Abstract: A capturing unit captures and digitizes a printed image having an electronic watermark embedded therein and a lattice pattern image. A profile creation unit detects position deviations of intersections in the lattice pattern images captured at respective different zoom magnifications, generates correction information on distortion occurring in the images, and registers the correction information into a profile database in association with the zoom magnifications. An image correction unit selects correction information corresponding to a zoom magnification employed at the time of capturing of the printed image from the profile database, and corrects distortion occurring in the captured image of the printed image. An image area determination unit determines an original image area in the distortion-corrected captured image. A watermark extraction unit extracts watermark information from the original image area in the distortion-corrected captured image.

Abstract: A reproducing apparatus reproduces a signal recorded in a magneto-optical disk. The magneto-optical disk includes a layered structure having a recording layer, an intermediate layer and a reproducing layer. Laser light is illuminated from an optical head to the magneto-optical disk in such an intensity that no magnetic domain is transferred from the recording layer to the reproducing layer only by the laser light. In this state, alternating magnetic field is applied through a magnetic head to the magneto-optical disk, thereby concurrently causing transfer and expansion of a magnetic domain to the reproducing layer. As a result, transfer of the magnetic domain is effected with expansion.

Abstract: A magneto-optical disk apparatus (100) includes an optical pickup (101) and a magnetic head (113). The optical pickup (101) irradiates a magneto-optical recording medium (10) with a laser beam of such intensity that a part of a reproducing layer of the magneto-optical recording medium (10) is heated to a temperature over the compensation temperature. The magnetic head (113) applies to the magneto-optical recording medium (10) a DC magnetic field having intensity weaker than the intensity at which magnetization of a transition-metal-rich area in a part of the reproducing layer heated to a temperature over the compensation temperature is inverted. The optical pickup (101) detects a magneto-optical signal varying in intensity between two levels. As a result, a signal can be reproduced correctly from the magneto-optical recording medium (10) by a magnetic domain enlargement system.

Abstract: An magneto-optical disk device (100) includes a magnetic head (11), a DC magnetic field applying device (12), an optical head (13) and a magnetic field control circuit (16). The DC magnetic field applying device (12) applies a DC magnetic field to a magneto-optical recording medium (10) through a core of the magnetic head (11). The magnetic field control circuit (16) applies the DC magnetic field of a variable intensity to the magneto-optical recording medium (10) to determine the appropriate intensity of the DC magnetic field providing an error rate not exceeding a predetermined reference value in a reproduced signal of a predetermined recording pattern detected by the optical head (13). Consequently, the signal can be accurately reproduced from the magneto-optical recording medium (10) by domain-enlarging reproduction using the DC magnetic field.

Abstract: A magneto-optical recording medium of magnetic domain enlarging/reproducing system including a recording layer and a reproducing layer, a gate layer selectively extracting each magnetic domain within the recording layer is formed on the recording layer, a magnetic field reinforcement layer reinforcing a leakage magnetic field reaching the reproducing layer is formed on the gate layer, and a blocking layer blocking an exchange coupling force from the magnetic field reinforcement layer to the reproducing layer is formed on the magnetic field reinforcement layer.

Abstract: A magnetic head is configured of a core and a coil wound around the core and passing current through the coil in a variable direction allows the core to have an edge generating an alternating magnetic field Hex1 and another edge generating an alternating magnetic field Hex2. Alternating magnetic fields Hex1 and Hex2 are applied to the respective edges. Furthermore, a laser beam LB1 is directed such that its optical axis L01 matches the edge receiving the alternating magnetic field Hex1, and a laser beam LB2 is directed such that its optical axis L02 matches the edge receiving the alternating magnetic field Hex2. A first magneto-optical signal detected through the alternating magnetic field Hex1 and the laser beam LB1 and a second magneto-optical signal detected through the alternating magnetic field Hex2 and the laser beam LB2 are composited together.

Abstract: A reproducing apparatus reproduces a signal recorded in a magneto-optical disk. The magneto-optical disk includes a layered structure having a recording layer, an intermediate layer and a reproducing layer. Laser light is illuminated from an optical head to the magneto-optical disk in such an intensity that no magnetic domain is transferred from the recording layer to the reproducing layer only by the laser light. In this state, alternating magnetic field is applied through a magnetic head to the magneto-optical disk, thereby concurrently causing transfer and expansion of a magnetic domain to the reproducing layer. As a result, transfer of the magnetic domain is effected with expansion.

Abstract: A magneto-optical recording medium including a substrate, a reproducing layer formed on the substrate, an intermediate layer formed on the reproducing layer, a recording layer formed on the intermediate layer and a high magnetization layer formed on the recording layer. The intermediate layer is made of a non-magnetic material, and set at a prescribed thickness so that a leakage magnetic field from the recording layer to the reproducing layer is so distributed that the intensity thereof is increased from an end to the center of its domain. The high magnetization layer is made of an alloy or a multilayer film of a noble metal and a transition metal having saturation magnetization stronger than that of the recording layer under a reproducing temperature. At room temperature, the coercive force of the recording layer is larger than that of the high magnetization layer. Consequently, transfer/enlargement from the recording layer to the reproducing layer is readily caused in this magneto-optical recording medium.

Abstract: A reproducing apparatus reproduces a signal recorded in a magneto-optical disk. The magneto-optical disk includes a layered structure having a recording layer, an intermediate layer and a reproducing layer. Laser light is illuminated from an optical head to the magneto-optical disk in such an intensity that no magnetic domain is transferred from the recording layer to the reproducing layer only by the laser light. In this state, alternating magnetic field is applied through a magnetic head to the magneto-optical disk, thereby concurrently causing transfer and expansion of a magnetic domain to the reproducing layer. As a result, transfer of the magnetic domain is effected with expansion.

Abstract: A magneto-optical head includes an optical member, objective lens, SIL and coil. The magneto-optical head converts a laser beam to an evanescent light and directs it to a magneto-optical recording medium. Further, the magneto-optical head applies a magnetic field to the magneto-optical recording medium. When tilt is caused, it decreases the tilt angle. The optical member refracts the laser beam to a prescribed direction to be directed to the objective lens when the laser beam is displaced from a designed optical axis. The objective lens allows the laser beam to be focused onto a point on an end face of the SIL. Further, the SIL emits the evanescent light. The optical member is arranged in contact with the optical member. As a result, a signal can accurately be recorded or reproduced even when tilt is caused to an optical disk while alleviating the problem associated with the tilt.

Abstract: A magnetic head comprises a core having a first leg, a second leg and a third leg and a coil wound on the second leg of the core. An end of the second leg is formed by a first portion formed by two inclined surfaces and a second portion formed by a flat surface. When a current is fed to the coil, a magnetic field oblique to a magnetooptical recording medium is generated from the first portion of the second leg, and a magnetic field perpendicular to the magnetooptical recording medium is generated from the second portion. Consequently, a magnetic field perpendicular to the magnetooptical recording medium can be applied to the magnetooptical recording medium for recording a signal, while a magnetooptical field having a prescribed angle with respect to the in-plane direction of the magnetooptical recording medium can be applied to the magnetooptical recording medium for reproducing a signal.

Abstract: When recording a recorded signal consisting of “01011001110” in a magnetooptical recording medium, (1,1) corresponding to a domain of 2T is converted to (1,0,1), and (0,0) is converted to (0,1,0) in the recorded signal. In other words, the first “1” of (1,1) is converted to unit bits “1,0” and the first “0” of (0,0) is converted to unit bits “0,1”. Similarly, the first “1” of (1,1,1) corresponding to a domain of 3T is converted to unit bits “1,0”, and the second “1” is converted to unit bits “1,0”. “1” or “0” of the final unit bit is not converted but recorded as such. Consequently, a signal can be correctly reproduced by extension ally transferring domains having different domain lengths from a recording layer to a reproducing layer under the same reproducing conditions.

Abstract: A magneto-optical recording medium has a plane structure in which are alternately arranged a groove having discontinuous regions formed at every 120 &mgr;m, for example, and land having discontinuous regions formed at the same every 120 &mgr;m. The position where the discontinuous region of the groove is formed differs from the position where the discontinuous region of the land is formed. The discontinuous region of the land is provided at a position corresponding to substantially the middle of respective continuous regions of the groove. The discontinuous region of the groove is provided at a position corresponding to substantially the center of the continuous region of the land. The width of the groove and land is approximately 0.4 &mgr;m. Therefore, a synchronizing signal arising from a discontinuous region formed periodically at the groove or land can be output properly even when the width of the groove and land is narrowed.