The object of the present invention is to provide an optical recording medium which includes a substrate, a first information layer and a second information layer, the first information layer and the second information layer are disposed on the substrate through an intermediate layer in a laminar structure; recording and reproducing is performed on each of the two information layers by laser beam irradiation from the first information layer side; the second information layer is provided with at least a reflective layer, a dielectric layer, and a second dye recording layer formed in this order; and the dielectric layer is formed from any one of materials selected from the group consisting of oxides, nitrides, sulfides, carbides or mixtures thereof from any one of elements which are not same as metal elements and semi-metal elements used for forming the reflective layer.

Optical Recording Medium

A lens device which can be used as an objective lens in an optical pickup apparatus includes an objective lens provided along a light path facing a disc and having a predetermined effective diameter, and light controlling means provided along the light path for controlling the light in an intermediate region between near and far axes of an incident light beam, thus providing a simplified and inexpensive device for using discs of differing thickness in a single disc drive, by reducing the spherical aberration effect.

Lens device comprising light blocking means and an optical pickup apparatus using the lens device

An optical pickup (1) for irradiating a first recording medium and a second recording medium with light, at least one of the substrate thickness and the refractive index of the first recording medium being different from that of the second recording medium, where the optical pickup includes: a light source (23) for emitting the light; a polarized beam splitter (22) for receiving the light and for transmitting at least a portion of the light while reflecting the remaining portion of the light depending on the polarization direction of the light; a first objective (5) lens for focusing the portion of the light reflected by the polarized beam splitter (22) onto the first recording medium; and a second objective lens (4) for focusing the portion of the light transmitted through the polarized beam splitter (22) onto the second recording medium.

Optical pickup having two objective lenses

A data storage master disk and method of making a data storage master disk. The data storage disk master is for use in a data storage disk replication process. The data storage disk molding processes produces replica disks having a surface relief pattern with replica lands and replica grooves. The method includes providing a master substrate. The master substrate is at least partially covered with a layer of photosensitive material. A surface relief pattern having master lands and master grooves is recorded in the data storage disk master, including the steps of exposing and developing the photosensitive material. The exposing and developing of a specified thickness of photosensitive material is controlled to form master grooves extending down to a substrate interface between the master substrate and the layer of photosensitive material, such that the width of the master grooves at the substrate interface corresponds to a desired width of the replica lands.

Reverse optical mastering for data storage disks

Mastering techniques are described that can improve the quality of a master used in data storage disk manufacturing. In particular, the techniques can improve resolution of the features created on the master. The techniques include coating a master substrate layer (32) with a tri-layer structure composed of a top photoresist layer (36), a bottom photoresist layer (34), and a non-resist layer (35) interposed between the two photoresist layers. The bottom photoresist layer (34) comprises a deep ultraviolet (DUV) resist material. Mastering the top photoresist layer (36) defines a portable conformable mask (PCM) for the bottom photoresist layer. A variety of PCM may be defined for the bottom photoresist layer. The PCM may be defined using conventional tip recording with a focused laser spot that provides fine feature definition. A blanket DUV light (48) may then illuminate the bottom photoresist layer (34) through the PCM to provide enhanced feature resolution in a data storage disk master.

Portable conformable deep ultraviolet master mask

A holder (60) is suspended on a carriage (21), and a magnetic circuit (32, 45, 46, 47) is disposed adjacent to the holder (60). The magnetic circuit has a first magnetic pole (46) and a second magnetic pole (47). A focus coil (63) having a magnetic flux receiving portion (63a) is provided around a vertical axis of the holder (60). A tracking coil (66) having a magnetic flux receiving portion (66a) is provided around a horizontal axis of the holder (60). Both the magnetic flux receiving portions (63a, 66a) are disposed so as not to be overlapped with each other, and are disposed in parallel with one of the surfaces of the first and second magnetic poles (46, 47). Both of the magnetic flux receiving portions (63a, 66a) are flush with each other.

O Pioneer Electr. Corp. Koyama

Papers

Optical pickup for an optical disc player