JP2009294612A - Optical unit and method for fixing optical member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical unit capable of highly accurately positioning an optical member and capable of preventing a positional deviation when the optical member is fixed. <P>SOLUTION: A fixing frame 101 for fixing a lens 10 has three engaging parts 102. In each engaging part 102, a pawl part 103 engaged with the lens 10, so as to regulate the movement of the lens 10 in an optical axis direction and a fixing part 104 are formed. Each engaging part 102 holds the lens 10 in such a state that each engaging part 102 is elastically displaced in a direction orthogonal to an optical axis (in other words, in such a state that each engaging part 102 is pressed in the direction orthogonal to the optical axis). At this time, the pawl parts 103 of respective engaging parts 102 are engaged with the circumferential part of the lens 10 respectively, to regulate the movement of the lens 10 in the optical axis direction. Meanwhile, each fixing part 104 comes into contact with a welding surface 106, and each fixing part 104 and the welding surface 106 are fixed by irradiation with an infrared laser. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical unit used in an optical apparatus such as a camera and a method for fixing an optical member.

  In recent years, downsizing of photographing apparatuses such as digital cameras has been attempted. In addition, the image taken by the photographing device is displayed on a large screen, or the photographed image is printed on a print paper of A4 size or larger so that the photographed image can be appreciated in a large size. There is a demand for higher image quality.

  In order to improve the image quality of the captured image, it is necessary to optimize the lens design, and further improve the processing accuracy and the assembly position accuracy. On the other hand, making the manufacturing, assembly, and adjustment processes complicated and increasing the number of parts will increase the cost.

  Here, due to advances in lens design tools and cost reduction of aspherical processing, it is sufficiently possible to construct a good optical system with few aberrations with a small number of lenses. As a method for fixing the lens to the lens frame, a heat caulking method and an ultraviolet curing adhesive method are used.

  The heat caulking method is a method in which a part of a resin lens frame is melted by a heating means to cover the periphery of the lens, and the lens is fixed to the lens frame. In this method, assembly is easy and the equipment is inexpensive, but the positioning of the lens depends on the fitting accuracy with the lens frame, and the lens is heated in addition to the lens frame, so it is fixed with high accuracy. There is a problem that you can not.

  Therefore, when positioning with high accuracy is necessary, a method of applying and curing an ultraviolet curable adhesive in the gap between the lens outer peripheral portion and the lens frame is used. In the case of this method, since the adhesive is in a liquid state at the time of application, the handling thereof is inconvenient, and a technique for applying an appropriate amount to an appropriate place is required.

  In addition, the UV irradiation time required for curing requires several tens of seconds. Even if lens position adjustment such as eccentricity adjustment is performed, there is no cure shrinkage until the adhesive is completely cured. There is a case where the lens position gradually changes due to uniformity and deviates from a desired position.

  In addition, it is necessary to mitigate the difference in thermal shrinkage between the lens and the lens frame and the impact from the outside with an adhesive.If the elastic modulus of the cured adhesive layer is too high, the lens is damaged or the lens is removed from the lens frame. It may come off. On the other hand, if the elastic modulus of the cured adhesive layer is too low, the lens position may deviate from the desired position. Therefore, the selection of the adhesive is difficult and the options are limited.

  In addition, the adhesive strength of the adhesive varies depending on the lens material, lens coating material, and the application of the black ink, and it takes much time to select the optimum adhesive, set the curing conditions, and manage the adhesive.

  Therefore, several methods have been proposed as a method for fixing the lens to the lens frame using the laser welding technique. For example, in order to maintain the lens fixing position with high accuracy, a method of fixing the lens without heating the lens and the lens frame positioning portion has been proposed (see Patent Document 1).

Further, in order to maintain the lens fixing position with high accuracy, a method of instantaneously fixing the lens after performing lens positioning (eccentricity adjustment) has been proposed (see Patent Document 2).
JP 2005-345653 A JP 2006-184780 A

  However, in the case of the above-described lens fixing method by laser welding, there is a possibility that play occurs between the lens and the holding frame fitted to the lens, or the welding position of the holding frame shifts. It is difficult to adjust the position of the lens with high accuracy.

  In the latter case, the lens fixing method by laser welding makes it possible to position the lens with high accuracy in a plane perpendicular to the optical axis, but an intermediate member is interposed between the lens and the lens frame. There is a possibility of causing a positional shift in the optical axis direction.

  An object of the present invention is to provide an optical unit and an optical member fixing method capable of performing positioning of an optical member with high accuracy and preventing a positional deviation when fixing the optical member. is there.

  In order to achieve the above object, the present invention comprises an optical member, a frame body to which the optical member is fixed, and a fixing frame for fixing the optical member to the frame body. An engaging portion that holds the optical member in a state of being elastically displaced in a direction orthogonal to the axis, and the engaging portion includes the optical member so as to restrict movement of the optical member in the optical axis direction. An optical unit is provided in which an engaging claw portion and a fixing portion are provided, and the fixing portion and the frame are fixed.

  In order to achieve the above object, the present invention includes an optical member and a fixed frame for fixing the optical member, and the fixed frame holds the optical member in a state of being elastically displaced in a direction orthogonal to the optical axis. A claw portion that engages with the optical member so as to restrict movement of the optical member in the optical axis direction, and a fixing portion; In the state where the optical member is elastically displaced in a direction perpendicular to the optical axis in order to hold the optical member, the fixing portion is formed to overlap a part of the fixed frame, and the overlapping fixing portion and the fixing frame An optical unit characterized in that a part thereof is fixed.

  In order to achieve the above object, the present invention has an engaging portion that can be elastically displaced in a direction orthogonal to the optical axis, and a claw portion and a fixing member that restrict movement of the optical member in the optical axis direction to the engaging portion. An optical member fixing method for fixing the optical member to the frame body using a fixing frame provided with a portion, wherein the engaging portion is elastically displaced in a direction perpendicular to the optical axis to engage the engagement member. The step of causing the joint portion to hold the optical member and engaging the claw portion with the optical member, and pressing the engagement portion holding the optical member to elastically displace in a direction perpendicular to the optical axis. A step of positioning in a direction orthogonal to the optical axis of the optical member, and a step of fixing the fixing portion and the frame body after positioning in a direction orthogonal to the optical axis of the optical member. An optical member fixing method is provided.

  In order to achieve the above object, the present invention has an engaging portion that can be elastically displaced in a direction orthogonal to the optical axis, and a claw portion and a fixing member that restrict movement of the optical member in the optical axis direction to the engaging portion. An optical member fixing method for fixing the optical member using a fixing frame provided with a portion, wherein the engaging portion is placed on an optical axis so that the fixing portion overlaps a part of the fixing frame. Elastically moving in a direction orthogonal to the engagement member to hold the optical member at the engagement portion, and engaging the claw portion with the optical member, and pressing the engagement portion holding the optical member. The step of positioning the optical member in a direction orthogonal to the optical axis by elastically displacing the optical member in a direction orthogonal to the optical axis, and the fixing portion overlapping after positioning in the direction orthogonal to the optical axis of the optical member And a part of the fixed frame, It provides a method of fixing that the optical member.

  According to the present invention, it is possible to position the optical member with high accuracy and to prevent a positional shift when the optical member is fixed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a longitudinal view showing a configuration of a lens barrel as an optical unit according to the first embodiment of the present invention.

  As shown in FIG. 1, the lens barrel includes an outer cylinder 7, an inner cylinder 6 disposed in the outer cylinder 7, and an inner cylinder 5 disposed in the inner cylinder 6. A first group lens frame 100 is held on the inner cylinder 6. Fixed to the first group lens frame 100 are a lens 10 facing forward (subject side) and a lens 11 disposed behind the lens 10.

  The inner cylinder 5 holds the second group lens frame 2 and the third group lens frame 3 disposed behind the second group lens frame 2. A plurality of lenses 20, 21, and 22 are fixed to the second group lens frame 2. A lens 30 is fixed to the third group lens frame 3. An imaging element 4 is disposed behind the third group lens frame 3.

  The lenses 10, 11, 20 to 22, 30 are respectively arranged in the first group lens frame 100, the second group so that positioning, inclination, and the like in the optical axis direction and the direction orthogonal to the optical axis are within a predetermined accuracy range. The lens frame 2 and the third group lens frame 3 are fixed. Here, it is not necessary to adjust the position and the inclination with respect to all the lenses with the same accuracy, and the adjustment method and the fixing method are different for each lens.

  In the present embodiment, a method for fixing the lens 10 to the first group lens frame 100 to which the lenses 10 and 11 are fixed will be described.

  Since the lens 10 is a lens disposed at a position closest to the subject, the assembly and adjustment work of the lens 10 is easy. Further, the positioning (eccentricity adjustment) and fixing of the lens 10 are performed in a state where the assembly of the other lens (group) is completed, and therefore, it is important to determine the actual photographing performance.

  Here, in order to clarify the difference between the fixing method of the lens 10 of the present embodiment and the fixing method of the conventional lens 10, first, the fixing method of the conventional lens 10 will be described with reference to FIG. FIG. 10A is a perspective view showing a first group lens frame used in a conventional fixing method. FIG. 10B is a perspective view showing a state in which the lens frame of FIG. 10A is positioned in the direction orthogonal to the optical axis of the lens and the lens and the first group lens frame are bonded. Here, a method of fixing the lens 10 to the conventional first group lens frame 1 will be described.

  As shown in FIG. 10A, the first group lens frame 1 to which the conventional lens 10 is fixed has a plurality of wall portions 1a protruding in the optical axis direction. Each wall part 1a is arrange | positioned along the circumferential direction so that the circular receiving space which can receive the lens 10 may be formed mutually spaced apart.

  The lens 11 is already fixed to the first group lens frame 1 in the pre-process of the fixing process of the lens 10. In the fixing process of the lens 10, the lens 10 is inserted into a receiving space formed by each wall portion 1 a of the first group lens frame 1. In this state, a gap is generated between the lens 10 and each wall 1a, and positioning on the plane orthogonal to the optical axis of the lens 10 is not performed (eccentricity adjustment is not performed).

  Next, the lens 10 is positioned in a direction orthogonal to the optical axis and fixed with an adhesive. Specifically, as shown in FIG. 10B, the eccentricity adjusting pins 60 are brought into contact with the outer peripheral portion of the lens 10 from three directions. Then, by the operation of each eccentricity adjustment pin 60, the lens 10 is moved on a plane orthogonal to the optical axis, and positioning on the plane orthogonal to the optical axis of the lens 10 is performed. Actually, in a state where the other lenses 11, 20, 21, 22, and 30 are incorporated in the lens barrel, a chart image or the like is taken through the optical system, and is projected from the image pickup device 4 side. The lens 10 is moved by the operation of each eccentricity adjusting pin 60. Then, the lens 10 is positioned so that the lens 10 is at a position where the best resolution is obtained.

  When the positioning of the lens 10 is completed in this way, the ultraviolet curable adhesive 50 is applied to the outer peripheral portion of the lens 10 and the adhesive 50 is irradiated with ultraviolet rays. Thereby, the lens 10 is fixed to the first group lens frame 1. Since the adhesive 50 is liquid at the time of application, the amount of application may vary. As a result, the adhesive 50 may protrude from the effective surface of the lens 10, or the position of the lens 10 may change due to incomplete curing of the adhesive 50.

  Next, a fixing method according to the present embodiment will be described with reference to FIGS. FIG. 2A is a perspective view showing the configuration of the first group lens frame 100 of FIG. FIG. 2B is a plan view of the first group lens frame 100 of FIG. FIG. 2C is a longitudinal cross-sectional view showing a main part configuration of the fixed frame 101 of the first group lens frame 100 of FIG. FIG. 3A is a perspective view showing a state where the lens 10 is placed on the fixed frame 101 of the first group lens frame 100. FIG. 3B is a plan view showing a state in which the lens 10 is placed on the fixed frame 101 of the first group lens frame 100. FIG. 4A is a perspective view showing a state where the eccentricity adjustment of the lens 10 placed on the fixed frame 101 is performed by each eccentricity adjusting pin. FIG. 4B is a longitudinal sectional view showing a state where the fixing frame 101 on which the lens 10 is placed and the fixing portion 104 are fixed by laser welding.

  In the present embodiment, a first group lens frame 100 (frame body) shown in FIGS. 2A and 2B is used instead of the conventional first group lens frame 1. The first group lens frame 100 is made of a thermoplastic resin material and has a cylindrical shape. This resin material is a polycarbonate containing an infrared absorbing material such as carbon black, for example, and has a characteristic of generating heat when irradiated with an infrared laser. A partition plate 107 having a plane orthogonal to the optical axis is provided in the first group lens frame 100. The partition plate 107 has an opening 108 disposed coaxially with the optical axis. Further, one surface (subject side surface) of the partition plate 107 includes a lens positioning surface 105 that extends in an annular shape around the opening 108 and a welding surface 106 that extends in an annular shape around the lens positioning surface 105.

  A fixing frame 101 for fixing the lens 10 is integrally formed on one surface of the partition plate 107. The fixed frame 101 has a plurality of (three in this embodiment) engaging portions 102.

  Each engaging portion 102 has a band shape extending in an arc shape around the optical axis. Each engaging portion 102 is integrally connected to the partition plate 107 at one end, and the other portion (the portion up to the other end) excluding the one end is connected to one surface of the partition plate 107 (the positioning surface 105 and the welding surface 106). 2) (see FIG. 2C). Each engaging portion 102 is elastically displaceable in a direction perpendicular to the optical axis with one end as a center, and is arranged so as to form a space S for receiving the lens 10 in cooperation with each other.

  At the other end of each engaging portion 102, a claw portion 103 that protrudes inward in a direction orthogonal to the optical axis and fixes the lens 10 is integrally formed. Further, at the other end of each engaging portion 102, a fixing portion 104 that protrudes outward in a direction orthogonal to the optical axis is integrally formed, and each fixing portion 104 is, as will be described later, It is fixed to the welding surface 106 facing the fixing portion 104 by laser welding.

  Here, each engaging portion 102 defines a diameter dimension in a direction orthogonal to the optical axis of the space S. Each engaging portion 102 defines a smaller diameter dimension to the outer diameter dimension of the lens 10 when the lens 10 is in a state before being inserted into the space S.

  On the other hand, when the lens 10 is inserted into the space S, as shown in FIGS. 3A and 3B, each engaging portion 102 is moved outward in a direction perpendicular to the optical axis with one end as the center. The lens 10 is inserted into a space S that is elastically displaced toward each other and is formed by the engagement portions 102 working together. Then, the lens 10 is placed on the positioning surface 105 of the fixed frame 101. At this time, the claw portion 103 of each engaging portion 102 is engaged with the outer peripheral portion of the lens 10, and each engaging portion 12 is in contact with the outer peripheral portion of the lens 10 (see FIG. 4B). ). Thereby, the lens 10 is pressed by each claw part 103 so as to be pressed against the positioning surface 105, and the movement of the lens 10 in the optical axis direction is restricted. Each engaging portion 102 holds the lens 10 in a state where it is elastically displaced outward in a direction orthogonal to the optical axis. That is, each engaging portion 102 holds the lens 10 in a state where it is pressed in a direction orthogonal to the optical axis direction. Further, with the elastic displacement of each engaging portion 102 in the direction orthogonal to the optical axis, each fixing portion 104 is displaced to a position facing the welding surface 106 and abuts against the welding surface 106 (FIG. 4 ( b)).

  Next, in order to adjust the eccentricity of the lens 10, as shown in FIGS. 4A and 4B, the eccentricity adjusting pins 60 corresponding to the claw portions 103 are brought into contact with each other. And each engaging part 102 is elastically displaced to the direction orthogonal to an optical axis by operating each eccentric adjustment pin 60 so that the corresponding nail | claw part 103 may be pushed or pulled from diagonally upward. Thereby, the lens 10 is moved on the positioning surface 105 (a plane orthogonal to the optical axis). That is, positioning (eccentricity adjustment) on a plane orthogonal to the optical axis of the lens 10 is performed. In this case as well, the best resolution can be obtained by taking a chart image through the optical system while the other lenses 11, 20, 21, 22, and 30 are incorporated in the lens barrel, as in the conventional case. As shown, the lens 10 is positioned.

  Here, there are various methods for operating each eccentricity adjustment pin 60. For example, of the three eccentricity adjustment pins 60, one eccentricity adjustment pin 60 is provided with a spring, a mechanism for pushing and pulling the remaining two eccentricity adjustment pins 60 is provided, and each eccentricity adjustment pin 60 is moved by a micrometer head. There is a way to make it work. Further, there is a method of driving each eccentricity adjusting pin 60 electrically.

  In the present embodiment, unlike the conventional method, the eccentricity adjustment pin 60 does not come into direct contact with the outer peripheral portion of the lens 10, so that dirt adheres to the lens 10 due to contact with the eccentricity adjustment pin 60 and It is possible to prevent damage to the lens.

  In the state where the positioning (eccentricity adjustment) in the direction orthogonal to the optical axis of the lens 10 is performed as described above, the fixing portion 104 is in close contact with the welding surface 106 as shown in FIG. is there. An infrared laser 70 is irradiated from above on the fixing portion 104. Since the fixing portion 104 has such characteristics and thickness that it can transmit 10% or more of the infrared laser 70, the infrared laser 70 passes through the fixing portion 104 and reaches the welding surface 106.

  Due to the irradiation of the infrared laser 70, the fixing portion 104 and the welded surface 106 are heated and melted. When the irradiation of the infrared laser 70 is stopped, the respective melted portions are solidified, and the fixing portion 104 and the welding surface 106 are fixed. As a result, the lens 10 is fixed to the first group lens frame 100 via the fixed frame 101.

  Here, as the infrared laser 70, a semiconductor laser having a wavelength of 800 nm to 1100 nm, a YAG laser, or the like is used, and its irradiation diameter (spot diameter) is set to about 0.5 mm to 1 mm. The output of the infrared laser 70 is set to an output of about several watts. When the infrared laser 70 is irradiated with this output, a predetermined fixing strength can be obtained. In this embodiment, since the irradiation time of the infrared laser 70 is about 2 to 5 seconds, the fixing can be completed in half or less than the curing time of the ultraviolet curable adhesive in the conventional fixing method. it can. Therefore, the time for the fixing process can be shortened.

  As an infrared laser irradiation method, a method of irradiating each fixing portion 104 with an infrared laser, an optical system using a prism or the like, one infrared laser is divided into three infrared lasers, and each infrared laser is divided. There is a method of simultaneously irradiating a laser. When the latter irradiation method is used, the time required for fixing the fixing portion 104 and the forgiving surface 106 can be shortened as compared with the former irradiation method. In the case of the latter irradiation method, the output of the laser oscillator is increased according to the number of divisions so that the energy of each irradiation unit is equivalent to that at the time of one point irradiation and the irradiation time is about several seconds. become.

  Further, the irradiation area may be widened by scanning the irradiated portion of the infrared laser along the shape of the fixing portion 104. Moreover, you may make it irradiate an infrared laser in the state which shielded parts other than the laser irradiation required range with the metal plate.

  The above-described conditions are an example of fixing a lens having a diameter of about 5 mm to 15 mm used for a digital camera or the like with an adhesive strength of about 9.8 N to 14.8 N (1 kgf to 15 kgf).

  Moreover, it is not limited to laser irradiation, You may make it fix using heating means, such as heat welding.

  In addition, since the conventional fixing method uses an adhesive to fix the resin-made first group lens frame and the glass lens, there are few options for the optimal adhesive. On the other hand, since the fixing method of the present embodiment fixes parts made of the same resin material, an adhesive can be used for the fixing. In addition, there are more options for the adhesive.

  As described above, the lens 10 can be positioned with high accuracy, and a positional shift when the lens 10 is fixed can be prevented.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is an exploded perspective view of the first group lens frame of the lens barrel according to the second embodiment of the present invention. FIG. 6A is a perspective view of the first group lens frame of FIG. FIG. 6B is a perspective view showing a state in which a lens is inserted into the first group lens frame of FIG.

  This embodiment is different from the first embodiment in that a lens group and a first group lens frame (frame body) including a fixed frame coupled to the lens frame are used.

  In the present embodiment, a first group lens frame 200 shown in FIG. 5 is used as the first group lens frame. The first group lens frame 200 includes a lens frame 201 made of a thermoplastic resin material having a cylindrical shape, and a fixed frame 300 made of the same resin material as the lens frame 201.

  A partition plate 205 having a plane orthogonal to the optical axis is formed in the lens frame 201. The partition plate 205 is formed with an opening 206 disposed coaxially with the optical axis. One surface (subject side surface) of the partition plate 205 includes a lens positioning surface 202 that extends in an annular shape around the opening 206, and a welding surface 204 that extends in an annular shape around the lens positioning surface 202. The lens positioning surface 202 is formed in a concave portion of the partition plate 205, and the lens 10 is placed on the lens positioning surface 202. Two shaft portions 203 are formed on the welding surface 204 so as to face each other in a direction orthogonal to the optical axis.

  The fixed frame 300 has an annular main body 301, and the main body 301 is formed with two hole portions 305 arranged to face each other in the diametrical direction, and each hole portion 305 has a corresponding axis. This is a hole into which the portion 203 is press-fitted.

  The main body 301 is provided with three engaging portions 302. Each engaging portion 302 has a band shape extending in an arc around the optical axis. Each engaging portion 302 is formed so that one end thereof is integrally connected to the main body 301 and the other portion (the portion up to the other end) excluding the one end is separated from the main body 301. Each engaging portion 302 is elastically displaceable in a direction perpendicular to the optical axis with one end as a center, and is disposed so as to form a space S for receiving the lens 10 in cooperation with each other.

  At the other end of each engaging portion 302, a claw portion 303 is integrally formed to protrude inward in a direction orthogonal to the optical axis and to fix the lens 10. In addition, the other end of each engaging portion 302 is integrally formed with a fixing portion 304 that protrudes outward in a direction orthogonal to the optical axis. As will be described later, each fixing portion 304 is fixed to the welding surface 204 facing the fixing portion 304 by laser welding.

  As shown in FIG. 6A, the fixed frame 300 is positioned with respect to the lens frame 201 by press-fitting the shaft portion 203 of the lens frame 201 corresponding to each of the holes 305 of the fixed frame 300. The lens frame 201 is integrally coupled.

  Here, each engaging portion 302 defines a diameter dimension in a direction orthogonal to the optical axis of the space S. Each engaging portion 302 is not elastically displaced in a state before the lens 10 is inserted into the space S, and defines a smaller diameter dimension to the outer diameter dimension of the lens 10.

  On the other hand, when the lens 10 is inserted into the space S, as shown in FIG. 6B, each engaging portion 302 is elastically displaced outward in a direction orthogonal to the optical axis, The lens 10 is inserted into a space S formed by the engagement portions 302 working together. Then, the lens 10 is placed on the positioning surface 202 of the lens frame 201. At this time, the claw portion 303 of each engaging portion 302 is engaged with the outer peripheral portion of the lens 10, and each engaging portion 302 is in contact with the outer peripheral portion of the lens 10. Thereby, the lens 10 is pressed against the positioning surface 202 by each claw portion 303, and the movement of the lens 10 in the optical axis direction is restricted. Further, the lens 10 is held in a state of being pressed by each engaging portion 302 in a direction orthogonal to the optical axis direction. Further, along with the elastic displacement of each engagement portion 302, each fixing portion 304 is displaced to a position facing the welding surface 204 and is brought into contact with the welding surface 204.

  Next, in order to perform positioning (eccentricity adjustment) of the lens 10, as in the first embodiment, the eccentricity adjustment pins corresponding to the claw portions 303 of the fixed frame 300 are brought into contact with each other. Each engaging portion 302 is displaced in a direction orthogonal to the optical axis by pushing or pulling each eccentricity adjusting pin. As a result, the lens 10 is moved on the positioning surface 202. That is, positioning on the positioning surface 202 (plane orthogonal to the optical axis) of the lens 10 is performed. In this case as well, the best resolution can be obtained by taking a chart image through the optical system while the other lenses 11, 20, 21, 22, and 30 are incorporated in the lens barrel, as in the conventional case. As described above, positioning (eccentricity adjustment) of the lens 10 is performed.

  When the lens 10 is positioned in this manner, the fixing part 304 is irradiated with an infrared laser from above, and the fixing part 304 and the welding surface 204 are fixed. As a result, the lens 10 is fixed to the first group lens holding frame 200.

  In the present embodiment, the fixed frame 300 and the lens frame 201 are made of the same resin material. However, the fixed frame 300 is made of a material that easily transmits an infrared laser, and the lens frame 201 is absorbed by the infrared laser. However, it may be made of a material having a high value. In this case, compared with the case where the fixed frame 300 and the lens frame 201 are made of the same material, the irradiation energy of the infrared laser can be reduced, and the irradiation time can be shortened and the fixing strength can be increased.

  In addition to the fixing portions 304, the fixing frame 300 and the lens frame 201 can be fixed by irradiating an infrared laser to a portion around the positioning shaft portion 203 fitted in the hole 305 of the fixing frame 300. It will be done reliably.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 7A is a front view showing a first group lens frame of a lens barrel according to the third embodiment of the present invention. FIG. 7B is a perspective view of the first lens group frame of FIG. 7A as viewed from the image sensor side. FIG. 8 is a plan view showing a state in which a lens is incorporated in a fixed frame on the subject side of the first group lens frame of FIG. 7A). FIG. 9A is a perspective view showing a state in which a lens is incorporated in a fixed frame provided on the image pickup element side of the first group lens frame of FIG. 7B. FIG. 9B is a plan view showing a state in which a lens is incorporated in the fixed frame on the image sensor side of the first group lens frame of FIG. 7B.

  The present embodiment is provided with a fixing frame for the lens 10 (first optical member) and the lens 11 (second optical member) (see FIG. 1), compared to the first embodiment. The difference is that a first group lens frame (frame body) is used. Then, positioning (eccentricity adjustment) and fixing of the lenses 10 and 11 are performed in a state where the lenses 10 and 11 are held by the corresponding fixing frames.

  In the present embodiment, a first group lens frame 400 shown in FIGS. 7A and 7B is used.

  The first group lens frame 400 is made of a thermoplastic resin material and has a cylindrical shape. In the first group lens frame 400, a partition plate 420 having flat surfaces 421 and 422 orthogonal to the optical axis is provided. The partition plate 420 is provided with an opening 423 arranged coaxially with the optical axis.

  As shown in FIG. 7A, one surface (subject side surface) 421 of the partition plate 420 has an annular shape around the opening 423 and an annular shape around the lens positioning surface 424. It has a welding surface 425 that expands. The lens positioning surface 424 is formed in the concave portion of the partition plate 420, and the lens 10 is placed on the lens positioning surface 424.

  A fixing frame 401 for fixing the lens 10 is formed on one surface 421 of the partition plate 420. The fixed frame 401 has three engaging portions 402 (first engaging portions).

  Each engaging portion 402 has a band shape extending in an arc around the optical axis. Each engaging portion 402 has one end integrally connected to the partition plate 420, and the other portion (the portion up to the other end) excluding the one end includes one surface 421 (positioning surface 424 and welding surface 425) of the partition plate 420. ). Each engaging portion 402 can be elastically displaced in a direction perpendicular to the optical axis with one end as a center, and is disposed so as to form a space S1 for receiving the lens 10 in cooperation with each other.

  At the other end of each engagement portion 402, a claw portion 403 for projecting inward in a direction orthogonal to the optical axis and fixing the lens 10 is integrally formed. Further, at the other end of each engaging portion 102, a fixing portion 404 that protrudes outward in a direction orthogonal to the optical axis is integrally formed, and each fixing portion 404 is formed by laser welding. It is fixed to the welding surface 425 facing the fixing portion 104.

  Here, each engaging part 402 prescribes | regulates the diameter dimension of the direction orthogonal to the optical axis of space S1. Each engaging portion 402 is not elastically displaced in the state before the lens 10 is inserted into the space S1, and is based on the outer diameter of the lens 10 as a diameter in a direction perpendicular to the optical axis of the space S1. Define small diameter dimensions.

  On the other hand, when the lens 10 is inserted into the space S1, as shown in FIG. 8A, each engagement portion 402 is elastically displaced outward in a direction orthogonal to the optical axis, The lens 10 is inserted into a space S1 formed by the engagement portions 402 working together. Then, the lens 10 is placed on the positioning surface 424. At this time, the claw portion 403 of each engaging portion 402 is engaged with the outer peripheral portion of the lens 10, and each engaging portion 402 is in contact with the outer peripheral portion of the lens 10. At this time, the lens 10 is pressed against the positioning surface 424 by the claw portions 403, and the movement of the lens 10 in the optical axis direction is restricted. Further, the lens 10 is held in a state of being pressed by each engaging portion 402 in a direction orthogonal to the optical axis direction. Further, along with the elastic displacement of each engagement portion 402, each fixing portion 404 is displaced to a position facing the welding surface 425 of the partition plate 420 and is brought into contact with the welding surface 425.

  The other surface (image sensor side surface) 422 of the partition plate 420 includes a lens positioning surface 426 that extends in an annular shape around the opening 423 and a circle around the lens positioning surface 426 as shown in FIG. It has a welding surface 427 that expands in an annular shape. The lens positioning surface 426 is formed in the concave portion of the partition plate 420, and the lens 11 is placed on the lens positioning surface 426.

  A fixing frame 411 for fixing the lens 11 is formed on the other surface 422 of the partition plate 420. The fixed frame 411 has three engaging portions 412 (second engaging portions).

  Each engaging portion 412 has a band shape extending in an arc around the optical axis. Each engaging portion 412 has one end integrally connected to the partition plate 420, and the other portion (the portion up to the other end) except the one end includes the other surface 422 (positioning surface 426 and welding surface 427) of the partition plate 420. ). Each engaging portion 412 is elastically displaceable in a direction perpendicular to the optical axis with one end as a center, and is arranged so as to form a space S2 for receiving the lens 11 in cooperation with each other.

  At the other end of each engaging portion 412, a claw portion 413 for projecting inward in a direction perpendicular to the optical axis and fixing the lens 11 is integrally formed. Also, the other end of each engaging portion 412 is integrally formed with a fixing portion 414 that protrudes outward in a direction orthogonal to the optical axis, and each fixing portion 414 is formed by laser welding. It is fixed to the welding surface 427 facing the fixing portion 414.

  Here, each engaging portion 412 defines a diameter dimension in a direction orthogonal to the optical axis of the space S2. Each engaging portion 412 is not elastically displaced when the lens 11 is in the state before being inserted into the space S <b> 2, and defines a smaller diameter dimension to the outer diameter dimension of the lens 11.

  On the other hand, when the lens 11 is inserted into the space S2, as shown in FIG. 8B, each engaging portion 412 is elastically displaced outward in a direction orthogonal to the optical axis, The lens 11 is inserted into a space S2 formed by the engagement portions 412 working together. Then, the lens 11 is placed on the positioning surface 426. At this time, the claw portions 413 of the engaging portions 412 are respectively engaged with the outer peripheral portion of the lens 11, and the engaging portions 412 are in contact with the outer peripheral portion of the lens 10. Accordingly, the lens 11 is pressed against the positioning surface 426 by the claw portions 413, and the movement of the lens 11 in the optical axis direction is restricted. Further, the lens 11 is held by each engaging portion 412 while being pressed in a direction orthogonal to the optical axis. Further, along with the elastic displacement of each engaging portion 412, each fixing portion 414 is displaced to a position facing the welding surface 427 of the partition plate 420 and abuts on the welding surface 427.

  When the lenses 10 and 11 are assembled into the lens frame 400, the lens 11 is first assembled into the fixed frame 411. Then, positioning (eccentricity adjustment) and fixing of the lens 11 are performed. The procedure at this time is the same as the procedure for the lens 10 of the first embodiment.

  Next, the lens 10 is assembled into the fixed frame 401. The procedure at this time is the same procedure.

  In each of the above embodiments, the method of fixing the lens of the lens barrel has been described. However, the fixing method is not limited to the lens, and other optical members such as a filter and a glass plate are fixed. Needless to say, the method is applicable.

It is a longitudinal view which shows the structure of the lens barrel as an optical unit which concerns on the 1st Embodiment of this invention. FIG. 2A is a perspective view illustrating a configuration of a first group lens frame 100 in FIG. 1. FIG. 2B is a plan view of the first group lens frame 100 of FIG. FIG. 3C is a longitudinal sectional view showing a main part configuration of the fixed frame 101 of the first group lens frame 100 of FIG. FIG. 4A is a perspective view illustrating a state where the lens 10 is placed on the fixed frame 101 of the first group lens frame 100. FIG. 6B is a plan view showing a state where the lens 10 is placed on the fixed frame 101 of the first group lens frame 100. (A) is a perspective view which shows the state in which the eccentric adjustment of the lens 10 mounted in the fixed frame 101 is performed by each eccentric adjustment pin. (B) is a longitudinal cross-sectional view which shows the state which fixes the fixed frame 101 in which the lens 10 was mounted, and the adhering part 104 by laser welding. It is a disassembled perspective view of the 1st group lens frame of the lens barrel which concerns on the 2nd Embodiment of this invention. (A) is a perspective view of the 1st group lens frame of FIG. FIG. 7B is a perspective view showing a state where a lens is inserted into the first group lens frame of FIG. (A) is a front view which shows the 1st group lens frame of the lens-barrel which concerns on the 3rd Embodiment of this invention. (B) is the perspective view which looked at the 1st group lens frame of Drawing 7 (a) from the image sensor side. It is a top view which shows the state in which the lens was integrated in the fixed frame by the side of a subject of the 1st group lens frame of Fig.7 (a). FIG. 8A is a perspective view illustrating a state in which a lens is incorporated in a fixed frame provided on the imaging element side of the first group lens frame in FIG. FIG. 8B is a plan view showing a state in which a lens is incorporated in a fixed frame on the image sensor side of the first group lens frame in FIG. (A) is a perspective view which shows the 1 group lens frame used for the conventional fixing method. FIG. 11B is a perspective view showing a state in which the decentering adjustment of the lens and the lens and the first group lens frame are bonded to the lens frame of FIG.

Explanation of symbols

10, 11 Lens 70 Infrared laser 100, 200, 400 First group lens frame 101, 300, 401, 411 Fixed frame 102, 302, 402, 412 Engaging portion 103, 303, 403, 413 Claw portion 104, 304, 404, 414 Adhering part

Claims (10)

An optical member;
A fixing frame for fixing the optical member,
The fixed frame has an engagement portion that holds the optical member in a state of being elastically displaced in a direction perpendicular to the optical axis,
The engaging portion is provided with a claw portion and a fixing portion that engage with the optical member so as to restrict movement of the optical member in the optical axis direction,
In the state where the engaging portion is elastically displaced in a direction perpendicular to the optical axis in order to hold the optical member, the fixing portion is formed so as to overlap a part of the fixing frame, An optical unit, wherein a part of the fixed frame is fixed.   The engaging portion is formed so that the fixing portion does not overlap a part of the fixed frame in a state where the fixing portion is not elastically displaced in a direction orthogonal to the optical axis. The optical unit according to claim 1. An optical member;
A frame to which the optical member is fixed;
A fixing frame for fixing the optical member to the frame,
The fixed frame has an engagement portion that holds the optical member in a state of being elastically displaced in a direction perpendicular to the optical axis,
The engaging portion is provided with a claw portion and a fixing portion that engage with the optical member so as to restrict movement of the optical member in the optical axis direction,
The optical unit, wherein the fixing part and the frame are fixed. The fixed frame has a plurality of band-shaped engaging portions extending in an arc shape around the optical axis as the engaging portion,
The plurality of engaging portions are elastically displaced in a direction perpendicular to the optical axis so as to form a space having a diameter dimension capable of receiving the optical member by cooperating with each other. The optical unit according to any one of 1 to 3.   The said claw part provided in the said engaging part engages with the outer peripheral part of the said optical member so that the said optical member may be pressed in an optical axis direction. The optical unit described in 1. The fixed frame includes a first engagement portion that holds a first optical member, and a second engagement portion that holds a second optical member different from the first optical member,
6. The optical unit according to claim 1, wherein the first engaging portion and the second engaging portion are formed side by side in a direction orthogonal to the optical axis. .   The optical unit according to any one of claims 1 to 6, wherein the fixed frame is formed of a resin material containing a material that absorbs infrared rays. Using a fixed frame having an engaging portion that can be elastically displaced in a direction orthogonal to the optical axis, and provided with a claw portion and a fixing portion for restricting movement of the optical member in the optical axis direction to the engaging portion. An optical member fixing method for fixing the optical member,
The engaging portion is elastically displaced in a direction orthogonal to the optical axis so that the fixing portion overlaps a part of the fixed frame, and the optical member is held by the engaging portion, and the claw portion is moved to the optical member. Engaging with,
A step of positioning the optical member in a direction orthogonal to the optical axis by pressing the engagement portion holding the optical member and elastically displacing the engaging portion in a direction orthogonal to the optical axis;
A method of fixing an optical member, comprising: fixing the overlapping fixing portion and a part of the fixing frame after positioning in a direction perpendicular to the optical axis of the optical member. Using a fixed frame having an engaging portion that can be elastically displaced in a direction orthogonal to the optical axis, and provided with a claw portion and a fixing portion for restricting movement of the optical member in the optical axis direction to the engaging portion. An optical member fixing method for fixing the optical member to a frame,
Elastically displacing the engaging portion in a direction perpendicular to the optical axis to hold the optical member in the engaging portion, and engaging the claw portion with the optical member;
A step of positioning the optical member in a direction orthogonal to the optical axis by pressing the engagement portion holding the optical member and elastically displacing the engaging portion in a direction orthogonal to the optical axis;
A method of fixing an optical member, comprising: a step of fixing the fixing portion and the frame after positioning in a direction orthogonal to the optical axis of the optical member.   The method for fixing an optical member according to claim 8 or 9, wherein laser welding is used to fix the overlapping fixing part and a part of the fixing frame.

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