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US4860045A Expired / Lapsed US ⏱️ 0.0 years remaining

Automatic focusing device

Assignee: Minolta Co Ltd
•
Filing: 1987-08-10
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Granted: 1989-08-22
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Expires: 2007-08-10
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Abstract

Abstract An automatic focusing device for a camera is disclosed. The automatic focusing device has focus detection means for detecting defocus amount of the image, object movement detection means for detecting movement of the object based on defocus data detected by the focus detection means and correction means for correcting the detected defocus amount according to the detected movement of the object. The objective lens of the camera is driven according to the corrected defocus amount for focus adjustment.

Inventors

  • 👤 Masataka Hamada
  • 👤 Tokuji Ishida

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 20:52
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 153 words
An automatic focusing device for a camera having an objective lens for forming an image of an object, comprising: focus detection means for repeatedly detecting a defocus amount of the image formed by an optical lens to generate a defocus signal corresponding to the detected defocus amount upon each detecting operation; object movement detection means for detecting movement of the object based on the defocus signals generated by the focus detection means to generate a movement signal corresponding to the movement of the object; drive means for driving the objective lens for focus adjustment; corrected defocus signal generating means for generating a corrected defocus signal based on the movement signal; drive control means for causing the drive means to drive the objective lens in accordance with the corrected defocus signal; and inhibition means for inhibiting the generation of the corrected defocus signal by the corrected defocus signal generating means under a predetermined condition.
Claim 2
Dependent Claim 153 words
An automatic focusing device for a camera having an objective lens for forming an image of an object, comprising: focus detection means for repeatedly detecting a defocus amount of the image formed by an optical lens to generate a defocus signal corresponding to the detected defocus amount upon each detecting operation; object movement detection means for detecting movement of the object based on the defocus signals generated by the focus detection means to generate a movement signal corresponding to the movement of the object; drive means for driving the objective lens for focus adjustment; corrected defocus signal generating means for generating a corrected defocus signal based on the movement signal; drive control means for causing the drive means to drive the objective lens in accordance with the corrected defocus signal; and inhibition means for inhibiting the generation of the corrected defocus signal by the corrected defocus signal generating means under a predetermined condition.
Claim 3
Dependent Claim 40 words
An automatic focusing device as defined in claim 1, wherein the generation of the corrected defocus signal is inhibited by the inhibition means when the amount of defocus detected by the focus detecting means is larger than a predetermined value.
Claim 4
Dependent Claim 34 words
An automatic focusing device as defined in claim 1, wherein the generation of the corrected defocus signal is inhibited by the inhibition means when the brightness of the object is below a predetermined level.
Claim 5
Dependent Claim 155 words
An automatic focusing device for a camera having an objective lens for forming an image of an object, comprising: focus detection means for repeatedly detecting a defocus amount of the image formed by an optical lens to generate a defocus signal corresponding to the amount and the direction of the detected defocus upon each detecting operation; object movement detection means for detecting movement of the object based on the defocus signals generated upon repeated detecting operation of the focus detection means to generate a movement signal when the direction of the defocus represented by the defocus signals remains unchanged and the amount of defocus represented by the defocus signal is increasing correction means for generating a corrected defocus signal based on the movement signal; drive means for driving the objective lens for focus adjustment; and drive control means for causing the driven means to drive the objective lens in accordance with the corrected defocus signal.
Claim 6
Dependent Claim 155 words
An automatic focusing device for a camera having an objective lens for forming an image of an object, comprising: focus detection means for repeatedly detecting a defocus amount of the image formed by an optical lens to generate a defocus signal corresponding to the amount and the direction of the detected defocus upon each detecting operation; object movement detection means for detecting movement of the object based on the defocus signals generated upon repeated detecting operation of the focus detection means to generate a movement signal when the direction of the defocus represented by the defocus signals remains unchanged and the amount of defocus represented by the defocus signal is increasing correction means for generating a corrected defocus signal based on the movement signal; drive means for driving the objective lens for focus adjustment; and drive control means for causing the driven means to drive the objective lens in accordance with the corrected defocus signal.

References Cited (Backward Citations)

US4218119A Cited
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JPS60214325A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-08-21 1993-02-20 1993-08-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-08-21 1997-02-20 1997-08-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-08-21 2001-02-20 2001-08-22 $7700.00 Window Closed / Lapsed

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