JP5794336B2 - Image processing apparatus and program - Google Patents

Description

The present invention relates to an image processing apparatus and a program.

  Conventionally, a two-dimensional imager device that images and scans a barcode as a symbol is used in a scanner device. Since the conventional imager device uses a fixed-focus lens, the higher the resolution of the barcode, the narrower the focusing range, and there is a possibility that the convenience for scanning the barcode is not good.

  On the other hand, in order to widen the depth of focus range in the scanner device, it may be possible to mount an auto focus such as a camera module as an imager device, but the physical focus is adjusted by moving the lens. In other words, the focus position of the subject is checked while shifting the focus position over the entire range by moving the lens to find the focus position, and it takes 500 milliseconds or more to focus. The operability is deteriorated.

  In recent years, a liquid lens capable of adjusting the focus without physical movement of the lens has been developed, and it has become possible to adjust the focus at high speed. For example, as a device for detecting the life of a liquid lens, the maximum point of contrast is obtained while checking the direction of contrast increase / decrease by changing the refractive index by applying a voltage to the liquid lens, and focusing on the maximum point A technique for obtaining a focal position assuming that there is a subject to be detected, and detecting that the liquid lens is at the end of its life when a difference between an applied voltage at the focal position and a predetermined reference value exceeds a predetermined amount. Is known (see, for example, Patent Document 1).

JP 2006-93805 A

  However, since the conventional liquid lens has a lens structure based on an oil / water interface curve having a different refractive index, the focus adjustment time varies depending on the viscosity depending on the temperature. Also, the focus adjustment time was different depending on the individual difference of the liquid lens.

An object of the present invention is to read a subject with a shorter focal point movement time.

According to another aspect of the present invention, there is provided an image processing apparatus that reads an image of a subject and processes the image. When the image is read, the focus control moves a focus position for capturing the subject to a predetermined focus position. And the detection of detecting successively the contrast value at the imaged position of the subject in the process of moving the focus position to the predetermined focus position by the means and the focus control means. And an image recognition process for an image obtained by imaging the subject when the contrast value detected by the detection means becomes equal to or higher than a predetermined value even before the focal position reaches the predetermined focal position. and recognition control means for controlling the execution, when the recognition by the image recognition processing by the recognition control unit is successful, the movement of the focal position in the predetermined focal position Even before, characterized by comprising an end control means for controlling so as to terminate the movement of the focal position.

According to the present invention, it is possible to read a subject with a shorter focal point movement time.

1 is a front external view of a scanner device according to an embodiment of the present invention. It is a block diagram which shows the function structure of a scanner apparatus. It is a top view which shows the structure of an imager module. It is a figure which shows the focus change of a liquid lens. It is a figure which shows the mode of the scanning of the barcode placed in the short distance or the long distance. (A) is a figure which shows the frame image which imaged the barcode of the short distance focus position. (B) is a figure which shows the frame image which imaged the barcode of the focus position of a long distance. It is a figure which shows the focus position with respect to the elapsed time in the focus adjustment of an imager module. It is a figure which shows a frame image and the position of the image | video of an aimer. It is a figure which shows the structure of an applied voltage table. It is a figure which shows the frame image containing a barcode image and the image | video of Aimer. It is a figure which shows the focus position with respect to the elapsed time in the focus adjustment of the imager module at the normal temperature. It is a figure which shows the cut-out image in the point of FIG. It is a flowchart which shows the barcode reading process which CPU performs. It is a flowchart which shows the scan control process which an imager controller performs.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. The present invention is not limited to the illustrated example.

  First, the external configuration of the apparatus according to the present embodiment will be described with reference to FIG. FIG. 1 shows an external configuration of the front of the scanner device 1 according to the present embodiment.

  The scanner device 1 according to the present embodiment is a portable device having functions such as information input reception, information storage, information transmission / reception, and barcode reading.

  As shown in FIG. 1, the scanner device 1 includes a case 2 as a housing. The scanner device 1 includes a trigger key 12A, various keys 12B, a display unit 14, and a speaker 18A on the front surface of the case 2. The scanner device 1 includes a trigger key 12 </ b> C on the side surface of the case 2. The scanner device 1 also includes an imager module 21 at the tip of the case 2. The speaker 18A outputs a buzzer sound or the like at the time of successful decoding of barcode reading.

  The trigger keys 12 </ b> A and 12 </ b> C are trigger keys that receive a scan start input from the imager module 21. The various keys 12B include input keys such as numbers and characters, function keys, and the like, and accept input of various information. The display unit 14 displays display information such as a through screen at the time of barcode reading using the imager module 21 and a decoding result.

  Next, an internal functional configuration of the scanner device 1 will be described with reference to FIG. FIG. 2 shows a functional configuration of the scanner device 1.

  As illustrated in FIG. 2, the scanner device 1 includes a central processing unit (CPU) 11 as a contrast detection unit, a decoding unit, and a transfer unit, an operation unit 12, and a RAM (Random Access Memory) 13 as a storage unit, A display unit 14, a ROM (Read Only Memory) 15, a communication unit 16, a flash memory 17, a sound output unit 18, an imager controller 19 as a focus adjustment unit and a cut-out image generation unit, and a voltage boosting unit 20 The imager module 21 and the power supply unit 22 are provided. Each unit of the scanner device 1 except for the imager module 21 and the power supply unit 22 is connected via a bus 23. The imager module 21 includes an imaging element 211 as an imaging unit, a liquid lens 212 as a variable focus lens, an aimer 213 as a spot light irradiation unit, and an illumination 214 as an illumination light irradiation unit.

  The CPU 11 controls each part of the scanner device 1. The CPU 11 reads a program from the ROM 15 and develops it in the RAM 13, and executes various processes in cooperation with the program developed in the RAM 13. Specifically, the CPU 11 (computer) executes a program shown in the processing flow of FIG.

  In accordance with the barcode reading program 151, the CPU 11 causes the imager controller 19 to output the image data of the cut-out image including the image of the light of the aimer 213 by causing the image sensor 211 to image the barcode via the liquid lens 212. A voltage corresponding to the focal position of the liquid lens 212 is applied to the liquid lens 212 from the image of the light 213. Further, the CPU 11 calculates the contrast of the optical image of the image data input to the imager controller 19, and when the contrast exceeds a predetermined value or a predetermined time elapses, the CPU 11 calculates the barcode via the liquid lens 212. The image pickup device 211 causes the image pickup device 211 to output image data of a frame image and decodes a barcode image included in the image data.

  In addition, the CPU 11 has a DMA transfer function for transferring line data of an image input from the image sensor 211 to the imager controller 19 and storing it in the RAM 13 by DMA (Direct Memory Access). Note that the DMA transfer function may be included in the imager controller 19.

  The operation unit 12 includes a key group such as various keys 12B and trigger keys 12A and 12C, receives a pressing input to each key of the key group, and outputs the operation information to the CPU 11.

  The RAM 13 is a volatile semiconductor memory and has a work area for storing various data and various programs.

  The display unit 14 includes an LCD (Liquid Crystal Display), an EL (electroluminescent) display, and the like, and displays various types of information.

  The ROM 15 is a read-only semiconductor memory. The ROM 15 stores a barcode reading program 151.

  The communication unit 16 includes a communication antenna, a signal processing unit, a modulation unit, a demodulation unit, and the like, and is a wireless communication unit that communicates with a server device via an access point. The communication unit 16 processes a signal of transmission information with a signal processing unit, modulates the signal with a modulation unit, and wirelessly transmits the transmission information as a radio wave from the communication antenna to the access point. In addition, the communication unit 16 receives radio waves transmitted from the access point through the communication antenna, demodulates them by the demodulation unit, and performs signal processing on the signals by the signal processing unit to obtain reception information.

  Moreover, the communication part 16 is good also as a radio | wireless communication part which carries out radio | wireless communication with a server apparatus via a base station by a mobile telephone communication system. The communication unit 16 may be a wired communication unit that performs wired communication with the server device via a cradle on which the scanner device 1 is placed.

  The flash memory 17 is a nonvolatile semiconductor memory that can read and write various data.

  The sound output unit 18 includes a sound source unit, an amplifier, and a speaker 18A, and outputs a buzzer sound when decoding is successful. In response to a buzzer sound output instruction input from the CPU 11, the sound output unit 18 generates a buzzer sound signal in the sound source unit, amplifies it with an amplifier, and outputs the sound from the speaker 18A.

  The imager controller 19 is a control unit for the imager module 21 and the voltage booster 20. The imager controller 19 is configured by a semiconductor circuit such as an ASIC (Application Specific Integrated Circuit).

  The imager controller 19 synchronizes with the image data from the image sensor 211, the frame synchronization signal synchronized with the output timing of one frame of the captured image data, the line synchronization signal synchronized with the output timing of one line of the image data, and the image data. And a clock signal for input. The imager controller 19 monitors the transfer timing of the image data to the RAM 13 based on the frame synchronization signal, line synchronization signal, and clock signal. Then, the imager controller 19 changes the focus of the liquid lens 212 in real time by controlling the boost level of the voltage booster 20 for driving the liquid lens 212 with a PWM (Pulse Width Modulation) signal according to the monitoring situation.

  Further, the imager controller 19 generates an image area designation signal that designates an image area of the input image data, and outputs the image area designation signal to the image sensor 211.

  The voltage booster 20 applies a voltage to the liquid lens 212 in accordance with the PWM signal input from the imager controller 19.

  The imager module 21 is a module that takes a barcode by adjusting the focus. The imaging element 211 is a complementary metal oxide semiconductor image sensor (CMOS) image sensor, and is an imaging element that can output image data by designating an image region. The image sensor 211 exposes a subject image incident through an optical system including the liquid lens 212, photoelectrically converts the subject image into an electrical signal of image data of the subject.

  The image sensor 211 outputs the image data of the line designated by the image area designation signal input from the imager controller 19 to the imager controller 19 as line data line by line. Further, the image sensor 211 outputs a frame synchronization signal, a line synchronization signal, and a clock signal to the imager controller 19. The liquid lens 212 is an optical element that constitutes a part of the optical system of the imager module 21, and is a variable focus lens that can change a focal position at high speed according to an applied voltage. The liquid lens 212 will be described later in detail.

  The aimer 213 is composed of a light source such as an LD (LASER Diode), and emits laser light as spot light (target light) serving as a reference for directing the imager module 21 toward the subject to or near the subject. The illumination 214 includes a light source such as an LED (Light Emitting Diode), and emits irradiation light (referred to as illumination light) for brightening the subject and the surrounding area.

  The power supply unit 22 is composed of a secondary battery or the like, and supplies power to each unit of the scanner device 1.

  Next, the arrangement of each part of the imager module 21 will be described in detail with reference to FIG. FIG. 3 shows a planar configuration of the imager module 21.

  As shown in FIG. 3, in the imager module 21, the image sensor 211 is disposed at a position corresponding to the optical axis of the optical system including the liquid lens 212. Further, an aimer 213 and an illumination 214 are arranged beside the optical system 212A including the liquid lens 212. The aimer 213 is arranged so that the laser beam of the aimer 213 is included within the angle of view of the imager module 21 (the optical system and the image sensor 211). The illumination 214 is arranged so that the fan-shaped light of the illumination 214 includes the angle of view of the imager module 21 (optical system and image sensor 211).

  The aimer 213 is mounted so that aimer light is irradiated in parallel to the angle of view. For this reason, the position of the aimer 213 with respect to the angle of view of the imager module 21 spreading in a fan shape varies depending on the distance.

  Next, the liquid lens 212 will be described in detail with reference to FIG. FIG. 4 shows a change in focus of the liquid lens 212 due to a change in applied voltage. FIG. 4 shows the change in focus of the liquid lens 212.

  As shown in FIG. 4, the liquid lens 212 includes liquid portions 2121 and 2122, a container 2123, and an electrode 2124. The liquid parts 2121 and 2122 are an aqueous solution and oil having different refractive indexes and the same specific gravity. The container 2123 is a container in which the liquid parts 2121 and 2122 are sealed. The electrode 2124 is an electrode provided around the liquid parts 2121 and 2122 in order to apply a voltage.

  Consider a configuration in which the power supply 30 is connected between an electrode 2124 on the liquid part 2121 side and an electrode 2124 on the liquid part 2122 side. By applying a voltage between the electrode 2124 on the liquid part 2121 side and the electrode 2124 on the liquid part 2122 side by the power supply 30, the interface at the central part of the liquid parts 2121 and 2122 is curved like a lens. Realize the lens function. Further, by increasing the applied voltage of the power source 30, the curvature of the interface at the central portion of the liquid parts 2121 and 2122 becomes larger. When the curvature of the interface is small, the focus of the liquid lens 212 is adjusted to a position at a far distance. When the curvature of the interface increases, the focus of the liquid lens 212 matches the position of a close distance.

  In addition, since the lens curvature changes according to the voltage applied to the liquid lens 212, the lens curvature of the liquid lens 212 changes electrically at high speed without causing the lens to move as in the conventional autofocus mechanism. can do. Thus, the focus adjustment of the liquid lens 212 can be performed by the lens curvature change by adjusting the applied voltage. Therefore, there is an advantage that the time required for changing the focus is shortened as compared with the conventional autofocus mechanism. As described above, the liquid lens 212 is characterized by the fact that the lens curvature can be changed according to the applied voltage level, the durability is high because there is no physical moving part, and the applied voltage level is high but the current flows. Because there is no power consumption, it can be mentioned.

  Next, the relationship between the position of the aimer light in the image captured by the image sensor 211 and the distance from the imager module 21 to the subject will be described with reference to FIGS. FIG. 5 shows how the bar code 41 is scanned at a short distance or a long distance. FIG. 6A shows a frame image q1 in which the barcode 41 at the focal position A is captured. FIG. 6B shows a frame image q2 obtained by capturing the barcode 41 at the focal position B.

  As shown in FIG. 5, a barcode 41 is placed at a focal position A having a short focal distance from a scanner apparatus 1 (imager module 21) and a focal position B having a long focal distance. And As an example, a case will be described in which the scanner 41 performs image capture and decoding on the barcode 41 placed at the focal position A and the focal position B.

  When the barcode 41 is read from the proximity (focal position A) by the scanner device 1, the barcode image has a relatively large size with respect to the angle of view of the image sensor 211. Thus, the image can be decoded in the image area at the focal position A. As shown in FIG. 6A, the frame image q1 when the barcode 41 is placed at a short distance includes the barcode image Q1 and the image E1 of the laser light of the aimer 213. The image E1 is located at the end of the barcode image Q1, indicating that the barcode 41 of the reading target is nearby.

  On the other hand, when the barcode 41 is read from a distance (focal position B) by the scanner device 1, the relative size of the barcode image with respect to the angle of view of the image sensor 211 is small. And can be decoded in the image area at the focal position B. As shown in FIG. 6B, the frame image q2 when the barcode 41 is placed at a long distance includes the barcode image Q2 and the image E2 of the laser light of the aimer 213. This is because the video E2 is outside the barcode image Q2, but the barcode image Q2 is small. The distance from the center of the frame image q2 to the video E2 is smaller than the distance from the center of the frame image q1 to the video E1.

  As described above, when the frame images have the same size, the distance from the center of the frame image to the laser beam image of the aimer 213 increases, and the distance from the scanner device 1 to the subject (barcode 41) increases. It has become. From this, the distance to the target barcode can be measured from the image position of the aimer in the frame image, and the focus of the liquid lens 212 can be adjusted accordingly.

  Next, with reference to FIG. 7, adjustment of the focus position (focus position) of the imager module 21 when the temperature of the liquid lens 212 changes will be described. FIG. 7 shows the focus position with respect to the elapsed time in the focus adjustment of the imager module 21.

  Consider the case where the environmental temperature of the liquid lens 212 is changed to high temperature, normal temperature, and low temperature as shown in FIG. By applying a predetermined voltage to the liquid lens 212, the time until the focus position of the imager module 21 is adjusted to the focused focus adjustment target position varies depending on the temperature. This is because there is variation in the rate of curvature change with temperature, which is a characteristic of the liquid lens 212. The lower the environmental temperature, the longer the time during which the focus position is stabilized at the focus adjustment target position. That is, a waiting time corresponding to the maximum change time at a low temperature is required even at a normal temperature and a high temperature.

  Next, information stored in the flash memory 17 will be described with reference to FIGS. FIG. 8 shows the frame image q and the positions of the images Ea and Eb of the aimer 213. FIG. 9 shows the configuration of the applied voltage table 171.

  As shown in FIG. 8, the x-axis and y-axis are taken in the frame image q of the image sensor 211 in the scanner device 1 and the x-coordinate and y-coordinate are considered. Assume that the coordinates of the image Ea of the aimer 213 when the target barcode is far from the imager module 21 are (xa, ye). Assume that the coordinates of the video Eb of the aimer 213 when the target barcode is close to the imager module 21 are (xb, ye). In addition, in the frame image q, an image of a video and its surrounding area that can include the video of the aimer 213 at least at all distances is defined as a cut-out area image F1. The coordinates of the upper left and upper right of the area image F1 are (x1, y1) and (x2, y2) in this order.

  As shown in FIG. 9, an applied voltage table 171 that defines the applied voltage to the appropriate liquid lens 212 corresponding to the x coordinate of the image of the aimer 213 in the frame image q will be described. The applied voltage table 171 includes an aimer position 1711 that is an x coordinate of the image of the aimer 213 in the frame image q, and an applied voltage that is an applied voltage to an appropriate liquid lens 212 that focuses on the target corresponding to the aimer position 1711. 1712 is stored in advance for each aimer position.

  The flash memory 17 stores in advance an applied voltage table 171 and coordinates (x1, y1) and (x2, y2) of the cutout region image F1. The applied voltage table 171 and the coordinates (x1, y1), (x2, y2) are set and stored by calibration at the time of shipment. The cut-out area image F1 includes the coordinates (xa, ye) of the image Ea of the aimer 213 when the target barcode is far from the imager module 21, and the image Eb of the aimer 213 when the target barcode is close to the imager module 21. Is a range including the coordinates (xb, ye).

  Next, the operation of the scanner device 1 will be described with reference to FIGS. First, an outline of focus adjustment of the liquid lens 212 according to the present embodiment will be described with reference to FIGS. FIG. 10 shows a frame image q3 including the barcode image Q3 and the video E3 of the aimer 213. FIG. 11 shows the focus position with respect to the elapsed time in the focus adjustment of the imager module 21 at normal temperature. FIG. 12 shows cut-out images p1, p2, and p3 at points P1, P2, and P3 in FIG.

  Consider a case in which a barcode 41 at an arbitrary distance from the scanner device 1 is scanned when the ambient temperature is normal. As shown in FIG. 10, the scanner device 1 obtains a frame image q3 including a barcode image Q3 and a video E31 of the aimer 213 in the initial state.

  On the other hand, as shown in FIG. 11, a decodable focus range is set in advance in a curve of a focus position with respect to an elapsed time in focus adjustment of the imager module 21 at normal temperature. Then, points P1, P2, and P3 are taken in order from the focus adjustment start to the decodable focus range.

  The scanner apparatus 1 repeatedly acquires frame images from the start of focus adjustment, and cuts out an area determined from the coordinates (x1, y1) to the coordinates (x2, y2) in FIG. 8 from each frame image. To get. As shown in FIG. 12, cut-out images p1, p2, and p3 are acquired corresponding to the points P1, P2, and P3. The cut-out images p1, p2, and p3 include the images E31, E32, and E33 of the aimer 213 in order. It is assumed that the cutout image of the frame image q3 at the start of focus adjustment is the cutout image p1.

  First, the scanner device 1 starts focus adjustment, detects the position (aimer position) of the video E31 from the cut-out image p1 of the frame image q3, and the barcode of the subject from the scanner device 1 corresponding to the aimer position of the video E31. Estimate the distance to the position. In practice, the scanner device 1 sets the applied voltage to the liquid lens 212 corresponding to the aimer position of the image E31 using the applied voltage table 171 in order to adjust the focus of the liquid lens so as to match the estimated distance. To do. Then, the scanner device 1 applies the estimated applied voltage to the liquid lens 212, acquires a frame image and acquires a cut-out image including the image of the aimer 213 while the liquid lens 212 is changing. Repeatedly, the contrast of the video in the clipped image is monitored. While the image is out of focus, the contour of the spot shape of the image is blurred, but it becomes clear when the image is in focus. The scanner device 1 determines whether or not the contrast of the cut-out image is equal to or higher than a predetermined value set in advance.

  For example, when the contrast of the cutout image is smaller than a certain value, the images E31 and E32 are blurred and are not in focus (focus position) as shown in the cutout images p1 and p2. Then, when the contrast of the cut-out image exceeds a certain value, the scanner device 1 assumes that the focus (focus position) is almost in focus, turns off the aimer 213 at the focal length, turns on the illumination 214, and displays the barcode. And the barcode image in the obtained frame image is decoded. For example, when the contrast of the cutout image becomes a certain value or more, the outline of the video E33 is clear as shown in the cutout image p3.

  Further, the scanner device 1 ends the waiting for a focus change of the liquid lens 212 after a predetermined time has elapsed from the start of focus adjustment to monitor the contrast of the clipped image, and the focus (focus position) is almost in focus. As a result, the barcode scanning and decoding are performed. This fixed time is the time when the focus position first becomes the focus adjustment target position corresponding to the case where the assumed environmental temperature is the lowest. This is because the environmental temperature is equal to or higher than the temperature corresponding to the certain time, and the time for the focus position to become the focus adjustment target position is equal to or less than the certain time.

  Next, operations of the CPU 11 and the imager controller 19 of the scanner device 1 will be described with reference to FIGS. 13 and 14. FIG. 13 shows a flowchart of the barcode reading process executed by the CPU 11. FIG. 14 shows a flowchart of scan control processing executed by the imager controller 19.

  The barcode reading process executed by the CPU 11 will be described with reference to FIG. The barcode reading process is a process of scanning a barcode using the imager module 21 and decoding the acquired barcode image data. In the scanner device 1, triggered by the user pressing the trigger keys 12 </ b> A and 12 </ b> C as a trigger, the CPU 11 reads a barcode in cooperation with a barcode reading program 151 that is read from the ROM 15 and appropriately expanded in the RAM 13. Execute the process.

  First, the CPU 11 performs initial setting and outputs an instruction signal for starting the imager module 21 to the imager controller 19 (step S11). The initial setting in step S11 is, for example, the setting of the storage area in the RAM 13 when the image data (line data) input from the image sensor 211 to the imager controller 19 is DMA-transferred to the RAM 13.

  Then, the CPU 11 outputs an instruction signal for turning on the aimer 213 and an instruction signal for cut-out capture of the image sensor 211 to the imager controller 19 (step S12). The clipping capture instruction signal is an instruction signal for acquiring line data of the clipping area defined by the coordinates (x1, y1) and coordinates (x2, y2) stored in the flash memory 17.

  Then, the CPU 11 DMA-transfers and stores the line data of the cut-out image input from the image sensor 211 to the imager controller 19 by the DMA function (step S13). Then, the CPU 11 reads out the image data (line data) of the clipped image stored in the RAM 13, and detects the aimer position (video x coordinate) in the clipped image (step S14). The detection of the aimer position corresponds to the estimation of the distance from the scanner device 1 to the barcode.

  Then, the CPU 11 reads the applied voltage 1712 corresponding to the aimer position 1711 detected in step S14 in the applied voltage table 171 stored in the flash memory 17, and applies the voltage applied to the liquid lens 212 to focus on the target. An instruction signal to be changed to 1712 is output to the imager controller 19 (step S15).

  And CPU11 performs the process similar to step S12, S13 as step S16, S17. Then, the CPU 11 reads out the image data (line data) of the cutout image stored in the RAM 13, and calculates the contrast of the video of the aimer 213 in the cutout image (step S18). Then, the CPU 11 determines whether or not the contrast calculated in step S18 is a preset constant value, or whether a preset preset time has elapsed from the first execution of step S16 (step S19). . If the contrast is not equal to or greater than a certain value and has not timed out (step S19; NO), the process proceeds to step S16. This is a case where the focus adjustment of the liquid lens 212 is performed, and as shown in FIG. 12, the images E31 and E32 are blurred and are out of focus (focus position). In such a state, the processing from step S16 to step S19 is repeated.

  When the contrast is equal to or higher than a certain value or times out (step S19; YES), the CPU 11 outputs an instruction signal for turning off the aimer 213 to the imager controller 19 (step S20). Then, the CPU 11 outputs an instruction signal for turning on the illumination 214 (turning on the illumination 214 during the next image capture and then turning it off) to the imager controller 19 (step S21).

  Then, the CPU 11 outputs an image capture instruction signal for the entire screen of the image sensor 211 to the imager controller 19 (step S22). And as step S23, CPU11 performs the process similar to step S13. Then, the CPU 11 reads out the image data (line data) of the entire screen stored in the RAM 13, and performs image processing (such as processing for combining the image data) to facilitate decoding of the frame image of the entire screen. Then, the barcode image in the frame image after the image processing is decoded (step S24).

  Then, the CPU 11 determines whether or not the decoding in step S24 is successful (step S25). If the decoding is not successful (step S25; NO), the process proceeds to step S12. If the decoding is successful (step S25; YES), the CPU 11 outputs a power-off instruction signal for the imager module 21 to the imager controller 19 (step S17). Then, the CPU 11 displays the decoding result on the display unit 14 and causes the sound output unit 18 to sound a buzzer sound that is successfully decoded (step S27), and ends the barcode reading process.

  Next, the scan control process executed by the imager controller 19 will be described with reference to FIG. The scan control process is a process of scanning the barcode by adjusting the focal position using the imager module 21 and obtaining image data of a cut-out image including the image of the aimer 213 and a frame image including the barcode image. In the scanner device 1, the imager controller 19 executes a scan control process in response to step S <b> 11 of the barcode reading process, triggered by the activation instruction signal input from the CPU 11.

  First, the imager controller 19 performs initial setting (step S31). The initial setting in step S31 is, for example, a setting relating to reception of image data from the imager module 21. Then, the imager controller 19 turns on the power of the imager module 21 (step S32).

  Then, the imager controller 19 determines whether or not an instruction signal for powering off the imager module 21 is input from the CPU 11 in response to step S26 of the barcode reading process (step S33). When the power-off instruction signal is not input (step S33; NO), the imager controller 19 receives an instruction signal for changing the applied voltage to the liquid lens 212 from the CPU 11 in response to step S15 of the barcode reading process. It is determined whether or not an input has been made (step S34).

  When the applied voltage change instruction signal is input (step S34; YES), the imager controller 19 generates a PWM signal corresponding to the applied voltage value of the applied voltage change instruction signal and outputs the PWM signal to the voltage booster 20 ( Step S35). The voltage booster 20 changes the voltage applied to the liquid lens 212.

  After the execution of step S35, or when an instruction signal for changing the applied voltage is not input (step S34; NO), the imager controller 19 outputs an image from the CPU 11 corresponding to steps S12, S16, and S22 of the barcode reading process. It is determined whether or not a capture instruction signal is input (step S36). When the image capture instruction signal is not input (step S36; NO), the process proceeds to step S33.

  When an image capture instruction signal is input (step S36; YES), the imager controller 19 cuts out the image capture area of the image sensor 211 in accordance with the image capture instruction signal input in step S36, or an image or a full screen. (Step S37). Then, the imager controller 19 determines whether or not an instruction signal for turning on the aimer 213 is input from the CPU 11 in response to steps S12 and S16 of the barcode reading process (step S38).

  When the instruction signal for lighting the aimer 213 is input (step S38; YES), the imager controller 19 lights the aimer 213 (step S39). When the instruction signal for turning on the aimer 213 is not inputted (step S38; NO), the instruction signal for turning off the aimer 213 is inputted from the CPU 11 corresponding to step S20 of the barcode reading process, and the imager controller 19 Turns off the aimer 213 (step S40).

  Then, the imager controller 19 determines whether or not an instruction signal for lighting the illumination 214 is input from the CPU 11 in response to step S21 of the barcode reading process (step S41). When an instruction signal for lighting the illumination 214 is not input (step S41; NO), the imager controller 19 generates an image area designation signal for the image capture area of the cut-out image set in step S37 and supplies the image sensor 211 with the image area designation signal. Then, the image sensor 211 captures the image, and the image data of the clipped image is input from the image sensor 211 (step S42), and the process proceeds to step S33.

  When an instruction signal for lighting the illumination 214 is input (step S41; NO), the imager controller 19 lights the illumination 214 (step S43). Then, the imager controller 19 generates an image area designation signal for the image capture area of the full screen set in step S <b> 37, outputs the image area designation signal to the image sensor 211, causes the image sensor 211 to capture an image, and causes the image sensor 211 to capture the full screen. Image data of a frame image is input (step S44). Then, the imager controller 19 turns off the illumination 214 (step S45), and proceeds to step S33.

  When the power-off instruction signal is not input (step S33; NO), the imager controller 19 turns off the power of the imager module 21 (step S46) and ends the scan control process.

  As described above, according to the present embodiment, the scanner device 1 includes the aimer 213, the liquid lens 212, the image sensor 211, and the image of spot light (light of the aimer 213) in the image captured by the image sensor 211. The voltage corresponding to the focal position from the position to the subject is calculated, and the calculated voltage is applied to the liquid lens 212 to adjust the focus of the liquid lens 212. From the image including the spot light image to generate a clipped image, detecting the contrast of the spot light image from the clipped image, and detecting a contrast equal to or higher than a predetermined value, An imager controller 19 and a CPU 11 that decode a symbol image included in the captured image are provided. For this reason, focus adjustment can be completed in the shortest time regardless of variations in the focus change time of the variable focus lens due to temperature or individual.

  The image sensor 211 sequentially captures the images while the liquid lens 212 is being driven, and the imager controller 19 includes a predetermined image including the video from the sequentially captured images. Cut out the image of the area. For this reason, a cut-out image including a spotlight image can be acquired at high speed.

  In addition, the image sensor 211 and the imager controller 19 repeatedly perform image segmentation and contrast detection of a predetermined region including the video until the contrast of a predetermined value or more of the video of the spot light is detected. For this reason, the transfer time of image data and the detection time of contrast can be further shortened by the cut image acquired repeatedly.

  Further, when a contrast equal to or higher than a predetermined value of the spotlight video is detected, the CPU 11 causes the image sensor 211 to capture a full-screen frame image and decodes the captured full-screen image. For this reason, it is possible to reliably decode the barcode image included in the frame image of the full screen.

  Further, the CPU 11 transfers the image data of the cut image and the frame image input from the image sensor 211 to the imager controller 19 and stores them in the RAM 13. For this reason, the image data can be easily stored in the RAM 13.

  Further, the CPU 11 turns off the aimer 213 and causes the image pickup device 211 to pick up an image when detecting a contrast equal to or higher than a predetermined value of the spotlight video. For this reason, it is possible to remove the spot light video unnecessary for decoding from the barcode image, and to improve the decoding accuracy.

  Further, the CPU 11 turns on the illumination 214 and causes the image sensor 211 to pick up an image when detecting a contrast equal to or higher than a predetermined value of the image of the spot light. For this reason, the contrast of the barcode image can be increased, and the decoding accuracy can be increased.

  Further, the CPU 11 picks up an image when detecting a contrast equal to or higher than a predetermined value of the image of the spot light, or when an elapsed time from the start of focus adjustment exceeds a predetermined time corresponding to a preset low-temperature focus adjustment time. A symbol image included in an image captured by the element 211 is decoded. For this reason, it is possible to reduce the influence of the variation in the focus change time of the variable focus lens due to the temperature, and to read the symbol in the shortest time.

  The description in the above embodiment is an example of the scanner device and the program according to the present invention, and the present invention is not limited to this.

  In the above embodiment, the liquid lens 212 is used as the variable focus lens. However, the present invention is not limited to this. For example, another variable focus lens such as a variable focus lens using KTN (potassium niobate tantalate, KTa1-xNbxO3), which is a kind of “electro-optic crystal” whose refractive index changes with applied voltage, may be used.

  In the above-described embodiment, the configuration for reading a one-dimensional barcode as a symbol has been described. However, the present invention is not limited to this. For example, a symbol such as a two-dimensional code may be read.

  Moreover, although the example of the image of the spot light irradiated from the aimer 213 has been described in the above embodiment, the present invention is not limited to this. The image of the reference spot light may be an image of light emitted from another light source. This video may be any video as long as the position of the video changes relative to the entire image in accordance with the distance between the scanner device and the subject. For example, the spot light may be irradiated substantially in parallel along the optical axis direction of the optical system 212A including the liquid lens 212.

  In the above embodiment, the cut-out image including the light image of the aimer 213 is described as an example of a predetermined region (rectangular region represented by coordinates (x1, y1) and coordinates (x2, y2)). However, the present invention is not limited to this. For example, since the position of the cut-out image including the image of the aimer light has already been detected in step S12 of FIG. 13, in step S16 of FIG. An area narrower than a predetermined area can be determined, and an image of the determined area may be cut out. Since this partial area is narrower than the predetermined area, the processes in steps S16 to S18 that are repeated until a contrast of a certain value or more is detected, that is, the image data transfer process of the cut-out image, the contrast detection process, Time can be further shortened, and rapid processing becomes possible.

  In the above embodiment, the relationship between the position of the light image of the aimer 213 indicating the distance to the subject and the voltage applied to the liquid lens 212 has been described as an example stored in the applied voltage table 171 in advance. It is not limited. The relationship between the position of the image of the light of the aimer 213 and the voltage applied to the liquid lens 212 is expressed by a calculation formula, and the voltage applied to the liquid lens 212 from the position (distance) of the image of the light of the aimer 213 is directly calculated by the above calculation formula. It is good also as a structure to calculate.

  Moreover, in the said embodiment, although the image shape of the spot light irradiated from the aimer 213 was demonstrated as circular, it is not limited to this. The image shape of the spot light may be another shape such as a cross shape.

  In the above embodiment, the imager controller 19 is described as a semiconductor circuit such as an ASIC, but the present invention is not limited to this. For example, the imager controller 19 may be configured by a CPU, a RAM, and a ROM, and the imager controller 19 may execute processing in cooperation with a program that is read from the ROM and expanded in the RAM.

  In addition, it is needless to say that the detailed configuration and detailed operation of each component of the scanner device according to the above-described embodiment can be appropriately changed without departing from the spirit of the present invention.

1 Scanner device 2 Case 11 CPU
12 Operation unit 12A, 12C Trigger key 12B Various keys 13 RAM
14 Display 15 ROM
DESCRIPTION OF SYMBOLS 16 Communication part 17 Flash memory 18 Sound output part 18A Speaker 19 Imager controller 20 Voltage booster 21 Imager module 211 Image pick-up element 212 Liquid lens 2121,122 Liquid part 2123 Container 2124 Electrode 212A Optical system 213 Aimer 214 Illumination 22 Power supply part 23 Bus 30 Power supply 41 Bar code

Claims (6)

An image processing apparatus that reads an image of a subject and processes the image,
When reading the image, a focus control means for moving a focus position for imaging the subject to a predetermined focus position;
In the process of moving the focus position to the predetermined focus position by the focus control means, the detection means for continuously detecting the position of the subject and successively detecting the contrast value at the imaged position of the subject;
Even before the focal position reaches the predetermined focal position, when the contrast value detected by the detection means becomes equal to or higher than a predetermined value , the start execution of the image recognition process for the image obtained by imaging the subject is controlled. Recognition control means for
If the recognition by the image recognition processing by the recognition control means is successful, even before the movement of the focal position reaches a predetermined focal position, and the end control means for controlling so as to terminate the movement of the focal position ,
An image processing apparatus comprising: The predetermined focal position is a focal position determined according to a distance to the subject,
Setting means for setting the predetermined focal position prior to reading the image;
The image processing apparatus according to claim 1, further comprising: The end control means , when the image recognition processing by the recognition control means is not successful, controls to continue detection by the detection means;
The image processing apparatus according to claim 1, wherein the image processing apparatus is an image processing apparatus. The detection means sequentially detects the contrast value of the spot light irradiated to the position of the subject as the contrast value at the position of the subject in the process of moving the focal position.
The image processing apparatus according to any one of claims 1 to 3 . Illumination control means for illuminating the entire subject with illumination light when the contrast value detected by the detection means is equal to or greater than the predetermined value;
Further comprising
The recognition control means executes an image recognition process on an image obtained by imaging a subject illuminated with the illumination light.
The image processing apparatus according to any one of claims 1-4, characterized in that. A program for controlling a computer of an image processing apparatus that reads an image of a subject and processes the image,
The computer,
When reading the image, a focus control means for moving a focus position for imaging the subject to a predetermined focus position;
In the process of moving the focus position to the predetermined focus position by the focus control means, the detection means for continuously detecting the position of the subject and successively detecting the contrast value at the imaged position of the subject;
Even before the focal position reaches the predetermined focal position, when the contrast value detected by the detection means becomes equal to or higher than a predetermined value , the start execution of the image recognition process for the image obtained by imaging the subject is controlled. Recognition control means,
Wherein when the recognition by the image recognition processing by the recognition control unit succeeds, even before the movement of the focal position reaches a predetermined focal position, end control means for controlling so as to terminate the movement of the focus position,
A program designed to function as