Electronic imaging apparatus with anti-dust function

• US 7,492,408 B2
• Filed: 05/15/2003
• Issued: 02/17/2009
• Est. Priority Date: 05/17/2002
• Status: Expired due to Fees

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Ito, Junichi
• Primary Examiner(s): Ye; Lin
• Assistant Examiner(s): WHIPKEY, JASON T
• Application Number:
  US10/438,756
• Publication Number:
  US 20040047625A1
• Time in Patent Office: 2,105 Days
• Field of Search: 396/529, 396/533, 348/335, 348/340, 359/507, 359/508
• US Class Current: 348/335
• CPC Class Codes: G03B 17/48 adapted for combination with other photographic or optical apparatus
• CPC Class Codes: G03B 19/12 Reflex cameras with single objective and a movable reflector or a partly-transmitting mirror
• CPC Class Codes: H04N 23/52 Elements optimising image sensor operation, e.g. for electromagnetic interference [EMI] protection or temperature control by heat transfer or cooling elements
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• CPC Class Codes: H04N 23/81 for suppressing or minimising disturbance in the image signal generation

Abstract

An electronic imaging apparatus includes an imaging optical system which forms an optical image of an object. A photoelectric conversion element converts the optical image into an electric signal. The optical element is arranged between the imaging optical system and the photoelectric conversion element. An excitation unit vibrates the optical element at a set frequency, and vibrates the optical element at least in in accordance with the mounting of an accessory device.

Claims

1. An electronic imaging apparatus having imaging means for converting an optical image of an object into an electric signal, comprising:

an accessory device which can be attached/detached to the electronic imaging apparatus;

an optical element arranged on a front surface of the imaging means;

exciting means for vibrating the optical element; and

drive controlling means for driving the exciting means by supplying a frequency signal to the exciting means,

wherein the drive controlling means has a resonance frequency detecting mode to drive the exciting means in order to detect a resonance frequency of the optical element and a dust removing mode to drive the exciting means in order to remove dust which has adhered to the optical element, and

the electronic imaging apparatus controls so as to continuously execute the resonance frequency detecting mode and the dust removing mode at a timing that the accessory device is attached.

2. An electronic imaging apparatus having imaging means for converting an optical image of an object into an electric signal, comprising:

an imaging optical system which can be attached/detached to the electronic imaging apparatus and forms the optical image on the imaging means;

an optical element arranged between the imaging optical system and the imaging means;

exciting means for vibrating the optical element; and

drive controlling means for driving the exciting means by supplying a frequency signal based on a resonance frequency of the optical element to the exciting means,

wherein the drive controlling means controls so as to vibrate the optical element by driving the exciting means when the imaging optical system is attached to the electronic imaging apparatus, and

wherein the drive controlling means executes a resonance point detecting operation to detect a resonance frequency of the optical element and thereafter drives the exciting means at a resonance frequency detected by the resonance point detecting operation.

3. An electronic imaging apparatus having imaging means for converting an optical image of an object into an electric signal, comprising:

an imaging optical system which can be attached/detached to the electronic imaging apparatus and forms the optical image on the imaging means;

an optical element arranged between the imaging optical system and the imaging means;

exciting means for vibrating the optical element; and

drive controlling means for driving the exciting means by supplying a frequency signal based on a resonance frequency of the optical element to the exciting means,

wherein the drive controlling means controls so as to vibrate the optical element by driving the exciting means when the imaging optical system is attached to the electronic imaging apparatus, and

wherein the drive controlling means

has a resonance frequency detecting mode to drive the exciting means in order to detect a resonance frequency of the optical element and a dust removing mode to drive the exciting means in order to remove dust which has adhered to the optical element,

continuously executes the resonance frequency detecting mode and the dust removing mode at a timing that the imaging optical system is attached, and

controls so as to execute only the dust removing mode at a predetermined timing in advance of the imaging operation.

4. An electronic imaging apparatus having imaging means for converting an optical image of an object into an electric signal, comprising:

an imaging lens which can be attached to, and detached from, the electronic imaging apparatus;

an optical element arranged on a front surface of the imaging means;

exciting means for vibrating the optical element;

drive controlling means for driving the exciting means by supplying a frequency signal to the exciting means;

attachment/detachment detecting means for detecting a state of the imaging lens by performing a communication operation with an electric circuit provided in the imaging lens; and

resonance frequency detecting means for detecting a vibration state of the optical element,

wherein the drive controlling means has a resonance frequency detecting mode to drive the exciting means in order to detect a resonance frequency of the optical element based on a result of detection by the resonance frequency detecting means, and a dust removing mode to drive the exciting means in order to remove dust which has adhered to the optical element, and

wherein the electronic imaging apparatus controls so as to continuously execute the resonance frequency detecting mode and the dust removing mode when the attachment/detachment detecting means detects attachment of the imaging lens to the electronic imaging apparatus.

5. An electronic imaging apparatus having an imaging element which converts an optical image of an object into an electric signal, comprising:

an imaging optical system which can be attached to, and detached from, the electronic imaging apparatus and which forms the optical image on a light receiving surface of the imaging element;

an optical element arranged between the imaging optical system and the imaging element;

an exciting mechanism which vibrates the optical element, the exciting mechanism including a piezoelectric element which causes the optical element to generate vibrations, and a drive circuit which drives the piezoelectric element;

a control circuit which supplies a frequency signal for driving the piezoelectric element to the drive circuit, the frequency signal being based on a resonance frequency of the optical element; and

a detection circuit which detects a vibration state of the optical element,

wherein the control circuit supplies the frequency signal to the drive circuit after a communication operation with an electric circuit provided in the imaging optical system is performed, and

wherein the drive circuit executes a resonance point detecting operation to detect a resonance frequency of the optical element based on an output of the detection circuit, and thereafter supplies the frequency signal to the drive circuit in accordance with the resonance frequency detected by the resonance point detecting operation.

6. An electronic imaging apparatus having an imaging element which converts an optical image of an object into an electric signal, comprising:

an imaging optical system which can be attached to, and detached from, the electronic imaging apparatus and which forms the optical image on a light receiving surface of the imaging element;

an optical element arranged between the imaging optical system and the imaging element;

an exciting mechanism which vibrates the optical element, the exciting mechanism including a piezoelectric element which causes the optical element to generate vibrations, and a drive circuit which drives the piezoelectric element; and

a control circuit which supplies a frequency signal for driving the piezoelectric element to the drive circuit, the frequency signal being based on a resonance frequency of the optical element;

wherein the control circuit supplies the frequency signal to the drive circuit after a communication operation with an electric circuit provided in the imaging optical system is performed, and

wherein the control circuit

has a resonance frequency detecting mode to detect a resonance frequency of the optical element and a dust removing mode to remove dust which has adhered to the optical element,

continuously executes the resonance frequency detecting mode and the dust removing mode at a time that the imaging optical system is attached, and

controls so as to execute only the dust removing mode at a predetermined timing in advance of the imaging operation.