Real-time Detection System For The Mtf Of The Projector Lens

MTF (Modulation Transfer Function) is recognized as one of most effective and objective methods to evaluate optical imaging systems and is extensively used in the process control of the optical system design and the imaging quality evaluation and detection of the optical imaging system. But there is no standard quantitative method for the measurement of projection lens in the production of projection display system. Based on the need of the production and measurement of projection lens, this thesis analyzed a real-time MTF measurement system based on image analysis for projection lens. The system uses CCD as an image receiver and can acquire tangential and sagittal MTF data at one measure, according to analyze a single pixel image.First, the thesis generally analyzes the test technology of OTF (Optical Transfer Function), and introduces the actuality and development of the test technology of OTF. In addition, the method of the measurement system is introduced.Considered DLP (Digital Light Processor) projection lens as experiment object, the second part of this thesis proposes a real-time MTF measurement system. The structure and theoretical model of the test system are expounded. In addition, it makes a summary of the practical problems and difficulties of this research. The processing methods of discrete signal are analyzed. System calibration in frequency domain and the common problems of spectrum analysis are resolved. According to character of Fourier transform, the data process is simplified, transforming two-dimensional data to one-dimensional data.The third part of the thesis constructs the whole platform of the measurement system, including hardware and software. The principles of hardware and the process of the software modules are expounded.Finally, the thesis presents the results of experiment. The factors that influence the results and how to correct the noise effect are also analyzed.In addition, the conclusion and future research direction are given.Simply structured, convenient, this system well fit the practical need of MTFmeasurement of projection lens and can be applied into practical application.