Imaging apparatus

• US 8,310,552 B2
• Filed: 03/11/2009
• Issued: 11/13/2012
• Est. Priority Date: 03/11/2008
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Noguchi, Masaaki
• Primary Examiner(s): Daniels, Anthony J
• Application Number:
  US12/402,243
• Publication Number:
  US 20090231452A1
• Time in Patent Office: 1,343 Days
• Field of Search: 34820899-2084, 348/208.7, 348/208.8
• US Class Current: 348/208.4
• CPC Class Codes: G03B 17/00 Details of cameras or camera bodies; Accessories therefor lens hoods or caps G03B11/04
• 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 imaging apparatus includes a correction unit, a vibration detection unit, a filter passing and outputting frequency of a predetermined band of vibration signals periodically entered from the vibration detection unit: the filter setting, as intermediate value, sum of a value based on a vibration signal of current period and a value based on a vibration signal of last period and setting, as output signal, a value obtained by adding a value based on intermediate value of the current period and a value based on intermediate value of the last period, a calculation unit calculating vibration correction amount, a driving control unit driving the correction unit by using the vibration correction amount, and an offset unit performing feedback control so that an intermediate value is shifted to predetermined value by changing the intermediate value and an offset value added to a signal based on output from the vibration detection unit.

Claims

1. A shake compensation device comprising:

a shake detection unit configured to detect shakes;

a calculation unit configured to calculate a shake compensation amount based on the shake detection result; and

a driving unit configured to compensate for the shakes by moving a compensation member based on the shake compensation amount,

wherein the calculation unit comprises;

a filter unit configured to pass a frequency of a predetermined band of shake signals periodically, wherein the filter unit comprises a delay element which has an intermediate value and that a cut-off frequency is changeable;

an intermediate value reading unit configured to read the intermediate value of the delay element in the filter unit;

an offset calculation unit configured to calculate a changing amount of an offset value based on the intermediate value, and to add an offset value to an output signal of the shake detection unit;

a cutoff frequency reading unit configured to read the cut-off frequency of the filter unit; and

an intermediate value changing unit configured to shift the intermediate value to a predetermined value, wherein the intermediate value changing unit changes the intermediate value based on the cutoff frequency from the cutoff frequency reading unit and the changing amount of the offset value when the offset calculation unit changes the offset value.

2. The device according to claim 1, wherein the offset calculation unit calculates the offset value to remove DC components included in the signal that is based on the output of the shake detection unit.

3. The device according to claim 1, wherein the predetermined value of the intermediate value is zero.

4. The device according to claim 1, wherein the changing of the intermediate value of the filter is carried out within the same period as that of the offset value.

5. The device according to claim 1, wherein the offset calculation unit stops the changing of the offset value during exposure.

6. The device according to claim 1, wherein the intermediate value changing unit adjusts a changing amount of the intermediate value when the offset value is changed according to a cutoff frequency of the filter.

7. The device according to claim 1, wherein an update period is determined based on the intermediate value of the filter or a state of the shake compensation device.

8. The device according to claim 1, wherein the changing amount of the offset value is set so that the larger the changing amount of the offset value is, the shorter an upload period of the intermediate value gets.

9. An optical apparatus including the device according to claim 1.

10. An image capturing apparatus including the device according to claim 1.