Focus detecting apparatus

摘要

A focus detecting apparatus includes: a lens; a light-transmitting unit; a light-receiving unit; and an optical film that transmits a beam of light passing through the lens and includes a holographic optical element, a diffractive optical element, or a pellicle mirror, wherein a beam of light from the light-transmitting unit is reflected on a reflection mirror including the optical film, passes through a first exit pupil area on one side of an optical axis, and is transmitted to the subject, a beam of reflected light of light irradiated onto the subject passes through a second exit pupil area on another side of the optical axis, is reflected on the reflection mirror and received by the light-receiving unit, and a focal position is obtained using position information of the beam of light received by the light-receiving unit. Autofocusing can be continuously performed during continuous photographing operation and in low brightness environment.

主权项

1. A focus detecting apparatus comprising:
an image capturing lens that allows light from a subject to be transmitted through the image capturing lens; a light-transmitting unit that emits a beam of light having a predetermined wavelength through the image capturing lens in order to perform active Auto-Focusing; a light-receiving unit that receives the beam of light through the image capturing lens emitted by the light-transmitting unit; and an optical film that reflects the beam of light that has passed through the image capturing lens and comprises one selected from the group consisting of a holographic optical element, a diffractive optical element, and a pellicle mirror, wherein:
the beam of light emitted from the light-transmitting unit is reflected on the optical film, passes through a first exit pupil area on one side of an optical axis of the image capturing lens, and is transmitted to the subject,the beam of light reflected from the subject passes through a second exit pupil area on another side of the optical axis of the image capturing lens, is reflected on the optical film, and is received by the light-receiving unit, anda focal position is obtained by using information regarding a position of the beam of light received by the light-receiving unit, wherein, both the emitted light passing through the first exit pupil area and the received light passing through the second pupil area pass above the optical axis, or both the emitted light passing through the first exit pupil area and the received light passing through the second pupil area pass under the optical axis.