JP2001170852A - Machining method, machining device, tool and die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining method, a machining device, a tool and a die for machining a die for an optical element with high accuracy at a low cost by setting a tool path making starting, a direction change and its end of machining out of an optically effective region. SOLUTION: The machining device 10 has a spherical tool 12 inclined in its rotation axis 11a by a fixed angle for being contacted with the die 13 when machining the die 13 with the tool 12 by moving the tool 12 and the die 13 relatively on the tool path 14 for machining. The tool path 14 has a left upper end position outside a boundary L of the die 13 as a machining starting point Ps for changing a machining direction of the die 13 by the tool 12 at a direction changing position Ph of an optically unnecessary region Ao on both side of the die 13 to finish machining at a finishing position of the optically unnecessary region Ao. Thereby the die 13 does not have a groove 3 formed around the boundary L to be capable of forming a smooth machined face from the optically effective region Ai to the optically unnecessary region Ao with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machining method, a machining apparatus, a tool, and a mold, and more particularly, to a machining method, a machining apparatus, a tool, and a machining method for machining a mold for an optical element with high accuracy. The present invention relates to a method, a processing apparatus, and a mold processed by a tool.

[0002]

2. Description of the Related Art A mold, particularly a mold for an optical element, is required to have high precision, and is manufactured by a machining process such as cutting and polishing, grinding and polishing, cutting only, or grinding only.

[0003] It is generally considered that the starting point, the ending point, and the switching position of the processing direction when processing the die are outside the die or on the die.

If the switching position is outside the mold, the tool comes into contact with the boundary between the outside of the mold and the top of the mold, that is, the outer peripheral edge, and the machining is intermittent.

[0005] However, when the tool comes into contact with the outer peripheral edge, a sharp load is applied to the tool, and the tool is easily damaged by chipping or damage. When the mold is machined with such a damaged tool, there arises a problem that scratches or scratches occur on the machined surface of the workpiece, and a desired shape accuracy cannot be obtained.

Further, when the switching position is on the die, there occurs a phenomenon that the starting point, the ending point, and the switching position of the processing direction are excessively cut. In other words, in the polishing of the mold, the polishing time becomes longer or the number of times of polishing increases at the start and end of the polishing or at the switching position of the processing direction. Therefore, as shown in FIG. The groove 3 due to excessive cutting is formed at the boundary line L of No. 2.

There is a problem that as the removal amount of the excessively cut groove 3 becomes larger as compared with other parts, the range where it can be used effectively becomes smaller.

In view of the above, conventionally, Japanese Patent Application Laid-Open No. 62-246467
As described in Japanese Patent Application Laid-Open Publication No. H10-260, an auxiliary die (jatoy) having the same height as the periphery of the die is fitted around the die, and the start and end of the polishing operation or switching of the processing direction are performed on the auxiliary die. There has been proposed a polishing method for performing the above.

[0009]

However, according to the technology described in the above publication, a pseudo mold is required outside the surface to be processed, and the pseudo mold is almost the same as the original lens mold. Because it is manufactured through the same process,
This is a factor that greatly increases the total processing time of mold production. Furthermore, it is necessary to process the mold and the toy as an integral unit, and almost the same high-precision processing is required for both the mold and the toy. As a result, there is a problem that the machining area increases, the machining time becomes longer, the wear of the tool becomes severe, and furthermore, a toy is required and the production cost is increased.

In view of the above, according to the first aspect of the present invention, a tool which is rotated about a predetermined axis and a mold for an optical element are relatively moved along a predetermined tool path, and the tool is turned on the working surface of the tool. When machining the mold, as a tool path, start machining at a position where the machining action surface of the tool does not contact the outer peripheral edge of the mold, and outside the optically effective area of the mold.
By setting a movement path for switching the processing direction and terminating the processing, processing can be performed in a short time without using a toy, thereby suppressing wear of the tool, and preventing damage to the tool, An object of the present invention is to provide a processing method that can efficiently process a mold with a desired shape accuracy.

According to a second aspect of the present invention, a tool rotated about a predetermined axis and a mold for an optical element are relatively moved along a predetermined tool path, and the mold is moved on a working surface of the tool. At the time of machining, as the tool path, the machining operation surface of the tool does not contact the outer peripheral edge of the mold, and is outside the optically effective area of the mold. By setting the movement path for the end, it is possible to process the tool in a short period of time without using a toy, to suppress wear of the tool, and to prevent damage to the tool, and to achieve efficient with desired shape accuracy. It is an object of the present invention to provide a processing apparatus capable of processing a metal mold.

[0012] The invention according to claim 3 is that, at the start of machining along the tool path, switching of the machining direction, and at the end of machining, the rotation speed of the tool is reduced as compared with that at the time of machining, thereby starting machining, Switching the processing direction and reducing the amount of removal of the mold by the tool at the end of the processing, preventing the optical effective area from being narrowed by excessive cutting outside the effective area of the mold, It is an object of the present invention to provide a processing method or a processing apparatus capable of performing processing with better shape accuracy.

According to a fourth aspect of the present invention, a predetermined load is applied to a tool at the time of machining, and machining is performed. When starting machining along a tool path, switching a machining direction, and ending machining, a load is applied during machining. By reducing the amount of removal of the die by the tool at the start of processing, switching of the processing direction and at the end of processing, the optical effective area is narrowed due to excessive cutting outside the effective area of the die. To prevent
It is an object of the present invention to provide a processing method or a processing apparatus capable of processing a mold with better shape accuracy.

According to a fifth aspect of the present invention, by performing predetermined masking outside the effective area of the mold, the amount of removal of the mold by the tool at the start of processing, switching of the processing direction, and completion of processing is further improved. A processing method or process capable of appropriately reducing the size of the mold with even better shape accuracy by further preventing the optical effective range from being narrowed due to excessive cutting outside the effective range of the mold. It is intended to provide a device.

According to a sixth aspect of the present invention, a tool is provided with an effective area tool portion involved in machining the effective area of the mold and an unnecessary area tool portion involved in machining outside the effective area of the mold. The area tool part is formed of a member having a predetermined sharpness suitable for processing of the effective area, and the unnecessary area tool part is formed of a member having a predetermined amount of sharpness lower than the sharpness of the effective area tool part, The amount of removal of the die by the tool at the start of processing, switching of the processing direction and at the end of processing is more appropriately reduced, and the optical effective area is narrowed due to excessive cutting outside the effective area of the die. It is an object of the present invention to provide a processing method or a processing apparatus capable of processing a die with even better shape accuracy by further preventing the die.

According to a seventh aspect of the present invention, free abrasive grains are used as abrasive grains, and a tool is involved in machining of the effective area of the mold and an outside of the effective area of the mold. Unnecessary area tool part, and the effective area tool part is formed of a member having fine holes or fibers on the surface capable of holding loose abrasive grains,
The unnecessary area tool portion is formed by a member having no fine holes or fibers on its surface capable of holding loose abrasive grains, so that the tool can be used to start machining, switch the machining direction, and finish machining. The removal amount of the mold is more appropriately reduced, the optical effective area is prevented from being narrowed due to excessive shaving outside the effective area of the mold, and the mold is machined with better shape accuracy. It is an object of the present invention to provide a processing method or a processing apparatus that can perform the processing.

According to an eighth aspect of the present invention, when the mold is processed by being relatively moved along a predetermined tool path with a mold for an optical element while being rotated about a predetermined axis.
As a tool path, the start of processing, the switching of the processing direction, and the end of processing are performed at a position where the working surface of the tool does not contact the outer peripheral edge of the mold and outside the effective area of the mold as an optical element. A movement path is set, and an effective area tool part involved in machining of the effective area of the mold and an unnecessary area tool part involved in machining outside the effective area of the mold are provided. It is formed of a member with a predetermined sharpness suitable for
Since the unnecessary area tool portion is formed of a falling member having a predetermined amount of sharpness more than the sharpness of the effective area tool portion, the removal amount of the mold at the start of processing, switching of the processing direction, and at the end of processing. It is an object of the present invention to provide a tool capable of efficiently processing a mold with a desired shape accuracy while reducing wear and damage by performing processing in a short time without using a toy. .

According to the ninth aspect of the present invention, the tool is formed of a member having fine holes or fibers on its surface where the effective area tool portion can hold the free abrasive grains. The unnecessary area tool portion is formed by a member having no fine holes or fibers on the surface capable of holding loose abrasive grains, so that the processing can be started, the switching of the processing direction and the tool at the end of the processing can be performed. The amount of removal of the mold has been reduced more appropriately, and less wear and damage has been achieved without using a toy. It is an object of the present invention to provide a tool capable of processing a mold more efficiently with a desired shape accuracy while further preventing the die.

According to a tenth aspect of the present invention, the tool is formed such that the unnecessary area tool portion is joined to both sides of the effective area tool portion around the effective area tool portion, thereby starting the machining, switching the machining direction and The amount of removal of the mold at the end of processing is reduced more appropriately, and processing is performed in the effective range with high precision while suppressing wear and damage by processing in a short time without using a toy. It is another object of the present invention to provide a tool capable of efficiently processing a mold with desired shape accuracy by preventing the optical effective area from being narrowed due to excessive cutting outside the effective area.

According to an eleventh aspect of the present invention, when the tool is relatively moved along a predetermined tool path with respect to a tool rotated about a predetermined axis and is machined on a machining operation surface of the tool, the tool path is used as a tool path. A movement path for starting machining, switching the machining direction, and ending machining is set at a position where the working surface of the tool does not contact the outer peripheral edge of the mold and outside the optically effective area of the mold. By using a tool, it is possible to form a high-precision optical element that can be efficiently processed with the desired shape accuracy without using a toy and without abrasion or damage to the tool in a short time. The purpose is to provide a mold that can be used.

[0021]

According to a first aspect of the present invention, there is provided a machining method wherein a tool and a mold for an optical element are relatively moved along a predetermined tool path while rotating the tool about a predetermined axis. In the machining method for machining the mold with the machining operation surface of the tool, the machining path of the tool is a position not in contact with an outer peripheral edge of the mold, and the mold is used as the tool path. The above object is achieved by setting a movement path for starting the processing, switching the processing direction, and ending the processing outside the optically effective range of the above.

According to the above arrangement, the tool rotated about a predetermined axis and the mold for the optical element are relatively moved along the predetermined tool path, and the mold is machined on the working surface of the tool. In this case, as a tool path, the working surface of the tool is a position that does not contact the outer peripheral edge of the mold, and
A movement path for starting machining, switching machining direction, and ending machining is set outside the optical effective area of the mold, so machining can be done in a short time without using a toy to reduce tool wear. It is possible to suppress the damage and prevent the tool from being damaged, and it is possible to efficiently process the mold with desired shape accuracy.

According to a second aspect of the present invention, in the processing apparatus, the tool and the mold for an optical element are relatively moved along a predetermined tool path while rotating the tool about a predetermined axis. In a processing apparatus for processing the mold with a working surface, the tool path is a position where the working surface of the tool does not contact an outer peripheral edge of the mold, and the optically effective shape of the mold is used as the tool path. The above object is achieved by setting a movement route for starting the processing, switching the processing direction, and ending the processing outside the region.

According to the above configuration, the tool rotated about a predetermined axis and the mold for the optical element are relatively moved along the predetermined tool path, and the mold is machined on the working surface of the tool. In this case, as a tool path, the working surface of the tool is a position that does not contact the outer peripheral edge of the mold, and
A movement path for starting machining, switching machining direction, and ending machining is set outside the optical effective area of the mold, so machining can be done in a short time without using a toy to reduce tool wear. It is possible to suppress the damage and prevent the tool from being damaged, and it is possible to efficiently process the mold with desired shape accuracy.

In each of the above cases, for example, at the time of starting the machining along the tool path, switching the machining direction, and ending the machining, the rotation speed of the tool is set at The speed may be reduced as compared with the time of processing.

According to the above configuration, at the time of starting machining along the tool path, switching the machining direction, and ending the machining, the rotational speed of the tool is reduced as compared with the time of machining. It is possible to reduce the amount of removal of the mold by the tool at the time of switching the direction and at the end of the processing, and to prevent the optical effective area from being narrowed due to excessive shaving outside the effective area of the mold. Can be processed with even better shape accuracy.

Further, for example, as described in claim 4, during the machining, the machining is performed by applying a predetermined load to the tool, the machining is started along the tool path, and the machining direction is changed. At the time of the switching and the end of the processing, the load may be smaller than that at the time of the processing.

According to the above configuration, a predetermined load is applied to the tool at the time of machining, and machining is performed. At the start of machining along the tool path, switching of the machining direction, and at the end of machining, the load is reduced compared to the time of machining. Because of the reduction, the amount of removal of the mold by the tool at the start of processing, switching of the processing direction and the end of processing can be reduced, and the optical effective area due to excessive cutting outside the effective area of the mold Can be prevented from narrowing, and the mold can be machined with better shape accuracy.

Further, for example, as described in claim 5, a predetermined masking may be performed outside the effective area of the mold.

According to the above configuration, since the predetermined masking is performed outside the effective area of the mold, the amount of removal of the mold by the tool at the time of starting the processing, switching the processing direction, and ending the processing is more appropriate. It is possible to further prevent the optical effective area from being narrowed due to excessive shaving outside the effective area of the mold, and to process the mold with even better shape accuracy.

In addition, for example, as described in claim 6, the tool is involved in machining of the effective area of the mold, and is involved in machining of the mold outside the effective area. Unnecessary area tool part, the effective area tool part is formed of a member having a predetermined sharpness suitable for machining of the effective area, and the unnecessary area tool part is a predetermined amount greater than the sharpness of the effective area tool part. It may be formed of a member with sharpness.

According to the above configuration, the tool is provided with an effective area tool portion involved in machining the effective area of the mold and an unnecessary area tool portion involved in machining outside the effective area of the mold. Since the portion is formed of a member having a predetermined sharpness suitable for machining of the effective area, and the unnecessary area tool portion is formed of a member having a predetermined amount of sharpness lower than the sharpness of the effective area tool portion, the machining is started. In addition, the amount of removal of the mold by the tool at the time of switching the machining direction and at the end of the machining can be more appropriately reduced, and the optical effective area is narrowed due to excessive cutting outside the effective area of the mold. It is possible to process the mold with even better shape accuracy by further preventing the die.

Further, for example, as set forth in claim 7, the processing method or the processing apparatus uses loose abrasive grains as abrasive grains, and the tool is involved in processing the effective area of the mold. An effective area tool part, and an unnecessary area tool part involved in processing outside the effective area of the mold, wherein the effective area tool part has fine holes or fibers on its surface capable of holding the loose abrasive grains. The unnecessary area tool portion may be formed of a member having no fine holes or fibers on its surface capable of holding the loose abrasive grains.

According to the above configuration, free abrasive grains are used as the abrasive grains, and the tool is divided into an effective area tool portion involved in machining the effective area of the mold and an unnecessary area involved in machining outside the effective area of the mold. And a tool part, wherein the effective area tool part is formed of a member having fine holes or fibers that can hold loose abrasive grains on the surface, and the unnecessary area tool part has fine holes or fibers that can hold loose abrasive grains. Because it is assumed to be formed of members that do not exist on the surface,
The amount of removal of the mold by the tool at the start of processing, switching of the processing direction and at the end of processing can be more appropriately reduced, and the optical effective area is narrowed due to excessive cutting outside the effective area of the mold. It is possible to further prevent the die from being deformed and process the mold with a better shape accuracy.

According to a eighth aspect of the present invention, there is provided a tool for processing a mold for an optical element which is relatively moved along a predetermined tool path while being rotated about a predetermined axis. As the tool path, at the position where the working surface of the tool does not contact the outer peripheral edge of the mold, and outside the effective area of the mold as the optical element, start the machining and switch the machining direction. And a movement path for ending the machining is set, an effective area tool part involved in machining the effective area of the mold, and an unnecessary area tool part involved in machining of the mold outside the effective area. The effective area tool portion is formed of a member having a predetermined sharpness suitable for machining of the effective area, and the unnecessary area tool portion is formed of a falling member having a predetermined amount of sharpness than the sharpness of the effective area tool portion. To be Ri, has achieved the above object.

According to the above configuration, the optical element mold is relatively moved along the predetermined tool path while being rotated about the predetermined axis, and when the mold is processed, the tool path is used as a tool path. At a position where the working surface is not in contact with the outer peripheral edge of the mold, and outside the effective area of the mold as an optical element, a movement path for starting the processing, switching the processing direction and ending the processing is set, An effective area tool part involved in machining the effective area of the mold and an unnecessary area tool part involved in machining outside the effective area of the mold, the effective area tool part having a predetermined sharpness suitable for machining the effective area. Since the unnecessary area tool portion is formed by a falling member having a predetermined amount of sharpness greater than the sharpness of the effective area tool portion, the machining is started, the machining direction is switched, and the machining is terminated. Reduces mold removal So that it is, without using the lens holder unit, while suppressing wear and damage by processing in a short time, can be processed efficiently mold a desired shape accuracy.

In this case, for example, as described in claim 9, the tool is used for machining using loose abrasive grains, and the effective area tool portion can hold fine loose holes or fibers capable of holding the loose abrasive grains. May be formed of a member present on the surface, and the unnecessary area tool portion may be formed of a member having no fine holes or fibers capable of holding the loose abrasive grains on the surface.

According to the above construction, the tool used for machining using the free abrasive grains is formed by a member in which the effective area tool portion has fine holes or fibers on the surface capable of holding the free abrasive grains. Since the tool portion is formed of a member having no fine holes or fibers on the surface capable of holding loose abrasive grains, the tool is used to start the machining, switch the machining direction, and finish the machining with the tool. The removal amount can be reduced more appropriately, the wear and damage are less likely to occur without using a toy, and the optical effective area is narrowed due to excessive shaving outside the effective area of the mold. The mold can be more efficiently processed with a desired shape accuracy while further preventing the die.

Further, for example, in the tool, the unnecessary area tool part may be joined to both sides of the tool centering on the effective area tool part.

According to the above configuration, the tool is configured such that the unnecessary area tool part is joined to both sides of the effective area tool part with the center as the center, so that the processing is started, the processing direction is switched, and the processing is ended. In this case, the amount of removal of the mold can be reduced more appropriately, and processing can be performed in a short period of time without using a toy, and processing in the effective area can be performed with high accuracy while suppressing wear and tear. In addition to this, it is possible to prevent the optical effective area from being narrowed by excessive shaving outside the effective area, and to efficiently process the mold with desired shape accuracy.

According to a twelfth aspect of the present invention, there is provided an optical tool which is relatively moved along a predetermined tool path with respect to a tool which is rotated about a predetermined axis, and is processed on a working surface of the tool. In the mold for an element, as the tool path, a position where the working surface of the tool is not in contact with the outer peripheral edge of the mold, and the start of the machining outside the optically effective area of the mold. The above object is achieved by performing the processing by setting a moving path for switching the processing direction and ending the processing.

According to the above arrangement, when the tool is relatively moved along a predetermined tool path with respect to a tool rotated about a predetermined axis and is machined on the working surface of the tool, the tool path is defined as a tool path. Processing is performed by setting a movement path for starting processing, switching a processing direction, and ending processing, at a position where the working surface does not contact the outer peripheral edge of the mold and outside the optically effective area of the mold. As a result, it is possible to prevent the tool from being worn or damaged in a short period of time without using a toy, and to efficiently process with the desired shape accuracy, and to achieve high-precision optics. The element can be molded.

[0043]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. It should be noted that the embodiments described below are preferred embodiments of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description. The embodiments are not limited to these embodiments unless otherwise specified.

FIGS. 1 to 3 are views showing a first embodiment of a processing method, a processing apparatus, a tool and a mold according to the present invention.
FIG. 1 is a front view of a main part of a processing apparatus 10 to which a first embodiment of a processing method, a processing apparatus, a tool, and a mold according to the present invention is applied.

In FIG. 1, a processing apparatus 10 includes a motor 1
A tool 12 is attached to the tip of one rotating shaft 11a, and the tool 12 is, for example, a spherical grinding wheel. The motor 11 drives the tool 12 to rotate around a rotation axis 11a thereof at a predetermined rotation speed.

The tool 12 is, for example, a grindstone having a particle size
A grinding wheel using 8000 diamond abrasive grains is used.

The processing apparatus 10 adjusts the relative position between the tool 12 and a mold 13 to be machined set on a table (not shown) while rotating the mold 13 with the rotating tool 12.
To process.

The mold 13 is used for producing an optical element such as a resin lens or a mirror, and the optical surface of the optical element is usually an optically effective area (optically effective area) in one plane. It is designed and manufactured by setting the optically unnecessary area outside of it. This is because when forming an optical surface by molding a resin, it is difficult to ensure accuracy up to the contour ridge of the optical surface.

Therefore, the mold 13 for producing the optical element
In FIG. 2, there is a region serving as an optically effective region and an optically unnecessary region of the optical element. For example, in FIG. The effective area Ai, and the area outside the boundary line L is the optically unnecessary area Ao.

Next, the operation of the present embodiment will be described. When processing the die 13 with the tool 12, the processing device 10 is located at a position where the processing action portion of the tool 12 does not contact the outer peripheral edge of the die 13, and outside the optically effective area Ai, that is, In the optically unnecessary area Ao, processing is performed by starting and ending the processing of the mold 13 by the tool 12 and switching the processing direction. That is, when the processing of the mold 13 is performed by the tool 12, The tool 12 is brought into contact with the mold 13 with its rotating shaft 11a inclined at a predetermined angle, and the tool 12 and the mold 13 are relatively moved by a tool path 14 shown by a broken line in FIG. Process at 12.

As shown in FIG. 2, the tool path 14 is formed by, for example, machining the mold 13 with the tool 12 by setting the upper left position of the mold 13 outside the boundary line L in FIG. Is started, and the machining direction of the mold 13 is switched by the tool 12 at the direction switching position Ph located outside the boundary line L in FIG. 2 on both sides of the mold 13 in the optically unnecessary area Ao.

That is, the machining of the mold 13 by the tool 12 is started in the width direction of the mold 13 from the machining start position Ps,
When processing is performed to the direction switching position Ph which is the optically unnecessary area Ao on the right side outside the boundary line L, the tool 12 and the mold 13
Is changed to the vertical direction to switch the machining direction, and the relative position of the tool 12 and the mold 13 is moved in the vertical direction by a predetermined pitch, and the position is changed to the direction switching position P.
As h, the relative movement direction of the tool 12 and the mold 13 is changed in the width direction, and the machining of the mold 13 by the tool 12 is performed again.

When processing is performed by the tool 12 to the direction switching position Ph which is the optically unnecessary area Ao on the left side of the mold 13 with the tool 12, the relative movement direction of the tool 12 and the mold 13 is changed to the vertical direction. The relative position between the tool 12 and the mold 13 is moved in the vertical direction by a predetermined pitch in the vertical direction, and the relative position in the relative movement direction between the tool 12 and the mold 13 is set as the direction switching position Ph. Change the direction, and again
Processing of the mold 13 by 2 is performed.

The relative movement between the tool 12 and the mold 13 is shown in FIG.
When the relative position between the tool 12 and the mold 13 reaches the machining end position Po, the machining is finished.

As described above, when the tool 12 moves on the processing surface of the mold 13, the tool 12 moves as a tool path 14 at a position not in contact with the outer peripheral edge of the mold 13.

As described above, the processing apparatus 10 of the present embodiment
When machining the mold 13 with the tool 12,
Is a position where the outer peripheral edge of the mold 13 is not in contact with the mold 13 and the start, end, and
Alternatively, the processing direction is switched in the optically unnecessary area Ao outside the optically effective area Ai.

Therefore, unlike the mold 1 machined by the conventional machining apparatus shown in FIG. 4, the mold 13 is not formed with the groove 3 near the boundary line L, as shown in FIG. From the optically effective area Ai to the optically unnecessary area Ao across the boundary line L
A highly smooth processed surface can be formed with high precision.

When the mold 13 is machined, the machining apparatus 10 controls the rotation speed of the tool 12 in the optically effective area Ai.
The optically effective area Ai is controlled to the optimum rotational speed for obtaining a desired processing accuracy, for example, 2500 rpm, and in the optically unnecessary area Ao, the relationship between the rotational speed and the removal depth is experimentally obtained, for example, the rotational speed. , 300 rpm.

The number of revolutions of the tool 12 is determined by the optical effective area A
When the tool 12 moves from i to the optically unnecessary area Ao, the rotational speed of the optically effective area Ai cannot be suddenly switched from the rotational speed of the optically unnecessary area Ao to the optically effective area Ao. From the optically unnecessary area Ao to the optically unnecessary area Ao, or the tool 12 moves from the optically unnecessary area Ao to the optically effective area Ao.
Prior to moving to i, the transition is made quickly and continuously in the optically unnecessary area Ao. The switching of the rotation speed of the tool 12 is performed by changing the processing start position Ps and the direction switching position Ph.
And at the processing end position Po.

In this manner, the mold 1 by the tool 12 at the start of machining, switching of the machining direction, and the end of machining.
3 can be reduced, and the optical effective area Ai is prevented from being narrowed due to excessive shaving of the mold 13 in the optically unnecessary area Ao, and the mold 13 can be formed with better shape accuracy. Can be processed.

Further, when a spherical tool 12 as in the present embodiment is used as the tool 12 and as shown in FIG. Of these, the convergence of the part involved in processing the left area of FIG. 1 is greater than the convergence of the part involved in processing the right area.

Therefore, if the rotation speed of the tool 12 is controlled so that such a difference in convergence of the parts involved in the processing of the tool 12 does not occur on the entire surface of the mold 13, the mold 13 can be more precisely controlled. Processing can be performed.

In this case, for example, the number of revolutions for machining the right optical unnecessary area Ao is set slightly faster than the number of revolutions of the tool 12 for machining the left optical unnecessary area Ao in FIG. Then, the influence of the convergence difference of the tool 12 used inclining can be suppressed.

In the processing of the mold 13, the processing device 10 may perform processing by applying a predetermined load to the tool 12 in the vertical direction by a load applying mechanism (not shown).

In this case, in the optically effective area Ai,
By the load applying mechanism, the optical effective area Ai is controlled to a load optimal for obtaining a desired processing accuracy, for example, 100 gf. In the optically unnecessary area Ao, the load obtained by experimentally determining the relationship between the load and the removal depth is measured. , For example, 50 gf.

As a method of setting the load, for example, the load can be set using Preston's rule of thumb generally known. Preston's rule of thumb is:
The polishing amount h is calculated by the following equation (1) from a constant p based on a metal material or a tool, a polishing pressure v, a relative speed between the mold 13 and the tool 12, and a polishing time (polishing times).

H = k × p × v × t (1) The switching of the load may be performed on the boundary line L.

As described above, the load applying mechanism controls the optical effective area Ai in the optical effective area Ai to the optimum load for obtaining a desired processing accuracy, and the optical unnecessary area Ao sets the removal depth for the load. When the mold 13 is processed by controlling the relationship of the height to the load obtained by the experiment, the mold 13 is moved to the position shown in FIG.
As shown in FIG. 3, the groove 3 is not formed near the boundary line L as in the mold 1 processed by the conventional processing apparatus shown in FIG. A smoother processed surface can be formed with high precision from Ai to the optically unnecessary area Ao.

Further, when the mold 13 is processed by the processing apparatus 10, a predetermined area of the optically unnecessary area Ao, for example, all areas of the optically unnecessary area Ao with the boundary line L as a boundary are masked with a predetermined magic ink. Or optically unnecessary area A
o, the optically unnecessary area Ao outside the processing start position Ps, the direction switching position Ph, and the processing end position Po
May be masked with a predetermined magic ink.

As the magic ink, any ink can be used as long as it reduces the amount of processing by the tool 12 of the mold 13 and does not adversely affect the processing in the optically effective area Ai and can be easily removed after processing. can do.

As described above, by masking the optically unnecessary area Ao with the magic ink, the removal amount of the mold 13 by the tool 12 in the optically unnecessary area Ao can be further reduced. Unlike the mold 1 processed by the conventional processing apparatus shown in FIG. 4, the groove 3 is not formed near the boundary line L, and as shown in FIG. From the effective area Ai to the optically unnecessary area Ao, a smoother processed surface can be formed with high precision.

The control of the number of revolutions of the tool 12, the application of a load to the tool 12, and the masking of the optically unnecessary area Ao with magic ink may be performed by two methods or by a combination of all methods. .

<Experimental Example 1> The mold 13 was ground by using the same processing apparatus 10 as in the first embodiment.
As the tool 12, a spherical grinding wheel is used.
The one using diamond abrasive grains having a particle size of ♯8000 was used.

Using the tool 12, the rotating shaft 11a of the motor 11 (the rotating shaft of the tool 12) is inclined by a predetermined angle, and the mold 13 is moved by the tool path 14 as shown in FIG. 13 was relatively moved to perform grinding.
At this time, the rotation speed of the tool 12 is 2500 rpm in the optically effective area Ai, and 30 in the optically unnecessary area Ao.
It was set to 0 rpm. The switching of the rotation speed of the tool 12 was continuously performed at the processing start position Ps, the direction switching position Ph, and the processing end position Po.

As a result of this experiment, as shown in FIG. 3, no groove was formed near the boundary line L, and the mold 13 was not optically required from the optically effective area Ai. Smooth, high-precision grinding could be performed on the region Ao.

<Experimental Example 2> The mold 13 was ground by using the same processing apparatus 10 as in the first embodiment.
As the tool 12, spherical polyurethane foam capable of holding free abrasive grains was used, and as the abrasive grains, fine diamond powder having a particle diameter of 2 μm or less, which is free abrasive grains, was used.

Using this tool 12, the rotating shaft 11a of the motor 11 (the rotating shaft of the tool 12) is inclined at a predetermined angle, and the mold 13 is moved by the tool path 14 as shown in FIG. 13 was relatively moved to perform grinding.

At this time, machining was performed by applying a predetermined load to the tool 12 in the vertical direction by the load applying mechanism.

The load to be applied is the optically effective area Ai
, 100 gf is added to the optically effective area Ai as an optimal load for obtaining desired processing accuracy. In the optically unnecessary area Ao, particularly, the processing start position Ps, the direction switching position Ph, and the processing end position Po Then, 50 gf, which is the load determined by the above equation (1), was added.

As a result of this experiment, as shown in FIG. 3, no groove was formed near the boundary line L, and the optical mold 13 was not optically required from the optically effective area Ai without using a die. Smooth, high-precision grinding could be performed on the region Ao.

<Experimental Example 3> Grinding of the mold 13 was performed using the same processing apparatus 10 as in the first embodiment.
As the tool 12, spherical polyurethane foam capable of holding free abrasive grains was used, and as abrasive grains, fine diamond powder having a particle diameter of 1 μm or less, which is free abrasive grains, was used.

Further, the boundary line L of the mold 13 to be ground is
The entire area of the optically unnecessary area Ao from the boundary was masked with the above-mentioned magic ink.

Then, using the tool 12, the rotating shaft 11a of the motor 11 (the rotating shaft of the tool 12) is inclined at a predetermined angle, and the mold 13 masked with the above-mentioned magic ink is used as a tool path 14 as shown in FIG. Tool 12 and mold 13
Was relatively moved to perform grinding. Mold 13 with tool 12 in optically unnecessary area Ao by magic ink
Could be reduced.

As a result of this experiment, as shown in FIG. 3, no groove was formed near the boundary line L, and the mold 13 was not optically required from the optically effective area Ai. Smooth, high-precision grinding could be performed on the region Ao.

FIG. 4 is a view showing a processing method, a processing apparatus, a tool and a mold according to a second embodiment of the present invention.
The second of the processing method, processing apparatus, tool and mold of the present invention
It is a principal part front view of the processing apparatus 20 to which Embodiment 1 is applied.

In FIG. 4, the processing device 20 includes a motor 2
A tool 22 is attached to the tip of one rotating shaft 21a, and the tool 22 is, for example, a tire-shaped grinding wheel. The motor 21 moves the tool 22 to its rotating shaft 21.
It is rotationally driven at a predetermined rotational speed around a. The tool 22 is not limited to a tie or a shape, and may be, for example, a sphere.

The processing apparatus 20 adjusts the relative position between the tool 22 and the mold 13 similar to that of the first embodiment, which is a processing object set on a table (not shown), by the rotating tool 22. The mold 13 is processed.

The mold 13 is used as a mold for producing optical elements such as a resin lens and a mirror, as in the first embodiment, and as shown in FIG. An area Ai and an optically unnecessary area Ao exist, and the boundary between them is a boundary line L.

The tool 22 is disposed so that the rotating shaft 21a of the motor 21, which is the tool axis thereof, is substantially parallel to the machining surface of the mold 13. In this state,
The tool 22 has an effective area tool part 22a involved in machining of the mold 13 in the optically effective area Ai and an unnecessary area tool part 22b involved in machining of the mold 13 in the optically unnecessary area Ao. are doing.

The tool 22 has an effective area tool portion 22a.
However, it is formed of a sharpening stone suitable for polishing the optically effective area Ai, for example, a grinding stone having a concentration of abrasive grains of 100 (volume ratio of abrasive grains is 25 vol%). The part 22b has a sharpness of a predetermined amount less than the sharpness of the effective area tool part 22a, for example, the degree of concentration of abrasive grains is 2
It is formed with a grinding stone of 0 (volume ratio of abrasive grains is 5 vol%). The tool 22 includes an unnecessary area tool part 22b on both sides of the effective area tool part 22a with the effective area tool part 22a interposed therebetween.
Are formed in a joined state.

The tool 22 determines the joining position of the effective area tool part 22a and the unnecessary area tool part 22b at the position where the optical unnecessary area Ao of the mold 13 and the unnecessary area tool part 22b of the tool 22 coincide, that is, the boundary. It is formed at a position corresponding to the line L. In addition, the joining position of the effective area tool part 22a and the unnecessary area tool part 22b is not limited to the one set at the position coinciding with the boundary line L, and may be changed as appropriate.

Next, the operation of the present embodiment will be described. The processing device 20 includes a tool 2 as in the first embodiment.
When machining the mold 13 with the tool 2, the tool 2 is located at a position where the tool 22 does not contact the outer peripheral edge of the mold 13 and outside the optically effective area Ai, that is, at the optically unnecessary area Ao.
2 to start and end the processing of the mold 13 or switch the processing direction to perform processing, that is, the processing apparatus 2
0, when processing the mold 13 with the tool 22, the tire-shaped tool 22 is brought into contact with the mold 13 with the rotation axis 11 a of the tire 22 being substantially parallel to the processing surface of the mold 13, and FIG. The tool 13 is machined by the tool 22 by relatively moving the tool 22 and the mold 13 in a plane direction (a direction perpendicular to the circumferential direction) of the tire-shaped tool 22 by a tool path 14 indicated by a broken line.

More specifically, machining of the mold 13 by the tool 22 is started from the machining start position Ps in the width direction of the mold 13 and is directed to the right side of the optically unnecessary area Ao outside the boundary line L. When the machining is performed up to the switching position Ph, the relative movement direction of the tool 22 and the mold 13 is changed to the vertical direction to switch the machining direction, and the relative movement of the tool 22 and the mold 13 is vertically shifted by a predetermined pitch. The position is moved, the position is set as the direction switching position Ph, the relative movement direction of the tool 22 and the mold 13 is changed in the width direction, and the machining of the mold 13 by the tool 22 is performed again.

When the tool 22 performs machining to the direction switching position Ph which is the optically unnecessary area Ao on the left side of the mold 13, the tool 2
When the relative movement direction of the tool 2 and the mold 13 is changed to the vertical direction and the processing direction is switched, and the relative position of the tool 22 and the mold 13 is moved in the vertical direction by a predetermined pitch, the position is changed to the direction. The relative movement direction of the tool 22 and the mold 13 is changed in the width direction as the switching position Ph, and the machining of the mold 13 by the tool 22 is performed again.

The relative movement between the tool 22 and the mold 13 is shown in FIG.
The tool 13 is sequentially machined by the tool 22 along the tool path 14 shown in (1). When the relative position between the tool 22 and the mold 13 reaches the machining end position Po, the machining is finished.

Then, as described above, the tool 22 is located between the effective area tool part 22a and the effective area tool part 22a.
The unnecessary area tool portion 22b is formed in a state where the unnecessary area tool portion 22b is joined to both sides of the optical effective area A.
i is formed of a grindstone having a sharpness suitable for polishing, for example, a grindstone having an abrasive concentration of 100, and the unnecessary area tool portion 22b is sharper than the effective area tool portion 22a by a predetermined amount. Grinding stones, for example, the concentration of abrasive grains is 2
It is formed with a 0 whetstone. Further, when the tool 22 moves on the processing surface of the mold 13, the tool 22 moves as a tool path 14 at a position that does not contact the outer peripheral edge of the mold 13.

Therefore, unlike the mold 1 machined by the conventional machining apparatus shown in FIG. 4, the mold 13 is not formed with the groove 3 near the boundary line L, as shown in FIG. From the optically effective area Ai to the optically unnecessary area A across the boundary line L.
It is possible to form a smooth machined surface with a high degree of accuracy and to further reduce the amount of removal of the machining of the optically unnecessary area Ao.

In this embodiment, the tool 22
For example, the effective area tool portion 22a is formed of foamed polyurethane capable of holding free abrasive grains, and the unnecessary area tool portion 22b is made of non-foamed material that does not hold free abrasive grains. Formed with polyurethane,
The effective area tool portion 22a and the unnecessary area tool portion 22b may be joined together, and, for example, diamond powder having a particle size of 2 μm or less may be used as abrasive grains.

<Experimental Example 4> The die 13 was ground by using the same processing apparatus 20 as in the second embodiment.
As the tool 22, a tire-shaped grinding wheel is used, and as the grinding wheel, diamond abrasive grains having a particle size of ０００8000 are used.
A grindstone in which the unnecessary area tool portion 22b has a concentration of abrasive grains of 20 was used.

By using this tool 22, the rotating shaft 11a of the motor 11 is made substantially parallel to the machining surface of the
Was ground by moving the tool 22 and the mold 13 relative to each other in the tool path 14 as shown in FIG.

As a result of this experiment, the amount of removal of the mold 13 by the tool 22 in the optically unnecessary area Ao can be reduced, and the mold 13 can be removed without using a toy as shown in FIG. Thus, smooth high-precision grinding from the optically effective area Ai to the optically unnecessary area Ao could be performed without forming a groove near the boundary line L.

<Experimental Example 5> Grinding of the mold 13 was performed by using the same processing apparatus 20 as in the second embodiment.
As the tool 22, a tire-shaped tool is used.
The effective area tool portion 22a is formed of polyurethane foam,
The unnecessary area tool part 22b is formed of non-foamed polyurethane,
Diamond powder having a particle diameter of 2 μm or less may be used as the abrasive.

Using the tool 22, the rotating shaft 11a of the motor 11 (the rotating shaft of the tool 12) is substantially parallel to the processing surface of the mold 13, and the mold 13 is moved to the tool path 14 as shown in FIG. Then, the tool 22 and the mold 13 were relatively moved to perform a grinding process.

As a result of this experiment, the removal amount of the mold 13 by the tool 22 in the optically unnecessary area Ao can be reduced, and the mold 13 can be removed without using a toy as shown in FIG. Thus, smooth high-precision grinding from the optically effective area Ai to the optically unnecessary area Ao could be performed without forming a groove near the boundary line L.

The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to the above, and various modifications can be made without departing from the gist of the invention. It goes without saying that it is possible.

[0106]

According to the working method of the present invention, the tool rotated about a predetermined axis and the mold for the optical element are relatively moved along a predetermined tool path, and When processing the mold with the working surface, as a tool path, the working surface of the tool is at a position where it does not contact the outer peripheral edge of the mold, and outside the optical effective area of the mold,
Since the movement path for starting the processing, switching the processing direction, and ending the processing is set, the processing is performed in a short time without using a toy, thereby suppressing tool wear and damaging the tool. Therefore, it is possible to efficiently process the mold with a desired shape accuracy.

According to the processing apparatus of the second aspect,
When a tool rotated around a predetermined axis and a mold for an optical element are relatively moved along a predetermined tool path to machine the mold on the working surface of the tool, the tool path is used as a tool path. Since the working surface is located at a position where it does not contact the outer peripheral edge of the mold and is outside the optically effective area of the mold, a movement path for starting the processing, switching the processing direction, and ending the processing is set. Without using yatoys,
The processing can be performed in a short time to suppress wear of the tool, prevent the tool from being damaged, and efficiently process the mold with a desired shape accuracy.

According to the machining method or the machining apparatus according to the third aspect of the present invention, when starting machining along the tool path, switching the machining direction, and ending the machining, the rotational speed of the tool is reduced as compared with the machining. The amount of removal of the die by the tool at the start of processing, switching of the processing direction and the end of processing can be reduced, and the optical effective area is reduced due to excessive cutting outside the effective area of the mold. By preventing the mold from becoming narrow, the mold can be machined with better shape accuracy.

According to the machining method or the machining apparatus of the invention, the machining is performed by applying a predetermined load to the tool at the time of machining, starting machining along the tool path, switching the machining direction, and machining. Since the load is reduced at the end of the machining, the amount of removal of the mold by the tool at the start of machining, switching of the machining direction and at the end of machining can be reduced, and the outside of the effective area of the mold can be reduced. It is possible to prevent the optical effective area from being narrowed by excessive shaving, thereby processing the mold with even better shape accuracy.

According to the machining method or the machining apparatus according to the fifth aspect of the present invention, since the predetermined masking is performed outside the effective area of the mold, the tool is used at the time of starting the machining, switching the machining direction, and ending the machining. The amount of removal of the mold by the can be more appropriately reduced, further preventing that the optical effective area is narrowed by excessive shaving outside the effective area of the mold,
The mold can be processed with better shape accuracy.

According to the machining method or the machining apparatus of the invention described in claim 6, the tool is provided with an effective area tool portion involved in machining the effective area of the mold and an unnecessary area involved in machining outside the effective area of the mold. A tool part, and the effective area tool part is formed of a member having a predetermined sharpness suitable for processing of the effective area, and the unnecessary area tool part is formed of a member that is less sharp by a predetermined amount than the sharpness of the effective area tool part. Therefore, the amount of removal of the die by the tool at the start of processing, switching of the processing direction and at the end of processing can be more appropriately reduced, and excessive cutting outside the effective area of the die can be performed. It is possible to further prevent the optically effective area from being narrowed, and to process the mold with better shape accuracy.

According to the processing method or the processing apparatus of the invention described in claim 7, free abrasive grains are used as abrasive grains, and a tool is used.
An effective area tool part involved in machining the effective area of the mold, and an unnecessary area tool part involved in machining outside the effective area of the mold, and the effective area tool part has fine holes or holes that can hold loose abrasive grains. Since the fiber is formed by the member on the surface and the unnecessary area tool part is formed by the fine hole capable of holding the loose abrasive or the member without the fiber on the surface, the processing is started and the processing direction is switched. And the amount of removal of the mold by the tool at the end of processing can be more appropriately reduced, and it is further prevented that the optical effective area is narrowed by excessive cutting outside the effective area of the mold. In addition, the mold can be processed with better shape accuracy.

According to the tool of the present invention, when the mold is processed by being relatively moved along the predetermined tool path with the mold for the optical element while being rotated about the predetermined axis, As a tool path, the start of processing, the switching of the processing direction, and the end of processing are performed at a position where the working surface of the tool does not contact the outer peripheral edge of the mold and outside the effective area of the mold as an optical element. The travel route is set,
An effective area tool part involved in machining the effective area of the mold and an unnecessary area tool part involved in machining outside the effective area of the mold, the effective area tool part having a predetermined sharpness suitable for machining the effective area. Since the unnecessary area tool portion is formed by a falling member having a predetermined amount of sharpness greater than the sharpness of the effective area tool portion, the machining is started, the machining direction is switched, and the machining is terminated. The amount of mold removal can be reduced,
It is possible to efficiently process the mold with a desired shape accuracy while suppressing wear and damage by performing processing in a short time without using a toy.

According to the tool of the ninth aspect, the tool is used for machining using free abrasive grains, and the effective area tool portion is a member having fine holes or fibers on its surface capable of holding free abrasive grains. Since the formed and unnecessary area tool portion is formed of a member having no fine holes or fibers on the surface capable of holding loose abrasive grains, the tool at the start of processing, switching of the processing direction and the end of processing Can reduce the amount of mold removal more appropriately, reduce wear and damage without using a toy, and reduce the optical effective area by cutting too much outside the effective area of the mold It is possible to process the mold more efficiently with a desired shape accuracy while further preventing the die from forming.

According to the tool of the tenth aspect, the tool is
Unnecessary tool parts are assumed to be joined to both sides of the effective area tool part, so the amount of mold removal at the start of processing, switching of the processing direction and the end of processing is more appropriate It is possible to perform machining in the effective range with high precision while suppressing wear and damage by processing in a short time without using a toy, and using too much cutting outside the effective range. The mold can be efficiently processed with desired shape accuracy by preventing the optical effective area from becoming narrow.

According to the eleventh aspect of the present invention, when the tool is relatively moved along a predetermined tool path with respect to a tool rotated about a predetermined axis to perform machining on a machining operation surface of the tool. As a tool path, the start of the processing, the switching of the processing direction, and the end of the processing are performed at a position where the working surface of the tool does not contact the outer peripheral edge of the mold and outside the optically effective area of the mold. Since the machining is performed by setting the movement path, it is possible to prevent the tool from being worn or damaged by machining in a short time without using a toy, and efficiently with the desired shape accuracy. It can be processed to form a highly accurate optical element.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of a processing apparatus to which a first embodiment of a processing method, a processing apparatus, a tool, and a mold according to the present invention is applied.

FIG. 2 is a plan view of a mold showing a tool path and an optically effective area and an optically unnecessary area of the tool of FIG. 1;

FIG. 3 is a front sectional view of a mold ground by the processing apparatus of FIG. 1;

FIG. 4 is a main part front view of a processing apparatus to which a processing method, a processing apparatus, a tool, and a mold according to a second embodiment of the present invention are applied.

FIG. 5 is a front sectional view of a mold polished by a conventional processing apparatus.

[Explanation of symbols]

 Reference Signs List 10 processing device 11 motor 11a rotation axis 12 tool 13 mold 14 tool path Ai optically effective area Ao optically unnecessary area Ps processing start position Ph direction switching position Po processing end position 20 processing device 21 motor 21a rotating shaft 22 tool 22a effective Area tool part 22b Unnecessary area tool part

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 3C049 AA03 AA07 AA11 AA16 CA02 CB01 3C058 AA07 AA09 AA11 BA02 BA04 BA05 BA07 BA09 BB06 CA01 CA03 CB01 CB05

Claims (11)

[Claims] 1. A tool and a mold for an optical element are relatively moved along a predetermined tool path while rotating the tool about a predetermined axis, and the mold is machined on the working surface of the tool. In the machining method, as the tool path, the machining action surface of the tool is a position that does not contact the outer peripheral edge of the mold, and outside the optically effective area of the mold,
A processing method, comprising setting a movement path for starting the processing, switching the processing direction, and ending the processing. 2. The method according to claim 1, wherein the tool and the mold for the optical element are relatively moved along a predetermined tool path while rotating the tool about a predetermined axis. In the processing device to perform, as the tool path,
The start of the machining, the switching of the machining direction, and the end of the machining are performed at a position where the working surface of the tool does not contact the outer peripheral edge of the mold and outside the optically effective area of the mold. A processing device for setting a movement route. 3. The method according to claim 1, wherein at the start of the machining along the tool path, at the switching of the machining direction and at the end of the machining, the rotational speed of the tool is reduced as compared with the machining. The processing method according to claim 1 or the processing apparatus according to claim 2. 4. The method according to claim 1, wherein said processing is performed by applying a predetermined load to said tool during said processing, and said load is changed at the start of said processing along said tool path, switching of said processing direction and ending of said processing. The processing method or the processing apparatus according to any one of claims 1 to 3, wherein the processing method or the processing apparatus is reduced from the processing time. 5. The processing method or apparatus according to claim 1, wherein predetermined masking is performed outside the effective area of the mold. 6. The tool according to claim 1, further comprising: an effective area tool portion involved in machining the effective area of the mold, and an unnecessary area tool portion involved in machining the mold outside the effective area. The area tool part is formed of a member having a predetermined sharpness suitable for machining of the effective area, and the unnecessary area tool part is formed of a member that is less sharp by a predetermined amount than the sharpness of the effective area tool part. The processing method or the processing apparatus according to claim 1, wherein the processing method or the processing apparatus includes: 7. The processing method or the processing apparatus uses loose abrasive grains as abrasive grains, and the tool includes an effective area tool part involved in processing the effective area of the mold, An unnecessary area tool part involved in machining outside the effective area,
The effective area tool portion is formed of a member having fine holes or fibers on the surface capable of holding the loose abrasive grains, and the unnecessary area tool section has fine holes or fibers capable of holding the free abrasive grains on the surface. The processing method or the processing apparatus according to any one of claims 1 to 5, wherein the processing method or the processing apparatus is formed of a member that is not used. 8. A tool for processing the mold by rotating relative to a mold for an optical element along a predetermined tool path while being rotated about a predetermined axis, wherein the tool path is used as the tool path. Movement for starting the processing, switching the processing direction, and ending the processing outside the effective area of the mold as the optical element, where the working surface does not contact the outer peripheral edge of the mold. A path is set, an effective area tool part involved in machining of the effective area of the mold, and an unnecessary area tool part involved in machining of the mold outside the effective area, wherein the effective area tool part is provided. A tool formed of a member having a predetermined sharpness suitable for machining of the effective area, and the unnecessary area tool portion being formed of a falling member having a predetermined amount of sharpness more than the sharpness of the effective area tool portion. . 9. The tool according to claim 1, wherein said tool is used for processing using loose abrasive grains, and said effective area tool portion is formed of a member having fine holes or fibers on its surface capable of holding said loose abrasive grains, and said unnecessary area. 9. The tool according to claim 8, wherein the area tool portion is formed of a member having no fine holes or fibers capable of holding the loose abrasive grains on the surface. 10. The tool according to claim 8, wherein the unnecessary area tool part is joined to both sides of the tool centering on the effective area tool part. 11. A mold for an optical element which is relatively moved along a predetermined tool path with respect to a tool rotated about a predetermined axis and is machined on a working surface of the tool. As a path, a position where the working surface of the tool does not contact the outer peripheral edge of the mold, and
A mold, wherein a movement path for starting the machining, switching the machining direction, and ending the machining is set outside the optically effective area of the mold, and the machining is performed.