Patent Publication Number: US-11659264-B2

Title: Photographing apparatus with mobile carriage and photographing method therefor

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2020-055432, filed on Mar. 26, 2020, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a photographing apparatus and a photographing method. 
     BACKGROUND 
     A store such as a supermarket uses, as a part of an energy saving strategy, an apparatus that photographs commodity shelves in the store with cameras and automatically checks whether price tags of the commodity shelves are correct. 
     The check of the price tags of the commodity shelves by this apparatus is performed in quiet hours when shoppers are absent in the store. In particular, from the viewpoint of automation, it is highly likely that the check of the price tags are automatically performed by going around the store at night. In photographing at night, it is likely that illumination in the store is not lit. The photographing needs to be performed by a set of the illumination and the cameras. 
     On the other hand, in most cases, the price tags of the commodity shelves are held by transparent resin and set at ends of the commodity shelves. The shoppers see the price tags through the transparent resin. Accordingly, in the photographing by the apparatus, it is likely that reflection of an illumination light source on the transparent resin occurs and the light source is reflected in the price tags of the commodity shelves. If the light source is reflected in the price tags in this way, a white void occurs in a photographed image. Price tag information printed on the price tags cannot be seen. 
     Related art is described in, for example, JP-A-2012-053711. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a block diagram illustrating a hardware configuration of a photographing apparatus in a first embodiment; 
         FIG.  2    is a schematic diagram illustrating an attachment state of illumination light sources and a camera to a traveling robot; 
         FIG.  3    is a top schematic view of a commodity shelf illustrating a traveling direction of the traveling robot with respect to the commodity shelf; 
         FIG.  4    is a schematic diagram illustrating a photographing range of the camera with respect to the commodity shelf; 
         FIG.  5    is a schematic diagram illustrating an example of photographed image data before correction photographed by the camera; 
         FIG.  6    is a schematic diagram illustrating an example of photographed image data after the correction; 
         FIG.  7    is a schematic diagram illustrating photographed image data of a comparative example; 
         FIG.  8    is a flowchart illustrating a main control procedure of a processor of a photographing control device; 
         FIG.  9    is a flowchart illustrating a control procedure of image correction processing in  FIG.  8   ; 
         FIG.  10    is a schematic diagram illustrating a disposition example of the camera and the illumination light sources in a first modification of the first embodiment; 
         FIG.  11    is a schematic diagram illustrating a photographing range of the camera with respect to the commodity shelf in the first modification; 
         FIG.  12    is a flowchart illustrating a main control procedure of the processor of the photographing control device in a second modification of the first embodiment; 
         FIG.  13    is a schematic diagram illustrating an attachment state of a camera and a light source to a traveling robot in a photographing apparatus in a second embodiment; 
         FIG.  14    is a schematic top view of a commodity shelf illustrating a traveling direction of the traveling robot with respect to the commodity shelf in the second embodiment; and 
         FIG.  15    is a flowchart illustrating a main control procedure of a processor of a photographing control device. 
     
    
    
     DETAILED DESCRIPTION 
     An object of embodiments is to provide a photographing apparatus and a photographing method with which an illumination light source is not reflected in a photographed image. 
     In one embodiment, a photographing apparatus includes a moving mechanism, a light source, and a camera. The moving mechanism moves in a first direction. The light source is mounted on the moving mechanism. The camera is disposed linearly or substantially linearly to the light source along a height direction and is attached to the moving mechanism to face a third direction rotated about an axis extending along the height direction with respect to a second direction orthogonal to the first direction and the height direction and performs photographing. 
     In one embodiment, a photographing method includes moving, in a first direction, a moving mechanism, to which a light source and a camera disposed linearly or substantially linearly along a height direction are attached such that the camera faces a third direction rotated about an axis extending along the height direction with respect to a second direction orthogonal to the first direction and the height direction and performs photographing, while maintaining a predetermined distance to one or more photographing target objects arranged side by side along the first direction. The photographing method further includes correcting distortion of an image photographed by the camera and acquiring a photographed image equivalent to a case in which the camera faces the second direction and performs the photographing. 
     Embodiments of a photographing apparatus with which an illumination light source is not reflected in a photographed image are explained below with reference to the drawings. 
     [First Embodiment] 
       FIG.  1    is a block diagram illustrating a hardware configuration of a photographing apparatus  1  according to a first embodiment. The photographing apparatus  1  includes a photographing control device  10 , a traveling robot  20 , illumination  30 , and a camera  40 . The photographing apparatus  1  may further include a touch panel  50  and/or an image recognition device  60 . 
     The photographing control device  10  controls units of the photographing apparatus  1 . The traveling robot  20  autonomously travels along a predetermined route according to an instruction of the photographing control device  10 . The illumination  30  includes a plurality of illumination light sources. The illumination light sources may be white light sources or may be infrared light sources. The camera  40  photographs a photographing target. The camera  40  is, for example, a digital camera in which a Charge Coupled Device (CCD) is used as an imaging element. If the illumination light sources are white light sources, the camera  40  may be a color camera or may be a monochrome camera. If the illumination light sources are infrared light sources, the camera  40  may be an infrared camera. A user of the photographing apparatus  1  inputs, to the touch panel  50 , an instruction to the photographing control device  10 . The touch panel  50  displays various kinds of information generated by the photographing apparatus  1 . The image recognition device  60  recognizes the photographing target from photographed image data photographed by the camera  40 . 
     The photographing control device  10  (e.g., a controller) includes a processor  11 , a memory  12 , a storage  13 , a robot interface  14 , an illumination interface  15 , and a camera interface  16 . The photographing control device  10  sometimes further includes an instruction interface  17  and/or a transmission interface  18 . In  FIG.  1   , interface is abbreviated as I/F. The processor  11 , the memory  12 , the storage  13 , the robot interface  14 , the illumination interface  15 , the camera interface  16 , the instruction interface  17 , and the transmission interface  18  are respectively connected to a system transmission path  19 . The system transmission path  19  includes an address bus, a data bus, and a control signal line. In the photographing control device  10 , the processor  11  and the memory  12  are connected by the system transmission path  19  to configure a computer that performs information processing for controlling the photographing control device  10 . 
     The robot interface  14  is connected to the traveling robot  20 . The illumination interface  15  is connected to the illumination  30 . The camera interface  16  is connected to the camera  40 . The instruction interface  17  is connected to the touch panel  50 . The transmission interface  18  is connected to the image recognition device  60 . 
     The processor  11  of the photographing control device  10  is equivalent to a central part of the computer. The processor  11  controls the units according to an operating system or application programs in order to realize various functions of the photographing control device  10 . The processor  11  is, for example, a Central Processing Unit (CPU). 
     The memory  12  is equivalent to a main storage part of the computer. The memory  12  includes a nonvolatile memory region and a volatile memory region. The memory  12  stores the operating system or the application programs in the nonvolatile memory region. The memory  12  stores, in the volatile memory region, data necessary for the processor  11  to execute processing for controlling the units. The processor  11  uses the volatile memory region of the memory  12  as a work area where data is rewritten as appropriate. The nonvolatile memory region is, for example, a Read Only Memory (ROM). The volatile memory region is, for example, a Random Access Memory (RAM). 
     The storage  13  stores, in a nonvolatile manner, photographed image data photographed by the camera  40 . As the storage  13 , a well known storage device such as an Electric Erasable Programmable Read-Only Memory (EEPROM), a Hard Disc Drive (HDD), or an Solid State Drive (SSD) can be used alone or a plurality of thereof can be used in combination. 
     The robot interface  14  is an interface for the processor  11  to exchange data between the processor  11  and the traveling robot  20 . The robot interface  14  includes a wireless communication unit for transmitting and receiving data through wireless communication such as a wireless Local Area Network (LAN) or Bluetooth (registered trademark). With the robot interface  14 , the photographing control device  10  can be disposed in a control room or the like of the store and remotely control the traveling robot  20 . The data transmitted from the processor  11  to the traveling robot  20  can include, for example, traveling instruction data for instructing traveling of the traveling robot  20 . The traveling robot  20  stores a traveling route indicating where in the store the traveling robot  20  travels. The traveling instruction data is data for designating one of a plurality of traveling start points included in the traveling route. The traveling instruction data may include data for designating a stop point of the traveling. Data received by the processor  11  from the traveling robot  20  can include, for example, state data relating to the autonomous traveling of the traveling robot  20 . The state data includes arrival data indicating that the traveling robot  20  reaches a stop point corresponding to a designated traveling start point or a designated stop point. The state data can include information data of a failure or the like. 
     The illumination interface  15  is an interface for transmitting, for example, illumination control data for instructing lighting and extinction of the illumination light sources included in the illumination  30  from the processor  11 . The illumination interface  15  includes a wireless communication unit for transmitting illumination control data through wireless communication such as a wireless LAN or Bluetooth. With the illumination interface  15 , the photographing control device  10  can remotely control a lighting state of the illumination  30 . 
     The camera interface  16  is an interface for the processor  11  to exchange data between the processor  11  and the camera  40 . The camera interface  16  includes a wireless communication unit for transmitting and receiving data through wireless communication such as a wireless LAN or Bluetooth. With the camera interface  16 , the photographing control device  10  can remotely control the camera  40 . The data transmitted from the processor  11  to the camera  40  can include, for example, photographing instruction data for causing the camera  40  to perform photographing (e.g., perform photography, capture one or more images, etc.). The data received by the processor  11  from the camera  40  can include, for example, photographed image data photographed by the camera  40 . The photographed image data can be stored in the storage  13 . 
     The instruction interface  17  is an interface for the processor  11  to receive instruction data from the touch panel  50  (e.g., a user interface). The instruction data can include, for example, an operation start instruction for the photographing apparatus  1 , a selection instruction for photographed image data photographed by the camera  40 , and an output of the selected photographed image data to the image recognition device  60 . 
     The transmission interface  18  is an interface for the processor  11  to transmit the photographed image data stored in the storage  13  to the image recognition device  60 . The transmission interface  18  includes a wireless communication unit for transmitting the photographed image data through wireless communication such as a wireless LAN or Bluetooth. With the transmission interface  18 , the photographing control device  10  can cause the image recognition device  60  to recognize, from the photographed image data, information concerning a photographing target such as price tag information printed on a price tag. 
     In the following explanation, a disposition relation among the traveling robot  20 , the illumination light sources included in the illumination  30 , and the camera  40  is explained with reference to  FIGS.  2  to  4   .  FIG.  2    is a schematic diagram illustrating an attachment state of the illumination light sources  31  and the camera  40  to the traveling robot  20 .  FIG.  3    is a top schematic view of a commodity shelf  70  illustrating a traveling direction of the traveling robot  20  with respect to the commodity shelf  70 .  FIG.  4    is a schematic diagram illustrating a photographing range of the camera  40  with respect to the commodity shelf  70 . 
     The traveling robot  20  includes a robot body  21  (e.g., a carriage, a chassis, a powertrain, etc.) including three or four wheels and an attachment section  22  (e.g., a tower, a frame, a fixture, etc.) extending upward from the robot body  21 . The robot body  21  is capable of moving (e.g., under its own power, using one or more electric motors, etc.) in a forwarding direction (e.g., a forward direction) and a retracting direction (e.g., a reverse direction) and turning to the left or the right with two-wheel differential driving. A plurality of illumination light sources  31  and the camera  40  are attached to the attachment section  22 . The illumination light sources  31  and the camera  40  are linearly disposed along the height direction. The attachment section  22  holds the camera  40  to face a direction deviating from the normal direction of the side surface of the robot body  21 . 
     Specifically, the traveling robot  20  travels substantially in parallel to the commodity shelf  70  from a traveling start point  81  to a stop point  82  (e.g., in a travel direction). This direction hereinafter referred to as first direction. Consequently, the traveling robot  20  functions as a moving mechanism that moves in the first direction. 
     Although not particularly illustrated, the commodity shelf  70  includes display shelves in a plurality of stages. In display shelves in the stages, the same commodities are arrayed and displayed in the depth direction of the display shelves (the up-down direction of  FIG.  3   ). In the shelves in the stages, different commodities are arranged side by side and displayed in the first direction, which is the left-right direction of the display shelves. In the display shelves, price tags on which price tag information indicating prices of the commodities are presented in association with the commodities. Since the commodity shelf  70  includes the display shelves in the plurality of stages, the commodity shelf  70  has height. The attachment section  22  of the traveling robot  20  holds the camera  40  at an attachment angle at which the camera  40  can photograph the price tags presented in the display shelves in the plurality of stages of the commodity shelf  70 . The distance between the camera  40  and a price tag presentation surface of the commodity shelf  70  in a second direction orthogonal to the first direction and the height direction, that is, the normal direction of the side surface of the robot body  21  is specified such that the camera  40  is capable of performing such photographing. That is, the distance between the camera  40  and the commodity shelf  70  is specified according to an angle of view in the height direction determined by the attachment angle of the camera  40 . In this way, a distance from the commodity shelf  70  that the traveling robot  20  travels is determined. The attachment section  22  of the traveling robot  20  holds the plurality of illumination light sources  31  side by side in the height direction across the camera  40  such that a plurality of price tags distributed and arranged in the height direction are photographed by the camera  40 . 
     The attachment section  22  of the traveling robot  20  holds the camera  40  at an attachment angle at which the camera  40  faces a third direction (e.g., a camera direction) rotated about an axis extending along the height direction (e.g., a vertical axis, a height axis, etc.) with respect to the second direction and performs photographing. That is, the attachment section  22  holds the camera  40  such that a photographing optical axis O of the camera  40  faces the third direction rotated by an angle θ with respect to the second direction. A photographing width W of the commodity shelf  70  photographed by the camera  40  at this time is determined according to the rotation angle θ in a yaw direction of the camera  40  and the distance between the camera  40  and the commodity shelf  70 . The attachment section  22  holds the camera  40  such that the rotation angle θ in the yaw direction of the camera  40  has an angle equal to or larger than a half of an angle of view AoV in the first direction of the camera  40 . If the yaw direction rotation angle θ is smaller than the half of the angle of view AoV, reflected light of light of the illumination light sources  31  reflected by a price tag is reflected in the photographed image data of the camera  40 . 
       FIG.  5    is a schematic diagram illustrating an example of photographed image data before correction photographed by the camera  40 .  FIG.  6    is a schematic diagram illustrating an example of photographed image data after correction photographed by the camera  40 .  FIG.  7    is a schematic diagram illustrating photographed image data in a comparative example. 
     If the camera  40  is attached to the attachment section  22  of the traveling robot  20  at the rotation angle θ in the yaw direction of the camera  40  as explained above, such that the camera  40  is not oriented at a right angle (i.e., right opposed) to the price tag presentation surface of the commodity shelf  70 , the photographed image data  41  of the camera  40  experiences trapezoidal distortion as shown in  FIG.  5   . The processor  11  of the photographing control device  10  applies trapezoidal distortion correction processing to the photographed image data  41  according to an application program stored in the memory  12 . Consequently, the processor  11  can correct the photographed image data  41  having the distortion illustrated in  FIG.  5    to photographed image data  42  not having trapezoidal distortion as illustrated in  FIG.  6   . That is, the processor  11  can obtain the photographed image data  42  corresponding to photographed image data obtained if the camera  40  is arranged at a right angle to the price tag presentation surface of the commodity shelf  70  to perform photographing, that is, equivalent to such photographed image data. If the camera  40  were arranged right opposed to the price tag presentation surface of the commodity shelf  70  to perform photographing, as illustrated in  FIG.  7   , the illumination light sources  31  are reflected in obtained photographed image data  43  and white voids  44  occurs. On the other hand, as illustrated in  FIG.  6   , the photographed image data  42  after the correction is an image without such white voids. 
       FIG.  8    is a flowchart illustrating a main control procedure of the processor  11  of the photographing control device  10 . In the following explanation, the operation of the photographing control device  10  is explained with reference to  FIG.  8   . A procedure and content of the operation explained below are an example. The procedure and the content are not limited if the same result is obtained. 
     If receiving, for example, a photographing start instruction for the photographing apparatus  1  from the touch panel  50  via the instruction interface  17 , the processor  11  starts the operation illustrated in  FIG.  8   . First, the processor  11  transmits, with the robot interface  14 , traveling instruction data for instructing the traveling robot  20  to start traveling (ACT  11 ). 
     The traveling instruction data transmitted from the photographing control device  10  to the traveling robot  20  may be data for designating the traveling start point  81 . The traveling robot  20  stores a traveling route indicating where in the store the traveling robot  20  travels. That is, since the traveling robot  20  stores the stop point  82  corresponding to the designated traveling start point  81 , the stop point  82  does not have to be designated. Naturally, the traveling instruction data may include data for designating the stop point  82  of the traveling. The traveling start point  81  (and the stop point  82 ) to be designated is the traveling start point  81  (and the stop point  82 ) of any one traveling route among a plurality of traveling routes for going around all stores to which the traveling robot  20  should travel. Naturally, the traveling instruction data may be the traveling start point  81  of a first traveling route (and the stop point  82  of a last traveling route) of all the traveling routes. 
     The processor  11  determines whether the traveling robot  20  reaches the traveling start point  81  (ACT  12 ). The traveling robot  20  autonomously travels from a standby position to the traveling start point  81 . If reaching the traveling start point  81 , the traveling robot  20  transmits, to the photographing control device  10 , state data including arrival data indicating that the traveling robot  20  reaches the traveling start point  81 . Therefore, the processor  11  can determine, according to whether the arrival data is received via the robot interface  14 , whether the traveling robot  20  reaches the traveling start point  81 . If the traveling robot  20  does not reach the traveling start point  81  yet (NO in ACT  12 ), the processor  11  repeats the processing in ACT  12 . In this way, the processor  11  waits for the traveling robot  20  to reach the traveling start point  81 . 
     In some cases, the traveling start point  81  of the instructed one traveling route is the standby position of the traveling robot  20  or is the same point as the stop point  82  of the immediately preceding traveling route. In such a case, the processor  11  immediately determines that the traveling robot  20  reaches the traveling start point  81 . 
     If the traveling robot  20  reaches the traveling start point  81  in this way (YES in ACT  12 ), the processor  11  starts clocking (e.g., begins timing, begins recording the passage of time) with a photographing timer provided in the memory  12  (ACT  13 ). 
     The processor  11  determines whether the traveling robot  20  reaches the stop point  82  (ACT  14 ). The traveling robot  20  autonomously travels at constant speed from the traveling start point  81  to the stop point  82 . Upon reaching the stop point  82 , the traveling robot  20  transmits, to the photographing control device  10 , state data including arrival data indicating that the traveling robot  20  has reached the stop point  82 . Therefore, the processor  11  can determine, according to whether the arrival data is received via the robot interface  14 , whether the traveling robot  20  has reached the stop point  82 . 
     If the traveling robot  20  has not yet reached the stop point  82  (NO in ACT  14 ), the processor  11  determines whether a fixed time has elapsed from a clocking start of the photographing timer (ACT  15 ). If the fixed time has not yet elapsed (NO in ACT  15 ), the processor  11  returns to the processing in ACT  14 . 
     If the fixed time has elapsed (YES in ACT  15 ), the processor  11  outputs a photographing instruction (ACT  16 ). The photographing instruction includes photographing instruction data for the camera  40  and illumination control data for the illumination  30 . The processor  11  transmits, with the camera interface  16 , photographing instruction data for causing the camera  40  to perform photographing to the camera  40 . The processor  11  transmits, with the illumination interface  15 , illumination control data for instructing lighting of the plurality of illumination light sources  31  included in the illumination  30  to the illumination  30 . 
     The processor  11  receives, with the camera interface  16 , photographed image data photographed by the camera  40  and temporarily stores the photographed image data in the memory  12  (ACT  17 ). 
     The processor  11  applies image correction processing to the photographed image data temporarily stored in the memory  12  (ACT  18 ).  FIG.  9    is a flowchart illustrating a control procedure of the image correction processing. In the image correction processing, first, the processor  11  applies trapezoidal distortion correction processing to the photographed image data (ACT  181 ). Consequently, the processor  11  functions as a correcting unit that corrects distortion of the photographed image data photographed by the camera  40  and acquires or generates photographed image data equivalent to a case in which the camera  40  faces the second direction and performs photographing. Thereafter, the processor  11  applies light amount unevenness correction processing to the photographed image data after the trapezoidal distortion correction processing (ACT  182 ). The processor  11  ends the image correction processing and returns to the processing in  FIG.  8   . The trapezoidal distortion correction processing and the light amount unevenness correction processing are well-known correction processing. Therefore, explanation thereof is omitted. 
     If the image correction processing is applied to the photographed image data in this way, the processor  11  saves, in the storage  13 , the photographed image data to which the image correction processing is applied (ACT  19 ). 
     Thereafter, the processor  11  once clears the photographing timer (ACT  20 ). The processor  11  starts clocking with the photographing timer anew (ACT  21 ). Thereafter, the processor  11  returns to the processing in ACT  14 . 
     In this way, while the traveling robot  20  autonomously travels along the traveling route at the constant speed, the commodity shelf  70  including the price tag illuminated by the illumination light sources  31  is photographed by the camera  40  at an interval of the fixed time (e.g., a predetermined time interval). The traveling robot  20  travels at the constant speed. Therefore, the camera  40  performs the photographing at every fixed distance. The processor  11  saves a plurality of photographed image data photographed at every fixed distance in the storage  13  after performing image correction. 
     If the photographing is performed by the camera  40  in this way and the traveling robot  20  reaches the stop point  82  (YES in ACT  14 ), the processor  11  clears the photographing timer (ACT  22 ). The operation illustrated in  FIG.  8    is ended. 
     Thereafter, by receiving the photographing start instruction for the photographing apparatus  1 , the processor  11  can perform photographing for the next traveling route. 
     The processor  11  can receive, with the touch panel  50 , via the instruction interface  17 , a selection instruction for photographed image data saved in the storage  13  and an output of the photographed image data to the image recognition device  60 . In this case, the processor  11  transmits the selected photographed image data to the image recognition device  60  with the transmission interface  18 . The image recognition device  60  can recognize, from the transmitted photographed image data, information concerning a photographing target such as price tag information printed on a price tag. 
     In the photographed image data photographed at the interval of the fixed time, in some case, a price tag portion is included in an end position of an image and the entire price tag is not photographed. Accordingly, an interval for photographing the photographed image data is set to an interval for photographing images such that an overlapping portion is included in continuous two photographed image data. The processor  11  may transmit the continuous two photographed image data to the image recognition device  60  after combining the continuous two photographed image data into one photographed image data with well-known image matching processing. 
     [Modification 1] 
     In the first embodiment, the camera  40  and the illumination light sources  31  are linearly disposed along the height direction as illustrated in  FIG.  2   . However, the camera  40  and the illumination light sources  31  may be substantially linearly disposed.  FIG.  10    is a schematic diagram illustrating a disposition example of the camera  40  and the illumination light sources  31  in the first modification.  FIG.  11    is a schematic diagram illustrating a photographing range of the camera  40  with respect to the commodity shelf  70  in the first modification. 
     As illustrated in  FIG.  10   , the camera  40  and the illumination light sources  31  may be apart (e.g., offset from one another) by a distance L in the first direction. The distance L is sufficiently small compared with the photographing width W of the camera  40 . Specifically, the distance L in the first direction is determined as follows:
 
 L≤ 2 ×a  tan(AoV/2−θ)× wd  
 
     where, as illustrated in  FIG.  11   , AoV represents the photographing angle of the camera  40 , wd represents a distance in the second direction between the camera  40  and the price tag presentation surface of the commodity shelf  70 , which is the photographing target object on the photographing optical axis O of the camera  40 , and θ represents a rotation angle in the yaw direction of the camera  40  in a third direction. If the camera  40  and the illumination light sources  31  are disposed at such a distance L, as in the first embodiment, it is possible to prevent the illumination light sources  31  from being reflected in the photographed image data. 
     The illumination light sources  31  need to face, in the first direction, the opposite side of a side that the camera  40  faces. If the illumination light sources  31  are disposed on the same side as the side that the camera  40  faces, the illumination light sources  31  are reflected in the photographed image data. 
     If the camera  40  is arranged right opposed to a price tag of the commodity shelf  70  to perform photographing, the illumination light sources  31  are reflected in photographed image data photographed by the camera  40  unless the illumination light sources  31  are disposed in a place further part from the camera  40  than the photographing width W. If the camera  40  and the illumination light sources  31  are separated by a distance larger than the photographing width W in this way, the entire apparatus is increased in size. 
     On the other hand, in the first modification, the illumination light sources  31  only have to be separated from the camera  40  by the distance L sufficiently smaller than the photographing width W. Therefore, a reduction in the size of the apparatus can be achieved. 
     The distance L is specified from the photographing angle of view AoV, the distance wd in the second direction, and the yaw direction rotation angle θ. The camera  40  and the illumination light sources  31  are disposed at such a distance L. However, substantially linear disposition at any distance L of the camera  40  and the illumination light sources  31  may be determined first. In such a case, all that has to be done is to determine the rotation angle θ in the yaw direction based on the above expression and attach the camera  40  to the traveling robot  20  to form the rotation angle θ. Alternatively, the distance wd in the second direction may be adjusted. 
     [Modification 2] 
       FIG.  12    is a flowchart illustrating a main control procedure of the processor  11  of the photographing control device  10  in a second modification of the first embodiment. The operation of the photographing control device  10  is explained with reference to  FIG.  12   . A procedure and content of the operation explained below are an example. The procedure and the content are not limited if the same result is obtained. 
     The same processing as the processing in the first embodiment is denoted by the same reference signs as the reference signs in  FIG.  8    to omit explanation of the processing. In the second modification, if the traveling robot  20  reaches the traveling start point  81  (YES in ACT  12 ), the processor  11  acquires a reference position of the traveling robot  20  (ACT  31 ). The processor  11  stores the acquired reference position in the memory  12 . The reference position is the position of the traveling start point  81 , for example, a XY coordinate in a map describing the disposition of the commodity shelf  70  and a traveling route of the traveling robot  20  inside the store. 
     As in the first embodiment, in ACT  14 , the processor  11  determines whether the traveling robot  20  has reached the stop point  82 . If the traveling robot  20  has not yet reached the stop point  82  (NO in ACT  14 ), in the second modification, the processor  11  acquires the position of the traveling robot  20  (ACT  32 ). In order to autonomously travel, the traveling robot  20  always measures the position of the traveling robot  20  itself. Therefore, the processor  11  can acquire the position by causing the traveling robot  20  to output the position and receiving the position with the robot interface  14 . Naturally, the processor  11  may acquire the position of the traveling robot  20  by other means such as using a beacon. 
     The processor  11  calculates a difference between the acquired position of the traveling robot  20  and the reference position stored in the memory  12  and determines whether the traveling robot  20  has moved a fixed distance (ACT  33 ) (e.g., a predetermined distance). If the traveling robot  20  has not yet moved the fixed distance (NO in ACT  33 ), the processor  11  returns to the processing in ACT  14 . 
     If the traveling robot  20  has moved the fixed distance (YES in ACT  33 ), the processor  11  proceeds to ACT  16  and outputs a photographing instruction. Thereafter, the processor  11  executes the processing in ACT  17  to ACT  19  explained in the first embodiment. The processor  11  rewrites the reference position of the traveling robot  20  stored in the memory  12  to the position acquired in ACT  32  (ACT  33 ). Thereafter, the processor  11  returns to the processing in ACT  14 . 
     In this way, while the traveling robot  20  autonomously travels in the traveling route at the constant speed, every time the traveling robot  20  travels the fixed distance, the commodity shelf  70  including the price tag illuminated by the illumination light sources  31  is photographed by the camera  40 . By acquiring the photographed image data at every fixed distance in this way, it is possible to perform combination processing for continuous two photographed image data without performing the image matching processing and the like. Although the traveling robot  20  travel at the constant speed, if some obstacle is present, the traveling robot  20  sometimes stops in the position of the obstacle. If the obstacle disappears, the traveling robot  20  starts traveling again. In such a case, it is desirable to perform the photographing at every fixed distance rather than the photographing in every fixed time in the first embodiment. 
     If the photographing is performed by the camera  40  in this way and the traveling robot  20  reaches the stop point  82  (YES in ACT  14 ), the processor  11  clears the photographing timer (ACT  22 ). The processor  11  ends the operation illustrated in  FIG.  8   . 
     The photographing apparatus  1  according to the first embodiment or the modifications explained above includes the traveling robot  20 , which is the moving mechanism that moves in the first direction, the illumination light sources  31  mounted on the traveling robot  20 , and the camera  40  disposed linearly or substantially linearly to the illumination light sources  31  along the height direction and attached to the traveling robot  20  to face the third direction rotated with the height direction as the axis with respect to the second direction orthogonal to the first direction and the height direction and perform photographing. 
     In this way, the camera  40  faces the third direction and performs photographing according to the movement of the traveling robot  20 . Consequently, it is possible to prevent the illumination light sources  31  from being reflected in the photographed image data. 
     The processor  11  corrects distortion of an image photographed by the camera  40  and acquires photographed image data equivalent to a case in which the camera  40  faces the second direction and performs photographing. 
     Consequently, even if the camera  40  faces the third direction and performs photographing, it is possible to acquire the same photographed image data as photographed image data in the case in which the camera  40  faces the second direction and performs photographing. 
     [Second Embodiment] 
       FIG.  13    is a schematic diagram illustrating an attachment state of the camera  40  and the illumination light sources  31  to the traveling robot  20  in the photographing apparatus  1  in a second embodiment.  FIG.  14    is a top plan view of the commodity shelf  70  illustrating a traveling direction of the traveling robot  20  with respect to the commodity shelf  70  in the second embodiment. 
     In the first embodiment and the modifications of the first embodiment, the camera  40  is attached to the traveling robot  20  at the rotation angle θ in the yaw direction with respect to the traveling robot  20 . On the other hand, in the second embodiment, the camera  40  is attached to the traveling robot  20  to face the normal direction of the side surface of the robot body  21 . That is, the attachment section  22  of the traveling robot  20  disposes the camera  40  linearly to the illumination light sources  31  along the height direction and holds the camera  40  to face the second direction orthogonal to the first direction and the height direction, such that the camera  40  faces in the second direction when (a) the traveling robot  20  moves in the first direction parallel to the commodity shelf  70  and (b) the robot body  21  is in a first orientation relative to the first direction. 
     In this case, as the traveling robot  20 , a traveling robot that can move straight forward in the first direction parallel to the commodity shelf  70  while maintaining an orientation in which the robot body  21  is rotated in the yaw direction as illustrated in  FIG.  14    (i.e., while the robot body  21  is in a second orientation relative to the first direction). In such a traveling robot  20  that can move straight forward, for example, omni wheels or mecanum wheels are used. The omni wheels or the mecanum wheels are wheels that do not turn using steering like a general tire but turn using a rotation difference of driving wheels. The omni wheels or the mecanum wheels control a rotation difference of wheels to enable not only movement of the wheels in a rotating direction like a normal tire but also turning and parallel movement in all directions. In the traveling robot  20  in which the omni wheels or the mecanum wheels are used, a moving mechanism is simplified and a reduction in size and a reduction in weight can be expected compared with a tire in which steering or a crawler is used. 
       FIG.  15    is a flowchart illustrating a main control procedure of the processor  11  of the photographing control device  10  in the second embodiment. In the following explanation, the operation of the photographing control device  10  is explained with reference to  FIG.  15   . A procedure and content of the operation explained below are an example. The procedure and the content are not limited if the same result is obtained. 
     The same processing as the processing in the first embodiment is denoted by the same reference signs as the reference signs in  FIG.  8    to omit explanation of the processing. In the second embodiment, first, the processor  11  transmits, with the robot interface  14 , robot rotation start instruction data to the traveling robot  20  (ACT  41 ). The robot rotation start instruction data instructs the traveling robot  20  to rotate at the rotation angle θ in the yaw direction (e.g., from the first orientation in which the camera  40  faces the second direction to the second orientation in which the camera  40  faces the third direction). 
     Thereafter, as in the first embodiment, the processor  11  executes the processing in ACT  11  to ACT  21  and acquires photographed image data with the camera  40  in every fixed time. 
     If the traveling robot  20  reaches the stop point  82  (YES in ACT  14 ), the processor  11  proceeds to ACT  22  and clears the photographing timer. Thereafter, the processor  11  transmits, with the robot interface  14 , robot rotation end instruction data to the traveling robot  20  (ACT  42 ). The robot rotation end instruction data instructs the traveling robot  20  to end the rotation at the rotation angle θ in the yaw direction (e.g., such that the robot body  21  returns to the first orientation). The processor  11  ends the operation illustrated in  FIG.  15   . 
     As explained above, the photographing apparatus  1  having the configuration according to the second embodiment includes the traveling robot  20 , which is the moving mechanism that moves in the first direction, the illumination light sources  31  mounted on the traveling robot  20 , and the camera  40  disposed linearly to the illumination light sources  31  along the height direction and attached to the traveling robot  20  to face the second direction orthogonal to the first direction and the height direction. The traveling robot  20  moves in the first direction in a state in which the traveling robot  20  is rotated such that the camera  40  faces the third direction rotated with the height direction as the axis with respect to the second direction and performs photographing. 
     Even with such a configuration, the camera  40  faces the third direction and performs photographing according to the movement of the traveling robot  20 . Consequently, it is possible to prevent the illumination light sources  31  from being reflected in the photographed image data. 
     In the second embodiment, it goes without saying that modifications same as the first modification and the second modification of the first embodiment can be performed. 
     The embodiments of the photographing apparatus  1  and the photographing method with which the illumination light sources are not reflected in the photographed image data are explained above. However, such embodiments are not limited to this. 
     For example, the photographing target photographed by the camera  40  may be a commodity itself rather than the price tag. The camera  40  faces the third direction and photographs the commodity illuminated by the illumination light sources  31 . Consequently, it is possible to acquire photographed image data in which texture of the commodity is more easily discriminated. 
     The photographing control device  10  and the image recognition device  60  may be incorporated in the robot body  21  of the traveling robot  20 . Consequently, the wireless communication unit can be omitted. The photographing apparatus can be inexpensively configured. 
     Besides, the embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in other various forms. Various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications of the embodiments are included in the scope and the gist of the invention and included in the inventions described in claims and the scope of equivalents of the inventions.