Anti-shake apparatus

• US 20050195286A1
• Filed: 03/04/2005
• Published: 09/08/2005
• Est. Priority Date: 03/08/2004
• Status: Active Grant

• Current Assignee: PENTAX RICOH IMAGING COMPANY, LTD.
• Original Assignee: Pentax Corporation (Hoya Corporation)
• Inventors: Uenaka, Yukio, Seo, Shuzo
• Granted Patent: US 7,598,981 B2
• Time in Patent Office: Days
• US Class Current: 348/208.99
• CPC Class Codes: G03B 2205/0015 by displacing one or more optical elements normal to the optical axis
• CPC Class Codes: G03B 2205/0038 by displacing the image plane with respect to the optical axis in case of an electronic image sensor H04N23/68
• CPC Class Codes: G03B 5/02 Lateral adjustment of lens
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

An anti-shake apparatus comprises a movable-unit, a fixed-unit, a signal-processor, and a controller. The movable-unit has an imaging-device and is movable in first- and second-directions, supported by the fixed-unit. The fixed-unit has a horizontal-hall-element for detecting a first-location, and a vertical-hall-element for detecting a second-location. The signal-processor outputs a first-signal specifying the first-location, from output signals of the horizontal-hall-element, to a first A/D-converter of the controller, and outputs a second-signal specifying the second-location, from output signals of the vertical-hall-element, to a second A/D-converter of the controller. The controller calculates the first-location in an A/D-converting-operation for the first-signal, and the second-location in an A/D-converting-operation for the second-signal. An optimized-horizontal-current-value is calculated in an initial-adjustment-operation for adjusting a detecting-resolution in the A/D-converting-operation for the first-signal, by changing the current-value flowing through the horizontal-hall-element. Current having the optimized-horizontal-current-value, flows through the horizontal-hall-element when detecting the position of the movable unit.

Claims

1. An anti-shake apparatus of a photographing apparatus, comprising:

a movable unit that has one of an imaging device and a hand-shake correcting lens, and that can be moved in first and second directions, said first direction being perpendicular to an optical axis of a camera lens of said photographing apparatus, and said second direction being perpendicular to said optical axis and said first direction;

a fixed unit that slidably supports said movable unit in both said first and second directions;

a signal-processing unit; and

a control unit that controls said movable unit, said fixed unit, and said signal-processing unit, and that has first and second A/D converters;

one of said movable unit and said fixed unit having a magnetic-field change-detecting unit which has a horizontal magnetic-field change-detecting element for detecting a position of said movable unit in said first direction as a first location, and a vertical magnetic-field change-detecting element for detecting a position of said movable unit in said second direction as a second location;

another of said movable unit and said fixed unit having a position-detecting magnet which is used for detecting said first and second locations, and which faces said magnetic-field change-detecting unit;

said signal-processing unit outputting a first detected-position signal, which specifies said first location on the basis of output signals of said horizontal magnetic-field change-detecting element, to said first A/D converter, and outputting a second detected-position signal, which specifies said second location on the basis of output signals of said vertical magnetic-field change-detecting element, to said second A/D converter;

said control unit calculating said first location on the basis of an A/D converting operation by said first A/D converter, for said first detected-position signal, and calculating said second location on the basis of an A/D converting operation by said second A/D converter, for said second detected-position signal;

an optimized horizontal current-value being calculated in a first initial-adjustment operation which adjusts a first detecting-resolution when said first detected-position signal is A/D converted by said first A/D converter, by changing the value of the current which flows through the input terminals of said horizontal magnetic-field change-detecting element;

current having said optimized horizontal current-value, flowing through the input terminals of said horizontal magnetic-field change-detecting element when detecting the position of said movable unit;

an optimized vertical current-value being calculated in a second initial-adjustment operation which adjusts a second detecting-resolution when said second detected-position signal is A/D converted by said second A/D converter, by changing the value of the current which flows through the input terminals of said vertical magnetic-field change-detecting element; and

current having said optimized vertical current-value, flowing through the input terminals of said vertical magnetic-field change-detecting element when detecting the position of said movable unit.

2. The anti-shake apparatus according to claim 1, wherein said optimized horizontal current-value is the smaller value of first and second horizontal current-values;

said optimized vertical current-value is the smaller value of first and second vertical current-values;

said first horizontal current-value is the value of the current which flows through said input terminals of said horizontal magnetic-field change-detecting element, under the condition where the output value of said first detected-position signal is the same as the maximum value in the A/D converting range of said first A/D converter, when said movable unit contacts a first horizontal edge-point which is one of the edge-points in a movement range of said movable unit in said first direction;

said second horizontal current-value is the value of the current which flows through said input terminals of said horizontal magnetic-field change-detecting element, under the condition where the output value of said first detected-position signal is the same as the minimum value in the A/D converting range of said first A/D converter, when said movable unit contacts a second horizontal edge-point which is another of the edge-points in said movement range of said movable unit in said first direction;

said first vertical current-value is the value of the current which flows through said input terminals of said vertical magnetic-field change-detecting element, under the condition where the output value of said second detected-position signal is the same as the maximum value in the A/D converting range of said second A/D converter, when said movable unit contacts a first vertical edge-point which is one of the edge-points in a movement range of said movable unit in said second direction; and

said second vertical current-value is the value of the current which flows said input terminals of said vertical magnetic-field change-detecting element, under the condition where the output value of said second detected-position signal is the same as the minimum value in the A/D converting range of said second A/D converter, when said movable unit contacts a second vertical edge-point which is another of the edge-points in said movement range of said movable unit in said second direction.

3. The anti-shake apparatus according to claim 1, wherein said fixed unit has said magnetic-field change-detecting unit;

said movable unit has said position-detecting magnet; and

said magnetic-field change detecting unit has first and second horizontal magnetic-field change-detecting elements whose input terminals are connected in series, as said horizontal magnetic-field change-detecting element, and has first and second vertical magnetic-field change-detecting elements whose input terminals are connected in series, as said vertical magnetic-field change-detecting element.

4. The anti-shake apparatus according to claim 3, wherein said position-detecting magnet has a front-surface, which faces said magnetic-field change-detecting unit and which is a square having peripheral sides which are parallel to one of said first direction and said second direction;

and

said position-detecting magnet has an N pole and an S pole, which are arranged in a third direction being parallel to said optical axis.

5. The anti-shake apparatus according to claim 4, wherein when the center of one of said imaging device and said hand-shake correcting lens which is included in said movable unit, passes through said optical axis, said first horizontal magnetic-field change-detecting element is located at a place which faces midway along a side of said square front-surface, in said second direction, of said position-detecting magnet;

said second horizontal magnetic-field change-detecting element is located at a place which faces midway along another side of said square front-surface, in said second direction, of said position-detecting magnet;

said first vertical magnetic-field change-detecting element is located at a place which faces midway along a side of said square front-surface, in said first direction, of said position-detecting magnet; and

said second vertical magnetic-field change-detecting element is located at a place which faces midway along another side of said square front-surface, in said first direction, of said position-detecting magnet.

6. The anti-shake apparatus according to claim 3, wherein said magnetic-field change-detecting unit is a two-axes hall element;

and

said first and second horizontal magnetic-field change-detecting elements, and said first and second vertical magnetic-field change-detecting elements are hall elements.

7. The anti-shake apparatus according to claim 1, wherein said movable unit has said magnetic-field change-detecting unit;

said fixed unit has said position-detecting magnet;

said magnetic-field change-detecting unit has one said horizontal magnetic-field change-detecting element and one said vertical magnetic-field change-detecting element; and

said position-detecting magnet has a first position-detecting magnet which is used for detecting said first location and faces said horizontal magnetic-field change-detecting element, and a second position-detecting magnet which is used for detecting said second location and faces said vertical magnetic-field change-detecting element.

8. The anti-shake apparatus according to claim 7, wherein said movable unit has a first driving coil which is used for moving said movable unit in said first direction, and a second driving coil which is used for moving said movable unit in said second direction;

said first position-detecting magnet is used for moving said movable unit in said first direction; and

said second position-detecting magnet is used for moving said movable unit in said second direction.

9. The anti-shake apparatus according to claim 7, wherein said magnetic-field change-detecting unit is a one-axis hall element;

and

said horizontal magnetic-field change-detecting element and said vertical magnetic-field change-detecting element are hall elements.

10. The anti-shake apparatus according to claim 1, wherein said movable unit has said position-detecting magnet;

said fixed unit has said magnetic-field change-detecting unit;

said magnetic-field change-detecting unit has one said horizontal magnetic-field change-detecting element and one said vertical magnetic-field change-detecting element; and

said position-detecting magnet has a first position-detecting magnet whose N pole and S pole are arranged in said first direction and which faces said horizontal magnetic-field change-detecting element, and a second position-detecting magnet whose N pole and S pole are arranged in said second direction and which faces said vertical magnetic-field change-detecting element.

11. The anti-shake apparatus according to claim 1, further comprising a memory unit that is connected with said control unit, and stores said optimized horizontal current-value and said optimized vertical current-value;

a content which is stored in said memory unit is not deleted even if said memory unit is set to the off state.

12. The anti-shake apparatus according to claim 1, wherein when the center area of one of said imaging device and said hand-shake correcting lens which is included in said movable unit, is located on said optical axis, the location relation between said movable unit and said fixed unit is set up so that said movable unit is located at the center of its movement range in both said first direction and said second direction.

13. A method for adjusting a detecting-resolution when A/D converting in an anti-shake apparatus of a photographing apparatus according to claim 1, comprising:

calculating a first horizontal current-value;

calculating a second horizontal current-value;

calculating a first vertical current-value;

calculating a second vertical current-value; and

calculating said optimized horizontal current-value on the basis of said first and second horizontal current-values, and said optimized vertical current-value on the basis of said first and second vertical current-values;

said optimized horizontal current-value being the smaller value of said first and second horizontal current-values;

said optimized vertical current-value being the smaller value of said first and second vertical current-values;

said first horizontal current-value being the value of the current which flows through said input terminals of said horizontal magnetic-field change-detecting element, under the condition where the output value of said first detected-position signal is the same as the maximum value in the A/D converting range of said first A/D converter, when said movable unit contacts a first horizontal edge-point which is one of the edge-points in a movement range of said movable unit, in said first direction;

said second horizontal current-value being the value of the current which flows through said input terminals of said horizontal magnetic-field change-detecting element, under the condition where the output value of said first detected-position signal is the same as the minimum value in the AND converting range of said first A/D converter, when said movable unit contacts a second horizontal edge-point which is another of the edge-points in said movement range of said movable unit, in said first direction;

said first vertical current-value being the value of the current which flows through said input terminals of said vertical magnetic-field change-detecting element, under the condition where the output value of said second detected-position signal is the same as the maximum value in the A/D converting range of said second A/D converter, when said movable unit contacts a first vertical edge-point which is one of the edge-points in a movement range of said movable unit, in said second direction; and

said second vertical current-value being the value of the current which flows through said input terminals of said vertical magnetic-field change-detecting element, under the condition where the output value of said second detected-position signal is the same as the minimum value in the A/D converting range of said second A/D converter, when said movable unit contacts a second vertical edge-point which is another of the edge-points in said movement range of said movable unit in said second direction.

14. The method according to claim 13, further comprising storing said optimized horizontal current-value and said optimized vertical current-value in a memory unit of said photographing apparatus;

a content which is stored in said memory unit is not deleted even if said memory unit is set to the off state.

15. An anti-shake apparatus of a photographing apparatus, comprising:

a movable unit that has one of an imaging device and a hand-shake correcting lens, and that can be moved on a plane which is perpendicular to an optical axis of a camera lens of said photographing apparatus;

a fixed unit that supports said movable unit so as to be movable on said plane;

a signal-processing unit; and

one of said movable unit and said fixed unit having a magnetic-field change-detecting unit for detecting a position of said movable unit on said plane;

said signal-processing unit outputting a detected-position signal, which specifies said position;

a value of an optimized control-signal being calculated in an initial-adjustment operation which adjusts the value of said detected-position signal, by changing the value of the control-signal which drives said magnetic-field change-detecting unit; and

said optimized control-signal driving said magnetic-field change-detecting unit when detecting the position of said movable unit.

16. A method for adjusting a detecting-resolution when A/D converting in an anti-shake apparatus of a photographing apparatus which has a movable unit, a fixed unit, a signal-processing unit, and a control unit;

said movable unit having one of an imaging device and a hand-shake correcting lens, and being able to be moved on a plane which is perpendicular to an optical axis of a camera lens of said photographing apparatus;

said fixed unit supporting said movable unit so as to be movable on said plane;

one of said movable unit and said fixed unit having a magnetic-field change-detecting unit for detecting a position of said movable unit on said plane;

said signal-processing unit outputting a detected-position signal, which specifies said position, on the basis of output signals of said magnetic-field change-detecting unit, to an A/D converter of said control unit; and

said control unit calculating said position on the basis of an A/D converting operation by said A/D converter, for said detected-position signal, comprising;

calculating a first current-value;

calculating a second current-value; and

calculating an optimized current-value on the basis of said first and second current-values;

said optimized current-value being the smaller value of said first and second current-values;

current having said optimized current-value flowing through said magnetic-field change-detecting unit when detecting said position;

said first current-value being the value of the current which flows through said magnetic-field change-detecting unit, under the condition where the output value of said detected-position signal is the same as the maximum value in the A/D converting range of said A/D converter, when said movable unit contacts a first edge-point which is one of the edge-points in a movement range of said movable unit; and

said second current-value being the value of the current which flows through said magnetic-field change-detecting unit, under the condition where the output value of said detected-position signal is the same as the minimum value in the A/D converting range of said A/D converter, when said movable unit contacts a second edge-point which is another of the edge-points in said movement range of said movable unit.