Patent Publication Number: US-2011063194-A1

Title: Head mounted display device

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority from Japanese Patent Application No. 2009-215085, filed on Sep. 16, 2009, the entire subject matter of which is incorporated herein by reference. 
     BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The invention relates to a head mounted display device that displays a content image generated based on content data to a user. 
     2. Description of the Related Art 
     Compact apparatuses that display an image have been proposed. For example, a portable data display is proposed. This portable data display is connected to a digital camera, video camera, or memory card via a data conversion adapter. The portable data display displays images, which are memorized in the apparatus that connects to the data conversion adapter, on a data display. The data display is platelike, and hence it is light-weight and compact. The data conversion adapter is also light-weight and compact. Thus, the portable data display has three advantages: (1) facile portability, (2) little space for storing and installation, (3) reasonable manufacturing cost because of its simple structure (see e.g., JP-A-11-249589). 
     As an example of compact apparatuses that display an image, head mounted display devices (hereinafter interchangeably referred to as “HMDs”), which is mounted on a head of a user, have been proposed (see e.g., JP-A-2004-21931). 
     SUMMARY OF THE DISCLOSURE 
     When a sequence of works including a plurality of processes is carried out, a worker may refer to a manual in which points of each process are written while the worker proceeds the sequence of works. In this case, for the purpose of efficient operation, it would be useful for the worker to display a content image, i.e., a page of the manual that includes a point of an ongoing process, in HMDs. 
     When each process has finished, the worker may images an object that is visible by his eyes, namely objects within a field of view of the worker. The image data would be benefit for a predetermined management. For example, objects and place related to a operation that is carried out by the worker are imaged, and it is confirmed whether the processes in the sequence of works are carried out preferably using the image data. In this case, the objects should be imaged at the end of each process. 
     Accordingly, it is an aspect of the present invention to provide a HMD that can prevent a user from missing out on imaging a predetermined object when a plurality of content images are sequentially displayed thereof. 
     In an embodiment of the invention, a head mounted display device comprises an image display displaying a content image based on content data, an imager imaging an object based on an imaging command, and a processor executing software units including, a display control unit configured to control the image display such that the image display sequentially displays a plurality of content images, at least one of the plurality of content images being connected to the imaging command; a first judgment unit configured to judge whether the imaging command is connected to one content image that is being displayed by the image display, wherein the display control unit is configured to control the image display such that the image display displays another content image, when the first judgment unit judges that the imaging command is connected to the one content image, and when the imager images the object. 
     According to another embodiment of the invention, a head mounted display device comprises an image display displaying a plurality of content images, an imager imaging an object based on an imaging command that is connected to at least one of the plurality of content images, and a processor executing software units including a first judgment unit configured to judge whether the imaging command is connected to one content image that is being displayed by the image display, and a display control unit configured to control the image display such that the image display sequentially displays the plurality of content images, the display control unit controlling the image display such that the image display displays another content image, when the first judgment unit judges that the imaging command is connected to the one content image, and when the imager images the object regarding to the one content image. 
     According to another embodiment of the invention, a head mounted display device comprises an image display displaying a plurality of content images regarding to different successive operations to be performed by an operator, an imager imaging an object based on an imaging command, the imaging command being connected to at least one of the plurality of content images, and a processor executing software units including a first judgment unit configured to judge whether the imaging command is connected to one content image that is being displayed by the image display regarding to one operation of the different successive operations, and a display control unit configured to control the image display so as to shift from displaying the one content image to displaying another content image following to the one content image, when the first judgment unit judges that the imaging command is connected to the one content image, and when the imager images the object in the one operation regarding to the one content image. 
     Other objects, features, and advantages of embodiments of the invention will be apparent to those skilled persons of ordinary skill in the art from the following detailed description and of embodiments with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the invention, the needs satisfied thereby, and the objects, features, and advantages thereof, reference now is made to the following description taken in connection with the accompanying drawings. 
         FIG. 1  is a schematic view of a HMD, e.g., HMD  10 , according to an embodiment of the invention. 
         FIG. 2A  is a plan view of the HMD  10  according to an embodiment of the invention. 
         FIG. 2B  is a front view of the HMD  10  according to an embodiment of the invention. 
         FIG. 2C  is a left side view of the HMD  10  according to an embodiment of the invention. 
         FIG. 3  is a functional block diagram of the HMD  10  according to an embodiment of the invention. 
         FIG. 4  is a functional block diagram of an image display unit according to an embodiment of the invention. 
         FIG. 5  is a flow chart showing a content image display process of the HMD  10  according to an embodiment of the invention. 
         FIG. 6  is a schematic drawing showing a content image. 
         FIG. 7  is a schematic drawing showing a imaging command table. 
         FIG. 8  is a flow chart showing a content image display process of the HMD  10  according to another embodiment of the invention. 
         FIG. 9  is a schematic drawing showing a content image including an imaging command and a content image including a matching image. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Embodiments of the invention and their features and technical advantages may be understood by referring to  FIGS. 1-9 , like numerals being used for like corresponding portions in the various drawings. 
     &lt;Mechanical Description of the HMD  10 &gt; 
     As shown in  FIGS. 1 and 2 , the HMD  10  may includes a HMD body  100  and a control box  200 . The HMD body  100  is mounted on a head of a user. The control box  200  is mounted on any preferable portion of the user, e.g., a waist of the user. 
     The HMD body  100  may include a front frame  108 , a left connection portion  106 A, a right connection portion  106 B, a left temple portion  104 A, and a right temple portion  104 B. The front frame  108  may include a nose pad  110 , which contacts with a nose of the user, in the central portion thereof. The left connection portion  106 A and the right connection portion  106 B may be fixed to a left side edge and a right side edge of the front frame  108 , respectively. One end portions of the left temple portions  104 A and the right temple portion  104 B may be rotatably connected to the connection portions  106 A and  106 B by a left hinge  112 A and a right hinge  112 B. A left ear pad  102 A and a right ear pad  102 B, which contact to ears of the user, may be fixed to the other end portions of the left temple portion  104 A and the right temple portion  104 B. Specifically, the left temple portion  104 A and the right temple portion  104 B may be rotatable around rotation axes that extend in the up-and-down direction of the left hinge  112 A and the right hinge  112 B, respectively. The front frame  108 , the left connection portion  106 A, the right connection portion  106 B, the left temple portion  104 A, and the right temple portion  104 B may construct a skeleton of the HMD body  100  which is the same as that of an ordinal eyeglass. The HMD body  100  may be mounted on the head of the user by the left ear pad  102 A, the right ear pad  102 B, and the nose pat  110 . Note that the left ear pad  102 A, the right ear pad  102 B, the left temple portion  104 A, and the right temple portion  104 B are omitted in  FIG. 2B . 
     An image display  114  may be mounted on the skeleton of the HMD body  100  by an mounting member  122  that is mounted around the left connection portion  106 A. When the image display  114  is mounted around the left connection portion  106 A by the mounting member  122 , it may be placed on a position that is level with a left eye  118  of the user who wears the HMD body  100 . A charge-coupled device (CCD) sensor  260  may be fixed on an upper surface of the image display  114  (see  FIG. 1 ). The image display  114  and the CCD sensor  260  may be connected to the control box  200  via a signal cable  250 . The control box  200  may play (i.e., perform rendering process to) content data  2062  memorized in a predetermined memory area. Image signals, which includes a content image generated by the rendering process, may be sent to the image display  114  via the signal cable  250 . The image display  114  may receive the image signals from the control box  200 , and the image display  114  may project the content image, which is based on the image signals, to a half mirror  116 . 
     An image light  120   a,  which represents the content image projected from the image display  114 , may be reflected by the half mirror  116 . A reflected image light  120   b  may enter the left eye  118 , which allow the user to view the content image. Since the half mirror  116  may be configured to be translucent to visible wavelengths, the user may view the content image superimposed on background substances with the HMD body  100  mounted on the head of the user. 
     Various kind of displays, e.g., a liquid crystal display and an organic electroluminescent display, may be adopted as the image display  114 . In this embodiment, a retinal scanning display may be adopted. That is, the image display  114  may two-dimensionally scan the image lights  110   a,    110   b,  according to the image signals received thereby. The scanned image lights may enter the pupil of left eye  118 , drawing the content image on the retina of the left eye  118 . 
     &lt;Control Box  200 &gt; 
     As shown in  FIG. 3 , the control box  200  may include a CPU  202  to control the control box  200 , a program ROM  204  to memorize programs for various processes including a content image display process (see below), a flash RAM  206  which is nonvolatile, a RAM  208  as a working storage area. For example, the CPU  202  may execute a program for the content image display process, memorized in the program ROM  204 , in the RAM  208 . Various software units may be accomplished by the CPU  202  which executes various programs memorized in the program ROM  204 . The flash RAM  206  may memorize content data  2062 , an imaging command table  2064 , a matching image  2066 , an imaged data table  2068 , and imaged data  2070 . 
     The control box  200  may further include a video RAM  210 , a HMD interface (I/F) controller  220 , an external I/F controller  230 , and a peripheral I/F  240 . The video RAM  210  may be a frame memory that memorizes the content images that are generated by the rendering process and are received by an external apparatus  400 . The HMD I/F controller  220  may be connected to the HMD body  100  via the signal cable  250 . On the basis of commands from the CPU  202 , the HMD I/F controller  220  may control input-output of various signals between the HMD body  100  and the image display  114 . Specifically, the HMD I/F controller  220  may send to the image display  114  the image signals, which includes the content image, and a control signal for the image display  114 . The external I/F controller  230  may be connected to the external apparatus  400 , e.g., a personal computer, via a predetermined cable. The external I/F controller  230  may receive image signals from the external apparatus  400 . The external I/F controller  230  may store content images based on the received image signals in the video RAM  210 . The peripheral I/F  240  may be an interface device to which the CCD sensor  240 , a power switch  270 , a power lamp  280 , and an operation unit  290  connect. The CPU  202  may receive a imaged data  2070  imaged by the CCD sensor  260  via the peripheral I/F  240 . The user may switch the image display  114  and the control box  200  via the power switch  270 . The power lamp  280  may light when the power switch is in the on position, and may be go off when the power switch is in the off position. The operation unit  290  may receive input of a predetermined command from the user. In other word, the user may input the predetermined command via the operation unit  290 . 
     &lt;Image Display  114 &gt; 
     The image display  114  may include a light generator  2 , an optical fiber  19 , a collimate optical system  20 , a horizontal scan unit  21 , a first relay optical system  22 , a vertical scan unit  23  and a second relay optical system  24 . The light generator  2  may include an image signal processor  3 , a light source unit  30  and an optical multiplexer  40 . The image signal processor  3  may generate a B signal, a G signal, an R signal, a horizontal synchronizing signal and a vertical synchronizing signal, which are elements for composing the content image based on image signals supplied from the HMD I/F controller  220 . 
     The light source unit  30  may include a B laser driver  31 , a G laser driver  32 , an R laser driver  33 , a B laser  34 , a G laser  35  and an R laser  36 . The B laser driver  31  may drive the B laser  34  so as to generate blue light having intensity in accordance with a B signal from the image signal processor  3 . The G laser driver  32  may drive the G laser  35  so as to generate green light having intensity in accordance with a G signal from the image signal processor  3 . The R laser driver  33  may drive the R laser  36  so as to generate red light having intensity in accordance with an R signal from the image signal processor  3 . The B laser  34 , the G laser  35  and the R laser  36  may be configured by a semiconductor laser or a solid laser having harmonic producer. 
     The optical multiplexer  40  may include collimate optical systems  41 ,  42 ,  43  that collimate the laser light, dichroic mirrors  44 ,  45 ,  46  that multiplex the collimated laser light and a collecting optical system  47  that guides the multiplexed laser light to the optical fiber  19 . The blue laser light emitted from the B laser  34  may be collimated by the collimate optical system  41  and then incident onto the dichroic mirror  44 . The green laser light emitted from the G laser  35  may be collimated by the collimate optical system  42  and then incident onto the dichroic mirror  45 . The red laser light emitted from the R laser  36  may be collimated by the collimate optical system  43  and then incident onto the dichroic mirror  46 . The laser lights of three primary colors, which are respectively incident onto the dichroic mirrors  44 ,  45 ,  46 , are reflected or transmitted in a wavelength selection manner and multiplexed into one light that is then incident onto the collecting optical system  47 . The multiplexed laser light is collected by the collecting optical system  47  and then incident to the optical fiber  19 . 
     The horizontal scan unit  21  may include a horizontal optical scanner  21   a , a horizontal scanning driver  21   b,  and a horizontal scanning angle detector  21   c.  The horizontal scanning driver  21   b  may drive the horizontal optical scanner  21   a  in accordance with the horizontal synchronizing signal from the image signal processor  3 . The horizontal scanning angle detector  21   c  may detect a rotational status of the horizontal optical scanner  21   a,  e.g., a rotational angle and a rotational frequency thereof. A signal that represents the rotational status, detected by the horizontal scanning angle detector  21   c , may be transmitted to the HMD I/F controller  220 , and may feed back to the horizontal synchronizing signal. 
     The vertical scan unit  23  may include a vertical optical scanner  23   a,  a vertical scanning driver  23   b,  and a vertical scanning angle detector  23   c.  The vertical scanning driver  23   b  may drive the vertical optical scanner  23   a  in accordance with the vertical synchronizing signal from the image signal processor  3 . The vertical scanning angle detector  23   c  may detect a rotational status of the vertical optical scanner  23   a,  e.g., a rotational angle and a rotational frequency thereof. A signal that represents the rotational status, detected by the vertical scanning angle detector  23   c,  may be transmitted to the HMD I/F controller  220 , and may feed back to the vertical synchronizing signal. 
     The laser light may be converted into a light horizontally and vertically scanned and then allowed to be projected as the content image by the horizontal optical scanner  21   a  and the vertical optical scanner  23   a.  Specifically, the laser light emitted from the optical fiber  19  may be converted into collimated light by the collimate optical system  20  and then guided to the horizontal optical scanner  21   a . The laser light that is horizontally scanned by the horizontal optical scanner  21   a  may pass through the first relay optical system  22  and may be then incident on the vertical optical scanner  23   a  as parallel light. At this time, an optical pupil may be formed at the position of the optical vertical scanner  23   a  by the first relay optical system  22 . The laser light, scanned vertically by the vertical optical scanner  23   a,  may pass through the second relay optical system  24  and may be then incident on the pupil of the left eye  118 . Herein, the pupil of the left eye  118  and the optical pupil at the position of the vertical optical scanner  23   a  may have a conjugate relation by the second relay optical system  24 . 
     In this embodiment, the laser light may be first horizontally scanned by the horizontal optical scanner  21   a  and then may be vertically scanned by the vertical optical scanner  23   a.  However, the horizontal optical scanner  21   a  and the vertical optical scanner  23   a  may be interchangeable each other. That is, the laser light may be first vertically scanned by the vertical optical scanner  23   a  and then may be horizontally scanned by the horizontal optical scanner  21   a.    
     &lt;Content Image Display Process&gt; 
     Here, two examples are explained as for content image display processes; one is related to manual imaging and another is related to automatic imaging. The content image display processes may be accomplished by the CPU  202  which executes dedicated programs for those processes, memorized in the program ROM  204 , in the RAM  208 . In these processes, the CPU  202  may use image data  2070  imaged by the CCD sensor  260  and like. 
     The content data  2062  may be data of a manual that explains assembly operations of a predetermined product. The content data  2062  may include a plurality of pages and each of the plurality of pages corresponds to each process of the assembly operation. The user who uses the HMD  10  may carry out the assembly operations with viewing a content image corresponding to each operation of the assembly operations. The user may input a command to start playing the content data  2062  by operating the operation unit  290 . The CPU  202  may start a content image display processes, which is described below, in response to the command. 
     &lt;An Example of the Content Image Display Processes&gt; 
     An example of the content image display processes may be explained with referring to  FIGS. 5-7 . The CPU  202 , which starts the content image display process, may display a content image that shows a predetermined page of the manual showed by the content data  2062  (S 100 ). For example, the CPU  202  may display a content image that shows the first page of the manual. As shown in  FIG. 6 , the content image may include text data and image data. The text data may be a text that explains inserting a □ 8  pin to an upper-right hole in the base plate. The image data may include an image of targets of the process such as a base plate, a hole, and a pin. 
     When the content image is displayed, the CPU  202  may load the content data  2062 , memorized in the flash ROM  206 , into the RAM  208 . The CPU  202  may perform the rendering process to the content data  2062 . The CPU  202  may store a content image, generated by the rendering process, in the video RAM  210 . Otherwise, the CPU  202  may store a content image, received via the external I/F controller  230 , to the video RAM  210 . The CPU  202  may render the image display  114  displays the content image. That is, the CPU  202  may send image signals, which include the content image memorized in the video RAM  210 , and control signals for displaying the content image to the image display  114  via the HMD I/F controller  220 . These processes allow the user to view the content image. 
     In step S 102 , the CPU  202  may judge whether the user inputs a page feed command by operating the operation unit  290 . If the page feed command is not input (i.e., S 102 : No), the CPU  202  may wait until the page feed command is input. On the other hand, If the page feed command is input (i.e., S 102 : Yes), the CPU may receive the page feed command. Then, the CPU  202  may refer to the imaging command table  2064  (see  FIG. 7  for the details) that is memorized in the flash ROM  206  (S 104 ). 
     The CPU  202  may judge whether a imaging command is connected to a page of the manual, shown by the content image displayed by the image display  114 , in the imaging command table  2064  (S 106 ). If an imaging command is connected to a page of the manual in the imaging command table  2064  (i.e., S 106 : Yes), the process may proceed to step S 108 . On the other hand, if a imaging command is not connected to a page of the manual in the imaging command table  2064  (i.e., S 106 : No), the process may proceed to step S 118 . When the step S 106  is “No”, the CPU  202  may skip steps from S 108  to S 116 . For example, according to the imaging command table  2064  in  FIG. 7 , when the first or nth page of the manual is displayed as the content image, the judgment in the step S 106  is affirmative (S 106 : Yes). On the other hand, when pages of the manual except for the first or nth page are displayed as the content image, the judgment in the step S 106  is negative (S 106 : No). 
     In step S 108 , The CPU  202  may render the image display  114  display a message that includes a imaging request to image an object. For example, a massage “Image the product that is in the middle of the assembling before the process proceeds.” may be displayed as a part of an image displayed by the image display  114 . When a plurality of objects should be imaged, a massage, which means that each object should be imaged respectively, may be displayed. The CPU  202  may refer to the imaging command table  2064  to check the number of objects to be imaged for each page of the manual. When the first page of the manual is displayed as a content image, the CPU  202  may determine the number of objects to be images to be “one”. When the nth page of the manual is displayed as a content image, the CPU  202  may determine the number of objects to be images to be “two”. 
     In step S 110 , the CPU  202  may judge whether an object is imaged by the CCD sensor  260 . The imaging of the object may be accomplished by the operation of the operation unit  290  by the user. The object may be a product that is in the middle of the assembling or a working area. When the imaging has not finished (S 110 : No), the CPU  202  may continue to display the content image, and the process backs to step S  108 . Note that if there are a plurality of object to be imaged, a message, which means that all the objects should be imaged, may be displayed sequentially until all the objects are imaged. For example, a message, which means that one object should be imaged, may be displayed at first. When the object is imaged, another message, which means that another object should be imaged, may be displayed. 
     On the other hand, the imaging has finished for the object(s) (S 110 : Yes), the CPU  202  may verify the imaged data  2070  (S 112 ). Specifically, the CPU  202  may judge whether the imaged data  2070  is a defocused image. Otherwise, when the matching image  2066 , which is connected to each page of the manual, is recorded in the imaging command table  2064 , the CPU  202  may compare the imaged data  2070  with the matching image  2066  that connects to a corresponding page of the manual. Specifically, the CPU  202  may judge whether a target, which is shown by the matching image  2066 , is included as the object in the imaged data  2070 . This judgment may be accomplished by a well-known pattern recognition process. The matching image  2066  is memorized in the flash ROM  206 . When a plurality of the imaged data  2070  are imaged, the CPU  202  may judge the defocusing and the analogy of the corresponding matching image  2066  for each imaged data  2070 . According to the imaging command table  2064  shown in  FIG. 7 , when the content image, which is displayed by the image display  114 , means the first page of the manual, the CPU  202  may verify the first imaged data  2070   a  and the matching image  2066 A. When the content image, which is displayed by the image display  114 , means the nth page of the manual, the CPU  202  may verify the second imaged data  2070   r  and the matching image  2066 R, and the CPU  202  may verify the third imaged data  2070   d  and the matching image  2066 D. 
     In step S 114 , the CPU  202  may judge the result of the verification in step S 112 . If the imaged data  2070  is not appropriate, the process may back to step S 108  and steps from S 108  to S 112  may be performed again. Note that when the number of the imaged data  2070  is plural, the judgment in step S 114  may be negative if at least one of the imaged data  2070  is not appropriate. In this case, it may be possible to perform imaging for the imaged data  2070  that are not judged to be appropriate. On the other hand, if imaged data  2070  is appropriate (S 114 : Yes), the process may proceed to step S 116 . Note that the term “imaged data  2070  is appropriate” may mean that imaging condition of the imaged data  2070  is appropriate (e.g., clear focusing, not overexposure/underexposure), and when the matching image  2066  is recorded in the imaging command table  2064 , the term may further mean that the imaged data  2070  and the matching image  2066  are analogous. 
     In step S 116 , the CPU  202  may connect the imaged data  2070  to the content image, specifically the manual page that is shown by the content image, displayed in step S 110  or S 118 . The imaged data  2070  may be recorded in the imaged data table  2068 , and hence memorized in the flash ROM  206 . For example, when the first page of the manual is displayed, the CPU  202  may connect the first imaged data  2070   a  to the first page of the imaged data table  2068  to record thereof, and hence memorize the first imaged data  2070   a  to the flash ROM  206 . When the nth page of the manual is displayed, the CPU  202  may connect the second imaged data  2070   r  and the third imaged data  2070   r  to the nth page of the imaged data table  2068  to record thereof, and hence memorize the second imaged data  2070   r  and the third imaged data  2070   r  to the flash ROM  206 . Then the process may proceed to step S 118 . 
     In step S 118 , the CPU  202  may display the next page of the manual. For example, when a content image that means the first page of the manual is displayed, a content image that means second page of the manual may be displayed. In step S 120 , the CPU  202  may judge whether a finish command is received. The finish command in step S 120  may be generated by inputting a finish input to the operation unit  290  by the user. If the finish command is not received (S 120 : No), the process may back to step S 104 . On the other hand, the finish command is received (S 120 : Yes), process may terminate. 
     &lt;Another Example of the Content Image Display Processes&gt; 
     Another example of the content image display processes may be explained with referring to  FIG. 8 . The CPU  202 , which starts the content image display process, may perform steps from S 200  to S 206  sequentially. Here, steps from S 200  to S 206  correspond to steps from S 100  to S 106  shown in  FIG. 5 . Thus, explanations of steps from S 200  to S 206  are omitted. Note that the process may proceed to step S 208  if the judgment of step S 206  is affirmative (S 206 : Yes), and the process may proceed to step S 218  without performing steps from S 208  to S 216  if the judgment of step S 206  is negative (S 206 : No). 
     In step S 208 , the CPU  202  may display a message that includes count down to image (i.e., residual seconds to start imaging) and an image of a target to be imaged as an object. In this message, a message may include the message that urges the user to look at the object by the left eye  118 . Since the CCD sensor  260  may be fixed on an upper surface of the image display  114 , preferable imaging may be performed by including such a message. When the time has come to image, the CPU  202  may render the CCD sensor  260  image automatically (S 210 ). If a plurality of objects to be imaged is recorded as for the content image displayed, such as the nth page of the manual, the step S 208  and S 210  may be iterated for each of the object. 
     After the object is imaged in step S 210 , the CPU  202  may perform steps from S 212  to S 220  sequentially. Here, steps from S 212  to S 220  correspond to steps from S 112  to S 120  shown in  FIG. 5 . Thus, explanations of steps from S 212  to S 220  are omitted. 
     &lt;Advantages of the embodiment&gt; 
     In the embodiment above, when an imaging of a certain object is required (S 106 : Yes in  FIGS. 5  and S 206 : Yes in  FIG. 8 ) as for a page of the manual shown by a content image displayed by the image display  114  (S 100  and S 118  in  FIGS. 5  and S 200  and S 218  in  FIG. 8 ), a content image that shows the next page of the manual may be displayed (S 118  in  FIGS. 5  and S 218  in  FIG. 8 ) if an appropriate imaged data  2070  is obtained (S 114 : Yes in  FIGS. 5  and S 214 :Yes in  FIG. 8 ). Thus, the appropriate imaged data  2070 , which includes the object, can be obtained. In other word, forgetting to image the object and obtaining the inappropriate imaged data  2070  can be avoided. 
     When it is required to check whether all the assembly processes of a predetermined product have preferably finished, an imaging of a specific object may be required. In this case, the user can confirm all the assembly processes by the imaged data  2070  after he has finished all the assembly processes. 
     In an embodiment above, the HMD body  100  and the control box  200 , which are elements of the HMD  10 , may be separated. However, a HMD may include the HMD body  100  and the control box  200  in an integrated manner. In this case, each element of the control box  200  (see  FIG. 3 ) may be contained in a chassis of the image display unit  114 . 
     In an embodiment above, the image command table  2064  (see  FIG. 7 ) may be used in step S 106  (see  FIG. 5 ). That is, in step S 106 , the CPU  202  may judge whether a imaging command is connected to a page of the manual, shown by the content image displayed by the image display  114 , in the imaging command table  2064 . If the judgment if affirmative (i.e., S 106 : Yes), the object may be imaged (S 108 ), the imaged data  2070  may be verified based on the matching image  2066 , and (S 112 ), and the appropriateness of the imaged data  2070  may be judged (S 114 ). On the other hand, if the judgment is negative (i.e., S 106 : No), the process may proceed to step S 118  without performing steps from S 108  to S 116 . 
     Here, steps S 106 , S 112  and S 114  may be accomplished by using a content image and a matching image, both are shown in  FIGS. 9A-9C , that include imaging commands without the image command table  2064 . Specifically, in step S 106 , the CPU  202  may judge whether a specific object is located in a predetermined position of a content image which is displayed in the image display  114 . When an object  2162  is located in a lower-right area of the content image, as shown in  FIG. 9A , the judgment in S 106  may be affirmative (S 106 : Yes). On the other hand, when an object  2162  is not located in a lower-right area of the content image, as shown in  FIG. 9B , the judgment in S 106  may be negative (S 106 : No). 
     In steps S 112  and S 114 , content data may include specific data that shows a matching image. In this case, the judgment of the appropriateness of the imaged data  2070  may be accomplished by comparing the matching image included in the content data and the imaged data  2070 . Specifically, a matching image that is identical with an object may be placed in the next page of a content image that shows a manual page in which the object  2162 , which indicates an imaging command, is included as shown in  FIG. 9A . 
     As shown in  FIG. 9C , the matching image may include an object  2262  in a lower right area thereof. The object  2262  may be different from the object  2162  in configurations such as shape, colors, and patterns. The CPU  202  may verify the matching image on the basis of the object  2262 . Then, after the CPU  202  finishes imaging (S 110 ), the CPU  202  may compare the imaged data  2070  with the matching image (S 112 ), and thereby may judge whether the imaged data  2070  is appropriate (S 114 ). The CPU  202  may control the HMD  10  such that the matching data is not displayed in step S 118 . This can be applied to steps in S 208 , S 212  and S 212 . 
     The apparatus and methods described above with reference to the various embodiments are merely examples. It goes without saying that they are not confined to the depicted embodiments. While various features have been described in conjunction with the examples outlined above, various alternatives, modifications, variations, and/or improvements of those features and/or examples may be possible. Accordingly, the examples, as set forth above, are intended to be illustrative. Various changes may be made without departing from the broad spirit and scope of the underlying principles.