JPS5975035A - Apparatus for measuring cornea shape - Google Patents
Apparatus for measuring cornea shapeInfo
- Publication number
- JPS5975035A JPS5975035A JP57185290A JP18529082A JPS5975035A JP S5975035 A JPS5975035 A JP S5975035A JP 57185290 A JP57185290 A JP 57185290A JP 18529082 A JP18529082 A JP 18529082A JP S5975035 A JPS5975035 A JP S5975035A
- Authority
- JP
- Japan
- Prior art keywords
- optical system
- measurement
- corneal
- cornea
- image
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Eye Examination Apparatus (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
本発明は、眼科測定装置に関し、特に角膜形状の測定装
置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ophthalmological measuring device, and more particularly to a corneal shape measuring device.
角膜の形状を測定する角膜計は一般に角膜の曲率。A keratometer that measures the shape of the cornea generally measures the curvature of the cornea.
乱視度そして乱視軸方向の三要素を測定するために使わ
れるが、その他、コンタクトレンズのベースカーブの検
査等にも使われる。It is used to measure the three elements of astigmatism and astigmatic axis direction, but it is also used to inspect the base curve of contact lenses.
従来の角膜計では、リング状のチャートの角膜反射像の
形状を肉眼で観察測定していたので、満足できる精度を
得るため倍−率を高く設定し角膜反射像を拡大していた
。In conventional keratometers, the shape of the corneal reflection image on a ring-shaped chart was observed and measured with the naked eye, so in order to obtain satisfactory accuracy, the magnification was set high to enlarge the corneal reflection image.
その結果、位置合わせ中、及び測定中に観察できる範囲
は角膜のわずか一部にすぎず、実際に角膜全体のうちど
の領域を測定しているのかを把握することが非常に困難
であった。As a result, the range that can be observed during alignment and measurement is only a small portion of the cornea, making it extremely difficult to grasp which region of the entire cornea is actually being measured.
また成る種のものは光路を切換えて前眼部が観察できる
ものもあったが、測定に際しては再び光路な戻して行な
わなければならないために測定中は前述の欠点を避けら
れなかった。In addition, there were some types that allowed observation of the anterior segment of the eye by switching the optical path, but the above-mentioned drawbacks could not be avoided during measurement because the optical path had to be returned again.
本発明は如上の点に鑑み測定の精度を低くすることなく
位置合わせ、測定中に拘らず、前眼部と角膜反射像を観
察できる角膜形状測定装置を提供することを目的とする
。この目的を達成するため本発明においては測定光路と
分岐した又は測定光束と分岐した観察光学系を設は観察
光学系の倍率を測定光学系の倍率より小さくし観察視野
を広げることを特゛徴゛とする。In view of the above-mentioned points, it is an object of the present invention to provide a corneal shape measuring device that allows positioning and observation of the anterior segment of the eye and the corneal reflection image even during measurement without reducing measurement accuracy. In order to achieve this object, the present invention is characterized in that an observation optical system is provided that is branched from the measurement optical path or the measurement light beam, and the magnification of the observation optical system is smaller than that of the measurement optical system to widen the observation field of view.゛.
以下、本発明の詳細な説明する０
第１図は自動角膜計に応用した実−雄側である０１は円
環状の光源で光源１から出た光は円環状シリンドリカル
レンズ２によって光軸ｌを含む各平面で平行に射出され
る。The present invention will be explained in detail below.0 Fig. 1 shows the real-male side of an automatic keratometer. The beam is emitted parallel to each plane containing the beam.
円環状シリンドリカルレンズ２は光軸ｌを含む各平面内
で角膜に対する方の面は曲率半径ｒを持ち、その焦点距
ＩＩ ｊだけ離れた位置に円環状のスリット２′を宿す
る。スリット２′から出た光は光＠ｌを含む各平面内で
平行に射出して被検眼角膜Ｅｃを照明する。The toric cylindrical lens 2 has a surface facing the cornea with a radius of curvature r in each plane including the optical axis l, and has a toric slit 2' at a position separated by a focal length IIj. The light emitted from the slit 2' is emitted in parallel within each plane including the light @l, and illuminates the cornea Ec of the eye to be examined.
角膜Ｅｃで反射された光は発散し見かけ上、角膜反射像
位置臣から射出される。この角膜反射像Ｅ１．は対物レ
ンズ６、光分割ミラー４を透過して、複数穴絞り７．偏
向プリズム８によって光路を分割。The light reflected by the cornea Ec diverges and appears to be emitted from the corneal reflected image. This corneal reflection image E1. is transmitted through the objective lens 6 and the light splitting mirror 4, and then passes through the multi-hole aperture 7. The optical path is divided by a deflection prism 8.
偏向され、受光素子９上にＥｉｉとして結像される０こ
のような被検眼から受光素子９に至る光路は測定に供さ
れる光路である。The optical path from the eye to be examined to the light receiving element 9 is an optical path used for measurement.
受光素子９は例えば−次元イメージセンサであり例えば
第２図の如く、円周上に５個配設され、複数穴絞り７．
偏向プリズム８で５光束に偏向された光束を各々受光す
る。第２図に示される如く、−次元イメージセンサと、
円環状スリットの角膜反射像との交点が５個求まれば２
次曲線の一般式ａｘ２＋ｂｙ２＋ｃｘｙ＋ｄ、ｘ＋ｅｙ
＋ｆ ＝０に代入して各係数を求めることで角膜の一般
楕円形状が求まり、これより角膜の曲率、乱視度、乱視
軸方向が算出できる。The light-receiving elements 9 are, for example, -dimensional image sensors, and as shown in FIG.
Each of the five light beams deflected by the deflection prism 8 is received. As shown in FIG. 2, a -dimensional image sensor,
If 5 points of intersection with the corneal reflection image of the annular slit are found, 2
General formula for the following curve ax2+by2+cxy+d, x+ey
By substituting +f = 0 and finding each coefficient, the general elliptical shape of the cornea can be found, and from this, the curvature of the cornea, the degree of astigmatism, and the direction of the astigmatism axis can be calculated.
以上が測定光学系であるが本発明に係わる観察光学系を
以下に説明する。Although the measurement optical system has been described above, the observation optical system according to the present invention will be explained below.
第１図で、光分割ミラー４によって反射された光束は結
像レンズ５によって撮像管６上に角膜反射像及びそのま
わりの前眼部を結像する。In FIG. 1, the light beam reflected by the light splitting mirror 4 forms an image of the corneal reflection and the surrounding anterior segment on the imaging tube 6 by the imaging lens 5.
光分割ミラー４は撮像管６と受光素子９０分光感度に合
わせて光を反射、透過する波長分割ミラーであっても良
く、また撮像管と受光素子の相対感度に合わせた反射、
透過の比を持つビームスプリッタ−であっても良い。The light splitting mirror 4 may be a wavelength splitting mirror that reflects and transmits light in accordance with the spectral sensitivities of the image pickup tube 6 and the light receiving element 90, or may reflect light in accordance with the relative sensitivities of the image pickup tube and the light receiving element.
It may also be a beam splitter with a transmission ratio.
結像レンズ５は角膜反射像及び前眼部を撮像管の大きさ
に合わせた倍率で結像させるレンズである。The imaging lens 5 is a lens that forms an image of the corneal reflection image and the anterior segment of the eye at a magnification that matches the size of the imaging tube.
このレンズを用い、観察光学系の倍率が測定光学系の倍
率より小さく設定される。なお結像レンズ５として倍率
可変の可変焦点レンズを用いることができ、例えばズー
ムレンズにより観察視野を適宜調整することが可能であ
る０
測定用光学系と観察用光学系は対物レンズ６を共有し、
光分割ミラー４以後の光路は各々独立であるから各光学
系の倍率、ＦＡ等の光学定数は必要に応じて選択するこ
とができる０
第６図は本発明の第２の実施例で手動角膜計に応用した
ものである。Using this lens, the magnification of the observation optical system is set to be smaller than the magnification of the measurement optical system. Note that a variable focus lens with variable magnification can be used as the imaging lens 5, and the observation field of view can be adjusted appropriately using a zoom lens, for example. The measurement optical system and the observation optical system share the objective lens 6. ,
Since the optical paths after the light splitting mirror 4 are independent, the optical constants such as the magnification and FA of each optical system can be selected as necessary. FIG. This is applied to a meter.
符号１乃至６は第１図と同様である。Reference numerals 1 to 6 are the same as in FIG.
光分割ミラー４を透過する光路は測定用に供されイメー
ジローテータ１１を通った光束はミラー１０で反射され
、偏向プリズム１２で偏向されミラー１６、反射プリズ
ム１４で反射され撮像管６上に達し、角膜反射像を結像
する。The optical path passing through the light splitting mirror 4 is used for measurement, and the light beam passing through the image rotator 11 is reflected by the mirror 10, deflected by the deflection prism 12, reflected by the mirror 16, the reflection prism 14, and reaches the image pickup tube 6. A corneal reflection image is formed.
偏向プリズム１２は光軸方向に移動可能であり、分割さ
れた像が合致するまでの移動量から角膜曲率半径を測定
する。The deflection prism 12 is movable in the optical axis direction, and the radius of corneal curvature is measured from the amount of movement until the divided images match.
イメージローテータ１１は偏向プリズム１２と同期して
回転可能であり、これによって乱視角を測定するととが
できる。The image rotator 11 is rotatable in synchronization with the deflection prism 12, thereby making it possible to measure the angle of astigmatism.
第４図は第６図実施例の撮像管での結像状態を示してい
る。FIG. 4 shows an imaging state in the image pickup tube of the embodiment shown in FIG.
第５図は本発明の第６の実施例で測定用光学系と観察用
光学系を分離する手段として、複数穴絞りを用いたもの
である。この複数穴絞り７′は第６図に示される。すな
わち複数穴絞り７′の外周部の穴７ｂ〜７ｆを介して測
定光学系に導き、また中心部の穴７ａを介して観察光学
系へ導くもので、複数穴絞り７′にて両光学系へ光束が
分岐される○受光素子９と撮像管６との光軸方向から眺
めた相対位置関係図は第７図に示される。この実施例に
おいても、観察光学系の倍率を測定光学系の倍率より小
さくして観察視野を広げることができる。FIG. 5 shows a sixth embodiment of the present invention in which a multi-hole diaphragm is used as means for separating the measurement optical system and the observation optical system. This multi-hole aperture 7' is shown in FIG. That is, the multi-hole diaphragm 7' is guided to the measuring optical system through holes 7b to 7f on the outer periphery, and to the observation optical system through the hole 7a in the center. A diagram of the relative positional relationship between the light receiving element 9 and the image pickup tube 6 viewed from the optical axis direction is shown in FIG. In this embodiment as well, the observation field of view can be expanded by making the magnification of the observation optical system smaller than that of the measurement optical system.
以上、本発明によれば測定と観察の光学系を分離し、測
定精度を低下することなく前眼部を広く観測しながら測
定が可能になり、測定時における被検眼の様子と測定部
位の把握が容易になる０As described above, according to the present invention, the measurement and observation optical systems are separated, making it possible to perform measurements while observing a wide area of the anterior eye without reducing measurement accuracy, and to understand the state of the eye to be examined and the measurement site during measurement. becomes easier 0
第１図は本発明の第１実施例の図、
第２図は受光素子と角膜反射像の位置関係図、第６図は
本発明の第２実施例の図、
第４図は第２実施例の撮像管での結像状態の図、第５図
は本発明の第６実施例の図、
第６図は複数穴絞りの図、
第７図は受光素子と撮像管の配置図、
図中１は光源、２は円環状シリンドリカルレンズ、６は
対物レンズ、４は光分割ミラー、５は結像レンズ、６は
撮像管、７，７′は複数穴絞り、８は偏向プリズム、９
は受光素子、ｉｏ、ｉｓはミラー、１１はイメージロー
チーター、１２は偏向プリズム、１４は反射プリズム、
Ｅｃは被検眼角膜、Ｅｉは角膜反射像、Ｅｉｉは角膜反
射像の像、ｌは光軸である。
出願人 キャノン株式会社
代理人 丸 島 儀 −Fig. 1 is a diagram of the first embodiment of the present invention, Fig. 2 is a diagram of the positional relationship between the light receiving element and the corneal reflection image, Fig. 6 is a diagram of the second embodiment of the invention, and Fig. 4 is a diagram of the second embodiment. FIG. 5 is a diagram of the sixth embodiment of the present invention; FIG. 6 is a diagram of a multi-hole diaphragm; FIG. 7 is a diagram of the arrangement of the light receiving element and the imaging tube. 1 is a light source, 2 is an annular cylindrical lens, 6 is an objective lens, 4 is a light splitting mirror, 5 is an imaging lens, 6 is an imaging tube, 7 and 7' are a multi-hole aperture, 8 is a deflection prism, 9
is a light receiving element, io and is are mirrors, 11 is an image low cheater, 12 is a deflection prism, 14 is a reflection prism,
Ec is the cornea of the eye to be examined, Ei is the corneal reflection image, Eii is the corneal reflection image, and l is the optical axis. Applicant Canon Co., Ltd. Agent Gi Marushima −
Claims (1)
形状を測定光学系を介して検出し、角膜形状を測定する
装置において、 測定光路と分岐した又は測定光束と分岐した観察光学系
を形成し、該観察光学系の倍率を測定光学系の倍率より
小さくし、前眼部及び角膜反射像を観察可能としたこと
を竹、徴とする角膜形状測定装置。 ２、前記観察光学系がズームレンズを有する特許請求の
範囲第１項記載の角膜形状測定装置。[Claims] 1. In an apparatus for measuring the shape of the cornea by projecting a chart onto the cornea of the eye to be examined and detecting the shape of the reflected corneal image via a measurement optical system, A corneal shape measuring device is characterized in that a branched observation optical system is formed, and the magnification of the observation optical system is made smaller than that of the measurement optical system, thereby making it possible to observe the anterior segment of the eye and the corneal reflection image. 2. The corneal shape measuring device according to claim 1, wherein the observation optical system includes a zoom lens.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57185290A JPS5975035A (en) | 1982-10-21 | 1982-10-21 | Apparatus for measuring cornea shape |
| US06/833,660 US4710003A (en) | 1982-10-21 | 1986-02-21 | Cornea shape measuring apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57185290A JPS5975035A (en) | 1982-10-21 | 1982-10-21 | Apparatus for measuring cornea shape |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5975035A true JPS5975035A (en) | 1984-04-27 |
| JPS6331213B2 JPS6331213B2 (en) | 1988-06-22 |
Family
ID=16168260
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57185290A Granted JPS5975035A (en) | 1982-10-21 | 1982-10-21 | Apparatus for measuring cornea shape |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5975035A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6324927A (en) * | 1986-07-17 | 1988-02-02 | 株式会社トプコン | Ophthalmic measuring apparatus |
| JPS63216528A (en) * | 1987-03-06 | 1988-09-08 | キヤノン株式会社 | Cornea shape measuring apparatus |
| JP2013056152A (en) * | 2011-08-30 | 2013-03-28 | Oculus Optikgeraete Gmbh | Ophthalmic analytical instrument and method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57139636A (en) * | 1981-02-23 | 1982-08-28 | Nippon Kogaku Kk <Nikon> | Radius-of-curvature measuring device |
-
1982
- 1982-10-21 JP JP57185290A patent/JPS5975035A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57139636A (en) * | 1981-02-23 | 1982-08-28 | Nippon Kogaku Kk <Nikon> | Radius-of-curvature measuring device |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6324927A (en) * | 1986-07-17 | 1988-02-02 | 株式会社トプコン | Ophthalmic measuring apparatus |
| JPS63216528A (en) * | 1987-03-06 | 1988-09-08 | キヤノン株式会社 | Cornea shape measuring apparatus |
| JP2013056152A (en) * | 2011-08-30 | 2013-03-28 | Oculus Optikgeraete Gmbh | Ophthalmic analytical instrument and method |
| US8899753B2 (en) | 2011-08-30 | 2014-12-02 | Oculus Optikgeraete Gmbh | Ophthalmological analysis instrument and method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6331213B2 (en) | 1988-06-22 |
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