JP2012048441A - Scanner device and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To focus on a symbol and increase a response speed for a subsequent symbol reading.SOLUTION: A scanner device 1 comprises: a liquid lens 212; an imaging element 211 for imaging a subject via the liquid lens 212; a flash memory 17 for storing an imaging area in a frame image corresponding to a focus position; an imager controller 19 for variably controlling a focus position of the liquid lens 212; and a CPU 11 for detecting a focus position of a symbol of the subject to move the focus position of the liquid lens 212 by the imager controller 19 to the detected focus position, reading out an imaging area corresponding to the detected focus position from the flash memory 17 to take in an image of the read-out imaging area from the imaging element 211, and decoding a symbol image included in the taken-in image of the imaging area.

Description

  The present invention relates to a scanner device and a program for reading a symbol.

  Conventionally, scanner devices that scan symbols such as one-dimensional barcodes and two-dimensional codes are known. The scanner device uses a two-dimensional imager device that captures a symbol, decodes the captured image, and reads the symbol.

  There is also known an imager device scanner device that shortens the symbol reading time. Specifically, it is a scanner device that captures an image of the entire area, checks the presence and outline of the symbol from the image of the entire area, and re-acquires and decodes the image of the partial area estimated to contain the confirmed symbol. (For example, refer to Patent Document 1).

JP 2005-38374 A

  However, the above-described conventional scanner device has to perform image capture a plurality of times, and it takes a long time to capture and decode the image. For this reason, the response time from the user's symbol reading operation to the completion of decoding is long (the reading response speed is low), and the operability of the scanner device is lowered.

  Furthermore, when autofocus is applied to the above conventional scanner device, the presence or outline of the symbol cannot be confirmed until the symbol to be read is focused, the reading response speed is further reduced, and the operability of the scanner device is further improved. It was falling.

  It is an object of the present invention to focus on a symbol and increase the reading response speed of subsequent symbols.

In order to solve the above problems, a scanner device according to claim 1 is provided.
A variable focus lens,
A storage unit for storing an imaging region in the frame image according to the focal position;
A drive unit that drives and controls the focal position of the variable focus lens;
A detection unit for detecting the focal position of the symbol of the subject;
Imaging in which the driving unit moves the focal position of the variable focus lens to the detected focal position, reads an imaging area corresponding to the detected focal position from the storage unit, and captures an image of the read imaging area A control unit;
A decoding unit that decodes a symbol image included in the captured image of the imaging region.

The invention according to claim 2 is the scanner apparatus according to claim 1,
The storage unit stores an imaging region corresponding to a symbol type and a focal position,
The imaging control unit reads an imaging area corresponding to the type of the symbol of the subject and the detected focal position from the storage unit.

The invention according to claim 3 is the scanner apparatus according to claim 1 or 2,
The storage unit stores an imaging region that becomes smaller as the focal position is further away.

According to a fourth aspect of the present invention, in the scanner device according to the third aspect,
The imaging area is composed of a symbol area having a symbol size that becomes smaller as the focal position becomes farther, and a margin around the symbol area,
It has an operation unit that accepts input of margin values,
The imaging control unit captures an image of the imaging area by setting a margin value input from the operation unit as a margin of the imaging area read from the storage unit.

According to a fifth aspect of the present invention, in the scanner device according to any one of the first to fourth aspects,
Provided with a spot light irradiation unit that irradiates spot light,
The imaging control unit captures an image including an image of the spot light,
The detection unit detects a focal position of the subject from a position of a spot light image in an image captured by the imaging control unit.

A sixth aspect of the present invention is the scanner device according to the fifth aspect,
The imaging control unit turns off the spot light irradiation unit after the detection unit detects a focal position, and captures an image of an imaging region corresponding to the detected focal position.

The invention described in claim 7 is the scanner device according to any one of claims 1 to 4,
The detection unit captures an image of a specific region of a part of the frame image from the imaging control unit, and detects a focal position where the image of the specific region has a contrast of a predetermined value or more as a focal position to the subject.

The program of the invention described in claim 8 is:
Computer
A storage unit for storing an imaging region in a frame image according to a focal position;
A drive unit that drives and controls the focal position of the variable focus lens;
A detection unit for detecting the focal position of the symbol of the subject;
Imaging in which the driving unit moves the focal position of the variable focus lens to the detected focal position, reads an imaging area corresponding to the detected focal position from the storage unit, and captures an image of the read imaging area Control unit,
A decoding unit for decoding a symbol image included in the captured image of the imaging region;
To function as.

  According to the present invention, it is possible to focus on a symbol, increase the response speed for reading a subsequent symbol, and improve the operability of the scanner device.

It is a front view of the scanner apparatus of embodiment of this invention. It is a block diagram which shows the function structure of a scanner apparatus. It is a top view 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 scan of the symbol placed in the near 1st focus position and the distant 2nd focus position. (A) is a figure which shows the frame image which imaged the symbol of the 1st focus position. (B) is a figure which shows the frame image which imaged the symbol of the 2nd focus position. It is a figure which shows a frame image and the cut-out area | region containing the image | video of the aimer's laser beam. It is a figure which shows the cut-out area | region image according to time passage. It is a figure which shows the frame image which imaged the symbol of the two-dimensional code in a 1st focus position. It is a figure which shows the frame image which imaged the symbol of the two-dimensional code in a 2nd focus position. It is a figure which shows the frame image which imaged the symbol of the one-dimensional barcode in a 1st focus position. It is a figure which shows the structure of the applied voltage table of embodiment. It is a figure which shows the structure of an imaging area table. It is a flowchart which shows a 1st symbol reading process. It is a flowchart which shows a scan control process. It is a figure which shows a frame image, a center area | region, and the image | video of the aimer's laser beam. It is a figure which shows the structure of the applied voltage table of a modification. It is a flowchart which shows a 2nd symbol reading process. It is a flowchart which shows the applied voltage change process of a 2nd symbol reading process.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments and modifications according to the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the illustrated example.

  Embodiments according to the present invention will be described with reference to FIGS. First, with reference to FIGS. 1-4, the apparatus structure of this Embodiment is demonstrated. FIG. 1 shows an external configuration of the front of the scanner device 1 according to the present embodiment. FIG. 2 shows a functional configuration of the scanner device 1. FIG. 3 shows a planar configuration of the imager module 21. FIG. 4 shows the change in focus of the liquid lens 212.

  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 symbol reading such as a one-dimensional barcode and a two-dimensional code.

  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 symbol 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. As shown in FIG. 2, the scanner device 1 includes a CPU (central processing unit) 11, an operation unit 12, a RAM (Random Access Memory) 13, and a display unit 14 as a detection unit, an imaging control unit, and a decoding unit. A ROM (Read Only Memory) 15, a communication unit 16, a flash memory 17 as a storage unit, a sound output unit 18, an imager controller 19 as a driving unit, a voltage boosting unit 20, an imager module 21, And a power supply unit 22.

  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, a liquid lens 212 as a variable focus lens, an aimer 213 as a spot light irradiation unit, and an illumination 214.

  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 a processing flow described later.

  The CPU 11 reads the focal position of the symbol corresponding to the position of the image of the laser beam of the aimer 213 in the cutout area from the applied voltage table stored in the flash memory 17 in accordance with the first symbol reading program 151. Then, the CPU 11 adjusts the focal position of the liquid lens 212 to the read focal position, reads the imaging area in the frame image corresponding to the read focal position from the imaging area table stored in the flash memory 17, The read image of the imaging area is captured from the image sensor 211, and the symbol image included in the captured image of the imaging area is decoded.

  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 according to display information input from the CPU 11.

  The ROM 15 is a read-only semiconductor memory. The ROM 15 stores a first symbol 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 performs wireless communication with an access point. An access point is a device that relays communication. That is, the scanner device 1 communicates with an external device such as a server device connected to the access point via the access point by the communication unit 16. 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 cradle on which the scanner device 1 is placed, or a wired communication unit that performs wired communication with the server device via a communication cable.

  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.

  In addition, the imager controller 19 generates an image area designation signal that designates an image area (image area to be captured (captured)) of 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 adjusts the focal point and images a barcode. The imaging device 211 is a CMOS (Complementary Metal Oxide Semiconductor Image Sensor) image sensor, and is an imaging device capable of designating an image area and outputting image data. The image sensor 211 photoelectrically converts a subject image incident via an optical system including the liquid lens 212 and converts the subject image data into an electrical signal of subject image data.

  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 includes a light source such as an LD (LASER Diode), and emits laser light as spot light (target light) that serves as a reference for directing the imaging direction of the imager module 21 to a 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.

  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 212 </ b> A 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 laser light is irradiated in a direction parallel to the optical axis of the optical system 212A. For this reason, the position of the laser beam of the aimer 213 with respect to the angle of view of the imager module 21 spreading like a fan 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.

  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. A voltage is applied 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, and the interface at the center part of the liquid parts 2121, 2122 is curved like a lens to provide a lens function. To realize. 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.

  Further, since the lens curvature changes according to the voltage applied to the liquid lens 212, the liquid lens can be electrically moved at high speed without causing physical movement of the lens as in the conventional mechanical autofocus mechanism. The lens curvature of 212 can be changed. 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 mechanical 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 image of the laser beam of the aimer 213 in the frame 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 symbols 41 are scanned at the near focal position D1 and the far focal position D2. FIG. 6A shows a frame image q1 obtained by imaging the symbol 41 at the focal position D1. FIG. 6B shows a frame image q2 obtained by imaging the symbol 41 at the focal position D2.

  As shown in FIG. 5, a one-dimensional barcode symbol 41 is present at a focal position D1 having a short focal distance from the scanner device 1 (imager module 21) and a focal position D2 having a long focal distance. It shall be placed. As an example, a case will be described in which the scanner device 1 captures an image with respect to the symbol 41 placed at the focal position D1 and the focal position D2. However, the symbol 41 is affixed to a cardboard or the like, and it is assumed that there is a white area around the symbol 41 when viewed from the scanner device 1.

  When the symbol 41 is read from the proximity position by the scanner device 1, the relative size of the symbol image increases with respect to the angle of view of the image sensor 211, so that a large symbol image is captured in the frame image. As shown in FIG. 6A, the frame image q1 when the symbol 41 is placed at the focal position D1 at a short distance includes the symbol image Q1 and the image E1 of the laser light from the aimer 213. The image E1 is located at the end of the symbol image Q1, indicating that the reading target symbol 41 is nearby.

  On the other hand, when the symbol 41 is read from a far position by the scanner device 1, the symbol image is picked up small in the frame image because the relative size of the symbol image with respect to the angle of view of the image sensor 211 is small. As shown in FIG. 6B, the frame image q2 when the symbol 41 is placed at the focal point D2 at a long distance includes the symbol image Q2 and the image E2 of the laser light from the aimer 213. The video E2 is outside the symbol image Q2 because the symbol 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.

  Thus, when the frame images have the same size, the distance from the scanner device 1 to the subject (symbol 41) increases as the distance from the center of the frame image to the image of the laser beam of the aimer 213 decreases. ing. 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, the focal position adjustment of the liquid lens 212 will be described with reference to FIGS. FIG. 7 shows a frame image q and a cutout region p including the images Ea and Eb of the laser light of the aimer 213. FIG. 8 shows cutout region images p1, p2, and p3 corresponding to the passage of time.

  In the scanner apparatus 1, by applying a predetermined voltage to the liquid lens 212, the focal position of the imager module 21 is adjusted to a target position where the symbol as the subject is in focus. For example, when the imager module 21 is focused on the symbol 41 at the focal position D1, an applied voltage that focuses on the focal position D1 is applied to the liquid lens 212.

  As shown in FIG. 7, the x-axis and the y-axis are taken in the frame image q captured by the image sensor 211 in the scanner device 1, and these coordinates are taken as the x-coordinate and the y-coordinate. For example, the upper left corner of the frame image q is the origin. Assume that the coordinates of the video Ea of the aimer 213 when the target symbol is far from the imager module 21 are (xa, ye). A focal position at a distance from the imager module 21 to the symbol corresponding to the coordinates (xa, ye) is defined as a focal position Da.

  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). A focal position at a distance from the imager module 21 to the symbol corresponding to the coordinates (xb, ye) is defined as a focal position Db. Further, in the frame image q, an image and a surrounding area that can include an image of the laser beam of the aimer 213 at least at all distances are set as a cut-out area p. The coordinates of the upper left corner and the lower right corner of the cutout area p are (x1, y1) and (x2, y2) in this order, and these coordinates indicate the range of the cutout area p.

  The time until the focal position of the liquid lens 212 is adjusted to the target position varies depending on the environmental temperature of the liquid lens 212. The lower the temperature of the liquid lens 212, the longer the time until the focal position of the liquid lens 212 is stabilized at the target position of the symbol. Therefore, a waiting time corresponding to the maximum change time at a low temperature is required even at a normal temperature and a high temperature. It is.

  Here, the positions of the scanner device 1 and the symbol 41 are fixed, and after applying an applied voltage to the liquid lens 212 so as to match the focal position of the liquid lens 212 with the target position of the symbol, the focal position of the liquid lens 212 is actually set. The state until the match is explained. As shown in FIG. 8, consider cutout region images p1, p2, and p3 as images of the cutout region p of the frame image q of FIG. The cut-out area images p1, p2, and p3 include images E31, E32, and E33 of laser light from the aimer 213 in order.

  In the cut-out region images p1, p2, and p3, it is assumed that the time elapsed from the start of applying an applied voltage to the liquid lens 212 that matches the focal position of the liquid lens 212 with the target position of the symbol. An image of the cutout region p at the start of the focus position adjustment of the liquid lens 212 is referred to as a cutout region image p1.

  As the focus position adjustment of the liquid lens 212 starts and the cutout region image p1 → cutout region image p2 → cutout region image p3 changes, the image of the laser light of the aimer 213 is in the order of video E31 → video E32 → video E33. Has changed to fit. In addition, since the positions of the scanner device 1 and the symbol 41 are fixed, the coordinates of the laser light images (images E31, E32, E33) in the cutout region p (frame image q) change regardless of the passage of time. Not.

  Next, a symbol image in the frame image and other images will be described with reference to FIGS. FIG. 9 shows a frame image q4 obtained by imaging the symbol of the two-dimensional code at the focal position D1. FIG. 10 shows a frame image q5 obtained by imaging the symbol of the two-dimensional code at the focal position D2. FIG. 11 shows a frame image q6 obtained by imaging a one-dimensional barcode symbol at the focal position D1.

  First, consider a case where the imager module 21 captures a two-dimensional code symbol at the focal position D1, and a frame image q4 shown in FIG. 9 is obtained. However, the image of the laser beam of the aimer 213 is omitted in the frame image q4, and the same applies to the frame images q5 and q6.

  The frame image q4 includes a symbol image r4 and an unnecessary image t4. The symbol image r4 is an image area image of the symbol of the two-dimensional code at the focal position D1. When the symbol is read, the symbol image r4 is decoded. The unnecessary image t4 is an image of an area unnecessary for decoding the symbol image r4. Since the focal position D1 of the symbol is relatively close to the scanner device 1, the symbol image r4 has a large area in the frame image q4, and the unnecessary image t4 has a small area.

  Here, a case is considered where the imager module 21 captures the same two-dimensional code symbol as in FIG. 9 at the focal position D2 and obtains the frame image q5 shown in FIG. The frame image q5 includes a symbol image r5 and an unnecessary image t5. The symbol image r5 is an image region image of the symbol of the two-dimensional code at the focal position D2. The unnecessary image t5 is an image of an area unnecessary for decoding the symbol image r5. Since the focal position D2 of the symbol is relatively far from the scanner device 1, the symbol image r5 has a smaller area than the symbol image r4 in the frame image q5, and the unnecessary image t5 has a larger area than the unnecessary image t4.

  As shown in FIGS. 9 and 10, when the same kind of symbol is imaged by changing the focal position, the area necessary for decoding also changes in accordance with the focal position. For this reason, it is preferable that the imaging area (image data) captured from the imaging element 211 for decoding is as small as possible in accordance with the focal position in order to improve the symbol reading speed. However, since the imaging area captured from the imaging device 211 for decoding depends on the operation technique of the operator of the scanner device 1, it is preferable to provide a certain margin. For this reason, the imaging region includes a symbol region corresponding to a symbol image corresponding to the focal position, and a margin around the symbol region.

  Also, consider a case where the imager module 21 captures a one-dimensional barcode symbol at the focal position D1, and a frame image q6 shown in FIG. 11 is obtained. The frame image q6 includes a symbol image r6 and an unnecessary image t6. The symbol image r6 is an image area image of the symbol of the one-dimensional barcode at the focal position D1. The unnecessary image t6 is an image of an area unnecessary for decoding the symbol image r6. Since the focal position D1 of the symbol is relatively close to the scanner device 1, the symbol image r6 has a relatively large area in the frame image q6, and the unnecessary image t6 has a small area.

  In addition, since the symbol is a rectangular one-dimensional barcode, the symbol image r6 has a smaller area in the frame image q6 than the square two-dimensional code symbol image r4, and the unnecessary image t6 is relatively small. Has a large area.

  As shown in FIGS. 9 and 11, when different types of symbols are imaged at the same focal position, the regions necessary for decoding differ depending on the types of symbols. For this reason, the imaging area (image data) captured from the imaging element 211 for decoding is preferably as small as possible in accordance with the type of symbol in order to improve the symbol reading speed.

  Next, information stored in the flash memory 17 of the scanner device 1 will be described with reference to FIGS. 12 and 13. FIG. 12 shows the configuration of the applied voltage table 171. FIG. 13 shows the configuration of the imaging area table 172.

  As shown in FIG. 12, the flash memory 17 stores an applied voltage table 171. The applied voltage table 171 has fields of an aimer position 1711, an applied voltage 1712, and a focus position 1713.

  The aimer position 1711 is the x coordinate of the image of the laser beam of the aimer 213 in the frame image q. The applied voltage 1712 is an applied voltage to the liquid lens 212 for adjusting the focal position to the symbol placed at the focal position 1713 corresponding to the aimer position 1711. The focal position 1713 is a focal position of the target symbol from the scanner device 1 corresponding to the aimer position 1711.

  Further, as shown in FIG. 13, an imaging area table 172 is stored in the flash memory 17. The imaging area table 172 includes a focal position 1721, a symbol type 1722, and an imaging area 1723.

  A focal position 1721 is a focal position of a target symbol from the scanner device 1. The symbol type 1722 is a type of symbol placed at the focal position 1721. The symbol type 1722 is a (matrix) two-dimensional code, a one-dimensional barcode, a stack type two-dimensional code, or the like. The imaging area 1723 is a coordinate indicating an image area that is necessary for decoding and actually captured among images (frame images) of the entire screen of the imaging element 211.

  Decoding is possible when the imaging region 1723 includes a symbol image. The imaging region 1723 is represented by the coordinates of the upper left corner and the lower right corner of the imaging region. For example, the imaging region 1723 of the two-dimensional code at the focal position Da is (xa1-α, ya1-α) to (xa2 + α, ya2 + α). Here, (xa1, ya1) to (xa2, ya2) indicate symbol image regions (symbol regions) corresponding to the focal position Da whose center in the frame image is horizontal (x-axis direction). The margin α indicates a margin value corresponding to the focal position Da. A deviation (parallel deviation and rotational deviation) of the symbol image is allowed by the margin α from the symbol area. The margin β indicates a margin value corresponding to the focal position Db. In FIG. 13, the margin has a different value depending on the focal position 1721, but the present invention is not limited to this. For example, the margin may be the same value according to the focal position 1721.

  Next, the operation of the scanner device 1 will be described with reference to FIGS. 14 and 15. FIG. 14 shows the first symbol reading process. FIG. 15 shows the scan control process.

  In the first symbol reading process, the focal position of the liquid lens 212 is adjusted to the focal position of the target symbol in accordance with the position of the laser beam image of the aimer 213, and the imager module 21 has an imaging region corresponding to the symbol type. This is a process of imaging a symbol and decoding the acquired symbol image data. In the scanner apparatus 1, triggered by the user pressing the trigger keys 12 </ b> A and 12 </ b> C as a trigger, the CPU 11 cooperates with the first symbol reading program 151 read from the ROM 15 and appropriately expanded in the RAM 13. 1 symbol reading process is executed.

  As shown in FIG. 14, first, the CPU 11 receives input of the symbol type and margin values (margins α, β,...) From the user via the operation unit 12 and stores them in the RAM 13 for initial setting. Then, an instruction signal for starting the imager module 21 is output 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 (image pickup of the cut-out area) 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 uses the DMA function to DMA transfer the line data of the cut-out area input from the image sensor 211 to the imager controller 19 and store it in the RAM 13 (step S13). Then, the CPU 11 reads out the image data (line data) of the cutout area stored in the RAM 13, and detects the aimer position in the image of the cutout area (the x coordinate of the image of the laser beam of the aimer 213 in the frame 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 refers to the applied voltage table 171 stored in the flash memory 17, reads the applied voltage 1712 corresponding to the aimer position 1711 detected in step S 14, and reads the applied voltage to the liquid lens 212 as the read applied voltage. 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 area stored in the RAM 13, and calculates the contrast of the image of the laser beam of the aimer 213 in the image of this cutout area (step S18). Then, the CPU 11 determines whether or not the contrast calculated in step S18 is greater than or equal to a predetermined value set in advance, or whether a predetermined time set in advance from the execution of the first step S16 has timed out (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 of the liquid lens 212 is being adjusted, and the image of the laser light from the aimer 213 is blurred as shown in the images E31 and E32 of FIG. 8, and the focus (focus position) is not in alignment. State. 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 refers to the applied voltage table 171 stored in the flash memory 17 and reads and acquires the focal position 1713 corresponding to the aimer position 1711 detected in step S14 (step S21).

  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 S22). Then, the CPU 11 reads the symbol type and margin value input in step S11 stored in the RAM 13 (step S23).

  Then, the CPU 11 refers to the imaging area table 172 stored in the flash memory 17 and reads the imaging area 1723 corresponding to the symbol type 1722 read out in step S23 and the focal position 1721 acquired in step S21 (step S21). S24). Then, the CPU 11 calculates the imaging region by substituting the margin value read in step S23 for the margins α, β,... Of the imaging region read in step S11 (step S25).

  Then, the CPU 11 outputs to the imager controller 19 an image capture instruction signal for the imaging region calculated in step S25 of the imaging device 211 for decoding (step S26). In step S27, the CPU 11 executes the same processing as step S13 on the line data of the imaging region acquired by the imaging element 211 in step S26. Then, the CPU 11 reads out image data (line data) of the imaging area stored in the RAM 13, and performs image processing (such as a process of synthesizing into one image data) that facilitates decoding of the image of the imaging area. The symbol image in the image of the imaging area after the image processing is decoded (step S28).

  Then, the CPU 11 determines whether or not the decoding in step S28 is successful (step S29). If the decoding is not successful (step S29; NO), the process proceeds to step S12. If the decoding is successful (step S29; YES), the CPU 11 outputs a power-off instruction signal for the imager module 21 to the imager controller 19 (step S30). Then, the CPU 11 displays the decoding result on the display unit 14, causes the buzzer sound of successful decoding to sound in the sound output unit 18 (step S31), 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 symbol by adjusting the focal position using the imager module 21 and acquiring the image data of the cutout area including the image of the laser light of the aimer 213 and the imaging area including the symbol image. . In the scanner device 1, the imager controller 19 executes a scan control process, triggered by the activation instruction signal input from the CPU 11, corresponding to step S 11 of the first symbol reading process.

  As shown in FIG. 15, first, the imager controller 19 performs initial setting (step S41). 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 S42).

  Then, in response to step S30 of the first symbol reading process, the imager controller 19 determines whether or not an instruction signal for powering off the imager module 21 is input from the CPU 11 (step S43). When the power-off instruction signal is not input (step S43; NO), the imager controller 19 instructs the application voltage change to the liquid lens 212 from the CPU 11 in response to step S15 of the first symbol reading process. It is determined whether or not a signal has been input (step S44).

  When the applied voltage change instruction signal is input (step S44; 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 S45). In step S45, the voltage booster 20 changes the voltage applied to the liquid lens 212.

  After execution of step S45, or when an instruction signal for changing the applied voltage is not input (step S44; NO), the imager controller 19 corresponds to steps S12, S16, and S26 of the first symbol reading process. It is determined whether or not an image capture instruction signal is input from (step S46). If no image capture instruction signal is input (step S46; NO), the process proceeds to step S43.

  When an image capture instruction signal is input (step S46; YES), the imager controller 19 sets an image capture region of the image sensor 211 in accordance with the image capture instruction signal input at step S46 (step S47). ). Then, the imager controller 19 determines whether or not an instruction signal for lighting the aimer 213 is input from the CPU 11 in response to steps S12 and S16 of the first symbol reading process (step S48).

  When the instruction signal for lighting the aimer 213 is input (step S48; YES), the imager controller 19 lights the aimer 213 (step S49). When the instruction signal for turning on the aimer 213 is not inputted (step S48; NO), the instruction signal for turning off the aimer 213 is inputted from the CPU 11 in correspondence with step S20 of the first symbol reading process. The controller 19 turns off the aimer 213 (step S50).

  Then, in response to step S22 of the first symbol reading process, the imager controller 19 determines whether or not an instruction signal for turning on the illumination 214 is input from the CPU 11 (step S51). When an instruction signal for lighting the illumination 214 is not input (step S51; NO), the imager controller 19 generates an image area designation signal for the image capture area (which is a cut-out area) set in step S47. The image is output to the element 211 and is captured by the image sensor 211. Image data (in the cutout area) is input from the image sensor 211 (step S52), and the process proceeds to step S43.

  When an instruction signal for lighting the illumination 214 is input (step S51; YES), the imager controller 19 lights the illumination 214 (step S53). Then, the imager controller 19 generates an image area designation signal for the image capture area (which is the imaging area) set in step S47, outputs the image area designation signal to the imaging element 211, causes the imaging element 211 to capture an image, and Image data of a frame image (in the imaging area) is input (step S54). Then, the imager controller 19 turns off the illumination 214 (step S55), and proceeds to step S43.

  When a power-off instruction signal is input (step S43; YES), the imager controller 19 turns off the power of the imager module 21 (step S56) and ends the scan control process.

  As described above, according to the present embodiment, the scanner device 1 reads the focal position 1713 of the symbol corresponding to the position of the image of the laser beam of the aimer 213 in the cutout area (the aimer position 1711) from the applied voltage table 171. Then, the scanner device 1 adjusts the focal position of the liquid lens 212 to the read focal position 1713, reads the imaging area 1723 in the frame image corresponding to the read focal position 1713, and reads the readout. The captured image of the imaging region 1723 is captured from the image sensor 211, and the symbol image included in the captured image of the captured region is decoded.

  For this reason, since the focal position of the liquid lens 212 is adjusted to the symbol, and the symbol can be imaged in an imaging region having an appropriate size according to the subsequent focal position, the symbol read response speed can be increased, and the scanner device 1 Operability can be improved.

  Further, the imaging area table 172 includes an imaging area 1723 corresponding to the symbol type 1722 and the focal position 1721. The scanner device 1 captures an image of the imaging region 1723 corresponding to the symbol type 1722 and the focal position 1721 from the imaging element 211. For this reason, since a symbol can be imaged in an imaging region having an appropriate size according to the type and focal position of the symbol, the symbol read response speed can be further increased, and the operability of the scanner device 1 can be further improved.

  Further, the imaging area 1723 of the imaging area table 172 becomes smaller as the focal position 1721 becomes larger (far). For this reason, it is possible to acquire an imaging region having an appropriate size according to the focal position.

  The imaging area 1723 of the imaging area table 172 includes a symbol area having a symbol size that decreases as the focal position 1721 increases (far), and a margin around the symbol area. The scanner device 1 includes an operation unit 12 that receives an input of a margin value, substitutes the input margin value for the margin of the imaging region 1723 read from the imaging region table 172, and substitutes the margin value for imaging. An image of the area is captured from the image sensor 211. For this reason, the value of the margin of the imaging region can be set arbitrarily. For example, a beginner operating the scanner apparatus 1 can set a margin value small, and an expert can set a margin value small.

  Further, the scanner device 1 reads the focal position 1713 of the symbol corresponding to the aimer position 1711 of the cutout area from the applied voltage table 171. For this reason, the focal position of the symbol can be easily detected according to the aimer position.

  Further, after reading the focal position 1713, the scanner device 1 turns off the aimer 213, and captures an image of the imaging region 1723 corresponding to the read focal position 1713 from the imaging element 211. For this reason, the image of the laser beam of the aimer 213 unnecessary for decoding can be removed from the image of the imaging region to prevent decoding failure, and the symbol read response speed can be further increased.

(Modification)
A modification of the above embodiment will be described with reference to FIGS. As a device configuration of this modification, the scanner device 1 is used as in the above embodiment. For this reason, a different part from the said embodiment is mainly demonstrated.

  Assume that the ROM 15 of the scanner apparatus 1 stores a second symbol reading program 152 instead of the first symbol reading program 151. Further, it is assumed that an applied voltage table 173 described later is stored in the flash memory 17 instead of the applied voltage table 171.

  Next, the focal position adjustment of the liquid lens 212 will be described with reference to FIG. FIG. 16 shows a frame image q, a center region v, and images Ea and Eb of laser light from the aimer 213.

  In the above embodiment, by applying an applied voltage corresponding to the position of the laser beam image of the aimer 213 to the liquid lens 212, the focal position of the imager module 21 is adjusted to the target position where the symbol as the subject is focused. did. In this modification, an application voltage at which the contrast of the center area image fixed at the center of the frame image q is equal to or greater than a certain value is applied to the liquid lens 212, so that the focal position of the imager module 21 is made a symbol as a subject. Adjust the target position to be in focus.

  As shown in FIG. 16, the frame image q picked up by the image pickup device 211 in the scanner device 1 includes the center region v and the image of the laser beam from the aimer 213. The center region v is a fixed region located at the center of a preset frame image q. The center region v is a region that does not include the image of the laser beam of the aimer 213 even if the focal position of the symbol is changed. The center area v is assumed to be a rectangular area of 80 × 80 pixels, for example. The coordinates of the upper left corner of the center region v are (xv1, yv1), and the coordinates of the lower right corner are (xv2, yv2). These coordinates indicate the range of the center region v.

  Next, information stored in the flash memory 17 will be described with reference to FIG. FIG. 17 shows the configuration of the applied voltage table 173.

  As shown in FIG. 17, the applied voltage table 173 has fields of an applied voltage 1731 and a focal position 1732. The applied voltage 1731 is an applied voltage to the liquid lens 212 for adjusting the focal position to the symbol placed at the focal position 1732. A focal position 1732 is a focal position of a target symbol from the scanner device 1.

  The flash memory 17 stores coordinates (xv1, yv1) and (xv2, yv2) indicating the center region v, and initial values, MIN values, and MAX values of applied voltages applied to the liquid lens 212. It shall be. The MIN value of the applied voltage is the maximum value of the applied voltage in which the focal position of the symbol to be combined becomes the farthest (maximum focal length) within the adjustable range. The MAX value of the applied voltage is the minimum value of the applied voltage in which the focal position of the symbol to be matched is closest (focal length is minimized) within an adjustable range. The initial value of the applied voltage is a value of a preset applied voltage that is between the MAX value and the MIN value.

  Next, the operation of the scanner device 1 will be described with reference to FIGS. FIG. 18 shows the second symbol reading process. FIG. 19 shows an applied voltage changing process of the second symbol reading process.

  In the second symbol reading process, the focal position of the liquid lens 212 is adjusted to the focal position of the target symbol in accordance with the contrast of the center area of the frame image, and the symbol is displayed in the imaging area corresponding to the type of symbol in the imager module 21. This is a process of decoding the image data of the symbol obtained by scanning. In the scanner apparatus 1, triggered by the user pressing the trigger keys 12 </ b> A and 12 </ b> C as a trigger, the CPU 11 cooperates with the second symbol reading program 152 that is read from the ROM 15 and appropriately expanded in the RAM 13. 2 symbol reading processing is executed.

  As shown in FIG. 18, first, step S61 is the same as step S11 of the first symbol reading process of FIG. Then, the CPU 11 reads the initial value of the applied voltage stored in the flash memory 17, sets the applied voltage to the liquid lens 212 to the read initial value of the applied voltage, and sets 0 to the flag F (step S62). ). The flag F is a flag that takes three states of 0, N, and M. 0 of the flag F is a value indicating a state where the applied voltage is an initial value. N of the flag F is a value indicating a state in which the applied voltage is increased. M of the flag F is a value indicating a state in which the applied voltage is decreased. And CPU11 performs an applied voltage change process (step S63).

  Here, with reference to FIG. 19, the applied voltage changing process in step S63 will be described. First, the CPU 11 determines whether or not the flag F is 0 (step S631). When the flag F is 0 (step S631; YES), the CPU 11 sets N to the flag F (step S632). Then, the CPU 11 outputs an instruction signal for changing the applied voltage to the liquid lens 212 to the applied voltage being set to the imager controller 19 (step S633), and ends the applied voltage changing process.

  When the flag F is not 0 (step S631; NO), the CPU 11 determines whether or not the flag F is N (step S634). When the flag F is N (step S634; YES), the CPU 11 sets the voltage applied to the liquid lens 212 to increase by a predetermined value (step S635).

  Then, the CPU 11 determines whether or not the applied voltage being set is larger than the MAX value stored in the flash memory 17 (step S636). When the applied voltage being set is larger than the MAX value (step S636; YES), the CPU 11 reads the initial value of the applied voltage stored in the flash memory 17, and sets the applied voltage to the liquid lens 212 to the read applied voltage. The initial value is set, M is set in the flag F (step S637), and the process proceeds to step S633. When the applied voltage being set is not larger than the MAX value (step S636; NO), the process proceeds to step S633.

  If the flag F is not N (step S634; NO), the flag F is M, and the CPU 11 sets the voltage applied to the liquid lens 212 to be decreased by a predetermined value (step S638). Then, the CPU 11 determines whether or not the applied voltage being set is smaller than the MIN value stored in the flash memory 17 (step S639).

  If the applied voltage being set is smaller than the MIN value (step S639; YES), the CPU 11 reads the initial value of the applied voltage stored in the flash memory 17, and sets the applied voltage to the liquid lens 212 to the read applied voltage. The initial value is set, N is set in the flag F (step S640), and the process proceeds to step S633. When the applied voltage being set is not smaller than the MIN value (step S639; NO), the process proceeds to step S633.

  Returning to FIG. 18, after executing step S <b> 63, the CPU 11 outputs an instruction signal for lighting the aimer 213 and an instruction signal for capturing (imaging) the center region v of the image sensor 211 to the imager controller 19 (step S <b> 64). ). The instruction signal for capturing the center region v is an instruction signal for acquiring line data of the center region v defined by the coordinates (xv1, yv1) and the coordinates (xv2, yv2) stored in the flash memory 17.

  Then, the CPU 11 DMA-transfers and stores the line data of the center region v input from the image sensor 211 to the imager controller 19 to the RAM 13 by the DMA function (step S65). Then, the CPU 11 reads the image data (line data) of the central area v stored in the RAM 13 and calculates the contrast of the central area image (step S66).

  Then, the CPU 11 determines whether or not the contrast calculated in step S66 is greater than or equal to a predetermined value set in advance, or whether a predetermined time set in advance from the execution of the first step S63 has timed out (step S67). ). If the contrast is not equal to or greater than a certain value and has not timed out (step S67; NO), the process proceeds to step S63.

  If the contrast is equal to or greater than a certain value or times out (step S67; YES), the CPU 11 executes step S68. Step S68 is the same as step S20 of the first symbol reading process of FIG. Then, the CPU 11 refers to the applied voltage table 173 stored in the flash memory 17 and reads and acquires the focal position 1732 corresponding to the applied voltage 1731 changed in step S63 (step S69). Steps S70 to S79 are the same as steps S22 to S31 of the first symbol reading process of FIG.

  As described above, according to the present modification, the scanner device 1 captures an image of a part of the central region v of the frame image from the image sensor 211, and determines the focal position where the image of the central region v has a contrast of a certain value or more. The focus position 1732 to the subject corresponding to the applied voltage 1731 at that time is read out from the applied voltage table 173. Therefore, similarly to the embodiment, the focal position of the liquid lens 212 can be adjusted to the symbol, the reading response speed of the subsequent symbol can be increased, the operability of the scanner device 1 can be improved, and the central region v can be improved. The focal position of the symbol can be easily detected according to the contrast of the image.

  In the above description, the example in which the ROM 15 is used as the computer-readable medium of the program according to the present invention is disclosed, but the present invention is not limited to this example. As other computer-readable media, a non-volatile memory such as a flash memory 17 and a portable recording medium such as a CD-ROM can be applied. A carrier wave is also applied to the present invention as a medium for providing program data according to the present invention via a communication line.

  Note that the descriptions in the above-described embodiments and modifications are examples of the scanner device and the program according to the present invention, and the present invention is not limited thereto.

  In the above embodiment, the configuration in which the focal position of the symbol is acquired from the position of the image of the laser beam of the aimer 213 has been described. However, the present invention is not limited to this. The image for specifying the focal position of the symbol may be an image of another spot light serving as a reference. This video image may be any image whose position changes relative to the entire frame image according to the distance from the scanner device 1. For example, the spot light may be irradiated substantially in parallel along the optical axis direction of the optical system 212A.

Moreover, in the said embodiment and modification, although it was set as the structure which uses the liquid lens 212 as a focus variable lens, it is not limited to this. For example, a variable focus lens using KTN (potassium niobate tantalate, KTa _1-x Nb _x O ₃ ), which is a kind of “electro-optic crystal” whose refractive index changes depending on the applied voltage, or a mechanical lens position. Other variable focus lenses such as a variable focus lens for adjusting and focusing may be used. In the present application, these are collectively referred to as a variable focus lens.

  In the above embodiment, the cutout area including the light image of the aimer 213 is described as an example of a predetermined area (rectangular area 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 in FIG. 14, in step S16 in FIG. The area narrower than the predetermined area may be determined, and an image of the determined area may be acquired as an image of the cutout area. Since this partial area is narrower than the predetermined area, the processes in steps S16 to S19 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 image of the laser beam of the aimer 213 indicating the distance to the subject, the voltage applied to the liquid lens 212, and the focal position of the symbol is stored in the applied voltage table 171 in advance. However, the present invention is not limited to this. The relationship between the position of the image of the laser beam of the aimer 213, the voltage applied to the liquid lens 212, and the focal position of the symbol is expressed by a calculation formula. The voltage applied to 212 and the focal position of the symbol may be directly calculated by the above formula. Similarly, instead of the applied voltage table 173 in the modified example, the relationship between the applied voltage to the liquid lens 212 and the focal position of the symbol may be expressed by a calculation formula. The above calculation formula is stored in the flash memory 17, for example.

  Moreover, in the said embodiment and modification, although the image shape of the spot light (laser beam) 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-described embodiments and modifications, 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.

  Further, in the above modification, the focus position is fixed in the frame image q and the focal position where the contrast of the central region v which is a specific region not including the image of the laser beam of the aimer 213 is a certain value or more is detected. However, the present invention is not limited to this. For example, it may be configured to detect a focal position where the contrast of a specific area in which the image of the laser beam of the aimer 213 in the frame image q is always included is a certain value or more. For example, the specific area is fixed in size with the image of the laser beam of the aimer 213 as the center.

  In the above modification, the initial value of the voltage applied to the liquid lens 212 is set to a value between the MAX value and the MIN value, and the applied voltage is changed from the initial value to the MAX value and from the initial value to the MIN value. However, the present invention is not limited to this. For example, the initial value of the voltage applied to the liquid lens 212 may be the MAX value, and the applied voltage may be changed from the initial value (MAX value) to the MIN value. Conversely, the initial value of the voltage applied to the liquid lens 212 may be the MIN value, and the applied voltage may be changed from the initial value (MIN value) to the MAX value.

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

1 Scanner device 2 Case 11 CPU
12 Operation units 12A, 12C Trigger key 12B Various keys 13 RAM
14 Display 15 ROM
16 Communication unit 17 Flash memory 18 Sound output unit 18A Speaker 19 Imager controller 20 Voltage booster unit 21 Imager module 211 Image sensor 212 Liquid lens 2121, 1222 Liquid unit 2123 Container 2124 Electrode 212A Optical system 213 Aimer 214 Illumination 22 Power supply unit 23 Bus 30 Power supply 41 symbol

Claims (8)

A variable focus lens,
A storage unit for storing an imaging region in the frame image according to the focal position;
A drive unit that drives and controls the focal position of the variable focus lens;
A detection unit for detecting the focal position of the symbol of the subject;
Imaging in which the driving unit moves the focal position of the variable focus lens to the detected focal position, reads an imaging area corresponding to the detected focal position from the storage unit, and captures an image of the read imaging area A control unit;
And a decoding unit that decodes a symbol image included in the captured image of the imaging region. The storage unit stores an imaging region corresponding to a symbol type and a focal position,
The scanner device according to claim 1, wherein the imaging control unit reads an imaging region corresponding to the type of the symbol of the subject and the detected focal position from the storage unit.   The scanner device according to claim 1, wherein the storage unit stores an imaging region that becomes smaller as the focal position becomes farther. The imaging area is composed of a symbol area having a symbol size that becomes smaller as the focal position becomes farther, and a margin around the symbol area,
It has an operation unit that accepts input of margin values,
The scanner apparatus according to claim 3, wherein the imaging control unit captures an image of the imaging area by setting a margin value input from the operation unit as a margin of the imaging area read from the storage unit. Provided with a spot light irradiation unit that irradiates spot light,
The imaging control unit captures an image including an image of the spot light,
5. The scanner device according to claim 1, wherein the detection unit detects a focal position of the subject from a position of a spot light image in an image captured by the imaging control unit.   The scanner device according to claim 5, wherein the imaging control unit turns off the spot light irradiation unit after the detection unit detects a focal position, and captures an image of an imaging region corresponding to the detected focal position.   The detection unit captures an image of a specific region of a part of a frame image from the imaging control unit, and detects a focal position where the image of the specific region has a contrast of a predetermined value or more as a focal position to a subject. Item 5. The scanner device according to any one of Items 1 to 4. Computer
A storage unit for storing an imaging region in a frame image according to a focal position;
A drive unit that drives and controls the focal position of the variable focus lens;
A detection unit for detecting the focal position of the symbol of the subject;
Imaging in which the driving unit moves the focal position of the variable focus lens to the detected focal position, reads an imaging area corresponding to the detected focal position from the storage unit, and captures an image of the read imaging area Control unit,
A decoding unit for decoding a symbol image included in the captured image of the imaging region;
Program to function as.