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: A hybrid induction motor comprises a stator fixedly installed in a casing, an induction rotor rotatably inserted into a center of the stator and having a shaft at a center thereof, a first synchronous rotor slid in a longitudinal direction of the shaft between the stator and the induction rotor and free-rotatably installed in a circumferential direction of the shaft, and a second synchronous rotor facing the first synchronous rotor, slid in a longitudinal direction of the shaft between the stator and the induction rotor, and free-rotatably installed in a circumferential direction of the shaft.

Abstract: An optical modulator using a plurality of ribbons for rendering a pixel of an image is disclosed. An embodiment of the present invention provides an optical modulator having a multiple ribbon structure that can include a substrate and a first driving ribbon group and a second driving ribbon group, each of which includes at least one ribbon spaced from the substrate and driven upward or downward in accordance with a supplied voltage. A relative displacement between the first driving ribbon group and the second driving ribbon group can modulate an incident beam. By alternately driving the first driving ribbon group and the second driving ribbon group, the image quality of the optical modulator in accordance with an embodiment of the present invention can be robust against environmental factors, such as time, time, temperature and fatigue, and hysteresis.

Abstract: Disclosed is an optical modulator including: a substrate; an insulation layer disposed on the substrate; a ribbon layer, a center portion of which is spaced apart from the insulation layer by a predetermined gap; a piezoelectric element that is disposed on the ribbon layer and allows the center portion of the ribbon layer to bend vertically; and a passivation layer that is disposed on the piezoelectric element and comprises a main passivation film.

Abstract: A cleaner that can be operated at motive force of sufficient strength by using a battery voltage as well as by using a AC voltage. The cleaner uses a low-resistance-mode motor to rotate a collecting fan. The low-resistance-mode motor is driven by a motor driver. The motor driver drops a DC voltage converted from the AC voltage, depending on whether the AC voltage is received. Depending on whether the AC voltage is received, the motor driver drives the low-resistance-mode motor using one of the battery voltage and the dropped voltage.

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: The hybrid induction motor includes a housing; a stator installed in the housing and having a stator core portion and a stator coil portion; a rotor coupling body having a rotary shaft rotatably installed in at the housing, a cage rotor portion rotating integrally with the rotary shaft, and a permanent magnet rotor portion coupled to a circumference of the cage rotor portion with a certain air gap so as to rotate freely with respect to the rotary shaft; and a reverse rotation preventing switch, when the rotary shaft rotates reversibly, coming in contact with the permanent magnet rotor portion which is moved along the shaft by thrust generated by the rotor coupling body and cutting off power being supplied to the stator coil portion.

Abstract: An induction motor having a reverse-rotation preventing function, comprises: a stator provided with a winding coil generating flux by a current; an induction rotor provided with a cage and rotatably inserted in the stator, wherein a rotary shaft is coupled to its inside; a synchronous rotor provided with a permanent magnet and rotatably coupled between the stator and the induction rotor; an induction-force generating unit generating a force for moving the synchronous rotor in an axial direction; and a rotation preventing unit preventing a reverse rotation by fixing the synchronous rotor moved by the induction-force generating unit at the time of reverse rotation of the synchronous rotor.

Abstract: Disclosed herein is an interdigitation-type diffractive light modulator. In the interdigitation-type diffractive light modulator of the present invention, each of a pair of ribbons has a plurality of diffractive branches which are arranged in a comb shape, and the diffractive branches of the ribbons interdigitate with each other. Furthermore, the respective ribbons moves upwards and downwards or, alternatively, one ribbon moves upwards and downwards, so that the diffractive branches of the ribbons which interdigitate with each other form a stepped structure, thus diffracting incident light.

Abstract: A hybrid induction motor comprises a stator fixedly installed in a casing, an induction rotor rotatably inserted into a center of the stator and having a shaft at a center thereof, a first synchronous rotor installed between the stator and the induction rotor in a circumferential direction of the shaft so as to be freely rotatable, and a second synchronous rotor facing the first synchronous rotor in a longitudinal direction of the shaft and installed between the stator and the induction rotor so as to be freely rotatable.

Abstract: Disclosed herein is an apparatus for calibrating the displacement of reflective parts in a diffractive optical modulator. The apparatus includes a diffractive optical modulator, a light intensity measurement unit, a projection unit, and display electronics. The light intensity measurement unit is disposed near one side of the diffractive optical modulator and measures and outputs the intensity of incident linear diffracted light having a predetermined diffraction order.

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 a method of producing a diffractive micromirror. More particularly, the present invention pertains to a method of producing a diffractive micromirror, in which a recess having a desired depth and width is precisely formed in a piezoelectric operation manner.

Abstract: An aspect of the present invention provides a device for inspecting an optical modulator. The device can comprise: a probe card that converts an inputted control signal to a driving signal, and provide the driving signal by contacting with each driving signal input pad of an optical modulator—wherein the optical modulator comprises one or more micromirrors and one or more driving signal input pads connected to the micromirrors, respectively, and the micromirror moves up and down according to the driving signal inputted through the driving signal input pad—; and an image control circuit that generates the control signal for checking if the optical modulator is operation properly, and is connected electrically to the probe card to transmit the control signal. A device and a method for inspecting an optical modulator according to the present invention can inspect performance and function of the optical modulator at a chip level.

Abstract: Disclosed herein is an image nonuniformity reduction device for a display system. The display system has a light source unit, an illumination optical unit, a diffractive optical modulator, a projection and scanning optical unit, and a screen. The image nonuniformity reduction device includes an image input unit, an image mixing unit, and an optical modulator driving circuit. The image mixing unit detects single color regions from the image data received by the image input unit, mixes a predetermined image with each of the detected single color regions, and outputs a resulting image.

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: An axial air-gap type motor includes a rotor having a magnet, a stator, having an accommodating space therein, separated from the magnet in an axial direction of the motor by an air gap, and a printed circuit board disposed in the accommodating space of the stator.