Image capturing apparatus with blur compensation

• US 7,483,056 B2
• Filed: 08/15/2003
• Issued: 01/27/2009
• Est. Priority Date: 08/20/2002
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Shinohara, Junichi, Hirahara, Keiichiroh, Chiba, Hiroyuki, Yamaguchi, Kunihisa, Koshida, Naoki
• Primary Examiner(s): Misleh; Justin P
• Application Number:
  US10/641,050
• Publication Number:
  US 20040100561A1
• Time in Patent Office: 1,992 Days
• Field of Search: 348/208.99, 3482081-2084, 348/208.5, 3482087-20811
• US Class Current: 348/208.7
• CPC Class Codes: H04N 23/634 Warning indications
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/81 for suppressing or minimising disturbance in the image signal generation

Abstract

An image capturing apparatus in which an image of a subject formed by lenses and a low pass filter of a photographic optical system is provided to an imaging device unit that supplies a corresponding signal to an A/D converter that in turn provides an output to an image processing unit. A blur-detecting device with a blur detecting part and a blur detecting unit detect blur that is compensated by a blur compensating unit with a blur-compensation driving unit. A system controller computes a displacement amount for blur compensation by the blur-compensation driving unit driving the blur compensating unit based on an output of the blur detecting device. A memory group is included for calibrating a conversion coefficient used by the system controller in calculating the displacement amount.

Claims

1. An image capturing apparatus comprising:

an apparatus body provided with an imaging device unit including an imaged plane on which an image of a subject is provided;

the imaging device unit including the imaged plane being configured to be capable of being displaced,

a photographic optical system that projects a light-flux from said subject toward said imaging device to form an image of the subject on the imaged plane of said imaging device unit;

a blur detecting device that detects an amount of a blur produced by said apparatus body;

a blur compensating device that compensates for said blur produced by the apparatus body by displacing the imaging device unit including the imaged plane; and

a system controller to control the blur compensating device based on the amount of blur detected by the blur detecting device,

wherein the system controller includes a blur compensation controlling unit that computes an amount of displacement with which the blur compensating device drives the imaging device unit including the imaged plane and is configured to control displacement of the imaging device unit including the imaged plane by the blur compensating device based on the computed amount of the displacement,

wherein the system controller includes a calibrating unit which calibrates a conversion coefficient which is used to convert an output of the blur detecting device into the amount of displacement, and an executing unit that executes a calibrating operation to execute a calibration mode for calibrating the conversion coefficient.

2. The image capturing apparatus according to claim 1, wherein said calibrating unit for the conversion coefficient has a memory device that stores the conversion coefficient, and said executing unit for the calibrating operation causes the conversion coefficient to reset and to store in the memory device when a mode for calibrating the conversion coefficient is executed.

3. The image capturing apparatus according to claim 1, wherein the image capturing apparatus further comprises a unit for judging an execution of the calibrating operation which judges that the mode for calibrating the conversion coefficient should be executed, if a predetermined condition is satisfied.

4. The image capturing apparatus according to claim 3, wherein the image capturing apparatus further comprises a temperature detecting device, and if a temperature out of a predetermined range is detected by the temperature detecting device, said judging unit for execution judges that the mode for calibrating the conversion coefficient should be executed.

5. The image capturing apparatus according to claim 3, wherein the image capturing apparatus further comprises a unit for counting a blur-compensation operation, and when more than a predetermined number or a predetermined operating time is counted by the counting unit, said judging unit judges that the mode for calibrating the conversion coefficient should be executed.

6. The image capturing apparatus according to claim 1, wherein said calibrating unit for the conversion coefficient includes a memory device for storing the conversion coefficient, a unit for generating a provisional conversion coefficient which generates a plurality of provisional conversion coefficients from the conversion coefficient stored in the memory device and a unit for generating a blur evaluating value which generates an evaluating value corresponding to a blur degree, and wherein

said calibrating unit for the conversion coefficient generates a blur evaluating value in each time by said unit for generating the blur evaluating value with respect to a plurality of photographed images obtained by photographs of blur-compensation in plural times by use of the plurality of provisional conversion coefficients generated by the generating unit for the provisional conversion coefficient, and an optimum conversion coefficient is determined based on the provisional conversion coefficients and blur evaluating value.

7. The image capturing apparatus according to claim 6, wherein said generating unit for the provisional conversion coefficient generates a plurality of provisional conversion coefficients by use of more than one of some information such as a temperature, a blur-compensation operating number and a blur-compensation operating time.

8. The image capturing apparatus according to claim 1, wherein said calibrating unit for the conversion coefficient has a memory device for storing the conversion coefficient, said photographic optical system has a variable focal length, said memory device stores a plurality of conversion coefficients according to a plurality of focal lengths, and said calibrating unit for the conversion coefficient carries out a calibration of the conversion coefficient with respect to one particulate or any focal length and computes a conversion coefficient in the focal length based on one optimum conversion coefficient obtained by the calibrated operation to store the computed conversion coefficient into the memory device.

9. The image capturing apparatus according to claim 1, wherein said calibrating unit for the conversion coefficient has a memory device for storing an initiate conversion coefficient or a prior conversion coefficient and a memory device for storing a present conversion coefficient, the present conversion coefficient is replaced by the initiate or prior conversion coefficient.

10. The image capturing apparatus according to claim 1, wherein said blur compensating device employs a laminated type piezoelectric element as a drive source.