JPS58114851A - Center aligning machine of lens - Google Patents

Abstract

PURPOSE:To correct the position of a lens and to discharge a defective lens, by a method wherein a beam of light is projected toward the lens supplied between cup bodies, and difference between a light receiving position and a reference light receiving position is detected by receiving permeated light or reflected light. CONSTITUTION:Supposing that an optical axis of a lens 2 supplied between cup bodies 7 and 8 is displaced from an axis Z of the cup body 8 by (e), a beam of light (a) projected from a light projector 1 is refracted by the lens 2 and projected to a position displaced by (r) from a reference optical position O of an image sensor 3. This displacement is detected by a detecting circuit 19, a pusher 4 is advanced and a positional displacement of the lens is corrected. The circumference of the lens is ground by a grinding wheel 15 under the corrected state.

Description

Detailed Description of the Invention The present invention relates to a lens centering machine, which is capable of automatically correcting the position of lenses supplied on the spindle of the centering machine or ejecting defective lenses. The aim is to provide an opportunity.

The centering machine grips the lens with cup bodies installed at opposite ends of rotating upper and lower spindles, and grinds the outer periphery of the lens while rotating the spindles, finishing the outer periphery in line with the optical axis of the lens. It is something to do. Therefore, if the lens to be processed is not held in the correct position, the processed lens will have a misaligned optical axis, and if the lens is defective and the optical axis is not aligned with the original lens, then the lens will To position the lens,
This is done by taking advantage of the fact that when held between two cup bodies, the lens slides along its spherical surface, and the optical axis of the lens automatically aligns with the axis of the cup bodies. However, such means do not work accurately when the curvature of the lens surface is small or when the lens diameter is small, and automatic positioning cannot be expected. The reality is that the lens is judged by the tactile sensation as to whether the lens is being held correctly. Therefore, with conventional means, there is a limit to the productivity of lenses, and the defect rate of lenses after processing is high (furthermore, even if the lens to be centered is originally a defective product, unnecessary work is done to increase the number of cores). There are drawbacks.

This invention solves the problems of such conventional devices.
1. It was made for the purpose of erasing the centering machine, and the lens supplied to the centering machine can be accurately automatically positioned based on its optical axis, or the lens supplied to the centering machine is a defective product. The object of the present invention is to provide a centering machine that can automatically remove the centering material before processing.

In other words, the lens centering machine of the present invention is a lens centering machine that grinds the outer circumference of the lens by sandwiching the lens with cup bodies provided at opposite ends of rotating upper and lower spindles, and the lens centering machine grinds the outer periphery of the lens. A projector that projects a beam of light toward a lens, an image sensor that receives transmitted light or reflected light of the beam by the lens, and a detection that detects a difference between an actual light receiving position and a reference light receiving position on the image sensor. It is characterized by having a circuit. Since the lens supplied to the centering machine is held between two cup bodies from above and below, it is reasonable to project the beam to the lens from the axis of this cup body, that is, the center axis of rotation of the spindle. An optical system is formed in which a projector and an image sensor are disposed on the central axis of rotation, or a reflecting mirror is disposed on the central axis of rotation. If the position of the lens on the cup body is incorrect or the optical axis is incorrect, the direction of the transmitted light or reflected light of the projected beam will be biased, and the position of the received beam will be shifted. deviates from the reference position, this can be detected by the detection circuit. Based on the output signal of this detection path, the position of the lens can be automatically corrected, or lenses whose optical axes do not match can be automatically removed. As a device for correcting the position of the lens or removing a defective lens, there is a bushing device that moves the lens by pushing the outer periphery of the lens on the cup body;
An arm device that suctions and holds the lens with a vacuum cup attached to the tip to supply and remove it, and a device that grips the outer periphery of the lens and moves it in the X-Y direction to position or remove the lens. By controlling the operation of these devices based on the output signal of the image sensor, it is possible to automatically correct the lens position or eliminate defective lenses, improving productivity in centering machines and reducing the defective rate. It is possible to reduce the

Next, the embodiment shown in the drawings will be described.

1 to 3 show that when the linear image sensor 3 receives the transmitted light of the beam a projected from the projector 1 onto the lens 2, and there is a positional shift in the lens 2, the lens 2
This shows an example of a centering machine in which a lens button 4 is advanced from the side to align the optical axis of the lens 2 with the center axis of rotation of the spindle, and is capable of accurately and automatically positioning a lens with a small surface curvature. It is possible to grind the outer periphery.

Here, 5 is the upper spindle, 6 is the lower spindle, 7.8
are cup bodies attached to opposite ends of the upper and lower spindles 5.6, respectively, and the lens 2 is held between the cup bodies 7.8. 9 is a spindle drive shaft, 10 and 11
12 is an intermediate shaft that connects the gear trains 10 and 11, and a pulse is connected to the intermediate shaft 12 via a clutch 13. A motor 14 is connected. This pulse motor 14 is connected to the spindle 5 when detecting a positional deviation of the lens 2.
, 6, and when a linear image sensor is used as the image sensor, a device such as a pulse motor 14 that can accurately rotate the lens or linear image sensor by a controlled amount is required. It is. 15 is a grinding wheel for grinding the outer periphery of the lens 2, 16 is a bracket fixed to the lens grinder 4, 17 is a feed screw that is screwed into the bracket 16, 18 is a pulse motor that rotates the feed screw/17, and 19 is a linear imager. This is a detection circuit that controls the pulse motors 14 and 18 based on the beam detection signal from the sensor 3.

As shown in FIG. 2, if the optical axis of the supplied lens 2 is deviated by e from the axis 2 of the cup body 8, the beam a projected from the projector 1 is refracted by the lens 2. Reference light receiving position O to r of linear image sensor 3
It is projected to a position shifted by the same amount. Here, the pulse motor 14
When the lens 2 is rotated, the beam a traces a circular locus as shown in FIG. The amount of deviation of the A position and the B position from the reference position O can be easily detected by the detection circuit 19. Therefore, when the spot of the beam ray a reaches position A, the pulse motor 14 is stopped to stop the rotation of the lens 2, and the pulse motor 18 is driven to move the lens gripper 4 from position A to position A.
If the lens 2 is moved forward in the direction of This can be confirmed by detecting whether light is received at the reference position O of the linear eye sensor 213.

In the embodiment shown in FIGS. 2, 4 to 6, the reflected light from the lens 2 is detected by a two-dimensional image sensor 20, and when the light receiving position is deviated from the reference position, the output signal of the detection circuit 21 is used to detect the reflected light from the lens 2. The lens 2 is removed by operating a vacuum cup 22. This may occur, for example, if the lens 2 has a curvature sufficient to automatically center the lens 2 by simply holding it between the cup bodies 7.8. It is used to discover and eliminate defective products. When the image sensor has a two-dimensional light-receiving surface, by detecting the light-receiving position on the image sensor 20, it is possible to simultaneously detect the heel 4, the ρ displacement region, and its direction. A device such as the pulse motor 14 shown in the figure is not required, and the direction and amount of deviation of the optical axis of the lens 2 can be detected while the lens 2 is stopped. In addition, in the figure, 23 is a No.-7 mirror installed diagonally with its reflective surface facing toward the lens 2, 24 is a norinda device for moving the vacuum cup 22 forward and backward, and 25 is a linda device for moving the vacuum cup 22 up and down. 26 is a pressure supply device to the Norinta device 24, 25, and the vacuum cup 22 is used to suction and hold the lens 2 and supply and carry out the centering machine. The structure is such that it can also be used to eliminate defective lenses.

As shown in FIGS. 5 and 6, the beam projected from the projector 1 passes through the half mirror 23 and passes through the lens 2.
The reflected light from both surfaces 2 a and 2 b of the lens 2 is laterally reflected by the half mirror 23 and projected onto the two-dimensional image sensor 20 . If the optical axis of the lens 2 coincides with the axis of the cup body 8, the reflected lights a and b from both surfaces of the lens 2 will pass through the same path and be projected onto the two-dimensional image sensor 20 at the reference point O. , when the optical axis of the lens 2 is misaligned, the reflected lights a and b on both surfaces of the lens 2 pass through different trajectories and form two spora (A, B) on the light receiving surface of the two-dimensional image sensor 20. and is projected. Therefore, by detecting the direction of the line segment connecting the spots A and B and the distance between A and 8, the direction and amount of deviation of the optical axis of the lens 2 can be detected. As shown in FIG. 4, when the purpose is to eliminate defective lenses, the direction of the deviation of the optical axis is not important, and if the distance between spots A and B is greater than a specified amount, the cylinder device 24. 25 to remove the lens.

As explained above, the centering machine of the present invention projects a beam onto a supplied or held lens and causes an image sensor to receive the transmitted light or reflected light, thereby correcting the positional deviation of the lens. Alternatively, since the optical axis deviation can be optically accurately detected, it is possible to easily perform automatic centering of lenses with small curvatures that cannot be accurately centered using conventional means. In addition, it is also possible to discover and eliminate defective lenses during centering in the centering machine, which is extremely useful for improving productivity and reducing the defective rate in the centering machine.

[Brief explanation of the drawing]

1 to 3 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a partially sectional side view schematically showing the entire device, and FIGS. 2 and 3 are diagrams showing transmitted light passing through a lens. FIG. 6 is a side view and a perspective view showing the state of light. 4 to 6 are views showing a second embodiment of the present invention. FIG. 4 is a partially sectional side view schematically showing the entire device, and FIGS. 5 and 6 are views showing reflections on the lens surface. FIG. 3 is a side view and a perspective view showing the state of light. In the figure, 1 is the projector, 2 is the lens, 3 is the linear image sensor, 4 is the lens pusher, 5 is the upper spindle,
6 is a lower spindle, 7 and 8 are cup bodies, 14 is a pulse motor, 15 is a grinding wheel, 17 is a feed screw, 18 is a pulse motor, 19 is a detection circuit, 20 is a two-dimensional image sensor,
21 is a detection circuit, 22 is a vacuum cup, and 23 is a half mirror. Agent Patent Attorney Takao NishiFigure 1, 19 Figure 2 Figure 3 Figure 4 Figure 1

Claims (1)

[Claims] 1. In a lens centering machine that grinds the outer periphery of a lens by holding the lens between cup bodies provided at opposite ends of rotating upper and lower spindles, the lens is supplied between the cup bodies. a light projector that projects a beam, an image sensor that receives transmitted light or reflected light of the beam by the lens, and a detection circuit that detects a difference between a beam receiving position on the image sensor and a reference position. This lens centering machine is characterized by: 2. The lens centering machine according to claim 1, wherein a light projector and an image sensor are disposed on the central axis of rotation of the spindle, sandwiching the cup body, and the image sensor emits a beam of light that passes through the lens. 3. A projector is placed on the rotation center axis of the spindle, and a half mirror is placed between the projector and the cup body at an angle with its reflective surface facing the cup body. The lens centering machine according to claim 1, wherein the lens centering machine is arranged to receive the reflected light. 4. In a lens centering machine that grinds the outer periphery of a lens by holding the lens between cup bodies with halves at opposite ends of the rotating upper and lower spindles, a beam of light is projected toward the lens supplied between the cup bodies. an image sensor that receives transmitted light or reflected light of a beam by the lens; a detection circuit that detects a difference between a beam reception position on the image sensor and a reference position; and an output from this detection circuit. A lens centering machine characterized by having a lens position correction device that operates based on a signal. 5. In a lens centering machine that grinds the outer circumference of a lens by holding the lens between cup bodies provided at opposite ends of the rotating upper and lower spindles, a beam of light is projected toward the lens supplied between the cup bodies. A projector, an image sensor that receives transmitted light or reflected light of a beam by the lens, a detection circuit that detects a difference between a beam reception position on the image sensor and a reference position, and an output signal from this detection circuit. A lens centering machine characterized by a defective lens ejecting device that operates based on the above.