Projection system and calibration apparatus

1. A projection system comprising:

a projection unit that emits projection light for displaying a prescribed image;

an optical path change unit that changes an optical path for the projection light from the projection unit and guides the projection light toward a prescribed projection surface;

a capture unit that captures a projection image that is projected onto the projection surface from the optical path change unit, based on the prescribed image; and

a controller that controls the projection image,

wherein the controller calculates a first distance that is a length from the projection unit to the optical path change unit along the optical path and a second distance that is a length from the projection unit to the projection surface along a vertical direction, based on the captured image by the capture unit, and controls the projection image based on the first distance and the second distance that are calculated.

2. The projection system of claim 1 ,

wherein the optical path change unit includes a reflection surface from which the projection light is reflected, and

wherein the controller calculates the first distance and the second distance based on an inclination angle of the reflection surface and on the captured image.

3. The projection system of claim 2 ,

wherein the capture unit captures the projection image that is formed on the projection surface by the projection light which is reflected from the reflection surface, and

wherein the controller calculates the first distance based on at least one of a form and a size of the projection image in the captured image by the capture unit and on a size of the reflection surface.

4. The projection system of claim 2 ,

wherein the projection unit projects an image including a reference mark onto the projection surface,

wherein the capture unit captures a projection image including the reference mark that is projected on the projection surface, and

wherein the controller controls the optical path change unit and thus causes the reference mark to move on the projection surface, and specifies an inclination angel of the reflection surface based on a trace of the reference mark in the captured image of the projection image including the reference mark, which is captured by the capture unit.

5. The projection system of claim 1 ,

wherein the projection unit projects an image including a reference mark onto the projection surface,

wherein the capture unit captures a projection image including the reference mark that is projected on the projection surface, and

wherein the controller calculates an angle that is made between a first direction from the capture unit to a position onto which the reference mark is projected, and a second direction that specifies the second distance, based on the captured image of the projection image including the reference mark, which is captured by the capture unit, and calculates the second distance based on the angle and the first distance.

6. The projection system of claim 1 ,

wherein the capture unit captures a prescribed photographic subject, and

wherein the controller controls the projection image based on the captured image by the capture unit.

7. The projection system of claim 1 ,

wherein the capture unit is configured with an omnidirectional camera.

8. The projection system of claim 1 ,

wherein the optical path is horizontal.

9. A calibration apparatus that performs calibration of a projection system,

wherein the projection system includes

a projection unit that emits projection light for displaying a prescribed image,

an optical path change unit that changes an optical path for the projection light from the projection unit and guides the projection light toward a prescribed projection surface, and

a capture unit that captures a projection image that is projected onto the projection surface from the optical path change unit, based on the prescribed image,

the calibration apparatus comprising:

a first calculation unit that calculates a first distance that is a length from the projection unit to the optical path change unit along the optical path based on the captured image by the capture unit;

a second calculation unit that calculates a second distance that is a length from the projection unit to the projection surface along a vertical direction based on the captured image by the capture unit; and

a calibration unit that performs calibration of the projection image based on the first distance and the second distance that are calculated.