• 제목/요약/키워드: ultra-precision

검색결과 925건 처리시간 0.043초

Design of a See-Through Head-Mounted Display with a Freeform Surface

  • Wang, Junhua;Liang, Yuechao;Xu, Min
    • Journal of the Optical Society of Korea
    • /
    • 제19권6호
    • /
    • pp.614-618
    • /
    • 2015
  • This paper described an off-axis head-mounted display system. It is composed of a 7-piece coaxial relay lens group and a freeform surface combiner. This configuration has a simple structure and a wide field of view (FOV). In this design, a freeform surface is chosen as the combiner, to simplify the structure and attain good image quality. We generated this freeform surface by considering both coordinates and normals of discrete data points. Moreover, we realize a coaxial structure in the relay lens group, which is compact and benefits from a loose tolerance requirement. The HMD system we finally realized has a 40° × 30° FOV and 15-mm exit pupil diameter.

PZT를 이용한 Semi-inchworm구동기법의 초정밀 회전 스테이지 개발 (Development of ultra precision rotational stage using Semi-inchworm driving mechanism with PZT)

  • 윤덕원;안강호;한창수
    • 반도체디스플레이기술학회지
    • /
    • 제6권1호
    • /
    • pp.37-41
    • /
    • 2007
  • Recently PZT is used in ultra precision mechanism field. PZT has a small motion range although it has a high resolution. Many methods, such as inchworm, impact driving, etc., have been applied for the expansion of the motion range.? In this study, the new actuating mechanism for rotational motion with two PZT actuators is proposed. The ultra precision rotational actuator which is made by proposed mechanism is able to operate both coarse and fine motion. The design parameters of the proposed mechanism are considered to improve the performance of the system. The rotational stage which is applied by the proposed mechanism is fabricated. The resolution and velocity for fabricated rotational stage are measured by laser interferometer.

  • PDF

반도체용 대구경관의 전해 복합연마에 대한 초정밀 가공 특성연구 (A Study on the characteristics of ultra precision about Buffing and Electropolishing for Semiconductor Large Radius Pipe)

  • 이정훈;이은상
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2004년도 추계학술대회 논문집
    • /
    • pp.609-613
    • /
    • 2004
  • On this study, electrochemical polishing is adapted to ultra-fine surface for semiconductor large radius gas-tube. The system which buffing and electrochemical polishing can be performed simultaneously was constructed in connection with developing exclusive system. Based on existing papers and the research of background, electrode gap and electrolyte flow were fixed. Current density and electrochemical precision time were chosen as variables. On this study, it is objected to find optimal precision condition and precision variables on the in-process electrochemical polishing.

  • PDF

Dynamic Analysis on Belt-Driven Spindle System of Machine Tools

  • Kim, Seong-Keol
    • International Journal of Precision Engineering and Manufacturing
    • /
    • 제3권3호
    • /
    • pp.82-89
    • /
    • 2002
  • The need of ultra-precision machine tools, which manufacture and machine the high precision parts used in computers, semi-conductors and other precision machines, has been increased over years. Therefore it is important to design the driving parts, which affect significantly on their performances. In this paper, the dynamic analyses on the belt-driven system were explored. Relation of the acoustical natural frequency and the tension of belt was derived and presented through experiments. Also, while the dynamic loads on motor system were changed, dynamic deflections were calculated through finite element analysis. Nonlinear characteristics of the bearings having an effect on the dynamic performance were studied and the belt connecting the motor (driving part) to spindle of a machine tool (driven part) was modeled as truss and beam elements fur simulations under various conditions, and a beam element model was verified to be more useful.

Influence of Rolling Friction in Linear Ball Guideways on Positioning Accuracy

  • Tanaka, Toshiharu;Ikeda, Kyohei;Otsuka, Jiro;Masuda, Ikuro;Oiwa, Takaaki
    • International Journal of Precision Engineering and Manufacturing
    • /
    • 제8권2호
    • /
    • pp.85-89
    • /
    • 2007
  • Linear ball guideways have been used recently in precision or ultra-precision positioning devices. However, when the inner balls begin to roll or the moving direction reverses, these guideways are subject to rolling friction or nonlinear spring behavior. An ultra-precision device with a linear motor, referred to as a 'tunnel actuator' (TA), has been constructed to measure these phenomena. The application of a TA is beneficial for two reasons: it mostly cancels the attractive magnetic force between the stator and mover (armature), and its magnetic flux leakage is very low. The influence of the nonlinear spring behavior in ball guideways was investigated in this study using the pure driving force from a TA. The equilibrium between the driving force from the TA and the nonlinear spring force provided great accuracy for a positioning stage using a linear ball guideway.

복합가공기용 초정밀급 새들 가공을 위한 최적의 고정구 개발 (Development of the optimal Jig & fixture applied to ultra-precision saddle machining)

  • 김병창
    • 한국기계가공학회지
    • /
    • 제13권3호
    • /
    • pp.89-95
    • /
    • 2014
  • The increasing level of demand for multi-tasking machines requires a saddle with an ultra-precise machining accuracy level of $15{\mu}m$, as such a saddle is one of the main components of these machines. The manner of achieving ultra-precise machining accuracy mainly depends on the fixed forces. In this paper, we optimized the number of contact points and the contact positions to reduce the deformation of the saddle while it is machined. The performance levels of the proposed optimal jig and fixture are determined by measuring the flatness, parallelism and perpendicularity of a machined saddle. The machining accuracy is found to be lower than $15{\mu}m$ at all measured points.

기계학습기반 초신뢰·저지연 무선통신기술 연구동향 (Research Trends of Ultra-reliable and Low-latency Machine Learning-based Wireless Communication Technology)

  • 이현;권동승
    • 전자통신동향분석
    • /
    • 제34권3호
    • /
    • pp.93-105
    • /
    • 2019
  • This study emphasizes the importance of the newly added Ultra-Reliable and Low-Latency Communications (URLLC) service as an important evolutionary step for 5G mobile communication, and proposes a remedial application. We analyze the requirements for the application of 5G mobile communication technology in high-precision vertical industries and applications, introduce the 5G URLLC design principles and standards of 3GPP, and summarize the current state of applied artificial intelligence technology in wireless communication. Additionally, we summarize the current state of research on ultra-reliable and low-latency machine learning-based wireless communication technology for application in ultra-high-precision vertical industries and applications. Furthermore, we discuss the technological direction of artificial intelligence technology for URLLC wireless communication.