JP3594266B2 - Optical system - Google Patents

Description

ただし、Ｚは面形状の原点に対する接平面からのずれ量、ＣＸはＸ軸方向曲率、ＣＹはＹ軸方向曲率、Ｋ_ｘ はＸ軸方向円錐係数、Ｋ_ｙ はＹ軸方向円錐係数、Ｒ_ｎ は非球面項回転対称成分、Ｐ_ｎ は非球面項回転非対称成分である。
なお、次の構成パラメータでは、
Ｒ_ｘ ：Ｘ軸方向曲率半径
Ｒ_ｙ ：Ｙ軸方向曲率半径
を用いており、曲率ＣＸ、ＣＹとの間には、
Ｒ_ｘ ＝１／ＣＸ，Ｒ_ｙ ＝１／ＣＹ
の関係にある。また、データの記載されていない非球面に関する項は０である。
屈折率については、ｄ線（波長５８７．５６ｎｍ）に対するものを表記してある。
【００３９】
なお、実施例４〜１４については、構成パラメータを略している。また、指標の位置についても、図示を省略しているが、実施例１と同様の指標を設けているので、図６、図７より明らかである。
【００４０】
なお、構成パラメータは、以下のものに限定されるものではなく、回転非対称な面形状をし、光軸に対して傾いて配置され、かつ、外形で決まる面の中心と面形状の中心とが一致しない光学面を少なくとも１面有する光学系であれば、本発明を実施することができる。
【００４１】

【００４２】
以上の本発明の光学系は、例えば次のように構成することができる。
〔１〕 回転非対称な面形状を有し、光軸に対して傾いて配置され、かつ、外形で決まる面の中心と面形状の中心とが一致しない光学面を少なくとも１面有する光学系において、
前記回転非対称な光学面の少なくとも１面に、面形状の基準位置を示す少なくとも１つの指標が設けられていることを特徴とする光学系。
【００４３】
〔２〕 回転非対称な面形状を有し、光軸に対して傾いて配置され、かつ、外形で決まる面の中心と面形状の中心とが一致しない光学面を少なくとも１面有する光学系において、
前記回転非対称な光学面の少なくとも１面に、面形状の基準位置を示す少なくとも２つの指標が設けられていることを特徴とする光学系。
【００４４】
〔３〕 回転非対称な面形状を有し、光軸に対して傾いて配置され、かつ、外形で決まる面の中心と面形状の中心とが一致しない光学面を少なくとも１面有する光学系において、
前記回転非対称な光学面の少なくとも１面に、面形状の基準位置を示す少なくとも３つの指標が設けられていることを特徴とする光学系。
【００４５】
〔４〕 前記指標が光学面の窪みあるいは突起として設けられていることを特徴とする上記〔１〕から〔３〕の何れか１項に記載の光学系。
【００４６】
〔５〕 前記指標が光学面の有効領域の外側に設けられていることを特徴とする上記〔１〕から〔４〕の何れか１項に記載の光学系。
【００４７】
〔６〕 回転非対称な面形状を有し、光軸に対して傾いて配置され、かつ、外形で決まる面の中心と面形状の中心とが一致しない光学面を少なくとも１面有する光学系において、
非光学面である光学系の側面に、前記回転非対称な光学面の位置又は傾きを示す少なくとも１つの指標を設けたことを特徴とする光学系。
【００４８】
〔７〕 前記光学系において、前記回転非対称な形状をした光学面が反射面であることを特徴とする上記〔１〕から〔６〕の何れか１項に記載の光学系。
【００４９】
〔８〕 前記光学系が画像表示素子と共に頭部又は顔面装着式の画像表示装置に用いられることを特徴とする上記〔１〕から〔７〕の何れか１項に記載の光学系。
【００５０】
〔９〕 前記光学系が少なくとも２つの面を有し、透過面を形成する第１面と、反射面を形成する第２面とを含み、前記の少なくとも２つの面は観察者の視軸に対して傾いて配置されており、かつ、前記第１面と第２面との間の領域が屈折率が１よりも大きな媒質で満たされていることを特徴とする上記〔８〕記載の光学系。
【００５１】
〔１０〕 前記光学系が互いに偏心して配置された少なくとも２つの反射鏡を有し、その中の少なくとも１つが凹面鏡であることを特徴とする上記〔８〕記載の光学系。
【００５２】
〔１１〕 前記光学系が観察者の視軸に対して傾いて配置された少なくとも１つの凹面鏡を有し、前記凹面鏡と前記画像表示素子との間に少なくとも１つの正の屈折力を有する光学素子が配置されていることを特徴とする上記〔８〕記載の光学系。
【００５３】
〔１２〕 前記光学系が少なくとも３つの面を有し、画像表示素子から射出された光線の通過する順に、少なくとも透過面を形成する第３面と、反射面を形成する第２面と、透過面を形成する第１面とを含むことを特徴とする上記〔８〕記載の光学系。
【００５４】
〔１３〕 前記光学系の第１面が透過面と同時に反射面を形成していることを特徴とする上記〔１２〕記載の光学系。
【００５５】
〔１４〕 前記光学系が少なくとも３つの面を有し、画像表示素子から射出された光線の通過する順に、少なくとも透過面と同時に反射面を形成する第２面と、反射面を形成する第４面と、透過面を形成する第１面とを含むことを特徴とする上記〔８〕記載の光学系。
【００５６】
〔１５〕 前記光学系が第２面において、光線が１度の透過と２度の反射を行い、かつ、第４面において２度の反射を行うことを特徴とする上記〔１４〕記載の光学系。
【００５７】
〔１６〕 前記光学系が少なくとも３つの面を有し、画像表示素子から射出された光線の通過する順に、少なくとも透過面と同時に反射面を形成する第２面と、反射面と同時に透過面を形成する第１面と、反射面を形成する第４面とを含むことを特徴とする上記〔８〕記載の光学系。
【００５８】
〔１７〕 前記光学系が少なくとも４つの面を有し、画像表示素子から射出された光線の通過する順に、少なくとも透過面を形成する第３面と、反射面を形成する第４面と、反射面を形成する第２面、透過面を形成する第１面とを含むことを特徴とする上記〔８〕記載の光学系。
【００５９】
〔１８〕 前記光学系が、第２面において光線が２度の反射を行うことを特徴とする上記〔１７〕記載の光学系。
【００６０】
〔１９〕 前記光学系の第３面が透過面と同時に反射面を形成していることを特徴とする上記〔１７〕記載の光学系。
【００６１】
〔２０〕 前記光学系が少なくとも４つの面を有し、画像表示素子から射出された光線の通過する順に、少なくとも１度の透過と２度の反射とを行う第２面と、反射面を形成する第５面と、反射面を形成する第４面と、透過面を形成する第１面とを含むことを特徴とする上記〔８〕記載の光学系。
【００６２】
【発明の効果】
以上の説明から明らかなように、本発明においては、光学系に含まれる光学面の外形と面形状の中心とが一致しない回転非対称な光学面の少なくとも１面に、面形状の基準位置を示す１つ以上の指標が設けられているので、測定データを設計値にフィッティングする際の設計値に対する測定データの位置、傾きの自由度が半分以下に減少し、被測定物のずれ、傾きを正確に求めることが可能になり、精度の良い面精度の測定が可能になる。
【図面の簡単な説明】
【図１】本発明の第１の本発明の構成を示す模式図である。
【図２】本発明の第２の本発明の構成を示す模式図である。
【図３】本発明の第３の本発明の構成を示す模式図である。
【図４】本発明による光学系を用いた頭部装着式画像表示装置の側面図である。
【図５】本発明の実施例１の光学系の光路図である。
【図６】実施例１の第１面に設けた指標の位置を示す図である。
【図７】実施例１の第２面に設けた指標の位置を示す図である。
【図８】実施例２の指標を示す図である。
【図９】実施例２の指標の形状、位置を示す図である。
【図１０】実施例３の指標を示す図である。
【図１１】実施例３の指標の形状、位置を示す図である。
【図１２】本発明の実施例４の光学系の光路図である。
【図１３】本発明の実施例５の光学系の光路図である。
【図１４】本発明の実施例６の光学系の光路図である。
【図１５】本発明の実施例７の光学系の光路図である。
【図１６】本発明の実施例８の光学系の光路図である。
【図１７】本発明の実施例９の光学系の光路図である。
【図１８】本発明の実施例１０の光学系の光路図である。
【図１９】本発明の実施例１１の光学系の光路図である。
【図２０】本発明の実施例１２の光学系の光路図である。
【図２１】本発明の実施例１３の光学系の光路図である。
【図２２】本発明の実施例１４の光学系の光路図である。
【図２３】光軸に対し傾いて配置された回転非対称な光学面によりディストーションが発生する様子を示す図である。
【図２４】光軸に対し傾いて配置された回転非対称な光学面を光軸に対してずらして配置することによりディストーションを補正する様子を示す図である。
【図２５】三次元形状測定機を用いて面形状を測定する様子を示す図である。
【図２６】設計式の面と測定値の面とのフィッティングの際のずれを示す模式図である。
【図２７】光学面の６つの自由度を示す図である。
【符号の説明】
１…観察者瞳位置
２…観察者視軸
３…光学系の第１面
４…光学系の第２面
５…光学系の第３面
６…光学系の第４面
７…光学系の第５面
８…画像表示素子
９…第１の反射鏡
１０…第２の反射鏡
１１…裏面鏡（凹面鏡）
１２…正レンズ
１３…アナモルフィック面の軸
１４…面形状の中心
２１…接眼光学系
２２…画像表示素子
３１…回転非対称な光学面
３２…光学系の光軸
３３…面形状の中心
６１…指標
６６…測定機
６７…光学面
６８…プローブ
７１…設計式の面
７２…測定値の面
８１…板状の指標
８２…三角形の指標[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical system that can be used as an eyepiece optical system or an imaging optical system, and more particularly, to an optical system having a rotationally asymmetric optical surface.
[0002]
[Prior art]
In recent years, along with technological innovations in various fields, new optical systems have never been required before. To respond to this, various special optical systems have been developed. Among them, there is a rotationally asymmetric optical surface, and various designs are made.
[0003]
For example, in an optical system requiring a small size and light weight, such as a head or a face-mounted image display device, a concave mirror arranged to be inclined with respect to the optical axis may be used for miniaturization. At this time, when the concave mirror is tilted, large aberrations such as coma and astigmatism occur. In order to correct these aberrations, it is conceivable that the surface shape of the concave mirror or other surfaces is a rotationally asymmetric surface, for example, an anamorphic surface or a toric surface. However, simply tilting the optical surface generates an asymmetric distortion in the eccentric direction. That is, as shown in FIG. 23, when the optical axis 32 direction of the optical system is set as the Z axis, the Y axis is set in the eccentric direction of the optical system, and the X axis is set perpendicular to the Y and Z axes, the surface shape becomes Asymmetric distortion occurs in the Y-axis direction due to the rotationally asymmetric optical surface 31 having the center 33. In order to correct this, as shown in FIG. 24, the correction can be performed by displacing the center 33 of the surface shape of the rotationally asymmetric optical surface 31 with respect to the optical axis 32. Here, the center 33 of the surface shape is the origin of a mathematical expression representing the surface shape in an anamorphic surface, a toric surface, or the like, and more generally, the surface shape is symmetric in at least two directions orthogonal to each other at least in a certain region. Is a point. When the center of the surface shape is displaced with respect to the optical axis in this way, the center determined by the outer shape of the optical surface and the center of the surface shape generally do not match. The center determined by the outer shape of the optical surface here is the center of the circle when the outer diameter of the optical surface is a circle, and at the intersection of the diagonal of the square if the outer diameter of the optical surface is a square. is there.
[0004]
However, if the center of the surface shape and the center determined by the outer shape of the optical surface are arranged to be shifted, the following problems occur.
When measuring a surface shape after processing a rotationally asymmetric optical surface, a so-called three-dimensional shape measuring machine is often used. For example, as shown in FIG. 25, this measuring machine converts three-dimensional X, Y, and Z three-dimensional coordinates of thousands to tens of thousands of points on the surface of an optical surface 67 which is a measured surface placed on the measuring machine 66. The measurement is performed by the probe 68, and the deviation from the design formula is measured from the coordinates. When the outer shape of the optical surface matches the center of the surface shape, the position of the optical surface 67, which is the object to be measured, can be accurately determined based on the outer shape. Can be accurately compared.
[0005]
[Problems to be solved by the invention]
However, if the center of the outer shape of the optical surface does not match the center of the surface shape, the optical surface cannot be positioned with reference to the outer shape. From the surface shape measurement results, for example, by a method of fitting thousands to tens of thousands of coordinate data, which are the measurement results for the design formula of the surface shape. The fitting of the measurement data is performed by, for example, a method of changing each variable so as to minimize a residual by a least square method or the like.
[0006]
At this time, the fitting is performed with as many as six variables including the degree of freedom of the three-dimensional position and the degree of freedom of the inclination in addition to the degree of freedom of the surface shape. That is, in general, as schematically shown in FIG. 26, since the surface 71 of the design formula and the surface 72 of the measured value are shifted, as shown by arrows in FIG. By changing the position and the inclination having a degree of freedom, the total amount of the deviation of the measured value from the design equation, that is, the position and the inclination that minimize the residual error are obtained.
[0007]
In this method, since the positioning of the object to be measured is performed by approximation to many variables, the exact position of the optical surface is unknown, and the measurement accuracy has deteriorated. In particular, since the reflection surface requires particularly strict surface accuracy, high accuracy is also required for measurement, and it has been a serious problem that the position of the object to be measured cannot be accurately obtained.
[0008]
The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a rotationally asymmetric optical surface that can perform accurate measurement and that does not coincide with the outer shape of the optical surface and the center of the surface shape. An optical system having the following.
[0009]
[Means for Solving the Problems]
The optical system according to the first aspect of the present invention that achieves the above object has a rotationally asymmetric surface shape, is arranged to be inclined with respect to the optical axis, and has a center determined by the outer shape and a center of the surface shape. In an optical system having at least one optical reflection surface that does not match,
At least one index indicating a reference position of a surface shape is provided on at least one of the rotationally asymmetric optical reflection surfaces.
[0010]
The optical system according to the second aspect of the invention has a rotationally asymmetric surface shape, is disposed at an angle to the optical axis, and has at least one optical reflection surface whose center determined by the outer shape does not coincide with the center of the surface shape. In an optical system having a reflective optical element having a surface,
At least one index indicating a position or an inclination of the rotationally asymmetric optical surface is provided on a side surface that is a non-optical surface of the reflective optical element.
[0011]
An optical system according to a third aspect of the present invention is an optical system having at least one optical reflection surface having a rotationally asymmetric surface shape and inclined with respect to the optical axis.
At least one index indicating a reference position of a surface shape is provided on at least one of the rotationally asymmetric optical reflection surfaces.
An optical system according to a fourth aspect of the present invention is an optical system including a reflective optical element having a rotationally asymmetric surface shape and having at least one optical reflective surface that is arranged to be inclined with respect to the optical axis,
At least one index indicating a position or an inclination of the rotationally asymmetric optical surface is provided on a side surface that is a non-optical surface of the reflective optical element.
[0012]
Hereinafter, the reason and operation of the above configuration in the present invention will be described.
The first aspect of the present invention, as schematically shown in FIG. 1, has a rotationally asymmetric surface shape, is arranged inclined with respect to the optical axis, and has a center determined by the outer shape and a center of the surface shape. The present invention relates to an optical system having at least one optical surface that does not match, and at least one index 61 indicating a reference position of the surface shape is provided on at least one surface 67 of the rotationally asymmetric optical surface. In this way, the degree of freedom of the position and inclination of the measured data with respect to the design value when fitting the measured data to the design value is changed from 6 to 3 as shown by an arrow in FIG. , The inclination can be accurately obtained, so that highly accurate surface accuracy measurement can be performed.
[0013]
In addition, as schematically shown in FIG. 2, an optical surface having a rotationally asymmetric surface shape, being arranged to be inclined with respect to the optical axis, and having a center determined by the outer shape and a center of the surface shape not coincident with each other. And at least two indices 61 indicating the reference position of the surface shape are provided on at least one surface 67 of the rotationally asymmetric optical surface. In this case, the degree of freedom of the position and inclination of the measured data with respect to the design value when fitting the measured data to the design value becomes, for example, 1 as indicated by an arrow in FIG. Can be accurately obtained, so that highly accurate surface accuracy measurement can be performed.
[0014]
In addition, as schematically shown in FIG. 3, an optical surface having a rotationally asymmetric surface shape, being inclined with respect to the optical axis, and having the center of the surface determined by the outer shape not coincident with the center of the surface shape. And at least three indices 61 indicating the reference position of the surface shape are provided on at least one surface 67 of the rotationally asymmetric optical surface. By doing so, the position of the measurement data and the degree of freedom of the inclination with respect to the design value when fitting the measurement data to the design value become zero, for example, as shown in FIG. Since it is possible to obtain the surface accuracy, it is possible to measure the surface accuracy with a very high accuracy.
[0015]
Such an index is desirably provided as a depression or projection on the optical surface. That is, to process a rotationally asymmetric optical surface, a molding method is generally used. At this time, if the index is a depression or a projection on the optical surface, the index can be transferred simultaneously with the surface shape, so that the index can be provided accurately and easily.
[0016]
It is desirable that such an index is provided outside the effective area of the optical surface. This is more preferable because the index can be provided without affecting the light passing through the optical surface.
[0017]
Further, in the present invention, at least one optical surface having a rotationally asymmetric surface shape, being inclined with respect to the optical axis, and having the center of the surface determined by the outer shape and the center of the surface shape not coincident is provided. In the optical system, at least one index indicating the position or inclination of the rotationally asymmetric optical surface may be provided on a side surface of the optical system that is a non-optical surface. This is more preferable because the index can be provided without affecting the light beam passing through the optical surface. Here, the non-optical surface means a surface that does not contribute to transmission or reflection of the optical axis.
[0018]
In such an optical system, the rotationally asymmetric optical surface can be used as a reflection surface. Since the reflection surface is required to have higher surface accuracy than the transmission surface, it is more effective to use the present invention for the reflection surface.
[0019]
Such an optical system can be used together with an image display element in a head- or face-mounted image display device. In a head-mounted or face-mounted image display device, since an optical system that is smaller in size and in which aberration is well corrected is required, use of an eccentric concave mirror has been considered. Therefore, as shown in a side view in FIG. 4, it is more effective to use the optical system 21 according to the present invention together with the image display element 22 in a head or face-mounted image display device. In this drawing, the optical system 21 according to the first embodiment described later is used as the optical system 21.
[0020]
In addition, by adopting the configuration described in each embodiment described later, clear observation is possible at a wide angle of view, little reduction in image brightness occurs, and further, a very small and lightweight For this reason, it is possible to realize an optical system that can be used for an image display device such as a head or a face-mounted type that is hardly fatigued.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the optical system according to the present invention is applied to an eyepiece optical system and used together with an image display element as shown in FIG. 4 and applied to a head mounted image display device will be described.
Example 1
The optical system of this embodiment is a prism composed of three surfaces, a first surface 3, a second surface 4, and a third surface 5, as shown in the optical path of FIG. Sequentially, the light enters the prism from the third surface 5, is totally reflected by the first surface 3, is reflected by the second surface 4, transmits through the first surface 3, and reaches the observer pupil 1. In the drawing, reference numeral 2 denotes the visual axis of the observer, 13 denotes the axis of the optical surface, and 14 denotes the center of the surface shape.
[0022]
Although the configuration parameters of this embodiment will be described later, the first surface 3 and the second surface 4 are rotationally asymmetric anamorphic surfaces, and three indices 61 are provided as shown in FIGS. The position of the origin of the anamorphic surface is clarified, enabling highly accurate measurement of the surface shape. That is, when fitting the measurement data to the design value of the surface shape, the positions of the three indices 61 at the time of the measurement are matched with the positions of the indices at the time of the design, so that the degree of freedom of the position and the inclination is set to 0, and the surface shape is measured. Can be performed with high accuracy. 6 and 7 are views as viewed from the direction of the symmetry axis. The positions of the indices are as shown in these figures, and are constituted by depressions on the optical surface.
[0023]
Example 2
The optical system of this embodiment is the same as that of the first embodiment, and the configuration parameters are the same as those of the first embodiment.
As shown in FIG. 8, a plate-like index 81 composed of two reference surfaces is provided on the side surface of the non-optical surface of the eyepiece optical system, so that the first surface 3 and the second surface, which are rotationally asymmetric optical surfaces, are provided. The position and inclination of 4 are clarified, and highly accurate measurement of the surface shape is enabled. The shape and position of the index are as shown in FIG.
[0024]
Example 3
The optical system of this embodiment is the same as that of the first embodiment, and the configuration parameters are the same as those of the first embodiment.
As shown in FIG. 10, by providing triangular indices 82 including three reference planes on the side surfaces of the non-optical surface of the eyepiece optical system, the positions and inclinations of the respective surfaces are clarified, and the surface shape is highly accurate. Enables measurement. As shown in FIG. 11, the three reference planes are inclined at an angle equal to the eccentricity of each of the planes 3, 4, and 5.
[0025]
Example 4
As shown in FIG. 12, the optical system according to the present embodiment includes a concave mirror 11 serving as a rear mirror and a positive lens 12, and light rays emitted from the image display element 8 are sequentially transmitted to the rear mirror 11 , The reflection surface of the back mirror 11, and the transmission surface of the back mirror 11 again. After passing through the positive lens 12, the light reaches the observer pupil 1.
In this embodiment, the transmission surface and the reflection surface of the concave mirror 11 are rotationally asymmetric optical surfaces, and the same index as in the first embodiment is provided for each.
[0026]
Example 5
As shown in FIG. 13, the optical system of this embodiment includes a first reflecting mirror 9 which is a back mirror and a second reflecting mirror 10 which is also a back mirror. Light rays emitted from the image display element 8 are sequentially transmitted through the transmission surface of the second reflection mirror 10, the reflection surface of the second reflection mirror 10, the transmission surface of the second reflection mirror 10, and the first reflection mirror 9 in that order. After passing through the transmission surface of the first reflection mirror 9 and the transmission surface of the first reflection mirror 9 again, the light reaches the observer pupil 1.
In this embodiment, the transmitting surface and the reflecting surface of the first reflecting mirror 9 are rotationally asymmetric optical surfaces, and the same index as in the first embodiment is provided for each.
[0027]
Example 6
As shown in FIG. 14, the optical system of this embodiment includes a positive lens 12 and a concave mirror 11, which is a rear mirror. Light rays emitted from the image display element 8 sequentially pass through the positive lens 12, pass through the transmitting surface of the concave mirror 11, the reflecting surface of the concave mirror 11, and again the transmitting surface of the concave mirror 11, and then reach the observer pupil 1.
In this embodiment, the transmission surface and the reflection surface of the concave mirror 11 are rotationally asymmetric optical surfaces, and the same index as in the first embodiment is provided for each.
[0028]
Example 7
The optical system of the present embodiment is a prism composed of a first surface 3, a second surface 4, and a third surface 5, as shown in the optical path in FIG. The light enters the prism from the third surface 5, is reflected by the second surface 4, transmits through the first surface 3, and reaches the observer pupil 1.
In this embodiment, the first surface 3, the second surface 4, and the third surface 5 of the optical system are rotationally asymmetric optical surfaces, and the same index as in the first embodiment is provided for each.
[0029]
Example 8
The optical system of the present embodiment is a prism composed of three surfaces, a first surface 3, a second surface 4, and a fourth surface 6, as shown in the optical path in FIG. In turn, the light enters the prism from the second surface 4, is reflected by the fourth surface 6, is reflected by the second surface 4, passes through the first surface 3, and reaches the observer pupil 1.
In this embodiment, the first surface 3 and the fourth surface 6 of the optical system are rotationally asymmetric optical surfaces, and each is provided with the same index as that of the first embodiment.
[0030]
Example 9
The optical system of this embodiment is a prism composed of three surfaces, a first surface 3, a second surface 4, and a fourth surface 6, as shown in the optical path of FIG. In order, the light enters the prism from the second surface 4, is reflected on the fourth surface 6, is reflected on the second surface 4, is reflected on the fourth surface 6 again, is reflected on the second surface 4 again, and The light passes through the surface 3 and reaches the observer pupil 1.
In this embodiment, the second surface 4 and the fourth surface 6 of the optical system are rotationally asymmetric optical surfaces, and the same index as in the first embodiment is provided for each.
[0031]
Example 10
The optical system of this embodiment is a prism composed of three surfaces, a first surface 3, a second surface 4, and a fourth surface 6, as shown in an optical path in FIG. In order, the light enters the prism from the second surface 4, is reflected by the first surface 3, is reflected by the fourth surface 6, is reflected by the second surface 4, is transmitted through the first surface 3, and is transmitted through the first surface 3. Reach
In this embodiment, the first surface 3 and the fourth surface 6 of the optical system are rotationally asymmetric optical surfaces, and each is provided with the same index as that of the first embodiment.
[0032]
Example 11
As shown in FIG. 19, the optical system of this embodiment is a prism composed of four surfaces of a first surface 3, a second surface 4, a third surface 5, and a fourth surface 6. The emitted light rays sequentially enter the prism from the third surface 5, are reflected on the fourth surface 6, are reflected on the second surface 4, pass through the first surface 3, and reach the observer pupil 1.
In this embodiment, the second surface 4 of the optical system is a rotationally asymmetric optical surface, and the same index as in the first embodiment is provided.
[0033]
Example 12
The optical system of the present embodiment is a prism composed of four surfaces of a first surface 3, a second surface 4, a third surface 5, and a fourth surface 6, as shown in the optical path in FIG. The emitted light rays sequentially enter the prism from the third surface 5, are reflected on the second surface 4, are reflected on the fourth surface 6, are again reflected on the second surface 4, and then pass through the first surface 3. And reaches the observer's pupil 1.
In this embodiment, the second surface 4 of the optical system is a rotationally asymmetric optical surface, and the same index as in the first embodiment is provided.
[0034]
Example 13
The optical system of the present embodiment is a prism composed of four surfaces of a first surface 3, a second surface 4, a third surface 5, and a fourth surface 6, as shown in an optical path in FIG. The emitted light rays are sequentially incident on the prism from the third surface 5, reflected on the fourth surface 6, reflected on the third surface 5, reflected on the second surface 4, and then transmitted on the first surface 3. To observer pupil 1.
In this embodiment, the second surface 4 of the optical system is a rotationally asymmetric optical surface, and the same index as in the first embodiment is provided.
[0035]
Example 14
The optical system of the present embodiment is a prism composed of four surfaces of a first surface 3, a second surface 4, a fourth surface 6, and a fifth surface 7, as shown in the optical path in FIG. The emitted light rays sequentially enter the prism from the second surface 4, are reflected on the fifth surface 7, are reflected on the second surface 4, are reflected on the fourth surface 6, and are reflected on the second surface 4 again. Thereafter, the light passes through the first surface 3 and reaches the observer's pupil 1.
In this embodiment, the second surface 4 and the fourth surface 6 of the optical system are rotationally asymmetric optical surfaces, and the same index as in the first embodiment is provided.
[0036]
The configuration parameters of the first embodiment (the same applies to the second and third embodiments) are shown below. In these configuration parameters, as shown in FIG. 5, the pupil position 1 of the observer is set as the origin of the optical system, and the visual axis 2 of the observer is set as the Z axis. Note that the sign of the Z axis is positive in the direction away from the pupil 1. Further, the Y axis is set in the plane of FIG. 5 so that the top of the figure is positive and orthogonal to the Z axis. Further, it is assumed that the X axis is taken so as to be orthogonal to the Y axis and the Z axis, that is, perpendicular to the plane of FIG. The ray tracing is performed by reverse tracing with the observer's eyeball side as the object side and the image display element 8 side as the image plane side.
[0037]
In these constituent parameters, the amounts of eccentricity Y and Z and the amount of inclination θ are the amounts of shift in the Y and Z directions of the top of the surface from the observer pupil 1 which is the origin of the optical system, and the central axis of the surface Represents an inclination angle with respect to the Z axis. The tilt angle is positive in the counterclockwise direction.
[0038]
The shape of the anamorphic surface is defined by the following equation. A straight line passing through the origin of the surface shape and perpendicular to the optical surface is the axis of the anamorphic surface.

Here, Z is the amount of deviation of the surface shape from the tangent plane to the origin, CX is the curvature in the X-axis direction, CY is the curvature in the Y-axis direction, K is _x Is the cone coefficient in the X-axis direction, K _y Is the Y-axis cone coefficient, R _n Is the aspheric term rotationally symmetric component, P _n Is an aspherical term rotationally asymmetric component.
For the following configuration parameters,
R _x ： X-axis direction radius of curvature
R _y : Y-axis direction radius of curvature
Is used between the curvatures CX and CY.
R _x = 1 / CX, R _y = 1 / CY
In a relationship. The term relating to an aspheric surface for which no data is described is zero.
The refractive index for d-line (wavelength 587.56 nm) is shown.
[0039]
In Examples 4 to 14, the configuration parameters are omitted. The positions of the indices are also omitted from the drawing, but since the indices similar to those in the first embodiment are provided, it is clear from FIGS.
[0040]
Note that the configuration parameters are not limited to the following, but have a rotationally asymmetric surface shape, are arranged inclined with respect to the optical axis, and the center of the surface determined by the outer shape and the center of the surface shape are different. The present invention can be implemented as long as the optical system has at least one optical surface that does not match.
[0041]

[0042]
The above optical system of the present invention can be configured, for example, as follows.
[1] An optical system having at least one optical surface that has a rotationally asymmetric surface shape, is arranged to be inclined with respect to the optical axis, and does not coincide with the center of the surface determined by the outer shape and the center of the surface shape,
An optical system, wherein at least one index indicating a reference position of a surface shape is provided on at least one of the rotationally asymmetric optical surfaces.
[0043]
[2] In an optical system having at least one optical surface having a rotationally asymmetric surface shape, arranged to be inclined with respect to the optical axis, and having the center of the surface determined by the outer shape and the center of the surface shape not coincident,
An optical system, wherein at least two indices indicating a reference position of a surface shape are provided on at least one of the rotationally asymmetric optical surfaces.
[0044]
[3] In an optical system having at least one optical surface having a rotationally asymmetric surface shape, arranged to be inclined with respect to the optical axis, and having a center determined by the outer shape and a center of the surface shape not coincident with each other,
An optical system, wherein at least one index indicating a reference position of a surface shape is provided on at least one of the rotationally asymmetric optical surfaces.
[0045]
[4] The optical system according to any one of [1] to [3], wherein the index is provided as a depression or a projection on an optical surface.
[0046]
[5] The optical system according to any one of [1] to [4], wherein the index is provided outside an effective area of the optical surface.
[0047]
[6] In an optical system having at least one optical surface having a rotationally asymmetric surface shape, being inclined with respect to the optical axis, and having a center determined by the outer shape and a center of the surface shape not coincident with each other,
An optical system, wherein at least one index indicating a position or an inclination of the rotationally asymmetric optical surface is provided on a side surface of the optical system that is a non-optical surface.
[0048]
[7] The optical system according to any one of [1] to [6], wherein in the optical system, the optical surface having the rotationally asymmetric shape is a reflection surface.
[0049]
[8] The optical system according to any one of [1] to [7], wherein the optical system is used together with an image display element in a head- or face-mounted image display device.
[0050]
[9] The optical system has at least two surfaces, and includes a first surface forming a transmission surface, and a second surface forming a reflection surface, wherein the at least two surfaces are aligned with a visual axis of an observer. The optical system according to the above [8], wherein the optical system is arranged so as to be inclined with respect to the first surface, and a region between the first surface and the second surface is filled with a medium having a refractive index larger than 1. system.
[0051]
[10] The optical system according to [8], wherein the optical system has at least two reflecting mirrors arranged eccentrically to each other, and at least one of the reflecting mirrors is a concave mirror.
[0052]
[11] The optical system has at least one concave mirror arranged to be inclined with respect to the visual axis of the observer, and has at least one positive refractive power between the concave mirror and the image display element. The optical system according to the above [8], wherein is disposed.
[0053]
[12] The optical system has at least three surfaces, and in the order of passage of light rays emitted from the image display element, at least a third surface forming a transmission surface, a second surface forming a reflection surface, and a transmission surface. The optical system according to the above [8], including a first surface forming a surface.
[0054]
[13] The optical system according to the above [12], wherein the first surface of the optical system forms a reflective surface simultaneously with a transmission surface.
[0055]
[14] The optical system has at least three surfaces, and a second surface forming a reflecting surface at least simultaneously with a transmitting surface and a fourth surface forming a reflecting surface in the order of passage of light rays emitted from the image display element. The optical system according to the above [8], comprising a surface and a first surface forming a transmission surface.
[0056]
[15] The optical system according to [14], wherein the optical system performs one-time transmission and two-time reflection on the second surface, and performs two-time reflection on the fourth surface. system.
[0057]
[16] The optical system has at least three surfaces, a second surface forming a reflecting surface at the same time as the transmitting surface, and a transmitting surface at the same time as the reflecting surface in the order of passage of light rays emitted from the image display element. The optical system according to the above [8], including a first surface to be formed and a fourth surface to form a reflection surface.
[0058]
[17] The optical system has at least four surfaces, and in the order of passage of light rays emitted from the image display element, at least a third surface forming a transmission surface, a fourth surface forming a reflection surface, and a reflection surface. The optical system according to the above [8], including a second surface forming a surface and a first surface forming a transmission surface.
[0059]
[18] The optical system according to the above [17], wherein the optical system reflects light rays twice on the second surface.
[0060]
[19] The optical system according to the above [17], wherein the third surface of the optical system forms a reflection surface simultaneously with a transmission surface.
[0061]
[20] The optical system has at least four surfaces, and forms a second surface that performs at least one transmission and two reflections in the order of passage of light rays emitted from the image display element, and a reflection surface. The optical system according to the above [8], further comprising: a fifth surface that forms a reflective surface, a fourth surface that forms a reflective surface, and a first surface that forms a transmissive surface.
[0062]
【The invention's effect】
As is clear from the above description, in the present invention, the reference position of the surface shape is indicated on at least one of the rotationally asymmetric optical surfaces where the outer shape of the optical surface included in the optical system does not coincide with the center of the surface shape. Since one or more indices are provided, the degree of freedom of the position and inclination of the measurement data with respect to the design value when fitting the measurement data to the design value is reduced to less than half, and the deviation and inclination of the DUT are accurately determined. , And accurate surface accuracy measurement becomes possible.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration of a first present invention of the present invention.
FIG. 2 is a schematic diagram showing a configuration of a second present invention of the present invention.
FIG. 3 is a schematic diagram showing a configuration of a third invention of the invention.
FIG. 4 is a side view of a head mounted image display device using an optical system according to the present invention.
FIG. 5 is an optical path diagram of the optical system according to the first embodiment of the present invention.
FIG. 6 is a diagram illustrating positions of indices provided on a first surface according to the first embodiment.
FIG. 7 is a diagram illustrating a position of an index provided on a second surface according to the first embodiment.
FIG. 8 is a diagram illustrating indices according to the second embodiment.
FIG. 9 is a diagram illustrating shapes and positions of indices according to the second embodiment.
FIG. 10 is a diagram illustrating indices according to a third embodiment.
FIG. 11 is a diagram illustrating shapes and positions of indices according to the third embodiment.
FIG. 12 is an optical path diagram of an optical system according to a fourth embodiment of the present invention.
FIG. 13 is an optical path diagram of an optical system according to a fifth embodiment of the present invention.
FIG. 14 is an optical path diagram of an optical system according to a sixth embodiment of the present invention.
FIG. 15 is an optical path diagram of an optical system according to a seventh embodiment of the present invention.
FIG. 16 is an optical path diagram of an optical system according to an eighth embodiment of the present invention.
FIG. 17 is an optical path diagram of an optical system according to a ninth embodiment of the present invention.
FIG. 18 is an optical path diagram of an optical system according to a tenth embodiment of the present invention.
FIG. 19 is an optical path diagram of an optical system according to Example 11 of the present invention.
FIG. 20 is an optical path diagram of an optical system according to a twelfth embodiment of the present invention.
FIG. 21 is an optical path diagram of an optical system according to a thirteenth embodiment of the present invention.
FIG. 22 is an optical path diagram of an optical system according to Example 14 of the present invention.
FIG. 23 is a diagram illustrating a state in which distortion is generated by a rotationally asymmetric optical surface that is arranged to be inclined with respect to the optical axis.
FIG. 24 is a diagram showing how distortion is corrected by disposing a rotationally asymmetric optical surface inclined with respect to the optical axis to be displaced from the optical axis.
FIG. 25 is a diagram showing a state of measuring a surface shape using a three-dimensional shape measuring instrument.
FIG. 26 is a schematic diagram showing a deviation at the time of fitting between the surface of the design formula and the surface of the measured value.
FIG. 27 is a diagram illustrating six degrees of freedom of an optical surface.
[Explanation of symbols]
1: Observer pupil position
2 ... Visual axis of observer
3. First surface of optical system
4: Second surface of optical system
5: Third surface of optical system
6: fourth surface of the optical system
7: Fifth surface of the optical system
8 Image display element
9: First reflecting mirror
10 second mirror
11 ... back mirror (concave mirror)
12 Positive lens
13 ... Anamorphic surface axis
14: Center of surface shape
21 ... Eyepiece optical system
22 ... Image display element
31 ... rotationally asymmetric optical surface
32: Optical axis of optical system
33: Center of surface shape
61… Index
66… Measuring machine
67 ... Optical surface
68… Probe
71: Design equation
72: Measured value plane
81: Plate-like index
82 ... Triangle index

Claims (17)

In an optical system having a rotationally asymmetric surface shape, disposed at an angle to the optical axis, and having at least one optical reflection surface in which the center of the surface determined by the outer shape does not match the center of the surface shape,
An optical system, wherein at least one index indicating a reference position of a surface shape is provided on at least one of the rotationally asymmetric optical reflecting surfaces. The optical system according to claim 1, wherein the index is provided as a depression or a projection on an optical reflection surface. The optical system according to claim 1, wherein the index is provided outside an effective area of the optical reflection surface. A reflecting optical element having a rotationally asymmetric surface shape, being arranged inclined with respect to the optical axis, and having at least one optical reflecting surface in which the center of the surface determined by the outer shape does not coincide with the center of the surface shape; In the optical system,
Non the optical surface der Ru aspects, the optical system characterized by comprising at least one indicator indicating the position or tilt of the rotationally asymmetric optical surface of the reflective optical element. The optical system according to claim 4, wherein the index is a reference plane. The index optical system according to any one of claims 1-5, characterized in that provided by the transfer. In an optical system having a rotationally asymmetric surface shape and having at least one optical reflection surface arranged to be inclined with respect to the optical axis,
An optical system, wherein at least one index indicating a reference position of a surface shape is provided on at least one of the rotationally asymmetric optical reflecting surfaces. An optical system including a reflection optical element having a rotationally asymmetric surface shape and having at least one optical reflection surface that is arranged to be inclined with respect to the optical axis,
Non the optical surface der Ru aspects, the optical system characterized by comprising at least one indicator indicating the position or tilt of the rotationally asymmetric optical surface of the reflective optical element. 8. The optical system according to claim 1, wherein at least three indices are provided on at least one of the rotationally asymmetric optical reflecting surfaces. 9. The optical system according to claim 7, wherein the index is provided as a depression or a protrusion on an optical reflection surface. 11. The optical system according to claim 7, wherein the index is provided outside an effective area of the optical surface. The optical system according to any one of claims 1 to 11, wherein the optical system includes an optical element including a transmission surface and the optical reflection surface. The optical system according to any one of claims 1 to 11, wherein the optical system has at least two reflecting mirror surfaces decentered from each other, and at least one of the reflecting mirror surfaces is a concave surface. 12. The optical system according to claim 1, wherein the optical system has at least one concave reflecting mirror surface and at least one optical element having a positive refractive power. The optical system according to any one of claims 1 to 11, wherein the optical system includes a prism optical element including at least a transmission surface, the optical reflection surface, and a transmission surface in the order in which light beams pass. system. 16. The optical system according to claim 15, wherein the prism optical element of the optical system integrally forms any one of the transmission surface and the optical reflection surface. The optical system according to claim 5, wherein the reference surface is inclined at an angle equal to the rotationally asymmetric optical surface.

Images