Data base searching

Claim 2

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrences of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which together comprise an object, wherein the said item sought is a similarly coded pattern and is disposed in the input plane after recordal of said memory content and the matched filter then serves to locate the position of said item sought against a background comprised by said object, and including means whereby the coded pattern of said item sought can be moved step-by-step across the input plane in a first direction, and detection means in the output plane which serve to detect peak correlation signals within a predetermined range that corresponds to said location.

Claim 3

A correlator as claimed in claim 1 wherein the coded pattern of said item sought is replicated in the input plane in a second direction perpendicular to said first direction and the replicated coded patterns are moved step-by-step synchronously across the input plane.

Claim 4

A correlator as claimed in claim 2 and including means whereby all but any one of the replicated patterns may have their presence removed from the input plane in order to determine which replicated pattern is, or which replicated patterns are, producing the peak correlation signals.

Claim 5

A correlator as claimed in claim 1 and including a respective shift register with optical output for producing the coded pattern of each said item sought.

Claim 6

A correlator as claimed in claim 1 and wherein the detection means comprises a column of detectors placed centrally in the output plane and extending in said second direction.

Claim 7

A correlator as claimed in claim 5 wherein the coded pattern of said item sought is replicated in the input plane in a second direction perpendicular to said first direction and the replicated coded patterns are moved step-by-step synchronously across the input plane, and including means whereby when the replicated coded patterns have been moved in the first direction and the detection means indicate an approximate match, the replicated coded patterns are moved in the input plane in the second direction until a match is achieved on a middle detector of the column.

Claim 8

A correlator as claimed in claim 2 and wherein there are dual reference beams displaced from an axis extending in the first direction by equal amounts whereby the memory content is recorded twice.

Claim 9

A correlator as claimed in claim 1 wherein said item sought comprises a scene, and wherein complementary coding is used for the object and scene, the scene coded pattern being the complement of the object coded pattern.

Claim 10

A correlator as claimed in claim 1 and for searching a file containing a list of records, wherein the memory includes a file store, and including an electronic bit map store for holding a map corresponding to file record patterns on the file store.

Claim 11

A correlator as claimed in claim 1 and for searching a predetermined number of files and selecting records meeting predetermined conditions, and including an electronic integer mapping store capable of storing an integer for each member of a predetermined list.

Claim 12

A correlator as claimed in claim 10 further including an auxiliary correlator which performs correlation operations on data received from the matched optical filter.

Claim 13

A correlator as claimed in claim 1 and wherein the memory is in optical disc form and including transfer optic means between said disc and the input plane.

Claim 14

A correlator as claimed in claim 12 and including an electronic store map coupled to said control means.

Claim 15

A correlator as claimed in claim 1 wherein the said sought item and the memory contents comprise variable length records which are arranged in a two dimensional format whereby to minimise storage space.

Claim 16

A correlator as claimed in claim 1, wherein the detection means comprise a plurality of columns of detectors extending in a direction perpendicular to the first direction and disposed in the output plane, whereby the peak correlation signals within the predetermined range that correspond to said location can be detected in any one of the plurality of columns.

Claim 17

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrence of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which comprises an object, wherein the said item sought is a single similarly coded pattern and is disposed in the input plane after recordal of said memory content and wherein said reference beam source is located in the input plane as far as possible from the position of the single coded pattern in at least one dimension in order to reduce the effect of astigmatism.

Claim 18

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrence of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which comprises an object, wherein the said item sought is a single similarly coded pattern and is disposed in the input plane after recordal of said memory content and wherein said reference beam source is located in the input plane as far as possible from the position of the single coded pattern in at least one dimension in order to reduce the effect of astigmatism.

Claim 19

A correlator as claimed in claim 16 wherein the coded pattern of the item comprises a scene, and wherein the scene is illuminated by said light source and is positioned on an edge of the input plane opposite to an edge thereof used for the reference beam during the recording phase.

Claim 20

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrences of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which comprises an object, wherein the said item sought is a single coded pattern comprising a scene, or a plurality of similarly coded patterns, wherein complementary coding is used for the object and scene, the scene coded pattern being the complement of the object coded pattern, and wherein, for searching a predetermined number of files and selection records meeting predetermined conditions, the memory includes an electronic integer map store capable of storing an integer for each member of a predetermined list, and further including an auxiliary correlator which performs correlation operations on data received from the matched optical filter.

Claim 21

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrences of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which comprises an object, wherein the said item sought is a single coded pattern comprising a scene, or a plurality of similarly coded patterns, wherein complementary coding is used for the object and scene, the scene coded pattern being the complement of the object coded pattern, and wherein, for searching a predetermined number of files and selection records meeting predetermined conditions, the memory includes an electronic integer map store capable of storing an integer for each member of a predetermined list, and further including an auxiliary correlator which performs correlation operations on data received from the matched optical filter.

Claim 22

A correlator as claimed in claim 16 wherein said item sought comprises a scene, and wherein complementary coding is used for the object and scene, the scene coded pattern being the complement of the object coded pattern.

Claim 23

A correlator as claimed in claim 16 and for searching a file containing a list of records, wherein the memory includes a file store and an electronic bit map store for holding a map corresponding to file record positions on the file store.

Claim 24

A correlator as claimed in claim 18 and for searching a file containing a list of records, wherein the memory includes a file store and an electronic bit map store for holding a map corresponding to file record positions on the file store.

Claim 25

A correlator as claimed in claim 16 and for searching a predetermined number of files and selecting records meeting predetermined conditions, the memory including an electronic integer mapping store capable of storing an integer for each member of a predetermined list.

Claim 26

A correlator as claimed in claim 22 further including an auxiliary correlator which performs correlation operations on data received from the matched optical filter.

Claim 27

A correlator as claimed in claim 16 and wherein the memory is in optical disc form and including transfer optic means between said disc and the input plane.

Claim 28

A correlator as claimed in claim 24 and including an electronic store map coupled to said control means.

Claim 29

A correlator as claimed in claim 25 further including an auxiliary correlator which performs correlation operations on data received from the matched optical filter.

Claim 30

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrences of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which comprises an object, wherein the said item sought is a single coded pattern comprising a scene, or a plurality of similarly coded patterns, wherein complementary coding is used for the object and scene, the scene coded pattern being the complement of the object coded pattern, and wherein the message is in optical disc form, and including transfer optic means between said disc and the input plane, an electronic store map coupled to said control means and an auxiliary correlator which performs correlation operations on data received from the matched optical filter.

Claim 31

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrences of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which comprises an object, wherein the said item sought is a single coded pattern comprising a scene, or a plurality of similarly coded patterns, wherein complementary coding is used for the object and scene, the scene coded pattern being the complement of the object coded pattern, and wherein the message is in optical disc form, and including transfer optic means between said disc and the input plane, an electronic store map coupled to said control means and an auxiliary correlator which performs correlation operations on data received from the matched optical filter.

Claim 32

A correlator as claimed in claim 16 wherein the said sought item and the memory contents comprise variable length records which are arranged in a two dimensional format whereby to minimise storage space.

Claim 33

A correlator as claimed in claim 18 wherein the said sought item and the memory contents comprise variable length records which are arranged in a two dimensional format whereby to minimise storage space.

Claim 34

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrences of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which comprises an object, wherein the said item sought is a single coded pattern comprising a scene, or a plurality of similarly coded patterns, wherein complementary coding is used for the object and scene, the scene coded pattern being the complement of the object coded pattern, wherein the said image sought is disposed in an input plane after recordal of said memory content and the matched filter then serves to locate the position of said item against a background comprised by said object, and including means whereby the coded pattern of said item sought can be moved step-by-step across the input plane in a first direction, and including detection means in the output plane, which detection means comprise a plurality of columns of detectors extending in a direction perpendicular to the first direction and disposed in the output plane, whereby minimum correlation signals within a predetermined range that correspond to said location can be detected in any one of the plurality of columns.

Claim 35

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrences of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which comprises an object, wherein the said item sought is a single coded pattern comprising a scene, or a plurality of similarly coded patterns, wherein complementary coding is used for the object and scene, the scene coded pattern being the complement of the object coded pattern, wherein the said image sought is disposed in an input plane after recordal of said memory content and the matched filter then serves to locate the position of said item against a background comprised by said object, and including means whereby the coded pattern of said item sought can be moved step-by-step across the input plane in a first direction, and including detection means in the output plane, which detection means comprise a plurality of columns of detectors extending in a direction perpendicular to the first direction and disposed in the output plane, whereby minimum correlation signals within a predetermined range that correspond to said location can be detected in any one of the plurality of columns.

Claim 36

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrences of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which comprises an object, wherein the said item sought is a similarly coded pattern and is disposed in the input plane after recordal of said memory content and the matched filter then serves to locate the position of said item sought against a background comprised by said object, and including detection means in the output plane which serve to detect correlation signals within a predetermined range that correspond to said location, and wherein once having detected said location said item sought is removed from the input plane and a point source of light substituted at a specific one of said item's previous bit positions, whereupon N bits of information stored adjacently to said detected location are read out on N columns of detectors in the output plane which comprise said detection means.

Claim 37

A holographic optical correlator including a matched optical filter and coupled thereto a control means including a memory, and wherein in use for searching the memory for occurrences of an item the control means controls the input and Fourier transform planes of the filter and a coherent light source for parallel optical processing of the memory content and the output plane of the filter provides information to the control means as to the location in the memory of occurrences of said item, and including means whereby the memory content is recorded in the Fourier transform plane, using a reference beam from said light source, as at least one coded pattern which comprises an object, wherein the said item sought is a similarly coded pattern and is disposed in the input plane after recordal of said memory content and the matched filter then serves to locate the position of said item sought against a background comprised by said object, and including detection means in the output plane which serve to detect correlation signals within a predetermined range that correspond to said location, and wherein once having detected said location said item sought is removed from the input plane and a point source of light substituted at a specific one of said item's previous bit positions, whereupon N bits of information stored adjacently to said detected location are read out on N columns of detectors in the output plane which comprise said detection means.

Claim 38

A correlator as claimed in claim 31 wherein the coded pattern of said item sought is replicated in the input plane and the replicated coded patterns are moved step-by-step synchronously across the input plane.

Claim 41

A method as claimed in claim 33 wherein the item sought is replicated in the input plane in a direction perpendicular to said step-wise movement, and said replications are moved step-wise synchronously across the input plane.

Claim 42

A method as claimed in claim 34 and wherein the detection is performed by a column of detectors in the output plane and when a peak correlation signal within the predetermined range is achieved the replications are moved in the input plane in said perpendicular direction until the peak correlation signal is detected on a middle detector of said column.

Claim 43

A method as claimed in any claim 33 wherein the items sought and the data base comprise coded patterns.

Claim 44

A method as claimed in claim 34 wherein the items sought and the data base comprise coded patterns and wherein once having detected said item sought it is removed from the input plane and a point source of light substituted at a specific one of said item's previous bit position, whereupon N bits of information stored adjacently to said detected item's location are read out on N columns of detectors in the output plane.