Abstract: A polarizer includes a base and a plurality of grids arranged on a surface of the base parallel to one another. Each of the grids comprises an intermediate layer and a semi-transmissive metal layer that reflects a part of external light incident thereon and transmits a part of the external light incident thereon. The semi-transmissive metal layer and the intermediate layer are alternately deposited to include at least two semi-transmissive metal layers. The thicknesses of the semi-transmissive metal layers increases in a direction in which the semi-transmissive metal layer is disposed away from the external light. An organic light emitting display apparatus includes the polarizer and has improved contrast and brightness.

Abstract: An image forming apparatus includes a main body unit which has an image forming unit; a door unit which couples with the main body unit to open and close the main body unit, and has a projection at one side thereof; a mid-transfer unit which couples with the door unit; a coupling knob which is provided in the main body unit and rotates in cooperation with pressure of the projection when the door unit is closed; and a coupling apparatus which is provided in the main body and transmits a driving force from the main body unit to the mid-transfer unit in cooperation with the rotation of the coupling knob.

Abstract: Disclosed is an apparatus for manufacturing an electrolytic metal foil, which includes an electrolytic cell containing electrolyte; an upper drum installed in an upper portion of the electrolytic cell to be rotatable and to which a negative potential is applied; a lower drum soaked in the electrolyte of the electrolytic cell and installed to be rotatable together with the upper drum; a cathode belt mounted around outer circumferences of the upper and lower drums to move along an endless track and electrically connected to the upper drum so that the negative potential is applied thereto; and an anode unit installed to form a space from a metal electroplating surface of the cathode belt soaked in the electrolytic cell so that a positive potential is applied thereto, the anode unit having a slit for supplying the electrolytic to the space. This apparatus may increase a production rate of electrolytic metal foils.