中国开放科研知识云: 检索

A brightness and color correction method of LED display based on CCD camera (EI CONFERENCE) 会议论文
2012 International Applied Mechanics, MechatronicsAutomation and System Simulation Meeting, AMMASS 2012, June 24, 2012 - June 26, 2012, Hangzhou, China
Zhao Z.; Wang R.

收藏 | 浏览/下载：16/0 | 提交时间：2013/03/25

The correction methods of LED displays are aiming to address the uniform issues which includes brightness aspect and color aspect. The correction method use a 33 correction coefficients matrix to reshape the pulse width of each LED. To calculate the correction coefficients a linear system is established which includes a color CCD and a LED display. And a correction algorithm is introduced based on the color CCD. This algorithm describes the relationships of the main color components of a LED when the gray level of a LED is increasing or decreasing the three main color components would change according to the correction coefficients. The results shows that the correction based on this algorithm improved the performance of LED displays. (2012) Trans Tech Publications Switzerland.

The application of diagnostic equipment in the Tokamak fusion reaction (EI CONFERENCE) 会议论文
2011 International Conference on Optical Instruments and Technology: Optical Systems and Modern Optoelectronic Instruments, November 6, 2011 - November 9, 2011, Beijing, China
Zhang B.-S.; Chang J.; Gong X.-Z.; Gan J.-F.; Feng S.-L.

收藏 | 浏览/下载：13/0 | 提交时间：2013/03/25

This paper introduces the infrared optical system in the Tokamak fusion reaction device. In this optical system 3.the relay group lenses. This paper describes the decrease of the modulation transfer function (MTF) when the temperature changes and how to compensate the decrease of the MTF in order to maintain the image quality in a high level. As a result the traditional optical structure can't meet the requirements 2.the Cassegrain system the image quality of this optical system can reach the requirements when the temperature changes. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE). because the length of the infrared optical system in the Tokamak is very long. The design of optical system in the detection facility includes three parts:1.the combination of the concave aspheric mirror and flat mirror

Development and radiance calibration of three-waveband camera (EI CONFERENCE) 会议论文
International Symposium on Photonics and Optoelectronics, SOPO 2010, June 19, 2010 - June 21, 2010, Chengdu, China
Lu Z.; Sun Q.; Wang J.; Lu Z.; Liu Y.

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

An imaging system with three-waveband sharing one lens and an area CCD was developed. By rotating different filters into the beam path the required waveband was selected. The optical system which can image in ultraviolet visible and near infrared region was designed and the signal collecting system was integrated. The optical design and system integration have some advantages such as low cost small size and light in weight. To obtain a high imaging quality the radiation calibration is carried out in order to establish the relation between the average grey level of output image and the input radiance from the integrating sphere. According to the calibration data in experiments the radiation dynamic range and the best working point of the system are determined. The experiment result shows that the dynamic range of the image system is maximal when the exposure time is 8ms in ultraviolet 0.5ms in visible and 0.125ms in near infrared region. 2010 IEEE.

Application of multi-sensors parallel fusion system in photoelectric tracing (EI CONFERENCE) 会议论文
2008 International Conference on Optical Instruments and Technology: Optoelectronic Measurement Technology and Applications, November 16, 2008 - November 19, 2008, Beijing, China
Cheng G.-Y.; Cai S.; Gao H.-B.; Zhang S.-M.; Qiao Y.-F.

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To solve the real-time and reliability problem of tracking servo-control system in optoelectronic theodolite a multisensors parallel processing system was proposed. Misdistances of three different wavebands were imported into system and then prediction was done in DSP1 to get the actual position information. Data fusion was accomplished in PPGA imported by multi channel buffer serial port. The compound position information was used to control the theodolite. The results were compared with external guide data in DSP2 to implement correction of above calculation and then were imported to epistemic machine through PXI interface. The simulation experiment of each calculation unit showed that this system could solve the real-time problem of feature level data fusion. The simulation result showed that the system can satisfy the real-time requirement with 1.25ms in theodolite with three imaging systems while sampling frequency of photoelectric encoder was 800 Hz. 2009 SPIE.

Design of dual-FOV refractive/diffractive LWIR optical system (EI CONFERENCE) 会议论文
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Advanced Optical Manufacturing Technologies, July 8, 2007 - July 12, 2007, Chengdu, China
Zhang J.-P.; Wang L.-J.; Zhang X.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

An infrared-optical zoom system using binary element is proposed in this paper. The two main advantages of the zoom system introducing here are: bigger F-number and lower cost. The primary optical properties are: F/#=1 Second Others zoom ratio =1:4 binary element is used to correct the chromatical aberration by taking the advantage of negative dispersion characteristics and the cost of the system is lower than that of conventional ones with Zinc Selenide (Znse) material at the same level. In the binary element is rotational symmetric with one step which is easy to fabricate in order to balance 5th spherical aberration and dual field are 26.6 and 5.6respectively. Wider field of view is used for search and the smaller one is used for imaging details. This system uses un-cooled infrared detector with 320240 pixels and 45m pixel size. The F-number matches the sensitivity range of the detector array. Three aspects are considered during design process to make the system more satisfactory and more achievable. First 5th coma aberration and 5th astigmatic aberration the manner of zoom is accomplished by exchanging tow lenses into the smaller field of view system layout. The lens exchange manner faces the requirement of simple system structure and good image quality in both focal points. It can also make the system more feasible in the alignment process than mechanical-zooming manner and optical-zooming manner high-order asphere surfaces with 2th order to 10 th order are also hired in the system. Asphere surface is useful in compressing the system and improving optical system transmittance. This kind asphere surface is on industrial level featuring low cost and easy to fabricate. It is shown that good image quality can achieved by implementing five Germanium lenses and the transmittance of system is 72%. All aberrations are diffraction-limited both spherical aberration and astigmatic aberration are corrected. When the field of view(FOV) is 26.6 and the focal length is 152mm MTF at Nyquist frequency(11lp/mm) is great than 0.7. The spherical aberration is -0.0073. The coma aberration is 0.0978 and the astigmatic aberration is -0.013. When the field of view(FOV) is 5.6 and the focal length is 38mm MTF at Nyquist frequency is great than 0.8 with spherical aberration -0.0046 the coma aberration 0.055 and astigmatic aberration 0.034.

A new high-precision measurement system used in the image calibration of large-sized photographic instrument (EI CONFERENCE) 会议论文
Optical Design and Testing II, November 8, 2004 - November 11, 2004, Beijing, United states
Li Y.; Liu Z.

收藏 | 浏览/下载：10/0 | 提交时间：2013/03/25

The purpose of characterizing the image of large-sized photographic instrument is to make the directionality of three coordinate axises in the three-dimensional coordinate of the image and the directionality of three axises of coordinate in the frame of axes of the instrument keep the same direction. This problem was solved by a high-precision measurement system composed of double-theodolite and a set of communication system. Two cube prisms will be respectively placed on the image surface and the instrument. Every cube prism will stand for a three-dimensional coordinate from the image surface or the instrument. As a result the interdependence of both coordinates from the image surface and the instrument can be obtained by measuring the interdependence of the both cube prisms with autocollimation survey axiom. In the survey system two high-precision stations TDA5005 from Leica Company will be selected as double-theodolite and the interdependence of both coordinates can be achieved by moving the station only at one time. Therefore this measurement system is a high efficient and high-precision surveying method to the image calibration of the large-sized photographic instrument. Based on the experiment its measuring accuracy can reach arc-second level.

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