US4870439A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focal length varying device for camera
Assignee: Canon Inc
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Filing: 1989-01-13
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Granted: 1989-09-26
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Expires: 2009-01-13
Abstract
Abstract A focal length varying device for a camera comprises a photo taking optical system having a variable focal length; a discriminating device for discriminating whether or not adequate photographing is possible; and a system for automatically changing the focal length of the photo taking optical system on the basis of the result of discrimination made by the discriminating device.
Inventors
- 👤 Takayuki Tsuboi
- 👤 Isao Nakazawa
- 👤 Hiroshi Maeno
- 👤 Yasuhiko Shiomi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:02
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/02; G02B7/04; G02B7/10
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
100 words
A camera comprising: (A) focal length changing means for changing a focal length of a photo-taking optical system; (B) first discriminating means for discriminating whether or not an object distance is in a predetermined range; (C) second discriminating means for discriminating whether or not an object brightness is in a predetermined range; and (D) control means for causing said focal length changing means to change the focal length to a shorter focal length in response to the discrimination of one of said first and said second discriminating means that the object distance or brightness is not in the predetermined range.
Claim 2
Dependent Claim
100 words
A camera comprising: (A) focal length changing means for changing a focal length of a photo-taking optical system; (B) first discriminating means for discriminating whether or not an object distance is in a predetermined range; (C) second discriminating means for discriminating whether or not an object brightness is in a predetermined range; and (D) control means for causing said focal length changing means to change the focal length to a shorter focal length in response to the discrimination of one of said first and said second discriminating means that the object distance or brightness is not in the predetermined range.
Claim 3
Dependent Claim
25 words
A camera according to claim 1, wherein said control means includes an OR gate which receives the outputs of said first and second discriminating means.
Claim 4
Dependent Claim
103 words
A focal length changing device for a camera, comprising: focal length changing means for changing a focal length of an optical system of said camera; first discriminating means for discriminating whether or not an object distance is in a predetermined range; second discriminating means for discriminating whether or not object brightness is in a predetermined range; and control means for causing said focal length changing means to change the focal length to a shorter focal length in response to the discrimination of one of said first and said second discriminating means that the object distance or brightness is not in the predetermined range.
Claim 5
Dependent Claim
103 words
A focal length changing device for a camera, comprising: focal length changing means for changing a focal length of an optical system of said camera; first discriminating means for discriminating whether or not an object distance is in a predetermined range; second discriminating means for discriminating whether or not object brightness is in a predetermined range; and control means for causing said focal length changing means to change the focal length to a shorter focal length in response to the discrimination of one of said first and said second discriminating means that the object distance or brightness is not in the predetermined range.
Claim 6
Dependent Claim
25 words
A device according to claim 3, wherein said control means includes an OR gate which receives the outputs of said first and second discriminating means.
Claim 7
Dependent Claim
71 words
A camera comprising: focal length changing means for changing a focal length of an optical device; discriminating means for discriminating whether an object distance is within a predetermined range; control means for causing said focal length changing means to change the focal length without detecting a depth of focus of the optical device in response to the discrimination of said discriminating means that the object distance is within the predetermined range.
Claim 8
Dependent Claim
71 words
A camera comprising: focal length changing means for changing a focal length of an optical device; discriminating means for discriminating whether an object distance is within a predetermined range; control means for causing said focal length changing means to change the focal length without detecting a depth of focus of the optical device in response to the discrimination of said discriminating means that the object distance is within the predetermined range.
Claim 9
Dependent Claim
74 words
A focal length changing device comprising: focal length changing means for changing a focal length of an optical device; discriminating means for discriminating whether an object distance is within a predetermined range; control means for causing said focal length changing means to change the focal length without detecting a depth of focus of the optical device in response to the discrimination of said discriminating means that the object distance is within the predetermined range.
Claim 10
Dependent Claim
74 words
A focal length changing device comprising: focal length changing means for changing a focal length of an optical device; discriminating means for discriminating whether an object distance is within a predetermined range; control means for causing said focal length changing means to change the focal length without detecting a depth of focus of the optical device in response to the discrimination of said discriminating means that the object distance is within the predetermined range.
Claim 11
Dependent Claim
23 words
A device according to claim 6 wherein said discriminating means includes means for setting said predetermined range to a predetermined short distance range.
Claim 12
Dependent Claim
46 words
A device according to claim 6 wherein said control means includes means for causing said focal length changing means to change the focal length to a shorter focal length in response to discrimination of said discriminating means that the object distance is within the predetermined range.
Claim 13
Dependent Claim
66 words
A device according to claim 6 further comprising second discriminating means for discriminating whether an object brightness is within a predetermined range, and wherein said control means causes said focal length changing means to change the focal length in response to the discrimination of one of said discriminating means and said second discriminating means that the object distance or brightness is within the respective predetermined range.
Claim 14
Dependent Claim
23 words
A device according to claim 9 wherein said discriminating means includes means for setting said predetermined range to a predetermined short distance range.
Claim 15
Dependent Claim
24 words
A device according to claim 10, wherein said second discriminating means includes means for setting said predetermined range to a predetermined low brightness range.
Claim 16
Dependent Claim
71 words
A device according to claim 6, further comprising second discriminating means for discriminating whether an object brightness is within a predetemriend range, and wherein said control means causes said focal length changing means to change the focal length to a shorter focal length in response to the discrimination of one of said discriminating means and said second discriminating means that the object distance or brightness is within the respective predetermined range.
Claim 17
Dependent Claim
23 words
A camera according to claim 6 wherein said discriminating means includes means for setting said predetermined range to a predetermined short distance range.
Claim 18
Dependent Claim
46 words
A camera according to claim 6 wherein said control means includes means for causing said focal length changing means to change the focal length to a shorter focal length in response to discrimination of said discriminating means that the object distance is within the predetermined range.
Claim 19
Dependent Claim
66 words
A camera according to claim 6 further comprising second discriminating means for discriminating whether an object brightness is within a predetermined range, and wherein said control means causes said focal length changing means to change the focal length in response to the discrimination of one of said discriminating means and said second discriminating means that the object distance or brightness is within the respective predetermined range.
Claim 20
Dependent Claim
23 words
A camera according to claim 9 wherein said discriminating means includes means for setting said predetermined range to a predeterminrd short distance range.
Claim 21
Dependent Claim
24 words
A camera according to claim 10, wherein said second discriminating means includes means for setting said predetermined range to a predetermined low brightness range.
Claim 22
Dependent Claim
71 words
A camera according to claim 6, further comprising second discriminating means for discriminating whether an object brightness is within a predetermined range, and wherein said control means causes said focal length changing means to change the focal length to a shorter focal length in response to the discrimination of one of said discriminating means and said second discriminating means that the object distance of brightness is within the respective predetermined range.
Claim 23
Dependent Claim
75 words
A focal length changing device comprising: focal length changing means for changing a focal length of an optical device; discriminating means for discriminating whether an object brightness is within a predetermined range; and control means for causing said focal length changing means to change the focal length without detecting a depth of focus of the optical device in response to the discrimination of said discriminating means that the object brightness is within the predetermined range.
Claim 24
Dependent Claim
75 words
A focal length changing device comprising: focal length changing means for changing a focal length of an optical device; discriminating means for discriminating whether an object brightness is within a predetermined range; and control means for causing said focal length changing means to change the focal length without detecting a depth of focus of the optical device in response to the discrimination of said discriminating means that the object brightness is within the predetermined range.
Claim 25
Dependent Claim
22 words
A device according to claim 19, wherein said discriminating means includes means for setting said predetermined range to a predetermined brightness range.
Claim 26
Dependent Claim
46 words
A device according to claim 19, wherein said control means includes means for causing said focal length changing means to change the focal length to a shorter focal length in response to discrimination of said discriminating means that the object brightness is within the predetermined range.
Claim 27
Dependent Claim
22 words
A camera according to claim 19, wherein said discriminating means includes means for setting said predetermined range to a predetermined brightness range.
Claim 28
Dependent Claim
46 words
A camera according to claim 19, wherein said control means includes means for causing said focal length changing means to change the focal length to a shorter focal length in response to discrimination of said discriminating means that the object brightness is within the predetermined range.
Claim 29
Dependent Claim
72 words
A camera comprising: focal length changing means for changing a focal length of an optical device; discriminating means for discriminating whether an object brightness is within a predetermined range; and control means for causing said focal length changing means to change the focal length without detecting a depth of focus of the optical device in response to the discrimination of said discriminating means that the object brightness is within the predetermined range.
Claim 30
Dependent Claim
72 words
A camera comprising: focal length changing means for changing a focal length of an optical device; discriminating means for discriminating whether an object brightness is within a predetermined range; and control means for causing said focal length changing means to change the focal length without detecting a depth of focus of the optical device in response to the discrimination of said discriminating means that the object brightness is within the predetermined range.
References Cited (Backward Citations)
US4290679A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |