Patent Publication Number: US-2023148052-A1

Title: Display apparatus, display method, and computer program

Description:
TECHNICAL FIELD 
     The invention relates to a data processing technique, and particularly, to a display apparatus, a display method, and a computer program. 
     BACKGROUND ART 
     A cylindrical transparent screen display that can display a video 360 degrees has been proposed. 
     SUMMARY 
     Technical Problem 
     When an image drawn on a plane including a moving object is displayed on a cylindrical screen, the display of the object at a boundary corresponding to both ends of the image becomes unnatural in some cases. 
     The present invention has been made in view of the problem, and one object of the present invention is to provide a technique for reducing unnaturalness of image display in a cylindrical screen. 
     Solution to Problem 
     To solve the problem, an aspect of the present invention provides a display apparatus including a generation unit that generates an image provided with a movement object as an object that moves, the image including a display target area displayed on a cylindrical screen, a first margin area provided outside of one end of the display target area, and a second margin area provided outside of an end on an opposite side of the one end of the display target area, and a display control unit that causes the cylindrical screen to sequentially display content of the display target area of a plurality of images generated by the generation unit. When a first movement object that moves in the display target area comes into contact with a boundary of the display target area and the first margin area, the generation unit arranges, in the second margin area, a second movement object in a same mode as a mode of the first movement object such that the second movement object comes into contact with a boundary of the display target area and the second margin area, and the generation unit generates the plurality of images such that as the first movement object moves out to the first margin area from the display target area, the second movement object enters the display target area from the second margin area. 
     Another aspect of the present invention also provides a display apparatus. The apparatus includes a generation unit that generates an image provided with a movement object as an object that moves and a trail object indicating a trajectory of the movement of the movement object, the image including a display target area displayed on a cylindrical screen, a first margin area provided outside of one end of the display target area, and a second margin area provided outside of an end on an opposite side of the one end of the display target area, and a display control unit that causes the cylindrical screen to sequentially display content of the display target area of a plurality of images generated by the generation unit. A width of the movement object is equal to or smaller than a width of the trail object, when a first movement object that moves in the display target area comes into contact with a boundary of the display target area and the first margin area, the generation unit is configured to arrange, in the second margin area, a second movement object in a same mode as a mode of the first movement object such that the second movement object comes into contact with a boundary of the display target area and the second margin area, and delete the first movement object, after deleting the first movement object, the generation unit gradually shortens the trail object added to the first movement object up to that time and generates a plurality of images such that the second movement object enters the display target area from the second margin area, and when the entire second movement object enters the display target area from the second margin area, the generation unit starts to generate a trail object to be added to the second movement object. 
     Yet another aspect of the present invention provides a display method. The method is executed by a display apparatus, the display apparatus executing a step of generating an image provided with a movement object as an object that moves, the image including a display target area displayed on a cylindrical screen, a first margin area provided outside of one end of the display target area, and a second margin area provided outside of an end on an opposite side of the one end of the display target area, a step of causing the cylindrical screen to sequentially display, content of the display target area of a plurality of images generated in the step of generating, in which in the step of generating, when a first movement object that moves in the display target area comes into contact with a boundary of the display target area and the first margin area, the display apparatus arranges, in the second margin area, a second movement object in a same mode as a mode of the first movement object such that the second movement object comes into contact with a boundary of the display target area and the second margin area, and in the step of generating, the display apparatus generates the plurality of images such that as the first movement object moves out to the first margin area from the display target area, the second movement object enters the display target area from the second margin area. 
     Yet another aspect of the present invention also provides a display method. The method is executed by a display apparatus, the display apparatus executing a step of generating an image provided with a movement object as an object that moves and a trail object indicating a trajectory of the movement of the movement object, the image including a display target area displayed on a cylindrical screen, a first margin area provided outside of one end of the display target area, and a second margin area provided outside of an end on an opposite side of the one end of the display target area, and a step of sequentially displaying, on the cylindrical screen, content of the display target area of a plurality of images generated in the step of generating, in which a width of the movement object is equal to or smaller than a width of the trail object, in the step of generating, when a first movement object that moves in the display target area comes into contact with a boundary of the display target area and the first margin area, the display apparatus is configured to arrange, in the second margin area, a second movement object in a same mode as a mode of the first movement object such that the second movement object comes into contact with a boundary of the display target area and the second margin area, and delete the first movement object, in the step of generating, after deleting the first movement object, the display apparatus gradually shortens the trail object added to the first movement object up to that time and generates a plurality of images such that the second movement object enters the display target area from the second margin area, and in the step of generating, when the entire second movement object enters the display target area from the second margin area, the display apparatus starts to generate a trail object to be added to the second movement object. 
     Note that any combination of the constituent elements as well as expressions obtained by converting the expressions of the present invention among systems, programs, recording media storing programs, and the like are also effective as aspects of the present invention. 
     Advantageous Effect of Invention 
     According to the present invention, unnaturalness of image display in a cylindrical screen can be reduced. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a diagram illustrating an appearance of a display apparatus of a first embodiment. 
         FIG.  2    is a diagram schematically illustrating a relation between an image and a cylindrical screen that displays the image. 
         FIG.  3    is a block diagram illustrating functional blocks of the display apparatus of the first embodiment. 
         FIG.  4 A  is a diagram illustrating an example of an App image. 
         FIG.  4 B  is a diagram illustrating an example of the App image. 
         FIG.  4 C  is a diagram illustrating an example of the App image. 
         FIG.  5 A  is a diagram illustrating an example of the App image. 
         FIG.  5 B  is a diagram illustrating an example of the App image. 
         FIG.  5 C  is a diagram illustrating an example of the App image. 
         FIG.  6    is a diagram illustrating a configuration of a system of a modification. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
       FIG.  1    illustrates an appearance of a display apparatus  10  of a first embodiment. The display apparatus  10  is a cylindrical transparent screen display that can display a video 360 degrees with a hologram screen technique. The display apparatus  10  is a display that can project a video onto a cylindrical transparent screen  12  to allow enjoying the video from anywhere around 360 degrees. 
     The display apparatus  10  includes a projector  14  and a mirror  16 . The projector  14  projects light of an image (video) upward. The mirror  16  reflects the light projected from the projector  14  to the screen  12  to project the image (video) onto the screen  12 . 
     The image (video) projected onto the screen  12  includes a particle  20  and a trail  22 . The particle  20  is an object that moves in a virtual space, and the particle  20  in the embodiment is a drawing object indicating a particle of light flying around in the space. The trail  22  is an object that follows the particle  20  to move in the space, and the trail  22  in the embodiment is a drawing object indicating a trajectory of the movement of the particle  20 . The display apparatus  10  causes the screen  12  to display the image (video), in which the particle  20  and the trail  22  continue to rotate in the cylinder according to the motion of the hand of the user imaged by a camera not illustrated. 
       FIG.  2    schematically illustrates a relation between the image and the cylindrical screen that displays the image. As illustrated on the left side of  FIG.  2   , an application that generates the image generates a plane image  32  illustrating an appearance from the viewpoint of a virtual camera  30  installed at a certain position. The display apparatus  10  projects the plane image onto the cylindrical screen  12  as if the plane image  32  is rolled up in a cylindrical shape as illustrated on the right side of  FIG.  2   . Therefore, the image displayed on the screen  12  of the display apparatus  10  actually includes a boundary  36  that is a joint part of a left end and a right end of the plane image  32 . 
     In the past, the display of the particle  20  and the trail  22  becomes unnatural in some cases when the particle  20  and the trail  22  are moved across the boundary  36 . For example, the display of the particle  20  and the trail  22  are interrupted for a moment, or the display is lagged in some cases. In the embodiment, a technique for reducing the unnaturalness of the image display in the cylindrical screen  12  is proposed. 
       FIG.  3    is a block diagram illustrating functional blocks of the display apparatus  10  of the first embodiment. Each block illustrated in block diagrams of the present specification can be realized by a processor of a computer, a central processing unit (CPU), an element and an electronic circuit, such as a memory, and a mechanical apparatus in terms of hardware and can be realized by a computer program and the like in terms of software. Here, functional blocks realized by cooperation between hardware and software are depicted. Therefore, those skilled in the art will understand that the functional blocks can be realized in various forms based on combinations of hardware and software. 
     The display apparatus  10  includes a camera  40 , a processing unit  42 , and a display unit  44 . The camera  40  images the user near the display apparatus  10 . The display unit  44  includes the screen  12 , the projector  14 , and the mirror  16  already described in relation to  FIG.  1   . The processing unit  42  executes data processing for displaying the particle  20  and the trail  22  on the screen  12  according to the motion of the hand of the user imaged by the camera  40 . 
     The processing unit  42  includes an action detection unit  50 , an image generation unit  52 , and a display control unit  54 . A computer program with functions of the plurality of functional blocks may be stored in a predetermined recording medium, and the computer program may be installed on a storage of the display apparatus  10  through the recording medium. Alternatively, the computer program may be downloaded through a network and installed on the storage of the display apparatus  10 . A CPU of the display apparatus  10  may read out the computer program to a main memory and execute the computer program to fulfill the functions of the plurality of functional blocks. 
     The action detection unit  50  detects the motion of the hand of the user based on the image of the user output from the camera  40 . For example, the action detection unit  50  detects that the hand of the user has moved to the left or to the right. 
     The image generation unit  52  generates an image to be projected onto the cylindrical screen  12 , the image including the particle  20  and the trail  22 . The image generated by the image generation unit  52  will also be referred to as an “App image.”  FIG.  4 A  illustrates an example of the App image. An App image  60  includes a display target area  62 , a left margin area  64   a , and a right margin area  64   b . The display target area  62  is an area to be displayed in the screen  12 . The left margin area  64   a  is an area provided outside a left end of the display target area  62 . The right margin area  64   b  is an area provided outside a right end of the display target area  62 . The length of the width (horizontal width in the first embodiment) of the left margin area  64   a  and the right margin area  64   b  is the same as the length of the width (horizontal width in the first embodiment) of the particle  20 . 
     For a plurality of App images  60  sequentially generated by the image generation unit  52 , the display control unit  54  causes the screen  12  to sequentially display the content of the display target areas  62  of the plurality of App images  60 . For example, the display control unit  54  may output, to the projector  14 , a signal for instructing to project the content of the display target area  62  of each of the App images  60 , and the projector  14  may sequentially project, onto the screen  12 , the content of the display target area  62  of each of the App images  60  instructed from the display control unit  54 . In this way, a video of the particle  20  and the trail  22  flying around is displayed on the screen  12 . 
     The image generation unit  52  includes a particle drawing unit  56  and a trail drawing unit  58 . The particle drawing unit  56  arranges the particle  20  in the display target area  62  based on the motion of the hand of the user detected by the action detection unit  50 . For example, when a movement of the hand of the user to the right is detected, the particle drawing unit  56  gradually shifts the arrangement position of the particle  20  to the right across a plurality of App images  60  to generate a video in which the particle  20  moves to the right. 
     The trail drawing unit  58  monitors the motion of the particle  20  across a plurality of App images  60  and arranges, in the display target area  62 , the trail  22  indicating the trajectory of the movement of the particle  20 , in a mode of adding the trail  22  to the particle  20 . The maximum length of the particle  20  is set in advance. When there are a plurality of particles  20  in the display target area  62 , the trail drawing unit  58  adds the trail  22  to each of the plurality of particles  20 . 
       FIG.  4 A  illustrates the App image  60  typically generated when the user moves the hand to the right. A trail  22   a  in  FIG.  4 A  indicates that a particle  20   a  has moved to the right. In the App image  60  generated next following the App image  60  of  FIG.  4 A , the particle  20   a  and the trail  22   a  are displayed at positions shifted to the right from the positions illustrated in  FIG.  4 A . Note that the App image  60  may include a plurality of particles  20  and a plurality of trails  22 , or a plurality of particles  20  and a plurality of trails  22  may be newly generated according to one action of the user. 
       FIG.  4 B  also illustrates an example of the App image. When the particle  20   a  moving in the display target area  62  comes into contact with a boundary (hereinafter, also referred to as “right boundary”) of the display target area  62  and the right margin area  64   b , in other words, when the right end coordinates of the particle  20   a  coincide with the coordinates of the right boundary, the particle drawing unit  56  arranges, in the left margin area  64   a , a particle  20   b  in the same mode as the mode of the particle  20   a  such that the particle  20   b  comes into contact with a boundary (hereinafter, also referred to as “left boundary”) of the display target area  62  and the left margin area  64   a . That is, the particle drawing unit  56  arranges the particle  20   b  in the left margin area  64   a  such that the right end coordinates of the particle  20   b  coincide with the coordinates of the left boundary. The ordinate of the particle  20   a  and the ordinate of the particle  20   b  are the same. In addition, the particle  20   b  may have the same shape, pattern, and color as those of the particle  20   a , or the particle  20   b  may be a copied image of the particle  20   a.    
     The particle drawing unit  56  arranges the particle  20   a  and the particle  20   b  at positions moved in the same mode (same direction and same speed), across a plurality of App images  60  following the App image  60  of  FIG.  4 B . The particle drawing unit  56  generates the plurality of App images  60  such that as the particle  20   a  enters the right margin area  64   b  from the display target area  62  (that is, gradually hidden), the particle  20   b  enters the display target area  62  from the left margin area  64   a  (that is, the displayed part is expanded). Until the entire particle  20   a  enters the right margin area  64   b  from the display target area  62 , that is, until the entire particle  20   b  enters the display target area  62  from the left margin area  64   a , the trail generation function for the particle  20   b  is not enabled. 
       FIG.  4 C  also illustrates an example of the App image. As illustrated in  FIG.  4 C , the particle drawing unit  56  ends drawing the particle  20   a , that is, deletes the particle  20   a  from the App images  60  generated subsequently, when the entire particle  20   a  enters the right margin area  64   b  from the display target area  62 . The trail drawing unit  58  gradually shortens, with time, the length of the trail  22   a  added to the particle  20   a  up to that time when the entire particle  20   a  enters the right margin area  64   b  from the display target area  62 . In other words, the trail drawing unit  58  gradually shortens the length of the trail  22   a  across a plurality of App images  60  after the deletion of the particle  20   a  and deletes the trail  22   a  from the App image  60  after a predetermined time from the deletion of the particle  20   a.    
     In addition, the trail drawing unit  58  starts a generation process of the trail  22   b  to be added to the particle  20   b  (for example, monitoring of the motion of the particle  20   b  and drawing of the trail  22   b ) when the entire particle  20   a  enters the right margin area  64   b  from the display target area  62 , that is, when the entire particle  20   b  enters the display target area  62  from the left margin area  64   a . The trail drawing unit  58  may detect that the entire particle  20   b  has entered the display target area  62  from the left margin area  64   a  when the left end coordinates of the particle  20   b  arranged by the particle drawing unit  56  coincide with the coordinate values of the left boundary of the display target area  62 . The trail drawing unit  58  gradually increases the length of the trail  22   b  across a plurality of App images  60  after the entire particle  20   b  has entered the display target area  62  from the left margin area  64   a , until the length reaches the maximum length set in advance. 
     The speed of the reduction of the trail  22   a  with respect to the particle  20   a  after the disappearance and the speed of the elongation of the trail  22   b  with respect to the particle  20   b  are the same. In other words, the trail drawing unit  58  elongates the trail  22   b  at the same speed as the speed of the reduction of the trail  22   a . In this way, as for the sum of the trail  22   a  and the trail  22   b , the maximum length of the trail set in advance is maintained. 
     Although the particle  20   a  moves to the right in the examples of  FIGS.  4 A to  4 C , the right and the left are switched in the process when the particle  20   a  moves to the left. That is, when the particle  20   a  comes into contact with the boundary of the display target area  62  and the left margin area  64   a , the particle drawing unit  56  arranges the particle  20   b  in the right margin area  64   b  such that the particle  20   b  comes into contact with the boundary of the display target area  62  and the right margin area  64   b . The particle drawing unit  56  generates a plurality of App images  60  such that as the particle  20   a  moves out to the left margin area  64   a  from the display target area  62 , the particle  20   b  enters the display target area  62  from the right margin area  64   b.    
     In addition, the trail drawing unit  58  gradually shortens the trail object added to the particle  20   a  when the entire particle  20   a  enters the left margin area  64   a  from the display target area  62 , that is, when the entire particle  20   b  enters the display target area  62  from the right margin area  64   b . Along with this, the trail drawing unit  58  starts to generate a trail object to be added to the particle  20   b.    
     According to the display apparatus  10  of the first embodiment, the margin areas are provided at both ends of the display target area  62 , and as the particle  20  enters one of the margin areas, the replacing particle  20  appears from the other margin area. This can suppress the lag of display when the particle  20  crosses the boundary of the image (for example, when the particle  20  moves from the right end to the left end of the display target area  62 ), and the particle  20  can be displayed as if the particle  20  moves on a continuously connected surface. Similarly, this can suppress the lag of display when the trail  22  crosses the boundary of the image, and the trail  22  can be displayed as if the trail  22  moves on a continuously connected surface. 
     In addition, as described in relation to  FIG.  4 C , the generation process of the trail  22   b  added to the particle  20   b  is started when the entire particle  20   b  enters the display target area  62  from the left margin area  64   a , and this can suppress the increase in the amount of calculation of the image generation unit  52 . Furthermore, the width (horizontal width) of the left margin area  64   a  and the right margin area  64   b  is the same as the width (horizontal width) of the particle  20 , and this can suppress the increase in the size of the App image  60  and suppress the increase in the amount of calculation of the image generation unit  52 . Note that the technique described in the first embodiment is also useful when only one type of object (for example, particle  20 ) is moved on the App image  60 . 
     Second Embodiment 
     Parts of the present embodiment different from the first embodiment will be mainly described, and common parts will not be described. In the description, the same reference signs are provided to the constituent elements of the present embodiment that are the same as or corresponding to the constituent elements of the first embodiment. 
     The external configuration of the display apparatus  10  of a second embodiment is the same as the external configuration of the display apparatus  10  of the first embodiment illustrated in  FIG.  1   . In addition, the functional blocks of the display apparatus  10  of the second embodiment are the same as the functional blocks of the display apparatus  10  of the first embodiment illustrated in  FIG.  3   . 
     The width of the particle  20  of the second embodiment is equal to or smaller than the width of the trail  22 . The width in the second embodiment is the vertical width, that is, the length in the direction perpendicular to the movement direction of the particle  20 . In addition, it is preferable that the color of the particle  20  in the second embodiment be the same color or a color similar to the color of the trail  22  (for example, a color at an adjacent or close position in the hue circle). 
       FIGS.  5 A and  5 B  illustrate an example of the App image. When the particle  20   a  moving in the display target area  62  comes into contact with the boundary of the display target area  62  and the right margin area  64   b  as illustrated in  FIG.  5 A , the particle drawing unit  56  arranges the particle  20   b  in the left margin area  64   a  such that the particle  20   b  comes into contact with the boundary of the display target area  62  and the left margin area  64   a  as illustrated in  FIG.  5 B . Along with this, the particle drawing unit  56  deletes the particle  20   a . In other words, the particle drawing unit  56  does not arrange the particle  20   a  in the App image  60  following  FIG.  5 A . 
     The trail drawing unit  58  turns off the monitor function for the particle  20   a  at the time that the particle  20   a  is deleted. However, the trail drawing unit  58  gradually shortens, with time, the trail  22   a  added to the particle  20   a  up to that time, across a plurality of App images  60  after the deletion of the particle  20   a . Along with this, the particle drawing unit  56  draws the particle  20  such that the particle  20   b  gradually enters the display target area  62  from the left margin area  64   a , across a plurality of App images  60  after the deletion of the particle  20   a.    
       FIG.  5 C  also illustrates an example of the App image. As illustrated in  FIG.  5 C , the trail drawing unit  58  starts to generate the trail  22   b  to be added to the particle  20   b  when the entire particle  20   b  enters the display target area  62  from the left margin area  64   a.    
     According to the display apparatus  10  of the second embodiment, when the size of the particle  20  is small and is equal to or smaller than the width of the trail  22 , the particle  20  is not displayed in the display target area  62  for a short time as illustrated in  FIG.  5 B . However, the display of the trail  22  can compensate for the non-display of the particle  20 . This can prevent the boundary of the image from becoming conspicuous, and the particle  20  and the trail  22  can be displayed as if the particle  20  and the trail  22  move on a continuously connected surface. In addition, the number of arranged particles  20  does not increase even temporarily in the display apparatus  10  of the second embodiment, and the increase in the amount of calculation of the image generation unit  52  can be suppressed. 
     The present invention has been described based on the first and second embodiments. The embodiments are illustrative, and those skilled in the art will understand that there can be various modifications for the combinations of the constituent elements and the processes and that the modifications are also within the scope of the present invention. 
     Although the display apparatus  10  generates the image projected onto the screen  12  of the display apparatus  10  in the embodiments, an apparatus outside the display apparatus  10  may generate the image in a modification.  FIG.  6    illustrates a configuration of a system of the modification. In the system, the display apparatus  10  includes a communication unit  70  in place of the image generation unit  52  of the embodiments. The communication unit  70  transmits a video of the user imaged by the camera  40  to an information processing apparatus  80  through a communication network  72  including a local area network (LAN), a wide area network (WAN), the Internet, or the like. In addition, the communication unit  70  receives data of an image (for example, the App image  60  of the embodiments) transmitted from the information processing apparatus  80  through the communication network  72 . The display control unit  54  controls the projector  14  to cause the screen  12  to display the image transmitted from the information processing apparatus  80 . 
     The information processing apparatus  80  may be a server or a personal computer (PC). The information processing apparatus  80  includes a communication unit  82  and the processing unit  42 . The communication unit  82  inputs, to the processing unit  42 , the video of the user transmitted from the display apparatus  10  and transmits, to the display apparatus  10 , the image data that is output from the processing unit  42  and that is to be displayed on the screen  12  of the display apparatus  10 . The processing unit  42  includes the action detection unit  50 , the image generation unit  52 , and an output unit  84 . As already described in the embodiments, the functional blocks of the processing unit  42  may be implemented as computer programs. 
     The processes of the action detection unit  50  and the image generation unit  52  are similar to the processes in the embodiments, and the description will not be repeated. The output unit  84  outputs, to the communication unit  82 , the content of at least the display target areas  62  of the plurality of App images  60  generated by the image generation unit  52  and transmits the content to the display apparatus  10  through the communication unit  82 . The output unit  84  may transmit the content of the display target area  62  of the App image  60  to the display apparatus  10  or may transmit the entire App image  60  to the display apparatus  10 . In the latter case, the display control unit  54  of the display apparatus  10  extracts the content of the display target area  62  of the App image  60  and causes the screen  12  to display the content. The configuration of a first modification can be applied to either one of the first embodiment and the second embodiment, and the system of the first modification attains the advantageous effects of each of the first embodiment and the second embodiment. 
     In addition, although not mentioned in the embodiments, the margin areas of the App image  60  may be provided above and below instead of the left and the right of the display target area  62 , and the margin areas may also be provided above and below in addition to the left and the right of the display target area  62 . 
     Any combination of the embodiments and the modification is also useful as an embodiment of the present disclosure. The new embodiment created by the combination has advantageous effects of both the combined embodiment and modification. In addition, those skilled in the art will also understand that the functions to be fulfilled by the constituent elements described in the claims are realized by individual constituent elements illustrated in the embodiments and the modification or by cooperation between the constituent elements illustrated in the embodiments and the modification. 
     INDUSTRIAL APPLICABILITY 
     The invention can be used for a display apparatus that displays an image on a cylindrical screen. 
     REFERENCE SIGNS LIST 
     
         
           10 : Display apparatus 
           12 : Screen 
           52 : Image generation unit 
           54 : Display control unit 
           56 : Particle drawing unit 
           58 : Trail drawing unit