Patent EP0350336A2 successfully refreshed from Google Patents.
EP0350336A2
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EP
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Optical memory system
Assignee: Sharp Corp
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Filing: 1989-07-10
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Granted: —
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Expires: 2009-07-10
Abstract
Abstract An optical memory system comprises light beam generating means for generating a plurality of light beams; a recording medium comprising a plurality of guide grooves for guiding each of the light beams, and ID sections utilised for identifying a guide groove on which each of the light beams is projected; a plurality of photo-detectors for detecting the intensity of the reflected light or transmitted light of each of the light beams projected on the recording medium; a plurality of comparators for converting a signal released from each of the photo-detectors into a binary signal; a majority logic circuit for issuing a signal whose level is equivalent to the levels of the signals released from the majority of the comparators and a moving amount detector for detecting the moving amount of the said light beams by counting the number of pulses in the pulse signal released from the majority logic circuit when the light beams move in a direction perpendicular to the guide grooves. This optical memory system is designed such that at least either the plurality of light beams or the plurality of ID sections of the guide grooves are so arranged that at least more than half of the light beams or more than half of the ID sections are not overlapped in a parallel direction to the guide grooves whereby the number of light beams projected on the ID sections at the same time is limited to less than half of the total number of light beams projected on the recording medium. Accordingly, even when the light beams are moved in a perpendicular direction to the guide grooves, the number of pulses in the pulse signal is not influenced by ID signals or the like but coincident with the number of the guiding grooves through which the light beams have actually passed. With use of the optical memory system having such an arrangement, the accurate moving amount of a light beam is obtained resulting in high accuracy of access operation.
Inventors
- 👤 Tsuneo Fujiwara
- 👤 Masaru Nomura
- 👤 Toshihisa Deguchi
- 👤 Kunio Kojima
- 👤 Takeshi Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 07:51
CPC Classifications
G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/1055; G11B11/10556; G11B11/10563; G11B7/00; G11B7/002; G11B7/0033; G11B7/08; G11B7/085; G11B7/12; G11B7/14
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
263 words
An optical memory system comprising: A. light beam generating means for generating a plurality of light beams; B. a recording medium comprising a plurality of guide grooves for guiding each of said light beams, and ID sections utilised for identifying a guide groove on which each of said light beams is projected; C. a plurality of photo-detectors for detecting the intensity of the reflected light or transmitted light of each of said light beams projected on said recording medium; D. a plurality of comparators for converting a signal released from each of said photo-detectors into a binary signal; E. a majority logic circuit for issuing a pulse signal whose level is equivalent to the levels of the signals released from the majority of said comparators; and F. moving amount detecting means for detecting the moving amount of said light beams by counting the number of pulses in the pulse signal released from said majority logic circuit when said light beams move in a direction perpendicular to said guide grooves; said optical memory system being designed such that at least either the plurality of light beams or the plurality of ID sections of said guide grooves are so arranged that at least more than half of said light beams or more than half of said ID sections are not perfectly overlapped one another in a parallel direction to said guide grooves whereby the number of light beams projected on the ID sections at the same time is limited to less than half of the total number of light beams projected on said recording medium.
Claim 2
Dependent Claim
263 words
An optical memory system comprising: A. light beam generating means for generating a plurality of light beams; B. a recording medium comprising a plurality of guide grooves for guiding each of said light beams, and ID sections utilised for identifying a guide groove on which each of said light beams is projected; C. a plurality of photo-detectors for detecting the intensity of the reflected light or transmitted light of each of said light beams projected on said recording medium; D. a plurality of comparators for converting a signal released from each of said photo-detectors into a binary signal; E. a majority logic circuit for issuing a pulse signal whose level is equivalent to the levels of the signals released from the majority of said comparators; and F. moving amount detecting means for detecting the moving amount of said light beams by counting the number of pulses in the pulse signal released from said majority logic circuit when said light beams move in a direction perpendicular to said guide grooves; said optical memory system being designed such that at least either the plurality of light beams or the plurality of ID sections of said guide grooves are so arranged that at least more than half of said light beams or more than half of said ID sections are not perfectly overlapped one another in a parallel direction to said guide grooves whereby the number of light beams projected on the ID sections at the same time is limited to less than half of the total number of light beams projected on said recording medium.
Claim 3
Dependent Claim
42 words
An optical memory system according to Claim 1 wherein said recording medium is made of a plastic in the form of a disk and includes a magnetic film comprising Cd, Te, Fe, Co, or the like attached to the back face thereof.
Claim 4
Dependent Claim
41 words
An optical memory system according to Claim 1 wherein said recording medium is made of glass in the form of a disk and includes a magnetic film comprising Cd, Te, Fe, Co, or the like attached to the back face thereof.
Claim 5
Dependent Claim
14 words
The recording medium of Claim 2 which is in the form of a card.
Claim 6
Dependent Claim
14 words
The recording medium of Claim 3 which is in the form of a card.
Claim 7
Dependent Claim
16 words
An optical memory system according to Claim 1 wherein said majority logic circuit comprises logical elements.
Claim 8
Dependent Claim
18 words
An optical memory system according to Claim 1 wherein said moving amount detecting means comprises a digital counter.
Claim 9
Dependent Claim
41 words
An optical memory system according to Claim 1 wherein said recording medium has the adjacent ID sections arranged such that at least more than half of the ID sections are not perfectly overlapped in a parallel direction to said guiding grooves.
Claim 10
Dependent Claim
74 words
An optical memory system according to Claim 1 wherein said recording medium is designed such that while the ID sections are aligned in a direction perpendicular to said guiding grooves, said light beams are projected such that at least more than half of said light beams are not perfectly overlapped in a parallel direction to said guiding grooves, and said light beams are projected at intervals longer than the length of the ID section.
Claim 11
Dependent Claim
40 words
An optical memory system according to Claim 1 wherein said light beams, said photo-detectors and said comparators respectively correspond in number to the number of pulse signals with which a majority decision by the majority logic circuit can be performed.
Claim 12
Dependent Claim
35 words
An optical memory system according to Claim 1 wherein said light beam generating means comprises a diffraction grating for diffracting a light beam from a light source into one zero-order light and two first-order lights.
Claim 13
Dependent Claim
177 words
An optical memory apparatus for use with an optical memory medium having parallel guide grooves and ID groove sections formed in said guide grooves, the apparatus comprising means for projecting a set of light beams onto the medium, sensor means for separately detecting the intensities of the individual beams resulting from the reflection or transmission by said medium of said set of light beams, the apparatus having means for selectively positioning the set of beams relative to the medium by moving said set transverse the guide grooves and means for measuring the movement of the beams across the grooves by processing the outputs of said sensor means, wherein said processing comprises generating a count pulse whenever during said transverse movement at least a predetermined number of the sensors each produce a predetermined signal level indicative of a beam crossing a guide groove, the relative arrangement of incident beams and ID groove sections being such that at no time can the number of beams which are not incident on ID groove sections be less than said predetermined number.
Claim 14
Dependent Claim
177 words
An optical memory apparatus for use with an optical memory medium having parallel guide grooves and ID groove sections formed in said guide grooves, the apparatus comprising means for projecting a set of light beams onto the medium, sensor means for separately detecting the intensities of the individual beams resulting from the reflection or transmission by said medium of said set of light beams, the apparatus having means for selectively positioning the set of beams relative to the medium by moving said set transverse the guide grooves and means for measuring the movement of the beams across the grooves by processing the outputs of said sensor means, wherein said processing comprises generating a count pulse whenever during said transverse movement at least a predetermined number of the sensors each produce a predetermined signal level indicative of a beam crossing a guide groove, the relative arrangement of incident beams and ID groove sections being such that at no time can the number of beams which are not incident on ID groove sections be less than said predetermined number.
References Cited (Backward Citations)
No citation records indexed.
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