在有限景深的光学系统中,由于发光平面具有纵深方向的分布而不能清晰地成像于一个像面上;X光激发的发光玻璃成像系统具有这种性质.针对不同发光平面的发光强度呈现指数衰减规律的发光玻璃的成像问题,用几何光学原理模拟了成像清晰度的变化规律,为这类成像系统的调节提供了依据,并获得了与理论推导的成像清晰度的变化规律相符的实验结果.

In an optical image-formation system with very narrow depth of field,it is impossible to get a very clear image because of the longitudinal distribution of different illuminant plane.The image-formation system adopting X-ray excitated glass scintillator features this character. In glass scintillator,luminous intensity of different planes decay exponentially with the depth X-ray penetrate through.In order to get a clear image from such a system,changing law of image definition is simulated in the way of geometrical optics and some very meaningful results are derived.The reasons how to adjust such a system according to the X-ray energy and the width of the glass are also explained.The experimental results according with the simulated image definition are displayed.