Abstract: A system for producing a sound having a certain frequency range to maintain laying hens in stable and comfortable conditions. includes a basic wave generator for generating a pair of first basic waves having the same phase and a pair of second basic waves having opposite phases, a relaxation wave generator for generating a pair of relaxation waves by combining the pair of first basic waves and the pair of second basic waves with time, a modulator for generating a pair of relaxation sounds by modulating the pair of relaxation waves with a sound wave having an audible frequency, and an audio output unit composed of two left and right parts such that stereo sound is outputted, for receiving the pair of relaxation sounds and outputting the pair of relaxation sounds to the left and right parts, respectively.

Abstract: Disclosed is a system and method for producing a sound having a certain frequency range to maintain laying hens in more stable and comfortable conditions. The system comprises a basic wave generator for generating a pair of first basic waves having the same phase and a pair of second basic waves having opposite phases, a relaxation wave generator for generating a pair of relaxation waves by combining the pair of first basic waves and the pair of second basic waves with time, a modulator for generating a pair of relaxation sounds by modulating the pair of relaxation waves with a sound wave having an audible frequency, and an audio output unit composed of two left and right parts such that stereo sound is outputted, for receiving the pair of relaxation sounds and outputting the pair of relaxation sounds to the left and right parts, respectively.

Abstract: The present invention relates to a head mounted display which is constructed such that stereoscopic images can be seen on a liquid crystal display screen disposed adjacent to eyes, and more particularly, to an optical system for the head mounted display wherein image resolution can be enhanced and a distortion phenomenon caused by eye's movement can be minimized.

Abstract: The present invention relates to a head mounted display that is constructed such that stereoscopic images can be seen on a liquid crystal display screen disposed adjacent to eyes. The present invention provides an optical system for a head mounted display, comprising a light source; an illuminating prism for controlling an optical path of light rays from the light source by reflecting and refracting the light rays; a polarizer for polarizing the light rays emitted from the illuminating prism; a polarization beam splitter for reflecting the polarized light rays emitted from the polarizer; a frontlight liquid crystal display screen on which images are displayed by means of the light rays reflected by the polarization beam splitter; and a free-form-surface prism disposed in front of the polarization beam splitter for magnifying the images on the liquid crystal display screen by reflecting and converging the light rays emitted from the liquid crystal display screen.

Abstract: The present invention relates to a head mounted display that is constructed such that stereoscopic images can be seen on a liquid crystal display screen disposed adjacent to two human eyes.

Abstract: The present invention provides an optical system for a head mounted display. The optical system of the present invention comprises a light source, a reflector for diffusing light from the light source, a reflection-type liquid crystal display panel for displaying an image by means of the light which is irradiated from the reflector, and a prism disposed in front of the reflector for magnifying the image of the liquid crystal display panel. In particular, the light source is a light emitting diode, and the reflector is constructed to be aspheric such that distortion aberration of the image of the liquid crystal display panel, which is emitted from the reflector, can be corrected. According to the present invention, an advantage of enhancing light efficiency can be obtained by including the light emitting diode and the reflector for diffusing the light generated from the light emitting diode.

Abstract: Disclosed is an antenatal training device for a pregnant woman comprising: a fetal vital sound generating unit for collecting and outputting a signal representative of a fetal vital sound generated to correspond to the detected heartbeats and movement of a fetus; and a brain wave sound generating unit connected to the fetal vital sound generating unit, for generating a brain wave frequency signal generated in the most stable and comfortable state of the body and mind among various brain waves of the human body, modulating it with an audio frequency signal, mixing the modulated brain wave sound signal and the fetal vital sound signal, and amplifying the mixed brain wave sound and fetal vital sound signals for application to an audio output part, thereby allowing a user to hear them which in turn induces the user to a psychologically serene state or a relaxing state.