JP7714895B2 - Step formation data setting device, eyeglass lens processing device, and step formation data setting program - Google Patents

Description

This disclosure relates to a step formation data setting device that sets data for forming a step portion on the rear surface of an eyeglass lens after finishing, an eyeglass lens processing device equipped with the same, and a step formation data setting program.

Eyeglass frames include high-curve frames, which are primarily used for sunglasses and have a sharp frame curve (a strong degree of curvature). When fitting prescription lenses (for example, negative-power lenses with thick edges) into these high-curve frames, there is a known eyeglass lens processing device that can process the periphery of the rear surface of the lens after finishing (for example, flattening) to form a step (also known as step processing) to remove corners of the lens periphery that would interfere with the frame (see, for example, Patent Documents 1 and 2).

Furthermore, some eyeglass frames for sunglasses are of the interchangeable lens type, allowing the user to change lenses of different colors. The rim of these interchangeable lens type eyeglass frames is partially formed with a groove into which part of the edge of the built-in lens is fitted. Since there is a demand for these interchangeable lens type eyeglass frames to accommodate prescription lenses with thick edges, an eyeglass lens processing shape acquisition device has been proposed that makes it easy to obtain the shape of the partial step portion (partial step) required to fit eyeglass lenses into partial rims (see, for example, Patent Document 3).

JP 2009-131939 A JP 2015-131374 A JP 2012-185490 A

However, when machining a step portion into an eyeglass lens, there are cases where machining cannot be performed according to the target step contour shape data due to constraints imposed by the size of the step-forming tool. If the eyeglass lens machining device terminates machining without machining the target step contour shape, the worker will only realize that machining of the eyeglass lens is incomplete after framing the eyeglass lens into the rim, and necessary measures such as additional machining of the eyeglass lens will not be taken.

In consideration of the problems with the above-mentioned conventional devices, the technical objective of this disclosure is to provide a step formation data setting device, eyeglass lens processing device, and step formation data setting program that allow workers to know that there are parts that cannot be processed when forming step portions on eyeglass lenses and take appropriate measures.

A step formation data setting device according to a first aspect of the present disclosure is a step formation data setting device that sets data for forming a step portion on the rear surface of an eyeglass lens after finishing, and is characterized by comprising: a data acquisition means for acquiring data of a target step contour shape for the step portion; a calculation means for determining, based on the step contour shape, the diameter of a step forming tool for forming the step portion, and the inclination angle of a rotation axis to which the step forming tool is attached relative to a lens holding shaft that holds the eyeglass lens, whether or not processing of the step contour shape can be completed by the step forming tool that rotates on the rotation axis at the inclination angle; a calculation means for determining, based on the inclination angle, an elliptical locus drawn by the outline of the step forming tool when viewed from the axial direction of the lens holding shaft, and determining, for each radius vector angle of the eyeglass lens, the locus of the processing point when the elliptical locus touches the step contour shape, thereby determining whether or not processing can be completed by the step forming tool ; and an output means for outputting the determination result by the calculation means.

The eyeglass lens processing device according to the second aspect of the present disclosure is equipped with the above-described step formation data setting device.

A step formation data setting program according to a third aspect of the present disclosure is a step formation data setting program executed by a step formation data setting device that sets data for forming a step portion by a step forming tool for forming the step portion on a rear surface of an eyeglass lens after finishing, the step formation data setting program including a data acquisition step for acquiring data of a target step contour shape for the step portion, and a step formation data setting step for setting a step contour shape based on the step contour shape , the diameter of the step forming tool, and the inclination angle of a rotation axis to which the step forming tool is attached relative to a lens holding axis that holds the eyeglass lens. and a control unit of the step formation data setting device executes a calculation step of determining whether or not processing can be completed by the step forming tool rotated on the rotation axis of the tilt angle, in which an elliptical locus described by the outline of the step forming tool when viewed from the axial direction of the lens holding shaft is calculated based on the tilt angle, and the locus of the processing point when the elliptical locus contacts the step contour shape is calculated for each radius vector angle of the eyeglass lens, thereby determining whether or not processing can be completed by the step forming tool , and an output step of outputting the determination result obtained by the calculation step.

This disclosure allows workers to know when there are areas that cannot be processed when forming step portions on eyeglass lenses, and to take appropriate action.

2 is a diagram illustrating the configuration of a processing mechanism unit provided in the eyeglass lens processing device. FIG. FIG. 4 is a schematic configuration diagram of a second processing tool unit. 10A and 10B are diagrams showing examples of step forming tools. FIG. 2 is a schematic diagram illustrating the configuration of a measurement unit for measuring the shape of the rear surface of a lens. FIG. 2 is a control system block diagram of the step formation data setting device and the eyeglass lens processing device. FIG. 10 is a diagram showing a typical example of an eyeglass frame that requires the formation of a partial step portion. 10A and 10B are diagrams illustrating examples of target target step contour shape data and target target target shape data acquired by a data acquisition unit. 10 is a display example of an edit screen for step machining. 10 is a diagram illustrating the positional relationship between the X direction and the rotation axis of the step forming tool, and the positional relationship between the lens and the step forming tool when forming a step portion on a lens after flat finishing. FIG. 10A and 10B are diagrams illustrating a determination as to whether machining can be completed without machining interference based on an elliptical locus, in relation to step contour shape data. FIG. 10 is a diagram showing an example of an enlarged screen of a figure indicating an area that cannot be processed; 10A and 10B are diagrams illustrating a method for calculating a planned machining path by a step forming tool. This is a diagram showing an example in which the target lens shape data includes a hook portion read from the contour of the demo lens and a small recessed portion in the vicinity of the hook portion.

Embodiments of an eyeglass lens processing device, a step formation data setting device, and a step formation data setting program according to the present disclosure will be described with reference to Figures 1 to 13.

[overview]
For example, an eyeglass lens processing apparatus (e.g., eyeglass lens processing apparatus 1) according to the present disclosure includes a lens holding shaft (e.g., lens chuck shaft 102). The lens holding shaft holds an eyeglass lens. For example, the eyeglass lens processing apparatus includes a step forming tool (e.g., step forming tool 437). The step forming tool forms a step portion on the rear surface of the eyeglass lens after finishing. For example, the step forming tool is attached to a rotation shaft (e.g., rotation shaft 431). For example, the rotation shaft of the step forming tool is inclined at a set angle relative to the lens holding shaft. For example, the eyeglass lens processing apparatus includes a periphery processing tool (e.g., processing tool 168) for processing the periphery of the eyeglass lens. For example, the periphery processing tool includes at least one of a roughing tool (e.g., roughing tool 166) and a finishing tool (e.g., normal finishing tool 164) for finishing the periphery of the roughly processed lens. For example, the eyeglass lens processing device may be equipped with a large-diameter first peripheral processing tool (e.g., a normal finishing tool 164) as a peripheral processing tool, and a second peripheral processing tool (e.g., an end mill 435) having a smaller diameter than the first peripheral processing tool.

For example, the eyeglass lens processing device includes a moving means (e.g., a moving unit 300). The moving means is configured to adjust the relative position between the eyeglass lens held by the lens holding shaft and the processing tool (e.g., the processing tool 168, the step forming processing tool 437, etc.). For example, the eyeglass lens processing device includes a processing control means (e.g., a control unit 50). The processing control means controls the moving means.

For example, a step formation data setting device (e.g., step formation data setting device 55) is provided in an eyeglass lens processing device. For example, the step formation data setting device includes data acquisition means (e.g., data acquisition unit 60). For example, the data acquisition means acquires data on the target step contour shape for the step portion to be formed on the rear surface of the eyeglass lens. For example, the data acquisition means acquires outer shape data of the eyeglass lens (e.g., lens shape data TD).

For example, the step formation data setting device includes a calculation means (e.g., control unit 50). The calculation means determines whether the step contour shape can be completed by the step forming tool in accordance with the step contour shape data, based on the step contour shape and the diameter of the step forming tool acquired by the data acquisition means.

For example, the calculation means may determine whether or not machining of the step contour shape can be completed using the step forming tool based on the diameter of the step forming tool and the inclination angle (e.g., inclination angle α) of the rotation axis to which the step forming tool is attached relative to the lens holding shaft. For example, the calculation means may determine whether or not machining can be completed using the step forming tool by calculating the elliptical locus traced by the outline of the step forming tool when viewed from the axial direction of the lens holding shaft, and calculating the locus of the machining point when the elliptical locus touches the step contour shape for each radius vector angle of the eyeglass lens. By calculating the machining locus taking into account the inclination of the step forming tool, the calculation means can accurately determine whether or not machining is possible. For example, if the calculation means determines that machining is not possible, it may determine the unmachinable area of the step contour shape based on the elliptical locus.

The angle of inclination of the rotation axis may be fixed or may be changeable (for example, the value of the angle LSA on the display 62 may be changeable). For example, when the angle of inclination of the rotation axis is changed, the area that can be machined by the step forming tool also changes.

For example, if the calculation means determines that machining is not possible, it calculates the trajectory traced by the outline of the step-forming tool when the step-forming tool is positioned in a position where machining is possible relative to the contour shape for the unmachinable area, and determines the intersection of the calculated trajectory with a radius vector angle line changed for each radius vector angle of the eyeglass lens to determine the planned machining trajectory to be used by the step-forming tool. For example, the calculation means determines the elliptical trajectory traced by the outline of the step-forming tool when viewed from the axial direction of the lens holding shaft as the trajectory traced by the outline of the step-forming tool. By determining this machining trajectory, the area requiring additional machining of the step portion can be minimized, allowing the operator to perform the additional machining efficiently.

For example, the step formation data setting device includes an output means (e.g., control unit 50). For example, the output means outputs the determination result obtained by the calculation means. This notifies the worker that there is a portion of the step portion of the eyeglass lens that cannot be machined, allowing the worker to take appropriate action (such as additional machining or other necessary measures).

For example, the output means is a display control means (e.g., control unit 50) that controls the display on a display (e.g., display 62). For example, the display control means outputs the judgment result of the calculation means by identifiably displaying the unmachinable area determined by the calculation means on the display. For example, the display control means controls the display to display a first figure (e.g., step contour shape figure GTSD) indicating the target step contour shape on the screen of the display, and to display a second figure (e.g., machining path GPP) indicating the planned machining area for the step contour shape using a step forming tool superimposed on the first figure.

This allows the worker to visually easily confirm the extent of the unmachinable area, making it easier to perform additional machining on the unmachined, stepped areas that are unmachinable. Furthermore, to make additional machining easier for the unmachinable areas (unmachined areas), the actual distance (for example, horizontal distance, vertical distance) may be displayed on the display.

For example, if the outer shape data contains a concave portion smaller than the diameter of the first peripheral processing tool, the processing control means determines a processing path for outer shape processing based on the outer shape data and the diameter of the first peripheral processing tool that avoids processing interference that would result in the lens being processed smaller than the outer shape, controls the movement means based on the determined processing path, performs a first processing to process the eyeglass lens with the first peripheral processing tool, controls the movement means based on the outer shape data to process the unprocessed portion by the first processing, and performs a second processing to process the unprocessed portion with the second peripheral processing tool. This processing results in an eyeglass lens that has been finished before being processed with the step-forming processing tool.

Note that this disclosure is not limited to the devices described in the present embodiment. For example, a control program (software) that performs the functions of the above embodiment may be supplied to a system or device via a network or various storage media. The control unit (e.g., a CPU) of the system or device may then read and execute the program.

For example, the step formation data setting program causes the control unit of the step formation data setting device to execute a data acquisition step for acquiring data on the target step contour shape for the step portion, a calculation step for determining whether the step contour shape can be completely processed using the step forming tool based on the acquired step contour shape and the diameter of the step forming tool, and an output step for outputting the determination result from the calculation step.

[Example]
One exemplary 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 unit provided in an eyeglass lens processing apparatus 1 according to the embodiment.

For example, the eyeglass lens processing apparatus 1 includes a lens holding unit 100, which is an example of a lens holding means. For example, the eyeglass lens processing apparatus 1 includes a lens shape measuring unit 200. For example, the eyeglass lens processing apparatus 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 apparatus 1 includes a second processing tool unit 400. The second processing tool unit 400 is configured to rotate a processing tool that forms a step portion on the rear surface of the lens LE after finishing processing. For example, the eyeglass lens processing apparatus 1 includes a movement unit 300, which is an example of a movement means. The movement 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. The movement unit 300 is also configured to change (adjust) the relative positional relationship between the lens LE and the processing tool held by the second processing tool unit 400.

The lens holding unit 100 comprises a lens chuck shaft 102 for holding and rotating the lens LE, and a carriage 101. The lens chuck shaft 102 comprises 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 shafts 102 are rotated by a motor 120.

The first processing tool unit 150 is equipped with a motor 160 for rotating a processing tool rotation shaft 161. The processing tool rotation shaft 161 is rotatably held on the main body base 170 in a positional relationship parallel to the lens chuck shaft 102. A plurality of processing tools 168 for processing the periphery of the lens LE are attached to the processing tool rotation shaft 161.

For example, the processing tools 168 include a front bevel processing tool 162, a rear bevel processing tool 163, a normal finishing tool 164, a mirror-finishing tool 165, and a roughing tool 166. In the embodiment, grinding wheels are used as the processing tools 162 to 166, but cutters may also be used. The roughing tool 166 is used to roughly process the peripheral edge of the lens LE. The normal finishing tool 164 has a V-groove and a flat finishing surface to form a normal small bevel on a low-curve lens LE. The flat finishing surface of the normal finishing tool 164 is used during flat finishing. The mirror-finishing tool 165 is used to further mirror-finish the lens peripheral edge finished by the normal finishing tool 164. The rear bevel processing tool 163 is used to form a rear bevel (the bevel slope on the rear side of the lens LE) on the peripheral edge of a high-curve lens LE. The pre-beveling tool 162 is used to form a pre-bevel on the periphery of the highly curved lens LE.

In this embodiment, the axial direction of the lens chuck shaft 102 is the X direction, the direction in which the inter-axial distance between the lens chuck shaft 102 and the processing tool rotation shaft 161 is changed is the Y direction, and the direction perpendicular to the X and Y directions is the Z direction.

In Figure 1, the second processing tool unit 400 is disposed behind the carriage 101. Figure 2 is a schematic diagram of the second processing tool unit 400. A fixed plate 401, which serves as the base of the second processing tool unit 400, is fixed to a support block 172 erected on the base 170 in Figure 1. A movable support base 404 is slidably attached to the fixed plate 401 along a rail 402 extending in the Z-axis direction. The movable support base 404 is moved in the Z-axis direction by a motor 405 rotating a ball screw 406. A rotary support base 410 is rotatably held on the movable support base 404. The rotary support base 410 is rotated around its axis by a motor 416 via a rotation transmission mechanism.

A rotating unit 430 is attached to the tip of the rotary support base 410. A rotary shaft 431, which is perpendicular to the axial direction of the rotary support base 410, is rotatably held by the rotating unit 430. The rotary shaft 431 is rotated by a motor 440 attached to the movable support base 404 via a rotation transmission mechanism located inside the rotating unit 430 and the rotary support base 410. An end mill 435, an example of a hole machining tool, is coaxially attached to one end of the rotary shaft 431. The end mill 435 also serves as a small-diameter finishing tool for partially cutting the periphery of the lens LE after rough machining. A groove cutting tool 433 is also coaxially attached to the rotary shaft 431.

A step forming tool 437 is coaxially attached to the other end of the rotating shaft 431 to form a step on the rear surface of the lens LE after finishing. For example, the step forming tool 437 is a grindstone. The step forming tool 437 is not limited to a grindstone and may be a cutter or the like. Note that the configuration of the second processing tool unit 400 can basically be that described in JP 2003-145328 A, so details are omitted here.

Figure 3 shows an example of a step forming tool 437. The step forming tool 437 has a first processing surface 437a for forming the wall surface (first processing surface) STa on the rear side of the lens LE, and a second processing surface 437b for forming the skirt surface (second processing surface) STb extending toward the rear side of the lens LE. The second processing surface 437b has a conical shape whose diameter decreases toward the tip. The first processing surface 437a also has a conical shape whose diameter decreases toward the rear end. For example, the angle SA between the first processing surface 437a and the second processing surface 437b is 86 degrees, less than 90 degrees. The processing surface of the step forming tool 437 may be cylindrical. For example, the diameter of the step forming tool 437 is approximately 15 mm. Of course, the diameter of the step forming tool 437 is not limited to this, and can be set appropriately depending on the processing performance, durability, and processing accuracy required when processing the lens LE.

The moving unit 300 is configured to adjust the relative position between the lens LE held by the lens chuck shaft 102 and the processing tool (processing tool 168, step forming tool 437, etc.). In this embodiment, the moving unit 300 includes a first moving unit 310 and a second moving unit 330.

The first moving unit 310 is used to change the axial distance between the lens chuck shaft 102 and the processing tool rotation shaft 161 and rotation shaft 431. The second moving unit 330 is used to move the lens LE in the axial direction of the lens chuck shaft 102. The moving unit 300 also includes a third moving unit, the motor 405 and motor 440 of the second processing tool unit 400.

The first moving unit 310 is equipped with a motor 315. Rotation of the motor 315 moves the moving support base 301 in the X direction. This causes the carriage 101 and lens chuck shaft 102 (lens LE) mounted on the moving support base 301 to move in the X direction. Note that the first moving unit 310 may also be configured to move the tool rotation shaft 161 and rotation shaft 431 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. The carriage 101 is held by the moving support base 301 so that it can move in the Y direction along shafts 333 and 334. Rotation of the motor 335 is transmitted to a ball screw 337 extending in the Y direction, and rotation of the ball screw 337 moves the carriage 101 (lens chuck shaft 102 and lens LE) in the Y direction. Note that in this 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 processing tool rotation shaft 161 and the rotation shaft 431 in the Y direction. In other words, the second moving unit 330 may be configured to relatively change the inter-axial distance between the lens chuck shaft 102 and the processing tool rotation shaft 161 and the rotation shaft 431.

In FIG. 1, the lens shape measuring unit 200 is disposed above the carriage 101. The lens shape measuring unit 200 is used to measure the shape of the front lens surface (front refractive surface) and the rear lens surface (rear refractive surface) of the lens LE. The lens shape measuring unit 200 includes, for example, a measuring unit 200F for measuring the shape of the front lens surface and a measuring unit 200R for measuring the shape of the rear lens surface.

Figure 4 is a schematic diagram of the measurement unit 200F. The measurement unit 200F has a contact point 206F that contacts the front surface of the lens. The contact point 206F is attached to the tip of an arm 204F. The arm 204F is held by a mounting base 201F so that it can move in the X direction. The arm 204F is connected to a motor 216F via a rack 211F, a pinion 212F, a gear 214F, etc. The arm 204F is moved in the X direction by driving the motor 216F, and the contact point 206F is pressed against the front surface of the lens LE. The pinion 212F is attached to the rotation axis of a detector 213F (e.g., an encoder). The position of the contact point 206F, which is moved in the X direction, is detected by the detector 213F.

The configuration of measurement unit 200R, which is used to measure the rear surface shape of a lens, is bilaterally symmetrical to measurement unit 200F, so a detailed description will be omitted. Measurement unit 200R includes a stylus 206R that comes into contact with the rear surface of the lens, a motor 216R that moves stylus 206R in the X direction, and a detector 213R that detects the movement position of stylus 206R in the X direction.

When measuring the lens shape, stylus 206F is brought into contact with the front surface of the lens, and stylus 206R is brought into contact with the rear surface of the lens. In this state, lens LE is rotated by lens holding unit 100, and lens chuck axes 102L and 102R are moved in the Y direction by movement unit 300 based on the target lens shape data, thereby simultaneously measuring the lens shapes of the front and rear surfaces of the lens corresponding to the target lens shape. That is, measurement unit 200F measures the edge position of the front surface of the lens corresponding to the target lens shape, and measurement unit 200R measures the edge position of the rear surface of the lens corresponding to the target lens shape.

Figure 5 is a control system block diagram for the step formation data setting device 55 and the eyeglass lens processing apparatus 1. The eyeglass lens processing apparatus 1 includes the step formation data setting device 55. The step formation data setting device 55 includes a data acquisition unit 60. The data acquisition unit 60 may also function as a data input unit. For example, the data acquisition unit 60 includes a display 62. For example, the data acquisition unit 60 includes a data input unit 63. For example, the display 62 may have touch panel functionality and be configured to include the data input unit 63. The data acquisition unit 60 is connected to the contour reading device 30. The contour reading device 30 can be, for example, a device that has the function of reading the outer shape (lens shape) of a demo lens (installed lens) removed from an eyeglass frame and the function of reading the shape of a step portion marked on the demo lens. For details of the contour reading device 30, the technology described in JP 2012-185490 A can be used, and this is incorporated herein by reference.

The step formation data setting device 55 includes a control unit 50. The control unit 50 is connected to a data acquisition unit 60 and has the function of controlling the display 62. The control unit 50 functions as a calculation means for performing various calculations related to the formation of the step portion. The control unit 50 also functions as an output means for outputting the calculation results. For example, the control unit 50 outputs the calculation results by controlling the display 62. The data acquisition unit 60 includes a memory 70, which is an example of a storage means. The memory 70 stores various data acquired by the data acquisition unit 10. The memory 70 also stores various programs that the control unit 50 uses to control the operation of the step formation data setting device 55.

In addition, in this embodiment, the control unit 50 also serves as the control unit for the eyeglass lens processing apparatus 1 and is configured to control the entire eyeglass lens processing apparatus 1. The electrical components (motors, etc.) of each unit shown in Figures 1, 2, and 4 are connected to the control unit 50. The control unit 50 is configured to perform various calculations for lens processing.

The step formation data setting device 55 may be separate from the eyeglass lens processing apparatus 1. In this case, for example, the step formation data setting device 55 and the control unit of the eyeglass lens processing apparatus 1 are configured to be able to communicate data with each other.

<Operation>
The following describes the operation of the step formation data setting device 55 and the eyeglass lens processing device 1 having the above configuration. The following describes the case where a step portion is formed on the periphery of the lens LE in order to fit a prescription lens into the rim of a lens-interchangeable eyeglass frame.

<Acquisition of target lens shape data and step contour shape>
First, an example will be described in which the contour reading device 30 is used to obtain the target lens shape (external shape of the lens LE) and the partial stepped contour shape of the target eyeglass lens.

Figure 6 shows a typical example of an eyeglass frame SF that requires the formation of a partial step portion. Figure 6(a) shows a front view of the eyeglass frame SF. Figure 6(b) shows a partial cross-sectional view of the eyeglass frame SF when cut at position C. A groove (depressed groove) G, shown by the dotted line, is formed in the rim of the eyeglass frame SF. The groove G has a constant width FW. The depth of the groove G is the distance FD from the edge GC of the rim of the eyeglass frame SF. A demo lens SL is fitted into the groove G in the eyeglass frame SF. The demo lens SL has a constant thickness.

Figure 6(c) shows a front view of the demo lens SL attached to the eyeglass frame SF. The demo lens SL has protruding hook portions SLa formed on both the left and right ends to prevent the demo lens SL from falling off when fitted into the recessed groove G on the rim of the eyeglass frame SF.

To obtain the lens shape and partial step contour shape, with the demo lens SL attached to the eyeglass frame SF, the worker marks the inner boundary of the rim on the lens surface of the demo lens SL using a pen or clay. After removing the demo lens SL from the eyeglass frame SF, the worker reads the outline of the demo lens SL and the marked inner boundary using the contour reading device 30. Then, as shown in Figure 7, image processing is performed to obtain the lens shape data TD (Tr, θ), which represents the outer shape of the demo lens SL, and the step contour shape data TSD (Sr, θ), which represents the contour shape for forming a step portion on the rear side of the lens LE. Tr is the radius vector length of the lens shape TD based on the lens shape center FC, Sr is the radius vector length of the step contour shape TSD based on the lens shape center FC, and θ is the radius vector angle. In Figure 7, the area surrounded by the lens shape data TD and the step contour shape data TSD is the step processing portion.

The target step contour shape data TSD and target step contour shape data TD read by the contour reading device 30 are input to and acquired by the data acquisition unit 10. The target step contour shape data TSD, like the target ... For example, layout data may include the wearer's interpupillary distance (PD value), the distance between the frame centers of the eyeglass frame F (FPD value), and the height of the optical center relative to the geometric center of the lens shape.

The layout data setting screen also displays various switches for setting the processing conditions for the eyeglass lens LE. Processing conditions that can be set include, for example, the lens material, frame type, processing mode (bevel processing, flat finish processing mode), whether or not to perform chamfering, and whether or not to perform step processing. When processing a step portion on the lens LE, the operator sets both the flat finish processing mode and the step processing mode.

When the step machining mode is set, the operator can operate a specified touch key to display the step machining editing screen on the display 62. Figure 8 shows an example of the step machining editing screen 501.

The editing screen 501 displays, for example, a right-eye lens shape figure GTD based on the lens shape data TD. A target stepped contour shape figure GTSD based on the stepped contour shape TSD data is superimposed on the lens shape figure GTD and displayed. A cross-sectional view GSB of the stepped portion of the lens LE is displayed in the lower left corner of the editing screen 501. Using the cross-sectional view GSB as a reference, the operator can set the width of the stepped portion (the width between the lens front surface and the rear wall surface STa) LSW and the angle of the base of the stepped portion (the angle relative to the direction of the lens chuck axis 102) LSA by operating the touch keys. For example, the width LSW of the stepped portion is set by measuring the thickness of the demo lens SL. Alternatively, the width FW of the groove G of the eyeglass frame SF is measured and set based on this width FW. The angle LSA of the base surface STb relative to the X direction is also set by the operator. For example, the angle LSA can be set within the range of 5 to 15 degrees. The initial value is set to 5 degrees.

The height information LSD of the step portion is obtained by the control unit 50 calculating the difference between the radius vector length Tr of the target lens shape data TD and the radius vector length Sr of the step contour shape data TSD for each radius vector angle θ.

The partial rims of interchangeable lens eyeglass frames SF are designed in a variety of shapes. However, when forming a step portion to fit prescription lenses LE into the partial rim, the size of the step forming tool 437 may be limited, making it impossible to process the portion in accordance with the step contour shape data TSD. Therefore, the control unit 50 determines whether processing can be completed in accordance with the step contour shape data TSD based on the step contour shape data TSD and the diameter of the step forming tool 437. In this determination, the rotation axis 431 of the step forming tool 437 used when processing the step portion is set to be inclined, rather than parallel, to the X direction, which is the axial direction of the lens chuck shaft 102, and therefore the angle of inclination of the rotation axis 431 must be taken into consideration.

Figure 9 illustrates the positional relationship between the X direction and the rotation axis 431, and the positional relationship between the lens LE and the step forming tool 437 when forming a step portion on the lens LE after flat finishing. When processing the step portion, the lens LE and the step forming tool 437 are moved relative to each other so that the vertex CM of the first processing surface 437a and the second processing surface 437b of the step forming tool 437 coincides with the vertex position LT of the wall surface STa and the base surface STb of the step portion. The inclination angle α of the rotation axis 431 of the step forming tool 437 relative to the X direction (axial direction of the lens chuck shaft 102) at this time is determined by the angle LSA of the base surface STb set in the editing screen 501 and the angle (symbol omitted) of the second processing surface 437b relative to the rotation axis 431. Then, based on the tilt angle α, as shown on the right side of Figure 9, an elliptical locus EP drawn by the vertex CM (the outer shape of the step forming tool 437) when viewed from the X direction is determined (an elliptical locus based on the center MO of the rotation axis 431). Whether or not machining can be completed according to the step contour shape data TSD is determined based on the elliptical locus EP, which differs from the circular locus drawn by the tool 168 attached to the tool rotation axis 161 that is parallel to the lens chuck axis 102.

Figure 10 is a diagram that explains whether or not processing can be completed without processing interference based on the elliptical trajectory EP for the step contour shape data TSD shown in Figure 7. In the processing device 1 of Figure 1, the elliptical trajectory EP of the step forming tool 437 contacts the step contour shape as the lens LE rotates, but Figure 10 shows the elliptical trajectory EP contacting the step contour shape data TSD in relative terms. Note that the step contour shape data TSD is set to a range that will not be processed by the step forming tool 437 within the radius vector angle range where the target lens shape data TD is not located outside.

When the radius vector length at radius vector angle θn in the step contour shape data TSD is Srn, the radius of the step forming tool 437 (distance from the rotation center to the vertex CM) is R, the inter-axis distance between the center of the lens chuck shaft 102 and the center MO of the elliptical locus EP is Yn, and the inclination angle of the rotation axis 431 is α, the inter-axis distance Yn is expressed by the following equation. Note that n = 1, 2, 3, ..., N, where N is, for example, 1,000 points.

Here, θn is changed within a certain range to determine the angle θi at which Yn is maximized. The machining point PMi on the step contour shape data TSD at this time is determined as the point at which the elliptical locus EP touches the step contour shape data TSD at the angle θi. In Fig. 10, when the radius vector angle is θa (the direction in which the center MO is located), the machining point PMa on the step contour shape data TSD where the elliptical locus EP touches is located on the radius vector angle θa. On the other hand, when the radius vector angle is θb, the machining point PMb where the elliptical locus EP touches is at an angle θb different from the radius vector angle θa. When the radius vector angle is θc, the machining point PMc where the elliptical locus EP touches is located.

From machining point PMa to machining point PMc on the step contour shape data TSD, the machining point changes by a small distance for each unit change in radius vector angle θn (for example, when there are 1,000 machining points, the unit change in radius vector angle θn is 0.36 degrees).

The control unit 50 determines whether each machining point PMi is located inside the step contour shape data TSD, thereby determining whether machining can be performed according to the step contour shape data TSD without machining interference.

From machining point PMa to machining point PMc, the step contour shape data TSD is in a convex range, and basically within the convex range, machining is possible without the elliptical trajectory EP interfering with the step contour shape data.

However, in Figure 10, the step contour shape data TSD is concave from machining point PMc at radius vector angle θc to machining point PMd at radius vector angle θd, and if an attempt is made to position each machining point PMi on the step contour shape data TSD in this area, it will interfere with the step contour shape data TSD of other parts, making machining impossible. Therefore, the area from machining point PMc to machining point PMd is determined to be an area (range) where machining is not possible.

When the control unit 50 determines that there is an unmachinable area in the step contour shape data TSD, it outputs a message to that effect. For example, the control unit 50 controls the display 62 to display a message indicating that machining is not possible on the editing screen 501 shown in FIG. 8. For example, in the step contour shape data TSD of FIG. 7, to warn that there is an unmachinable area near the radius vector angle of 180 degrees, the control unit 50 displays a warning mark NMa on the display 62 near the radius vector angle of 180 degrees on the step contour shape figure GTSD on the editing screen 501. Furthermore, because there is also an unmachinable area near the radius vector angle of 0 degrees, the control unit 50 also displays a warning mark NMa on the display 62 near the radius vector angle of 0 degrees. This allows the operator to recognize that there is an unmachinable area in the step contour shape data TSD and that machining cannot be completed using the step forming tool 437.

Furthermore, when the operator touches the caution mark NMa, an enlarged screen 520 showing the graphic indicating the non-machinable area is displayed as a pop-up on the editing screen 501, as shown in FIG. 11, to enable identification of the non-machinable area. The enlarged screen 520 in FIG. 11(a) displays a graphic of the machining path GPP that is actually planned for machining by the step forming tool 437. The machining path GPP is displayed superimposed on the step contour shape graphic GTSD. The area GNA between the machining path GPP and the step contour shape graphic GTSD is shown as the non-machinable area (unmachined area). The non-machinable area GNA is displayed so as to be distinguished from the area GSD that can be machined by the step forming tool 437. For example, the area GNA is displayed in a different color from the area GSD. This display allows the operator to visually identify the non-machinable area by the step forming tool 437. Additionally, the actual distance in the up-down direction (y direction) in the non-machining area GNA is displayed in display field 521, and the actual maximum distance in the left-right direction (x direction) is displayed in display field 522. By displaying these distances, the worker can recognize the range of additional machining of the lens LE, making additional machining easier.

The enlarged screen 520 in Figure 11(b) shows another example of a display that makes it possible to identify areas that cannot be machined. In the enlarged screen 520 in Figure 11(b), the areas that cannot be machined are displayed as curved figures GNL. The area from the start point to the end point of the curved figure GNL is shown as an area that cannot be machined. This type of display also allows the worker to visually identify areas that cannot be machined with the step forming tool 437.

Here, we will explain the calculation method for determining the machining path GPP in the non-machining area. The area between machining points PMc and PMd in Figure 10 is machined by the vertex CM of the step forming tool 437 on the elliptical path EP. For this reason, the machining point for each unit angle between machining points PMc and PMd cannot be determined based on the above-mentioned equation 1. Therefore, the control unit 50 determines the machining path GPP in the non-machining area as follows:

Figure 12 is a diagram illustrating a method for calculating the planned machining path GPP using the step forming tool 437. For ease of explanation, Figure 12 illustrates the explanation assuming that the center MO of the elliptical path EP is located in the x-axis direction (0-degree direction of the radius vector angle) in an x-y coordinate system with the center FC of the target lens as the origin. For example, the machining path GPP is calculated for each radius vector angle of a unit change angle (0.36 degrees in this example) centered on the center FC. Note that the x-y directions in Figure 12 are for convenience of explanation and differ from the X-Y directions shown in Figure 1.

In FIG. 12, a radial angle line LLP of a certain radial angle θi (i=1, 2, 3, . . . , N) is expressed by the following formula 2.
In FIG. 12, the coordinates on the elliptical locus EP are expressed by the following equation 3.
D indicates the distance in the x direction from the center FC to the center MO of the elliptical locus EP, R indicates the radius of the step forming tool 437 (see FIG. 9), and α indicates the inclination angle of the step forming tool 437 with respect to the axial direction of the lens chuck shaft 102 (see FIG. 9).

By solving the simultaneous equations of Equation 2 and Equation 3 above, the x and y coordinates of the intersection point where the radial angle line LLP and the elliptical locus EP intersect can be found. Two intersection points are found, but the intersection point closest to the center FC is used as the calculation result. Then, by changing the radial angle θi by unit change angle and finding the intersection point for each radial angle θi, the coordinates on the elliptical locus EP shown in Figure 12 can be found.

In Figure 10, the elliptical locus EP can have a radius vector angle θc that is tangent to the machining point PMc in the step contour shape data TSD, or a radius vector angle θd that is tangent to the machining point PMd in the step contour shape data TSD, so coordinates on each elliptical locus EP are determined. In areas where the elliptical loci EP overlap, the coordinates closer to the center FC are used. This allows the planned machining locus GPP to be determined in the non-machining area (the area between the machining point PMc and the machining point PMd).

By determining the machining path GPP in this way and displaying it on the screen of the display 62, the difference between it and the non-machinable area GNA becomes visually clear, making it easier for the worker to understand the additional machining area when performing additional machining.

After the operator sets the necessary data for forming the step portion and checks the areas that cannot be machined on the editing screen 501, the lens LE is clamped by the lens chuck shafts 102R and 102L. When the operator presses the machining start switch (not shown), the step machining data set by the step formation data setting device 55 is output to the control unit 50, an example of a control unit for the eyeglass lens machining apparatus 1. The control unit 50 starts operations related to machining the peripheral edge of the lens LE.

First, the control unit 50 operates the lens shape measurement unit 200 to measure the lens shape. The control unit 50 acquires position information in the X direction corresponding to the target lens shape on the front and rear refractive surfaces of the lens LE. At this time, the control unit 50 acquires curve information (tilt information) of the refractive surfaces (front and rear refractive surfaces) of the lens LE from the data obtained by the lens shape measurement unit 200. For example, the curve information of the front refractive surface can be mathematically acquired by using at least four points of the front refractive surface data corresponding to the target lens shape. Note that the curve information of the front refractive surface may also be acquired by acquiring position information at different distances from the center of the lens chuck for each radius vector angle near a position corresponding to the target lens shape.

Once the lens shape measurement is complete, the control unit 50 begins rough machining. Based on the target lens shape data TD and layout data, the control unit 50 calculates machining control data for driving each component to rough-machine the lens periphery. The rough machining control data is obtained by calculating the inter-axis distance between the tool rotation axis 161 and the lens chuck axis 102 (the rotation center of the lens LE) for each rotation angle of the lens LE based on the diameter (radius) of the rough machining tool 166 and the target lens shape data TD. Note that the rough machining control data is acquired as data that is increased by a certain amount by the inter-axis distance between the grinding wheel rotation axis 161 and the lens chuck axis 102 during finish machining.

Once the roughing control data is acquired, the control unit 50 drives the motor 315 to move the carriage 101 so that the lens LE is positioned at the roughing grindstone 166, and then controls the motor 150 based on the roughing control data to perform roughing on the periphery of the lens LE.

Once rough machining is complete, flat machining (flat finish machining) is then performed. The control unit 50 calculates flat machining control data for flat machining the lens periphery based on the target lens shape data TD and layout data. The flat machining control data is obtained by calculating the axial distance between the tool rotation axis 161 and the lens chuck axis 102 for each rotation angle of the lens LE based on the diameter of the flat finish machining surface of the finishing tool 164 and the target lens shape data TD.

As shown in Figure 13, the target lens shape data TD includes a hook portion SLa read from the contour of the demo lens SL, which is surrounded by a small recess SLb. If the diameter of the finishing tool 164 is larger than the recess SLb, the recess SLb cannot be machined according to the target lens shape data. Therefore, the control unit 50 calculates a correction trajectory TDLb that can be machined with the finishing tool 164 based on the diameter of the finishing tool 164. Because the tool rotation axis 161 of the finishing tool 164 is parallel to the lens chuck axis 102, the control unit 50 does not need to consider the inclination of the rotation axis 431 as in the case of the step-forming tool 437. By calculating the machining point assuming that the finishing tool 164 is a perfect circle, the control unit 50 can calculate a correction trajectory TDLb for outer shape machining that avoids machining interference that would result in the lens being machined smaller than the target lens shape data TD. In Figure 13, the correction trajectory TDLb is set in two locations: the left and right sides. The area not machined by the finishing tool 164 is set as the area to be machined by an end mill 435 with a smaller diameter than the finishing tool 164.

Based on the target lens shape data TD and the correction trajectory TDLb, the control unit 50 controls the driving of the moving unit 300, and finishes the periphery of the lens LE with the finishing tool 164. Next, the control unit 50 controls the driving of the first moving unit 310 and the driving of the motors 405 and 416 of the second processing tool unit 400, causing the end mill 435 to process the area not machined by the finishing tool 164. This completes the finishing process.

Once the finishing of the lens LE is complete, the control unit 50 uses the step forming tool 437 to form a step portion on the periphery of the finished lens LE. The control unit 50 obtains the Y-axis step formation control data (control data for the interaxial distance between the center of the lens chuck shaft 102 and the center MO of the step forming tool 437) by calculating the processing point for each radius vector angle based on the step contour shape data TSD, as described above. At this time, the control unit 50 sets the inclination of the rotation axis 431 of the step forming tool 437 based on the angle LSA set on the editing screen 501. Furthermore, for the X-axis step formation control data, the control unit 50 obtains the X-axis position corresponding to the step contour shape data TSD for each radius vector angle based on the front refractive surface shape of the lens LE and the width LSW of the step portion set on the editing screen 501. The front refractive surface shape of the lens LE is obtained based on the measurement results from the lens shape measurement unit 200.

The control unit 50 controls the drive of each motor of the moving unit 300 and the second processing tool unit 400 based on the Y-direction and X-direction control data, and forms a step portion on the lens LE by rotating the lens LE while aligning the vertex CM of the step forming tool 437 with the vertex position LT of the lens LE for each radius vector angle, as shown in Figure 9. At this time, the control unit 50 completes processing while leaving an area that cannot be processed (area GNA in Figure 11(a)) so that the processing point of the vertex CM does not enter the center side of the step contour shape data TSD.

When processing of the lens LE by the eyeglass lens processing apparatus 1 is complete, the worker removes the lens LE from the lens chuck shaft 102. The worker then uses a device other than the eyeglass lens processing apparatus 1 (for example, a hand grinder for engraving) to perform additional processing on the unprocessed area of the step portion. For example, when performing additional processing, the worker operates the display 62 of the eyeglass lens processing apparatus 1 to display the enlarged screen 520 shown in FIG. 11(a). The worker can easily perform additional processing on the unprocessed area by referring to the unprocessable area GNA displayed on the enlarged screen 520, the vertical distance displayed in display field 521, the horizontal distance displayed in display field 522, etc.

<Example of transformation>
In the above description, an example has been described in which the step forming tool 437 is used as a tool for forming a step portion (step), but this is not limiting. For example, the groove excavating tool 433 may also be used as a tool for forming a step. Even when the groove excavating tool 433 is used as a tool for forming a step, the rotation axis 431 is inclined relative to the lens chuck axis 102 during processing, so the locus traced by the apex of the groove excavating tool 433 is an elliptical locus. Therefore, whether processing can be completed according to the step contour shape data TSD is determined based on the elliptical locus, as with the step forming tool 437.

In the embodiment, the inclination angle α of the rotation axis 431 of the step forming tool 437 relative to the axial direction of the lens chuck shaft 102 is set by rotating the rotating part 430 of the second tool unit 400, but this is not limited to this. For example, the rotation axis 431 may be placed at the processing position by a separate turning mechanism, and the turning angle may be set indirectly, thereby setting the inclination angle α of the rotation axis 431.

In the above explanation, flat finishing (flat processing) was used as an example of finishing, but this is not limiting. For example, finishing may involve beveling using a V-groove provided by the finishing tool 164. Furthermore, finishing may involve further groove-chamfering using the groove-digging tool 433 on the periphery after flat finishing.

The above describes typical embodiments of the present disclosure, but the present disclosure is not limited to the embodiments 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 55 step formation data setting device 60 data acquisition unit 62 display 102 lens chuck shaft 431 rotation shaft 437 step formation processing tool

Claims (6)

A step formation data setting device for setting data for forming a step portion on a rear surface of an eyeglass lens after finishing,
a data acquisition means for acquiring data on a target step contour shape related to the step portion;
a calculation means for determining whether or not machining of the step contour shape can be completed by the step forming tool rotated on the rotation axis at the inclination angle, based on the step contour shape, the diameter of a step forming tool for forming the step portion, and the inclination angle of a rotation axis to which the step forming tool is attached relative to a lens holding shaft that holds the eyeglass lens; the calculation means for determining whether or not machining can be completed by the step forming tool by determining an elliptical locus drawn by the outline of the step forming tool when viewed from the axial direction of the lens holding shaft based on the inclination angle, and determining a locus of a processing point when the elliptical locus contacts the step contour shape for each radius vector angle of the eyeglass lens;
an output means for outputting the determination result by the calculation means;
A step formation data setting device comprising: 2. The step formation data setting device according to claim 1,
The output means is a display control means for controlling the display of a display,
The step formation data setting device is characterized in that the display control means outputs the judgment result by the calculation means by displaying on the display an area that cannot be machined relative to the step contour shape in an identifiable manner. 3. The step formation data setting device according to claim 2,
The display control means displays a first figure indicating the step contour shape on the display screen, and a second figure indicating the planned processing area for the step contour shape to be processed by the step forming tool, superimposed on the first figure, thereby making it possible to identify areas that cannot be processed for the step contour shape. In the step formation data setting device according to any one of claims 1 to 3 ,
When the calculation means determines that processing is impossible, it calculates the trajectory that the contour of the step forming tool will trace when the step forming tool is positioned in a position where processing is possible for the step contour shape in the area where processing is impossible, and calculates the intersection of the calculated trajectory and a radius vector angle line that is changed for each radius vector angle of the eyeglass lens, thereby calculating the planned processing trajectory by the step forming tool. An eyeglass lens processing device for processing the periphery of an eyeglass lens,
An eyeglass lens processing device comprising the step formation data setting device according to any one of claims 1 to 4 . A step formation data setting program executed by a step formation data setting device that sets data for forming a step portion by a step forming tool for forming a step portion on a rear surface of an eyeglass lens after finishing,
a data acquisition step for acquiring data on a target step contour shape related to the step portion;
a calculation step for determining whether or not the step contour shape can be completely processed by the step forming tool rotated on the rotation axis at the inclination angle based on the step contour shape, the diameter of the step forming tool, and the inclination angle of the rotation axis to which the step forming tool is attached relative to a lens holding shaft that holds the eyeglass lens, the calculation step determining whether or not the step contour shape can be completely processed by the step forming tool rotated on the rotation axis at the inclination angle, the calculation step determining whether or not the step contour shape can be completely processed by the step forming tool by determining an elliptical locus drawn by the outline of the step forming tool when viewed from the axial direction of the lens holding shaft based on the inclination angle, and determining a locus of a processing point when the elliptical locus contacts the step contour shape for each radius vector angle of the eyeglass lens;
an output step of outputting a determination result obtained by the calculation step;
A step formation data setting program that causes a control unit of a step formation data setting device to execute the above steps.