Patent Publication Number: US-11393196-B2

Title: Line of sight assistance device and method

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2018-231164 filed in Japan on Dec. 10, 2018. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to an assistance device, an assistance method, and a computer-readable recording medium. 
     2. Related Art 
     A technique for displaying on a mobile phone an image around a vehicle seen from a viewpoint of a user in the vehicle is known (for example, refer to JP 2013-162328 A). In this technique, when the user in the vehicle aims the mobile phone, an image in which the vehicle is transparent in a direction in which the user aims the mobile phone is displayed on a display of the mobile phone. 
     SUMMARY 
     Meanwhile, along with development of high-speed and high-capacity communication, a device that can acquire a large amount of information via a network has been manufactured. Under such circumstances, it is expected that the device can make the user wearing the device intuitively grasp a danger hidden in a surrounding environment of the user based on information that the device has acquired by means of communication. 
     The disclosure is accomplished by taking such matters as mentioned above into consideration thereof, and it is desirable to provide an assistance device, an assistance method, and a computer-readable recording medium enabling a user to intuitively grasp a surrounding environment. 
     In some embodiments, provided is an assistance device enabling communication with a wearable device. The assistance device includes: a memory; and a processor including hardware, the processor being configured to acquire line-of-sight information about a line of sight of a user wearing the wearable device, based on the line-of-sight information, generate blind region state information indicating a state of a blind region shielded by a shielding object in a visual field region of the user, and output the blind region state information to the wearable device. 
     In some embodiments, provided is an assistance device configured to be worn by a user. The assistance device includes: a memory; and a processor including hardware. The processor is configured to acquire line-of-sight information about a line of sight of the user, based on the line-of-sight information, generate blind region state information indicating a state of a blind region shielded by a shielding object in a visual field region of the user, and output the blind region state information. 
     In some embodiments, provided is an assistance method performed by an assistance device enabling communication with a wearable device. The assistance method includes: acquiring line-of-sight information about a line of sight of a user wearing the wearable device, based on the line-of-sight information read out from a memory, generating blind region state information indicating a state of a blind region shielded by a shielding object in a visual field region of the user, and outputting the blind region state information to the wearable device. 
     In some embodiments, provided is a non-transitory computer-readable recording medium with an executable program stored thereon. The program causes an assistance device enabling communication with a wearable device to execute: acquiring line-of-sight information about a line of sight of a user wearing the wearable device; based on the line-of-sight information, generating blind region state information indicating a state of a blind region shielded by a shielding object in a visual field region of the user; and outputting the blind region state information to the wearable device. 
     The above and other objects, features, advantages and technical and industrial significance of this disclosure will be better understood by reading the following detailed description of presently preferred embodiments of the disclosure, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating a schematic configuration of an assistance system according to a first embodiment; 
         FIG. 2  illustrates a schematic configuration of a wearable device according to the first embodiment; 
         FIG. 3  is a block diagram illustrating a functional configuration of the wearable device according to the first embodiment; 
         FIG. 4  is a flowchart illustrating an overview of processing executed by the wearable device according to the first embodiment; 
         FIG. 5  schematically illustrates an example of a shielding object; 
         FIG. 6  schematically illustrates an example of blind region state information according to the first embodiment; 
         FIG. 7  is a flowchart illustrating an overview of processing executed by the wearable device according to a second embodiment; 
         FIG. 8  schematically illustrates an example of blind region state information according to the second embodiment; 
         FIG. 9  is a flowchart illustrating an overview of processing executed by the wearable device according to a third embodiment; 
         FIG. 10  schematically illustrates an example of blind region state information according to the third embodiment; 
         FIG. 11  schematically illustrates an example of blind region state information that a control unit outputs to a projection unit according to a modification example of the third embodiment; 
         FIG. 12  illustrates a schematic configuration of an assistance system according to a fourth embodiment; 
         FIG. 13  is a block diagram illustrating a functional configuration of the assistance system according to the fourth embodiment; 
         FIG. 14  is a flowchart illustrating an overview of processing executed by an assistance device according to the fourth embodiment; 
         FIG. 15  schematically illustrates an example of blind region state information according to the fourth embodiment; 
         FIG. 16  schematically illustrates another example of blind region state information according to the fourth embodiment; 
         FIG. 17  schematically illustrates another example of blind region state information according to the fourth embodiment; 
         FIG. 18  illustrates an example of a shape in an image corresponding to blind region state information according to the fourth embodiment; 
         FIG. 19  illustrates an example of another shape in an image corresponding to blind region state information according to the fourth embodiment; 
         FIG. 20  illustrates an example of another shape in an image corresponding to blind region state information according to the fourth embodiment; 
         FIG. 21  is a schematic view illustrating a schematic configuration of an assistance system according to a fifth embodiment; 
         FIG. 22  illustrates a schematic configuration of a wearable device according to another embodiment; 
         FIG. 23  illustrates a schematic configuration of a wearable device according to another embodiment; 
         FIG. 24  illustrates a schematic configuration of a wearable device according to another embodiment; 
         FIG. 25  illustrates a schematic configuration of a wearable device according to another embodiment; and 
         FIG. 26  illustrates a schematic configuration of a wearable device according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinbelow, embodiments of the disclosure will be described with reference to the drawings. Note that the disclosure is not limited to the following embodiments. Also, in the following description, identical components are labeled with the same reference signs. 
     First Embodiment 
     Configuration of Assistance System 
       FIG. 1  is a schematic view illustrating a schematic configuration of an assistance system according to a first embodiment.  FIG. 2  illustrates a schematic configuration of a wearable device according to the first embodiment.  FIG. 3  is a block diagram illustrating a functional configuration of the wearable device according to the first embodiment. 
     An assistance system  1000  illustrated in  FIGS. 1 to 3  includes a wearable device  1  that a user U 1  can wear and a server  2 . The wearable device  1  and the server  2  are configured to enable mutual information communication via a base station  3  and a network  4 . Also, the wearable device  1  receives a signal from a plurality of global positioning system (GPS) satellites  5  and calculates a position of the wearable device  1  itself based on the received signal. Also, the server  2  acquires via the base station  3  and the network  4  image data generated when the GPS satellite  5  captures from the air an image of the user U 1  wearing the wearable device  1  and a surrounding area. Note that, in the first embodiment, the wearable device  1  functions as an assistance device. 
     Configuration of Wearable Device 
     First, a configuration of the wearable device  1  will be described. As illustrated in  FIGS. 1 to 3 , the wearable device  1  includes an image capturing unit  11 , a nine-axis sensor  12 , a line-of-sight sensor  13 , a projection unit  14 , a global positioning system (GPS) sensor  15 , a wearing sensor  16 , a communication unit  17 , and a control unit  18 . Although the nine-axis sensor  12  is used in the present example, the sensor may function less in a case in which a three-axis or six-axis sensor is sufficient. 
     Under control of the control unit  18 , the image capturing unit  11  captures an image along a line of sight of a user, for example, to generate image data and outputs the image data to the control unit  18 . The image capturing unit  11  includes an optical system including one or a plurality of lens(es) and a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), or the like light-receiving an object image obtained by converging light by means of the optical system to generate image data. As illustrated in  FIG. 2 , a plurality of image capturing units  11  may be provided in the wearable device  1 . 
     The nine-axis sensor  12  includes a three-axis gyro sensor, a three-axis acceleration sensor, and a three-axis geomagnetic sensor (compass). The nine-axis sensor  12  detects angular velocity and acceleration generated in the wearable device  1  and outputs the detection results to the control unit  18 . The nine-axis sensor  12  also detects geomagnetism to detect an absolute direction and outputs the detection result to the control unit  18 . 
     The line-of-sight sensor  13  detects a direction of a line of sight of a driver, who is a wearer of the wearable device  1 , and outputs the detection result to the control unit  18 . The line-of-sight sensor  13  includes an optical system, a CCD or a CMOS, a memory, and a processor including hardware such as a CPU and a GPU. With use of known template matching, for example, the line-of-sight sensor  13  detects an unmoving part of a driver&#39;s eye (for example, the inner corner of the eye) as a reference point and a moving part of the eye (for example, the iris) as a moving point and detects the direction of the line of sight of the driver based on a positional relationship between the reference point and the moving point. 
     The projection unit  14  projects image, video, and character information to a display unit (for example, a lens unit) of the wearable device or the retina of the driver under control of the control unit  18 . The projection unit  14  includes RGB laser beams emitting R, G, and B laser beams, a MEMS mirror reflecting the laser beams, a reflection mirror projecting the laser beams reflected on the MEMS mirror to the retina of the driver, and the like. 
     The GPS sensor  15  calculates positional information about a position of the wearable device  1  based on signals received from the plurality of GPS satellites and outputs the calculated positional information to the control unit  18 . The GPS sensor  15  includes a GPS reception sensor and the like. 
     The wearing sensor  16  detects a user&#39;s wearing state and outputs the detection result to the control unit  18 . The wearing sensor  16  includes a pressure sensor detecting pressure when the user wears the wearable device  1 , a vital sensor detecting vital information such as a body temperature, a pulse, brain waves, blood pressure, and a sweating state, and the like. 
     The communication unit  17  transmits various information to the server  2  and receives various information from the server  2  via the network  4  in conformity to predetermined communication standard under control of the control unit  18 . The communication unit  17  includes a communication module enabling wireless communication. 
     The control unit  18  controls operations of the respective units included in the wearable device  1 . The control unit  18  includes a memory and a processor including hardware such as a CPU. The control unit  18  acquires from the line-of-sight sensor  13  line-of-sight information about a line of sight of the user U 1  wearing the wearable device  1  and, based on the line-of-sight information, generates and outputs to the projection unit  14  blind region state information indicating a state of a blind region shielded by a shielding object in a visual field region of the user U 1 . Meanwhile, in the first embodiment, the control unit  18  functions as a processor. 
     Configuration of Server 
     Next, a configuration of the server  2  will be described. The server  2  includes a communication unit  201  and a control unit  202 . 
     The communication unit  201  transmits various information and receives various information via the network  4  and the base station  3  in conformity to predetermined communication standard under control of the control unit  202 . The communication unit  201  also transmits various information to the wearable device  1  and receives various information from the GPS satellite  5  and the wearable device  1  in conformity to predetermined communication standard under control of the control unit  202 . The communication unit  201  includes a communication module enabling wireless communication. 
     The control unit  202  includes a memory and a processor including some sort of hardware such as a CPU. The control unit  202  controls operations of the respective units included in the server  2 . 
     Processing of Wearable Device 
     Next, processing executed by the wearable device  1  will be described.  FIG. 4  is a flowchart illustrating an overview of processing executed by the wearable device  1 . 
     As illustrated in  FIG. 4 , the control unit  18  first determines whether or not the user U 1  wears the wearable device  1  based on a detection result input from the wearing sensor  16  (Step S 101 ). In a case in which it is determined by the control unit  18  that the user U 1  wears the wearable device  1  (Step S 101 : Yes), the wearable device  1  moves to Step S 102  described below. 
     Subsequently, the control unit  18  acquires positional information of the wearable device  1  detected by the GPS sensor  15  (Step S 102 ) and transmits the positional information of the wearable device  1  via the communication unit  17  to the server  2  (Step S 103 ). 
     The control unit  18  then acquires image data generated by the image capturing unit  11  and line-of-sight information about a line of sight of the user U 1  from the line-of-sight sensor  13  (Step S 104 ). 
     Subsequently, the control unit  18  determines whether or not the user U 1  stares at a shielding object in a visual field region for a predetermined staring period or longer based on the image data generated by the image capturing unit  11  and the line-of-sight information acquired from the line-of-sight sensor  13  (Step S 105 ). Specifically, as illustrated in  FIG. 5 , the control unit  18  detects a staring region of a shielding object Q 1  which the user U 1  stares at based on the image data generated by the image capturing unit  11  and the line-of-sight information acquired from the line-of-sight sensor  13 . The control unit  18  then determines whether or not the staring period for which the user U 1  stares at the staring region of the shielding object Q 1  is a predetermined period or longer, such as one second to two seconds or longer. Here, the shielding object Q 1  is a wall, a member, or the like shielding a blind region that the user U 1  cannot visually recognize. Also, the blind region is a region or a space which is shielded by the shielding object Q 1  and which the user. U 1  cannot visually recognize. Also, the predetermined period can arbitrarily be changed in accordance with the operation of the user U 1  and the walking speed of the user U 1 . In a case in which it is determined by the control unit  18  that the staring period for which the user U 1  stares at the shielding object is the predetermined period or longer (Step S 105 : Yes), the wearable device  1  moves to Step S 106  described below. Conversely, in a case in which it is determined by the control unit  18  that the staring period for which the user U 1  stares at the shielding object is less than the predetermined period (Step S 105 : No), the wearable device  1  moves to Step S 108  described below. 
     In Step S 106 , the control unit  18  acquires blind region state information indicating a state of the blind region shielded by the shielding object in the visual field region of the user U 1  from the server  2  via the communication unit  17 . Specifically, the control unit  18  acquires from the server  2  image data in the visual field direction of the user U 1  defined by a detection result detected by the nine-axis sensor  12 , that is, current image data captured from the air a current position of the wearable device  1  detected by the GPS sensor  15 . Here, the current image data is image data acquired by the GPS satellite  5 , for example. 
     Subsequently, the control unit  18  outputs the blind region state information to the projection unit  14  so that the blind region state information may be displayed at a region corresponding to the line of sight of the user U 1  (Step S 107 ). Specifically, as illustrated in  FIG. 6 , the control unit  18  outputs to the projection unit  14  an image corresponding to the image data acquired from the server  2  so that blind region state information A 1  may be displayed at the staring region of the shielding object Q 1 . Accordingly, since the blind region state information A 1  is an image for the current state, the user U 1  can intuitively grasp a state of the blind region behind the shielding object Q 1 . 
     Subsequently, the control unit  18  determines whether or not the user U 1  takes off the wearable device  1  to end safety assistance by means of the wearable device  1  (Step S 108 ). In a case in which it is determined by the control unit  18  that the user U 1  ends the safety assistance by means of the wearable device  1  (Step S 108 : Yes), the wearable device  1  ends the processing. Conversely, in a case in which it is determined by the control unit  18  that the user U 1  does not end the safety assistance by means of the wearable device  1  (Step S 108 : No), the wearable device  1  returns to Step S 101  described above. 
     According to the first embodiment described above, since the control unit  18  outputs the image data acquired from the server  2  to the projection unit  14  so that the blind region state information A 1  may be displayed at the shielding object Q 1 , the user U 1  can intuitively grasp the state of the blind region behind the shielding object Q 1 . 
     Also, according to the first embodiment, since the control unit  18  outputs the blind region state information to the projection unit  14  so that the blind region state information may be displayed at the region corresponding to the line of sight of the user U 1 , and the blind region state information A 1  is the image for the current state, the user U 1  can intuitively grasp the state of the blind region behind the shielding object Q 1 . 
     Also, according to the first embodiment, in a case in which the staring period for which the user U 1  stares at the shielding object Q 1  is the predetermined period or longer, the control unit  18  outputs the blind region state information. Thus, the user can grasp the state of the blind region only when the user desires. 
     Second Embodiment 
     Next, a second embodiment will be described. An assistance system according to the second embodiment has an equal configuration to that of the assistance system  1000  according to the first embodiment and differs in terms of processing executed by the wearable device. Processing executed by the wearable device will be described below. Note that identical components to those in the assistance system  1000  according to the first embodiment described above are labeled with the same reference signs, and detailed description of the duplicate components is omitted. 
     Processing of Wearable Device 
       FIG. 7  is a flowchart illustrating an overview of processing executed by the wearable device  1  according to the second embodiment. In  FIG. 7 , Steps S 201  to S 206  correspond to Steps S 101  to S 106  described above in  FIG. 4 , respectively. 
     In Step S 207 , the control unit  18  performs known pattern matching or the like to the image data acquired from the server  2  to determine whether or not there exists an object in the blind region. For example, the control unit  18  performs pattern matching or the like to an image corresponding to the image data acquired from the server  2  to determine whether or not there exists an object such as a person, a car, a bicycle, or an animal. In a case in which it is determined by the control unit  18  that there exists an object in the blind region (Step S 207 : Yes), the wearable device  1  moves to Step S 208  described below. Conversely, in a case in which it is determined by the control unit  18  that there exists no object in the blind region (Step S 207 : No), the wearable device  1  moves to Step S 209  described below. 
     In Step S 208 , the control unit  18  outputs blind region state information to the projection unit  14  so that the blind region state information may be displayed at the staring region of the shielding object Q 1 . Specifically, as illustrated in  FIG. 8 , the control unit  18  outputs blind region state information A 2  and A 21  to the projection unit  14  so that blind region state information A 2  and A 21  may be displayed at the staring region of the shielding object Q 1 . Accordingly, since the user U 1  can intuitively grasp the blind region state information A 2  and A 21 , the user U 1  can grasp existence of an object in the blind region behind the shielding object Q 1 . Meanwhile, although the arrow icon and the mark icon are output as the blind region state information A 2  and A 21  in  FIG. 8 , a graphic, a symbol, a color, a message, or the like corresponding to the object, such as a person-shaped icon or a message in a case of a person, may be output instead of the arrow and the mark. As a matter of course, the control unit  18  may output a sound by means of a not-illustrated loudspeaker or the like at the same time as output of the blind region state information A 2 . 
     Subsequently, the control unit  18  determines whether or not the user U 1  takes off the wearable device  1  to end safety assistance by means of the wearable device  1  (Step S 209 ). In a case in which it is determined by the control unit  18  that the user U 1  ends the safety assistance by means of the wearable device  1 . (Step S 209 : Yes), the wearable device  1  ends the processing. Conversely, in a case in which it is determined by the control unit  18  that the user U 1  does not end the safety assistance by means of the wearable device  1  (Step S 209 : No), the wearable device  1  returns to Step S 201  described above. 
     According to the second embodiment described above, since the control unit  18  outputs the blind region state information A 2  to the projection unit  14  so that the blind region state information A 2  may be displayed at the staring region of the shielding object Q 1 , the user U 1  can intuitively grasp the blind region state information A 2  and can thus grasp existence of an object in the blind region behind the shielding object Q 1 . 
     Third Embodiment 
     Next, a third embodiment will be described. An assistance system according to the third embodiment has an equal configuration to that of the assistance system  1000  according to the first embodiment and differs in terms of processing executed by the wearable device. Processing executed by the wearable device will be described below. Note that identical components to those in the assistance system  1000  according to the first embodiment described above are labeled with the same reference signs, and detailed description of the duplicate components is omitted. 
     Processing of Wearable Device 
       FIG. 9  is a flowchart illustrating an overview of processing executed by the wearable device  1  according to the third embodiment. In  FIG. 9 , Steps S 301  to S 306  correspond to Steps S 101  to S 106  described above in  FIG. 4 , respectively. 
     In Step S 307 , the control unit  18  performs known pattern matching or the like to the image data acquired from the server  2  to determine whether or not there exists an object in the blind region. In a case in which it is determined by the control unit  18  that there exists an object in the blind region (Step S 307 : Yes), the wearable device  1  moves to Step S 308  described below. Conversely, in a case in which it is determined by the control unit  18  that there exists no object in the blind region (Step S 307 : No), the wearable device  1  moves to Step S 312  described below. 
     In Step S 308 , the control unit  18  determines whether or not the object existing in the blind region is a moving object. Specifically, the control unit  18  uses at least two chronologically-adjacent image data pieces acquired from the server  2  to calculate the moving amount of the object, such as a moving vector of the object, and determines whether or not the calculated moving amount is a predetermined value or higher. Here, the moving object is an object moving at certain speed such as a child, an animal, a pedestrian, a bicycle, a motorcycle, and a vehicle. In a case in which it is determined by the control unit  18  that the object existing in the blind region is a moving object (Step S 308 : Yes), the wearable device  1  moves to Step S 309  described below. Conversely, in a case in which it is determined by the control unit  18  that the object existing in the blind region is not a moving object (Step S 308 : No), the wearable device  1  moves to Step S 310  described below. 
     In Step S 309 , the control unit  18  outputs blind region state information corresponding to the moving object to the projection unit  14  based on the image data generated by the image capturing unit  11  and the image data acquired from the server  2 . Specifically, as illustrated in  FIG. 10 , the control unit  18  outputs to the projection unit  14  a synthetic image corresponding to synthetic image data obtained by synthesizing the image data generated by the image capturing unit  11  with the image data of the blind region acquired from the server  2  at a predetermined ratio (for example, 5:5) so that the synthetic image may be displayed at the staring region of the shielding object Q 1 . Accordingly, since the blind region behind the shielding object Q 1  is displayed in a virtually semi-transmissive state, the user U 1  can grasp the current state of the blind region without feeling strange. Also, in a case in which the control unit  18  detects a moving object H 1  such as a child as a result of known pattern matching or the like to the image data of the blind region acquired from the server  2 , the control unit  18  outputs to the projection unit  14  marks M 1  and M 2  so that the marks M 1  and M 2  may be displayed around the moving object H 1 . At this time, the control unit  18  calculates speed of the moving object H 1  and walking speed of the user U 1  wearing the wearable device  1  with use of at least two chronologically-adjacent image data pieces acquired from the server  2  and calculates the degree of urgency based on relative speed between the moving object H 1  and the wearable device  1  and traveling directions of the moving object H 1  and the user U 1  wearing the wearable device  1 . The control unit  18  then outputs the marks M 1  and M 2  to the projection unit  14  so that ways to display the marks M 1  and M 2  may be changed in accordance with the degree of urgency, e.g., so that the marks M 1  and M 2  may be displayed in red or yellow in accordance with the degree of urgency. Accordingly, since the user U 1  can intuitively grasp blind region state information A 3 , the user U 1  can grasp a state of the moving object H 1  hidden behind the shielding object Q 1 . Further, since the user U 1  can grasp speed of the moving object H 1  based on the states of the marks M 1  and M 2 , the user U 1  can predict time until an encounter with the moving object H 1 . Note that, although the control unit  18  performs the synthesis at a synthetic ratio of 5:5 in  FIG. 10 , the synthetic ratio is not limited to this and can arbitrarily be changed. Also, the control unit  18  is not required to express the moving object H 1  in the blind region state information A 3  accurately and may express the moving object H 1  with use of a simple graphic, such as an icon and an avatar, in accordance with processing speed for image generation. After Step S 309 , the wearable device  1  moves to Step S 312  described below. 
     In Step S 310 , the control unit  18  outputs blind region state information corresponding to a still object to the projection unit  14  based on the image data acquired from the server  2 . Specifically, the control unit  18  outputs the blind region state information A 2  (refer to  FIG. 8  described above) to the projection unit  14  so that the blind region state information A 2  may be displayed at a region corresponding to the shielding object Q 1 . Accordingly, since the user U 1  can intuitively grasp the blind region state information A 2 , the user U 1  can grasp existence of an object in the blind region behind the shielding object Q 1 . After Step S 310 , the wearable device  1  moves to Step S 312  described below. 
     Subsequently, the control unit  18  determines whether or not the user U 1  takes off the wearable device  1  to end safety assistance by means of the wearable device  1  (Step S 312 ). In a case in which it is determined by the control unit  18  that the user U 1  ends the safety assistance by means of the wearable device  1  (Step S 312 : Yes), the wearable device  1  ends the processing. Conversely, in a case in which it is determined by the control unit  18  that the user U 1  does not end the safety assistance by means of the wearable device  1  (Step S 312 : No), the wearable device  1  returns to Step S 301  described above. 
     According to the third embodiment described above, since the blind region behind the shielding object Q 1  is displayed in a virtually semi-transmissive state, the user U 1  can intuitively grasp the blind region state information A 3 , and the user U 1  can thus grasp the state of the moving object H 1  hidden behind the shielding object Q 1  without feeling strange. 
     Also, according to the third embodiment, since the control unit  18  outputs the marks M 1  and M 2  to the projection unit  14  so that ways to display the marks M 1  and M 2  may be changed in accordance with the relative speed between the moving object H 1  and the wearable device  1 , the user U 1  can intuitively grasp the blind region state information A 3 , and the user U 1  can thus grasp the state of the moving object H 1  hidden behind the shielding object Q 1 . 
     Also, according to the third embodiment, since the control unit  18  generates blind region state information with use of image data and outputs the blind region state information to the wearable device  1 , the user can grasp the current state in the blind region. 
     Modification Example of Third Embodiment 
     Next, a modification example of the third embodiment will be described.  FIG. 11  schematically illustrates an example of blind region state information that the control unit  18  outputs to the projection unit  14  according to the modification example of the third embodiment. 
     As illustrated in  FIG. 11 , the control unit  18  generates image data including an opening portion obtained by virtually hollowing a predetermined region including the staring region of the shielding object Q 1  based on the image data for the blind region acquired from the server  2  and the line-of-sight information detected by the line-of-sight sensor  13  and outputs an image corresponding to the image data as blind region state information A 4  to the projection unit  14 . Accordingly, since the blind region behind the shielding object Q 1  is displayed in a state in which the region including the staring region of the shielding object Q 1  which the user U 1  stares at is hollowed, the user U 1  can grasp the current state of the blind region without feeling strange. Further, the control unit  18  may calculate the degree of urgency based on relative speed between a moving object H 2  and the user U 1  wearing the wearable device  1  and traveling directions of the moving object H 2  and the user U 1  wearing the wearable device  1  and circle the opening portion with an arbitrary color in accordance with the degree of urgency, e.g., with green, yellow, or red in accordance with the degree of urgency. 
     According to the modification example of the third embodiment described above, since the blind region behind the shielding object Q 1  is displayed in a state in which the staring region of the shielding object Q 1  which the user U 1  stares at is hollowed, the user U 1  can grasp the current state of the blind region without feeling strange. 
     Fourth Embodiment 
     Next, a fourth embodiment will be described. In the aforementioned first to third embodiments, the wearable device  1  acquires image data via the network  4  from the server  2 . In an assistance system according to the fourth embodiment, an electronic control unit (ECU) provided in a vehicle outputs blind region state information to the wearable device in cooperation with the wearable device, and the wearable device projects and displays the blind region state information. Note that identical components to those in the assistance system  1000  according to the first embodiment described above are labeled with the same reference signs, and detailed description of the duplicate components is omitted. 
     Configuration of Assistance System 
       FIG. 12  illustrates a schematic configuration of the assistance system according to the fourth embodiment.  FIG. 13  is a block diagram illustrating a functional configuration of the assistance system according to the fourth embodiment. 
     An assistance system  1001  illustrated in  FIGS. 12 and 13  includes the wearable device  1  and an assistance device  6  performing two-way communication with the wearable device  1  in conformity to predetermined communication standard. 
     Configuration of Assistance Device 
     Next, a configuration of the assistance device  6  will be described. The assistance device  6  illustrated in  FIGS. 12 and 13  is mounted in a vehicle  600  and assists safety of a driver in the vehicle  600  at the time of driving and at the time of parking in cooperation with another ECU mounted in the vehicle  600 . The assistance device  6  includes an ignition switch  60  (hereinbelow referred to as “an IG switch  60 ”), a vehicle speed sensor  61 , a line-of-sight sensor  62 , an image capturing unit  63 , a communication unit  64 , a car navigation system  65 , and an ECU  66 . 
     The IG switch  60  accepts start and stop of electric systems such as an engine and a motor. The IG switch  60  starts an IG power supply in a case in which the IG switch  60  is in an on state and stops the IG power supply in a case in which the IG switch  60  is in an off state. 
     The vehicle speed sensor  61  detects vehicle speed when the vehicle  600  is running and outputs the detection result to the ECU  66 . 
     The line-of-sight sensor  62  detects a line of sight of the driver and outputs the detection result to the ECU  66 . The line-of-sight sensor  62  includes an optical system, a CCD or a CMOS, a memory, and a processor including hardware such as a CPU and a GPU. With use of known template matching, for example, the line-of-sight sensor  62  detects an unmoving part of a driver&#39;s eye (for example, the inner corner of the eye) as a reference point and a moving part of the eye (for example, the iris) as a moving point and detects the line of sight of the driver based on a positional relationship between the reference point and the moving point. Note that, although the line of sight of the driver is detected using a visible camera as the line-of-sight sensor  62  in the fourth embodiment, the disclosure is not limited to this, and the line of sight of the driver may be detected using an infrared camera. In a case in which the infrared camera is used as the line-of-sight sensor  62 , infrared light is emitted to the driver by means of an infrared light emitting diode (LED) or the like, a reference point (for example, the corneal reflection) and a moving point (for example, the pupil) are detected from image data generated by capturing an image of the driver with use of the infrared camera, and the line of sight of the driver is detected based on a positional relationship between the reference point and the moving point. 
     As illustrated in  FIG. 12 , a plurality of image capturing units  63  are provided outside the vehicle  600  at three or more locations including at least a front lateral side, a rear side, and both lateral sides so that an image capturing viewing angle may be 360°, for example. Under control of the ECU  66 , the image capturing unit  63  captures an image of a periphery of the vehicle  600  to generate image data and outputs the image data to the ECU  66 . The image capturing unit  63  includes an optical system including one or a plurality of lens(es) and a CCD, a CMOS, or the like light-receiving an object image obtained by converging light by means of the optical system to generate image data. 
     The communication unit  64  transmits various information to the wearable device  1 , another vehicle, a user terminal device, or the like and receives various information from the wearable device  1 , another vehicle, the user terminal device, or the like in conformity to predetermined communication standard under control of the ECU  66 . The communication unit  64  also transmits various information to a not-illustrated server and receives various information from the server via a network in conformity to predetermined communication standard under control of the ECU  66 . The communication unit  64  includes a communication module enabling wireless communication. 
     The car navigation system  65  includes a GPS sensor  651 , a map database  652 , and a notification unit  653 . 
     The GPS sensor  651  receives a signal from a plurality of GPS satellites and transmission antennae and calculates a position of the vehicle  600  based on the received signal. The GPS sensor  651  includes a GPS reception sensor and the like. Note that a plurality of GPS sensors  651  may be mounted to improve direction accuracy of the vehicle  600 . 
     The map database  652  stores various kinds of map data. The map database  652  may include a recording medium such as a hard disk drive (HDD) and a solid state drive (SSD). 
     The notification unit  653  may include a display unit  653   a  displaying image, video, and character information, a sound output unit  653   b  generating a sound such as a voice and a warning sound, a conduction unit conducting a sound by means of bone conduction, and the like. The display unit  653   a  includes a display such as a liquid crystal display and an organic electroluminescence (EL) display. The sound output unit  653   b  includes a loudspeaker. 
     The car navigation system  65  configured as above superimposes a current position of the vehicle  600  acquired by the GPS sensor  651  on the map data stored in the map database  652  to notify the driver of information including a road on which the vehicle  600  is currently traveling, a route to a destination, and the like by means of the display unit  653   a  and the sound output unit  653   b.    
     The ECU  66  controls operations of the respective units included in the assistance device  6 . The ECU  66  includes a memory and a processor including hardware such as a CPU. The ECU  66  acquires line-of-sight information about a line of sight of the user U 1  wearing the wearable device  1  and, based on the line-of-sight information, generates and outputs to the projection unit  14  blind region state information indicating a state of a blind region shielded by a shielding object in a visual field region of the user U 1 . Meanwhile, in the fourth embodiment, the ECU  66  functions as a processor. 
     Processing of Assistance Device 
     Next, processing executed by the assistance device  6  will be described.  FIG. 14  is a flowchart illustrating an overview of processing executed by the assistance device  6 . 
     As illustrated in  FIG. 14 , the ECU  66  determines whether or not the user U 1  has ridden the vehicle  600  (Step S 401 ). For example, the ECU  66  calculates a distance between the vehicle  600  and the wearable device  1  based on positional information detected by the GPS sensor  15  of the wearable device  1  via the communication unit  64  and positional information detected by the GPS sensor  651  of the car navigation system  65  to determine whether or not the calculated distance is less than a predetermined value and determines that the user U 1  has ridden the vehicle  600  in a case in which the distance is less than the predetermined value. In a case in which it is determined by the ECU  66  that the driver has ridden the vehicle  600  (Step S 401 : Yes), the assistance device  6  moves to Step S 402  described below. Conversely, in a case in which it is determined by the ECU  66  that the user U 1  has not ridden the vehicle  600  (Step S 401 : No), the assistance device  6  ends the processing. 
     In Step S 402 , the ECU  66  determines whether or not the user U 1  wears the wearable device  1 . Specifically, the ECU  66  receives a wearing signal indicating a detection result from the wearing sensor  16  of the wearable device  1  via the communication unit  64  and determines whether or not the user U 1  wears the wearable device  1  based on the received wearing signal. In a case in which it is determined by the ECU  66  that the user U 1  wears the wearable device  1  (Step S 402 : Yes), the assistance device  6  moves to Step S 403  described below. Conversely, in a case in which it is determined by the ECU  66  that the user U 1  does not wear the wearable device  1  (Step S 402 : No), the assistance device  6  moves to Step S 407  described below. 
     In Step S 403 , the ECU  66  acquires vehicle speed information about vehicle speed of the vehicle  600  from the vehicle speed sensor  61 , line-of-sight information about a line of sight of the user U 1  riding the vehicle  600  from the line-of-sight sensor  62 , and image data from the image capturing unit  63 . 
     Subsequently, the ECU  66  determines based on the vehicle speed information acquired from the vehicle speed sensor  61  whether or not the vehicle speed of the vehicle  600  is equal to or less than predetermined speed (Step S 404 ). For example, the ECU  66  determines whether or not the vehicle speed of the vehicle  600  is 10 km/h. Note that the predetermined speed can arbitrarily be set. In a case in which it is determined by the ECU  66  that the vehicle speed of the vehicle  600  is equal to or less than the predetermined speed (Step S 404 : Yes), the assistance device  6  moves to Step S 405  described below. Conversely, in a case in which it is determined by the ECU  66  that the vehicle speed of the vehicle  600  is not equal to or less than the predetermined speed (Step S 404 : No), the assistance device  6  moves to Step S 410  described below. 
     In Step S 405 , the ECU  66  acquires line-of-sight information about a line of sight of the user U 1  from the line-of-sight sensor  62 . 
     Subsequently, the ECU  66  performs known pattern matching or the like to an image corresponding to the image data acquired from the image capturing unit  63  to determine whether or not there exists an object in a blind region of the vehicle  600  (Step S 406 ). In a case in which it is determined by the ECU  66  that there exists an object in the blind region of the vehicle  600  (Step S 406 : Yes), the assistance device  6  moves to Step S 407  described below. Conversely, in a case in which it is determined by the ECU  66  that there exists no object in the blind region of the vehicle  600  (Step S 406 : No), the assistance device  6  moves to Step S 411  described below. 
     In Step S 407 , the ECU  66  determines whether or not the object existing in the blind region is a moving object. In a case in which it is determined by the ECU  66  that the object existing in the blind region is a moving object (Step S 407 : Yes), the assistance device  6  moves to Step S 408  described below. Conversely, in a case in which it is determined by the ECU  66  that the object existing in the blind region is not a moving object (Step S 407 : No), the assistance device  6  moves to Step S 409  described below. 
     In Step S 408 , the ECU  66  generates and outputs blind region state information corresponding to the moving object based on the image data of the blind region acquired from the image capturing unit  63 . Specifically, as illustrated in  FIG. 15 , the ECU  66  generates image data including an opening portion obtained by virtually hollowing a region of the blind region in which a moving object H 10  exists, such as a predetermined region including a portion of shielding objects Q 10  and Q 11  such as an instrument panel and a front pillar. The ECU  66  then outputs blind region state information A 10  corresponding to the image data to the wearable device  1 . Accordingly, since the blind region state information A 10  behind the shielding object Q 10  is displayed, the user U 1  can intuitively grasp a state of the blind region without feeling strange. In this case, the ECU  66  calculates speed of the moving object with use of at least two chronologically-adjacent image data pieces acquired from the image capturing unit  63 , acquires speed of the vehicle  600  acquired from the vehicle speed sensor  61 , calculates relative speed between the moving object and the vehicle  600  (subject vehicle) and traveling directions of the moving object and the vehicle  600 , and calculates the degree of urgency based on the relative speed between the moving object and the vehicle  600  (subject vehicle) and the traveling directions of the moving object and the vehicle  600 . Based on the degree of urgency, the ECU  66  may output the aforementioned marks M 1  and M 2  in accordance with the degree of urgency as in  FIG. 10  to the wearable device  1  so that the marks M 1  and M 2  may be displayed. After Step S 408 , the assistance device  6  moves to Step S 410  described below. 
     In Step S 409 , the ECU  66  generates and outputs blind region state information corresponding to a still object based on the image data of the blind region acquired from the image capturing unit  63 . Specifically, the ECU  66  generates blind region state information (for example, the icon in  FIG. 8  or the like) corresponding to the still object based on the image data of the blind region acquired from the image capturing unit  63 . The ECU  66  then outputs the blind region state information to the wearable device  1  so that the blind region state information may be displayed at a region of the shielding object Q 10  at which the object exists. After Step S 409 , the assistance device  6  moves to Step S 410  described below. 
     In Step S 410 , in a case in which it is determined by the ECU  66  that the IG switch  60  is turned off to end driving of the vehicle  600  (Step S 410 : Yes), the assistance device  6  ends the processing. Conversely, in a case in which it is determined by the ECU  66  that the IG switch  60  is not turned off, and that driving of the vehicle  600  is not ended (Step S 410 : No), the assistance device  6  returns to Step S 402  described above. 
     In Step S 411 , the ECU  66  determines based on the line-of-sight information about the line of sight of the user U 1  from the line-of-sight sensor  62  whether or not the staring period for which the user U 1  stares at a predetermined region of the vehicle  600 , such as the front pillar, is a predetermined period (for example, two seconds) or longer (Step S 411 ). In a case in which it is determined by the ECU  66  that the staring period for which the user U 1  stares at the predetermined region of the vehicle  600  is the predetermined period or longer (Step S 411 : Yes), the assistance device  6  moves to Step S 412  described below. Conversely, in a case in which it is determined by the ECU  66  that the staring period for which the user U 1  stares at the predetermined region of the vehicle  600  is not the predetermined period or longer (Step S 411 : No), the assistance device  6  moves to Step S 413  described below. 
     In Step S 412 , the ECU  66  outputs image data acquired from the image capturing unit  63  via the communication unit  64  as blind region state information to the wearable device  1  to project and display the blind region state information at the blind region behind the shielding object of the vehicle  600  on the wearable device  1 . Specifically, similarly to  FIG. 15  described above, the ECU  66  generates image data including an opening portion obtained by virtually hollowing the staring region of the shielding objects Q 10  and Q 11 . The ECU  66  then outputs the blind region state information A 10  corresponding to the image data to the wearable device  1  so that the blind region state information A 10  may be displayed at the staring region at which the user U 1  stares. Accordingly, since the blind region state information A 10  behind the shielding object Q 10  is displayed, the user U 1  can intuitively grasp a state of the blind region without feeling strange. After Step S 412 , the assistance device  6  moves to Step S 410 . 
     In Step S 413 , the ECU  66  determines based on the line-of-sight information about the line of sight of the user U 1  from the line-of-sight sensor  62  whether or not the line of sight of the user is moving. In a case in which it is determined by the ECU  66  that the line of sight of the user is moving (Step S 413 : Yes), the assistance device  6  moves to Step S 414  described below. Conversely, in a case in which it is determined by the ECU  66  that the line of sight of the user is not moving (Step S 413 : No), the assistance device  6  moves to Step S 410 . 
     In Step S 414 , the ECU  66  determines whether or not the wearable device  1  is outputting the blind region state information. In a case in which it is determined by the ECU  66  that the wearable device  1  is outputting the blind region state information (Step S 414 : Yes), the assistance device  6  moves to Step S 415  described below. Conversely, in a case in which it is determined by the ECU  66  that the wearable device  1  is not outputting the blind region state information (Step S 414 : No), the assistance device  6  moves to Step S 410 . 
     In Step S 415 , the ECU  66  causes the wearable device  1  to output the blind region state information for a predetermined period. Specifically, as illustrated in  FIG. 16 , in a case in which the wearable device  1  is outputting blind region state information A 10 , A 11 , and A 12 , and even in a case in which the line of sight of the user U 1  moves, the ECU  66  keeps outputting the image data so that the blind region state information A 10 , A 11 , and A 12  may be projected and displayed on the wearable device  1  for a predetermined period such as for five seconds. Accordingly, even in a case in which the user U 1  moves the line of sight, the user U 1  can reliably prevent moving objects and objects from being overlooked. After Step S 415 , the assistance device  6  moves to Step S 410 . 
     According to the fourth embodiment described above, since, the ECU  66  outputs to the wearable device  1  the blind region state information A 10  corresponding to the image data including the opening portion obtained by virtually hollowing the staring region of the shielding object Q 10  to cause the blind region state information A 10  behind the shielding object Q 10  or the shielding object Q 11  to be displayed in a state in which the staring region which the user U 1  stares at is hollowed, the user U 1  can intuitively grasp the state of the blind region without feeling strange. 
     Also, according to the fourth embodiment, in a case in which the vehicle speed of the vehicle  600  is equal to or less than the predetermined speed, the ECU  66  outputs the blind region state information A 10  to the wearable device  1 . This can prevent the processing from being performed unnecessarily and prevent the user from feeling strange. 
     Meanwhile, although the ECU  66  outputs to the wearable device  1  the image data including the opening portion obtained by virtually hollowing the shielding object as the blind region state information in the fourth embodiment, the shielding object may be in a see-through state, for example. Specifically, as illustrated in  FIG. 17 , the ECU  66  acquires respective image data pieces from the image capturing unit  11  of the wearable device  1  and the image capturing unit  63  and, with use of the two image data pieces, outputs to the wearable device  1  image data obtained by virtually seeing through the shielding objects in the vehicle  600  such as an instrument panel and a front pillar. Subsequently, the wearable device  1  causes the projection unit  14  to project and display an image corresponding to the image data, received from the assistance device  6 , obtained by virtually seeing through the shielding objects in the vehicle  600  such as an instrument panel and a front pillar. Consequently, since the shielding objects in the vehicle  600  are in a see-through state, the user U 1  can intuitively grasp a position of an object. 
     Also, although the ECU  66  outputs to the wearable device  1  the image data including the opening portion obtained by virtually hollowing the shielding object in the fourth embodiment, the hollowing shape can arbitrarily be changed. For example, as illustrated in  FIG. 18 , the ECU  66  may generate image data including an opening portion O 1  obtained by virtually hollowing a shielding object Q 100  located a predetermined distance L 1  away from the wearable device  1  in a columnar shape and output the image data to the wearable device  1 . Also, as illustrated in  FIG. 19 , the ECU  66  may generate image data obtained by virtually hollowing the shielding object Q 100  located the predetermined distance L 1  away from the wearable device  1  in a conical shape O 2  and output the image data to the wearable device  1 . Further, as illustrated in  FIG. 20 , the ECU  66  may generate image data obtained by virtually hollowing the shielding object Q 100  located the predetermined distance L 1  away from the wearable device  1  in a spherical shape O 3  and output the image data to the wearable device  1 . 
     Also, although the ECU  66  projects and displays an image having a predetermined size on the wearable device  1  in the fourth embodiment, the size of the image to be projected and displayed on the wearable device  1  may be changed in accordance with a pinch operation, in which the distance between the thumb and the index finger is shifted from a distance D 1  to a distance D 2 , as illustrated in  FIG. 21 , for example. 
     Fifth Embodiment 
     Next, a fifth embodiment will be described. In the aforementioned fourth embodiment, the ECU  66  serving as an assistance device transmits blind region state information to the wearable device  1 . However, in the fifth embodiment, a server transmits blind region state information to the wearable device. Note that identical components to those in the assistance system  1001  according to the fourth embodiment described above are labeled with the same reference signs, and detailed description of the duplicate components is omitted. 
       FIG. 22  is a schematic view illustrating a schematic configuration of an assistance system according to a fifth embodiment. An assistance system  1002  illustrated in  FIG. 22  includes the wearable device  1  which the user U 1  wears, a server  2 A, and assistance devices  6  respectively mounted on a plurality of vehicles  600 . The wearable device  1 , the server  2 A, and the plurality of assistance devices  6  are configured to enable mutual information communication via the base station  3  and the network  4 . 
     Configuration of Server 
     Next, a configuration of the server  2 A will be described. The server  2 A includes the communication unit  201  and a control unit  202 A. 
     The control unit  202 A includes a memory and a processor including some sort of hardware such as a CPU, a GPU, an FPGA, a DSP, and an ASIC. The control unit  202 A acquires line-of-sight information about a line of sight of the user wearing the wearable device  1  via the communication unit  201  and, based on the line-of-sight information, generates and outputs to the wearable device  1  blind region state information indicating a state of a blind region shielded by a shielding object in a visual field region of the user. The control unit  202 A functions similarly to the control unit  18  according to the aforementioned first to third embodiments or the ECU  66  according to the aforementioned fourth embodiment. Meanwhile, in the fifth embodiment, the control unit  202 A functions as a processor. 
     According to the fifth embodiment described above, since the control unit  202 A outputs blind region state information to the wearable device  1  so that the blind region state information may be displayed at a staring region of the shielding object, the user U 1  can intuitively grasp the blind region state information and can thus grasp existence of an object in the blind region behind the shielding object. 
     Other Embodiments 
     Although examples of using the glasses-type wearable device  1  which the driver can wear have been described in the first to fifth embodiments, the disclosure is not limited to this and can be applied to various wearable devices. For example, as illustrated in  FIG. 23 , the disclosure can be applied to a contact-lenses-type wearable device  1 A having an image capturing function. Also, the disclosure can be applied to a wearable device  1 B in  FIG. 24  or a brain-chip-type wearable device  1 C in  FIG. 25 , which is a device transmitting information directly to the brain of the user U 1 . Further, as a wearable device  1 D in  FIG. 26 , a helmet-like device including a visor may be used. In this case, in the wearable device  1 D, an image may be projected and displayed on the visor. 
     Also, in the first to fifth embodiments, although the wearable device  1  projects an image to the retina of the driver to let the driver visually recognize the image, the image may be projected and displayed on a lens of glasses or the like. 
     Also, in the first to fifth embodiments, the aforementioned “units” can be replaced with “circuits”. For example, the control unit can be replaced with the control circuit. 
     Also, a program to be executed by the assistance device according to each of the first to fifth embodiments is provided by recording installable or executable file data on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, a digital versatile disk (DVD), a USB medium, and a flash memory. 
     Also, the program to be executed by the assistance device according to each of the first to fifth embodiments may be provided by storing the program on a computer connected to a network such as the Internet and downloading the program via the network. 
     Meanwhile, in the description of the flowcharts in the present specification, although the expressions “first”, “then”, “subsequently”, and the like are used to clarify a processing order of the steps, the processing order required to carry out each of the present embodiments shall not be defined uniquely by these expressions. That is, the processing order in each of the flowcharts described in the present specification can be changed unless it is inconsistent. 
     Although several embodiments of the present application have been described above in detail with reference to the drawings, these embodiments are illustrative only, and the disclosure can be embodied in other ways by modifying or improving the embodiments described in the section of the disclosure of the disclosure in various ways based on knowledge of those skilled in the art. 
     According to the disclosure, since the processor outputs the blind region state information to the wearable device so as to display the blind region state information in a region corresponding to the line of sight of the user, the user can grasp a state of the blind region intuitively. 
     According to the disclosure, since the processor outputs the blind region state information when there exists the object, the user can grasp that there exists an object. 
     According to the disclosure, since the processor outputs the blind region state information corresponding to the moving object in the blind region, the user can grasp a state of the moving object approaching the blind region. 
     According to the disclosure, since the processor outputs the blind region state information in accordance with relative speed between the moving object in the blind region and the assistance device, the user can grasp a state of the moving object approaching the blind region in real time. 
     According to the disclosure, since the processor generates and outputs the blind region state information with use of the image data piece obtained by capturing an image of the blind region, the user can grasp a current state in the blind region. 
     According to the disclosure, since the blind region state information is output to the staring region at which the user stares, the user can grasp a state of the blind region that the user needs. 
     According to the disclosure, in a case in which the staring period of the user is the predetermined period or longer, the processor outputs the blind region state information. Thus, the user can grasp a state of the blind region only when the user desires. 
     According to the disclosure, since the synthetic image in which the shielding object is in a semi-transmissive state is output as the blind region state information, the user can grasp a state of the blind region without feeling strange. 
     According to the disclosure, since the processor outputs the image corresponding to the image data piece obtained by capturing an image of the blind region as the blind region state information, the user can grasp an actual state of the blind region. 
     According to the disclosure, since the processor outputs the image including the opening portion as the blind region state information, the user can grasp a state of the blind region without feeling strange. 
     According to the disclosure, since the processor outputs the blind region state information only at the time of low speed or a stop, this can prevent the processing from being performed unnecessarily and prevent the user from feeling strange. 
     According to the disclosure, since blind region state information indicating a state of a blind region shielded by a shielding object which is blind as seen in a visual field region of a user is output, this exerts an effect of enabling the user to intuitively grasp a surrounding environment. 
     Although the disclosure has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.