Patent ID: 6201891
Filing Date: 2001-03-13
Classification: G06T,H04N

Abstract:
An X-ray imaging apparatus comprising:signal outputting means for receiving X-rays, and for outputting an analog image signal corresponding to an intensity of the X-rays;signal amplifying means for amplifying the analog image signal at different amplification factors in accordance with a level of the analog image signal;A/D converting means for converting the amplified analog image signal into a digital value;storing means for storing the digital value of said A/D converting means; anddisplaying means for displaying an X-ray image on the basis of the digital value stored in said storing means,wherein, in said signal amplifying means, as the analog image signal has a lower level, the amplification factor is larger and, as the analog image signal has a higher level, the amplification factor is smaller and wherein said apparatus has conversion characteristics in which conversion is conducted so that a predetermined number or rate of digital values having levels among the plural digital values that are outside of a range are discarded and therefore not set to a predetermined value, and maximum and minimum values of the remaining digital values have respective predetermined values.