JPH11125582A - Ophthalmic lens meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make evaluatable the performance of an ophthalmic lens with respect to object points from infinite distance to a finite distance, by switching the distance from an ophthalmic lens to be inspected at the conjugated point of a screen created by an optical system between the ophthalmic lens and the screen to a plurality of specific distances. SOLUTION: Distance L from an ophthalmic lens 10 to be inspected of the conjugated point of a screen 15 created by an optical system that is located between the ophthalmic lens 10 to be inspected and the screen 15 is switched to either distance of L=∞, or L=200-1000 mm. By setting the focus distance of a regular lens 14 to be (f) mm, and the distance from the opening of a receiving base 13 for lens to be inspected to the front side main point of the regular lens 14 to (d) mm and then moving the screen 15 toward the side of the regular lens 14 with reference to the rear side focus position of the regular lens 14 by Z mm, distance Z0 from the opening of the pad base 13 can be set to a position of Z0 =d-f-f<2> /Z mm regarding the conjugated point of the screen 15. In this case, the maximum thickness of the ophthalmic lens to be inspected is several mm, so it may be regarded that L is nearly equal to Z0 . Also, d=f=30 mm may be set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ophthalmic lens meter used for evaluating the performance of ophthalmic lenses (including spectacle lenses (including contact lenses)).

[0002]

2. Description of the Related Art A lens meter is generally used as an apparatus for measuring the optical performance of an ophthalmic lens. In principle, this lens meter measures or calculates the light condensing position (back focus or deviation) when a light beam is incident on the ophthalmic lens from infinity at the optical center of the ophthalmic lens. It is intended to measure the vertex power or prism power. When the ophthalmic lens is composed of a spherical lens, there is no particular problem with this conventional evaluation method. On the other hand, in recent years, with the advancement of functions of ophthalmic lenses, a need has emerged that it is desired to evaluate the performance when worn not only near the center of the lens but also around it. For example, performance evaluation of an aspherical lens or a progressive multifocal lens. However, since the conventional lens meter measures the performance of an object point at infinity, it is not suitable for use in evaluating the performance of an ophthalmic lens when used at a finite distance.

FIG. 6 is an explanatory diagram of an optical system (conventional example 1) of a typical telephoto or projection lens meter disclosed in Japanese Patent Application Laid-Open No. 56-90233. In this optical system,
Target 1 movable in the optical axis direction in order from the left of the figure
1. Positive lens (or lens group: hereinafter, simply referred to as a lens in the same manner includes a lens group) 12,
A screen 15 is disposed at the rear focal point of the lens receiving base 13, the positive lens 14, and the positive lens 14 which are located substantially at the rear focal position of the positive lens 12. Target 11
Is illuminated by a light source (not shown) from the left side of the figure. In the case of the telephoto type, the screen 15 is directly observed through an eyepiece optical system (not shown), and in the case of the projection type, the diffusing screen 15 is directly observed to confirm the focus state. In this lens meter, the position of the target 11 when a clear image of the target 11 is formed on the screen 15 (broken line) without the ophthalmic lens to be inspected (hereinafter simply referred to as a lens to be inspected) 10 is used as a reference point. , The reference point and the screen 15 when the test lens 10 is inserted.
The vertex refractive power of the lens to be measured can be obtained from the distance from the position of the target 11 when a clear image of the target 11 is formed on the upper side (solid line).

FIG. 7 is an explanatory view of an optical system (conventional example 2) of an auto lens meter disclosed in Japanese Patent Laid-Open No. 60-17335. In this optical system, a plurality of point light sources 26, a positive lens 27, and a substantially rear focal position of the positive lens 27, which are located at positions apart from the optical axis in a substantially front focal plane of the lens 27 in order from the left side of the figure, And the target 21 located at the front focal position of the positive lens 22, the positive lens 22, and the test lens cradle 2 located substantially at the rear focal position of the positive lens 22.
3, a positive lens 24, and a light receiving element 25 located at a rear focal position of the positive lens 24 are arranged. In this example, the light receiving element 25 uses a one-dimensional line sensor. The light rays in the figure indicate the principal rays of the light beam emitted from the point light source 26. In this lens meter, an image of the target 21 is formed at the center of the light receiving element 25 when the test lens 20 is not inserted (broken line). When the test lens 20 is inserted (solid line), the image of the target is slightly blurred and deviates from the center of the light receiving element 25. The apex refractive power and the like of the test lens can be obtained from the amount of this shift. Alternatively, the target image can be returned to the center of the light receiving element 25 by moving the target 21, and the apex refractive power of the lens to be measured can be obtained from the amount of movement of the target at that time.

FIG. 8 is an explanatory view of an optical system (conventional example 3) of an auto lens meter disclosed in Japanese Patent Application Laid-Open No. 62-225920. The optical system includes a point light source 35 located at the front focal point of the positive lens 34,
4. Lens mount 33 to be inspected, mask plate 36, light receiving element 3
1 is arranged. In this lens meter, the apex refractive power and the like of the test lens 30 are determined from the difference between the projection pattern of the mask plate 36 on the light receiving element 31 when the test lens 30 is not inserted (dashed line) and when the test lens 30 is inserted (solid line). Can be requested. As a modification of this principle, an optical system in which a lens is disposed between the lens holder 33 to be inspected and the mask plate 36 (Japanese Patent Application Laid-Open No. 32-225920), the light beam is split on the light source side instead of placing the mask plate 36. Optical system (Japanese Unexamined Patent Publication No.
No. 31012) is also known. Further, there is also a method in which a narrow beam is scanned instead of using a wide light beam in each lens meter, and a vertex refracting power is obtained from a beam trajectory on a light receiving element or time modulation.

In each of the prior arts 1, 2, and 3, the light beam from the light source is made incident on the ophthalmic lens to be examined, and the state of the light beam after passing through the ophthalmic lens to be examined is observed on a screen or a light receiving element. In a lens meter, with a conjugate point of a light source, a screen, or a light receiving element made at infinity from an ophthalmic lens to be inspected by each lens, an apparatus for determining a vertex power or a prism optical power of the ophthalmic lens to be inspected. Common in some respects. More specifically, in Conventional Examples 1 and 2, in a lens meter in which a light beam enters from the inner surface side (eye side) of the test lenses 10 and 20, an optical system located on the outer surface side of the test lenses 10 and 20 is used. , The conjugate point of the screen 15 or the light receiving element 25 (the conjugate point of the screen 15 by the lens 14 and the conjugate point of the light receiving element 25 by the positive lens 24)
Is formed at a position at infinity from the test lenses 10 and 20. Further, in the third conventional example, in a lens meter in which a light beam enters from the outer surface side of the test lens 30, a conjugate point of the light source 35 (a conjugate point of the light source 35 by the positive lens 34) by an optical system located on the outer surface side of the test lens 30. ) For the lens 3 to be inspected.
It is made from 0 to infinity.

FIG. 9 shows an example of a test lens holding mechanism used in such a lens meter. Test lens Q
The inner surface of the lens 3 comes into contact with the lens holder 3 to be measured by a lens holder (not shown), and the measurement light beam passes through the inner surface of the lens vertically. SPH-4.00 using this lens holding mechanism to be inspected and the lens meter of Conventional Example 1.
FIG. 10 shows an example of evaluating the rotationally symmetric aspherical lens.
The vertical axis H in the figure is the distance [mm] from the optical axis, the horizontal axis ΔAP is the field curvature [Diopter], and ΔAS is the astigmatism [Di
opter]. However, as described above, what can be measured by the principle of the conventional lens meter is only the performance of the test lens with respect to the object point at infinity. It is far from the evaluation result in the wearing state, and it is almost meaningless result.

[0008] As shown in FIG.
Is worn on the eye, the light beam passes through the lens to be examined so as to pass through the eyeball rotation point E. It does not necessarily pass perpendicular to the inner surface of the lens. Therefore, it is a natural result that the measurement in the state of FIG. 9 does not show the performance in the wearing state. A lens evaluation method using a lens holding mechanism that can rotate the lens to be tested around the assumed rotation point of the eyeball in order to make the passing angle of the light flux on the lens surface the same as that in the wearing state is described in "Hitoyuki Kido: Measurement of aberration of progressive multifocal lens considering rotation, Science of Vision Vol.15, No.2
(1994) pp. 124-131 ".

FIG. 12 shows the movement of the lens to be inspected and the way the light beam passes when such a lens rotation holding mechanism is used. The test lens Q moves about the assumed eyeball rotation point 8, and the measurement light beam can pass through the lens surface at substantially the same angle as the wearing state. The combination of a lens meter and a lens rotation holding mechanism makes it possible to evaluate the optical performance of a test lens in a worn state.

FIG. 13 shows SPH-4.00 using such a lens rotation holding mechanism and the lens meter of Conventional Example 2.
3 shows an example of evaluating a rotationally symmetric aspheric lens. The vertical axis VA in the figure is the rotation angle (viewing angle) [degre] of the test lens.
e], and {AP on the horizontal axis is the field curvature [Diopter],}
AS is astigmatism [Diopter].

In the same manner, SPH + 4.00, AD
FIG. 14 shows an example in which a progressive multifocal lens of D2.00 is evaluated. The left side of FIG. 14 represents the average refractive power distribution, and the right side represents astigmatism, and each contour line is 0.25 [Diopter].
In each case, the solid line is every 1 [Diopter]. The dotted grid in the figure is a mesh for each rotation angle (viewing angle) of 10 [degree].

[0012] However, these evaluation results are evaluated in combination with a conventional lens meter even if a lens rotation holding mechanism is used. It is evaluation of.
The actual object observed through the ophthalmic lens exists at various distances from infinity to about 20 cm in front of the eye, and the optical performance of the ophthalmic lens varies depending on the object distance. Therefore, it is not sufficient to evaluate the performance of only the object point at infinity. . In particular, since the near portion of the progressive multifocal lens is a portion for observing a short-distance object point, it is almost meaningless to perform the evaluation at an object point at infinity.

Progressive addition lens (Progressive addition)
Lens) is, in ISO, "ISO 08980-2: 1996 (E)
Opthalmic optics-Uncut finished spectacle lenses-P
art 2: Specification for progressive power lenses "
The Annex B (informative) describes a method for evaluating the performance of a progressive multifocal lens in a worn state, but the object distance used for evaluation is infinite (For p.
rogressiveaddition lens charactgeristics a measure
ment with infinity distance has been chosen.). That is, the problem as raised by the present invention is not recognized in ISO.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional method for evaluating the performance of a spectacle lens using an ophthalmic lens meter, and it has become possible to evaluate the performance of a spectacle lens with respect to an object point from infinity to a finite distance. It is an object of the present invention to provide an ophthalmic lens meter.

[0015]

SUMMARY OF THE INVENTION According to a first aspect of the ophthalmic lens meter according to the present invention, a light beam from a light source is incident on an ophthalmic lens to be inspected from the inner surface side, and the light beam after passing through the ophthalmic lens to be inspected. By observing the state with a screen or a light receiving element, in an ophthalmic lens meter that determines the apex refractive power or prism refractive power of the ophthalmic lens to be examined, an optical system located between the ophthalmic lens to be examined and the screen or the light receiving element, The conjugate point position at which the distance L from the ophthalmic lens to be examined of the conjugate point of the screen or the light receiving element formed by the optical system is switched to at least L = ∞L = any distance within 200 to 1000 [mm]. A switching means is provided.

The conjugate point position switching means is, specifically, at least an optical system located on the outer surface side of the ophthalmic lens to be examined;
Element moving means for moving at least one of the screen and the light receiving element in the optical axis direction, an attachment lens inserting / removing means for inserting and removing an attachment lens between the ophthalmic lens to be inspected and the screen or the light receiving element, or an ophthalmic lens to be inspected And an optical system located between the screen and the light receiving element is composed of at least two groups of lenses.
It can be constituted by lens interval changing means for changing the interval between the two groups of lenses.

According to the second aspect of the ophthalmic lens meter of the present invention, the light beam from the light source is made incident on the ophthalmic lens to be examined from the outer surface side, and the state of the light beam after passing through the ophthalmic lens to be examined is changed. In an ophthalmic lens meter that obtains a vertex refractive power or a prism refractive power of an ophthalmic lens to be examined by observing with a screen or a light receiving element, the optical system located between the light source of the ophthalmic lens to be inspected, the outer surface side, and the light source includes The distance L of the conjugate point of the light source made by the system from the ophthalmic lens to be examined is
At least L = -∞ L = −200 to −1000 [mm] The conjugate point position switching means is provided for switching over any two distances.

The conjugate point position switching means is, specifically, at least an optical system located on the outer surface side of the ophthalmic lens to be examined;
Element moving means for moving at least one of the light sources in the optical axis direction, between the ophthalmic lens to be examined and the light source, attachment lens inserting and removing means for inserting and removing the attachment lens, or between the ophthalmic lens to be examined and the light source After the located optical system is constituted by at least two groups of lenses, it can be constituted by a lens interval changing means for changing an interval between the two groups of lenses.

The attachment lens preferably has a meniscus shape concave toward the ophthalmic lens to be examined in order to minimize aberrations generated by the lens.

In the ophthalmic lens meter according to the present invention, the measured value SPH [Diopter] of spherical power or the equivalent spherical power AP [Diopter] is corrected by the distance L [mm] of the conjugate point from the ophthalmic lens to be examined. .

[0021]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1 Embodiment 1 is shown in FIG. The first embodiment is an improvement of the ophthalmic lens meter of the first conventional example, in which the screen 15 can be moved in the optical axis direction. Screen 15
Is movable in the optical axis direction by, for example, a rack 15a fixed to the screen 15 and parallel to the optical axis, and a pinion 15b screwed to the rack 15a.

If this screen moving mechanism is used to place the screen 15 at the rear focal position of the positive lens 14, the conjugate point of the screen 15 by the positive lens 14 can be set to infinity. This is the same as before. On the other hand, the focal length of the positive lens 14 is f [mm], the distance from the opening of the lens holder 13 to be measured to the front principal point of the positive lens 14 is d [mm], and the screen 15 is moved to the rear focal point of the positive lens 14. By moving Z [mm] toward the positive lens 14 with reference to the position, the conjugate point of the screen 15 moves from the opening of the lens holder 13 to be inspected to Z ₀ = df-f ² / Z [mm]. Position. If d = f = 30 [mm], Table 1
As described above, it is possible to evaluate the performance of the ophthalmic lens to be inspected for an arbitrary object distance from infinity to a finite distance according to Z.

[0023]

[Table 1] Z [mm] Z ₀ [mm] 0.0 ∞ -0.90 1000 -1.80 500 -3.00 300

[0024] The distance L from the subject ophthalmic lens outer surface to the conjugate point is minus the thickness of the test ophthalmic lens from Z _0, the thickness of the normal subject ophthalmic lens several millimeters at most Therefore, it can be considered that L ≒ Z ₀ . The above first
In the embodiment, instead of moving the screen 15, the distance between the screen 15 and the positive lens 14 may be changed by moving the positive lens 14.

Embodiment 2 FIG. 2 shows Embodiment 2. The second embodiment is an improvement of the ophthalmic lens meter of the second conventional example, in which a means for inserting and removing an attachment lens 29 having a negative refractive power is provided between the ophthalmic lens 20 to be examined and the positive lens 24. The fact that the conjugate point of the light receiving element 25 by the positive lens 24 can be set to infinity in a state where the attachment lens 29 is not inserted is not different from the conventional case. On the other hand, when the attachment lens 29 is inserted, if the refractive power of the attachment lens 29 is D [Diopter] and the distance of the attachment lens 29 from the opening of the lens holder 23 is s [mm], the light receiving element The conjugate point 25 can be located at the position of Z ₀ = s−1000 / D [mm] from the opening of the lens holder 23 to be measured. If a plurality of attachment lenses are prepared with s = 25 [mm], the ophthalmic lens can be evaluated with respect to the object distance according to the refractive power of the attachment lens as shown in Table 2. It is preferable that the attachment lens 29 has a meniscus shape concave toward the ophthalmic lens to be examined in order to minimize the occurrence of aberration due to insertion of the attachment lens 29.

[0026]

[Table 2] z [mm] Z ₀ [mm] 0.00 ∞ -1.03 1000 -2.11 500 -3.64 300

FIG. 4 shows a combination of the ophthalmic lens meter according to the second embodiment and the lens rotation holding mechanism shown in FIG.
The example which evaluated the rotationally symmetric aspherical lens of SPH-4.00 is shown. The vertical axis VA in the figure is the rotation angle (viewing angle) [degree] of the ophthalmic lens to be inspected, [Delta] AP on the horizontal axis is curvature of field [Diopter], and [Delta] AS is astigmatism [Diopte].
r], and FIGS. 4A, 4B, and 4C correspond to the object distance 物体, 1000 [mm], and 300 [mm], respectively.

FIG. 5 shows SPH + 4.00, A by combining the ophthalmic lens meter and the rotation holding mechanism of the second embodiment.
FIG. 5 shows an example in which a progressive multifocal lens of DD2.00 is evaluated. The left side of FIG. 5 shows the average refractive power distribution, and the right side shows astigmatism, and each contour line is 0.25 [Diopter].
In each case, the solid line is every 1 [Diopter]. The dotted grid in the figure is a mesh for each viewing angle of 10 [degree]. In the distance portion evaluation of the progressive multifocal lens, no attachment lens was used, and in the near portion evaluation, -3.64 [D
iopter], and in the middle part, the measurement was performed while sequentially changing to an attachment lens having a refractive power corresponding to the object distance assumed by the lens. These evaluation results were in good agreement with the performance simulation in actual use of the test lens.

The value measured by the ophthalmic lens meter is a value that includes both the refractive power of the ophthalmic lens to be inspected and information on the divergent state of the measurement light beam. Therefore, in order to obtain only the refraction effect by the ophthalmic lens to be examined, it is necessary to correct the measured value. Assuming that the measured value of the spherical refractive power by the ophthalmic lens meter is SPH [Diopter], the measured value of the cylindrical refractive power is CYL [Diopter], and the distance of the conjugate point from the ophthalmic lens to be examined is L [mm], the corrected spherical surface. The refractive power is SPH ′ = SPH−1000 / | L |. Further, the corrected equivalent spherical refractive power is AP '= SPH' + CYL / 2. FIG. 5 is a plot of the values subjected to such correction processing.

Third Embodiment FIG. 3 shows a third embodiment. Embodiment 3 is an improvement of the ophthalmic lens meter of Conventional Example 3, in which a lens between the light source 35 and the lens 30 to be inspected is composed of a lens 39 having a negative refractive power and a lens 34 having a positive refractive power. In this configuration, one of the positive lenses 34 is movable in the optical axis direction. The means for making the positive lens 34 movable in the optical axis direction can be constituted by, for example, a rack 34a fixed to the positive lens 34 and parallel to the optical axis, and a pinion 34b screwed to the rack 34a. By changing the distance between the positive lens 34 and the negative lens 39 by this lens distance changing means, the position of the conjugate point of the light source 35 can be changed, and the performance evaluation of the ophthalmic lens to be inspected for any object distance from infinity to finite distance. Becomes possible.

That is, the distance from the light source 35 to the front principal point of the negative lens 39 is d0 [mm], and the distance from the rear principal point of the negative lens 39 to the front principal point of the positive lens 34 is d1 [m].
m], the lens holder 3 to be inspected from the rear principal point of the positive lens 34.
Assuming that the distance to the opening 6 is d2 [mm], the light source 3
The conjugate point of No. 5 is Z ₀ from the opening of the lens holder 13 to be inspected.
= 1 / (1 / f2 + 1 / (1 / (1 / f1-1 / d0))
−d1))-d2 [mm]. f1 = -4
0 [mm], f2 = 25 [mm], d0 = 20 [m]
m], d1 + d2 = 30 [mm], and the positive lens 34
Is moved, the performance of the ophthalmic lens to be examined can be evaluated for an arbitrary object distance from infinity to a finite distance according to d1 as shown in Table 3.

[0032]

[Table 3] _{d1 [mm] Z 0 [mm} ] 11.67 ∞ 11.05 1000 10.43 500 9.62 300

In the above embodiment, the conjugate point position switching means is inserted, the element moving means for changing the distance between the screen 15 and the positive lens 14 in the ophthalmic lens meter of FIG. 1, and the attachment lens 19 in the second ophthalmic lens meter. The detachable attachment lens inserting / removing means, and the third ophthalmic lens meter is constituted by the lens interval changing means for changing the interval between the two groups of lenses 34 and 39. These element moving means, the attachment lens inserting / removing means, the lens interval The changing means is applicable to each of the spectacle lens meters of FIGS. That is, in the example of FIG. 1, instead of the moving mechanism of the screen 15 (or the positive lens 14), an insertion / removal mechanism of the negative attachment lens 19 or a lens interval changing mechanism is used, and in the example of FIG. Instead of the insertion / removal mechanism, a mechanism for moving the light receiving element 25 (or the positive lens 24) or the attachment lens 2
In the example of FIG. 3, instead of the mechanism for changing the distance between the lenses 34 and 39, a mechanism for changing the distance between the lens 9 and the positive lens 24 is used.
The same conjugate point position switching means can be configured by using a moving mechanism of the light source 35 (or the positive lens 34) or an insertion / removal mechanism of the attachment lens 39.

The ophthalmic lens meter according to the present invention is
For accurate positioning of the lens, it is preferable to use it together with the lens rotation holding mechanism. However, the lens may be held by other means if the angle of passage of the light beam to the lens is the same as the wearing state. Further, an optical element such as a prism compensator may be included.

[0035]

By using the ophthalmic lens meter according to the present invention, it is possible to evaluate the performance of the spectacle lens for object points from infinity to a finite distance.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of an ophthalmic lens meter according to the present invention.

FIG. 2 is an explanatory diagram showing another embodiment of the ophthalmic lens meter (optical system).

FIG. 3 is an explanatory view showing still another embodiment of the ophthalmic lens meter (optical system).

FIG. 4 is a diagram showing an evaluation result of an aspheric lens by the ophthalmic lens meter of the present invention.

FIG. 5 is a diagram showing evaluation results of the progressive multifocal lens.

FIG. 6 is an explanatory diagram of an optical system of a conventional ophthalmic lens meter.

FIG. 7 is an explanatory diagram of an optical system of another conventional ophthalmic lens meter.

FIG. 8 is an explanatory diagram of an optical system of still another conventional ophthalmic lens meter.

FIG. 9 is an explanatory diagram of a lens evaluation example using a conventional ophthalmic lens meter.

FIG. 10 is a diagram illustrating evaluation results of an aspheric lens using the ophthalmic lens meter of FIG. 6;

FIG. 11 is an explanatory diagram of a state of rotation of an eye.

FIG. 12 is an explanatory diagram showing a principle diagram of a rotation holding mechanism of a lens.

FIG. 13 is a diagram showing evaluation results of an aspheric lens using the ophthalmic lens meter of FIG. 7;

FIG. 14 is a diagram showing evaluation results of a progressive multifocal lens by the conventional ophthalmic lens meter.

[Explanation of symbols]

 Q 10 20 30 Test lens 11 21 Target 12 22 32 Positive lens (or lens group) 3 13 23 33 Test lens holder 14 24 34 Lens (or lens group) 15 Screen 25 31 Light receiving element 23 35 Light source 27 Lens 19 29 39 Attachment lens 36 Mask plate E Eyeball rotation point 8 Eyeball rotation assumption point

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[Procedure amendment]

[Submission date] June 5, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

In the same manner, SPH + 4.00, AD
FIG. 14 shows an example in which a progressive multifocal lens of D2.00 is evaluated. The right side of FIG. 14 shows the average refractive power distribution, and the left side shows the astigmatism, and each contour line is 0.25 [Diopter].
In each case, the solid line is every 1 [Diopter]. The dotted-line grid in the figure is a mesh for each rotation angle (visual) of 10 [degree].

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction contents]

FIG. 5 shows SPH + 4.00, A by combining the ophthalmic lens meter and the rotation holding mechanism of the second embodiment.
FIG. 5 shows an example in which a progressive multifocal lens of DD2.00 is evaluated. The right side of FIG. 5 shows the average refractive power distribution and the left side shows the astigmatism, and each contour line is 0.25 [Diopter].
In each case, the solid line is every 1 [Diopter]. The dotted grid in the figure is a mesh for each viewing angle of 10 [degree]. In the distance portion evaluation of the progressive multifocal lens, no attachment lens was used, and in the near portion evaluation, -3.64 [D
iopter], and in the middle part, the measurement was performed while sequentially changing to an attachment lens having a refractive power corresponding to the object distance assumed by the lens. These evaluation results were in good agreement with the performance simulation in actual use of the test lens.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Change

[Correction contents]

[EXPLANATION OF SYMBOLS] Q 10 20 30 test lens 11 21 Target 12 2 2 lenses (or lens group) 3 13 23 33 sample lens cradle 14 24 34 lenses (or lens group) 15 Screen 25 31 receiving element 2 6 35 Light source 27 Lens 19 29 39 Attachment lens 36 Mask plate E Eyeball rotation point 8 Eyeball rotation assumed point

Claims (12)

[Claims] A light beam from a light source is made incident on an ophthalmic lens to be inspected from the inner surface side, and the state of the light beam after passing through the ophthalmic lens to be inspected is observed by a screen or a light receiving element. In an ophthalmic lens meter for determining a vertex refractive power or a prism refractive power of a lens, an optical system positioned between the subject ophthalmic lens and a screen or a light receiving element has a conjugate point of the screen or the light receiving element formed by the optical system. An ophthalmic lens comprising conjugate point position switching means for switching the distance L from the ophthalmic lens to be examined to at least two of the following: L =＝ L = any distance within 200 to 1000 [mm]. Meter. 2. The ophthalmic lens meter according to claim 1, wherein the conjugate point switching means is configured to move at least one of the optical system located on the outer surface side of the ophthalmic lens to be examined and the screen or the light receiving element in an optical axis direction. An ophthalmic lens meter as an element moving means for moving the lens. 3. The ophthalmic lens meter according to claim 1, wherein said conjugate point position switching means is an attachment lens insertion / removal means for inserting / removing an attachment lens between said subject ophthalmic lens and a screen or a light receiving element. An ophthalmic lens meter. 4. The ophthalmic lens meter according to claim 3, wherein the attachment lens has a meniscus shape concave toward the ophthalmic lens to be examined. 5. The ophthalmic lens meter according to claim 1, wherein the optical system located between the subject ophthalmic lens and a screen or a light receiving element includes at least two groups of lenses, and the conjugate point position switching means includes: An ophthalmic lens meter which is a lens interval changing means for changing the interval between the two groups of lenses. 6. The ophthalmic lens meter according to claim 1, wherein the measured value SPH of the spherical refractive power.
[Diopter] or equivalent spherical refractive power AP [Di
ophthalmic lens meter having a correcting unit for correcting [opter] by a distance L [mm] of the conjugate point from the ophthalmic lens to be inspected. 7. A luminous flux from a light source is made to enter the ophthalmic lens to be examined from the outer surface side, and the state of the luminous flux after passing through the ophthalmic lens to be examined is observed by a screen or a light receiving element, thereby obtaining the ophthalmic lens to be examined. An ophthalmic lens meter for determining a vertex refractive power or a prism refractive power of a lens, wherein an optical system positioned between the ophthalmic lens to be inspected, an outer surface side, and a light source is provided with a test point of a conjugate point of the light source formed by the optical system. An ophthalmic lens comprising conjugate point position switching means for switching a distance L from an ophthalmic lens to at least two of the following: L = -∞ L = any distance within a range of -200 to -1000 [mm]. Meter. 8. The ophthalmic lens meter according to claim 7, wherein the conjugate point position switching means moves at least one of the optical system located on the outer surface side of the ophthalmic lens to be examined and the light source in the optical axis direction. An ophthalmic lens meter that is an element moving means. 9. An ophthalmic lens meter according to claim 7, wherein said conjugate point position switching means is an attachment lens inserting / removing means for inserting / removing an attachment lens between said subject ophthalmic lens and a light source. Meter. 10. The ophthalmic lens meter according to claim 9, wherein the attachment lens has a meniscus shape concave toward the ophthalmic lens to be examined. 11. An ophthalmic lens meter according to claim 7, wherein the optical system located between the ophthalmic lens to be inspected and the light source comprises at least two groups of lenses, and the conjugate point position switching means comprises: An ophthalmic lens meter which is a lens interval changing means for changing the interval between the lenses of the group. 12. The ophthalmic lens meter according to claim 7, wherein the measured value S of the spherical refractive power is used.
PH [Diopter] or equivalent spherical refractive power AP
An ophthalmic lens meter, wherein [Diopter] is corrected by a distance L [mm] of the conjugate point from the ophthalmic lens to be inspected.