Abstract: In a light-emission and reception module for use in an optical pickup, a polarization beam splitter transmits an outgoing laser beam from the laser-emitting element and reflects, as a reflected laser beam, a return laser beam reflected by the optical disc in a direction perpendicular to the outgoing laser beam. The laser-emitting element, the polarization beam splitter, and the photo-detecting element are mounted on the holder. The reflected laser beam is perpendicular to a reception surface of the photo-detecting element.

Abstract: An objective lens holder for use in an objective lens driving device of a symmetry type has an upper member and a lower member assembled with the lower member. The lower member has a pair of main bobbin portions for winding two tilting coils and two focusing coils. The pair of main bobbin portion is symmetrically disposed with respect to an optical axis of a laser beam. The upper member and the lower member have openings for passing through the laser beam. Each of the upper member and the lower member has four hook portions for winding four tracking coils.

Abstract: In an objective lens driving device of a symmetry type having an object lens, an objective lens holder for holding the objective lens, and a damper base apart from the objective lens holder in a tangential direction, a suspension member elastically supports the objective lens holder with respect to the damper base. The suspension member consists of four suspension wires disposed on both sides of the damper base and the objective lens holder. The suspension member inclines upward in a direction from the damper base to the objective lens holder by a predetermined angle in an inactive state.

Abstract: An optical pickup unit comprises an objective lens driving device including an objective lens holder, a damper base, and a yoke for forming a magnetic circuit together with coils. The optical pickup unit further comprises an optical base in which the objective lens driving device is assembled and a mirror for entering a laser beam into an optical disc through the objective lens. The yoke comprises a bottom portion and a first rising portion extending upward from an end of the bottom portion near the damper base, and has a first opening extending from the proximal end of the first rising portion to the end opposite from the first rising portion. The optical base comprises a projection extending from the proximal side of the first rising portion within the first opening and a mirror mounting portion provided at the distal end of the projection.

Abstract: A cellulose acylate which is a polymer obtained by substituting cellulose with acyl groups in 2-, 3-, 6-positions. The total degree of acyl substitution in the 2- and 3-positions is regulated to from 1.70 to 1.90. The degree of 6-position acyl substitution is regulated to 0.88 or higher.

Abstract: In an objective lens driving device having a lens holder which is movable and holds an objective lens, coil devices are disposed around the objective lens and held by the lens holder. Around the objective lens, main magnets are disposed for applying driving forces to the coil devices according to energization to the coil devices. Furthermore, each of auxiliary magnets are disposed between adjacent ones of the coil devices. The auxiliary magnets apply forces to the coil devices according to the energization to the coil devices for supplementing the driving forces.

Abstract: In a cellulose acylate solution, cellulose acylate is dissolved in an essentially non-chlorinated solvent. The essentially non-chlorinated solvent is a mixture of a ketone having a solubility parameter of 19 to 21 and an ester having a solubility parameter of 19 to 21. The solution further contains a releasing agent.

Abstract: In an objective lens driving device having a lens holder movably holding an objective lens, a damper base, and a suspension member elastically supporting the lens holder with respect to the damper base, the suspension member consists of four suspension wires disposed on both sides of the damper base and the lens holder. The damper base has first supporting portions for supporting one end of each suspension wire while the lens holder has second supporting portions for supporting another end of each suspension wire. The second supporting portions are apart from the first supporting portion by a first distance. The damper base has damper portions which are disposed between the first and the second supporting portions and which are apart from the first supporting portions by a second distance. The second distance is laid in a range between one-fifths and two-fifths of the first distance.

Abstract: A cellulose acetate film is produced from a solution of a cellulose acylate in a mixed solvent. The mixed solvent comprises a main solvent and an alcohol. The mixed solvent essentially does not contain chlorine atom. The main solvent comprises an ester and a ketone. The ester has a solubility parameter of 16 to 23. The ketone has a solubility parameter of 16 to 23. The alcohol has a solubility parameter of 20 to 30. The mixed solvent comprises the ester in an amount of 58 to 96 wt. %, the ketone in an amount of 2 to 15 wt. %, and the alcohol in an amount of 2 to 40 wt. %.

Abstract: An optical filter comprising a transparent support having a tensile impact strength of 392 kJ/m2 or more having provided thereon a filter layer having an absorption maximum in the range of from 560 to 620 nm.

Abstract: An optical filter comprising a filter layer absorbing visible light, a transparent support, in particular a transparent support comprising a biaxially stretched film, and an antireflection layer, with which an image display such as a plasma display is equipped for preventing reflection and improving color reproduction. An optical filter comprising a transparent support having provided at least on one side of the support a filter layer containing a dye and a polymer binder, wherein an antireflection layer having an antireflection property to visible light is provided on the side opposite to the side on which the filter layer is provided when the filter layer is provided on either one side, and the antireflection layer is provided on either one side when the filter layers are provided on both sides, and the transparent support comprises a biaxially stretched film having a thickness of from 10 to 500 ?m.

Abstract: In an objective lens driving apparatus which includes a lens holder (22) provided with a plurality of coils (23, 24) and swingably supported by a suspension wire (28), and a magnet (27) for supplying a driving force to the lens holder by an electromagnetic action produced between the magnet and the coils, the center (Mc) of the magnet in a height direction is located above the center (Dc) of driving of the lens holder.

Abstract: In order to fix a laser diode 12 to an optical base 11, a plurality of threaded pins 15 are at first fixed to the optical base by the use of, for example, an anaerobic adhesive. Then, the laser diode is faced to the optical base in an area between the threaded pins. The laser diode is adjusted in position and angle with respect to the optical base by, for example, 5 axes 3D adjustment. Thereafter, the laser diode is fixed to the threaded pins by the use of solder pieces 16.

Abstract: A cellulose acylate film is produced by using a cellulose acylate solution and forming a film consisting of two or more layers by the co-casting method. The cellulose acylate to be used is selected so that the association molecular weight of cellulose acylate due to the static light scattering in the solution forming the outer layer becomes smaller than the association molecular weight of cellulose acylate due to the static light scattering in the solution forming the inner layer.

Abstract: In a flexible printed circuit (10) for electrically connecting between a fixed portion and a movable portion comprising a flexible base layer (11), a conductive layer (13) formed on a principal surface (11a) of the flexible base layer through a first adhesive agent (12), and a cover lay (15) formed on the conductive layer through a second adhesive agent (14), copper foil (22) is pasted on an upper surface (15a) of the cover lay through a conductive adhesive agent (21). The copper foil is electrically connected to a ground portion (110) using solder. The fixed portion may be an optical disc drive's body (300). The movable portion may be an optical pickup unit (100) comprising an electromagnetic radiation source (200). The copper foil is for shielding electromagnetic noises radiated from the electromagnetic radiation source. The copper foil may be disposed only the vicinity of the electromagnetic radiation source.

Abstract: A cellulose acetate film is produced from a solution of a cellulose acylate in a mixed solvent. The mixed solvent comprises a main solvent and an alcohol. The mixed solvent essentially does not contain chlorine atom. The main solvent comprises an ester and a ketone. The ester has a solubility parameter of 16 to 23. The ketone has a solubility parameter of 16 to 23. The alcohol has a solubility parameter of 20 to 30. The mixed solvent comprises the ester in an amount of 58 to 96 wt. %, the ketone in an amount of 2 to 15 wt. %, and the alcohol in an amount of 2 to 40 wt. %.

Abstract: A cellulose acylate which is a polymer obtained by substituting cellulose with acyl groups in 2-, 3-, 6-positions. The total degree of acyl substitution in the 2- and 3-positions is regulated to from 1.70 to 1.90. The degree of 6-position acyl substitution is regulated to 0.88 or higher.

Abstract: A hard coat film comprising; a transparent support; and a hard coat layer thereon; the hard coat layer containing surface-treated inorganic fine particles and a crosslinked binder polymer; the surface treatment being carried out using, as a surface treatment agent, an organic compound containing an anionic functional group or an organometallic compound; and the binder polymer being formed by crosslinking a radiation polymerizable compound. A display device is also disclosed wherein a hard coat film having antireflection properties is formed on the display surface thereof.

Abstract: A cellulose acetate film is produced from a solution of a cellulose acylate in a mixed solvent. The solvent comprises a main solvent and an alcohol. The main solvent essentially does not contain chlorine atom. The main solvent has a solubility parameter of 16 to 23. The alcohol has a solubility parameter of 20 to 30.

Abstract: In a cellulose acylate solution, cellulose acylate is dissolved in an essentially non-chlorinated solvent. The essentially non-chlorinated solvent is a mixture of a ketone having a solubility parameter of 19 to 21 and an ester having a solubility parameter of 19 to 21. The solution further contains a releasing agent.