Abstract: A dual mass flywheel includes a primary flywheel having a ring gear and connected to an output shaft of an engine; a secondary flywheel connected to an input shaft of a transmission; a coupling unit for coupling the primary flywheel and the secondary flywheel; a plurality of drive units coupled to the primary flywheel and the secondary flywheel and in which spring guides are coupled to opposite sides of a torsion spring.

Abstract: A dual mass flywheel includes: a primary flywheel having a ring gear and connected to an output shaft of an engine; a secondary flywheel connected to an input shaft of a transmission; a coupling unit for coupling the primary flywheel and the secondary flywheel; and a plurality of drive units coupled to the primary flywheel and the secondary flywheel and in which spring guides are coupled to opposite sides of a torsion spring to dampen noise and vibrations while a torque of the primary flywheel is transferred to the secondary flywheel.

Abstract: A finder system for a single lens reflex camera includes a focusing screen having a split prism, a penta roof mirror and an eyepiece lens system. The penta roof mirror has a hollow housing made of plastic material in the shape of a pentagonal prism whose three surfaces are coated inside to reflect light. The eyepiece lens system includes two plastic lenses, each of which has a different dispersion.

Abstract: An image magnification apparatus, for use in a video display system that displays an image of an object, comprising a connecting module for connecting the image magnifying apparatus to a lens module of the video display system, and an objective lens system for forming an optical image of the object. The apparatus also includes a conversion optical system for magnifying the optical image formed by the objective lens system. The conversion optical system further includes a first biconvex lens unit having a positive refractive power, a second biconvex lens unit having a positive refractive power, and a third biconcave lens unit having a negative refractive power.