JP2010054474A - Optical performance evaluation method of progressive refractive power lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for reliably obtaining optical characteristics of a progressive refractive power lens by a simpler method. <P>SOLUTION: An optical performance evaluation method of a progressive refractive power lens has: a distant view part region; a near view part region; and a progressive band where refractive power changes progressively between the two regions. The optical performance evaluation method includes: measuring addition refractive power of a sample lens for deriving a correction function by a measuring device for actual evaluation used for evaluating a lens to be evaluated; measuring the addition refractive power of the sample lens by a reference measuring device; deriving a correction function for correcting addition refractive power measured by the measuring device for actual evaluation to the addition refractive power measured by the reference measuring device; measuring at least one kind of optical performance selected from a group comprising refractive power for a distant view part and that for a near view part in a lens to be evaluated by the measuring device for actual evaluation; and obtaining the optical performance of the lens to be evaluated, for example, by correcting the optical performance measured by the measuring device for actual evaluation by the correction function. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for evaluating the optical performance of a progressive power lens, and more particularly to a method for evaluating a progressive power lens that can easily and accurately evaluate a lens prescription value of a progressive power lens. is there.

A lens meter is widely used as an optical characteristic evaluation apparatus for spectacle lenses (see, for example, Patent Document 1).
JP-A-2005-214701

  In recent years, progressive-power lenses have been widely used as presbyopia correction lenses. The progressive power lens is a lens that distributes the far, middle, and near field of view according to the frequency of use. It is standard to measure (difference between distance portion refractive power and near portion refractive power) and prism refractive power using a lens meter or a method equivalent thereto.

However, inspection of progressive power lenses using a lens meter has the following problems.
(1) Although the measurement value of the lens meter is high in reliability, it requires skillful techniques for operation, and therefore the measurement value is greatly influenced by the individual skill of the measurer.
(2) The lens meter measures the average frequency of the measurement region (usually a region having a diameter of about 8 mm) by one measurement. That is, one measurement value is obtained in one measurement. Therefore, in order to measure the above three kinds of refractive power with respect to the progressive-power lens, the measurement is performed at least once for each of the distance measurement reference point, the near measurement reference point, and the prism measurement reference point, that is, at least three times in total. It must be made. Therefore, the operation becomes complicated and a long time is required for the inspection.

  Therefore, it is conceivable to use a measuring device capable of simple measurement as an alternative device for the lens meter. As mentioned above, in JIS, it is standard to measure the lens prescription value of a progressive power lens using a lens meter or a method equivalent thereto, so that an alternative device obtains a measurement value equivalent to that of a lens meter. If it is possible, it becomes possible to use the measured value by the alternative device in the actual production process, and as a result, the productivity can be greatly improved.

  As a means for performing a highly reliable evaluation equivalent to a lens meter by an alternative device, it is conceivable to correct a measurement value obtained by the alternative device with respect to a measurement value obtained by the lens meter. However, if it is necessary to derive the correction function for each refractive power, many measurements must be repeated to derive the correction function. In this case, it is difficult to perform simple measurement using an alternative device.

  SUMMARY OF THE INVENTION An object of the present invention is to provide means capable of obtaining the optical characteristics of a progressive power lens with high reliability by a simple method.

As a result of intensive studies to achieve the above object, the present inventors have obtained the following knowledge.
The lens meter is originally a device for measuring the distance power of a single focus lens. Therefore, conventionally, in order to correct the measurement value obtained by another measuring device with respect to the measurement value obtained by the lens meter, the measurement value of the distance portion refractive power has been used. However, the measured values of the distance power are not correlated with the measured values of the near distance, so each measured value of the power other than the distance is corrected individually. It was necessary to derive a function.
In contrast, the present inventors pay attention to the fact that the addition refractive power is the difference between the distance portion refractive power and the near portion refractive power, and the correction function derived for the addition refractive power is determined as the distance portion refractive power and the near portion refractive power. As a result of studying the application to the correction of the refractive power of the use part, it was newly found that a good correction is possible.
The present invention has been completed based on the above findings.

That is, the above object was achieved by the following means.
[1] An optical performance evaluation method for a progressive power lens having a distance portion region, a near portion region, and a progressive zone in which the refractive power gradually changes between the two regions,
Measuring the addition refractive power of the sample lens for deriving the correction function with a measuring device for actual evaluation used for evaluating the lens to be evaluated;
Measuring the addition power of the sample lens using a reference measuring device;
Deriving a correction function for correcting the addition power measured by the measurement device for actual evaluation with respect to the addition power measured by the reference measurement device;
Measuring at least one optical performance selected from the group consisting of the distance-use refractive power and the near-use refractive power of the lens to be evaluated using an actual evaluation measuring device;
The optical performance of the lens to be evaluated is obtained by correcting the optical performance measured using the measurement device for actual evaluation using the correction function or by determining that correction is not necessary based on the correction function. thing,
Including said method.
[2] The measurement device for actual evaluation includes a measuring unit that measures the optical path of the outgoing light emitted from the measuring point on the second surface on the opposite side when light is incident from the first surface of the lens, and the measuring unit. [1] The method according to [1], wherein the measurement device includes a calculation unit that calculates the optical performance of the lens at the measurement point based on the obtained measurement value.
[3] The method according to [1] or [2], wherein the reference measuring device is a lens meter.
[4] The method according to any one of [1] to [3], wherein the correction function is a linear function.
[5] Measuring the addition power of the lens to be evaluated and correcting the measured addition power using the correction function or determining that no correction is necessary based on the correction function. The method according to any one of [1] to [4], further including determining an addition refractive power of the lens.

  According to the present invention, the optical performance of a progressive-power lens can be easily and accurately measured.

The present invention relates to a method for evaluating optical performance of a progressive power lens having a distance portion region, a near portion region, and a progressive zone in which the refractive power changes progressively between the two regions. The method of the present invention includes the following steps.
(1) Measure the addition refractive power of the correction function derivation sample lens with an actual evaluation measuring device used for evaluating the evaluation target lens;
(2) measuring the addition refractive power of the sample lens using a reference measuring device;
(3) Deriving a correction function for correcting the addition power measured by the measurement device for actual evaluation with respect to the addition power measured by the reference measurement device;
(4) measuring at least one optical performance selected from the group consisting of the distance-use refractive power and the near-use refractive power of the lens to be evaluated using an actual evaluation measuring device;
(5) The optical performance of the lens to be evaluated is determined by correcting the optical performance measured using the measurement device for actual evaluation using the correction function or by determining that correction is not necessary based on the correction function. Seeking performance.

  Regarding the evaluation of the optical performance of a progressive power lens, JIST 7315 stipulates that the lens refractive power should be determined using a lens meter conforming to JISB7183 or using a method equivalent to the lens meter. However, because the lens meter has the above-mentioned problems, establishing a highly accurate and simple measurement method that replaces the lens meter is essential for improving productivity, especially in the mass production process for manufacturing a large number of lenses. It is thought that it becomes.

  As a measuring device that replaces the lens meter, for example, as proposed in International Publication No. 03/098181 pamphlet, from the measurement of the optical path length of the lens transmitted light, the refractive power distribution (frequency distribution or And an apparatus for measuring (also called aberration). Since the above apparatus is used to calculate the refractive power (frequency) at a plurality of points included in the measurement region and to obtain the refractive power distribution in the measurement region, it has a function of calculating the refractive power at a certain measurement point. Have. However, as a result of studies by the inventors of the present application, it has been found that the lens prescription value obtained by the transmission aberration measuring device may not always match the value obtained by the lens meter. As described above, when an error occurs between the measurement value obtained by the actual measurement device and the measurement value obtained by the reference measurement device, in order to perform measurement with the same accuracy as that of the reference measurement device, the correction function is used. It is conceivable to correct the measured value. However, since JIS standardizes the measurement of multiple types of refractive power, if it is necessary to derive a correction function for each refractive power, it takes a long time to derive the correction function. It is difficult to greatly improve the performance.

  On the other hand, in the present invention, a correction function is derived only for the addition power among various refractive powers, and the distance power and / or the near power is measured by an alternative device using the derived correction function. Correct the value. Previously, it was thought that correction could not be performed unless a correction function was derived for each refractive power, but it was extremely surprising that other types of refractive power could be corrected satisfactorily by the addition power correction function. This has been newly found by the inventors of the present application. The reason why the measured value of the distance power and / or the near power can be corrected using the addition power correction function is that, as described above, the addition power is the distance power and the near power. This is a difference from the refractive power, and is considered to include elements of both refractive powers.

Actual Evaluation Measuring Device and Reference Measuring Device As described above, since a lens meter can perform highly reliable measurement, it is preferable to use a lens meter as a reference measuring device used for deriving a correction function. The lens meter includes an auto lens meter, an eyepiece lens meter, and a projection lens meter, and any of them is suitable in the present invention. A highly reliable evaluation can be performed by using the correction value for the measured value of the lens meter. The lens meter is a device that calculates an average value (average power) of refractive power in a region having a diameter of about 8 mm, and is different from the above-described measuring device that can measure the refractive power at each measurement point.

  On the other hand, as the measurement device for actual evaluation, it is preferable to use a measurement device capable of simple evaluation as compared with a lens meter. As such an apparatus, when light is incident from the first surface of the lens, the measuring means for measuring the optical path of the outgoing light emitted from the measuring point on the second surface on the opposite side, and the measuring means obtained. A measuring device having calculation means for calculating the optical performance of the lens at the measurement point based on the measurement value can be used. As the measurement apparatus, an apparatus generally called “transmission frequency distribution measurement apparatus” or “transmission aberration measurement apparatus” can be used. Hereinafter, the apparatus is referred to as a “transmission aberration measuring apparatus”. The apparatus is preferably a refracting power measuring apparatus that simultaneously measures the lens geometric center 50φ or the optical surface 60 to 80% of the measuring lens. The above apparatus is used for calculating the refractive power (frequency) at a plurality of points (two or more points) included in the measurement region and obtaining the refractive power distribution (also referred to as power distribution or aberration) in the measurement region. Therefore, it has a function of calculating the refractive power at a certain measurement point. In the present invention, the optical performance at a measurement point with a lens to be measured can be obtained using the above function. Examples of the measuring apparatus that can be used in the present invention include VM2000 and VM2500 manufactured by Visionics, but are not particularly limited as long as they have the above-described measuring means and calculating means. As for the transmission type aberration measuring apparatus that can be used in the present invention, reference can be made to, for example, International Publication No. 03/098181 pamphlet, Japanese Patent Publication No. 10-507825, and the like.

In the present invention, the optical performance evaluated with respect to the evaluation target lens can include a distance portion refractive power and / or a near portion refractive power. Furthermore, the addition refractive power can be evaluated together with the above refractive power. Reference points for measuring each refractive power are defined in JIST7315, JIST7313, or JIST7330. The refractive power measurement reference point is a portion surrounded by a circle having a diameter of, for example, about 6.0 to 10.0 mm on the object side or eyeball side surface of the spectacle lens. FIG. 3 is an explanatory diagram of the refractive power measurement reference point of the progressive-power lens. By setting a refractive power measurement reference point corresponding to a desired optical performance (refractive power) from the above refractive power measurement reference points as a measurement point for measuring the optical path of the outgoing light in the transmission type aberration measuring apparatus, Optical performance can be measured. As described above, according to the transmission aberration measuring apparatus, various optical performances can be obtained by one measurement.
Hereinafter, although the specific aspect of the optical performance measurement which uses a transmissive | pervious aberration measuring apparatus is demonstrated, this invention is not limited to the following aspect.

Transmission Aberration Measuring Device The transmission aberration measuring device that can be used in the present invention measures the optical path of outgoing light that is emitted from the measurement point on the opposite second surface when light is incident from the first surface of the lens to be tested. And a data server for storing data necessary for evaluation of the test lens and a calculation result, and a measurement server for calculating the optical performance at the measurement point from the optical path measured by the measurement unit. Can do.

  FIG. 1 shows a schematic configuration example of the transmission aberration measuring apparatus. In the embodiment shown in FIG. 1, the transmission aberration measurement apparatus includes a light source device 11 that irradiates the test lens 100 with parallel light, and a plurality of lights that are arranged on the opposite side of the light source device 11 with the test lens 100 interposed therebetween. A beam splitter 12 having a transmission hole, a screen 13 on which light transmitted through the beam splitter 12 arrives, a CCD camera 14 for capturing an image displayed on the screen 13, and data received from the CCD camera 14 It comprises a calculation device (calculation means) 15 that measures the path of light transmitted through the test lens 100 and calculates the optical performance at the measurement point of the test lens 100. Furthermore, the computing device may be connected to a data server.

  The transmission aberration measuring apparatus measures the path of light after passing through the lens from the image projected on the screen 13 when the test lens 100 is irradiated with parallel light from the light source device 11, and the test lens is determined from the measurement result. The optical performance at 100 measurement points is calculated. For example, when the measurement point is a distance measurement reference point, the distance refractive power can be calculated from the measured optical path, and when the measurement point is a near measurement reference point, the distance from the measured optical path can be calculated. When the measurement point is a prism measurement reference point, the prism refractive power can be calculated from the measured optical path. Alternatively, by adding the distance measurement reference point and the near measurement reference point as measurement points and obtaining the distance refractive power and the near refractive power, the addition refractive power, which is the difference between them, can be calculated. As shown in FIG. 1, the transmission type aberration measuring apparatus has an advantage that it is not necessary to perform measurement for each spot unlike the lens meter because the entire lens surface can be evaluated by one measurement.

  Specifically, in the transmission aberration measuring apparatus, a beam splitter 12 having a plurality of light transmission holes is disposed between the test lens 100 and the screen 13, and passes through the test lens 100 by the beam splitter 12. The light is separated into a plurality of light beams, and a plurality of light spots corresponding to the plurality of light transmission holes are projected on the screen 13.

FIG. 2 is an explanatory diagram of measurement data obtained by the transmission aberration measurement apparatus.
The transmission type aberration measuring apparatus receives reference coordinates RefX and RefY indicating the position of a light spot (hereinafter referred to as a calibration spot) on the screen 13 in a state where the test lens 100 is not set, and the light from the light source device 11. Coordinates X and Y indicating the position (hereinafter referred to as a measurement point) when exiting from the beam splitter side surface of the test lens 100, and a light spot (hereinafter referred to as the test lens 100) in a state where the test lens 100 is set. Deviations DX and DY between the position of the measurement spot) and the corresponding calibration spot (calibration spot that has passed through the same light transmission hole as the measurement spot) and the optical path of the light that has passed through the test lens 100 The refractive power calculated based on this is output as measurement data.
Since the reference coordinates RefX and RefY, the measurement point coordinates X and Y, the deviations DX and DY, and the refractive power are output in association with each spot, the refractive power at each measurement point coordinate X and Y of the lens 100 to be measured is output. Can be requested.

Next, a specific example of measurement by the transmission type aberration measuring apparatus will be described. However, the present invention is not limited to the following specific examples.
(1) Marking or painting is performed on the progressive power lens to specify the measurement position. At this time, the measurement reference point (see FIG. 3) is specified based on the permanent mark (alignment reference mark 231 in FIG. 3) implemented on the lens. In the case of an uncut finish lens, positioning can also be performed based on the outer shape, and in this case, the measurement reference point can be specified without performing stamping and painting.
(2) Set the lens to be measured on the measuring section of the transmission type aberration measuring apparatus. At this time, the test lens is held by a method determined by the transmission aberration measurement device manufacturer (such as bringing the rear surface of the test lens into contact with the measurement aperture). A conversion lens adapter may be used as necessary.
(3) Send the measurement reference point information to the transmission aberration measurement apparatus, press the measurement start button, and calculate the measured value of the refractive power measurement. Alternatively, measurement is performed by pressing a measurement start button of the transmission aberration measuring apparatus, and an actual measurement value such as refractive power at a plurality of measurement reference points is calculated from the output result.

  In the refractive power measurement using the transmission aberration measuring apparatus, the measured values of the refractive power (distance power, addition refractive power) at a plurality of measurement reference points can be calculated at once. On the other hand, in the lens meter, the optical performance that can be measured by one measurement is an average value of refractive power in a measurement reference region (usually a region having a diameter of about 8 mm). Further, when using a lens meter, the measurement requires a very large number of steps as described later, and is complicated and unsuitable in a manufacturing process in which a large number of lenses must be measured. According to the present invention, after derivation of the correction function, the actual product can be measured using a transmission aberration measuring apparatus, and measurement by a lens meter is unnecessary, so that refractive power measurement can be performed quickly and easily. It becomes possible.

  A general measurement apparatus is provided with a smoothing processing means for smoothing data in order to eliminate measurement noise. Therefore, the data output from the measuring device is usually subjected to a smoothing process. Examples of the function applied in the smoothing processing means included in the transmissive aberration measuring apparatus include a B-spline function and a Zernike approximation polynomial (Zernike polynomial) generally used for the smoothing processing. This smoothing process is considered to be one of the causes of the error with the measurement value by the lens meter. In the present invention, a highly reliable evaluation result is obtained by correcting the measurement value with a correction function. Can do. For example, the above-mentioned transmission type aberration measuring apparatus manufactured by Visionics Co. includes a smoothing processing means using Zernike approximation polynomials. In the present invention, as shown in an example described later, highly reliable evaluation can be performed by correcting a measurement value that has been smoothed by a Zernike approximation polynomial, calculated by a transmission aberration measurement apparatus. .

  Further, the transmission type aberration measuring apparatus converts the calculated optical performance into input means for inputting the position information of the measurement point to the transmission type aberration measuring apparatus, and outputs the data to other devices such as a display device and a printer. Means such as output means may be included.

  Next, a method for deriving a correction function for correcting the value obtained by the actual measurement device with respect to the measurement value obtained by the reference measurement device will be described.

Method for deriving the correction function Measurement of sample lens First of all, a sample lens for deriving a correction function is determined. The sample lens may be a lens of the same item having the same progressive zone length as the evaluation target lens, or may be a lens having a different progressive zone length. A progressive power lens having a distance portion region and a near portion region is generally classified into one of two categories called “far and near progressive power lenses” and “middle and near progressive power lenses”. When focusing on far vision, which is a general-purpose usage method, use a "peripheral progressive power lens", which requires limited distance vision, such as rarely looking indoor wall clocks, etc., and more comfortable intermediate vision and near vision. In the case where importance is attached to the lens, it is common to use a “middle and near refractive power progressive lens”. Normally, in the "proximal progressive-power lens", the area on the lens that uses the distance is a wide area above the datum line of the lens, and in the "middle-progressive power lens", the area that uses the distance is more than the datum line. It exists above 12 mm, and its clear vision area is a very small range compared to the perspective progressive addition lens. In the present invention, the “middle and near progressive addition lens” refers to a lens in which the distance portion area exists in an area of +12 mm or more above the datum line (0 mm) as the reference (0 mm). A lens whose use area is above the datum line and that does not correspond to a medium progressive power lens.
On the other hand, as a progressive-power lens, there is also a “near-progressive power lens” having a progressive zone in which the refractive power changes progressively between two near-use portions and the two near-use portions. Are known. In a near progressive power lens, the refractive power measurement reference point located above exists only by design, and measurement may not be performed during actual mass production / sales. This is why the near progressive addition lens is sometimes classified as a single focus lens. In the present invention, of the two near-distance measurement reference positions in the near progressive addition lens, the reference position having a small refractive power is regarded as a distance refractive power reference point, and the reference position having a large refractive power is regarded as a near refractive power reference point. The regions including the respective reference points are referred to as a distance portion region and a near portion region. Hereinafter, the above classification is referred to as “class A”.

  More specifically, in the perspective progressive addition lens, the distance measurement reference point is preferably located at +0 mm to 10 mm above the datum line as a reference (0 mm), and the length of the progressive zone is about 10 to 17 mm. In the middle and near progressive addition lens, the distance measurement power measurement reference point is preferably located at +12 mm or more above the datum line, specifically +12 mm to 20 mm, and the progressive zone length is 20 to 23.5. It is about mm. In the near progressive power lens, there is no distance portion refractive power measurement reference point, but in the present invention, as described above, a reference point having a small refractive power is virtually used as the distance portion refractive power measurement reference point. The distance-use refractive power measurement reference point of the near progressive power lens is preferably located at +14 mm to 25 mm with respect to the datum line, and the progressive zone length is about 19 to 28 mm.

As described above, progressive-power lenses can be classified based on refractive power measurement reference points. As a classification method based on the refractive power measurement reference point, a method of classifying into the following three categories based on the position of the distance measurement reference point is also suitable. Hereinafter, the following classification is referred to as “class B”.
Category 1: Progressive power lens in which distance reference refractive power measurement reference point is located in an area of +0 mm to +10 mm above the datum line. Category 2: Distance reference refractive power measurement reference point above the datum line. Progressive power lens category 3 located in the region from +10 mm to +14 mm: Progressive power lens in which the distance measurement power reference point is located in the region above +14 mm above the datum line

The above categories 1 to 3 can be further classified into the following three categories based on the progressive zone length. Hereinafter, the following classification is referred to as “class C”.
Category 1 ′: Progressive power lens category 2 ′ belonging to the above category 1 and progressive zone length in the range of 10 to 17 mm Category 2 ′: belonging to the above category 2 and progressive zone length in the range of 20 to 23.5 mm Progressive power lens category 3 ′: Progressive power lens belonging to the above category 3 and having a progressive zone length in the range of 19 to 26 mm.

According to the study by the inventors of the present application, it has been clarified that the sample lens used for deriving the correction function is preferably a lens belonging to the same category as the lens to be evaluated. This is because, in each category of lens, the region where the refractive power changes greatly and the region where the change in refractive power is relatively stable are different, so the amount of difference between the actual lens by the smoothing means and the calculation result is different. Conceivable. In other words, in a lens of the same category, the arrangement of a region in which the refractive power changes greatly and a region in which the change in refractive power is relatively stable approximates each other. It is thought that the same tendency appears in the difference between the calculation result and the calculation result.
Therefore, in the present invention, in any one of the above classifications A to C, it is preferable to select at least two lenses having different design addition powers as sample lenses from lenses belonging to the same category as the lens to be evaluated. In order to increase the accuracy of the correction function, it is preferable to select three or more sample lenses. Further, the sample lens may be selected from lenses that are evaluation target lenses.
Next, for each sample lens, the addition refractive power is measured by a reference measuring device, preferably by the transmission aberration measuring device. The details of the measurement method are as described above.

2. Measurement by Actual Evaluation Measuring Device Next, for the sample lens, the same optical performance as that measured by the reference measuring device is measured by the actual evaluation measuring device.

As described above, it is preferable to use a lens meter as the reference measuring device. In the progressive lens power measurement using the lens meter, in order to perform the addition power measurement specified in JIST7315, the following steps are generally required.
(1) Marking the alignment reference position to specify the measurement position and / or paint marks to specify the distance power measurement reference position and addition power reference position for the progressive power lens To do. At this time, the measurement reference point is specified based on a permanent mark (alignment reference mark) provided on the lens.
(2) The rear surface (for example, concave surface, eyeball side) of the lens to be examined is positioned with the distance measurement reference point at the lens contact, and the distance apex power evaluation is performed.
(3) Position the lens so that the progressive surface of the test lens faces the lens contact of the lens meter, position the lens at the near-point measurement reference point, and measure the near-point vertex refractive power. Next, the lens is arranged so that the progressive surface faces the lens contact of the lens meter at the distance measurement reference point, positioned at the distance measurement reference point, and the distance vertex refractive power is measured. The add power is specified by subtracting the distance vertex power from the near portion vertex power.

  For details of the measurement by the lens meter, JIS B 7183 can be referred to. As described above, the measurement using the lens meter is troublesome because it is necessary to perform positioning and measurement for each spot, and operation requires skill. On the other hand, in the present invention, if a lens meter is used for deriving the correction function, it is not necessary to use the lens meter thereafter, so that the workability in the actual production process can be greatly improved.

3. Derivation of correction function After the above 1 and 2, a correction function is derived. The correction function can be derived by a known correction function derivation method, but according to the study of the present inventor, good results were obtained by correcting with a linear function. Therefore, in the present invention, the correction function is preferably derived as a linear function. For example, for each measurement result, the error amount between the measurement value by the transmission aberration measurement device and the measurement value by the lens meter is specified, and the specified error amount is approximated by the least square method, whereby the gradient and intercept of the linear function are obtained. And a correction function can be determined.

Evaluation of optical performance of target lens After deriving the above correction function, actual evaluation of at least one optical performance selected from the group consisting of the distance power and the near power is performed for the progressive power lens to be evaluated. Measure with a measuring device. The details of the measurement method are as described above. Thereafter, the optical performance of the lens to be measured is obtained by correcting the obtained measurement value using a correction function derived for the addition power.

The addition power is the difference between the distance power and the near power. Accordingly, the addition refractive power is calculated from the measured values of the distance portion refractive power and the near portion refractive power. According to the study by the inventors of the present application, the distance portion refractive power and the near portion refractive power measured by the transmission aberration measuring apparatus can be approximated by a linear function with respect to the reference lens meter value, respectively. Has an error amount. When the distance power error function is f _f (x) and the near power error function is f _n (x) (where X is the value of each addition power), the reference measurement of the addition power The error amount function f _a (x) with the device (lens meter) is obtained from f _f (x) −f _n (x). Since both f _f (x) and f _n (x) are linear functions, the addition power error amount function f _a (x) is also approximated by a linear function. Here, the differential coefficient of each function has _a relationship of f _a (x) ′ = f _f (x) ′ − f _n (x) ′. Since each error amount function is a linear function, the differential value of each function is a numerical value indicating the gradient of the function.

After deriving the correction function for the addition power, the measurement value (distance power and / or near power) of the actual evaluation measurement device is substituted into the addition power error amount function f _a (x). Then, the measurement value is corrected by the actual evaluation measuring device by obtaining the correction value. In the present invention, the correction function may be applied to the value output from the measurement device for actual evaluation to perform correction. The correction function is input to the calculation unit of the measurement device for actual evaluation, and the corrected value is output from the calculation unit. May be output. Alternatively, it may be determined from the derived correction function that high-accuracy measurement is possible without correction by the actual evaluation measurement device. In this case, it may be determined that no correction is required based on the correction function, and the measurement value obtained by the actual evaluation measuring device may be used as it is as the evaluation result.

Through the above steps, for example, as shown in an example described later, an evaluation result having high reliability comparable to a measurement value obtained by a lens meter can be obtained by a transmission aberration measurement apparatus.
According to the transmission type aberration measuring apparatus, unlike a lens meter that performs measurement at a spot, the refractive power at various measurement reference points (for example, a distance measurement reference point and a near measurement reference point) of the lens is obtained by one measurement. Therefore, it is possible to quickly respond in the refractive power measurement process. Further, unlike the lens meter, the transmission type aberration measuring apparatus is less subject to individual variation by the individual measurer. Therefore, a highly reliable evaluation result can be obtained quickly by performing the above correction.

Hereinafter, the present invention will be described with reference to examples. However, the present invention is not limited to the embodiment shown in the examples.
1. Refractive power measurement of the progressive power lens (progressive band length 11mm)

[Comparative Example 1]
Three types of progressive addition power lenses (progressive band length 11mm) of design addition power 1.00D, 2.00D, and 3.00D are used, and 6 samples are prepared for each addition power display value. The addition refractive power was determined by a lens meter in accordance with JIS B 7183 standard by the method described above. The results are shown as “LM actual measurement” in Table 1.
(1) For the progressive-power lens, the distance-use refractive power measurement reference point and the near-portion refractive power measurement reference point were specified based on the permanent mark (alignment reference mark) on the lens.
(2) The lens was placed so that the progressive surface of the test lens was directly opposite to the lens contact of the lens meter, positioned at the near reference measurement reference point, and the near vertex power was measured. Next, the lens was arranged so that the progressive surface at the distance measurement reference point was directly opposite to the lens contact of the lens meter, positioned at the distance measurement reference point, and the distance vertex refractive power was measured. The add power was specified by subtracting the distance apex power from the near apex power.

[Example 1]
(1) Derivation of correction function and correction of addition refractive power Using a VM 2500 manufactured by Visionics Co., Ltd. as a transmission type aberration measuring apparatus, the addition refractive power of the 18 lenses whose addition refractive power was obtained in Comparative Example 1 was determined by the following method. It was measured. The VM 2500 manufactured by Visionics, Inc. is a device that can measure the refractive power of the central portion 50φ of the progressive addition lens by a single measurement.
(1) The progressive power lens was marked with a mark for specifying the distance-use refractive power measurement reference point and the near-use refractive power measurement reference point based on the permanent mark on the lens.
(2) The test lens was set in the measurement section of the transmission type aberration measurement apparatus.
(3) Measurement was performed by pressing the measurement start button of the transmission type aberration measuring apparatus, and the addition refractive power was calculated from the measured values of refractive power at the distance-use refractive power measurement reference point and the near-use refractive power measurement reference point. The calculated addition power is shown as “VM measurement” in Table 1.

  Next, an error amount from the LM actual measurement value of Comparative Example 1 was calculated for each lens, and a correction function (y = 1.08x; hereinafter referred to as F (ADD)) was obtained as a linear function from the calculated error amount. . The slope and intercept of the correction function were obtained by the least square method.

  Using the above F (ADD), the VM actual measurement value was corrected. The corrected addition power is shown as “VM evaluation value” in Table 1.

As shown in Table 1, the error amount of the corrected addition power from the actual measurement value of the lens meter is within an allowable error of 0.12D defined in JIS T 7315. It was possible to obtain the addition power of the progressive addition lens with an accuracy comparable to that of the lens.
In this example, an actual evaluation lens is used as a sample lens for derivation of a correction function, and data collection of 18 points (measurement of three kinds of addition powers for each of six) is performed in order to improve data accuracy. F (ADD) was calculated. However, since F (ADD) is a linear function, the number of data points may be at least (minimum) 2 points. For example, out of the 18 lenses listed in Table 1, two lenses are used as sample lenses to derive a correction function, and the derived correction function is used to correct the measurement value of the transmission aberration measurement device of another lens. It is also possible to obtain evaluation results.

(2) Measurement of the distance power of the distance Use two types of distance progressive power lenses (progressive zone length 11mm) of design distance power + 4.00D and -4.00D, and each distance power Six samples were prepared for the displayed value, and the distance portion refractive power was measured by a lens meter and a transmission type aberration measuring device in the same manner as in (1) above. In Table 2, the measured value by the lens meter is shown as “LM actual measurement”, and the measured value by the transmission type aberration measuring apparatus is shown as “VM actual measurement”.

(3) Correction of distance refractive power measured by the transmission aberration measuring device obtained in (2) above was corrected by the correction function F (ADD) derived in (1) above. . The corrected distance refractive power after correction is shown as “VM evaluation value” in Table 2.

(4) Measurement of near-part refractive power Using near-distance progressive power lens (progressive zone length 11mm) of design near-part refractive power + 5.00D and -2.00D, and each near-part refractive power Six samples were prepared for the displayed value, and the near-field refractive power was measured by a lens meter and a transmission type aberration measuring device in the same manner as in (1) above. In Table 3, the measured value by the lens meter is shown as “LM actual measurement”, and the measured value by the transmission type aberration measuring apparatus is shown as “VM actual measurement”.

(5) Correction of distance portion refractive power The measured value of near portion refractive power obtained by the transmission type aberration measuring device obtained in (4) above was corrected by the correction function F (ADD) derived in (1) above. . The corrected distance refractive power after correction is shown as “VM evaluation value” in Table 3.

  As shown in Tables 2 and 3, it was possible to perform a good correction by correcting the actually measured value by the transmission aberration measuring apparatus using the correction function derived for the addition refractive power.

2. Refracting power measurement of the progressive power lens (progressive band length 14mm)

[Example 2, Comparative Example 2]
(1) Derivation of correction function and evaluation of addition refractive power using transmission type aberration measurement device Three types of progressive addition power lenses (progressive band length 14mm) of design addition refractive power 1.00D, 2.00D and 3.00D are used. In addition, six samples were prepared for each addition power display value, and addition power measurement was performed using a lens meter and a transmission type aberration measurement apparatus in the same manner as in Example 1 and Comparative Example 1. In Table 4, the measured value by the lens meter is shown as “LM actual measurement”, and the measured value by the transmission type aberration measuring apparatus is shown as “VM actual measurement”.

  The measured value of the addition power by the transmission type aberration measuring apparatus obtained above was corrected by the correction function F (ADD) derived in Example 1. The corrected addition power is shown as “VM evaluation value” in Table 4.

  As shown in Table 4, the error amount of the corrected addition power from the actual measured value of the lens meter was within an allowable error of 0.12D defined in JIS T 7315. From the above results, using the correction function derived for progressive-power lenses belonging to the same category, and correcting the measured values by the transmission aberration measurement device for lenses with different progressive band lengths, the accuracy equivalent to a lens meter can be obtained. It has been shown that it is possible to determine the addition power of a progressive power lens.

(2) Evaluation of distance-use refractive power by transmission type aberration measuring device Two types of distance progressive power lenses (progressive zone length 14mm) of design distance-use refractive power + 4.00D and -4.00D are used. Six samples were prepared for the distance portion refractive power display values, and the distance portion refractive power was measured by a lens meter and a transmission type aberration measuring apparatus in the same manner as in Example 1. The measurement value obtained by the transmission aberration measurement apparatus was corrected by the correction function F (ADD) derived in Example 1. In Table 5, the measured value by the lens meter is shown as “LM measured value”, the measured value by the transmission type aberration measuring device is shown as “VM measured”, and the corrected refractive power for the distance is shown as “VM evaluation value”.

(3) Evaluation of near-field refractive power using transmission type aberration measuring device Two types of near-distance progressive power lenses (progressive zone length 14mm) of design near-field refractive power + 5.00D and -2.00D are used. Six samples were prepared for the near portion refractive power display values, and the near portion refractive power was measured by a lens meter and a transmission type aberration measuring apparatus in the same manner as in Example 1. The measurement value obtained by the transmission aberration measurement apparatus was corrected by the correction function F (ADD) derived in Example 1. In Table 6, the measured value by the lens meter is shown as “LM measured value”, the measured value by the transmission type aberration measuring device is shown as “VM measured”, and the corrected near portion refractive power is shown as “VM evaluation value”.

  As shown in Table 5 and Table 6, using the correction function derived for the addition refractive power using lenses belonging to the same category, and correcting the actual measurement value by the transmission type aberration measuring apparatus, good correction is performed. I was able to.

3. Refractive power measurement of medium and near progressive power lenses (progressive band length 23.5mm)

[Example 3, Comparative Example 3]
(1) Derivation of correction function and evaluation of addition refractive power using transmission aberration measurement device Three types of intermediate progressive addition power lenses (progressive band length 23.5mm) with design addition refractive powers of 1.00D, 2.00D and 3.00D are used. In addition, six samples were prepared for each addition power display value, and addition power measurement was performed by a lens meter and a transmission type aberration measurement apparatus in the same manner as in Example 1 and Comparative Example 1. In Table 7, the measured value by the lens meter is shown as “LM actual measurement”, and the measured value by the transmission type aberration measuring apparatus is shown as “VM actual measurement”.

  A correction function (y = 1.04x) was derived by the same method as in Example 1 using the measured addition power measured by the transmission aberration measurement apparatus obtained above.

  The measurement value obtained by the transmission aberration measurement apparatus was corrected by the derived correction function. The corrected addition power is shown as “VM evaluation value” in Table 7.

  As shown in Table 7, the error amount of the corrected addition power from the actual measurement value of the lens meter is within an allowable error of 0.12D defined in JIS T 7315. It was possible to obtain the addition refractive power of the near-neighbor progressive-power lens with an accuracy comparable to

(2) Evaluation of distance-use refractive power by transmission type aberration measuring device Using two types of near-distance progressive power lenses (progressive zone length 23.5mm) of design distance-use refractive power + 4.00D and -4.00D, Further, six samples were prepared for each distance portion refractive power display value, and the distance portion refractive power was measured by a lens meter and a transmission type aberration measuring apparatus in the same manner as in Example 1. The measured value by the transmission aberration measuring device was corrected by the correction function F (ADD) derived in (1) above. In Table 8, the measured value by the lens meter is shown as “LM measured value”, the measured value by the transmission type aberration measuring device is shown as “VM measured”, and the corrected distance power is shown as “VM evaluation value”.

(3) Evaluation of near-field refractive power using transmission-type aberration measuring device Using near-near progressive power lens (progressive zone length 23.5mm) of design near-field refractive power + 5.00D and -2.00D, Also, six samples were prepared for each near portion refractive power display value, and the near portion refractive power was measured by a lens meter and a transmission type aberration measuring apparatus in the same manner as in Example 1. The measured value by the transmission aberration measuring device was corrected by the correction function F (ADD) derived in (1) above. In Table 9, the measured value by the lens meter is shown as “LM measured value”, the measured value by the transmission type aberration measuring device is shown as “VM measured”, and the corrected near portion refractive power is shown as “VM evaluation value”.

  As shown in Tables 8 and 9, the correction function derived for the addition refractive power was used to correct the actual measurement value by the transmission type aberration measuring apparatus, and thus good correction could be performed.

3. Refractive power measurement of medium and near progressive power lenses (progressive band length 18mm)

[Example 4, Comparative Example 4]
(1) Derivation of correction function and evaluation of addition refractive power using transmission aberration measuring device Two types of intermediate progressive addition power lenses (progressive band length 18mm) with design addition refractive powers of 0.50D and 1.00D are used, respectively. Six samples were prepared with respect to the added refractive power display value, and the added refractive power was measured by a lens meter and a transmission type aberration measuring apparatus in the same manner as in Example 1 and Comparative Example 1. In Table 10, the measured value by the lens meter is shown as “LM actual measurement”, and the measured value by the transmission type aberration measuring apparatus is shown as “VM actual measurement”.

  A correction function (y = x) was derived by the same method as in Example 1 using the measured value of the addition power by the transmission aberration measuring apparatus obtained above.

  The measurement value obtained by the transmission aberration measurement apparatus was corrected by the derived correction function. The corrected addition power is shown as “VM evaluation value” in Table 10.

  From the results of Table 10, from the correction function derived in Example 4, for the lens to be evaluated in Example 4, the transmission aberration measurement device can obtain a measurement result having reliability comparable to the measurement value by the lens meter. I understand that.

(2) Evaluation of the distance power by the transmission type aberration measuring device Uses two types of near-distance progressive power lenses (progressive zone length 18mm) of design distance power + 3.50D and -5.00D. Six samples were prepared for each distance portion refractive power display value, and the distance portion refractive power was measured by a lens meter and a transmission type aberration measuring apparatus in the same manner as in Example 1. The measured value by the transmission aberration measuring device was corrected by the correction function F (ADD) derived in (1) above. In Table 11, the measured value by the lens meter is shown as “LM actual measurement”, the measured value by the transmission type aberration measuring device is shown as “VM actual measurement”, and the corrected refracting part refractive power is shown as “VM evaluation value”.

(3) Evaluation of near-field refractive power using a transmission type aberration measurement device Using near-near progressive-power lenses (progressive zone length 18mm) of design near-field refractive power + 4.00D and -4.00D, and Six samples were prepared for each near portion refractive power display value, and the near portion refractive power was measured by a lens meter and a transmission type aberration measuring apparatus in the same manner as in Example 1. The measured value by the transmission aberration measuring device was corrected by the correction function F (ADD) derived in (1) above. In Table 12, the measured value by the lens meter is shown as “LM measured value”, the measured value by the transmission type aberration measuring device is shown as “VM measured”, and the corrected near portion refractive power is shown as “VM evaluation value”.

  From the results in Tables 11 and 12, it was shown that it is possible to determine that the actual measurement value by the transmission aberration measurement device does not need to be corrected, from the correction function derived for the addition power.

  The method of the present invention is suitable as an evaluation method in a lens mass production process for mass production of a wide variety of progressive power lenses.

1 shows a schematic configuration example of a transmission aberration measuring apparatus. It is explanatory drawing of the measurement data by a transmissive aberration measuring apparatus. It is explanatory drawing of the refractive power measurement reference point of a progressive-power lens.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Light source device 12 Beam splitter 13 Screen 14 CCD camera 15 Calculation apparatus 100 Test lens 231 Alignment reference mark 207 Distance portion refractive power measurement reference point 209 Near portion refractive power measurement reference point 202 Prism refractive power measurement reference point 201 Progressive refraction Force lens 203 horizontal reference (datum line)
210 Main meridian direction 211 Eye point position 204 Left and right division display (right in the figure)

Claims (5)

A method for evaluating optical performance of a progressive power lens having a distance portion region, a near portion region, and a progressive zone in which the refractive power gradually changes between the two,
Measuring the addition refractive power of the sample lens for deriving the correction function with a measuring device for actual evaluation used for evaluating the lens to be evaluated;
Measuring the addition power of the sample lens using a reference measuring device;
Deriving a correction function for correcting the addition power measured by the measurement device for actual evaluation with respect to the addition power measured by the reference measurement device;
Measuring at least one optical performance selected from the group consisting of the distance-use refractive power and the near-use refractive power of the lens to be evaluated using an actual evaluation measuring device;
The optical performance of the lens to be evaluated is obtained by correcting the optical performance measured using the measurement device for actual evaluation using the correction function or by determining that correction is not necessary based on the correction function. thing,
Including said method. The measurement device for actual evaluation is obtained by the measurement means for measuring the optical path of the outgoing light emitted from the measurement point on the second surface on the opposite side when light is incident from the first surface of the lens, and the measurement means. The method according to claim 1, wherein the measuring device has calculation means for calculating the optical performance of the lens at the measurement point based on the measurement value. The method according to claim 1 or 2, wherein the reference measuring device is a lens meter. The method according to claim 1, wherein the correction function is a linear function. The addition power of the evaluation target lens is measured by measuring the addition power of the evaluation target lens and correcting the measured addition power using the correction function, or by determining that no correction is necessary based on the correction function. The method according to claim 1, further comprising determining a refractive power.

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