Patent attributes
Aspects of the invention provide a projector for displaying an image on a projection surface. The projector can include a test pattern projecting unit that projects a predetermined test pattern on the projection surface, a focus changing unit that moves a focal point of the projector, an imaging unit that performs imaging the projected test pattern to generate a shot image, an indicator value calculating unit that calculates an indicator value relating to a focus state of the shot image varying with movement of the focal point, and a focus adjustment unit that performs focus adjustment for focusing the focal point on the projection surface using the indicator value. The test pattern including a first kind and a second kind of density areas alternately arranged and having different density with each other, and at least the first kind of density areas include a narrow area and a broad area.