Storage phosphor reader calibration technique
AssigneeEastman Kodak Company
InventorMichael K. Rogers
Life of this patent
Estimating the term…
Abstract
A calibration technique for a storage phosphor reader which calibrates the storage phosphor reader to the exposure value of the x-ray source measured at the time that the storage phosphor to be read is exposed.
Claims4
In a storage phosphor reader including a source of a beam of stimulating light, a scanner for repetitively scanning said beam of stimulating light in a line scan direction across a storage phosphor moved in a page scanning direction past said beam of light, and a plurality of photodetectors arrayed in a line scanning direction for converting light emitted by a scanned storage phosphor into an electrical image signal, the method of calibrating said storage phosphor reader comprising the steps of:
- exposing a storage phosphor to a uniform field of x-ray radiation;
- measuring the exposure value of said uniform field of x-ray radiation at the time of said exposing said storage phosphor with a transportable x-ray radiation measuring device which includes a phosphor for converting said x-ray radiation into a light signal, wherein said phosphor has a responsivity curve which is similar to the responsivity curve of said storage phosphor;
- moving said storage phosphor in a page scan direction past said line scanning beam of stimulating light to produce an emitted light signal;
- calibrating the signal channel of each of said plurality of photodetectors as a function of said measured x-ray radiation signal so that the image signal read from said storage phosphor by said plurality of photodetectors is accurate:
- and
- measuring the signal produced by said plurality of photodetectors to determine the leading edge of the storage phosphor as taken in the page scan direction;
- while overscanning the storage phosphor in a line scan direction, measuring the signal produced by said plurality of photodetectors to determine the front and rear edges of said storage phosphor and from said measurements, setting the start and end points of the oscillation of said mirror so that the traverse of said stimulating light on said storage phosphor begins at said front edge and ends at said rear edge;
- thereafter, measuring the signal produced by each of said plurality of photodetectors to determine whether each is operating;
- adjusting the signal channel of each of said plurality of photodetectors so that the signal produced by said plurality of photodetectors is substantially uniform across a line scan;
- and
- determining a collector profile correction signal to be added to each line scan of a storage phosphor read by said reader.
Dependencies are inferred from the claim text.