Focus control device, lens apparatus, imaging apparatus, and control method

Patent metadata

Field	Value
Publication number	US-11809017-B2
Application number	US-202017071799-A
Country	US
Kind code	B2
Filing date	Oct 15, 2020
Priority date	Oct 23, 2019
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

Abstract

A lens control unit as a control device includes a second position profile generator that generates a second target position profile indicating a target position of a second focus lens unit of a lens apparatus in driving the second focus lens unit. A trajectory shift amount calculator of the lens control unit calculates a shift between an ideal position of the second focus lens unit corresponding to a position of the first focus lens unit and a position of the second focus lens unit in the second target position profile. A correction value calculator corrects the target position of the second focus lens unit based on this shift.

First claim

What is claimed is:

1. A control device that controls a lens apparatus including a first focus lens unit and a second focus lens unit that move in trajectories different from each other in focusing, the control device comprising:
a generation unit configured to generate a second target position profile indicating a target position of the second focus lens unit in driving the second focus lens unit;
an acquisition unit configured to acquire relationship information indicating relationships between respective positions of the first focus lens unit and the second focus lens unit and an object distance;
a calculation unit configured to calculate a shift between an ideal position of the second focus lens unit and a position of the second focus lens unit in the second target position profile, the ideal position being calculated while the second focus lens unit is driven for focusing using the relationship information and corresponding to a position of the first focus lens unit;
a correction unit configured to correct the target position of the second focus lens unit based on the shift; and
a control unit configured to control the position of the second focus lens unit depending on the target position corrected by the correction unit,
wherein the control unit controls the position of the second focus lens unit with a first period,
wherein the calculation unit calculates the shift with a second period, and
wherein the second period is longer than the first period.

2. The control device according to claim 1 , wherein the generation unit generates the second target position profile based on a driving amount and a velocity of the first focus lens unit.

3. The control device according to claim 1 ,
wherein the generation unit further generates a first target position profile indicating a target position of the first focus lens unit in driving the first focus lens unit, and
wherein the calculation unit calculates the ideal position based on the first target position profile.

4. The control device according to claim 3 , wherein the calculation unit calculates a position of the second focus lens unit corresponding to the target position of the first focus lens unit, as the ideal position.

5. The control device according to claim 1 , further comprising a position detection unit that detects a position of the first focus lens unit,
wherein the calculation unit calculates the ideal position based on the position of the first focus lens unit detected by the position detection unit.

6. The control device according to claim 5 , wherein the calculation unit calculates a position of the second focus lens unit corresponding to the position of the first focus lens unit detected by the position detection unit, as the ideal position.

7. The control device according to claim 1 , wherein the correction unit divides a correction amount of the target position based on the shift to correct the target position with the first period.

8. The control device according to claim 1 , wherein, in a case where the shift is greater than a predetermined value, the correction unit sets a limit on a correction amount of the target position based on the shift.

9. The control device according to claim 1 , wherein focus sensitivity of the first focus lens unit is higher than focus sensitivity of the second focus lens unit.

10. A lens apparatus comprising:
a first focus lens unit;
a second focus lens unit; and
a controller,
wherein the controller includes
a generation unit configured to generate a second target position profile indicating a target position of the second focus lens unit in driving the second focus lens unit,
an acquisition unit configured to acquire relationship information indicating relationships between respective positions of the first focus lens unit and the second focus lens unit and an object distance,
a calculation unit configured to calculate a shift between an ideal position of the second focus lens unit and a position of the second focus lens unit in the second target position profile, the ideal position being calculated while the second focus lens unit is driven for focusing using the relationship information and corresponding to the position of the first focus lens unit,
a correction unit configured to correct the target position of the second focus lens unit based on the shift, and
a control unit configured to control the position of the second focus lens unit depending on the target position corrected by the correction unit,
wherein the control unit controls the position of the second focus lens unit with a first period,
wherein the calculation unit calculates the shift with a second period, and
wherein the second period is longer than the first period.

11. The lens apparatus according to claim 10 , wherein the generation unit generates the second target position profile based on a driving amount and a velocity of the first focus lens unit.

12. The lens apparatus according to claim 10 ,
wherein the generation unit further generates a first target position profile indicating a target position of the first focus lens unit in driving the first focus lens unit, and
wherein the calculation unit calculates the ideal position based on the first target position profile.

13. The lens apparatus according to claim 10 , wherein the controller further includes a position detection unit that detects a position of the first focus lens unit,
wherein the calculation unit calculates the ideal position based on the position of the first focus lens unit detected by the position detection unit.

14. An imaging apparatus comprising:
an image sensor; and
a controller that controls an optical system including a first focus lens unit and a second focus lens unit that move in trajectories different from each other in focusing,
wherein the controller includes
a generation unit configured to generate a second target position profile indicating a target position of the second focus lens unit in driving the second focus lens unit,
an acquisition unit configured to acquire relationship information indicating relationships between respective positions of the first focus lens unit and the second focus lens unit and an object distance,
a calculation unit configured to calculate a shift between an ideal position of the second focus lens unit and a position of the second focus lens unit in the second target position profile, the ideal position being calculated while the second focus lens unit is driven for focusing using the relationship information and corresponding to the position of the first focus lens unit,
a correction unit configured to correct the target position of the second focus lens unit based on the shift, and
a control unit configured to control the position of the second focus lens unit depending on the target position corrected by the correction unit,
wherein the control unit controls the position of the second focus lens unit with a first period,
wherein the calculation unit calculates the shift with a second period, and
wherein the second period is longer than the first period.

15. The imaging apparatus according to claim 14 , wherein the generation unit generates the second target position profile based on a driving amount and a velocity of the first focus lens unit.

16. The imaging apparatus according to claim 14 ,
wherein the generation unit further generates a first target position profile indicating a target position of the first focus lens unit in driving the first focus lens unit, and
wherein the calculation unit calculates the ideal position based on the first target positio

Assignees

• Canon Kk

Inventors

• Maruyama Satoshi

Classifications

• G02B7/282 Primary

  Autofocusing of zoom lenses · CPC title

• G02B7/08

  adapted to co-operate with a remote control mechanism · CPC title

• G03B3/10

  Power-operated focusing · CPC title

• G02B7/102 Primary

  controlled by a microcomputer (cameras with interchangeable lenses G03B17/14) · CPC title

• G03B13/36

  Autofocus systems · CPC title