JP6363896B2 - Imaging unit manufacturing method and imaging unit - Google Patents

Description

  The present invention relates to an imaging unit manufacturing method and an imaging unit, and more particularly to a manufacturing method of an extremely small endoscope imaging unit built in a small-diameter endoscope and an endoscope imaging unit.

  When assembling the imaging unit of the camera, it is necessary to align the objective lens and the imaging device so that the imaging surface of the objective lens coincides with the imaging surface of the imaging device (see, for example, Patent Documents 1 and 2). ).

JP 2006-270264 A JP 2005-12327 A

  When the objective lens and the imaging device are as small as several millimeters, it is difficult to handle them directly. Furthermore, if the relative position between the objective lens and the image sensor is slightly shifted, the image acquired by the image sensor will be significantly out of focus or optical axis misaligned. Requires strict precision in the micrometer range. Therefore, the following method is used for assembling the extremely small imaging unit.

  First, an objective lens unit holding an objective lens with a lens frame and an image sensor unit holding an image sensor with a lens frame are each held by a relatively large holder of several centimeters, and each holder is attached to a jig. Next, the lens frames to which the bonding agent is applied are telescopically fitted to each other, and the holders are adjusted so that the relative position between the objective lens and the image sensor is optimized by finely adjusting the position of the holder with a jig. Align. Next, the bonding frames are cured to bond the lens frames together, and each unit is removed from the holder. By the above procedure, an imaging unit in which the objective lens and the imaging device are aligned with high accuracy can be manufactured.

  However, in the production line, the alignment between the holders and the curing of the bonding agent are performed in different places by different apparatuses, and thus the holders aligned with each other must be moved. At this time, the holders are moved after being temporarily fixed so that the relative positions of the holders do not change. However, since the bonding agent is uncured, a slight deviation tends to occur in the relative positions of the holders during temporary fixing. As described above, the relative position shift greatly affects the quality in a minimal imaging unit.

  The present invention has been made in view of the above-described circumstances, and even when the objective lens and the imaging element are extremely small, it is possible to stably manufacture a high-quality imaging unit in which these are strictly aligned. An object of the present invention is to provide an imaging unit manufacturing method and an imaging unit.

In order to achieve the above object, the present invention provides the following means.
The present invention includes a cylindrical first lens frame for holding either one of the imaging device or the objective lens, the first fastening portion to the portion protruded from the outer peripheral surface or outer peripheral surface of the first lens frame wherein a first unit provided integrally with either the other includes a cylindrical second lens frame for holding the portion that protrudes from the outer peripheral surface of the second lens frame of the imaging element or the objective lens imaging assembled by causing fitting the second unit comprising integrally the first engagement portion and the second engagement portion capable of mechanically fastened, the second lens frame to the first mirror frame A method for manufacturing a unit, comprising: an applying step of applying a bonding agent to a fitting portion of the lens frame; and fitting the second lens frame into the first lens frame ; An alignment step for performing relative alignment with the second unit, and the alignment step; And fastening step of mechanically fastening the said to the first engagement portion of the first unit and the second unit which is combined relative position the second fastening portion in-up, curing the bonding agent A curing step for fixing the first unit and the second unit frame of the second unit to which the first fastening unit and the second fastening unit are fastened, and curing of the bonding agent. A method of manufacturing an imaging unit is provided that includes a cutting step of cutting a portion of the first fastening portion and the second fastening portion that protrudes from the outer peripheral surface of the first lens frame .

  According to the present invention, the objective lens unit and the imaging element unit, in which the bonding agent is applied to the fitting portion of the lens frame in the application step, are assembled and aligned in the alignment step. The objective lens and the image sensor are each held by the lens frame so that the optical axis substantially coincides with the central axis in the longitudinal direction of the lens frame, and the relative positions of the two lens frames that are nested with each other are finely adjusted. By adjusting, the units can be aligned so that the imaging plane of the objective lens exactly matches the imaging plane of the imaging device. At this time, the units can be aligned with each other by directly holding each unit at the position of the fastening portion provided outside each lens frame and finely adjusting the position of the fastening portion.

  Subsequently, in the fastening step, the units are temporarily fixed by mechanically fastening the fastening portions. At this time, since the fastening portions that are a part of each unit are directly fastened, the units can be temporarily fixed without causing a shift in the relative positions of the units that are strictly aligned in the positioning step. it can. Even in the next curing step, the relative positions of the units are maintained, so that even if the objective lens and the imaging device are extremely small, it is possible to stably manufacture a high-quality imaging unit in which these are strictly aligned. it can. In addition, after the bonding agent is cured, a small-sized imaging unit can be manufactured by cutting away a fastening portion that is unnecessary for the imaging unit in the cutting step.

In the above invention, the first fastening portion, said first et al provided in a portion which projects radially from the outer peripheral surface of the lens frame is a first thick region located radially outwardly, the first and a first thin region located between said one lens frame outer peripheral surface of the first thick-walled region, the second fastening portion, radially from the outer peripheral surface of the second lens frame And a second thick region located between the outer peripheral surface of the second lens frame and the second thick region. with the door, crossing the first thin region, in a direction intersecting the radial direction, and has a size smaller than said first thick region, the second thin region, the radial in the direction of, Rukoto which have a size smaller than said second thick region is preferred.
By doing in this way, a fastening part can be easily excised in a thin area. It is preferable that the dimension of the thin region in the direction intersecting with the radial direction is 80% or less of the dimension of the fastening portion in the direction intersecting with the radial direction.

In the above invention, the first fastening portion, the projecting amount of the radial direction from the outer peripheral surface of the first mirror frame, der least 1mm is, of the second fastening portion, the first the amount of projection of the radial direction from the outer peripheral surface of the second mirror frame, preferably der Rukoto than 1 mm.
By doing in this way, a dimension sufficient for mechanical fastening of fastening parts can be secured. When the protruding amount is less than 1 mm, the fastening portion is too small and it is difficult to fasten the fastening portions.
The present invention also provides an imaging unit manufactured by any one of the imaging unit manufacturing methods described above.

  According to the present invention, it is possible to stably manufacture a high-quality imaging unit in which the objective lens and the imaging device are strictly aligned even if the objective lens and the imaging device are extremely small.

It is a perspective view of an objective lens unit and an image sensor unit used in a method for manufacturing an image pickup unit according to an embodiment of the present invention. It is a flowchart which shows the manufacturing method of the imaging unit which concerns on one Embodiment of this invention. It is a perspective view which shows the state which assembled the objective lens unit and imaging device unit of FIG. It is sectional drawing in the A line of the assembly body of the objective lens unit of FIG. 3, and an image pick-up element unit. It is sectional drawing in the B line of the assembly body of the objective lens unit of FIG. 3, and an image pick-up element unit. It is a perspective view of the modification of the objective-lens unit of FIG. 1, and an image pick-up element unit. It is a perspective view which shows the state which assembled the objective lens unit and imaging device unit of FIG. It is sectional drawing in the C line | wire of the assembly body of the objective lens unit of FIG. 7, and an image pick-up element unit. It is sectional drawing in the D line of the assembly body of the objective lens unit of FIG. 7, and an image pick-up element unit. FIG. 10 is a perspective view of another modification of the objective lens unit and the image sensor unit in FIG. 1. It is a perspective view which shows the state which assembled the objective lens unit and imaging device unit of FIG. It is sectional drawing in the E line of the assembly body of the objective lens unit of FIG. 11, and an image pick-up element unit. It is sectional drawing in the F line | wire of the assembly body of the objective lens unit of FIG. 11, and an image pick-up element unit.

Below, the manufacturing method of the imaging unit concerning one embodiment of the present invention is explained with reference to drawings.
First, the objective lens unit 10 and the imaging element unit 20 used in the manufacturing method of the imaging unit according to the present embodiment will be described with reference to FIG. In the following description, an orthogonal coordinate system is used in which the optical axes P and Q directions of the units 10 and 20 are defined as the Z direction and directions perpendicular to the optical axes P and Q are defined as the X direction and the Y direction. . In particular, the protruding direction of the fastening portions 3 and 6 from the lens frames 2 and 5 is defined as the Y direction.

The objective lens unit 10 includes an objective lens 1, a substantially cylindrical lens frame 2 that holds the objective lens 1 inside, and a fastening portion (second fastening portion) 3 provided outside the lens frame 2. It has.
The objective lens 1 has a cylindrical shape as a whole, and in this example, it is assumed that the objective lens 1 has a minimum size having an outer dimension of 1 mm and a total length of 5 mm.

The lens frame 2 has a cylindrical hole 2a penetrating in the longitudinal direction. The objective lens 1 is accommodated in the hole 2a so that the optical axis P of the objective lens 1 substantially coincides with the central axis in the longitudinal direction of the lens frame 2, and is fixed to the inner peripheral surface of the hole 2a with an adhesive. .
The fastening portion 3 is a rectangular thin flat plate projecting from a part of the outer peripheral surface of the lens frame 2 in the Y direction in the radial direction over the entire length in the length direction of the outer peripheral surface. Is formed.

The image sensor unit 20 includes an image sensor 4 such as a CCD image sensor or a CMOS image sensor, a substantially cylindrical lens frame 5 that holds the image sensor 4, and a fastening portion (outside of the lens frame 5). 1st fastening part) 6.
The imaging element 4 is a rectangular flat plate, and in this example, it is assumed that the side is a minimum of 2 mm.

  The lens frame 5 has a substantially cylindrical hole 5a penetrating in the longitudinal direction. The imaging device 4 is in a rectangular opening formed on one end surface (base end surface) of the lens frame 5 so that the optical axis Q of the imaging device 4 substantially coincides with the longitudinal center axis of the hole 5a. It is fitted and fixed with adhesive. The hole 5a has an inner diameter slightly larger than the outer diameter of the lens frame 2 so that the lens frame 2 of the objective lens unit 10 can be telescopically fitted in the longitudinal direction with play in the radial direction. Have dimensions.

The fastening portion 6 is provided at a position away from the outer peripheral surface of the lens frame 5 in the Y direction in the radial direction, and is a prismatic thick region 6a extending in parallel with the lens frame 5, and the outer peripheral surface of the lens frame 5 and the thickness thereof. The thick region 6 a and the thin region 6 b are formed integrally with the lens frame 5. The thin region 6 b is connected to the thick region 6 a.
The thick region 6a has the same dimensions as the lens frame 5 in the Z direction and the X direction. Further, the amount of protrusion in the Y direction from the outer peripheral surface of the lens frame 5 of the fastening portion 6 (the dimension from the outer peripheral surface of the lens frame 5 to the radially outer end of the thick region 6a) is 2 mm.
The thickness dimension in the X direction of the thin area 6b is 80% or less of the thickness dimension in the X direction of the thick area 6a, and is designed to be 50% in this example.

  The fastening portion 6 is formed with a groove 7 that guides the fastening portion 3 in the Z direction when the lens frame 2 is fitted into the hole 5a. The groove 7 penetrates the fastening portion 6 in the Y direction, and the end portion on the radially outer side of the fastening portion 3 protrudes from the groove 7 when the lens frame 2 is fitted in the hole 5a. Yes. In addition, the groove 7 terminates at a midpoint position in the Z direction of the fastening portion 6, and the imaging surface of the objective lens 1 is brought into contact with the imaging surface of the image sensor 4 in a state where the fastening portion 3 hits the end of the groove 7. Almost matches. Further, the groove 7 has a width dimension slightly larger than the thickness dimension of the fastening portion 3 so that the fastening portion 3 can be inserted with play in the X direction.

  Further, a through hole 3c is formed in the fastening portion 3 and a screw hole 6c fastened to the screw 8 is formed in the thick region 6a of the fastening portion 6 so as to penetrate in the X direction. The through hole 3c and the screw hole 6c are formed at positions corresponding to each other in a state where the fastening portion 3 is inserted into the groove 7 and the fastening portion 6 and the fastening portion 3 are overlapped with each other in the X direction. Thus, the screw 8 can be inserted into the screw hole 6c. Here, the through hole 3c has an inner diameter dimension slightly larger than the outer diameter dimension of the screw 8 so that the screw 8 penetrates the through hole 3c with play in the Y direction and the Z direction.

Next, a manufacturing method of the imaging unit according to the present embodiment using the objective lens unit 10 and the imaging element unit 20 will be described.
As shown in FIG. 2, the manufacturing method of the imaging unit according to the present embodiment includes a coating step S <b> 1 for applying a bonding agent to a fitting portion between the lens barrels 2 and 5, and fitting the lens barrels 2 and 5 together. The positioning step S2 for relatively aligning the units 10 and 20, the fastening step S3 for fastening the fastening portions 3 and 6 with the screw 8, the curing step S4 for curing the bonding agent, and the fastening portions 3 and 6 Excision step S5 for excising.

  Each unit 10 and 20 is a small member of several millimeters and is difficult to handle by hand. Accordingly, jigs for holding and operating the units 10 and 20 are used for handling the units 10 and 20 to be described later. The jig can hold the fastening portions 3 and 6 of the units 10 and 20, and the gripping fastening portions 3 and 6 can be held by X and Y of the units 10 and 20 by a fine movement mechanism such as a roller table. , And can be moved and positioned in micrometer units in the three axis directions corresponding to the Z direction.

  First, in the application step S <b> 1, the bonding agent 9 is applied to the outer surface of the lens frame 2 and the fastening portion 3 of the objective lens unit 10. At this time, when the units 10 and 20 are assembled in the subsequent positioning step S2, the gap between the outer peripheral surface of the lens frame 2 and the inner peripheral surface of the lens frame 5, and the outer surface of the fastening portion 3 A sufficient amount of the bonding agent 9 is applied so that the gap with the inner surface of the groove 7 is filled with the bonding agent 9. The bonding agent 9 is made of a thermosetting resin that is cured by being heated to a high temperature.

  Next, in the alignment step S2, as shown in FIGS. 3 to 5, the fastening portion 3 is inserted into the groove 7 until it comes into contact with the end of the groove 7, so that the lens frame 2 is moved into the lens frame 5. And the objective lens unit 10 is assembled to the image sensor unit 20. Further, the screw 8 is inserted into the screw hole 6c through the through hole 3c, so that the screw 8 is loosened. In this state, the objective lens unit 10 and the imaging device unit 20 are arranged at a relative position where the imaging surface of the objective lens 1 substantially coincides with the imaging surface of the imaging device 4, and further the play of the lens frame 2 in the hole 5a. The play of the fastening portion 3 in the groove 7 allows the objective lens unit 10 to be moved slightly in the X, Y, and Z directions with respect to the image sensor unit 20.

  Further, in the alignment step S2, a fine adjustment mechanism provided in the jig is used to finely adjust the positions of the objective lens unit 10 and the image pickup device unit 20 in the X, Y, and Z directions with an accuracy of a micrometer unit. Do. Specifically, while observing an image captured by the image sensor 4, the fastening portion 3 is positioned in the Z direction at a position where the image formed by the objective lens 1 is best focused, and the center of the image of the objective lens 1 is determined. The fastening portion 3 is positioned in the X direction and the Y direction at a position that coincides with the center of the image. Thereby, the objective lens unit 10 and the image sensor unit 20 are strictly aligned so that the imaging surface of the objective lens 1 exactly matches the image sensor surface of the image sensor 4. The fine adjustment amount of the position in each direction at this time is about 1 μm to 100 μm.

  Next, in fastening step S3, the fastening portions 3 and 6 are mechanically fastened by tightening the screws 8 inserted in the screw holes 6c, and the objective lens unit 10 and the image pickup device unit 20 are temporarily fixed. . Thereby, the relative position of the objective lens unit 10 and the image sensor unit 20 adjusted with high accuracy in the alignment step S2 is maintained constant.

  After the fastening, the units 10 and 20 are removed from the jig, and the assembly of the objective lens unit 10 and the image sensor unit 20 is moved to the curing furnace. In the curing step S4, the bonding agent 9 is cured by heating the assembly in a curing furnace. Thereby, the lens frames 2 and 5 are firmly fixed, and the relative position between the objective lens 1 and the image pickup device 4 is completely fixed.

  Next, in the cutting step S5, the assembly taken out from the curing furnace is cut in the X direction at the position of the thin region 6b adjacent to the outer peripheral surface of the lens frame 5, and the fastening portions 3 and 6 to which the screw 8 is fastened. Is removed from the assembly. 3 and 4, a two-dot chain line L indicates a cutting position. Since the thin area 6b is thin in the X direction, it can be easily cut in the X direction. Thus, the imaging unit 100 (the portion on the left side of the cutting position L in FIGS. 3 and 4) including the lens frames 2 and 5 and the objective lens 1 and the image sensor 4 held in each lens frame 2 and 5. ) Is manufactured.

  As described above, according to the present embodiment, since the fastening portion 3 having a dimension of several millimeters is provided outside the lens frames 2 and 5, the units 10 and 20 are assembled in the assembly work of the units 10 and 20. A separate member such as a holder for holding the lens becomes unnecessary. That is, the units 10 and 20 can be operated by directly holding the jigs at the positions of the fastening portions 3 and 6, and can be directly fastened by the screws 8 at the positions of the fastening portions 3 and 6. Accordingly, the units 10 and 20 are temporarily fixed without causing a shift in the relative positions of the units 10 and 20 that are strictly aligned in the alignment step S2, and the bonding agent 9 is maintained while maintaining the relative positions. It can be cured. Thereby, there is an advantage that the high-quality image pickup unit 100 in which the objective lens 1 and the image pickup device 4 are strictly aligned can be stably manufactured.

In addition, since the cured bonding agent 9 seals the gap between the lens frame 2 and the lens frame 5 and the gap between the fastening portion 3 and the groove 7, a cleaning liquid or There is an advantage that the waterproofness of the imaging unit 100 can be ensured so that a liquid such as a chemical liquid does not enter.
Further, since the fastening portions 3 and 6 provided on the outside of the lens frames 2 and 5 are cut off after the bonding agent 9 is cured, the extremely small imaging unit 100 that can be built in the ultrafine endoscope is finally manufactured. There is an advantage that you can.

  In the present embodiment, the form of the fastening portions 3 and 6 and the fastening direction of the screw 8 can be changed as appropriate. A first modification of the objective lens unit 10 and the image sensor unit 20 is shown in FIGS. 6 to 9, and a second modification is shown in FIGS.

  In the first modification, the fastening portion 3 of the objective lens unit 10 includes a thin area 3b extending in the Y direction from the outer peripheral surface of the lens frame 2, and the tip of the thin area 3b, as shown in FIGS. And a thick region 3a extending in the X direction perpendicular to the thin region 3b. In this example, the thickness dimension in the X direction of the thin area 3b is 20% of the thickness dimension in the X direction of the thick area 3a. Further, the amount of protrusion in the Y direction from the outer peripheral surface of the lens frame 2 of the fastening portion 3 (the dimension from the outer peripheral surface of the lens frame 2 to the radially outer end of the thick region 3a) is 1 mm.

  The fastening portion 6 of the image sensor unit 20 is formed of a part of the outer peripheral surface of the lens frame 5. In other words, in the present modification, the lens frame 5 has a semi-cylindrical shape, and a flat surface (surface corresponding to the string in the XY plane) that connects the ends of the curved side surfaces is the fastening portion 6. On this flat surface, a groove 7 into which the thin region 3b of the objective lens unit 10 can be inserted is formed in the Z direction from the tip surface. The through hole 3c and the screw hole 6c are formed in the respective fastening portions 3 and 6 in the Y direction, and the screw 8 is inserted and fastened into the through hole 3c and the screw hole 6c in the Y direction. The cutting position L in the cutting step S5 is a boundary between the fastening portion 3 and the fastening portion 6 as shown in FIGS. 7 and 8, and the thin region 3b can be easily cut in the X direction.

  In the second modified example, the objective lens unit 10 and the image sensor unit 20 are, as shown in FIGS. 10 to 13, two fastening portions that protrude from the outer peripheral surfaces of the lens frames 2 and 5 to both sides in the Y direction. 3 and 6 respectively. The protruding amount of the fastening portions 3 and 6 in the Y direction from the outer peripheral surfaces of the lens frames 2 and 5 is 1.5 mm.

  Each fastening portion 3, 6 includes thick regions 3 a, 6 a located on the outer side in the radial direction, and thin regions 3 b, 6 b connecting the lens frames 2, 5 and the thick regions 3 a, 6 a, respectively. In this example, the thickness dimension in the Z direction of the thin areas 3b and 6b is 30% of the thickness dimension in the Z direction of the thick areas 3a and 6a. The through hole 3c and the screw hole 6c are formed in the fastening portions 3 and 6 in the Z direction, and the screw 8 is fastened in the Z direction. The cutting position L in the cutting step S5 is the position of the thin regions 3b and 6b as shown in FIG. 12, and the thin regions 3b and 6b can be easily cut in the Z direction. Reference numeral 11 denotes an elastic member (a spring in the illustrated example) that urges the fastening portions 3 and 6 in directions away from each other. By disposing the elastic member 11 between the fastening portions 3 and 6, rattling during and after the screw 8 is fastened can be prevented.

DESCRIPTION OF SYMBOLS 1 Objective lens 2, 5 Mirror frame 2a, 5a Hole 3, 6 Fastening part 3a, 6a Thick area | region 3b, 6b Thin area | region 3c Through-hole 4 Image pick-up element 6c Screw hole 7 Groove 8 Screw 9 Bonding agent 10 Objective lens unit 20 Imaging Element unit 100 Imaging unit S1 Application step S2 Positioning step S3 Fastening step S4 Curing step S5 Cutting step

Claims (5)

A cylindrical first lens frame that holds either the imaging element or the objective lens is provided, and the first fastening portion is integrally provided on the outer peripheral surface of the first lens frame or a portion protruding from the outer peripheral surface. A first unit, and a cylindrical second lens frame that holds either the image sensor or the objective lens, and the first fastening on a portion protruding from the outer peripheral surface of the second lens frame And a second unit integrally including a second fastening part that can be mechanically fastened with the part by assembling the second lens frame into the first lens frame. Because
An application step of applying a bonding agent to the fitting portion of the lens frame;
An alignment step of fitting the second lens frame into the first lens frame and performing relative alignment between the first unit and the second unit;
A fastening step of mechanically fastening the first fastening portion and the second fastening portion of the first unit and the second unit, the relative positions of which are matched in the positioning step;
A curing step of fixing the first frame and the second unit of the second unit to which the first fastening part and the second fastening part are fastened by curing the bonding agent;
A method of manufacturing an imaging unit, comprising: a cutting step of cutting a portion of the first fastening portion and the second fastening portion that protrudes from the outer peripheral surface of the first lens frame after the bonding agent is cured. The first fastening portion, the outer peripheral surface of the first mirror frame are found provided in a portion that protrudes in the radial direction, a first thick region located radially outwardly of the first lens frame A first thin region located between an outer peripheral surface and the first thick region;
The second fastening portion is provided in a portion protruding in the radial direction from the outer peripheral surface of the second lens frame, and has a second thick region located on the outer side in the radial direction and the outer periphery of the second lens frame. A second thin region located between a surface and the second thick region,
The first thin region, in a direction intersecting the radial direction, have a size smaller than said first thick region,
Said second thin region, the direction crossing the radial direction, a method of manufacturing the image pickup unit according to claim 1, have a size smaller than said second thick region. In the ablation step, a method of manufacturing the image pickup unit according to claim 2, cut in said second thin region before Symbol second fastening portion with the first fastening portion to ablate at said first thin region . Said first fastening portion, the projecting amount of the radial direction from the outer peripheral surface of the first mirror frame state, and are more 1 mm,
Said second engagement portion, the projecting amount of the radial direction from the outer circumferential surface of the second mirror frame, a method of manufacturing the image pickup unit according to claims 1 Ru der least 1mm to claim 3 . The imaging unit manufactured by the manufacturing method of the imaging unit in any one of Claims 1-4 .

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