Lens centering mechanism, centering device, and centering method

Abstract

To provide a lens centering mechanism, centering device, and centering method that do not require the use of equipment to measure eccentricity, have a simple configuration, offer high-precision centering, and allow for easy and efficient centering work. [Solution] The driven lens moving means 21 has a contact portion 24 that contacts the upper surface and / or side surface of the driven lens L2, and is formed so that the driven lens L2 can slide on the reference lens L1 using the frictional force generated by the contact when it moves in the X,Y axis direction.

Description

Technical Field

[0001] The present invention relates to a mechanism, an apparatus, and a method for easily performing the work of aligning the optical axes of two lenses in the manufacturing process of a cemented lens.

Background Art

[0002] In recent years, with the high performance of optical units, high performance is also required for lenses. In order to remove various aberrations of the optical system and improve characteristics, cemented lenses in which a plurality of lenses are bonded together are frequently used. A cemented lens is formed by bonding glass lenses having different refractive indexes with an adhesive. The surfaces of the two lenses facing each other are formed with the same curvature of convex and concave, and a synthetic resin-based adhesive is applied and bonded between them. After applying a solvent-free resin so as to cover the end portion of the adhesive exposed between the bonded optical surfaces, it is generally formed by applying a solvent-based antireflection coating to a portion outside the optical surface.

[0003] In the manufacturing process of this cemented lens, when overlapping two lenses, the work of aligning their optical axes is conventionally performed manually using an eccentric microscope because the glass lens is a transparent and easily damaged material. However, since this alignment work requires a high eccentricity accuracy of less than one minute, skilled techniques are required for the operator, and it is very inefficient to perform manually. In addition, problems such as foreign matter and dirt adhering due to contact with a finger or the like on the glass lens during the alignment work were likely to occur.

[0004] Therefore, various devices have been developed to mechanically simplify the process of aligning the optical axis. For example, the device disclosed in Patent Document 1 comprises an eccentric microscope, a rotating roller that rotates one lens to be centered, which is mounted on a lens holder, and two pressing plates positioned at 180° apart on either side of the other lens to be centered, in order to move the other lens to be centered in a straight line. The test lens, which is a combination of the two lenses to be centered, is placed on the lens holder, the rotating roller and the regulating plate opposite to the rotating roller are brought into contact with the outside of the lens positioned on the bottom, and the rotating roller is rotated to rotate the lens by more than 180°, thereby measuring the maximum eccentricity (△X1) and its direction. Subsequently, while rotating the rotating roller, the direction of the maximum eccentricity of the lens is brought to coincide with the position of one of the pressing plates. Then, the other lens is pressed against the other press plate with the other press plate (let's call the amount of movement at this time △X2), and then the other lens is pushed back by (△X2-△X1) with the other press plate. This process is repeated until alignment is confirmed, and the lens is centered.

[0005] Furthermore, the applicant of this application has also developed a device that uses four ultrasonic motors to alternately move each lens constituting the cemented lens in the XY axis direction, thereby performing fine positional control (see Patent Document 2). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 4-248507 [Patent Document 2] Japanese Patent Publication No. 2019-148646 [Overview of the project] [Problems that the invention aims to solve]

[0007] Conventional centering devices, such as the one shown in Patent Document 1, perform centering by repeatedly moving the upper lens relative to the fixed lower lens until the optical axes of the two lenses align, while optically measuring whether the optical axes of both lenses coincide when joining the upper and lower lenses which are stacked vertically with their lens surfaces facing each other. In other words, each time the two lenses are centered, the direction of movement of the upper lens is switched using a device that measures the amount of eccentricity, and optical axis alignment is measured and detected. This makes the centering process complicated, time-consuming, and inefficient.

[0008] The alignment device and alignment method described in Patent Document 2 solved the problem of improving work efficiency by making the alignment work easy and quick, but there was room to develop a device and method that could perform high-precision alignment work with an even simpler configuration and method.

[0009] The present invention has been made in view of these points, and aims to provide a lens centering mechanism, centering device, and centering method that do not require the use of equipment to measure the amount of eccentricity, have a simple structure, perform centering with high precision, and allow for easy and efficient centering work. [Means for solving the problem]

[0010] To achieve the aforementioned objective, the centering mechanism described in claim 1 of the present invention is a centering mechanism for aligning the optical axes of a reference lens and a driven lens, the reference lens and a driven lens, the reference lens and a driven lens, the reference lens and the driven lens moving means are capable of moving toward and away from the driven lens, which is positioned on the concave surface of the reference lens, from above in the optical axis direction, and are capable of moving the driven lens in the X and Y axis directions, wherein the driven lens moving means has a contact portion that contacts the upper surface and / or side surface of the driven lens, and is formed so that the driven lens can slide on the reference lens by the frictional force generated by the contact when moving in the X and Y axis directions.

[0011] The centering mechanism configured in this way offers an extremely simple configuration for moving the driven lens in the X and Y axis directions.

[0012] Furthermore, the centering mechanism described in claim 2 is characterized in that the contact portion comprises a pad whose surface that contacts the driven lens is formed in an annular shape, and a holder case into which the pad is fitted, and the holder case is held by the tips of three claws which are arranged at equal intervals on the lens-facing surface of an annular frame whose center is positioned on the optical axis, and which rotate together within the annular frame and can be fixed in a state in which their respective tips are positioned on a desired coaxial circle.

[0013] With the centering mechanism configured in this way, by appropriately selecting the contact portion considering the pad dimensions, etc., according to the diameter of the driven lens, etc., even if the diameter of the holder case changes, the pad can be positioned at the center of the annular frame when held by the three claws, so that the pad can be reliably brought into contact with the upper surface of the driven lens and slid to the desired position.

[0014] Furthermore, the centering device according to claim 3 is a centering device comprising the centering mechanism according to claim 1, and is characterized by comprising: a light source; a camera; a rectil; a driven lens moving means for adjusting the position of the driven lens, comprising a first adjustment means for moving the contact portion toward and toward the driven lens, and a second adjustment means for adjusting the horizontal position of the contact portion; a reference lens driving means for adjusting the position of the reference lens, comprising a first adjustment means for adjusting the horizontal position of the lens holder having a holding mechanism for the mounted reference lens; and a reference lens driving means disposed on the first adjustment means and comprising a second adjustment means for adjusting the inclination of the lens holder; and a monitor for displaying the optical axis of the light from the light source and an image of the camera projected onto the rectil.

[0015] The centering device configured in this way has a simple configuration that does not use equipment to measure the amount of eccentricity as shown in the conventional example, and when used in the centering method of the present invention, it becomes possible to perform high-precision centering easily and efficiently.

[0016] Furthermore, the centering method described in claim 4 is a centering method using the centering device described in claim 3, comprising the steps of: housing a sample lens in the lens holder; using the reference lens moving means, positioning the lens holder so as to obtain an acceptable centering accuracy while checking on the monitor the image of the camera in which the light emitted from the light source through the sample lens is imaged onto the rectil; housing the reference lens, on which the driven lens is superimposed, in the positioned lens holder in place of the sample lens; and using the driven lens moving means, bringing the contact portion into contact with the upper surface and / or side surface of the driven lens, and sliding only the driven lens using the frictional force generated by the contact of the contact portion so as to obtain an acceptable centering accuracy while checking on the monitor the image of the camera in which the light from the light source through the reference lens and the driven lens is imaged onto the rectil.

[0017] According to the centering method of the present invention, which has such a process, a reference lens moving means is used to position a lens holder that can obtain an acceptable centering accuracy for one sample lens that has been precisely centered. Subsequently, the reference lens is placed in the positioned lens holder, and with the driven lens on top, the driven lens moving means is used to slide only the driven lens to a position where an acceptable centering accuracy can be obtained using the frictional force generated by the contact of the contact protrusions, thereby completing the centering. This makes it possible to perform high-precision centering simply and efficiently, as if copying a sample lens. [Effects of the Invention]

[0018] Thus, according to the lens centering mechanism and centering method of the present invention, high-precision centering can be easily performed with a simple configuration that does not require the use of equipment to measure the amount of eccentricity. [Brief explanation of the drawing]

[0019] [Figure 1]An overall perspective view for explaining an embodiment of an alignment device including a lens alignment mechanism of the present invention [Figure 2] A perspective view for explaining a main part of an alignment device including a lens alignment mechanism of FIG. 1 [Figure 3] A bottom view for explaining a main part configuration of a driven lens moving means and a chuck mechanism [Figure 4] A cross-sectional view for explaining a contact state between a contact portion and a driven lens in an alignment device including a lens alignment mechanism of FIG. 1

Embodiment for Implementing the Invention

[0020] First, an alignment device using a lens alignment mechanism for a cemented lens according to the present invention will be described with reference to FIG. 1. Reference numeral 1 in FIG. 1 showing the alignment device of the present embodiment is a breadboard 1 placed on a vibration isolation table (not shown), and reference numeral 2 is an optical rail 2 erected at the center of one side of the breadboard 1. A light source 3 is disposed on the breadboard 1 so as to irradiate light in the vertical direction. Above the rail 2, a camera (light receiving element) 4 for capturing an image of the cross chart of the rectil 7 projected on the optical axis of the emitted light of the light source 3 and a monitor 10 for displaying the image are disposed (FIG. 1 shows a device in which the camera 4 and the monitor 10 are integrally formed).

[0021] [[ID=二十]] [[ID=二十ー]]On the rail 2 between the light source 3 and the camera 4, a lens holder 6 for holding a reference lens L1 constituting the cemented lens L is moved in the X and Y axis directions from the breadboard 1 side to adjust the horizontal position and the inclination to adjust the position of the reference lens L1. A reference lens moving means 11, a driven lens moving means 21 for moving the driven lens L2 constituting the cemented lens L together with the reference lens L1 in the X, Y, and Z axis directions to adjust the position, and the rectil 7 of the cross chart are respectively disposed via a carriage ⑧ so as to be fixed at a desired position by a screw 9. [[ID=二十二]] [[ID=二十三]]

[0022] [[ID=二十四]] Figure 2 shows the main parts of the reference lens moving means 11. Reference numeral 12 denotes the lens holder holding mechanism 12 that holds the reference lens L1 in the lens holder 6 at the centering position. Reference numeral 13 denotes the first adjustment means 13 that adjusts the shift (position misalignment) by moving the lens holder 6 in the X and Y axis directions. Reference numeral 14 denotes the second adjustment means 14, which is a so-called tip-tilt mechanism disposed on the first adjustment means 13 and adjusts the tilt (inclination) of the lens holder 6.

[0023] The first adjustment means 13 is a so-called fine adjustment unit using a lead screw, and comprises a first plate 13a arranged to slide in the X-axis direction, and a second plate 13b arranged to slide in the Y-axis direction along a slide guide groove 15 formed in the first plate 13a. Each plate 13a and 13b is configured to move forward and backward in their respective axes by driving a known micro-fine adjustment device.

[0024] A second adjustment means 14 is provided on the upper center of the second plate 13b, which is mounted on the upper side, via a mounting base 16. In this embodiment, the second adjustment means 14 is a fine adjustment unit whose tilt can be adjusted by tightening with a hex wrench 17, and comprises a first plate 14a mounted on the mounting base 16, which adjusts the tilt by the amount of tightening of a hex wrench 17a located on one side in the X-axis direction, and a second plate 14b mounted on the upper surface of the first plate 14a, which adjusts the tilt by the amount of tightening of a hex wrench 17b located on one side in the Y-axis direction.

[0025] Furthermore, a lens holder 6 is provided on the upper surface of the second plate 14b, which has two pins 18 that contact and position the reference lens L1 at an angle smaller than 180° (90° in this embodiment) on the outer circumference of the reference lens L1. In this embodiment, the reference lens L1 is held in a predetermined position in the lens holder 6 by being pressed from the side in the intermediate angular direction of the two pins 18 by a shaft member 20 held by a stay 19 erected from the second plate 13b of the first adjustment means 13a. The holding mechanism 5 for the reference lens L1 is composed of these pins 18 and shaft member 20.

[0026] In Figures 1 and 2, reference numeral 22 denotes a first adjustment means 22 that moves the contact portion 24 that contacts the driven lens L2 in the Z-axis direction, and reference numeral 23 denotes a second adjustment means 23 that moves the contact portion 24 in the X and Y axis directions. In this embodiment, the first adjustment means 22 is slidably arranged along the rail 2 and can be fixed by tightening a screw 9.

[0027] Furthermore, the driven lens moving means 21 has a contact portion 24 formed so that when it contacts the upper surface of the driven lens L2 from above in the optical axis direction (Z axis) and moves in the X and Y axis directions, the frictional force generated by the contact allows the driven lens L2 to slide on the reference lens L1.

[0028] In this embodiment, as shown in Figure 2, the contact portion 24 consists of a pad 25 made of a material such as resin that has an annular shape on the surface that contacts the driven lens L2, is flexible, and generates friction for moving the driven lens L2, and a cylindrical holder case 26 that exposes the contact surface of the pad 25 with the driven lens L2 and fits into it.

[0029] The driven lens moving means 21, as shown in Figure 3, includes a chuck mechanism 27 having three claws 28 that hold the holder case 26 by the pressure of a spring (not shown). Each of the three claws 28 of the chuck mechanism 27 has a rotating base disposed at equal intervals on the lens-facing surface of the outer annular frame of the double-layered annular frame 29 that constitutes the chuck mechanism 27, with its center positioned on the optical axis. By compressing the distance between the levers 30 provided on each of the inner and outer annular frames 29, a pin provided on the inner annular frame slides within the guide groove formed in the lever, rotates together within the annular frame 29 to open, closes when the force is released, and can then be fixed by tightening the clamp 31. Thus, by holding the holder case 26 with the three claws 28, each with its tip positioned on a desired coaxial circle, it is possible to position the pad 25 facing the driven lens L2. The lens holder 6 is one in which the positions of the two pins 18 are set according to the diameter of the lens to be centered.

[0030] Next, the lens alignment mechanism and alignment device of this embodiment, as well as the alignment method, will be explained.

[0031] First, activate light source 3 and camera 4, and adjust the position of rectil 7 so that the light emitted from light source 3 is focused in the center.

[0032] Next, the sample of the cemented lens L (sample lens), which has already been centered, is placed in the lens holder 6. At this time, the reference lens L1 of the sample lens is pushed by the shaft member 20 toward the two pins 18 arranged in the lens holder 6, and is held in place by being sandwiched between the two pins 18 and the tip of the shaft member 20.

[0033] In this state, the first adjustment means 13 of the reference lens moving means 11 is operated to move the lens holder 6 in the X and Y axis directions to adjust the shift (position misalignment), and the second adjustment means 14 is operated to tilt the lens holder 6 to adjust the tilt (inclination) of the lens holder, while checking the image on the monitor 10 of the light emitted from the light source 3 through the sample lens captured by the camera 4 and projected onto the reticle 7, the lens holder 6 holding the sample lens is positioned so that an acceptable centering accuracy (for example, within 1 minute) can be obtained.

[0034] Next, without changing the setting of the first adjustment means 13, the pressure on the shaft member 20 of the lens holding mechanism 5 is released, and the sample lens is removed from the lens holder 6. Subsequently, the reference lens L1, with the driven lens L2 superimposed on it, is placed on the positioned lens holder 6, and the shaft member 20 of the lens holding mechanism 5 presses the reference lens L1 toward the two pins 18 arranged on the lens holder 6 to hold it in place. As a result, the reference lens L1 is positioned in the same position as the reference lens of the sample lens.

[0035] Next, the centering mechanism of this embodiment is used. Specifically, the first adjustment means 22 of the driven lens moving means 21 is operated to bring the contact portion 24, which consists of a pad 25 fitted into a holder case 26 that is held in place by three claw portions 28 so that the center of the lens is positioned in the center of the annular frame 29, into contact with the upper surface of the driven lens L2, as shown in Figure 4. Figure 4 shows the state in which a silicone rubber pad, formed in an annular shape with an inner diameter of 6.2 mm, is in contact with the upper surface of the driven lens L2, which has an outer diameter of 9 mm.

[0036] Then, while checking the image on the monitor 10, which shows the light emitted from the light source through the reference lens L1 and the driven lens L2 captured by the camera 4 and projected onto the rectilator 7, the second adjustment means 23 of the driven lens moving means 21 is operated to obtain an acceptable centering accuracy, and the driven lens L2 is slid along the concave surface of the reference lens L1 using the frictional force generated by the contact of the pad 25, thereby completing the centering.

[0037] Thus, the centering mechanism and apparatus of this embodiment have an extremely simple configuration and can be applied even if the size of the lens to be centered or the radius of curvature of the lens surface differs. If necessary, by changing the diameter of the annular pad to match the size of the lens, the driven lens can be easily and reliably slid on the reference lens, and the effect of easily performing high-precision centering can be obtained.

[0038] Furthermore, according to the centering method of this embodiment, there is no need to measure or detect the movement of the upper lens and the optical axis alignment using an instrument that measures the amount of eccentricity. Once the position of the reference lens is set by driving the reference lens moving means, for cemented lenses identical to the sample lens, there is no need to drive the reference lens moving means each time. High-precision centering can be easily and efficiently performed as if copying the sample lens by simply operating the driven lens moving means, and it is also possible to reduce production losses when mass-producing cemented lenses.

[0039] Furthermore, the present invention is not limited to the embodiments described above, and can be modified in various ways without impairing the features of the present invention.

[0040] For example, the contact portion of the driven lens moving means may be a spherical contact protrusion formed at the tip of three claw portions, each having a rotating base portion arranged at equal intervals on the lens-facing surface of the annular frame. This contact portion may contact the upper and / or side surface of the driven lens, and when it moves in the X,Y axis direction, the frictional force generated by the contact portion may be used to hold the driven lens and allow it to slide on the reference lens. [Explanation of Symbols]

[0041] 1 Breadboard 2 rails 3 light source 4 cameras 6 Lens holder 7 Reticuli 8 carriages 9 screws 10 monitors 11. Reference lens moving means 12. Lens holder retention mechanism 13 First adjustment means 13a Plate 1 13b Plate 2 14 Second adjustment means 14a Plate 1 14b Plate 2 15 Slide guide groove 16 Mounting base 17 Hex wrench 18 pins 19 Stay 20 Shaft member 21 Driven lens moving means 22 First adjustment means 23 Second adjustment means 24 Contact part 25 pads 26 Holder Case 27. Chuck mechanism 28 Nail area 29 Circular frame 30 Lever 31 Clamp L-type bonding lens L1 Reference Lens L2 Driven Lens

Claims

1. A centering mechanism for aligning the optical axes of a reference lens and a driven lens, the reference lens and the driven lens having opposing surfaces formed with the same curvature, one concave and the other convex. A lens holding means for holding the reference lens in the lens holder at the centering position, A driven lens moving means is provided that can move the driven lens, which is positioned on top of the concave surface of the reference lens, toward and toward it from above in the optical axis direction, and that can move the driven lens in the X and Y axes. It has, The lens centering mechanism is characterized in that the driven lens moving means has a contact portion that contacts the upper surface and / or side surface of the driven lens and, when moving in the X, Y axis direction, holds the driven lens with the frictional force generated by the contact and is formed to slide on the reference lens.

2. The aforementioned contact portion comprises a pad whose surface that contacts the driven lens is formed in an annular shape, and a holder case into which the pad is fitted. The lens centering mechanism according to claim 1, characterized in that the holder case has a ring frame positioned with its center on the optical axis, and rotating bases are arranged at equal intervals on the lens-facing surface of the ring frame, and the holder case is held by the tips of three claws that rotate together within the ring frame and can be fixed in a state where their respective tips are positioned on a desired coaxial circle.

3. A centering device comprising the centering mechanism described in claim 1, Light source and Camera and, Rectil and, The system includes a first adjustment means for moving the contact portion toward or away from the driven lens, and a second adjustment means for adjusting the horizontal position of the contact portion, and a driven lens moving means for adjusting the position of the driven lens, A first adjustment means for adjusting the horizontal position of the lens holder having the reference lens holding mechanism, and a reference lens moving means disposed on the first adjustment means and comprising a second adjustment means for adjusting the tilt of the lens holder, for adjusting the position of the reference lens, A monitor that displays an image projected onto the optical axis of the light emitted from the light source captured by the camera and the rectil, A lens centering device characterized by comprising the following:

4. A centering method using the centering device described in claim 3, A step of housing the sample lens in the lens holder, The process involves using the reference lens moving means to position the lens holder when an acceptable centering accuracy is obtained, while checking the image of the camera, which is obtained by imaging the light emitted from the light source through the sample lens onto the rectil, on the monitor. A step of housing the reference lens, which consists of the driven lens superimposed on the sample lens, in the positioned lens holder, The process of centering the lens by using a driven lens moving means to bring the contact portion into contact with the upper surface and / or side surface of the driven lens, and while checking the image of the camera, which is formed on the rectil by the light emitted from the light source through the reference lens and the driven lens, on the monitor, sliding only the driven lens using the frictional force generated by the contact of the contact portion, A method for centering a lens, characterized by having [a certain feature].

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