Image capturing apparatus

• US 20040100561A1
• Filed: 08/15/2003
• Published: 05/27/2004
• Est. Priority Date: 08/20/2002
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Chiba, Hiroyuki, Shinohara, Junichi, Hirahara, Keiichiroh, Yamaguchi, Kunihisa, Koshida, Naoki
• Granted Patent: US 7,483,056 B2
• Time in Patent Office: Days
• US Class Current: 348/208.1
• 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 or digital camera in which an image of a subject formed by lenses (L1 and L2), and a low pass filter (F), in a photographic optical system is inputted by an imaging device unit (IS), an A/D converter (11, 111 or 211) and an image processing unit (12, 112 or 212), in an imaging device, comprises the a blur detecting part (16) and a blur detecting unit (17) in a blur-detecting device (SD), a compensating unit (BU) and a blur-compensation driving unit (20, 120 or 220) in a blur compensating device, a blur-compensation controlling device or system controller (15) for computing a displaced amount for compensation in a blur compensating device from an output of the blur detecting device and driving the blur compensating device, a device or the system controller (15) and a memory group (19) for calibrating a conversion coefficient for converting the output of the blur detecting device into the displaced amount, and a device for executing a calibrating operation, or the system controller (15) to execute a mode for calibrating by the device for calibrating the conversion coefficient.

Claims

1. An image capturing apparatus comprising:

an apparatus body on which an imaging device for imaging a subject is provided;

a photographic optical system for projecting a light-flux from said subject toward said imaging device to form an image of the subject on said imaging device;

a blur detecting device for detecting an amount of a blur of said apparatus body;

a blur compensating device for compensating said blur by displacing an imaged plane and/or the image of the subject on the imaged plane;

a blur-compensation controlling unit for computing an amount of displacement for a compensation in said blur compensating device based on an output from said blur detecting device and for driving said blur compensating device;

a unit for calibrating a conversion coefficient to convert the output of the blur detecting device into the displaced amount; and

a unit for executing a calibrating operation to execute a mode for calibrating the conversion coefficient by said calibrating unit for the conversion coefficient.

2. 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, and said executing unit for the calibrating operation causes the conversion coefficient to reset and to store in the memory device when the mode for calibrating the conversion coefficient is executed.

3. The image capturing apparatus according to claim 1, wherein it 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 1, wherein it 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 1, wherein it 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 1, 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 second 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.