JPH05220794A - Gate cut relative positioning device for plastic lenses - Google Patents

Abstract

(57) [Abstract] [Object] An object of the present invention is to provide a gate-cut relative positioning device for a plastic lens that is inexpensive and can be positioned easily. According to the present invention, a jig 3 for holding a lens and a runner for fixing the lens system by inclining the lens system by θ (θ: an angle equal to or less than the outer angle of the lens guard on the top side of the lens), and this jig 3
, A finely movable uniaxial stage 4, a visible light semiconductor laser unit 5 that applies visible light semiconductor laser light (collimated light) to the upper surface of the side of the lens from an angle of 2θ with respect to the vertical direction, and advances in the vertical direction. And a cutter 6 whose tilt is adjusted so that the blade hits the reflected light and is parallel to the reflected light, and the position at which the reflected light in the vertical direction disappears is defined as the horizontal reference position of the relative position. This is a gate cut relative positioning device for a plastic lens in which a position that is horizontally separated from the position by a predetermined distance is the position where the cutter enters the lens system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate cut relative positioning device for a plastic lens, which is suitable for gate cut relative positioning of a plastic lens for CD, for example.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 5 and 7, a gate of a plastic lens for CD has been cut by applying a laser beam to a cutting portion. However, this conventional method has been problematic because burrs are generated on the reference surface side of the lens.
In order to eliminate this, as shown in FIG. 6, a method of obliquely cutting the reference surface so that the cutter does not pass has been proposed.

[0003]

However, this method has a drawback that it is difficult to simply perform relative positioning between the plastic lens and the cutter. In the conventional positioning, as shown in FIG. 7, the lens is applied to the reference plane A to measure the position, but in the method of obliquely cutting the present method, the lens main body or the cutter is inclined, Positioning cannot be done simply with conventional measurements. Further, when an attempt is made to measure as shown in FIG. 8 using a laser displacement meter, since the laser displacement meter observes the reflected scattered light, the plastic lens is transparent, so diffuse reflection is large, and measurement errors occur. There was a problem that it would become extremely large.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a gate-cut relative positioning device for a plastic lens, which is inexpensive and can be positioned easily.

[0005]

A gate cut relative positioning device for a plastic lens according to the present invention is shown in FIG.
As shown in, a lens and a runner pressing jig 3 for tilting and fixing the lens system by θ (θ: an angle equal to or less than the outer angle of the lens guard on the top side of the lens) and a finely movable single axis on which the jig 3 is installed. Stage 4 and 2θ in the vertical direction
The visible light semiconductor laser unit 5 that applies visible light semiconductor laser light (collimated light) to the upper surface of the side of the lens from the angle of, and the reflected light traveling in the vertical direction is hit by the blade and is parallel to this reflected light. And a cutter 6 whose tilt is adjusted, and a position where reflected light in the vertical direction disappears is set as a horizontal reference position of the relative position, and a position apart from this position by a predetermined distance in the horizontal direction is set to a lens system. This is the position where the cutter enters.

[0006]

According to the present invention, the jig for fixing the lens and the runner and the jig for fixing the lens system by inclining the lens system by θ (θ: an angle equal to or smaller than the outer angle of the lens guard on the top side of the lens) and the jig 3 are installed. The uniaxial stage 4 that can be finely moved, the visible light semiconductor laser unit 5 that applies visible light semiconductor laser light (collimated light) to the upper surface of the side of the lens from an angle of 2θ with respect to the vertical direction, and the reflected light that travels in the vertical direction. It has a cutter 6 whose blade hits and whose tilt is adjusted so as to be parallel to this reflected light, and the position at which the reflected light in the vertical direction disappears is set as the horizontal reference position of the relative position, and a predetermined position is set from this position. Gate cut relative positioning of plastic lens that can be positioned inexpensively and easily by making the position where the cutter enters the lens system a position horizontally separated by It is possible to provide a location.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a gate cut relative positioning device for a plastic lens according to the present invention will be described below with reference to FIGS.
Will be described.

First, a plastic lens for CD (see FIG. 4) is taken out in a shape as shown in FIG. 3 by injection molding. At this time, the lens portion, the runner, and the gate portion are cut, and the subsequent process (antireflection is performed). Film coating, annealing, etc.).

This cutting is generally called a gate cut. Conventionally, the gate cutting has been performed by a laser melting cutting method or the like. However, this method has problems that the cost of the entire system is high and the lens performance is affected by the heat of the laser light. As a method of eliminating this, there is a diagonal gate cutting method using an ultrasonic cutter (see FIG. 6). This method is advantageous in that it is low in cost and that the elements for cutting are two cutting elements, one is cutting by a cutter and the other is melting by heat. However, on the other hand, as a problem, burrs are generated when the reference plane of the lens is cut by the cutter, so it is necessary to sufficiently consider the position where the cutter enters the lens. In other words, the relative position of the lens and the cutter must be determined with such an accuracy that the reference plane is not cut and the condition for cutting off all the gates is provided. This example is a simple and inexpensive measuring device that enables this.

As shown in FIG. 1, the measuring system comprises a visible light semiconductor laser (λ = 670 nm) unit, a plastic lens, a lens and a runner holding jig, and a finely movable uniaxial stage. A jig that tilts the entire lens system (lens and runner) by the same angle as the outer angle of the top side of the lens (10 degrees for internally manufactured lenses) is irradiated with laser light from the positional relationship shown in FIG. (Towards the side of the lens). The laser light that hits the upper surface of the frame of the lens is reflected in the vertical direction. However, when the lens system is moved in the x direction (+ direction), the light is reflected after the point where x = 0 as shown in the figure. Does not move in the vertical direction, so that the innermost point of entry of the blade into the lens (referred to as the zero point) can be determined (the error fits within the spot size of the beam). In addition, θ can be performed in the same manner as described above even when the angle is equal to or smaller than the outer angle of the lens guard.

At this 0 point, the lens system is fixed, and the position and tilt of the blade are adjusted so that the reflected light in the vertical direction at that time hits and is parallel to the blade of the cutter. The error here is also within the spot size of the laser light.

The cutting position x for cutting the gate is given by x = (10-dtan θ) cos θ as shown in FIG. 2. Therefore, by moving the lens system in the-direction by this amount, an appropriate lens can be obtained. The relative position of can be determined.

In this measuring system, the positioning accuracy is determined by the spot size of the laser beam used (the accuracy of the jig and the stage is within 10 μm, which is sufficiently small). Currently available laser units include a visible light semiconductor laser unit of λ = 670 nm with a spot diameter of about 100 μm (a spread angle of about 0.2 deg) at a distance of 30 mm from the emission point of the unit (for example, ,
Already used in such as Keyence made laser displacement meter). If the distance from the laser unit is about 10 mm, a beam with a spot size of 30 μm or more can be obtained, so that the measurement system can perform measurement within an error of about 50 μm (peak-to-peak). It can be said that the positioning range of the gate cut is sufficient because it is about 100 μm. Further, the reflectance of the laser light on the plastic lens is as small as 4%, but since it is visible light, an output of about 1 mw can be viewed directly (normal laser output is several to
About 10 mw).

From the above, according to this example, the lens and runner holding jig 3 for fixing the lens system by inclining it by θ (θ: an angle equal to or less than the outer angle of the lens guard on the top side of the lens), and this jig 3 A uniaxially movable stage 4 on which a jig 3 is installed, a visible light semiconductor laser unit 5 for applying visible light semiconductor laser light (collimated light) to the upper surface of the side of the lens from an angle of 2θ with respect to the vertical direction, and the vertical direction. And a cutter 6 whose tilt is adjusted so that it is parallel to this reflected light, and the position where the reflected light in the vertical direction disappears is taken as the horizontal reference position of the relative position. , A plastic lens gate that can be positioned inexpensively and simply by setting a position horizontally separated from this position by a predetermined distance as the position where the cutter enters the lens system. It is possible to provide a Tsu bets relative positioning device. For this reason, the diagonal cutting method using an ultrasonic cutter can be used for the gate cutting method. By using the ultrasonic cutter in this way, it was possible to perform gate cutting at a lower cost than the fusion cutting method using laser light, and it was possible to significantly reduce the effect of heat on lens performance compared to the laser method. .. Further, since the visible light semiconductor laser is used as the light source, the measuring system can be made compact and the measurement can be performed without contact, and the tilt of the cutter can be visually corrected at the same time as the positioning.

[0015]

As described above, according to the present invention,
It is possible to provide a gate-cut relative positioning device for a plastic lens that is inexpensive and can be positioned simply. Therefore, an oblique cutting method using an ultrasonic cutter can be used as the gate cutting method. By using the ultrasonic cutter as described above, gate cutting can be performed at a lower cost than the fusion cutting method using laser light, and the influence of heat on the lens performance can be significantly reduced as compared with the laser method. Further, since the visible light semiconductor laser is used as the light source, the measurement system can be made compact and measurement can be performed without contact, and the tilt of the cutter can be visually corrected simultaneously with positioning.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a gate cut relative positioning device for a plastic lens of the present invention.

FIG. 2 is a diagram showing an example of determining a cutting position in this example.

FIG. 3 is a diagram showing a plastic lens and the like after injection molding.

FIG. 4 is a diagram showing an example of a plastic lens.

FIG. 5 is a diagram showing an example of a cutting position for cutting a gate.

FIG. 6 is a diagram showing an example of a cutting position for cutting a gate.

FIG. 7 is a diagram showing an example of a conventional cutting position determination method.

FIG. 8 is a diagram showing an example of a conventional cutting position determination method.

[Explanation of symbols]

 1 lens 1a reference surface 1b lens guard 1c frame 1d top side 2 runner 3 lens and runner holding jig 4 finely movable uniaxial stage 5 visible light semiconductor laser unit (collimated light) 6 cutter 7 gate

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[Procedure amendment]

[Submission date] August 13, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title: Relative positioning device for gate cut of plastic lens

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate cut relative positioning device for a plastic lens, which is suitable for gate cut relative positioning of a plastic lens for CD, for example.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 5 and 7, a gate of a plastic lens for CD has been cut by applying a laser beam to a cutting portion. However, this conventional method has been problematic because burrs are generated on the reference surface side of the lens.
In order to eliminate this, as shown in FIG. 6, a method of obliquely cutting the reference surface so that the cutter does not pass has been proposed.

[0003]

However, this method has a drawback that it is difficult to simply perform relative positioning between the plastic lens and the cutter. In the conventional positioning, as shown in FIG. 7, the lens is applied to the reference plane A to measure the position, but in the method of obliquely cutting the present method, the lens main body or the cutter is inclined, Positioning cannot be done simply with conventional measurements. Further, when an attempt is made to measure as shown in FIG. 8 using a laser displacement meter, since the laser displacement meter observes the reflected scattered light, the plastic lens is transparent, so diffuse reflection is large, and measurement errors occur. There was a problem that it would become extremely large.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a gate-cut relative positioning device for a plastic lens, which is inexpensive and can be positioned easily.

[0005]

A gate cut relative positioning device for a plastic lens according to the present invention is shown in FIG.
As shown in, the lens and runner pressing jig 3 for tilting and fixing the lens system by θ (θ: an angle equal to or less than the outer angle of the lens guard on the top side of the lens), and the jig 3 can be finely moved. Uniaxial stage 4 and 2θ in the vertical direction
The visible light semiconductor laser unit 5 that applies visible light semiconductor laser light (collimated light) to the upper surface of the side of the lens from the angle of, and the reflected light traveling in the vertical direction is hit by the blade and is parallel to this reflected light. And a cutter 6 whose tilt is adjusted, and a position where reflected light in the vertical direction disappears is set as a horizontal reference position of the relative position, and a position apart from this position by a predetermined distance in the horizontal direction is set to a lens system. This is the position where the cutter enters.

[0006]

According to the present invention, the jig 3 for fixing the lens and the runner and the jig 3 for fixing the lens system by inclining the lens system by θ (θ: an angle equal to or smaller than the external angle of the lens guard on the top side of the lens). A finely movable uniaxial stage 4 to be installed, a visible light semiconductor laser unit 5 for applying visible light semiconductor laser light (collimated light) to the upper surface of the side of the lens from an angle of 2θ with respect to the vertical direction, and reflection that advances in the vertical direction. And a cutter 6 whose tilt is adjusted so that the light hits the blade and is parallel to the reflected light, and the position at which the reflected light in the vertical direction disappears is defined as the horizontal reference position of the relative position. Gate cut relative positioning of plastic lens that can be positioned inexpensively and easily by making the position where the cutter enters the lens system at a position that is horizontally more separated by a predetermined distance. It is possible to provide a location.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a gate cut relative positioning device for a plastic lens according to the present invention will be described below with reference to FIGS.
Will be described.

First, a plastic lens for CD (see FIG. 4) is taken out in a shape as shown in FIG. 3 by injection molding. At this time, the lens portion, the runner, and the gate portion are cut, and the subsequent process (antireflection is performed). Film coating, annealing, etc.).

This cutting is generally called a gate cut. Conventionally, the gate cutting has been performed by a laser melting cutting method or the like. However, this method has problems that the cost of the entire system is high and the lens performance is affected by the heat of the laser light. As a method of eliminating this, there is a diagonal gate cutting method using an ultrasonic cutter (see FIG. 6). This method is advantageous in that it is low in cost and that the elements for cutting are two cutting elements, one is cutting by a cutter and the other is melting by heat. However, on the other hand, as a problem, burrs are generated when the reference plane of the lens is cut by the cutter, so it is necessary to sufficiently consider the position where the cutter enters the lens. In other words, the relative position of the lens and the cutter must be determined with such an accuracy that the reference plane is not cut and a condition for cutting off all the gates is provided. This example is a simple and inexpensive measuring device that enables this.

As shown in FIG. 1, the measuring system comprises a visible light semiconductor laser (λ = 670 nm) unit, a plastic lens, a lens and a runner holding jig, and a finely movable uniaxial stage. Irradiate laser light to a jig that can tilt the entire lens system (lens and runner) by the same angle as the outer angle of the top side of the lens (10 degrees for internally manufactured lenses) from the positional relationship shown in the figure. Do (toward the side of the lens). The laser light that hits the upper surface of the frame of the lens is reflected in the vertical direction. However, when the lens system is moved in the x direction (+ direction), the light is reflected after the point where x = 0 as shown in the figure. Does not move in the vertical direction, so that the innermost point of entry of the blade into the lens (referred to as the zero point) can be determined (the error fits within the spot size of the beam). In addition, θ can be performed in the same manner as described above even when the angle is equal to or smaller than the outer angle of the lens guard.

At this 0 point, the lens system is fixed, and the position and tilt of the blade are adjusted so that the reflected light in the vertical direction at that time hits and is parallel to the blade of the cutter. The error here is also within the spot size of the laser light.

The cutting position x for cutting the gate is given by x = (10-dtan θ) cos θ as shown in FIG. 2. Therefore, by moving the lens system in the-direction by this amount, an appropriate lens can be obtained. The relative position of can be determined.

In this measuring system, the positioning accuracy is determined by the spot size of the laser light used (the accuracy of the jig and stage is within 10 μm, which is sufficiently small). Currently available laser units include a visible light semiconductor laser unit of λ = 670 nm with a spot diameter of about 100 μm (a spread angle of about 0.2 deg) at a distance of 30 mm from the emission point of the unit (for example, ,
Already used in such as Keyence made laser displacement meter). If the distance from the laser unit is about 10 mm, a beam with a spot size of 30 μm or more can be obtained, so that the measurement system can perform measurement within an error of about 50 μm (peak-to-peak). It can be said that the positioning range of the gate cut is sufficient because it is about 100 μm. Further, the reflectance of the laser light on the plastic lens is as small as 4%, but since it is visible light, it can be viewed directly if the output of the laser is about 1 mw (normally the output of the laser is about several to 10 mw). ..

From the above, according to this example, the lens and runner holding jig 3 for fixing the lens system by inclining it by θ (θ: an angle equal to or less than the outer angle of the lens guard on the top side of the lens), A finely movable uniaxial stage 4 on which the jig 3 is installed, a visible light semiconductor laser unit 5 that applies visible light semiconductor laser light (collimated light) to the upper surface of the side of the lens from an angle of 2θ with respect to the vertical direction, and It has a cutter 6 whose blade hits the reflected light traveling in the vertical direction and whose tilt is adjusted so as to be parallel to this reflected light, and the position at which the reflected light in the vertical direction disappears is the horizontal reference of the relative position. A gate of a plastic lens that can be positioned inexpensively and simply by setting the position as a position where the cutter enters the lens system at a position horizontally separated from this position by a predetermined distance. It is possible to provide a Tsu bets relative positioning device. For this reason, the diagonal cutting method using an ultrasonic cutter can be used for the gate cutting method. By using the ultrasonic cutter in this way, it was possible to perform gate cutting at a lower cost than the fusion cutting method using laser light, and it was possible to significantly reduce the effect of heat on lens performance compared to the laser method. .. Further, since the visible light semiconductor laser is used as the light source, the measuring system can be made compact and the measurement can be performed without contact, and the tilt of the cutter can be visually corrected at the same time as the positioning.

[0015]

As described above, according to the present invention,
It is possible to provide a gate-cut relative positioning device for a plastic lens that is inexpensive and can be positioned simply. Therefore, an oblique cutting method using an ultrasonic cutter can be used as the gate cutting method. By using the ultrasonic cutter as described above, gate cutting can be performed at a lower cost than the fusion cutting method using laser light, and the influence of heat on the lens performance can be significantly reduced as compared with the laser method. Further, since the visible light semiconductor laser is used as the light source, the measurement system can be made compact and measurement can be performed without contact, and the tilt of the cutter can be visually corrected simultaneously with positioning.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a gate cut relative positioning device for a plastic lens of the present invention.

FIG. 2 is a diagram showing an example of determining a cutting position in this example.

FIG. 3 is a diagram showing a plastic lens and the like after injection molding.

FIG. 4 is a diagram showing an example of a plastic lens.

FIG. 5 is a diagram showing an example of a cutting position for cutting a gate.

FIG. 6 is a diagram showing an example of a cutting position for cutting a gate.

FIG. 7 is a diagram showing an example of a conventional cutting position determination method.

FIG. 8 is a diagram showing an example of a conventional cutting position determination method.

[Explanation of Codes] 1 lens 1a reference surface 1b lens guard 1c frame part 1d top side 2 runner 3 lens and runner holding jig 4 finely movable uniaxial stage 5 visible light semiconductor laser unit (collimated light) 6 cutter 7 gate

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (1)

[Claims] 1. A jig for fixing a lens and a runner, which tilts and fixes a lens system by θ (θ: an angle equal to or less than an outer angle of a lens guard on the top side of the lens), and a finely movable uniaxial stage on which the jig is installed. , A visible light semiconductor laser unit that applies visible light semiconductor laser light (collimated light) to the upper surface of the side of the lens from an angle of 2θ with respect to the vertical direction, and a blade that hits the reflected light traveling in the vertical direction, and this reflected light It has a cutter whose tilt is adjusted to be parallel to, and the position where the reflected light in the vertical direction disappears is set as the horizontal reference position of the relative position, and a position separated from this position in the horizontal direction by a predetermined distance. Is a position where the cutter enters the lens system, which is a relative position device for gate cut of a plastic lens.