JP2019015541A - Lens measuring device - Google Patents

Abstract

To provide a lens measuring device with which it is possible to accurately measure the optical characteristics of a lens to be tested.SOLUTION: The lens measuring device comprises: irradiation means capable of irradiating measurement light by switching between a first irradiation pattern in which a first index pattern is formed and a second irradiation pattern in which the first index pattern is not formed; an index plate for forming a second index pattern in measurement light; a light-receiving element for receiving the measurement light having gone through the lens and the index plate; control means for acquiring the first image of the lens that includes the first index pattern and the second index pattern by receiving the first irradiation pattern having gone through the index plate by the light-receiving element, as well as acquiring the second image of the lens that includes the second index pattern by receiving the second irradiation pattern having gone through the index plate by the light-receiving element; acquisition means for acquiring the third image of the first index pattern by processing the first image and the second image; and computation means for acquiring lens information regarding the lens on the basis of the second image and the third image.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a lens measurement device that measures optical characteristics of a lens.

  As a lens measuring device, a lens meter and a cup mounting device are known. The lens meter measures the optical characteristics (for example, refractive power) of the test lens by projecting the measurement light onto the test lens and receiving the measurement light that has passed through the test lens with a light receiving element (patent) Reference 1). The cup mounting device projects the test lens based on the measurement result of the test lens obtained by projecting the measurement light onto the test lens and receiving the measurement light that has passed through the test lens with the light receiving element. The attachment position of the cup for performing is determined (refer patent document 2).

JP 2008-241694 A JP 2000-079545 A JP 2001-021449 A

  As a method for measuring the optical characteristics of the test lens using the lens measuring device, the optical characteristics are adjusted by moving the index plate up and down relative to the test lens and changing the index pattern projected onto the test lens. A calculation method has been known (see Patent Document 3). However, it is difficult to correct the minute shift caused by moving the index plate in parallel. If the index plate is tilted during movement, the index pattern projected on the lens to be measured is shifted, and accurate optical characteristics are acquired. There were cases where it was not possible. In addition, since the index plate is moved up and down, there is a problem that the lens measuring device may break down and the measurement takes time.

  In view of the above prior art, it is an object of the present disclosure to provide a lens measuring device that can accurately measure the optical characteristics of a lens to be examined.

  In order to solve the above problems, the present disclosure is characterized by having the following configuration.

  (1) A lens measurement device according to a first aspect of the present disclosure is a lens measurement device that measures optical characteristics of a lens, and forms a first index pattern and uses the first index pattern as a first irradiation pattern. Irradiating means capable of irradiating the lens with the first irradiating pattern and a second irradiating pattern that does not form the first index pattern, and irradiating means capable of irradiating the lens with measurement light; and The first irradiation pattern is formed by an index plate for forming a second index pattern on the emitted measurement light, a light receiving element that receives the measurement light via the lens and the index plate, and the irradiation unit. Is applied to the lens, and the first irradiation pattern via the indicator plate is received by the light receiving element, whereby the first indicator pattern and the second indicator pattern are received. A first image of the lens including the second irradiation pattern is irradiated to the lens by the irradiation unit, and the second irradiation pattern via the indicator plate is received by the light receiving element. Control means for acquiring a second image of the lens including the second index pattern; and arithmetic means for acquiring lens information of the lens by processing the first image and the second image. It is characterized by that.

It is an external view of the lens measuring apparatus which concerns on a present Example. It is a figure which shows the optical system in a lens measuring device. It is a figure which shows an indicator plate. It is a figure explaining a light source. It is an example of the image which a light receiving element receives in a 0D reference | standard state. It is an example of the image which a light receiving element receives in the state which mounted the to-be-tested lens. It is a figure which shows the control system in a lens measuring device. It is a figure which shows the relationship between a reference | standard image and the image of a to-be-tested lens. It is a figure explaining the light ray received by the light receiving element. It is the figure which expanded a part of image of the to-be-tested lens containing the index pattern different from a 1st index pattern.

<Overview>
Hereinafter, one exemplary embodiment will be described with reference to the drawings. FIGS. 1-10 is a figure explaining the lens measuring device which concerns on this embodiment. In the present embodiment, the depth direction (front-rear direction) of the lens measuring apparatus is the Z direction, the horizontal direction (left-right direction) on the plane perpendicular to the depth direction is the X direction, and the vertical direction (up-down direction on the plane perpendicular to the depth direction). (Direction) is described as the Y direction. In addition, the parallel state in this embodiment includes a completely parallel state and a substantially parallel state. In addition, the items classified by <> below can be used independently or in association with each other.

  For example, the lens measurement device (for example, the lens measurement device 1) in the present embodiment measures the optical characteristics of the lens (for example, the test lens LE). For example, the lens measurement device 1 may be any device having a measurement optical system (for example, the measurement optical system 10) for measuring the optical characteristics of the lens. That is, the lens measuring device is a lens meter that measures the optical characteristics of the test lens by projecting the measurement light onto the test lens and receiving the measurement light that has passed through the test lens with the light receiving element. Good. Further, the lens measuring device projects the measurement light onto the test lens, and receives the measurement light that has passed through the test lens by the light receiving element, based on the measurement result of the test lens. A cup mounting device that determines a mounting position of a cup for processing may be used.

  For example, the measurement optical system projects measurement light onto a lens, and receives the measurement light that has passed through the lens and the indicator plate (for example, the indicator plate 14) with a light receiving element (for example, the light receiving element 11). It may be configured to measure the optical characteristics of the lens. For example, such a measurement optical system may include a light receiving element, a diaphragm (for example, the diaphragm 12), a condenser lens (for example, the condenser lens 13), an indicator plate, an irradiation unit (for example, the light source 15), and the like. .

  For example, the indicator plate may have a second indicator pattern (for example, the second indicator pattern M2). For example, the second index pattern only needs to be able to grasp the position coordinates on the index plate, and various shapes can be applied. For example, the second index pattern may be composed of a large number of lines. For example, the second index pattern may be a lattice shape, a radial shape, a concentric shape, or the like. Further, for example, the second index patterns may be arranged at regular intervals or may be arranged at non-uniform intervals.

  For example, the second index pattern may be formed on the index plate by a technique such as photolithography, coating treatment, printing, or the like. These methods may be used to form the second index pattern, or may be used to form portions other than the second index pattern. Further, for example, the second index pattern may be formed on the index plate by arranging holes such as circular holes, square holes, and slit holes. For example, this makes it possible to form the second index pattern on the measurement light emitted by the irradiation means.

  For example, the irradiation unit forms a first index pattern (for example, the first index pattern M1), and irradiates the lens with the first index pattern as the first irradiation pattern. Further, for example, the irradiation unit irradiates the lens with a second irradiation pattern that does not form the first index pattern. For example, the irradiation unit may be configured to be able to irradiate the lens with measurement light by switching between a first irradiation pattern and a second irradiation pattern. For example, as such an irradiation means, an LCD, an organic EL display, a plasma display, or the like can be used. For example, it may be switched whether or not the first index pattern is formed by controlling the display screen in these displays. Thus, the first index pattern can be formed on the measurement light emitted from the irradiation unit.

  The irradiating means is not limited to the above-described display as long as the first index pattern can be formed on the lens. For example, the structure using light sources, such as LED, and the pattern formation board which has a 1st parameter | index pattern may be sufficient. In this case, the pattern forming plate may be an indicator plate or a screen. For example, the first index pattern may be formed on the lens by irradiating measurement light from the light source toward the pattern forming plate.

  For example, the first index pattern only needs to be able to grasp the position coordinates on the irradiation unit, and various shapes can be applied. For example, the first index pattern may be composed of a large number of points. Further, for example, the first index pattern may have a lattice shape, a radial shape, a concentric shape, or the like. Further, for example, the first index patterns may be arranged at equal intervals or may be arranged at non-equal intervals.

  In the lens measurement device according to the present embodiment, the first index pattern and the second index pattern are configured in different shapes, but the first index pattern and the second index pattern may be configured in the same shape. Good.

<Acquisition of optical characteristics>
For example, the control unit (for example, the control unit 60) irradiates the lens with the first irradiation pattern by the irradiation unit, and receives the first irradiation pattern via the indicator plate by the light receiving element, so that the first index pattern and the first A first image (for example, the first image P1) of the lens including the two index patterns may be acquired. In addition, for example, the control unit irradiates the lens with the second irradiation pattern by the irradiation unit, and receives the second irradiation pattern via the indicator plate by the light receiving element, whereby the second image of the lens including the second index pattern. (For example, the second image P2) may be acquired.

  Further, for example, the calculation unit (for example, the control unit 60) acquires lens information of the lens by processing the first image and the second image. For example, in this case, the calculation means acquires the optical characteristics of the lens as lens information. For example, the optical characteristics of the lens may be spherical power S, columnar power C, astigmatic axis angle A, prism amount Δ, and the like.

  For example, the lens measuring apparatus can acquire two lens images irradiated with the index patterns placed at different positions without moving the index plate or the lens by having such a configuration. These can be used to accurately acquire the optical characteristics of the lens.

  Note that, for example, the lens measurement device processes the first image and the second image to obtain a third image (for example, the third image P3) of the first index pattern (for example, the control unit 60). May be provided. In this case, the acquisition unit may acquire the third image by performing a difference process between the first image and the second image. For example, as the difference processing, a luminance value may be detected from each pixel position of the first image and the second image, and these values may be divided. Further, for example, as the difference processing, a luminance value may be detected from each pixel position of the first image and the second image, and these values may be subtracted. The lens measurement device may be configured to perform processing capable of extracting different portions in the first image and the second image, and is not limited to difference processing. Further, what is detected from the pixel position may be saturation, hue, or the like, and is not limited to the luminance value. Accordingly, it is possible to easily obtain a third image in which only the first index pattern is removed by removing the second index pattern that is included in common in the first image and the second image.

  For example, the calculation unit acquires lens information of the lens based on the second image and the third image. In this case, the calculation means may perform the ray tracing process based on the second image and the third image. This makes it possible to know through which position of the irradiation means and the indicator plate the measurement light emitted from the irradiation means toward the lens has reached the lens. For example, since the distance from the light source to the index plate is known, this distance and the position coordinates obtained by the ray tracing process (the position coordinates on the light source from which the measurement light is emitted and the index plate on which the measurement light has passed) Position coordinates), the angle at which the light beam is refracted can be obtained where the distance from the lens mounting table to the lens back surface is not affected. Thereby, the optical characteristic of the lens can be calculated with high accuracy using the angle at which the light beam is refracted.

<Detection of hidden marks>
For example, the lens measurement device according to the present embodiment may include a configuration for detecting a hidden mark (for example, the hidden mark 50) applied to the lens as lens information of the lens. For example, in this case, the irradiation unit may be able to form at least one index pattern (for example, an index pattern M3) different from the first index pattern. For example, the at least one index pattern different from the first index pattern may be an index pattern composed of two images with different brightness. In this case, for example, a regular pattern such as a striped pattern or a lattice pattern may be used. Of course, an irregular pattern may be used.

  For example, the control unit may irradiate the lens with a plurality of index patterns formed by the irradiation unit. For example, the control unit may acquire a plurality of images of a lens including a plurality of index patterns. For example, the calculation means may acquire a hidden mark of the lens as lens information based on a plurality of images of the lens. For example, with a lens measurement device having such a configuration, it is possible to acquire a hidden mark of a lens satisfactorily.

  For example, the lens measuring apparatus may include a driving unit (for example, the driving unit 16) that moves the indicator plate in the optical path of the measurement light. For example, when acquiring the optical characteristics of the lens, the second index pattern is formed on the measurement light by the index plate. However, when the hidden mark of the lens is detected, the second index pattern is not formed on the measurement light. May be. For example, by providing such a configuration, when irradiating an index pattern different from the first index pattern, the index plate is disposed outside the optical path of the measurement light, and the second index pattern formed by the index plate is Can be excluded. Therefore, only a plurality of index patterns can be projected onto the lens, and lens information such as hidden marks can be detected with high accuracy.

  For example, the second indicator pattern may be formed entirely on the indicator plate or may be partially formed. For example, when the second index pattern is formed on the entire surface of the index plate, the second index pattern can be projected on the entire lens. For this reason, for example, the lens measurement apparatus may switch the first irradiation pattern and the second irradiation pattern to irradiate the lens, and acquire optical characteristics at an arbitrary point of the lens. Further, for example, the lens measurement device may switch the first irradiation pattern and the second irradiation pattern to irradiate the lens, and acquire the optical characteristics of the entire lens. In this case, the optical characteristics of the lens may be shown as a distribution.

  For example, when the second index pattern is formed on a part of the index plate, the second index pattern can be projected onto a part of the lens. For example, the part of the lens may be a region between one hidden mark and the other hidden mark applied to the lens and including a distance point and a near point of the lens. . Accordingly, for example, the lens measurement apparatus may acquire the optical characteristics from the distance point to the near point of the lens by switching the first irradiation pattern and the second irradiation pattern and irradiating the lens. Further, for example, the lens measuring device may acquire the hidden mark with high accuracy by irradiating the lens with an index pattern different from the first index pattern without moving the index plate. Of course, even when the second index pattern is projected onto a part of the lens, the index plate may be moved when detecting the hidden mark.

<Example>
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. For example, the lens measurement device 1 projects a measurement light onto a test lens, and receives a measurement light that has passed through the test lens with a light receiving element, thereby measuring a lens meter including a measurement optical system that measures the test lens. It may be. In addition, for example, the lens measurement device projects measurement light onto the test lens, receives the measurement light that has passed through the test lens with a light receiving element, obtains the measurement result of the test lens, and A cup mounting device that determines a mounting position of a cup for processing may be used. In the present embodiment, as a lens measuring device, a cup mounting device for measuring a lens to be tested and mounting a cup will be described as an example.

  FIG. 1 is an external view of a lens measuring apparatus 1 according to the present embodiment. For example, the lens measuring device 1 includes a display (monitor) 2, an input switch 3, a lens mounting table 6, a spectacle frame shape measuring unit 7, a cup mounting mechanism 8, and the like. The lens measuring device 1 includes a measuring optical system 10 therein (details will be described later).

  For example, an LCD (Liquid Crystal Display) is used for the display 2. In addition, as a display 2, the structure using an organic EL (Electro Luminescence) display, a plasma display, etc. may be sufficient, and it is not limited to a present Example.

  For example, the display 2 is a touch panel. That is, in the present embodiment, the display 2 functions as an operation unit (controller). For example, a signal corresponding to an operation instruction input from the display 2 is output to a control unit 60 (see FIG. 7) described later. In addition, the display 2 may not be a touch panel type, and the structure which provides the display 2 and the operation part separately may be sufficient. For example, in this case, at least one of a mouse, a joystick, a keyboard, a portable terminal, and the like can be used as the operation unit.

  For example, the display 2 may be a display mounted on the lens measurement device 1. The display 2 may be a display connected to the lens measuring device 1. For example, in this case, a display using a personal computer may be used. The display 2 may be configured to use a plurality of displays together.

  For example, lens information or the like is displayed on the display 2. For example, the lens information includes the optical characteristics (for example, the spherical power S, the columnar power C, the astigmatic axis angle A, the prism amount Δ, etc.) and the optical characteristic distribution, the outer shape of the test lens LE, the target lens LE. These are the hidden mark of the test lens LE, the print mark of the test lens LE, the markings attached to the test lens LE, the outer shape of the cup fixed to the test lens LE, and the like.

  For example, the input switch 3 is used when inputting a signal for causing the lens measuring apparatus 1 to execute various processes. For example, various types of processing include measurement mode switching, determination of processing conditions for the lens LE to be measured, and the like. For example, in this embodiment, the input switch 3 is electronically displayed on the screen of the display 2. That is, the input switch 3 can be operated by touching the screen of the display 2. The input switch 3 may be configured to be installed on the main body cover 4, the display cover 5, and the like, and is not limited to the present embodiment.

  For example, the lens mounting table 6 is a table for mounting the test lens LE. For example, in this embodiment, the test lens LE is placed with the convex surface (front surface) facing upward. The test lens LE may be placed with the concave surface (rear surface) facing upward. For example, the lens mounting table 6 may be formed of a transparent member such as a glass plate, a plastic plate, or an acrylic plate.

  For example, the spectacle frame shape measurement unit 7 is used when tracing the shape of the spectacle frame. For example, by using the spectacle frame shape measuring unit 7, the lens shape of the lens to be framed in the spectacle frame can be acquired. For details of the configuration of the spectacle frame shape measuring unit 7 and the spectacle frame shape tracing method using the spectacle frame shape measuring unit 7, refer to Japanese Patent Laid-Open No. 2015-007536.

  For example, the cup attachment mechanism 8 is for fixing (shaking) a cup to the lens LE to be examined. For example, in the present embodiment, a cup is fixed to the front surface of the lens LE to be tested. Of course, a configuration may be adopted in which the cup is fixed to the rear surface of the lens LE to be examined. For details of the cup mounting mechanism 8, refer to Japanese Patent Application Laid-Open No. 2007-268700.

  FIG. 2 is a diagram showing an optical system in the lens measuring apparatus 1. For example, the measurement optical system 10 includes a light receiving element 11, a diaphragm 12, a condenser lens 13, an indicator plate 14, a light source 15, and the like. In addition, about arrangement | positioning of each member with which the measurement optical system 10 is provided, it is not limited to a present Example. For example, the indicator plate 14 may be configured to be disposed between the test lens LE and the condenser lens 13.

  For example, the light receiving element 11 receives measurement light that has passed through the test lens LE and the indicator plate 14. As a result, the light receiving element 11 can capture a first image P1 and a second image P2 (see FIG. 6) of the lens LE to be described later. For example, as the light receiving element 11, a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), or the like can be used. For example, the diaphragm 12 is disposed at the focal length of the condenser lens 13. For example, the condenser lens 13 condenses the measurement light parallel to the optical axis L <b> 1 among the measurement light irradiated from the light source 15 and passed through the test lens LE at the position of the diaphragm 12.

  For example, the measurement light emitted from the light source 15 diffuses in various directions (directions of arrows indicated by a dotted line and a solid line in FIG. 2), but depending on the angle at which the measurement light is incident on the test lens LE, the arrow indicated by the solid line As shown, the measurement light is refracted parallel to the optical axis L1. Of course, depending on the angle at which the measurement light is incident on the test lens LE, the measurement light may not be refracted parallel to the optical axis L1 as indicated by the dotted line. For example, in this embodiment, of the measurement light refracted by the lens LE to be measured, the measurement light refracted parallel (or substantially parallel) to the optical axis L1 (that is, measurement light indicated by a solid line) is a condenser lens. 13 and the diaphragm 12 reach the light receiving element 11. For example, among the measurement light refracted by the lens LE, measurement light that is not refracted parallel to the optical axis L1 (that is, measurement light indicated by a dotted line) enters the condenser lens 13 and is refracted. Incidence to the light receiving element 11 is suppressed by the diaphragm 11.

<Indicator plate>
FIG. 3 is a view showing the indicator plate 14. For example, the indicator plate 14 forms the second indicator pattern M2. For example, the second index pattern M2 may be formed on the index plate 14 using a photolithography technique. Further, for example, the second index pattern M2 may be formed by coating the index plate 14. In this case, techniques such as immersion, vapor deposition, and painting can be used. Further, for example, the second index pattern M2 may be formed by printing the index plate 14 such as silk printing. Further, for example, the second index pattern M2 may be formed by arranging holes such as a circular hole, a square hole, and a slit hole in the index plate 14.

  For example, the second index pattern M2 includes a reference index pattern M2a and a peripheral index pattern M2b. For example, the reference index pattern M2a in the present embodiment is a quadrangular point arranged in the center of the index plate 14. Of course, the reference index pattern M2a is not limited to a rectangular shape, but may be a point such as a circular shape or a triangular shape. Further, the reference index pattern M2a is not limited to the center of the index plate 14, and may be disposed at any position on the index plate. Further, the number of the reference index patterns M2a is not limited to one, and any number may be arranged on the index plate 14.

  For example, the peripheral index pattern M2b in the present embodiment has a grid pattern shape in which vertical lines and horizontal lines are arranged at equal intervals. Of course, the peripheral index pattern M2b may have a shape such as a vertical grid, a horizontal grid, or a cross grid. For example, the peripheral index pattern M2b is not limited to a line such as a vertical line or a horizontal line, but may be a shape in which circles, dots, or the like are arranged. Further, for example, the peripheral index pattern M2b is not limited to the lattice shape, and may be a radial shape, a concentric circular shape, or the like. In the present embodiment, the case where the peripheral index patterns M2b are arranged at equal intervals is described as an example, but they may be arranged at non-equal intervals.

  For example, the presence of the reference index pattern M2a makes it easy to grasp the positional relationship between the intersection points of the respective grids in the peripheral index pattern M2b. More specifically, an intersection of a grid having a peripheral index pattern M2b photographed in the 0D reference state, which will be described later, is a lattice point of the peripheral index pattern M2b photographed in a state where the test lens LE is placed on the lens mounting table 6. Which of the intersection points can be specified.

  For example, the indicator plate 14 has the second indicator pattern M2 as described above, so that the second indicator pattern can be formed in the measurement light emitted from the light source 15.

  For example, the lens measuring apparatus 1 in the present embodiment may include a drive mechanism 16 (see FIG. 2) for moving the indicator plate 14 in the optical path of the measurement light. For example, the drive mechanism 16 includes a motor 16a, a gear 16b, and a support portion 16c. For example, the support portion 16 c is coupled to a part of the indicator plate 14. Further, the support portion 16c has a gear portion that meshes with the gear 16b. For example, the motor 16a is connected to the gear 16b. For example, when the motor 16a is driven, the gear 16b rotates and the indicator plate 14 slides in the direction of the arrow. As a result, the indicator plate 14 can be inserted into and removed from the optical path of the measurement light from the light source 15. For example, if the indicator plate 14 is provided with a portion having the second indicator pattern and a portion having no second indicator pattern, the indicator plate 14 is slid by the drive mechanism 16 to change the portion located in the optical path of the measurement light. May be. For example, in this embodiment, by moving the index plate 14 in this way, the second index pattern formed by the measurement light passing through the index plate 14 is projected onto the test lens LE, and the test It is possible to switch between the case of not projecting on the lens LE.

<Light source>
For example, the light source 15 irradiates the measurement lens LE with measurement light. For example, as the light source 15, an LCD, an organic EL display, a plasma display, or the like can be used. In this embodiment, the case where an LCD is used as the light source 15 will be described as an example.

  FIG. 4 is a diagram for explaining the light source 15. FIG. 4A shows the light source 15 displaying the first index pattern M1. FIG. 4B shows the light source 15 that does not display the first index pattern M1. FIG. 4C shows the light source 15 displaying an index pattern different from the first index pattern. For example, the light source 15 displays the background image W and the first index pattern (first index pattern image) M1. For example, as the background image W, a white background image is used. Of course, the background image may be different from the present embodiment and is not limited to a white background.

  For example, the first index pattern M1 includes a reference index pattern M1a and a peripheral index pattern M1b. For example, the reference index pattern M <b> 1 a in the present embodiment is a circular point arranged at the center of the light source 15. Of course, the reference index pattern M1a is not limited to a circular shape, but may be a point such as a square shape or a triangular shape. Further, the reference index pattern M1a is not limited to the center of the light source 15, and may be disposed at any position of the light source 15. Further, the number of reference index patterns M1a is not limited to one, and any number may be arranged on the light source 15. The number, shape, position, size, and the like of the reference index pattern M1a are not limited as long as it can be distinguished from many points in the peripheral index pattern M1b described later.

  For example, in the peripheral index pattern M1b in this embodiment, a large number of points are arranged at equal intervals. Of course, the peripheral index pattern M1b is not limited to a large number of points, and lines such as vertical lines and horizontal lines, circles, and the like may be arranged. Further, for example, the peripheral index pattern M1b may have a large number of points arranged in a radial shape, a concentric circular shape, or the like. In the present embodiment, the case where a large number of points are arranged at equal intervals in the peripheral index pattern M1b is described as an example, but may be arranged at non-equal intervals.

  For example, the presence of the reference index pattern M1a makes it easy to grasp the positional relationship between a large number of points in the peripheral index pattern M1b. More specifically, a point on the peripheral index pattern M1b photographed in the 0D reference state, which will be described later, is a point on the peripheral index pattern M1b photographed in a state where the lens LE is mounted on the lens mounting table 6. It is possible to identify whether this is the case.

  For example, as shown in FIG. 4A, the light source 15 emits measurement light of a first irradiation pattern that displays a background image W and a first index pattern M1. For example, the first irradiation pattern is an irradiation pattern including the background image W and the first index pattern M1, and thereby the first index pattern is formed in the measurement light. Further, for example, as shown in FIG. 4B, the light source 15 emits measurement light of the second irradiation pattern that displays the background image W and does not display the first index pattern M1. For example, the second irradiation pattern is an irradiation pattern including only the background image W, and the first index pattern is not formed in the measurement light. In other words, the light source 15 changes the screen display to switch between the first irradiation pattern in which the first index pattern is formed and the second irradiation pattern in which the first index pattern is not formed, and applies it to the lens LE. Measurement light can be irradiated.

  For example, the light source 15 may have a configuration capable of displaying an index pattern M3 different from the first index pattern M1, as shown in FIG. For example, as such an index pattern, the light source 15 displays an index pattern M3 such as a striped pattern or a lattice pattern (for example, a checkered pattern). Thereby, at least one index pattern different from the first index pattern can be formed in the measurement light.

<Test lens image received by light receiving element>
For example, in this embodiment, when the first index pattern M1 is displayed on the light source 15 and when the first index pattern M1 is not displayed, the irradiation pattern emitted from the light source 15 (that is, the first irradiation pattern and Since the second irradiation pattern is different, the index pattern projected on the test lens LE changes.

  Here, first, a state where the test lens LE is not mounted on the lens mounting table 6 (hereinafter referred to as 0D reference state) will be described. FIG. 5 is an example of an image received by the light receiving element 11 in the 0D reference state. FIG. 5A shows an image 20 of the first index pattern M1 and the second index pattern M2. FIG. 5B shows an image 30 of the second index pattern M2. FIG. 5C shows an image 40 of the first index pattern M1. For example, in the present embodiment, an example is given in which each point of the first index pattern M1 and the intersection of the lattice of the second index pattern M2 are arranged at the same interval. Of course, the distance between each point of the first index pattern M1 and the intersection of the grid of the second index pattern M2 may be different, and is not limited to the present embodiment.

  For example, when the first index pattern M1 is displayed on the light source 15, the light source 15 emits the measurement light on which the first index pattern is formed as the first irradiation pattern. At this time, since the measurement light passes through the indicator plate 14, a second indicator pattern is further formed in the measurement light. For example, in the 0D reference state, the measurement light emitted from the light source 15 is not refracted by the test lens LE. For this reason, the light receiving element 11 receives the measurement light of the first irradiation pattern, whereby each point of the first index pattern M1 and the intersection of each lattice of the second index pattern M2 match each other. An image 20 of the index pattern M1 and the second index pattern M2 is acquired. For example, in such an image 20, the coordinates (for example, pixel coordinates) in the XZ direction at each point of the first index pattern M1 and the intersection of each grid of the second index pattern M2 are the same. ing.

  For example, when only the background image W is displayed on the light source 15, the light source 15 emits measurement light that does not form the first index pattern as the second irradiation pattern. At this time, the measurement light forms a second index pattern via the index plate 14. For example, in the 0D reference state, the light receiving element 11 acquires the image 30 of the second index pattern M2 by irradiating the measurement light of the second irradiation pattern from the light source 15. The second index pattern M2 in the image 30 and the second index pattern M2 in the image 20 described above have the same coordinate in the XZ direction.

  For example, the control unit 60 to be described later stores the image 30 when the measurement light of the second irradiation pattern is irradiated in the 0D reference state in the memory 75 to be described later as the reference image S2 of the second index pattern M2. For example, by this, the XZ coordinates of the intersection of each grid in the reference image S2 are stored in advance. In addition, for example, the control unit 60 described later performs image processing on the image 20 when the measurement light of the first irradiation pattern is irradiated in the 0D reference state and the image 30 when the measurement light of the second irradiation pattern is irradiated. The image 40 of the first index pattern acquired by doing so is stored in the memory 75 as the reference image S3 of the first index pattern. For example, the XZ coordinates of each point in the reference image S3 are stored in advance. As the image processing, the control unit 60 to be described later can compare the image 20 and the image 30, and details thereof will be described later.

  Next, a state where the test lens LE is mounted on the lens mounting table 6 will be described. FIG. 6 is an example of an image received by the light receiving element 11 in a state where the test lens LE is placed. FIG. 6A is a first image P1 of the test lens LE including the first index pattern M1 and the second index pattern M2 when the measurement light of the first irradiation pattern is irradiated. FIG. 6B is a second image P2 of the test lens LE including the second index pattern M2 when the measurement light of the second irradiation pattern is irradiated. FIG. 6C shows a third image P3 of the test lens LE including the first index pattern M1 obtained by comparing the first image P1 and the second image P2.

  For example, the first index pattern M1 is displayed on the light source 15, and the measurement light from the light source 15 is irradiated on the lens LE as the first irradiation pattern. In this case, as described above, since the first index pattern and the second index pattern are formed in the measurement light of the first irradiation pattern, the first index pattern is formed on the lens LE irradiated with the first irradiation pattern. M1 and the second index pattern M2 are projected. For example, the light receiving element 11 receives the measurement light of the first irradiation pattern that has passed through the test lens LE, so that the first image P1 of the test lens LE including the first index pattern M1 and the second index pattern M2 is received. get. For example, the outer shape 80 of the test lens LE is reflected in the first image P1.

  Note that the measurement optical system 10 in the present embodiment has a distance from the first index pattern M1 displayed on the light source 15 to the lens to be examined LE and a distance from the second index pattern M2 of the index plate 14 to the lens to be examined LE. Since the distance is different, the influence of the refraction that the measurement light forming the respective index patterns receives by the lens LE is also different. That is, since the light source 15 is farther from the test lens LE than the index plate 14, the first index pattern M1 is refracted to the test lens LE more than the second index pattern M2. For this reason, in the state where the test lens LE is mounted on the lens mounting table 6, the size of the first index pattern and the second index pattern is enlarged or reduced, and each point of the first index pattern M1 A first image P1 is obtained that is shifted from the intersection of each grid of the index pattern M2.

  More specifically, for example, when the test lens LE is a minus lens, a first image P1 in which the first index pattern M1 and the second index pattern M2 are reduced as compared with the image 20 in the 0D reference state is obtained. However, the first index pattern M1 is the first image P1 positioned inside the second index pattern M2. Further, for example, when the test lens LE is a plus lens, the first image P1 in which the first index pattern M1 and the second index pattern M2 are enlarged as compared with the image 20 in the 0D reference state is obtained. The second index pattern M2 is the first image P1 positioned inside the first index pattern M1.

  For example, only the background image W is displayed on the light source 15, and the measurement light from the light source 15 is irradiated to the lens LE as the second irradiation pattern. In this case, as described above, since only the second index pattern is formed in the measurement light of the second irradiation pattern, the second index pattern M2 is projected onto the lens LE irradiated with the second irradiation pattern. The For example, the light receiving element 11 receives the measurement light of the second irradiation pattern that has passed through the test lens LE, thereby acquiring the second image P2 of the test lens LE including the second index pattern M2. For example, the outer shape 80 of the test lens LE is also reflected in such a second image P2. Note that the second index pattern M2 in the second image P2 and the second index pattern M2 in the first image P1 have the same coordinates in the XZ direction.

  For example, the control unit 60 described later has the first image P1 and the measurement light of the second irradiation pattern when the measurement light of the first irradiation pattern is irradiated in a state where the lens LE to be tested is mounted on the lens mounting table 6. The third image P3 on which only the first index pattern is formed is obtained by performing image processing on the second image P2 at the time of irradiation. As the image processing, the first image P1 and the second image P2 may be compared as in the case of the reference image S3, and details thereof will be described later.

<Control unit>
FIG. 7 is a diagram showing a control system in the lens measuring apparatus 1. For example, the display 2, the input switch 3, the light receiving element 11, the light source 15, the motor 16 a included in the drive mechanism 16, the storage unit (memory) 75, and the like are connected to the control unit 60. In addition, for example, the controller 60 is connected to a motor, a drive mechanism, and the like (not shown) that the spectacle frame shape measurement unit 7 and the cup attachment mechanism 8 have.

  For example, the control unit 60 includes a CPU (processor), a RAM, a ROM, and the like. For example, the CPU controls driving of each member in the lens measuring device 1. Further, for example, the CPU of the control unit 60 performs various types of calculation processing (for example, calculation of lens information based on the second image P2 and the third image P3). For example, the RAM temporarily stores various information. For example, the ROM stores a program executed by the CPU. The control unit 60 may be configured by a plurality of control units (that is, a plurality of processors).

  For example, the memory 75 is a non-transitory storage medium that can retain stored contents even when power supply is interrupted. For example, as the memory 75, a hard disk drive, a flash ROM, a USB memory that is detachably attached to the lens measuring apparatus 1, and the like can be used. For example, the memory 75 stores the reference image S2 and the reference image S3 in the 0D reference state, the position coordinates of the index pattern in the reference image, the first image P1, the second image P2, and the like.

<Control action>
The control operation of the lens measuring apparatus 1 having the above configuration will be described. For example, the lens measurement device 1 in the present embodiment includes a first measurement mode and a second measurement mode. For example, the first measurement mode is a mode for acquiring optical characteristics as lens information of the test lens LE. For example, the second measurement mode is a mode for detecting a hidden mark as lens information of the test lens LE. Of course, the lens measuring apparatus 1 can acquire lens information such as the outer shape of the test lens LE, the mark, and the print mark in addition to the optical characteristics of the test lens LE and the hidden mark. The explanation is omitted in the example.

<First measurement mode>
Hereinafter, the first measurement mode will be described in detail. For example, the operator places the test lens LE on the lens placing table 6 and selects a start button (not shown) for starting the first measurement mode from the input switch 3 displayed on the display 2. For example, the control unit 60 causes the light source 15 to display the background image W and the first index pattern M1, and irradiates the test lens LE with the measurement light of the first irradiation pattern that forms the first index pattern. For example, the light receiving element 11 receives the measurement light of such a first irradiation pattern, whereby the first image P1 of the test lens LE including the first index pattern M1 and the second index pattern M2 (FIG. 6A). ) See).

  For example, when the light receiving element 11 acquires the first image P1, the control unit 60 outputs a signal indicating that the first image P1 has been acquired. For example, when the light receiving element 11 acquires the first image P <b> 1, the control unit 60 stores the first image P <b> 1 in the memory 75.

  For example, when a signal indicating that the first image P1 has been acquired is output, the control unit 60 displays only the background image W on the light source 15 and emits measurement light of the second irradiation pattern that does not form the first index pattern. Irradiate the lens LE. For example, the light receiving element 11 acquires the second image P2 (FIG. 6B) of the test lens LE including the second index pattern M2 by receiving the measurement light of the second irradiation pattern. For example, when the light receiving element 11 acquires the second image P <b> 2, the control unit 60 stores the second image P <b> 2 in the memory 75.

  For example, the control unit 60 performs image processing on the first image P1 and the second image P2, thereby obtaining a third image P3 (see FIG. 6C) of the test lens LE including only the first index pattern M1. To do. For example, as the image processing, the first image P1 and the second image P2 are compared. In this case, the first image P1 and the second image P2 may be subjected to differential processing. As the difference processing, processing such as division and subtraction can be performed. In the present embodiment, the case of performing division will be described as an example.

  For example, the control unit 60 detects the luminance value for each pixel position in the first image P1. Further, for example, the control unit 60 detects the luminance value for each pixel position in the second image P2. Next, the control unit 60 divides the luminance value at the predetermined pixel position of the first image P1 by the luminance value at the predetermined pixel position of the second image P2. For example, when division processing is performed at all pixel positions and luminance values are set based on the respective division values, portions having different luminance values are emphasized in the first image P1 and the second image P2. For example, the control unit 60 thus acquires the third image P3 of the test lens LE including only the first index pattern M1.

  For example, the control unit 60 may set the luminance value by binarizing the division value calculated at each pixel position, and may acquire the third image P3 of the lens LE to be examined. In this case, a threshold value for binarizing the division value may be set in advance by experiment, simulation, or the like. Of course, such a threshold value may be arbitrarily set, or may be set by using statistical information based on an average and standard deviation of luminance values at all pixel positions.

  For example, in this case, the control unit 60 replaces the respective luminance values at the pixel position having a division value greater than or equal to the threshold and the pixel position having a division value less than the threshold. For example, in this embodiment, the luminance value at the pixel position where the division value is equal to or greater than the threshold value is replaced with 255 (white). Further, for example, in this embodiment, the luminance value at the pixel position where the division value is less than the threshold value is replaced with 0 (black). Note that the luminance value is not limited to the above-described luminance value as long as two different values are used with the threshold as a boundary.

  For example, since the outer shape 80 of the test lens LE is reflected in the first image P1 and the second image P2, the third image P3 may include the outer shape 80 of the test lens LE. By binarizing, the third image P3 excluding the outer shape 80 of the test lens LE may be acquired.

  For example, the control unit 60 acquires lens information of the test lens LE based on the second image P2 and the third image P3. For example, when acquiring lens information, a ray tracing process is performed based on the second image P2 and the third image P3. Hereinafter, the ray tracing process will be described with reference to FIGS. FIG. 8 is a diagram showing the relationship between the reference image and the image of the lens LE to be examined. FIG. 8A shows the relationship between the reference image S2 and the second image P2 of the test lens LE. FIG. 8B shows the relationship between the reference image S3 and the third image P3 of the test lens LE. FIG. 9 is a diagram for explaining light rays received by the light receiving element 11. For example, FIG. 9 illustrates only the light rays R1 and R2 that are refracted by the test lens LE and become parallel to the optical axis L1 after being radiated from the light source 15 toward the test lens LE. ing. In FIG. 9, for convenience, the position where the light rays R1 and R2 are refracted by the test lens LE will be described as the front surface of the test lens LE.

  First, the control unit 60 determines the positions where the light rays R1 and R2 pass through the indicator plate 14 (that is, the positions xa1 and xa2 in FIG. 9) and the positions where the light rays R1 and R2 are emitted from the light source 15 (that is, In order to obtain the position xb1 and the position xb2 in FIG. 9, any two points (for example, the arbitrary point X1 and the arbitrary point X2 in FIGS. 8 and 9) are selected in the reference image S2 and the reference image S3. . For example, in this embodiment, the intersection of the grid of the second index pattern M2 in the reference image S2 and each point of the first index pattern M1 in the reference image S3 match. That is, the position coordinates of the arbitrary points X1 and X2 on the reference image S2 and the arbitrary points X1 and X2 on the reference image S3 are the same. It should be noted that the position coordinates (for example, the arbitrary point X1 of the position coordinates (1, 5) shown in FIG. 8A) on the reference image S2 are the pixels (for example, the pixel coordinates) of the intersection of the grid of the second index pattern. ) Is stored in the memory 75 in advance. Further, which pixel the position coordinate of each point of the first index pattern (for example, the arbitrary point X1 of the position coordinate (1, 5) shown in FIG. 8B) corresponds to on the reference image S3 is: Stored in the memory 75 in advance.

  For example, the control unit 60 determines where the arbitrary points X1 and X2 on the reference image S2 in the 0D reference state have moved on the second image P2 by mounting the test lens LE on the lens mounting table 6. To detect. At this time, the second index pattern M2 in the second image P2 expands or contracts more than the second index pattern M2 in the 0D reference state, but the control unit 60 uses any of the expanded or contracted second index patterns M2 The position coordinates of the points X1 and X2 are obtained. For example, when an arbitrary point X1 having a position coordinate (1, 5) is selected in the reference image S2 shown in FIG. 8A, the arbitrary point X1 has a position coordinate (0.5, 5.4). Similarly, for example, when an arbitrary point X2 whose position coordinates are (2, 4) in the reference image S2 shown in FIG. 8A is selected, this arbitrary point X2 has a position coordinate (1) in the second image P2. .7, 4.2).

  For example, the control unit 60 can detect the position xa1 where the light ray R1 has passed through the indicator plate 14 by obtaining the position coordinates of the arbitrary point X1 on the second image P2. Further, for example, the control unit 60 can detect the position xa2 where the light ray R2 has passed through the indicator plate 14 by obtaining the position coordinates of the arbitrary point X2 on the second image P2 in this way.

  In addition, for example, the control unit 60 performs the third image by placing the test lens LE on the lens mounting table 6 at arbitrary points X1 and X2 on the reference image S3 in the 0D reference state in the same manner as described above. It detects where it moved on P3. For example, when an arbitrary point X1 having a position coordinate (1, 5) is selected in the reference image S3 shown in FIG. 8B, the arbitrary point X1 has a position coordinate (0.2, 5.6). Similarly, for example, when an arbitrary point X2 whose position coordinates are (2, 4) in the reference image S3 shown in FIG. 8B is selected, this arbitrary point X2 has a position coordinate (1) in the third image P3. .5, 4).

  For example, the control unit 60 can detect the position xb1 at which the light ray R1 is emitted from the light source 15 by obtaining the position coordinates of the arbitrary point X1 on the third image P3 in this way. For example, the control unit 60 can detect the position xb2 at which the light ray R2 is emitted from the light source 15 by obtaining the position coordinates of the arbitrary point X2 on the third image P3 in this way.

  For example, by performing the ray tracing process based on the second image P2 and the third image P3 as described above, the ray R1 is emitted from the position xb1 in the light source 15, passes through the position xa1 in the indicator plate 14, It can be seen that the position X1 of the test lens LE has been reached. Further, for example, it can be seen that the light ray R2 is emitted from the position xb2 in the light source 15, passes through the position xa2 in the indicator plate 14, and reaches the position X2 of the lens LE to be measured.

  Next, the control unit 60 calculates the angles (that is, the irradiation angle θ1 and the irradiation angle θ2) of the light rays R1 and R2 irradiated toward the lens LE. For example, the irradiation angle θ1 of the light ray R1 includes a distance ΔB from the light source 15 to the indicator plate 14, a position coordinate xb1 at which the light ray R1 is emitted from the light source 15, a position coordinate xa1 at which the light ray R1 passes through the indicator plate 14, Can be obtained by the following mathematical formula.

また、例えば、光線Ｒ２の照射角度θ２は、光源１５から指標板１４までの距離ΔＢと、光線Ｒ２が光源１５から照射された位置座標ｘｂ２と、光線Ｒ２が指標板１４を通過した位置座標ｘａ２と、を用いて以下の数式により求めることができる。

Further, for example, the irradiation angle θ2 of the light ray R2 includes the distance ΔB from the light source 15 to the indicator plate 14, the position coordinate xb2 at which the light ray R2 is emitted from the light source 15, and the position coordinate xa2 at which the light ray R2 has passed through the indicator plate 14. And can be obtained by the following mathematical formula.

例えば、これによって、制御部６０は、光線Ｒ１の照射角度θ１と、光線Ｒ２の照射角度θ２と、を求めることができる。次いで、制御部６０は、任意の点Ｘ１及びＸ２の位置から求められる焦点距離ωの位置座標と、被検レンズＬＥの光学中心Ｏの位置座標と、を求める。例えば、焦点距離ωは、光線Ｒ１及び光線Ｒ２の照射角度と、被検レンズＬＥの位置Ｘ１及び位置Ｘ２の位置座標と、を用いて、以下の数式により算出することができる。

For example, this allows the control unit 60 to obtain the irradiation angle θ1 of the light ray R1 and the irradiation angle θ2 of the light ray R2. Next, the control unit 60 obtains the position coordinates of the focal distance ω obtained from the positions of the arbitrary points X1 and X2 and the position coordinates of the optical center O of the lens LE to be measured. For example, the focal length ω can be calculated by the following formula using the irradiation angles of the light ray R1 and the light ray R2 and the position coordinates of the position X1 and the position X2 of the test lens LE.

また、被検レンズＬＥの光学中心Ｏの位置座標は、被検レンズＬＥの位置Ｘ１の位置座標と、光線Ｒ１の照射角度θ１と、焦点距離ωの位置座標と、を用いて以下の数式により算出することができる。

Further, the position coordinate of the optical center O of the test lens LE is expressed by the following equation using the position coordinate of the position X1 of the test lens LE, the irradiation angle θ1 of the light ray R1, and the position coordinate of the focal length ω. Can be calculated.

なお、本実施例においては、位置Ｘ１の位置座標と、光線Ｒ１の照射角度と、を用いて被検レンズＬＥの光学中心Ｏの位置座標を求めているが、位置Ｘ２の位置座標と、光線Ｒ２の照射角度と、を用いて被検レンズＬＥの光学中心Ｏの位置座標を求めてもよい。

In the present embodiment, the position coordinate of the optical center O of the lens LE to be measured is obtained using the position coordinate of the position X1 and the irradiation angle of the light ray R1, but the position coordinate of the position X2 and the light ray The position coordinates of the optical center O of the test lens LE may be obtained using the irradiation angle of R2.

  For example, the control unit 60 sets two points at positions separated from the optical center O of the test lens LE by a predetermined distance in a predetermined meridian direction. For example, the control unit 60 performs the ray tracing process on the two set points in the same manner as described above. For example, each meridian direction from the optical center O is set for each predetermined angle t. That is, if the angle t is 35 degrees, each meridian direction is set to 0 degrees, 35 degrees, 70 degrees, and so on. As a result, the control unit 60 sets two points at positions separated from the optical center O by a predetermined distance for each angle t (meridian direction), and obtains the position coordinates of the focal length ω at the two set points. be able to. The two points set in each meridian direction are respectively set at positions where a predetermined distance is the same distance in each meridian direction.

  Next, the control unit 60 calculates the refractive power E (t) by taking the reciprocal of the focal length ω obtained at each angle t. For example, the control unit 60 calculates the refractive power E (t) in each meridian direction. Next, for example, the control unit 60 plots the angle t on the horizontal axis and the refractive power E (t) on the vertical axis. For example, the control unit 60 obtains an approximate curve for the plotted result using the least square method. For example, the obtained approximate curve is represented by the following mathematical formula. Note that each of α, β, and γ in the mathematical expression is expressed as a constant.

例えば、制御部６０は、上記の数式に基づいて、被検レンズＬＥの光学特性（すなわち、球面度数Ｓ、柱面度数Ｃ、乱視軸角度Ａ等）を取得してもよい。また、例えば、制御部６０は、レンズ測定装置１のディスプレイ２に、被検レンズＬＥの光学特性分布をマップとして表示するようにしてもよい。

For example, the control unit 60 may acquire the optical characteristics (that is, the spherical power S, the column surface power C, the astigmatic axis angle A, and the like) of the lens LE to be tested based on the above mathematical formula. For example, the control unit 60 may display the optical characteristic distribution of the test lens LE as a map on the display 2 of the lens measuring device 1.

<Second measurement mode>
Hereinafter, the second measurement mode will be described in detail. For example, the operator places the test lens LE on the lens placing table 6 and selects a start button (not shown) for starting the second measurement mode from the input switch 3 displayed on the display 2. For example, the control unit 60 moves the indicator plate 14 out of the optical path of the measurement light. For example, the control unit 60 displays the index pattern M3 different from the background image W and the first index pattern M1 on the light source 15. As a result, the measurement light of the irradiation pattern in which the index pattern different from the first index pattern M1 is formed is irradiated on the test lens LE.

  FIG. 10 is an enlarged view showing a part of the image of the test lens LE including the index pattern M3 different from the first index pattern. FIG. 10A is an image when the position of the index pattern M3 displayed on the light source 15 is moved. FIG. 10B is an image when a plurality of images of the test lens LE are arithmetically processed. For example, in FIG. 10, the light source 15 displays the background image W and the horizontal stripe pattern index pattern M3, and irradiates the test lens LE with the horizontal stripe pattern index pattern. For example, the measurement light applied to the hidden mark 50 (or the scratch on the test lens LE) applied to the test lens LE is scattered, so that the hidden mark 50 and the horizontal stripe pattern index pattern M3 overlap. The portion is not received by the light receiving element 11 and appears to be white.

  For example, the control unit 60 controls the light source 15 to move the position at which the horizontal striped index pattern M3 is displayed. For example, in the present embodiment, the control unit 60 moves the index pattern M3 by a predetermined pixel amount in the Z direction. For example, if the index pattern is a vertical stripe pattern, the index pattern M3 may be moved by a predetermined pixel amount in the X direction. Further, for example, if the index pattern is a lattice pattern, the index pattern M3 may be moved by a predetermined pixel amount in the X direction or the Z direction, or the index pattern M3 may be moved by a predetermined pixel amount in both directions. Good. Thereby, the test lens LE is irradiated with a plurality of index patterns formed by moving the index pattern M3. For example, the light receiving element 11 acquires an image (G1 and G2 in FIG. 10A) of the test lens LE each time the position where the index pattern M3 is displayed is moved. In this embodiment, the index pattern M3 is moved so that the background image W and the horizontal striped index pattern M3 are inverted from each other in the image G1 and the image G2 of the test lens LE. The index pattern M3 may be moved by an amount.

  For example, the control unit 60 detects the luminance value at each pixel position for a plurality of images of the test lens LE acquired by the light receiving element 11. In addition, the control unit 60 calculates a luminance value at a predetermined pixel position in a plurality of images of the test lens LE. For example, when calculation processing is performed at all pixel positions, an image G3 as shown in FIG. 10B is acquired, and the entire shape of the hidden mark 50 applied to the lens LE can be detected. For example, the control unit 60 may further binarize the acquired image G3 so that the entire shape of the hidden mark 50 can be easily detected.

  As described above, for example, the lens measuring apparatus according to the present embodiment switches the first irradiation pattern in which the first index pattern is formed and the second irradiation pattern in which the first index pattern is not formed, and measures the measurement light to the lens. Irradiating means that can irradiate the measurement light, an index plate for forming the second index pattern on the measurement light, and a light receiving element that receives the measurement light via the lens and the index plate. In addition, for example, the lens measurement apparatus according to the present embodiment includes a control unit that acquires a first image of a lens including a first index pattern and a second index pattern, and a second image of a lens including a second index pattern. Computing means for acquiring lens information of the lens by processing the first image and the second image. As a result, it is possible to obtain two lens images irradiated with index patterns placed at different positions without moving the index plate or lens, and using these, the optical characteristics of the lens can be easily and accurately obtained. Can get well.

  In addition, for example, the lens measurement device according to the present exemplary embodiment can acquire the third image of the first index pattern by processing the first image and the second image. Therefore, lens information of the lens can be acquired based on the second image and the third image.

  In addition, for example, the lens measurement device according to the present embodiment performs a ray tracing process based on the second image and the third image. This makes it possible to know through which position of the light source and the indicator plate the measurement light emitted from the light source toward the lens has reached the lens. For example, since the distance from the light source to the index plate is known, this distance and the position coordinates obtained by the ray tracing process (the position coordinates on the light source from which the measurement light is emitted and the index plate on which the measurement light has passed) Position coordinates), the angle at which the light beam is refracted can be obtained where the distance from the lens mounting table to the lens back surface is not affected. Thereby, the optical characteristic of the lens can be calculated with high accuracy using the angle at which the light beam is refracted.

  In addition, for example, the lens measurement device according to the present embodiment performs difference processing between the first image and the second image. Accordingly, it is possible to easily obtain a third image in which only the first index pattern is removed by removing the second index pattern that is included in common in the first image and the second image.

  In addition, for example, the lens measuring apparatus according to the present embodiment can form at least one index pattern different from the first index pattern and irradiate the lens with a plurality of index patterns. Thereby, a plurality of images of the lens including a plurality of index patterns are acquired, and based on this, a hidden mark of the lens is detected. Therefore, the hidden mark of the lens can be acquired well as the lens information.

  In addition, for example, the lens measuring apparatus according to the present embodiment includes a driving unit that moves the indicator plate in the optical path of the measuring light. Thereby, when irradiating an index pattern different from the first index pattern, the index plate can be arranged outside the optical path of the measurement light, and the second index pattern formed by the index plate can be excluded. Therefore, only a plurality of index patterns can be projected onto the lens, and lens information such as hidden marks can be detected with high accuracy.

<Transformation example>
In the present embodiment, the configuration in which the measurement optical system 10 includes one light receiving element is described as an example. However, the present invention is not limited to this. For example, the measurement optical system 10 may include two light receiving elements. . In this case, in FIG. 2, a beam splitter may be provided between the light receiving element 11 and the stop 12, and the light receiving element may be disposed at the tip of the measurement light reflected by the beam splitter. In this case, in FIG. 2, a beam splitter may be provided between the diaphragm 12 and the condenser lens 13, and the diaphragm and the light receiving element may be disposed ahead of the measurement light reflected by the beam splitter. For example, by arranging two light receiving elements, the entire test lens LE may be photographed with one light receiving element, and the vicinity of the center of the test lens LE may be photographed with the other light receiving element. For example, in the case of a test lens having a small refractive power, there is little change when the first index pattern M1 and the second index pattern M2 are enlarged or reduced. It can be measured well.

  In the present embodiment, the configuration in which the brightness value is detected from the first image P1 and the second image P2 and the third image P3 is acquired based on the detected brightness value has been described as an example, but the present invention is not limited to this. For example, in addition to the luminance value, saturation, hue, and the like may be detected, and the third image P3 may be acquired based on this.

  In the present embodiment, the configuration in which the first index pattern is formed in the measurement light using the light source 15 has been described as an example, but the present invention is not limited to this. For example, the first index pattern can be formed in the measurement light using a light source such as an LED and a pattern forming plate having a first index pattern. In this case, as a pattern formation board, the structure which arrange | positions the index board which has arbitrary index patterns may be sufficient, and the structure which arrange | positions a screen may be sufficient. For example, the lens measurement apparatus 1 in the present embodiment may form the first index pattern in the measurement light by emitting the measurement light from the light source toward the pattern forming plate.

  In the present embodiment, the case where the third image P3 is acquired by performing division when performing the difference processing between the first image P1 and the second image P2 in the first measurement mode has been described as an example. However, it is not limited to this. For example, in the present embodiment, the third image P3 may be acquired by performing subtraction when performing the difference processing between the first image P1 and the second image P2. In this case, the control unit 60 detects the luminance value at each pixel position of the first image P1 and the luminance value at each pixel position of the second image P2, and from the luminance value at a predetermined pixel position of the second image P2, The luminance value at a predetermined pixel position in the first image P1 is subtracted. For example, the control unit 60 performs the subtraction process at all the pixel positions and sets the luminance value based on each subtraction value, thereby acquiring the third image P3 of the test lens LE including the first index pattern. May be. Of course, the luminance value may be set by binarizing the subtraction value, and the third image P3 of the test lens LE may be acquired. The third image P3 is not limited to the division process or the subtraction process, and may be acquired by taking the absolute value of the difference between the first image P1 and the second image P2.

  In the present embodiment, the configuration in which the index plate 14 is moved out of the optical path of the measurement light when the second measurement mode is set is described as an example, but the present invention is not limited to this. For example, in the image of the test lens LE received by the light receiving element 11, the second index pattern M2 formed by the index plate 14 does not overlap with the position of the hidden mark image 50 formed on the test lens LE. Then, the hidden mark image 50 can be accurately detected without moving the indicator plate 14 outside the optical path of the measurement light. Further, for example, in the image of the test lens LE received by the light receiving element 11, the second index pattern M2 formed by the index plate 14 overlaps the distance point and the near point of the test lens LE. The optical characteristic distribution of the lens LE to be measured in the first measurement mode and the detection of the hidden mark in the second measurement mode can be performed without moving the index plate 14 out of the optical path of the measurement light.

  For example, in the case of the above configuration, the lens measuring device 1 may include a centripetal mechanism not shown. Thereby, even if the test lens LE is placed at a position away from the center of the lens mounting table 6, it can be moved around the test lens LE. In addition, when the direction of the lens LE mounted on the lens mounting table 6 is deviated and the hidden mark image 50 cannot be detected from the image of the lens LE, the centripetal mechanism (not shown) The lens LE may be rotated on the lens mounting table 6. Alternatively, the indicator plate 14 may be rotated by a rotation mechanism (not shown) that rotates the indicator plate 14. As a result, the second index pattern M2 formed by the index plate 14 is positioned so as not to overlap the hidden mark image 50 in the test lens LE, and is positioned to overlap the distance point and the near point in the test lens LE. Can be adjusted as follows.

  For example, in this way, the lens measuring apparatus in the present embodiment is an area between one hidden mark and the other hidden mark applied to the lens, and the distance point and the near point of the lens are determined. An index plate capable of forming the second index pattern is included in the area to be included. Thereby, when the first index pattern and the second index pattern are formed, the optical characteristic distribution from the distance point to the near point of the lens can be acquired, and an index pattern different from the first index pattern can be obtained. When formed, the hidden mark can be accurately obtained without moving the indicator plate.

  In the present embodiment, a configuration in which each point of the first index pattern M1 and the intersection of the lattices of the second index pattern M2 are preliminarily positioned on the same line in the 0D reference state will be described as an example. However, it is not limited to this. For example, when each point of the first index pattern M1 and the intersection of the lattices of the second index pattern M2 are not located on the same line, the control unit 60 controls the light source 15 to change the first index pattern M1. The display position may be moved.

  In this embodiment, the third image P3 including the first index pattern is obtained by processing the first image P1 and the second image P2, and the second image P2 and the third image P3 are used to obtain the target image. Although the configuration for acquiring the optical characteristics of the analyzing lens LE has been described as an example, the configuration is not limited thereto. For example, the control unit 60 may extract the first index pattern M1 from the first image P1 by image processing. The control unit 60 may extract the second index pattern M2 from the second image P2 by image processing. For example, the optical characteristics of the test lens LE may be acquired without going through the third image P3 in this way.

DESCRIPTION OF SYMBOLS 1 Lens measuring apparatus 2 Display 10 Measurement optical system 11 Light receiving element 12 Aperture 13 Condenser lens 14 Indicator plate 15 Light source 60 Controller 75 Memory

Claims (8)

A lens measuring device for measuring optical characteristics of a lens,
An irradiation unit capable of forming a first index pattern and irradiating the lens with the first index pattern as a first irradiation pattern, the first irradiation pattern and a second irradiation pattern not forming the first index pattern; Irradiating means that can irradiate measurement light to the lens by switching
An indicator plate for forming a second indicator pattern in the measurement light emitted by the irradiation means;
A light receiving element that receives the measurement light via the lens and the indicator plate;
By irradiating the lens with the first irradiation pattern by the irradiation unit and receiving the first irradiation pattern via the indicator plate by the light receiving element, the first indicator pattern and the second indicator pattern are included. The first image of the lens is acquired, the second irradiation pattern is irradiated onto the lens by the irradiation unit, and the second irradiation pattern via the indicator plate is received by the light receiving element, thereby Control means for acquiring a second image of the lens including two index patterns;
A computing means for obtaining lens information of the lens by processing the first image and the second image;
A lens measuring device comprising: The lens measuring device according to claim 1.
An acquisition means for acquiring a third image of the first index pattern by processing the first image and the second image;
The lens measuring device, wherein the computing means acquires the lens information based on the second image and the third image. The lens measuring device according to claim 2,
The lens measurement device, wherein the calculation means acquires the lens information by performing a ray tracing process based on the second image and the third image. In the lens measuring device in any one of Claims 1-3,
The lens measuring device, wherein the computing means acquires optical characteristics of the lens as the lens information. The lens measuring device according to claim 2 or 3,
The lens measurement apparatus according to claim 1, wherein the acquisition unit acquires a third image by performing a difference process between the first image and the second image. In the lens measuring device according to any one of claims 1 to 5,
The irradiation unit can form at least one index pattern different from the first index pattern,
The control unit irradiates the lens with a plurality of index patterns formed by the irradiation unit, acquires a plurality of images of the lens including the plurality of index patterns,
The lens measuring apparatus according to claim 1, wherein the calculation unit acquires a hidden mark of the lens as the lens information based on the plurality of images. The lens measurement device according to claim 6.
The indicator plate is an area between one hidden mark on the lens and the other hidden mark, and includes an area including a distance point and a near point of the lens. A lens measuring device characterized by forming a pattern. The lens measuring device according to claim 6 or 7,
A lens measuring apparatus comprising drive means for moving the indicator plate in an optical path of the measurement light passing through the indicator plate.

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