JPS6284964A - lens polishing equipment - Google Patents

Abstract

PURPOSE:To make it possible to obtain a lens having a highly qualified polished surface with less machining distortion, by constituting a drive source with a windmill device having a swingable tool shaft so that the lens is polished in a contactless condition. CONSTITUTION:When an air pump 9 is operated to increase the flow rate of air exceeding a predetermined rate, a lifting force is effected at an impeller 7 so that a polishing tool 2a on rotation floats up. The degree of such float-up is detected by a contactless displacement sensor 13 and is delivered to a displacement detecting and controlling device 14 which therefore, controls the control valve 12 in accordance with the delivered signal to adjust the degree of float up of the tool 2a. Thus, it is possible to polish a lens 1 with the use of the fluid motion of an abrasive material in association with the rotation of the polishing tool 2a which are held spaced from a surface to be polished of the lens 1 with a predetermined gap. Accordingly the lens 1 is polished in the contactless condition with respect to the tool 2a, thereby it is possible to obtain a highly qualified polished surface with less distortion.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a lens polishing device.

[Background of the invention]

Conventionally, polishing mainly focused on lenses has been carried out for a long time as is well known, and its basic principle has not changed. This principle will be explained based on a conventional example of a lens polishing apparatus shown in FIG. 5, taking a concave surface as an example.

As shown in the figure, a lens 2, which is a 1Vi polished object, is a polishing tool, for example, a polisher 2 having a convex surface equal to the radius of curvature of the lens 1, and is forcibly rotated by a driving source, for example, a motor. The lens 1 is attached to a lens holding stand, such as a lens attaching plate 3, and a seat 5 for supporting a hairpin 4, commonly called a hairpin, is provided on the opposite side of the lens attaching plate 5. A polishing load is applied to the hairpin 4, and at the same time, a swinging motion of a constant amplitude is applied by the motor. In the lens polishing device having the grooved bottom as described above, the lens 1 is rotated dependently by the rotational movement of the polishing surface 2 and the swinging movement of the hairpin 4.
Zero-spherical polishing is possible by supplying abrasive.

However, when polishing a microspherical surface with an oil chamber radius of 1 mm or less using this lens polishing apparatus, there is a problem that the rotational vibration of the polishing surface 2 causes the lens 1C to move, making the polishing unstable and causing the edges to break.

In addition, when targeting a microspherical surface, the swing amplitude of the hairpin 4 cannot be large because the lens 1 is polished without coming off the polishing surface 2. Therefore, it is difficult for the lens 1 to obtain dependent rotation, and the polishing There is a problem with not progressing. Furthermore, there is also the problem that the polishing load applied to the lens 1 cannot be kept small due to its mechanism. In this way, in the conventional device, the lens 1 has a high e.g.
! ! I couldn't polish it at once.

2 Regarding this, optical element processing technology '81.
Published 10-10-1980 9 Edited 1 Published by 2 Optical Industry Technology Association p. 220-222 (Keisuke Shioya) 0 [Object of the Invention] The present invention was made in view of the above points, and it It is an object of the present invention to provide a lens polishing device that enables highly accurate polishing.

[Summary of the invention]

That is, the present invention includes a lens, a lens holder holding the lens, a polishing tool for polishing the lens, and a drive source for driving the polishing tool, and rotates the polishing tool to polish the lens. The lens polishing apparatus is characterized in that the drive source is formed by a windmill device having a swingable tool shaft, thereby making it possible to perform stable polishing.

[Embodiments of the invention]

The present invention will be described below based on illustrative embodiments. FIG. 1 shows an embodiment of the invention. Note that parts that are the same as those in the conventional system are given the same reference numerals, and therefore their explanations will be omitted. In this embodiment, the drive source for driving the polishing tool 2a is formed by a windmill device having a swingable tool shaft 6. By doing this, the drive source is formed by a windmill device having a swingable tool shaft 6, which makes it possible to perform stable polishing and to polish the lens 1 with high precision. It is possible to obtain a lens polishing device that has the following characteristics.

That is, although the drive source is formed by a wind turbine device having a swingable tool shaft 6, this wind turbine device #L is formed by an impeller 7 fixed to the tool shaft 6 and an air blowing device that rotates this impeller 7. did. This air blowing device was formed by an air supply nozzle 8 facing the impeller 7 and an air pump 9 supplying air to the air supply nozzle 8. The tool shaft 6 is guided and supported by a guide hole 11 having a clearance provided in a guide 10, so that it can swing freely. In addition, in the same figure, 3a is a lens holding stand. By doing so, the lens 1 can be polished as described below. The lens 1 is positioned by adjusting the lens holding table 5a, and the tip of the polishing tool 2a is pressed against the surface of the lens 1 to be polished. In this case, the abrasive is the polishing tool 2a or the lens 1.
It may be applied to the lens 1 or supplied from the outside, or a frame may be provided around the lens 1 to pool it. In this state, the air pump 9 is operated to blow air from the air supply nozzle 8 toward the impeller 7. This allows polishing tool 2
A is rotated and polishing progresses. In this case, since the guide hole 11 has a clearance with respect to the tool shaft 6 as described above, even if the tool shaft 6 has rotational runout, the polishing tool 2a is guided and supported by the surface of the lens 1 to be polished. The tool shaft 6 is not constrained in position, and a stable polishing state can be obtained. In this way, according to this embodiment, the tool shaft 6 can be driven by airflow without being mechanically connected, and stable polishing can be performed without being controlled by mechanical precision as in the past. , it is possible to obtain a high-quality polished surface with excellent surface roughness without fracturing the edges. In addition, since the tool shaft 6 equipped with the polishing tool 2a is rotated by the air flow in this manner, and the surface to be polished of the lens 1 is used as a guide support surface for polishing, the polishing load applied to the lens 1 can be reduced. can.

Another embodiment of the invention is shown in FIG. In this embodiment, the air blowing device TIL includes an air supply nozzle 8 facing the impeller 7, an air pump 9 that supplies air to the air supply nozzle 8, and a flow rate that is provided in a part of the nozzle 8 to adjust the blowout amount. It is formed of a valve 12, a non-contact displacement sensor 13 and a displacement detection control device [14] that control the flow rate valve 12.

By doing so, the air blowing device has an air supply nozzle 8 facing the impeller 7. An air pump 9 that supplies air to this air supply nozzle 8. Provided in a part of the nozzle 8,
Flow valve for adjusting the amount of ejection 12. The flow rate valve 12 is controlled by a non-contact displacement sensor 15, a displacement detection control device 14, etc., so that the flow rate of air blown to the impeller 7 can be adjusted. Polishing can now be performed with 2a floating.

That is, when the air pump 9 is operated and the air flow rate is increased to a certain amount or more, floating blades are generated, and the polishing tool 2a floats in a rotating state. This floating amount is measured by the non-contact displacement sensor 15.
is detected and inputted to the displacement detection control device 14. Based on this input signal, the displacement detection control device 14 controls the flow rate valve 12 to adjust the floating 'Ik. In this case, a frame is provided around the lens 1 to pool the abrasive. By doing so, the lens 1 can be polished by the fluid movement of the polishing agent accompanying the rotational movement of the polishing tool 2a while maintaining a constant distance between the polishing tool 2a and the surface to be polished. As described above, according to this embodiment, the lens 1 is polished without contact with the polishing tool 2a, and a high-quality polished surface with small processing distortion can be obtained.

FIG. 3 shows yet another embodiment of the invention. In this embodiment, the lens 1a is a flat surface. In this case as well, the lens 1a can be polished with the polishing tool 2b floating, and the same effects as in the above case can be achieved.In other words, the polishing tool 2b also has its tip formed flat. The guide hole 11a provided in the guide 10a has a longer guide surface than the case described above. By doing this, when the air pump 9 is operated, the lens 1a can be polished with or without contact with the polishing tool 2a by adjusting the flow rate valve 12. The shaft 6 does not fall down when starting to rotate.
Planar lenses 1a can also be polished stably.

FIG. 4 shows the polishing characteristics of each of the above examples. This figure shows the relationship between the surface roughness, the flying height, and the rotational speed of the polishing tool, with the vertical axis representing the surface roughness and the flying height, and the horizontal axis representing the rotational speed of the polishing tool. As is clear from the figure, the flying height increases, that is, the surface roughness decreases in the non-contact polishing area between the lens and the polishing tool. Polish the lens to a high ffl! Thus, it is possible to obtain a lens polishing device t that can perform polishing at once.

[Brief explanation of drawings]

FIG. 1 is a partially longitudinal side view of an embodiment of the lens polishing apparatus of the present invention, FIG. 2 is a partially longitudinal side view of another embodiment of the lens polishing apparatus of the present invention, and FIG. FIG. 4 is a partial vertical sectional view of still another embodiment of the lens polishing device of the invention, and FIG. FIG. 5 is a partially vertical side view of a conventional lens polishing device.1, 1a...lens 2a, 2b...polishing tool 6
a... Lens holder 6... Tool shaft 7... For blades
8...Air supply nozzle 9...-Air pump
10.10a...Guide 11.11a...Guide hole 12...Flow rate valve 13...Non-contact displacement sensor 14...Displacement detection control device [Direct ('3 Ritoto Patent Attorney Masaru Ogawa') 1 Figure 2 and Figure 3 S ↓

Claims (1)

[Claims] 1. A lens, a lens holder holding the lens, a polishing tool for polishing the lens, and a drive source for driving the polishing tool, the polishing tool being rotated. In a lens polishing device configured to polish a lens,
A lens polishing device characterized in that the driving source is formed by a windmill device having a swingable tool shaft. 2. The windmill device includes an impeller fixed to the tool shaft;
The lens polishing device according to claim 1, which comprises an air blowing device for rotating the impeller. 3. The air ejection device includes an air supply nozzle facing the impeller, an air pump that supplies air to the air supply nozzle, a flow valve that is provided in a part of the nozzle and adjusts the amount of ejection; 3. The lens polishing device according to claim 2, wherein the lens polishing device is formed of a non-contact displacement sensor that controls a flow valve and a displacement detection control device.