Abstract: Provided are a method for purifying mitomycin C, comprising a step of recrystallizing crude mitomycin C crystals using a high-purity methanol; mitomycin C obtainable by the method; and the like.

Abstract: Provided are a method for purifying mitomycin C, comprising a step of recrystallizing crude mitomycin C crystals using a high-purity methanol; mitomycin C obtainable by the method; and

Abstract: An optical information recording and reproducing device that records information on a recording medium and/or reproduces information on the recording medium, using holography is configured to include a laser light source that performs irradiation with laser light, a first light-shielding portion which is capable of switching between transmission and shielding of laser light emitted from the laser light source, and a driving circuit that drives the switching between transmission and shielding of the first light-shielding portion, and a first movement portion that moves the first light-shielding portion.

Abstract: The optical information recording and reproducing method realizes an increased number of multiplexing in recording and favorably stabilized signal recording in a manner of uniforming media consumption in angle-multiplexed recording by changing a phase of signal light on a pixel basis in a manner in which the speed of a phase change on a pixel basis is constant or is greater than or equal to a certain speed in a page and between pages when the driving speed of a phase mask changes at the time of recording. The optical information recording and reproducing method, while moving an optical element that adds phase information to a light flux which includes two-dimensional page data information in a direction that is perpendicular to an optical axis of the light flux, records the page data on the recording medium by adding the phase information to the light flux.

Abstract: A method for performing recording on a multilayered optical disk which has three or more recordable or rewritable information recording layers with a first recording layer and a second recording layer located nearer to a light incident surface than the first recording layer, and which respectively has a first test area configured by a plurality of segments in the first recording layer and in the second recording layer, wherein a predetermined radial distance L is defined beforehand. When an arbitrary segment in the second test area is test-recorded, a segment in the first test area, the radial distance of which from the recorded test area in the second test area is within the range of the predetermined radial distance L, is set as a segment in which test recording is not performed.

Abstract: An optical information recording and reproducing device that records information on a recording medium and/or reproduces information on the recording medium, using holography is configured to include a laser light source that performs irradiation with laser light, a first light-shielding portion which is capable of switching between transmission and shielding of laser light emitted from the laser light source, and a driving circuit that drives the switching between transmission and shielding of the first light-shielding portion, and a first movement portion that moves the first light-shielding portion.

Abstract: The optical information recording and reproducing method realizes an increased number of multiplexing in recording and favorably stabilized signal recording in a manner of uniforming media consumption in angle-multiplexed recording by changing a phase of signal light on a pixel basis in a manner in which the speed of a phase change on a pixel basis is constant or is greater than or equal to a certain speed in a page and between pages when the driving speed of a phase mask changes at the time of recording. The optical information recording and reproducing method, while moving an optical element that adds phase information to a light flux which includes two-dimensional page data information in a direction that is perpendicular to an optical axis of the light flux, records the page data on the recording medium by adding the phase information to the light flux.

Abstract: An optical information recording/reproducing apparatus for recording an interference pattern between signal light and reference light information-multiplexed as a hologram in an optical information recording medium and for reproducing information recorded in the optical information recording medium on the basis of the recorded hologram with use of the reference light. The apparatus includes a light source for emitting light and a coherency controller for controlling a coherency of the light source. The apparatus controls the coherency controller in such a manner as to switch between a coherency required in a recording mode and a coherency required in a reproducing mode.

Abstract: An electromagnetic type retarder includes a stator having spaced, circularly arranged magnetic coils forming multi-phase connections and a steel rotor surrounding the stator and rotated according to the rotation of a tire; a control device; and a driving device including at least two transistors opened and closed by a drive pulse from the control device, respectively. The multi phase connections are formed by the magnetic coils, the magnetic coils of each phase are connected with capacitors to form a resonance circuit, respectively, and each of the transistors is connected in series to at least two phase connections. The revolution speed of a rotary magnetic field induced in he magnetic coils by the rotation of the steel rotor is set smaller than the revolution speed of the steel rotor. A braking torque is controlled by turning ON and OFF the transistor inserted in one phase connection.

Abstract: An optical information recording/reproducing apparatus for recording an interference pattern between signal light and reference light information-multiplexed as a hologram in an optical information recording medium and for reproducing information recorded in the optical information recording medium on the basis of the recorded hologram with use of the reference light. The apparatus includes a light source for emitting light and a coherency controller for controlling a coherency of the light source. The apparatus controls the coherency controller in such a manner as to switch between a coherency required in a recording mode and a coherency required in a reproducing mode.

Abstract: Obtain an expanded address without altering the bit number of an address which is embedded in a wobble. Generate a virtual bit which is not recorded on a disc, and which is expressed by the disparity from the rules and the presence or absence of information embedded in part or all of the wobble address.

Abstract: The present invention is to realize a proper inner zone layout in a quadruple-layer disk. A test area is provided in the inner zone (inner circumference side area) in each of recording layers. If two test areas closer to the outer circumference, of four test areas, are defined as a first pair and two test areas closer to the inner circumference are defined as a second pair, the test areas of the first pair and the test areas of the second pair are so disposed as to be prevented from overlapping with each other in the layer direction. Two test areas of the first pair have the same consumption direction of the test area, and are so disposed that the areas to be used next hardly overlap with each other in the layer direction. Two test areas of the second pair have the same consumption direction of the test area opposite to the consumption direction of the test area in the first pair, and are so disposed that the areas to be used next hardly overlap with each other in the layer direction.

Abstract: There are provided an optical disc device and its recording/reproducing method for managing the management information about plural optical discs efficiently. In the present invention, the management information about the plural optical discs is stored in a memory. Moreover, the management information about part or all of the optical discs stored in the memory is recorded in the optical disc.

Abstract: The present invention provides a video transmission apparatus including a connection terminal to which a video reproduction device is connected; a wireless transmission unit for wirelessly transmitting a video signal input through the connection terminal; a transmission quality detection unit for detecting transmission quality of when wirelessly transmitted by the wireless transmission unit; and a reproduction control unit for controlling the video reproduction device to stop the reproduction of the video when degradation of the transmission quality is detected and to resume the reproduction of the video when the transmission quality is recovered.

Abstract: When a phase shift is to be evaluated, based on a difference between an output from a waveform equalization circuit to equalize an input reproduced signal to a predetermined target equalization characteristic and the target equalization characteristic, the phase shift of the reproduced signal relative to a channel clock, a group delay characteristic with respect to the frequency of the waveform equalization circuit is fixed. Hence, an equalized waveform as an output from the waveform equalization circuit can preserve phase shift information of the inputted reproduced signal to correctly detect the phase shift of the reproduced waveform using the equalized waveform. It is hence possible to realize, with high precision, optimal value learning of various parameters for the recording, reproduction, and servo by use of the phase shift as an index.

Abstract: Amplitude and frequency of a high-frequency signal superposed on a reproduction laser beam are changed in accordance with a reproduction spot diameter on the surface of the recording layer upon discrimination of an optical disk in initial adjustment after insertion of the optical disk and change of a layer of a multi-layer optical disk. Further, the high-frequency signal is not superposed on the reproduction laser beam until end of the discrimination and change to a target layer upon discrimination of the optical disk and change of a layer of a multi-layer optical disk.

Abstract: Obtain an expanded address without altering the bit number of an address which is embedded in a wobble. Generate a virtual bit which is not recorded on a disc, and which is expressed by the disparity from the rules and the presence or absence of information embedded in part or all of the wobble address.

Abstract: The present invention provides a projection display apparatus realizing improved operability at the time of registration adjustment irrespective of a use situation of the apparatus. In the case where misregistration occurs between primary color lights, video signals for three colors are corrected (registration adjustment is performed) so as to reduce the misregistration in accordance with an input adjustment value. An image inverting process is performed on an input video signal so that the image is inverted in a display screen. By a configuration by the user, the image is properly inverted in the display screen. When the image inverting process is performed, an adjustment value, with a sign different from that in the misregistration direction in a coordinate system where the image is not inverted, is input by an operation on the display screen.

Abstract: Obtain an expanded address without altering the bit number of an address which is embedded in a wobble. Generate a virtual bit which is not recorded on a disc, and which is expressed by the disparity from the rules and the presence or absence of information embedded in part or all of the wobble address.

Abstract: Obtain an expanded address without altering the bit number of an address which is embedded in a wobble. Generate a virtual bit which is not recorded on a disc, and which is expressed by the disparity from the rules and the presence or absence of information embedded in part or all of the wobble address.