Head-up display

1. A head-up display for irradiating an image light including a display object toward a projection target member so as to display the display object as a virtual image, the head-up display comprising:

an image display device including a light source and a display element, the image display device being configured to output the image light generated by a light which has been emitted from the light source and transmitted through the display object displayed on a display surface of the display element; and

a main controller connected to the image display device,

wherein

the main controller is configured to:

acquire road surface information of a front road surface based on a plurality of measurement points on the front road surface, the plurality of measurement points being detected by a road surface detection sensor mounted on a vehicle with the head-up display and being positioned forward of a traveling direction of the vehicle;

calculate, by using the road surface information, a virtual image plane position on a virtual image plane where the virtual image of the display object is displayed, the virtual image plane position being a display position of the virtual image for displaying the virtual image of the display object displayed on the display surface of the display element along the front road surface;

calculate a display position of the display surface of the display element corresponding to the virtual image plane position so as to output, to the image display device, a control signal for displaying the display object on the display position of the display surface of the display element; and

calculate a height from the ground surface for displaying the virtual image on the virtual image plane as the virtual image plane position.

2. The head-up display according to claim 1 , wherein

the main controller is further configured to acquire the road surface information of the slope of the front road surface based on three-dimensional coordinates of each of the detected plurality of measurement points, and

the three-dimensional coordinates are defined by a three-axis rectangular coordinate system in a real space.

3. The head-up display according to claim 1 , wherein

the main controller is further configured to calculate the display position of the display surface corresponding to the virtual image plane position based on the virtual image plane position of the virtual image in the real space by referring to virtual image plane-and-display surface linkage data in which coordinates on the virtual image plane and coordinates on the display surface are linked with each other.

4. The head-up display according to claim 1 , wherein

the main controller is further configured to calculate, as the virtual image plane position of the virtual image, a position of a point at which a line of sight connecting a viewpoint of a driver who visually recognizes that the virtual image with the front road surface intersects the virtual image plane.

5. The head-up display according to claim 2 , wherein

the three-axis rectangular coordinate system includes an x-z axis rectangular coordinate system included in a ground surface on which a traveling body mounted on the vehicle contacts and a y-axis perpendicular to the x-z axis rectangular coordinate system.

6. The head-up display according to claim 5 , wherein

the main controller is further configured to acquire an: for a plane including the plurality of measurement points as the road surface information, and calculate the virtual image plane position based on the estimation formula.

7. The head-up display according to claim 5 , wherein

the main controller is further configured to:

further acquire or calculate, as the road surface information, a road surface angle which is an angle formed by a plane including the plurality of measurement points with respect to the ground surface; and

set a shape of the display object at a time of being displayed on the ground surface as a basic shape so as to display the display object after rotation, which is obtained by rotating the basic shape based on the road surface angle, at the display position for the display object on the image display device.

8. The head-up display according to claim 5 , wherein

the main controller is further configured to:

acquire, as the road surface information, a road surface angle which is an angle formed by a plane including the plurality of measurement points with respect to the ground surface;

calculate the virtual image plane position of the virtual image by using the road surface angle; and

set a shape of the display object at a time of being displayed on the ground surface as a basic shape so as to display the display object after rotation, which is obtained by rotating the basic shape based on the road surface angle, at the display position for the display object on the image display device.

9. A head-up display for irradiating an image light including a display object toward a projection target member so as to display the display object as a virtual image, the head-up display comprising:

an image display device including a light source and a display element, the image display device being configured to output the image light generated by a light which has been emitted from the light source and transmitted through the display object displayed on a display surface of the display element; and

a main controller connected to the image display device, wherein

the main controller is configured to:

acquire road surface information of a front road surface based on a plurality of measurement points on the front road surface, the plurality of measurement points being detected by a road surface detection sensor mounted on a vehicle with the head-up display and being positioned forward of a traveling direction of the vehicle;

calculate, by using the road surface information, a virtual image plane position on a virtual image plane where the virtual image of the display object is displayed, the virtual image plane position being a display position of the virtual image for displaying the virtual image along the front road surface;

calculate a display position of the display surface corresponding to the virtual image plane position so as to output, to the image display device, a control signal for displaying the display object on the display position of the display surface;

acquire positional information of a virtual image display target object in a captured image of the front road surface which has been captured by a camera mounted on the vehicle;

refer to camera-and-real space linkage data in which coordinates of a three-axis rectangular coordinate system in a real space and two-dimensional coordinates of a camera coordinate system are linked with each other so as to convert the positional information of the virtual image display target object into the coordinates of the three-axis rectangular coordinate system;

refer to the positional information of the virtual image display target object after conversion and the road surface information so as to calculate a plane including the plurality of measurement points near the virtual image display target object, and calculate the virtual image plane position for displaying a virtual image of a display object to be added to the virtual image display target object along the plane;

refer to virtual image plane-and-display surface linkage data, in which coordinates on the virtual image plane and coordinates on the display surface are linked with each other, so as to convert the virtual image plane position of the display object to be added to the virtual image display target object into the display position of the display surface; and

output, to the image display device, a control signal for displaying the display object to be added to the virtual image display target object on the display position of the display surface.

10. The head-up display according to claim 1 , wherein

the image display device is a liquid crystal display including:

the light source;

the display element; and

an illumination optical system disposed between the light source and the display element, which is configured to guide a light emitted from the light source to the display element.

11. The head-up display according to claim 1 , wherein

the image display device is a microelectromechanical system including:

a laser light source;

a scanning mirror that reflects a laser light emitted from the laser light source;

a scanning mirror drive unit configured to change an orientation of a mirror surface of the scanning mirror;

a diffusion plate that forms an image by the laser light reflected by the scanning mirror; and

a relay optical system on which an image light including image information of the display object, which has been formed on the diffusion plate, is made incident.

12. The head-up display according to claim 9 , wherein

the image display device is a liquid crystal display including:

the light source;

the display element; and

an illumination optical system disposed between the light source and the display element, which is configured to guide a light emitted from the light source to the display element.

13. The head-up display according to claim 9 , wherein

the image display device is a microelectromechanical system including:

a laser light source;

a scanning mirror that reflects a laser light emitted from the laser light source;

a scanning mirror drive unit configured to change an orientation of a mirror surface of the scanning mirror;

a diffusion plate that forms an image by the laser light reflected by the scanning mirror; and

a relay optical system on which an image light including image information of the display object, which has been formed on the diffusion plate, is made incident.