JP2007248937A - Method for manufacturing lens unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly productive method for manufacturing a lens unit capable of preventing a lens of a defective contour having a small contour from being put in, which does not need an alignment process. <P>SOLUTION: The present invention is a method for manufacturing a lens unit comprising a tubular holder 1 having a through-hole 2 and lenses 8-10 which are pressed into the through-hole 2 and fixed. The method for manufacturing a lens unit has the third process in which the lenses are pressed into the predetermined position of the tubular holder 1, and then the suction of the lenses 8-10 is released. The first lens 8, the second lens 9, and the third lens 10 are pressed into the predetermined position of the tubular holder 1 sequentially from bottom to top vertically. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a lens unit in which a lens is press-fitted and fixed in a cylindrical holder.

  In recent years, camera modules have been built in mobile phones, and their functions have been enhanced. For this reason, a lens unit, which is an important part constituting a camera module, is required to be small and low in profile, and a plurality of aspheric lenses are used. In such a lens system, since the amount of eccentricity allowed for one lens is within several microns, conventionally, it has been a manufacturing method with low productivity in which the position of each lens is adjusted and assembled. In view of this, a highly productive manufacturing method has been developed in which the processing accuracy of the components, that is, the cylindrical holder and the lens, is assured without any adjustment process. This is a manufacturing method in which a plurality of ribs are provided on the inner wall of a cylindrical holder, and a lens is thrown in from vertically above. The diameter of the inscribed circle of the rib is slightly smaller than the outer shape of the lens to be inserted, and is a so-called press-fit structure in which the center of the inscribed circle of the rib and the center of the cylindrical holder are designed to be approximately equal. This is a method of manufacturing a lens unit that can guarantee the amount of eccentricity based on the outer shape.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
JP 2006-30243 A

  However, according to the above conventional technique, since the lens is inserted vertically above the cylindrical holder, even a lens having a small outer shape is incorporated. Therefore, the eccentricity between the cylindrical holder and the lens cannot be guaranteed. For this reason, even when the subsequent lenses are accurately press-fitted, the decentering amount of the entire optical system becomes large, so that the optical characteristics of the lens unit deteriorate, that is, defective products are formed, resulting in a decrease in productivity. Become.

  Therefore, the present invention aims to increase productivity.

  In order to achieve this object, the present invention is a method of manufacturing a lens unit comprising a cylindrical holder having a through hole and a lens that is press-fitted and fixed in the through hole. A first step of positioning and fixing the lens to the movable lens suction portion; a second step of positioning and fixing the cylindrical holder vertically above the lens suction portion; and the lens vertically upward. A method of manufacturing a lens unit comprising a third step of moving and press-fitting into a predetermined position of the cylindrical holder, and then releasing the adsorption of the lens. According to this manufacturing method, the lens is moved from below to above. Therefore, a lens with a defective outer shape having a small outer shape will be returned without being press-fitted, and this prevents the introduction of a lens with a defective outer shape, thereby increasing productivity. Is shall.

  As described above, in the manufacturing method of the lens unit of the present invention, since the lens is always inserted into the cylindrical holder from below and press-fitted and fixed, a lens having a small outer shape is not press-fitted and remains in the suction portion as it is. become. That is, since a lens having a defective outer shape can be easily detected and removed in the manufacturing process, a centering process is unnecessary and a method for manufacturing a lens unit with high productivity can be provided. Furthermore, since the lens is inserted into the cylindrical holder from below and is press-fitted and fixed, it is difficult for foreign matter to enter between the lenses, and as a result, the optical characteristics of the lens unit can be further improved.

  Hereinafter, a structure of a lens unit and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings.

  1 is a perspective view of a cross section of a cylindrical holder in an embodiment of the present invention, FIG. 2 is a bottom view of the cylindrical holder, and FIG. 3 is a cross section of a lens unit after a lens is press-fitted and fixed to the cylindrical holder. Each figure is shown.

  1-3, 1 is the cylindrical holder which consists of resin materials, such as a polycarbonate and a liquid crystal polymer, 2 is the through-hole which penetrates the cylindrical holder 1, 3 is the rib provided in the inner wall of the through-hole 2, and 4 is a rib 3 is a step portion provided in a tapered shape so as to be smoothly connected to 3, 5 to 7 are step portions provided inside the through-hole 2, and 8 to 10 are lenses made of glass or resin material constituting the optical system, respectively. Yes.

  As shown in the cross-sectional view of FIG. 3, the lens unit of the present invention positions the lenses 8 to 10 by bringing the outer peripheral portions of the lenses 8 to 10 into contact with the stepped portions 5 to 7 provided in the cylindrical holder 1. It has a prescribed structure, and is mainly used for a solid-state imaging device characterized by a small and low profile mounted on a camera-equipped mobile phone or the like.

  In the lens unit described above, as shown in FIGS. 1 and 2, ribs 3 that are a plurality of convex portions are provided on the inner walls of the stepped portions 5 to 7 provided in the through hole 2. The diameters of the inscribed circles connecting the tips of the ribs 3a to 3c in the step portions 5 to 7 are set to be slightly smaller than the diameters of the corresponding lenses 8 to 10, and the lenses are arranged via the swash portions 4a to 4c. This is a so-called press-fitting method in which the lenses 8 to 10 are fixed by elastic deformation of the ribs 3 a to 3 c by abutting 8 to 10 with the step portions 5 to 7.

  The difference between the diameter of the inscribed circle of the ribs 3a to 3c and the diameter of the lenses 8 to 10 is designed in consideration of the stress due to elastic deformation of the ribs 3a to 3c. Although it depends on the outer shape of the lens, it is often set to 10 microns or less at maximum so as not to cause birefringence or cracking. For this reason, the diameters of the lenses 8 to 10 to be incorporated also require an accuracy of 10 microns or less. However, since the outer shape of the lens is complicated, it is very difficult to measure and inspect the lens diameter with micron accuracy regardless of contact type or non-contact type. Accordingly, a lens having a defective outer shape is likely to be mixed, and even when mixed, the lenses 8 to 10 are inserted from vertically above the cylindrical holder 1, so that the process proceeds to the next step even in a poorly pressed or unpressed state. As a result, the optical characteristics of the lens unit deteriorate due to the movement of the lenses 8 to 10.

  Furthermore, in the press-fitting method, the press-fit state of the first lens may affect the press-fit state of the second lens. Specifically, the diameter of the inscribed circle of the rib 3b for press-fitting the second lens 6 may be increased by press-fitting the first lens 5 into the step portion 5 of the cylindrical holder 1. Therefore, even if the external accuracy of the second lens 9 is as designed, a press-fitting failure or a non-press-fitting occurs as a result. Even in such a case, the process proceeds to the next step for the same reason as described above, and the optical characteristics of the lens unit are deteriorated.

  Therefore, according to the manufacturing method of the lens unit of the present invention, it is possible to easily detect and remove the press-fitting failure and the non-press-fitted state, and therefore it is possible to provide a highly productive manufacturing method that does not require the alignment process. Details will be described below.

  4 to 6 are manufacturing process diagrams showing the manufacturing method of the lens unit according to the embodiment of the present invention.

  4A to 4C show a manufacturing process showing a manufacturing method of the lens unit according to the embodiment of the present invention, and particularly show a press-fitting process of the first lens 8.

  11 is a holding plate for regulating the position of the cylindrical holder 1, 12 is a first positioning jig, 13 is a cylindrical lens suction jig, and 13a is provided on the top surface of the cylindrical lens suction jig. 14 is a cylindrical second positioning jig, R1 is the diameter of the stepped portion 5 provided inside the through hole 2, R2 is the diameter of the stepped portion 6, and R3 is also the stepped portion 7. The diameter of each is shown.

  The first positioning jig is for coarse adjustment, and the second positioning jig is for fine adjustment.

  First, as shown in FIG. 4A, the cylindrical holder 1 is transported to a predetermined position by a transport system (not shown) and then sandwiched from the left and right by a first positioning jig 12. The positioning is rough. At this time, there is a cylindrical lens suction jig 13 vertically below the cylindrical holder 1, and the first lens 8 is positioned and sucked by the cylindrical lens suction portion 13a (first step).

  At this time, the outer shape of the cylindrical lens suction portion 13a is designed to be slightly smaller than the outer shape of the first lens 8, and a countersink is provided to escape the convex portion of the lens. Further, the bottom surface of the counterbore part is provided with a through hole so that vacuum suction can be performed.

  Next, the second cylindrical fixing jig 14 is moved in the vertical direction simultaneously with the cylindrical lens adsorption jig 13 that adsorbs the first lens 8, and the second cylindrical fixation is performed. The cylindrical holder 1 is clamped and fixed by the tool 14 and the pressing plate 11 (second step).

  At this time, the cylindrical lens chucking jig 13 and the second cylindrical fixing jig 14 have a double structure that can slide up and down and move up and down. That is, the second cylindrical fixing jig 14 is coaxially provided on the outer peripheral side of the cylindrical lens suction jig 13. Further, the top surface portion of the second cylindrical fixing jig 14 reaches a rib 3c that is substantially equal to the diameter R3 of the step portion 7 provided in the through hole 2 and provided on the inner wall of the step portion 7. The convex part of the height which is not carried out is provided. Therefore, by inserting the convex portion of the second cylindrical fixing jig into the cylindrical holder 1, the coaxiality between the cylindrical holder 1 and the cylindrical suction jig 13 is the second cylinder. It is guaranteed by the fixed fixing jig 14, and is positioned precisely by sandwiching the first fixing jig and the pressing plate 11 from three directions.

  Finally, only the cylindrical lens suction jig 13 that has positioned and fixedly fixed the first lens 8 is moved to a predetermined position in the vertical direction so that the stepped portion 5 of the cylindrical holder 1 is moved to the stepped portion 5. After bringing the outer periphery of the first lens 8 into contact, the vacuum suction of the cylindrical lens suction portion 13a is released (third step).

  At this time, in order to prevent the movement of the first lens 8 due to the kickback of the cylindrical holder 1, it is better to leave it for a while after the contact and then release the vacuum suction of the cylindrical lens suction portion 13a.

  According to the method for manufacturing a lens unit according to the embodiment of the present invention described above, the first lens 8 is inserted and press-fitted upward from the vertically lower side of the cylindrical holder 1. Therefore, when the first lens 8 is poorly pressed or not pressed, the first lens 8 remains on the cylindrical lens suction portion 13a. Therefore, only a good cylindrical holder 1 into which a lens is press-fitted with a certain force or more can be advanced to the next process.

  If the above-mentioned defect is caused by a defect in the outer shape of the first lens 8, another lens is replaced and press-fitting is performed again. Moreover, if it originates in the shaping | molding precision defect of the cylindrical holder 1, what is necessary is just to replace | exchange and insert into another cylindrical holder.

  As a result, since it is possible to prevent the introduction of a defective part, it is possible to provide a highly productive manufacturing method that does not require alignment and can be assembled only by press-fitting.

  Further, since the step of pressing and fixing the lens is always performed from the vertically lower side of the cylindrical holder 1, it is difficult for foreign matter to be mixed in the cylindrical holder 1, and the already mixed one is gravity when the cylindrical holder 1 is positioned and fixed. It falls by. Therefore, when a lens system using a plurality of lenses is configured, it is possible to prevent foreign matters from being mixed between the lenses, so that the optical characteristics of the lens unit can be improved.

  FIGS. 5A to 5C show a manufacturing process showing a manufacturing method of the lens unit according to the embodiment of the present invention, and particularly show a press-fitting process of the second lens 9.

  6A to 6C show a manufacturing process showing a manufacturing method of the lens unit according to the embodiment of the present invention, and particularly show a press-fitting process of the third lens 10.

  5 and 6, the outer shape of the lens and the cylindrical lens suction jigs 15, 17 corresponding thereto, cylindrical lens suction portions 15 a, 17 a provided on the top surface thereof, and a second cylindrical fixing jig. The description is simplified because only the shapes of the tools 16 and 18 are different.

  In the method of manufacturing a lens unit according to the present invention, since a lens is always inserted and fixed by press-fitting into a cylindrical holder from below vertically, a lens having a small outer shape with a small outer shape is not press-fitted and remains in the suction portion. In other words, a lens having a cylindrical walder can be easily detected and removed in a manufacturing process, and an effect of providing a manufacturing method of a highly productive lens unit that does not require an alignment process can be provided. This is useful for a method of manufacturing a lens unit that is press-fitted into a lens and fixed.

Sectional perspective view of the cylindrical holder in one embodiment of the present invention Bottom view of the cylindrical holder Sectional drawing which shows an example of the lens unit in one embodiment of this invention (A)-(c) Manufacturing process figure which shows the manufacturing method of the lens unit in one embodiment of this invention (A)-(c) Manufacturing process figure which shows the manufacturing method of the lens unit in one embodiment of this invention (A)-(c) Manufacturing process figure which shows the manufacturing method of the lens unit in one embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical holder 2 Through-hole 8 1st lens 9 2nd lens 10 3rd lens 13 Cylindrical lens adsorption jig | tool 13a Cylindrical lens adsorption | suction part 15 Cylindrical lens adsorption jig | tool 15a Cylindrical shape Lens adsorption part 17 Cylindrical lens adsorption jig 17a Cylindrical lens adsorption part

Claims (1)

A method of manufacturing a lens unit comprising a cylindrical holder having a through-hole and a lens press-fitted into the through-hole, wherein the lens is positioned and adsorbed on a lens adsorbing portion that is vertically movable in the vertical direction. A first step of fixing, a second step of positioning and fixing the cylindrical holder vertically above the lens suction portion, and a movement of the lens vertically upward to press-fit into a predetermined position of the cylindrical holder. Then, a method for manufacturing a lens unit comprising a third step of releasing the adsorption of the lens.

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