| 摘要 |
The Parallax Error Measurement Device (PEMED) is an instrument used to measure parallax error associated with military night sights and other sights containing reticles. The PEMED consists of the following components: aperture translation stage; camera lens positioning and translation stage; coherent fiber optic image transfer bundle; automated translation stage controller; low light level camera; video wave form monitor and storage oscilloscope. The measurement concept involves the principle of translating an aperture across a relatively large collecting optic instead of translating the collecting optic itself. This technique eliminates alignment and focus errors which might occur when the collecting optic is translated. The aperture translation stages are driven by servo motors under computer control where a positive verification signal is monitored by the computer after each specific translation distance is achieved. The entire PEMED is designed to operate remotely inside of an environmental chamber such as that used to condition and test equipment at extreme temperatures. Moving parts associated with parallax measurements are restricted to the aperture plate between the eyepiece objective lens and the camera objective lens. The aperture plate is initialized prior to each parallax measurement and the entire measurement is conducted in a short period of time (approximately one minute), therefore, cancelling the effects of temperature on the other components such as the test item mount, camera lens, and ancillery components.
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