公开(公告)号：US4655540A

公开(公告)日：1987-04-07

申请号：US726125

申请日：1985-04-23

申请人： Robert B. Wood ,  Jen-Lih Hung ,  Norman S. Jee

发明人： Robert B. Wood ,  Jen-Lih Hung ,  Norman S. Jee

IPC分类号： G02B27/00 ,  G02B27/01 ,  G02B5/32 ,  G02B27/14

CPC分类号： G02B27/0103 ,  G02B2027/0109 ,  G02B2027/0118

摘要： An optical display system employs a holographic optical element that has a holographic fringe pattern which is coordinated with the phosphor emission peak of a cathode ray tube to eliminate perceptible variations in image brightness. The holographic optical element has a reflection characteristic that defines two diffraction efficiency peaks which are resolved by a low diffraction efficiency dip that is interposed between them. The optimum wavelength spacing between the two diffraction efficiency peaks for a given wavelength spacing is determined by computing for all observer head positions and look angles of concern the differences among the areas under the integrated efficiency characteristics for the reflection characteristic of the holographic optical element and the phosphor emission characteristic of the image-producing cathode ray tube. The optimum wavelength spacing is that which provides the desired variation among the computed difference values, which respresent the display brightness uniformity. The center dip reflection characteristic increases the spectral bandwidth of the holographic optical element and thereby increases its reflectivity to promote good contrast with the use of a cathode ray tube operating at reduced beam current levels. When installed as a combiner in a head-up display sytem for aircraft, the holographic optical element superimposes the image on an outside scene without introducing significant discoloration of the scene.

摘要翻译： 光学显示系统采用具有与阴极射线管的荧光体发射峰配合的全息条纹图案的全息光学元件，以消除图像亮度的可察觉的变化。 全息光学元件具有限定两个衍射效率峰值的反射特性，其通过介于它们之间的低衍射效率下降来解析。 通过计算所有观察者头部位置和观察角度来确定给定波长间隔的两个衍射效率峰值之间的最佳波长间隔，涉及全息光学元件的反射特性的积分效率特性下的面积之间的差异 图像产生阴极射线管的荧光体发射特性。 最佳波长间隔是在计算出的差值之间提供期望的变化，其表示显示器亮度均匀性。 中心浸渍反射特性增加了全息光学元件的光谱带宽，从而增加了其反射率，从而通过使用以减小的光束电流水平操作的阴极射线管来促进良好的对比度。 当作为飞机的平视显示系统中的组合器安装时，全息光学元件将图像叠加在外部场景上，而不引起显着的场景变色。

公开(公告)号：US4936642A

公开(公告)日：1990-06-26

申请号：US788073

申请日：1985-10-16

申请人： Jen-Lih Hung ,  Robert B. Wood

发明人： Jen-Lih Hung ,  Robert B. Wood

IPC分类号： G03H1/04

CPC分类号： G03H1/04

摘要： A method of constructing flare-free reflection holograms uses a light scattering mechanism positioned between a first exposure beam and holographic recording material to remove the spatial coherence from all but adjacent rays within a relatively small angular range before the light rays of the first exposure beam strike the hologram surface. A second exposure beam of spatially coherent light rays interferes with mutually spatially coherent light rays of the first exposure beam to form a primary hologram. Light rays reflected off the holographic recording material noncontacting surface of the substrate interfere with the light rays of the first exposure beam but do not form parasitic hologram recordings because the interfering light rays are not mutually spatially coherent. The size of the region on the scattering device illuminated by the first exposure beam can also be selectively adjusted to determine the angular range of spatial coherence of the exposure beam and thereby create a primary hologram whose thickness is independent of and, if desired, may be made less than the thickness of the holographic recording material.

摘要翻译： 一种构建无光束反射全息图的方法使用位于第一曝光光束和全息记录材料之间的光散射机构，以在第一曝光光束的光线入射之前在相对较小的角度范围内去除与所有相邻光线的空间相干性 全息图表面。 空间相干光线的第二曝光光束干扰第一曝光光束的相互空间相干的光线以形成主要全息图。 从基板的全息记录材料反射的光线与第一曝光光束的光线相干，但是由于干涉光线不相互空间相干，所以不形成寄生全息图记录。 也可以选择性地调节由第一曝光光束照射的散射装置上的区域的大小，以确定曝光光束的空间相干性的角度范围，从而产生其厚度独立于主要全息图，如果需要，可以是 小于全息记录材料的厚度。