Patent ID: 6198801
Filing Date: 2001-03-06
Classification: H04N,H05G

Abstract:
An X-ray examination apparatus, comprising: an X-ray detector for forming an X-ray image, wherein the x-ray detector further comprises a conversion unit for deriving an optical image from the X-ray image, and an image pick-up apparatus for deriving an image signal and a measurement signal from the optical image, wherein the image pick-up apparatus further comprises an image sensor comprising means to derive the image signal from the entire optical image, wherein the image sensor further comprises means to derive electrical charges from the optical image, means to derive the measurement signal from a measurement component of the electrical charges, means to derive the image signal from an image component of the electrical charges, and an image pick-up section for deriving the electrical charges of the measurement component and the electrical charges of the image component from the optical image, andan exposure control for adjusting the X-ray examination apparatus on the basis of the measurement signal in order to control the image sensor,wherein the measurement signal relates predominantly to relevant image information in a substantial part of the X-ray image,wherein the image pick-up apparatus further comprises a photosensor for measuring the mean brightness of the optical image, and means to adjust the image sensor on the basis of the mean brightness of the optical image.