US5113209A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for detecting photographic distance or image magnification and photographic lens to be attached thereto
Assignee: Minolta Co Ltd
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Filing: 1990-07-26
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Granted: 1992-05-12
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Expires: 2010-07-26
Abstract
Abstract A device is so constructed as to highly accurately detect the photographic distance or the image magnification data by correcting output data of a position detecting means based on the amount of difference between the basic positions of the position detecting means and a focus detecting means. A photographic lens is attached to the device for detecting the photographic distance and the image magnification, which issues data for correcting the output data of the position detecting means.
Inventors
- 👤 Masayuki Ueyama
- 👤 Kenji Tsuji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:02
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
97 words
A device for detecting photographic distance or image magnification comprising: a photographic lens including a focusing lens having movable scope on the infinity side thereof, said focusing lens being movable beyond an optical infinity position of said focusing lens to a most retracted position; a position detecting means for detecting an extension amount of said focusing lens from the most retracted position; means for correcting said extension amount; and means for issuing a signal corresponding to photographic distance or image magnification based on the corrected extension amount of said focusing lens detected by said position detecting means.
Claim 2
Independent Claim
97 words
A device for detecting photographic distance or image magnification comprising: a photographic lens including a focusing lens having movable scope on the infinity side thereof, said focusing lens being movable beyond an optical infinity position of said focusing lens to a most retracted position; a position detecting means for detecting an extension amount of said focusing lens from the most retracted position; means for correcting said extension amount; and means for issuing a signal corresponding to photographic distance or image magnification based on the corrected extension amount of said focusing lens detected by said position detecting means.
Claim 3
Dependent Claim
123 words
A device for detecting the photographic distance or the image magnification as claimed in claim 1 further comprising: focus detecting means for detecting a defocus amount representing a distance between an expected image-forming position and an actual image-forming position; and wherein the issuing means issues a signal corresponding to the photographic distance or the image magnification based on a first data A peculiar to the photographic lens and relating to the focal length thereof, a second data n output from the position detecting means and representing the extension amount of the focusing lens from the infinity basic position, and a third data DF representing the amount of difference between the infinity basic positions of the position detecting means and the focus detecting means.
Claim 4
Dependent Claim
50 words
A device for detecting the photographic distance or the image magnification as claimed in claim 2, wherein the issuing means issues a signal corresponding to the photographic distance or the image magnification further based on a fourth data representing the backlash of the position detecting means and the focusing lens.
Claim 5
Dependent Claim
62 words
A device for detecting the photographic distance or the image magnification ass claimed in claim 2, wherein the third data is obtained from the following formula: DF=DF.sub.O +ΔDF.sub.T ×ΔT wherein DF O is DF value at the normal temperature at the ∞ basic position, ΔDF T is temperature coefficient of DF, and ΔT is temperature difference with respect to the normal temperature.
Claim 6
Dependent Claim
37 words
A device for detecting the photographic distance or the image magnification as claimed in claim 4, wherein in the case of a zoom lens. ΔDF T is represented by a temperature coefficient at an arbitrary focal length.
Claim 7
Dependent Claim
34 words
A device for detecting the photographic distance or the image magnification as claimed in claim 2 wherein n is the pulse number and the correcting means issues DF data converted into the pulse number.
Claim 8
Dependent Claim
92 words
A device for detecting the photographic distance or the image magnification as claimed in claim 1, wherein the issuing means issues a signal corresponding to the photographic distance or the image magnification based on a first data A peculiar to a photographic lens and relating to the focal length thereof, a second data n issued output from the position detecting means and representing the extension amount of the focusing lens from the infinity basic position, and a third data BL representing the backlash of the position detecting means and the focusing lens.
Claim 9
Dependent Claim
30 words
A device for detecting the photographic distance or the image magnification as claimed in claim 7, wherein data BL=δ·BL, and when the focusing lens is moved in one direction, δ=0.
Claim 10
Dependent Claim
28 words
A device for detecting the photographic distance or the image magnification as claimed in claim 8 wherein when the focusing lens is moved in the other direction, δ=1.
Claim 11
Dependent Claim
50 words
A device for detecting photographic distance or image magnification as claimed in claim 1, wherein said correcting means corrects said extension amount based on the temperature, said position detecting means taking into consideration an extra value beyond an optical infinity position of said focusing lens in the most retracted position.
Claim 12
Dependent Claim
33 words
A device for detecting photographic distance or image magnification as claimed in claim 1, wherein said issuing means calculates the photographic distance or the image magnification based on the detected amount of movement.
Claim 13
Dependent Claim
53 words
A device for detecting photographic distance or image magnification as claimed in claim 1, wherein said position detecting means includes a pulse generator which outputs pulses in conjunction with the movement of said focusing lens, number of which pulses representing the amount of movement of said focusing lens from the most retracted position.
Claim 14
Independent Claim
95 words
A device for detecting distance or image magnification comprising: a photographic lens including a focusing lens, said focusing lens being movable beyond an optical infinity position of the focusing lens to a most retracted position; a position detecting means for detecting an extension distance of said focusing lens from the most retracted position; means for correcting said extension distance based on a backlash of said position detecting means and said focusing lens; and means for issuing a signal corresponding to photographic distance or image magnification based on the corrected extension distance of said focusing lens.
Claim 15
Independent Claim
95 words
A device for detecting distance or image magnification comprising: a photographic lens including a focusing lens, said focusing lens being movable beyond an optical infinity position of the focusing lens to a most retracted position; a position detecting means for detecting an extension distance of said focusing lens from the most retracted position; means for correcting said extension distance based on a backlash of said position detecting means and said focusing lens; and means for issuing a signal corresponding to photographic distance or image magnification based on the corrected extension distance of said focusing lens.
Claim 16
Dependent Claim
19 words
The device of claim 13 wherein said correcting means additionally corrects said extension distance based on a detected temperature.
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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) | 1995-05-12 | 1995-11-11 | 1996-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-12 | 1999-11-11 | 2000-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-12 | 2003-11-11 | 2004-05-12 | $7700.00 | Window Closed / Lapsed |