JP7732255B2 - Eyeglass lens processing device and processing control data creation program - Google Patents

Description

This disclosure relates to an eyeglass lens processing device capable of processing the periphery of eyeglass lenses, and a processing control data creation program for creating processing control data used in the eyeglass lens processing device.

Various methods have been proposed for processing the periphery of a lens to fit it into the rim of an eyeglass frame. For example, the eyeglass lens processing device described in Patent Document 1 determines whether the lens can be processed into a spherical shape using only a large-diameter peripheral processing tool. If it is determined that processing using only a large-diameter peripheral processing tool is not possible, the area that cannot be processed using a large-diameter peripheral processing tool is additionally processed using a small-diameter peripheral processing tool to form a spherical shape. As a result, a spherical shape is processed that has a concave shape smaller than the diameter of the large-diameter peripheral processing tool.

JP 2013-178432 A

Even if the lens is precisely machined to match the lens shape, when the machined lens is fitted into the rim of the frame, stress from the rim can cause distortion in the lens. Lens distortion can cause defects such as changes in the optical properties of the lens and deterioration of the coating applied to the lens. To prevent lens distortion when the lens is fitted into the rim, workers could perform additional processing on the lens by hand. However, performing additional processing by hand requires skilled workers and increases the worker's workload.

A typical objective of the present disclosure is to provide an eyeglass lens processing device and a processing control data creation program that can appropriately process the lens periphery so as to reduce distortion of the lens when it is fitted onto the rim.

A typical embodiment of the present disclosure provides an eyeglass lens processing device that processes the periphery of a lens using a periphery processing tool that processes the periphery of the lens in order to fit the lens into the rim of an eyeglass frame. A control unit of the eyeglass lens processing device executes a lens shape acquisition step that acquires the lens shape, and a lens shape correction step that corrects at least a portion of the lens shape contour inward based on information indicating the curvature of the lens shape, thereby suppressing distortion of the lens when the processed lens is fitted into the rim . In the lens shape correction step, based on the information indicating the curvature of the lens shape, a display unit displays the shape of the lens shape, whose curvature changes depending on the radius vector angle, along with positions where the curvature is equal to or greater than a threshold value. For each area where the curvature of the lens shape is equal to or greater than the threshold value, the control unit accepts input of instructions from a user as to whether to correct the lens shape inward and the degree of correction if corrected, and corrects at least a portion of the lens shape contour inward according to the instructions input by the user .

A processing control data creation program provided by a typical embodiment of the present disclosure is a processing control data creation program executed by a data creation device to create processing control data used in an eyeglass lens processing device that processes the periphery of a lens to fit the lens into the rim of an eyeglass frame. The program is executed by a control unit of the data creation device to cause the data creation device to execute a lens shape acquisition step of acquiring the lens shape of the lens, and a lens shape correction step of correcting at least a portion of the lens shape contour inward based on information indicating the curvature of the lens shape, thereby suppressing distortion of the lens when the processed lens is fitted into the rim . In the lens shape correction step, based on the information indicating the curvature of the lens shape, the shape of the lens shape whose curvature changes depending on the radius vector angle is displayed on a display unit along with positions where the curvature is equal to or greater than a threshold value. For each area where the curvature of the lens shape is equal to or greater than the threshold value, the program accepts input of instructions from a user regarding whether to correct the lens shape inward and the degree of correction if corrected, and corrects at least a portion of the lens shape contour inward according to the instructions input by the user .

The eyeglass lens processing device and processing control data creation program disclosed herein appropriately processes the lens periphery to reduce distortion of the lens when it is fitted onto the rim.

1 is a schematic diagram of a processing mechanism of an eyeglass lens processing device 1. FIG. 2 is a block diagram showing the electrical configuration of the eyeglass lens processing device 1. FIG. 10 is a flowchart of a spectacle lens processing control process. FIG. 1A is a plan view of the lens 10, FIG. 1B is lens data of the lens 10, and FIG. 1C is a comparison of curvature data of the lens 10. 10 is a diagram showing a state in which the outline of the target lens 10 in the range of radius vector angles of 90° to 180° has been corrected inward by the first automatic target lens correction process. 5 is a graph showing the results of correcting the target lens shape 10 shown in FIGS. 4A to 4C so that the curvature of the portion where the curvature is equal to or greater than a threshold value T is reduced. 5 is a graph showing the results of correcting the target lens shape 10 shown in FIGS. 4A to 4C so that the curvature of the entire contour smoothly decreases. FIG. 10 is a diagram showing an example of an image displayed on the display unit 7 when a manual target lens shape correction process is executed.

<Overview>
The eyeglass lens processing device (data creation device that creates processing control data) exemplified in this disclosure processes the periphery of a lens using a peripheral processing tool that processes the periphery of the lens in order to fit the lens into the rim of an eyeglass frame. The control unit of the eyeglass lens processing device executes a lens shape acquisition step and a lens shape correction step. In the lens shape acquisition step, the control unit acquires the lens shape. In the lens shape correction step, the control unit corrects at least a portion of the lens shape contour inward based on information indicating the curvature of the lens shape, thereby suppressing lens distortion when the processed lens is fitted into the rim.

After conducting various experiments and studies, the inventors of the present invention newly discovered that stress that causes lens distortion is more likely to be applied to portions of the lens with a large curvature than portions of the lens with a small curvature. The eyeglass lens processing device exemplified in this disclosure corrects at least a portion of the lens shape outline inward based on information indicating the lens shape curvature, thereby preventing stress that causes lens distortion from being applied to the lens. As a result, the occurrence of lens distortion when the lens is fitted onto the rim is appropriately suppressed.

In the lens shape correction step, the control unit may correct at least a portion of the lens shape contour inward based on at least one of the positions where the lens shape curvature, which changes depending on the radius vector angle, takes a maximum value. As mentioned above, according to new findings obtained by the inventors of the present invention, stress that causes lens distortion is likely to be applied in areas where the lens shape curvature is large. Therefore, the control unit can appropriately correct the lens shape position that is likely to cause lens distortion by identifying the position where the lens shape curvature takes a maximum value and correcting the lens shape contour inward based on the identified position.

Note that curvature is a quantity that represents the degree of curvature of a curve (in this disclosure, the curve of the outline of the target lens). Curvature can be expressed in various units. For example, the reciprocal of curvature is the radius of curvature. Therefore, it is also possible to express the degree of curvature of the curve of the outline of the target lens using the radius of curvature. In other words, in this disclosure, the term "large curvature" is synonymous with "small radius of curvature," and the term "small curvature" is synonymous with "large radius of curvature." Therefore, the position where the curvature of the target lens is at its maximum value coincides with the position where the radius of curvature of the target lens is at its minimum value.

A specific method for correcting the outline of the lens shape based on the position where the curvature takes a maximum value can be selected as appropriate. For example, the control unit may correct the outline of the lens shape so that the position of at least one of one or more points on the outline of the lens shape where the curvature of the lens shape takes a maximum value is corrected to be more inward on the lens than the original position. In this case, the stress that causes lens distortion is appropriately reduced. Alternatively, the control unit may correct the outline of a position adjacent to a maximum point (referred to as a "maximum point") more inward without changing the position of at least one point where the curvature of the lens shape takes a maximum value. In this case, the stress applied to the lens from the rim near the maximum point is also reduced.

In the lens shape correction step, the control unit may correct the lens shape contour inward so that the curvature of the lens shape contour at the portion where the curvature is equal to or greater than the threshold value decreases. In this case, the curvature of the lens shape contour at the portion where the curvature is less than the threshold value does not change. As a result, excessive correction of the lens shape is suppressed. Therefore, lens distortion is appropriately suppressed while suppressing a decrease in the lens holding force by the rim.

In the lens shape correction step, the control unit may correct the outline of the lens shape inward so that the greater the curvature of the lens shape, the greater the reduction in curvature after correction. According to new findings by the inventors of the present invention, the greater the curvature of the lens shape, the more likely it is that stress that causes lens distortion will be applied. Therefore, by the control unit correcting the outline of the lens shape according to the magnitude of the curvature, lens distortion can be more appropriately suppressed. Furthermore, by correcting the outline of the lens shape according to the magnitude of the curvature, the outline of the lens shape is smoothly corrected, making it less likely that excessive irregularities will form in the outline of the lens shape. Therefore, deterioration in the functionality and appearance of the eyeglasses caused by excessive irregularities in the outline of the lens shape is also suppressed.

The control unit may also correct the outline of the target lens shape in accordance with the magnitude of curvature for portions of the outline of the target lens shape where the curvature is equal to or greater than a threshold value. In this case, both a decrease in the lens holding force by the rim and lens distortion are more appropriately suppressed. The control unit can also correct the outline of the target lens shape in accordance with the magnitude of curvature for the entire outline of the target lens shape. In this case, lens distortion is also appropriately suppressed.

The specific method for correcting the outline of the target lens shape according to the magnitude of curvature can also be selected as appropriate. For example, the control unit may make the magnitude of the target lens shape curvature proportional to the amount of reduction in curvature after correction.

In the lens shape correction step, the control unit may correct at least a portion of the lens shape contour inward by performing a smoothing process on the data indicating the lens shape curvature, smoothly reducing the curvature. In this case, by using a known smoothing process, both a decrease in the lens holding force by the rim and lens distortion are more appropriately suppressed. Furthermore, by using a smoothing process, the lens shape contour is smoothly corrected, making it less likely that excessive irregularities will form in the lens shape contour. Therefore, deterioration in the functionality and appearance of the eyeglasses caused by excessive irregularities in the lens shape contour is also suppressed.

The control unit may also perform curvature smoothing processing on portions of the outline of the target lens where the curvature is equal to or greater than a threshold value. In this case, both a decrease in the lens holding force due to the rim and lens distortion are more appropriately suppressed. The control unit can also perform curvature smoothing processing on the entire outline of the target lens. In this case, lens distortion is also appropriately suppressed.

It is also possible to change the specific method for correcting the outline of the lens shape inward. For example, the control unit may correct the data indicating the lens shape so that the portion of a graph showing the curvature data of the lens shape where the curvature is equal to or greater than a threshold fits to the circumference of a circle of a predetermined shape. In other words, the control unit may correct the data indicating the lens shape so that the maximum value of the curvature of the lens shape is limited to a value equal to or less than a threshold. Even in this case, both the reduction in the lens holding force due to the rim and lens distortion are appropriately suppressed. Furthermore, the outline of the lens shape is smoothly corrected.

In the lens shape correction step, the control unit may accept input of an instruction from the user to correct at least a portion of the lens shape contour while displaying on the display unit the shape of the lens shape whose curvature changes depending on the radius vector angle based on information indicating the lens shape curvature. The control unit may correct at least a portion of the lens shape contour inward in accordance with the instruction input by the user. In this case, the user can correct positions of the lens shape contour that are likely to cause lens distortion inward at their own discretion.

The user may specify the position at which the outline of the target lens is to be corrected inward, and the amount of correction to that inward. The control unit may correct the position of the outline of the target lens specified by the user inward by the specified amount of correction. In this case, the user can correct the outline of the target lens more precisely.

In the lens shape correction step, the control unit may cause the display unit to display at least one of the positions where the curvature of the lens shape, which changes depending on the radius vector angle, takes a maximum value and the positions where the curvature is equal to or greater than a threshold value, together with the shape of the lens shape. In this case, the user can determine whether or not to correct the lens shape after properly understanding the positions on the contour of the lens shape that are likely to cause lens distortion.

The control unit may receive input from the user to specify whether or not to execute the lens shape correction step. The control unit may determine whether or not to execute the lens shape correction step in accordance with the input instruction. The effect of lens distortion varies depending on various conditions (for example, whether or not the lens is coated). Therefore, by specifying whether or not to execute the lens shape correction step depending on the condition, the user can cause the eyeglass lens processing device to perform more appropriate processing.

<Embodiment>
A typical embodiment of the present disclosure will be described below with reference to the drawings. First, an eyeglass lens processing apparatus 1 of this embodiment will be described. The eyeglass lens processing apparatus 1 processes an eyeglass lens LE in accordance with processing control data for processing the periphery of the lens LE along the lens shape. The eyeglass lens processing apparatus 1 of this embodiment also serves as a data creation device that creates the processing control data. However, a data creation device (e.g., a personal computer) separate from the eyeglass lens processing apparatus 1 may also be used.

(mechanical configuration)
1, the eyeglass lens processing apparatus 1 of this embodiment includes a lens holding unit 100, a lens shape measuring unit 200, a first processing tool unit 300, and a second processing tool unit 400. The lens holding unit 100 includes lens holding shafts (lens chuck shafts) 102R and 102L that sandwich and hold a lens LE. Furthermore, the lens holding unit 100 includes a lens rotation unit 100a, a holding shaft moving unit 100b, and an axis distance variation unit 100c.

The lens rotation unit 100a rotates a pair of lens holding shafts 102R, 102L around their axes. The holder shaft movement unit 100b moves the lens holding shafts 102R, 102L in the axial direction (this is referred to as the X direction). The inter-shaft distance variation unit 100c moves the lens holding shafts 102R, 102L in a direction (this is referred to as the Y direction) toward or away from the rotation axes of the processing tools (details will be described later) provided on each of the first processing tool unit 300 and the second processing tool unit 400. The inter-shaft distance variation unit 100c also varies the distance between the lens shape measurement unit 200 and the lens holding shafts 102R, 102L.

Specific examples of each component of the eyeglass lens processing device 1 are described in detail below. The lens holding unit 100 is mounted on the base 170 of the main body of the eyeglass lens processing device 1.

The lens rotation unit 100a will now be described. A lens holding shaft 102R is held on the right arm 101R of the carriage 101 of the lens holding unit 100, and a lens holding shaft 102L is held on the left arm 101L, both of which are rotatable and coaxial with each other. When the lens holding shaft 102R is moved toward the lens holding shaft 102L by a motor 110 attached to the right arm 101R, the lens LE is sandwiched and held between the two lens holding shafts 102R and 102L. The two lens holding shafts 102R and 102L are rotated in sync by a motor 120 attached to the right arm 101R.

The holder shaft movement unit 100b will now be described. An X-axis movement support base 140 is provided on shafts 103 and 104 that extend parallel to the lens holder shafts 102R and 102L and the grindstone rotation shaft 161a. The X-axis movement support base 140 can move in the X-axis direction along the shafts 103 and 104 by the power of an X-axis movement motor 145. The carriage 101 is mounted on the X-axis movement support base 140. An encoder 146 (see Figure 2) is provided on the rotation shaft of the X-axis movement motor 145. In this embodiment, the X-axis positions of the lens holder shafts 102R and 102L detected by the encoder 146 are used to measure the shapes of the front and rear surfaces of the lens LE.

The axis distance variation unit 100c will now be described. A shaft 156 extending in a direction connecting the lens holding shafts 102R, 102L and the grindstone rotation shaft 161a is fixed to the X-axis movement support base 140. When the Y-axis movement motor 150 rotates, the ball screw 155 extending in the Y direction rotates. As a result, the carriage 101 moves in the Y-axis direction along the shaft 156. An encoder 158 is attached to the rotation shaft of the Y-axis movement motor 150, which detects the position of the carriage 101 in the Y direction.

The lens shape measuring unit 200 will now be described. In this embodiment, the lens shape measuring unit 200 is fixed to the base 170 at a position opposite the first processing tool unit 300 via the carriage 101. The lens shape measuring unit 200 includes a lens edge position measuring unit 200F and a lens edge position measuring unit 200R. The lens edge position measuring unit 200F has a probe that contacts the front surface of the lens LE. The lens edge position measuring unit 200R has a probe that contacts the rear surface of the lens LE. With the probes of the lens edge position measuring units 200F and 200R in contact with the front and rear surfaces of the lens LE, the carriage 101 is moved in the Y-axis direction based on target lens shape data, and the lens holding shafts 102R and 102L are rotated, thereby simultaneously measuring the edge positions of the front and rear surfaces of the lens LE. The lens shape measuring unit 200 functions as a lens thickness measuring unit that measures the thickness of the lens LE. The lens edge position measurement units 200F and 200R can be configured using, for example, the configuration described in Japanese Patent Application Laid-Open No. 2003-145328.

The first processing tool unit 300 will now be described. The first processing tool unit 300 is equipped with a lens edge processing tool 168, which is one of the lens processing tools. In this embodiment, the edge processing tool 168 includes a rough grindstone 162 for glass, a finishing grindstone 164 with a V-groove (bevel groove) for forming a bevel on the lens and a flat processing surface, a grindstone 165 for flat mirror finishing, a finishing grindstone 166 for high-curve lenses, and a rough grindstone 167 for plastic. The multiple grindstones of the edge processing tool 168 are coaxially attached to a grindstone rotation shaft (grindstone spindle) 161a. The grindstone rotation shaft 161a is rotated by a motor 160. The edge of the lens LE held by the lens holding shafts 102L and 102R is pressed against the edge processing tool 168 and processed.

The second processing tool unit 400 will now be described. The second processing tool unit 400 includes a finishing tool, a drilling tool, a motor 421, and a motor 482. The finishing tool rotates around a rotation axis to perform finishing on the periphery of the lens LE (for example, at least one of grooving, bevel formation, step formation, etc.). The drilling tool forms a hole in the lens LE. In this embodiment, the drilling tool moves axially while rotating around the rotation axis to form an axially extending hole in the lens LE. Motor 421 rotates the finishing tool and the drilling tool. Motor 482 pivots the finishing tool and the drilling tool.

(Electrical configuration)
The electrical configuration of the eyeglass lens processing apparatus (which also serves as a data creation apparatus) 1 will be described with reference to Figure 2. The eyeglass lens processing apparatus 1 includes a CPU (processor) 2 that controls the eyeglass lens processing apparatus 1. A RAM 3, a ROM 4, a non-volatile memory 5, an operation unit 6, a display unit (display) 7, and an external communication I/F 8 are connected to the CPU 2 via a bus. Furthermore, various devices such as the motors mentioned above (motor 110, motor 120, X-axis movement motor 145, Y-axis movement motor 150, motor 160, motor 421, motor 482, encoder 146, and encoder 158) are connected to the CPU 2 via a bus.

RAM 3 temporarily stores various information. ROM 4 stores various programs, initial values, etc. Non-volatile memory 5 is a non-transitory storage medium (e.g., flash ROM, hard disk drive, etc.) that can retain stored contents even when power is cut off. Non-volatile memory 5 may also store a control program (e.g., a processing control data creation program, etc.) for controlling the operation of the eyeglass lens processing device (data creation device) 1. Operation unit 6 accepts various instructions input from an operator (device user). For example, a touch panel or operation buttons provided on the surface of display unit 7 may be used as operation unit 6. External communication I/F 8 connects eyeglass lens processing device 1 to external devices.

The CPU 2 controls the drive of various motors and the like in accordance with the processing control data to appropriately process the lens LE. As an example, in this embodiment, the eyeglass lens processing apparatus 1 itself creates the processing control data. More specifically, in this embodiment, the control unit (including the CPU 2) of the eyeglass lens processing apparatus 1 executes a processing control data creation program to create at least a portion of the processing control data. In other words, in this embodiment, the eyeglass lens processing apparatus 1 also serves as a data creation device that creates the processing control data. However, a device other than the eyeglass lens processing apparatus 1 may also function as a data creation device. For example, a personal computer connected to the eyeglass lens processing apparatus 1 may function as a data creation device. In this case, the processing control data is created when the control unit of the personal computer executes the processing control data creation program.

(Control Processing)
3 to 8, the eyeglass lens processing control process executed by the eyeglass lens processing apparatus 1 of this embodiment will be described. When a trigger to start processing the lens LE is input, the CPU 2 of the eyeglass lens processing control process executes the eyeglass lens processing control process shown in FIG. 3 in accordance with the control program stored in the nonvolatile memory 5.

As mentioned above, in this embodiment, the eyeglass lens processing device 1 also functions as a data creation device. Therefore, the eyeglass lens processing control process illustrated in FIG. 3 includes both a process for creating processing control data (S1 to S7) and a process for processing the lens LE based on the processing control data. Part of the processing control data creation process in this embodiment includes a process for correcting at least a portion of the outline of the lens shape inward (hereinafter referred to as the "lens shape correction process") in order to suppress distortion of the lens LE when the processed lens LE is fitted onto the rim. Note that "inner side" refers to the side closer to the center of the lens LE than the outline of the lens shape before correction. The "inner side" can also be expressed as the inside in the radial direction of the lens LE.

First, the CPU 2 acquires data on the lens shape of the lens LE to be processed (S1). The lens shape data may be generated, for example, by measuring the shape of the rim of the frame (eyeglasses frame) on which the lens LE will be attached using an eyeglasses frame shape measuring device (not shown), or may be provided by a manufacturer that manufactures the frame. Alternatively, the lens shape data may be generated by measuring the shape of a demo lens that corresponds to the shape of the rim. Details will be described later, but the lens shape data in this embodiment is represented by a radius vector angle and a radius vector length based on a reference point of the lens shape (e.g., the geometric center of the lens shape) (see Figures 4(A) and (B)).

Next, the CPU 2 determines whether an instruction to execute the lens shape correction process has been input by the user (S2). In this embodiment, the user can input an instruction to the eyeglass lens processing device 1 via the operation unit 6 or the like as to whether or not to execute the lens shape correction process to suppress distortion of the lens LE. If an instruction to execute the lens shape correction process has not been input (S2: NO), the lens shape data acquired in S1 is not corrected, and the process proceeds directly to S7.

If an instruction to execute the lens shape correction process has been input (S2: YES), the CPU 2 determines whether an instruction to automatically correct the lens shape has been input (S3). In this embodiment, the user can input an instruction to execute the lens shape correction process automatically or manually to the eyeglass lens processing apparatus 1 via the operation unit 6 or the like. If an instruction to execute automatic correction has been input (S3: YES), the CPU 2 executes the lens shape automatic correction process (S4). Furthermore, if an instruction to execute manual correction has been input (S3: NO), the CPU 2 executes the lens shape manual correction process (S5). Details of the lens shape automatic correction process and the lens shape manual correction process will be described later with reference to Figures 4 to 8.

Next, the CPU 2 creates data for processing a bevel on the periphery of the lens LE based on the lens shape data obtained in S1 to S5 (the lens shape data acquired in S1 or the lens shape data corrected in S4 and S5) (S7). As a result, processing control data for processing the lens LE is completed. The CPU 2 then controls various motors (e.g., at least one of motors 110, 120, 145, 150, 160, etc.) based on the processing control data to move the relative position between the lens LE held by the lens holding shafts 102R and 102L and the periphery processing tool 168, and processes the lens LE with the periphery processing tool 168. The lens shape correction process (S4, S5) is described in detail below.

(Lens shape, lens shape data, lens shape curvature data)
First, an example of the lens shape, lens shape data, and curvature data of the lens LE will be described with reference to Fig. 4. Fig. 4(A) is a plan view of the lens shape 10. The center of the coordinates is aligned with the reference point of the lens shape 10 (the geometric center of the lens shape 10 in Fig. 4). Fig. 4(B) is a graph of the lens shape data of the lens shape 10 with the horizontal axis representing the radius vector angle and the vertical axis representing the radius vector length. Fig. 4(C) is a graph of the curvature data of the lens shape 10 with the horizontal axis representing the radius vector angle and the vertical axis representing the curvature of the lens shape.

As shown in FIG. 4(B), the lens shape data of this embodiment is represented, as an example, by a radius vector angle and a radius vector length based on a reference point of the lens shape 10. That is, in the lens shape data of this embodiment, information on the distance from the reference point to the contour of the lens shape 10 is recorded for each radius vector angle. Furthermore, in the lens shape correction process of this embodiment, curvature data of the lens shape 10 is used. As shown in FIG. 4(C), in the curvature data of the lens shape 10, information on the curvature of the contour of the lens shape 10 is recorded for each radius vector angle. The curvature data of the lens shape 10 shown in FIG. 4(C) can be calculated from the lens shape data shown in FIG. 4(B).

Curvature is a quantity that represents the degree of curvature of a curve (in this disclosure, the curve of the contour of the lens 10). Therefore, in this embodiment, the degree of curvature of the curve of the contour of the lens 10 shown in FIG. 4(A) is greater in the area of large curvature shown in FIG. 4(C). Note that the degree of curvature of the contour of the lens 10 can also be expressed using the radius of curvature (the reciprocal of the curvature). In this case, the graph in FIG. 4(C) is upside down.

In the lens 10 shown in FIG. 4(A), there are areas where the curvature increases in the radius vector angle ranges of 0° to 90°, 90° to 180°, 180° to 270°, and 270° to 360°. Therefore, as shown in FIG. 4(C), the curvature of the lens 10 reaches maximum values at four positions. In the example shown in FIG. 4(C), the maximum value in the radius vector angle range of 0° to 90° is M1, the maximum value in the range of 90° to 180° is M2, the maximum value in the range of 180° to 270° is M3, and the maximum value in the range of 270° to 360° is M4.

(First automatic target lens shape correction process)
The first automatic lens shape correction process (S4) will be described with reference to Fig. 5. In the first automatic lens shape correction process, the CPU 2 identifies at least one of the positions (M1 to M4) where the curvature of the lens shape 10, which changes depending on the radius vector angle, takes on a maximum value. The CPU 2 corrects the outline of the lens shape 10 to the inside of the lens LE based on the identified position.

Figure 5 is a diagram showing the state in which the contour of the lens 10 in the radius vector angle range of 90° to 180° has been corrected inward by the first automatic lens shape correction process. In the example shown in Figure 5, the CPU 2 first identifies the maximum point PA2 of the lens 10, which is the position where the curvature takes on the maximum value M2 (see Figure 4(C)). The CPU 2 corrects the lens shape data (contour of the lens 10) so that the identified maximum point PA2 moves to position PB2, which is closer to the inside of the lens than its original position (the position on the contour indicated by the dotted line in Figure 5). As a result, stress that causes distortion of the lens LE when the lens LE is fitted onto the rim is appropriately reduced.

In this embodiment, the CPU 2 corrects the contour of the target lens 10 inward for all positions where the curvature of the target lens 10 takes on a maximum value (in this embodiment, four positions corresponding to each of the four maximum values M1 to M4). This more appropriately suppresses distortion of the lens LE. However, the CPU 2 may also correct the contour of the target lens 10 inward for only some of the positions where the curvature takes on a maximum value.

As shown in FIG. 5, in the first automatic lens shape correction process of this embodiment, the CPU 2 corrects inward the portion of the contour of the lens 10 within a region R that is centered on the identified maximum point PA2 and has a predetermined radius. The radius of region R may be a predetermined fixed value or may be changed by the user. In detail, the CPU 2 smoothly corrects the contour of the lens 10 so that unnecessary irregularities do not occur in the contour of the lens 10 after correction (in other words, so that the curvature of the lens 10 does not increase excessively at the correction point).

However, it is also possible to change the method for correcting the contour of the target lens 10 based on the maximum point. For example, the CPU 2 may correct the contour adjacent to the maximum point inward without changing the position of the maximum point. Even in this case, the stress applied to the lens from the rim near the maximum point is reduced.

(Second automatic lens shape correction process)
The second automatic lens shape correction process (S4) will be described with reference to Fig. 6. In the second automatic lens shape correction process, the CPU 2 corrects the contour of the lens 10 inward so as to reduce the curvature of a portion of the contour of the lens 10 whose curvature is equal to or greater than a threshold value.

Figure 6 is a graph showing the results of correcting the lens shape 10 shown in Figures 4 (A) to (C) so that the curvature of the portion where the curvature is equal to or greater than the threshold value T decreases. In Figure 6, the horizontal axis represents the radius vector angle and the vertical axis represents the lens shape curvature, with the dotted line representing the graph before correction and the solid line representing the graph after correction. As shown in Figure 6, in the second automatic lens shape correction process, the CPU 2 corrects the outline of the lens shape 10 inward so that the curvature of the portion where the curvature is equal to or greater than the threshold value T decreases smoothly. In this case, in the portion of the outline of the lens shape 10 where the curvature is less than the threshold value T, the curvature does not change before and after correction. Therefore, distortion of the lens LE is suppressed while excessive correction of the lens shape 10 is suppressed.

After correcting the curvature data of the lens 10, the CPU 2 calculates the lens data from the corrected curvature data, thereby obtaining the lens data after contour correction. Similar processing is performed below.

The second automatic lens shape correction process will now be described in detail. For portions where the curvature is equal to or greater than the threshold value T, the CPU 2 corrects the contour of the lens shape 10 inward so that the greater the curvature of the lens shape 10, the greater the reduction in curvature of the lens shape 10 after correction. As a result, distortion of the lens LE is more appropriately suppressed. Furthermore, when correction of the contour of the lens shape 10 is performed according to the magnitude of the curvature, the contour of the lens shape 10 is smoothly corrected, making it less likely that excessive irregularities will be formed in the contour of the lens shape 10.

The CPU 2 can also correct at least a portion of the contour of the lens 10 inward by performing a known smoothing process that smoothly reduces the curvature for portions of the curvature data of the lens 10 where the curvature is equal to or greater than the threshold value T. In other words, the CPU 2 can also correct the contour of the lens 10 by performing a smoothing process on portions of the curvature data where the curvature is equal to or greater than the threshold value T and calculating the lens data from the obtained curvature data. In this case, by using a known smoothing process, both the reduction in the holding force of the lens LE by the rim and distortion of the lens LE are more appropriately suppressed. Furthermore, by using a smoothing process, the contour of the lens 10 is smoothly corrected, making it less likely that excessive irregularities will form in the contour of the lens 10.

The CPU 2 can also correct the target lens shape data so that the portion of the graph of the target lens shape 10 where the curvature is equal to or greater than the threshold value T fits the circumference of a circle of a predetermined shape (a perfect circle or an ellipse). In other words, the CPU 2 can correct the curvature data so that the maximum value of the target lens shape 10 is limited to a threshold value or less, and calculate the target lens shape data from the corrected curvature data, thereby correcting the contour of the target lens shape 10. Even in this case, both the reduction in the holding force of the lens LE by the rim and distortion of the lens LE are appropriately suppressed. Furthermore, the contour of the target lens shape 10 is smoothly corrected.

(Third automatic lens shape correction process)
The third automatic lens shape correction process (S4) will be described with reference to FIG. 7. In the third automatic lens shape correction process, the CPU 2 corrects the lens shape data so that the overall curvature of the lens shape 10 decreases smoothly. FIG. 7 is a graph showing the results of correcting the lens shape 10 shown in FIGS. 4A to 4C so that the curvature of the entire contour decreases smoothly. In FIG. 7, the horizontal axis represents the radius vector angle and the vertical axis represents the curvature of the lens shape, with the graph before correction shown by a dotted line and the graph after correction shown by a solid line. As shown in FIG. 7, even when the curvature of the entire contour is smoothly decreased, distortion of the lens LE is appropriately suppressed.

In detail, the CPU 2 can correct the contour of the lens 10 inward so that the greater the curvature of the lens 10 across the entire contour, the greater the reduction in curvature of the lens 10 after correction. The CPU 2 can also perform curvature smoothing processing on the entire contour of the lens 10. In either case, the contour of the lens 10 is smoothly corrected.

(Manual lens shape correction processing)
The manual lens shape correction process (S5) will be described with reference to FIG. 8 . In the manual lens shape correction process, the CPU 2 accepts input of instructions from the user to correct at least a portion of the contour of the lens 10 while displaying the shape of the lens 10, whose curvature changes depending on the radius vector angle, on the display unit 7. After checking the shape of the lens 10 displayed on the display unit 7, the user inputs the position at which the lens 10 is to be corrected inward and the amount of inward correction into the eyeglass lens processing apparatus 1 via the operation unit 6 or the like. The CPU 2 corrects at least a portion of the contour of the lens 10 inward in accordance with the instructions input by the user. This allows the user to more precisely correct the contour of the lens 10.

In detail, in the manual lens shape correction process of this embodiment, the CPU 2 displays on the display unit 7 the positions where the curvature of the lens 10 takes on maximum values (in FIG. 8, the maximum points indicated by white circles corresponding to the maximum values M1 to M4 shown in FIG. 4(C)) along with the shape of the lens 10. The CPU 2 also displays on the display unit 7 the positions where the curvature of the lens 10 is equal to or greater than the threshold value T (in FIG. 8, the four areas AREA1, AREA2, AREA3, and AREA4 surrounded by frames attached to the lens 10) along with the shape of the lens 10. Therefore, the user can determine whether or not to correct the lens 10 after properly understanding the positions on the contour of the lens 10 that are likely to cause distortion of the lens LE.

In this embodiment, the user can specify whether to correct the lens shape 10 inward for each area (AREA1 to AREA4 in FIG. 8) where the curvature of the lens shape 10 is equal to or greater than the threshold value T, and the degree of correction if correction is required. In the example shown in FIG. 8, if the lens shape 10 is not to be corrected, "0" is input. If the lens shape 10 is to be corrected, one of "1" to "5" is input depending on the degree of correction. The CPU 2 executes correction processing of the lens shape 10 according to the input instruction using at least one of the correction methods described in the automatic lens shape correction processing (S4) described above. This allows the user to easily and appropriately input correction instructions for the lens shape 10.

However, it is also possible to change the method by which the user inputs correction instructions for the lens shape 10. For example, the user may input correction instructions for the lens shape 10 by moving any position on the displayed outline of the lens shape 10 inward by any amount using an operation such as clicking or dragging.

The technology disclosed in the above embodiment is merely an example. Therefore, it is possible to modify the technology exemplified in the above embodiment. For example, it is possible to execute only a part of the technology exemplified in the above embodiment. Specifically, the eyeglass lens processing apparatus 1 may execute only one of the automatic lens shape correction process (S4) and the manual lens shape correction process (S5). Furthermore, the CPU 2 may change the degree to which the lens shape 10 is corrected in accordance with instructions input by the user.

The process of acquiring data on the target lens 10 in S1 of FIG. 3 is an example of a "target lens acquisition step." The process of correcting the outline of the target lens 10 to the inside in S4 and S5 of FIG. 3 is an example of a "target lens correction step."

1. Eyeglass lens processing device (data creation device)
2 CPUs
5 Non-volatile memory 6 Operation unit 7 Display unit 10 Bead shape 168 Periphery processing tool

Claims (3)

An eyeglass lens processing device that processes a periphery of a lens by a periphery processing tool that processes the periphery of the lens in order to fit the lens into a rim of an eyeglass frame,
The control unit of the eyeglass lens processing device
a target lens shape acquisition step of acquiring a target lens shape of the lens;
a lens shape correction step of correcting at least a part of the contour of the lens shape inward based on information indicating the curvature of the lens shape, thereby suppressing distortion of the lens when the processed lens is fitted into the rim;
Run
In the target lens shape correction step,
Based on the information indicating the curvature of the lens shape, the shape of the lens shape whose curvature changes depending on the radius vector angle is displayed on a display unit together with the position where the curvature is equal to or greater than a threshold value,
For each region where the curvature of the lens shape is equal to or greater than the threshold value, an input of an instruction from a user as to whether or not to correct the lens shape inward and the degree of correction if corrected is received;
An eyeglass lens processing device, characterized in that at least a part of the outline of the lens shape is corrected inward in accordance with an instruction input by a user . The eyeglass lens processing apparatus according to claim 1,
The control unit, in the target lens shape correction step,
At least one of the positions where the curvature of the lens shape, which changes depending on the radius vector angle, takes a maximum value is identified, and the outline of the lens shape is corrected inward based on the identified position. A processing control data creation program executed by a data creation device to create processing control data used in an eyeglass lens processing device that processes a periphery of a lens to fit the lens into a rim of an eyeglass frame, comprising:
When executed by the control unit of the data creation device,
a target lens shape acquisition step of acquiring a target lens shape of the lens;
a lens shape correction step of correcting at least a part of the contour of the lens shape inward based on information indicating the curvature of the lens shape, thereby suppressing distortion of the lens when the processed lens is fitted into the rim;
causing the data creation device to execute the above;
In the target lens shape correction step,
Based on the information indicating the curvature of the lens shape, the shape of the lens shape whose curvature changes depending on the radius vector angle is displayed on a display unit together with the position where the curvature is equal to or greater than a threshold value,
For each region where the curvature of the lens shape is equal to or greater than the threshold value, an input of an instruction from a user as to whether or not to correct the lens shape inward and the degree of correction if corrected is received;
A processing control data creation program, characterized in that at least a part of the outline of the target lens shape is corrected inward in accordance with an instruction input by a user .