JP7359425B2 - Aspherical convex lens processing system - Google Patents

Description

The present invention relates to an aspherical convex lens processing system that grinds a lens surface including an aspherical surface by pressing a rotating grindstone against a lens workpiece.

Conventionally, when manufacturing (processing) optical lenses, the lens surface is ground (including polishing) by pressing a rotating grindstone or other grinding tool (including polishing tools) against the lens workpiece. A grinding device (including a polishing device) is used to carry out this process, and as this type of grinding device, for example, the polishing device disclosed in Patent Document 1 is known.

The polishing device disclosed in Document 1 aims to provide a polishing technique that can polish optical elements with various external shapes with high precision using a single polishing device, and specifically, , a lower shaft unit that is swingably provided to support the polishing plate, and an upper shaft unit that is opposite to the lower shaft unit and is swingably provided to support the lens to be processed via a lens holder. , a linear shaft that provides rocking displacement and linear displacement in a direction perpendicular to the rocking plane to the upper shaft unit, and a lower shaft that slides the polishing plate and the lens to be processed according to the shape specifications of the lens to be processed. By combining the swing angle of the unit and the upper shaft unit and the linear displacement in the direction orthogonal to the swing plane, the structure allows polishing of lenses with various shapes and specifications with one polishing device. This is what I did.

Japanese Patent Application Publication No. 2009-113162

However, the grinding device used in the conventional lens processing system described above has the following problems.

That is, in this type of grinding device, a grinding tool such as a rotating whetstone is used as a grinding means, but the grinding surface (including the polishing surface) of the grinding tool wears out with use, resulting in the problem of deformation of the grinding surface. There is. Such deformation due to wear does not immediately reduce the grinding ability itself, but from the viewpoint of use in a lens processing system, it causes a problem that immediately reduces the grinding accuracy (processing accuracy) of the lens.

In particular, with the advancement of the times, aspheric lenses used in optical equipment such as cameras are required to have higher precision, including miniaturization, and higher quality. This is an important problem to be solved from the perspective of obtaining high-precision lenses, but in the past, it was possible to achieve sufficient precision and high quality when processing aspherical lenses by taking measures against wear and tear on the grinding surface of grinding wheels, etc. The reality is that no grinding equipment (processing system) is provided to achieve this.

The present invention aims to provide a processing system for an aspherical convex lens that solves the problems existing in the background art.

In order to solve the above-mentioned problems, an aspherical convex lens processing system 1 according to the present invention presses a rotating grindstone 2 against a lens workpiece W to produce a lens surface including an aspherical surface in the lens workpiece W. When configuring a system that performs grinding (including polishing) of Wf, a straight line Ls perpendicular to the normal Ln of the ground portion Ps of the lens work W is included, and a flat surface A grinding mechanism part Ms that performs grinding on the lens surface Wf of the lens work W by press-contacting a grinding wheel 2 having a grinding surface 2s formed on Af, and a grinding mechanism part Ms selected on the center line Lb of the lens work W, A radial direction offset by a predetermined distance Lof with respect to the radial direction Fd of the rotating grinding surface 2s of the lens work W, or the direction perpendicular to this radial direction Fd, centering on a predetermined fulcrum position Pc whose position can be changed. A workpiece rotation mechanism Mp that relatively rotates and displaces the grinding surfaces 2s in the surface direction Ff by setting the direction Fdp parallel to Fd, and a grindstone that moves the grinding wheels 2 in the rotation axis direction Fr of the grinding wheels 2. Rotation control is performed to rotate the moving mechanism part Mm and the lens workpiece W around the center line Lb, a turning angle control process is performed for the workpiece turning mechanism part Mp, and a position control process is performed for the grindstone moving mechanism part Mm. The present invention is characterized in that it includes a system controller Mc that performs the following operations.

According to the aspherical convex lens processing system 1 according to the present invention, the following remarkable effects are achieved.

(1) A grindstone 2... having a grinding surface 2s including a straight line Ls perpendicular to the normal line Ln of the part to be ground Ps is pressed against the part to be ground Ps of the workpiece for lenses W, and the center line of the workpiece for lenses W is Centering on the selected predetermined fulcrum position Pc on Lb, a turning angle control process is performed to relatively turn the lens work W in the surface direction Ff of the grinding surfaces 2s, and at the same time, the grinding wheel 2 By performing position control processing in the rotation axis direction Fr for ..., the lens surface Wf of the lens workpiece W is ground, thereby significantly reducing the wear of the grinding surface 2s caused by the use of the grindstone 2... can be reduced to Thereby, the adverse effect on the processing accuracy due to the deformation of the grinding surfaces 2s is greatly reduced, and the grinding accuracy of the lens can be dramatically improved. In particular, it can fully meet the demands for higher precision and higher quality, including miniaturization, for aspherical lenses (aspherical convex lenses) used in optical equipment such as cameras, which are required with the advancement of the times.

(2) Since the lens workpiece W is rotated around the center line Lb, the ground portion Ps of the lens workpiece W can be displaced in the circumferential direction at the same time as the rotational displacement. This can contribute to further homogenization and efficiency in the grinding process of the lens workpiece W.

(3) The surface direction Ff that is turned and displaced by the turning angle control processing is set in the radial direction Fd of the rotating grinding surface 2s, or in a direction parallel to the radial direction Fd offset by a predetermined distance Lof with respect to the direction perpendicular to this radial direction Fd. Since it is set to Fdp, the surface direction Ff can be turned not only in the radial direction Fd but also in the offset parallel direction Fdp, and the wear mode can be further randomized and distributed. This contributes to higher precision and homogenization in the grinding process of the lens work W, and also makes it possible to utilize the grinding surface 2s formed by the narrow ring end surface Ar.

(4) Since the grindstone 2 has the grinding surface 2s formed on the plane Af, a simple-shaped grindstone can be used. Thereby, in the case of the plane Af, it is possible to easily construct a processing system 1 with high cost performance from the viewpoints of parts and control.

(5) Since the predetermined fulcrum position Pc on the center line Lb of the lens work W is configured to be changeable, the rotation angle range and the whetstone 2 (or the lens The displacement range of the position of the workpiece W) in the rotation axis direction Fr can be set flexibly. Thereby, it is possible to construct an optimal processing system 1 that matches the size, shape, etc. of the lens to be processed.

A diagram explaining the principle of a processing system according to a preferred embodiment of the present invention, A characteristic diagram of the position of the part to be ground with respect to the rotation angle of the lens workpiece when the fulcrum position on the center line of the lens workpiece in the same processing system is used as a parameter, A characteristic diagram of the position of the grindstone in the rotational axis direction with respect to the rotation angle of the lens workpiece when the fulcrum position on the center line of the lens workpiece in the same processing system is taken as a parameter, An explanatory diagram of the surface direction that is rotated and displaced by the rotation angle control process in the same processing system, Overall configuration diagram of the processing system, A flowchart to explain the operation of the processing system, An explanatory diagram showing a modification example of the processing system and a reference example related to the shape of the grindstone,

Next, preferred embodiments of the present invention will be described in detail based on the drawings.

First, the system configuration of an aspherical convex lens processing system 1 according to the present embodiment will be described with reference to FIG. 1(a) and FIG. 5.

As shown in FIG. 5, the illustrated processing system 1 has a basic configuration roughly divided into a mechanical unit section 20 and an electrical unit section 50.

In the mechanical unit section 20, reference numeral 21 denotes a fixed base frame, and each mechanism section, that is, the grinding mechanism section Ms, the workpiece rotation mechanism section Mp, and the grindstone moving mechanism section, is mounted on the front surface 21f of the upright base frame 21. Mm are arranged respectively.

The grinding mechanism section Ms includes a rotational drive section 24 using an electric motor or the like, and this rotational drive section 24 is supported by a subframe 25 that is separate from the base frame 21. A rotation output shaft 24s protrudes downward from the rotation drive unit 24, and the center portion of the upper surface of the grindstone holder 26 is fixed to the lower end of the rotation output shaft 24s. Then, the upper end surface of the grindstone 2 formed in the shape of a flat cylinder is attached to the lower surface of the grindstone holder 26. In the illustrated case, the attachment hole 2h provided at the center of the grindstone 2 is fixed by a bolt/nut portion 26c provided at the center of the grindstone holder 26. Note that the grindstone 2 is conceptually equipped with both a grinding function and a polishing function, and is not limited to only the grinding function.

As a result, as shown in FIG. 1(a), the lower end surface of the grinding wheel 2 functions as a circular (ring-shaped) grinding surface 2s that becomes a plane Af in the horizontal direction. The rotation of the grinding surface 2s is controlled to have a rotational speed of about 1000 rpm about the center line La. In this way, if a grindstone having the grinding surface 2s formed on the plane Af is used as the grindstone 2..., a simple-shaped grindstone can be used, so that the machining system 1 has high cost performance from the viewpoint of parts and control. can be easily constructed. Therefore, this grinding mechanism part Ms has a grinding surface 2s including a straight line Ls perpendicular to the normal line Ln of the ground part Ps to the ground part Ps of the lens workpiece W shown in FIG. 1(a). Since the grindstone 2 is provided, the grinding surface 2s of the grindstone 2 can be pressed against the lens workpiece W to perform grinding on the lens surface Wf.

In the case of illustration, the grindstone moving mechanism section Mm includes a ball screw mechanism 27 and a rotation drive section 28 using an electric motor or the like fixed to the front part 21f of the base frame 21. The ball screw mechanism 27 includes a ball nut portion 29n screwed onto a screw portion 29s having an axis in the vertical direction, and allows the ball nut portion 29n to be rotationally driven by the rotational drive portion 28. The lower end is fixed to the upper end of the subframe 25 described above. Furthermore, linear guides 30 and 31 are provided on both the left and right sides of the screw portion 29s. Each linear guide 30, 31 includes a pair of left and right guide shafts 30g, 31g arranged parallel to the screw portion 29s, and sliders 30s, 31s slidably arranged on each guide shaft 30g, 31g. , 31s are fixed to the left and right parts of the subframe 25, respectively.

As a result, the screw portion 29s is moved up and down along the guide shafts 30g and 31g by the operation of the rotation drive portion 28, and the grindstone 2 is also moved up and down by the subframe 25 fixed to the screw portion 29s. That is, the movement (elevation) and position control of the grindstone 2 in the rotation axis direction Fr shown in FIG. 1(a) can be performed.

The workpiece turning mechanism section Mp includes a turning drive section 35 composed of an electric motor, a speed reducer, and the like. A turning output shaft 35s of this turning drive section 35 is in the horizontal direction. Further, the lower end portion of the rotary drive unit 36 is fixed to the rotation output shaft 35s. A rotation output shaft 36s of the rotation drive section 36 projects in a direction perpendicular to the rotation output shaft 35s, and a workpiece set section 37 is fixed to the tip of the rotation output shaft 36s. A lens workpiece W to be processed can be positioned and fixed on the upper surface of the workpiece setting section 37 . The lens work W in this embodiment is for processing an aspherical convex lens G as a final product, and the work material may be a glass material or a plastic material, and the type of the material is No question.

Thereby, the rotation of the lens work W is controlled to rotate around the center line Lb at a rotational speed of about 50 to 100 rpm by the operation of the rotation drive section 36. In this way, by controlling the rotation of the lens work W around the center line Lb, the ground portion Ps of the lens work W can be displaced in the circumferential direction at the same time as the rotational displacement. , it can contribute to further homogenization and efficiency in the grinding process of the lens work W.

Furthermore, at the angle at which the rotational output shaft 36s stands vertically upward, the setting surface of the workpiece setting section 37 is positioned horizontally. Therefore, in this position, as shown in FIGS. 1A and 5, when the grindstone 2 is lowered, the grinding surface 2s is the upper surface of the lens workpiece W set on the setting surface of the workpiece setting section 37. Contact (pressure contact) with. In this case, the center position (ground portion Ps) of the lens work W comes into contact with the center of the circular (ring-shaped) grinding surface 2s. Then, by operating the rotation drive unit 35 from this position, the lens work W is moved to a fulcrum position Pc set at a predetermined position on the center line Lb of the lens work W (see FIG. 1(a)). The lens work W can be relatively pivoted (swivel controlled) in the surface direction Ff of the grinding surface 2s, centering on . In the illustrated case, the fulcrum position Pc is located on the rotation output shaft 35s, and the rotation direction is the radial direction Fd on the grinding surface 2s of the grindstone 2 (see FIG. 4(a)). In addition, in FIG. 5, the lens workpiece W shown by a virtual line is shown in a state where it has been turned by a predetermined angle from a horizontal position.

On the other hand, the electrical system unit section 50 includes a system controller Mc shown in FIG. 5, and the system controller Mc includes a controller unit 51 and a drive driver 52 connected to the output section of the controller unit 51. The system controller Mc includes a system controller main body 55 constituted by hardware such as a CPU having a computer processing function, and also includes a memory 56 attached to the system controller main body 55. The memory 56 has a program area 56p that stores a control program (software) that executes various control processes including sequence control processes, and a data area 56d in which various data including a database can be written.

Therefore, in the program area 56p, there is a control program (sequence control program) for functioning the processing system 1 according to the present embodiment, that is, a normal line to the ground part Ps of the lens work W is provided. A grindstone 2... having a grinding surface 2s... including a straight line Ls perpendicular to Ln is pressed against the lens workpiece W, and the lens workpiece W is ground around the selected fulcrum position Pc on the center line Lb of the lens workpiece W. The lens of the lens work W is performed by performing a turning angle control process for relatively turning and displacing the surfaces 2s... in the surface direction Ff, and at the same time, performing a position control process on the grindstone 2... in the rotation axis direction Fr. A series of control processes for performing grinding on the surface Wf can be executed.

Further, a display 57 that displays various types of information is connected to the system controller main body 55, and a touch panel 57p that can perform various settings and/or inputs is attached to this display 57. Further, a drive driver 52 is connected to the system controller main body 55, and the above-mentioned rotation drive unit 24, rotation drive unit 28, swing drive unit 35, and rotation drive unit 36 are connected to the drive driver 52, respectively. . As a result, the system controller main body 55 provides the drive driver 52 with a control command signal Dc based on various settings, and the drive driver 52 controls the rotation drive unit 24 and the rotation drive unit based on the control command signal Dc. 28, the swing drive section 35, and the rotation drive section 36 can be controlled.

Next, a method of processing the aspherical convex lens G using the processing system 1 configured as described above will be described with reference to FIGS. 1 to 5.

First, the principle of the processing method will be explained with reference to FIG. 1(a). Note that FIG. 1(a) shows the principle corresponding to the processing system 1 shown in FIG. 5. In this case, since the predetermined fulcrum position Pc, which is the center of rotation of the lens work W, can be selected, if the position of the grinding surface 2s in the rotational axis direction Fr of the grindstone 2 is set to "0", FIG. ) is assumed to be located on the "positive" side.

The processing method by this processing system 1 includes, as a first control process, a grinding wheel having a grinding surface 2s, which includes a straight line Ls perpendicular to a normal line Ln of the grinding part Ps, on the grinding part Ps of the lens work W. 2... is brought into pressure contact with the lens workpiece W, and the lens workpiece W is pivoted relative to the lens workpiece W in the surface direction Ff of the grinding surface 2s... about the selected fulcrum position Pc on the center line Lb of the lens workpiece W. While performing the angle control process, as a second control process, simultaneously with the turning angle control process, a position control process is performed on the grindstones 2 in the rotation axis direction Fr.

Therefore, now, let the coordinates of the part to be ground Ps, that is, the machining coordinates, be (xp, yp, zp), and by turning from this position by α [deg] around the fulcrum position Pc, (xp', yp , zp'), the following relational expression [Equation 1] holds true since yp does not change. In this case, the amount of movement of the grindstone 2 in the Z-axis direction is zp'-Zc=d.

Further, the formula for determining the aspherical surface is expressed by the following [Equation 2]. In [Equation 2], Co=1/Ro (Ro is the radius of curvature of the vertex Pp), K is a conic coefficient, and A is an N-order (fourth-order, sixth-order, etc.) aspheric coefficient.

Since the angle α [deg] of the normal Ln is tanα=dz/dx, the desired pitches p1, p2, etc. are set in the processing system 1, and (x1, z1, α1), (x2, z2, By calculating α2)..., calculating d based on [Equation 1], and setting the pair data of (αK, dK), the processing system 1 can process the lens to obtain the desired aspherical convex lens G. It can be performed.

On the other hand, FIG. 1(a) shows a case where the position of the grinding surface 2s in the rotation axis direction Fr of the grindstone 2 is set to "0" and the fulcrum position Pc on which the lens workpiece W rotates is set to the "positive" side. However, FIG. 1(b) shows the case where it is set to the "negative" side, and FIG. 1(c) shows the case where it is set to "0". Furthermore, FIG. 2 shows a case where the fulcrum position Pc (Zc) of the lens work W is set to a plurality of different parameters, that is, Zc is set to "-10.0 mm", "0.0 mm", "12.0 mm", Fig. 3 shows a characteristic diagram of the position Xp [mm] of the part to be ground against the rotation angle α [deg] of the lens work W when set to "22.0 mm" and "60.0 mm". When the fulcrum position Pc (Zc) of the workpiece W is set to a plurality of different parameters, that is, Zc is set to "-10.0 mm", "0.0 mm", "12.0 mm", "22.0 mm", "60 A characteristic diagram of the position (movement amount) d [mm] of the grinding surface 2s in the rotation axis direction of the grindstone 2 with respect to the rotation angle [deg] when set to .0 mm is shown.

Further, the fulcrum position Pc can be arbitrarily selected, and can be changed as necessary by making the position perpendicular to the rotation output shaft 35s adjustable. In this way, if the predetermined fulcrum position Pc on the center line Lb of the lens workpiece W is configured to be changeable, the rotation angle range in which the lens workpiece W is relatively rotated and the rotational axis direction Fr of the grindstone 2 can be changed. Since the positional displacement range can be set flexibly, it is possible to construct an optimal processing system 1 that matches the size, shape, etc. of the lens to be processed.

On the other hand, in the case of FIGS. 1(a), (b), and (c), the fulcrum position Pc is located on the swing output shaft 35s shown in FIG. The direction Fd is assumed. That is, the radial direction Fd shown in FIG. 4(a) is assumed. On the other hand, it is also possible to turn in the parallel direction Fdp offset with respect to the radial direction Fd. Specifically, as shown in FIG. 4(b), the surface direction Ff of the turning displacement is set to a direction Fdp parallel to the radial direction Fd offset by a predetermined distance Lof with respect to the direction perpendicular to the radial direction Fd. You can also do it. If the parallel direction Fdp is set like this, the surface direction Ff can be turned not only in the radial direction Fd but also in the offset parallel direction Fdp, so that the wear mode can be further randomized and distributed. . This contributes to higher precision and homogenization in the grinding process of the lens work W, and also makes it possible to utilize the grinding surface 2s formed by the narrow ring end surface Ar. FIG. 4(c) shows a case where the present invention is applied to such a ring end face Ar.

Next, a method for processing the aspherical convex lens G using the processing system 1 according to the present embodiment will be described according to the flowchart shown in FIG. 6 with reference to each figure.

First, in the processing system 1, processing coordinates related to the aspherical convex lens G to be processed are set using the system controller Mc (step T1). Furthermore, the amount of machining at each machining coordinate is set (step T2). That is, the above-mentioned (αK, dK) is set as pair data.

On the other hand, a lens work W is prepared and set in the work setting section 37 (step S1). Then, a start key (not shown) is turned on (step S2). As a result, the position of the lens work W is controlled to the set initial machining coordinates by the rotation angle control process for the rotation drive unit 35, and the position control process for the rotation axis direction Fr for the rotation drive unit 28 causes the lens work W to be controlled by the grinding wheel. 2 descends from the home position (step S3). Further, the rotation drive unit 24 is drive-controlled, and the grindstone 2 is rotated at a set rotation speed, and the rotation drive unit 36 is drive-controlled, and the lens work W is rotated at a set rotation speed (step S4, S5). Then, the grinding process is performed by the set processing amount by drive control of the rotation drive unit 28 described above, that is, by controlling the position of the grindstone 2 in the rotation axis direction Fr.

After that, when the set machining amount has been grinded, the lens workpiece W is moved to the next setting so that the next set machining coordinate is ground by the turning angle control process for the turning drive unit 35. The machine is rotated to the machining coordinates determined (step S6). Then, the grinding process of the part to be ground Ps, which is the next processing coordinate, is performed, and the rotation drive unit 28 is drive-controlled so that the grinding process is performed by the set processing amount, and the position in the rotation axis direction Fr relative to the grindstone 2 is Control processing is performed (step S7).

Once the set machining amount has been grinded at this machining coordinate, the lens workpiece W is moved to the next position by the rotation angle control process for the rotation drive unit 35 so that the next set machining coordinate is ground. The rotary drive unit 28 is drive-controlled so that the grinding wheel 2 is rotated to the set machining coordinates and grinding is performed by the set machining amount, and position control processing is performed in the rotation axis direction Fr with respect to the grindstone 2 (step S8, S4, S5, S6, S7).

The above control processing is performed sequentially according to the sequence control processing program, and the grinding processing (machining processing) ends when the final processing coordinates are reached (step S8). Then, when the processing system 1 is stopped, the grindstone 2 is raised to the home position (step S9). Thereafter, the processed lens work W, that is, the processed target aspherical convex lens G is taken out (step S10).

Therefore, according to the processing system 1 for the aspherical convex lens G according to the present embodiment, a straight line Ls perpendicular to the normal Ln of the ground portion Ps of the lens work W is drawn to the ground portion Ps of the lens work W. A grinding mechanism part Ms that performs grinding on the lens surface Wf of the lens workpiece W by press-contacting a grindstone 2 having a grinding surface 2s formed on a plane Af; By a predetermined distance Lof with respect to the radial direction Fd of the rotating grinding surface 2s of the lens work W or the direction perpendicular to this radial direction Fd, centering on a predetermined fulcrum position Pc which can be selected and whose position can be changed. A workpiece turning mechanism Mp that relatively turns and displaces the grinding surfaces 2s in the surface direction Ff by setting the parallel direction Fdp to the offset radial direction Fd, and the grinding wheels 2... The grindstone moving mechanism Mm moves the lens workpiece W to the center line Lb, and the workpiece turning mechanism Mp performs rotation angle control processing, and the grindstone moving mechanism Mm rotates the lens workpiece W around the center line Lb. Since the system controller Mc that performs position control processing is provided, the basic effect is that wear and tear on the grinding surfaces 2s caused by use of the grindstones 2 can be significantly reduced. Thereby, the adverse effect on the processing accuracy due to the deformation of the grinding surfaces 2s is greatly reduced, and the grinding accuracy of the lens can be dramatically improved. In particular, it can fully meet the demands for higher precision and higher quality, including miniaturization, for aspherical lenses (aspherical convex lenses) used in optical equipment such as cameras, which are required with the advancement of the times.

Next, modifications and reference examples of the aspherical convex lens G processing system 1 according to the present embodiment will be described with reference to FIGS. 7(a) to 7(d).

FIG. 7A shows a modification example in which the basic operations of the lens work W and the grindstone 2 are exchanged. That is, a modification example is shown in which the grindstone 2 is pivoted about the fulcrum position Pc without pivoting the lens work W. In this case, the position control of the lens work W or the grindstone 2 in the rotational axis direction may be performed by moving the lens work W or by moving the grindstone 2. Even in the case of this modified example, it can be implemented using the same principle as the basic embodiment shown in FIG.

On the other hand, FIGS. 7(b) to 7(d) all show reference examples of the shape of the grindstone 2. FIG. 7(b) shows a reference example in which a cylindrical grindstone 2b is used and the cylindrical circumferential surface Ap of this grindstone 2b is used as the grinding surface 2sb. In this case, the grinding surface 2sb becomes a curved surface, and the convex curved surface contacts the lens work W in the part to be ground Ps, so that the grinding efficiency can be improved. FIG. 7(c) shows a reference example in which a grindstone 2c having a conical portion is used, and the tapered surface Ac of this grindstone 2c is used as the grinding surface 2sc. In this case, the grinding surface 2sc becomes a curved surface similar to that shown in FIG. 7(b), but since the grinding surface 2sc can be set at any angle with respect to the rotational output shaft 24s, the degree of freedom in design can be increased. FIG. 7(d) shows a reference example in which a cylindrical grindstone 2d having the ring end surface Ar shown in FIG. 4(c) described above is used at the tip, and in addition, this ring end surface Ar is formed as a grinding surface 2sd with a tapered concave surface. Give an example. Therefore, FIG. 7(d) is, so to speak, formed as a composite shape of the ring end surface Ar of FIG. 4(c) and the tapered concave surface. In the case of FIG. 7(d), the concave curved surface comes into contact with the lens work W in the part to be ground Ps, unlike the case of FIG. 7(c).

As shown in these reference examples, if a grinding wheel 2 having a grinding surface 2s formed on any of the cylindrical peripheral surface Ap, conical surface Ac, or ring end surface Ar is used, the size and shape of the lens, and even the system Since it becomes possible to respond flexibly to constraints such as the overall size and configuration, the degree of freedom in designing the processing system 1 can be increased. The above-mentioned grindstones 2, 2a, as well as the above-mentioned grindstones 2b, 2c, and 2d are shown as examples, and various shapes can be applied to the shape of the grindstones 2. In FIGS. 7A to 7D, the same parts as those in FIG. 1 are given the same reference numerals to clarify the structure, and detailed explanation thereof will be omitted.

Although the preferred embodiments including modifications have been described in detail above, the present invention is not limited to such embodiments, and the present invention is not limited to the detailed configuration, shape, material, quantity, numerical value, method, etc. Any changes, additions, or deletions may be made without departing from the gist of the invention.

For example, the processing system according to the present invention is most suitable for grinding the lens surface of a convex lens that includes an aspherical surface, but it can of course also be used for a lens surface that has a mixture of spherical and aspherical surfaces, or a lens surface that only has a spherical surface. . Furthermore, the concept of "grinding" in the present invention includes "polishing". That is, a whetstone (grinding tool) is normally used for grinding, and a pad coated with a slurry containing free abrasive grains is used for polishing, but the basic functions are the same. Note that as a grindstone, a rubber bond grindstone is also known. This rubber bond grindstone is an elastic grinding tool in which abrasive grains are present not only on the surface of the bond but also inside the bond, and such a grinding tool is also included in the concept of the grindstone in the present invention. Furthermore, there is also a method of polishing by fixing abrasive grains on the pad surface, but this method cannot be called free abrasive grains, and this elastic pad is mainly used as a polishing tool for polishing. However, such a polishing tool is also included in the concept of the grindstone in the present invention. On the other hand, the detailed configurations of the grinding mechanism section Ms, work rotation mechanism section Mp, grindstone moving mechanism section Mm, and system controller Mc that constitute the processing system 1 can be replaced with various configurations that perform the same functions.

The aspherical convex lens processing system according to the present invention can be used to grind various lens surfaces including aspherical surfaces by pressing a rotating grindstone against a lens workpiece.

1: processing system, 2...: grindstone, 2s...: grinding surface, W: lens workpiece, Wf: lens surface, Ps: part to be ground, Pc: fulcrum position, Ln: normal line, Ls: perpendicular to the normal line Straight line, Lb: Center line of the lens workpiece, Lof: Predetermined distance, Ff: Planar direction of the grinding surface, Fr: Rotation axis direction of the grindstone, Fd: Radial direction of the grinding surface, Fdp: Parallel direction to the offset radial direction , Ms: Grinding mechanism section, Mp: Work rotation mechanism section, Mm: Grinding wheel movement mechanism section, Mc: System controller, Af: Plane

Claims (1)

In an aspherical convex lens processing system that grinds (including polishing) a lens surface including an aspherical surface in the lens workpiece by pressing a rotating grindstone against the lens workpiece, a grinding mechanism unit that performs a grinding process on the lens surface of the lens workpiece by press-contacting a grindstone having a straight line perpendicular to the normal line of the part to be ground and a flat grinding surface to the grinding part; , selected on the center line of the lens workpiece and at a predetermined position in the radial direction of the rotating grinding surface of the lens workpiece or in the direction perpendicular to this radial direction, about a predetermined fulcrum position whose position can be changed. a workpiece turning mechanism that rotates and displaces the grinding surface relatively in the direction of the surface of the grinding surface by setting it in a direction parallel to the radial direction offset by a distance; and a grindstone movement that moves the grindstone in the direction of the rotation axis of the grindstone. A system that performs rotation control to rotate a mechanism section and the lens workpiece around the center line, performs rotation angle control processing for the workpiece rotation mechanism section, and performs position control processing for the grindstone movement mechanism section. An aspherical convex lens processing system characterized by comprising a controller.

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