The lenticular raster system for 3D movies non-glasses show designed by NIKFI demonstrated commercially in Moscow in the 40'st of the last century. Essential lack of this method was narrow individual viewing zone as only two images on the film used. To solve this problem, we propose to use digital video projective system with modular principle of its design. Increase of the general number of the pixels forming the stereo image is reached by using of more than one projector. The modular projection autostereoscopic system for demonstration of the 3D movies includes diffuser screen; lenticular plate located in front of the screen; projective system consisted from several projectors and the block of parallax panoramogram fragments creator. By means of this block the parallax panoramogram is broken into fragments which quantity corresponds to number of projectors. For the large dimension lenticular screen making rectangular fragments of inclined raster were joined in a uniform leaf. To obtain the needed focal distance of the screen lenses we used immersion - aqueous solution of glycerin. The immersion also let essentially decrease visibility of fragments joints. An experimental prototype of the modular projection autostereoscopic system was created to validate proposed system.
Operation of the device is based on alternative generation of pictures for left and right eyes on the monitor screen. Controller gives pulses on LCG so that shutter for left or right eye opens synchronously with pictures. The device provides frequency of switching more than 100 Hz, and that is why the flickering is absent. Thus, a separate demonstration of images to the left eye or to the right one in turn is obtained for patients being unaware and creates the conditions of binocular perception clsoe to natural ones without any additional separation of vision fields. LC-cell transfer characteristic coodination with time parameters of monitor screen has enabled to improve stereo image quality. Complicated problem of computer stereo images with LC-glasses is so called 'ghosts' - noise images that come to blocked eye. We reduced its influence by adapting stereo images to phosphor and LC-cells characteristics. The device is intended for diagnostics and treatment of stabismus, amblyopia and other binocular and stereoscopic vision impairments, for cultivating, training and developing of stereoscopic vision, for measurements of horizontal and vertical phoria, phusion reserves, the stereovision acuity and some else, for fixing central scotoma borders, as well as suppression scotoma in strabismus too.
The overwhelming majority of LCD projectors that are used for polarized stereoscopic projection have linear polarized output with two colors in one direction and the third color in an orthogonal direction (e.g. green is horizontal and red and blue are vertical). During standard conversion of two projectors light to orthogonal or circular clockwise and counter-clockwise polarization more than fifty percent of light energy is lost. This paper considers a method of polarized stereoscopic projection that gives less light loss. For this purpose the light of each LCD projector is converted to circular polarization by using quarter wave retarder plates. Orientation of its optical axes are chosen so that green light from the first projector and red and blue light from the second projector are circularly polarized in the clockwise direction. The remaining colors are circular polarized in the counter-clockwise polarization. Simultaneously color transformation of stereo pairs pictures is realized. Green component of first picture is mixed with red and blue component of second picture and vice versa. This method enables the observation of good quality stereoscopic images using glasses with circular polarizers. In the case of glasses with linear polarization, half wave plates for conversion of LCD projectors light are used.
New way for investigation of visual field, based on virtual reality methods, is presented. It can use for central and paracentral scotomas registration. The study is realized by presentation of the luminous stimuli at monitor screen and its observation with two open eyes. The liquid-crystal shutters are fixed before eyes. Special driver alternately opens that right, that left eyes with frequency exceeding frequency of flicker fusion. This enables to control visibility of vision field separate areas. Program provides stimulus presentation in accident manner in different areas of visual field, so that some of presentation coincides by phase with right eye opening, but some with left. Patient press space bar if he observe stimulus. As the result computer print two vision field maps in which stimulus is invisible by right, or by left eyes, that is to say draws scotomas. Thereby this enables to fix central scotoma borders, as well as suppression scotoma in strabismus too. In program are provided possibility to change brightness and color of stimuli, background and fixation point, time and frequency of appearance of stimulus, its dimension and shape. Modification of device is considered in stationary (on the base of personal computer) and portable variant.
Strabismus and amblyopia are two main impairments of our visual system, which are responsible for the loss of stereovision. A device is developed for diagnosis and treatment of strabismus and amblyopia, and for training and developing stereopsis. This device is composed of a liquid crystal glasses (LCG), electronics for driving LCG and synchronizing with an IBM PC, and a special software. The software contains specially designed patterns and graphics for enabling to train and develop stereopsis, and do objective measurement of some stereoscopic vision parameters such as horizontal and vertical phoria, fusion, fixation disparity, and stereoscopic visual threshold.