JPS6012188B2 - Lens centering clamp method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for centering and clamping a lens, and more particularly, to a method for clamping a lens when the lens is clamped by opposing cup bodies provided on a lens holding device.

For example, a lens centering machine that grinds the outer periphery of a lens includes a lens holding device that holds the lens and rotates it around its optical axis, and a grindstone device that grinds the outer periphery of the lens.

When grinding the outer periphery of a lens using this lens centering machine, it is impossible to perform accurate processing unless the optical axis of the lens and the center axis of the rotating spindle of the lens holding device are aligned precisely. . The lens holding device holds the lens by providing a cup body on the opposite side of rotating spindles arranged above and below and applying pressure to the lens with this cup body. When the lens is clamped by this cup body, the lens is held by the cup body. The centering of the lens is performed by utilizing the fact that the center axis of the cup body and the optical axis of the lens automatically coincide with each other by sliding along the spherical surface. However, this type of centering method is performed using only the horizontal component force generated when the edge of the cup body comes into contact with the inclined lens surface when the lens is held between the cup bodies. When the curvature of the lens is large (more precisely, when the Z coefficient of the lens is approximately 0.15 or more, the Z coefficient will be described later).

This method is only effective for centering lenses with small curvature (lenses with a Z coefficient of approximately less than 0.15). A method for centering a lens with such a small Z coefficient is, for example, to rotate the spindle at high speed while holding the lens between the cup body under low pressure, or to apply vibration to the lens to promote sliding between the lens and the cup body. Similar methods have been proposed, but these merely apply an unspecified force to make the lens and cup body more compatible.
There are limits to its effectiveness, and it is difficult to detect when the lens will be centered when these operations are applied, and furthermore, the rotation and vibration may cause the lens to be centered again. Some prisoners move and become misaligned.

This invention was made with the aim of providing a more effective method for centering and clamping lenses with small Z coefficients. When trying to remove the lens, place the lens on the lower cup body, rotate the upper cup body towards this lens at low speed and move it forward at low pressure and low speed to sandwich the lens between the upper and lower cup bodies, and then remove the upper cup body. The lens is firmly clamped by pressing the body against the lens with high pressure.

If the lens is unevenly placed on the lower cup body,
The edge of the upper cup body, which descends while rotating, contacts the lens at its highest point, and at that time, the lens is rotated and moved by the tangential frictional force applied from the upper cup body to the lens. ``When the lens is held between the upper and lower cup bodies, the centering of the lens is performed.Hereinafter, it will be explained in detail based on the drawings.
Figure 1 shows an example of a lens holding device that employs the method of the present invention.
It's called the "machine frame."

2 is the upper spindle holder "S" which is attached to the machine frame so that it can be raised and lowered but cannot be rotated.
? The spindles 5 and 6 are respectively fixed to the spindle holders 2 and 5 and 6 are a lower cup body and an upper cup body respectively fixed to opposite ends of the spindle 3. The upper spindle holder 2 is a rack fixed in the rutting direction, 8 is a pinion that is pivoted to the machine frame, and g is the rack attached to the rod end of the cylinder fixed to the machine frame. When the rack is completed, the gear 0 and the pinion crab are engaged and the upper spindle holder 2 is raised and lowered by operating the sill g, the upper cup body 6 is raised and lowered, and the lens 11 layered on the lower cup body is raised and lowered. 12. Army 3 each has a spindle of 89 W.
These are fixed gears with the same number of teeth ~ Tomigame and Kame 6 are gears with the same number of teeth meshing with gears 2 and 13, respectively, and Tobi is the intermediate shaft connecting gear 4 and a5. The one-way clutch installed in the connecting part between the gear 15 and the intermediate shaft turtle S is the one-way clutch "1st base DC motor".
A gear fixed to the shaft 28 of the gear turtle 5 and a gear fixed to the shaft 28 of the gear turtle 5 mesh with the gear wings 9.

When the DC motor 18 rotates in the forward direction, the one-way clutch 7 also transmits the rotation of the gear blades to the gear turtle 4 to take over the upper and lower spindles; The function is to disconnect the gear turtle 5 and the turtle hub and rotate only the upper spindle base. Here, normal rotation is the direction in which the lens turtle 1 is rotated when, for example, grinding the outer periphery of the lens turtle blade. This will be done while being reversed. Gear 1 in the diagram
The reason why gear holder 3 has a much larger face width than gear guard 6 is to ensure that the gear 13 and gear 1 mesh with each other even when the kissing spindle 4 moves up and down. Upper spindle holder 2
Dogs 22 and 23 are attached to the lower and upper ends of the t, respectively, and the dog 22 at the lower end has an adjuster 2 to finely adjust its position.

Proximity switches 25 and 26 are installed on the machine frame in correspondence with these dogs 22 and 23, and when these proximity switches 2 and 26 detect the dogs 22 and 3, the lifting end of the upper spindle holder 2 is activated. The reason why the adjuster 24 is provided on the dog 22 is to finely adjust the lowering end position of the upper cup body 6 according to the thickness of the lens amount 1 to be attached. The lower spindle 3 is provided with a hollow hole 7 that is connected to the inside of the lower cup body 5. The lotus is brewed in a vacuum source (not shown).

The hydraulic circuit (not shown) connected to the cylinder G is equipped with a pressure reducing valve, a function valve, a flow rate regulating valve, etc., so that the pressure of the hydraulic oil applied to the cylinder can be switched between high and low levels. The mechanism is such that the operating speed of the t-cylinder 9 can be adjusted as necessary.Next, we will explain the procedure for clasping a lens using the device configured as described above.

When the lens is loaded onto the lower cup body by a loader (not shown), the lens is absorbed by the negative pressure supplied to the lower cup body through the rotary joint, and the DC
At the same time as the motor 8 rotates in reverse, low-pressure oil pressure is supplied to the rod end side of the cylinder 9, and the upper cup body 6 rotates and descends toward the lens Kamegawa on the stopped lower cup body 5. If the lens a is eccentrically layered on the lower cup body S as shown in Figures 2 and 3 or Figure 5, the edge of the upper cup body 6 will be Attach the lenticular dragon fin to the highest point P of the lenticular tortoise and apply a pressing force and the tangential force shown at A in Figures 3 and 5 to this point P.

As in the case of the conventional device, this pressing force attempts to cause the lens 11 to slide along its spherical surface and move the inside JD of the lens 11 toward the center of the cup bodies 5 and 6, and at the same time, the tangential force A , attempts to rotate the lens 11 around a point Q located between the center M of the cup bodies 5 and 6 and the point of action P of the tangential force A. The reason why point Q appears closer to point P than the center M of the cup body is because the supporting force of the lens 11 acting from the lower cup body 5 due to the pressing force of the upper cup body 6 is largely distributed on the side of point P. This is because it will become like that. However, when the lens 11 attempts to rotate around a point Q, the thick part of the lens 11 passes through the edge of the lower cup body 5 at the upper part of point P represented by point S, and the lens 11 rotates around the lower cup body. 5
This passage is blocked because the lens 11 is pressed by the point S, and the holding force of the lens 11 at the point S increases, and the center of rotation of the lens 11 moves further upwards, and eventually the lens 1 rotates around the point R. That will happen. The pivoting movement of the lens 11 around the point R causes the center N of the lens 11 to move toward the center M of the cup body.Since the upper cup body 6 descends while rotating, the tangential force P is continuous. acts on the lens surface, and the lens turtle 1 slides while turning, so that its optical axis is aligned with the cup bodies 5 and 6.
Matched to the center of Wisteria. When the lens 11 is clamped with the optical axis of the lens aligned with the axes of the cup bodies 5 and 6, the proximity switch 25 detects the dog 22, stops the DC motor 8, and switches the hydraulic circuit. cylinder 9
A high hydraulic pressure is supplied to the lens 11 so that the lower cup body 5
It is firmly clamped by the upper cup body 6 and the upper cup body 6. Next, the results of an experiment comparing the centering accuracy between a case where a lens is clamped by the method of the present invention and a case where a lens is clamped by a conventional method will be shown.

Sample tins misty sound layered board Gokou Kage Tatsumi f Yukata Z shaped Shape of the present invention Conventional method Diameter, Z coefficient meniscus 50 50 30. Orbit, 0.14 5 0
50 double concave 40 2921 m, 0.1
2 40 38 meniscus
6 037.5's enemy, 0.07
10 10 In the table above, the amount of eccentricity is defined as the angle between the center axis of the spindle and the center axis of the lens, and the Z coefficient is defined as ZED/4R and 10D/Fox 2 for a biconvex or biconcave lens, and Z=D/fox,
- It is a coefficient defined by D/4R2.

Here, D is the diameter of the shins, and R and R2 are the radii of curvature of each side of the shins. As explained above, according to the clamping method of the present invention, it is possible to automatically center a lens with a Z coefficient of about 0.1, which was previously impossible to center using only the clamping force of the cup body. This makes it possible to automatically center and clamp the lens without the need for manual work by skilled workers or optical equipment.Furthermore, it is possible to easily detect when the centering of the lens has been completed. Since there is no movement of the lens that has been removed and the centering operation is performed extremely quickly, the productivity and precision of the lens can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a lens holding device employing the method of this invention, and FIGS. 2 to 5 are explanatory diagrams showing how lens centering is performed by the method of this invention. . In the figure, i is a lower spindle holder, 2 is an upper spindle holder, 3 and 4 are spindles, 6 is a lower cup body, 6 is an upper cup body, 8 is a pinion, 9 is a cylinder, 11 is a cylinder, 1
2, 13, 14, and 15 are gears, 16 is an intermediate shaft, 17 is a one-way clutch, and 18 is a DC motor. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A method of clamping a lens in a lens holding device in which a lens 11 is clamped and held between upper and lower cup bodies 6 and 5 facing each other, the lens 1 being placed on a lower cup body 5.
1, the upper cup body 6 is rotated and advanced at low pressure and low speed to clamp the lens, and then the upper cup body 6
A method for centering and clamping a lens, characterized by pressing the lens against the lens at high pressure.