Abstract: The present invention provides a PWM current adjustment apparatus including a triangle wave generator (8) for generating a triangle wave voltage signal, a comparator (9), an FET (10), a power supply (14), a first resistor (11) and a second resistor (12). The triangle wave voltage signal generated by the triangle wave generator and a modulation signal provided by a modulation voltage source (13) are fed to the comparator, an output of the comparator is connected to a gate terminal of the FET, the power supply is connected to a source terminal of the FET through the first resistor, and a drain terminal of the FET outputs a driving current through the second resistor to a load.

Abstract: An optical pick-up device includes a light source (2), a polarized light beam converter (4), a splitter (6), a collimating lens (7), and a photo-detector (9). A linear polarized light beam with a first type of polarized component and a second type of polarized component is emitted from the light source, and passes through the polarized light beam converter. The first type of polarized component is converted into the second type of polarized component by the polarized light beam converter. Then part of the light beam with the second type of polarized component passes through the splitter and is focused onto an optical disc (8) by the collimating lens. The optical disc reflects the light beam that contains recorded information read from the optical disc. The reflected light beam passes back through the collimating lens, is reflected by the splitter, and is received by the photo-detector.

Abstract: A planar light source device (100) for a display device includes a light guide plate (120) and pluralities of light emitting diodes (110). The light guide plate has a light incident surface (121). The light emitting diodes are located in the vicinity of the light incident surface. Each light emitting diode has a light emission surface opposite to the light incident surface of the light guide plate, and has a diffraction grating (117) provided on the light emission surface for improving a range of divergence of light beams emitted therefrom.

Abstract: A backlight module (3) includes a light source group (31) and a light guide plate (32). The light source group includes at least a light source, and the light guide plate has a light input surface (321) for receiving light, a light output surface (322) for emitting light, which is adjacent to the light input surface, and a bottom surface opposite to the light output surface and adjacent the light input surface. The light source group faces the light input surface, which is curved such that its curvature matches with the light distribution of the light source group.

Abstract: A planar light device (30) for emitting light beams, including a light guide plate (31) having a plurality of diffraction grating units (33). The light guide plate includes a light-emitting surface (313), an opposite bottom surface, and a light incident surface (311) disposed therebetween. A light source (32) is disposed adjacent to the light incident surface. The diffraction grating units cover the bottom surface of the light guide plate. Each diffraction grating unit is divided into a first part (A) and a second part (B), the first and second parts having different alignment directions from each other.

Abstract: A driving apparatus (2) for cold cathode fluorescent lamps (CCFLs) includes a primary and a secondary driving circuits (22, 21), a primary and a secondary light tubes (24, 23), a primary and a secondary feedback circuits (26, 27), and two photosensitive elements (25) corresponding to the primary and the secondary light tubes, respectively. The primary and the secondary driving circuits provide power to drive the primary and the secondary light tubes, respectively. The primary feedback circuit receives photoelectric current of a corresponding photosensitive element and provides an output signal to the primary driving circuit. The secondary feedback circuit receives currents of both photosensitive elements, and provides an output signal to the secondary driving circuit to keep a brightness of the secondary light tube the same as the brightness of the primary light tube.

Abstract: A heat sink (11) includes a base (12), a plurality of fins (14) extending from a first surface of the base, and a plurality of carbon nanotubes (18) formed on an opposite second surface (16) of the base. The carbon nanotubes are substantially parallel to each other and substantially perpendicular to the base. A method for manufacturing the heat sink includes the steps of: (a) providing a heat sink preform comprising a base and a plurality of fins extending from a first surface of the base; (b) polishing an opposite second surface of base; (c) depositing a catalyst film on the second surface of the base; and (d) providing a carbon source gas to grow a plurality of carbon nanotubes on the second surface of the base.

Abstract: A light guide plate (32) in accordance with the present invention includes a base (23), and an intervening layer (22) formed on the base. The intervening layer includes a light emitting surface (24) defining a plurality of V-shaped grooves (241) thereat. An index of refraction of the intervening layer is less than an index of refraction of the base.

Abstract: A current driving apparatus includes a first square wave generator (100), a second square wave generator (200), an FET (Field Effect Transistor) (3), and a power supply (9). The first square wave generator has an output connected to the second square wave generator's input. The second square wave generator has an output connected to the FET gate. A current clamping resistor (11) is provided between the FET source and the power supply. The FET drain provides current to a possible load (not shown). The first square wave generator generates a low frequency square wave signal for timing control, and the second square wave generator generates a high frequency square wave signal for amplitude control.

Abstract: A PWM driving apparatus for an LED includes a sawtooth wave generator (1) for generating a sawtooth wave signal, a comparator (2), an FET (3), a first resistor (4), a second resistor (5), a power supply (7), and a light emitting diode array (8). A modulation signal provided by a modulation signal source (6) and the sawtooth wave signal are fed to the comparator, an output of the comparator is connected to a gate terminal of the FET, the power supply is connected to a source terminal of the FET through the first resistor, and a drain tenninal of the FET outputs a driving current through the second resistor to the light emitting diode array.

Abstract: An LED driving circuit includes a current limiting resistor (24), an FET (22), and a feedback circuit (23). The FET has a drain electrode connected to the current limiting resistor to provide current to a load such as an LED (25), and the feedback circuit has a variable reference voltage source (234) for controlling a current of the drain electrode of the FET.

Abstract: A surface light source unit (3) includes a light source (31) and a light guide plate (30). The light guide plate includes a light incidence surface (301) for receiving light beams, an emission surface (302) for emitting the light beams, and a bottom surface (303) for scattering and diffusing the light beams. A plurality of diffusion dots (311) is formed on the bottom surface and a plurality of protrusions (312) parallel to the light incidence surface is formed on the emission surface with decreasing an interval between two adjacent protrusions as goes away from the light incidence surface. The amount (N) of the protrusions satisfies a condition of N=R/220, wherein R is a distance from the light incidence surface to an opposite surface of the light guide plate. The surface light source unit provides uniform illumination and high brightness for a liquid crystal display panel.

Abstract: A heat sink (11) includes a base (12), a plurality of fins (14) extending from a first surface of the base, and a plurality of carbon nanotubes (18) formed on an opposite second surface (16) of the base. The carbon nanotubes are substantially parallel to each other and substantially perpendicular to the base. A method for manufacturing the heat sink includes the steps of: (a) providing a heat sink preform comprising a base and a plurality of fins extending from a first surface of the base; (b) polishing an opposite second surface of base; (c) depositing a catalyst film on the second surface of the base; and (d) providing a carbon source gas to grow a plurality of carbon nanotubes on the second surface of the base.

Abstract: A planar light device (30) for emitting light beams, including a light guide plate (31) having a plurality of diffraction grating units (33). The light guide plate includes a light-emitting surface (313), an opposite bottom surface, and a light incident surface (311) disposed therebetween. A light source (32) is disposed adjacent to the light incident surface. The diffraction grating units cover the bottom surface of the light guide plate. Each diffraction grating unit is divided into a first part (A) and a second part (B), the first and second parts having different alignment directions from each other.

Abstract: A planar light source device (100) for a display device includes a light guide plate (120) and pluralities of light emitting diodes (110). The light guide plate has a light incident surface (121). The light emitting diodes are located in the vicinity of the light incident surface. Each light emitting diode has a light emission surface opposite to the light incident surface of the light guide plate, and has a diffraction grating (117) provided on the light emission surface for improving a range of divergence of light beams emitted therefrom.

Abstract: A surface light source unit (3) includes a light source (31) and a light guide plate (30). The light guide plate includes a light incidence surface (301) for receiving light beams, an emission surface (302) for emitting the light beams, and a bottom surface (303) for scattering and diffusing the light beams. A plurality of diffusion dots (311) is formed on the bottom surface and a plurality of protrusions (312) parallel to the light incidence surface is formed on the emission surface with decreasing an interval between two adjacent protrusions as goes away from the light incidence surface. The amount (N) of the protrusions satisfies a condition of N=R/220, wherein R is a distance from the light incidence surface to an opposite surface of the light guide plate. The surface light source unit provides uniform illumination and high brightness for a liquid crystal display panel.

Abstract: A light guide plate (32) in accordance with the present invention includes a base (23), and an intervening layer (22) formed on the base. The intervening layer includes a light emitting surface (24) defining a plurality of V-shaped grooves (241) thereat. An index of refraction of the intervening layer is less than an index of refraction of the base.

Abstract: An optical pick-up device includes a light source (2), a polarized light beam converter (4), a splitter (6), a collimating lens (7), and a photo-detector (9). A linear polarized light beam with a first type of polarized component and a second type of polarized component is emitted from the light source, and passes through the polarized light beam converter. The first type of polarized component is converted into the second type of polarized component by the polarized light beam converter. Then part of the light beam with the second type of polarized component passes through the splitter and is focused onto an optical disc (8) by the collimating lens. The optical disc reflects the light beam that contains recorded information read from the optical disc. The reflected light beam passes back through the collimating lens, is reflected by the splitter, and is received by the photo-detector.

Abstract: An LED driving circuit includes a current limiting resistor (24), an FET (22), and a feedback circuit (23). The FET has a drain electrode connected to the current limiting resistor to provide current to a load such as an LED (25), and the feedback circuit has a variable reference voltage source (234) for controlling a current of the drain electrode of the FET.

Abstract: A driving apparatus (2) for cold cathode fluorescent lamps (CCFLs) includes a primary and a secondary driving circuits (22, 21), a primary and a secondary light tubes (24, 23), a primary and a secondary feedback circuits (26, 27), and two photosensitive elements (25) corresponding to the primary and the secondary light tubes, respectively. The primary and the secondary driving circuits provide power to drive the primary and the secondary light tubes, respectively. The primary feedback circuit receives photoelectric current of a corresponding photosensitive element and provides an output signal to the primary driving circuit. The secondary feedback circuit receives the both photoelectric currents of the photosensitive elements and providing an output signal to the secondary driving circuit to keep a brightness of the secondary light tube the same as the brightness of the primary light tube.