GB741154A - Arrangement for amplifying the light intensity of an optically projected image - Google Patents

Abstract

741,154. Semi-conductor devices. GES. ZUR FORDERUNG DER FORSCHUNG AN DER EIDGEN TECHNISCHEN HOCHSCHULE. April 10, 1953 [April 16, 1952], No. 9866/53. Class 37. [Also in Groups XX and XL (b)] In an arrangement for increasing the light intensity of an optically-projected image in which the deformation of a control layer included in an optical system modulates the light of a separate light source, the control layer includes a combination of a light-sensitive layer and a deformable layer with a mirror layer. The incident light is effective to vary the resistance or dielectric constant of the lightsensitive layer so that with a D.C. or A.C. biasing voltage applied to suitable electrodes, the deformed layer varies the amount of light reflected from the separate light-source via the mirror layer. In one form of control layer, Fig. 1, a glass carrier 1 has a transparent electrode 2 with a layer of light-sensitive material, such as selenium or copper-activated zinc sulphide. The deformable layer 4, which may be .formed of a high polymer such as polyvinylchloride with a plasticizer, carries a covering 5 forming a mirror and a second electrode. The layer 4 may be opaque. In a modified combination, Fig. 2, a separate glass carrier 6 supports the deformable layer 4 and the metallic mirror 5, the elements carried by the carrier 6 being separated from the composite layer on the carrier 1 by a medium 7 of suitable conductivity, dielectric constant and internal friction, such as ionized air or benzene plus an electrolyte. Specifications 543,485 and 561,926, [both in Group XL], are referred to.