JP2015045804A5

JP2015045804A5 -

Info

Publication number: JP2015045804A5
Application number: JP2013177852A
Authority: JP
Filing date: 2013-08-29
Publication date: 2016-09-29
Anticipated expiration: 2033-08-29

Description

上記目的を達成するために、本発明に係る焦点検出装置は、撮像光学系により形成される像の光強度分布を複数の波長領域について波長領域ごとに検出する第１の撮像素子と、前記撮像光学系の瞳の異なる領域を通過した光により形成される複数の像の光強度分布を検出する第２の撮像素子と、前記第１の撮像素子と前記第２の撮像素子から出力される画像に基づいてデフォーカス値を算出する制御手段を有する焦点検出装置であって、前記第１の撮像素子の画素は第１のピッチで配列されており、前記第２の撮像素子の画素は、前記第１のピッチよりも長い第２のピッチで配列されており、前記制御手段は、前記第２の撮像素子に形成される複数の像の位相差に基づいて第１のデフォーカス値を算出し、前記第１の撮像素子から出力される画像について、前記第２のピッチに対応する空間周波数以下の空間周波数の画像を生成し、生成された画像における前記複数の波長領域の光の強度の比率とコントラストの比率の少なくとも一方に基づいて前記第１のデフォーカス値を補正することにより、第２のデフォーカス値を算出することを特徴とする。
また、本発明に係る撮像装置は、上記焦点検出装置を有することを特徴とする。
また、本発明に係る焦点検出方法は、第１のピッチで画素が配列された第１の撮像素子を用いて、撮像光学系により形成される像の光強度分布を複数の波長領域について波長領域ごとに検出するステップと、前記第１のピッチよりも長い第２のピッチで画素が配列された第２の撮像素子を用いて、前記撮像光学系の瞳の異なる領域を通過した光により形成される複数の像の光強度分布を検出するステップと、前記第２の撮像素子に形成される複数の像の位相差に基づいて第１のデフォーカス値を算出するステップと、前記第１の撮像素子から出力される画像について、前記第２のピッチに対応する空間周波数以下の空間周波数の画像を生成するステップと、生成された画像における前記複数の波長領域の光の強度の比率とコントラストの比率の少なくとも一方に基づいて前記第１のデフォーカス値を補正することにより、第２のデフォーカス値を算出するステップと、を含むことを特徴とする。
また、本発明に係るプログラムは、焦点検出装置のコンピュータに、第１のピッチで画素が配列された第１の撮像素子を用いて、撮像光学系により形成される像の光強度分布を複数の波長領域について波長領域ごとに検出するステップと、前記第１のピッチよりも長い第２のピッチで画素が配列された第２の撮像素子を用いて、前記撮像光学系の瞳の異なる領域を通過した光により形成される複数の像の光強度分布を検出するステップと、前記第２の撮像素子に形成される複数の像の位相差に基づいて第１のデフォーカス値を算出するステップと、前記第１の撮像素子から出力される画像について、前記第２のピッチに対応する空間周波数以下の空間周波数の画像を生成するステップと、生成された画像における前記複数の波長領域の光の強度の比率とコントラストの比率の少なくとも一方に基づいて前記第１のデフォーカス値を補正することにより、第２のデフォーカス値を算出するステップと、を実行させることを特徴とする。 In order to achieve the above object, a focus detection apparatus according to the present invention includes a first imaging element that detects a light intensity distribution of an image formed by an imaging optical system for each of a plurality of wavelength regions, and the imaging A second image sensor that detects light intensity distributions of a plurality of images formed by light that has passed through different regions of the pupil of the optical system, and images that are output from the first image sensor and the second image sensor The focus detection apparatus includes a control unit that calculates a defocus value based on the first imaging element, the pixels of the first imaging element are arranged at a first pitch, and the pixels of the second imaging element are Arranged at a second pitch longer than the first pitch, the control means calculates a first defocus value based on a phase difference between a plurality of images formed on the second image sensor. And output from the first image sensor For an image, the second generated image of the following spatial frequency space frequency corresponding to the pitch, on the basis of the generated image to at least one of the ratios Ratio and the contrast of the light intensity of the plurality of wavelength regions wherein The second defocus value is calculated by correcting the first defocus value.
An imaging apparatus according to the present invention includes the focus detection apparatus.
In addition, the focus detection method according to the present invention uses the first imaging element in which pixels are arranged at the first pitch, and the light intensity distribution of the image formed by the imaging optical system is divided into wavelength regions for a plurality of wavelength regions. Each detection step, and a second imaging device in which pixels are arranged at a second pitch longer than the first pitch, and formed by light passing through different regions of the pupil of the imaging optical system. Detecting a light intensity distribution of a plurality of images, calculating a first defocus value based on a phase difference between the plurality of images formed on the second imaging element, and the first imaging A step of generating an image having a spatial frequency equal to or lower than the spatial frequency corresponding to the second pitch for an image output from the element; and a ratio of intensity of light and a ratio of contrast in the plurality of wavelength regions in the generated image By correcting the first defocus value based on at least one, characterized in that it comprises a step of calculating a second defocus value.
In addition, the program according to the present invention uses a first image sensor in which pixels are arranged at a first pitch in a computer of a focus detection apparatus, and outputs a plurality of light intensity distributions of an image formed by an imaging optical system. Detecting each wavelength region and passing through different regions of the pupil of the imaging optical system using a second imaging element in which pixels are arranged at a second pitch longer than the first pitch. Detecting a light intensity distribution of a plurality of images formed by the light, calculating a first defocus value based on a phase difference of the plurality of images formed on the second image sensor, Generating an image having a spatial frequency equal to or lower than the spatial frequency corresponding to the second pitch for the image output from the first imaging element; and intensity of light in the plurality of wavelength regions in the generated image. By correcting the ratio and the first defocus values based on at least one of the ratio of contrast, it is characterized by executing the steps of calculating a second defocus value.

Claims

A first imaging element that detects a light intensity distribution of an image formed by the imaging optical system for each of a plurality of wavelength regions;
A second imaging element that detects light intensity distributions of a plurality of images formed by light that has passed through different regions of the pupil of the imaging optical system;
A focus detection apparatus including a control unit that calculates a defocus value based on images output from the first image sensor and the second image sensor;
The pixels of the first image sensor are arranged at a first pitch, and the pixels of the second image sensor are arranged at a second pitch longer than the first pitch,
The control means calculates a first defocus value based on a phase difference between a plurality of images formed on the second image sensor, and outputs the second defocus value for the image output from the first image sensor. Generating an image having a spatial frequency equal to or lower than the spatial frequency corresponding to the pitch of the first defocus value based on at least one of a light intensity ratio and a contrast ratio in the plurality of wavelength regions in the generated image. A focus detection apparatus that calculates a second defocus value by correcting

The control means performs Fourier transform on the image output from the first image sensor, extracts a component having a spatial frequency or less corresponding to the second pitch, and corresponds to the extracted second pitch. The focus detection apparatus according to claim 1, wherein an image having a spatial frequency equal to or lower than the spatial frequency corresponding to the second pitch is generated by performing inverse Fourier transform on a component equal to or lower than the spatial frequency.

The focus detection apparatus according to claim 1, wherein the first image sensor is a photometric sensor.

The focus detection apparatus according to claim 1, wherein the first image sensor is an image sensor that images a subject.

The focus detection apparatus according to claim 1, wherein the second image sensor is a plurality of line sensors.

An imaging apparatus comprising: the focus detection apparatus according to claim 1; and the imaging optical system.

Detecting a light intensity distribution of an image formed by the imaging optical system for each wavelength region for each wavelength region using the first imaging element in which pixels are arranged at a first pitch; and
Light intensity of a plurality of images formed by light passing through different regions of the pupil of the imaging optical system using a second imaging element in which pixels are arranged at a second pitch longer than the first pitch Detecting a distribution;
Calculating a first defocus value based on a phase difference between a plurality of images formed on the second image sensor;
The image output from the first image sensor, and generating an image of said second spatial frequency below the spatial frequency corresponding to the pitch,
Calculating a second defocus value by correcting the first defocus value based on at least one of a light intensity ratio and a contrast ratio in the plurality of wavelength regions in the generated image; and ,
A focus detection method comprising:

In the computer of the focus detection device,
Detecting a light intensity distribution of an image formed by the imaging optical system for each wavelength region for each wavelength region using the first imaging element in which pixels are arranged at a first pitch; and
Light intensity of a plurality of images formed by light passing through different regions of the pupil of the imaging optical system using a second imaging element in which pixels are arranged at a second pitch longer than the first pitch Detecting a distribution;
Calculating a first defocus value based on a phase difference between a plurality of images formed on the second image sensor;
The image output from the first image sensor, and generating an image of said second spatial frequency below the spatial frequency corresponding to the pitch,
Calculating a second defocus value by correcting the first defocus value based on at least one of a light intensity ratio and a contrast ratio in the plurality of wavelength regions in the generated image; and ,
A program characterized by having executed.