Lens measuring device

Abstract

To provide a lens measuring device that can more accurately measure the optical properties of lenses. [Solution] A lens measuring device comprising a light source that emits a measuring light beam, an indicator plate that forms an indicator in a predetermined pattern with the measuring light beam, an image sensor that captures at least a portion of the indicator image formed by the measuring light beam that has passed through the lens and the indicator plate, and a control unit, wherein the control unit performs an acquisition step of acquiring a plurality of indicator image images captured by the image sensor in a plurality of different shooting areas of at least a portion of the refractive surface of the lens, a panoramic image generation step of generating a panoramic indicator image image by aligning the plurality of indicator image images based on the position of the defective portion in each indicator image where the transmission of the measuring light beam is obstructed by a mark provided on the refractive surface of the lens, and a calculation step of acquiring the optical characteristics of the lens based on the panoramic indicator image image.

Description

Technical Field

[0001] The present disclosure relates to a lens measuring apparatus for measuring the optical characteristics of a lens.

Background Art

[0002] There is known a lens measuring apparatus that measures the optical characteristics (e.g., refractive power, etc.) of a lens by projecting a measurement light beam onto the lens and imaging the measurement light beam that has passed through the lens and a reticle with an image sensor (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When measuring the optical characteristics of a lens with a lens measuring apparatus, the measurement region of the optical characteristics basically depends on the size of the image sensor (i.e., the imageable range). It is also conceivable to add an optical member such as a lens to narrow the measurement light beam incident on the image sensor, thereby expanding the measurement region of the optical characteristics. However, when an optical member is added, it is necessary to correct for the aberration caused by the added optical member. Therefore, ultimately, the measurement regions of the optical characteristics of many lens measuring apparatuses still depend on the size of the image sensor, and the current situation is that the measurement region cannot be expanded. As a result, it becomes difficult to grasp the distribution of refractive power, etc. in the lens, especially when measuring a progressive lens, and it takes time and effort for the measurement, or it may be difficult for an inexperienced operator to perform an appropriate measurement. Therefore, a technique that can more appropriately measure the optical characteristics of a lens is desired.

[0005] In view of the above-mentioned prior art, the technical objective of this disclosure is to provide a lens measuring device capable of more appropriately measuring the optical properties of lenses. [Means for solving the problem]

[0006] To solve the above problems, this disclosure is characterized by having the following configuration.

[0007] (1) A lens measuring device according to a first aspect of the present disclosure is a lens measuring device for measuring the optical properties of a lens, comprising: a light source that emits a measuring light beam; an indicator plate disposed on the optical path of the measuring light beam emitted from the light source and forming an indicator in a predetermined pattern with the measuring light beam; an image sensor disposed on the optical path of the measuring light beam and capturing at least a portion of the indicator image formed by the measuring light beam that has passed through the lens and the indicator plate; and a control unit, wherein the control unit performs an acquisition step of acquiring a plurality of indicator image images captured by the image sensor in each of a plurality of different shooting areas of at least a portion of the refractive surface of the lens; a panoramic image generation step of generating a panoramic indicator image image by aligning the plurality of indicator image images based on the position of a defect in which the transmission of the measuring light beam is obstructed by a mark provided on the refractive surface of the lens; and a calculation step of acquiring the optical properties of the lens based on the panoramic indicator image. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the lens meter 1. [Figure 2] This is a cross-sectional view of the optical system of lensmeter 1, seen from the front. [Figure 3] This figure shows an example of an indicator pattern. [Figure 4] This is a schematic diagram of the control system for Lensmeter 1. [Figure 5] This is a diagram of the printing mechanism 9. [Figure 6] This is an external view of the lens LE with the markings placed on it. [Figure 7] This is an example of the measurement screen 50. [Figure 8] This is an example of a diagram showing index images captured in each of the two imaging ranges within the lens LE. [Figure 9] This figure shows an example of aligning two index images. [Modes for carrying out the invention]

[0009] <Overview> An overview of the lens measuring device according to this embodiment is described below. The items classified in <> below can be used independently or in relation to each other.

[0010] The lens measuring device illustrated in this disclosure comprises a light source, an indicator plate, an image sensor, and a control unit. The light source emits a measurement light beam. The indicator plate and the image sensor are positioned on the optical path of the measurement light beam emitted from the light source. The indicator plate forms an indicator in a predetermined pattern by passing the measurement light beam through it. The image sensor captures at least a portion of the indicator image formed by the measurement light beam that has passed through the lens and the indicator plate. The control unit controls various aspects of the lens measuring device. Marks that obstruct the transmission of the measurement light beam may be placed on the refractive surface of the lens. In this case, the control unit performs an acquisition step, a panoramic image generation step, and a calculation step. In the acquisition step, the control unit acquires a plurality of indicator image images captured by the image sensor in each of a plurality of different shooting areas, at least a portion of the shooting area of ​​the refractive surface of the lens. In the panoramic image generation step, the control unit generates a panoramic indicator image image by aligning the plurality of indicator image images based on the position of the missing portion in each indicator image where the transmission of the measurement light beam is obstructed by the marks provided on the refractive surface of the lens. In the calculation step, the control unit acquires the optical properties of the lens based on the panoramic index image.

[0011] According to the lens measuring device of this disclosure, the measurement area of ​​optical properties, which previously depended on the imaging range (imaging area) of the image sensor, is appropriately expanded by using a wider panoramic index image obtained by panoramic stitching of multiple index image images. As a result, by obtaining a wider measurement area, it becomes easier to detect the optical properties of the lens (e.g., refractive power distribution). Therefore, the effort and time required for the operator of the lens measuring device to measure the lens are reduced. In addition, the possibility that an inexperienced operator may not be able to measure the lens properly is appropriately reduced. Therefore, it becomes easier and more convenient to measure the optical properties of a lens using the lens measuring device.

[0012] <Explanation of the symbols> The marks placed on the refractive surface of the lens only need to be made of a material that obstructs the transmission of the measurement light beam. For example, the marks may be made of ink, paint, or stickers. There may be one or more marks on the lens. If there are multiple marks on the lens, it becomes easier to detect movement in the rotational direction of the lens. If there is only one mark on the lens, for example, the shape of the mark may be made asymmetrical or non-point symmetrical to make it easier to detect movement in the rotational direction of the lens during measurement. However, even if the shape of the single mark placed on the lens is symmetrical or point symmetrical, the technology of this disclosure can be employed. In this case, for example, the accuracy of generating the panoramic index image may be improved by displaying a message prompting the operator to move the lens in parallel without rotating it, or by using a jig that restricts the rotational movement of the lens. The phrase "marks that obstruct the passage of the measurement light beam" includes not only cases where the transmission of the measurement light beam to the transmission area is completely blocked, but also cases where the amount of measurement light beam transmitted through the transmission area is reduced compared to when no marks are present. Furthermore, the "predetermined pattern" formed on the indicator plate is not limited to a single predetermined pattern, but also includes various known patterns.

[0013] <Specific example of a method for alignment using the location of the missing part> When generating a panoramic index image, the specific method for aligning multiple index images based on the location of the missing area can be appropriately selected. For example, if the same mark forms the missing area in each of the multiple index images (for example, if there is one mark placed on the lens, or if each of the multiple marks can be identified), the control unit may align the multiple index images so that the locations of the missing areas in the multiple index images coincide. Alternatively, the control unit may extract multiple index images showing the missing area due to the mark from the multiple index images captured by the image sensor, and then perform alignment based on the location of the missing area. In this case, a panoramic index image is generated in which alignment based on the location of the missing area is appropriately performed.

[0014] <Even just performing a rough alignment can be effective.> Furthermore, if the size of the marks placed on the lens is larger than the size of the light-transmitting area of ​​the indicator plate, it may be difficult to accurately align multiple indicator images even using the position of the missing area. However, even if the alignment of multiple indicator images is performed with a certain degree of accuracy, it is possible to obtain useful optical properties of the lens (for example, the approximate position and range of the progressive band in a progressive lens).

[0015] The marks provided on the refractive surface of the lens may be marks applied by a marking mechanism for applying marks to the refractive surface of the lens. Of course, the marking mechanism may be provided in the lens measuring device exemplified in this disclosure. Alternatively, a marking mechanism provided in another device may be used. A lens measuring device may include a marking mechanism for applying a marking point to an optical center point of a lens refractive surface, a point corresponding to the pupil center of the eye under examination, or the like. The marking by the marking mechanism can be used as a mark that obstructs the transmission of the measurement light beam. In that case, since the operator can also utilize the marking mechanism used for aligning the axis of the lens for generating a panoramic index image, the labor of separately preparing a tool for applying the mark can be saved. As a result, the operator can smoothly proceed with the operation from placing the mark on the lens refractive surface to lens measurement.

[0016] Incidentally, for example, marks applied to the lens refractive surface for other purposes may be used also for lens measurement. Of course, marks applied to the lens refractive surface for lens measurement may be used for lens measurement.

[0017] The control unit may identify a missing part mark that forms a missing part in the index image from among a plurality of marks applied to the refractive surface of the lens in different manners by analyzing the index image. In the panoramic image generation step, the control unit may perform a process of aligning a plurality of index images by matching the positions of the missing part marks in each of the plurality of index images.

[0018] The larger the number of marks arranged on the lens (that is, marks that can form a missing part in the index image), the more reference points there are when aligning a plurality of index images, and the control unit can perform the alignment of the plurality of index images with higher accuracy in the panoramic image generation step. On the other hand, when all of the plurality of marks applied to the lens are the same, it may be difficult to determine which of the plurality of marks applied to the lens formed the missing part in the captured index image. Then, there is also a possibility that the control unit cannot appropriately perform the alignment of the index images.

[0019] In contrast, even when multiple marks are placed on the refractive surface of the lens, the control unit can more easily grasp the positional relationship of each reference point by identifying the marks that form individual defects in the indicator image. As a result, alignment of multiple indicator images can be performed with higher precision. Consequently, this leads to the generation of a more accurate panoramic indicator image, making it easier to obtain more favorable lens measurement results.

[0020] Furthermore, for each mark to be in a different form means, for example, that at least one of the marks, such as shape, size, or color, is different. If the marks on the lens forming each of the multiple missing areas projected onto the index image are individually identifiable, then differences between the marks may be established in other ways.

[0021] If multiple marks are placed on the lens, each mark may be colored differently from the others. The image sensor may be capable of capturing a color-identifiable image (e.g., a color image). The control unit may identify which of the multiple marks on the lens the defect mark forming the defect in the index image is based on the color of the defect in the index image.

[0022] By making multiple marks on a lens distinguishable by color, when applying multiple marks to a lens, it is possible to apply multiple marks that are distinguishable by the control unit by using inks of different colors, without intentionally changing the shape or size of each individual mark. For example, a marking mechanism provided in a lens measuring device may have multiple marking members with the same tip shape or thickness. For example, when marking a lens with such a marking mechanism, multiple marks of the same shape and size are applied. In contrast, by using inks of different colors for each marking member, the control unit can distinguish by color the marks that form individual defects (defect marks) displayed in the index image, while still utilizing the conventional marking mechanism.

[0023] The control unit may, in the calculation step, exclude optical characteristic information obtained from the missing parts of each of the multiple indicator images used to generate the panoramic indicator image, and then calculate the optical characteristics of the lens. The missing parts that appear in the indicator image are used as reference points for alignment when generating a panoramic indicator image by aligning multiple indicator images. However, at the same time, the missing area is prone to affecting the information necessary to calculate the optical characteristics of the lens (such as the size, shape, or distance between bright spots in the indicator image created by the measurement light beam that has passed through the lens and the indicator plate). For example, if a mark blocks the measurement light beam, the information necessary for the optical characteristics will not appear in the missing area. Also, if the colors of multiple marks attached to the lens are changed, the difference in refractive index due to the difference in mark colors may affect the indicator image that appears in the indicator image. Consequently, when calculating the optical characteristics of the lens, the information obtained from the missing parts of the indicator image may act as faulty data, potentially reducing the accuracy of the calculated optical characteristic values.

[0024] In contrast, by excluding information obtained from the missing portion of the index image from the parameters used to calculate the optical properties of the lensmeter during the calculation step, the control unit can perform calculations using higher-quality information (parameters), making it easier to maintain the accuracy of the calculation results. As a result, it becomes easier to obtain more suitable lens measurement results.

[0025] <Examples> The lens measuring device in this embodiment (for example, lensmeter 1) is a device for measuring the optical properties of a lens. Hereinafter, embodiments of this disclosure will be described with reference to the drawings.

[0026] <Device configuration> The configuration of the lens meter 1 will be explained using Figure 1. Figure 1 is an external perspective view of the lens meter 1. For example, the lens meter 1 includes a display (monitor) 2, an input switch 3, a nosepiece 4, a lens holder 5, a lens table 6, a lever 7, a READ switch 8, a marking mechanism 9, etc. However, the configuration of the lens meter 1 in this embodiment is not limited to this. The lens meter 1 in this embodiment only needs to include at least the measuring optical system 10 which will be described later.

[0027] In this embodiment, an LCD (Liquid Crystal Display) is used for display 2. It is also possible to use a device other than an LCD as display 2. For example, an OLED (Electro-Lumiescence) display or a plasma display may be used as display 2. As an example, display 2 in this embodiment is a touch panel. That is, in this embodiment, display 2 functions as an operating unit (controller). Of course, display 2 does not have to be a touch panel. Also, for example, display 2 may be a configuration in which multiple displays are used in combination.

[0028] For example, the display 2 outputs signals corresponding to operation instructions input via the touch panel on its surface to the control unit 30 (see Figure 4), which will be described later. Of course, the display 2 and the operation unit may be configured separately. For example, the operation unit may be configured to use at least one of the following: a mouse, joystick, keyboard, or mobile terminal.

[0029] For example, display 2 displays various types of information. These include, for instance, the optical properties of the lens (e.g., spherical power S, prismatic power C, astigmatism axis angle A, etc.), or a display screen for aligning the lens with lensmeter 1.

[0030] For example, the input switch 3 is used to input signals to the lens meter 1 to perform various processes. For example, these processes include switching measurement modes. In this embodiment, for example, 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. Note that the configuration of the input switch 3 is not limited to this embodiment. For example, the input switch 3 may be installed on the display cover 2a or the like.

[0031] For example, the nosepiece 4 is a mounting platform for the lens. For example, the lens holder 5 is used to hold the lens stably by pressing it from above. For example, the lens table 6 is used when measuring the optical properties of a lens set in an eyeglass frame. For example, the lower ends of the left and right rims of the eyeglass frame are brought into contact with the lens table 6. For example, the lever 7 is used to move the lens table 7 in the front-back direction (Z direction). For example, the READ switch 8 is used to read the optical properties of the lens. For example, the marking mechanism 9 is used to mark the lens. The marking mechanism 9 will be explained in more detail later.

[0032] <Measurement optical system> The measuring optical system 10 in the lensmeter 1 will be explained using Figure 2. Figure 2 is a cross-sectional view of the optical system of the lensmeter 1 as seen from the front. For example, the optical system in this embodiment includes a measuring optical system 10.

[0033] The measurement optical system 10 includes a light source 11, a collimating lens 12, an indicator plate 13, an image sensor 14, etc. For example, the light source 11 is composed of an LED (Light Emitting Diode). For example, the measurement light source 11 is arranged on the measurement optical axis L1. For example, the measurement optical axis L1 is arranged perpendicular to the plane of the aperture 4a (circular shape with a diameter of 8 mm) of the nosepiece 4. For example, the indicator plate 13 has a measurement indicator 20 formed by a central hole 21 and a small hole 22, which will be described later. For example, the indicator plate 13 is held by a holding member 15 of the lens meter 1. For example, the image sensor 14 may be an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal-Oxide-Semiconductor). Also, for example, the image sensor 14 may be capable of capturing an image in which color can be distinguished.

[0034] For example, Figure 3 shows an example of an index pattern formed on the index plate 13. In order to measure the refractive power at multiple locations on the lens LE at once, numerous measurement indicators 20 are formed on the index plate 13. A central hole 21 with a diameter of 0.4 mm is made in the center of the index plate 13, and numerous small holes 22 with a diameter of 0.2 mm are made around the central hole 21. That is, in the index plate 13, the central hole 21 and the numerous small holes 22 are configured as light-transmitting areas that allow the measurement light beam to pass through, and the remaining area is configured as a light-shielding area that blocks the measurement light beam. The small holes 22 are arranged in a grid pattern at equal intervals of 0.5 mm. The light beam from the light source 11 becomes a parallel light beam through the collimating lens 12 and is projected onto the lens LE. Of the light beam that has passed through the lens LE, the light beam that has passed through the nosepiece opening 4a and the measurement indicators 20 on the index plate 13 reaches the image sensor 14. The image sensor 14 captures an index image formed by these measurement indicators 20. The index image captured by the image sensor 14 shows a grid-like pattern shape because the measurement indicators 20 are arranged in a grid pattern. In this embodiment, the configuration in which the measurement indicators 20 are arranged in a grid pattern is used as an example, but the invention is not limited to this. For example, the measurement indicators 20 may be arranged at non-equal intervals. Also, for example, the measurement indicators 20 may be arranged radially or concentrically. In this case, the image sensor 14 captures a radial or concentric index image.

[0035] For example, the central hole 21 serves as a reference indicator for determining its positional relationship with the other small holes 22. When the lens meter is powered on, the control unit 30 detects the indicator image in the "0D reference" state, when the lens LE is not placed on the nosepiece 4, and stores its coordinate position in the memory 31 (the control unit 30 and memory 31 will be described later). When the lens LE is placed on the nosepiece 4, the light beam from the light source 11 is refracted by the lens LE, so the coordinate position of the indicator image changes compared to the 0D reference state. In other words, the central hole 21 is a reference indicator for identifying each indicator image corresponding to this change in coordinate position with and without the lens LE. In this embodiment, one reference indicator is placed in the center of the indicator plate 13, but the number, shape, position, etc. of the reference indicators are not limited to this, as long as they can be distinguished from other measurement indicators. For example, when using three reference indicators, they may be arranged at the vertices of an equilateral triangle. For example, when using four reference indicators, one configuration could be to place three of the four reference indicators at the vertices of an equilateral triangle and one at the incenter of the equilateral triangle, or one configuration could be to place each reference indicator at the vertices of a square (i.e., at the four corners of the square).

[0036] For example, the index image of the measurement index 20 in the 0D reference state is used to calculate the optical properties of the lens LE. For example, when a lens LE having only spherical power is placed, the index image is enlarged or reduced in a circular and equidistant manner from the optical center of the lens LE relative to the index image in the 0D reference state. The spherical power S is determined based on this enlargement or reduction amount. When a lens LE having only prismatic power is placed, the index image is enlarged or reduced in an elliptical manner from the axis center of the lens LE relative to the index image in the 0D reference state. The prismatic power C and astigmatism axis angle A are determined based on this enlargement or reduction amount. In addition, the prism amount Δ is determined from the amount of translation in the central index image of the lens LE, or the index image near the central index image. When a lens LE having spherical power, prismatic power, and prism is placed, these can be considered in combination (see Japanese Patent Publication No. 50-145249). When measuring progressive lenses, the measured optical properties change between the distance and near vision regions of the lens LE. Therefore, it is desirable to measure the optical properties over as wide a range as possible when measuring progressive lenses.

[0037] For example, the optical characteristics of the lens LE can be calculated by taking four (at least three) adjacent index images from among the numerous measurement indexes 20 formed on the index plate 13 as a set, or by taking index images of 3x3 points, 4x4 points, or 5x5 points as a set and calculating from the average change of each index image. Since this applies to well-known techniques, please refer to Japanese Patent Publication No. 2005-315654 or Japanese Patent Publication No. 2008-241694 for details.

[0038] In this embodiment, a configuration in which the measurement indicator 20 is formed by a central hole 21 and small holes 22 has been described as an example, but the embodiment is not limited to this. For example, the measurement indicator can also be formed by a light-transmitting portion that transmits the light beam emitted from the light source and a light-shielding portion that blocks the light beam emitted from the light source. In this case, for example, the light-transmitting portion and the light-shielding portion are arranged on the indicator plate so that the light-transmitting portion forms a grid-like pattern. For example, the light-transmitting portion and the light-shielding portion can be formed by applying a coating or the like to the indicator plate. Alternatively, for example, the indicator plate may be configured to display a predetermined pattern indicator on a transmissive display. The pattern of the measurement indicator formed by the indicator plate only needs to be known at the time of measurement, and the pattern of the measurement indicator does not need to be fixed to one.

[0039] <Control System> The control system of the lens meter 1 will be explained using Figure 4. Figure 4 is a schematic diagram of the control system in the lens meter 1. For example, the control unit 30 oversees and controls the entire lens meter 1 device. For example, the control unit 30 is connected to the display 2, input switch 3, READ switch 8, memory 31, etc. Also, for example, the light source 11 and image sensor 14 of the measurement optical system 10 are connected to the control unit 30.

[0040] For example, the control unit 30 includes a CPU (processor), RAM, ROM, etc. For example, the CPU of the control unit performs various calculations (for example, calculations of the optical properties of a lens, etc.). For example, the RAM of the control unit 30 temporarily stores various information. For example, the ROM of the control unit 30 stores programs executed by the CPU, initial values, etc. Note that the control unit 30 may be composed of multiple control units (i.e., multiple processors). The control unit 30 may include dedicated circuits for performing specific calculations.

[0041] For example, the control unit 30 generates a panoramic image of the indicator image by processing multiple indicator image images of the lens LE captured using the image sensor 14. For example, the control unit 30 calculates the optical characteristics of the lens by comparing the indicator image when the lens LE is mounted with the indicator image of the measurement indicator 20 in the 0D reference state. For example, the control unit 30 controls the display screen of the display 2.

[0042] For example, memory 31 is a non-transient storage medium that can retain its contents even when the power supply is interrupted. For example, memory 31 can be a hard disk drive, flash ROM, or USB memory. For example, memory 31 can store the coordinate position of the index image in the lens's 0D reference state, or the measurement results of its optical characteristics.

[0043] <Mark mechanism> The marking mechanism 9 of the lens meter 1 in this embodiment will be described using Figure 5. Figure 5(a) is a view from the right side showing the marking member in the marking position. Figure 5(b) is a view from the front showing the marking member in the marking position. For example, the marking mechanism 9 includes an arm 40, a marking base 41, a lever 42, a relay member 43, a base 44, a marking member 45, etc.

[0044] For example, the arm 40 moves vertically (Y-direction) of the lens meter 1 by a sliding mechanism (not shown). For example, one end of the arm 40 is attached to the marking base 41. For example, the marking base 41 has a spring (not shown) inside it. For example, the marking base 41 is always biased in one rotational direction by the force of the spring (not shown). Therefore, the marking mechanism 9 is always in a standby position. For example, a lever 42 is fixed to the marking base 41. Also, for example, a relay member 43 is fixed to the marking base 41. For example, a base 44 is fixed to the relay member 43. For example, the relay member 43 rotates integrally with the axis of the marking base 41. For example, a marking member 45 is attached to the base 44. For example, the marking member 45 has an ink pen or ink pen tip at its tip.

[0045] For example, the marking member 45 has an ink bottle inside. For example, the ink colors supplied to each ink bottle of multiple marking members 45 may be different from each other. For example, the marking member 45 comprises a first marking member 45a, a second marking member 45b, and a third marking member 45c. For example, the first marking member 45a, the second marking member 45b, and the third marking member 45c are arranged in a straight line. In this embodiment, the marking mechanism 9 is mounted on the lens meter 1. Therefore, the operator can efficiently perform the operation of measuring the optical properties of the lens LE using the lens meter 1 and the operation of applying marks to the lens LE using the marking mechanism 9. However, the marking mechanism 9 may be provided separately from the lens meter 1.

[0046] <Control operation> As an embodiment of the lensmeter 1 having the above configuration, the control operation of the lensmeter 1 when measuring the optical characteristics of a lens LE will be described.

[0047] <Placement of marks (dots)> First, as preparation for the lensmeter 1 to measure the optical properties of the lens LE, a mark (e.g., a dot) is placed on the refractive surface of the lens LE to obstruct the transmission of the light beam measured by the lensmeter 1. For example, the operator places the lens LE on the nosepiece 4 (see Figure 5). While the lens LE is placed on the nosepiece 4, the dot mechanism 9 is in a standby position. With the lens LE placed on the nosepiece 4, the operator pushes the lever 42 of the dot mechanism 9 backward, causing the dot base 41, relay member 43, base 44, dot member 45, etc., to rotate together. As a result, the dot mechanism 9 moves from the standby position to the dot position shown in Figure 5. In the dot position, the pen tip of the dot member 45 is facing downward. At this time, for example, each of the multiple dot members 45 may be filled with ink of a different color in an ink bottle. For example, the first dot member 45a is filled with black ink, the second dot member 45b with red ink, and the third dot member 45c with blue ink. Furthermore, when the operator pushes the lever 42 downward, the arm 40, dot base 41, relay member 43, base 44, dot member 45, etc. move downward as a whole, and the pen tip of the dot member 45 comes into contact with the lens LE, making a dot.

[0048] Figure 6 is an example of an external view of a lens LE with a first mark M1, a second mark M2, and a third mark M3 arranged on the refractive surface of the lens. For example, the first mark M1 is black, the second mark M2 is red, and the third mark M3 is blue. For example, the first mark member 45a applies the first mark M1 to the lens LE. For example, the second mark member 45b applies the second mark M2 to the lens LE. For example, the third mark member 45c applies the third mark M3 to the lens LE.

[0049] In this way, by using the marking mechanism 9 to mark the lens LE, it is possible to utilize a tool (marking mechanism) that can also be provided in a lens measuring device, thus eliminating the need to separately prepare a tool for marking. In other words, the operator can also use the marking mechanism 9, which can be used to mark the lens LE, for measuring the optical properties of the lens LE (specifically, for generating a panoramic index image, which will be described later). As a result, the operator can smoothly proceed with the operation from marking the lens LE to measuring the optical properties of the lens LE. In this embodiment, the case in which the operator manually marks the lens LE is illustrated. However, the lens meter 1 or the like may automatically mark the lens LE.

[0050] <Acquisition Steps: Place the lens LE and launch the measurement screen> For example, the operator places the lens LE, on which the markings are located as described above, onto the nosepiece 4. The operator selects the power switch (not shown) of the lens meter 1. When the control unit 30 receives the operation signal from the power switch, it displays the measurement screen 50 for measuring the lens LE on the display 2.

[0051] The measurement screen 50 will be explained using Figure 7. Figure 7 is an example of the measurement screen 50 displayed on the display 2. For example, the measurement screen 50 displays a measurement result display unit 51, an alignment display unit 52, an alignment circle 53, a ring mark 54, and a panoramic image generation button 55. For example, the measurement result display unit 51 displays the measurement result of the lens LE. For example, the alignment display unit 52 displays alignment information for the operator to adjust the positional relationship between the lens LE and the measurement optical system 10. For example, the alignment circle 53 shows the positional relationship between the lens LE and the measurement optical system 10. The alignment circle 53 has a crosshair where vertical and horizontal lines are perpendicular, and the center point 53a of the crosshair is an electronically displayed center point of the nosepiece aperture 4a. For example, the center point 53a is used as a target when aligning the measurement position of the lens LE. For example, the ring mark 54 electronically displays the position of a mark (for example, at least one of the first mark M1, the second mark M2, and the third mark M3) attached to the lens LE. For example, the display position of the ring mark 54 is determined based on the position or shape of the missing portion on the index image formed by the marks attached to the lens LE. For example, the panoramic image generation button 55 is a button for initiating control to generate a panoramic index image by combining multiple index images acquired by the image sensor 14. For example, the operation of the panoramic image generation button 55 may be activated (or displayed) only when the control unit 30 has acquired multiple index images.

[0052] <Acquisition Step: Acquisition of multiple indicator images> Furthermore, for example, when the control unit 30 receives an operation signal for the power switch, it emits a measurement light beam from the light source 11. For example, when a measurement light beam is emitted from the light source 11, the lens meter 1 becomes capable of measuring the optical characteristics of the lens LE.

[0053] For example, the operator moves the position of the lens LE while looking at the alignment display unit 52 on the measurement screen 50 (particularly the position of the ring mark 54 displayed on the alignment circle 53), moving the part of the lens surface of the lens LE that is in contact with the nosepiece opening 4a (i.e., the area of ​​the lens LE that is imaged by the image sensor 14). At this time, for example, the control unit 30 may display an indicator (not shown) on the alignment circle 53 to guide the shooting area of ​​the lens so that indicator images can be acquired in multiple shooting areas that differ in at least some of the shooting areas. The control unit 30 may also control the image sensor 14 at predetermined timings (for example, once every 3 seconds, etc.) to automatically acquire multiple indicator images in succession. Note that the method by which the control unit 30 acquires multiple indicator images may be different from this. For example, each time the operator manually selects the shooting button (not shown) provided on the lens meter 1, the control unit 30 may receive the operation signal of the shooting button and control the image sensor 14 to acquire multiple indicator images.

[0054] For example, using the method for acquiring the index image described above, the control unit 30 acquires multiple index image images captured by the image sensor 14 in each of multiple shooting areas (i.e., multiple shooting areas in which at least some shooting areas differ) of the refractive surface of the lens LE.

[0055] <Panoramic image generation step: Extraction of missing image> For example, when multiple indicator images are acquired, the control unit 30 displays the panoramic image generation button 55 on the measurement screen 50 (see Figure 7). For example, the operator selects the panoramic image generation button 55 when they want the lens meter 1 to generate a panoramic indicator image by aligning and combining multiple indicator images. For example, when the control unit 30 receives the selection signal for the panoramic image generation button 55, it extracts only the target images that can be used to generate the panoramic indicator image from the multiple indicator images acquired in the acquisition step. That is, it extracts from the multiple acquired indicator images the multiple indicator images that show a missing portion (formed by a mark on the lens LE) which will be used as positional information when aligning the multiple indicator images to generate the panoramic indicator image.

[0056] <Panoramic image generation step: Identification of marks that form missing areas> For example, the control unit 30 determines the position of the mark point based on the color of the missing portion from the extracted multiple indicator image images. Since the image sensor 14 can capture images in which color is discernible, for example, in this embodiment, the indicator image captured by the image sensor 14 is assumed to be an image in which color is discernible (a color image).

[0057] Figure 8 shows an example of an index image captured by the image sensor 14 in each of the two imaging ranges within the lens LE. For example, the lens LE has three marks: a first mark M1 (black), a second mark M2 (red), and a third mark M3 (blue), each made of ink of a different color. The two areas enclosed by dotted lines in the lens LE indicate the imaging range captured by the image sensor 14. In Figure 8, the first imaging range A1 includes the second mark M2 and the third mark M3. The second imaging range A2 includes the first mark M1 and the second mark M2. The first index image I1 is an image of the first imaging range A1 captured by the image sensor 14. The first index image I1 shows the defect D2 formed by the second mark M2 and the defect D3 formed by the third mark M3. The second index image I2 is an image of the second imaging range A2 captured by the image sensor 14. The second index image I2 shows the defect D1 formed by the first mark M1 and the defect D2 formed by the second mark M2.

[0058] For example, the control unit 30 extracts a first index image I1 and a second index image I2 as part of a plurality of index image images in which the defective area is visible. The control unit 30 detects the defective area D2 and the defective area D3 from the first index image I1. Furthermore, the control unit 30 analyzes at least one of the shape, color, or positional relationship of each defective area (in this embodiment, mainly the color of each defective area) to identify that the defective area D2 corresponds to the second mark M2 (i.e., the defective area D2 is formed by the second mark M2 (defect mark) applied to the lens LE), and that the defective area D3 (blue) corresponds to the third mark M3 (i.e., the defective area D3 is formed by the third mark M3 (defect mark)). Similarly, the control unit 30 detects the defective area D1 and the defective area D2 from the second index image I2. Furthermore, the control unit 30 analyzes at least one of the shape, color, or positional relationship of each missing portion to identify that the missing portion D1 corresponds to the first mark M1 and that the missing portion D2 corresponds to the second mark M2.

[0059] Furthermore, when applying three or more marks to the lens LE, it is not necessary for all three or more marks to be of different colors; it is sufficient for three or more marks to be made with two or more different colored inks. Even in this case, it becomes easier to identify the marks that form the missing areas in the index image compared to when all marks are the same color. For example, in the example shown in Figure 8, even if the first mark M1 and the third mark M3 are black and the second mark M2 is red, it is still possible to align the two index images I1 and I2.

[0060] <Panoramic image generation step: Alignment of multiple indicator images> In this embodiment, the control unit 30 aligns the first index image I1 and the second index image I2 based on the positions of the missing parts D1, D2, and D3 identified in the first index image I1 and the second index image I2, respectively.

[0061] Figure 9 shows an example of the alignment of two index images. In the example shown in Figure 9, the control unit 30 aligns the first index image I1 and the second index image I2, using the position of the missing portion D2 common to both the first index image I1 and the second index image I2 as a reference, so that the missing portion D2 of the first index image I1 and the missing portion D2 of the second index image I2 overlap.

[0062] At this time, the control unit 30 detects that the missing portion D2 is commonly visible in both the first indicator image I1 and the second indicator image I2. Subsequently, the control unit 30 performs a process to superimpose (align) the first indicator image I1 and the second indicator image I2 at the position where the position of the missing portion D2 in the first indicator image I1 and the position of the missing portion D2 in the second indicator image I2 coincide. As a result, the control unit 30 generates a panoramic indicator image using the first indicator image I1 and the second indicator image I2. For example, the control unit 30 superimposes a message indicating that a panoramic indicator image has been generated onto the measurement image 50 and saves the generated panoramic indicator image to the memory 31.

[0063] <Calculation Steps> For example, the operator selects the READ button 8. When the control unit 30 receives the operation signal from the READ button 8, it calculates the optical characteristics of the lens LE using the generated panoramic index image. For example, the control unit 30 analyzes the amount of change in the generated panoramic index image relative to the index image in the 0D reference state stored in the memory 31 to obtain the optical characteristics of the lens LE. Therefore, the control unit 30 can obtain the optical characteristics of the lens LE over a wider range compared to when using a single index image. Thus, for example, when obtaining the optical characteristics of a progressive lens, or when determining whether the lens LE being measured is a progressive lens, it is possible to process the data more appropriately than in the conventional method.

[0064] Furthermore, the control unit 30 may exclude optical characteristic information obtained from defective portions that may result in defective data among the multiple indicator images used to generate the panoramic indicator image. That is, when the control unit 30 analyzes the amount of change in the generated panoramic indicator image relative to the indicator image in the 0D reference state stored in the memory 31, it may exclude portions containing defective portions from the analysis. As a result, by excluding portions containing defective portions that may result in defective data during the analysis process, it becomes easier to obtain more suitable lens LE measurement results (optical characteristics).

[0065] As described above, with the lens measuring device of this embodiment, the measurement area of ​​the lens LE, which was dependent on the shooting area of ​​the image sensor 14, can be appropriately expanded by using a wider panoramic index image obtained by panoramic stitching of multiple index image images. Obtaining a wider measurement area makes it easier to acquire the optical characteristics of the lens LE. As a result, the effort and time required for the operator to measure the lens is reduced. In addition, the possibility that an inexperienced operator may not be able to measure the lens appropriately is appropriately reduced. In this way, the measurement of the optical characteristics of the lens using the lens measuring device becomes easier and more favorable. [Explanation of Symbols]

[0066] 1 Lensmeter 2 displays 4 Nosepiece 9 Marking mechanism 11 Light source 13 Index board 14 Image sensor 30 Control Unit 50 Measurement screens

Claims

1. A lens measuring device for measuring the optical properties of a lens, A light source that emits the measurement beam, An indicator plate is placed on the optical path of the measurement light beam emitted from the light source, and the measurement light beam forms an indicator in a predetermined pattern; An image sensor is positioned on the optical path of the measurement light beam and captures at least a portion of the index image formed by the measurement light beam that has passed through the lens and the index plate. Control unit and Equipped with, The control unit, An acquisition step of acquiring multiple index image images captured by the image sensor in each of a plurality of different shooting areas, at least a portion of the refractive surface of the lens, A panoramic image generation step of generating a panoramic index image image by aligning the plurality of index image images based on the position of the missing portion in each of the index image images where the transmission of the measurement light beam is obstructed by a mark provided on the refractive surface of the lens, A calculation step to acquire the optical characteristics of the lens based on the panoramic index image, A lens measuring device characterized by performing the following actions.

2. A lens measuring device according to claim 1, A lens measuring device characterized in that a mark applied by a marking mechanism for applying a mark to the refractive surface of a lens is used as the mark.

3. A lens measuring device according to claim 1 or 2, The control unit identifies, from among a plurality of marks attached to the refractive surface of the lens in different manners, the defect mark that forms the defect in the index image by analyzing the index image. The lens measuring device is characterized in that, in the panoramic image generation step, the position of each of the missing portion marks in the multiple index image images is matched to align the multiple index image images.

4. A lens measuring device according to claim 3, The multiple marks placed on the lens are colored differently from each other. The aforementioned image sensor is capable of capturing images in which colors can be distinguished. The lens measuring device is characterized in that the control unit identifies which of the plurality of marks the defect mark forming the defect in the index image is, by identifying the color of each of the defect portions that appear in the index image.

5. A lens measuring device according to any one of claims 1 to 4, The lens measuring device is characterized in that, in the calculation step, when the control unit obtains the optical characteristics of the lens by calculation, it excludes the optical characteristic information obtained from the missing portion of each of the plurality of index image images used to generate the panoramic index image.

Images