像增强器的荧光屏亮度均匀性测试的校正法研究

像增强器荧光屏亮度均匀性参数是判断其性能好坏的一个重要技术指标。设计了一种测试系统来测试它的亮度均匀性参数。该系统利用标定过的具有均匀亮度的荧光屏(裸屏),以标准像增强器的图像作为标准来校正面源电子枪。由于校正后的面源电子枪仍然存在误差,所以具有均匀亮度的荧光屏(裸屏)的图像不可能是完全均匀的,呈现边缘暗中间亮。分析其图像的亮度曲线,建立校正函数,改变校正函数中的调节系数,直到计算机上显示出图像均匀为止,这时可得出系数确定的校正函数。首先利用校正后的电子枪轰击待测荧光屏,采集其图像,以确定的校正函数对其进行修正,然后观察由计算机显示出的图像是否均匀,从而判断待测荧光屏的均匀性。

Research on correction method of the testing of the uniformity of image intensifier fluorescence screen brightness

The uniformity performance of image intensifier fluorescence screen brightness is an important technical index to judge its property.A testing system is designed to test its brightness uniformity.The system uses a calibrated brightness uni- form screen (bare screen),taking the image of a standard image intensifier as the standard to calibrate the area source electron gun.Due to the uniformity error of the area source electron gun,the image of the brightness uniform screen(bare screen) is not completely uniform,it shows brighter in middle and darker at edge.The brightness curve of the image is analyzed,and a cor- rection function is created,and the factor in the function is changed,the image showing becomes uniform,the factor fixed for- mula is got.The screen is shot with the corrected electron gun,and its image is collected.Its image with the fixed formula is corrected.If the corrected image is uniform or not to judge the performance of its brightness uniformity,thus a correct testing result is acheived.