JP2009244393A - Lens assembling method and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens assembling method for simply adjusting eccentricity of axis of each lens of a lens assembly provided with a lens frame having a hollow part and to provide an imaging device provided with the lens assembly assembled by this lens assembling method. <P>SOLUTION: This lens assembling method comprises an insertion step for inserting a plurality of optical members 11-16, SP1-SP4 into the hollow part 100 in the lens frame 10 according to the prescribed procedures, a next vibration step for applying vibration to the lens frame 10 in which a plurality of optical members are inserted by extending optical axes of the lenses constituting a plurality of optical members vertically, and a final fixing step for sticking and fixing a plurality of lenses in the lens frame mutually after applying vibration by pouring adhesive through adhesive holes H1-H4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lens assembly method for a lens assembly, and an imaging apparatus including a lens assembly assembled by the assembly method.

  Recently, a camera for allowing a driver to visually recognize a blind spot of a driver has been deployed in an automobile. In addition, many fixed-point cameras have been deployed for monitoring in department stores and condominiums.

  Since these cameras are often provided outdoors, strict waterproof performance and dustproof function are required. For this reason, a lens assembly including a lens frame having a hollow portion may be used for these cameras. This is because a plurality of lenses and an interval ring for determining the interval between the lenses are inserted in a prescribed order in the hollow portion of the lens frame, and finally the objective side opening is sealed with the lens located closest to the objective side. This is because waterproof performance and dust proof performance according to the above requirements can be obtained.

  As is well known, in a normal lens assembly, it is necessary to adjust the eccentricity of each lens in the lens frame using, for example, an eccentricity adjusting device as disclosed in Patent Document 1.

However, in the lens assembly having a structure in which a plurality of optical members including a plurality of lenses are inserted into the hollow portion of the lens frame in a prescribed order as described above, the connection to connect the lens frame to an external eccentricity adjustment device If a new mechanism is not provided, eccentricity adjustment cannot be performed for each lens. If a connection mechanism for connecting to an external eccentricity adjusting device is provided on the wall of the lens frame having a hollow portion, the dustproof performance and waterproof performance may be lowered. In Patent Document 1, it is necessary to adjust the eccentricity of the lens while observing the chart image that has passed through the lens on a monitor, which is a complicated operation.
JP 2001-27723 A

  In view of the above circumstances, the present invention provides a lens assembly method capable of easily adjusting the eccentricity of each lens of a lens assembly including a lens frame having a hollow portion, and a lens assembly assembled by the lens assembly method. An object of the present invention is to provide an imaging apparatus including the above.

The lens assembling method of the present invention that achieves the above object includes a plurality of optical members including an interval ring for defining a distance between the lenses and a plurality of lenses, and a hollow portion into which the plurality of optical members are inserted in a prescribed order. A lens assembly comprising a lens frame having,
A loading step of loading the plurality of optical members into the hollow portion of the lens frame in a prescribed order;
A vibration step of applying vibration to the lens frame in a posture in which the optical axis of the lens constituting the plurality of optical members extends vertically, with the lens frame in a state in which the plurality of optical members are inserted,
And a fixing step for fixing the plurality of optical members in the lens frame after the vibration is applied.

  According to the lens assembling method of the present invention, after the plurality of optical members are inserted into the lens frame, the plurality of optical members are provided with vibrations in the posture in which the plurality of optical members extend vertically. Are adjusted at once.

  That is, the operator can easily adjust the eccentricity of each lens in the lens frame by inserting a plurality of optical members into the lens frame and then applying vibration to the lens frame. become.

  Here, at least one of the lens frame or the spacing ring has a receiving portion for receiving the peripheral edge of the lower surface of the lens located directly above the lens frame when the optical axis extends vertically. In addition, it is preferable that the surface of the lens in contact with the receiving portion is a convex surface.

  With the above configuration, the position of the convex surface of the lens received by the receiving portion of the lens frame or the interval ring converges to a predetermined position according to the center of gravity of the lens by applying vibration to the lens frame. Go. In other words, by applying vibration to the lens frame, the optical axis of each convex lens becomes uniform when the position of the convex surface of the convex lens received by the receiving part of the lens frame or the interval ring converges to a predetermined position and stops moving. In other words, the optical axes coincide with each other in a state where the other lenses are movably connected by the spacing ring.

  Moreover, it is preferable that the said hollow part is a hollow part of the diameter which has backlash in the direction at right angles to an optical axis between these optical members when it inserts in the hollow part.

  In order to be able to adjust the eccentricity after a plurality of optical members are inserted into the lens frame, the plurality of optical members are moved in a plane perpendicular to the optical axis of the optical members. It needs to be free. That is, the play defines a range of eccentricity adjustment of the plurality of optical members.

  In addition, the plurality of optical members when the hollow portion is inserted into the hollow portion by heating the lens frame to a temperature relatively higher than that of the plurality of optical members before the loading step. A heating step for forming backlash in a direction perpendicular to the optical axis may be provided between the two.

  The lens frame is often made of resin, and generally expands when heated. Therefore, the heating step is provided before the charging step, and a looseness is formed in the hollow portion by the heating step. After the lens is inserted into the lens frame in the next charging step, the fixing step is performed. Then, the lens frame may be contracted by natural cooling to eliminate the backlash and hold the lens firmly on the lens frame.

  In addition, an image pickup apparatus of the present invention that achieves the above object includes a lens assembly assembled by the lens assembling method and an image pickup element.

  According to the image pickup apparatus of the present invention, an inexpensive image pickup apparatus in which the manufacturing cost is reduced by incorporating the lens assembly easily assembled by the lens assembling method is realized.

  As described above, the lens assembly method capable of easily adjusting the eccentricity of each lens of the lens assembly including the lens frame having the hollow portion, and the lens assembly assembled by the lens assembly method are provided. An imaging device is realized.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a side view of a cut surface of a lens assembly 1 according to an embodiment of the present invention cut along the optical axis of a lens. The upper side of FIG. 1 is the objective side, and the lower side of FIG. 1 is the imaging side.

  FIG. 1 shows a lens assembly 1 including a lens frame 10 having a hollow portion 100 into which a plurality of lenses 11 to 16 are inserted in a prescribed order together with spacing rings SP1 to SP4 that determine the distance between lenses. . In FIG. 1, two concave lenses 13 and 16 and four convex lenses 11, 12, 14, and 15 are combined to form an example of a lens according to the present invention. The lens, four spacing rings, Thus, an example of the plurality of optical members referred to in the present invention is configured.

  As shown in FIG. 1, after the lenses 11 to 16 and the spacing rings SP1 to SP4 are inserted into the lens frame 10, the adhesive is injected from the adhesive holes H1 to H4 penetrating the lens frame outer wall and the hollow portion inner wall. Thus, the lenses 11 to 15 in the lens frame 10 are bonded and fixed. However, a lid 10A constituting a part of the lens frame 10 is provided on the objective side of the lens frame 10, and after the plurality of lenses 11 to 16 are inserted into the lens frame 10, the lid 10A is covered. Since the opening on the objective side is sealed, no bonding hole is provided at a position located on the outer peripheral surface of the lens 16 on the objective side.

  Although only one bonding hole H1 to H4 shown in FIG. 1 is shown in FIG. 1, in some cases, three bonding holes H1 to H4 are provided in a direction around the lens inserted into the lens frame 10. . Each of the lenses 11 to 15 is firmly bonded to the lens frame 10 by injecting an adhesive through these three bonding holes.

  In addition, the bonding holes H1 to H4 shown in FIG. 1 have openings in the outer wall that have a larger area than the openings opened in the hollow portion, and the openings opened in the hollow portion 100 are each in the lens frame 10. It is comprised so that it may each be located in the outer peripheral surface of the lenses 12-16. For this reason, an effect is obtained in which the lens frame 10 and each of the lenses 12, 13, 14, and 15 can be securely bonded by injecting an adhesive while checking the outer peripheral surface of the lens through the wide opening on the outer wall side. It is done. In addition, when the adhesive is excessively injected by mistake due to the ease of injection, it is possible to receive an excessive amount of adhesive at the wide area opening on the outer wall side and prevent the adhesive from flowing out. Can also be obtained.

  In this way, when the adhesive is injected through the bonding holes H1 to H4 while confirming the outer peripheral surface of the lens from the outside and the lenses 12 to 16 and the lens frame 10 are bonded and fixed, a strong bonding force is obtained, and FIG. Even if the lens assembly 1 is mounted on an automobile, it is difficult to cause a problem that the lenses 11 to 16 are detached from the lens frame 10 due to vibration and fall down.

  Here, in the lens assembly 1 of the present embodiment, a plurality of receiving elements SP11, SP21, and SP31 that receive the convex surfaces of the lenses 12, 14, and 15 are provided on the spacing rings SP1 to SP3. Since the assembling of the lens assembly 1 is simplified by making it possible to adjust the eccentricity of the lens at once, the assembling method will be briefly described.

  The assembling method will be described with reference to FIG.

  First, in the first loading step, the lenses 11 to 16 are loaded into the hollow portion 100 of the lens frame 10 in a prescribed order. In the next vibration step, the lens frame 10 in which the lenses 11 to 16 are inserted is placed in a posture in which the optical axis of the lens extends vertically, and vibrations are applied to the lens frame 10 in any direction, up, down, left, and right. Eccentricity adjustment is performed so that the optical axes of the lenses coincide.

  In the present embodiment, a receiving portion SP11 that receives the lower peripheral edge of the lens positioned directly above when the optical axis of the lens frame 10 extends vertically in the interval ring SP1, the interval ring SP2, and the interval ring SP3. , SP21, SP31 are provided, the surfaces of the lenses 12, 14, 15 in contact with the receiving portions SP11, SP21, SP31 are made convex, and the outer periphery of the hollow portion 100 of the lens frame 10 and the lenses 11-16 A backlash G is formed between the surfaces and the lens frame 10 is vibrated so that the eccentricity adjustment of the optical axes of the plurality of lenses can be performed at a time. In the present embodiment, a backlash G of 0.002 to 0.030 mm is provided in consideration of the use of a lens having a diameter of φ8 to φ10.

  When vibration is applied to the lens frame 10, the receiving portions SP11. Of the spacing rings SP2, SP3, SP4. This utilizes the property that the positions of the convex surfaces of the lenses 12, 13, and 15 received at SP21 and SP31 converge to a predetermined position on the outer peripheral edge of the convex lens according to the center of gravity of the lens. In other words, when the lens frame 10 is in a posture in which the optical axis extends vertically, and the vibration is applied in any of the up, down, left and right directions, the position of the convex surface of the lens received by the receiving portions of the spacing rings SP2, SP3, SP4. Converges at a predetermined position and stops moving. Thus, when the position of the convex lens received by the receiving portion of the interval ring converges to a predetermined position and stops moving, the optical axes of the lenses 12, 14, and 15 coincide with each other and are further moved by the interval rings SP1 to SP4. The other lenses 11, 13, and 16 that are continuously and freely connected follow the optical axes.

  In this way, in this embodiment, the lens frame 10 in FIG. 1 is vibrated in one of the upper, lower, left, and right directions so that the optical axes of the lenses in the lens frame coincide with each other, and then the bonding hole H1 in FIG. Each lens in the lens frame is firmly fixed to the lens frame by injecting an adhesive while checking the outer peripheral surface of the lens from ~ H4.

  In this way, the effect that the assembly becomes very easy can be obtained, and the adhesion work can be performed while checking the outer peripheral surface of the lens, so that the lens can be firmly adhered and fixed to the lens frame. An effect is obtained. As a result, a lens assembly having vibration resistance that can be mounted on an automobile is formed.

  Moreover, in the example of FIG. 1, the example which provided the play of about 0.002-0.03 mm was shown, However, The lens frame of a figure is manufactured with resin, and when it warms, about 0.002-0.03 mm If so, it will expand immediately, so a heating step is added before the charging step, the lens frame is warmed and inflated, and the lens is inserted in the place where the backlash is formed and the eccentric step is performed in the next vibration step A configuration may be adopted in which the adhesive is fixed after a predetermined time after adjustment.

  Finally, an example in which the lens assembly assembled by the lens assembling method is applied to an in-vehicle camera will be described.

  FIG. 2 is a diagram illustrating the camera unit 2 including the lens assembly.

  FIG. 2 shows a view in which the camera unit 2 is cut along the optical axis and the cut surface is viewed obliquely from above.

  A camera unit 2 shown in FIG. 2 includes the lens assembly 1 of FIG. 1, a camera body frame 20, and an image sensor 21. The image sensor 21 is mounted on an image sensor substrate 210 and is mounted on the camera body frame 20. It is fixed to the adhesive. Screw portions are respectively formed on the outer peripheral surface of the lens frame 10 and the inner peripheral surface of the camera body frame 20 of the lens assembly 1 of FIG.

  When the camera unit 2 is assembled, the lens assembly 1 shown in FIG. 1 is first inserted into the camera body frame 20 while being screwed, and then the lens assembly 1 is bonded and fixed to the camera body frame 20. At this time, by applying an adhesive to the outer peripheral edge of the lens frame 10 and the front end portion of the camera body frame 20, waterproofing is performed so that water does not enter the camera unit from the front end side. Further, a substrate 210 on which an image pickup device 21 such as a CCD solid-state image pickup device is mounted is bonded and fixed to the camera body frame 20. The lens assembly 1 shown in FIG. 1 can be incorporated into the camera unit 2 by such a simple procedure.

  When the lens assembly 1 that has been simplified in this way can be easily incorporated into the camera unit 2, the assembly time per unit of the camera unit can be shortened to reduce the manufacturing cost. It becomes possible to plan.

It is the figure which looked at the surface which cut | disconnected and cut | disconnected the lens assembly 1 which is one Embodiment of this invention along the optical axis of a lens from the side. It is a figure which shows the camera provided with the lens assembly of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens assembly 10 Lens frame 11-16 Lens SP1-SP4 Space | interval ring 100 Hollow part 2 Camera unit 20 Camera main body frame 21 Imaging element 210 Board | substrate

Claims (5)

A method of assembling a lens assembly, comprising: a plurality of optical members including an interval ring for defining a distance between lenses; and a plurality of lenses; and a lens frame having a hollow portion into which the plurality of optical members are inserted in a prescribed order. Because
A loading step of loading the plurality of optical members into the hollow portion of the lens frame in a prescribed order;
A vibration step in which the lens frame in a state in which the plurality of optical members are inserted is placed in a posture in which an optical axis of a lens constituting the plurality of optical members extends vertically, and vibration is applied to the lens frame;
And a fixing step of fixing a plurality of optical members in the lens frame after vibration is applied.   At least one of the lens frame and the spacing ring has a receiving portion for receiving a lower peripheral edge of the lens located directly above the lens frame when the optical axis extends vertically. 2. The lens assembling method according to claim 1, wherein a surface of the lens that contacts the receiving portion is a convex surface.   2. The hollow portion having a diameter having a backlash in a direction perpendicular to the optical axis between the plurality of optical members when inserted into the hollow portion. Or the lens assembly method of 2.   Prior to the loading step, the lens frame is heated to a temperature relatively higher than that of the plurality of optical members, so that the hollow portion is inserted into the hollow portions with the plurality of optical members. 3. The lens assembling method according to claim 1, further comprising a heating step for forming a backlash in a direction perpendicular to the optical axis.   An imaging apparatus comprising: a lens assembly assembled by the lens assembling method according to claim 1; and an imaging element.

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