JP2001050738A - Lens measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure lens highly accurately by correcting a center deviation of a styluses. SOLUTION: This method obtains position data on front/rear lens surfaces on a profile line defined by a lens frame shape data by using tips of a pair of styluses to trace the front/rear lens surfaces, and detecting the displacement of the individual stylus in a thickness direction of a lens. The position data on the front/rear lens surfaces obtained by tracing with the styluses are corrected based on center deviation value of the both styluses detected beforehand. The center deviation value is obtained by making the tips a pair of styluses 161, 162 in contact with front and rear surfaces of a flat plate part 57 of a measuring prototype 50, displacing the measuring prototype to alternately match the tips of the both styluses with a V groove 58A on the flat plate part, and assuming the difference between the displacement of the measuring prototype at the points where the individual styluses matches the V groove as the center deviation of the both styluses.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to processing a peripheral edge of a lens to be processed for spectacles in accordance with lens frame shape data, based on the lens frame shape data, the position of a lens surface of a lens to be processed. The present invention relates to a lens measuring method for measuring a lens.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 8-166 discloses this type of technology.
There is known a method for measuring the edge thickness of a lens described in JP-A-11. This edge thickness measurement method traces the tips of a pair of styluses disposed on a front and back lens surface of a lens to be processed held by a lens holding unit on a straight line substantially orthogonal to the lens to be processed according to lens frame shape data. Then, by detecting the displacement of each stylus in the lens thickness direction, the position data of the front and back lens surfaces on the contour defined by the lens frame shape data is obtained, and by subtracting these position data, the lens cover is obtained. It is to calculate the thickness.

[0003]

By the way, a pair of styluses arranged coaxially have the same positions of the tips contacting the lens surface, that is, there is no misalignment between both styluses. Although ideal, it is inevitable that there will be slight misalignment in reality. Therefore, if measurement is performed with the misalignment, high-accuracy measurement cannot be expected.

An object of the present invention is to provide a lens measuring method capable of performing high-accuracy measurement by correcting a stylus misalignment that cannot be avoided due to manufacturing reasons or the like in consideration of the above circumstances. I do.

[0005]

According to the first aspect of the present invention, when processing the periphery of a lens to be processed for spectacles according to lens frame shape data, the lens on the front and back lens surfaces of the lens to be processed held by a lens holding unit. By tracing the tips of a pair of styluses disposed on a straight line substantially orthogonal to the lens to be processed in accordance with the lens frame shape data, and detecting the displacement of each stylus in the lens thickness direction, the lens frame In the lens measurement method for obtaining the position data of the front and back lens surfaces on the contour line defined by the shape data, the position data of the front and back lens surfaces obtained by tracing the stylus is used for both styluses that have been detected in advance. The correction is performed based on the misalignment amount.

In the present invention, the misalignment of both styluses is detected in advance, and the position data of the lens surface acquired by the stylus is corrected based on the misalignment. Considered, highly accurate measurement of the lens surface position becomes possible.

According to a second aspect of the present invention, in the first aspect, the front and rear surfaces of the flat plate portion of the prototype for measuring the amount of misalignment in which the tips of the pair of styluses are held by the lens holding unit instead of the lens to be processed. And by relative displacement of the measurement standard and the stylus in the plane direction of the flat plate portion,
The tips of both styluses are alternately matched with a reference line formed on the flat plate portion, and the difference in the relative displacement between the measurement standard and the stylus at the point where each stylus matches the reference line is determined by the misalignment between the styluses. It is characterized in that it is obtained as a quantity.

In the present invention, the amount of misalignment of the stylus is
Instead of the lens to be processed, the stylus is actually brought into contact with the flat part of the measurement standard held by the lens holding unit for measurement.
The amount of misalignment can be easily obtained, and the amount of misalignment can be directly used for the correction calculation.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Here, first, a lens processing apparatus for performing the lens measuring method of the present invention will be described. The lens measuring method of the present invention is performed when performing lens processing with this lens processing apparatus. FIG. 1 is a perspective view showing the overall configuration of the lens processing apparatus, FIG. 2 is a plan view showing the overall configuration, and FIG. 3 is a front view of the overall configuration viewed from the front side of the apparatus.

The processing apparatus 10 is not a conventional grinding apparatus for grinding a lens peripheral surface with a grindstone, but a cutting lens processing apparatus for forcibly cutting a lens peripheral surface with a rotary cutting tool. is there. This type of cutting lens processing apparatus is effective for a plastic lens and can improve processing efficiency.

In this processing apparatus 10, each of the mechanism parts is a base 11
It is configured by being attached to. Base 11
The substrate 11a is provided horizontally, and the substrate 11a
Above are provided a lens holding unit 12, a cutter rotation mechanism section 13 for cutting the peripheral surface of the lens, and an end mill rotation mechanism section 14 for performing groove processing and chamfering. These are laid out in substantially the same plane on the substrate 11a, the cutter rotation mechanism 13 and the end mill rotation mechanism 14 are both arranged on the front side of the apparatus, and the lens holding unit 12 is arranged on the apparatus rear side. ing.

A measurement unit 15 is provided on the substrate 11a. The measuring unit 15 has a measuring head 16 as a lens shape measuring means. The measuring unit 16 has a cutter rotating mechanism 1 for avoiding interference between the cutter rotating mechanism 13 and the end mill rotating mechanism 14.
3 and an empty space above the end mill rotation mechanism 14.

The lens holding unit 12 holds the lens 1 to be processed and rotates the lens 1 around the center of the lens in order to move the processing position in the lens circumferential direction. The cutter rotation mechanism unit 13 includes a cutter (peripheral surface processing unit) 131 for forcibly cutting the peripheral edge of the lens 1 to be processed.
By rotating the cutter 131 about a horizontal axis, flat cutting and bevel cutting of the peripheral surface of the lens 1 to be processed are performed. End mill rotation mechanism 14
Has a ball end mill (hereinafter simply referred to as an “end mill”) 141 as a groove carving means and a chamfering means, and by rotating the end mill 141 about a horizontal axis, a groove is formed on the peripheral surface of the lens 1. (This groove is used to pass a thread such as nylon when the lens is mounted on the rimless frame.) Or chamfers the intersection edge between the peripheral surface of the lens 1 to be processed and the lens surface. Things.

The measuring unit 15 has a measuring head 16 for measuring the edge thickness of the lens 1 and the lens position in the edge thickness direction, and can turn the measuring head 16 in the vertical direction as required. It is.

The lens holding unit 12 is provided so as to be slidable in a direction parallel to the surface of the substrate 11a and perpendicular to the axis of the cutter 131 (hereinafter referred to as the Y-axis direction) by a mechanism to be described later. And is slidable in a direction parallel to the axis of the cutter 131 (hereinafter referred to as a Z-axis direction).

The cutter rotation mechanism 13 is fixed on the substrate 11a. The cutter 131 of the cutter rotating mechanism 13
Is attached to a spindle 132, and the rotation of a cutter rotation motor 133 is
By transmitting it to 2, it can be rotated around its own axis.

The substrate 11a is provided with a cutting operation mechanism 24. The cutting operation mechanism section 24 is a mechanism that moves the lens holding unit 12 in the Y-axis direction and performs a cutting operation on the lens 1 with respect to the cutter 131 and the ball end mill 141.

A duct (not shown), which constitutes a means for sucking and removing the processing powder, is provided below the substrate 11a. The duct is connected to a cleaning port 993 opened in the substrate 11a. Above the cleaning port 993, a plurality of air injection nozzles 992 as air injection means are arranged. These air injection nozzles 992 are disposed near the cutter 131 and near the end mill 141, and perform peripheral surface cutting, groove engraving or chamfering on the lens 1 to be processed mounted on the lens holding unit 12. The processing powder that has been blown is blown off by the air jet nozzle 992, and the blown-out processing powder is sucked and removed from the cleaning port 993.

Each mechanism of the lens processing apparatus 10 includes a substrate 1
It is electrically controlled by a control device (not shown) provided below or below 1a.

On the substrate 11a of the base 11, a Y table 20 which moves in the Y axis direction is provided. The Y table 20 is slidably provided on two parallel rails 21 fixed to the substrate 11a so as to face the Y-axis direction, and is connected to the above-described cutting operation mechanism 24. The cutting operation mechanism 24 controls the movement in the Y-axis direction.

On the upper surface of the Y table 20, two rails 31, 31 are fixed so as to face in the Z-axis direction. A Z table 30 is slidably provided on these rails 31. The Z table 30 is the Y table 20
The movement is controlled by a Z-table moving mechanism (axial moving mechanism for moving the lens in the axial direction) 33 fixed thereon. The Z-table moving mechanism 33 is provided with a Z-axis motor 331. Z-axis motor 331
A ball screw 332 is connected to the rotating shaft of the, and a slide block 333 fixed to the Z table 30 is screwed to the ball screw 332. The Z-axis motor 331 rotates in both forward and reverse directions according to a command from a control device described later.

The rotation of the Z-axis motor 331 causes the ball screw 332 to rotate. Then, the slide block 333 is moved by the rotation of the ball screw 332, and the Z table 30 is integrated with the slide block 333.
Moves along the rails 31, 31. Z table 3
The lens holding unit 12 is fixed to the upper surface of the lens 0.

FIG. 4 is a plan view showing a detailed configuration of the lens holding unit 12. As shown in FIG. The lens holding unit 12 has a lens holding shaft 121 parallel to the axis of the cutter 131 (see FIG. 2).
have. The lens holding shaft 121 is rotated by a rotation mechanism in the lens holding unit 12. A lens holder receiver 121a is provided at the tip of the lens holding shaft 121.
Is fixed, and a lens holder 19 to which the lens 1 to be processed is fixed is detachably attached to the lens holder receiver 121a.

In the lens holding unit 12, a lens holding shaft (also referred to as a lens holding shaft) 122 is slidable in the direction of the lens holding shaft 121 via an arm portion 122b coaxially with the lens holding shaft 121. Installed. The lens holding shaft 122 is connected to the air cylinder 1
The lens 1 is moved to the lens 1 side under the pressure of 23, the lens 1 is pressed by the lens holder 122 a at the tip thereof, and the lens 1 is sandwiched and held between the lens 1 and the lens holding shaft 121.

In this case, the convex side lens surface 1A of the lens 1 is bonded to the end surface (formed in a concave shape) of the lens holder 19 via a double-sided adhesive pad 191. 1 is pressed against the concave side lens surface 1B. Further, the lens press 122a is attached to the tip of the lens press shaft 122 so as to be swingable in all directions, so that the lens press 122a is pressed against the concave lens surface 1B of the lens 1 in a well-balanced manner without a single contact.

The air cylinder 123 provided in the case 12a of the lens holding unit 12 moves its rod 123a in the Z-axis direction by the pressure of air sent from an air pump (not shown) provided outside. . At the end of the rod 123a, an arm 123b
Are fixed and provided so as to move integrally with the rod 123a. The arm 123b includes an arm portion 122 of the guide table 123c and the lens holding shaft 122.
b is fixed. The lens pressing shaft 122 is provided so as to be movable along an elongated hole 12b formed in the case 12a and extending in the Z-axis direction. Lens holding shaft 1
A lens holder 122a is provided at the tip of the lens 22 such that the lens holder 122a can freely rotate forward and backward around the Z axis.

[0027] The guide table 123c is
4 is slidably fitted to a rail 124a provided so as to be parallel to the Z-axis direction on the side surface of the rail 4. Thus, when the rod 123a of the air cylinder 123 moves, the arm 123b, the guide table 123c,
The lens pressing shaft 122 moves in the Z-axis direction, and the lens pressing 122a comes into pressure contact with the lens 1 or separates from the lens 1.

A lens rotation motor 125 is provided in the case 12a. A small-diameter gear 125c is connected to a shaft 125a of the lens rotation motor 125 via a coupling 125b. This gear 1
25c is connected to a large-diameter gear 125d. Further, a pulley 125e is provided coaxially with the gear 125d, and the pulley 125e is connected to a pulley 121b fixed on the shaft 121 via a belt 125f.

Thus, when the lens rotation motor 125 is driven, the rotation of the shaft 125 a
b, transmitted to the gear 125c, and further reduced by the gear 125d. The reduced rotation is transmitted to the lens holding shaft 12 via the pulley 125e, the belt 125f, and the pulley 121b.
1 and the lens 1 rotates.

A slit plate 121c is fixed to the lens holding shaft 121, and the rotational position of the slit plate 121c is adjusted by the optical sensor 12 fixed in the case 12a.
6, the origin position of the lens 1 held on the lens holding shaft 121 is detected.

The lens holding unit 12 having such a configuration
Then, when the lens 1 is fixed to the lens holder receiver 121a, the air cylinder 123 is driven, and the lens pressing shaft 122 moves to the left in the drawing. The lens 1 is fixed by pressing the lens 1 with the lens holder 122a. During processing of the lens 1 and measurement of the lens, the lens rotation motor 125 is driven, and the lens holding shaft 121 is rotated, whereby the lens 1 is rotated. The rotation of the lens 1 causes the lens holder 12 to rotate.
2a also rotates together.

FIG. 5A is a plan view showing a schematic configuration of a cutting operation mechanism 24 as a Y-axis direction moving mechanism.
(B) is a view on arrow Vb-Vb of (a). The cutting operation mechanism 24 is fixed to the upper surface of the concave portion of the concave member 68 attached to the lower surface of the opening of the substrate 11a. Concave member 6
8, two bearing support members 6 are spaced apart from each other.
1, 61 are provided, and a ball screw 62 oriented in the Y-axis direction is rotatably attached to these support members 61, 61. One end of the ball screw 62 is connected to a shaft of a cutting motor 63 fixed to the concave member 68.

The cutting motor 63 rotates in both forward and reverse directions in accordance with a command from a control device described later, and the ball screw 62 rotates in conjunction with the rotation of the cutting motor 63. A moving block 64 is screwed to the ball screw 62, and the moving block 64 is connected to the Y table 20 described above. Therefore, the Y table 20 and the lens holding unit 12 move in the Y-axis direction integrally with the moving block 64 of the cutting operation mechanism 24. Thereby, the cutting operation of the lens 1 into the cutter 131 is performed.

A switch piece 641 is attached to the moving block 64. The switch piece 641 turns on the optical sensor 642 fixed to the concave member 68 when the moving block 64 is at the origin position serving as a reference for measuring the cutting depth. When the moving block 64 is at one of the limit positions, the optical sensor 643 fixed to the concave member 68 is turned on. When the moving block 64 is at the other limit position, the optical sensor 644 fixed to the concave member 68 is turned on.

Next, the end mill rotation mechanism 14 will be described. The end mill rotation mechanism 14 is disposed adjacent to the cutter 131 of the cutter rotation mechanism 13, and the axis of the end mill 141 is placed on the substrate 11 a by the lens holding shaft 121 and the lens holding shaft of the lens holding unit 12. It is fixed in a direction perpendicular to the direction 122 and in a direction parallel to the substrate 11a. In addition, the axis of the end mill 141, the axis of the cutter 131, and the axes of the lens holding shaft 121 and the lens pressing shaft 122 are located at the same height.
The end mill rotation mechanism section 14 is provided with a spindle motor 142 that drives the end mill 141 to rotate.

Next, the measuring unit 15 will be described with reference to FIGS. The measurement unit 15 has a measurement head 16 provided with a pair of styluses 161, 162. As shown in FIG. 8, the measuring head 16 is
Two support walls 151, 151 erected at an interval above
Is mounted via a turning shaft 152. The turning shaft 152 is disposed in parallel with the axis of the cutter 131, and is supported at a height near the upper ends of the support walls 151 and 151 so as to be rotatable in the vertical direction. Two arms 163 and 163 projecting below the measuring head 16 are provided on the turning shaft 152.
Is fixed, and by rotating the turning shaft 152, the measuring head 16 is moved to the unloading position shown in FIGS. 6A and 7A (a retracted position when not used for measurement).
And a load position (a position used for measurement) shown in FIGS. 6B and 7B.

The pivot shaft 152 has a support wall 151 having one end at one end.
From the substrate 11, and the projecting end is
a on a rotating shaft 155a of an air-driven measuring head rotating actuator 155 fixed on a
They are connected via a coupling 152a. Since the measurement head 16 is moved to the unload position and the load position by the air-driven rotary actuator 155, the measurement head 1 is moved to the unload position and the load position.
Stoppers 156 and 157 are provided so as to securely stop 6 (see FIG. 6). Stoppers 156, 157
Are provided on members on the non-swirl side, that is, brackets 156a and 157a fixed to the support wall 151. When a specific portion of the measurement head 16 hits these stoppers 156 and 157, the measurement head 16 is positioned. Is being done.

The stopper 156 at the unload position does not need to exhibit a particularly accurate positioning function.
Because it affects measurement accuracy, it is necessary to exhibit a very accurate positioning function. Therefore, as the load-side stopper 157, a micro head (1/1000 mm) that can accurately adjust the positioning position is used. By positioning with the micro head type stopper 157, the styluses 161 and 162 of the measuring head 16 moved to the loading position are at the same height level as the rotation center of the lens holding shaft 121 and the rotation center of the cutter 131. Precisely retained.

Further, when the measuring head 16 is moved to the unload position or the loading position by the rotary actuator 155, a shock may occur if a specific portion of the measuring head 16 collides with the stoppers 156, 157. The brackets 156a fixed to the arm 163 and the support wall 151 are provided with shock absorbers (shock absorbers) 158 and 159 that perform a shock absorbing action. Immediately before the measuring head 16 hits the stoppers 156 and 157, these shock absorbers 158 and 159 come into contact with a mating member to exert a buffering action, and
It serves to soften the contact of the measuring head 16 with 57.

When the measuring head 16 is moved to the load position, it is necessary to confirm that the measuring head 16 has fallen to the load position. Therefore, as shown in FIGS. , An optical sensor 160 is provided on a bracket 160 a fixed to the support wall 151 to detect the presence or absence of the measuring head 16.

As described above, the measuring head 16 is configured to be pivotable between the loading position and the unloading position, so that the measuring head 16 is supplied from above to a position to be measured (loading position) when necessary, and is unnecessary. Sometimes, it is possible to retreat to an upper retreat position (unload position). Therefore, since the measuring head 16 is mounted so as not to hinder the work by the cutter 131 and the end mill 141, once the lens 1 is held by the lens holding unit 12, the chucking is not released from the measurement to the processing without releasing the chucking. Work can proceed with one chuck. Also, as a special case, when performing the measurement as needed during the processing of the lens 1, without releasing the chucking of the lens 1, holding the lens 1 as it is, the edge thickness of the lens 1, etc. Can be measured.

The specific configuration of the measuring head 16 will be described. As shown in FIGS. 2 and 7A, the measuring head 16 has a convex lens of the lens 1 to be processed held by the lens holding unit 12. A pair of styluses (probes) 161 and 162 that are in contact with the surface and the concave lens surface are provided.
The pair of styluses 161 and 162 are located on a straight line parallel to the lens thickness direction (the direction parallel to the rotation axis 152), and are arranged with their spherical tips facing each other.

FIG. 9 is a diagram showing the principle configuration of the measuring head 17. Each of the styluses 161 and 162 is moved by a guide mechanism (not shown).
4, 165. Stylus 161
(The other stylus 162 has the same configuration) as shown in FIG.
As shown in detail in (b) and (c), a structure in which a true spherical steel ball (a steel ball of about 2φ made of super steel, which is resistant to wear and shape deformation) 161b is attached to the tip of a rod-shaped stylus main body 161a. belongs to. Stylus body 161a
A flat surface is formed on the side surface of the steel ball 1
The stylus body 161 moves toward the flat surface side.
It is mounted by welding eccentrically to a.

In this case, it is conceivable to attach a steel ball to the center of the stylus body. However, in this case, there is a great possibility that the steel ball will be attached to a position deviating from the center due to an attachment error or a processing error. It is difficult to correct coordinate shift. In this regard, as described above, the flat surface is formed on the side surface of the stylus main body 161a, and the steel ball 1 is formed so that the outer periphery of the steel ball 161b contacts the extended surface of the flat surface.
61b, the steel ball 16
The center position of 1b is located at a distance of the radius of the steel ball 161b from the flat surface of the stylus body 161a. Therefore, exactly steel ball 1
The coordinates of the center position of 61b can be grasped, and this can be reflected in the measurement.

The arms 164 and 165 to which the styluses 161 and 162 are attached are moved parallel to each other to open or close the gap therebetween. Arm 16
4, 165 are springs (compression springs in the illustrated example) 166a,
The linear encoders 166, 167 having the built-in 167a are connected to the movers 166b, 167b of the linear encoders 167, 167.
a and 167a urge each other in the closing direction. The linear encoders 166 and 167
The linear encoders 166 and 167 electrically detect the movement positions of the stylus 16 and the stylus 16.
1,162 positions are detected.

As described above, the styluses 161 and 162
Is automatically biased in the closing direction by the springs 166a and 167a, but must be moved in the opening direction by some drive mechanism. Therefore, a pair of pulleys 171 and 17 are provided above the arms 164 and 165.
2, a pulley 171 is rotated by a stylus opening / closing DC motor 170 to rotate the belt 173 around, and thereby the belt 1 is rotated.
73, the arm 16 is engaged with the engagement pieces 173a and 173b.
4,165 is hooked and moved in the opening direction.

In this case, too, the optical sensors 174, 17
By detecting the position of the engagement piece 173a at 5, it is possible to detect whether the stylus 161 or 162 is open or closed. Also, the optical sensors 176, 1
77 makes it possible to detect whether each of the arms 164 and 165 is at the origin position.

FIGS. 10 and 11 show the principle of measuring the lens position using the styluses 161 and 162 of the measuring head 16. The styluses 161 and 162 are attached to the lens holding shaft 121.
And on the same straight line parallel to. Here, when the belt 173 of FIG. 9 is driven to move the lens 1 between the tips of the styluses 161 and 162 while the styluses 161 and 162 are opened and the belt 173 is returned to the opposite side, the linear encoder 166 is moved. , 167a and 167
By the action of a, the styluses 161 and 162 are closed, and FIG.
As shown in FIG. 0, one stylus 161 has its tip abutting on the convex side lens surface 1A of the lens 1 and the other stylus 1
Reference numeral 62 designates the tip of the lens 1 in contact with the concave lens surface 1B.

Now, lens frame shape data (= shape data)
When the movement of the lens 1 is controlled based on, the styluses 161 and 162 trace the trajectory S along the shape data, as shown in FIG.

For example, radial information (ρi,
θi) is given, by controlling the cutting operation mechanism 24 by an amount based on the radial length ρi,
Move in the lens radial direction with respect to the styluses 161 and 162, and the styluses 161 and 162
21 from the center axis line. Also, by controlling the lens rotation mechanism of the lens holding unit 12 by an amount based on the radial angle θi,
Is rotated by the radial angle θi with respect to the styluses 161 and 162. Since the tips of the styluses 161 and 162 trace on the convex lens surface 1A and the concave lens surface 1B of the lens 1, the moving amounts of the styluses 161 and 162 are detected by the linear encoders 166 and 167, so that the radial information is obtained. , Lens position data (Zi) in the edge thickness direction (Z-axis direction) can be obtained. By executing this detection operation for all the radial information (ρi, θi), the position data of the convex lens surface 1A and the concave lens surface 1B on the lens radial shape locus (ρi, θi) are obtained.
Can be obtained (ρi, θi, Zi).
Then, the lens thickness (edge thickness) on the lens radial shape locus (ρi, θi) can be calculated from the position data of the convex lens surface 1A and the position data of the concave lens surface 1B.

Next, the cutter 131 of the cutter rotating mechanism 13
Will be described. FIG. 12 shows the configuration of the cutter 131. As shown in FIG. 12B, the cutter 131 has two cutting blades 131a protruding from the outer peripheral surface, and the cutting blades 131a are provided at 180-degree intervals in the circumferential direction. . As shown in FIG. 12A, the cutter 131 has a small bevel cutter Y1 having a small bevel groove Y1a.
Three cutters, a large bevel cutter Y2 having a large bevel groove Y2a (for example, for a plastic cell frame) and a planing cutter H1 without a bevel groove (for example, for a frame without a frame). Are arranged on the same axis and are integrally connected, so that each cutter portion can be used properly according to a processing item.

The bevel grooves Y1a and Y2a are as shown in FIG.
It is shown as follows. The bevel angle is, for example, 110 to
125 °, the bevel height is, for example, 0.1 in the case of a small bevel.
4 to 0.68 mm, for a large bevel, for example, 0.7 to
0.9 mm. Also, bevel grooves Y1a, Y2
The flat portion adjacent to “a” has a tapered surface of, for example, 3.5 to 5 degrees only on one side. This is to create an escape for the frame next to the bevel.

FIG. 13 shows the principle of cutting the periphery of the lens 1 by the cutter 131. When viewed from the interference portion between the cutter 131 and the lens 1, the cutter 131 rotates from top to bottom, and the lens 1 rotates from bottom to top. Then, cutter 1
The 31 cutting blades 131a forcibly cut the lens 1 by the set cutting amount. Now, a machining program is created based on the lens frame shape data (= shape data), and when the movement of the lens 1 is controlled according to the machining program, the cutter 131 cuts the peripheral surface of the lens 1 according to the movement of the lens 1. Go.

In the case of planing, the lens 1 is positioned at an appropriate position in front of the planing cutter H1, and the cutting operation mechanism 24 is driven while rotating the cutter 131 to perform processing. In the case of beveling, FIG.
As shown in FIG. 4, the lens 1 is positioned at an appropriate position in front of the bevel cutters Y1, Y2, and the Z table moving mechanism 3
The cutting is performed by driving the cutting operation mechanism 24 while rotating the cutter 131 in accordance with the movement of the cutter 131 in the Z-axis direction. In the figure, 1a indicates a bevel.

FIGS. 15, 16, 17 (a), (b)
The principle of grooving by the end mill 141 and chamfering of both edges of the edge (lens peripheral surface) are shown below. When the groove 1b is carved in the end surface (peripheral surface) of the lens 1 whose shape has been processed, the movement of the lens 1 is controlled so that the lens end surface approaches the tip of the rotating end mill 141 as shown in FIGS. I do.

When the approach is completed, the cutting amount is appropriately set by the cutting operation mechanism 24 while rotating the lens 1. Then, as the lens 1 rotates, a groove 1b having a preset depth (cut amount) is continuously formed on the lens end face. During processing, the distance between the end face position where the end mill 141 is currently in contact and the center of the lens is calculated based on the shape data of the lens 1, and the position of the lens 1 in the Y-axis direction is moved and controlled according to this distance. .
Also, during processing, based on the shape data, a specific position of the end face, for example, the center position in the width direction (edge thickness direction) of the end face,
Alternatively, the movement of the lens 1 in the Z-axis direction is controlled such that the end of the end mill 141 is always located at a position at a fixed distance from the front surface of the lens (convex side lens surface 1A).

When the lens 1 makes one rotation while continuing such control, a groove 1b is formed on the lens end surface over the entire circumference of the lens. When the end mill 141 returns to the original starting point, the end mill 141 moves in the direction opposite to the approaching direction and separates from the lens 1.

In the case where the edges of both ends of the edge (the intersection edge between the lens peripheral surface and the lens surface) are subjected to thread chamfering to prevent cracking or chipping, as shown in FIG. Use the R part. FIG. 3A shows a case where chamfering is performed on a lens having a groove 1b formed on a peripheral surface thereof.
FIG. 4B shows a case where chamfering is performed on a lens whose peripheral surface is processed with a bevel 1a. The edge 1c on the convex side or the edge 1d on the concave side is
When dropping at the end of the end mill 141, the shoulder of the end R of the end mill 141 is used.

At this time, using the position coordinate data of the edge portions 1c and 1d, the lens 1 with respect to the end mill 141 is used.
Position (for chamfering). That is, the chamfer dimensions (ΔZ, ΔY) are determined by the shapes of the edge portions 1c and 1d.
Is determined, the center position of the end mill 141 for chamfering, the radius of the R portion, and the position data of the edge portions 1c and 1d are included in the calculation, so that the edge portion 1c of the lens 1 is obtained.
The allowances Q11, Q12, Q21, and Q22, which are the mutual positional relationship between 1d and the end of the end mill 141, are determined.
Therefore, the position coordinate data of the edges 1c and 1d of the lens 1 to be controlled can be determined from the coordinates of the center of the end mill 141 and the data of the allowances Q11, Q12, Q21 and Q22. The position of the lens 1 and the end mill 141 for proper chamfering are determined by controlling the position of the lens 1 in the Y-axis direction and the Z-axis direction and rotating the lens 1 based on the above. That is, by moving the lens 1 in the Y-axis direction and the Z-axis direction and making it rotate, the edge portion 1 to be processed is formed.
c and 1d can be accurately positioned with respect to the tip R of the end mill 141 that is rotationally driven at a fixed position. This is possible because the shape and position information of the end mill 141 and the position information of the lens 1 are accurately grasped. Note that the chamfering on the convex side and the chamfering on the concave side are performed independently, including the approach of the lens 1 to the end mill 141.

FIG. 18 shows the structure of the lens holder 19 used in the processing apparatus 10. FIG. 18 (a)
As shown in FIG. 4, the lens holder 19 is configured such that the fitting shaft portion 1 fitted on the inner periphery of the cylindrical lens holder receiver 121a shown in FIG.
93, a fitting shaft portion flange 194 that contacts the end surface of the lens holder receiver 121a, and as shown in FIG.
Is a pipe-shaped member having a lens holding flange 196 pressed against the convex side lens surface 1A via a double-sided adhesive pad 191. The fitting shaft portion flange 194 is formed with a rotation preventing notch 195 that fits into a projection (not shown) on the lens holder receiver 121a side.

The annular end surface of the lens holding flange 196 is a lens holding surface 197, which is formed in a concave spherical shape corresponding to the convex lens surface 1A of the lens 1. FIG.
As shown in (b), fine concaves and convexes 198 are formed radially in the circumferential direction on the lens holding surface 197 formed of the concave spherical surface to increase the tight bonding force with the double-sided adhesive pad 191. Each of the peaks and valleys extends at a substantially constant angle in the radial direction of the annular lens holding surface 197.

FIGS. 18C and 18D show the cross-sectional shape of the fine irregularities 198 formed on the lens holding surface 197 of the lens holder 19 and the state in which the pad 191 is in close contact with the minute irregularities 198, respectively. FIG. 18 (e),
(F) is a diagram showing, as a comparative example, a cross-sectional shape of the fine unevenness 199 in the conventional lens holder and a state in which the pad 191 is adhered to the fine unevenness 199, respectively. Each of them has a cross-sectional shape in which peaks of minute irregularities 198 and 199 are continuous in the circumferential direction of the lens holding surface 197.

In the conventional lens holder, FIG.
As shown in (f), the cross-sectional shape of the fine unevenness 199 is made into a single slope shape in consideration of the rotation direction, and the pad 19 generated by rotation is formed.
Due to the biting effect on the pad 1, the bonding force with the pad 191 is maintained. That is, the wall surface 199 on the front side in the rotation direction is located at the vertex 199a of the mountain of the minute unevenness 199.
b was composed of a vertical surface, and the opposite wall surface 199c was composed of a slope.

However, such a single-slope microscopic unevenness 1
When 99 is formed on the lens holding surface 197, the pad 19
Although the binding force with the pad 191 can be obtained by the biting action on the pad 191, as shown in FIG.
Therefore, there is a problem that a high lens holding power cannot always be exerted because the degree of adhesion to the lens is low. In addition, since the pad 191 has a single-slope shape, when a pressure contact force is applied between the pad 191 and the pad 191, the pad 191 exerts an unbalanced rotational force when the pad is thick, and the pad 191 is slightly shifted in the rotational direction. Therefore, there is a possibility that high-precision lens holding may be affected.

On the other hand, the lens holder 19 (φ2
In FIG. 18C, a thick adhesive pad is used, and the cross-sectional shape of the unevenness 198 of the lens holding surface 197 is changed as shown in FIG.
As shown in (d), it is formed in both slopes. That is, the wall surface 198b on the front side in the rotation direction and the wall surface 198c on the opposite side are formed by slopes having the same inclination angle (45 degrees) with the peak 198a of the mountain of the unevenness 198 as a boundary.

Therefore, as shown in FIG. 18 (d), when the pad 191 is pressed against the minute unevenness 198, the pad 191 is evenly brought into close contact with both slopes. The appropriate flexibility and deformability are utilized, and the lens holding force can be increased. In addition, since the pad 191 is uniformly pressed against the two inclined surfaces having the same inclination angle, the unbalanced rotational force is canceled out and the pad 191 is not generated, so that the pad 191 is rotationally shifted and the lens holding accuracy is reduced. Is also gone.

Further, since the lens holding force can be increased, the diameter of the lens holding flange 196 can be reduced. This has the advantages described below.

First, processing of a lens having a small diameter becomes possible. In addition, the number of types of lens holders prepared according to the lens curve can be reduced (weakness and strength, or only one or two types can be added between them). That is, generally, a plurality of types of lens holders 19 are prepared in which the curvature of the lens holding surface 197 is changed stepwise so that the lens holder 19 can be properly used according to the lens curve. In that case, it is not practical to prepare a lens holder according to all the lens curves, so that one type of lens holder requires several types of lens curves (for weakness, strength, or intermediate power). I try to cover the range.

FIG. 19 shows a lens holding surface 197 having a certain curvature.
And the relationship between the lens surface 1A. Lens holding surface 1
When the curvature of the lens surface 1A is larger than the curvature of 97, the outer peripheral edge of the lens holding surface 197 hits the lens surface 1A, and a difference F in the depth between the curve of the lens holding surface 197 and the curve of the lens surface 1A is formed. If the difference F in the depth is large, the degree of adhesion between the lens holding surface 197 and the lens surface 1A is low. Therefore, a lens holder corresponding to the lens surface 1A is prepared and selected so that the difference does not increase. ing.

However, even in the case of the same curve, if the outer diameter of the lens holding surface 197 (lens holding flange 196) is reduced, the above-described depth difference F can be reduced, and the lens having many curves can be obtained. Will be able to respond. Therefore, according to the lens holder having a reduced diameter, the range of the lens curve that can be covered can be expanded, and as a result, the types of lens holders can be reduced.

In the above example, the lens holding surface 197
Although the cross-sectional shape of the minute unevenness 198 formed in the shape of the peak is a mountain shape, the peak of the mountain or the bottom of the valley may be rounded to form a smooth wave shape. In the above example, the peaks and valleys of the minute unevenness 198 are continuously extended in the radial direction of the annular lens holding surface 197, but the minute unevenness may be dispersedly arranged on the entire lens holding surface 197. .

FIG. 20 is a block diagram showing an electrical connection relationship centering on the control device in the lens processing apparatus 10. However, only the main configuration is shown here. The control device includes a servo motor control unit 1001 and an I / O control unit 1
002. The two control units 1001 and 1002 exchange data with each other, and also exchange data with a host computer (not shown). From the host computer that manages the entire processing system, lens shape data (including radial information, lens thickness, outer diameter, and the like) and processing information are transmitted. The control units 1001 and 1002 transmit the transmitted shape data. And performs necessary processing on the lens based on the processing information.

The servo motor control unit 1001 controls the driving of the X-axis servo motor (lens rotating motor 125), the Y-axis servo motor (cutting motor 63), and the Z-axis servo motor (Z-direction moving motor 331). Do. Also, the I / O control unit 1002 includes a cutter rotation motor (TOOL motor) 133 of the cutter rotation mechanism unit 13, a chamfering motor (spindle motor 142 of the end mill rotation mechanism unit 14), a lens chuck air cylinder 123, and a measurement head. The rotation actuator 155, the cooling air blow 1010, and the stylus opening / closing DC motor 170 are drive-controlled via a control unit and electromagnetic valves 1021 to 1026,
Perform necessary actions. At that time, signals from various sensors are used for control.

The I / O control unit 1002 counts the detection signals of the measurement linear encoders 166 and 167 by the counter unit 1030 and takes in the signals. Further, necessary display is performed on the display operation unit 1100, and an operation signal is captured. It also sends necessary signals to the dust collector interface and the transfer robot interface.

Next, the flow of control performed by the control units 1001 and 1002 will be described with reference to the flowchart of FIG. When the lens 1 to be processed is set in the lens holding unit 12 and a start operation is performed, first, measurement trajectory data sent from the host computer is input (step S1). Next, the measuring head 16 is lowered to position it at the load position (step S2), and the stylus 1
61 and 162 are loaded onto the lens 1 (step S3), and the lens positions are measured (step S4).
The measurement data is sent to the host computer (step S5).

When the measurement is completed for the entire circumference of the lens,
The styluses 161 and 162 are unloaded from the lens 1 (Step S6), and the measuring head 16 is raised to the unload position (Step S7). Next, processing locus data is input from the host computer (step S).
8) While rotating the motor (TOOL motor) 133 of the cutter rotation mechanism 13, start air blowing (step S 9), and operate the dust collector (step S 1).
0).

Then, rough cutting is performed by forcible cutting by rotating the cutter 131 at a predetermined number of revolutions (step S1).
1) Next, the rotation speed of the cutter motor 133 is changed (step S12), and the
1 (step S13). At this time, if beveling is necessary, bevel cutters Y1, Y
2 is selected and processed.

When the finishing is completed, the cutter 131 is stopped (step S14), the chamfering motor 142 is rotated (step S15), and the end mill 141 chamfers the edges of the convex lens surface and the concave lens surface. (Step S17). Before that, if groove engraving on the lens peripheral surface is required instead of beveling, prior to chamfering, the end mill 141 is rotated by the chamfering motor 142 to execute groove engraving on the lens end surface (step). S16). When the chamfering is completed over the entire circumference, the chamfering motor 142 and the air blow are stopped (step S18), and the dust collector is also stopped (step S1).
9) Processing of one lens is completed.

The above roughing and finishing are performed with the same cutter. That is, in the case of planing, the planing cutter H1 is selected, in the case of a small bevel, the small bevel cutter Y1 is selected, and in the case of a large bevel, the large bevel cutter Y2 is selected. Therefore, continuous processing can be performed with one chuck without performing the process movement, and the processing time can be reduced and the apparatus can be downsized. Further, since it is not necessary to separately prepare tools for roughing and finishing, the space for arranging the tools can be reduced, and the management of the tools becomes easier.

Further, since the lens 1 is forcibly cut by the cutter 131, the cutting can be advanced while appropriately setting the cut amount. Therefore, the process leading to the finished shape can be determined under the optimum processing conditions for the shape data. For example, it is possible to arbitrarily set a target such as how many rotations to complete the cutting or how many seconds to complete the cutting, so that the processing time can be reduced and the processing accuracy can be improved.

Also, since the chamfering is performed at the R portion (R) at the tip of the small-diameter end mill 141 for grooving, there is less interference with other parts and a small chamfer can be accurately finished as compared with a grindstone. Can be. In particular, since one end mill 141 is used for both grooving and chamfering, the number of tools can be reduced, which can contribute to cost reduction. In addition, the grooving and chamfering can be performed with one chuck. Since it can be performed continuously, the processing time can be reduced. In addition, since only one drive system is required because the tool is shared, the size and cost of the apparatus can be reduced. In addition, since the number of tools is not increased, the management of tools becomes easy.

In the case of the present lens processing apparatus 10, a measuring head 16 for measuring a lens is disposed above a cutter 131 and an end mill 141 as processing means, and the measuring head 16 is tilted forward only when necessary. Since the measurement of the lens 1 held by the lens holding unit 12 can be performed, the measuring head 16 can be mounted on the processing apparatus 10 without an unreasonable layout. Also,
Since the measuring head 16 is mounted on the processing device 10 by effectively utilizing the empty space above the cutter 131 and the end mill 141, the plane area of the processing device 10 does not need to be increased, and the size of the processing device 10 can be reduced. Can be planned. Also,
Since a series of steps from measurement to processing can be performed in a state where the lens is held in the lens holding unit 12, there is no need to change the lens for the movement of the process, and there is a concern that the processing accuracy may be degraded due to changing the lens. No more, the lens shape can be finished accurately.

Next, various methods executed in the lens processing apparatus 10 in order to improve the processing accuracy and the processing efficiency will be described.

First, in the lens processing apparatus 10, the rotation speed of the cutter 131, the rotation speed (feed speed) of the lens holding shaft 121 when the peripheral surface is cut by the cutter 131, the number of rotations of the lens 1 for peripheral surface cutting. The rotation speed of the end mill 141 at the time of grooving or chamfering, the rotation speed (feed speed) of the lens holding shaft 121 at that time, and the like can be changed, and the material type of the lens 1 (glass type =
Here, the optimum processing conditions can be selected by setting these parameters according to the type of plastic), the frequency (edge thickness), and the distinction between finishing and roughing processing steps.

For example, by changing parameters (cutter rotation speed, lens holding shaft rotation speed, number of processing rounds) according to the material type (glass type) and frequency (edge thickness) of the lens 1,
Irrespective of the material type and frequency of the lens 1, the processing load can be made uniform, so that the lens size and lens shape (including the bevel position) can be accurately and uniformly finished, and the processed portion can be finely finished. be able to. Also,
By selecting appropriate processing conditions, the processing stress can be reduced to reduce the displacement of the lens axis, the tool life can be prolonged, and the processing time can be shortened.

Further, by changing the parameters (cutter rotation speed, lens holding shaft rotation speed) according to the processing steps of the finishing processing and the roughing processing, it is possible to improve the finished surface while processing with the same cutter. And the lens size and lens shape (including the bevel position) can be accurately finished. Further, by selecting appropriate processing conditions, it is possible to reduce the processing stress and to reduce the displacement of the lens axis, and it is also possible to extend the tool life.

In the same machining step, the cutter 13
By changing the rotation speed 1 or the rotation angular speed of the lens, the cutting speed can be made uniform, so that the processed surface can be finished in a uniform state.

Further, the material of the lens 1 (glass type =
Here, by changing the parameters (end mill rotation speed, lens holding shaft rotation speed) in accordance with the type of plastic, grooves and chamfered portions can be formed with high accuracy regardless of the material type of the lens 1. Further, by selecting appropriate processing conditions, the tool life can be extended and the processing time can be shortened.

The lens processing apparatus 10 has the following calculation function in order to accurately obtain lens position data required for beveling. This will be described with reference to FIG.

Usually, in order to obtain the position data of the lens surfaces 1A and 1B, the styluses 161 and 162 of the measuring head are required.
Is traced on the lens surfaces 1A and 1B in accordance with the lens shape data, and each stylus 1 is
The positions 1e and 1f of the lens surface are measured by detecting the positions 61 and 162. In this case, the trace positions of the styluses 161 and 162 are on the extension line ST in the lens holding axis direction of the vertex of the bevel 1a formed when the lens 1 is beveled.

However, if the beveling is performed as it is based on the position data (the coordinate data of 1e and 1f) thus obtained, there is a problem that the position of the bevel 1a cannot be accurately finished. In other words, in order to accurately determine the position of the bevel 1a on the peripheral surface of the lens in the processed state with reference to both edge portions 1c and 1d of the lens peripheral surface, actual beveling is performed at both edge portions 1c and 1d.
Position 1e, 1 on the outer peripheral side by the bevel height SH from the position
This is performed based on the data measured in f. Therefore, the bevel 1a is not finished with high accuracy.

Therefore, the styluses 161 and 162 are traced at positions where the bevel height SH is subtracted from the positions specified in advance by the lens shape data, so that both end edges 1c and 1d of the lens peripheral surface in the processed state. It has been considered to measure the position in advance and perform beveling based on the position data.

However, when doing so, the stylus 161,
Since the 162 must be traced on the lens center side from the position specified by the lens shape data, data for tracing the styluses 161 and 162 must be created separately from the lens shape data in advance. . Further, since the trace is performed on the center side of the lens, there is a possibility that the contact marks of the styluses 161 and 162 may remain in the range of the lens surfaces 1A and 1B which can be finally used.

Therefore, in the present lens processing apparatus 10, the point 1
e, 1f coordinate measurement data and separately given lens 1
Design data (radial data, convex lens surface shape data,
The coordinate values of the points 1c and 1d are calculated based on the concave lens surface shape data, lens thickness data, and outer diameter data). The design data of the lens 1 in this case includes a finite number of coordinate data (ρi, θi, Zi) defining the shapes of the convex lens surface 1A and the concave lens surface 1B. Also, the coordinates of arbitrary points on the convex lens surface 1A and the concave lens surface 1B can be extracted. Therefore, the extension line S of the bevel apex in the lens holding axis direction is obtained.
By using the actually measured data measured at the trace points on H and the design data, the positions of the points 1c and 1d can be calculated with high accuracy.
By using the coordinate data of, the bevel 1a can be processed with high accuracy. The design data is provided from lens design program data of a host computer.

In the present lens processing apparatus 10, the measuring head 16 for measuring the lens shape and the lens position is connected to the lens 1 held by the lens holding unit 12 as necessary.
On the other hand, since the approach can be made from the shelter, the lens shape and the lens position can be measured during the processing in special cases in addition to the measurement before the processing. Next, an example in which measurement is performed during such processing will be described.

FIG. 23 shows an example of a processing step. (A) shows a processing step in a normal case, and (b) shows a processing step in a special case (when the processing method of the present invention is carried out). The processing step (a) performs the lens measurement at the stage of the unprocessed lens, and the processing step (b) performs the lens measurement at the stage of the rough processing. In the present lens processing apparatus 10, according to the material type (glass type) and the frequency (edge thickness) of the lens, (a)
Or the processing step (b) is selected to perform the processing. As described above, the reason for providing the special processing step (b) as an option is that, depending on the lens, there may be a difference between the lens measurement values at the stage of the unprocessed lens and at the stage of the rough processing. This is because if the case is unified with the normal processing step (a), the bevel position may not be accurately finished in the final finishing processing.

In the case of the normal processing step shown in FIG. 9A, the lens is measured first. Next, rough processing is performed, thereafter, finishing processing is performed, and finally, chamfering processing is performed to obtain a lens having a final shape. Roughing is performed until a cutting allowance (for example, 0.25 to 0.35 mm) for finishing is left, and the final machining allowance is removed to finish to the final dimensions.

On the other hand, in the case of the special processing step shown in (b), the first rough processing is performed first, and then the measurement of the lens is performed. As shown in FIGS. 24 (a) and 24 (b), the primary roughing is performed up to a dimension leaving a measurable width SK with respect to a finished dimension. In the rough machining in the ordinary machining process, the remaining cutting allowance for finishing is left, but it is difficult to trace the styluses 161 and 162 within such a cutting allowance. Therefore, in this processing step, the width (for example, 1.5 to 1.8 mm) of a range that can be measured by the primary roughing is dared.
) To the place where it is left.

The reason for this is that, as described above, if rough processing is performed at once from the unprocessed lens to the area where the finishing allowance is left, the holding state of the lens may change, such as in the case of a special lens. . In other words, depending on the holding state of the lens, at the stage of the unprocessed lens, the part to be removed by rough processing exerts a reinforcing effect to balance the holding and keep the deformation from appearing in the surface, When the part is removed by the roughing, the reinforcing effect is lost, and the holding deformation may appear on the surface. Therefore, in such a case, even if the lens measurement value is obtained at the stage of the unprocessed lens, the position data of the original lens is changed at the stage after the actual rough processing, and the reliability is reduced. is there.

As described above, the lens measurement is performed at the stage of performing the primary roughing, and the lens information including the edge thickness is obtained in a state where the lens is not deformed, and then the secondary roughing is performed. To the stage where the cutting allowance is left,
After that, a finishing process is performed in the same manner as in a normal processing step, and finally, a chamfering process is performed to obtain a lens having a final shape.

By performing the lens measurement in the middle of the roughing process, a highly reliable lens measurement value can be obtained. Therefore, the subsequent finishing process is performed using the lens measurement value. , Lens shape and bevel shape can be accurately finished.

Next, a method of correcting various tolerances and errors will be described.

First, a method for correcting the tolerance and error of the cutter 131 will be described. In the present lens processing apparatus 10, after the peripheral surface is cut by the cutter 131, chamfering of both edge portions 1c and 1d of the lens peripheral surface is performed. Here, in order to perform chamfering accurately, it is necessary that the positions of the edge portions 1c and 1d at the stage when the peripheral surface is cut by the cutter 131 are accurately grasped. That is, the lens shape after the beveling must be accurately grasped.

Therefore, in the present lens processing apparatus 10,
The manufactured cutter 131 is actually measured, and the shape data of the cutter 131 is held as position data based on actually measured values in high-precision units exceeding the processing tolerance level, and is reflected in calculations at the time of processing. .

FIG. 25 shows an example of necessary measurement data. These data are values measured with reference to the bottoms of the bevel grooves Y1a and Y1b of the bevel cutters Y1 and Y2.
W1 to TD4 are distances between points. Based on these data, the shapes of the bevel cutters Y1 and Y2 are individually specified for each cutter. By inputting such data to the control unit of the lens processing apparatus 10 in advance, it is possible to grasp the lens shape including the processing error due to the tolerance and error of the cutter 131 at the peripheral surface cutting stage of the lens. . Therefore, the accuracy of the lens shape including the bevel position can be improved, and the chamfering by the end mill 141 after the peripheral surface cutting can be performed with high accuracy.

Next, the stylus 16 of the measuring head 16
A method for correcting the errors of the numbers 1 and 162 will be described. It is ideal that the positions of the tips of the pair of styluses 161 and 162 abutting on the lens surface are exactly coincident with each other, that is, it is ideal that they are exactly concentric. is assumed. Therefore, prior to the lens processing, the “center misalignment” of the two styluses 161 and 162 is measured by using a measurement prototype in advance.

FIG. 26 shows a configuration of the measurement prototype 50. As shown in FIG. 26 (a), the measurement prototype 50 is formed by integrally forming a portion 59 corresponding to a lens holder and a rectangular flat plate portion (4.00 mm thick) 57 corresponding to a lens. . The portion 59 corresponding to the lens holder includes a fitting shaft portion 53 fitted on the inner periphery of the lens holder receiver 121a, a fitting shaft flange 54 having a notch 55 for rotation prevention, and a flange 56 connected to the flat plate portion 57. have.

The flat plate portion 57 is formed so as to be orthogonal to the center axis of the fitting shaft portion 53 with high accuracy. As shown in FIG. 26B, an annular V-shaped groove 58A and a cross-shaped V-shaped groove 58B are formed on the front and back surfaces of the flat plate portion 57. The annular V-shaped groove 58A is inscribed at a predetermined diameter (a diameter smaller than an unprocessed lens to be normally processed) with its center located at the center axis of the fitting shaft portion 53. Also, a V-shaped groove 5 having a cross shape
8B is inscribed with its intersection at the center axis. What is important here is that one of the cross-shaped V-shaped grooves 58 </ b> B matches the position of the notch 55 for preventing rotation of the fitting shaft 53,
26 (c), that the V-grooves 58A, 58B on the front surface and the back surface accurately coincide with each other as shown in FIG. 26 (c). It is. Further, the opening angle of the V-grooves 58A and 58B is set to a predetermined angle (90 degrees) with high accuracy. Is Rukoto.

Next, a procedure for measuring the "deviation" between the styluses 161 and 162 using the measurement standard 50 will be described. In measurement, first, the measurement prototype 50 is set in the lens holder receiver 121a of the lens holding unit 12 in the same manner as a lens holder to which a normal lens is fixed. The “displacement” of the styluses 161 and 162 is measured separately in the lens radial direction (Y-axis direction) and in the vertical direction.

FIG. 27 shows a case of measuring the "shift" in the Y-axis direction. In this case, in order to use the annular V-shaped groove 58A, the flat plate portion 57 is turned by a certain angle so that the annular V-shaped groove 58A comes to the position of the stylus 161 or 162. In this state, the tips of the styluses 161 and 162 are inserted into the V-grooves 5 on the front and back surfaces of the flat plate portion 57 of the measurement standard 50.
Make contact with a place other than 8A.

Next, the measuring prototype 50 is moved in the Y-axis direction, and the tips of the styluses 161 and 162 are formed in an annular V-shaped groove 5.
Operate to cross 8A. Then, FIG. 27 (b)
As shown in the figure, the tips of the styluses 161 and 162 are V
The front and back surfaces of the flat plate portion 57 having the groove 58A are traced in the Y-axis direction. At that time, the styluses 161 and 162 are displaced in the depth direction of the V groove 58A in the process of passing through the V groove 58A. Therefore, the position of the measurement standard 50 in the Y-axis direction when the tips of the styluses 161 and 162 abut on the deepest portion of the V groove 58A is read. This is applied to each stylus 16
When performed for each of the styluses 161 and 162, the difference between the values read in the Y-axis direction is detected as a “displacement” in the Y-axis direction of the stylus 161 or 162.

FIG. 28 shows a case of measuring the "shift" in the vertical direction (the direction orthogonal to the Y-axis direction). In this case, in order to use one of the cross-shaped V grooves 58A, the flat plate portion 57 is turned by a certain angle so that one of the cross-shaped V grooves 58A is at the same horizontal position as the height of the stylus 161 or 162. To come. In this state, stylus 161, 1
Each tip of 62 is brought into contact with a place other than the V-groove 58B on the front and back surfaces of the flat plate portion 57 of the measurement standard 50.

Next, the measuring prototype 50 is slightly rotated (moved in the direction of the arrow X) so that the tips of the styluses 161 and 162 cross the horizontal V-shaped groove 58A positioned vertically. To operate. Then, as shown in FIG. 28B, the tips of the styluses 161 and 162 trace the front and back surfaces of the flat plate portion 57 having the V groove 58B in the vertical direction. At this time, in the process of passing through the V groove 58B, the stylus 16
1, 162 are displaced in the depth direction of the V-groove 58B in the same manner as described above. Therefore, the position (angle) of the measurement standard 50 in the rotational direction when the tips of the styluses 161 and 162 abut on the deepest part of the V groove 58B is read. When this is performed for each of the styluses 161 and 162, the difference between the values of the rotational directions read from each of the styluses 161 and 162 is calculated.
162 is detected as a “shift” in the vertical (rotating) direction.

When the "displacement" of the styluses 161 and 162 is detected as described above, data relating to the "displacement" is input to the control unit of the lens processing apparatus 10. Then, data obtained by lens measurement using the styluses 161 and 162 can be corrected in consideration of the above-mentioned “displacement”, and a more accurate measurement value can be obtained. That is, by giving the amount of misalignment of both styluses 161 and 162 as a correction value, stylus 161 and 162
It is reflected in the measurement value measured in.

The following modes can be considered as examples of the correction. That is, one stylus 161 (or 162 side) is determined as a reference side, and the stylus 161 determined as the reference side is traced along a correctly instructed point. Then, the stylus 162 on the opposite non-reference side traces a point different from the original, that is, a point shifted from the commanded point by the “displacement” amount, but the measurement data at that position is as described above. Since the amount of “shift” is known, if there is lens design data including lens surface information, it can be calculated and corrected to the measured value at the original point. Therefore, by performing correction using the lens design data in this manner, a highly accurate measured value can be obtained. The correction in the Z-axis direction is made by the thickness of the flat plate portion 57 (4.00 m
By setting the two styluses 161 and 162 to approach / separate from each other and measuring the thickness of the flat plate portion 57 with reference to m) as a reference value,
Determine the amount of deviation and correct it.

Next, a method of correcting a height difference between the cutter 131 and the end mill 141 will be described. End mill 14
1 chamfers the peripheral edge portions 1c and 1d of the lens 1 whose peripheral surface is ground by the cutter 131. For this reason, it is desirable that the center height of the cutter 131 and the end mill 141 be accurately matched in order to perform highly accurate chamfering. However, in order to accurately align the heights of the cutter 131 and the end mill 141, a special adjustment mechanism for adjusting the height must be newly provided, which causes a problem that the apparatus becomes complicated.

Therefore, the cutter 131 and the end mill 141 are used.
Rather than mechanically adjusting the delicate "shift" of the height of the lens, the "shift" amount is measured in advance, and the "shift" amount is given to the lens processing apparatus 10 as a correction value,
It enables easy and accurate chamfering.

FIG. 29 shows the cutter 131 and the end mill 141.
FIG. 4 is an explanatory diagram of a method for measuring a “shift” in the height of the object. First, as shown in FIG. 29A, the rectangular body 10 is cut by cutting the peripheral surface with the cutter 131 while controlling the position of the lens 1 in the Y-axis direction and the rotational angle position with respect to the cutter 131.
Form one. Next, the end mill 141 is attached to the cutter 131.
By moving the rectangular body 101 under the same driving conditions as when cutting with the cutter 131, except that the shaving depth is set to be constant, assuming that the rectangular body 101 is at the same height as Carve a groove.

Then, the cutter 131 and the end mill 1
If the heights 41 are actually the same, the depth SF of the groove 102 becomes constant as shown in FIG.
1 and the end mill 141 have different heights, FIG.
As shown in (c), the depth of the groove 102 does not become constant. This is because when the end mill 141 is displaced from the center height of the cutter 131 as shown in FIG.
This occurs because the actual processing point is shifted from the processing point performed assuming that the end mill 141 is at the same height as the cutter 131. Here, the groove 10
The difference between the two depths is the difference in the height of the end mill 141.
Is proportional to Accordingly, the difference (SF2-S) between the depths SF1 and SF2 of the groove 102 at a point separated from the center of the side of the rectangular body 101 by a certain distance in both end directions (corner direction).
By obtaining F1), the cutter 13 of the end mill 141 can be obtained.
The "shift" of the height with respect to 1 can be converted.

The deviation of the height thus obtained is used as a correction value, and is reflected in a control value at the time of grooving or chamfering by the end mill 141, so that the accuracy of the grooving or chamfering is improved. Can be raised. Further, since it is only necessary to provide a correction value, a mechanism for adjusting the height is not required, and the cost of the apparatus can be reduced.

Although the embodiments of the present invention have been described above, the present invention is not limited to the cutting-type lens processing apparatus as in the above-described embodiments, but is also applicable to a lens processing apparatus of a system in which a lens peripheral surface is ground with a grindstone. can do.

[0122]

As described above, according to the first aspect of the present invention, the amount of misalignment between both styluses is detected in advance,
Since the position data of the lens surface acquired by the stylus is corrected based on the misalignment amount, it is possible to measure the lens surface position with high accuracy.

According to the second aspect of the present invention, since the amount of misalignment of the stylus is measured by the measurement standard held by the lens holding unit instead of the lens to be processed, the amount of misalignment can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of a lens processing apparatus for performing a lens measuring method according to an embodiment of the present invention.

FIG. 2 is a plan view showing the overall configuration of the processing apparatus.

FIG. 3 is a front view showing the entire configuration of the processing apparatus.

FIG. 4 is a plan view showing a detailed configuration of a lens holding unit in the processing apparatus.

FIG. 5A is a plan view showing a detailed configuration of a cutting operation mechanism in the processing apparatus, and FIG. 5B is a plan view showing Vb- in FIG.
It is a Vb arrow view.

FIGS. 6A and 6B are side views of a measurement unit in the processing apparatus, wherein FIG. 6A shows a state where the measurement head is at an unload position, and FIG. 6B shows a state where the measurement head is at a load position.

FIG. 7 is a plan view of a measuring unit in the processing apparatus, in which (a) shows a state where the measuring head is at an unload position, and (b) shows a state where the measuring head is at a load position.

FIG. 8 is a front view of a measurement unit in the processing apparatus.

FIG. 9A is a diagram showing the principle configuration of the measuring head, and FIG.
FIG. 3 is a side view showing details of a tip portion of the stylus, and FIG.

FIG. 10 is a plan view showing a state in which a stylus of the measurement head is loaded on a lens.

FIG. 11 is a side view showing a state in which a stylus of the measurement head is loaded on a lens.

12A and 12B show a configuration of a cutter of a cutter rotation mechanism in the processing apparatus, wherein FIG. 12A is a half-sectional view, FIG.
(C) is an enlarged view of a main part of the bevel cutter.

FIG. 13 is a side view showing a state where a lens is being processed by the cutter.

FIG. 14 is a plan view showing a state where a lens is being processed by the bevel cutter.

FIG. 15 is a plan view showing a state in which a groove is formed in a lens end face and a state in which an edge of the lens end face is chamfered by an end mill of an end mill rotating mechanism in the processing apparatus.

FIG. 16 is a side view showing a state in which groove milling or chamfering is performed by the end mill.

FIG. 17 (a) is an enlarged view used to explain the case where groove cutting and chamfering are performed by the end mill, and FIG. 17 (b) is an explanatory view of chamfering when there is a bevel.

18A and 18B are explanatory views of a lens holder in the processing apparatus, wherein FIG. 18A is a side view of the lens holder, FIG. 18B is a plan view of a lens holding surface of the lens holder, and FIG. (D) is a cross-sectional view showing a state in which a pad is pressed against the fine irregularities.
(E) is a cross-sectional view of the fine unevenness formed on the lens holding surface of the conventional lens holder, and (f) is a cross-sectional view showing a state where a pad is pressed against the fine unevenness.

FIG. 19 is a cross-sectional view used to explain the degree of adhesion based on the relationship between the lens holder and the curvature of the lens.

FIG. 20 is a block diagram schematically showing an electrical configuration of the processing apparatus.

FIG. 21 is a flowchart showing a processing process performed by the processing apparatus.

FIG. 22 is an explanatory diagram of a correction method for lens measurement performed by the processing apparatus.

FIG. 23 shows processing steps (a) selectable by the processing apparatus;
It is a flowchart of (b), and the processing process of (b) is equivalent to the processing method of this invention.

FIG. 24 is an explanatory view of the processing step of FIG.
(A) is a front view of a lens, (b) is a sectional view of a lens.

FIG. 25 is a diagram showing correction data of a cutter shape performed by the processing apparatus.

26A and 26B are configuration diagrams of a measurement standard used for correcting misalignment of a stylus provided on the measurement head, where FIG. 26A is a side view, FIG. 26B is a front view, and FIG. 26C is C1 in FIG. It is sectional drawing of the C1 arrow view and C2-C2 arrow view part.

27 (a) is a front view, and FIG. 27 (b) is B1 of FIG. 27 (a).
It is sectional drawing in the -B1 arrow direction.

28 (a) is a front view, and FIG. 28 (b) is a diagram illustrating a method of calculating the amount of misalignment in a direction different from that of FIG.
It is B2 arrow sectional drawing.

29 (a) is a front view, FIG. 29 (b) is a front view of a rectangular body without any shift, and FIG. 29 (c) is a shift. It is a front view of the rectangular body in case there is.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens 12 Lens holding unit 50 Measurement standard 57 Flat plate part 58A, 58B V groove (reference line) 161,162 Stylus

Continued on the front page F-term (reference) 2F069 BB40 CC07 EE11 EE23 GG01 GG04 GG06 GG07 GG63 GG71 HH02 HH04 HH14 HH15 JJ08 JJ10 JJ27 LL02 LL03 LL04 MM02 MM04 MM24 MM26 MM32 MM34 NN00 PP02

Claims (2)

[Claims] In processing a peripheral edge of a processed lens for spectacles according to lens frame shape data, a straight line substantially orthogonal to the processed lens is formed on front and back lens surfaces of the processed lens held by a lens holding unit. By tracing the tips of a pair of styluses disposed opposite to each other on the line according to the lens frame shape data, and detecting the displacement of each stylus in the lens thickness direction, the front and back sides on the contour line defined by the lens frame shape data are detected. In a lens measurement method for obtaining position data of a lens surface, the position data of the front and back lens surfaces obtained by tracing the stylus is corrected based on a misalignment amount of both styluses detected in advance. Lens measurement method. 2. The tip of the pair of styluses is brought into contact with the front and back surfaces of a flat plate portion of the misalignment measurement standard held by the lens holding unit instead of the lens to be processed, and By relatively displacing the stylus and the plane direction of the flat plate portion, the tips of both styluses are alternately matched with a reference line formed on the flat plate portion, and a measuring prototype at a point where each stylus matches the reference line. 2. The lens measuring method according to claim 1, wherein a difference between a relative displacement amount with respect to the stylus is obtained as a misalignment amount between the two styluses.