Patent ID: 7382866

Claim:
An X-ray imaging apparatus comprising: an X-ray source for radiating X-ray to a subject; a movable diaphragm for adjusting an irradiation field of the X-ray; and a projector-collimator installed within said movable diaphragm to project a light beam to an irradiation field position on the subject, said projector-collimator comprising: a first reflecting section comprising a first mirror, said first reflecting section positioned outside the irradiation field, said first reflecting section producing a first luminous flux in a first direction orthogonal to an X-ray radiating direction and reflecting the first luminous flux within a plane orthogonal to the first direction to produce a second luminous flux, said first mirror moveable in the first direction to adjust a length of the first luminous flux; and a second reflecting section comprising a second mirror and a third mirror, said second reflecting section reflecting the second luminous flux in a direction of the irradiation field within the plane to produce a third luminous flux and reflecting the third luminous flux in the X-ray radiating direction inside the irradiation field within the plane to produce the light beam, said second mirror and said third mirror concurrently rotatable about the first direction to adjust a length of the third luminous flux.