JP7615534B2 - Eyeglass lens shape measuring device, eyeglass lens processing device equipped with the same, and eyeglass lens shape measuring program - Google Patents

Description

The present disclosure relates to an eyeglass lens shape measuring device that measures the shape of the refractive surface of an eyeglass lens, an eyeglass lens processing device equipped with the same, and an eyeglass lens shape measuring program that measures the shape of the refractive surface of an eyeglass lens.

A spectacle lens shape measuring device that measures the shape of the refractive surfaces of a spectacle lens (the front and rear surfaces of the lens that have refractive power) is provided, for example, in a spectacle lens processing device that processes the periphery of a spectacle lens using a processing tool. The spectacle lens shape measuring device has a measuring probe that contacts the front refractive surface (front lens surface) and rear refractive surface (rear lens surface) of the spectacle lens (see, for example, Patent Document 1).

JP 2014-004678 A

The measurement of the refractive surface of a lens using an eyeglass lens shape measuring device is performed, for example, by rotating the lens once while contacting a probe with the refractive surface based on the lens shape (the outer diameter shape of the target lens) and detecting the position of the probe in the axial direction of the lens chuck shaft that holds the eyeglass lens. When processing the periphery of an eyeglass lens, in order to obtain edge position information (edge position according to the lens shape and inclination information of the refractive surface at that edge position, etc.) planned after finishing processing of the lens, conventionally, one refractive surface is measured at least twice (two revolutions) with different measurement trajectories.

However, there was a problem with measuring one refracting surface twice (two revolutions), as this took a long time to measure.

In view of the above-mentioned conventional techniques, the technical objective of this disclosure is to shorten the measurement time for the refractive surface shape of a lens.

In order to solve the above problems, the present disclosure is characterized by having the following configuration.
(1) A spectacle lens shape measuring device according to a first aspect of the present disclosure is configured to measure the shape of a refractive surface of a spectacle lens based on a lens shape before grinding or cutting the periphery of the spectacle lens using a processing tool provided in a spectacle lens processing device, and is provided in the spectacle lens processing device, and is characterized in that it comprises: a holding means having a holding shaft that holds and rotates the spectacle lens, a measuring probe to be brought into contact with the refractive surface of the spectacle lens, a moving means for relatively changing the positional relationship between the measuring probe and the refractive surface of the spectacle lens held on the holding shaft, a detection means for detecting the position of the measuring probe in the axial direction of the holding shaft, a measurement trajectory determination means for determining a reference trajectory for one revolution of the spectacle lens based on the lens shape, and for determining a measurement trajectory having a component that is partially displaced in the radial direction with respect to the reference trajectory, and a control means for controlling the moving means based on the measurement trajectory, and for acquiring the shape of the refractive surface of the spectacle lens in the axial direction of the holding shaft based on the detection result of the detection means.
(2) A spectacle lens processing apparatus according to a second aspect of the present disclosure is characterized in that it includes the spectacle lens shape measuring apparatus according to (1).
(3) A spectacle lens shape measurement program according to a third aspect of the present disclosure includes a holding means having a holding shaft that holds and rotates a spectacle lens, a measuring element to be brought into contact with the refractive surface of the spectacle lens, a moving means that relatively changes the positional relationship between the refractive surface of the spectacle lens held on the holding shaft and the measuring element based on a lens shape, and a detection means that detects the position of the measuring element in the axial direction of the holding shaft, and is configured to measure the shape of the refractive surface of the spectacle lens based on a detection result of the detection means before grinding or cutting the periphery of the spectacle lens using a processing tool provided in the spectacle lens processing apparatus, and is executed by a spectacle lens shape measuring device provided in the spectacle lens processing apparatus, and is characterized in that the spectacle lens shape measurement program causes the spectacle lens shape measuring device to execute a reference trajectory determination step that determines a reference trajectory for one revolution of the spectacle lens based on the lens shape, a measurement trajectory determination step that determines a measurement trajectory so as to have a component that is partially displaced in the radial direction with respect to the reference trajectory, and a control step that controls the moving means based on the measurement trajectory and obtains the refractive surface shape of the spectacle lens in the axial direction of the holding shaft based on the detection result of the detection means.

2 is a diagram illustrating a configuration of a processing mechanism unit in the eyeglass lens processing apparatus according to the embodiment. FIG. 2 is a diagram illustrating a schematic configuration of a lens shape measuring unit included in the eyeglass lens shape measuring device. FIG. 2 is a control system block diagram relating to the eyeglass lens processing apparatus and the eyeglass lens shape measuring apparatus. FIG. 1A and 1B are diagrams illustrating an example of two-loop measurement trajectories in conventional lens shape measurement. 11A and 11B are diagrams illustrating an example of a conventional method for determining two measurement trajectories for beveling and grooving. 1 is an example of a typical measurement trajectory according to an embodiment. 13A and 13B are diagrams illustrating a fluctuation component caused by a radial shift with respect to a reference trajectory. 13 is a diagram for explaining a method of projecting an edge radial locus onto a sphere along the axial direction of a holding shaft. FIG. FIG. 13 is a diagram showing another example of a measurement trajectory. FIG. 13 is a diagram showing another example of a measurement trajectory.

The present embodiment will be described below with reference to the drawings. Figures 1 to 10 are diagrams for explaining the configuration of an eyeglass lens shape measuring device according to this embodiment, an eyeglass lens processing device equipped with the same, and an eyeglass lens shape measuring program.

[overview]
1 is a diagram illustrating the configuration of a spectacle lens shape measuring device according to an embodiment of the present disclosure, a spectacle lens processing device including the same, and a spectacle lens shape measuring program.

For example, the eyeglass lens shape measuring device includes a holding means (e.g., lens holding unit 100) configured to hold an eyeglass lens (hereinafter, lens) LE. For example, the holding means includes a holding shaft (e.g., lens chuck shaft 102) configured to hold the lens LE. For example, the eyeglass lens shape measuring device includes a measuring probe (e.g., measuring probe 260) that is brought into contact with the refractive surface of the lens LE (at least one of the front surface of the lens and the rear surface of the lens having refractive power). For example, the eyeglass lens shape measuring device includes a moving means (e.g., moving unit 300) that relatively changes the positional relationship between the lens LE held by the holding means and the measuring probe. For example, the eyeglass lens shape measuring device includes a detection means (e.g., sensor 280) that detects the position of the measuring probe in the axial direction of the holding shaft of the holding means (e.g., the axis L1 direction in FIG. 1). The position of this measuring probe is a position relative to a predetermined reference position in the axial direction of the holding shaft (e.g., the position of the front refractive surface of the lens LE on axis L1). The detection means may include control information (e.g., control unit 50) when the movement means changes the axial positional relationship between the lens LE and the probe.

For example, the eyeglass lens shape measuring device includes an acquisition means (e.g., data acquisition unit 10) that acquires the lens shape (the two-dimensional outer diameter shape of the target lens). For example, the eyeglass lens shape measuring device includes a measurement trajectory determination means (e.g., control unit 50) that determines a measurement trajectory for measuring the shape of the refractive surface of the lens LE based on the lens shape. The measurement trajectory determination means is configured to determine a reference trajectory (e.g., ST1 in FIG. 6) for one revolution of the lens LE based on the lens shape, and to determine the measurement trajectory so as to have a fluctuation component (e.g., Δd in FIG. 7) that is partially displaced in the radial direction with respect to the reference trajectory. For example, the measurement trajectory determination means determines a measurement trajectory for one revolution of the lens LE.

For example, the reference trajectory is a trajectory that has a certain relationship with the target lens shape, and is defined by data on the radius vector angle and the radius vector length. For example, the reference trajectory may be the same as the target lens shape, or may be a trajectory that is shifted a certain distance inward or outward with respect to the target lens shape, or the reference trajectory may be a trajectory that is shifted a certain distance inward or outward in the normal direction with respect to each point of the target lens shape. For example, in the case of bevel processing to form a bevel on the lens periphery, the trajectory of the shoulder of the bevel (for example, a trajectory shifted 0.8 mm inward with respect to the target lens shape) may be the reference trajectory. For example, in the case of flat processing to form a groove on the lens periphery, a trajectory that matches the target lens shape may be used. In addition, if the material of the measuring element is hard and there is a risk of scratching the refractive surface of the lens LE, the trajectory may be shifted outward by a certain distance (for example, 0.3 mm) from the trajectory of the shoulder of the bevel or the trajectory that matches the target lens shape.

For example, the "variable component that is changed in the radial direction" is the portion where the radial length of the measurement trajectory has changed relative to the radial length of the reference trajectory. For example, the variable component has a distance of 0.3 mm or more in the radial direction partially away from the reference trajectory so that the inclination of the lens refractive surface at the edge position of the lens can be obtained.

For example, the measurement trajectory may be a trajectory having a component that varies periodically in the radial direction relative to the reference trajectory. This allows the measurement time to be shortened by measuring in one revolution while maintaining measurement accuracy. Also, for example, the measurement trajectory may have at least one of a component that varies curvilinearly in the radial direction relative to the reference trajectory and a component that varies linearly. For example, the measurement trajectory may be a meandering trajectory that meanders in part with a variable component in the radial direction relative to the reference trajectory. This allows information on the refractive surface shape of the lens to be obtained more accurately while still measuring in one revolution, and also shortens the measurement time.

For example, the measurement trajectory determination means determines an auxiliary trajectory that is shifted a certain distance in the radial direction around the entire circumference of the reference trajectory, and determines the measurement trajectory so that it passes through this auxiliary trajectory. This makes it possible to determine a measurement trajectory that ensures measurement accuracy.

For example, the eyeglass lens shape measuring device includes a control means (e.g., control unit 50) that controls the moving means based on the measurement trajectory and obtains the refractive surface shape of the lens LE in the holding axial direction of the holding means based on the detection result of the detection means. This makes it possible to obtain the edge position after finishing of the lens LE and the inclination information of the lens refractive surface at that edge position by measuring one revolution of the lens LE, thereby shortening the measurement time compared to the conventional measurement of at least two revolutions.

For example, the control means obtains a sphere on which the measurement trajectory is located based on the detection result of the detection means, and projects the edge radial trajectory planned after finishing of the lens LE onto the obtained sphere, thereby acquiring shape information of the lens refractive surface related to the projected trajectory. For example, the control means obtains edge position information in the axial direction of the holding shaft corresponding to the projected trajectory and inclination information of the lens refractive surface at the edge position as shape information of the lens refractive surface.

For example, the eyeglass lens shape measuring device includes a two-lap trajectory determining means (e.g., control unit 50) that determines at least two different measurement trajectories of the lens LE based on the target lens shape, and a selection means (e.g., selection unit 52) configured to select a measurement trajectory when the control means controls the moving means, and the selection means selects whether the measurement trajectory is the measurement trajectory determined by the measurement trajectory determining means or the measurement trajectory of at least two laps determined by the two-lap trajectory determining means. For example, the two-lap trajectory determining means determines a first measurement trajectory of the first lap based on the target lens shape, and determines a second measurement trajectory of the second lap as a trajectory that is displaced by a certain distance in the radial direction from the first measurement trajectory. For example, the selection means may include a signal input means for an operator to input a selection signal, or may be configured such that the selection signal is automatically input by the control means.

In cases where there is a possibility that measuring the lens shape in one revolution may result in poor accuracy of information such as the inclination of the edge position (for example, when the lens LE has a high degree of astigmatism), by selecting to measure the lens shape in at least two revolutions, it is possible to obtain information that does not result in a decrease in accuracy.

For example, the eyeglass lens shape measuring device may be provided in an eyeglass lens processing device that processes the periphery of the lens LE using a processing tool. For example, the holding means may be shared with the holding means (e.g., lens holding unit 100) provided in the eyeglass lens processing device. For example, the moving means may be shared with the lens moving means (e.g., moving unit 300) provided in the eyeglass lens processing device.

Note that this disclosure is not limited to the device described in this embodiment. For example, a spectacle lens shape measurement program (software) that performs the functions of the following embodiment is supplied to a system or device via a network or various storage media. A control device (e.g., a CPU, etc.) of the system or device can then read and execute the program.

For example, the eyeglass lens shape measurement program is executed by an eyeglass lens shape measurement device that includes a moving means for relatively changing the positional relationship between the lens LE held by the holding means and a measuring element based on the lens shape, and a detection means for detecting the position of the measuring element in the holding axis direction of the holding means, and measures the shape of the refractive surface of the lens LE based on the detection result of the detection means. For example, the eyeglass lens shape measurement program includes a reference trajectory determination step for determining a reference trajectory for one revolution of the lens LE based on the lens shape. For example, the eyeglass lens shape measurement program includes a measurement trajectory determination step for determining a measurement trajectory so as to have a component that is partially displaced in the radial direction from the reference trajectory. For example, the eyeglass lens shape measurement program includes a control step for controlling the moving means based on the measurement trajectory, and obtaining the refractive surface shape of the eyeglass lens in the holding axis direction of the holding means based on the detection result of the detection means.

For example, the control step of the eyeglass lens shape measurement program finds a sphere on which the measurement trajectory is located based on the detection results of the detection means, and projects the edge radial trajectory planned after finishing processing of the lens LE onto the found sphere, thereby obtaining the refractive surface shape of the lens related to the projected trajectory.

[Example]
A typical embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a diagram illustrating the configuration of a processing mechanism in an eyeglass lens processing apparatus 1 according to the embodiment. For example, in this embodiment, an eyeglass lens processing apparatus 1 equipped with an eyeglass lens shape measuring apparatus 200 will be described as an example. Fig. 2 is a diagram illustrating the schematic configuration of a lens shape measuring unit 200A equipped in the eyeglass lens shape measuring apparatus 200.

For example, the eyeglass lens shape measuring device 200 includes a lens holding unit 100, which is an example of a holding means. In this embodiment, the lens holding unit 100 is shared with the holding means included in the eyeglass lens processing device 1. For example, the eyeglass lens shape measuring device 200 includes a lens shape measuring unit 200A provided with a measuring probe 260 (261, 262) that is brought into contact with the refractive surface of the lens LE (see FIG. 2). In this embodiment, the lens shape measuring unit 200A is provided on the base 2 of the eyeglass lens processing device 1. For example, the eyeglass lens shape measuring device 200 includes a moving unit 300, which is an example of a moving means. The moving unit 300 is configured to relatively change the positional relationship between the lens LE held by the lens holding unit 100 and the measuring probe 260 (261, 262).

For example, the eyeglass lens processing device 1 includes a first processing tool unit 150. The first processing tool unit 150 is configured to rotate a processing tool that processes the periphery of the lens LE. For example, the eyeglass lens processing device 1 includes a second processing tool unit 400. The second processing tool unit 400 is configured to rotate a processing tool that processes a groove on the periphery of the lens LE. In this embodiment, the moving unit 300 is also used as a moving means provided in the eyeglass lens processing device 1. The moving unit 300 is configured to change (adjust) the relative positional relationship between the lens LE and the processing tool held by the first processing tool unit 150. In addition, the moving unit 300 is configured to change (adjust) the relative positional relationship between the lens LE and the processing tool held by the second processing tool unit 400.

For example, the lens holding unit 100 includes a lens chuck shaft 102 for holding (clamping) and rotating the lens LE, and a carriage 101. The lens chuck shaft 102 includes a pair of lens chuck shafts 102L and 102R. The lens chuck shaft 102L is rotatably held by the left arm 101L of the carriage 101, and the lens chuck shaft 102R is rotatably held by the right arm 101R of the carriage 101. The lens chuck shaft 102 (i.e., the lens LE) is rotated by a motor 120, which is an example of a lens rotation means. In addition, a motor 110 for moving the right chuck shaft 102R toward the left chuck shaft 102L is disposed on the right arm 101R. By moving the right chuck shaft 102R toward the left chuck shaft 102L, the lens LE is held by the two lens chuck shafts 102L and 102R.

The first processing tool unit 150 includes a motor 160 for rotating a processing tool rotation shaft 161. The processing tool rotation shaft 161 is rotatably held on the base 2 in a positional relationship parallel to the lens chuck shaft 102. A plurality of processing tools 163 for processing the periphery of the lens LE are attached to the processing tool rotation shaft 161. For example, the processing tools 163 include at least one of a rough processing tool 163a for plastic, a finishing processing tool 163b for high curve lenses, a mirror finish processing tool 163c, a finishing processing tool 163d for low curves, and a rough processing tool 163e for glass. The mirror finish processing tool 163c and the finishing processing tool 163d each include at least one of a V-groove for bevel processing and a flat finishing surface for flat processing. For example, a grindstone is used for the processing tool 163, but a cutter may also be used. The terms "mirror finish," "bevel processing," and "flat processing" are well known to those skilled in the art, so detailed explanations will be omitted.

For example, the second processing tool unit 400 is disposed behind the carriage 101. The second processing tool unit 400 includes, for example, a groove digging tool 413 for forming a groove on the periphery of the lens LE. The groove digging tool 413 is attached to a rotating shaft 410. The rotating shaft 410 is rotated by a motor 415. The second processing tool unit 400 also includes a hole digging tool 423. The second processing tool unit 400 also includes a chamfering tool (not shown). The hole digging tool 423 and the chamfering tool are rotated by the motor 415 via a rotation transmission mechanism. The second processing tool unit 400 can adopt, for example, a configuration described in JP 2017-177234 A, so please refer to this for details. The terms "groove digging", "hole digging", and "chamfering" are well known to those skilled in the art, so detailed explanations will be omitted.

For example, the moving unit 300 includes a first moving unit 310 that relatively changes the positional relationship in the distance direction between the lens chuck shaft 102 and the probe 260, and a second moving unit 330 that relatively changes the positional relationship between the lens LE and the probe 260 in the axis L1 direction of the lens chuck shaft 102. In this embodiment, the axis L1 direction of the lens chuck shaft 102 is the X direction. The direction in which the distance between the lens chuck shaft 102 and the probe 260 is changed is the Y direction.

The first moving unit 310 is also used to change the axial distance between the lens chuck shaft 102 and the processing tool rotation shaft 161 and the rotation shaft 410 when processing the lens LE. The second moving unit 330 is also used to move the lens LE in the axial direction of the lens chuck shaft 102 when processing the lens LE.

The first moving unit 310 includes a motor 315. The rotation of the motor 315 moves the moving base 301 in the X direction. This causes the carriage 101 and the lens chuck shaft 102 (lens LE) mounted on the moving base 301 to move in the X direction. The first moving unit 310 may be configured to move the stylus 260 in the X direction. It may also be configured to move the processing tool rotation shaft 161 in the X direction.

The second moving unit 330 is equipped with a motor 335 for moving the carriage 101 (lens chuck shaft 102) in the Y direction. A shaft 333 extending in the Y direction is attached to the moving support base 301. A motor 335 is fixed to the moving support base 301. The rotation of the motor 335 is transmitted to a ball screw 337 extending in the Y direction, and the carriage 101 (lens chuck shaft 102 and lens LE) is moved in the Y direction by the rotation of the ball screw 337.

In the embodiment, the second moving unit 330 is configured to move the lens chuck shaft 102 in the Y direction, but it may also be configured to move the stylus 260 in the Y direction. It may also be configured to move the processing tool rotation shaft 161 and the rotation shaft 410 in the Y direction.

In FIG. 2, for example, the lens shape measuring unit 200A includes a probe 260 that is brought into contact with the refractive surface of the lens LE, the probe 261 being brought into contact with the front surface (front refractive surface) of the lens, and a probe 262 being brought into contact with the rear surface (rear refractive surface) of the lens. The probe 262 may have a cylindrical side surface. The side surface of the probe 262 may be used as a probe that is brought into contact with the outer periphery of the lens LE (demo lens) to measure the outer diameter shape of the lens LE.

For example, the probes 261 and 262 are held by an arm 265 that can move in the X direction. In this embodiment, the arm 265 has a U-shaped shape. The arm 265 is attached to a support 267, and the support 267 is held by a block 269 so as to be movable in the X direction. For example, in this embodiment, the support 267 can be tilted in the X direction around a support shaft 271 via a bearing 270 held by the block 269. The support 267 is biased toward the front side and the rear side of the lens by a spring (biasing member) (not shown) with the state in FIG. 2 as the neutral position. The positions of the probes 261 and 262 in the X direction are detected by a sensor (detector) 280, which is an example of a detection means, via the arm 265 and the support 267. The sensor 280 is configured as a known one.

The configuration for holding the stylus 260 (261, 262) movably in the X direction is not limited to the embodiment. For example, the stylus 260 (261, 262) may be held so as to be linearly movable in the X direction. The stylus 261 and the stylus 262 may be held so as to be movable separately in the X direction. In this device, the shape of the front refractive surface of the lens LE is measured by controlling the movement of the lens chuck shaft 102 in the X direction even during measurement, but this is not limited to this. The lens chuck shaft 102 may not be moved in the X direction during measurement, and the measurement may be performed by detecting the change in the position of the stylus 260 that moves with the change in the refractive surface of the lens LE. FIG. 3 is a control system block diagram for the eyeglass lens processing device 1 and the eyeglass lens shape measuring device 200. The eyeglass lens shape measuring device 200 includes a control unit 50. The control unit 50 is connected to the electrical components (motors, etc.) of each unit shown in FIGS. 1 and 2. The control unit 50 also serves as the control unit of the eyeglass lens processing apparatus 1. The control unit 50 is configured to control the entire apparatus. The control unit 50 is also configured to perform various calculations for measuring the refractive surface shape of the lens LE and various calculations for lens processing.

For example, the eyeglass lens processing device 1 and the eyeglass lens shape measuring device 200 are equipped with a data acquisition unit 10. The data acquisition unit 10 may also function as a data input unit. For example, the data acquisition unit 10 is equipped with a display 12. For example, the data acquisition unit 10 is equipped with a data input unit 13. For example, the display 12 may be equipped with a touch panel function and configured to include the data input unit 13.

For example, the eyeglass lens processing device 1 and the eyeglass lens shape measuring device 200 include a memory 20, which is an example of a storage means. The memory 20 stores various data acquired by the data acquisition unit 10. The memory 20 also stores various programs for controlling the operation of the eyeglass lens shape measuring device 200 and the eyeglass lens processing device 1. For example, the memory 20 stores a program for measuring the refractive surface shape of the lens LE. The memory 20 also stores a program related to peripheral processing of the lens LE.

For example, the eyeglass lens shape measuring device 200 includes a selection unit 52, which is an example of a selection means configured to select whether the measurement trajectory is a trajectory performed in one revolution or a trajectory performed in at least two revolutions. The selection unit 52 may be configured so that it is also the control unit 50. The selection unit 52 may be configured to be included in the data input unit 13.

The data acquisition unit 10, memory 20, and selection unit 52 are connected to the control unit 50. The data acquisition unit 10 may be connected to the lens shape measuring device 30. For example, the lens shape measuring device 30 obtains the lens shape (the target outer diameter shape for processing the lens edge) of the lens LE by measuring the rim of the eyeglass frame. The lens shape stored in the memory 20 may be used. The data acquisition unit 10 obtains the lens shape data from the lens shape measuring device 30 or the memory 20. The "lens shape" is a two-dimensional shape defined by the radius vector length and the radius vector angle, and is self-evident and well known to those skilled in the art, so a detailed explanation will be omitted.

<Operation>
The operation of the eyeglass lens shape measuring device 200 and eyeglass lens processing device 1 having the above-described configuration will be described.

First, the data acquisition unit 10 acquires the lens shape data (radial length r, radial angle θ) of the lens LE. For example, the contour shape of the rim of the eyeglass frame measured by the lens shape measuring device 30 is input to the data acquisition unit 10. The lens shape data may be acquired by the data acquisition unit 10 by calling up the data stored in the memory 20.

Once the lens shape data has been acquired, the operator sets (inputs) the processing conditions for processing the periphery of the lens LE via the display 12. For example, in order to process the periphery of the lens LE, layout data is input for locating the optical center position of the lens LE relative to the lens shape. For example, the layout data includes the distance FPD between the left and right lens shape centers, the interpupillary distance PD, and the height distance of the optical center relative to the center of the lens shape. In addition, the lens material, frame type (metal, cell, rimless, etc.), lens periphery processing type (bevel processing, flat processing, groove processing, etc.), whether or not mirror processing is performed, etc. are input as processing conditions.

When the input of the processing conditions is complete, the operator holds the lens LE on the lens chuck shaft 102 (102L, 102R) and starts the operation of the eyeglass lens processing device 1. Prior to peripheral processing of the lens LE, the eyeglass lens shape measurement program is executed by the control unit 50, and the shape of the lens LE is measured by the eyeglass lens shape measuring device 200.

The control unit 50 determines the measurement trajectory based on the target lens shape. For example, the target lens shape is assumed to be circular. For example, the position at which the lens chuck shaft 102 chucks the lens LE is set to the frame center (the geometric center of the target lens shape).

Here, in the conventional lens shape measurement, as shown in FIG. 4, two measurements of the first measurement trajectory CT1 and the second measurement trajectory CT2 were performed on the front and rear refractive surfaces of the lens LE. The first measurement trajectory CT1 and the second measurement trajectory CT2 are different trajectories. For example, the first measurement trajectory CT1 is determined based on the target lens shape, and the second measurement trajectory CT2 is determined as a trajectory that is displaced in the radial direction by a certain distance from the first measurement trajectory CT1. For example, in the case of bevel processing, as shown in FIG. 5(a), the first measurement trajectory CT1 is set to the position of the bevel shoulder Vs, and the second measurement trajectory CT2 is set to a certain distance outside the first measurement trajectory CT1 (for example, a position 0.8 mm outside that includes the bevel apex Vt). For example, in the case of groove cutting, as shown in FIG. 5B, the first measurement trajectory CT1 is set to the edge position Lc of the lens LE, and the second measurement trajectory CT2 is set to a certain distance outside the first measurement trajectory CT1 (for example, 0.3 mm outside). The measurement results of the first measurement trajectory CT1 provide information on the edge position of the lens LE after peripheral processing (after finishing processing), and this, together with the measurement results of the second measurement trajectory CT2, provides information on the inclination of the lens surface at the edge position. This allows chamfering to be performed with high accuracy. However, measuring the lens shape for at least two revolutions takes a long measurement time.

In this embodiment, for example, a reference trajectory for one revolution of the lens LE is determined, and a measurement trajectory is determined so as to have a component that is partially displaced in the radial direction from this reference trajectory, making it possible to obtain information on the edge position after peripheral processing of the lens LE and information on the inclination of the lens surface at the edge position from the measurement results for one revolution. Note that the following description will be given assuming that the target lens shape data is circular.

FIG. 6 is an example of a typical measurement trajectory according to the embodiment. The control unit 50 determines a reference trajectory ST1 of one revolution of the lens LE based on the target lens data (r, θ). The reference trajectory ST1 is a trajectory having a certain relationship with the target lens, and is defined by data of a radius vector angle and a radius vector length. For example, the reference trajectory ST1 may be a trajectory of the target lens, or a trajectory obtained by varying a certain distance in the radial direction (inward or outward) with respect to the target lens. Alternatively, the reference trajectory ST1 may be a trajectory obtained by varying a certain distance inward or outward in the normal direction with respect to each point of the target lens. The reference trajectory ST1 is determined in the same manner as the conventional first measurement trajectory CT1 (see FIG. 4). Next, the control unit 50 determines the measurement trajectory MT so as to have a component that is partially varied in the radial direction with respect to the reference trajectory ST1. For example, the measurement trajectory MT is determined so as to add a fluctuation component Δd that varies sinusoidally in the radial direction with respect to the reference trajectory ST1 (see FIG. 7). For example, the fluctuation component Δd has a distance that can obtain the inclination of the lens refractive surface at the edge position of the lens. For example, the fluctuation component Δd is at least 0.3 mm or more. For practical purposes, it is preferable that the fluctuation component Δd is 0.5 mm or more.

For example, the measurement trajectory MT may be determined so that a trajectory of a fluctuation component Δd that is periodically fluctuated in the radial direction with respect to the reference trajectory ST1 appears. The example of the measurement trajectory MT in Figure 6 is an example determined so that the trajectory of the sinusoidal fluctuation component Δd in Figure 7 appears over the entire circumference at regular distances, and is also an example of a trajectory that meanders in part with a fluctuation component in the radial direction with respect to the reference trajectory ST1. The number and period of the fluctuation components Δd may be determined taking into consideration the relationship between the measurement accuracy and the measurement speed. The height of the fluctuation component may also be determined taking into consideration the relationship between the measurement accuracy and the measurement speed.

For example, the trajectory of the fluctuation component Δd may be determined to pass through an auxiliary trajectory ST2 that is shifted a certain distance Δr in the radial direction from the reference trajectory ST1. For example, the certain distance Δr is determined to be the same distance as the conventional second measurement trajectory CT2 (see FIG. 4). The examples in FIGS. 6 and 7 are examples in which the maximum of the trajectory of the fluctuation component Δd is determined to be located on the auxiliary trajectory ST2.

The control unit 50 controls the moving unit 300 based on the measurement trajectory MT and measures the shape of the refractive surface of the lens LE based on the detection result of the sensor 280. For example, first, the shape of the front refractive surface of the lens LE is measured. When the measurement of the front refractive surface of the lens LE starts, the lens chuck shaft 102 is moved in the Y direction based on the measurement trajectory MT, and then the lens chuck shaft 102 is moved in the X direction so that the measuring probe 261 contacts the front refractive surface of the lens LE. The contact of the measuring probe 261 with the front refractive surface is detected based on the output of the sensor 280. Then, the lens LE is rotated by the rotation of the lens chuck shaft 102, and the lens chuck shaft 102 is moved in the Y direction based on the measurement trajectory MT. Based on the output of the sensor 280 at this time, the shape of the front refractive surface of the lens LE corresponding to the measurement trajectory MT (shape in the X direction, which is the axis L1 direction of the lens chuck shaft 102) is measured. In addition, in this device, the shape of the front refractive surface of the lens LE is measured by controlling the movement of the lens chuck shaft 102 in the X direction even during measurement, and information on the lens shape is also obtained by using information on the movement of the lens chuck shaft 102 in the X direction. The shape of the rear refractive surface of the lens LE is measured in the same way, so a description of this is omitted.

By performing the lens shape measurement, the control unit 50 obtains shape information of the refractive surface of the lens LE. For example, the measurement result of the lens front refractive surface is (mr, mθ, mz). mr is the radial length of the measurement trajectory MT, mθ is the radial angle, and mz is the position data of the lens refractive surface in the direction of the axis L1 of the lens chuck shaft 102 (distance data relative to a predetermined reference position).

After the measurement result of the refractive surface shape of the lens LE is obtained, the control unit 50 calculates and obtains the edge position in the axis L1 direction of the lens chuck shaft 102 and the inclination information of the lens refractive surface at the edge position with respect to the edge radial trajectory KA planned after the finishing process of the lens LE. The edge radial trajectory KA in this embodiment is the radial information (radial length and radial angle information) of the two-dimensional shape where the edge after the finishing process is located, for example, the conventional first measurement trajectory CT1. The edge position on the front and rear refractive surfaces of the lens LE corresponding to the edge radial trajectory KA is obtained, and the edge thickness of the lens LE after the finishing process is obtained. As a result, in the case of bevel processing, the bevel apex position in the thickness direction (X direction) of the lens LE can be determined, and in the case of groove engraving, the groove center position in the thickness direction of the lens LE can be determined. For example, the bevel apex position and the groove center position are determined to be located at a ratio of 3:7 with respect to the thickness of the lens LE.

A method for obtaining the edge position in the axis L1 direction with respect to the edge radial locus KA and the inclination information of the lens refractive surface at the edge position will be described. For example, the control unit 50 mathematically obtains the sphere Sc (see FIG. 8) on which the measurement locus MT is placed based on the measurement results (mr, mθ, mz) of the lens front refractive surface. For example, four arbitrary points are taken from the data of the measurement results (mr, mθ, mz) and a sphere through which these four points pass is obtained. For example, the arbitrary four points are points that pass through the geometric center of the measurement locus MT and are located in a direction perpendicular to the geometric center. Then, the method of taking the arbitrary four points is changed and the calculation to obtain the sphere is performed multiple times. For example, if there are 1,000 measurement points, the calculation to obtain 250 spheres is performed. Then, the least squares method or the like is used to obtain the radius and center of the most approximate sphere Sc on which the measurement locus MT is placed. Note that the center of the sphere Sc is obtained by assuming that it is located on the lens chuck axis 102.

Once the sphere Sc has been determined, as shown in FIG. 8, the edge radial trajectory KA (radial length, radial angle) is projected onto the sphere Sc along the axis L1 direction of the lens chuck shaft 102. The trajectory projected onto the sphere Sc (edge projection trajectory) is designated as Kp. This makes it possible to mathematically determine the edge position in the axis L1 direction corresponding to the trajectory Kp. In addition, since the radius of the sphere Sc is known, inclination information (i.e., inclination information of the lens refractive surface relative to the lens chuck shaft 102) at each edge position corresponding to the trajectory Kp can be obtained. This inclination information is used, for example, to determine the width of the chamfering of the edge of the lens LE.

For the rear refractive surface of the lens LE, the control unit 50 uses a similar method to obtain the edge position in the direction of the axis L1 relative to the edge radial locus KA and the inclination information of the lens refractive surface at that edge position.

As described above, the information required for processing the lens LE (for example, the edge position after finishing processing and the inclination information of the lens surface at that edge position) can be obtained by measuring the lens shape in one revolution for one side of the refractive surface of the lens LE, so the measurement time can be shortened compared to the conventional measurement of two or more revolutions. Also, it is possible to obtain more measurement data in the measurement time for one revolution than in the conventional one-revolution measurement, improving the accuracy of the information required for processing.

If the radius length (the radius length based on the geometric center of the lens shape) varies greatly depending on the radius angle, as in the case of a rectangular lens shape, it may be possible to estimate the sphere Sc shown in FIG. 8 by only measuring one revolution (for example, the first measurement trajectory CT1) out of the conventional two revolution measurements. However, if the lens shape is close to a sphere, the estimation accuracy of the sphere Sc decreases, and the accuracy of the edge position information (the edge position in the axis L1 direction and the inclination information at that edge position) planned after finishing processing decreases. In contrast, if the method for determining the measurement trajectory of this embodiment is used, measurement data equivalent to two revolutions can be obtained in the measurement time of one revolution, improving the accuracy of the edge position information.

When the lens LE has a high degree of astigmatism, the posterior refractive surface becomes aspheric, deviating from the spherical surface. In this case, the accuracy of the edge position and inclination information of the trajectory Kp obtained based on the above-mentioned sphere Sc may decrease. In such a case, the selection unit 52, which is an example of a selection means, may be made selectable so that at least two-round measurements of the lens can be performed. For example, the measurement trajectories of the two rounds are determined by the control unit 50 as different trajectories based on the target lens shape. For example, like the measurement trajectories C1 and CT2 of the conventional two-round measurement, the first measurement trajectory of the first round is determined based on the target lens shape, and the second measurement trajectory of the second round is determined as a trajectory that is displaced by a certain distance in the radial direction from the first measurement trajectory.

For example, the selection unit 52 is provided with a selection switch that allows the operator to input a selection signal, and when a signal is input from this selection switch, the control unit 50 executes a two-round measurement. The input of this selection signal may also be performed automatically by the control unit 50. For example, the cylindrical power of the lens LE is input by the data input unit 13, and the control unit 50 selects whether to perform a one-round measurement or a two-round measurement based on the cylindrical power.

Furthermore, it may be possible to select two-round measurement of the lens when the lens shape is closer to a circle than a certain reference. For example, depending on the setting of the fluctuation component Δd of the measurement trajectory MT relative to the reference trajectory ST1, if the lens shape is too close to a circle, the accuracy of acquiring edge position information may be poor. For example, the lens shape is close to a circle when the difference between the maximum and minimum values of the radius length relative to the geometric center of the lens shape is equal to or less than a predetermined value, and in this case, it may be possible to select by the selection unit 52 (at least one of manual selection by the operator and automatic selection by the control unit 50) to perform two-round measurement.

Once the shape information expected after the finishing of the lens LE is obtained, the peripheral processing of the lens LE is performed. A brief description of the peripheral processing of the lens LE will be given. Below, the case of bevel processing will be described. First, rough processing is performed. The control unit 50 acquires rough processing data based on the target shape, controls the moving unit 300 based on the rough processing data, and roughly processes the lens LE with the rough processing tool 163a. Next, the bevel is finished. The control unit 50 calculates the bevel trajectory (radius information and information on the position of the bevel apex in the axis L1 direction) based on the shape information expected after the finishing of the lens LE, controls the moving unit 300 based on this, and the peripheral edge of the lens LE after rough processing is beveled with the finishing tool 163d. If chamfering is required, the moving unit 300 is controlled based on the edge position information of the trajectory Kp and the inclination information at the edge position, and the edge of the lens LE is chamfered using the chamfering tool held by the second processing tool unit 400.

The measurement trajectory MT in FIG. 6 described above is merely an example. FIGS. 9 and 10 are diagrams showing other examples of the measurement trajectory MT. FIG. 9(a) is an example in which the trajectory of the fluctuation component Δd changes linearly compared to the example in FIG. 6. FIG. 9(b) is an example in which the measurement trajectory MT is determined such that a portion of the trajectory follows the reference trajectory ST1, a portion of the trajectory follows the auxiliary trajectory ST2, and the trajectory between the two is a straight or curved trajectory. Also, FIGS. 9(a) and 9(b) are examples in which the trajectory of the fluctuation component Δd appears periodically. Note that when multiple fluctuation components Δd appear, their height (the radial distance from the reference trajectory ST1) may differ depending on the location.

Even if the target trajectory (reference trajectory ST1) is circular, in principle it is possible to obtain the sphere Sc on which the measurement trajectory MT is located as long as it has at least a component that has shifted in the radial direction from the circular shape, so it is not necessarily necessary for it to appear periodically. For example, as shown in FIG. 9(c), it is also possible for only one trajectory of the shift component Δd to appear for the reference trajectory ST1.

Figure 9(d) shows an example in which two trajectories of the fluctuation component Δd appear, where one fluctuation component Δd is a trajectory in which 1/4 of the measurement trajectory MT has a fluctuation component along the auxiliary trajectory ST2, and the second fluctuation component Δd is arranged symmetrically at 180 degrees.

Figure 10 shows an example of a measurement trajectory MT in which the fluctuation component Δd coincides with the auxiliary trajectory ST2 at four points on the measurement trajectory MT with radial angles of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, and coincides with the reference trajectory ST1 at four points with radial angles of 45 degrees, 135 degrees, 225 degrees, and 315 degrees, with each point being connected by a curve.

In this way, the measurement trajectory MT can have various patterns, and it is sufficient if it has a component Δd that is partially displaced in the radial direction with respect to the reference trajectory ST1. There should be at least one displacement component Δd, and preferably there should be multiple displacement components.

The above describes typical examples of the present disclosure, but the present disclosure is not limited to the examples shown here, and various modifications are possible within the scope of the same technical concept of the present disclosure.

REFERENCE SIGNS LIST 1 eyeglass lens processing device 50 control unit 52 selection unit 100 lens holding unit 150 first processing tool unit 102 lens chuck shaft 200 eyeglass lens shape measuring device 200A lens shape measuring unit 260 probe 280 sensor 300 moving unit ST1 reference trajectory MT measurement trajectory Δd fluctuation component

Claims (6)

A spectacle lens shape measuring device that is configured to measure the shape of a refractive surface of a spectacle lens based on a target lens shape before grinding or cutting the peripheral edge of the spectacle lens using a processing tool provided in the spectacle lens processing device, and is provided in the spectacle lens processing device,
A holding means having a holding shaft that holds and rotates the eyeglass lens;
A measuring element to be brought into contact with a refractive surface of the eyeglass lens;
a moving means for relatively changing a positional relationship between a refractive surface of the eyeglass lens held by the holding shaft and the measuring element;
a detection means for detecting a position of the measuring element in an axial direction of the holder shaft;
A measurement trajectory determination means for determining a reference trajectory of one revolution of the eyeglass lens based on the lens shape, and determining a measurement trajectory so as to have a component partially displaced in a radial direction with respect to the reference trajectory;
a control means for controlling the moving means based on the measurement trajectory and acquiring a refractive surface shape of the eyeglass lens in the axial direction of the holder shaft based on a detection result of the detection means;
An eyeglass lens shape measuring device comprising: The eyeglass lens shape measuring device of claim 1, wherein the measurement trajectory is a trajectory having a component that is periodically changed in the radial direction with respect to the reference trajectory. The eyeglass lens shape measuring device according to claim 1 or 2, characterized in that the measurement trajectory has at least one of a component that is curvedly displaced in the radial direction relative to the reference trajectory and a component that is linearly displaced. The eyeglass lens shape measuring device according to claim 1 or 2, characterized in that the measurement trajectory has at least one of a component that is curvedly displaced in the radial direction relative to the reference trajectory and a component that is linearly displaced. The eyeglass lens shape measuring device according to any one of claims 1 to 3, characterized in that the measurement trajectory determination means determines an auxiliary trajectory that is shifted a certain distance in the radial direction around the entire circumference of the reference trajectory, and determines the measurement trajectory so as to pass through the auxiliary trajectory. An eyeglass lens processing device comprising the eyeglass lens shape measuring device according to any one of claims 1 to 4. A spectacle lens shape measuring program executed by a spectacle lens shape measuring device provided in the spectacle lens processing apparatus, the spectacle lens shape measuring program comprising: a holding means having a holding shaft which holds and rotates a spectacle lens; a measuring element which is brought into contact with a refractive surface of the spectacle lens; a moving means which changes the positional relationship between the refractive surface of the spectacle lens held by the holding shaft and the measuring element based on a lens shape; and a detection means which detects the position of the measuring element in the axial direction of the holding shaft, the spectacle lens shape measuring program being configured to measure the shape of the refractive surface of the spectacle lens based on a detection result of the detection means before grinding or cutting the peripheral edge of the spectacle lens with a processing tool provided in the spectacle lens processing apparatus, the program comprising:
A reference trajectory determination step of determining a reference trajectory of one revolution of the eyeglass lens based on the lens shape;
a measurement trajectory determination step of determining a measurement trajectory so as to have a component partially displaced in a radial direction with respect to the reference trajectory;
a control step of controlling the moving means based on the measurement trajectory and obtaining a refractive surface shape of the eyeglass lens in the axial direction of the holding shaft based on a detection result of the detection means;
A spectacle lens shape measuring program that causes a spectacle lens shape measuring device to execute the above.