JP2011010976A5

JP2011010976A5 -

Info

Publication number: JP2011010976A5
Application number: JP2009159539A
Authority: JP
Filing date: 2009-07-06
Publication date: 2012-08-09
Anticipated expiration: 2029-07-06

Description

（１）測定光源と、該測定光源から出射された光の一部の光路長を変化させるために所定の光学部材を移動させる駆動部と、受光素子と、を有し、前記測定光源から出射された光を被検眼に照射し、被検眼からの反射光を干渉光として前記受光素子で受光する干渉光学系と、
前記受光素子から出力される受光信号に基づいて被検者眼の軸方向における眼寸法を算出する演算処理部と、
を備える眼寸法測定装置において、
前記受光素子から出力される受光信号からビート成分を抽出するためのバンドパスフィルタと、
該バンドパスフィルタから出力されるビート信号の包絡線信号を得る包絡線検波手段と、
前記包絡線検波手段によって取得された包絡線信号のうち、干渉信号による包絡線に対応する所定の周波数成分の信号を通過させ、これを超える周波数成分の信号を遮断するフィルタ手段と、を備え、
前記演算処理部は、該フィルタ手段を通過した信号に基づいて眼寸法を求めることを特徴とする。
（２）
（１）の眼寸法測定装置において、前記フィルタ手段は、ローパスフィルタ、又はバンドパスフィルタを含むことを特徴とする。
（３）
（１）又は（２）のいずれかの眼寸法測定装置において、前記フィルタ手段は、前記測定光源のコヒーレンス長及び前記光学部材の移動速度に基づき理論上算出される干渉信号の包絡線に対応する周波数を基準とする所定の許容幅の帯域を通過させる特性を有することを特徴とする。

(1) A measurement light source, a drive unit that moves a predetermined optical member to change the optical path length of a part of the light emitted from the measurement light source, and a light receiving element, and is emitted from the measurement light source An interference optical system that irradiates the subject's eye with received light and receives the reflected light from the subject's eye as interference light by the light receiving element;
An arithmetic processing unit that calculates an eye dimension in the axial direction of the subject's eye based on a light reception signal output from the light receiving element;
In an eye dimension measuring device comprising:
A bandpass filter for extracting a beat component from a light receiving signal output from the light receiving element;
Envelope detection means for obtaining an envelope signal of a beat signal output from the band pass filter;
Among the envelope signals acquired by the envelope detection means, a filter means for passing a signal of a predetermined frequency component corresponding to the envelope due to the interference signal and blocking a signal of a frequency component exceeding this, and
The arithmetic processing unit obtains an eye size based on a signal that has passed through the filter means .
(2)
In the eye dimension measuring device according to (1), the filter means includes a low-pass filter or a band-pass filter.
(3)
In any one of the eye dimension measuring devices according to (1) or (2) , the filter unit corresponds to an envelope of an interference signal that is theoretically calculated based on a coherence length of the measurement light source and a moving speed of the optical member. It has a characteristic of allowing a band having a predetermined allowable width based on the frequency to pass.

Claims

Light emitted from the measurement light source, including a measurement light source, a drive unit that moves a predetermined optical member to change the optical path length of a part of the light emitted from the measurement light source, and a light receiving element An interference optical system that receives the reflected light from the eye to be examined as interference light by the light receiving element;
An arithmetic processing unit that calculates an eye dimension in the axial direction of the subject's eye based on a light reception signal output from the light receiving element;
In an eye dimension measuring device comprising:
A bandpass filter for extracting a beat component from a light receiving signal output from the light receiving element;
Envelope detection means for obtaining an envelope signal of a beat signal output from the band pass filter;
Among the envelope signals acquired by the envelope detection means, a filter means for passing a signal of a predetermined frequency component corresponding to the envelope due to the interference signal and blocking a signal of a frequency component exceeding this, and
The arithmetic processing unit obtains an eye size based on a signal that has passed through the filter means .

2. The eye dimension measuring apparatus according to claim 1, wherein the filter means includes a low pass filter or a band pass filter.

3. The eye dimension measuring apparatus according to claim 1 , wherein the filter means calculates a frequency corresponding to an envelope of an interference signal that is theoretically calculated based on a coherence length of the measurement light source and a moving speed of the optical member. An eye size measuring device having a characteristic of passing a band having a predetermined allowable width as a reference.