Abstract: Disclosed is a projection display apparatus including an optical modulator, configured to modulate a luminance of a beam; light sources in quantities of N, configured to output each beam having different polarization direction, N being a natural number and equal to or greater than 2; a lens unit, configured to allow each of the beams to be incident on an identical position of the optical modulator at a different incidence angle; a projection lens, configured to condense each of the N beams modulated and outputted from the optical modulator; an N-slit diaphragm, configured to allow some of the N beams to pass through the N-slit diaphragm; and N polarization filters, configured to perform a filtering of the beams having passed through N-slit diaphragm in different polarization directions. With the present invention, it is possible to suppress speckle noises which are generated on a video projected on a screen.

Abstract: A projection display apparatus of the present invention can include a light source; an optical modulator, configured to repeatedly output a modulation beam N times in a predetermined time range, the modulation beam being generated by identically modulating a bema of light emitted from the light source and N being a nature number and equal to or greater than 2; a mirror, configured to reflect the modulation beam, which is repeatedly outputted N times, to scan the modulation beam to an identical point of a screen; and a polarization rotating unit, configured to rotate a polarization direction of the modulation beam for each time the modulation beam is scanned. With the present invention, the speckle noises on a video scanned to a screen can be suppressed.

Abstract: Disclosed is a scanning display apparatus using a laser beam source. In accordance with an embodiment of the present invention, the scanning display apparatus can include a lighting optical system, configured to use a laser device as a light source, the laser device outputting a plurality of beams having different wavelengths that are recognized as an identical color; an optical modulator, configured to output a modulation beam by diffracting a beam transferred from the lighting optical system; a diffuser, placed on an optical path of the modulation beam outputted from the optical modulator and configured to expand a width of the modulation beam through a diffraction grating pattern formed on one surface of the diffuser; and a scanning mirror, configured to scan the modulation beam having passed through the diffuser on a screen.

Abstract: Disclosed are a method for driving a piezoelectric element or an optical modulator including a piezoelectric element and a recorded medium recorded with a program for executing the same. In accordance with an embodiment of the present invention, the method for driving a piezoelectric element causing a displacement object to be displaced by being contracted or expanded according to a supplied driving voltage, including supplying a driving signal to the piezoelectric element during a first driving period in a first voltage range; supplying a control signal for controlling a polarization hysteresis of the piezoelectric element according to a driving, performed during the first driving period, to the piezoelectric element; and supplying the driving signal to the piezoelectric element during a second driving period in a second voltage range.

Abstract: Disclosed are an optical modulator and an optical modulator module that can reduce a laser speckle. The optical modulator module can include an optical modulator, modulating an incident beam of light incident according to a driving signal and outputting the modulated beam of light; and a light transmissive substrate, placed in the optical modulator and formed with a phase control pattern, the incident beam of light and the outputted beam of light passing through the light transmissive substrate and the phase control pattern being formed in a part of a surface that is a light path of the incident beam of light and the outputted beam of light. Here, the phase control pattern, a central peak of an autocorrelation function can have a width that is smaller than a width of the phase control pattern, and a side lobe level is smaller than a level of the central peak.

Abstract: A spatial optic modulating system with speckle reduction and a method thereof are disclosed. According to an embodiment of the present invention, a spatial optic modulating system includes a spatial optic modulator, which modulates and reflects an image transferred in accordance with an upward or downward movement of a ribbon that is operated according to a contraction or expansion of a piezoelectric element, an image lens unit, which transfers an image modulated from the spatial optic modulator as a diffraction image to a scanner, and a phase modulator, which modulates a phase of the diffraction image transferred from the image lens unit. With the present invention, an image, from which a speckle is removed, can be displayed by modulating a phase of an image projected by using a spatial optic modulator.

Abstract: Disclosed are a light homogenizing device and a display apparatus including the same. The light homogenizing device can include a light source; a polarization rotator, including two planes of polarization that are vertical to each other, and receiving a beam of light incident from the light source and outputting a polarized linear beam of light having different polarization depending on driving voltage; and a birefringent plate, receiving the polarized linear beam of light and outputting two refracted beams of light proceeding by being refracted in different directions. Here, the two refracted beams of light can be combined at a predetermined point into a uniform beam of light. With the present invention, the light homogenizing device can improve the uniformity of an image through the decrease of a fringe pattern.

Abstract: Disclosed are a diffraction-type optical modulator and a display apparatus including the same. The diffraction-type optical modulator includes: a board; a lower mirror formed on the board; an upper mirror located apart from the lower mirror by a predetermined gap, having a hole, separated into at least two ridges by the hole, and movable up and down; and, an actuator moving the upper mirror in accordance with a driving signal and changing the separation distance, whereas a part of incident light beam reflects from the upper mirror, the rest of the incident light beam passes through the hole and reflects from the lower mirror, and then passes through the hole. A contrast ratio can be maximized by using the relation between the width of the hole and the ridge of an upper mirror, the ridge being measured in parallel with the direction of distribution of diffraction gratings.

Abstract: Disclosed are a method for driving a piezoelectric element or an optical modulator including a piezoelectric element and a recorded medium recorded with a program for executing the same. In accordance with an embodiment of the present invention, the method for driving a piezoelectric element causing a displacement object to be displaced by being contracted or expanded according to a supplied driving voltage, including supplying a driving signal to the piezoelectric element during a first driving period in a first voltage range; supplying a control signal for controlling a polarization hysteresis of the piezoelectric element according to a driving, performed during the first driving period, to the piezoelectric element; and supplying the driving signal to the piezoelectric element during a second driving period in a second voltage range.

Abstract: Disclosed are a piezoelectric driving device and a driving method thereof, and an optical modulating device using the same. In accordance with an embodiment of the present invention, the optical modulating device can include an optical modulator, having a piezoelectric element causing a displacement object to be displaced by being contracted or expanded according to a supplied driving voltage; and a driving unit, generating the driving voltage to be supplied to the piezoelectric element. Here, the driving voltage can be a square-wave signal having a shorter reset time than a minimum reaction time necessary to allow the displacement object to be displaced.

Abstract: Disclosed herein is a display device using a diffractive light modulator, which is provided with a plurality of light sources that emit different wavelengths, thus being capable of reducing speckles. The display device using a diffractive light modulator includes a light source unit, an illumination unit, a diffractive light modulator, and a projection unit.

Abstract: Disclosed herein is a diffractive waveguide-spatial optical modulator. The diffractive waveguide-spatial optical modulator includes a substrate member, a plurality of reflecting members, and an actuation means. The reflecting members are each formed in a plate shape, are arranged on the substrate member at regular intervals to form a grating array, are configured to form openings therebetween, and are provided with reflecting surfaces formed on the opposite vertical surfaces of the reflecting members and the bottoms of the openings. The actuation means varies the interval between the reflecting members by actuating the reflecting members. The openings between the reflecting members act as wave guides when light is incident on the open sides thereof, and shift the phase of the incident light and then reflect the incident light, so that the reflected light can form diffracted light, when the interval is varied by the reflecting members.

Abstract: Disclosed is an optical modulator module, including an optical modulator receiving and modulating incident lights, and outputting modulated lights as output lights, and a transparent substrate that is placed on the optical modulator, allowing the incident lights and the output lights to transmit, and that has a phase manipulating pattern formed on an area of a surface of the transparent substrate. With an optical modulator module according to an embodiment of the invention, laser speckles can be reduced.

Abstract: Disclosed herein is an apparatus and method for calibrating displacement of reflective parts. The apparatus includes memory, a sampling data output unit, an optical modulator drive circuit, a light detection unit, a control unit, and a calibration value calculation unit. The calibration value calculation unit receives a measured light intensity value, and outputs a constructed element-based calibration data.

Abstract: A spatial optic modulating system with speckle reduction and a method thereof are disclosed. According to an embodiment of the present invention, a spatial optic modulating system includes a spatial optic modulator, which modulates and reflects an image transferred in accordance with an upward or downward movement of a ribbon that is operated according to a contraction or expansion of a piezoelectric element, an image lens unit, which transfers an image modulated from the spatial optic modulator as a diffraction image to a scanner, and a phase modulator, which modulates a phase of the diffraction image transferred from the image lens unit. With the present invention, an image, from which a speckle is removed, can be displayed by modulating a phase of an image projected by using a spatial optic modulator.

Abstract: Disclosed herein is a pyramid-shaped near field probe which forms and changes a near field at the aperture of the probe. The pyramid-shaped near field probe of the present invention includes a probe body and metal films. The probe body is constructed in the form of a pyramid using a semiconductor process using a dielectric member and receives an electromagnetic wave. The metal films are symmetrically coated on two predetermined sides of four sides of the probe body while being spaced apart from each other. The pyramid-shaped near field probe allows a surface plasmon wave induced on the surfaces of the metal films due to the electromagnetic wave to progress to the aperture of the probe body through the boundary surface between the probe body and the metal films.

Abstract: An aspect of the present invention features a calibration apparatus for an optical modulator comprising: a light source emitting a beam to the optical modulator; an optical scanning unit scanning and projecting a beam emitted from the optical modulator; a light measuring unit measuring a beam emitted from the light source; and a light source control unit controlling the light source to the optical scanning unit to emit a calibration beam that is invisible and can be sensed by the light measuring unit.

Abstract: Disclosed herein is a diffractive waveguide-spatial optical modulator. The diffractive waveguide-spatial optical modulator includes a substrate member, a plurality of reflecting members, and an actuation means. The reflecting members are each formed in a plate shape, are arranged on the substrate member at regular intervals to form a grating array, are configured to form openings therebetween, and are provided with reflecting surfaces formed on the opposite vertical surfaces of the reflecting members and the bottoms of the openings. The actuation means varies the interval between the reflecting members by actuating the reflecting members. The openings between the reflecting members act as wave guides when light is incident on the open sides thereof, and shift the phase of the incident light and then reflect the incident light, so that the reflected light can form diffracted light, when the interval is varied by the reflecting members.

Abstract: Disclosed herein is a pyramid-shaped near field probe which forms and changes a near field at the aperture of the probe. The pyramid-shaped near field probe of the present invention includes a probe body and metal films. The probe body is constructed in the form of a pyramid using a semiconductor process using a dielectric member and receives an electromagnetic wave. The metal films are symmetrically coated on two predetermined sides of four sides of the probe body while being spaced apart from each other. The pyramid-shaped near field probe allows a surface plasmon wave induced on the surfaces of the metal films due to the electromagnetic wave to progress to the aperture of the probe body through the boundary surface between the probe body and the metal films.