JP2019211399A - Lens meter - Google Patents

Abstract

To readily measure optical characteristics characterizing an inspected lens.SOLUTION: A lens meter comprises: a loading part on which an inspected lens is loaded; a measurement unit that measures optical characteristics of the inspected lens loaded on the loading part; and a determination unit that determines whether or not a plurality of optical characteristics measured by the measurement unit are optical characteristics characterizing the inspected lens on the basis of the plurality of measured optical characteristics. The inspected lens is characterized by optical characteristics measured in a setting portion preliminarily set for each kind. The inspected lens loaded on the loading part relatively displaces with respect to the measurement unit, and thus, in the measurement unit, a measurement position is made adjustable that measures the optical characteristics on the inspected lens. The determination unit is configured to determine whether or not the measurement position locates in the setting portion preliminarily set in the inspected lens on the basis of the plurality of optical characteristics measured by the measurement unit, and determine whether or not the measurement position locates in the setting portion on the basis of information preliminarily prepared using machine learning.SELECTED DRAWING: Figure 3

Description

  The technology disclosed in this specification relates to a lens meter.

  Lens meters for measuring optical characteristics of lenses used in eyeglasses and the like have been developed. For example, the lens meter of Patent Document 1 includes a measurement optical system that measures the optical characteristics of the lens to be examined. The measurement optical system includes a measurement light source and a light receiving sensor. At the time of measurement, the test lens is disposed at a predetermined position on the optical axis of the measurement optical system. By changing the position of the test lens with respect to the measurement optical system, the position for measuring the optical characteristics in the test lens is changed. The lens meter acquires the optical characteristics of the lens to be tested by inputting light from the measurement light source to the light receiving sensor via the lens to be tested. In the test lens, a site that optically characterizes the test lens is set in advance for each type (hereinafter, this position is also referred to as a “set site”). That is, the test lens is characterized by the optical characteristics measured at the set site. For this reason, when the position where the optical characteristic is acquired is deviated from the set part, the measurer needs to move the position of the lens to be measured with respect to the measurement optical system and remeasure the optical characteristic in the set part. is there.

Japanese Patent Laid-Open No. 2018-9967

  In a lens meter as in Patent Document 1, it is desired that a plurality of types of lenses having different characteristics for each function can be measured. In different types of lenses, the position of the setting part that characterizes the lens may differ for each type of lens. If the position of the set part differs for each lens type, when measuring the optical characteristics that characterize the lens to be measured with a lens meter, the set part is specified for each type, and the optical characteristic is measured at the specified set part. There is a need.

  However, the lens to be measured is variously processed and used, and it may be difficult to easily determine which position is a set part. For example, when a lens is used for spectacles, the end of the lens is processed in accordance with the frame shape of the spectacles, so it is difficult to specify which position of the remaining lens is a set part. In particular, in recent years, many lenses having a plurality of functions such as progressive multifocal lenses and near-use wide lenses have been developed. In such a lens, it is necessary to measure optical characteristics at a plurality of positions (that is, within a plurality of setting portions) for each function in one lens. For example, the progressive multifocal lens includes a distance portion, a near portion, and a progressive portion disposed between the distance portion and the near portion. For this reason, it is necessary to measure the optical characteristics in the setting part of the distance portion and further measure the optical characteristics in the setting part of the near portion. As described above, when there are setting parts at a plurality of positions different for each type of lens, it is more difficult to specify the position in each setting part.

  The present specification discloses a technique for accurately and easily measuring optical characteristics characterizing a lens to be examined.

  The lens meter disclosed in this specification measures optical characteristics of a plurality of types of test lenses. The lens meter is based on a placement unit on which the test lens is placed, a measurement unit that measures optical characteristics of the test lens placed on the placement unit, and a plurality of optical characteristics measured by the measurement unit. And a determination unit that determines whether or not the plurality of measured optical characteristics are optical characteristics that characterize the lens to be measured. The lens to be examined is characterized by optical characteristics measured at a set part preset for each type. When the test lens placed on the placement unit is relatively displaced with respect to the measurement unit, the measurement unit can adjust the measurement position for measuring the optical characteristics on the test lens. The determination unit determines, based on the plurality of optical characteristics measured by the measurement unit, whether or not the measurement positions at which the plurality of optical characteristics are measured are located within a set part set in advance on the lens to be examined. To do. The determination unit determines whether the measurement position is located in the setting unit based on information created in advance using machine learning.

  In the above-mentioned lens meter, information created in advance by machine learning is used when determining whether or not the measurement position is located within the set part. For this reason, even when measuring a plurality of types of test lenses with a single lens meter, the measurement position for measuring the optical characteristics can be easily positioned within a preset set site. For this reason, it is possible to accurately and easily measure the optical characteristics that characterize the test lens.

The figure which shows schematic structure of the lens meter which concerns on an Example. The flowchart which shows an example of the process which produces the evaluation function used in order to determine whether the measurement position which measured the optical characteristic is in a setting site | part by machine learning. The flowchart which shows an example of the process which measures the optical characteristic which characterizes a to-be-tested lens using an evaluation function.

  The main features of the embodiments described below are listed. The technical elements described below are independent technical elements and exhibit technical usefulness singly or in various combinations, and are limited to the combinations described in the claims at the time of filing. It is not a thing.

(Characteristic 1) In the lens meter disclosed in the present specification, the plurality of optical characteristics used in the determination unit may be a spherical power, a cylindrical power, and a vertical prism amount when the lens to be examined is worn. According to such a configuration, it can be suitably determined whether or not the measurement position of the test lens is within the set region.

(Characteristic 2) In the lens meter disclosed in this specification, the plurality of optical characteristics used in the determination unit may further be a change rate in the vertical direction of the equivalent spherical power. According to such a configuration, even if the test lens is a progressive lens, for example, the measurement site of the test lens can be suitably determined.

(Characteristic 3) In the lens meter disclosed in this specification, the determination unit may determine whether or not the measurement position is located in the setting unit using an evaluation function. The evaluation function may include measured values of a plurality of optical characteristics and a binding parameter that weights the measured values of the optical characteristics for each optical characteristic. The lens meter may further include a calculation unit that creates the evaluation function by machine learning. The calculation unit optimizes the coupling parameter of each optical characteristic by using, as input values, measurement values of a plurality of optical characteristics measured at the measurement position and information regarding whether or not the measurement position is within the set part. The optimization process may be configured to be executable. According to such a configuration, the calculation unit is configured based on the measurement result (that is, the measurement values of the plurality of optical characteristics measured at the measurement position and information on whether or not the measurement position is within the set part). Optimize binding parameters. As a result, the calculation unit creates an evaluation function in which the coupling parameter is optimized. By using the evaluation function optimized in this way, the determination unit can measure the optical characteristic characterizing the lens to be measured more accurately.

  Hereinafter, the lens meter 10 according to the embodiment will be described. The lens meter 10 measures optical characteristics of the test lens. The test lens is characterized by optical characteristics measured at a site (hereinafter, also referred to as “set site”) in the test lens set in advance for each type. That is, by measuring the optical characteristics in the set part of the test lens, the optical characteristics such as the power of the test lens can be measured. The lens meter 10 is used to measure the optical characteristics of the measurement position within the set site of the lens to be examined.

  For example, in the case of a single focus lens, the set part is provided at one place such as near the center of the lens. For this reason, the lens meter 10 adjusts the measurement position to be within one set site within the lens, and measures the optical characteristics at the measurement position. In recent years, lenses having a plurality of functions in one lens, such as a bifocal lens and a progressive multifocal lens, have been developed. In such a lens, the setting part is set at a different position for each of a plurality of functions. For example, in a progressive multifocal lens, in a state in which a user wears spectacles using a test lens (hereinafter, simply referred to as a state in which the test lens is mounted), a distance portion is set in the upper part, A near portion is set at the lower portion, and a progressive portion is set between the distance portion and the near portion. In other words, in the progressive multifocal lens, the distance portion, the progressive portion, and the near portion are arranged in this order from the upper side to the lower side in a state where the test lens is mounted. In this embodiment, the up-down direction with the test lens attached may be referred to as the “up-down direction” of the test lens, and the left-right direction with the test lens attached is referred to as “ Sometimes referred to as “left-right direction”. The lens meter 10 measures optical characteristics at a measurement position in each set part in a test lens having a plurality of set parts.

  As shown in FIG. 1, the lens meter 10 includes a mounting unit 12 that mounts a test lens, a measuring unit 14 that measures optical characteristics of the test lens mounted on the mounting unit 12, and a display 16. And an arithmetic unit 20.

  The mounting unit 12 is disposed on a measurement optical system (not shown) provided in the measurement unit 14 and mounts the test lens so that the measurement surface of the test lens is orthogonal to the optical axis of the measurement optical system. Put. The mounting position of the test lens with respect to the mounting part 12 can be adjusted by the measurer. The measurement unit 14 measures the optical characteristics of the portion of the test lens placed on the placement unit 12 that is located on the optical axis of the measurement optical system (hereinafter, this position is also referred to as “measurement position”). . The measurement position in the test lens can be changed by the measurer displacing the position of the test lens placed on the placement unit 12. That is, when the measurer shifts the position of the test lens placed on the placement unit 12, the measurement unit 14 measures optical characteristics at different positions in the test lens. The measurement unit 14 measures a plurality of types of optical characteristics at the measurement position of the test lens. In the present embodiment, the measurement unit 14 measures the spherical power, the cylindrical power, the equivalent spherical power, the prism amount in the vertical direction, the change rate in the horizontal direction of the equivalent spherical power, and the change rate in the vertical direction of the equivalent spherical power. The types of optical characteristics measured by the measurement unit 14 are not limited, and more types of optical characteristics may be measured. In addition, since the mounting part 12 and the measurement part 14 can use what is used for a well-known lens meter, detailed description about these structures is abbreviate | omitted.

  The display 16 displays information related to the lens meter 10. For example, the display 16 displays the optical characteristics measured at the measurement position within the set region of the test lens.

  The calculation unit 20 can be configured by a computer including a CPU, a ROM, a RAM, and the like, for example. When the computer executes the program, the calculation unit 20 functions as the setting site determination unit 22, the calculation unit 24, the determination unit 26, and the like illustrated in FIG. The processing executed by the calculation unit 20 will be described in detail later.

  With reference to FIG.2 and FIG.3, the process which measures the optical characteristic of a to-be-tested lens using the lens meter 10 is demonstrated. The process of measuring the optical characteristics of the lens to be examined using the lens meter 10 is a process of creating an evaluation function used for determining whether or not the measurement position where the optical characteristics are measured is within the set part by machine learning ( 2) and a process (see FIG. 3) for measuring optical characteristics characterizing the lens to be examined using the created evaluation function.

  First, with reference to FIG. 2, a process of creating an evaluation function by machine learning used for determining whether or not the measurement position where the optical characteristic is measured is within the set part will be described. As shown in FIG. 2, first, the measurer places a machine learning lens on the placement unit 12 (S12). As the lens for machine learning, a lens whose optical characteristics characterizing the lens and the position of the set part are known is used. In this embodiment, the machine learning lens is a progressive multi-point lens that is not processed for spectacles and has known optical characteristics. A lens processed for spectacles has a peripheral portion of the lens cut in accordance with the shape of the frame of the spectacles, and it is difficult to specify the positions of the distance portion, the near portion, and the progressive portion. For this reason, it is preferable to use a machine learning lens whose peripheral part or the like is not processed. In this embodiment, the lens before machine processing is used as the machine learning lens. However, it is sufficient that the optical characteristics and the position of the set part are known, and the machined lens is used as the machine learning lens. Also good.

  Next, the calculation unit 20 acquires the optical characteristics of the machine learning lens measured by the measurement unit 14 (S14). Specifically, the measurement unit 14 measures the optical characteristics at the measurement position when the measurer is placed on the placement unit 12 in step S12. In the present embodiment, the optical characteristics obtained here are 6 of spherical power, cylindrical power, equivalent spherical power, vertical prism amount, left-right change rate of equivalent spherical power, and vertical change rate of equivalent spherical power. It is a kind. The acquired optical characteristics are stored in a memory (not shown) of the calculation unit 20.

  Next, the set site determination unit 22 determines whether or not the measurement position is within the set site based on the acquired optical characteristics (S16). Specifically, the setting site determination unit 22 compares the obtained measured value of the optical characteristic with the known optical characteristic value of the lens (hereinafter also simply referred to as “true value”), and sets the measurement position. Determine if it is within the site.

  For example, the set site determination unit 22 determines whether or not the measurement site is within the set site of the distance unit using the spherical power and the cylindrical power in the optical characteristics. When both the spherical power and the cylindrical power of the measurement site are within the predetermined range, the setting site determination unit 22 determines that the measurement site is within the setting site of the distance portion. In addition, even when one of the spherical power and the cylindrical power of the measurement site is within a predetermined range and the measurement position is within a set site known as a distance unit, the set site determination unit 22 performs measurement. The position is determined to be within the setting part of the distance portion. On the other hand, when both the spherical power and the cylindrical power of the measurement site are outside the predetermined range, the setting site determination unit 22 determines that the measurement site is not within the setting site of the distance unit. In this embodiment, the range within ± 0.125D from the true value is set as the predetermined range, but the predetermined range is not particularly limited and can be set as appropriate.

  Moreover, the setting part determination part 22 determines whether a measurement part is in the setting part of a near part using the equivalent spherical power of optical characteristics. When the equivalent spherical power of the measurement site is within the predetermined range, the set site determination unit 22 determines that the measurement site is within the set site of the near-use part. In addition, even when the equivalent spherical power of the measurement site is outside the predetermined range and the measurement position is within the set site known as the near-field unit, the set-site determination unit 22 sets the measurement site to the near site. It is determined that it is within the set site. On the other hand, when the equivalent spherical power of the measurement part is outside the predetermined range and the measurement position is outside the setting part known as the near part, the setting part determination unit 22 sets the measurement part to the near part. It is determined that it is not within the set site. In this embodiment, a range within ± 0.125D from the true value is set as the predetermined range, but the predetermined range is not particularly limited. Information on the determined setting part (that is, whether the measurement position is within the setting part of the distance portion and whether the measuring position is within the setting part of the near part) is stored in the memory (not shown) of the calculation unit 20. ).

  Next, the measurer determines whether or not the determination in step S16 has been made for all measurement positions (S18). If the determination in step S16 has not been made for all measurement positions (NO in step S18), the measurer moves the measurement positions in the machine learning lens (S20). That is, the measurer displaces (shifts) the position of the machine learning lens placed on the placement unit 12 to move the measurement position. Then, it returns to step S14 and repeats the process of step S14-step S18.

  On the other hand, when step S16 is determined for all measurement positions (YES in step S18), the calculation unit 24 is used to determine whether or not the measurement position at which the optical characteristic is measured is within the set region. An evaluation function is created (S22). The measurer determines whether or not the determination of step S16 has been made for all measurement positions, and the process of step S22 is started when the measurer inputs that fact from an input device (not shown).

  The process of step S22 will be described in further detail. The calculation unit 24 creates an evaluation function using a neural network. The neural network outputs one output based on a plurality of input parameters, and the plurality of input parameters (input node) and one output (output node) are respectively connected by a coupling load. By optimizing each connection weight by machine learning, the output accuracy can be improved. Since machine learning using a neural network can use a known technique, a detailed description thereof will be omitted.

  In this embodiment, measured values of a plurality of optical characteristics at a measurement position are used as a plurality of input parameters. Based on the measured values of the plurality of optical characteristics, it is determined whether or not the measurement position is within a set part. Output. As the measurement values of the optical characteristics used for the input parameters, as a result of intensive studies by the present inventors, the measurement values of the six types of optical characteristics with high determination accuracy as to whether or not the measurement position is within the set site are used. . The six optical characteristics are a spherical power, a cylindrical power, an equivalent spherical power, a prism amount in the vertical direction, a change rate in the horizontal direction of the equivalent spherical power, and a change rate in the vertical direction of the equivalent spherical power. The calculation unit 24 uses the neural network based on the measurement values of the six types of optical characteristics at the measurement position of the machine learning lens acquired in step S14 and information on whether or not the set part is determined in step S16. Each connection weight is optimized by machine learning using. Then, the calculation unit 24 creates an evaluation function using the optimized coupling load. The created evaluation function is stored in a memory (not shown) of the calculation unit 20.

  The processing of Step S12 to Step S18 (that is, data acquisition processing for machine learning) should be performed a plurality of times using many lenses. As a result, the amount of data used for machine learning in step S22 increases, and each coupling load used for the evaluation function can be optimized more accurately.

  Next, with reference to FIG. 3, a process for measuring optical characteristics that characterize the test lens using the created evaluation function will be described. Hereinafter, processing for measuring the optical characteristics of the distance portion of the progressive multifocal lens will be described as an example.

  As shown in FIG. 3, first, the measurer places the lens to be examined on the placement unit 12 (S32). Next, the calculation unit 20 acquires the optical characteristics of the test lens measured by the measurement unit 14 (S34). The optical characteristics at the measurement position acquired here are the spherical power, the cylindrical power, the equivalent spherical power, the prism amount in the vertical direction, the change rate in the horizontal direction of the equivalent spherical power, and the change rate in the vertical direction of the equivalent spherical power. The acquired optical characteristics are stored in a memory (not shown) of the calculation unit 20.

  Next, the determination unit 26 determines whether or not the measurement position is within the setting part of the distance unit based on the optical characteristics acquired in step S32 (S36). Specifically, the determination unit 26 inputs the measurement values of the six types of optical characteristics acquired in step S32 to the evaluation function created in step S22 described above, and the measurement position is within the set part of the distance unit. Output whether or not. As described above, the connection weight in the evaluation function is optimized using machine learning. For this reason, by using the evaluation function created in step S22, it can be accurately output whether or not the measurement position is within the set region.

  If it is determined that the measurement position is not within the setting portion of the distance portion (NO in step S36), the optical characteristic acquired in step S34 is determined not to be an optical characteristic that characterizes the distance portion of the test lens. Is done. In this case, the calculation unit 20 displays the fact on the display 16 and notifies the measurer that the optical characteristic characterizing the distance portion of the lens to be examined has not been measured. Therefore, the measurer moves the measurement position in the lens to be examined (S38). That is, the measurer displaces (shifts) the position of the test lens placed on the placement unit 12 to move the measurement position. Then, it returns to step S34 and repeats the process of step S34 and step S36.

  On the other hand, when it is determined that the measurement position is within the setting portion of the distance portion (YES in step S36), the optical characteristics acquired in step S34 are optical characteristics that characterize the distance portion of the lens to be examined. It is judged that there is. For this reason, the calculating part 20 displays the optical characteristic acquired by step S34 on the display 16 (S40). Then, the measurement of the optical characteristics of the distance portion of the test lens is finished. Thereafter, when the test lens is a progressive multifocal lens, the optical characteristics of the near portion of the test lens are measured by the same processing as in steps S34 to S40.

  In the present embodiment, an evaluation function used for determining whether or not the measurement position at which the optical characteristic is measured by the measurement unit 14 is within a setting portion that characterizes the lens to be examined is represented by a combined load optimized by machine learning. It is created using. For this reason, the determination part 26 can determine accurately whether the said measurement position is in a setting site | part. This makes it possible to accurately and easily measure the optical characteristics that characterize the test lens.

  Note that the process of creating the evaluation function used by the determination unit 26 (that is, the process of optimizing the coupling load) may be performed continuously. By continuously performing the process of creating the evaluation function, the reliability of each binding load is increased, and the accuracy of determining whether or not the measurement position executed by the determination unit 26 is within the set part can be increased. it can. For example, when the reliability of each coupling load included in the evaluation function becomes sufficiently high, the calculation unit 20 may stop the process of creating the evaluation function.

  In addition, the lens meter 10 according to the present exemplary embodiment includes the setting part determination unit 22 and the calculation unit 24 and has a configuration capable of executing the process of creating the evaluation function used by the determination unit 26. However, the configuration is limited to such a configuration. Not. For example, an evaluation function created by another device is input from an input device (not shown), and the determination unit 26 determines whether the measurement position is within the set site using the evaluation function input from the outside. Also good.

  In the present embodiment, it is determined whether or not the measurement site is within the setting site of the distance portion and whether or not the measurement site is within the setting site of the near vision portion, but the configuration is not limited thereto. For example, you may be comprised so that it can be determined whether a measurement region | part is in the setting site | part of a progressive part. In other words, the evaluation function may be created using machine learning so that it can be determined whether or not the measurement site is within the set site of the progressive part. Further, in such a case, it can be configured such that the type of the test lens can be determined by determining whether or not the progressive portion exists in the test lens. That is, when it is determined that there is a progressive portion in the test lens, the test lens is determined to be a progressive multifocal lens, and when it is determined that there is no progressive portion in the test lens, the test lens May be determined to be a single focus lens.

  As mentioned above, although the specific example of the technique disclosed by this specification was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing.

10: Lens meter 12: Placement unit 14: Measurement unit 16: Display 20: Calculation unit 22: Setting part determination unit 24: Calculation unit 26: Determination unit

Claims (4)

A lens meter for measuring optical characteristics of a plurality of types of test lenses,
A mounting portion on which the test lens is mounted;
A measuring unit for measuring the optical characteristics of the test lens placed on the placing unit;
Based on a plurality of optical characteristics measured by the measurement unit, a determination unit that determines whether or not the measured optical characteristics are optical characteristics characterizing the lens to be examined, and
The test lens is characterized by optical characteristics measured at a preset site set for each type,
When the test lens placed on the placement unit is displaced relative to the measurement unit, the measurement unit can adjust the measurement position for measuring the optical characteristics on the test lens. And
The determination unit determines whether or not the measurement positions at which the plurality of optical characteristics are measured based on the plurality of optical characteristics measured by the measurement unit are within a set region set in advance on the lens to be examined. Is determined,
The determination unit is a lens meter that determines whether or not the measurement position is located in the setting unit based on information created in advance using machine learning.   2. The lens meter according to claim 1, wherein the plurality of optical characteristics used in the determination unit are a spherical power, a cylindrical power, and a prism amount in a vertical direction when the test lens is worn.   The lens meter according to claim 2, wherein the plurality of optical characteristics used in the determination unit are further the rate of change of the equivalent spherical power in the vertical direction. The determination unit determines whether or not the measurement position is located in the setting unit using an evaluation function,
The evaluation function includes measured values of the plurality of optical characteristics, and a binding parameter that weights the measured values of the optical characteristics for each of the optical characteristics,
The lens meter further includes a calculation unit that creates the evaluation function by machine learning,
The calculation unit uses the measurement values of a plurality of optical characteristics measured at the measurement position and information on whether or not the measurement position is within the set part as input values, and the coupling parameter of each optical characteristic. The lens meter according to claim 1, wherein the lens meter is configured to be able to execute an optimization process for optimizing the lens.

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