US5081479A
Expired / Lapsed
US
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Automatic focusing device
Assignee: Canon Inc
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Filing: 1990-01-18
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Granted: 1992-01-14
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Expires: 2010-01-18
Abstract
Abstract This invention relates to an automatic focusing device, particular capable of foreseeing the position of an object after a predetermined future time based on the results of a plurality of past focusing operations, thus enabling the focusing to the object. An automatic focusing device is provided which executes calculations for the abovementioned foreseeing after the execution of a predetermined number of focusing operations. However, if a focused state is identified in a focusing operation in the course of the execution of the predetermined number of focusing operations, the device is adapted to disregard the first-mentioned focusing operation as if it had not been conducted and to exclude the first-mentioned focusing operation from the counting of the predetermined number of focusing operations.
Inventors
- 👤 Terutake Kadohara
- 👤 Akira Akashi
- 👤 Masaki Higashihara
- 👤 Ichiro Ohnuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:06
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
99 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, base on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) an enabling circuit for enabling said correction calculating mode after the execution of a plurality of focusing operations; and (b) a processing circuit for treating, when the lens is identified as being in-focus in a particular cycle of the plurality of focusing cycles, a next focusing operation as the particular focusing cycle.
Claim 2
Dependent Claim
99 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, base on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) an enabling circuit for enabling said correction calculating mode after the execution of a plurality of focusing operations; and (b) a processing circuit for treating, when the lens is identified as being in-focus in a particular cycle of the plurality of focusing cycles, a next focusing operation as the particular focusing cycle.
Claim 3
Dependent Claim
47 words
A device or a camera according to claim 1, wherein said processing circuit continues to treat a next focusing operation as said particular focusing cycle when the lens is identified as being in-focus by the focusing operation which said processing circuit treats as said particular focusing cycle.
Claim 4
Dependent Claim
61 words
An automatic focusing device or a camera according to claim 1, wherein each of said focusing cycles includes a focus detection operation and a lens driving operation based on the result of the focus detection operation, and wherein the lens driving operation is omitted from the focusing cycle when the lens is determined to be in-focus by the focus detection result.
Claim 5
Dependent Claim
48 words
An automatic focusing device or a camera according to claim 1, further comprising focus state detecting means for widening the range of identifying said in-focus state in comparison with the range used before, in a focusing operation succeeding the focusing operation in which said in-focus state is identified.
Claim 6
Dependent Claim
45 words
An automatic focusing device or a camera according to claim 1, wherein said automatic focusing device determines a lens driving amount for each lens driving operation on the basis of data obtained in the latest predetermined number of focusing cycles in said correction calculating mode.
Claim 7
Dependent Claim
53 words
An automatic focusing device or a camera according to claim 1, wherein said automatic focusing device determines coefficients of a predetermined high-order function by using data in a plurality of past focusing cycles in the correction calculating mode and determines a lens driving amount on the basis of the thus determined high-order function.
Claim 8
Dependent Claim
19 words
An automatic focusing device or a camera according to claim 6, wherein the high-order function is a 2nd-order function.
Claim 9
Dependent Claim
68 words
An automatic focusing device or a camera according to claim 7, wherein the high order function is represented by X=at 2 +bt+c, wherein X is the position of an imaging plane at time t and coefficients a and b are determined on the basis of X being represented by data at the time of the focusing cycle and t being represented at the time of the focusing cycle.
Claim 10
Dependent Claim
119 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, based on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) an enabling circuit for enabling, after execution of a plurality of (N) focusing operations, the calculation in said correction calculating mode utilizing the data of the 1st to N-th focusing operations; and (b) a process circuit which, if an in-focus state is identified in an M-th focusing operation among said N focusing operations, processes the next focusing operation again as the M-th operation, wherein M is a particular number such that M≦N.
Claim 11
Dependent Claim
119 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, based on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) an enabling circuit for enabling, after execution of a plurality of (N) focusing operations, the calculation in said correction calculating mode utilizing the data of the 1st to N-th focusing operations; and (b) a process circuit which, if an in-focus state is identified in an M-th focusing operation among said N focusing operations, processes the next focusing operation again as the M-th operation, wherein M is a particular number such that M≦N.
Claim 12
Dependent Claim
46 words
A device or a camera according to claim 9, further comprising focus state detecting means for widening the range of identifying said in-focus state in comparison with the range used before, in a focusing operation succeeding the focusing operation in which said in-focus state is identified.
Claim 13
Dependent Claim
53 words
An automatic focusing device or a camera according to claim 9, wherein said process circuit shifts a previous 1st through Mth operation by one operation and processes the shifted previous 1st through Mth operations as the new 1st through Mth operations when the next focusing operation is processed as the M-th focusing operation.
Claim 14
Dependent Claim
53 words
An automatic focusing device or a camera according to claim 9, wherein said automatic focusing device determines coefficients of a predetermined high-order function by using data in a plurality of past focusing cycles in the correction calculating mode and determines a lens driving amount on the basis of the thus determined high-order function.
Claim 15
Dependent Claim
19 words
An automatic focusing device or a camera according to claim 12, wherein the high-order function is a 2nd-order function.
Claim 16
Dependent Claim
68 words
An automatic focusing device or a camera according to claim 12, wherein the high order function is represented by X=at 2 +bt+c, wherein X is the position of an imaging plane at time t and coefficients a and b are determined on the basis of X being represented by data at the time of the focusing cycle and t being represented at the time of the focusing cycle.
Claim 17
Dependent Claim
106 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, based on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) enabling means for enabling said correction calculating mode after the execution of a plurality of (N) focusing operations; and (b) a process circuit which, if an in-focus state is identified in an M-th focusing operation among said N focusing operations, processes the next focusing operation as the M-th focusing operation, wherein M is a particular number such that M≦N.
Claim 18
Dependent Claim
106 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, based on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) enabling means for enabling said correction calculating mode after the execution of a plurality of (N) focusing operations; and (b) a process circuit which, if an in-focus state is identified in an M-th focusing operation among said N focusing operations, processes the next focusing operation as the M-th focusing operation, wherein M is a particular number such that M≦N.
Claim 19
Dependent Claim
42 words
A device or a camera according to claim 15, further comprising retaining means for retaining said process circuit in an activated state as long as the focusing operation processed as the M-th focusing operation by said process circuit indicates the in-focus state.
Claim 20
Dependent Claim
48 words
An automatic focusing device or a camera according to claim 15, further comprising focus state detecting means for widening the range of identifying said in-focus state in comparison with the range used before, in a focusing operation succeeding the focusing operation in which said in-focus state is identified.
Claim 21
Dependent Claim
53 words
An automatic focusing device or a camera according to claim 15, wherein said automatic focusing device determines coefficients of a predetermined high-order function by using data in a plurality of past focusing cycles in the correction calculating mode and determines a lens driving amount on the basis of the thus determined high-order function.
Claim 22
Dependent Claim
19 words
An automatic focusing device or a camera according to claim 18, wherein the high-order function is a 2nd-order function.
Claim 23
Dependent Claim
68 words
An automatic focusing device or a camera according to claim 18, wherein the high order function is represented by X=at 2 +bt+c, wherein X is the position of an imaging plane at time t and coefficients a and b are determined on the basis of X being represented by data at the time of the focusing cycle and t being represented at the time of the focusing cycle.
Claim 24
Dependent Claim
122 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, based on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) a counter circuit for counting the number of focusing operations executed by the automatic focusing device; (b) a transfer control circuit for transferring to said correction calculating mode when the number counted by said counter circuit reaches a predetermined number; and (c) a cancellation circuit for cancelling, when the in-focus state is identified in a particular cycle of the plurality of focusing cycles, the counting operation of said counter circuit for the particular focusing cycle.
Claim 25
Dependent Claim
122 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, based on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) a counter circuit for counting the number of focusing operations executed by the automatic focusing device; (b) a transfer control circuit for transferring to said correction calculating mode when the number counted by said counter circuit reaches a predetermined number; and (c) a cancellation circuit for cancelling, when the in-focus state is identified in a particular cycle of the plurality of focusing cycles, the counting operation of said counter circuit for the particular focusing cycle.
Claim 26
Dependent Claim
96 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, based on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) enabling means for enabling said correction calculating mode after the execution of a plurality of focusing operations; and (b) a widening circuit for widening the range of identifying of the in-focus state when an in-focus state is identified in the course of execution of said plurality of focusing operations.
Claim 27
Dependent Claim
96 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, based on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) enabling means for enabling said correction calculating mode after the execution of a plurality of focusing operations; and (b) a widening circuit for widening the range of identifying of the in-focus state when an in-focus state is identified in the course of execution of said plurality of focusing operations.
Claim 28
Dependent Claim
22 words
An automatic focusing device or a camera according to claim 22, wherein said widening circuit stops operation in said correction calculation mode.
Claim 29
Dependent Claim
103 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, based on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) enabling means for enabling said correction calculating mode after the execution of a plurality of focusing operations; and (b) a widening circuit for widening the range of identifying of the in-focus state, such that said widening circuit starts to operate when the in-focus state is identified in a particular cycle during said plurality of focusing cycles.
Claim 30
Dependent Claim
103 words
An automatic focusing device having a correction calculating mode for calculating the lens drive amount for focusing to an object at a predetermined future time, based on the data of a plurality of past focusing cycles, or a camera provided with said automatic focusing device, comprising: (a) enabling means for enabling said correction calculating mode after the execution of a plurality of focusing operations; and (b) a widening circuit for widening the range of identifying of the in-focus state, such that said widening circuit starts to operate when the in-focus state is identified in a particular cycle during said plurality of focusing cycles.
Claim 31
Dependent Claim
22 words
An automatic focusing device or a camera according to claim 24, wherein said widening circuit stops operation in said correction calculation mode.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-13 | 1995-07-15 | 1996-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-13 | 1999-07-15 | 2000-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-13 | 2003-07-15 | 2004-01-14 | $7700.00 | Window Closed / Lapsed |