KR101948939B1 - Method and apparatus for centering of spin finishing of lens - Google Patents

Abstract

[PROBLEMS] To provide a technical means capable of performing accurate focusing on a lens having a small Z value without damaging the lens.
[MEANS FOR SOLVING PROBLEMS] An optical measuring instrument for receiving reflected or transmitted light of a light beam projected toward a lens surface on a holder and outputting the light receiving position, a pusher provided separately from a rotating grindstone for processing the periphery of the lens, And a transfer device for moving the transfer device toward the axis. The holder is rotated in the direction in which the eccentric direction of the lens is directed toward the pusher based on the measurement value of the optical measuring instrument and the pusher is advanced toward the holder center based on the measurement value of the optical measuring instrument.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for a lens-

The present invention relates to a method of manufacturing an optical lens having an optical axis of a lens placed on a holder for holding a lens, which is a center of a lens pick-up machine that processes an outer circumference with reference to an optical axis of the lens, And a method and an apparatus for aligning the center of gravity with the center of rotation or center of rotation of the holder.

The lens is subjected to spherical surface processing of the front and back surfaces, and then outer circumferential processing is performed with reference to the optical axis determined by the processed spherical surface. The apparatus for performing the peripheral machining of the lens with reference to this optical axis is referred to as a deep-drawn machine. A general grasp machine includes a holder for holding and rotating a lens, a rotating grindstone which is closely spaced toward the periphery of the lens held by the holder, and an NC controller for controlling the moving position of the grindstone in the close spacing direction. Since the NC controller sets the position of the rotary grindstone on the basis of the axial center or the rotation center of the holder, in order to precisely perform the outer circumferential machining, the lens to be processed as its precondition must have its optical axis exactly aligned with the rotation center of the holder ).

A lens having a thicker central portion in the convex lens than in the peripheral portion and a thinner lens in the concave lens but having a large rate of change in the thickness in the lens radial direction, When the holder is rotated while the top and bottom surfaces of the lens are lightly fitted with the cup-shaped upper and lower holders 1b and 1a having a rounded edge 14 as described above, the lens thickness becomes the thickest or thinnest The optical axes of the optical axes are slid in the direction coinciding with the center of rotation of the holders 1a and 1b, and are automatically transferred. However, a lens having a small Z value or a lens whose spherical surface on the lens surface is close to a concentric spherical surface (whose thickness is close to parallel) can not be accurately measured by such a method.

Therefore, as shown in Fig. 11, the lens having a small Z value rotates the holders 1a and 1b at predetermined angles while lightly holding the lens L by the holders 1a and 1b, The position of the peripheral portion of the spherical surface of the lens is measured by the dial gauge 8 and the direction of eccentricity between the center of curvature of the lens spherical surface and the axis of the holder is calculated on the basis of the measured value, The grinding wheel 2 is caused to advance toward the lens so that the grinding wheel 2 is moved toward the lens by a distance corresponding to the amount of eccentricity And the optical axis of the lens was moved by aligning the optical axis of the lens with the center or center of rotation of the holder.

However, in the conventional means shown in Fig. 11, when the measurement end (measuring end) of the dial gauge touches the lens and presses the lens with the grindstone for contact measurement by a dial gauge or the like, There is a problem that it is called. Further, since the contact between the grindstone and the lens can not be detected when the grindstone is pressed with the grindstone, there is a problem that the amount of pressing can not be precisely controlled and the surface of the grindstone (pressing surface) There was a problem that the pressing amount was not stabilized.

An object of the present invention is to solve the above-mentioned problem and to obtain a technical means capable of rapidly correcting a lens having a small Z value without damaging the lens.

The optical centering device in the lens grater of the present invention is an optical centering device for receiving the reflected light 33 or transmitted light of the light beam 31 projected toward the surface of the lens L on the holder 1, A pusher (lens press moving body) {4 (4a, 4b)} provided separately from the rotary grindstone 2 for processing the periphery of the lens, and a pusher Stroke control means 66 for moving the pusher 4 toward the center of the holder based on the measurement values of the X- or Y-direction or X- and Y-direction transfer devices 42, 43 and 41 and the optical measuring instrument 3 ). In the case of having the conveying device for conveying the pusher 4 in the X direction or the Y direction, the eccentric direction of the lens L is set in the pushing direction of the pusher 4 based on the measurement value of the optical measuring instrument 3, (65) for rotating the rotating shaft (1). The phase control means 65 and the stroke control means 66 are installed as software in the NC controller 6 for controlling the depth of field.

The optical measuring instrument 3 projects the light beam 31 from the light projector 32 toward the lens L on the holder above the holder 1 so that the reflected light from the lens surface of the lens L, The light receiving element 35 receives the transmitted light that has passed through the light receiving element L. [ It is preferable that the pusher 4 is made of a material softer than the lens L, for example, a synthetic resin, at least in contact with the lens.

The pushing and moving control means 67 of the NC controller for controlling the pushing of the pusher can perform various pushing and moving patterns, for example, step feeding at a minute interval, oscillating feeding accompanied by vibration in the feeding direction, low speed feeding at a low feeding speed, It is preferable to provide various feeding patterns such as a low friction feeding in which air pressure is fed into the cup-like holder 1 on which the lens L is placed and feeding is performed. It is preferable to be able to select a pattern.

The optical measuring instrument 3 is mounted directly above the holder 1 with its measurement origin o coinciding with the center of rotation of the holder 1 but the optical measuring instrument 3 is mounted on the light receiving element when the holder 1 is rotated once (E) of the light receiving point s from the circular locus c of the light receiving point s of the optical measuring instrument is measured so that the bias amount o between the origin o of the optical measuring instrument and the rotational center a of the holder The amount of eccentricity E of the lens L including the amount of eccentricity E can be measured.

When the pusher 4 is contacted with the lens L and moves by pressing the lens L, the optical measuring instrument 3 presses and moves while monitoring the light receiving point s so that the light receiving point s reaches the rotational center a The movement of the pusher 4 may be stopped or the pusher 4 may be moved by the eccentric amount E measured from the position where the pusher 4 contacts the lens L. [ The contact between the pusher 4a and the lens L when the pusher 4a having a structure for pressing the outer periphery of the lens is used is such that the signal when the light receiving point s of the optical measuring instrument 3 starts to move is controlled by the stroke control And then transferred to the means 66.

For example, in the case of a press-formed lens or the like, when measuring the eccentric direction and the eccentric amount of the lens on the holder, the distance from the center (optical axis) of the lens to the outer periphery of the lens is measured, When there is a protruding portion that interferes with the centering operation, it is preferable to perform roughing processing to remove the protruding portion with the grindstone (2) prior to the centering operation. The measurement of the distance from the center of the lens to the outer periphery of the lens is performed by providing the outer measuring instrument 7 in the depth gauge.

On the other hand, when the pusher 4b having a structure in which the lens is pressed against the lens surface of the lens L is used, even if there is an irregular protrusion on the outer periphery of the lens, . For a lens that requires rough machining, it is advisable to perform rough machining before grinding operation (finish grinding) after grinding.

It is possible to move the pusher in the two-dimensional plane to carry out the focusing of the lens by using the pusher 4b having a structure in which the lens is pressed against the lens surface of the lens L and moves. That is, when the eccentric direction and the eccentric amount of the lens are measured by the optical measuring instrument 3, the lens L is moved in the direction opposite to the eccentric direction by the pusher 4b, and the optical axis of the lens L is moved to the rotation center The pusher 4b is brought into pressure contact with the lens L and then the pusher 4b is moved to the position where the pusher 4b is moved The movement of the lens 1 at the rotation center of the holder 1 can be performed.

The lens carried on the holder is measured in the direction (phase) in which the lens is eccentrically decentered with an optical instrument such as an autocollimator or the like, and the phase of eccentricity of the holder is calculated by rotation of the main shaft (main shaft) By pressing the lens with the pusher to the position where the eccentricity is not detected or by pushing the pressing amount calculated from the eccentricity amount E measured in advance by the pusher.

Since the measurement is made in a non-contact manner with the optical measuring instrument, there is no risk of damaging the lens, and the contact of the pusher and the lens or the detection of the position of the lens after the movement can be carried out by monitoring with the optical measuring instrument. The lens can be precisely controlled, and the lens can be accurately detected. Further, since the lens is pushed by the dedicated pusher, it is possible to achieve a high accuracy without sacrificing the lens without damaging the lens due to the material of the pusher and the shape of the contact portion.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing an embodiment of a depth gauge equipped with an aligning device of the present invention; Fig.
Fig. 2 is an explanatory diagram showing an enlarged view of the deviation of the eccentricity and reflected light of the lens; Fig.
3 is a view showing the light receiving point on the two-dimensional light receiving element of the auto collimator.
4 is an explanatory diagram of the outer peripheral measurement performed together with the measurement of the eccentricity.
5 is a schematic side view of a main part of a depth gauge for performing eccentric measurement and outward measurement.
FIG. 6 is a flowchart showing the order of the depth measurement performed with the outer measurement. FIG.
Fig. 7 is a schematic side view of a main part of a depth gauge having a pusher that moves the lens in a two-dimensional plane. Fig.
Figure 8 is a perspective view of the pusher of Figure 7;
9 is a view showing the contact of the concave lens and the pusher of Fig.
10 is an explanatory view showing a focusing means for a lens having a large Z value;
11 is an explanatory view showing a conventional focusing device for a lens having a small Z value.

Hereinafter, embodiments of the present invention will be described with reference to the embodiments shown in the drawings. The tip of the illustrated embodiment includes a main shaft 11 having an upward cup-shaped holder 1 (a member corresponding to the holder 1a in the conventional structure of Figs. 10 and 11) (Upper shaft) 17 provided at the lower end of a ring-shaped pressing pad 16 opposed to the holder 1 and the lens 16 held by the holder 1 and the pad 16 And a grindstone 2. The main shaft 11 and the upper shaft 17 are disposed on the main shaft axis a in the vertical direction and connected to the main shaft motor 12 and the connecting shaft 15 rotatingly connecting the main shaft 11 and the upper shaft 17 As shown in FIG. Therefore, the holder 1 and the pad 16 rotate synchronously about the axis a. The upper shaft 17 can be lifted and lowered by a lifting device not shown and the lens L is carried on the holder 1 in a state in which the upper shaft 17 is lifted, The lens L is held in a state in which the upper and lower surfaces of the lens L are held by the holder 1 and the pad 16. The upper shaft 17 and the main shaft 11 are a hollow shaft and the hollow hole 13 of the main shaft is connected to the cup 1 of the holder 1.

The rotary grindstone 2 is mounted on a grindstone 21 and is provided with a feed screw and a grindstone feed motor for driving the grindstone 21 to advance and retract toward the lens L in a close spacing direction ). The spindle motor 12 and the grindstone feed motor are controlled by the NC controller 6. The rotational angle (phase) and rotational speed of the holder 1 and the moving position of the grindstone 21 of the main shaft 11 , And can be set by the NC controller (6).

The placing apparatus of the present invention in the embodiment of the present invention includes an autocollimator 3 arranged above the upper shaft 17 and a mounting unit 41 mounted on the moving stand 41 via a piezoelectric element 44 And a feed screw 42 and a feed motor 43 for feeding the movable base 41 and an air pressure feeding device 5. The feed screw 4,

The autocollimator 3 includes a light projector 32 for projecting a light beam 31 toward the lens L on the holder 1 through a hollow hole 18 in the upper shaft and a light projector 32 for projecting the reflected light 33 from the lens L, Dimensional light receiving element 35 that reflects light perpendicularly to the half mirror 34 and receives it. The light beam projected from the light projector 32 is irradiated on the surface of the lens L with a light spot (focus), and the reflected light 33 is focused on the light receiving surface of the light receiving element 35 , And the position information thereof is output as an electric signal.

The pusher 4 is mounted on a moving table 41 with a piezoelectric element 44 interposed therebetween and the piezoelectric element 44 is provided with an AC power source 45 for vibrating the piezoelectric element 44 in the moving direction of the moving table 41, Respectively. The movable base 41 is connected to a feed screw 42 via a ball nut (not shown), and the feed screw is rotationally driven by a feed motor 43, which is servo-controlled by the NC controller 6. [

The NC controller 6 is provided with a step feeding means 61 for giving a feed command and a stop command to the feed motor 43 at short time intervals, a standard feed means 62 for giving a continuous feed command at a normal speed, A low-speed feed means 63 for giving a continuous feed command at a lower speed, and a selection switch 64 for selecting one of these means. The NC controller 6 also controls the on / off switch 46 of the AC power supply 45 which vibrates the piezoelectric element 44. [ The air pressure supply device 5 is provided with a negative pressure source 51, a positive pressure source 52, pressure setting devices 53 and 54 and a switching valve 55, The negative pressure or the positive pressure adjusted according to the lens to be supplied is supplied into the holder 1 through the switching valve 55, the rotary joint 56 and the hollow hole 13 of the main shaft 11.

When the lens L is eccentrically held in the holder 1, the lens is inclined as shown in Fig. This inclination is larger as the curvature of the lower surface of the lens which abuts on the circular edge 14 of the holder 1 is larger, and the direction of inclination is reversed depending on whether it is a convex surface or a concave surface. At the center of the optical axis of the lens, the lens surface is at right angles to the optical axis, and the light projected therefrom is reflected in the incidence direction. However, if the lens is eccentrically inclined, the reflected light deviates from the incident light, The position of the light receiving point s on the light receiving element 35 is shifted. The inclination of the lens L can be measured from the deviation amount e and the eccentricity amount E of the lens L can be measured from the inclination and the curvature of the lens bottom surface.

When the eccentric direction and the amount of eccentricity are measured with the origin 1 being the center of the circular locus (the center of rotation of the holder) by drawing the circular locus c at the light receiving point s by rotating the holder 1, The accurate eccentric direction and eccentricity amount can be measured even if the origin o of the light receiving surface of the holder 3 deviates from the rotational center of the holder 1. [

Based on the individual detection signals of the auto collimator 3 and the unevenness of the lower surface of the lens (the direction of eccentricity is reversed by 180 degrees), the NC controller 6 is provided with a lens L Phase control means 65 for detecting the eccentric direction of the optical axis of the spindle motor 12 and controlling the rotation angle of the spindle motor 12 such that the eccentric direction is directed to the movement direction of the pusher 4, And a stroke control means (66) for controlling the rotation angle of the feed motor (43) based on the signal.

When the lens L is carried on the holder 1 in the state in which the upper shaft 17 is moved upward, the autocollimator 3 causes the light beam 31 to be projected onto the lens L The main axis 11 is slowly rotated while receiving the reflected light by the two-dimensional light receiving element 35 so as to draw a circular locus c at the light receiving point s on the light receiving element 35, the eccentricity E of the lens L with respect to the rotational center of the holder 1 is measured from the center e of the holder 1 to determine the relative position between the light receiving point s and the center of the circle a when the holder 1 is stopped From the relationship, the eccentric direction is measured. The NC controller 6 gives a rotation command to the spindle motor 12 so that the detected eccentric direction is directed to the movement direction of the pusher 4. [

Next, the NC controller drives the feed motor 43 to move the lens L on the holder 1 to the pusher 4 to align the optical axis of the lens L with the rotation center of the holder 1, . 1 and 5) having a structure in which the pusher 4 presses the outer periphery of the lens, a forward command is given to the moving base 41 so that a light receiving point (from the auto collimator 3) s is received, the stroke control means 66 is given a measurement start command. The stroke control means 66 stops the feed motor 43 at a position where the pusher 4a is advanced by the amount of eccentricity already measured from the position of the pusher 4a when the measurement start command is given.

When the pusher 4a is moved forward, the selection switch 64 is switched in accordance with the size or the curvature of the lens L, so that the pattern of the pushing movement operation can be selected as one of step feed, standard feed and low speed feed. Also, by switching on the switch 46 of the AC power source 45 at each of the transfer patterns, the vibration transfer can be selected. The step feeding and the vibration feeding are effective for preventing the lens L from moving beyond its stop position due to the so-called stick slip phenomenon.

The lens (L) carried on the holder (1) is measured and imaged in a state in which it is lightly attracted by a negative pressure supplied to the holder (1). The lens is prevented from moving during the measurement, and the lens slides lightly on the holder without damaging the lens when the pusher 4a is pushed, and is not too slippery due to the pressed tactility. Therefore, in order to release the lens of the ordinary lens, a negative pressure is supplied from the negative pressure source 51 to the holder 1. When the lens is heavy, the switching valve 55 is switched to supply the positive pressure from the positive pressure source 52 to the holder 1, and the load on the lens acting on the holder 1 is reduced, So that the lens L can be moved by pressing the lens L in a state in which the friction load when the lens is moved is reduced.

When the lens L is pushed by the pusher 4a, the lens L may move in a direction deviated from the advancing direction of the pusher 4a during pushing movement, and the lens may unnecessarily move due to inertia. Therefore, after the end of the pushing movement operation, the eccentricity of the lens L is confirmed by the optical measuring instrument 3, and when it is within the predetermined error range (threshold value), the outer peripheral machining is started. And repeats the above operation.

The main shaft 11 and the spindle motor 12 are held by the holder 1 and the pad 16 and the spindle motor 12 is rotated by the spindle motor 12, (Synchronous) rotation of the lens 17 to rotate the lens L about the optical axis that has been found. Then, the rotary grindstone 2 is rotated, and the grindstone 21 is advanced so that the outer periphery shape of the lens becomes a predetermined shape, thereby performing the outer peripheral processing with reference to the optical axis of the lens L. [

In the press-formed lens, the material pressed by the upper and lower molds is pushed out of the periphery of the lens into the frame, and the outer shape of the lens is sometimes twisted. The pusher 4a rapidly approaches the lens and then decelerates at a predetermined pressing moving speed to shorten the processing cycle when the pusher 4a is advanced toward the lens L to press the lens L ). If there is a projecting portion formed by a material pushed out of the frame around the lens L, the pusher 4a may come into contact with the projecting portion during rapid approach, which may cause the lens to move greatly. Further, the pusher 4a may contact the portion where the edge of the end portion of the projecting portion is inclined, and the lens may move in a direction deviating from the pushing and moving direction. Further, when the lens is carried on the holder 1 on the outer circumference basis, the lens on the holder may be largely eccentric.

Therefore, it is preferable to check the outer shape of the lens before the deep processing (original peripheral processing) and to perform rough processing (rough cutting) to remove the partial projection. Confirmation of the shape of the outer periphery of the lens is performed by using a noncontact or contact type outer circumferential measuring device 7 such as a camera or an electromagnetic micrometer to measure the eccentricity of the lens optical axis and the eccentric direction, Can be confirmed by detecting the position.

4 is a graph showing the relationship between the center (optical axis) p of the lens eccentrically placed on the holder, the rotational center a of the lens (holder 1) and the rotational center a measured by the outer measuring instrument 7 The relationship between the distance d to the outer circumference of the lens and the distance r from the lens center p to the outer circumference is shown in FIG. E is used to calculate the distance r at the position of each rotation angle? When the lens is rotated once, and the roughness of the outer periphery of the region where r exceeds the threshold value is cut off Processing may be performed.

5 shows an example in which the pusher 4 and the electron micrometer 7 are mounted on a moving base 41 with a platform 48 raised and lowered by a short stroke by means of a cylinder 47 or the like to be. When the eccentric direction and the eccentricity amount of the optical axis of the lens are detected by the auto collimator 3 by one rotation of the holder 1, the elevating table 48 is lowered to move the movable table 41 forward, ) Is brought into contact with the outer periphery of the lens (L), and the outer shape of the lens (L) is measured.

The distal end of the pusher 4a is located on the side of the lens L so that the distance from the outer periphery of the lens to the pusher 4a can be known when the eccentric direction of the lens L is directed to the pusher 4a. It is possible to shorten the machining cycle by rapidly approaching the pusher 4a to a position immediately adjacent to the outer periphery of the pusher 4a.

6 is a flowchart showing the procedure. When the lens is carried on the holder 1, a negative pressure is supplied to the holder to attract the lens. Next, the platform 48 is lowered to face the electron micrometer 7 to the outer periphery of the lens (Fig. 5). And advances the movable stage 41 while monitoring the output of the electromagnetic micrometer 7. [ When the electromagnetic micrometer 7 touches the outer periphery of the lens, the output of the electromagnetic micrometer 7 is shaken. Therefore, after detecting the contact, the moving base 41 is further advanced by a predetermined amount and stopped. This set amount is the maximum projected amount of the outer periphery of the lens that is expected.

In this state, the holder 1 is rotated one time while the measurement values of the electron micrometer 7 at the respective rotation positions are stored. Since the eccentric amount and the eccentric direction of the lens on the holder are detected by the auto collimator 3 by this rotation, the dimension r in Fig. 4 at each rotational position of the lens is calculated and the range in which r exceeds the threshold value Check whether there is. In the meantime, the platform 48 is raised so that the pusher 4 is opposed to the lens.

If there is an area where the dimension r exceeds the threshold value, the movable base 41 is retracted and the upper shaft 17 is lowered to clamp the lens. Then, the area r exceeds the threshold value is directed to the grindstone 2, 21 by rubbing by the advance of the holder 1 to the predetermined position and the rotation of the holder 1 in the above range, the projecting portion of the region where r exceeds the threshold value is removed and the upper shaft 17 is raised, Release the clamp.

Next, the eccentric direction detected by the auto collimator is directed to the pusher, the distance d from the position d in Fig. 4 and the stand-by position of the pusher in the eccentric direction are calculated to calculate the distance from the tip of the pusher to the outer periphery of the lens, The movable base 41 is moved to a position immediately before the contact with the movable base 41. [ Then, after the advancing speed of the movable stage 41 is switched to low speed and the abutment of the pusher 4a and the lens L is detected, the movable stage 41 is further advanced by the detected eccentric amount to complete the lens . Then, the movable base 41 is retracted (retracted), the upper shaft is lowered to clamp the lens, and then the deep-seated working is started.

In this manner, the outer periphery measurement is performed simultaneously with the detection of the optical axis of the lens, and rough processing of the outer periphery of the lens by the grindstone is performed on the necessary lens before the grindstone 2 performs the grasp processing, If the pushing operation of the pusher 4a is carried out rapidly, it is possible to efficiently and accurately perform the deep-seated processing with respect to the lens group having the difference in the peripheral shape.

The above procedure is an example of the procedure of performing the extrusion of the lens having the protruding portion on the outer periphery by using the pusher 4a having a structure for extruding the lens by pressing the outer periphery. However, the pusher 4b having the structure of contacting the lens surface, , Even if the lens has a projection on the outer periphery, it is possible to concentrate the lens without performing the peripheral measurement. FIG. 7 is a side view of the main part of the apparatus, FIG. 8 is a perspective view of the pusher, and FIG. 9 is a cross-sectional view And the pusher 4b is in contact with the lens. The contact state of the pusher 4b with respect to the lens whose top surface is convex is represented by an imaginary line in Fig.

The pusher 4b in the drawing has a structure in which a cylindrical portion 58 protruding downward is provided on the plate member 57. A through hole of the same shape as the hollow hole of the cylindrical portion is also formed in the plate member 57, So that it can pass through the light beam and the reflected light. The pusher 4b is mounted on the XY moving table 41 moving in the two-dimensional plane between the left and right direction in Fig. 7 and the plane perpendicular to the paper plane with a platform 48 ascending and descending to the cylinder 47 have.

When the optical measuring instrument 3 measures the eccentric direction and the eccentric amount of the lens L on the holder 1 as described above, the elevating table 48 is raised so that the XY moving table 41 is moved in the left- The pusher 4b is moved to a position where the center of the cylindrical portion of the pusher 4b coincides with the optical axis of the lens measured and the lower portion of the platform 48 is lowered to the lower edge of the cylindrical portion 58, (Press-contact) with the upper surface of the lens (L).

In this state, the XY moving table 41 is moved in the two-dimensional plane between the left and right direction in the figure and the plane perpendicular to the plane of the drawing, and the center of the cylindrical portion of the pusher 4b is moved to the rotation center of the holder 1, The lifting base 48 is then raised and the XY moving table 41 is retracted to complete the lens lifting operation. The frictional force between the lens and the holder 1 is reduced by, for example, forming the cylindrical portion 58 of the pusher as a material having a friction coefficient larger than that of the holder 1 or supplying a positive pressure to the holder 1, It is possible to slide the lens on the holder 1 by the frictional force of the cylindrical portion 58 that is in pressure contact with the holder.

Thereafter, the upper shaft 17 is lowered to hold the lens L, and the grinding wheel 2 is grasped by grinding the outer periphery of the lens with the grinding wheel 2 while rotating the lens L. However, When the grinding wheel 2 is advanced to the position, the lens is rotated to perform coarse machining. Thereafter, the amount of cutting depth of the grinding wheel 2 is reduced and the grinding is performed by finishing grinding. .

As described above, by using the pusher having a structure in which the lens is pressed and moved in contact with the lens surface of the lens, the lens can be moved accurately in the two-dimensional plane, It is unnecessary to perform an operation of rotating the pushing movement direction of the lens in accordance with the moving direction of the pusher so that the control sequence is simplified and the pusher movement at the time of advancement can be performed at a high speed.

1: Holder
2: rotating grindstone
3: Optical measuring instrument
4 (4a, 4b): Pusher
6: NC controller
7: Outside measuring instrument
31: Light beam
32: Floodlight
33: Reflected light
35: Light receiving element
41: XY moving table
42: Feed screw
43: Feed motor
48:
65: phase control means
66: stroke control means
67: pushing movement control means
a: center of rotation
c: circle locus
o: origin
s: light receiving point
L: Lens

Claims (11)

1. A lens centering device in a lens-extender having a holder rotatable around a main axis of a vertical direction,
An optical measuring instrument for receiving reflected or transmitted light of a light beam projected toward a lens surface on a holder and outputting the light receiving position,
A pusher having a contact tip which is in contact with the lens and formed of a material softer than the lens, a feed device for moving the pusher toward the rotation center of the holder,
An NC controller,
The NC controller includes stroke control means for moving the pusher toward the rotation center of the holder based on the measurement value of the optical measuring instrument,
Wherein the NC controller includes a pushing movement control means for controlling a pushing movement of the pusher, and the pushing movement control means moves the pusher in a pushing movement operation selected from a plurality of pushing movement operations including step feeding and vibration feeding And the lens centering device for moving the lens in the lens depth detector. The pusher according to claim 1, wherein the pusher is a pusher for pressing and moving the lens by advancing in the X direction or the Y direction, wherein the NC controller controls the eccentric direction of the lens based on the measurement value of the optical instrument in the moving direction of the pusher And a phase control means for rotating the holder so as to face the lens. 3. The apparatus according to claim 2, further comprising an outer measuring device for measuring a distance from a rotation center of the holder to an outer periphery of the lens on the holder. 2. The apparatus according to claim 1, wherein the pusher is a pusher for pushing the lens by a movement operation in a two-dimensional plane formed by a lateral direction and a direction perpendicular to the paper. delete The optical measuring device according to any one of claims 1 to 4, wherein the optical measuring instrument comprises: a light source that reflects a light beam projected from above the holder as a light spot on the surface of the lens, forms a reflected light on the two-dimensional light receiving surface, And detects the eccentric direction and eccentricity of the reflected light with respect to the transmitted light. A focusing device according to any one of claims 1 to 4 is mounted on a lens grater and a circle is drawn on the light receiving surface of the optical measuring instrument by rotating the holder with the lens mounted on the holder, The eccentric direction of the lens is measured from the center of the locus and the position of the light receiving point when the holder is stopped, the amount of eccentricity of the lens is measured from the diameter of the circular locus, and the lens is pushed and moved by the moving pusher based on the measured value A method of concentrating a lens on a holder, wherein the lens concentrates. An optical system according to claim 2 or 3 is mounted on a lens tip, a lens is mounted on the holder, an eccentric direction and an eccentric amount of the lens on the holder are measured by an optical meter, the holder is rotated in the eccentric direction, When the pusher is advanced toward the lens by the measured eccentric amount and the lens is pushed, the light receiving point is monitored by the optical measuring instrument, and it is judged that the pusher and the lens are in contact with each other at the time when the light receiving point starts to move on the light receiving surface. Wherein the stroke of the pusher is controlled so that the amount of movement of the pusher becomes the measured eccentric amount. An optical system as set forth in any one of claims 1 to 4 is mounted on a lens tip, a lens is mounted on the holder, an eccentric direction of the lens on the holder is measured by an optical instrument, Wherein the movement of the pusher is stopped when the light receiving point on the light receiving surface coincides with the rotation center of the holder on the light receiving surface when the light receiving point on the light receiving surface coincides with the rotation center of the holder on the light receiving surface. An optical system according to claim 3 is mounted on a lens tip, a lens is mounted on the holder, an optical measuring instrument measures the eccentric direction and eccentricity of the lens on the holder, and the distance from the axis of the holder to the outer periphery of the lens is measured When the distance exceeding the predetermined threshold value is measured, rough machining of the outer periphery of the lens is performed. Thereafter, the holder is rotated in the eccentric direction measured by the optical measuring instrument, and then the pusher is advanced toward the lens to push the lens , And a method for inserting a lens in a lens-extender. An optical device according to claim 4 is mounted on a lens tip, a lens is mounted on the holder, an eccentric direction and an eccentric amount of the lens on the holder are measured by an optical meter, To the lens, and then the pusher is moved to the center of rotation of the holder.

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