Image pickup apparatus and image pickup unit having device for removing foreign substance deposited on surface of optical member

Abstract

An image pickup unit integrally includes an optical lowpass filter, a piezoelectric element, and an image pickup element. The optical lowpass filter is separated into a plurality of grouped optical members in an imaging light axis direction. The optical lowpass filter includes first to third grouped optical members. To remove a foreign substance, such as dust or dirt, deposited on the surface of the first grouped optical member, the piezoelectric element vibrates the first grouped optical member. The first grouped optical member has a monocrystalline structure having a Q value indicating the sharpness of resonance higher than that of glass, which is an amorphous material, and a low attenuation characteristic so as to efficiently vibrate the first grouped optical member.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention generally relates to an image pickup apparatus and, in particular, to technology for removing a foreign substance deposited on a surface of an optical member disposed along an imaging light axis.[0003]2. Description of the Related Art[0004]Image pickup apparatuses, such as digital cameras, that capture an image by converting an image signal into an electrical signal receive light using an image pickup element, such as a charged coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) sensor. The image pickup apparatuses convert a photoelectrically converted signal output from the image pickup element to image data. Thereafter, the image pickup apparatuses store the image data on a recording medium, such as a memory card. In such image pickup apparatuses, an optical lowpass filter and an infrared cut filter are disposed on the front side (an object side) of the image pickup element.[...

AI Technical Summary

Benefits of technology

The present invention is about an image pickup apparatus that can efficiently remove foreign substances, like dust or dirt, without using an additional dust-proof member on the imaging light axis. The apparatus includes an image pickup element and an optical member with a plurality of grouped sub-optical members. The first grouped sub-optical member is vibrated to remove any dust or dirt that may accumulate on its surface. This feature helps to keep the image pickup apparatus clean and clear, ensuring consistent and high-quality image quality.

Problems solved by technology

If a foreign substance, such as dust or dirt, is deposited on surfaces of the cover glass of the image pickup element or these filters, the foreign substance generates a black spot in a captured image, and therefore, the quality of the image deteriorates.

In addition, when the lens is changed, a foreign substance may enter inside the camera body from the opening of a lens mount and may be deposited on the surfaces of the cover glass of the image pickup element and the filters.

Therefore, the layout of the members is restricted.

In addition, the optical functionality and optical performance, such as the transmittance for an imaging light beam, disadvantageously deteriorate.

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