Patent Publication Number: US-11650673-B2

Title: Display control system and display control method for changing a size of an object image in association with a location change of an operation device

Description:
INCORPORATION BY REFERENCE 
     This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Applications No. 2020-068984 filed on Apr. 7, 2020, and No. 2020-068985 filed on Apr. 7, 2020, the entire contents of which are incorporated herein by reference. 
     The present disclosure relates to a display control system and a display control method. 
     BACKGROUND 
     Conventionally, there has been proposed a system in which a computer graphics (CG) image of an object to be viewed is presented on a display device in accordance with the movement of a replica (model, doll) that imitates the shape of the object to be viewed created as CG data. According to this system, it is possible to present an image viewed from any direction that the viewer desires to see on the display device. 
     However, although the conventional system can change the orientation of the CG image on the display device in association with the movement of the replica, it is difficult to present detailed information (cross-section information, description, explanation, and the like) relating to the object to be viewed to the viewer in association with the movement of the replica. In particular, when the object to be viewed is an art object or the like, it is desirable that detailed information relating to the art object can be presented to the viewer. 
     SUMMARY 
     An object of the present disclosure is to provide a display control system which changes the orientation of an object image of an operation object displayed on a display device in association with the orientation change of an operation device, and which can display detailed information of the operation object, and a display control method thereof. 
     A display control system according to an aspect of the present disclosure changes an orientation of an object image of an operation object displayed on a display device in association with an orientation change of an operation device, and includes a cross-section display which, when the operation device moves in a direction away from the display device and overlaps a virtual plane at a position separated from the display device by a predetermined distance, causes the display device to display the object image comprising a cut plane obtained by cutting the operation device at the virtual plane. 
     Further, a display control system according to an aspect of the present disclosure changes an orientation of an object image of an operation object displayed on a display device in association with an orientation change of an operation device, and incudes a marker detector that detects a marker set at a specific position on the object image, and an information presenter that, when the marker is detected by the marker detector, presents specific information associated with the detected marker. 
     A display control method according to another aspect of the present disclosure changes an orientation of an object image of an operation object displayed on a display device in association with an orientation change of an operation device, and when the operation device moves in a direction away from the display device and overlaps a virtual plane at a position separated from the display device by a predetermined distance, executes by one or more processors to cause the display device to display the object image including a cut plane obtained by cutting the operation device at the virtual plane. 
     Further, a display control method according to another embodiment of the present disclosure changes an orientation of an object image of an operation object displayed on a display device in association with an orientation change of an operation device, detects a marker set at a specific position of the object image, and presents, when the marker is detected, specific information associated with the detected marker, wherein detecting the marker and presenting the specific information are executed by one or more processors. 
     A recording medium according to another aspect of the present disclosure stores a program executed by one or more processors to, in a display control method that changes an orientation of an object image of an operation object displayed on a display device in association with an orientation change of an operation device, when the operation device moves in a direction away from the display device and overlaps a virtual plane at a position separated from the display device by a predetermined distance, cause the display device to display the object image including a cut plane obtained by cutting the operation device at the virtual plane. 
     Further, a recording medium according to another embodiment of the present disclosure stores a program executed by one or more processors to, in a display control method that changes an orientation of an object image of an operation object displayed on a display device in association with an orientation change of an operation device, detect a marker set at a specific position of the object image, and present, when the marker is detected, specific information associated with the detected marker. 
     According to the present disclosure, in a display control system that changes the orientation of an object image of an operation object displayed on a display device in association with the orientation change of an operation device, it is possible to display detailed information of the operation object. 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description with reference where appropriate to the accompanying drawings. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram illustrating a configuration of a display control system according to an embodiment of the present disclosure. 
         FIG.  2    is a block diagram illustrating the configuration of the display control system according to the embodiment of the present disclosure. 
         FIG.  3    is a view illustrating an appearance of an operation device according to the embodiment of the present disclosure. 
         FIG.  4 A  is a view illustrating an example of a method for setting a facing orientation of the operation device according to an embodiment of the present disclosure. 
         FIG.  4 B  is a view illustrating an example of the method for setting the facing orientation of the operation device according to the embodiment of the present disclosure. 
         FIG.  4 C  is a view illustrating an example of the method for setting the facing orientation of the operation device according to the embodiment of the present disclosure. 
         FIG.  5    is a view illustrating an example of an object image displayed on a display device according to the embodiment of the present disclosure. 
         FIG.  6    is a view illustrating an example of the object image displayed on the display device according to the embodiment of the present disclosure. 
         FIG.  7    is a view illustrating an example of a marker of the object image displayed on the display device according to the embodiment of the present disclosure. 
         FIG.  8    is a view illustrating an example of the object image displayed on the display device according to the embodiment of the present disclosure. 
         FIG.  9    is a view illustrating an example of the object image displayed on the display device according to the embodiment of the present disclosure. 
         FIG.  10    is a view for explaining a cross-section display mode in the display control system according to the embodiment of the present disclosure. 
         FIG.  11    is a view illustrating an example of the object image displayed on the display device according to the embodiment of the present disclosure. 
         FIG.  12    is a flowchart illustrating an example of a procedure of display control processing executed by the operation device according to the embodiment of the present disclosure. 
         FIG.  13    is a view illustrating a relative position between the operation device and the user in the display control system according to the embodiment of the present disclosure. 
         FIG.  14    is a view illustrating an appearance of the operation device according to the embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure will now be described with reference to the accompanying drawings for the purpose of understanding the present disclosure. It should be noted that the following embodiments are examples that embody the present disclosure, and do not limit the technical scope of the present disclosure. 
     Display Control System  100   
     As illustrated in  FIGS.  1  and  2   , a display control system  100  according to an embodiment of the present disclosure includes an operation device  1  and a display device  2 . The operation device  1  and the display device  2  can communicate with each other via a communication network N 1  such as a wireless local area network (LAN) or a wired LAN. The operation device  1  is an example of an operation device of the present disclosure, and the display device  2  is an example of a display device of the present disclosure. 
     The display control system  100  can change the orientation (posture or attitude) of an object image  3  of an operation object displayed on the display device  2  in association with the orientation change of the operation device  1  having a shape simulating the operation object. For example, the operation object is an art object, the object image  3  is a three-dimensional image of the art object, and the operation device  1  is a replica (model) of the art object. In the present embodiment, a pottery tea bowl will be described as an example of the art object. The operation device  1  is, for example, a replica having the same material, shape, size, weight, texture, or the like as the tea bowl. 
     For example, as illustrated in  FIG.  1   , when a user (viewer) holds and rotates the operation device  1  (replica of the tea bowl) in the D 1  direction, the display control system  100  rotates the object image  3  displayed on the display device  2  in the D 1  direction according to the user&#39;s operation. Further, for example, when the user holds and rotates the operation device  1  in the D 2  direction, the display control system  100  rotates the object image  3  in the D 2  direction according to the user&#39;s operation. Further, for example, when the user extends her or his arm while holding the operation device  1  to move the operation device  1  in a direction away from her or his face (rear side), that is, when the user brings the operation device  1  closer to the display device  2  side, the display control system  100  displays the object image  3  with a reduced size on the display device  2 . Furthermore, for example, when the user folds her or his arm while holding the operation device  1  to move the operation device  1  in a direction closer to her or his face (front side), that is, when the user moves the operation device  1  away from the display device  2 , the display control system  100  displays the object image  3  with an enlarged size on the display device  2 . 
     As described above, the operation device  1  is a controller capable of changing the orientation of the object image  3  displayed on the display device  2  according to the operation of the user. The art object (for example, a tea bowl) is an example of an operation object according to the present disclosure. Further, the object image  3  is an example of an object image of the present disclosure. 
     In the present embodiment, the display control system  100  corresponds to a display control system according to the present disclosure, but the display control system according to the present disclosure may be realized by the operation device  1  alone or the display device  2  alone. 
     Operation Device  1   
     As illustrated in  FIG.  2   , the operation device  1  includes a controller  11 , a storage  12 , an orientation detection sensor  13 , a communicator  14 , and the like. Various processing executed by the operation device  1  may be executed by one or more processors in a distributed manner.  FIG.  3    illustrates an external view of the operation device  1 . In the present embodiment, the operation device  1  is a replica of a tea bowl. 
     The communicator  14  is a communication interface for connecting the operation device  1  to the communication network N 1  by wire or wirelessly and executing data communication according to a predetermined communication protocol with an external device such as the display device  2  via the communication network N 1 . 
     The orientation detection sensor  13  is a sensor for detecting the orientation of the operation device  1 , and includes a gyro sensor, an acceleration sensor, a geomagnetic sensor, and the like. For example, the orientation detection sensor  13  detects an orientation change such as the rotation or inclination of the operation device  1 , and outputs a detection signal to the controller  11 . The orientation detection sensor  13  is mounted on the operation device  1 . In the present embodiment, for example, as illustrated in  FIG.  3   , the orientation detection sensor  13  is fixed to the bottom portion inside the tea bowl. Note that the orientation detection sensor  13  may be covered with a lid so as not to be seen from the outside, or may be built in the operation device  1 . 
     The storage  12  is a non-volatile storage such as a hard disk drive (HDD), a solid state drive (SSD) or a flash memory for storing various kinds of information. The storage  12  stores a control program such as a display control program for causing the controller  11  to execute display control processing (see  FIG.  12   ) to be described later. For example, the display control program is non-temporarily recorded on a computer-readable recording medium such as a universal serial bus (USB), a compact disc (CD) or a digital versatile disc (DVD). Then, the display control program is read by a reading device (not illustrated) such as a USB drive, a CD drive or a DVD drive electrically connected to the operation device  1 , and then is stored in the storage  12 . Further, the display control program may be downloaded from a server accessible from the operation device  1 , and then stored in the storage  12 . 
     The controller  11  includes control devices such as a central processor unit (CPU), a read only memory (ROM) and a random access memory (RAM). The CPU is a processor for executing various kinds of arithmetic processing. The ROM is a non-volatile storage in which control programs such as a basic input output system (BIOS) and an operation system (OS) for causing the CPU to execute various arithmetic operations are stored in advance. The RAM is a volatile or non-volatile storage for storing various kinds of information, and is used as a temporary storage memory (work area) for various kinds of processing executed by the CPU. Then, the controller  11  controls the operation device  1  by executing various control programs stored in advance in the ROM or the storage  12  by the CPU. 
     Specifically, as illustrated in  FIG.  2   , the controller  11  includes various types of processors such as an orientation setter  111  and an orientation detector  112 . Note that the controller  11  functions as the orientation setter  111  and the orientation detector  112  by executing various processing according to the display control program by the CPU. Further, a part or all of the processors in the controller  11  may be configured by an electronic circuit. Note that the display control program may be a program for causing a plurality of processors to function as the various types of processors. 
     The orientation setter  111  sets the orientation of the operation device  1  to the facing orientation in which the operation device  1  faces the user. Specifically, the orientation setter  111  registers the orientation (facing orientation) of the operation device  1  at the position where the user faces the operation device  1 , that is, at the position where the user places at the front of the operation device  1 . For example, the orientation setter  111  acquires and registers the coordinates and the inclination of the operation device  1  in the X, Y and Z directions in the facing orientation from the orientation detection sensor  13 . 
     For example, the orientation setter  111  may use a geomagnetic sensor (compass) provided on the operation device  1  to set the facing orientation. For example, as illustrated in  FIG.  4 A , the display device  2  is positioned in advance so as to face a predetermined direction A, and the operation device  1  is placed at the front of the display device  2  for a predetermined time (for example, five seconds). Then, the orientation setter  111  calculates the front direction of the operation device  1  with respect to the display device  2  based on the relative relationship between the direction A of the display device  2  and a direction B (N pole) of the geomagnetic sensor. As a result, the orientation setter  111  sets the orientation of the operation device  1  to the facing orientation. 
     Further, for example, the orientation setter  111  may use a geomagnetic sensor (compass) provided on the operation device  1  and a magnet Mg disposed in front of the display device  2  to set the facing orientation. For example, as illustrated in  FIG.  4 B , the magnet Mg is arranged in front of the display device  2 , and the operation device  1  is placed in front of the magnet Mg for a predetermined time (for example, five seconds). Then, the geomagnetic sensor detects the direction of the magnet Mg, and the orientation setter  111  calculates the front direction of the operation device  1  with respect to the display device  2  based on the direction detected by the geomagnetic sensor. As a result, the orientation setter  111  sets the orientation of the operation device  1  to the facing orientation. 
     Further, for example, the orientation setter  111  may use an acceleration sensor provided on the operation device  1  to set the facing orientation. For example, as illustrated in  FIG.  4 C , an inclined table T, which is inclined by an angle d (for example, five degrees) toward the display device  2 , is installed in front of the display device  2 , and the operation device  1  is placed on the inclined table T for a predetermined time (for example, five seconds). Note that the dotted line in  FIG.  4 C  represents the position of the horizontal table. Then, the acceleration sensor detects acceleration in the X-axis, Y-axis, and Z-axis, and the orientation setter  111  calculates the front direction of the operation device  1  with respect to the display device  2  based on each acceleration detected by the acceleration sensor. As a result, the orientation setter  111  sets the orientation of the operation device  1  to the facing orientation. 
     Further, for example, the orientation setter  111  may set the orientation of the operation device  1  when the user presses a calibration button (not illustrated) provided on the operation device  1  to the facing orientation. For example, the user grips and positions the operation device  1  so that the operation device  1  faces the front direction of the user. Note that the terms “hold” and “grip” are interchangeable. Thereafter, when the user presses the calibration button, the orientation setter  111  sets the orientation of the operation device  1  at that time to the facing orientation. Note that the function of the calibration button may be replaced with a predetermined operation to the operation device  1 . For example, when the user positions the operation device  1  and then shakes the operation device  1  in a predetermined direction, the orientation setter  111  sets the orientation of the operation device  1  at that time to the facing orientation. 
     Further, for example, the orientation setter  111  may set the facing orientation by using a camera (not illustrated) provided in the operation device  1 . For example, the camera images the user and the surrounding environment such as the ceiling, floor and wall around the user, and the orientation setter  111  calculates the front direction of the operation device  1  with respect to the display device  2  based on the captured image acquired from the camera. As a result, the orientation setter  111  sets the orientation of the operation device  1  to the facing orientation. 
     As described above, the orientation setter  111  can set the front direction (facing orientation) of the operation device  1  by various methods. Further, the orientation setter  111  can set the facing orientation every time the user places the operation device  1  at a predetermined position. Note that when the front, back or other orientation is set to the operation device  1  itself, the orientation setter  111  sets the facing orientation in consideration of the orientation of the operation device  1 . For example, when the operation device  1  is placed at a predetermined position so as to face the user side (the front side of the display device  2 ), the orientation setter  111  sets the facing orientation. As a result, the display device  2  can display the object image  3  so that the object image  3  faces the user side (the front side of the display device  2 ). Further, the orientation setter  111  may detect the orientation of the operation device  1  placed at a predetermined position, and set the facing orientation. In this case, the display device  2  displays the object image  3  so that the orientation of the object image  3  is the same as the orientation of the operation device  1 . 
     When the user changes the orientation of the operation device  1 , the orientation detector  112  detects the orientation change of the operation device  1 . Specifically, the orientation detector  112  detects the orientation change of the operation device  1  based on the detection signal acquired from the orientation detection sensor  13 . The orientation detector  112  is an example of an orientation detector of the present disclosure. 
     For example, as illustrated in  FIG.  1   , when the user desires to change the orientation of the object image  3  displayed on the display device  2 , the user holds and rotates the operation device  1  in the right direction D 1  or the left direction D 2 . In this case, the orientation detector  112  detects the orientation change (right rotation or left rotation) of the operation device  1  based on the detection signal acquired from the orientation detection sensor  13 . 
     Further, for example, as illustrated in  FIG.  1   , when the user desires to change the size (display magnification) of the object image  3  displayed on the display device  2  (for example, desires to enlarge the object image  3 ), the user holds and moves the operation device  1  to the front side. In this case, the orientation detector  112  detects the orientation change (movement toward the front side) of the operation device  1  based on the detection signal acquired from the orientation detection sensor  13 . 
     When the orientation detector  112  detects the orientation change of the operation device  1 , the orientation detector  112  outputs information (orientation information) corresponding to the orientation change from the facing orientation to the display device  2 . The orientation information includes information such as a rotation angle, a tilt angle, a coordinate, and a display magnification (enlargement ratio, reduction ratio). 
     Display Device  2   
     As illustrated in  FIG.  2   , the display device  2  includes a controller  21 , a storage  22 , a display  23 , a position detection sensor  24 , a communicator  25 , and the like. The display device  2  may be an information processing device such as a personal computer, for example. 
     The communicator  25  is a communication interface for connecting the display device  2  to the communication network N 1  by wire or wirelessly and executing data communication according to a predetermined communication protocol with an external device such as the operation device  1  through the communication network N 1 . 
     The position detection sensor  24  detects the position of the operation device  1  with respect to the display device  2 . Specifically, the position detection sensor  24  detects the position (X, Y and Z coordinates) of the operation device  1  with the installation location of the position detection sensor  24  as a reference (coordinate origin), for example. For example, the position detection sensor  24  detects the distance and position to the operation device  1  by irradiating infrared rays to the operation device  1  and detecting the reflected light from the operation device  1 . Note that the position detection sensor  24  may be a camera. In this case, the position detection sensor  24  detects the distance and position to the operation device  1  based on the image captured by the camera. The position detection sensor  24  may be provided outside the display device  2 . For example, the position detection sensor  24  may be provided on the ceiling or wall of the room where the operation device  1  and the display device  2  are installed. 
     The display  23  is a liquid crystal display or an organic electro luminescence (EL) display for displaying various kinds of information. The display  23  displays, for example, the object image  3 . Note that the display device  2  may include an operator (not illustrated) such as a mouse, a keyboard, or a touch panel for receiving various operations. 
     The storage  22  is a non-volatile storage such as an HDD, an SSD, or a flash memory for storing various kinds of information. Data (three-dimensional image data) of the object image  3  displayed on the display  23  is stored in the storage  22 . 
     Further, a control program such as a display control program for causing the controller  21  to execute display control processing (see  FIG.  12   ) to be described later is stored in the storage  22 . For example, the display control program is non-temporarily recorded on a computer-readable recording medium such as an USB, a CD, or a DVD. Then, the display control program is read by a reading device (not illustrated) such as a USB drive, a CD drive or a DVD drive electrically connected to the display device  2 , and is then stored in the storage  22 . Further, the display control program may be downloaded from a server accessible from the display device  2  and then stored in the storage  22 . 
     The controller  21  includes control devices such as a CPU, a ROM, and a RAM. The CPU is a processor for executing various kinds of arithmetic processing. The ROM is a non-volatile storage in which control programs such as a BIOS and an OS for causing the CPU to execute various processing are stored in advance. The RAM is a volatile or non-volatile storage for storing various kinds of information, and is used as a temporary storage memory (work area) for various kinds of processing executed by the CPU. Then, the controller  21  controls the display device  2  by executing various control programs stored in the ROM or the storage  22  in advance by the CPU. 
     Specifically, as illustrated in  FIG.  2   , the controller  21  includes various types of processors such as a display processor  211 , an orientation controller  212 , a marker detector  213 , an information presenter  214 , and a cross-section display  215 . Note that the controller  21  functions as the display processor  211 , the orientation controller  212 , the marker detector  213 , the information presenter  214 , and the cross-section display  215  by executing various processing according to the display control program by the CPU. Further, a part or all of the processors in the controller  21  may be configured by an electronic circuit. Note that the display control program may be a program for causing a plurality of processors to function as the various types of processors. 
     The display processor  211  causes the display  23  to display various kinds of information. For example, the display processor  211  causes the display  23  to display the object image  3  (see  FIG.  1   ). 
     The orientation controller  212  receives the orientation information from the operation device  1 , and executes processing corresponding to the orientation information on the object image  3  displayed on the display  23 . Specifically, the orientation controller  212  changes the orientation of the object image  3  in accordance with the orientation change of the operation device  1 . The orientation controller  212  changes the orientation of the object image  3 , based on the rotation angle of the operation device  1  corresponding to the orientation change of the operation device  1  and the position of the operation device  1  with respect to the display device  2 . The orientation controller  212  is an example of an orientation controller of the present disclosure. 
     For example, when the user moves the operation device  1 , the orientation detector  112  of the operation device  1  outputs orientation information including information such as a rotation angle, a tilt angle, coordinates, and a display magnification acquired from the orientation detection sensor  13  to the display device  2 . When the orientation controller  212  receives the orientation information, the orientation controller  212  changes the rotation angle, the tilt angle, the coordinates, the display magnification, and the like of the object image  3  based on the orientation information. Note that when the front, back or other orientation is set to the operation device  1  itself, the orientation controller  212  changes the rotation angle, the tilt angle, the coordinates, the display magnification, and the like of the object image  3  in a state where the orientation of the operation device  1  matches the orientation of the object image  3 . Further, the orientation controller  212  may calculate the display coordinates and the display magnification of the object image  3  based on the detection signal from the position detection sensor  24 . 
     For example, as illustrated in  FIG.  5   , when the user moves the operation device  1  to the front side so as to bring the operation device  1  closer to her or his face, the orientation controller  212  calculates the enlargement ratio corresponding to the movement amount, and changes (enlarges) the display magnification of the object image  3 . Further, for example, as illustrated in  FIG.  6   , when the user moves the operation device  1  to the rear side so as to move the operation device  1  away from her or his face, the orientation controller  212  calculates the reduction ratio corresponding to the movement amount, and changes (reduces) the display magnification of the object image  3 . 
     The orientation controller  212  controls the orientation (display state) of the object image  3  displayed on the display  23  so that the orientation of the object image  3  matches the orientation of the operation device  1  visible to the user. Therefore, for example, when the user turns the bottom of the tea bowl (operation device  1 ) toward the user herself or himself, the orientation controller  212  rotates the tea bowl of the object image  3  so that the bottom of the tea bowl faces the user. 
     Note that the orientation controller  212  may also have the function of the orientation detector  112  of the operation device  1 . In this case, the orientation detector  112  may be omitted from the operation device  1 . 
     The marker detector  213  detects a marker M set at a specific position of the object image  3 . For example, as illustrated in  FIG.  7   , a plurality of markers M 1 , M 2  and M 3  are set on the object image  3  at each predetermined specific position. The number of markers M is not necessarily limited to plural, and may be one. For example, an exhibitor who exhibits a tea bowl at an exhibition sets a marker M at a characteristic portion of the tea bowl. Each marker M is displayed on the display device  2  so as to be distinguishable from the object image  3 . For example, the marker M is displayed by lighting or blinking on the display device  2 . 
     Specifically, the marker detector  213  detects the marker M when the marker M faces the front direction of the display device  2  by changing of the orientation of the object image  3  according to the orientation change of the operation device  1 . For example, as illustrated in  FIG.  8   , the user rotates the operation device  1  so that the marker M 1  of the object image  3  displayed on the display device  2  faces the front direction. When the object image  3  rotates in association with the rotation of the operation device  1  and the orientation of the marker M 1  coincides with the front direction, specifically, when the direction perpendicular to the portion (surface) of the object image  3  to which the marker M 1  is attached matches the direction perpendicular to the display surface of the display  23 , the marker detector  213  detects the marker M 1 . 
     When the marker detector  213  detects the marker M, the information presenter  214  presents the specific information associated with the specific position. For example, in the example illustrated in  FIG.  8   , when the marker detector  213  detects the marker M 1 , the information presenter  214  displays specific information C 1  associated with the marker M 1  on the display  23 . Similarly, when the marker detector  213  detects the marker M 2 , the information presenter  214  displays specific information C 2  associated with the marker M 2  on the display  23 . Further, when the marker detector  213  detects the marker M 3 , the information presenter  214  displays specific information C 3  associated with the marker M 3  on the display  23 . The specific information C 1 , C 2  and C 3  are, for example, information such as descriptions and explanations about the tea bowl, and register different information. The specific information C may be text information. Further, the specific information C may be image information such as a photograph or an illustration. Each marker M and each specific information C are stored in the storage  22  in association with each other. 
     Each time the marker detector  213  detects the marker M, the information presenter  214  presents the corresponding specific information C. 
     Here, when the marker detector  213  detects the marker M, the marker detector  213  may register information indicating that the marker M has been detected in the storage  22 . For example, the marker detector  213  registers the detection status indicating “detected” and “undetected” for each marker M. The marker detector  213  does not re-detect the detected marker M. Therefore, when the marker M is detected once and the information presenter  214  presents the corresponding specific information C, the specific information C is not re-presented. When the marker detector  213  detects the marker M, the marker detector  213  may delete the detected marker M from the object image  3 . When the operation device  1  is placed at a predetermined position, the marker detector  213  resets the detection status. According to this configuration, for example, when the user A appreciates a tea bowl and views all of the specific information C 1 , C 2  and C 3 , the specific information C 1 , C 2  and C 3  are not re-presented to the user A. Thereafter, when the user A returns the operation device  1  to the predetermined position, and the user B starts to appreciate the tea bowl, the specific information C 1 , C 2  and C 3  are presented. 
     Note that the information presenter  214  may output the specific information C by voice. For example, when the marker detector  213  detects the marker M 1 , the information presenter  214  causes a speaker (not illustrated) to output the text information of the specific information C 1  associated with the marker M 1  by voice. The speaker may be provided on the display device  2  or the operation device  1 . 
     Further, the marker M may be displayed only on the object image  3 , on both the object image  3  and the operation device  1 , or only on the operation device  1 . 
     When the operation device  1  moves in a direction away from the display device  2  so that the operation device  1  overlaps a virtual plane S 1  at a position separated from the display device  2  by a predetermined distance L 1 , the cross-section display  215  causes the display  23  to display the object image  3  including a cut plane obtained by cutting the operation device at the virtual plane S 1 . Specifically, first, as illustrated in  FIG.  9   , the controller  21  sets the virtual plane S 1  at a position separated by the predetermined distance L 1 . The predetermined distance L 1  is preset by an administrator or the like and can be changed as appropriate. The predetermined distance L 1  is registered in the storage  22 . The controller  21  identifies the position of the operation device  1  based on the detection result of the position detection sensor  24 , and displays the cross section of the object image  3  when the operation device  1  exceeds the predetermined distance L 1 . Note that the dotted line of the operation device  1  illustrated in  FIG.  9    represents the cutting position by the virtual plane S 1 . The cross-section display  215  is an example of a cross-section display of the present disclosure. 
     For example, when all the markers M set on the object image  3  are detected, and all the specific information C is presented, the controller  21  enables a cross-section display mode in which the cross-section of the object image  3  can be displayed. While the cross-section display mode is disabled, the controller  21  changes the display magnification of the object image  3  in accordance with the movement of the operation device  1  (see  FIGS.  5  and  6   ). 
     When the cross-section display mode is enabled, as illustrated in  FIG.  10   , the controller  21  changes the display magnification of the object image  3  when the operation device  1  moves within the range of the predetermined distance L 1  from the display device  2 , and displays the cross section of the object image  3  when the operation device  1  exceeds the range of the predetermined distance L 1  from the display device  2  so that the operation device  1  overlaps the virtual plane S 1 . For example, within the range of the predetermined distance L 1 , the orientation controller  212  displays the object image  3  with a reduced size when the operation device  1  approaches the display device  2 , and displays the object image  3  with an enlarged size when the operation device  1  moves away from the display device  2 . On the other hand, when the distance exceeds the range of the predetermined distance L 1 , the cross-section display  215  causes the display  23  to display the object image  3  including the cut plane obtained by cutting the operation device  1  at the virtual plane S 1 . Further, when the distance exceeds the range of the predetermined distance L 1 , the orientation controller  212  displays the object image  3  at a preset magnification. That is, when the distance exceeds the range of the predetermined distance L 1 , the orientation controller  212  changes the cutting position of the object image  3  in accordance with the movement of the operation device  1  and does not change the display magnification. 
     Further, when the virtual plane S 1  cuts a predetermined position of the operation device  1 , the information presenter  214  may present specific information C 4  associated with the predetermined position. For example, as illustrated in  FIG.  11   , when the virtual plane S 1  cuts an intermediate position of the operation device  1 , the cross-section display  215  displays the object image  3  including the cross section cut at the intermediate position, and the information presenter  214  presents the specific information C 4  associated with the intermediate position. Note that when the virtual plane S 1  overlaps the marker M described above (see  FIG.  7   ), the information presenter  214  may present the specific information C associated with the marker M. The information presenter  214  is an example of an information presenter of the present disclosure. 
     Display Control Processing 
     Next, display control processing executed in the display control system  100  will be described with reference to  FIG.  12   . Specifically, in the present embodiment, the display control processing is executed by the controller  11  of the operation device  1  and the controller  21  of the display device  2 . Note that the controllers  11  and  21  may terminate the display control processing in the middle by a predetermined operation of the operation device  1  or the display device  2 . 
     Note that the present disclosure can be regarded as a disclosure of a display control method (an example of a display control method of the present disclosure) for executing one or a plurality of steps included in the display control processing. Further, one or a plurality of steps included in the display control processing described herein may be appropriately omitted. It should be noted that each step in the display control processing may be executed in a different order within a range in which the similar effect is produced. Furthermore, although the case where the controllers  11  and  21  execute the respective steps in the display control processing will be described as an example, a display control method in which a plurality of processors execute the respective steps in the display control processing in a distributed manner is also considered as another embodiment. 
     Here, the operation device  1  can operate the object image  3  displayed on the display device  2  by activating a dedicated application. 
     First, in step S 1 , the controller  11  of the operation device  1  determines whether the orientation of the operation device  1  is set to the facing orientation (front direction). Specifically, the controller  11  activates the dedicated application, and sets the orientation of the operation device  1  at the position which is the front of the operation device  1  to the facing orientation. 
     The controller  11  sets the facing orientation based on the position coordinates and the inclination acquired from the orientation detection sensor  13 . For example, when the operation device  1  is placed at a predetermined position, the controller  11  sets the facing orientation. 
     When the operation device  1  is set to the facing orientation (S 1 : Yes), the processing proceeds to step S 2 . The controller  11  waits until the operation device  1  is set to the facing orientation (S 1 : No). 
     In step S 2 , the controller  21  of the display device  2  causes the display  23  to display the object image  3  in a predetermined direction corresponding to the facing orientation. 
     In step S 3 , the controller  11  of the operation device  1  starts accepting an operation from the user to the operation device  1 . Thus, the user (viewer) can operate the object image  3  using the operation device  1 . 
     In step S 4 , the controller  11  of the operation device  1  determines whether the orientation change of the operation device  1  has been detected. Specifically, the controller  11  detects the presence or absence of the orientation change of the operation device  1  based on the detection signal acquired from the orientation detection sensor  13 . For example, as illustrated in  FIG.  1   , when the user rotates the operation device  1  in the right direction D 1 , the controller  11  detects the orientation change (right rotation) of the operation device  1  based on the detection signal acquired from the orientation detection sensor  13 . Further, for example, as illustrated in  FIG.  5   , when the user moves the operation device  1  to the front side, the controller  11  detects the orientation change (position change) of the operation device  1  based on the detection signal acquired from the orientation detection sensor  13 . When the controller  11  detects the orientation change of the operation device  1  (S 4 : Yes), the processing proceeds to step S 5 . The controller  11  waits until the orientation change of the operation device  1  is detected (S 4 : No). Step S 4  is an example of an orientation detection step of the present disclosure. 
     In step S 5 , the controller  21  of the display device  2  changes the orientation of the object image  3  displayed on the display device  2  according to the orientation change of the operation device  1 . Specifically, the controller  11  of the operation device  1  outputs the orientation information including the rotation angle, the tilt angle, the coordinates, the display magnification, and the like acquired from the orientation detection sensor  13  to the display device  2 . When the controller  21  of the display device  2  receives the orientation information, the controller  21  of the display device  2  changes the rotation angle, the tilt angle, the coordinates, the display magnification, and the like of the object image  3  based on the orientation information (see  FIGS.  5  and  6   ). Step S 5  is an example of an orientation control step of the present disclosure. 
     In step S 6 , the controller  21  of the display device  2  determines whether a marker M set at the specific position of the object image  3  has been detected. For example, when three markers M 1 , M 2  and M 3  are set on the object image  3  (see  FIG.  7   ), the controller  21  determines whether any one marker M has been detected. When the controller  21  detects a marker M (S 6 : Yes), the processing proceeds to step S 7 . When the controller  21  does not detect any marker M (S 6 : No), the processing returns to step S 4 . Step S 6  is an example of a marker detection step of the present disclosure. 
     In step S 7 , the controller  21  of the display device  2  determines whether all the markers M have been detected. For example, the controller  21  determines whether all the markers M 1 , M 2  and M 3  set on the object image  3  have been detected by referring to the detection status of the storage  22 . When the controller  21  has not detected all the markers M (S 7 : No), the processing proceeds to step S 8 . On the other hand, when the controller  21  has detected all the markers M (S 7 : Yes), the processing proceeds to step S 9 . 
     In step S 8 , the controller  21  presents the specific information C associated with the detected marker M. For example, when the controller  21  detects the marker M 1 , the controller  21  displays the specific information C 1  associated with the marker M 1  on the display  23  (see  FIG.  8   ). Step S 8  is an example of an information presentation step of the present disclosure. 
     In step S 9 , the controller  21  presents the specific information C associated with the detected marker M as in step S 8 . In step S 9 , the controller  21  presents the specific information C associated with the marker M detected last among the plural markers M set on the object image  3 . By repeating steps S 4  to S 8 , all of the specific information C 1  associated with the marker M 1 , the specific information C 2  associated with the marker M 2 , and the specific information C 3  associated with the marker M 3  are sequentially presented to the user. When all the markers M are detected and all the specific information C is presented, the processing proceeds to step S 10 . 
     In step S 10 , the controller  21  enables the cross-section display mode. When the cross-section display mode is enabled, the controller  21  displays the cross-section of the object image  3  on the display  23  when the following conditions are satisfied. 
     In step S 11 , the controller  11  of the operation device  1  determines whether the orientation change of the operation device  1  has been detected. For example, as illustrated in  FIG.  5   , when the user moves the operation device  1  to the front side, the controller  11  detects the orientation change (position change) of the operation device  1  based on the detection signal acquired from the orientation detection sensor  13 . When the controller  11  detects the orientation change of the operation device  1  (S 11 : Yes), the processing proceeds to step S 12 . When the controller  11  does not detect the orientation change of the operation device  1  (S 11 : No), the processing proceeds to step S 15 . 
     In step S 12 , the controller  21  of the display device  2  determines whether the operation device  1  exceeds the virtual plane S 1  (or whether the operation device  1  overlaps the virtual plane S 1 ). Specifically, the controller  21  specifies the position of the operation device  1  based on the detection result of the position detection sensor  24 , and determines whether the tip of the operation device  1  exceeds the predetermined distance L 1  from the display device  2 . When the operation device  1  does not exceed the virtual plane S 1  (S 12 : No), the processing proceeds to step S 13 . On the other hand, when the operation device  1  exceeds the virtual plane S 1  (S 12 : Yes), the processing proceeds to step S 14 . 
     In step S 13 , the controller  21  of the display device  2  changes the orientation of the object image  3  displayed on the display device  2  according to the orientation change of the operation device  1 . In this case, since the operation device  1  moves to, for example, the rear side or the front side within the range of the predetermined distance L 1 , the controller  21  displays the object image  3  with a reduced size when the operation device  1  approaches the display device  2 , and displays the object image  3  with an enlarged size when the operation device  1  moves away from the display device  2 . Thereafter, the processing returns to step S 11 . When the operation device  1  changes its orientation within the range of the predetermined distance L 1 , the processing of steps S 11  to S 13  is repeated. Step S 13  is an example of an orientation control step of the present disclosure. 
     On the other hand, in step S 14 , the controller  21  causes the display  23  to display the object image  3  including the cut plane obtained by cutting the operation device  1  at the virtual plane S 1  (see  FIGS.  9  and  11   ). In this case, the controller  21  changes the cutting position to display the cross section of the object image  3  without changing the display magnification of the object image  3  in accordance with the movement of the operation device  1 . Step S 14  is an example of a cross-section display step of the present disclosure. 
     In step S 15 , the controller  21  determines whether the termination operation has been received from the user. For example, when the user places the operation device  1  at a predetermined place, the controller  21  determines that the termination operation has been received. When the controller  21  receives the termination operation (S 15 : Yes), the controller  21  ends the display control processing. The controller  21  repeats the processing of steps S 11  to S 14  until the termination operation is received (S 15 : No). 
     Note that, in the display control processing, when the predetermined position of the operation device  1  exceeds the virtual plane S 1 , that is, when the virtual plane S 1  cuts off the predetermined position of the operation device  1 , the controller  21  may present the specific information C 4  associated with the predetermined position (see  FIG.  11   ). The predetermined position may be an intermediate position of the operation device  1  or a position where the marker M (see  FIG.  7   ) is provided. As described above, the controller  11  executes the display control processing. 
     Here, the display control system  100  may terminate the display control processing when a predetermined period of time has elapsed from the setting (step S 1 ) of the facing orientation of the operation device  1 . Thus, for example, when a plurality of viewers sequentially view an art object, each viewer can equally appreciate the art object. Further, the display control system  100  may terminate the display control processing when a predetermined period of time has elapsed since all the markers M have been detected (step S 7 ). Thus, each viewer can browse all the specific information C. 
     Note that the display control processing described above is configured to enable the cross-section display mode (step S 10 ) on the condition that all the markers M are detected (step S 7 ). However, as another embodiment, the display control system  100  may enable the cross-section display mode when a predetermined operation by the user is received. For example, when the user presses a predetermined button (not illustrated) on the operation device  1  or the display device  2 , when the user changes the orientation of the operation device  1  to a predetermined orientation, when the user gives a voice instruction or the like, the display control system  100  may enable the cross-section display mode. 
     As described above, the display control system  100  according to the present embodiment detects the orientation change of the operation device  1  when the user changes the orientation of the operation device  1 , and changes the orientation of the object image  3  of the operation object displayed on the display device  2  according to the orientation change of the operation device  1 . Further, the display control system  100  detects the marker M set at the specific position of the object image  3 , and presents the specific information C associated with the detected marker M to the user (viewer). According to this configuration, it is possible to move the object image  3  in conjunction with the movement of the operation device  1 . Furthermore, the user can browse information (specific information) relating to the operation object by moving the operation device  1 . 
     Also, when the operation device  1  moves in the direction away from the display device  2  and overlaps the virtual plane S 1  located at a predetermined distance away from the display device  2 , the display control system  100  according to the present embodiment causes the display device  2  to display the object image  3  including the cut plane obtained by cutting the operation device  1  at the virtual plane S 1 . According to this configuration, the display control system  100  can display the cross-section information such as the thickness and the internal structure of the object image  3  in association with the movement of the operation device  1 . Therefore, the user can browse the cross-section information relating to the operation object by moving the operation device  1 . 
     The present disclosure is not limited to the embodiments described above. Other embodiments of the present disclosure will be described below. 
     In the embodiments described above, for example, when the user holds the operation device  1  and extends her or his arm, the relative position between her or his face and the operation device  1  is separated, so that the size of the operation device  1  as seen from the user becomes smaller. In this case, the object image  3  displayed on the display device  2  is displayed with a reduced size so as to reflect the size of the operation device  1  as seen from the user (see  FIG.  6   ). Similarly, for example, when the user holds the operation device  1  and folds his or her arm, the relative position between her or his face and the operation device  1  approaches each other, so that the size of the operation device  1  as seen from the user becomes larger. In this case, the object image  3  displayed on the display device  2  is displayed with an enlarged size so as to reflect the size of the operation device  1  as seen from the user (see  FIG.  5   ). As described above, when the relative position between the user and the operation device  1  changes by the user bending or stretching of her or his arm at a place (while the user is standing or sitting), the size of the operation device  1  as seen from the user is appropriately reflected on the object image  3 . 
     However, for example, when the user moves (walks) while holding the operation device  1 , it is conceivable that the size of the operation device  1  as seen from the user may not be appropriately reflected on the object image  3 . For example, when the user approaches the display device  2  on foot while holding the operation device  1 , the object image  3  is displayed with a reduced size even though the relative position between the user and the operation device  1  does not change and the size of the operation device  1  as seen from the user does not change. Similarly, for example, when the user moves away from the display device  2  on foot while holding the operation device  1 , the object image  3  is displayed with an enlarged size even though the relative position between the user and the operation device  1  does not change and the size of the operation device  1  as seen from the user does not change. As described above, when the size of the operation device  1  as seen from the user is not appropriately reflected on the object image  3 , there arises a problem that the operability of the operation device  1  and the visibility of the object image  3  are deteriorated. 
     Therefore, the display control system  100  according to another embodiment includes a configuration capable of solving the above problem in addition to the configuration of the embodiments described above. 
     Specifically, the position detection sensor  24  detects the position of the operation device  1  and the position of the user with respect to the display device  2 . Specifically, the position detection sensor  24  detects the position (X, Y and Z coordinates) of the operation device  1  and the position (X, Y and Z coordinates) of the user with the position of the position detection sensor  24  as a reference (coordinate origin). The orientation controller  212  calculates the relative position between the operation device  1  and the display device  2  and the relative position between the operation device  1  and the user, based on the detection signal from the position detection sensor  24 . For example, as illustrated in  FIG.  13   , the orientation controller  212  calculates a distance L 2  between the operation device  1  and the display device  2  and a distance L 3  between the operation device  1  and the user. Then, the orientation controller  212  changes the orientation of the object image  3  based on the distances L 2  and L 3 . 
     For example, when the user grips the operation device  1  placed at a predetermined place, the orientation setter  111  sets the orientation of the operation device  1  to the facing orientation in which the operation device  1  faces the user. At this time, the orientation controller  212  sets the distance L 3  between the operation device  1  and the user as a reference distance. Thereafter, for example, when the user extends her or his arm on the place and moves the operation device  1  to the rear side (display device  2  side), the distance L 3  becomes larger than the reference distance. When detecting that the distance L 3  is changed (increased), the orientation controller  212  displays object image  3  with a reduced size at a reduction ratio corresponding to the amount of change. Further, for example, when the user folds her or his arm on the place and moves the operation device  1  to the front side (user side), the distance L 3  becomes smaller than the reference distance. When detecting that the distance L 3  is changed (decreased), the orientation controller  212  displays the object image  3  with an enlarged size at a magnification ratio corresponding to the amount of change. 
     On the other hand, for example, when the user walks to the rear side (display device  2  side) while holding the operation device  1 , the distance L 3  does not substantially change from the reference distance, and only the distance L 2  becomes smaller. In this case, the orientation controller  212  does not change the display magnification of the object image  3  on the condition that the change in the distance L 3  is not detected. Similarly, for example, when the user walks to the front side (in a direction away from the display device  2 ) while holding the operation device  1 , the distance L 3  does not substantially change from the reference distance, and only the distance L 2  becomes larger. In this case, the orientation controller  212  does not change the display magnification of the object image  3  on the condition that the change in the distance L 3  is not detected. 
     According to this configuration, it is possible to appropriately reflect the size of the operation device  1  as seen from the user on the object image  3 . Therefore, it is possible to prevent the operability of the operation device  1  and the visibility of the object image  3  from deteriorating. Note that when the controller  21  detects only the change of the distance L 2  without detecting the change of the distance L 3 , the controller  21  may determine that the user is moving while holding the operation device  1  and display a predetermined message on the display  23 . For example, the controller  21  may display a message prompting the user to move the operation device  1  while the user do not move, such as “Please move the replica closer to or away from your body (face)”. 
     As another embodiment of the present disclosure, the position detection sensor  24  may be mounted on the operation device  1 . For example, as illustrated in  FIG.  14   , the operation device  1  may include a camera  15  which is an example of the position detection sensor  24 . The camera  15  is disposed vertically upward so as to be capable of capturing an image of the ceiling of the room. The operation device  1  detects the position (coordinates) of the operation device  1  based on the captured image (ceiling image) by the camera  15 . The operation device  1  outputs a detection signal (coordinate information) to the display device  2 . When the display device  2  receives the detection signal, the display device  2  detects the orientation change of the operation device  1 , and changes the orientation of the object image  3 . 
     The operation object of the present disclosure is not limited to an art object, but may be an article in various fields. For example, the operation object may be an organ, a building, an ornament, or the like. 
     It is to be understood that the embodiments herein are illustrative and not restrictive, since the scope of the disclosure is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims.