Abstract: An ophthalmic treatment apparatus uses therapy and diagnostic laser light sources whose beams are deflected two-dimensionally via an optical deflector and a galvanomirror and directed on the eye fundus to produce a fundus image on a display monitor. A photosensitive substance that accumulates specifically in neovascular regions is administered to the patient to define the region where the neovascular tissues are located. When the region is to be treated, the therapy laser light source is activated and its intensity is amplified by a controller and a driver for driving a light modulator. This arrangement assures a reliable definition of the affected region and enables only the neovascular tissues to be destroyed or sealed off because the laser intensity can be amplified at the region concerned.

Abstract: The mirror in a single-lens-reflex (SLR) camera is eliminated by employing a liquid crystal cell and a polarizing beam splitter. The light from an illuminating lamp (32) is linearly polarized in a horizontal direction by a polarizer (58). The polarized illuminating light is totally reflected by a polarizing beam splitter (PBS) (54) and passes through a quarterwave plate (QWP) (56) and an objective lens (36). After passing through QWP (56) for the second time, the light is vertically polarized and totally passes through PBS (54). A focusing lens (40) focuses the image onto a film (30). A voltage supply (46) is connected to a liquid-crystal (LC) cell (44) by an electric switch (52) that can turn LC cell (44) on or off. When LC cell (44) is off, the polarization of the light is rotated by 90.degree. to be horizontally polarized. Thus the light is reflected by another PBS (48) to a prism (24) for viewing by a user (26).

Abstract: In an apparatus for reading-out features such as characters and marks recorded on an object such as labels, boxes and cards, the object is scanned by a linear CCD array to produce a video signal and a background level is detected from the video signal on the basis of an edge signal derived from the video signal. A plurality of slice levels having span and pitch adjusted according to said background level are generated and the video signal is compared with the slice levels to produce an output video signal. Even if the level of the video signal changes abruptly, it is possible to obtain more accurate output video signal and to remove error in pattern recognition. In another preferred embodiment, an amplitude of the video signal is adjusted by a variable attenuator in accordance with the detected background level.