Abstract: A disc cartridge is provided. The disc cartridge includes: a lower housing having a window for allowing a recorder or reader to access to a read-out surface of a disc; and an upper housing coupled to the lower housing to ejectably receive the disc between the lower housing and the upper housing, and having at least a portion rotatable up and down with respect to one side of the lower housing until the disc can be ejected.

Abstract: The present invention provides a disc cartridge assembly, by which loading/unloading of a disc is facilitated to enable both one use in a cartridge state and the other a use as a single disc entity. The present invention includes a lower case having a window for a drive access, an upper case provided onto the lower case, the upper case having an exposure window provided to a central part to expose a label face of a disc, a rotating ring rotatably provided within the upper and lower cases to receive an outer circumference of the disc, at least one shutter provided within the upper and lower cases to open/close the window by interoperating with a rotation of the rotating ring, and a rotating means for rotating the rotating ring by interoperating with an external device.

Abstract: An optical pick-up apparatus which can adaptively compensate for the aberration of a light beam. The optical pick-up apparatus employees a first light source for generating a first light beam having a first wavelength to be irradiated on a first type of disk and a second light source for generating a second light beam having a second wavelength to be irradiated on a second type of disk. A light path enables the first light beam from the first light source to be irradiated on the disk in the shape of a spot by a finite optical system. The light path allows the second light beam from the second light source to be irradiated on the disk in the shape of a spot by an infinite optical system.