Papers by Keyword: Collimator

Abstract: Our research was conducted based on the development of some antitank missile CCD observer test system. Combining the function and working principal of a typical CCD observer, we undertook an in-depth study on the collection of the core output signal of the CCD observer, naming the video signal information, and the design of key software and hardware. Utilizing both digital and video collection technology, our study provides handling method of measuring angle precision, interference rejection as well as sensitivity. Using the most advanced technology, this system is characterized with a user-friendly interface, analytical visualization, and reliability.

Abstract: A collimator is one of the most popular optical instruments used in optical workshop and parallelism of the beams is the key technical indicator of collimator. A great deal of efforts has been expended to ensure reticle locate at the focal plane. In this paper, a new laser differential confocal collimator alignment method is proposed for precision alignment of collimators. Based on this principle an experimental setup is built up and used to align two collimators whose focal lengths are 600mm and 1000mm and f-numbers are both 10.The wave-front parallelism error of the laser differential confocal system and the tested collimator is measured by the verified experiment based on scanning penta prism method. At last some influence factors alignment precision is analyzed. Theoretical analysis and experimental results show that the alighment precision based on laser differential confocal method can reach to 0.004mm.and can be a high-efficiency approach to align collimators, especially in industry production.

Abstract: A new real-time angular distortion measurement system, composed of devices i.e. the photoelectrical auto-collimating collimator and the reflex light-tube installed on deck, is developed in this paper. Real-time measurement of vessels bi-dimensional angular distortion is achieved by using this computer control system. Two video signals of photoelectrical auto-collimating collimators are received by the computer control system, and real-time image processing is done to obtain the dynamic miss distance. Then relative distortion of vessel is calculated by overlying measuring results of these two-way images.

Abstract: Collimators are used in radiosurgery or radiotherapy systems to accurately focus their high-energy rays on the target to avoid causing damage to the collateral healthy tissues. With the development of conformal radiotherapy techniques, variable visual field collimators (VVFC) are widely used and many designs of VVFC have been proposed. However, these designs still exhibit different deficiencies, e.g. unable to completely eliminate the radiation leakage due to the inter-block gaps. Therefore, in this paper, an innovative design of VVFC is proposed through analyzing the original VVFC, determining the conflicts and solving them using the inventive problem solving methods (TRIZ). Compared with the existing designs of VVFC, the proposed design enables the selection of suitable size of field for the treatment of different size of targets, and completely eliminates the radiation leakage due to inter-block gaps.

Abstract: Objective lens is the core part of a collimator, its quality has a direct impact on the collimators quality. Due to the small field of view and low image quality requirement, general collimator objective lens is difficult to achieve the requirement of testing an aerial camera s performance. So designing a large field of view, apochromatic collimator objective lens has an important practical significance. In this paper, the major qualifications were first proposed to design the collimator objective lens,according to which the initial configuration was confirmed. Then we used the ZEMAX optical design software to optimize the initial structure and normalized the optimized structural parameters. Finally the image quality of collimator objective lens was evaluated to make it achieve the requirement of qualifications.

Abstract: The collimator has an extensive application as an experiment equipment that can provide an infinity goal in the instrument alignment and testing.This paper provides a new type of collimator with image stabilization function in consideration of human disturbance factors, including environment micro-vibration and so on. Liquid surface which appears natural level under gravity imaging optical path of collimator can emerge through liquid refraction and reflex later. And we should make use of this phenomenon. Mathematical modeling and analysis on the principle of dynamic imaging of the liquid wedge have been made to design several optical principle charts of the collimator with image stabilization function.One of the image stabilization optical principle structure styles has been designed based on its mechanical structure.An experiment prototype is produced and is made more practical.

Abstract: A single mode fiber assembled with a specified length graded index multimode fiber as a collimator, which is used in common-path optical coherence tomography (CPOCT) is described in this paper. Compared with conventional collimator lens, this assembled fibers structure possesses the advantages of small volume, easy to be fused or connected with other part of the CPOCT system. Furthermore, with this assembled structure an all fiber CPOCT system is constructed which has the potential to detect the internal bodily organs and tissues of human being. Numerical simulation and experiments are implemented to verify the effectiveness of this method.

Abstract: The use of LED for illumination offers significant advantages, such as lower power consumption, longer lifetime and improved colour management. Sharp gradients in luminous intensity patterns of LED are commonly controlled by the use of secondary optics that are mostly axisymmetric. In the current study, we proposed LED secondary optics forming non-axisymmetric luminous intensity distribution with an extremely narrow view angle. The proposed secondary optics dramatically reduced the view angle of the LED, with a view angle ( 10º) in full width at half maximum (FWHM) in simulations. Afterward, a prototype of the proposed lens was machined by single point diamond turning (SPDT). Luminous intensity distribution of the machined lens was off by about 8º from the optical axis and maintained a view angle of 12º. The peak luminous intensity was folded more than thirty-two times. The proposed lens showed high optical performance and can be used for specialized optical applications.

Abstract: A novel spatial filtering collimator is developed for the laser indication application. The mass produced, inexpensive, red and blue semiconductor laser modulars can easily be optimized as fine line laser indicator source. We have theoretically investigated the results, simulated the designs, and measure the laser beam spots and the laser fine lines. The spatial filtering collimator is designed and optimized for practical used and the results are very satisfactory.