Polishing method for optical elements

Abstract

A polishing device for optical elements includes: a tool shank (1), and a polishing disc base; wherein the tool shank (1) is connected to the polishing disc base and is mounted on a tool shaft of a numerical-controlled processing device; wherein a polishing film (3) is stuck on the polishing disc base; the polishing disc base is a profiling polishing disc base (7), a cylinder polishing disc base (2), a profiling polishing disc base (12) or a spherical polishing disc base (8); wherein the tool shank (1) is independent and universal, thereby reducing the processing cost of the polishing device. A polishing method for optical elements is based on the shapes mentioned above of the polishing disc base, including steps of: fixing a polishing disc connecting rod (11); sticking a polishing film (3); trimming the polishing film (3); and polishing an unprocessed work piece (6).

Claims

1. A partially surface-contacted polishing method for spherical and planar optical elements, comprising steps of: 1) pressing a polishing disc connecting rod (11) into a polishing disc fixing port (21), and fixing with screws (4), in such a manner that no interval exists; 2) sticking a polishing film (3) on an arc-portion at a bottom of a cylinder polishing disc base (2) with a binding agent, and trimming a curvature radius of the polishing film (3) after the binding agent is solidified; 3) during trimming, installing a polishing device (100) on a work piece shaft of a numerical-controlled device, and installing a trimming grinding wheel (5) on a tool shaft of the numerical-controlled device; trimming the curvature radius of the polishing film (3) by point-contacting, in such a manner that the curvature radius of the polishing film (3) is identical, and is same with a curvature radius of the spherical or the planar optical element in value and opposite in direction; a width of the polishing film (3) after trimming is less than a diameter of the work piece and covers only a part of a work piece surface, and 4) during utilization, installing the polishing device (100) on the tool shaft of the numerical-controlled device, and installing an unprocessed work piece (6) on the work piece shaft of the numerical-controlled device; during polishing, firstly inputting surface forming parameters of the unprocessed work piece (6) and size parameters of the polishing device (100) into a processing software, and generating a numerical-controlling file, so as to precisely position the polishing device (100) and the unprocessed work piece (6) by the numerical-controlled device, in such a manner that a curvature center of the polishing film (3) coincides with a curvature center of the unprocessed work piece (6) at any processing position; a surface of the polishing device (100) forms ring-surface-contact with a surface of the unprocessed work piece (6) for polishing.

2. The partially surface-contacted polishing method, as recited in claim 1, wherein during utilization, the polishing device (100) is installed on the tool shaft of the numerical-controlled device; the polishing device (100) rotates around an axis of the tool shaft and swings around a swinging center B of the tool shaft; the polishing device (100) is also movable along a horizontal direction; the unprocessed work piece (6) is installed on the work piece shaft of the numerical-controlled device; the unprocessed work piece (6) rotates around an axis of the work piece shaft and is movable along a vertical direction; a moving speed of the cylinder polishing disc base (2) and a rotation speed of the unprocessed work piece (6) are controlled by the numerical-controlled device at each processing position; wherein a curvature radius of the bottom, which is arc-shaped, of the cylinder polishing disc base (2) is r.sub.1; before utilization, the polishing film (3) stuck on the arc portion of the cylinder polishing disc base (2) is trimmed, in such a manner that a surface section curve thereof is a precise arc with a curvature radius of r.sub.2; a height of the polishing film (3) is h, which satisfies r.sub.2=r.sub.1+h.

3. A line-contacted polishing method for spherical and planar optical elements, comprising steps of: 1) pressing a polishing disc connecting rod (11) into a polishing disc fixing port (21), and fixing with screws (4), in such a manner that no interval exists therebetween; 2) sticking a polishing film (3) on a bottom of a polishing disc base with a binding agent, and trimming a curvature radius of the polishing film (3) after the binding agent is solidified; 3) during trimming, installing a polishing device (100) on a work piece shaft of a numerical-controlled device, and installing a trimming grinding wheel (5) on a tool shaft of the numerical-controlled device; trimming the curvature radius of the polishing film (3) by point-contacting, in such a manner that the curvature radius of the polishing film (3) is identical; and 4) during utilization, installing the polishing device (100) on the tool shaft of the numerical-controlled device, and installing an unprocessed work piece (6) on the work piece shaft of the numerical-controlled device; during polishing, firstly inputting surface forming parameters of an aspheric surface of the unprocessed work piece (6) and size parameters of the polishing device (100) into a processing software, and generating a numerical-controlling file, so as to control the polishing device (100) and the unprocessed work piece (6) by the numerical-controlled device, in such a manner that the polishing device (100) line-contacts with the unprocessed work piece (6) at any processing position; wherein during polishing, a contacting trace of a profiling polishing disc base (7) and the unprocessed work piece (6) is a portion of a meridian section curve of the unprocessed work piece (6), which belongs to profiling processing; a contacting trace of a cylinder polishing disc base (2) and the unprocessed work piece (6) is a envelope circle, which belongs to generating processing.

4. The line-contacted polishing method, as recited in claim 3, wherein during utilization, the polishing device (100) is installed on the tool shaft of the numerical-controlled device; the polishing device (100) rotates around an axis of the tool shaft and swings around a swinging center B of the tool shaft; the polishing device (100) is also movable along a horizontal direction; the unprocessed work piece (6) is installed on the work piece shaft of the numerical-controlled device; the unprocessed work piece (6) rotates around an axis of the work piece shaft and is movable along a vertical direction; a moving speed of the cylinder polishing disc base (2) and a rotation speed of the unprocessed work piece (6) are controlled by the numerical-controlled device at each processing position.

5. The line-contacted polishing method, as recited in claim 3, wherein the polishing film (3) is stuck on a revolution surface of the profiling polishing disc base (7), and a sticking height ensures that the polishing film (3) is fixedly stuck and covers the whole revolution surface; or the polishing film (3) is stuck on a bottom, which is arc-shaped, of the cylinder polishing disc base (2).

6. The line-contacted polishing method, as recited in claim 3, wherein the profiling polishing disc base (7) is a solid of revolution, a generating curve thereof is an arc with a curvature radius of r.sub.1; a generating curve of the polishing film (3) after being precisely trimmed is an arc with an curvature radius of r.sub.2; and a height of the polishing film (3) is h, which satisfies r.sub.2=r.sub.1+h; or the polishing disc base is a cylinder, a first end thereof is arc-shaped with a curvature radius of r.sub.3, a section curve of the polishing film (3) after being precisely trimmed is an accurate arc with an curvature radius of r.sub.4; and the height of the polishing film (3) is h, which satisfies r.sub.4=r.sub.3+h.

7. A point-contacted polishing method for aspheric optical elements, comprising steps of: 1) pressing a polishing disc connecting rod (11) into a polishing disc fixing port (21), and fixing with screws (4), in such a manner that no interval exists; 2) sticking a polishing film (3) on an arc-portion at a bottom of a polishing disc base with binding agent, and trimming a curvature radius of the polishing film (3) after the binding agent is solidified; 3) during trimming, installing a polishing device (100) on a work piece shaft of a numerical-controlled device, and installing a trimming grinding wheel (5) on a tool shaft of the numerical-controlled device; trimming the curvature radius of the polishing film (3) by point-contacting, in such a manner that the curvature radius of the polishing film (3) is identical; and 4) during utilization, installing the polishing device (100) on the tool shaft of the numerical-controlled device, and installing an unprocessed work piece (6) on the work piece shaft of the numerical-controlled device; during polishing, firstly inputting surface forming parameters of an aspheric surface of the unprocessed work piece (6) and size parameters of the polishing device (100) into a processing software, and generating a numerical-controlling file, so as to control the polishing device (100) and the unprocessed work piece (6) by the numerical-controlled device, in such a manner that the polishing device (100) contacts with the unprocessed work piece (6) at a P point of any processing position; wherein the P point coincides with an aspheric meridian section curve relative to a moving trace of the unprocessed work piece (6).

8. The point-contacted polishing method, as recited in claim 7, wherein if the unprocessed work piece (6) is convex and is to be externally polished, trimming an external arc (31) of the polishing film (3); if the unprocessed work piece (6) is convex and is to be internally polished, trimming an internal arc (32) of the polishing film (3); if the unprocessed work piece (6) is concave, trimming the external arc (31) of the polishing film (3), or trimming the external arc (31) and the internal arc (32) of the polishing film (3).

9. The point-contacted polishing method, as recited in claim 7, wherein during utilization, the polishing device (100) is installed on the tool shaft of the numerical-controlled device; the polishing device (100) rotates around an axis of the tool shaft and swings around a swinging center B of the tool shaft; the polishing device (100) is also movable along a horizontal direction; the unprocessed work piece (6) is installed on the work piece shaft of the numerical-controlled device; the unprocessed work piece (6) rotates around an axis of the work piece shaft and is movable along a vertical direction; a moving speed of the cylinder polishing disc base (2) and a rotation speed of the unprocessed work piece (6) are controlled by the numerical-controlled device at each processing position.

10. The point-contacted polishing method, as recited in claim 7, wherein a curvature radius of the bottom of the bowl-like polishing disc base (12) is r.sub.1; a surface section curve of the polishing film (3) after being trimmed is a precise arc with a curvature radius of r.sub.2; a height of the polishing film (3) is h, which satisfies r.sub.2=r.sub.1+h; wherein a curvature radius of spherical polishing disc base (8) is r.sub.3; a curvature radius of the polishing film (3) after being trimmed is r.sub.4; and a height of the polishing film (3) is h, which satisfies r.sub.4=r.sub.3+h.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] FIG. 1 is a sketch view of a polishing device according to a preferred embodiment 1 of an embodiment 1 of the present invention.

[0060] FIG. 2 is a sketch view of a tool shank of the present invention.

[0061] FIG. 3 is a sketch view of a cylinder polishing disc base in FIG. 1.

[0062] FIG. 4 illustrates trimming a polishing film according to the preferred embodiment 1 of the embodiment 1.

[0063] FIG. 5 illustrates polishing a concave element according to the preferred embodiment 1 of the embodiment 1.

[0064] FIG. 6 is a sketch view of a polishing device according to a preferred embodiment 2 of the embodiment 1 of the present invention.

[0065] FIG. 7 is a sketch view of a cylinder polishing disc base in FIG. 6.

[0066] FIG. 8 illustrates polishing a convex element according to the preferred embodiment 2 of the embodiment 1.

[0067] FIG. 9 is a sketch view of a polishing device according to a preferred embodiment 3 of the embodiment 1 of the present invention.

[0068] FIG. 10 is a sketch view of a cylinder polishing disc base in FIG. 9.

[0069] FIG. 11 illustrates polishing a planar element according to the preferred embodiment 3 of the embodiment 1.

[0070] FIG. 12 is a sketch view of a polishing device according to a preferred embodiment 4 of an embodiment 2 of the present invention.

[0071] FIG. 13 is a sketch view of a profiling polishing disc base in FIG. 12.

[0072] FIG. 14 illustrates trimming a polishing film according to the preferred embodiment 4 of the embodiment 2.

[0073] FIG. 15 illustrates polishing a convex element according to the preferred embodiment 4 of the embodiment 2.

[0074] FIG. 16 is a sketch view of a polishing device according to a preferred embodiment 5 of the embodiment 2 of the present invention.

[0075] FIG. 17 is a sketch view of a bowl-like polishing disc base in FIG. 16.

[0076] FIG. 18 illustrates polishing a concave element according to the preferred embodiment 5 of the embodiment 2.

[0077] FIG. 19 is a sketch view of a polishing device according to a preferred embodiment 6 of the embodiment 2 of the present invention.

[0078] FIG. 20 is a sketch view of a cylinder polishing disc base in FIG. 19.

[0079] FIG. 21 illustrates polishing a convex element according to the preferred embodiment 6 of the embodiment 2.

[0080] FIG. 22 illustrates polishing a concave element according to the preferred embodiment 6 of the embodiment 2.

[0081] FIG. 23 illustrates polishing a planar element according to the preferred embodiment 6 of the embodiment 2.

[0082] FIG. 24 is a sketch view of a polishing device according to a preferred embodiment 7 of an embodiment 3 of the present invention.

[0083] FIG. 25 is a sketch view of a cylinder polishing disc base.

[0084] FIG. 26 illustrates trimming a polishing film of the cylinder polishing disc base.

[0085] FIG. 27 illustrates externally polishing a convex aspheric optical element according to the preferred embodiment 7.

[0086] FIG. 28 illustrates internally polishing the convex aspheric optical element according to the preferred embodiment 7. FIG. 29 illustrates polishing a concave aspheric optical element according to the preferred embodiment 7.

[0087] FIG. 30 is a sketch view of a polishing device according to a preferred embodiment 8 of the embodiment 3 of the present invention.

[0088] FIG. 31 is a sketch view of a spherical polishing disc base in FIG. 30.

[0089] FIG. 32 illustrates polishing a convex aspheric optical element according to the preferred embodiment 8 of the embodiment 3.

[0090] FIG. 33 illustrates polishing a concave aspheric optical element according to the preferred embodiment 8 of the embodiment 3.

[0091] Element reference: 1tool shank: 2cylinder polishing disc base; 3polishing film; 4screw; 5trimming grinding wheel; 6unprocessed work piece; 7profiling polishing disc base; 8spherical polishing disc base; 9work piece; 11polishing disc connecting rod; 12bowl-like polishing disc base; 21polishing disc fixing port; 31enternal arc; 32internal arc; 100polishing device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0092] Referring to preferred embodiments, the present invention is further illustrated.

[0093] Referring to FIGS. 1-11, an embodiment 1 of the present invention is illustrated.

[0094] Accordingly, the embodiment 1 provides a surface-contacted polishing device for spherical and planar optical elements.

[0095] Preferred embodiment 1:

[0096] Referring to FIGS. 1-5, a polishing disc connecting rod 11 is at a bottom of a tool shank 1, which is able to be pressed into a polishing disc fixing port 21 at a top of a cylinder polishing disc base 2. During installing, the polishing disc connecting rod 11 is pressed into the polishing disc fixing port 21, and is fixed with the cylinder polishing disc base 2, in such a manner that there is no interval between the polishing disc connecting rod 11 and the polishing disc fixing port 21; wherein the tool shank 1 is fixed on the cylinder polishing disc base 2 by any spanner type, such as inner triangle, inner rectangle, inner hexagon, and double hole, which not only ensures connecting reliability therebetween, but also is convenient to install and maintain.

[0097] A polishing film 3 is stuck on an arc portion at a bottom of the cylinder polishing disc base 2. The polishing film 3 is selected according to a material of the unprocessed work piece 6. There is no requirement for a shape of the polishing film 3 as long as sticking is convenient and fixed. The polishing film 3 is stuck on the arc portion at the bottom of the cylinder polishing disc base 2 by a binding agent, and a sticking height ensures that the polishing film 3 is fixedly stuck.

[0098] During installing, the polishing disc connecting rod 11 is pressed into the polishing disc fixing port 21. Preferably, screws 4, which are inner hexagon bolts, are used for fixing, in such a manner that no interval exists therebetween. One side of the polishing film 3 is applied with the binding agent for being stuck on the arc-portion at the bottom of the cylinder polishing disc base 2. Preparation is finished after the binding agent is solidified.

[0099] After installing as above, the polishing film 3 of the polishing device 100 is trimmed. The polishing device 100 is installed on a work piece shaft of a numerical-controlled device, and a trimming grinding wheel 5 is installed on a tool shaft of the numerical-controlled device. A curvature radius of the polishing film 3 is trimmed by point-contacting, in such a manner that the curvature radius of the polishing film 3 is identical, and is same with a curvature radius of the spherical or the planar optical element in value and opposite in direction for improving positioning accuracy and processing accuracy.

[0100] FIG. 5 illustrates polishing a concave element according to the preferred embodiment 1. During utilization, the polishing device 100 is installed on the tool shaft of the numerical-controlled device. The polishing device 100 rotates around an axis of the tool shaft and swings around a swinging center B of the tool shaft; and the polishing device 100 is also movable along a horizontal direction. An unprocessed work piece 6 is installed on the work piece shaft of the numerical-controlled device. The unprocessed work piece 6 rotates around an axis of the work piece shaft and is movable along a vertical direction. During polishing, surface forming parameters of the unprocessed work piece 6 and size parameters of the polishing device 100 are firstly inputted into a processing software, for generating a numerical-controlling file, so as to precisely position the polishing device 100 and the unprocessed work piece 6 by the numerical-controlled device, in such a manner that the polishing device 100 coincides with the unprocessed work piece 6 at any processing position for polishing.

[0101] Preferred embodiment 2:

[0102] FIG. 6 is a sketch view of a polishing device 100 according to the preferred embodiment 2, wherein a tool shank 1 and a cylinder polishing disc base 2 are respectively illustrated in FIGS. 2 and 7. Accordingly, the polishing device 100 comprises: a tool shank 1 for installing a cylinder polishing disc; a cylinder polishing disc base 2 for sticking a polishing film 3; and the polishing film 3 for contacting with an unprocessed work piece 6 (not shown) for polishing. The preferred embodiment 2 is suitable for polishing convex elements, and installation and trimming of the polishing film 3 are the same with the preferred embodiment 1 and will not be described again.

[0103] FIG. 8 illustrates polishing the convex element according to the preferred embodiment 2, and a utilization method thereof is the same as the one of the preferred embodiment 1 and will not be described again.

[0104] Preferred embodiment 3:

[0105] FIG. 9 is a sketch view of a polishing device 100 according to the preferred embodiment 3, wherein a tool shank 1 and a cylinder polishing disc base 2 are respectively illustrated in FIGS. 2 and 10. Accordingly, the polishing device 100 comprises: a tool shank 1 for installing a cylinder polishing disc; a cylinder polishing disc base 2 for sticking a polishing film 3; and the polishing film 3 for contacting with an unprocessed work piece 6 (not shown) for polishing. The preferred embodiment 2 is suitable for polishing planar elements, and installation and trimming of the polishing film 3 are the same with the preferred embodiment 1 and will not be described again. The preferred embodiment 3 is a specific type of the preferred embodiment 1 and 2, which is a special case when curvature radius of the arc portion of the polishing disc base in the preferred embodiment 1 or 2 tends to be infinity.

[0106] FIG. 11 illustrates polishing the convex element according to the preferred embodiment 3, and a utilization method thereof is the same as the one of the preferred embodiment 1 and will not be described again.

[0107] It should be understand that, no matter in the preferred embodiment 1, 2 or 3, a contacting area between the polishing film 3 and the unprocessed work piece 6 is relatively small. Therefore, the polishing film 3 is easy to be worn out, but the polishing device 100 has certain universality, which means that by precisely trimming the curvature radius of the polishing film 3, the polishing device 100 is suitable for polishing elements with different calibers and curvature radius.

[0108] An embodiment 2 of the present invention:

[0109] A line-contacted polishing device for spherical and planar optical elements is provided.

[0110] Preferred embodiment 4:

[0111] Referring to FIG. 12-14, a polishing disc connecting rod 11 is at a bottom of a tool shank 1, which is able to be pressed into a polishing disc fixing port 21 at a top of a profiling polishing disc base 7. During installing, the polishing disc connecting rod 11 is pressed into the polishing disc fixing port 21, and is fixed with the profiling polishing disc base 7, in such a manner that there is no interval between the polishing disc connecting rod 11 and the polishing disc fixing port 21; wherein the tool shank 1 is fixed on the profiling polishing disc base 7 by any spanner type, such as inner triangle, inner rectangle, inner hexagon, and double hole, which not only ensures connecting reliability therebetween, but also is convenient to install and maintain. The profiling polishing disc base 7 is a solid of revolution, and a generating curve thereof is an arc with a curvature radius of r.sub.1. A shape of a profiling polishing disc is suitable for polishing convex elements.

[0112] A polishing film 3 is stuck on an arc portion at a bottom of the profiling polishing disc base 7. The polishing film 3 is selected according to a material of the unprocessed work piece 6. There is no requirement for a shape of the polishing film 3 as long as sticking is convenient and fixed. The polishing film 3 is stuck on a revolution surface of the profiling polishing disc base 7 by a binding agent, and a sticking height ensures that the polishing film 3 is fixedly stuck and covers the whole revolution surface.

[0113] During installing, the polishing disc connecting rod 11 is pressed into the polishing disc fixing port 21. Preferably, screws 4, which are inner hexagon bolts, are used for fixing, in such a manner that no interval exists therebetween. One side of the polishing film 3 is applied with the binding agent for being stuck on the revolution surface of the profiling polishing disc base 7. Preparation is finished after the binding agent is solidified.

[0114] After installing as above, the polishing film 3 of the polishing device 100 is trimmed. FIG. 14 illustrates trimming the polishing film 3 according to the preferred embodiment 4. The polishing device 100 is installed on a work piece shaft (not shown) of a numerical-controlled device, wherein the polishing device 100 rotates around an axis of the tool shaft and swings around a swinging center B of the tool shaft; the polishing device 100 is also movable along a horizontal direction. A trimming grinding wheel 5 is installed on a tool shaft (not shown) of the numerical-controlled device, wherein the unprocessed work piece 6 rotates around an axis of the work piece shaft and is movable along a vertical direction. A curvature radius of the polishing film 3 is trimmed by point-contacting, in such a manner that the curvature radius of the polishing film 3 is identical for improving positioning accuracy and processing accuracy.

[0115] FIG. 15 illustrates polishing a convex element according to the preferred embodiment 4 with the polishing device 100. During utilization, the polishing device 100 is installed on the tool shaft (not shown) of the numerical-controlled device. The polishing device 100 rotates around an axis of the tool shaft and swings around a swinging center B of the tool shaft; and the polishing device 100 is also movable along a horizontal direction. An unprocessed work piece 6 is installed on the work piece shaft of the numerical-controlled device. The unprocessed work piece 6 rotates around an axis of the work piece shaft and is movable along a vertical direction. During polishing, surface forming parameters of an aspheric surface of the unprocessed work piece 6 and size parameters of the polishing device 100 are firstly inputted into a processing software, for generating a numerical-controlling file, so as to controlling the polishing device 100 and the unprocessed work piece 6 by the numerical-controlled device, in such a manner that the polishing device 100 line-contacts with the unprocessed work piece 6 at any processing position, and a contacting trace thereof coincides with a meridian section curve of the unprocessed spherical element.

[0116] Preferred embodiment 5:

[0117] FIG. 17 is a sketch view of a polishing device 100 according to the preferred embodiment 5, wherein a tool shank 1 and a profiling polishing disc base 7 are respectively illustrated in FIGS. 2 and 17. Accordingly, the polishing device 100 comprises: a tool shank 1 for installing a profiling polishing disc; a profiling polishing disc base 7 for sticking a polishing film 3; and the polishing film 3 for contacting with an unprocessed work piece 6 (not shown) for polishing. A shape of the profiling polishing disc base 7 is suitable for polishing concave elements, and installation and trimming of the polishing film 3 are the same with the preferred embodiment 4 and will not be described again.

[0118] FIG. 18 illustrates polishing the concave element according to the preferred embodiment 5, and a utilization method thereof is the same as the one of the preferred embodiment 4 and will not be described again.

[0119] Preferred embodiment 6:

[0120] FIGS. 19 and 20 are sketch views of a polishing device 100 according to the preferred embodiment 6, wherein a tool shank 1 and a cylinder polishing disc base 2 are respectively illustrated in FIGS. 2 and 20. Accordingly, the polishing device 100 comprises: a tool shank 1 for installing a cylinder polishing disc; a cylinder polishing disc base 2 for sticking a polishing film 3; and the polishing film 3 for contacting with an unprocessed work piece 6 (not shown) for polishing. According to the preferred embodiment 6, installation and trimming of the polishing film 3 (shown in FIG. 24) are the same with the preferred embodiment 4 and will not be described again.

[0121] According to the preferred embodiment 6, the cylinder polishing disc base 2 is cylinder-shaped, wherein an advantage of a shape thereof is that polishing discs with same sizes is suitable for polishing work pieces with different calibers and curvature radii. A processing principle thereof is same with the one of grinding, which belongs to profiling processing. A contacting trace of the cylinder polishing disc base 2 and the unprocessed work piece 6 is an envelope circle.

[0122] FIGS. 21, 22 and 23 respectively illustrate polishing a convex element, a concave element and a planar element according to the preferred embodiment 6.

[0123] An embodiment 3 of the present invention:

[0124] Preferred embodiment 7:

[0125] Referring to FIGS. 2, 24 and 25, a polishing disc connecting rod 11 is at a bottom of a tool shank 1, which is able to be pressed into a polishing disc fixing port 21 at a top of a cylinder polishing disc base 2. During installing, the polishing disc connecting rod 11 is pressed into the polishing disc fixing port 21, and is fixed with the cylinder polishing disc base 2, in such a manner that there is no interval between the polishing disc connecting rod 11 and the polishing disc fixing port 21; wherein the tool shank 1 is fixed on the cylinder polishing disc base 2 by any spanner type, such as inner triangle, inner rectangle, inner hexagon, and double hole, which not only ensures connecting reliability therebetween, but also is convenient to install and maintain.

[0126] A polishing film 3 is stuck on an arc portion at a bottom of the cylinder polishing disc base 2. The polishing film 3 is selected according to a material of the unprocessed work piece 6. There is no requirement for a shape of the polishing film 3 as long as sticking is convenient and fixed. The polishing film 3 is stuck on the arc portion at the bottom of the cylinder polishing disc base 2 by a binding agent, and a sticking height ensures that the polishing film 3 is fixedly stuck.

[0127] During installing, the polishing disc connecting rod 11 is pressed into the polishing disc fixing port 21. Preferably, screws 4, which are inner hexagon bolts, are used for fixing, in such a manner that no interval exists therebetween. One side of the polishing film 3 is applied with the binding agent for being stuck on the arc-portion at the bottom of the cylinder polishing disc base 2. Preparation is finished after the binding agent is solidified.

[0128] After installing as above, the polishing film 3 of the polishing device 100 is trimmed. The polishing device 100 is installed on a work piece shaft of a numerical-controlled device, and a trimming grinding wheel 5 is installed on a tool shaft of the numerical-controlled device. A curvature radius of the polishing film 3 is trimmed by point-contacting. If the unprocessed work piece 6 is convex and is to be externally polished, trimming an external arc 31 of the polishing film 3; if the unprocessed work piece 6 is convex and is to be internally polished, trimming an internal arc 32 of the polishing film 3; if the unprocessed work piece 6 is concave, trimming the external arc 31 of the polishing film 3, or trimming the external arc 31 and the internal arc 32 of the polishing film 3. After treatment, the curvature radius of the polishing film 3 is identical, which improves positioning accuracy and processing accuracy.

[0129] FIG. 27 illustrates externally polishing a convex aspheric optical element according to the preferred embodiment 7. During utilization, the polishing device 100 is installed on the tool shaft of the numerical-controlled device. The polishing device 100 rotates around an axis of the tool shaft and swings around a swinging center B of the tool shaft; and the polishing device 100 is also movable along a horizontal direction. An unprocessed work piece 6 is installed on the work piece shaft of the numerical-controlled device. The unprocessed work piece 6 rotates around an axis of the work piece shaft and is movable along a vertical direction. During externally polishing, a P point is at an outer area of the polishing film 3. During polishing, firstly inputting surface forming parameters of an aspheric surface of the unprocessed work piece 6 and size parameters of the polishing device 100 into a processing software, and generating a numerical-controlling file, so as to control the polishing device 100 and the unprocessed work piece 6 by the numerical-controlled device, in such a manner that the polishing device 100 contacts with the unprocessed work piece 6 at the P point of any processing position; wherein the P point coincides with an aspheric meridian section curve relative to a moving trace of the unprocessed work piece 6.

[0130] FIG. 28 illustrates internally polishing the convex aspheric optical element according to the preferred embodiment 7. The P point is at an inner area of the polishing film 3, which is different from externally polishing.

[0131] FIG. 29 illustrates polishing a concave aspheric optical element according to the preferred embodiment 7.

[0132] Preferred embodiment 8: Referring to FIGS. 2 and 30, a polishing device 100 according to the preferred embodiment 8 comprises a tool shank 1 and a spherical polishing disc base 8. The polishing device 1 is same with the one in preferred embodiment 1, and the spherical polishing disc base 8 is illustrated in FIG. 31. The tool shank 1 is for installing the spherical polishing disc base 8; the spherical polishing disc base 8 is for sticking a polishing film 3; and the polishing film 3 is for contacting with an unprocessed work piece 6 (not shown) at a P point for polishing. According to the preferred embodiment 8, installation and trimming of the polishing film 3 are the same with the preferred embodiment 1.

[0133] According to the preferred embodiment 8, the spherical polishing disc base 8 is spherical, whose advantage is that a position range of the P point is larger than the one of the preferred embodiment 7, in such a manner that a linear speed range of the P point is also larger for improving polishing. According to the preferred embodiment 8, a convex element is only able to be externally polished, which is different from the preferred embodiment 7.

[0134] FIGS. 32 and 33 respectively illustrate polishing a convex and a concave aspheric optical element according to the preferred embodiment 8.

[0135] It should be understand that, no matter in the preferred embodiment 7 or 8, a contacting area between the polishing film 3 and the unprocessed work piece 6 is point-contact. Therefore, the P point and nearby areas will be continuously worn out, which will lower processing accuracy. At that moment, a position of the P point on the polishing film 3 may be changed or the polishing film 3 may be trimmed again for regaining the processing accuracy. Preferably, the position of the P point is changed, because by trimming, an arc shape of the polishing film 3 is a standard circle, which means that a distant between the P point and an arc center is certain at any position on the arc. By changing the position of the P point, the polishing film 3 will not be trimmed again and again, which improves a coefficient of utilization thereof. After several changing, the polishing film 3 must be trimmed again for ensuring the process accuracy.

[0136] One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. It will thus be seen that the objects of the present invention have been fully and effectively accomplished. Its embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.