JP5188779B2

JP5188779B2 - Eye size measuring device

Info

Publication number: JP5188779B2
Application number: JP2007286817A
Authority: JP
Inventors: 昌明羽根渕; 雅和遠藤
Original assignee: Nidek Co Ltd
Current assignee: Nidek Co Ltd
Priority date: 2007-11-02
Filing date: 2007-11-02
Publication date: 2013-04-24
Anticipated expiration: 2027-11-02
Also published as: JP2009112430A

Description

本発明は、被検眼の寸法を測定する眼寸法測定装置に関する。 The present invention relates to an eye size measuring device that measures the size of an eye to be examined.

被検眼の寸法を測定する装置としては、低コヒーレント光を発する測定光源から出射された測定光を角膜照射光と眼底照射光に分割する光路分割部材と、光路分割部材によって分割された測定光を再度合成する光路合成部材と、を有し、被検眼角膜と被検眼眼底に向けて測定光を照射する照射光学系と、眼底からの反射光と角膜からの反射光との干渉光を受光して干渉信号を得る干渉光学系と、光路変更部材と、を備え、干渉信号と光路長変更部材の位置とに基づいて被験者眼の眼軸長を測定する装置が知られている（特許文献１参照）。 As an apparatus for measuring the size of the eye to be examined, an optical path dividing member that divides measurement light emitted from a measurement light source that emits low-coherent light into corneal irradiation light and fundus irradiation light, and measurement light divided by the optical path division member An optical path synthesis member that synthesizes again, and an irradiation optical system that irradiates measurement light toward the subject's cornea and the fundus of the subject's eye, and interference light between the reflected light from the fundus and the reflected light from the cornea An apparatus that includes an interference optical system that obtains an interference signal and an optical path changing member and that measures the axial length of the subject's eye based on the interference signal and the position of the optical path length changing member is known (Patent Document 1). reference).

また、特許文献１の装置では、光路分割部材によって分割された分割光路における眼底照射光の照射光路に高屈折率の光路長変更部材を挿入して、眼底照射光と角膜照射光の光路長差を短縮することにより、被検眼の前房深度を測定する構成が開示されている。
特開平２−２９７３３２号公報 Further, in the apparatus of Patent Document 1, an optical path length changing member having a high refractive index is inserted into the irradiation light path of the fundus irradiation light in the divided optical path divided by the optical path dividing member, and the optical path length difference between the fundus irradiation light and the cornea irradiation light The structure which measures the anterior chamber depth of the eye to be examined by shortening is disclosed.
JP-A-2-297332

しかしながら、特許文献１のような手法によって前房深度を測定する場合、被検眼の眼底に照射される眼底照射光が水晶体前面を通過する際の反射光と角膜反射光による干渉光を干渉光学系により受光することで干渉信号を得るため、干渉信号の出力レベルが小さく、測定結果にばらつきが生じやすい。 However, when the anterior chamber depth is measured by the technique as described in Patent Document 1, the interference optical system uses the reflected light when the fundus irradiation light irradiated on the fundus of the eye to be examined passes through the front surface of the crystalline lens and the interference light due to the corneal reflection light. Since the interference signal is obtained by receiving the light, the output level of the interference signal is small, and the measurement results tend to vary.

本発明は、上記問題点を鑑み、被検眼の眼軸長及び前房深度を精度よく測定できる眼寸法測定装置を提供することを技術課題とする。 In view of the above problems, an object of the present invention is to provide an eye dimension measuring device capable of accurately measuring the axial length and anterior chamber depth of an eye to be examined.

上記課題を解決するために、本発明は以下のような構成を備えることを特徴とする。 In order to solve the above problems, the present invention is characterized by having the following configuration.

（１）測定手段は、低コヒーレント光を出射する測定光源と、前記測定光源から出射された前記測定光を第１測定光として被検眼角膜に照射して角膜からの反射光を受光するための第１測定光学系と、前記測定光源から出射された前記測定光を第２測定光として被検眼眼底に照射して眼底からの反射光を受光するための第２測定光学系と、前記第１測定光学系または第２測定光学系のどちらかに配置され、前記第１測定光の光路長または前記第２測定光の光路長のいずれかを変更させるための光路長変更手段と、前記第１測定光学系及び第２測定光学系の共通光路に置かれ，前記第１測定光の反射光と前記第２測定光の反射光との合成による干渉光を受光し干渉信号を得るための受光光学系と、前記共通光路とならない前記第２測定光学系の光路中に配置される光学レンズを移動させることにより前記第２測定光の集光位置を切り換え、前記第２測定光の照射目標を被検眼眼底と被検眼の水晶体前面とに選択的に切り換える集光位置切換手段と、被検眼の眼軸長を測定する眼軸長測定モードと被検眼の前房深度を測定する前房深度測定モードを切り換えるモード切換手段と、該モード切換手段にて前記眼軸長測定モードとされているときは前記照射位置切換手段により前記第２測定光の照射目標を眼底として眼底からの反射光と角膜からの反射光との合成による前記干渉信号及び光路長変更手段の変更情報とに基づいて被検眼の眼軸長を測定し，前記前房深度測定モードとされているときは前記照射位置切換手段により前記第２測定光の照射目標を水晶体前面として、角膜からの反射光と水晶体前面からの反射光との合成による前記干渉信号及び光路長変更手段の変更情報とに基づいて被検眼の前房深度を測定する測定制御手段と、を備えることを特徴とする。
（２）（１）の眼寸法測定装置において、前記測定光源から出射された測定光の一部を透過し一部を反射することにより第１測定光と第２測定光とに分割する光路分割部材と、該光路分割部材により分割された第１測定光と第２測定光を合成する光路合成部材と、を備え、前記光路分割部材によって形成される測定光の透過光路には、前記光路分割部材を透過した測定光を反射する反射部材と，前記反射部材によって反射された測定光を前記光路合成部材へと導く導光部材と，によって形成される迂回光路が設けられていることを特徴とする。

(1) The measurement means is for measuring the measurement light source that emits low-coherent light and irradiating the eye cornea with the measurement light emitted from the measurement light source as the first measurement light to receive the reflected light from the cornea A first measurement optical system; a second measurement optical system for irradiating the fundus of the eye to be examined with the measurement light emitted from the measurement light source as second measurement light; and receiving the reflected light from the fundus. An optical path length changing unit that is arranged in either the measurement optical system or the second measurement optical system and changes either the optical path length of the first measurement light or the optical path length of the second measurement light; Light receiving optics that is placed in a common optical path of the measurement optical system and the second measurement optical system, receives interference light by combining the reflected light of the first measurement light and the reflected light of the second measurement light, and obtains an interference signal System and the second measuring optical system that does not become the common optical path. A focusing position of the second measurement light is switched by moving an optical lens disposed in the optical path, and the irradiation target of the second measurement light is selectively switched between the fundus of the eye to be examined and the front surface of the lens of the eye to be examined. Light position switching means, mode switching means for switching an axial length measurement mode for measuring the axial length of the eye to be examined, and an anterior chamber depth measurement mode for measuring the anterior chamber depth of the eye to be examined; When in the axial length measurement mode, the interference signal and optical path length changing means by combining the reflected light from the fundus and the reflected light from the cornea using the irradiation position switching means as the fundus of the second measurement light as the fundus The axial length of the eye to be examined is measured based on the change information of the eye, and when the anterior chamber depth measurement mode is set, the irradiation target of the second measurement light is set to the front surface of the crystalline lens by the irradiation position switching means from the cornea. The opposite of Characterized in that it comprises a measurement control means for measuring the anterior chamber depth of the eye on the basis of the change information of the interference signal and the optical path length changing means by synthesis and the reflected light from the optical and the lens front, the.
(2) In the eye dimension measuring apparatus according to (1), the optical path splitting that splits the first measurement light and the second measurement light by transmitting a part of the measurement light emitted from the measurement light source and reflecting a part thereof. A light path combining member that combines the first measurement light and the second measurement light split by the optical path splitting member, and the optical path splitting is provided in the transmitted optical path of the measurement light formed by the optical path splitting member A detouring optical path formed by a reflecting member that reflects measurement light transmitted through the member and a light guide member that guides the measuring light reflected by the reflecting member to the optical path combining member is provided. To do.

本発明によれば、被検眼の眼軸長及び前房深度を精度よく測定できる眼寸法測定装置を提供することを技術課題とする。 According to the present invention, it is an object of the present invention to provide an eye dimension measuring device that can accurately measure the axial length and anterior chamber depth of an eye to be examined.

以下、本発明の実施形態を図面に基づいて説明する。図１及び図２は、本実施形態に係る眼寸法測定装置の光学系の概略構成図である。図１は眼軸長測定時における光学系の配置を示す図であり、図２は前房深度測定時における光学系の配置を示す図である。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG.1 and FIG.2 is a schematic block diagram of the optical system of the eye dimension measuring apparatus based on this embodiment. FIG. 1 is a diagram showing the arrangement of the optical system when measuring the axial length, and FIG. 2 is a diagram showing the arrangement of the optical system when measuring the anterior chamber depth.

被検眼角膜と被検眼の所定部位に測定光を照射する照射光学系１００は、低コヒーレント光を出射する測定光源１を持ち、光源１から出射された測定光を光路分割部材（例えば、偏光ブームスプリッタ３）により被検眼角膜への測定光（第１測定光）が通る第１測定光路Ｔ１と被検眼の所定部位への測定光（第２測定光）が通る第２測定光路Ｔ２とに分割すると共に、再度、光路合成部材（例えば、偏光ビームスプリッタ６）により合成する。 An irradiation optical system 100 that irradiates measurement light to predetermined regions of the eye cornea and the eye to be examined has a measurement light source 1 that emits low-coherent light, and the measurement light emitted from the light source 1 is an optical path dividing member (for example, a polarization boom). Split by the splitter 3) into a first measurement optical path T1 through which measurement light (first measurement light) to the subject's eye cornea passes and a second measurement optical path T2 through which measurement light (second measurement light) to a predetermined part of the subject's eye passes. At the same time, the light is combined again by an optical path combining member (for example, the polarization beam splitter 6).

測定光源１からビームスプリッタ３の間には、コリメータレンズ２、ハーフミラー２０、１／２波長板５０、が順次配置されており、測定光源１から発せられた測定光は、コリメータレンズ２によって平行光束とされた後、ハーフミラー２０を透過後、１／２波長板５０によって偏光方向が回転された後、偏光ビームスプリッタ３によって透過光と反射光が互いに直交する直線偏光になるように分離される。なお、入射光の偏光面に対する１／２波長板５０の光学軸を変化させることにより、偏光ビームスプリッタ３によって分離される透過光と反射光の比率を調整できる。 A collimator lens 2, a half mirror 20, and a half-wave plate 50 are sequentially arranged between the measurement light source 1 and the beam splitter 3, and the measurement light emitted from the measurement light source 1 is parallel by the collimator lens 2. After being converted into a light beam, after passing through the half mirror 20, the polarization direction is rotated by the half-wave plate 50, and then the transmitted light and the reflected light are separated by the polarizing beam splitter 3 so as to be linearly polarized light orthogonal to each other. The Note that the ratio of transmitted light and reflected light separated by the polarization beam splitter 3 can be adjusted by changing the optical axis of the half-wave plate 50 with respect to the polarization plane of incident light.

ここで、ビームスプリッタ３を透過する第１測定光は、第１三角プリズム４の反射面４ａで反射され、第１三角プリズム４に対して移動可能な可動三角プリズム５の反射面５ａ及び反射面５ｂによって折り返された後、第１三角プリズム４の反射面４ｂで反射され、ビームスプリッタ６を透過する。すなわち、第１測定光は、第１測定光路Ｔ１（ビームスプリッタ３〜可動三角プリズム５〜ビームスプリッタ６）を通過する。なお、可動三角プリズム５は、第１測定光の光路長を変更させるための光路変更部材として用いられ、駆動部７１の駆動によって第１三角プリズム４に対して矢印Ａ方向に移動される。なお、可動三角プリズム５は、三角ミラーであってもよい。 Here, the first measurement light transmitted through the beam splitter 3 is reflected by the reflecting surface 4 a of the first triangular prism 4, and the reflecting surface 5 a and the reflecting surface of the movable triangular prism 5 movable with respect to the first triangular prism 4. After being folded back by 5 b, it is reflected by the reflecting surface 4 b of the first triangular prism 4 and passes through the beam splitter 6. That is, the first measurement light passes through the first measurement optical path T1 (beam splitter 3—movable triangular prism 5—beam splitter 6). The movable triangular prism 5 is used as an optical path changing member for changing the optical path length of the first measurement light, and is moved in the arrow A direction with respect to the first triangular prism 4 by driving of the driving unit 71. The movable triangular prism 5 may be a triangular mirror.

また、ビームスプリッタ３で反射された第２測定光は、全反射ミラー１１で反射された後、リレーレンズ（フォーカシングレンズ）１２、全反射ミラー１３を介して、ビームスプリッタ６にて反射される。すなわち、第２測定光は、第２測定光路Ｔ２（ビームスプリッタ３〜リレーレンズ１２〜ビームスプリッタ６）を通過する。 The second measurement light reflected by the beam splitter 3 is reflected by the total reflection mirror 11 and then reflected by the beam splitter 6 via the relay lens (focusing lens) 12 and the total reflection mirror 13. That is, the second measurement light passes through the second measurement optical path T2 (beam splitter 3 to relay lens 12 to beam splitter 6).

ここで、ビームスプリッタ６に到達した第１測定光及び第２測定光は、第１測定光を透過して第２測定光を反射する特性を有する偏光ビームスプリッタ６によって同軸にされた後、被検眼に向かう。 Here, the first measurement light and the second measurement light that have reached the beam splitter 6 are coaxially formed by the polarization beam splitter 6 having a characteristic of transmitting the first measurement light and reflecting the second measurement light, and Head to the optometry.

すなわち、ビームスプリッタ６を透過した第１測定光は、リレーレンズ７によって一旦集光された後、全反射ミラー８、ダイクロイックミラー９、対物レンズ１０、ダイクロイックミラー４３を介して、被検眼角膜に照射される。なお、前述のビームスプリッタ３〜第１三角プリズム５〜対物レンズ１０までの光学部材は、被検眼角膜に第１測定光を照射させるために前眼部に測定光を集光させる第１集光光学系１００ａとして用いられる。なお、本実施形態では、前述の第１集光光学系１００ａにより被検眼角膜に向けて第１測定光を照射させる際、被検眼の角膜頂点から水晶体側にずれた約３ｍｍの位置に向かって第１測定光が入射されるように測定光を集光させる構成となっている。このとき、対物レンズ１０は、測定光源１から出射された測定光を被検眼前眼部に向けて収束させる収束レンズとして用いられる。 That is, the first measurement light transmitted through the beam splitter 6 is once condensed by the relay lens 7 and then irradiated to the eye cornea through the total reflection mirror 8, the dichroic mirror 9, the objective lens 10, and the dichroic mirror 43. Is done. Note that the optical members from the beam splitter 3 to the first triangular prism 5 to the objective lens 10 described above collect the measurement light on the anterior eye part in order to irradiate the eye cornea with the first measurement light. Used as the optical system 100a. In the present embodiment, when the first measurement light is irradiated toward the eye cornea to be examined by the first condensing optical system 100a described above, the position is about 3 mm that is shifted from the apex of the cornea of the eye to the lens side. The measurement light is condensed so that the first measurement light is incident. At this time, the objective lens 10 is used as a converging lens that converges the measurement light emitted from the measurement light source 1 toward the anterior eye portion to be examined.

また、ビームスプリッタ６で反射された第２測定光は、リレーレンズ７、ミラー８を介して、一旦集光された後、ダイクロイックミラー９、対物レンズ１０、ダイクロイックミラー４３を介して、被検眼の眼底に集光される。また、第２測定光は、リレーレンズ１２によって、ミラー１３とビームスプリッタ６との間で一旦集光される。リレーレンズ１２は、駆動部７２の駆動により光軸方向（矢印Ｂ方向）に移動可能であり、その移動によってリレーレンズ１２〜ビームスプリッタ６の光路間のいずれかに形成される集光点Ｃの位置が移動され、被検眼の視度が補正される。これにより、被検眼の屈折誤差にかかわらず、被検眼の眼底上に第２測定光を集光できる。すなわち、第２測定光路に配置されたリレーレンズ１２は、被検眼の眼底に照射される測定光のフォーカス位置を調整するための光学部材として用いられる。なお、ビームスプリッタ３〜リレーレンズ１２〜対物レンズ１０までの光学部材は、第２測定光を被検眼の所定部位（例えば、被検眼眼底）に集光させるための第２集光光学系１００ｂとして用いられる。 Further, the second measurement light reflected by the beam splitter 6 is once condensed through the relay lens 7 and the mirror 8, and is then collected through the dichroic mirror 9, the objective lens 10, and the dichroic mirror 43. Focused on the fundus. The second measurement light is once condensed by the relay lens 12 between the mirror 13 and the beam splitter 6. The relay lens 12 can be moved in the optical axis direction (arrow B direction) by driving the driving unit 72, and the focal point C formed between the relay lens 12 and the optical path of the beam splitter 6 by the movement. The position is moved, and the diopter of the eye to be examined is corrected. Accordingly, the second measurement light can be condensed on the fundus of the subject eye regardless of the refraction error of the subject eye. That is, the relay lens 12 disposed in the second measurement optical path is used as an optical member for adjusting the focus position of the measurement light irradiated on the fundus of the eye to be examined. The optical members from the beam splitter 3 to the relay lens 12 to the objective lens 10 serve as a second condensing optical system 100b for condensing the second measurement light on a predetermined part of the eye to be examined (for example, the fundus of the eye to be examined). Used.

また、照射光学系１００における第２測定光路Ｔ２には、第２測定光の集光位置を切り換え、第２測定光の照射目標を被検眼眼底と水晶体前面とに選択的に切り換える集光位置切換機構７０が配置されている。 In addition, the second measurement light path T2 in the irradiation optical system 100 switches the condensing position of the second measurement light, and selectively switches the irradiation target of the second measurement light between the fundus oculi and the front surface of the crystalline lens. A mechanism 70 is arranged.

より具体的には、集光位置切換機構７０として、第２測定光路Ｔ２に配置された光学部材（リレーレンズ１２）を挿脱させるための駆動部７０が設けられている。ここで、制御部８０によって駆動部７０が駆動され、第２集光光学系１００ｂの光路からリレーレンズ１２が外される（図２参照）と、測定光源１から発せられビームスプリッタ３にて反射された第２測定光は、ミラー１１、ミラー１３、ビームスプリッタ６を介して、リレーレンズ７にて一旦集光された後、全反射ミラー８、ダイクロイックミラー９、対物レンズ１０、ダイクロイックミラー４３を介して、被検眼の角膜頂点から水晶体側に所定量ずれた被検眼前眼部のいずれかに第２測定光が集光される。なお、本実施形態では、前述の第２集光光学系１００ｂにより被検眼水晶体前面に向けて第２測定光を照射させる際、被検眼の角膜頂点から水晶体側にずれた約３ｍｍの位置に向かって第２測定光が入射されるような構成となっている。この場合、第２集光光学系１００ｂにより被検眼前眼部に向けて第２測定光を照射させるときの入射位置は、第１集光光学系１００ａによって被検眼前眼部に向けて第１測定光を入射させるときの入射位置と同一になる。 More specifically, a drive unit 70 for inserting and removing the optical member (relay lens 12) arranged in the second measurement optical path T2 is provided as the condensing position switching mechanism 70. Here, when the drive unit 70 is driven by the control unit 80 and the relay lens 12 is removed from the optical path of the second condensing optical system 100 b (see FIG. 2), the light is emitted from the measurement light source 1 and reflected by the beam splitter 3. The second measurement light is once condensed by the relay lens 7 via the mirror 11, the mirror 13, and the beam splitter 6, and then passed through the total reflection mirror 8, the dichroic mirror 9, the objective lens 10, and the dichroic mirror 43. Accordingly, the second measurement light is collected on any one of the anterior eye portions of the eye to be examined that is shifted from the corneal apex of the eye to be examined by a predetermined amount toward the crystalline lens side. In the present embodiment, when the second measurement light is irradiated toward the front lens of the eye to be examined by the above-described second condensing optical system 100b, it is directed to a position of about 3 mm shifted from the corneal apex of the eye to be examined toward the lens. Thus, the second measurement light is incident. In this case, the incident position when the second measurement light is irradiated toward the anterior eye portion to be examined by the second condensing optical system 100b is the first incident position toward the anterior eye portion to be examined by the first condensing optical system 100a. This is the same as the incident position when the measurement light is incident.

干渉光学系２００は、照射光学系１００によって照射される被検眼角膜からの反射光と被検眼の所定部位からの反射光との干渉光を受光し、干渉信号を得るために用いられる。ここで、干渉光学系２００は、対物レンズ１０〜ハーフミラー２０までの光路を照射光学系１００と共用し、さらに、所定の偏光方向成分の光を透過する直線偏光子５１、集光レンズ２１、受光素子２２、を有する。この場合、被検眼角膜及び被検眼前眼部の所定部位で反射された測定光は、被検眼角膜又は被検眼の所定部位（眼底又は水晶体前面）に照射されるまでの測定光の光路を逆行するように、偏光ビームスプリッタ６によって分離された後、偏光ビームスプリッタ３によって同軸にされた後、再び１／２波長板５０を通過し、ハーフミラー２０によって反射される。また、直線偏光子５１が透過する光の偏光方向が直線偏光子５１に入射されるときの第１測定光と第２測定光の各偏光方向に対して傾斜した関係（例えば、各偏光方向に対して４５°の関係）となるように直線偏光子５１が配置されている。 The interference optical system 200 is used to receive interference light between the reflected light from the eye cornea irradiated by the irradiation optical system 100 and the reflected light from a predetermined part of the subject eye, and obtain an interference signal. Here, the interference optical system 200 shares the optical path from the objective lens 10 to the half mirror 20 with the irradiation optical system 100, and further, a linear polarizer 51 that transmits light of a predetermined polarization direction component, a condenser lens 21, A light receiving element 22. In this case, the measurement light reflected by the predetermined part of the eye cornea and the anterior eye part of the eye to be examined reverses the optical path of the measurement light until it is irradiated to the eye cornea or the predetermined part (the fundus or the front surface of the lens) of the eye to be examined. As described above, after being separated by the polarization beam splitter 6, after being made coaxial by the polarization beam splitter 3, it passes through the half-wave plate 50 again and is reflected by the half mirror 20. Further, the polarization direction of the light transmitted through the linear polarizer 51 is inclined with respect to each polarization direction of the first measurement light and the second measurement light when entering the linear polarizer 51 (for example, in each polarization direction). The linear polarizer 51 is disposed so as to have a relationship of 45 ° with respect to the surface.

ここで、被検眼角膜から反射された第１測定光は、対物レンズ１０〜ビームスプリッタ６までの光路を逆行後、ビームスプリッタ６を透過して、第１測定光路を逆行し、ビームスプリッタ３を透過後、ハーフミラー２０によって反射される。そして、ハーフミラー２０で反射された第１測定光の一部は、直線偏光子５１を透過後、集光レンズ２１にて集光され、受光素子２２に入射する。 Here, the first measurement light reflected from the subject's eye cornea reverses the optical path from the objective lens 10 to the beam splitter 6, then passes through the beam splitter 6, reverses the first measurement optical path, and passes the beam splitter 3. After transmission, the light is reflected by the half mirror 20. A part of the first measurement light reflected by the half mirror 20 passes through the linear polarizer 51, is condensed by the condenser lens 21, and enters the light receiving element 22.

また、被検眼所定部位（眼底又は水晶体前面）から反射された第２測定光は、対物レンズ１０〜ビームスプリッタ６までの光路を逆行後、ビームスプリッタ６で反射されて、第２測定光路を逆行し、ビームスプリッタ３で反射された後、ハーフミラー２０によって反射される。そして、ハーフミラー２０で反射された第２測定光の一部は、直線偏光子５１を透過後、集光レンズ２１にて集光され、受光素子２２に入射する。 Further, the second measurement light reflected from a predetermined part of the eye to be examined (the fundus or the front surface of the crystalline lens) travels back through the optical path from the objective lens 10 to the beam splitter 6 and then is reflected by the beam splitter 6 to travel backward through the second measurement light path. Then, after being reflected by the beam splitter 3, it is reflected by the half mirror 20. A part of the second measurement light reflected by the half mirror 20 passes through the linear polarizer 51, is then collected by the condenser lens 21, and enters the light receiving element 22.

ここで、制御部８０によって集光位置切換機構７０が駆動制御され、被検眼の眼底に測定光が集光された状態（第２測定光の照射目標が眼底に設定されている状態）で、可動三角プリズム５の移動によって第１測定光（参照光）の光路長が変化されると、被検眼の角膜に照射された第１測定光の光路長（光源１〜角膜、角膜〜受光素子２２）と被検眼の眼軸長によって変動する眼底に照射された第２測定光の光路長とが干渉が起こり得る範囲でほぼ等しい関係になるときがある。この場合、第１三角プリズム４で反射されてビームスプリッタ３を透過する第１測定光と、ミラー１１で反射されてビームスプリッタ３で反射される第２測定光とが合成されて干渉光とされたのち、ハーフミラー２０を介して受光素子２２に受光される。 Here, the condensing position switching mechanism 70 is driven and controlled by the control unit 80, and the measurement light is condensed on the fundus of the eye to be examined (the irradiation target of the second measurement light is set on the fundus). When the optical path length of the first measurement light (reference light) is changed by the movement of the movable triangular prism 5, the optical path length of the first measurement light irradiated to the cornea of the eye to be examined (light source 1 to cornea, cornea to light receiving element 22). ) And the optical path length of the second measurement light applied to the fundus that varies depending on the axial length of the eye to be examined may be in a substantially equal relationship within a range where interference can occur. In this case, the first measurement light reflected by the first triangular prism 4 and transmitted through the beam splitter 3 and the second measurement light reflected by the mirror 11 and reflected by the beam splitter 3 are combined into interference light. Thereafter, the light is received by the light receiving element 22 through the half mirror 20.

一方、制御部８０によって集光位置切換機構７０が駆動制御され、被検眼前眼部に測定光が集光された状態（第２測定光の照射目標が水晶体前面に設定されている状態）で可動三角プリズム５の移動によって第１測定光の光路長が変化されると、被検眼の角膜に照射された第１測定光の光路長（光源１〜角膜、角膜〜受光素子２２）と被検眼の前房深度によって変動する水晶体前面に照射された第２測定光の光路長（光源１〜水晶体前面、水晶体前面〜受光素子２２）とが干渉が起こり得る範囲でほぼ等しい関係になるときがある。この場合、第１測定光は、第１三角プリズム４で反射されてビームスプリッタ３を透過する際に、ミラー１１で反射されてビームスプリッタ３で反射される第２測定光と合成され干渉光とされたのち、受光素子２２に受光される。 On the other hand, in the state where the condensing position switching mechanism 70 is driven and controlled by the control unit 80 and the measurement light is condensed on the anterior eye portion of the eye to be examined (the state where the irradiation target of the second measurement light is set on the front surface of the crystalline lens). When the optical path length of the first measurement light is changed by the movement of the movable triangular prism 5, the optical path length of the first measurement light (light source 1 to cornea, cornea to light receiving element 22) irradiated to the cornea of the eye to be examined and the eye to be examined. In some cases, the optical path lengths of the second measurement light (light source 1 to lens front surface, lens front surface to light receiving element 22) irradiated to the lens front surface, which fluctuate depending on the anterior chamber depth, are substantially equal in a range where interference can occur. . In this case, when the first measurement light is reflected by the first triangular prism 4 and transmitted through the beam splitter 3, the first measurement light is combined with the second measurement light reflected by the mirror 11 and reflected by the beam splitter 3. After that, the light receiving element 22 receives the light.

なお、上記構成において、第１測定光路に配置された光学部材と第２測定光路に配置された光学部材によって光路長の変更がなされ、第１測定光の光路長と第２測定光の光路長との光路差は、第１測定光と第２測定光がビームスプリッタ３によって分割されてからビームスプリッタ６で合成されるまでの分割光路での光路差によって生じる。よって、上記のように角膜に照射される第１測定光と眼底に照射される第２測定光との干渉光、及び角膜に照射される第１測定光と水晶体前面に照射される第２測定光との干渉光を発生させるためには、第１測定光路と第２測定光路との光路差をこれに対応させる必要がある。 In the above configuration, the optical path length is changed by the optical member arranged in the first measurement optical path and the optical member arranged in the second measurement optical path, and the optical path length of the first measurement light and the optical path length of the second measurement light are changed. Is caused by the optical path difference in the split optical path from when the first measurement light and the second measurement light are split by the beam splitter 3 until they are combined by the beam splitter 6. Therefore, as described above, the interference light between the first measurement light irradiated on the cornea and the second measurement light irradiated on the fundus, and the first measurement light irradiated on the cornea and the second measurement irradiated on the front surface of the crystalline lens. In order to generate interference light with light, it is necessary to correspond to the optical path difference between the first measurement optical path and the second measurement optical path.

そこで、前述のように測定光の一部を透過し測定光の一部を反射するビームスプリッタ３によって形成される測定光の透過光路には、ビームスプリッタ３を透過した測定光を反射する反射部材（例えば、三角プリズム４の反射面４ａ）と，反射面４ａによって反射された測定光をビームスプリッタ６へと導く導光部材（例えば、可動三角プリズム５及び三角プリズム４の反射面４ｂ）と，によって形成される迂回光路が設けられている
この場合、第１測定光は、ビームスプリッタ３を透過後に直進してビームスプリッタ６に向かうのではなく、ビームスプリッタ３の透過後、第１三角プリズム４の反射面４ａによって反射され、第２反射プリズム５によって折り返した後に、可動三角プリズム４の反射面４ｂによって反射させてからビームスプリッタ６に到達する。 Therefore, as described above, in the transmission light path of the measurement light formed by the beam splitter 3 that transmits a part of the measurement light and reflects a part of the measurement light, a reflecting member that reflects the measurement light transmitted through the beam splitter 3 (For example, the reflective surface 4a of the triangular prism 4), a light guide member that guides the measurement light reflected by the reflective surface 4a to the beam splitter 6 (for example, the reflective surface 4b of the movable triangular prism 5 and the triangular prism 4), In this case, the first measurement light does not travel straight after passing through the beam splitter 3 and travels toward the beam splitter 6, but after passing through the beam splitter 3, the first triangular prism 4 After being reflected by the reflecting surface 4a of the first and second reflecting prisms 5 and reflected by the reflecting surface 4b of the movable triangular prism 4, the beams are reflected. It reaches the presetter 6.

すなわち、ビームスプリッタ３の透過後、第１三角プリズム４及び可動三角プリズム５によって形成された迂回経路を通過させてからビームスプリッタ６にて第２測定光の光路との合流させることにより、ビームスプリッタ３の反射方向に形成されミラー１１及びミラー１３による迂回光路を持つ第２測定光路の光路長と第１測定光路の光路長との光路差を短くしている。この場合、第１三角プリズム４及び可動三角プリズム５による迂回光路の光路長を調整することにより、角膜に照射された第１測定光の光路長と水晶体前面に照射された第２測定光の光路長との光路差（前房深度測定用の光路差）に対応できる。これにより、被検眼の角膜からの反射光と被検眼の水晶体前面からの反射光との干渉光を受光素子２２に受光させることができる。 That is, after passing through the beam splitter 3, it passes through a detour path formed by the first triangular prism 4 and the movable triangular prism 5, and then merges with the optical path of the second measurement light by the beam splitter 6. The optical path difference between the optical path length of the second measurement optical path and the optical path length of the first measurement optical path which is formed in the reflection direction 3 and has a bypass optical path by the mirror 11 and the mirror 13 is shortened. In this case, by adjusting the optical path length of the detour optical path by the first triangular prism 4 and the movable triangular prism 5, the optical path length of the first measurement light irradiated on the cornea and the optical path of the second measurement light irradiated on the front surface of the crystalline lens. It is possible to cope with the optical path difference from the length (optical path difference for anterior chamber depth measurement). Thereby, the light receiving element 22 can receive the interference light between the reflected light from the cornea of the eye to be examined and the reflected light from the front surface of the crystalline lens of the eye to be examined.

また、第１三角プリズム４及び可動三角プリズム５による迂回光路の光路長をさらに延ばすことにより、角膜に照射された第１測定光の光路長と眼底に照射された第２測定光の光路長との光路差（眼軸長測定用の光路差）に対応できる。なお、上記構成においては、ビームスプリッタ３の透過方向を第１測定光路とするような構成としたが、これに限るものではなく、ビームスプリッタ３の透過方向を第２測定光路にするような構成であってもよい。 Further, by further extending the optical path length of the detour optical path by the first triangular prism 4 and the movable triangular prism 5, the optical path length of the first measurement light irradiated to the cornea and the optical path length of the second measurement light irradiated to the fundus Can be accommodated (optical path difference for measuring the axial length). In the above configuration, the transmission direction of the beam splitter 3 is set as the first measurement optical path. However, the configuration is not limited thereto, and the transmission direction of the beam splitter 3 is set as the second measurement optical path. It may be.

なお、上記光学系の構成において、上記照射光学系１００及び干渉光学系２００は、測定光源１から出射された測定光を第１測定光として被検眼角膜に照射して角膜からの反射光を受光するための第１測定光学系と、測定光源１から出射された測定光を第２測定光として被検眼眼底に照射して眼底からの反射光を受光するための第２測定光学系と、して機能する。そして、第１測定光の光路長または前記第２測定光の光路長のいずれかを変更させるための光路長変更手段は、第１測定光学系または第２測定光学系のどちらかに配置される。また、干渉光学系２００におけるビームスプリッタ３〜受光素子２２までの光路は、第１測定光学系及び第２測定光学系の共通光路に置かれ，第１測定光の反射光と第２測定光の反射光との合成による干渉光を受光し干渉信号を得るための受光光学系として機能する。そして、集光位置切換機構７０は、第１測定光学系及び第２測定光学系の共通光路の共通光路とならない第２測定光学系の光路中に配置される所定の光学部材（リレーレンズ１２）を移動させることにより、第２測定光の照射目標を被検眼眼底と被検眼の水晶体前面とに選択的に切り換える。 In the configuration of the optical system, the irradiation optical system 100 and the interference optical system 200 receive the reflected light from the cornea by irradiating the eye cornea with the measurement light emitted from the measurement light source 1 as the first measurement light. A second measurement optical system for irradiating the fundus of the subject's eye with the measurement light emitted from the measurement light source 1 as the second measurement light and receiving the reflected light from the fundus; Function. Then, the optical path length changing means for changing either the optical path length of the first measurement light or the optical path length of the second measurement light is arranged in either the first measurement optical system or the second measurement optical system. . The optical path from the beam splitter 3 to the light receiving element 22 in the interference optical system 200 is placed in the common optical path of the first measurement optical system and the second measurement optical system, and the reflected light of the first measurement light and the second measurement light It functions as a light receiving optical system for receiving interference light by combining with reflected light and obtaining an interference signal. The condensing position switching mechanism 70 is a predetermined optical member (relay lens 12) disposed in the optical path of the second measurement optical system that is not a common optical path of the common optical path of the first measurement optical system and the second measurement optical system. Is moved selectively between the fundus of the eye to be examined and the front surface of the crystalline lens of the eye to be examined.

被検眼を固視させるための固視標を被検眼に投影する固視標投影光学系４０は、固視用チャートを表示する液晶ディスプレイ４２、液晶ディスプレイ４２に表示された固視用チャートを被検眼眼底に結像させるための結像レンズ４１、可視光を反射して赤外光（測定光）を透過するダイクロイックミラー４３、を含む。なお、液晶ディスプレイ４２には、所定のパターン形状（例えば、十字マーク）を持つチャートが表示されるようになっており、制御部８０による表示制御によってチャートの表示位置が二次元的に移動できるような構成となっている。 A fixation target projection optical system 40 that projects a fixation target for fixing the eye to be examined on the eye to be examined includes a liquid crystal display 42 that displays a fixation chart, and a fixation chart displayed on the liquid crystal display 42. An imaging lens 41 for forming an image on the fundus of the optometric eye and a dichroic mirror 43 that reflects visible light and transmits infrared light (measurement light) are included. Note that a chart having a predetermined pattern shape (for example, a cross mark) is displayed on the liquid crystal display 42, and the display position of the chart can be moved two-dimensionally by display control by the control unit 80. It has become a structure.

被検眼の前眼部を観察するために被検眼の前眼部を撮像する前眼部撮像光学系３０は、対物レンズ１０、リレーレンズ３１、結像レンズ３２、二次元撮像素子３３、を含む。ここで、図示無き前眼部照明によって赤外照明された前眼部像は、ダイクロイックミラー４３、対物レンズ１０、測定光の大部分を反射し測定光の一部及び前眼部照明光を透過する波長特性を有するダイクロイックミラー９、リレーレンズ３１、結像レンズ３２を介して、二次元撮像素子３３に結像される。 An anterior segment imaging optical system 30 that images the anterior segment of the subject eye to observe the anterior segment of the subject eye includes an objective lens 10, a relay lens 31, an imaging lens 32, and a two-dimensional imaging element 33. . Here, the anterior ocular segment image that is illuminated in infrared by the anterior ocular segment illumination (not shown) reflects most of the dichroic mirror 43, the objective lens 10 and the measurement light, and transmits a part of the measurement light and the anterior ocular illumination light. The image is formed on the two-dimensional image sensor 33 through the dichroic mirror 9 having the wavelength characteristics to be achieved, the relay lens 31, and the imaging lens 32.

次に、本実施形態に係る装置の制御系について説明する。制御部８０は、表示モニタ８１、光源１、受光素子２２、駆動部７０、駆動部７１、駆動部７２、コントロール部８４、メモリ８５、等が接続される。なお、駆動部７１及び駆動部７２には、パルスモータを用いており、各駆動部に対する駆動量が検出できるようになっている。制御部８０は、受光素子２２から出力される干渉信号と，光路長変更のために駆動される駆動部７１に対する駆動結果（光路長の変更情報）に基づいて、被検眼の眼軸長及び前房深度を演算により求める。また、メモリ８５には、求められた測定値などが記憶される。また、コントロール部８４には、被検眼の眼軸長を測定する眼軸長測定モードと被検眼の前房深度を測定する前房深度測定モードとを切り換えるモード切換スイッチ８４ａ、測定開始のトリガ信号を発する測定開始スイッチ８４ｂ、被検眼の視度を補正するために眼屈折力測定装置（例えば、特開２００６−１８７４８２号公報参照）によって測定された屈折度数を入力する度数入力スイッチ８４ｃ、等の各種スイッチが設けられている。 Next, a control system of the apparatus according to the present embodiment will be described. The control unit 80 is connected to the display monitor 81, the light source 1, the light receiving element 22, the drive unit 70, the drive unit 71, the drive unit 72, the control unit 84, the memory 85, and the like. Note that a pulse motor is used for the drive unit 71 and the drive unit 72 so that the drive amount for each drive unit can be detected. Based on the interference signal output from the light receiving element 22 and the driving result (the optical path length change information) for the driving unit 71 that is driven to change the optical path length, the control unit 80 determines the axial length and the front of the eye to be examined. The tuft depth is calculated. The memory 85 stores the obtained measurement value and the like. The control unit 84 also includes a mode changeover switch 84a for switching between an axial length measurement mode for measuring the axial length of the eye to be examined and an anterior chamber depth measurement mode for measuring the anterior chamber depth of the subject eye, and a trigger signal for starting measurement. A measurement start switch 84b that emits light, a power input switch 84c that inputs a refractive power measured by an eye refractive power measurement device (see, for example, Japanese Patent Laid-Open No. 2006-187482) to correct the diopter of the eye to be examined, and the like. Various switches are provided.

以上のような構成を備える装置を用いて、被験者眼の眼軸長及び前房深度を測定する場合について説明する。なお、以下の説明では、眼軸長測定、前房深度測定、の順で測定を行う。 A case where the axial length and the anterior chamber depth of the subject's eye are measured using the apparatus having the above configuration will be described. In the following description, measurement is performed in the order of axial length measurement and anterior chamber depth measurement.

眼軸長モードに移行するようにモード切換スイッチ８４ａが検者によって操作されると、制御部８０は、測定モードを眼軸長測定モードに切り換え、駆動部７０を駆動させ、第２測定光路Ｔ２の光路中にリレーレンズ１２が配置された光学配置に切り換える。これにより、被検眼に向けて照射される第２測定光が被検眼の眼底に集光可能な状態となる。 When the mode selector switch 84a is operated by the examiner so as to shift to the axial length mode, the control unit 80 switches the measurement mode to the axial length measurement mode, drives the drive unit 70, and the second measurement optical path T2. To the optical arrangement in which the relay lens 12 is arranged in the optical path. Thereby, it will be in the state which can condense the 2nd measurement light irradiated toward the eye to be examined on the fundus of the eye to be examined.

次に、検者は、モニタ８１に表示される被験者眼のアライメント状態を見ながら、図示なきジョイスティック等の操作手段を用いて、装置を上下左右及び前後方向に移動させ、装置を被験者眼Ｅに対して所定の位置関係に置く。より具体的には、被験者眼の角膜頂点もしくは瞳孔中心と測定光軸とが略一致するように装置を上下左右に移動させると共に、装置と被験者眼との作動距離が所定の適正作動距離（例えば、ＷＤ＝４０ｍｍ）となるように装置を前後方向に移動させる。また、検者は、固視標投影光学系４０によって投影される固視標を被験者眼に固視させる。また、検者は、度数入力スイッチ８４ｃを用いて被検眼の眼屈折力を入力する。そして、制御部８０は、入力スイッチ８４ｃで入力された屈折度数に基づいて駆動部７２を駆動させリレーレンズ１２を移動させることにより、被検眼の視度を補正する。 Next, the examiner moves the apparatus up and down, right and left and back and forth using an operation means such as a joystick (not shown) while observing the alignment state of the subject eye displayed on the monitor 81, and moves the apparatus to the subject eye E. On the other hand, it is placed in a predetermined positional relationship. More specifically, the device is moved vertically and horizontally so that the corneal apex or pupil center of the subject's eye and the measurement optical axis substantially coincide with each other, and the working distance between the device and the subject's eye is a predetermined appropriate working distance (for example, , WD = 40 mm), the apparatus is moved in the front-rear direction. Further, the examiner fixes the fixation target projected by the fixation target projection optical system 40 to the subject's eye. Further, the examiner inputs the eye refractive power of the eye to be examined using the frequency input switch 84c. Then, the control unit 80 corrects the diopter of the eye to be examined by driving the driving unit 72 and moving the relay lens 12 based on the refractive power input by the input switch 84c.

ここで、測定開始のトリガ信号が発せられると、制御部８０は、測定光源１を点灯させ、照射光学系１００により測定光を被検眼に照射すると共に、測定光による被検眼からの反射光を干渉光学系２００の受光素子２２により受光する。また、制御部８０は、駆動部７１を駆動させることにより可動三角プリズム５を移動させていき、受光素子２２から得られる干渉信号と、プリズム５の移動によって変化される第１測定光の光路長（光路長変更部材の駆動結果）、から被検眼の眼軸長を求める。 Here, when a trigger signal for starting measurement is issued, the control unit 80 turns on the measurement light source 1 and irradiates the eye with measurement light by the irradiation optical system 100, and also reflects reflected light from the eye under measurement by the measurement light. Light is received by the light receiving element 22 of the interference optical system 200. Further, the control unit 80 moves the movable triangular prism 5 by driving the driving unit 71, and the optical signal length of the first measurement light changed by the interference signal obtained from the light receiving element 22 and the movement of the prism 5. From the (result of driving the optical path length changing member), the axial length of the eye to be examined is obtained.

なお、本実施形態では、第２測定光の光路長より第１測定光の光路長が短くなるようにプリズム５の基準位置（初期位置）が設定されている。したがって、第１測定光の光路長が長くなる方向（第１三角プリズム４から離れる方向）にプリズム５が基準位置から移動されていくと、まず、第１測定光による角膜からの反射光と第２測定光による角膜からの反射光（第２測定光が眼底に向かう際の角膜反射光）との干渉光が受光素子２２に検出される（眼軸長０ｍｍの位置）。さらに、プリズム５が移動されていくと、角膜に照射された第１測定光の光路長と眼底に照射された第２測定光との光路長との光路差が少なくなっていき、第１測定光による角膜からの反射光と第２測定光による眼底からの反射光との干渉光が受光素子２２に検出される。ここで、第１測定光と第２測定光による角膜からの反射光の干渉光が検出される位置から第１測定光による角膜反射光と第２測定光による眼底反射光との干渉光が検出されるまでのプリズム５の移動量Ｍ１は、被検眼の眼軸長に応じて異なる。したがって、所定の演算式を用いて、移動量Ｍ１と被検眼の眼軸長との関係を求めておくことにより、プリズム５の移動量Ｍ１に対応する眼軸長データを求めることができる。なお、取得された被験者眼の眼軸長の情報は、メモリ８５に記憶されるとともに、モニタ８１に表示される。また、制御部８０は、測定完了後、駆動部７１を駆動させることによりプリズム５の移動位置を初期位置に復帰させておく。 In the present embodiment, the reference position (initial position) of the prism 5 is set so that the optical path length of the first measurement light is shorter than the optical path length of the second measurement light. Therefore, when the prism 5 is moved from the reference position in the direction in which the optical path length of the first measurement light becomes longer (the direction away from the first triangular prism 4), first, the first reflected light from the cornea and the first reflected light. The interference light with the reflected light from the cornea due to the two measurement lights (the corneal reflection light when the second measurement light travels toward the fundus) is detected by the light receiving element 22 (position of the ocular axial length of 0 mm). Further, as the prism 5 is moved, the optical path difference between the optical path length of the first measurement light applied to the cornea and the optical path length of the second measurement light applied to the fundus is reduced, and the first measurement is performed. Interference light between the reflected light from the cornea due to the light and the reflected light from the fundus due to the second measurement light is detected by the light receiving element 22. Here, the interference light of the cornea reflection light by the first measurement light and the fundus reflection light by the second measurement light is detected from the position where the interference light of the reflection light from the cornea by the first measurement light and the second measurement light is detected. The amount of movement M1 of the prism 5 until it varies depends on the axial length of the eye to be examined. Therefore, by obtaining a relationship between the movement amount M1 and the axial length of the eye to be examined using a predetermined arithmetic expression, the axial length data corresponding to the movement amount M1 of the prism 5 can be obtained. The acquired information about the axial length of the subject's eye is stored in the memory 85 and displayed on the monitor 81. Further, after the measurement is completed, the control unit 80 drives the drive unit 71 to return the movement position of the prism 5 to the initial position.

以上のように被検眼の眼軸長測定が完了したら、前房深度測定に移行する。ここで、前房深度測定モードの移行するようにモード切換スイッチ８４ａが検者によって操作されると、制御部８０は、測定モードを前房深度モードに切り換え、駆動部７０を駆動させることにより、第２測定光路Ｔ２からリレーレンズ１２が外れた光学配置に切り換える。これにより、被検眼に向けて照射される第２測定光が被検眼の前眼部に集光された状態となる。なお、上記モード切換において、制御部８０は、所定の切換信号に基づいて自動的に眼軸長測定モードから前房深度測定モードに切り換えるようにしてもよい。 When the measurement of the axial length of the eye to be examined is completed as described above, the process proceeds to anterior chamber depth measurement. Here, when the mode switch 84a is operated by the examiner so as to shift to the anterior chamber depth measurement mode, the control unit 80 switches the measurement mode to the anterior chamber depth mode and drives the drive unit 70, thereby It switches to the optical arrangement | positioning which the relay lens 12 remove | deviated from 2nd measurement optical path T2. Thereby, it will be in the state where the 2nd measurement light irradiated toward the eye to be examined was condensed on the anterior eye part of the eye to be examined. In the mode switching, the control unit 80 may automatically switch from the axial length measurement mode to the anterior chamber depth measurement mode based on a predetermined switching signal.

次に、検者は、表示モニタ８１上の前眼部像における測定光の角膜反射による輝点と水晶体前面による輝点を見ながら、ディスプレイ４２に表示される固視灯の位置を二次元的に変化させ、モニタ８１に表示される角膜輝点と水晶体前面輝点とが重なるように（測定光軸Ｌａと被検眼の眼軸を一致させるため）、コントロール部８４に設けられた固視位置変更スイッチ８４ｃを操作する。この場合、制御部８０は、スイッチ８４ｃからの操作信号に基づいてディスプレイ４２に表示される固視位置を移動させる。ここで、検者によってスイッチ８４ｃが操作され、角膜輝点と水晶体前面輝点との重なりがモニタ８１で確認されると、検者は、コントロール部８４の測定開始スイッチ８４ｂを押して、被検眼の前房深度測定を開始する。 Next, the examiner two-dimensionally determines the position of the fixation lamp displayed on the display 42 while observing the bright spot due to the cornea reflection of the measurement light in the anterior segment image on the display monitor 81 and the bright spot due to the front surface of the crystalline lens. The fixation position provided in the control unit 84 so that the corneal luminescent spot displayed on the monitor 81 and the front luminescent spot of the crystalline lens overlap (in order to make the measurement optical axis La coincide with the eye axis of the eye to be examined). The change switch 84c is operated. In this case, the control unit 80 moves the fixation position displayed on the display 42 based on the operation signal from the switch 84c. Here, when the switch 84c is operated by the examiner and the overlap between the corneal bright spot and the front face bright spot is confirmed on the monitor 81, the examiner presses the measurement start switch 84b of the control unit 84 to Start anterior chamber depth measurement.

ここで、測定開始のトリガ信号が発せられると、駆動部７１を駆動させることにより可動三角プリズム５を移動させていき、受光素子２２から得られる干渉信号と、プリズム５の移動によって変化される第１測定光の光路長（光路長変更部材の駆動結果）、から被検眼の前房深度を求める。 Here, when a trigger signal for starting measurement is generated, the movable triangular prism 5 is moved by driving the driving unit 71, and the interference signal obtained from the light receiving element 22 and the first change which is changed by the movement of the prism 5 are performed. The anterior chamber depth of the eye to be examined is obtained from the optical path length of one measurement light (the driving result of the optical path length changing member).

ここで、第１測定光の光路長が長くなる方向にプリズム５が基準位置から移動されていくと、まず、第１測定光による角膜からの反射光と第２測定光による角膜からの反射光（第２測定光が水晶体に向かう際の角膜反射光）との干渉光が受光素子２２に検出される（前房深度０ｍｍの位置）。さらに、プリズム５が移動されていくと、角膜に照射（集光）された第１測定光の光路長と水晶体前面に照射（集光）された第２測定光との光路長との光路差が少なくなっていき、第１測定光による角膜からの反射光と第２測定光による水晶体前面からの反射光との干渉光が受光素子２２に検出される。ここで、第１測定光と第２測定光による角膜からの反射光の干渉光が検出される位置から第１測定光による角膜反射光と第２測定光による水晶体前面反射光との干渉光が検出されるまでのプリズム５の移動量Ｍ２は、被検眼の前房深度に応じて異なる。したがって、所定の演算式を用いて、移動量Ｍ２と被検眼の前房深度との関係を求めておくことにより、プリズム５の移動量Ｍ２に対応する前房深度を求めることができる。なお、取得された被験者眼の前房深度の情報は、メモリ８５に記憶されるとともに、モニタ８１に表示される。なお、前房深度測定モードの場合、所定の基準位置からのプリズム５の移動可能範囲は、前房深度の測定が可能な範囲内で移動されるものであればよく、眼軸長測定用に設定された移動可能範囲より短くなるように設定されたものであってもよい。この場合、プリズム５の移動可能範囲が小さい状態（光路長変更部材による光路長の変更範囲が小さい状態）で、プリズム５を往復移動させることで前房深度の測定を複数回行って測定結果の平均化を行うことにより、測定誤差の軽減、測定時間の短縮、が可能となる。 Here, when the prism 5 is moved from the reference position in the direction in which the optical path length of the first measurement light is increased, first, the reflected light from the cornea by the first measurement light and the reflected light from the cornea by the second measurement light. Interference light with (corneal reflection light when the second measurement light travels toward the crystalline lens) is detected by the light receiving element 22 (position at anterior chamber depth of 0 mm). Further, when the prism 5 is moved, the optical path difference between the optical path length of the first measurement light irradiated (condensed) on the cornea and the optical path length of the second measurement light irradiated (condensed) on the front surface of the crystalline lens. , And the interference light between the reflected light from the cornea by the first measurement light and the reflected light from the front surface of the crystalline lens by the second measurement light is detected by the light receiving element 22. Here, the interference light between the cornea reflection light by the first measurement light and the lens front reflection light by the second measurement light from the position where the interference light of the reflection light from the cornea by the first measurement light and the second measurement light is detected. The amount of movement M2 of the prism 5 until it is detected varies depending on the anterior chamber depth of the eye to be examined. Accordingly, the anterior chamber depth corresponding to the movement amount M2 of the prism 5 can be obtained by obtaining the relationship between the movement amount M2 and the anterior chamber depth of the eye to be examined using a predetermined arithmetic expression. The acquired information about the depth of the anterior chamber of the subject's eye is stored in the memory 85 and displayed on the monitor 81. In the anterior chamber depth measurement mode, the movable range of the prism 5 from the predetermined reference position is not limited as long as it can be moved within the range in which the anterior chamber depth can be measured. It may be set to be shorter than the set movable range. In this case, the anterior chamber depth is measured a plurality of times by reciprocating the prism 5 in a state where the movable range of the prism 5 is small (a state where the optical path length change range by the optical path length changing member is small). By performing averaging, measurement errors can be reduced and measurement time can be shortened.

以上のような構成とすれば、被検眼の所定部位に向けて照射される第２測定光を被検眼の眼底に集光するか被検眼の前眼部に集光させるかを切換可能な構成によって、眼底に集光された照射光による眼底反射光と角膜反射光との干渉により眼軸長測定がなされ、被検眼前眼部に集光された照射光による水晶体前面反射光と角膜反射光との干渉により前房深度測定がなされるため、被検眼の眼軸長と前房深度を精度よく測定できる。 With the above configuration, the second measurement light irradiated toward a predetermined part of the eye to be examined can be switched between focusing on the fundus of the eye to be examined or on the anterior eye portion of the eye to be examined. Is used to measure the axial length by the interference between the fundus reflection light and the cornea reflection light by the irradiation light collected on the fundus, and the front lens reflection light and the cornea reflection light by the irradiation light collected on the anterior eye portion of the eye to be examined. Since the anterior chamber depth is measured by the interference with the eye, the axial length and the anterior chamber depth of the eye to be examined can be accurately measured.

なお、以上の説明においては、第１測定光路中に光路変更部材（可動三角プリズム５）を設け、第１測定光の光路長を変更させることにより第１測定光と第２測定光との干渉を生じさせるような構成としたが、第１測定光路と第２測定光路のいずれかに光路変更部材を設け、第１測定光の光路長と第２測定光の光路長のいずれかを変更させることにより第１測定光と第２測定光との干渉を生じさせるような構成であればよい。すなわち、第１測定光と第２測定光の干渉を起こすべく、光路分割部材によって分割された分割光路中に光路長変更部材が設けられた構成により、第１測定光の光路長と第２測定光の光路長との光路差が調整されるものであればよい。この場合、第１測定光路と第２測定光路の各光路長が最も短くなるように各光路の光学部材の位置が調整されたときに（光学部材の可動範囲内）、光路長が短い方の光路に光路長変更部材が配置され、光路長変更部材が配置された光路の光路長が長くなるように光路長変更部材が移動可能な構成であればよい。 In the above description, an optical path changing member (movable triangular prism 5) is provided in the first measurement optical path, and interference between the first measurement light and the second measurement light is performed by changing the optical path length of the first measurement light. However, an optical path changing member is provided in either the first measurement optical path or the second measurement optical path to change either the optical path length of the first measurement light or the optical path length of the second measurement light. Therefore, any configuration that causes interference between the first measurement light and the second measurement light may be used. That is, in order to cause interference between the first measurement light and the second measurement light, the optical path length of the first measurement light and the second measurement light are provided by the configuration in which the optical path length changing member is provided in the divided optical path divided by the optical path dividing member. What is necessary is just to adjust the optical path difference with the optical path length of light. In this case, when the position of the optical member of each optical path is adjusted so that the respective optical path lengths of the first measurement optical path and the second measurement optical path are the shortest (within the movable range of the optical member), the shorter optical path length Any configuration is possible as long as the optical path length changing member is arranged in the optical path and the optical path length changing member is movable so that the optical path length of the optical path in which the optical path length changing member is arranged becomes long.

なお、以上の説明では、眼軸長測定モードにおける第１測定光の集光位置について、被検眼の角膜頂点から水晶体側に約３ｍｍの位置に向けて第１測定光を入射させるような構成としたが、これに限るものではなく、被検眼前眼部のいずれかに第１測定光を入射させることにより被検眼角膜からの反射光が受光素子２２に受光されるものであればよい。例えば、被検眼の角膜頂点又は角膜曲率中心に向けて第１測定光を入射させるようにしてもよい。 In the above description, the first measurement light is incident on the focusing position of the first measurement light in the axial length measurement mode from the apex of the cornea of the subject's eye toward the crystalline lens at a position of about 3 mm. However, the present invention is not limited to this, and any light beam may be used as long as the reflected light from the cornea of the eye to be examined is received by the light receiving element 22 when the first measurement light is incident on any one of the anterior eye portions of the eye to be examined. For example, the first measurement light may be incident toward the corneal apex or the corneal curvature center of the eye to be examined.

また、以上の説明では、前房深度測定モードにおける第２測定光の集光位置について、被検眼の角膜頂点から水晶体側に約３ｍｍの位置に向けて第２測定光を入射させるような構成としたが、これに限るものではなく、被検眼前眼部のいずれかに第２測定光を入射させることにより水晶体前面からの反射光が受光素子２２に受光されるものであればよい。例えば、被検眼の曲率中心に向けて第２測定光を入射させるようにしてもよい。なお、実験によれば、角膜と水晶体前面からの反射光による干渉信号を感度（効率）よく取得するためには、被検眼の角膜頂点から水晶体側に約２ｍｍ〜４ｍｍずれた位置に第２測定光を入射させる構成が良いことがわかった（より好ましくは、約３ｍｍ）。 In the above description, the second measurement light is incident on the condensing position of the second measurement light in the anterior chamber depth measurement mode from the apex of the cornea of the eye to the lens side toward the position of about 3 mm. However, the present invention is not limited to this, and it is only necessary that the light reflected from the front surface of the crystalline lens is received by the light receiving element 22 when the second measurement light is incident on any one of the anterior eye portions to be examined. For example, the second measurement light may be incident toward the center of curvature of the eye to be examined. In addition, according to the experiment, in order to acquire an interference signal by reflected light from the cornea and the front surface of the lens with high sensitivity (efficiency), the second measurement is performed at a position shifted from the apex of the cornea of the eye to be examined by about 2 mm to 4 mm toward the lens. It turned out that the structure which injects light is good (preferably about 3 mm).

なお、以上の説明においては、プリズム５の移動量Ｍ１及びＭ２から眼軸長及び前房深度を求めるような構成としたが、これに限るものではなく、受光素子２２から得られる干渉信号とプリズム５の駆動結果に基づいて眼軸長測定及び前房深度測定が可能な構成であればよい。例えば、第１測定光による角膜反射光と第２測定光による眼底反射光との干渉光、第１測定光による角膜反射光と第２測定光による水晶体前面反射光との干渉光、が検出されたときのプリズム５の移動位置に基づいて眼軸長及び前房深度を求めるような構成であってもよい。 In the above description, the configuration is such that the axial length and the anterior chamber depth are obtained from the movement amounts M1 and M2 of the prism 5, but the present invention is not limited to this, and the interference signal obtained from the light receiving element 22 and the prism Any configuration that can measure the axial length and the anterior chamber depth based on the driving result of 5 may be used. For example, interference light between the cornea reflection light by the first measurement light and the fundus reflection light by the second measurement light, and the interference light between the cornea reflection light by the first measurement light and the front lens reflection light by the second measurement light are detected. The configuration may be such that the axial length and the anterior chamber depth are obtained based on the movement position of the prism 5 at that time.

また、以上の説明においては、照射光学系１００の測定光の光路を第１測定光路Ｔ１と第２測定光路Ｔ２に分割する光路分割部材（但し、干渉光学系２００においては光路合成部材として利用される）、及び第１測定光路Ｔ１と第２測定光路Ｔ２に合成する光路合成部材（但し、干渉光学系２００においては光路分割部材として利用される）として、偏光ビームスプリッタ３及び偏光ビームスプリッタ６を用いるような構成により、ハーフミラー等を用いる場合よりも、光路分割部材及び光路合成部材を通過する際の測定光の減衰を軽減できるため、測定精度を向上させることができる。 In the above description, the optical path dividing member that divides the optical path of the measurement light of the irradiation optical system 100 into the first measurement optical path T1 and the second measurement optical path T2 (however, in the interference optical system 200, it is used as an optical path combining member. The polarizing beam splitter 3 and the polarizing beam splitter 6 are used as optical path combining members (used as optical path dividing members in the interference optical system 200) for combining the first measuring optical path T1 and the second measuring optical path T2. With the configuration to be used, since the attenuation of the measurement light when passing through the optical path splitting member and the optical path combining member can be reduced as compared with the case of using a half mirror or the like, the measurement accuracy can be improved.

また、以上の説明においては、リレーレンズ１２を第２測定光路Ｔ２から外すことにより第２測定光を前眼部に集光させるような構成としたが、第２測定光路中に配置される所定の光学部材を移動させることにより、第２測定光の照射目標が被検眼眼底と被検眼の水晶体前面とで選択的に切り換わるものであればよい。例えば、リレーレンズ１２より対物レンズ１０側に凹レンズを配置し、被検眼に照射される平行光束を収束光束に変換させることにより、被検眼前眼部に第２測定光が集光されるような構成であってもよい。また、ズームレンズ系を配置し、ズームレンズ系の移動によって被検眼に照射される平行光束を収束光束に変換するようにしてもよい。 In the above description, the second measurement light is condensed on the anterior eye portion by removing the relay lens 12 from the second measurement optical path T2, but a predetermined arrangement in the second measurement optical path. As long as the optical member is moved, the irradiation target of the second measurement light may be selectively switched between the fundus of the eye to be examined and the lens front surface of the eye to be examined. For example, a concave lens is disposed on the objective lens 10 side of the relay lens 12, and the second measurement light is focused on the anterior eye portion of the eye by converting a parallel light beam irradiated to the eye to be converged. It may be a configuration. Further, a zoom lens system may be arranged so that the parallel light beam irradiated to the eye to be examined by the movement of the zoom lens system is converted into a convergent light beam.

また、以上の説明においては、度数入力スイッチ８４ｃの入力値を基に視度補正を行うような構成としたが、上記装置の光学系に眼屈折力測定光学系を付加し、眼屈折力測定光学系によって得られた屈折度数に基づいて視度補正を行うような構成としてもよい。また、制御部８０は、第２測定光による眼底からの反射光の光量レベルを受光素子２２にてモニタリングし、光量レベルがピークを示す位置に視度補正用の光学部材（例えば、リレーレンズ１２）を移動させるようにしてもよい。 In the above description, the dioptric power correction is performed based on the input value of the power input switch 84c. However, an eye refractive power measurement optical system is added to the optical system of the above apparatus to measure the eye refractive power. The diopter correction may be performed based on the refractive power obtained by the optical system. Further, the control unit 80 monitors the light amount level of the reflected light from the fundus oculi by the second measurement light by the light receiving element 22, and an optical member for diopter correction (for example, the relay lens 12 at a position where the light amount level shows a peak). ) May be moved.

なお、以上の説明においては、照射光学系１００に形成された分割光路を被検眼反射光が通過した後に、ハーフミラー２０によって受光素子２２に導くような構成としたが、ビームスプリッタ６よりも被検眼側に照射光学系１００と干渉光学系２００を分離する光路分割部材を設けるような構成としてもよい。この場合、眼軸長測定時に測定光による角膜反射光と眼底反射光の波面が一致され、前房深度測定時に測定光による角膜反射光と水晶体前面からの反射光の波面を一致させることができるように、干渉光学系２００を構成するのが好ましい。 In the above description, the configuration is such that the reflected light from the eye to be examined is guided to the light receiving element 22 by the half mirror 20 after passing through the split optical path formed in the irradiation optical system 100. An optical path dividing member that separates the irradiation optical system 100 and the interference optical system 200 may be provided on the optometry side. In this case, the wavefronts of the corneal reflection light and fundus reflection light by the measurement light coincide with each other when measuring the axial length, and the wavefronts of the cornea reflection light by the measurement light and the reflection light from the front surface of the crystalline lens can coincide with each other when measuring the anterior chamber depth. Thus, the interference optical system 200 is preferably configured.

例えば、被検眼と対物レンズ１０の間にハーフミラーを設け、ハーフミラーの反射方向に、上記に示した干渉光学系における対物レンズ１０〜受光素子２２までの受光光路と同様の構成を設けるようなことが考えられる。この場合、光路が分割された照射光学系と干渉光学系の両方に分割光路が配置された状態となる。 For example, a half mirror is provided between the eye to be examined and the objective lens 10, and the same configuration as the light receiving optical path from the objective lens 10 to the light receiving element 22 in the interference optical system described above is provided in the reflection direction of the half mirror. It is possible. In this case, the split optical path is arranged in both the irradiation optical system and the interference optical system in which the optical path is split.

なお、以上の説明においては、ビームスプリッタ３のような光路分割部材によって分割される分割光路中に光路変更部材が設けられるような構成としたが、所定の光路分割部材によって分割される分割光路外に、第１測定光の光路長と第２測定光の光路長の少なくともいずれかを変更させるための光路長変更部材が配置された構成であってもよい。 In the above description, the optical path changing member is provided in the split optical path divided by the optical path splitting member such as the beam splitter 3, but the split optical path split by the predetermined optical path splitting member is used. In addition, an optical path length changing member for changing at least one of the optical path length of the first measurement light and the optical path length of the second measurement light may be arranged.

すなわち、測定光源から出射される低コヒーレント光を測定光として被検眼の軸方向において異なる位置に存在する２つの所定部位に向けて照射し，２つの所定部位からの反射光を合成して干渉させることにより所定部位間の眼寸法を測定するための構成を持つ眼寸法測定装置において、異なる所定部位間の眼寸法を測定するために用いる前記測定光の集光位置を実質的に切り換えるものであればよい。 That is, the low coherent light emitted from the measurement light source is irradiated as measurement light toward two predetermined parts existing at different positions in the axial direction of the eye to be examined, and the reflected lights from the two predetermined parts are combined and interfered with each other. Thus, in an eye dimension measuring apparatus having a configuration for measuring the eye dimension between predetermined parts, the condensing position of the measurement light used for measuring the eye dimension between different predetermined parts is substantially switched. That's fine.

図３は、第２の実施形態に係る眼寸法測定装置の光学系を示す概略光学図である。この場合、第１測定光路Ｔ１及び第２測定光路Ｔ２の光路外に光路長変更部材が配置された構成となっている。なお、図３において、図１及び図２にて示した番号と同様の番号を付したものについては、特段の説明が無い限り、図１及び図２で説明した構成と同様の構成を備えるものとし、説明を省略する。 FIG. 3 is a schematic optical diagram showing an optical system of the eye dimension measuring apparatus according to the second embodiment. In this case, the optical path length changing member is arranged outside the optical path of the first measurement optical path T1 and the second measurement optical path T2. In FIG. 3, the same reference numerals as those shown in FIGS. 1 and 2 have the same configurations as those described in FIGS. 1 and 2, unless otherwise specified. The description is omitted.

照射光学系１００によって被検眼に向けて照射された測定光は、第１測定光と第２測定光に分割され、第１測定光は第１集光光学系１００ａを介して主に被検眼角膜及び水晶体前面に照射され、第２測定光は第２集光光学系１００ｂを介して主に被検眼眼底に照射される。この場合、第１集光光学系１００ａは、被検眼の角膜頂点から水晶体側に所定量ずれた被検眼前眼部のいずれかに第２測定光が集光されるように被検眼の前眼部に向けて測定光が入射されるような構成となっている。なお、三角プリズム５は、第１三角プリズム４に対して固定されている。この場合、第１測定光路Ｔ１における光路長と第２測定光路Ｔ２における光路長が異なるように設定されている。 The measurement light emitted toward the subject's eye by the irradiation optical system 100 is divided into a first measurement light and a second measurement light, and the first measurement light mainly passes through the first condensing optical system 100a. The second measurement light is mainly applied to the fundus of the eye to be examined via the second condensing optical system 100b. In this case, the first condensing optical system 100a allows the anterior eye of the eye to be focused so that the second measurement light is focused on one of the anterior eye portions of the eye that is shifted from the corneal apex of the eye to the crystalline lens side by a predetermined amount. The measurement light is incident on the part. The triangular prism 5 is fixed with respect to the first triangular prism 4. In this case, the optical path length in the first measurement optical path T1 and the optical path length in the second measurement optical path T2 are set to be different.

そして、被検眼角膜及び水晶体前面から反射された第１測定光は、被検眼角膜に照射されるまでの第１測定光の光路に対して対物レンズ１０〜可動三角プリズム５〜ビームスプリッタ３までの光路を逆方向に進行し、ハーフミラー２０で反射される。一方、被検眼眼底から反射された第２測定光は、被検眼眼底に照射されるまでの第２測定光の光路に対して対物レンズ１０〜リレーレンズ１２〜ビームスプリッタ３までの光路を逆方向に進行し、ハーフミラー２０で反射される。 Then, the first measurement light reflected from the eye cornea and the front surface of the crystalline lens passes from the objective lens 10 to the movable triangular prism 5 to the beam splitter 3 with respect to the optical path of the first measurement light until the eye cornea is irradiated. The light travels in the opposite direction and is reflected by the half mirror 20. On the other hand, the second measurement light reflected from the eye fundus of the subject reverses the optical path from the objective lens 10 to the relay lens 12 to the beam splitter 3 with respect to the optical path of the second measurement light until the eye fundus is irradiated. And is reflected by the half mirror 20.

そして、ハーフミラー２０で反射された第１測定光による角膜反射光は、直線偏光子５１を介して、ハーフミラー１０３を透過した後、三角プリズム１０４で反射され、三角プリズム１０４に対して移動可能な可動三角プリズム１０５によって折り返された後、第１三角プリズム４で再び反射され、ハーフミラー１０６を透過する。そして、ハーフミラー１０６を透過した第１測定光は、集光レンズ２１にて集光された後、受光素子２２に入射する。なお、可動三角プリズム１０５は、測定に使用する第１測定光の光路長を変更させるための光路変更部材として用いられ、駆動部１７１の駆動によって三角プリズム１０４に対して矢印Ｄ方向に移動される。 Then, the corneal reflected light from the first measurement light reflected by the half mirror 20 passes through the half mirror 103 via the linear polarizer 51, is then reflected by the triangular prism 104, and can move with respect to the triangular prism 104. After being folded by the movable triangular prism 105, it is reflected again by the first triangular prism 4 and passes through the half mirror 106. The first measurement light transmitted through the half mirror 106 is collected by the condenser lens 21 and then enters the light receiving element 22. The movable triangular prism 105 is used as an optical path changing member for changing the optical path length of the first measurement light used for measurement, and is moved in the direction of arrow D with respect to the triangular prism 104 by driving of the driving unit 171. .

また、ハーフミラー２０で反射された第２測定光による眼底反射光及び第１測定光による水晶体前面反射光は、直線偏光子５１を介して、ハーフミラー１０３で反射され、全反射ミラー１１１で反射された後、全反射ミラー１１３を介して、ビームスプリッタ１０６にて第１測定光の光路と合成される。 Further, the fundus reflection light by the second measurement light reflected by the half mirror 20 and the lens front surface reflection light by the first measurement light are reflected by the half mirror 103 and reflected by the total reflection mirror 111 via the linear polarizer 51. After that, it is combined with the optical path of the first measurement light by the beam splitter 106 via the total reflection mirror 113.

なお、上記の場合、第１測定光による角膜反射光にはハーフミラー１０３を反射されるものが含まれ、第２測定光による眼底反射光及び第１測定光による水晶体前眼部反射光はハーフミラー１０３で透過されるものが含まれるが、眼寸法測定に使用するものではないため、以下の説明においては、説明を省略する。 In the above case, the corneal reflection light by the first measurement light includes light reflected from the half mirror 103, and the fundus reflection light by the second measurement light and the anterior ocular lens reflection light by the first measurement light are half. Although what is permeate | transmitted by the mirror 103 is contained, since it is not used for an eye dimension measurement, description is abbreviate | omitted in the following description.

ここで、可動三角プリズム５の移動によって角膜に照射された第１測定光の光路長が変化されると、角膜に照射された第１測定光の光路長（光源１〜角膜、角膜〜受光素子２２）と眼底に照射された第２測定光の光路長が干渉が起こり得る範囲でほぼ等しい関係になるときがある。この場合、三角プリズム１０４で反射されてハーフミラー１０６を透過する第１測定光と、ミラー１１３で反射されてハーフミラー１０６で反射される第２測定光とが合成されて干渉光とされたのち、集光レンズ２１を介して受光素子２２に受光される。 Here, when the optical path length of the first measurement light applied to the cornea is changed by the movement of the movable triangular prism 5, the optical path length of the first measurement light applied to the cornea (light source 1 to cornea, cornea to light receiving element). 22) and the optical path length of the second measurement light applied to the fundus may be substantially equal in a range where interference can occur. In this case, the first measurement light reflected by the triangular prism 104 and transmitted through the half mirror 106 and the second measurement light reflected by the mirror 113 and reflected by the half mirror 106 are combined into interference light. The light receiving element 22 receives light through the condenser lens 21.

また、可動三角プリズム５の移動によって角膜に照射された第１測定光の光路長が変化されると、角膜に照射された第１測定光の光路長（光源１〜角膜、角膜〜受光素子２２）と水晶体前面に照射された第１測定光の光路長（光源１〜水晶体前面、水晶体前面〜受光素子２２）とが干渉が起こり得る範囲でほぼ等しい関係になるときがある。この場合、角膜に照射された第１測定光は、ハーフミラー１０６を透過する際に、ミラー１１で反射されてハーフミラー１０６で反射される水晶体前面に照射された第１測定光と合成され干渉光とされたのち、受光素子２２に受光される。 When the optical path length of the first measurement light applied to the cornea is changed by the movement of the movable triangular prism 5, the optical path length of the first measurement light applied to the cornea (light source 1 to cornea, cornea to light receiving element 22). ) And the optical path length of the first measurement light irradiated to the lens front surface (light source 1 to lens front surface, lens front surface to light receiving element 22) may be in substantially the same relationship within a range where interference can occur. In this case, the first measurement light applied to the cornea is combined with the first measurement light applied to the front surface of the crystalline lens reflected by the mirror 11 and reflected by the half mirror 106 when passing through the half mirror 106. After being made light, the light receiving element 22 receives the light.

この場合、制御部８０は、駆動部１７１を駆動させることにより可動三角プリズム１０５を移動させていき、受光素子２２から得られる干渉信号と、プリズム１０５の移動によって変化される角膜に照射された第１測定光の光路長（光路長変更部材の駆動結果）、から被検眼の眼軸長及び前房深度を求める。 In this case, the control unit 80 moves the movable triangular prism 105 by driving the driving unit 171, and the interference signal obtained from the light receiving element 22 and the first cornea irradiated to the cornea that is changed by the movement of the prism 105. The axial length and anterior chamber depth of the eye to be examined are obtained from the optical path length of one measurement light (the driving result of the optical path length changing member).

すなわち、制御部８０は、角膜からの第１測定光と眼底からの第２測定光による干渉光が受光素子２２に受光されるように可動三角プリズム１０５を移動させていき、角膜からの第１測定光と眼底からの第２測定光による干渉光の干渉信号及び光路長変更手段の駆動結果とに基づいて被検眼の眼軸長を測定する。 That is, the control unit 80 moves the movable triangular prism 105 so that the light receiving element 22 receives the interference light from the first measurement light from the cornea and the second measurement light from the fundus. The control unit 80 moves the first measurement light from the cornea. The axial length of the eye to be examined is measured based on the measurement light and the interference signal of the interference light by the second measurement light from the fundus and the driving result of the optical path length changing means.

また、制御部８０は、角膜からの第１測定光と水晶体前面からの第１測定光による干渉光が受光素子２２に受光されるように可動三角プリズム１０５を移動させていき、角膜からの第１測定光と水晶体前面からの第１測定光による干渉光の干渉信号及び光路長変更手段の駆動結果とに基づいて被検眼の前房深度を測定する。この場合、上記眼軸長測定に対して、眼寸法を測定するために用いる測定光の集光位置が眼底から前眼部に実質的に切換えられる。 Further, the control unit 80 moves the movable triangular prism 105 so that the interference light generated by the first measurement light from the cornea and the first measurement light from the front surface of the crystalline lens is received by the light receiving element 22, and the first measurement light from the cornea is moved. The anterior chamber depth of the eye to be examined is measured based on the interference signal of the interference light by the first measurement light and the first measurement light from the lens front surface and the driving result of the optical path length changing means. In this case, with respect to the measurement of the axial length, the condensing position of the measurement light used for measuring the eye dimensions is substantially switched from the fundus to the anterior eye part.

なお、上記の光学系において、第１集光光学系１００ａは、測定光源１から出射された測定光を第１測定光とし被検眼角膜及び水晶体前面を照射目標として照射するための光学系を持つ第１照射光学系として機能する。第２集光光学系１００ｂは、測定光源１から出射された測定光を第２測定光とし被検眼眼底を照射目標として照射するための光学系を持つ第２照射光学系として機能する。また、ハーフミラー２０〜受光素子２２までの光路に配置された光学部材は、第１測定光による被検眼からの反射光と第２測定光による被検眼からの反射光とを干渉させて受光し干渉信号を得るための受光光学系であって，測定に使用する第１測定光の光路長または測定に使用する第２測定光の光路長のいずれかを受光光路における光路長の増減のみにて変更させるための光路長変更手段を持つ受光光学系として機能する。 In the optical system described above, the first condensing optical system 100a has an optical system for irradiating the subject's eye cornea and the front surface of the crystalline lens with the measurement light emitted from the measurement light source 1 as the first measurement light. It functions as a first irradiation optical system. The second condensing optical system 100b functions as a second irradiation optical system having an optical system for irradiating the fundus of the eye to be examined with the measurement light emitted from the measurement light source 1 as the second measurement light. Further, the optical member arranged in the optical path from the half mirror 20 to the light receiving element 22 receives the reflected light from the eye to be examined by the first measurement light and the reflected light from the eye to be examined by the second measurement light. A light receiving optical system for obtaining an interference signal, wherein either the optical path length of the first measurement light used for measurement or the optical path length of the second measurement light used for measurement is determined by only increasing or decreasing the optical path length in the light receiving optical path. It functions as a light receiving optical system having an optical path length changing means for changing.

そして、制御部８０は、第１測定光による角膜反射光と第２測定光による眼底反射光とを干渉させて得られる干渉信号及び光路長変更手段の変更情報とに基づいて被検眼の眼軸長を測定し，第１測定光による角膜反射光及び水晶体反射光を各々干渉用の前記第１測定光及び第２測定光の反射光として干渉させて得られる干渉信号及び光路長変更手段の変更情報とに基づいて被検眼の前房深度を測定する測定制御手段として機能する。 Then, the control unit 80 determines the eye axis of the subject's eye based on the interference signal obtained by causing the corneal reflection light by the first measurement light and the fundus reflection light by the second measurement light to interfere with each other and the change information of the optical path length changing means. Changes in interference signal and optical path length changing means obtained by measuring the length and causing the cornea reflection light and lens reflection light by the first measurement light to interfere with each other as reflected light of the first measurement light and the second measurement light for interference. It functions as a measurement control means for measuring the anterior chamber depth of the eye to be examined based on the information.

なお、上記の構成の場合、前房深度測定時に受光素子２２への眼底反射光の入射を回避するために、集光光学系１００ａにおける第２測定光路Ｔ２に遮光板を設けるような構成としてもよい。 In the case of the above configuration, a light shielding plate may be provided in the second measurement optical path T2 in the condensing optical system 100a in order to avoid incidence of fundus reflection light to the light receiving element 22 during anterior chamber depth measurement. Good.

本実施形態に係る眼寸法測定装置の光学系の概略構成図であり、眼軸長測定時における光学系の配置を示す図である。It is a schematic block diagram of the optical system of the eye dimension measuring apparatus which concerns on this embodiment, and is a figure which shows arrangement | positioning of the optical system at the time of axial length measurement. 本実施形態に係る眼寸法測定装置の光学系の概略構成図であり、前房深度測定時における光学系の配置を示す図である。It is a schematic block diagram of the optical system of the eye dimension measuring apparatus which concerns on this embodiment, and is a figure which shows arrangement | positioning of the optical system at the time of anterior chamber depth measurement. 第２の実施形態に係る眼寸法測定装置の光学系を示す概略光学図である。It is a schematic optical diagram which shows the optical system of the eye dimension measuring apparatus which concerns on 2nd Embodiment.

符号の説明Explanation of symbols

１測定光源
２ビームスプリッタ
４三角プリズム
５可動三角プリズム
６ビームスプリッタ
１０対物レンズ
１２リレーレンズ（フォーカシングレンズ）
２２受光素子
７０集光位置切換機構（駆動部）
７１駆動部
８０制御部
８４ａモード切換スイッチ
１００照射光学系
１００ａ第１集光光学系
１００ｂ第２集光光学系
２００干渉光学系 DESCRIPTION OF SYMBOLS 1 Measurement light source 2 Beam splitter 4 Triangular prism 5 Movable triangular prism 6 Beam splitter 10 Objective lens 12 Relay lens (focusing lens)
22 Light receiving element 70 Condensing position switching mechanism (drive unit)
71 Drive unit 80 Control unit 84a Mode changeover switch 100 Irradiation optical system 100a First condensing optical system 100b Second condensing optical system 200 Interference optical system

Claims

測定手段は、
低コヒーレント光を出射する測定光源と、
前記測定光源から出射された前記測定光を第１測定光として被検眼角膜に照射して角膜からの反射光を受光するための第１測定光学系と、
前記測定光源から出射された前記測定光を第２測定光として被検眼眼底に照射して眼底からの反射光を受光するための第２測定光学系と、
前記第１測定光学系または第２測定光学系のどちらかに配置され、前記第１測定光の光路長または前記第２測定光の光路長のいずれかを変更させるための光路長変更手段と、
前記第１測定光学系及び第２測定光学系の共通光路に置かれ，前記第１測定光の反射光と前記第２測定光の反射光との合成による干渉光を受光し干渉信号を得るための受光光学系と、
前記共通光路とならない前記第２測定光学系の光路中に配置される光学レンズを移動させることにより前記第２測定光の集光位置を切り換え、前記第２測定光の照射目標を被検眼眼底と被検眼の水晶体前面とに選択的に切り換える集光位置切換手段と、
被検眼の眼軸長を測定する眼軸長測定モードと被検眼の前房深度を測定する前房深度測定モードを切り換えるモード切換手段と、
該モード切換手段にて前記眼軸長測定モードとされているときは前記照射位置切換手段により前記第２測定光の照射目標を眼底として眼底からの反射光と角膜からの反射光との合成による前記干渉信号及び光路長変更手段の変更情報とに基づいて被検眼の眼軸長を測定し，前記前房深度測定モードとされているときは前記照射位置切換手段により前記第２測定光の照射目標を水晶体前面として、角膜からの反射光と水晶体前面からの反射光との合成による前記干渉信号及び光路長変更手段の変更情報とに基づいて被検眼の前房深度を測定する測定制御手段と、
を備えることを特徴とする眼寸法測定装置。 Measuring means
A measurement light source that emits low coherent light;
A first measurement optical system for irradiating the eye cornea with the measurement light emitted from the measurement light source as first measurement light and receiving reflected light from the cornea;
A second measurement optical system for irradiating the fundus of the eye to be examined with the measurement light emitted from the measurement light source as second measurement light and receiving reflected light from the fundus;
An optical path length changing unit arranged in either the first measurement optical system or the second measurement optical system, for changing either the optical path length of the first measurement light or the optical path length of the second measurement light;
In order to obtain an interference signal that is placed in a common optical path of the first measurement optical system and the second measurement optical system and receives interference light by combining the reflected light of the first measurement light and the reflected light of the second measurement light. Light receiving optical system,
The condensing position of the second measurement light is switched by moving an optical lens arranged in the optical path of the second measurement optical system that does not become the common optical path, and the irradiation target of the second measurement light is set as the fundus of the eye to be examined. Condensing position switching means for selectively switching to the front surface of the crystalline lens of the eye to be examined;
Mode switching means for switching between an axial length measurement mode for measuring the axial length of the eye to be examined and an anterior chamber depth measurement mode for measuring the anterior chamber depth of the eye to be examined;
When the mode switching means is set to the axial length measurement mode, the irradiation position switching means uses the irradiation target of the second measurement light as a fundus to combine the reflected light from the fundus and the reflected light from the cornea. Based on the interference signal and the change information of the optical path length changing means, the axial length of the eye to be examined is measured. When the anterior chamber depth measurement mode is set, the irradiation position switching means irradiates the second measuring light. Measurement control means for measuring the anterior chamber depth of the eye to be examined based on the interference signal and the change information of the optical path length changing means by combining the reflected light from the cornea and the reflected light from the front of the lens, with the target being the front of the lens ,
Eye size measuring apparatus comprising: a.

請求項１の眼寸法測定装置において、
前記測定光源から出射された測定光の一部を透過し一部を反射することにより第１測定光と第２測定光とに分割する光路分割部材と、該光路分割部材により分割された第１測定光と第２測定光を合成する光路合成部材と、を備え、
前記光路分割部材によって形成される測定光の透過光路には、前記光路分割部材を透過した測定光を反射する反射部材と，前記反射部材によって反射された測定光を前記光路合成部材へと導く導光部材と，によって形成される迂回光路が設けられていることを特徴とする眼寸法測定装置。 In the eye dimension measuring device according to claim 1,
An optical path dividing member that splits the first measurement light and the second measurement light by transmitting a part of the measurement light emitted from the measurement light source and reflecting a part thereof, and the first divided by the optical path division member An optical path combining member that combines the measurement light and the second measurement light,
The transmission light path of the measurement light formed by the optical path dividing member includes a reflection member that reflects the measurement light transmitted through the optical path division member, and a guide that guides the measurement light reflected by the reflection member to the optical path combining member. An eye dimension measuring device comprising a detour optical path formed by an optical member .