Claims
- 1. An automatic focus adjustment apparatus, comprising:
- having a focusing state detector having a charge accumulating type sensor;
- a calculator that processes output data from said focusing state detector to calculate a defocus amount from a focusing position; and
- a driver that drives a shooting lens to a said focusing position in accordance with a movement prediction curve based on said the defocus amount calculated by said calculator, wherein said driver determines said movement prediction curve by a regression calculation, said regression calculation estimates said focusing position by a movement function Qr(t) of an image plane based on a plurality of past data detected during a predetermined time, said movement function Qr(t) is defined by an equation
- Qr(t)=.alpha.+.beta.t where
- .beta.={.SIGMA.t(k).cndot.F(k)-nt.sub.ave .cndot.F.sub.ave }/{.SIGMA.t(k).sup.2)-nt.sub.ave.sup.2 } and
- .alpha.={.SIGMA.D(k)-.beta..cndot.n.cndot.t.sub.ave }/n, t(k)
- being an accumulated time of a sensor, F(k) being a focusing point, t.sub.ave being an average time of said accumulated time of said sensor and F.sub.ave being an average position of said focusing point.
- 2. The apparatus according to claim 1, further comprising a controller that simultaneously controls the overlapping accumulation of charge in the charge accumulating type sensor while driving the shooting lens.
- 3. The apparatus according to claim 2, wherein said driver determines a movement prediction curve of the image plane by detecting an image plane acceleration from changes of the image plane speed, determined by each regression calculation, to predict future positions of the image plane.
- 4. The apparatus according to claim 3, wherein said driver determines the movement prediction curve for said image plane so the curve passes through the image plane at a most recent accumulation time and a predicted point of the image plane at a next accumulation time.
- 5. A method for automatic focusing, comprising:
- detecting a focusing state using a charge accumulating type sensor;
- processing output data detected from said focusing state to calculate a defocus amount from a focusing position; and
- driving a shooting lens to said focusing position in accordance with a movement prediction curve based on said calculated defocus amount wherein driving said shooting lens determines said movement prediction curve by a regression calculation, said regression calculation estimates said focusing position by a movement function Qr(t) of an image plane based on a plurality of past data detected during a predetermined time, said movement function Qr(t) is defined by an equation
- Qr(t)=.alpha.+.beta.t
- where
- .beta.={.SIGMA.t(k).cndot.F(k)-nt.sub.ave .cndot.F.sub.ave }/{.SIGMA.t(k).sup.2 -nt.sub.ave.sup.2 } and
- .alpha.={.SIGMA.D(k)-.beta..cndot.n.cndot.t.sub.ave }/n, t(k)
- being an accumulated time of a sensor, F(k)being a focusing point, t.sub.ave being an average time of said accumulated time of said sensor and F.sub.ave being an average position of said focusing point.
- 6. The method according to claim 5 further comprising overlapping the accumulation of charge in the charge accumulating type sensor while simultaneously driving the shooting lens.
- 7. The method according to claim 5, further comprising determining a movement prediction curve of the image plane by detecting an image plane acceleration from changes of image plane speed, determined by each regression calculation, to predict future positions of the image plane.
- 8. The method according to claim 7, further comprising determining the movement prediction curve for said image plane so that the curve passes through the image plane at a most recent accumulation time and a predicted point of the image plane at a next accumulation time.
Priority Claims (1)
Number |
Date |
Country |
Kind |
7-223946 |
Aug 1995 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 08/704,245 filed Aug. 28, 1996 now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
5502537 |
Utagawa |
Mar 1996 |
|
5587762 |
Watanabe |
Dec 1996 |
|
Foreign Referenced Citations (7)
Number |
Date |
Country |
58-142306 |
Aug 1983 |
JPX |
59-107313 |
Jun 1984 |
JPX |
1-107224 |
Apr 1989 |
JPX |
2-256677 |
Oct 1990 |
JPX |
3-80235 |
Apr 1991 |
JPX |
4-133016 |
May 1992 |
JPX |
5-2127 |
Jan 1993 |
JPX |
Non-Patent Literature Citations (2)
Entry |
Abstract of JP-A-63-31733, Feb. 1994, Japan. |
Abstract of JP-A-1-288815, Nov. 1989, Japan. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
704245 |
Aug 1996 |
|