US3887906A
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Optical associative memory using complementary magnetic bubble shift registers
Assignee: Bull HN Information Systems Italia SpA
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Filing: 1973-06-28
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Granted: 1975-06-03
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Expires: 1993-06-28
Abstract
Abstract An associative memory system includes an optical supporting member having bit storage elements with an optical response variable between two distinct values, representing the bit values. Each bit is recorded in two complementary forms in two conjugate regions of the support with each pair of conjugate regions being assigned to bits of a same order of all words. Predetermined regions of the support conforming to the information content for which the associative memory is interrogated are selectively illuminated. The optical responses of these regions are superposed on an electro-optical detecting device so that the detecting device is responsive to all of the illuminated bits of a single word. In a first embodiment, the information is recorded as transparent and opaque elementary areas on a photographic plate which is interrogated by a pair of complementary matrixes of coincidence-selected photoemitters arranged in conjugate pairs, each pair being assigned to a bit order. The light from the photoemitters passes through the photographic plate and is concentrated by a ''''fly eye'''' optical system onto a detecting device. In a second embodiment, the information is recorded on a photographic plate as an array of pairs of complementary holograms. Read-out is effected by a coherent light beam deflected along two orthoganal directions to illuminate in sequence one or the other of the complementary holograms of the interrogated pair. The real image of the information stored in the illuminated hologram is thus formed in registration with an array of photodetector elements which memorize the signals set up in response to the illumination. In a third embodiment, the information is recorded by means of ''''magnetic bubbles'''' obtained in the presende of a magnetic field on a plate of orthferritic material. Since the magnetic bubbles are optically active and rotate the polarization state of incident light, with the use of polarizing and analyzing sheets they appear as opaque or transparent spots and are detected by photodetectors in response to associative interrogation as described above.
Inventors
- 👤 Nicola Minnaja
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:44
CPC Classifications
G; G11; G11C; G11C15/00; G11C13/00; G11C13/04; G11C13/042; G11C13/046; G11C13/048; G11C13/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
424 words
An optical associative memory system, comprising an optical support for recording information by means of a variable optical response to illumination of elementary areas in dependence on the recorded information, the optical response of each elementary area of the support being dependent on the transparency of said elementary area in the presence of polarized incident the transmitted light, said recorded information comprising a plurality of words formed each by an ordered set of an equal number of bits, illuminating means for illuminating said support, and an array of electro-optical detector elements for generating electrical signals in response to the illumination of said detectors, said system being characterized in that: each bit is recorded both in a first direct form and in a second inverse form, complementary to the first direct form; said support comprises a plurality of bit regions, each one recording in the same form the bits of equal order of all the recorded words; said illuminating means selectively illuminates at least one of said regions with polarized light; said array of detector elements comprises a number of detectors equal to the number of words which may be recorded on the support; the optical response of each bit region to the illumination is concentrated on said array of detector elements, each detector being responsive to the illumination resulting from the cumulative optical response of all the illuminated bits of a single word; said recording support includes a plate of crystal of rare-earth orthoferrite subject to a magnetic field and provided on at least a face with a suitable pattern of electrical conductors for generating local variation in said magnetic field in response to electrical current flowing therethrough, for generating duplicating, displacing or cancelling magnetic bubbles, said conductors forming magnetic bubble shift registers for recording the information by means of the presence or absence in predetermined time intervals of magnetic bubbles in prearranged memory locations, the presence of said bubbles being detected as a variation of the optical response of said incident polarized light emerging from an analyzing device; said shift registers are grouped in pairs of registers, each pair being assigned to the bits of equal order of all recorded words, homologous memory locations in each register of each pair being assigned for recording respectively in direct and inverse form the bits of the same word; said illuminating means selectively illuminates at least one of said registers; and said system comprises in addition a ''''fly-eye'''' optical device for focusing and superimposing the images of the iluminated register on said array of detector elements.
Claim 2
Dependent Claim
424 words
An optical associative memory system, comprising an optical support for recording information by means of a variable optical response to illumination of elementary areas in dependence on the recorded information, the optical response of each elementary area of the support being dependent on the transparency of said elementary area in the presence of polarized incident the transmitted light, said recorded information comprising a plurality of words formed each by an ordered set of an equal number of bits, illuminating means for illuminating said support, and an array of electro-optical detector elements for generating electrical signals in response to the illumination of said detectors, said system being characterized in that: each bit is recorded both in a first direct form and in a second inverse form, complementary to the first direct form; said support comprises a plurality of bit regions, each one recording in the same form the bits of equal order of all the recorded words; said illuminating means selectively illuminates at least one of said regions with polarized light; said array of detector elements comprises a number of detectors equal to the number of words which may be recorded on the support; the optical response of each bit region to the illumination is concentrated on said array of detector elements, each detector being responsive to the illumination resulting from the cumulative optical response of all the illuminated bits of a single word; said recording support includes a plate of crystal of rare-earth orthoferrite subject to a magnetic field and provided on at least a face with a suitable pattern of electrical conductors for generating local variation in said magnetic field in response to electrical current flowing therethrough, for generating duplicating, displacing or cancelling magnetic bubbles, said conductors forming magnetic bubble shift registers for recording the information by means of the presence or absence in predetermined time intervals of magnetic bubbles in prearranged memory locations, the presence of said bubbles being detected as a variation of the optical response of said incident polarized light emerging from an analyzing device; said shift registers are grouped in pairs of registers, each pair being assigned to the bits of equal order of all recorded words, homologous memory locations in each register of each pair being assigned for recording respectively in direct and inverse form the bits of the same word; said illuminating means selectively illuminates at least one of said registers; and said system comprises in addition a ''''fly-eye'''' optical device for focusing and superimposing the images of the iluminated register on said array of detector elements.
Claim 3
Dependent Claim
424 words
An optical associative memory system, comprising an optical support for recording information by means of a variable optical response to illumination of elementary areas in dependence on the recorded information, the optical response of each elementary area of the support being dependent on the transparency of said elementary area in the presence of polarized incident the transmitted light, said recorded information comprising a plurality of words formed each by an ordered set of an equal number of bits, illuminating means for illuminating said support, and an array of electro-optical detector elements for generating electrical signals in response to the illumination of said detectors, said system being characterized in that: each bit is recorded both in a first direct form and in a second inverse form, complementary to the first direct form; said support comprises a plurality of bit regions, each one recording in the same form the bits of equal order of all the recorded words; said illuminating means selectively illuminates at least one of said regions with polarized light; said array of detector elements comprises a number of detectors equal to the number of words which may be recorded on the support; the optical response of each bit region to the illumination is concentrated on said array of detector elements, each detector being responsive to the illumination resulting from the cumulative optical response of all the illuminated bits of a single word; said recording support includes a plate of crystal of rare-earth orthoferrite subject to a magnetic field and provided on at least a face with a suitable pattern of electrical conductors for generating local variation in said magnetic field in response to electrical current flowing therethrough, for generating duplicating, displacing or cancelling magnetic bubbles, said conductors forming magnetic bubble shift registers for recording the information by means of the presence or absence in predetermined time intervals of magnetic bubbles in prearranged memory locations, the presence of said bubbles being detected as a variation of the optical response of said incident polarized light emerging from an analyzing device; said shift registers are grouped in pairs of registers, each pair being assigned to the bits of equal order of all recorded words, homologous memory locations in each register of each pair being assigned for recording respectively in direct and inverse form the bits of the same word; said illuminating means selectively illuminates at least one of said registers; and said system comprises in addition a ''''fly-eye'''' optical device for focusing and superimposing the images of the iluminated register on said array of detector elements.
Claim 4
Dependent Claim
424 words
An optical associative memory system, comprising an optical support for recording information by means of a variable optical response to illumination of elementary areas in dependence on the recorded information, the optical response of each elementary area of the support being dependent on the transparency of said elementary area in the presence of polarized incident the transmitted light, said recorded information comprising a plurality of words formed each by an ordered set of an equal number of bits, illuminating means for illuminating said support, and an array of electro-optical detector elements for generating electrical signals in response to the illumination of said detectors, said system being characterized in that: each bit is recorded both in a first direct form and in a second inverse form, complementary to the first direct form; said support comprises a plurality of bit regions, each one recording in the same form the bits of equal order of all the recorded words; said illuminating means selectively illuminates at least one of said regions with polarized light; said array of detector elements comprises a number of detectors equal to the number of words which may be recorded on the support; the optical response of each bit region to the illumination is concentrated on said array of detector elements, each detector being responsive to the illumination resulting from the cumulative optical response of all the illuminated bits of a single word; said recording support includes a plate of crystal of rare-earth orthoferrite subject to a magnetic field and provided on at least a face with a suitable pattern of electrical conductors for generating local variation in said magnetic field in response to electrical current flowing therethrough, for generating duplicating, displacing or cancelling magnetic bubbles, said conductors forming magnetic bubble shift registers for recording the information by means of the presence or absence in predetermined time intervals of magnetic bubbles in prearranged memory locations, the presence of said bubbles being detected as a variation of the optical response of said incident polarized light emerging from an analyzing device; said shift registers are grouped in pairs of registers, each pair being assigned to the bits of equal order of all recorded words, homologous memory locations in each register of each pair being assigned for recording respectively in direct and inverse form the bits of the same word; said illuminating means selectively illuminates at least one of said registers; and said system comprises in addition a ''''fly-eye'''' optical device for focusing and superimposing the images of the iluminated register on said array of detector elements.
Claim 5
Dependent Claim
31 words
The optical associative memory system of the claim 1, wherein at least an output memory loction for each pair of registers is provided for holding in said location a magnetic bubble.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |