JPH1164722A5

JPH1164722A5 -

Info

Publication number: JPH1164722A5
Application number: JP1997217608A
Authority: JP
Filing date: 1997-08-12
Publication date: 2005-06-02

Description

【０００９】
【課題を解決するための手段】
上述の目的を達成するために、請求項１の発明は、撮影レンズ１００と、被写体からの光束を受光し、該光束の強度に応じた信号列を出力する、複数の光電変換素子からなるイメージセンサー２と、記録媒体上の、互いに寸法の異なる第１記録領域と第２記録領域のそれぞれに対応する撮影画面を切り替えることが可能な撮影画面設定手段４と、前記信号列の出力が所定の条件を満たしている場合に、撮影レンズ１００の焦点調節状態を求める焦点検出演算手段３、とを有するカメラの焦点検出装置において、前記所定の条件を、撮影画面設定手段４により設定された撮影画面に応じて設定する制御手段５を備える。 [0009]
[Means for solving the problem]
In order to achieve the above-mentioned object, the invention of claim 1 provides a focus detection device for a camera having a photographic lens 100, an image sensor 2 consisting of a plurality of photoelectric conversion elements that receives a light beam from a subject and outputs a signal string corresponding to the intensity of the light beam, a photographic screen setting means 4 that can switch between photographic screens corresponding to first and second recording areas on a recording medium that have different sizes, and a focus detection calculation means 3 that determines the focus adjustment state of the photographic lens 100 when the output of the signal string satisfies a predetermined condition, and further comprises a control means 5 that sets the predetermined condition in accordance with the photographic screen set by the photographic screen setting means 4.

請求項４の発明は、一対の前記信号列の一致度であり、撮影画面設定手段４により設定された撮影画面の大きさが小さいほど、より高い前記一致度を要求する条件に設定する。
請求項５の発明は、前記一致度は、一対の前記信号列の相関量の極小値Ｃｅｘを前記被写体のコントラストに依存する値Ｅで割った数値Ｃｅｘ／Ｅであり、第１の撮影画面において設定されている第１の数値を、前記第１の撮影画面より大きい第２の撮影画面において設定されている第２の数値より小さくする。 In accordance with a fourth aspect of the present invention, the condition is set to require a higher degree of match between the pair of signal sequences, and the smaller the size of the photographic screen set by the photographic screen setting means 4, the higher the degree of match required.
In the invention of claim 5, the degree of coincidence is a numerical value Cex/E obtained by dividing the minimum value Cex of the correlation amount between the pair of signal sequences by a value E that depends on the contrast of the subject, and a first numerical value set in a first photographic screen is made smaller than a second numerical value set in a second photographic screen that is larger than the first photographic screen.

Claims

The photographic lens and
an image sensor including a plurality of photoelectric conversion elements that receives a light beam from a subject and outputs a signal sequence corresponding to the intensity of the light beam;
a photographing screen setting means for switching photographing screens corresponding to a first recording area and a second recording area having different dimensions on a recording medium;
and a focus detection calculation means for determining a focus adjustment state of the photographing lens when the output of the signal sequence satisfies a predetermined condition,
A focus detection device for a camera, comprising control means for setting the predetermined conditions in accordance with the photographic screen set by the photographic screen setting means.

2. The focus detection device for a camera according to claim 1, wherein the predetermined condition is a condition relating to the contrast of the subject, and the smaller the size of the photographic screen set by the photographic screen setting means, the higher the condition requiring the contrast is set.

3. The camera focus detection device according to claim 2, wherein the condition related to contrast is a value dependent on the contrast of the subject, and a value dependent on a first contrast set in a first photographic screen is set to be greater than a value dependent on a second contrast set in a second photographic screen that is larger than the first photographic screen.

2. The camera focus detection device according to claim 1, wherein the predetermined condition is a degree of match between a pair of the signal sequences, and the smaller the size of the photographic screen set by the photographic screen setting means, the higher the condition requiring the degree of match is set.

5. The camera focus detection device according to claim 4, wherein the degree of coincidence is a numerical value obtained by dividing the minimum value of the correlation between the pair of signal sequences by a value that depends on the contrast of the subject, and a first numerical value set in a first photographic screen is made smaller than a second numerical value set in a second photographic screen that is larger than the first photographic screen.