11 changes the light blue light to the first mode (first mode) of the lighting switching pattern the next time the illumination 173 is lit. In such cases, the CPU 11 sets the second (second mode) of the above lighting switching pattern to red light, the third (third mode) to blue light, the fourth (fourth mode) to yellow light, the fifth (fifth mode) to magenta light, the sixth (sixth mode) to green light, and the seventh (seventh mode) to white light, so that for the second and subsequent lighting switching patterns, the CPU 11 sets the color whose frequency band is furthest from the color of the light (auxiliary light) emitted in the previous sequence.

[0064] Furthermore, in step S14, if it is determined that the code symbol was not successfully read in the processing of step S13 (step S14; NO), the CPU 11 controls the illumination 173 to read the code symbol under the illumination of the seventh mode (step S15). Here, in the initial state immediately after the code symbol reading process starts, as the seventh mode, as shown in Figure 8, only the red (R) and blue (B) LEDs of the illumination 173 are lit. In other words, magenta light, which is formed by the combination of red and blue light, is lit.

[0065] Next, the CPU 11 determines whether or not it succeeded in reading the code symbol in step S15 (step S16).

[0066] In step S16, if it is determined that the code symbol was successfully read in the process of step S15 (step S16; YES), the CPU 11 displays the result of reading the code symbol on the display unit 14 (step S18). Subsequently, the CPU 11 changes the lighting switching pattern for the illumination 173 (step S19). Then, the CPU 11 returns to the determination process of step S1 and repeatedly executes the subsequent processes. For example, if the magenta light was lit by the illumination 173 as the seventh mode, the CPU 11 changes the magenta light to the first mode (first mode) of the lighting switching pattern the next time the illumination 173 is lit. In such cases, the CPU 11 sets the second (second mode) of the above lighting switching pattern to green light, the third (third mode) to red light, the fourth (fourth mode) to blue light, the fifth (fifth mode) to yellow light, the sixth (sixth mode) to light blue light, and the seventh (seventh mode) to white light, so that for the second and subsequent lighting switching patterns, the CPU 11 sets the color whose frequency band is furthest from the color of the light (auxiliary light) emitted in the previous sequence.

[0067] Furthermore, in step S16, if it is determined that the code symbol was not successfully read in the processing of step S15 (step S16; NO), the CPU 11 returns to step S3 (see Figure 6) and repeatedly executes the subsequent processing.

[0068] Next, the code symbol reading operation will be explained with reference to Figure 10. Figure 10 is a sequence diagram showing the code symbol reading operation. In the example shown in Figure 10, the color of the auxiliary light emitted by the illumination 173 is sequentially switched based on the initial lighting switching pattern described above (see Figure 8).

[0069] As shown in Figure 10, the code symbol is first read under the first illumination conditions (when all three LEDs of illumination 173—red (R), green (G), and blue (B)—are illuminated). Specifically, when the auxiliary light W1 is irradiated by illumination 173 for a predetermined time (e.g., 0.02 seconds), the image sensor 172 takes the first image (exposure) of the code symbol, and the first decoding of the code symbol is performed based on the image data of the captured code symbol. If the first decoding is unsuccessful, the auxiliary light W2 is irradiated again by illumination 173 for a predetermined time, and the image sensor 172 takes the second image (exposure) of the code symbol with the exposure adjusted. Then, the second decoding of the code symbol is performed based on the image data of the captured code symbol. If the second decoding is also unsuccessful, the series of operations related to decoding is repeated up to 10 times until decoding is successful. If decoding is unsuccessful on the 10th attempt, the code symbol is read under the second illumination state (when only the red (R) LED of illumination 173 is lit). If the code symbol is still not read successfully under the second illumination state, the code symbol is read again by sequentially switching the color of the auxiliary light emitted by illumination 173 through the third, fourth, ..., seventh, ... states until the code symbol is successfully read. Furthermore, the code symbol reading operation (a series of operations related to decoding) in the second and subsequent embodiments is the same as the code symbol reading operation under illumination in the first embodiment described above, so a detailed explanation will be omitted.

[0070] As described above, the handheld terminal 10 of this embodiment includes an illumination (light source) 173 capable of emitting auxiliary light of multiple colors for reading code symbols, and a CPU (control unit) 11 that controls the irradiation of auxiliary light by the illumination 173. The CPU 11 switches the multiple colors of auxiliary light in a predetermined order to irradiate the illumination 173, and if it is successful in reading a code symbol while irradiating with the auxiliary light, it determines which of the multiple colors of auxiliary light was irradiated when the code symbol was read, and based on the result of the determination, it changes the predetermined order in which the auxiliary light will be irradiated next time. Therefore, with the handheld terminal 10, when illuminating the illumination 173 with auxiliary light, by switching between multiple colors of auxiliary light in a predetermined order, even if, for example, the margins on both sides of a barcode printed on a slip overlap with the vertical border of the slip, or if the bars or spaces constituting the barcode overlap with the vertical border of the slip, when the color of the auxiliary light becomes the same as the color of the border of the slip, the border can be made to blend with the background of the barcode and the barcode can be read, thereby improving the recognition rate of the code symbol. Furthermore, if a code symbol is read while the auxiliary light is being irradiated, the terminal determines which of the multiple colors of auxiliary light was used to make the reading, and based on the result of this determination, the order in which the auxiliary light is irradiated next time is changed. For example, by changing the order to one that is most likely to read the code symbol, the efficiency of the code symbol reading process can be improved and power consumption can be reduced.

[0071] Furthermore, when the CPU 11 of the handheld terminal 10 changes the predetermined order described above, it sets the color of the auxiliary light that was illuminated when the code symbol was read as the first in the sequence (first mode) based on the result of the above determination. Therefore, with the handheld terminal 10, for example, when reading barcodes printed on each of the same type of slips in succession, by setting the color of the auxiliary light that was illuminated when the code symbol was read as described above to the first in the sequence (first mode), the success rate of reading the barcode under the illumination of the first mode can be increased, thereby improving the efficiency of the barcode reading process.

[0072] Furthermore, when the CPU 11 of the handheld terminal 10 changes the predetermined order described above, it sets the color of the auxiliary light to be emitted from the second to the next to last to the color with the frequency band furthest from the color of the auxiliary light emitted in the previous sequence. Therefore, with the handheld terminal 10, when illuminating auxiliary light with the illumination 173, it is possible to suppress the continuous illumination of light of the same color. As a result, with the handheld terminal 10, for example, when the margins on both sides of a barcode printed on a slip overlap with the vertical border lines of the slip, or when the bars or spaces constituting the barcode overlap with the vertical border lines of the slip, it becomes possible to efficiently illuminate the slip with auxiliary light of the same color as the border lines of the slip, thereby improving the efficiency of the barcode reading process.

[0073] Furthermore, in the initial state before the predetermined sequence described above is changed, the CPU 11 of the handheld terminal 10 illuminates the illumination 173 with a white auxiliary light as the first step (first mode) in that sequence. Therefore, the handheld terminal 10 can smoothly read colored code symbols (e.g., color barcodes).

[0074] Although the present invention has been described in detail based on embodiments above, the present invention is not limited to the above embodiments and can be modified without departing from the spirit of the invention. For example, in the above embodiment, a determination process is continuously performed for a certain period of time to determine which of the multiple colors of auxiliary light was used to read the code symbol. Based on the history of the results of the determination process performed during that period, the order in which the auxiliary lights are irradiated next time (lighting switching pattern) is changed in order of the frequency of the colors of the auxiliary lights.

[0075] Furthermore, in the above embodiment, the code symbol is read while sequentially switching the color of the auxiliary light emitted by the illumination 173. However, the optimal color of the auxiliary light emitted by the illumination 173 when reading the code symbol may be automatically selected by the following method.

[0076] The first method involves first using the image sensor 172 to photograph a barcode BC printed within a predetermined frame on a slip SL, as shown in the upper part of Figure 11, while the illumination 173 is illuminating the barcode BC with multiple colors. The frame of the slip SL is assumed to be blue. Then, as shown in the lower left and lower right of Figure 11, the black and white distribution of each image of the barcode BC taken under conditions such as white auxiliary light illumination and blue auxiliary light illumination is checked, and the color of the auxiliary light that was illuminating the barcode BC (blue in the example of Figure 11) is automatically selected when the image with the highest contrast (clearest black and white), i.e., the image with the fewest gray areas, is taken.

[0077] The second method involves, for example, under the control of the CPU 11, first capturing a frame surrounding the code symbol to be read using the camera unit 18, and identifying the color of the frame. Here, the camera unit 18 is assumed to be a color camera. The CPU 11 then automatically selects the identified frame color as the optimal auxiliary light color to be illuminated by the illumination 173.

[0078] Furthermore, while the above embodiment discloses an example in which a storage unit 15 (e.g., flash memory) is used as a computer-readable medium for the program according to the present invention, the invention is not limited to this example. Portable recording media such as CD-ROMs can be used as other computer-readable media. In addition, a carrier wave can also be used as a medium for providing the program data according to the present invention via a communication line.

[0079] While embodiments of the present invention have been described, the scope of the present invention is not limited to the embodiments described above, but includes the scope of the invention as described in the claims and its equivalents. The invention described in the claims initially attached to the application for this patent is listed below. The claim numbers listed below are the same as those in the claims initially attached to the application for this patent.

[0080] [Note] <Claim 1> A light source capable of emitting multiple colored auxiliary lights for reading code symbols, A control unit that controls the irradiation of the auxiliary light by the light source, Equipped with, The control unit, The aforementioned multiple colors of auxiliary light are switched in a predetermined order and irradiated onto the light source. If the code symbol is successfully read while the auxiliary light is irradiated, it is determined which of the multiple colors of auxiliary light was used to read the code symbol. Based on the results of the determination, the predetermined order in which the auxiliary light is irradiated next is changed. A terminal device characterized by the following features. <Claim 2> When the control unit changes the predetermined order, it sets the color of the auxiliary light that was illuminating the code symbol when it was successfully read as the first color in the predetermined order, based on the result of the determination. The terminal device according to feature 1. <Claim 3> When the control unit changes the predetermined order, it sets the color of the auxiliary light to be irradiated from the second to the next to last color, to the color whose frequency band is furthest from the color of the auxiliary light irradiated in the previous order. The terminal device according to claim 2, characterized in that... <Claim 4> The control unit changes the predetermined order of the auxiliary light colors that were illuminated when the code symbol was successfully read, based on the history of the determination results over a certain period of time in the past, in descending order of frequency. The terminal device according to feature 1. <Claim 5> In the initial state before the predetermined order is changed, the control unit causes the white auxiliary light to be the first in the sequence to be shone onto the light source. The terminal device according to any one of claims 1 to 4. <Claim 6> The system includes a color identification means for identifying the color of the border surrounding the code symbol, The control unit, When reading the code symbol, the light source is illuminated with auxiliary light that is approximately the same color as the color of the frame identified by the color identification means. The terminal device according to any one of claims 1 to 5. <Claim 7> The control unit, When each of the multiple colors is illuminated by the aforementioned light source, an image of the code symbol is captured. When reading the code symbol, the light source is illuminated with the same color of auxiliary light that was illuminating the image with the highest contrast in the grayscale distribution among the images. The terminal device according to any one of claims 1 to 6. <Claim 8> A control method for a terminal device equipped with a light source capable of emitting multiple-colored auxiliary lights for reading code symbols, A step of switching the aforementioned multiple colored auxiliary lights in a predetermined order and irradiating the light source with them, If the code symbol is successfully read while the auxiliary light is irradiated, the process involves determining which of the multiple colors of auxiliary light was used to read the code symbol. A step of changing the predetermined order in which the auxiliary light is irradiated next time based on the result of the determination, A control method characterized by including <Claim 9> A computer in a terminal device equipped with a light source capable of emitting multiple colors of auxiliary light for reading code symbols, A process of switching the aforementioned multiple colored auxiliary lights in a predetermined order and irradiating the light source with them, If the code symbol is successfully read while the auxiliary light is irradiated, a process is performed to determine which of the multiple colors of auxiliary light was used when the code symbol was read. Based on the result of the determination, a process to change the predetermined order in which the auxiliary light will be irradiated next time, A program characterized by causing the execution of a specific action. [Explanation of Symbols]

[0081] 10. Handheld terminal (terminal device) 11. CPU (Control Unit) 12 Control section 121 Touch Panel 122 Physical Key Section 122a Physical trigger key 13 RAM 14 Display section 15 Storage section 16. Wireless Communication Section 17 Scanner section 171 Aimer 172 Image sensor 173 Illumination (light source) 18 Camera Section 19 Output section 20 batteries

Claims

1. A light source capable of emitting a white auxiliary light for reading code symbols and multiple auxiliary lights of different colors, A control unit that controls the irradiation of the auxiliary light by the light source, Equipped with, The control unit, If reading the code symbol based on the illumination of the white auxiliary light is unsuccessful, the multiple colored auxiliary lights are switched in a predetermined order and illuminated onto the light source. If the code symbol is successfully read while the aforementioned colored auxiliary light is irradiated, it is determined which of the multiple colors of auxiliary light was used when the code symbol was read. Based on the results of the determination, the predetermined order in which the multiple colors of auxiliary light are irradiated next time is changed. A terminal device characterized by the following features.

2. When the control unit changes the predetermined order, it sets the color of the auxiliary light that was illuminating the code symbol when it was successfully read as the first color in the predetermined order, based on the result of the determination. The terminal device according to feature 1.

3. When the control unit changes the predetermined order, it sets the color of the auxiliary light to be irradiated at least second to the color with the frequency band furthest from the color of the auxiliary light irradiated in the previous order. The terminal device according to claim 2, characterized in that...

4. The control unit changes the predetermined order of the auxiliary light colors that were illuminated when the code symbol was successfully read, based on the history of the determination results over a certain period of time in the past, in descending order of frequency. The terminal device according to feature 1.

5. A control method for a terminal device equipped with a light source capable of emitting a white auxiliary light for reading code symbols and auxiliary lights of multiple colors having different hues, If reading the code symbol based on the illumination of the white auxiliary light is unsuccessful, the process involves switching the multiple colored auxiliary lights in a predetermined order and illuminating the light source with them; If the code symbol is successfully read while the aforementioned colored auxiliary light is irradiated, the process includes determining which of the multiple colors of auxiliary light was used to read the code symbol. A step of changing the predetermined order in which the multiple colored auxiliary lights are irradiated next time, based on the result of the determination, A control method characterized by including

6. A computer in a terminal device equipped with a light source capable of emitting a white auxiliary light for reading code symbols and multiple auxiliary lights of different colors, If reading the code symbol based on the illumination of the white auxiliary light is unsuccessful, the process involves switching the multiple colored auxiliary lights in a predetermined order and illuminating the light source with them. If the code symbol is successfully read while the aforementioned colored auxiliary light is irradiated, a process is performed to determine which of the multiple colors of auxiliary light was used when the code symbol was read. Based on the result of the determination, a process to change the predetermined order in which the multiple colors of auxiliary light will be irradiated next time, A program characterized by causing the execution of a specific action.

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