Claims
- 1. A focus correcting apparatus for an auto focus camera having non-TTL type distance measuring means, characterized by:
- a photo-taking lens of a focusing type other than a total lens movement focusing type;
- first memory means for memorizing an amount of deviation of an imaging point from the surface of film caused by irregularity during lens assembly or irregularity of the dimensions of lens parts or the refractive indices of lens materials;
- calculating means for calculating an amount of correction movement of a focusing lens group from the memorized amount in said first memory means and an amount of movement of the imaging point per unit amount of movement of the focusing lens group; and
- lens driving means for driving the focusing lens group on the basis of the final amount of movement consisting of an amount of movement of the focusing lens group calculated from a measured distance value obtained by said non-TTL type distance measuring means, plus the amount of correction movement of the focusing lens group found by said calculation.
- 2. A focus correcting apparatus for an auto focus camera according to claim 1, further having second memory means for memorizing the amount of movement of the imaging point relative to the unit amount of movement of the focusing lens group.
- 3. A focus correcting apparatus for an auto focus camera according to claim 2, wherein said auto focus camera is provided with a multifocus lens as a photo-taking lens, said second memory means memorizes the amount of movement of the imaging point per unit amount of movement of the focusing lens group in a plurality of focal length states, and said first memory means memorizes the amount of deviation of the imaging point from the surface of film in a plurality of focal length states as represented by a single value.
- 4. A focus correcting apparatus for an auto focus camera according to claim 2, wherein said auto focus camera is provided with a zoom lens as a photo-taking lens, said second memory means memorizes the amount of movement of the imaging point per unit amount of movement of the focusing lens group in a plurality of focal length states, and said first memory means memorizes the amount of deviation of the imaging point from the surface of film in a plurality of focal length states as represented by a single value.
- 5. A focus correcting apparatus for an auto focus camera according to claim 1, wherein said auto focus camera is provided with a zoom lens as a photo-taking lens, the amount of movement of the imaging point per unit amount of movement of the focusing lens group is found from the focal length of the zoom lens by calculation, and said first memory means memorizes the amount of deviation of the imaging point from the surface of film in a plurality of focal length states as represented by a single value.
- 6. A focus correcting apparatus according to claim 5, wherein said zoom lens has a focusing lens group most adjacent to the object side, said apparatus has detecting means for detecting the focal length of the zoom lens, and when the focal length of said focusing lens group is f.sub.F and the focal length detected by said detecting means is f, the amount of movement .delta. of the imaging point per unit amount of movement of the focusing lens group is found by a calculation expressed by .delta.=(f/f.sub.F).sup.2.
- 7. A focus correcting apparatus according to claim 5, wherein the zoom lens has a focusing rear lens group most adjacent to the image side and a front lens group on the object side of said focusing rear lens group, said apparatus has detecting means for detecting the focal length of the zoom lens, and when the focal length of said front lens group is f.sub.A and the focal length detected by said detecting means is f, the amount of movement .delta. of the imaging point per unit amount of movement of the focusing rear lens group is found by a calculation expressed by .delta.=1-(f/f.sub.A).sup.2.
- 8. A focus correcting apparatus according to claim 7, wherein the focal length f.sub.A of said front lens group is found from the focal length f of the zoom lens detected by said detecting means.
- 9. A focus correcting apparatus according to claim 5, wherein the zoom lens has a focusing lens group, a front lens group on the object side of said focusing lens group, and a rear lens group on the image side of said focusing lens group, said apparatus has detecting means for detecting the focal length of the zoom lens, and when the focal length of said front lens group is f.sub.A and the imaging magnification of said rear lens group is .beta..sub.B and the focal length detected by said detecting means is f, the amount of movement .delta. of the imaging point per unit amount of movement of the focusing lens group is found by a calculation expressed by .delta.=.beta..sub.B.sup.2 -(f/f.sub.A).sup.2.
- 10. A focus correcting apparatus according to claim 9, wherein the focal length f.sub.A of said front lens group is found from the focal length f of the zoom lens detected by said detecting means.
- 11. A focus correcting apparatus according to claim 9, wherein the imaging magnification .beta..sub.B of said rear lens group is found from the focal length f of the zoom lens detected by said detecting means.
- 12. A focus correcting apparatus according to claim 9, wherein the focal length f.sub.A of said front lens group and the imaging magnification .beta..sub.B of said rear lens group are found from the focal length f of the zoom lens detected by said detecting means.
- 13. A focus correcting apparatus for an auto focus camera having a non-TTL type distance measuring device, characterized by:
- a photo-taking lens of a focusing type other than a total lens movement focusing type;
- a first memory for memorizing an amount of deviation of an imaging point from the surface of film caused by irregularity during lens assembly or irregularity of the dimensions of lens parts or the refractive indices of lens materials;
- a calculator for calculating an amount of correction movement of a focusing lens group from the memorized amount in said first memory and an amount of movement of the imaging point per unit amount of movement of the focusing lens group; and
- a lens driver for driving the focusing lens group on the basis of the final amount of movement consisting of an amount of movement of the focusing lens group calculated from a measured distance value obtained by said non-TTL type distance measuring device, plus the amount of correction movement of the focusing lens group found by said calculation.
- 14. A focus correcting apparatus for an auto focus camera according to claim 13, further having a second memory for memorizing the amount of movement of the imaging point relative to the unit amount of movement of the focusing lens group.
- 15. A focus correcting apparatus for an auto focus camera according to claim 14, wherein said auto focus camera is provided with a multifocus lens as a photo-taking lens, said second memory memorizes the amount of movement of the imaging point per unit amount of movement of the focusing lens group in a plurality of focal length states, and said first memory memorizes the amount of deviation of the imaging point from the surface of film in a plurality of focal length states as represented by a single value.
- 16. A focus correcting apparatus for an auto focus camera according to claim 14, wherein said auto focus camera is provided with a zoom lens as a photo-taking lens, said second memory memorizes the amount of movement of the imaging point per unit amount of movement of the focusing lens group in a plurality of focal length states, and said first memory memorizes the amount of deviation of the imaging point from the surface of film in a plurality of focal length states as represented by a single value.
- 17. A focus correcting apparatus for an auto focus camera according to claim 13, wherein said auto focus camera is provided with a zoom lens as a photo-taking lens, the amount of movement of the imaging point per unit amount of movement of the focusing lens group is found from the focal length of the zoom lens by calculation, and said first memory memorizes the amount of deviation of the imaging point from the surface of film in a plurality of focal length states as represented by a single value.
- 18. A focus correcting apparatus according to claim 17, wherein said zoom lens has a focusing lens group most adjacent to the object side, said apparatus has a detector for detecting the focal length of the zoom lens, and when the focal length of said focusing lens group is f.sub.F and the focal length detected by said detector is f, the amount of movement .delta. of the imaging point per unit amount of movement of the focusing lens group is found by a calculation expressed by .delta.=(f/f.sub.F).sup.2.
- 19. A focus correcting apparatus according to claim 17, wherein the zoom lens has a focusing rear lens group most adjacent to the image side and a front lens group on the object side of said focusing rear lens group, said apparatus has a detector for detecting the focal length of the zoom lens, and when the focal length of said front lens group is f.sub.A and the focal length detected by said detector is f, the amount of movement .delta. of the imaging point per unit amount of movement of the focusing rear lens group is found by a calculation expressed by .delta.=1-(f/f.sub.A).sup.2.
- 20. A focus correcting apparatus according to claim 19, wherein the focal length f.sub.A of said front lens group is found from the focal length f of the zoom lens detected by said detector.
- 21. A focus correcting apparatus according to claim 17, wherein the zoom lens has a focusing lens group, a front lens group on the object side of said focusing lens group, and a rear lens group on the image side of said focusing lens group, said apparatus has a detector for detecting the focal length of the zoom lens, and when the focal length of said front lens group is f.sub.A and the imaging magnification of said rear lens group is .beta..sub.B and the focal length detected by said detector is f, the amount of movement .delta. of the imaging point per unit amount of movement of the focusing lens group is found by a calculation expressed by .delta.=.beta..sub.B.sup.2 -(f/f.sub.A).sup.2.
- 22. A focus correcting apparatus according to claim 21, wherein the focal length f.sub.A of said front lens group is found from the focal length f of the zoom lens detected by said detector.
- 23. A focus correcting apparatus according to claim 21, wherein the imaging magnification .beta..sub.B of said rear lens group is found from the focal length f of the zoom lens detected by said detector.
- 24. A focus correcting apparatus according to claim 21, wherein the focal length f.sub.A of said front lens group and the imaging magnification .beta..sub.B of said rear lens group are found from the focal length f of the zoom lens detected by said detector.
- 25. A method for performing a focus correction of an auto focus camera having a non-TTL type distance measuring device and using a photo-taking lens of a focusing type other than a total lens movement focusing type, comprising the steps of:
- memorizing an amount of deviation of an imaging point from the surface of film caused by irregularity during lens assembly or irregularity of the dimensions of lens parts or the refractive indices of lens materials;
- calculating an amount of correction movement of a focusing lens group from the memorized amount and an amount of movement of the imaging point per unit amount of movement of the focusing lens group; and
- driving the focusing lens group on the basis of a final amount of movement consisting of the amount of movement of the focusing lens group calculated from a measured distance value obtained by said non-TTL type distance measuring device, plus the amount of correction movement of the focusing lens group found by said calculation.
- 26. A method according to claim 25, further comprising a step of memorizing the amount of movement of the imaging point relative to the unit amount of movement of the focusing lens group.
Priority Claims (1)
Number |
Date |
Country |
Kind |
4-013623 |
Jan 1992 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 08/008,283 filed Jan. 25, 1993, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (3)
Number |
Date |
Country |
1-201633 |
Jan 1989 |
JPX |
3-98004 |
Mar 1991 |
JPX |
3-141310 |
Mar 1991 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
8283 |
Jan 1993 |
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