1.  Field
The present invention relates to distance measurement using a mobile device such as a mobile phone.  The present invention, for example, relates to a distance measuring device and a distance measuring method performing distance measurement using gravity acceleration information and image information. 
2.  Description of the Related Art
In the conventional technique, distance measurement is performed by a unit, for example, which sends strong infrared rays to a measuring object and receives the reflected light.  However, the unit requires an infrared ray generating unit, a light receiving unit, and the like, and there is no unit for measuring a distance with a simple configuration. 
As a configuration for measuring a size or the like of an object by using an image by a camera or the like, Japanese Laid-open Patent Publication No.  2006-234545 discloses an imaging unit that images an object by facing the object and forming an image of the object.  The display unit displays image data that is imaged by the imaging unit.  A distance measuring unit measures a distance to the object that is imaged by the imaging unit.  An index display unit displays an index by superimposing the image data on the display unit.  An inclination angle measuring unit measures an inclination angle when the imaging unit is inclined in a way that the index displayed by the index display unit corresponds to a desired measuring object part, and an actual size calculation unit calculates an actual size of the object based on a measurement result of the distance measuring unit and a measurement result of the inclination angle measuring unit. 
As for calculation of a distance using an image by a CCD camera, Japanese Laid-open Patent Publication No.  2007-064890 discloses that a CCD camera 1E, as a home edge detecting sensor, is used to photograph a slit image E of reflection slit light acquired by irradiating a platform edge P region with laser slit light.  A data calculation processor 5 performs a specified calculation based on position information and the like of a laser light origin 1A and the CCD camera 1E on a vehicle body 101 that is specified in advance, resulting in a calculation of a distance A in a horizontal position between a side surface of the vehicle body 101 and the platform edge P of a platform 200. 
As for acquiring image information by considering the distance and inclination between a paper surface or the like and an imaging unit, Japanese Laid-open Patent Publication No 2005-084951 discloses a configuration in which an imaging unit outputs image information, a display unit displays identification information included in the image information that is output by the image unit, a recognition unit recognizes the identification information included in the image information output by the imaging unit, and a control unit controls in a way that all or part of the display position or the angle of the image information is converted according to the position of the display unit or the imaging unit when the recognition unit recognizes the identification information. 
When the above-described distance measuring function is newly mounted on a mobile device such as a mobile phone, the size of the mobile device has to be increased.  Mounting such a function on a miniaturized mobile device is difficult.  Even though calculation ability of the mobile device has been improved, a load of control processing of the distance measuring function is extremely heavy.  Therefore, mounting the distance measuring function on a mobile device is difficult. 
Japanese Laid-open Patent Publication No.  2006-234545, 2007-064890, and 2005-084951 have no disclosure and suggestion of such request and problem.  There is no disclosure and suggestion of configurations and the like to solve the request and problem.