公开(公告)号：US5714750A

公开(公告)日：1998-02-03

申请号：US320888

申请日：1994-10-05

Applicant: Jay M. Eastman ,  Anna M. Quinn ,  Kevin Whitcomb ,  James M. Zavislan

Inventor： Jay M. Eastman ,  Anna M. Quinn ,  Kevin Whitcomb ,  James M. Zavislan

IPC: G02B26/10 ,  G02B27/44 ,  G06K7/10

CPC classification number: G06K7/10881 ,  G02B26/10 ,  G02B27/4227 ,  G06K7/10653 ,  G06K7/1098 ,  G06K2007/10524 ,  G06K2207/1013 ,  G06K2207/1016

Abstract: A miniature scan engine for scanning a beam of monochromatic (laser) light across a bar code and receiving return light at a detector that provides electrical signals representing the code, utilizes an integral assembly of a laser (laser diode), the detector and a light collector mounted on flexures and rotated so as to scan the beam and receive the return light from the code. The collector is a body of material transmissive at the laser wavelength. The body presents an orientable surface so that the return light is incident at or close to perpendicular to the surface. In the body, parallel to the surface, is a volume hologram grating having Bragg planes arranged in rings around a center region in alignment with the detector. The angles of the Bragg planes vary progressively and decreases in a direction toward the center region so that light incident on the collector at angles of incidence, which vary from perpendicular to the surface by about + or -5.degree., are diffracted and propagate by guided mode propagation, including reflections at the internal surfaces of the body and transmission through the grating (because the light propagating along the paths intersects the grating Bragg planes off Bragg that is at an angle other than the Bragg angle) to the detector. Efficient collection of the light returned from the bar code symbol is obtained. The entire scan engine may occupy a volume of less than 1.25 cubic inch, thereby enabling bar code scanning and reading facilities in devices such as hand-held data collection terminals where space is at a premium.

Abstract translation: 一种用于在条形码上扫描单色（激光）光的微型扫描引擎，并在提供表示代码的电信号的检测器处接收返回光，利用激光（激光二极管），检测器和光的整体组件 收集器安装在弯曲上并旋转，以扫描光束并从代码接收返回光。 收集器是在激光波长下透射的材料体。 身体呈现可定向的表面，使得返回光入射到或接近垂直于表面。 在体内平行于表面，是一种体积全息图光栅，其具有布置在与检测器对准的中心区域周围的环中。 布拉格平面的角度逐渐变化，并且朝向中心区域的方向逐渐变小，从而入射到集电体上的入射角（其垂直于表面变化约+或-5°）入射的光被衍射并通过引导传播 模式传播，包括身体内表面的反射和通过光栅的透射（因为沿着路径传播的光将光栅布拉格平面与布拉格角以外的角度相交）到检测器。 获得从条形码符号返回的光的有效收集。 整个扫描引擎可能占用小于1.25立方英寸的体积，从而使得诸如手持式数据采集终端之类的设备中的条形码扫描和阅读设施是空间有限的。