JPH03114012A - Centering assembly device for lens - Google Patents

Abstract

PURPOSE:To simplify the constitution, and also, to surely assemble a lens to a lens barrel in a state that optical axes of lenses coincide with each other by pushing the side face of the lens by a pin of a small diameter through plural pieces of holes made on the side of the lens barrel, and allowing optical axes of plural lenses to align with each other in the lens barrel of the lens. CONSTITUTION:By arranging plural pieces of small holes on the side face of a lens barrel 1, and pushing the side of a lens 2 by a pin 4 of a small diameter through this hole, optical axes of lenses are allowed to align with each other. That is, the eccentric quantity and the direction of the lens 2 are measured by an eccentricity measuring means 7, and by moving forward and backward the pin 4 in the direction for correcting the eccentricity from a result of its measurement, a position of the lens is determined, and in this state, and adhesive agent is hardened in a state that the lens position remains held. In such a way, optical axes of each lens can be allowed to align with each other by a simple mechanism and the assembly is facilitated, and also, it is scarcely influenced by the contraction at the time when the adhesive agent is hardened and the centering assembly can be executed with high accuracy.

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a lens centering and assembling device for aligning the optical axes of a plurality of lenses and assembling the lenses into a lens barrel. (Prior art) Conventionally, when multiple lenses are assembled into one lens barrel, the single lens is centered, the center axis of the lens outer diameter is aligned with the optical axis, and a minute gap is created in the lens barrel. A common method is to assemble the lens by holding it in place, then gluing it, caulking it, tightening screws, etc. In addition, as a method of aligning the optical axes of the lenses with each other and assembling them into the lens barrel, measure the position of the center axis of the inner diameter of the lens barrel, and align the optical axis of the lens, which is centered and maintained using the Bell effect, at the center of the lens barrel. The method of assembling the lens at the same time is described in Japanese Patent Application Laid-Open No. 107-1983.
This method is known from Japanese Patent No. 307, and further includes a method in which a lens is assembled into a secondary lens frame, and the secondary lens frame is assembled into a primary lens frame after adjusting the optical axis using a plurality of adjusting rods extending in the radial direction of the lens. has been proposed in Japanese Utility Model Application Publication No. 59-63316. Method 1 is how to assemble the lens by aligning the optical axes and fixing it with adhesive. Japanese Patent Application Publication No. 5
It is described in Japanese Patent No. 6-92511. In addition, the lens barrel is placed in a semi-fluid state before curing. - is easily plastically deformed and can be hardened to 1-7 by adding a hardening agent or irradiating with ultraviolet rays, etc., and after temporarily holding the 1-non with the optical axis adjusted by this adhesive, this is A method of curing by a prescribed method is also disclosed in JP-A-59
It is proposed in the publication No.-228615. (Problems to be Solved by the Invention 7) In the conventional method of fitting the lens into the lens barrel, in order to facilitate the insertion of the lens and the assembly, the alignment between the lens barrel and lens was changed. If the clearance is large, the accuracy of optical axis alignment between the lenses will decrease, resulting in an increase of 17 points. On the other hand, if the clearance is narrowed, assembly becomes extremely difficult and automation becomes difficult. Furthermore, the sliding movement between the 1-nons and the lens barrel causes dust and the like to get mixed into the lens barrel. In addition, in the method of inserting a means for measuring the axis of the lens barrel into the lens barrel, and using the bell method to hold the 1/2 lens at center I7 and aligning it with the center axis of the lens barrel, The structure of the 1-nons holder, which also serves as a central axis measuring device, becomes complicated, and when the diameter of the lens becomes small, it becomes difficult to miniaturize the lens holder to a size that can be inserted into the lens barrel. . Furthermore, the method of using a secondary lens frame has the disadvantage that the structure of the lens frame is complicated, large and heavy. In addition, the method of temporarily holding the object with an adhesive has the disadvantage that the optical axis may shift due to shrinkage caused by the curing of the adhesive. The present invention has a simple configuration, and the centering of the above-mentioned types of lenses can be achieved by assembling the lens into the lens barrel while ensuring that the optical axes of the lenses are aligned. An object of the present invention is to provide an assembly device for assembling a lens with 6 lenses and 17 lenses according to the present invention. This device incorporates a lens barrel holding mechanism that rotatably supports the lens barrel, a stage that can move the entire lens barrel holding mechanism in the vertical direction, and a hole drilled in the side of the lens barrel that allows the inside of the lens barrel to be A plurality of pins capable of touching the side surface of the lens, a moving mechanism for moving the pins in the axial direction, an eccentricity measuring means for measuring the eccentricity of the optical axis of the lens, and a side surface of the lens barrel. a hole detection means for detecting the position of the hole drilled in the lens; an adhesive application device for bonding the lens to the lens barrel; The present invention is characterized by comprising a control device that controls the positions of each of the above-mentioned mechanisms. Fig. 1 shows a conceptual diagram of the lens centering and assembly device of the present invention. In the conventional device, the centering accuracy of the lens , the lens outer diameter,
Centered by the inner diameter of the lens barrel

[7] In contrast, in the device of the present invention, a plurality of small holes are provided on the side surface of the lens barrel 1, and by passing through these holes and pushing the side surface of the lens 2 with a small diameter pin 4, 1 Align the optical axes of the nons. That is, the eccentricity measuring means 7 measures the amount and direction of eccentricity of the lens 2, and based on the measurement results, the pin 4 is moved in the direction to correct the eccentricity.
Move the lens back and forth to determine the position of the lens, and in this state, while holding the lens position, allow the adhesive to harden. According to the present invention, there is no need to rely on the accuracy of lens centering, and even lenses that are not centered can be assembled with their optical axes reliably aligned. In addition, since all work is done from outside the lens barrel, even if the lens barrel is extremely small, it can be easily handled with the equipment. Since the inner diameter clearance can be relatively large, there are advantages such as automatic assembly being extremely easy. Furthermore, since the adhesive is cured while the lens is held in position by the pin 4, it is not affected by curing shrinkage. (Example) Below, the present invention will be described in detail with reference to the drawings. FIG. 2 shows the overall structure of an embodiment of the lens centering and assembly apparatus of the present invention. In the present invention, a lens barrel 11 for incorporating a lens 12 is provided with a step inside thereof for holding a lens. The inner periphery of this lens barrel 11 is configured so that it can fit with the outer periphery of the nozzle 12 with a suitable clearance. Further, this lens barrel 11 is held by a lens barrel holding device 13 so that the center axis of the outer diameter of the lens barrel 11 and the rotational axis of the spindle 14 substantially coincide with each other. The lens barrel 11 and lens barrel holding device 13 are rotatably held by a precision spindle 14 and can be rotated in any direction and position by a motor 16 via a belt 15. Further, 17 is a rotation angle detection device. Furthermore, the constituent members 11 to 17 are integrally constructed and placed on a stage 25 that is movable in the direction of the rotation axis of the spindle 14. The stage 25 is connected to a motor 28 via a lead screw 26 and a belt 27, and rotation of the motor 28 allows the spindle to move in the axial direction. The hole in the lens barrel 11 can be automatically detected by the motor 16, the rotation angle detection device 17, and the hole detection sensor 20. The pin drive unit 18 (described in detail later) is connected to the spindle 1
It is possible to move in a direction perpendicular to the rotation axis of No. 4, and the position at which it stops when it approaches the spindle rotation axis (hereinafter referred to as the "advance position") can be finely adjusted. A pin 19 is mounted on the pin drive unit 18 via a fine movement mechanism (described in detail later).
is provided so that this pin 19 can be drawn out minute by minute. The hole detection sensor 20 is of a light reflection type or a stylus type, so that the position of the hole on the side surface of the lens barrel 11 can be detected. This hole detection sensor 20 is also movable in a direction perpendicular to the spindle rotation axis, but does not need to be movable if the outer diameter of the lens barrel 11 is constant. A lens holding unit (described in detail later) 21 is used to prevent the lens 12 from lifting off the stepped portion of the lens barrel 11, but this is necessary if the lens's own weight is large enough to prevent it from lifting. do not have. This lens holding unit 21 is movable in the direction of the spindle rotation axis and in a direction perpendicular thereto in order to move it to a place where it will not become an obstacle when attaching and detaching the lens frame 11 and inserting the lens 12. The lens 12 and the lens barrel 11 are bonded together by an adhesive coating device 22. The eccentricity measuring device 23 observes the center of curvature of the lens and detects the amount of eccentricity. The ultraviolet curing adhesive for fixing the lens centered and held by the ultraviolet irradiation device 24 is cured. FIG. 3 shows the configuration of the pin drive unit 18 in detail. The pin 19 is held movably in the axial direction by a stage 30, and is biased by a spring 31 in a direction in which the pin 19 is retracted. The feed screw 32 is connected to a motor 36 via pulleys 33 and 34 and a belt 35, so that the rotation of the motor 36 allows the pin 19 to move slightly back and forth. The stage 37 supports the entire pin fine movement mechanism so as to be movable in the axial direction of the pin, and is moved by an air cylinder or a motor (not shown). Further, the stopper 38 determines the stop position of the stage 37 on the spindle side, and allows this stop position to be adjusted with high precision. FIG. 4a shows the structure of the lens holding unit 21 in detail. In this example as well, 11 is a lens barrel, and 12 is a lens. In this example, the hollow cylinder 40 has an outer diameter slightly smaller than the inner diameter of the lens barrel 11, and is fixed to the ring 42 by three pins 41. FIG. 4b shows a perspective view of the structure of a lens holding portion consisting of a cylinder 40, a pin 41 and a ring 42. As is clear from this figure, the cylinder 40 is hollow so as to hold the lens while not interfering with the optical path for measuring the eccentricity of the lens. Further, the ring 42 is configured to press the lens with its own weight. Further, the arm 43 is configured to be movable in the vertical direction by a cylinder 44. The stage 45 is movable in the direction of the arrow by an air cylinder or a motor (not shown). When the lens holder becomes an obstacle for inserting a lens, etc., the lens holder can be lifted by a cylinder 44, and the stage 45 is lowered rearward, so that the lens holder can be retracted. When the lens is held down by the lens holder (Fig. 4a), the ring 42 and the arm 43 are separated,
The lens holding parts 40 to 42 are configured to be able to rotate together with the lens 12. FIG. 5 is a block diagram of a control system for controlling the overall operation of the lens centering and assembly apparatus of the present invention. In the present invention, a combi coater (CPU) 48 is used as a controller and a controller for automatically performing the entire centering and assembling process of the 1 nons centering 12 assembly apparatus. The operation of the lens centering 15 assembly apparatus of the present invention will be described below with reference to the apparatus shown in FIG. First, the lens barrel 11 is attached to the lens barrel holding device 13. Next, the motor 28 is rotated to move the spindle 14 in the vertical direction, and the vertical position is adjusted so that the height of the hole detection sensor 20 matches the height of the hole in the lens barrel 11, and the spindle is rotated by the motor 1G. ;-1 The position of the hole in the lens barrel 11 is detected by the hole detection sensor 20 and the rotation angle detection device 17. Next, an ultraviolet curable adhesive is applied to the lens holding portion of the lens barrel 11 by the adhesive coating device 22, avoiding the position of the detected hole in the lens barrel 11. The lens 12 is dropped into the lens barrel 11, and then the lens is held down from the bottom by the lens holding unit 21. The spindle 14 is rotated by the motor IG, and the eccentricity measuring device 23 measures the amount and direction of eccentricity of the lens with respect to the axis of rotation of the spindle. Next, the spindle 14 is rotated by the motor 16 to match the already detected hole in the lens barrel 1 with the position of the pin 19, so that the pin 19 can be inserted into the hole. In this state, the spindle 37 (FIG. 3) of the pin drive unit 18 is moved forward until it is stopped just before the pin 19 touches the lens 12. Next, while observing the optical axis position of 1/lens using the eccentricity measuring device 23, the pin 19 is
The lens is moved forward one by one by a fine movement mechanism to detect movement of the spot image on the optical axis, and after detecting 17 the position where the pin 19 touches the side surface of the lens 1-2, the fine movement of the pin is stopped. The rotation axis of the spindle 14 and the central axis of the lens barrel 11 are held so that they coincide with each other.1. Therefore, by simply slightly moving each pin 19 back and forth, the optical axis of the lens 12 can be aligned with the spindle 1.
The position of the lens can be adjusted to match the rotation axis of 4. Contact between the pin 19 and the lens 12 can also be detected by installing a pressure sensor such as a voltage element or a strain gauge on the pin 19 side. Furthermore, if the central axis of the lens frame 11 and the rotational axis of the spindle 14 cannot be held in alignment, the center of curvature of the back surface of the lens 12 is on the central axis of the lens frame due to the Bell effect, so Measurement can also be performed by observing the 12 optical axis spots with the eccentricity measuring device 23 and matching the spot position on the surface with the spot position. In this way, the adhesive is applied while the optical axis of the lens 12 is held in alignment with the central axis of the lens frame 11 by the pin 19, and then the adhesive is cured by irradiation with ultraviolet rays by the ultraviolet irradiation device 24. to fix the lens 12. Finally, remove the pin 19 from the lens barrel and release the lens holder 21 from the lens. By repeating this procedure for the number of lenses to be assembled into the lens barrel, the optical axis of the lens is accurately aligned with the center axis of the lens barrel.
- It is possible to assemble a lens group. (Second Embodiment) Next, a second embodiment of the lens centering and assembly apparatus of the present invention will be described with reference to FIG. In this example, in addition to the configuration of the first example shown in FIG. 2, means for measuring the eccentricity of the lens barrel with respect to the rotation axis of the spindle is provided. First mentioned above. In the example, the position where the optical axis of the lens should match was determined based on the spindle rotation axis, but instead, in this example, the deflection of the outer diameter of the lens barrel was measured by contact or non-contact means. The center of the lens barrel is determined from the measured value. A contact type outer diameter runout measuring device is shown in FIG. 6a, and a non-contact type (that is, a light amount detection type) outer diameter runout measuring device is shown in FIG. 6b. In this example, 61 is a contact type minute displacement measuring means, 62
indicates an amplifier for signal conversion, 63 is a light emitter of a non-contact shake detection device, 64 is a light receiver thereof, and 62 is the same (indicates an amplifier for signal conversion, and these are configured and arranged as shown in the figure). The output from this amplifier 62 is supplied to the control device as described above, thereby measuring the amount and direction of eccentricity of the central axis of the lens barrel with respect to the spindle rotation axis, and aligning the optical axis of the lens with the central axis of the lens barrel. In the second embodiment configured as described above, even if the axis of rotation of the spindle and the center axis of the lens barrel are misaligned, the light of the lens is aligned with the center axis of the lens barrel. There is an advantage that the axes can be aligned accurately. (Effects of the Invention) As is clear from the above, according to the present invention, the optical axes of the lenses can be aligned with each other with a simple mechanism. It is extremely easy to assemble.Also, since the clearance between the lens and the lens barrel can be large, it is extremely suitable for automatic assembly, etc.In addition, the lens is held in a state where the optical axes are aligned. Since the adhesive is applied and cured while the adhesive is still in place, it is not affected by shrinkage when the adhesive hardens, and therefore, highly accurate centering and assembly can be performed.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the conceptual configuration of the lens centering and assembling device of the present invention, FIG. 2 is a perspective view showing the configuration of the first embodiment of the lens centering and assembling device of the present invention, and FIG. Fig. 4a is a side view showing the structure of the bottle drive device of the invention lens centering and assembling device; Fig. 4a is a side view showing the structure of the lens holding device; Fig. 4b is a perspective view showing the lens holding member; Fig. 5 is the main body. A block diagram showing the control of the operation of the inventive lens centering and assembling device, Fig. 6a is a perspective view showing the configuration of the contact type outer diameter runout measuring device, and Fig. 6b shows the configuration of the non-contact type outer diameter runout measuring device. FIG. Lens barrel holding device Pin hole detection means Adhesive application means Eccentricity measuring device Lens barrel holding device Spindle belt motor rotation angle detection device Pin drive unit Pin hole detection sensor Lens pressing unit Adhesive application device Eccentricity measuring device Ultraviolet irradiation device stage feed screw belt motor stage spring feed screw pulley pulley belt motor stage stopper cylindrical pin ring arm cylinder stage PU contact type minute displacement measuring means amplifier emitter light receiver Fig. 3 Fig. 4 ar Fig. 4 (b) Fig. 5 Figure 6 ( ) ( ) June 26, 1990

Claims (1)

[Claims] 1. A device for assembling lenses by aligning the optical axes of multiple lenses in a lens barrel, which includes a lens barrel holding mechanism that rotatably supports the lens barrel, and a lens barrel holding mechanism that supports the entire lens barrel in the vertical direction. a movable stage; a plurality of pins capable of protruding the side surface of a lens in the lens barrel through holes drilled in the side surface of the lens barrel; and a moving mechanism that moves the pins in the axial direction;
an eccentricity measuring means for measuring the eccentricity of the optical axis of the lens; a hole detecting means for detecting the position of the hole drilled in the side surface of the lens barrel;
The present invention is characterized by comprising an adhesive applicator for adhering the lens to the lens barrel, and a control device for processing signals from the eccentricity measuring means and the hole detecting means to control the positions of the respective mechanisms. Lens centering and assembly device.