JP4541175B2 - Lens meter - Google Patents

Description

  The present invention relates to a lens meter that measures an optical characteristic value of a spectacle lens, and particularly relates to a technique for measuring a refractive index of a lens material.

  In recent years, the demand for thinner and lighter spectacle lenses is increasing in consideration of the wearing feeling of spectacles. In a thin and light spectacle lens, a material having a high refractive index is used in order to obtain a refractive power equivalent to that of a thick lens. Such a lens material is different for each lens maker and is generally different for each product. Therefore, the refractive index of the lens material is also different.

  Conventionally, the refractive index of a lens material has been estimated based on the measurement value of the lens meter, the lens thickness, etc., but with the advent of such various lens materials, it is difficult to estimate the refractive index with high accuracy. It was. In order to cope with such a situation, various lens meters having a configuration for measuring the refractive index of various lens materials have been conventionally proposed (for example, see Patent Documents 1 and 2).

  The lens meter described in Patent Document 1 confirms the material of the spectacle lens by measuring the refractive index of the lens for the purpose of compensating the spectacle lens in optical work, and the outer surface is made parallel to the plane. In addition, the inner surfaces facing each other have two cushions that can be pressed against the spectacle lens. Each cushion has a known refractive index that is as large as possible, such as glycerin, immersion oil, silicone elastic rubber, etc., and is formed of a soft and transparent synthetic material. Each cushion is provided on a transparent plate.

  The refractive index measurement of the lens material by the lens meter of Patent Document 1 is based on the following two-stage measurement results: (1) The vertex refractive power of the test lens is measured without using the cushion; (2) A cushion is attached to the test lens, and the combined refractive power of the test lens and the cushion is measured. When the quotient of these two measurement results is calculated, the value does not depend on the radius of curvature of the lens to be examined, and can be used as a characteristic value of the lens material.

  The lens meter described in Patent Document 2 has a single cushion (referred to as “pad” in the same document), and the refractive index of the lens material based on the results of the following three-stage measurement. (1) Measure the refractive power of the test lens; (2) Mount a cushion on one surface of the test lens and measure the combined refractive power of the test lens and the cushion; (3) Test A cushion is attached to the other surface of the lens, and the combined refractive power of the test lens and the cushion is measured. Based on these three measurement results, the refractive index of the test lens is calculated.

  Further, in Patent Document 2, it is pointed out that the following problem arises when a configuration in which measurement is performed in a state in which both surfaces of a test lens are sandwiched between a pair of cushions as in the invention of Patent Document 1 is adopted. ing. That is, in the invention of Patent Document 1, since the test lens is supported by a flexible cushion, there is a possibility that the relative position between the test lens and the cushion may be shifted, and thereby the mounting position of the cushion is deviated from the center of the lens. It has been pointed out that if the plates on both sides of the lens are not parallel, aberrations are generated and measurement accuracy is reduced.

  However, according to the confirmation inspection by the present inventor, if the handling (operability) of the cushion can be improved, the cushion can be easily attached near the optical center of the lens to be examined, and the flexibility and surface of the cushion It has been confirmed that by adjusting the shape and the like to improve the adhesion of the cushion to the lens surface, it is possible to prevent deviation between the lens to be examined and the cushion.

  Furthermore, the present inventor has confirmed that with respect to the parallelism of the plates on both sides of the test lens, sufficient measurement accuracy can be maintained if the resulting prism power is about 2 prism diopters or less. In addition, it was confirmed that the measurement accuracy could be maintained even if the cushion and the plate (pad) were manually attached to the lens to be tested if the parallelism was limited to this extent.

  Considering the above background, it can be pointed out that the invention described in Patent Document 2 has the following practical problems. That is, in the invention of this document, since the measurement of three steps is required for obtaining the refractive index of the lens to be examined, the measurement procedure becomes complicated and the measurement time becomes long. In particular, when measuring a large number of lenses, such a complicated measurement is performed over a long period of time, which places a great burden on the user.

  In order to avoid such a situation, it is considered suitable to automate the refractive index measurement of the lens material. However, the refractive index measurement is automatically performed by a conventional lens meter such as Patent Document 1 or Patent Document 2. Could not be executed.

  Also, when inspecting a plurality of lenses, it may be desired to measure the normal optical characteristic value for some of them and to measure the refractive index of the lens material for some of them. In this way, when measuring in different modes, it is convenient for practical use if the measurement mode is automatically switched, but such switching could not be performed automatically with the conventional lens meter. .

Japanese Patent Laid-Open No. 1-145544 US Pat. No. 6,147,751

  The present invention has been made in view of the circumstances as described above, and an object thereof is to provide a lens meter in which the refractive index measurement of a lens material is automated.

  In order to achieve the above object, the invention described in claim 1 includes: a support unit that supports the test lens; an illumination optical system that projects measurement light onto the supported test lens; and the test lens. A light receiving optical system for receiving the transmitted measurement light and a first contact surface formed in conformity with the shape of one surface of the lens to be tested are transparent, flexible, and have a known refractive index. A second member having a first refractive index measurement member including a contact member and a second contact surface formed in accordance with the shape of the other surface of the lens to be tested, which is transparent, flexible, and has a known refractive index; And determining whether the first and second refractive index measuring members are attached to the second lens for refractive index measurement including the close contact member and the lens to be tested supported by the support means. And the first and second members for measuring refractive index are mounted on the lens to be examined. Based on the measurement light received by the light receiving optical system when it is determined that it is not, the refractive power of the test lens is calculated, and the first and second refractive index measuring members are Based on the measurement light received when it is determined that the lens is mounted, the combined refraction of the lens to be measured, the first refractive index measurement member, and the second refractive index measurement member The test lens is formed based on a first calculation means for calculating a force, the calculated refractive power and the combined refractive power, and the refractive indexes of the first and second contact members. And a second calculating means for calculating the refractive index of the material.

  The invention according to claim 2 is the lens meter according to claim 1, wherein the second calculating means measures the first and second refractive indexes on the lens to be measured by the judging means. When it is determined that the member is mounted, the refractive power of the test lens calculated immediately before the determination and the test where the first and second refractive index measuring members are mounted The refractive index of the material is calculated based on the combined refractive power calculated by the first calculation means for the lens and the refractive indexes of the first and second contact members.

  The invention according to claim 3 is the lens meter according to claim 1, wherein the lens to be examined is a left and right spectacle lens framed in a spectacle frame, and the left and right spectacle lenses are combined. Moving means for moving the spectacle frame so as to be supported by the supporting means one by one, and which of the left and right spectacle lenses is based on positional information when the moving means supports each of the left and right spectacle lenses. Discriminating means for discriminating whether the spectacle lens is supported, wherein the first calculation means supports one of the left and right spectacle lenses, and the first and second refractions of the one spectacle lens. The refractive power of the one spectacle lens is calculated based on the measurement light received by the light receiving optical system when it is determined that the rate measuring member is not attached, and the moving hand The eyeglass frame is moved to support the other eyeglass lens, and when it is determined that the first and second refractive index measurement members are not attached to the other eyeglass lens. Based on the received measurement light, the refractive power of the other spectacle lens is calculated, one of the left and right spectacle lenses is supported, and the first and second spectacle lenses are supported by the first spectacle lens. Based on the measurement light received when it is determined that the refractive index measurement member is mounted, any one of the spectacle lenses and the first and second refractive index measurement members The combined refractive power is calculated, and the second calculating means calculates the refractive power calculated for the one or other spectacle lens determined by the determining means to be the same as the one of the spectacle lenses, and the calculation. A combined refractive power which is, on the basis of said refractive index of said first and second contact members, calculates the refractive index of the material, characterized in that.

  According to a fourth aspect of the present invention, in the lens meter according to the first aspect, the test lens is a left and right spectacle lens framed in a spectacle frame. The first calculation means further includes a moving means for moving the spectacle frame so as to be supported by the support means one by one, and the one of the left and right spectacle lenses is supported by the one spectacle lens. Based on the measurement light received by the light receiving optical system when it is determined that the first and second refractive index measurement members are not mounted, the refractive power of the one spectacle lens is calculated. The eyeglass frame is moved by the moving means to support the other eyeglass lens, and the first and second refractive index measurement members are not attached to the other eyeglass lens. The refractive power of the other spectacle lens is calculated on the basis of the received measurement light, and the other spectacle lens is supported by the first spectacle lens. Based on the measurement light received when it is determined that the second refractive index measurement member is mounted, the other spectacle lens, the first refractive index measurement member, and the second The combined refractive power with the refractive index measuring member is calculated, and the second calculating means calculates the calculated refractive power of the other spectacle lens, the combined refractive power, and the first and second adhesions. The refractive index of the material is calculated based on the refractive index of the member.

  The invention according to claim 5 is the lens meter according to any one of claims 1 to 4, wherein a plurality of shapes of the first contact surfaces of the first contact members are different. The first refractive index measurement member is provided, and a plurality of second refractive index measurement members having different shapes of the second contact surface of the second contact member are provided.

  The invention according to claim 6 is the lens meter according to claim 5, wherein each of the plurality of first and second refractive index measuring members is provided with identification information. It is characterized by.

  The invention according to claim 7 is the lens meter according to any one of claims 1 to 6, wherein the calculation result by the first calculation means and / or the second calculation means is provided. It is further characterized by further comprising display means for displaying.

  The lens meter according to the present invention automatically determines whether or not the first and second refractive index measuring members are mounted on the test lens supported by the support means. The refractive power of the single lens is measured. When the lens is attached, the combined refractive power of the lens to be tested and the first and second refractive index measuring members is measured. Then, the refractive index of the material of the test lens is calculated from these two measurement results. Therefore, according to the present invention, whether the measurement object supported by the support means is a single lens to be tested or whether the lens to be tested is equipped with the first and second refractive index measuring members. It can be recognized automatically, and the refractive index measurement can be automated.

  The lens meter according to the present invention can be used as a normal lens meter and has a configuration that can be used for measuring the refractive index of a lens material by using a refractive index measuring member described later. Hereinafter, an example of a preferred embodiment of a lens meter according to the present invention will be described in detail with reference to the drawings.

[Appearance configuration]
FIG. 1 shows an example of an external configuration of a lens meter 1 according to the present invention. A display unit 3 composed of a liquid crystal display (LCD) or a CRT is provided on the upper front surface of the main body 2 of the lens meter 1. On the display screen 3a of the display unit 3, the optical characteristic values (spherical power, cylindrical power, cylindrical shaft angle, prism power, prism base direction, etc.) of the test lens L, and the distribution of the optical characteristic values of the test lens L are displayed. Various screens such as a mapping image to be displayed are displayed. The display unit 3 constitutes “display means” according to the present invention.

  Below the display unit 3, optical member storage units 4 and 5 for storing various optical members for measuring the optical characteristic values of the lens to be examined are arranged above and below.

  A lens receiving table 6 to which a lens receiver 13 on which the test lens L is placed is attached is provided at the upper end of the optical member storage section 5. The lens receiver 13 includes a flat transparent plate 13a made of transparent glass, transparent resin, or the like, and a lens support portion 13b that protrudes upward through a central portion of the transparent plate 13a. The lens support portion 13b corresponds to the “support means” of the present invention that supports the lens L to be examined. In addition, although mentioned later for details, the lower end of the lens support part 13b is connected to the Hartmann plate. The lens support portion 13b acts to keep the distance between the lens L to be examined and the Hartmann plate constant.

  A lens pad 7 is provided on the front surface of the main body 2 behind the lens support portion 13b so that the position of the lens support 7 can be adjusted back and forth. The lens pad 7 is moved back and forth by rotating the operation lever 8.

  A slider 9a supported so as to be movable in the horizontal direction is provided at the upper edge of the lens pad 7. A nose pad support member 9 is connected to the tip of the slider 9a so as to be rotatable up and down. .

  Here, as the test lens L, a circular unprocessed lens, a lens ground for spectacles, a lens framed in a spectacle frame, or the like is applied. When measuring the optical characteristic value of the lens framed in the spectacles, the nose pad of the spectacle frame is placed in engagement with the nose pad support member 9. Then, in this state, the glasses and the nose pad support member 9 are moved left and right together with the slider 9a to move downward while adjusting the position in the left-right direction, thereby placing the lens of the glasses on the lens support portion 13a. To measure the optical characteristic value.

  The front surface of the main body 2 of the lens meter 1 is provided with buttons and switches for various operations such as a mode switching button 10 for switching a measurement mode and a measurement button 11 for starting and stopping measurement. Yes.

[Configuration of optical system]
FIG. 2 shows a configuration of an optical system for measuring optical characteristic values provided in the lens meter 1. This figure shows a state in which the test lens L is placed on the upper end of the lens support portion 13b and can be measured. The optical system of the lens meter 1 has the same configuration as the conventional one, and is stored in the optical member storage portions 4 and 5 of the main body 2.

  The optical system of the lens meter 1 has an illumination optical system 100 housed in the upper optical member housing portion 4 and a light receiving optical system 110 housed in the optical member housing portion 5.

  The illumination optical system 100 is an optical system that projects measurement light onto the lens L to be measured, and an LED (light emitting diode) 101 serving as a light source that emits measurement light and the measurement light from the LED 101 are converted into parallel light. And a collimator lens 102 that projects the lens L. The measurement light emitted from the LED 101 is, for example, red light.

  The light receiving optical system 110 includes a Hartmann plate 111, a screen 112, a field lens (field lens) 113, an imaging lens 114, and a CCD (Charge Coupled Device) 115. The screen 112 and the CCD 115 are disposed at optically conjugate positions.

  As shown in FIG. 3A, the Hartmann plate 111 is formed with a large number of circular openings 111a arranged at equal intervals in the vertical and horizontal directions (two-dimensionally). The openings 111a are arranged vertically and horizontally at intervals of 2 millimeters, for example. The measurement light that has passed through the test lens L passes through the Hartmann plate 111 and is converted into a large number of measurement lights that have passed through the opening 111a. The lower end of the lens support portion 13b is joined to the Hartmann plate 111.

  In addition, it can replace with Hartmann plate 111 and can also measure using a 4 hole type plate (4 hole plate) 111 'as shown in FIG.3 (B). In the four-hole plate 111 ′, openings 111a ′ are formed at positions corresponding to the four apexes of the quadrangle.

  On the screen 112, a large number of measurement lights that have passed through the opening 111 a of the Hartmann plate 111 are projected. The projection position on the screen 112 and the shape of the projection image change in accordance with the optical characteristic value of the test lens L for each of a large number of measurement lights. As a result, the projection pattern of the large number of measurement lights on the screen 112 is reduced / enlarged or distorted.

  A large number of measurement lights projected on the screen 112 pass through the screen 112, and pass through the field lens 113 and the imaging lens 114. The light receiving surface of the CCD 115 provided at a position optically conjugate with the screen 112. Imaged on top.

  The CCD 115 receives the large number of measurement lights, converts them into electric signals (that is, photoelectrically converts them), and outputs them. The image signal (image signal) output from the CCD 115 includes information indicating the light receiving position and the shape of the received light image for each of the many measurement lights received. This information is expressed as the position (coordinates) of each pixel of the CCD 115. The lens meter 1 obtains the optical characteristic value of the lens L to be examined by analyzing the image signal output from the CCD 115.

[Configuration of refractive index measurement member]
FIG. 4 shows an example of the configuration of a member (referred to as a refractive index measurement member) used when measuring the refractive index of the material forming the lens L. 4A shows a side view of the refractive index measurement member, and FIG. 4B shows a top view thereof.

  4 includes a contact member 21 made of a transparent and flexible material such as silicon gel, and a flat holding member 22 made of a transparent material such as glass or plastic. Is done.

  The contact member 21 is in close contact with one surface (holding surface 22a) of the holding member 22, and is held by the holding member 22 by the adhesiveness of the contact member 21, for example. In addition, you may join the adhesion | attachment member 21 and the holding member 22 through transparent adhesive members, such as an adhesive agent. The contact member 21 has a sufficiently large refractive index (known) as compared with air.

  As shown in FIG. 4B, the holding member 22 is formed in a disc shape. Further, the contact member 21 is formed in a substantially cylindrical shape having a diameter smaller than that of the holding member 22.

  The surface of the contact member 21 that faces the holding member 22 constitutes a contact surface 21a that is in close contact with the lens surface of the lens L to be tested as described below.

  In the present embodiment, a plurality of such refractive index measurement members 20 are used corresponding to various shapes of the lens surface of the lens L to be examined. 5 and 6 schematically show the configuration of such a plurality of refractive index measurement members 20 (in order to make the explanation easy to understand, the shape of the contact surface of the contact member is exaggerated).

  By the way, as the test lens L, spectacle lenses having various refractive powers are applied. FIG. 7 is a schematic side view showing an example of a general shape of various test lenses L corresponding to differences in refractive power.

  The test lens L1 shown in FIG. 7A is a lens having a sum S + C (power in the strong principal meridian direction) of the spherical power S and the astigmatism power C of −5D or less, and a minus lens having a relatively high power. . The front surface (Otemen) L1a is formed in a substantially flat shape, and the back surface L1b is formed in a concave shape.

  Further, the test lens L2 shown in FIG. 7B is a lens having a power S + C in the strong principal meridian direction larger than −5D and smaller than 0D, and a minus lens having a relatively low power. The front surface L2a is formed in a convex shape, and the back surface L2b is formed in a concave shape in which the absolute value of the curvature is larger than that of the front surface L2a.

  A test lens L3 shown in FIG. 7C is a lens having a power S + C in the strong principal meridian direction larger than 0D and smaller than + 5D, and a relatively weak lens. The front surface L3a is formed in a convex shape, and the back surface L3b is formed in a concave shape in which the absolute value of curvature is smaller than that of the surface L3a.

  Further, the test lens L4 shown in FIG. 7D is a lens having a power S + C of + 5D or more in the strong principal meridian direction and a relatively strong power plus lens. The front surface L4a is formed in a convex shape, and the back surface L4b is formed in a substantially flat shape.

  Here, the front surfaces L1a to L4a mean surfaces that are arranged forward when the test lenses L1 to L4 are worn, and the back surfaces L1b to L4b are surfaces that are arranged on the eye side of the wearer. Shall mean.

  Each of the refractive index measurement members 20A to 20D shown in FIGS. 5A to 5D is mounted so as to be in close contact with the surface of the lens L to be tested, and is shown in FIGS. 6A to 6D. Each of the refractive index measurement members 20α to 20δ is mounted so as to be in close contact with the back surface of the lens L to be measured.

  Note that the refractive index measuring members 20A to 20D in FIG. 5 and the refractive index measuring members 20α to 20δ in FIG. 6 are the “first refractive index measuring member” and the “second refractive index measuring member” according to the present invention. Corresponding to “member” (in no particular order). The close contact member of the first refractive index measuring member and the close contact member of the second refractive index measuring member correspond to the “first close contact member” and the “second close contact member” of the present invention. Here, the contact surface of the “first contact member” corresponds to the “first contact surface” of the present invention, and the contact surface of the “second contact member” is the “second contact surface” of the present invention. Is equivalent to. Of the holding members 22A to 22D of the refractive index measuring members 20A to 20D and the holding members 22α to 22δ of the refractive index measuring members 20α to 20δ, the one that holds the first contact member is “first The “holding member” corresponds to the “second contact member” that holds the second contact member. Hereinafter, each of the refractive index measurement members 20A to 20D and 20α to 20δ will be described.

(Refractive index measuring member mounted on the front side of the lens to be tested; FIG. 5)
The refractive index measurement member 20A shown in FIG. 5A is selectively applied when the power S + C in the strong principal meridian direction of the test lens L is −5 or less, and is in close contact with the surface of the test lens L. It is attached in this way. The close contact surface 21Aa of the refractive index measuring member 20A is formed in a substantially flat shape in accordance with the shape (substantially flat shape) of the surface L1a of the lens L1 in FIG. That is, the contact surface 21Aa is formed in a shape that matches the typical surface shape (curvature) of a lens having the same power as the lens L1.

  The refractive index measuring member 20B shown in FIG. 5B is selectively applied when the power S + C of the test lens L in the strong principal meridian direction is larger than −5D and smaller than 0D. It is attached so as to be in close contact with the surface of the. The close contact surface 21Ba of the refractive index measuring member 20B is formed in a concave curved surface shape having a curvature matched to the shape (convex shape) of the surface L2a of the lens L2 to be measured in FIG. That is, the contact surface 21Ba is formed in a shape that matches a typical surface shape (curvature) of a lens having the same power as the lens L2.

  Further, the refractive index measuring member 20C shown in FIG. 5C is selectively applied when the power S + C of the test lens L in the strong principal meridian direction is larger than 0D and smaller than + 5D. It is mounted so that it is in close contact with the surface. The close contact surface 21Ca of the refractive index measuring member 20C is formed in a concave curved surface shape having a curvature that matches the shape (convex surface shape) of the surface L3a of the lens L3 to be measured in FIG. That is, the contact surface 21Ca is formed in a shape that matches a typical surface shape (curvature) of a lens having the same power as the lens L3 to be examined.

  Further, the refractive index measurement member 20D shown in FIG. 5D is selectively applied when the power S + C in the strong principal meridian direction of the test lens L is + 5D or more, and is applied to the surface of the test lens L. Mounted in close contact. The contact surface 21Da of the refractive index measurement member 20D is formed in a concave curved surface shape having a curvature that matches the shape (convex surface shape) of the surface L4a of the lens L4 to be measured in FIG. That is, the contact surface 21Da is formed in a shape that matches a typical surface shape (curvature) of a lens having the same power as the lens L4 to be examined.

(Refractive index measuring member mounted on the surface side of the lens to be tested; FIG. 6)
The refractive index measurement member 20α shown in FIG. 6A is selectively applied when the power S + C of the test lens L in the strong principal meridian direction is −5 or less, and is in close contact with the back surface of the test lens L. It is attached in this way. The close contact surface 21αa of the refractive index measuring member 20α is formed in a convex curved surface shape having a curvature matched to the shape (concave surface shape) of the back surface L1b of the lens L1 to be measured in FIG. That is, the contact surface 21αa is formed in a shape that matches a typical back surface shape (curvature) of a lens having the same power as the lens L1.

  The refractive index measuring member 20β shown in FIG. 6B is selectively applied when the power S + C of the test lens L in the strong principal meridian direction is larger than −5D and smaller than 0D. It is mounted so as to be in close contact with the back surface of the. The close contact surface 21βa of the refractive index measuring member 20β is formed in a convex curved surface shape having a curvature matched to the shape (concave surface shape) of the back surface L2b of the lens L2 to be measured in FIG. That is, the contact surface 21βa is formed in a shape that matches a typical back surface shape (curvature) of a lens having the same power as the lens L2.

  Further, the refractive index measuring member 20γ shown in FIG. 6C is selectively applied when the power S + C of the test lens L in the strong principal meridian direction is larger than 0D and smaller than + 5D. It is mounted so as to be in close contact with the back surface. The close contact surface 21γa of the refractive index measuring member 20γ is formed in a convex curved surface shape having a curvature that matches the shape (concave surface shape) of the back surface L3b of the lens L3 to be measured in FIG. That is, the contact surface 21γa is formed in a shape that matches a typical back surface shape (curvature) of a lens having the same power as the lens L3.

  6D is selectively applied when the power S + C in the strong principal meridian direction of the test lens L is + 5D or more, and is applied to the back surface of the test lens L. Mounted in close contact. The close contact surface 21δa of the refractive index measuring member 20δ is formed in a convex curved surface shape having a curvature matched to the shape (concave surface shape) of the back surface L4b of the lens L4 to be measured in FIG. That is, the contact surface 21δa is formed in a shape that matches a typical back surface shape (curvature) of a lens having the same power as the lens L4.

(Identification of multiple members for refractive index measurement)
In the measurement of the refractive index of the lens material by the lens meter 1 of the present embodiment, the plurality of refractive index measurement members 20A to 20D and 20α to 20δ are selectively selected according to the refractive power (S + C) of the lens L to be measured. To do. Therefore, it is considered desirable to be able to identify each of the refractive index measurement members 20A to 20D and 20α to 20δ so that the selection can be easily performed. Therefore, in this embodiment, identification information as shown below is provided in each of the refractive index measurement members 20A to 20D and 20α to 20δ.

  Now, the refractive index measuring members 20A to 20D shown in FIG. 5 are mounted on the surface of the lens L to be measured. Therefore, by providing the following identification information, it indicates that the lens surface on which these are to be mounted is a surface, and these can be distinguished from each other. Similarly, for the refractive index measurement members 20α to 20δ shown in FIG. 6, the following identification information indicates that the lens surface on which these members are to be mounted is the back surface, and allows these to be distinguished from each other.

  Regarding the refractive index measuring members 20A to 20D mounted on the surface of the lens L, a red letter “F” is formed on the side surface of the holding member 22A of the refractive index measuring member 20A or the holding surface 22Aa of FIG. ”And a blue letter“ F ”is formed on the side surface of the holding member 22B and the holding surface 22Ba of the refractive index measuring member 20B of FIG. 5B, and the refractive index measuring member of FIG. A green letter “F” is formed on the side surface of the holding member 22C of 20C and the holding surface 22Ca, and a yellow letter is formed on the side surface of the holding member 22D and the holding surface 22Da of the refractive index measurement member 20D in FIG. Of “F”. Here, “F” is an initial of “Front” indicating the surface.

  Further, the refractive index measuring members 20α to 20δ attached to the back surface of the lens L to be tested are shown in red on the side surface of the holding member 22α and the holding surface 22αa of the refractive index measuring member 20α in FIG. “B” is formed, blue “B” is formed on the side surface of the holding member 22β of the refractive index measuring member 20β and the holding surface 22βa of FIG. 6B, and the refractive index measurement of FIG. 6C is performed. A green letter “B” is formed on the side surface of the holding member 22γ and the holding surface 22γa of the member 20γ, and on the side surface of the holding member 22δ and the holding surface 22δa of the refractive index measurement member 20δ in FIG. The yellow letter “B” is formed. Here, “B” is an initial of “Back” indicating the back surface.

  The identification information is not limited to that described above, and may be sufficient if the refractive index measurement members 20 can be distinguished from each other. For example, any color, any character, any figure or any symbol, or any combination of two or more of them can be used as the identification information.

  Further, in the above example, for example, the identification information of the refractive index measuring member 20A and the refractive index measuring member 20α is made the same color (red) so that the two refractive index measuring members 20A and 20α are associated with each other. It has become. Thus, it is desirable to employ identification information that associates a pair of refractive index measurement members 20 that are used simultaneously. Note that the association can be performed using characters, figures, symbols, and the like in addition to the color method.

  Further, the position where the identification information is provided may be an arbitrary position of the refractive index measurement member 20. However, the position that affects the measurement light, for example, the region on the contact surface 21a of the contact member 21, the contact region with the contact member 21 on the holding surface 22a, or the contact surface on the surface opposite to the holding surface 22a. It should be avoided to provide identification information at a position that hinders measurement, such as a region facing the part.

  Further, identification information may be individually provided on both the contact member 21 and the holding member 22. In that case, it is desirable to provide the same identification information on both sides. Thereby, when the structure of the holding member 22 of the plurality of refractive index measuring members 20 is different, for example, when the contact member 21 is peeled off from the holding member 22, which contact member 21 is attached to which holding member 22. It should be obvious at a glance.

[Control system configuration]
Next, the configuration of the control system of the lens meter 1 according to the present embodiment will be described. The block diagram of FIG. 8 represents an example of the configuration of the control system of the lens meter 1.

  As described above, the lens meter 1 is based on the projection pattern on the screen 112 of a large number of measurement lights generated by the Hartmann plate 111, in other words, the arrangement state of the large number of measurement lights on the light receiving surface of the CCD 115. Is a device for obtaining the optical characteristic value of the lens L to be measured. Further, the lens meter 1 uses the refractive index measurement members 20A to 20D and 20α to 20δ described above to obtain the refractive index of the material forming the test lens L. Hereinafter, a configuration for suitably executing such processing will be described.

  The control system of the lens meter 1 includes an arithmetic control circuit such as a CPU (Central Processing Unit) 30 and a program storage unit 40 including a nonvolatile storage device such as a ROM (Read Only Memory).

  The program storage unit 40 stores in advance a control program 41 for causing the lens meter 1 to execute various operations and various data including related information 42. The related information 42 is data for associating the refractive power of the lens L (refractive power S + C in the strong main meridian direction) with the refractive index measurement members 20A to 20D and 20α to 20δ. That is, the related information 42 associates (1) S + C ≦ −5D with the refractive index measurement members 20A and 20α, (2) associates −5D <S + C <0D with the refractive index measurement members 20B and 20β, 3) Information including a table that associates 0D <S + C <5D with the refractive index measurement members 20C and 20γ, and (4) associates 5D ≦ S + C with the refractive index measurement members 20D and 20δ. Note that the refractive index measurement members 20B and 20β or the refractive index measurement members 20C and 20γ are associated with S + C = 0D.

  The CPU 30 develops the control program 41 and various data stored in the program storage unit 40 on a RAM (Random Access Memory: not shown), thereby executing operation control of each unit of the apparatus, optical characteristic value calculation processing, and the like. .

  The CPU 30 performs a control unit 31 that controls each unit of the lens meter 1, a display control unit 32 that controls display processing by the display unit 3, and various calculation processes related to the measurement of the optical characteristic value of the lens L to be tested. A measurement processing unit 33 is provided.

  The measurement processing unit 33 includes an attachment determination unit 34, a refractive power calculation unit 35, a calculation result storage unit 36, and a material refractive index calculation unit 37.

  The attachment determination unit 34 corresponds to “determination means” of the present invention that determines whether or not the refractive index measurement member 20 is attached to the lens L to be measured supported by the lens support portion 13b. The attachment determination unit 34 determines the presence or absence of a refractive index measurement member, for example, as follows. It is assumed that the control unit 31 controls the LED 101 to continuously output measurement light.

  The mounting determination unit 34 continuously monitors the intensity of the electrical signal from the CCD 115, and detects a change in the intensity of the electrical signal when the lens L to be tested is placed on the lens support 13b. When only the test lens L is arranged, the intensity of the electric signal changes discontinuously only when the edge portion of the test lens L crosses the measurement light.

  On the other hand, when the test lens L to which the refractive index measurement member 20 is attached is disposed, first, when the edge portion of the test lens L crosses the measurement light, the intensity of the electric signal changes discontinuously. In addition, the intensity of the electrical signal changes discontinuously when the holding member 22 of the refractive index measurement member 20 and the edge portion of the contact member 21 cross the measurement light.

  In consideration of this, the mounting determination unit 34 makes one discontinuous change in the intensity of the electrical signal output from the CCD 115 when the test lens L is inserted at a position on the lens support unit 13b. In the case where only the lens L is detected, it is determined that the lens L to be measured is disposed alone, and when a discontinuous change in the intensity of the electric signal is detected continuously a plurality of times, the refractive index measurement member It is determined that the lens L to be examined with 20 attached is disposed.

  Based on the signal output from the CCD 115, the refractive power calculator 35 is configured to measure the spherical power S, the cylindrical power C, the cylindrical power of the test lens L (or the test lens L with the refractive index measurement member 20 mounted). Processing for calculating optical characteristic values such as the axial angle A, the prism power P, and the refractive power S + C in the strong principal meridian direction is performed. This calculation process is executed in the same manner as a conventional lens meter. The refractive power calculator 35 corresponds to the “first calculator” according to the present invention. The optical characteristic value obtained for the test lens L with the refractive index measurement member 20 attached is the refractive power in a state where the test lens L and the refractive index measurement member 20 are combined. This is called “synthetic refractive power”.

  The calculation result storage unit 36 calculates the refractive power and synthetic refractive power of the lens L calculated by the refractive power calculation unit 35 and the refractive index (described later) of the lens material calculated by the material refractive index calculation unit 37. A process of saving in the calculation result storage unit 50 is performed. In particular, when it is determined that only the test lens L is supported by the lens support portion 13b, a flag is set in the calculation result of the refractive power of the test lens L measured in that state, and the calculation result is stored. Stored in the unit 50. In addition, when it is determined that only the test lens L is newly supported, the calculation result storage unit 36 deletes the flag that has already been set, and the measurement result of the newly supported test lens L. Flag the. Therefore, among the calculation results stored in the calculation result storage unit 50, only the latest calculation result in a state where only the lens L is supported is flagged. The calculation result storage unit 50 is configured by a storage device such as a writable RAM.

  The material refractive index calculation unit 37 corresponds to the “second calculation unit” of the present invention, and is calculated by the refractive power calculation unit 35 (1) The refractive power of the single lens L (the refractive power in the strong principal meridian direction). ), (2) synthetic refractive power (synthetic refractive power in the strong principal meridian direction) obtained when measuring the test lens L with the pair of refractive index measuring members 20 mounted thereon, and (3) mounting Based on the refractive index of the close contact member 21 of the refractive index measuring member 20, the refractive index of the material of the lens L is calculated. As the arithmetic expression, for example, the following expression is applied.

ｎ_１：レンズ素材の屈折率
ｎ_２：密着部材の屈折率
Ｄ_１：被検レンズの強主経線方向の屈折力
Ｄ_２：被検レンズ及び屈折率測定用部材の合成屈折力

n ₁ : Refractive index of the lens material n ₂ : Refractive index of the close contact member D ₁ : Refractive power in the strong principal meridian direction of the test lens D ₂ : Synthetic refractive power of the test lens and the refractive index measuring member

  Further, the measurement processing unit 33 refers to the related information 42 in the program storage unit 40, and a pair of refractions associated with the refractive power S + C in the strong principal meridian direction of the lens L calculated by the refractive power calculation unit 35. A process of selecting the rate measuring member 20 is performed. For example, in the case of calculation result S + C = −4.0D, a set of refractive index measurement members 20B and 20β is selected.

  As described above, the mode switching button 10 (see FIG. 1) is a button that presents the measurement mode by the lens meter 1 so that the user can select it. A plurality of measurement modes such as a measurement mode and an automatic refractive index measurement mode for automatically measuring the refractive index of the material forming the lens L can be selectively set. The measurement mode can also be switched by a “MODE” key (described later) provided on the screen displayed on the display unit 3.

[Processing procedure]
Processing executed by the lens meter 1 configured as described above will be described. The flowcharts shown in FIGS. 9 and 10 show an example of a process for measuring the refractive power of the material forming the lens L to be examined.

  When the mode switching button 10 is operated to set the “automatic refractive index measurement mode” (S1), the display control unit 32 displays the screen G shown in FIG. 11 on the display unit 3 (S2). When the process is started from the position where the screen G is displayed, an “automatic refractive index measurement mode” can be set by operating a “MODE” key 210 (described later).

  Here, the screen G will be described. In the upper part of the screen G, a lens type display unit 201 indicating the type of the lens L to be measured is provided. In the lens type display unit 201, “S” is displayed when the lens L to be examined is a single lens, “R” is displayed when the lens for the right eye is used, and “L” is displayed when the lens for the left eye is used. The

  On the screen G, a concentric scale 202 centered on the optical center of the lens L is displayed as in the conventional case (see, for example, JP-A-11-132905 by the present applicant). Each concentric circle (dotted line) represents the prism power, and corresponds to 0.5, 1.0, 2.0, 3.0, 4.0, 5.0 prism diopters in order from the inside (1.0 prism). The scale corresponding to the diopter is near the inner periphery of the thick ring scale).

  The measurement result of the optical characteristic value of the test lens L is displayed on the refractive power display unit 203. In particular, the refractive power display unit 203 displays the spherical power S, the astigmatic power C, the astigmatic axis angle A, and the refractive power S + C in the strong principal meridian direction. The measurement result when measured with the refractive index measurement member 20 attached is displayed on the combined refractive power display unit 204. The combined refractive power display unit 204 displays, in particular, the combined spherical power (S) and the combined astigmatic power (C). In addition, you may further display the refractive power (S + C) of a strong principal meridian direction. In the refractive index display unit 205 (IND; refractive INDEX: refractive index), the measurement result of the refractive index of the lens material of the lens L to be measured is displayed. In addition, in the stage displayed by step S2, since it is before a measurement, each display part 203-205 is zero (however, astigmatism axis angle is 180).

  Further, on the screen G, a step display unit 207 that displays setting values of numerical values displayed on the refractive power display unit 203, the combined refractive power display unit 204, and the refractive index display unit 205, and various messages are displayed. And a graphic display unit 209 for displaying various graphic messages and the like.

  At the bottom of the screen G, a “MODE” key 210 for mode switching, a “TRANS” key 211 for switching the display method of lens prescription values, a “CLEAR” key 212 for clearing data, and a measurement result, etc. Soft keys such as a “PRINT” key 213 are provided.

  When the image G as described above is displayed, the control unit 31 turns on the LED 101 and outputs measurement light (S3). The attachment determination unit 34 monitors the intensity of the electric signal output from the CCD 115 that detects the measurement light (S4). When the user inserts the measurement object (the test lens L alone or the test lens L on which the refractive index measurement member 20 is mounted) into a position on the lens support portion 13b (S5), the mounting determination unit 34 The number of signal intensity discontinuous changes at the time of insertion of the measurement object is detected (S6).

  When the number of times is one (S7; “once”), it is determined that the test lens L is inserted alone. Then, the refractive power is measured in this state, and optical characteristics such as the spherical power S, the astigmatism power C, the astigmatism shaft angle A, the prism power P, and the refractive power S + C in the strong principal meridian direction of the lens L alone are measured. The calculation result is calculated (S8), a flag is set on the calculation result, and the flag is stored in the calculation result storage unit 50 (S9), and the calculation result is displayed on the display unit 3 (S10). Here, a pair of refractive index measurement members 20 corresponding to the refractive power S + C of the test lens L may be selected, and a message or graphic (see FIG. 12) representing the identification information may be displayed.

  On the other hand, when the number of discontinuous changes in the signal intensity at the time of insertion of the measurement object is two or more (S7; “plurality”), the measurement processing unit 33 indicates that the calculation result with the flag set is the calculation result storage unit It is searched whether it is saved in 50 (S11). At this stage, since the first lens L is measured, the flagged calculation result is not stored (S12; N).

  Now, when the measurement object currently set on the lens support portion 13b is retracted and the next measurement object is inserted (S5), the mounting determination unit 34 determines the signal intensity when the measurement object is inserted. The number of discontinuous changes is detected (S6).

  When the number of times is one (S7; “once”), it is determined that the test lens L is inserted alone. Then, the refractive power is measured in this state, and optical characteristics such as the spherical power S, the astigmatism power C, the astigmatism shaft angle A, the prism power P, and the refractive power S + C in the strong principal meridian direction of the lens L alone are measured. A calculation is made (S8), a flag is set on the calculation result, and the result is stored in the calculation result storage unit 50 (S9). That is, this case corresponds to the case where the measurement of the refractive index of the lens material is not performed for the first lens to be measured and the measurement is shifted to the measurement of the second lens.

  On the other hand, when the number of discontinuous changes in signal intensity at the time of insertion of a new measurement object is 2 or more (S7; “plurality”), the test lens L in a state where the refractive index measurement member 20 is mounted. Is determined to have been inserted. The measurement processing unit 33 searches whether the calculation result with the flag set is stored in the calculation result storage unit 50 (S11). In this case, the calculation result stored in step S9 is searched (S12; Y).

  In this state, the refractive power is measured, and the combined spherical power (S), the combined astigmatic power (C), the combined astigmatic axis angle (A), and the combining prism of the lens L with the refractive index measuring member 20 mounted thereon. Optical characteristic values such as the frequency (P) and the combined refractive power (S + C) in the strong principal meridian direction are calculated (S13). The display control unit 32 displays the calculation results, particularly (S) and (C), on the combined refractive power display unit 204 of the screen G (S14). The calculation result is stored in a storage device (not shown) such as a RAM. This measurement result can be printed out or stored in an archive as required.

  It is determined whether the measurement is completed (S15). This determination is made in response to a measurement end request by the measurement button 11 or the like. If a new measurement object is inserted without completing the measurement (S15; N), the measurement is continued. If the end of measurement is requested (S15; Y), the process is terminated.

[Function and effect]
According to the lens meter 1 of the present embodiment as described above, the following operational effects can be obtained.

  First, the lens meter 1 automatically determines whether or not the refractive index measurement member 20 is attached to the test lens L supported by the lens support portion 13b. When the lens is mounted, the combined refractive power of the test lens L and the refractive index measuring member 20 is measured. Then, the refractive index of the material of the test lens L is calculated from these two measurement results. Therefore, according to the lens meter 1, it is determined whether the measurement object arranged on the lens support portion 13b is the test lens L alone or the test lens L to which the refractive index measurement member 20 is attached. It can be recognized automatically, and the refractive index measurement can be automated.

  In addition, the most recent measurement value of the refractive power of the single lens to be tested is flagged for identification, and when the test lens to which the refractive index measuring member 20 is attached is set, The refractive index of the lens material is determined based on the measured combined refractive power and the refractive power identified by the flag. In other words, when it is determined that the refractive index measurement member 20 is attached to the test lens, the refractive power of the test lens calculated immediately before that and the refractive index measurement member 20 are attached. The refractive index of the lens material is calculated based on the combined refractive power calculated for the test lens and the refractive index of the contact member 21. As a result, automation of refractive index measurement is promoted, and even when measurement of only the lens refractive power and measurement of the refractive index of the material are mixed, both measurements are automatically distinguished and smoothly performed. It can be carried out.

  When measuring the refractive index of the lens material, first, the refractive power of the lens to be tested is first measured, and immediately thereafter, the refractive index measuring member 20 is attached to the lens to be tested to obtain the combined refractive index. It is normal to measure. The processing of the present embodiment conforms to such a normal measurement procedure.

  Further, the contact member 21 is held by the transparent plate-like holding member 22 and the holding member 22 is intentionally formed to have a diameter larger than that of the contact member 21, so that the mounting operation is performed with the holding member 22. As a result, the handling of the refractive index measuring member 20 is improved, and the refractive index measuring member 20 can be easily and quickly mounted near the center of the lens L. According to the confirmation inspection by the present inventor, such a configuration enables the parallelism of the holding member 22 on both sides of the lens to be a predetermined prism value (for example, 2 prisms) even when the mounting operation is performed manually. It was confirmed that the measurement can be carried out with sufficient accuracy.

  In addition, since a plurality of refractive index measurement members 20A to 20D and 20α to 20δ having different contact surface shapes are provided, an appropriate one is selectively selected according to the shape (curvature) of the lens surface of the lens L to be examined. The measurement accuracy can be improved.

  Further, since the plurality of refractive index measurement members 20A to 20D and 20α to 20δ are provided with identification information, the possibility of confusion between them is avoided, and the target refractive index measurement member 20 is accurately selected. Can be used. Thereby, deterioration of measurement accuracy is prevented.

[Modification]
The configuration described in detail above is merely a specific example for suitably carrying out the present invention. Therefore, arbitrary modifications within the scope of the gist of the present invention can be made as appropriate. An example of a lens meter with such a modification will be described below.

(Modification 1)
The first modification includes a configuration suitable for measurement of the left and right eyeglass lenses framed in the eyeglass frame. The lens framed in the spectacle frame is arranged with the nose pad of the spectacle frame engaged with the nose pad support member 9 (see FIG. 1). The block diagram of FIG. 13 represents an example of the configuration of the control system of the modification.

  In addition to the configuration of the above-described embodiment (see FIG. 8), the lens meter 1 ′ according to the modified example has glasses such that left and right eyeglass lenses (test lenses) L are arranged on the lens support portion 13b one by one. A moving mechanism 60 (moving means) for moving the frame is provided. The moving mechanism unit 60 includes, for example, a pulse motor and the like, and moves the spectacle frame based on the control of the control unit 31. The eyeglass frame arranged with the nose pad engaged with the nose pad support member 9 is moved to the left and right together with the nose pad support member 9 and the slider 9a (see FIG. 1).

  Further, the moving mechanism unit 60 is provided with a detection unit configured to include a position detector (sensor) such as a potentiometer.

  When setting the left and right eyeglass lenses framed in the eyeglass frame, the attachment determination unit 34 determines whether or not the refractive index measurement member 20 is attached to the lens. When it is determined that the eyeglass frame is not attached, the eyeglass frame is moved left and right by the moving mechanism 60, and one lens (for example, the right lens) is supported by the lens support 13b. The detection unit of the moving mechanism unit 60 detects the position of the spectacle frame at this time. The detection result is sent to the control unit 31 as position information. Measurement is performed in this state, and the refractive power calculation unit 35 calculates the refractive power of the right lens. This calculation result is stored in the calculation result storage unit 50 in association with the detection result of the position of the spectacle frame.

  In addition, when the spectacle frame supported on the nose pad support member 9 is moved and inserted on the lens support portion 13b, the presence or absence of the refractive index measurement member 20 may be determined.

  The control unit 31 controls the moving mechanism unit 60 in response to a user operation or automatically in response to the completion of the measurement of the right lens, and the left lens (the other lens) is placed on the lens support unit 13b. The eyeglass frame is moved so as to place the lens). At this time, the attachment determination unit 34 determines whether or not the refractive index measurement member 20 is attached to the lens. The detection unit of the movement mechanism unit 60 detects the position of the eyeglass frame after movement. The detection result is sent to the control unit 31 as position information. When it is determined that the refractive index measurement member 20 is not attached, measurement is performed in that state, and the refractive power calculation unit 35 calculates the refractive power of the left lens. This calculation result is stored in the calculation result storage unit 50 in association with the detection result of the position of the spectacle frame.

  Subsequently, the user attaches the refractive index measurement member 20 to one of the left and right eyeglass lenses (for example, the right lens), and causes the nose pad support member 9 to support the eyeglass frame. The spectacle frame is moved by the moving mechanism unit 60, and the right lens on which the refractive index measurement member 20 is mounted is disposed on the lens support unit 13b. At this time, the attachment determination unit 34 determines whether or not the refractive index measurement member 20 is attached to the lens. Further, the detection unit of the movement mechanism unit 60 detects the position of the eyeglass frame after movement. The detection result is (substantially) equal to the position detected for the right lens first. This detection result is sent to the control unit 31 as position information. When it is determined that the refractive index measurement member 20 is attached to the right lens, the measurement is performed in that state, and the refractive power calculation unit 35 calculates the combined refractive power of the right lens and the refractive index measurement member 20. . This calculation result is stored in the calculation result storage unit 50 in association with the detection result of the position of the spectacle frame.

  The measurement processing unit 33 (discriminating means) obtains the detection result of the position of the spectacle frame when the combined refractive power is calculated and the detection result of the respective positions when the refractive power of the left lens and the right lens are calculated. In comparison, it is determined whether the combined refractive power is measured by the left or right lens. In this modification, the position detection result at the time of calculating the combined refractive power is substantially equal to the position detection result of the right lens, so the right lens is selected.

  Based on the refractive power of the right lens, the combined refractive power of the right lens, and the known refractive index of the contact member 21, the material refractive index calculation unit 37 determines the lens material of the right lens. Calculate the refractive index.

  In this modification, only the refractive index of one lens is measured. However, since the left and right lenses are usually formed of the same material, it is sufficient except for special glasses.

  When measuring the left and right spectacle lenses framed in the spectacle lens, it is usual to measure the right lens first and then the left lens. Therefore, it is considered that the measurement is often performed by attaching the refractive index measurement member 20 to the left lens after measuring the refractive power of the right lens and the left lens alone. That is, measuring the combined refractive power as it is at the position where the refractive power of the left lens alone is measured saves the trouble of moving the spectacle frame. In the above processing, in order to clarify the characteristics of this modification, the case where the refractive index measurement member 20 is intentionally attached to the right lens after the measurement with the right lens and the left lens alone has been described.

(Modification 2)
Similarly to the first modification, the second modification also has a configuration suitable for measuring the left and right eyeglass lenses framed in the eyeglass frame. This second modification is preferably used in an environment where the above-described normal measurement mode, that is, the normal measurement sequence in which the right lens is first measured and then the left lens is measured is applied. It is. The second modification has the same control system configuration as the first modification. Hereinafter, the first modification will be described with reference to the block diagram of FIG.

  When setting the left and right eyeglass lenses encased in the eyeglass frame, the attachment determination unit 34 determines whether or not the refractive index measurement member 20 is attached to the lens. If it is determined that the eyeglass frame is not attached, the moving mechanism 60 moves the spectacle frame left and right to support the right lens on the lens support 13b. Measurement is performed in this state, and the refractive power calculation unit 35 calculates the refractive power of the right lens. This calculation result is stored in the calculation result storage unit 50 with a flag set.

  The control unit 31 controls the moving mechanism unit 60 in response to a user operation or automatically in response to the completion of the measurement of the right lens, and the left lens (the other lens) is placed on the lens support unit 13b. The eyeglass frame is moved so as to place the lens). At this time, the attachment determination unit 34 determines whether or not the refractive index measurement member 20 is attached to the lens. When it is determined that the refractive index measurement member 20 is not attached, measurement is performed in that state, and the refractive power calculation unit 35 calculates the refractive power of the left lens. This calculation result is stored in the calculation result storage unit 50 with a flag set. At this time, the flag set in the calculation result regarding the right lens is deleted.

  The position of the nose pad support member 9 is unchanged from the time of measuring the refractive power of the left lens. The user attaches the refractive index measurement member 20 to the left lens and causes the nose pad support member 9 to support the spectacle frame. At this time, the attachment determination unit 34 determines whether or not the refractive index measurement member 20 is attached to the lens. If it is determined that it is attached, measurement is performed in that state, and the refractive power calculation unit 35 calculates the combined refractive power of the right lens and the refractive index measurement member 20.

  The material refractive index calculation unit 37 calculates the refractive index of the lens material of the left lens based on the refractive power of the left lens identified by the flag, the combined refractive power of the left lens, and the known refractive index of the contact member 21. calculate.

  Note that when the measurement is performed by reversing the measurement order of the right lens and the left lens in this modification, the processing may be performed by reversing the left and right in the above processing procedure.

  Further, instead of using the flag, as in the first modified example, the position of the spectacle frame at the time of measuring the refractive power of the left and right lenses is detected, and the result of the refractive power measurement at the same position as at the time of measuring the combined refractive index May be selected to calculate the refractive index.

(Other variations)
In the measurement of the refractive index of the lens material, both the refractive power measurement of the test lens alone (first stage) and the combined refractive power measurement of the test lens equipped with the refractive index measurement member (second stage) are tested. It is necessary to carry out at approximately the same measurement point on the lens. Therefore, it is possible to apply one of the following first and second configurations, or a combination of them.

  As a first configuration, a region where an opening is not formed (referred to as a defect region) is provided in the vicinity of the center of the Hartmann plate 111 (see FIG. 3A). This defect region is provided, for example, below the lens support portion 113b that supports the test lens. As a result, in the distribution of the large number of measurement light beams that pass through the large number of openings 111a of the Hartmann plate 111 and are projected onto the CCD 115, a region without the measurement light corresponding to the defect region is formed. Therefore, the measurement points in the first and second stages can be made substantially the same position by using the position of the defective region as a marker for specifying the measurement point in each measurement in the first stage and the second stage. .

  The second configuration is applicable when measuring the refractive index of a lens to be examined that is framed in a spectacle frame. That is, the lens meter 1 of the above embodiment is provided with a nose pad support member 9 that supports the nose pad of the spectacles and a slider 9a that moves the spectacles and nose pad support member 9 left and right. The glasses are always supported at substantially the same position by being engaged with the nose pad support member 9. Accordingly, if the first and second stage measurements are performed with the position of the slider 9a fixed, the measurement can be performed at substantially the same measurement point. Further, by providing a sensor (for example, a potentiometer) for detecting the position of the slider 9a that moves to the left and right, the slider 9a can be moved to a desired position. For each of the above, the first and second stage measurements can be performed at the same measurement point.

  As another modification, a configuration for obtaining the refractive index distribution (refractive index map) of the lens to be examined can be employed. For this purpose, for example, the refractive index is obtained for the plurality of measurement points of the lens to be measured by the method of the above-described embodiment or modification, and the obtained refractive index is associated with the coordinates of the measurement point to thereby obtain a refractive index map. Can be created. The created refractive index map can be displayed on the display unit 3 or printed out. This makes it possible to easily grasp the refractive index distribution state on the lens to be examined. This modification is suitable for applications such as obtaining the refractive index of a test lens formed by combining a plurality of lenses made of different materials.

It is a schematic perspective view showing an example of the appearance composition of the embodiment of the lens meter concerning the present invention. It is the schematic showing an example of the structure of the optical system with which embodiment of the lens meter which concerns on this invention is provided. It is the schematic showing an example of the structure of the optical system with which embodiment of the lens meter which concerns on this invention is provided. FIG. 3A is a schematic diagram illustrating an example of the configuration of the Hartmann plate. FIG. 3B is a schematic diagram illustrating an example of a four-hole type plate. It is the schematic showing an example of the structure of the member for refractive index measurement used in embodiment of the lens meter which concerns on this invention. FIG. 4A is a schematic side view of the refractive index measurement member, and FIG. 4B is a schematic top view thereof. In the embodiment of the lens meter concerning the present invention, it is the schematic showing an example of the composition of the member for refractive index measurement with which the surface of a lens to be examined is equipped. FIG. 5A shows a configuration of a refractive index measurement member used when the refractive power in the strong principal meridian direction of the lens to be examined is −5 diopters or less. FIG. 5B shows the configuration of a refractive index measurement member used when the refractive power of the test lens in the strong principal meridian direction is larger than −5 diopter and smaller than 0 diopter. FIG. 5C shows the configuration of the refractive index measurement member used when the refractive power of the test lens in the strong principal meridian direction is larger than 0 diopter and smaller than 5 diopter. FIG. 5D shows the configuration of a refractive index measurement member used when the refractive power of the test lens in the strong principal meridian direction is 5 diopters or more. In embodiment of the lens meter which concerns on this invention, it is the schematic showing an example of a structure of the member for refractive index measurement attached to the back surface of a to-be-tested lens. FIG. 6A shows the configuration of a refractive index measurement member used when the refractive power in the strong principal meridian direction of the test lens is −5 diopters or less. FIG. 6B shows the configuration of the refractive index measurement member used when the refractive power of the test lens in the strong principal meridian direction is larger than −5 diopter and smaller than 0 diopter. FIG. 6C shows the configuration of a refractive index measurement member used when the refractive power of the test lens in the strong principal meridian direction is larger than 0 diopter and smaller than 5 diopter. FIG. 6D shows the configuration of a refractive index measuring member used when the refractive power of the test lens in the strong principal meridian direction is 5 diopters or more. It is a schematic side view showing an example of composition of a lens for a test used for measurement by an embodiment of a lens meter concerning the present invention. FIG. 7A shows a configuration of a test lens having a refractive power in the strong principal meridian direction of −5 diopters or less. FIG. 7B shows a configuration of a test lens having a refractive power in the strong main meridian direction larger than −5 diopter and smaller than 0 diopter. FIG. 7C shows a configuration of a test lens having a refractive power in the strong main meridian direction larger than 0 diopter and smaller than 5 diopters. FIG. 7D shows a configuration of a test lens having a refractive power in the strong principal meridian direction of 5 diopters or more. It is a schematic block diagram showing an example of the composition of the control system with which the embodiment of the lens meter concerning the present invention is provided. It is a flowchart showing an example of the process which embodiment of the lens meter which concerns on this invention performs. It is a flowchart showing an example of the process which embodiment of the lens meter which concerns on this invention performs. It is the schematic showing an example of the screen which embodiment of the lens meter concerning this invention displays. It is the schematic showing an example of the screen which embodiment of the lens meter concerning this invention displays. It is a schematic block diagram showing an example of the composition of the control system with which the modification of the embodiment of the lens meter concerning the present invention is provided.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 'Lens meter 2 Main body 3 Display part 3a Display screen 4, 5 Optical member storage part 6 Lens receiving table 7 Lens contact 8 Operation lever 9 Nose pad support member 9a Slider 10 Mode switching button 11 Measurement button 13 Lens receiver 13a Transparent Plate 13b Lens support portion 20, 20A to 20D, 20α to 20δ Refractive index measurement member 21, 21A to 21D, 21α to 21δ Contact member 21a, 21Aa to 21Da, 21αa to 21δa Contact surface 22, 22A to 22D, 22α to 22δ Holding member 22a, 22Aa-22Da, 22αa-22δa Holding surface 30 CPU
Reference Signs List 31 Control Unit 32 Display Control Unit 33 Measurement Processing Unit 34 Attachment Determination Unit 35 Refractive Power Calculation Unit 36 Calculation Result Storage Unit 37 Material Refractive Index Calculation Unit 40 Program Storage Unit 41 Control Program 42 Related Information 50 Calculation Result Storage Unit 60 Movement Mechanism Unit 100 Illumination optical system 101 LED
102 collimator lens 110 light receiving optical system 111 Hartmann plate 111a opening 111 ′ four-hole plate 111a ′ opening 112 screen 113 field lens 114 imaging lens 115 CCD
201 Lens type display unit 202 Scale 203 Refractive power display unit 204 Synthetic refractive power display unit 205 Refractive index display unit 207 Step display unit 208 Message display unit 209 Graphic display unit L, L1 to L4 Test lenses L1a to L4a Surfaces L1b to L4b Back G screen

Claims (7)

Support means for supporting the lens to be examined;
An illumination optical system for projecting measurement light onto the supported test lens;
A light receiving optical system that receives the measurement light transmitted through the test lens;
A first refractive index measurement member including a first contact member having a first contact surface formed in conformity with the shape of one surface of the lens to be examined, transparent, flexible, and having a known refractive index; ,
A second refractive index measuring member including a second contact member having a second contact surface formed in conformity with the shape of the other surface of the lens to be examined, having a known refractive index and being transparent and flexible; ,
Determining means for determining whether or not the first and second refractive index measuring members are attached to the lens to be examined supported by the supporting means;
Based on the measurement light received by the light receiving optical system when it is determined that the first and second refractive index measurement members are not attached to the test lens, the refraction of the test lens And calculating the force, and based on the measurement light received when it is determined that the first and second refractive index measurement members are mounted, the test lens and the first First calculating means for calculating a combined refractive power of the refractive index measuring member and the second refractive index measuring member;
A second calculation for calculating a refractive index of a material forming the test lens based on the calculated refractive power and the combined refractive power and the refractive indexes of the first and second contact members. Means,
A lens meter comprising:   The second calculation means is calculated immediately before the determination when the determination means determines that the first and second refractive index measurement members are attached to the lens to be measured. The refractive power of the test lens, the combined refractive power calculated by the first calculation means for the test lens on which the first and second refractive index measurement members are mounted, and the first and second The lens meter according to claim 1, wherein the refractive index of the material is calculated based on the refractive index of the contact member. The test lens is a left and right spectacle lens framed in a spectacle frame,
Moving means for moving the eyeglass frame so that the supporting means supports the left and right eyeglass lenses one by one;
A discriminating means for discriminating which of the left and right spectacle lenses is supported based on positional information when each of the left and right spectacle lenses is supported by the moving means;
Further comprising
The first calculation means includes
Light is received by the light receiving optical system when it is determined that one of the left and right eyeglass lenses is supported and the first and second refractive index measurement members are not attached to the one eyeglass lens. Based on the measured measurement light, the refractive power of the one spectacle lens is calculated,
It is determined that the eyeglass frame is moved by the moving means to support the other eyeglass lens, and the first and second refractive index measurement members are not attached to the other eyeglass lens. Sometimes based on the received measurement light, the refractive power of the other spectacle lens is calculated,
One of the left and right eyeglass lenses is supported, and the light is received when it is determined that the first and second refractive index measurement members are attached to any one of the eyeglass lenses. Based on the measurement light, the combined refractive power of any one of the spectacle lenses and the first and second refractive index measurement members is calculated,
The second calculating means includes the calculated refractive power and the calculated combined refractive power for the one or other eyeglass lens determined by the determining means to be the same as any one of the eyeglass lenses, Calculating the refractive index of the material based on the refractive index of the first and second contact members;
The lens meter according to claim 1. The test lens is a left and right spectacle lens framed in a spectacle frame,
A moving means for moving the eyeglass frame so that the left and right eyeglass lenses are supported by the support means one by one;
The first calculation means includes
Light is received by the light receiving optical system when it is determined that one of the left and right eyeglass lenses is supported and the first and second refractive index measurement members are not attached to the one eyeglass lens. Based on the measured measurement light, the refractive power of the one spectacle lens is calculated,
It is determined that the eyeglass frame is moved by the moving means to support the other eyeglass lens, and the first and second refractive index measurement members are not attached to the other eyeglass lens. Sometimes based on the received measurement light, the refractive power of the other spectacle lens is calculated,
The measurement light received when it is determined that the other spectacle lens is supported and the first and second refractive index measurement members are attached to the other spectacle lens. Based on the other spectacle lens, the first refractive index measurement member and the second refractive index measurement member, the combined refractive power is calculated,
The second calculating means is configured to refract the material based on the calculated refractive power of the other spectacle lens, the combined refractive power, and the refractive indexes of the first and second contact members. Calculate the rate,
The lens meter according to claim 1. A plurality of the first refractive index measurement members having different shapes of the first contact surface of the first contact member;
A plurality of second refractive index measurement members having different shapes of the second contact surfaces of the second contact members;
The lens meter according to any one of claims 1 to 4, wherein the lens meter is provided.   6. The lens meter according to claim 5, wherein each of the plurality of first and second refractive index measurement members is provided with identification information. The lens meter according to any one of claims 1 to 6, further comprising display means for displaying a calculation result by the first calculation means and / or the second calculation means.

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