JPS60171031A - Eyesight meter - Google Patents

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】 本発明は視標を両眼視可能にした視力計に関する。[Detailed description of the invention] The present invention relates to a visual acuity meter that allows visual targets to be viewed binocularly.

従来、眼科医院、眼鏡店等で用いられる視力針として被
検者の左右眼に別々の視標を呈示し、左右眼光路を分離
したものが知られる。BACKGROUND ART Conventionally, vision needles used in eye clinics, opticians, etc. are known that present separate optotypes to the left and right eyes of a subject and separate the left and right eye optical paths.

すなわち、例えば左眼には左眼用の視標が呈示され、右
眼用の視標社・左眼に呈示されないような視力計である
。That is, for example, the visual acuity meter is such that the left eye is presented with an optotype for the left eye, and the right eye is not presented with the optotype for the left eye.

しかも該視力計は通例視標部のみが呈示され、栽標部以
外の装置内壁面等を被検者がみることができない。Moreover, in the visual acuity meter, only the optotype section is usually presented, and the subject cannot see the inner wall surface of the device other than the optotype section.

斯かる従来例においては、次のような欠点がある。This conventional example has the following drawbacks.

すなわち、 １）成る視標の片眼による目視であるためへ又視標のみ
の平面的な目視であるため、不自然であって、生理的に
いわゆる機械近視を生じ易い。That is, since the visual target consisting of 1) is viewed with one eye, and the visual target alone is viewed in a flat manner, it is unnatural and physiologically prone to so-called mechanical myopia.

２）左右眼に対し別々の視標が呈示されるため視野角が
狭い。2) The viewing angle is narrow because separate optotypes are presented to the left and right eyes.

この結果、調節力の弱い高齢者等においては調節が介入
して自然状態での視力に比べ恕い測定結果を生ずること
があ゛る。As a result, in elderly people and others who have weak accommodation, accommodation may intervene and produce measurement results that are worse than the visual acuity in the natural state.

本発明は斯かる従来例の欠点を除去する視力計を提供す
ることを目的とする。以下、添附する図面を用いて本発
明の詳細な説明する。It is an object of the present invention to provide a visual acuity meter that eliminates the drawbacks of the conventional example. Hereinafter, the present invention will be described in detail using the accompanying drawings.

第１図は本発明の第１の実施例である。FIG. 1 shows a first embodiment of the invention.

被検者Ｓは左右レンズ３Ｌ、３Ｒを通して見かけ上１遠
方にあるランドルト環等の視標１を見る。The subject S looks at a visual target 1, such as a Landolt ring, which is apparently one distance away, through the left and right lenses 3L and 3R.

視標１には視力測定用に複数のランドルト環等が呈示さ
れる。A plurality of Landolt rings and the like are presented on the optotype 1 for visual acuity measurement.

光路中、左右レンズ３Ｌ、３Ｒの近傍には、偏角プリズ
ム２Ｒ，２Ｌが設けられていて左右眼が同一の視標１を
見るように光路を屈折させている。In the optical path, near the left and right lenses 3L, 3R, deflection prisms 2R, 2L are provided to refract the optical path so that the left and right eyes see the same optotype 1.

偏角プリズム２Ｌ　、２Ｒ及び左右レンズ６Ｌ。Deflection prism 2L, 2R and left and right lenses 6L.

６Ｒを介した視線は左右はぼ平行となり、いわゆる輻繕
角はゼロ近傍となシ遠方視の状態とされる。The line of sight through 6R is approximately parallel to the left and right, and the so-called convergence angle is close to zero, resulting in a far viewing state.

なお遠方視として例えば５ｍの位置にある物体を見る場
合が該当する。ここで偏角プリズム２Ｌ。Note that this case corresponds to the case of viewing an object at a distance of 5 m, for example. Here is the declination prism 2L.

２几は高分散プリズムＨと、低分散プリズムＬを貼合わ
せた色消しプリズムとなっており、色収差に基づく視力
測定結果の悪化を予防する。The second prism is an achromatic prism in which a high dispersion prism H and a low dispersion prism L are pasted together to prevent deterioration of visual acuity measurement results due to chromatic aberration.

なお上記光学要素祉筐体４内に設けられていてコンパク
トな視力計となっている。Note that the optical element is provided within the housing 4, making it a compact visual acuity meter.

筺体４の内壁面社従来例の如く光吸収面とする必要が無
く、視線１を見る時の輻暢角とほぼ等しい輻鵬角で視標
近傍の内壁面を見ることができ、視野社従来の如（平面
的にで社なく、立体的である為、生理的ないわゆる機械
近視の発生を除去できる。The inner wall surface of the housing 4 does not need to be a light-absorbing surface as in the conventional example, and the inner wall surface near the visual target can be viewed at a convergence angle that is approximately equal to the convergence angle when viewing the line of sight 1. (Because it is three-dimensional rather than two-dimensional, it can eliminate the occurrence of physiological so-called mechanical myopia.)

第２図は本発明の第２の実施例である。第１図と同一の
符号社同一部材を示す。液晶視標６は図面内方向（水平
方向）に偏光方向を有する偏光板５を通して照明される
。FIG. 2 shows a second embodiment of the invention. The same reference numerals as in FIG. 1 indicate the same members. The liquid crystal optotype 6 is illuminated through a polarizing plate 5 whose polarization direction is in the direction in the drawing (horizontal direction).

ここで液晶視標６はランドルト環等の視標部に電極が設
けられ通電によシ該視標部の偏光方向が水より成る。Here, the liquid crystal optotype 6 has an electrode on an optotype section such as a Landolt ring, and when energized, the polarization direction of the optotype section is made of water.

通％＃の液晶視標６を第４図に示す。FIG. 4 shows a liquid crystal optotype 6 with a normal percentage of #.

図中、破線は各部位における偏光方向を示す。In the figure, broken lines indicate polarization directions at each location.

第２図中７Ｂ、７ＬはＴＮ型液晶であシ、全面に電極が
設けられ通電により偏光方向が水平方向から４５°方向
に変わる。In FIG. 2, 7B and 7L are TN type liquid crystals, electrodes are provided on the entire surface, and the direction of polarization changes from the horizontal direction to the 45° direction when energized.

８Ｒ，８Ｌｔｉ−偏光板で偏光方向は偏光板５と同様水
平方向である。8R, 8Lti-polarizing plates, and the polarizing direction is horizontal like the polarizing plate 5.

ＴＮ型液晶７几、７Ｌに通電しない状態で、液晶視標６
のランドルト環等の視標部に通電すると第４図に示す如
く、ランドルト環６′の部分が暗（、残部６′が明るく
見える０　゛ 両眼視による視力測定の場合、ＴＮ型液晶７Ｒ。When the TN type liquid crystal 7 and 7L are not energized, the liquid crystal optotype 6
When electricity is applied to the Landolt ring, etc., as shown in Fig. 4, the Landolt ring 6' appears dark (and the remaining part 6' appears bright).In the case of binocular visual acuity measurement, the TN type liquid crystal 7R.

７Ｌには通電しないが、片眼による視力測定の場合には
被検眼で無い方のＴＮｆｆｌ液晶７のみに通電する。7L is not energized, but in the case of visual acuity measurement using one eye, only the TNffl liquid crystal 7 of the eye other than the one to be examined is energized.

すると第５図に示す如く該ＴＮ型液晶７を通過する光の
偏光方向は、全面一様となり、ランドルト環部６′と残
部６′社一様に見える。Then, as shown in FIG. 5, the polarization direction of the light passing through the TN liquid crystal 7 becomes uniform over the entire surface, and appears uniform between the Landolt ring 6' and the remaining part 6'.

すなわち１片眼による視力測定の場合、非被検眼におい
て祉、ランドルト環のみが見えなくな）、他の部分例え
ば視標の縁とか筐体の内壁面等が見え両眼視が保たれる
。In other words, in the case of visual acuity measurement using one eye, only the Landolt ring becomes invisible in the non-tested eye, while other parts, such as the edge of the optotype or the inner wall surface of the housing, are visible, and binocular vision is maintained.

第３図は本発明の第６の実施例である。FIG. 3 shows a sixth embodiment of the present invention.

９Ｌ、９Ｂ、は偏光板、１０１．．１０Ｒ轄９０の旋光
性を有するＴＮｌ［晶、１ｉＬ、１１几は偏光板１１２
はビームスプリッタ−１ｌ３Ｌ、１３Ｂは偏光板である
。そこで偏光板９Ｌ、１１Ｌ。9L, 9B are polarizing plates, 101. ．． TNl [crystal, 1iL, 11L, which has optical rotation of 10R and 90 is a polarizing plate 112
is a beam splitter 1l3L, and 13B is a polarizing plate. Therefore, polarizing plates 9L and 11L are used.

１３Ｌは水平方向、又偏光板９Ｂ、１１　Ｂ、１３Ｂは
上下方向の偏光方向を有し、ＴＮ型液晶１０Ｌ。13L has a horizontal polarization direction, and polarizing plates 9B, 11B, and 13B have a vertical polarization direction, and the TN type liquid crystal 10L.

１０Ｂの指標部は通電時に各々水平方向から上下方向、
上下方向から水平方向へ偏光方向を変える。The indicator part of 10B moves from the horizontal direction to the vertical direction, respectively, when energized.
Change the polarization direction from vertical to horizontal.

部材９Ｌ、１０Ｌ、１１Ｌと部材９几、１０Ｒ。Members 9L, 10L, 11L and members 9L, 10R.

１１Ｒはビームスプリッタ−１２に関し、光学的に共役
の位置にある。11R is located at an optically conjugate position with respect to the beam splitter 12.

斯かる構成によって、ＴＮ型液晶１０Ｌは左眼のみによ
って見え、一方、ＴＮ型液晶１０Ｒは右眼のみによって
見える。With this configuration, the TN liquid crystal 10L is visible only to the left eye, while the TN liquid crystal 10R is visible only to the right eye.

両眼による視力測定の場合、ＴＮ型液晶１０　Ｌ’。For binocular visual acuity measurement, TN type liquid crystal 10L'.

１０Ｂに通電すると、各指標部のみが暗く見える。When 10B is energized, only each index portion appears dark.

片眼による視力測定の場合）例えば左眼の測定の場合に
は、ＴＮ型液晶１０Ｌに通電し、ＴＮ型液晶１０Ｒを通
電しないようにすれば良い。In the case of measuring visual acuity with one eye) For example, in the case of measuring the left eye, it is sufficient to energize the TN type liquid crystal 10L and not energize the TN type liquid crystal 10R.

該実施例の場合、第２実施例と異なり、片眼によ句 る視力測定の場合、非被検眼茫背景が暗くなることが無
い。In this embodiment, unlike the second embodiment, when visual acuity is measured using one eye, the background of the non-tested eye does not become dark.

なおビームスグリツタ−１２はハーフミ２−でも良いが
、偏光ビームスプリッタ−であると更に良〜ゝ０ 該実施例では光学的に共役な視標に対し偏光状態を考慮
しており、両眼視差を利用した立体視等の両眼視機能の
検査も可能である。なお以上、実施例では光屈折部材を
プリズムとしたが、レンズ例えば偏心したレンズ等を用
いても良い。Note that the beam splitter 12 may be a half beam splitter, but it is even better if it is a polarizing beam splitter. It is also possible to test binocular vision functions such as stereopsis using . Note that in the above embodiments, a prism is used as the light refracting member, but a lens, for example, an eccentric lens, etc. may also be used.

以上、本発明によれば、同−着しく祉光学的共役な視標
を両眼で目視でき、又視標近傍の筐体内壁面等も見えて
視野が立体的であって、自然状態の視野となり、調節が
完全に行なえ正確な視力測定が可能である◇そして一般
に従来、視標を５ｍ離していたものであるが、同じ輻轢
角を保って視標を５ｍより接近して設けることが可能で
あり、コンパクトな視力計を提供できる。As described above, according to the present invention, it is possible to visually see a visual target that is optically conjugate with both eyes, and the wall surface inside the housing near the visual target can also be seen, resulting in a three-dimensional field of view, which is a visual field in a natural state. This allows complete adjustment and accurate visual acuity measurement. ◇In general, the optotypes were placed 5m apart, but it is possible to set the optotypes closer than 5m while maintaining the same convergence angle. It is possible to provide a compact visual acuity meter.

例の図、第４図、第５図は液晶覗標の各部位の偏光方向
を示す図、 図中、１は視標、２Ｌ、２Ｂは偏角プリズム、３Ｌ　、
　５１ＦＬはレンズ、４は筐体、５，８Ｌ、８几。The example diagrams, Figures 4 and 5, are diagrams showing the polarization direction of each part of the liquid crystal sight target. In the figure, 1 is the sight target, 2L, 2B are polarization prisms, 3L
51FL is the lens, 4 is the housing, 5, 8L, 8L.

９Ｌ、９Ｊ１１Ｌ、１１Ｒ，１３Ｌ、１３Ｒは偏光板、
６，７Ｌ、７Ｒ，ＩＯＬ、１０Ｂはネマチックツイスト
（ＴＮ）型液晶、１２はビームスプリッタ−である。9L, 9J11L, 11R, 13L, 13R are polarizing plates,
6, 7L, 7R, IOL, and 10B are nematic twist (TN) type liquid crystals, and 12 is a beam splitter.

Claims (1)

【特許請求の範囲】 （１）被検眼近傍に設けられたレンズによシ、視標を見
かけ上、遠方に設けた視力計であって１光路中、光屈折
部材を設け、左右眼に同−若しくは光学的共役な視標を
呈示することを特徴とする視力計。 （２）前記光屈折部材は色消プリズムである特許請求の
範囲第（１）項記載の視力計。 （６）前、記視標祉旋光性の液晶視標である特許請求の
範囲第（１）項記載の視力計。 （４）左右眼に別々の偏光状態で目視させる特許請求の
範囲第（６）項記載の視力計。 （５）被検眼と非被検眼に別々の偏光状態で目視させる
特許請求の範囲第（６）項記載の視力計０[Scope of Claims] (1) A visual acuity meter in which a visual target is apparently provided at a distance using a lens provided near the subject's eye, and a light refracting member is provided in one optical path, so that the left and right eyes are provided with the same optical target. - or a visual acuity meter characterized by presenting an optically conjugate visual target. (2) The visual acuity meter according to claim (1), wherein the light refracting member is an achromatic prism. (6) The visual acuity meter according to claim (1), wherein the optotype is a liquid crystal optotype with optical rotation. (4) The visual acuity meter according to claim (6), which allows the left and right eyes to see in different polarization states. (5) Visual acuity meter 0 according to claim (6), which allows the eye to be examined and the eye not to be examined to view with different polarization states.