Patent Publication Number: US-2021182009-A1

Title: Display device, display system, and display method

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a display device, a display system, and a display method. 
     Description of the Background Art 
     Japanese Patent Laid-Open No. 2018-182511 discloses a technology that in a case where a user performs enlargement operation to a first display device among the first display device and a second display device, when the second display device is set so as to display the same image as the first display device, a trimming image of a display image is displayed on the first display device, and when the second display device is not set so as to display the same image as the first display device, an enlarged image of the display image is displayed on the first display device. 
     When the first display device and the second display device are daisy chain-connected, it is possible to extract one part of the display image displayed on the first display device and display an extracted image on the second display device. 
     However, a user needs to set enlargement (set the magnification of the extracted image and set a display place of the extracted image) for each display device, which is complicated. 
     An object of the present invention is to provide a display device, a display system, and a display method with which a user is capable of easily displaying an extracted image. 
     SUMMARY OF THE INVENTION 
     According to a first aspect of the present application, a display system includes a first display device and a second display device. The second display device is communicably connected to the first display device. The first display device includes a first display and an operator. The first display displays an image. The operator accepts a touch operation to the first display. The second display device includes a second display that displays an image. When one part of a display image displayed on the first display is designated by the touch operation, the second display displays an extracted image. The extracted image is an image obtained by extracting, from the display image, a partial image including a portion designated by the touch operation in the display image. 
     According to a second aspect of the present application, a display device is communicably connected to a display device including a first display. The display device includes a second display that displays an image. When one part of the display image displayed on the first display is designated by a touch operation to the first display, the second display displays an extracted image. The extracted image is an image obtained by extracting, from the display image, a partial image including a portion designated by the touch operation in the display image. 
     According to a third aspect of the present application, a display method uses a first display device and a second display device communicably connected to the first display device. The display method includes displaying a display image on a first display included in the first display device. The display method includes designating one part of the display image by a touch operation to the first display. The display method includes displaying an extracted image on a second display included in the second display device. The extracted image is an image obtained by extracting, from the display image, a partial image including a portion designated by the touch operation in the display image. 
     According to the present invention, a user can easily display an extracted image. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a display system according to an embodiment of the present invention; 
         FIG. 2  is a block diagram illustrating a configuration of a first display device; 
         FIG. 3  is a block diagram illustrating a configuration of a second display device; 
         FIG. 4  is a flow chart illustrating the operation of a display system; 
         FIG. 5  is a diagram illustrating the states of the first display device and the second display device at the start of the operation of the display system; 
         FIG. 6  is a diagram illustrating a state in which one part of a display image displayed on the first display is designated by a touch operation; 
         FIG. 7  is a diagram illustrating a partial image; 
         FIG. 8A  to  FIG. 8C  are schematic diagrams each illustrating a state in which a creator of the second display device creates an extracted image; 
         FIG. 9  is a diagram illustrating a state in which the extracted image is displayed on the second display; 
         FIG. 10  is a diagram illustrating a first example of a multiple display process; 
         FIG. 11  is a diagram illustrating a second example of a multiple display process; and 
         FIG. 12  is a flow chart illustrating the operation of the first display device that performs the multiple display process. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and will not be repeatedly described. 
     A display system  1  according to the embodiment of the present invention will be described with reference to  FIG. 1  to  FIG. 2 .  FIG. 1  is a schematic diagram illustrating the display system  1  according to the embodiment of the present invention. 
     As illustrated in  FIG. 1 , the display system  1  displays an image on a plurality of display devices. The display devices are each, for example, a liquid crystal display, an EL (Electro-Luminescence) display, or a plasma display (PDP). 
     The display system  1  includes a first display device  100  and a second display device  200 . 
     The first display device  100  and the second display device  200  are connected to each other by using a serial cable so as to enable mutual cable communication. The first display device  100  and the second display device  200  are, for example, daisy chain-connected. The first display device  100  and the second display device  200  may be connected to each other so as to enable wireless communication, for example, by Bluetooth (registered trademark) or Wifi. 
       FIG. 2  is a block diagram illustrating a configuration of the first display device  100 . 
     As illustrated in  FIG. 2 , the first display device  100  includes a first display  110 , a first operator  120 , a first communicator  130 , a first storage  140 , and a first control device  150 . 
     The first display  110  includes a panel that displays an image, such as a liquid crystal panel. 
     The first operator  120  accepts an instruction to the first display device  100 . The first operator  120  includes, for example, a resistive film type, a capacitance type, or an optical type touch panel, and accepts a touch operation to the first display  110 . The first operator  120  includes a receiver that receives an infrared code output from an operation key provided in a housing of the first display device  100  and/or a remote controller of the first display device  100 . 
     The first communicator  130  communicates with the second display device  200 . The first communicator  130  includes a communication module (communication device), such as a connection port for connecting a serial cable or a wireless LAN board. 
     The first storage  140  includes a main storage device (for example, a semiconductor memory) such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and may further include an auxiliary storage device (for example, a hard disk drive). The first storage  140  stores various computer programs executed by the first control device  150 . The first storage  140  stores image data of a display image G. The display image G will be later described. Further, the first storage  140  stores information about the second display device  200  (for example, information about the resolution of the second display  210  of the second display device  200 ). In the first embodiment, the resolution of the first display  110  is the same as that of the second display  210 . The resolution of the first display  110  may be different from that of the second display  210 . 
     The first control device  150  includes a processor such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit). The first control device  150  controls each element of the first display device  100  by executing the computer programs stored in the first storage  140 . 
     The first control device  150  has a specifier  151 , a creator  152 , and a controller  153 . Specifically, the processor of the first control device  150  functions as the specifier  151 , the creator  152 , and the controller  153  by executing a computer program stored in the first storage  140 . 
       FIG. 3  is a block diagram illustrating a configuration of the second display device  200 . 
     As illustrated in  FIG. 3 , the second display device  200  includes a second display  210 , a second operator  220 , a second communicator  230 , a second storage  240 , and a second control device  250 . 
     The second display  210 , the second operator  220 , the second communicator  230 , the second storage  240 , and the second control device  250  of the second display device  200  have the same configurations as the first display  110 , the first operator  120 , the first communicator  130 , the first storage  140 , and the first control device  150  of the first display device  100  (see  FIG. 2 ), respectively, and therefore detailed description will be omitted. 
     The second storage  240  stores various computer programs executed by the second control device  250 . The second storage  240  stores the image data of the display image G. 
     The second control device  250  controls each element of the second display device  200  by executing the computer program stored in the second storage  240 . The second control device  250  has a creator  251  and a controller  252 . Specifically, a processor of the second control device  250  functions as the creator  251  and the controller  252  by executing computer programs stored in the second storage  240 . 
     The operation of the display system  1  will be described with reference to  FIG. 2  to  FIG. 9 .  FIG. 4  is a flow chart illustrating the operation of the display system  1 .  FIG. 5  is a diagram illustrating the states of the first display device  100  and the second display device  200  at the start of the operation of the display system  1 . 
     First, the states of the first display device  100  and the second display device  200  at the start of the operation of the display system  1  will be first described with reference to  FIG. 5 . 
     As illustrated in  FIG. 5 , in this embodiment, the display system  1  is used in a medical field. Each of the first display device  100  and the second display device  200  is, for example, a medical display device. The first display  110  of the first display device  100  and the second display  210  of the second display device  200  are arranged side by side. The display image G is displayed on each of the first display  110  and the second display  210 . In this embodiment, the display image G is an X-ray image. The display image G may be an image other than the X-ray image, and the type of the display image G is not particularly limited. 
     Now, the operation of the first display device  100  among the operations of the display system  1  will be described with reference to  FIG. 2  and  FIG. 4  to  FIG. 7 . 
     As illustrated in  FIG. 2 ,  FIG. 4 , and  FIG. 5 , in step S 10 , the controller  153  of the first display device  100  determines whether or not one part of the display image G displayed on the first display  110  is designated by a touch operation in a state in which the display image G is displayed on each of the first display  110  and the second display  210 . 
       FIG. 6  is a diagram illustrating a state in which the one part of the display image G displayed on the first display  110  is designated by the touch operation. 
     As illustrated in  FIG. 6 , the one part of the display image G displayed on the first display  110  is designated by, for example, the touch operation by a touch pen P. In this case, a user slides the touch pen P on the first display  110 , and surrounds a desired portion of the display image G. As a result, the portion of the display image G, which is surrounded by the sliding operation of the touch pen P, becomes a portion designated by the touch operation. The touch operation may be performed with a finger. 
     When the touch operation to the first display  110  is performed, the controller  153  displays an annular line image L 1  illustrating the trajectory of the touch operation on the display image G displayed on the first display  110 . In other words, the trajectory of the touch operation is the trajectory of the movement of the touch pen P. The line image L 1  is displayed on, for example, an OSD (On Screen Display). 
     In this embodiment, a designated portion G 1  surrounded by the line image L 1  in the display image G is designated by the touch operation. The touch operation is not limited to the slide operation surrounding a desired portion of the display image G. The touch operation only needs to be operation in which an object such as a touch pen or a finger touches the display image G displayed on the first display  110 . The touch operation may be, for example, a tap operation. In this case, when the tap operation (long press operation) is performed on the display image G, a portion located within a predetermined range centered on a tapped location in the display image G becomes a portion designated by the touch operation. The predetermined range is determined, for example, according to the size of the display image G, or according to the resolution of the first display  110 . 
     By displaying the line image L 1  on the first display  110 , the user can visually recognize the designated portion G 1  designated by himself/herself in the display image G. 
     As illustrated in  FIG. 2 ,  FIG. 4 , and  FIG. 6 , when the controller  153  determines that one part of the display image G is designated by the touch operation (Yes in step S 10 ), the process shifts to step S 20 . On the other hand, when the controller  153  determines that one part of the display image G is not designated by the touch operation (No in step S 10 ), the process illustrated in step S 10  is repeated. 
     In step S 20 , the controller  153  determines a partial image G 11 . 
       FIG. 7  is a diagram illustrating the partial image G 11 . 
     As illustrated in  FIG. 7 , the partial image G 11  is an image including the designated portion G 1  designated by the touch operation in step S 10 . 
     A frame part G 12  of the partial image G 11  is formed in a rectangular shape (circumscribed rectangle) composed of two sides parallel to an X-axis and two sides parallel to a Y-axis. The frame part G 12  of the partial image G 11  circumscribes the designated portion G 1  (line image L 1 ). The X-axis and the Y-axis are axes perpendicular to each other. 
     In  FIG. 7 , the frame part G 12  of the partial image G 11  is displayed on the display image G displayed on the first display  110  for convenience of explanation, but an image representing the frame part G 12  is not actually displayed on the display image G. The image representing the frame part G 12  may be displayed on the display image G. 
     As illustrated in  FIG. 2 ,  FIG. 4 , and  FIG. 7 , in step S 30 , the specifier  151  specifies a partial image position. The partial image position indicates an area where the partial image G 11  is located on the first display  110 . The partial image position is composed of the coordinates (X 1 , Y 1 ) of the apex A 1  of the partial image G 11 , the dimension (number of pixels) H 1  in the Y-axis direction of the partial image G 11 , and the dimension (number of pixels) W 1  in the X-axis direction of the partial image G 11 . 
     In this embodiment, the frame part G 12  of the partial image G 11  is formed in a rectangular shape while circumscribing the line image L 1 . As a result, the specifier  151  can easily specify the partial image position on the basis of the coordinates of the line image L 1 . 
     In step S 40 , the specifier  151  specifies the extracted image position. 
     The extracted image position indicates an area where an extracted image G 13  (see  FIG. 8C ) is located on the second display  210 . 
     The extracted image G 13  is an image corresponding to the partial. image G 11  extracted from the display image G displayed on the first display  110 , and has a size which is the same as or similar to the size of the partial image G 11 . In this embodiment, the extracted image G 13  is a similarly enlarged image of the partial image G 11 . 
     The extracted image position is composed of the coordinates (PX 1 , PY 1 ) of the apex A 11  of the extracted image G 13 , the dimension (number of pixels) PH 1  in the Y-axis direction of the extracted image G 13 , and the dimension (number of pixels) PW 1  in the X-axis direction of the extracted image G 13  (See  FIG. 8C ). The coordinates (PX 1 , PY 1 ) are values that define the position of the extracted image G 13 . The dimension PH 1  and the dimension PW 1  are values that define the size of the extracted image G 13 . 
     The extracted image G 13  is generated by enlarging the dimension of the partial image G 11  from the dimensions H 1  and W 1  to the dimensions PH 1  and PW 1  (in other words, by enlarging the partial image G 11  at the same magnification). The size of the extracted image G 13  is determined on the basis of the size of the partial image G 11  and the resolution of the second display  210 . 
     The values (dimension PH 1  and dimension PW 1 ) that define the size of the extracted image G 13  are set to, for example, such values that the extracted image G 13  is larger than the partial image G 11  and the entire extracted image G 13  fits in the second display  210 . An upper limit of the values that define the size of the extracted image G 13  may be set in order to prevent the extracted image G 13  from becoming coarse. In addition, a lower limit of the values that define the size of the extracted image G 13  may be further set in order to prevent the crush of the extracted image G 13 . 
     The values (coordinates (PX 1 , PY 1 )) that define the position of the extracted image G 13  are, for example, such values that the extracted image G 13  is disposed with the central part in the image display area of the second display  210  as the center. 
     In step S 50 , the controller  153  controls the first communicator  130  such that the first communicator  130  transmits predetermined information to the second display device  200 . 
     The predetermined information includes information indicating a display request instruction, information indicating the partial image position specified in step S 30  (the coordinates (X 1 , Y 1 ), the dimensions H 1 , and the dimensions W 1 ), and information indicating the extracted image position specified in step S 40  (the coordinates (PY 1 , PY 1 ), the dimension PH 1 , and the dimension PW 1 ). 
     The display request instruction is a control command instructing the second display device  200  to display the extracted image G 13 . The information indicating the partial image position is an example of partial image position information of the present invention. The information indicating the extracted image position is an example of extracted image position information of the present invention. 
     When the process illustrated in step S 50  is completed, the process of the first display device  100  is completed. 
     In step S 60 , the second communicator  230  of the second display device  200  receives the predetermined information. When the process illustrated in step S 60  is completed, the process shifts to step S 70 . 
     Next, the operation of the second display device  200  among the operation of the display system  1  will be described with reference to  FIG. 3  to  FIG. 9 . 
       FIG. 8A  to  FIG. 8C  are schematic views each illustrating a state in which the creator  251  of the second display device  200  creates the extracted image G 13 .  FIG. 9  is a diagram illustrating a state in which the extracted image G 13  is displayed on the second display  210 . 
     The second display device  200  receives the display request instruction included in the predetermined information in step S 60  (see  FIG. 4 ), so that a process of displaying the extracted image G 13  ( FIG. 8C ) on the second display  210  is started in step S 70  and subsequent steps. 
     As illustrated in  FIG. 3 ,  FIG. 4 , and  FIG. 7 , in step S 70 , the creator  251  of the second display device  200  transmits, into a buffer of the second storage  240 , image data of the display image G disposed on a first display plane P 1  on the second display  210 . 
     As illustrated in  FIG. 3 ,  FIG. 4 , and  FIG. 8A , in step S 80 , the creator  251  sets a second display plane P 2  having the same resolution as the first display plane P 1  in the buffer, and disposes the display image G on the second display plane P 2 . 
     As illustrated in  FIG. 3 ,  FIG. 4 , and  FIG. 8B , in step  890 , the creator  251  specifies a portion where the partial image G 11  of the display image G on the second display plane P 2  is located, on the basis of the predetermined information (information indicating the partial image position) acquired in step S 60 . 
     As illustrated in  FIG. 3 ,  FIG. 4 , and  FIG. 8C , in step S 100 , the creator  251  creates the extracted image G 13  on the second display plane P 2  by enlarging the partial image G 11  and determining the position on the second display plane P 2  on the basis of the predetermined information (information indicating the extracted image position) acquired in step S 60 . 
     As illustrated in  FIG. 3 ,  FIG. 4 , and  FIG. 9 , in step S 110 , the controller  252  erases the display image G disposed on the first display plane P 1 , and disposes, on the first display plane P 1 , the extracted image G 13  (see  FIG. 8C ) created on the second display plane P 2  in step S 100 . The first display plane P 1  is located in the image display area of the second display  210 . As a result, the extracted image G 13  is displayed on the second display  210  instead of the display image G. 
     When the process illustrated in step S 110  is completed, the process is completed. 
     As described above with reference to  FIG. 2  to  FIG. 9 , when the one part of the display image G displayed on the first display  110  is designated by the touch operation, the second display  210  displays the extracted image G 13 . Therefore, the user can display the extracted image G 13  on the second display  210  by the touch operation to the first display  110 , and does not need to perform enlargement setting for each display device. As a result, the user can easily display the extracted image G 13  on the second display  210 . 
     The embodiment of the present invention is thus described with reference to the drawings ( FIG. 1  to  FIG. 9 ). However, the present invention is not limited to the above embodiment, and can be implemented in various embodiments without departing from the gist thereof (for example, (1) to (2)). In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the above embodiment. For example, some components may be deleted from all the components described in the embodiment. In order to facilitate understanding, the drawings schematically illustrate each component as a main body, and the number and the like of each of the components illustrated in the drawings may differ from actual ones for the convenience of drawing creation. Further, each component described in the above embodiment is an example and is not particularly limited, and various changes can be made without substantially deviating from the effects of the present invention. 
     (1) In this embodiment, the creator  251  of the second display device  200  creates the extracted image G 13 . However, the present invention is not limited to this. The creator  152  of the first display device  100  may create the extracted image G 13 . In this case, for example, the first display device  100  and the second display device  200  are non daisy chain-connected. 
     In this case, the creator  152  of the first display device  100  creates the extracted image G 13  by performing the processes illustrated in  FIG. 8A  to  FIG. 8C  in the buffer of the first storage  140 . Then, in step S 50  (see  FIG. 4 ), instead of the information indicating the partial image position and the information indicating the extracted image position, information indicating the extracted image G 13  created by the creator  152  of the first display device  100  is transmitted from the first display device  100  to the second display device  200 . As a result, the controller  252  of the second display device  200  erases the display image G from the second display  210  and displays the extracted image G 13  on the second display  210 . As a result, the second control device  250  of the second display device  200  does not need to create the extracted image G 13 , so that the arithmetic load of the second control device  250  can be reduced. 
     (2) In a case where a plurality of touch operations are performed on the first display  110 , the controller  252  may perform a multiple display process of displaying a plurality of extracted images on the second display  210 . 
     In the following, a first example of the multiple display process will be described with reference to  FIG. 2  and  FIG. 10 . 
       FIG. 10  is a diagram illustrating the first example of the multiple display process. 
     As illustrated in  FIG. 2  and  FIG. 10 , a plurality of touch operations performed on the first display  110  include a touch operation performed along a line image L 2  and a touch operation performed along a line image L 3 . 
     When the touch operation along the line image L 2  is performed on the first display  110 , a partial image G 21  is determined on the basis of the line image L 2 . The partial image G 21  is an image located in a rectangular frame part G 22  surrounding the line image L 2  in the display image G. The frame part G 22  may be displayed or may not be displayed on the display image G. Then, the partial image G 21  is extracted from the display image G, so that an extracted image G 23  is created. Then, the extracted image G 23  is displayed on the second display  210 . 
     When the touch operation along the line image L 3  is performed on the first display  110 , a partial image G 31  is determined on the basis of the line image L 3 . The partial image G 31  is an image located in a rectangular frame part G 32  surrounding the line image L 3  in the display image G. The frame part G 32  may be displayed or may not be displayed on the display image G. Then, the partial image G 31  is extracted from the display image G, so that the extracted image G 33  is created. Then, the extracted image G 33  is displayed on the second display  210 . 
     The position of the partial image G 21  and the position of the partial image G 31  are different from each other at the position in the Y-axis direction on the first display  110 . In this case, the extracted image G 23  and the extracted image G 33  are displayed on the second display  210  side by side along the Y-axis direction in a state in which such size that the extracted image G 23  and the extracted image G 33  fit within the second display  210  is ensured. For example, the position of the partial image G 21  indicates the coordinates (X 2 , Y 2 ) of the apex A 2  of the partial image G 21 , and the position of the partial image G 31  indicates the coordinates (X 3 , Y 3 ) of the apex A 3  of the partial image G 31 . 
     On the first display  110 , the partial image G 21  and the partial image G 31  are arranged along the Y-axis direction in the order of the partial image G 31  and the partial image G 21 . In accordance with the above, on the second display  210 , the extracted image G 23  and the extracted image G 33  are arranged along the Y-axis direction in the order of the extracted image G 33  and the extracted image G 23 . 
     When the line image L 3  is erased on the first display  110 , the extracted image G 33  is erased on the second display  210 , and the display position of the extracted image G 23  is changed to the central part of the second display  210 . When the line image L 2  is erased on the first display  110 , the extracted image G 23  is erased on the second display  210 , and the display position of the extracted image G 33  is changed to the central part of the second display  210 . As a result, in a case where the extracted image that is one of the extracted image G 23  and the extracted image G 33  is no longer needed, a user can leave only a necessary extracted image on the second display  210 . 
     In the following, a second example of the multiple display process will be described with reference to  FIG. 2  and  FIG. 11 . 
       FIG. 11  is a diagram illustrating the second example of the multiple display process. 
     As illustrated in  FIG. 2  and  FIG. 11 , a plurality of touch operations performed on the first display  110  include a touch operation performed along a line image L 4  and a touch operation performed along a line image L 5 . 
     When a touch operation along the line image L 4  is performed on the first display  110 , a partial image G 41  is determined on the basis of the line image L 4 . The partial image G 41  is an image located in a rectangular frame part G 42  surrounding the line image L 4  in the display image G. The frame part G 42  may be displayed or may not be displayed on the display image G. Then, the partial image G 41  is extracted from the display image G, so that the extracted image G 43  is created. Then, the extracted image G 43  is displayed on the second display  210 . 
     When a touched operation along a line image L 5  is performed on the first display  110 , a partial image G 51  is determined on the basis of the line image L 5 . The partial image G 51  is an image located in a rectangular frame part G 52  surrounding the line image L 5  in the display image G. The frame part G 52  may be displayed or may not be displayed on the display image G. Then, the partial image G 51  is extracted from the display image G, so that the extracted image G 53  is created. Then, the extracted image G 53  is displayed on the second display  210 . 
     The position of the partial image G 41  and the position of the partial image G 41  are the same at the position in the Y-axis direction on the first display  110 , In this case, the extracted image G 43  and the extracted image G 53  are displayed on the second display  210  side by side along the X-axis direction in a state in which such size that the extracted image G 43  and the extracted image G 53  fit within the second display  210  is ensured. 
     For example, the position of the partial image G 41  indicates the coordinates (X 4 , Y 4 ) of the apex A 4  of the partial image G 41 , and the position of the partial image G 51  indicates the coordinates (X 5 , Y 5 ) of the apex A 5  of the partial image G 51 . 
     The case where the position of the partial image G 41  and the position of the partial image G 41  are the same at the position in the Y-axis direction on the first display  110  includes not only a case where the Y coordinate Y 4  of the apex A 4  of the partial image G 41  and the Y coordinate Y 5  of the apex A 5  of the partial image G 51  are exactly the same, but also a case where the Y coordinate  14  of the apex A 4  of the partial image G 41  and the Y coordinate Y 5  of the apex A 5  of the partial image G 51  are slightly different (for example, a few pixels are different). 
     The partial image G 41  and the partial image G 51  are arranged on the first display  110  side by side along the X-axis direction in the order of the partial image G 51  and the partial image G 41 . In accordance with the above, the extracted image G 43  and the extracted image G 53  are arranged on the second display  210  side by side along the X-axis direction in the order of the extracted image G 53  and the extracted image G 43 . 
     When the line image L 5  is erased on the first display  110 , the extracted image G 53  is erased on the second display  210 , and the display position of the extracted image G 43  is changed to the central part of the second display  210 . When the line image L 4  is erased on the first display  110 , the extracted image G 43  is erased on the second display  210  and the display position of the extracted image G 53  is changed to the central part of the second display  210 . 
     Now, the operation of the first display device  100  when the multiple display process is performed will be described with reference to  FIG. 4  and  FIG. 10  to  FIG. 12 .  FIG. 12  is a flow chart illustrating the operation of the first, display device  100  that performs the multiple display process. Processes illustrated in step S 10  to step S 52  of  FIG. 12  are a modification of the processes (step S 10  to step S 50 ) performed by the first display device  100  among the processes illustrated in step S 10  to step S 110  of  FIG. 4 . 
     As illustrated in  FIG. 12 , when the processes illustrated in step S 10  to step S 30  are performed, the process shifts to step S 41 . 
     In step S 41 , the controller  153  of the first display device  100  determines whether a first touch operation is performed or a second touch operation is performed, in step S 10 . 
     In a case where the controller  153  determines that the first touch operation is performed (Yes in step S 41 ), the process shifts to step S 42 . 
     In this embodiment, in a case where the first touch operation is performed, the partial image G 11  (see  FIG. 7 ) is determined in step S 20 , and the partial image position of the partial image G 11  is specified in step S 30 . 
     In a case where the controller  153  determines that the second touch operation is performed (No in step S 41 ), the process shifts to step S 43 . 
     In this embodiment, in a case where the second touch operation is performed, the partial image G 21  is determined by the first touch operation of the two touch operations and the partial image G 31  is determined by the second touch operation (see  FIG. 10 ) in step S 20 . Then, in step S 30 , the partial image position of the partial image G 21  and the partial image position of the partial image G 31  are specified. 
     In step S 42 , the specifier  151  performs a first specification process. The first specification process is a process of specifying the extracted image position of the extracted image G 13  which is an enlarged image of the partial image G 11 . In this case, the specifier  151  specifies the extracted image position such that the extracted image G 13  is disposed in the central part of the image display area of the second display  210 . 
     In step S 51 , first predetermined information is transmitted from the first display device  100  to the second display device  200 . The first predetermined information includes information indicating a first display request instruction, information indicating the partial image position of the image G 11  specified in step S 30 , and information indicating the extracted image position of the extracted image G 13  specified in step S 42 . The first display request instruction is a control command instructing the second display device  200  to display the extracted image G 13  at the extracted image position. 
     Then, the second display device  200  receives the first predetermined information and performs the processes illustrated in step S 60  to step S 110  in  FIG. 4 . As a result, the extracted image G 13  is displayed on the second display  210  (see  FIG. 9 ). 
     In step S 43 , the specifier  151  performs a second specification process. The second specification process is a process of specifying the extracted image position of the extracted image G 23  which is an enlarged image of the partial image G 21 , and the extraction image position of the extracted image G 33  which is an enlarged image of the partial image G 31 . In this case, the specifier  151  divides the image display area of the second display  210  into a first area located on one side (upper side) in the Y-axis direction and a second area located on the other side (lower side), specifies the extracted image position of the extracted image G 23  such that, the extracted image G 23  is disposed with the central part of the first area as the center, and specifies the extracted position of the extracted image G 33  such that the extracted image G 33  is disposed with the central part of the second area as the center. 
     The magnification of the partial image G 21  at the time of generation of the extracted image G 23  and the magnification of the partial image G 31  at the time of generation of the extracted image G 33  are determined to such values that the extracted image G 23  fits in the first area and the extracted image G 33  fits in the second area, for example, in consideration of the resolution of the second display  210 , the size of the first area, the size of the second area, and the like. 
     The size of the first area and the size of the second area may be determined according to the size of the designated area on the first display  110  by the touch operation. For example, when the first designated area when the partial image G 21  is designated by the touch operation is wider than the second designated area when the partial image G 31  is designated by the touch operation, on the first display  110 , the image display area of the second display  210  is divided into two such that the first area in which the extracted image G 23  corresponding to the partial image G 21  is displayed is wider than the second area in which the extracted image G 33  corresponding to the partial image G 31  is displayed, on the second display  210 . When a difference between the size of the first designated area and the size of the second designated area is within a predetermined range, the image display area of the second display  210  is divided into two such that the size of the first area and the size of the second area are the same. 
     In step S 52 , second predetermined information is transmitted from the first display device  100  to the second display device  200 . The second predetermined information includes information indicating a second display request instruction, information indicating the partial image position of the partial image G 21  specified in step S 30 , information indicating the partial image position of the partial image G 31 , information indicating the extracted image position of the extracted image G 23  specified in step S 43 , and information indicating the extracted image position of the extracted image G 33 . The second display request instruction is a control command instructing the second display device  200  to display each of the extracted image G 23  and the extracted image G 33  at the extracted image position specified in step S 43 . 
     Then, the second display device  200  receives the second predetermined information, and performs the processes illustrated in step S 60  to step S 110  of  FIG. 4  for each of the extracted image G 23  and the extracted image G 33 . As a result, as illustrated  FIG. 10 , the extracted image G 23  is displayed in the first area (on the upper side) and the extracted image G 33  is displayed in the second area (on the lower side), on the second display  210 . 
     As illustrated in  FIG. 11  and  FIG. 12 , in a case where the partial image G 41  and the partial image G 51  arranged on the left and right are determined by the two touch operations on the first display  110 , No is determined in step S 41 , and the second specification process illustrated in step S 43  is performed. In this case, in the second specification process, the image display area of the second display  210  is divided into a third area located on one side (on the left side) in the X-axis direction and a fourth area located on the other side (on the right side). Then, the extracted image position of the extracted image G 43  and the extracted image position of the extracted image G 53  are specified such that the extracted image G 53  is disposed in the third area, and the extracted image G 43  is displayed in the fourth area. As a result, as illustrated in  FIG. 11 , the extracted image G 53  is displayed in the third area (left side), and the extracted image G 43  is displayed in the fourth area (right side), on the second display  210 . 
     In a case where the touch operation is performed on the first display  110  N times, N extracted images may be displayed so as to be arranged along the Y-axis direction or the X-axis direction on the second display  210 . N is an integer greater than or equal to 3. 
     The present invention can be used in the fields of a display device, a display system, and a display method.