摘要:
A magneto-optical memory apparatus for enhancing the recording density of a magneto-optical recording medium, thereby to increase its recording capacity. The magneto-optical recording medium having recording marks, each having two ends in which information is recorded. The apparatus also includes an optical head arranged such that at the time of recording onto the magneto-optical recording medium, the recording marks are recorded such that the ends of each recording mark correspond to a second code of digital information composed of two different types of codes; at the time of reproduction, a light beam having a condensing spot is projected to the magneto-optical recording medium and, when a reproduction light containing reproduction information is entered to the optical head from the magneto-optical recording medium, a reproduction signal is supplied; and when the light beam is projected to a recording mark, an information pulse corresponding to the second code is generated in the reproduction signal, only when the reproduction light from the recording mark interferes with the reproduction light from the non-marking part; and a signal detector circuit for detecting the information pulse in the reproduction signal obtained from the optical head and for converting the reproduction signal into a digital reproduction signal.
摘要:
A recording state detecting apparatus is provided with a saturated amplitude detecting unit for detecting a saturated amplitude level of a reproduced signal from a long mark obtained from a magneto-optical disk, an unsaturated amplitude detecting unit for detecting an unsaturated amplitude level of a reproduced signal from an isolation pattern of a short mark and a calculating unit for detecting a recording state (recording sensitivity or amplitude ratio) from the saturated amplitude level and the unsaturated amplitude level. As a result, an accurate recording state, namely, the recording sensitivity or the amplitude ratio of a recording mark can be detected, thereby making it possible to carry out a setting of an optimum recording condition by test-writing, a check on a recording error by verifying, etc. As a result, high-density recording can be realized.
摘要:
An information reproducing device in accordance with the present invention has at least a differentiating zero-cross detection circuit that differentiates analog reproduced signals that were detected as a light beam was irradiated on an information recording medium whereon information is digitally recorded, that generates differentiated signals, and generates binary zero-cross signals by comparing the differentiated signals and its zero level, a gate generating circuit that generates binary gate signals in accordance with the variation of the analog reproduced signals, a flip-flop that generates binary reproduced signals based on the comparison of the zero-cross signals and the gate signals, and an equalizer that emphasizes the high-frequency components of the analog reproduced signals. Provision is made such that the equalizer is installed ahead of the gate generating circuit. The equalizer thus generates gate signals that correspond accurately to the variation of the analog reproduced signals, thereby permitting data recorded on the information recording medium to be reproduced accurately.
摘要:
A method of controlling the rotational velocity of an information recording disk having one or more tracks in which patterns and marks are formed, the marks including at least one specific pattern having a predetermined length, which method comprises: measuring a time during which each of the patterns passes; detecting each of the marks on the basis of the values of the measured times; and controlling the rotational velocity of the disk on the basis of the measured time of the specific pattern of the detected mark, thereby making the linear velocity of the detected mark constant.
摘要:
An optical disc medium indexing system having a plurality of elongated parallel tracks wherein each track contains a nonerasable index portion located in less than a single frame. The index portions are formed on the substrate of the disc by a plurality of indentations representing the absolute address of each track on the disc recorded in a multiplex format. Each index portion containing information on the mark, track number and CRC. The disc is constructed so that information may be recorded on the entire surface of the medium including the indexed portions.
摘要:
A digital signal reproduction apparatus includes a first differential circuit for differentiating a reproduction signal reproduced from a recording medium. This differential circuit outputs a first order differential signal and second differential circuit differentiates the first order differential signal of the reproduction signal and outputs a second order differential signal. A comparator compares the second order differential signal with a predetermined level to produce a window signal. A peak detecting circuit detects zero-cross points in the first order differential signal and outputs a peak detecting signal. A gate gates the peak detecting signal with the window signal to output a reproduction data signal.
摘要:
An analog signal switching device for use in an optical memory device having a recording/erasing mode and a mode other than the recording/erasing mode is disclosed. The switching device includes a source for producing a switch control signal which is HIGH during the recording/erasing mode and LOW during the mode other than the recording/erasing mode. An analog switch is provided for receiving a direct input analog signal and a held input signal and for providing as output the direct input signal during the LOW state of the switch control signal, and the held input signal during the HIGH state of the switch control signal by a switching operation. Further provided is a mask signal generator for generating a mask signal which covers a period during the HIGH state of the switch control signal so as to cover a period during the switching operation of the analog switch, and a gate circuit controlled by the mask signal for allowing the direct input analog signal to pass therethrough during the absence of the mask signal and for preventing the held input signal to pass therethrough during the presence of the mask signal. Thus, noise signals produced by the switching operation of the analog switch are eliminated.
摘要:
A plant cultivation method of the present invention includes the steps of: placing a plant under a condition at a pressure of not less than 1.5 atmospheres and not more than 10 atmospheres; and cultivating the plant. A plant cultivation device (1) includes: a cultivation chamber (10); and a compressor (20) which supplies compressed air into the cultivation chamber. A carry-in opening (30), which is provided on a side wall (16) of the cultivation chamber (10) so that a material is carried in/out to/from the cultivation chamber (10) via the carry-in opening (30), is provided with a cover (31) which has a shape that is hemispherical and protrudes toward an inside of the cultivation chamber (10). The cover (31) closes the carry-in opening (30) by being in contact, via a packing (32), with an inner surface of the side wall (16) surrounding the carry-in opening (30). The cultivation chamber (10) has an internal pressure higher than an atmospheric pressure by causing the compressor (20) to supply compressed air into the cultivation chamber (10) in a state in which the carry-in opening (30) is closed. A plant growth rate is improved by cultivating a plant in a high pressure environment which is different from a natural environment. A plant cultivation device is provided for achieving plant cultivation in a high pressure environment.
摘要:
A lighting device (20) included in a plant cultivation device (10) includes: a light source unit (25) including an LED serving as a light source; and a cooling unit (30) including a cooling section (21) which allows a cooling medium to flow therein, the cooling unit (30) cooling the light source by heat exchange between the cooling medium supplied to the inside of the cooling section (21) and the light source unit (25). A fan (26) provided in the cooling unit (30) starts and stops supply of the cooling medium in accordance with the temperature (T) measured by a light source temperature sensor (27) provided to the light source unit (25). This makes it possible for a lighting device for plant cultivation and a plant cultivation device to reduce formation of condensation during cooling of the light source, while achieving efficient cooling of the light source.
摘要:
Tape-shaped superconducting wires, and a superconducting coil formed from said wires, wherein a plurality of electrically separated superconducting film parts, each having a rectangular cross section and arranged in parallel, form parallel conductors, providing superconducting wires capable of containing losses incurred in the presence of alternating current (A/C). A superconducting coil is made by winding the superconducting wires, wherein the coil structure contains at least a part wherein perpendicular interlinkage magnetic fluxes acting among conductor elements of the parallel conductors by the distribution of magnetic fields generated by the superconducting coils cancel mutually in order to contain circulating current within the wires and to make shunt current uniform, thereby providing a low-loss A/C superconducting coil.