JP2010078920A - Lens holder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens holder in which a plastic lens which is inexpensive without restricting the degree of freedom of a lens shape is used and in which the lens is fixed by suppressing an optical axis deviation, deformation due to the mutual interference of parts, the deterioration in optical performance due to the deformation, the deterioration in optical performance due to the change of a lens interval, etc. to the minimum, even when expansion and contraction are caused by the change of environment such as temperature. <P>SOLUTION: The lens holder includes: an annular first lens pressing member which is made of an elastic member, engaged with a lens barrel and presses and fixes an object-side lens circumferential part; and a second lens pressing member which extends while being in contact with the object-side lens circumference at three or more equal angle interval positions around an optical axis, presses and fixes the circumferential corner part of the lens located on an image forming surface side in an optical axis direction and includes an engaging pawl part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lens holder for fixing a lens to a lens barrel in a lens unit having a plurality of lenses, and in particular, while using a plurality of lenses including a plastic lens having a large linear expansion coefficient, The present invention also relates to a lens holder that can fix a lens with little performance deterioration even in a lens unit that is used in an environment where it is difficult to maintain imaging performance, such as an in-vehicle camera.

  6A is a cross-sectional view of a general lens unit in which the lens barrel 94 is viewed from the subject side, and FIG. 6B is a cross-sectional view of the lens barrel 94 in which the lenses 90 and 92 are accommodated and fixed. is there. In the lens unit shown in FIG. 6, the lenses 90 and 92 are brought into contact with the lens positioning portions 96 and 98 provided in the lens barrel 94, and the interval between the lenses 90 and 92 is defined by the lens interval ring 100. The threaded portion of the lens retainer ring 102 is screwed into the threaded portion of the cylinder 94 cut to the subject side, and the lens 90 is pressed and fixed.

  In this way, a lens unit constituted by a plurality of lenses 90 and 92 including a lens having a large linear expansion coefficient, such as a plastic lens, is held in a cylindrical lens barrel 94 to obtain imaging characteristics while being light and inexpensive. Widely used in cameras, in-vehicle cameras, etc. These lens units, for example, can be left outdoors or installed in a vehicle, resulting in high temperatures due to solar heat. The lens position changes due to thermal expansion in the optical axis direction, and the focal point changes. Due to the difference in expansion coefficient, there is no escape space for expansion in the radial direction of the lens, which causes distortion of the lens and the occurrence of coat cracks, which makes it difficult to maintain optical performance.

  That is, in the configuration shown in FIG. 6, the lens barrel 94 interferes (impedes) when the lens 92 expands when the temperature becomes high, while the lens barrel 94 expands in the radial direction, and the space ring 100 and the lens 90 and the presser ring 102 expand when the lens 92 expands. ) In the optical axis direction, this interference can be mitigated by utilizing the expansion of the lens barrel 94, but it is conceivable that the degree of freedom in shape and material is lost. Further, when contracted (at low temperature), the lens 92 acts in a direction in which a gap is generated in both the radial direction and the optical axis direction, so that the axial misalignment or inclination of the lens 92 may occur.

  However, in such a lens unit, if a glass lens or a material having a small linear expansion coefficient is used to avoid the influence of temperature, the cost is affected. There is a method of loosening the tolerance, but as a result, there may be a problem that the part accuracy is required and the cost becomes high, or the performance must be sacrificed to some extent. In recent years, aspheric surfaces are increasingly used for the purpose of reducing the number of lenses and miniaturization. However, aspheric surfaces often require higher surface accuracy than spherical surfaces, and the effect of deformation is large. Become.

  For these problems, a lens barrel provided with a stepped portion that protrudes in the optical axis direction at the lens edge and a fitting portion with a frame body that fits the outer diameter portion on the inner diameter side of the stepped portion is provided. There is a lens unit that prevents deformation due to a difference in linear expansion coefficient by inserting and pressing the outer periphery of the lens toward the lens barrel side with an elastic member. Further, an elastic member having a substantially L-shaped cross section formed of a material slightly softer than the lens hardness is provided to engage with the outer edge of the lens, and the deformation of the lens is absorbed by the elastic member having a substantially L-shaped cross section. There is also a lens unit that presses the lens surface to cope with the expansion and contraction of the lens.

  Patent Document 1 discloses a plastic lens having a tapered surface whose outer peripheral portion is inclined with respect to the optical axis, a taper washer formed with a tapered surface so as to abut against the tapered surface of the plastic lens, and the taper. An elastic body that biases the tapered washer in a direction in which the tapered surfaces of the washer and the plastic lens are in contact with each other; a lens positioning member that is in contact with the plastic lens and prohibits movement of the plastic lens in the optical axis direction; and the taper There is shown a plastic lens holding device which includes an outer peripheral portion of a washer and a lens holding frame to be fitted, which reduces the influence of thermal expansion.

  Further, in Patent Document 2, a flange portion sandwiched by parallel planes perpendicular to the optical axis is provided around the plastic lens, and the outer side reaches the outer periphery at three or more equal positions around the optical axis in the flange portion. A plastic lens holding mechanism is shown in which concave portions parallel to both side surfaces are provided, and on the other hand, a tongue-shaped spring portion that fits into the concave portion is provided on the push ring side that fixes the lens to the lens barrel. By this plastic lens holding mechanism, by pressing a plastic lens whose lens outer diameter is smaller than the inner diameter of the lens barrel, the influence of thermal expansion can be suppressed, and further, the radial play of the lens can be absorbed by the tongue-shaped spring portion that presses the recess. I am doing so.

Japanese Utility Model Publication No. 1-67614 JP-A-5-188253

  However, the method of providing a step portion protruding in the optical axis direction at the lens edge and fitting the outer diameter portion of the lens barrel to the inner diameter side of the step portion requires that both the lens and the lens barrel be formed in a complicated shape. As the cost increases, it cannot cope with a change in the lens interval due to thermal expansion. Further, the method of pressing the lens surface so as to absorb the deformation of the lens by the elastic member having a substantially L-shaped cross section requires an elastic member having a substantially L-shaped cross section formed of a material slightly softer than the hardness of the lens. This also increases the cost and cannot cope with a change in the lens interval due to thermal expansion.

  Furthermore, the plastic lens holding device and holding mechanism shown in Patent Literature 1 and Patent Literature 2 can cope with the expansion in the radial direction due to heat, but cannot cope with the change in the lens interval. In the holding device of Patent Document 1, it is necessary to provide a taper washer having a complicated shape, in the holding mechanism of Patent Document 2, a flange portion and a concave portion are provided on the plastic lens side, and a small tongue-like spring portion is provided on the push ring side. An increase in cost is inevitable.

  Therefore, in the present invention, a low-cost plastic lens is used without restricting the degree of freedom of the lens shape, and even if expansion or contraction occurs due to environmental changes such as temperature, the optical axis shifts, deformation due to interference between parts, deformation It is an object to provide a lens holder capable of fixing a lens while minimizing deterioration of optical performance due to, deterioration of optical performance due to change in lens interval, and the like.

In order to solve the above problems, the lens holder according to the present invention is:
A lens holder that presses and holds a plurality of lenses on a lens barrel;
The lens holding body is formed of an elastic member, engages with the lens barrel, and presses and fixes the first lens peripheral edge, and an annular first lens pressing member;
A second lens pressing member having an engaging claw that extends while contacting the outer periphery of the first lens and presses and fixes the second lens outer peripheral corner in the optical axis direction and the radial direction. It is characterized by.

  By configuring the lens holder in this way, even when the second lens expands in the radial direction, the engaging claw portion of the second lens pressing member presses the imaging surface side lens evenly from, for example, three directions. By doing so, it is possible to prevent the optical axis from shifting. In the first lens, for example, a contact portion of the second lens pressing member with the outer periphery of the first lens serves as a second lens side corner, and the second lens pressing member has a diameter of the first lens. The degree of curvature of the lens locking piece 18 is selected so that the pressing force in the optical axis direction and the radial direction of the second lens outer peripheral corner does not become extremely small even when pushed away from the optical axis due to directional expansion. Thus, even if the first lens expands in the radial direction, the optical axis shift can be prevented by pressing the subject side lens evenly from at least three directions as in the second lens. Note that the degree of curvature here indicates the degree of curvature of the lens locking piece 18.

  In addition, the lens is only pressed around by the second lens pressing member, and even if expansion or contraction occurs due to environmental changes such as temperature, interference between parts such as the lens barrel, other lenses, and the lens interval ring The deformation by does not occur. Therefore, even when expansion or contraction occurs due to environmental changes using a plastic lens with a large linear expansion coefficient without restricting the degree of freedom of lens shape, optical deformation due to optical axis misalignment, lens-to-lens interference, and optical due to deformation It is possible to provide a lens holder capable of fixing a lens while minimizing performance degradation, optical performance degradation due to a change in lens interval, and the like.

  The lens holding body is formed of a leaf spring-shaped elastic member, and the first lens pressing member and the second lens pressing member are integrally formed, so that the assemblability in the manufacturing process is also improved. A lens holder.

  In addition, since the lens contact portion in the engaging claw portion of the second lens pressing member is V-shaped or curved, the lens is always pressed in the optical axis direction and the radial direction even when the lens expands and contracts. Thus, the optical axis can be prevented from being displaced, and further, deformation due to interference between components can be prevented.

  Further, the engaging claw portion allows the second lens to be pressed and fixed from the first lens side so that performance degradation due to a change in the distance between the second lens and the other lens does not become a problem. It is possible to provide a lens holder effective in the above case.

  The engaging claw portion presses the second lens toward the first lens and integrally holds it, so that the distance between the imaging surface side lens and the other lens is always constant, and the distance between the lenses. An effective lens holder can be used when performance degradation due to changes or the like is a problem.

  Further, by providing a spacing ring between the plurality of lenses, a desired spacing can be obtained by the spacing ring even when the spacing between the subject side lens and the lens fixed by the second lens pressing member is arbitrary. it can.

  Further, the first lens pressing member is provided with an engaging portion that engages with a convex portion provided on the lens barrel and fixes the first lens pressing member to the lens barrel, thereby simplifying the lens holding body. It can be fixed to the lens barrel.

  The engaging claws are provided at three or more positions at substantially equal angular positions around the optical axis, so that the first lens and the second lens are held evenly around the optical axis. Even if it expands in the radial direction, the optical axis is not displaced.

  In addition, the lens holder is used in an in-vehicle or monitoring lens unit, and as described above, the in-vehicle or monitoring lens unit may be exposed to high temperatures. It can be set as the lens holding body which can prevent performance degradation.

  As described above, the lens holder according to the present invention uses a plastic lens having a large linear expansion coefficient without limiting the degree of freedom of the lens shape, and even when expansion and contraction occurs due to environmental changes such as temperature, the optical axis shift, Fix the lens by minimizing lens deformation due to interference between parts such as the lens barrel, other lenses, and lens interval ring, optical performance deterioration due to deformation, optical performance deterioration due to lens interval change, etc. Therefore, it is possible to provide a lens holder that is suitable for use in a lens unit that is used in a place where environmental changes such as temperature are large.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the shape of the component described in this embodiment is not intended to limit the scope of the present invention, but merely an illustrative example.

  Embodiments of the present invention will be described below with reference to the drawings. 1A is a perspective view of a lens holder that fixes a plurality of lenses to a lens barrel, and FIG. 1B is a lens holder shown in FIG. The figure which looked at the state which fixed the lens to the lens-barrel using the body from the subject side, (C) is a sectional view seen from the aa direction of (B) in the lens holder shown in (A), (D ) Is a perspective view of a state in which the lens is fixed to the lens barrel using the lens holding body shown in (A), and (E) is a state of (B) in which the lens shown in (D) is fixed to the lens barrel. It is sectional drawing seen from -a direction.

  The lens holder 10 according to the first embodiment of the present invention has the shape shown in the perspective view in FIG. 1A, and the protrusion 24 provided on the lens barrel 22 as shown in the perspective view in FIG. The engagement hole 16 of the lens barrel engaging member 14 is engaged with and locked to the object side lens 30 (first lens) as shown in the sectional view of FIG. 12 (first lens pressing member), the imaging surface side lens 32 (second lens) is pressed by the lens locking piece 18 (second lens pressing member) having the engaging claws 20, and is attached to the lens barrel 22. It is to be fixed.

  The lens holding body 10 is formed of a leaf spring-shaped elastic body such as, for example, bronze bronze and corresponds to the optical surface of the subject side lens 30 as shown in FIGS. 1 (A), (B), and (C). The lens holding member 12 that presses the periphery of the subject-side lens 30 toward the image plane is provided. The lens holding member 10 is fixed to the lens barrel 22 at, for example, three angular positions around the optical axis as shown in FIG. The lens barrel engaging member 14 formed to press the outer periphery of the lens barrel 22 is provided. The lens barrel engaging member 14 is provided with an engagement hole 16 that engages with a protrusion 24 provided on the lens barrel.

  Further, between the lens barrel engaging members 14 in the annular lens pressing member 12, the same as the lens barrel engaging member 14, for example, at three equal angular intervals around the optical axis, with a predetermined width, as shown in FIG. As shown in (E), a lens that extends from the outer peripheral side of the subject side lens 30 toward the imaging plane side lens 32 inside the lens barrel 22 and is provided at the outer peripheral corner of the imaging plane side lens 32. A lens locking piece 18 is provided that presses and fixes the side inclined portion 34 obliquely with respect to the optical axis direction by the engaging claw portion 20. As a result, even when the lens expands and contracts, it is always pressed from the optical axis direction and the radial direction, so that the optical axis shift can be prevented and deformation due to interference between components can be prevented. Here, the outer peripheral corner portion refers to a portion in contact with the engaging claw portion 20 in the imaging plane side lens 32.

  In the figure, the engaging claw portion 20 is shown in the shape of a “<” shape (ie, “V” shape), but the corner portion of the imaging surface side lens 32 is pressed obliquely with respect to the optical axis direction. If it can be fixed, it may be curved. The material of the lens holder 10 is not limited to the above-described bronze bronze, but may be made of, for example, stainless steel or plastic as long as it is a leaf spring-shaped elastic body. Obviously, the number of is not limited to three. Further, FIG. 1 shows an example in which the lens side inclined portion 34 is provided at the outer peripheral corner portion of the imaging surface side lens 32, but no particular problem occurs even if the inclined portion is not provided. In the figure, the first lens is the subject side lens 30 and the second lens is the imaging plane side lens 32. However, the first lens is the imaging plane side lens 32 and the second lens. May be configured with the subject-side lens 30. In this case, the lens locking piece 18 in the lens holding body 10 is inserted so as to press the subject side lens 32 from the periphery of the imaging plane side lens 32, but the lens barrel engaging member 14 is connected to the imaging plane side lens 32. Depending on the position, it can be fixed on the inner surface of the lens barrel 22 or can be fixed on the end surface on the imaging surface side of the lens barrel 22.

  1 shows the case where the lens pressing member 12, the lens barrel engaging member 14, and the lens locking piece 18 are integrated, for example, the lens barrel engaging member 14 is eliminated, and the lens pressing member 12 and The lens locking piece 18 is integrally attached to the subject side edge of the lens barrel 22 by screwing or caulking, or the lens pressing member 12 and the lens locking piece 18 are separate members, together with the object side edge of the lens barrel 22. It may be attached to the part with screws or caulking. In addition, the lens locking piece 18 is integrated with an annular member different from the lens pressing member 12 and the lens pressing member 12 and the lens barrel engaging member 14 are integrated, and the imaging surface side lens 32 is incorporated. The locking piece 18 side may be incorporated later, and then the lens pressing member 12 may be incorporated after the subject side lens 30 is assembled to hold the locking piece 18 side. Furthermore, the locking piece 18 side may be installed after the imaging surface side lens 32 and the subject side lens 30 are installed, and then the lens pressing member 12 may be installed to press the locking piece 18 side.

  On the other hand, the lens barrel 22 is made of plastic when configured at low cost, and is formed of metal such as aluminum when considering the environment such as temperature, humidity, and rain and wind. As shown in FIG. 1D, a protrusion 24 for engaging the engagement hole 16 of the lens barrel engagement member 14 and fixing the lens holding body 10 is provided on the outer periphery. In addition, lens fixing portions 26 and 28 for fixing and positioning the subject side lens 30 and the imaging surface side lens 32 are provided on the inner periphery, and further, the outer periphery of the subject side lens 30 on the inner periphery side of the lens barrel 22 is provided. A concave portion (not shown) that can accommodate the width and thickness of the lens locking piece 18 is provided at a portion where the lens locking piece 18 extends.

  In FIG. 1E, the subject side lens 30 and the imaging surface side lens 32 are drawn with their lower ends in contact with the inner wall of the lens barrel 22, but these subject side lens 30 and imaging surface side lens 32 are By extending the lens locking pieces 18 extending toward the image plane side lens 32 from three or more equiangular intervals around the optical axis on the subject side while being in contact with the outer periphery of the subject side lens 30, this subject side The lens 30 can be held. Further, since the imaging surface side lens 32 is pressed and held by the engaging claw portion 20 of the lens locking piece 18, the linear expansion of the lens barrel 22, the subject side lens 30 and the imaging surface side lens 32 described above. When interference with the lens barrel 22 due to radial expansion due to the difference in coefficients occurs, the inner diameter of the lens barrel 22 is made larger than the outer diameter of the subject side lens 30 and the imaging surface side lens 32 so as not to interfere. It becomes possible to.

  FIG. 2 is a diagram for explaining this. 2A is a cross-sectional view of the lens held by the first embodiment of the lens holder 10 according to the present invention in a normal state at room temperature, and FIG. 2B is a state in which the lens is expanded due to high temperature. It is sectional drawing. That is, in the cross-sectional view of the normal state at room temperature in FIG. 2A, the imaging surface side lens 32 is not expanded, so that the V-shaped portion of the engaging claw portion 20 in the lens locking piece 18 is imaged. The lens is held on the subject side of the lens side inclined portion 34 of the surface side lens 32.

  On the other hand, in the figure in which the imaging surface side lens 32 is expanded due to the high temperature in FIG. 2B, the engaging claw portion 20 in the lens locking piece 18 is pushed up by the radial expansion of the imaging surface side lens 32, The V-shaped part is moved to the imaging plane side of the lens side inclined part 34 of the imaging plane side lens 32. That is, even if the imaging surface side lens 32 expands in the radial direction, the engaging claws 20 of the lens locking piece 18 press the imaging surface side lens 32 evenly from at least three directions. It can be prevented.

  In addition, the subject side lens 30 also has, for example, a contact portion between the lens locking piece 18 and the outer peripheral portion of the lens locking piece 18 as an imaging surface side corner, and the lens locking piece 18 is in the radial direction of the subject side lens 30. The degree of curvature of the lens locking piece 18 is selected so that the force that pushes the outer peripheral corner of the imaging surface side lens 32 obliquely in the direction of the optical axis does not become extremely small even if it is pushed away from the optical axis due to expansion. As a result, even if the subject side lens 30 expands in the radial direction, the subject side lens 30 is pressed evenly from at least three directions as in the case of the imaging plane side lens 32, so that the optical axis shift can be prevented.

  Therefore, even in high-temperature and low-temperature environments, the lens is fixed by minimizing optical axis misalignment, lens deformation due to interference between components, optical performance deterioration due to deformation, optical performance deterioration due to lens interval change, etc. Capturing the operating status of a place where the environment changes greatly such as temperature, for example, an in-vehicle or monitoring lens unit that may become hot due to solar heat, or a machine that becomes hot when it is in operation Therefore, it is possible to provide a lens holder suitable for use in a lens unit for FA.

  The above is the first embodiment of the lens holder according to the present invention. In this first embodiment, the subject side lens 30 and the imaging surface side lens 32 are both formed on the imaging surface by the lens pressing member 12 and the lens locking piece 18. It is pressed and fixed to the side. Therefore, when the lens barrel 22 expands and contracts in the optical axis direction due to temperature, the distance between the subject side lens 30 and the imaging plane side lens 32 may change. Therefore, the first embodiment is effective in the case where the distance between the subject side lens 30 and the imaging surface side lens 32 is not a problem in terms of lens design, but it is important in design to keep this lens distance constant. There is a case. In this case, the lens holder 50 according to the second embodiment of the present invention shown in FIGS. 3 and 4 is considered.

  3A is a perspective view of a lens holder 50 for fixing a lens to a lens barrel 62, and FIG. 3B is a lens holder shown in FIG. 50 is a perspective view of a state in which the lenses 70 and 72 are held at 50, and FIG. 10C is a cross-sectional view of the state in which the lenses 70 and 72 are fixed to the lens barrel 62. FIG. 4 is an exploded perspective view for explaining a state in which the lens holder 50 and the lenses 70 and 72 are incorporated into the lens barrel 52 in the second embodiment of the lens holder 50 according to the present invention.

  The lens holder 50 according to the second embodiment of the present invention has the shape shown in the perspective view of FIG. Then, as shown in the perspective view of FIG. 4, the lens holder 50 is locked by engaging the engaging hole 56 of the lens barrel engaging member 54 with the protrusion 64 provided on the lens barrel 62. As shown in the cross-sectional view of FIG. 3C, the object side lens 70 (first lens) is an annular lens pressing member 52 (first lens pressing member), and the imaging plane side lens 72 (second lens). 3) is pressed from the imaging surface side by a lens locking piece 58 (second lens pressing member) having an engaging claw portion 60, and the subject side lens 70 and the imaging surface side lens 72 are shown in FIG. As described above, it is fixed to the lens barrel 62 while being integrally held.

  The lens holding body 50 is formed of a leaf spring-shaped elastic body such as, for example, bronze bronze, stainless steel, or plastic as in the case of the first embodiment, and as shown in FIGS. Similar to the first embodiment, the lens pressing member 52 that presses the periphery of the subject-side lens 70 toward the imaging surface side is formed in an annular shape with a portion corresponding to the optical surface 70 as an opening. Further, the lens holding member 50 is attached to the lens holding member 52 at three positions at equal angular intervals around the optical axis as shown in FIGS. 3A and 3B, for example. A lens barrel engaging member 54 is provided so as to press the outer periphery of the lens barrel 62. The lens barrel engaging member 54 is provided with an engaging hole 56 that engages with a protrusion 64 provided on the lens barrel 62.

  Further, between the lens barrel engaging members 54 of the annular lens pressing member 52, as in the lens barrel engaging member 54, there are, for example, three positions at equal angular intervals around the optical axis, as shown in FIG. , (B), the lens 62 extends from the outer peripheral side of the subject side lens 70 toward the imaging plane side lens 72 and is provided at the outer peripheral corner of the imaging plane side lens 72. A lens locking piece 58 is provided that presses the lens-side inclined portion 74 obliquely from the image forming surface side to the subject side at the engaging claw portion 60 in both the optical axis direction and the radial direction.

  In the figure, the engaging claw portion 60 has a “<” shape (that is, a “V” shape), but the corner portion of the imaging surface side lens 72 is pressed obliquely with respect to the optical axis direction. If it can be fixed, it may be curved. In addition, it is obvious that the number of the lens barrel engaging members 54 and the lens locking pieces 58 is not limited to three. Further, in FIG. Although an example in which the portion 74 is provided is shown, no particular problem occurs even if the inclined portion is not provided. In the figure, the first lens is an object side lens 70 and the second lens is an image plane side lens 72. However, the first lens is an image plane side lens 72 and the second lens is an image plane side lens 72. You may comprise as the to-be-photographed object side lens 70. FIG.

  3 shows the case where the lens pressing member 52, the lens barrel engaging member 54, and the lens locking piece 58 are integrated. As described in the case of the first embodiment, for example, the lens barrel engaging member is used. The joint member 54 is eliminated, and the lens pressing member 52 and the lens locking piece 58 are integrally attached to the subject side edge of the lens barrel 62 with screws or caulking, or the lens pressing member 52 and the lens locking piece 58 are separately provided. In addition, it may be attached to the subject side edge portion of the lens barrel 62 with screws or caulking together. Further, the lens locking piece 58 is integrated with an annular member different from the lens pressing member 52, and the imaging surface side lens 72 is incorporated by integrating the lens pressing member 52 and the lens barrel engaging member 54. The locking piece 58 side may be incorporated later, and then the lens-side pressing member 52 may be incorporated after the subject-side lens 70 is assembled to hold the locking piece 58 side. Further, the locking piece 58 may be incorporated after the imaging surface side lens 72 and the subject side lens 70 are assembled, and then the lens pressing member 52 may be incorporated to press the locking piece 58 side.

  On the other hand, the lens barrel 62 is made of plastic when configured at low cost, and is made of metal such as aluminum when considering environment such as temperature, humidity, and rain and wind. As shown in FIG. 4, a protrusion 64 for fixing the lens holding body 50 by engaging with the engagement hole 56 of the lens barrel engagement member 54 is provided on the outer periphery. In addition, a lens fixing portion 66 (see FIG. 3C) for fixing and positioning the imaging surface side lens 72 is provided inside, and further on the outer periphery of the subject side lens 70 on the inner peripheral side of the lens barrel 62. A concave portion 78 that can be accommodated by the width and thickness of the lens locking piece 58 is provided at a portion where the lens locking piece 58 extends.

  In FIG. 3C, the subject side lens 70 and the imaging plane side lens 72 are drawn with their lower ends in contact with the inner wall of the lens barrel 62. However, the subject side lens 70 and the imaging plane side lens 72 are As in the case of the first embodiment, the lens locking pieces 58 extending toward the imaging plane side lens 72 from three or more equiangular intervals around the optical axis on the subject side are in contact with the outer periphery of the subject side lens 70. The subject-side lens 70 can be held by extending while extending. Further, since the image forming surface side lens 72 is pressed and held by the engaging claw portion 60 of the lens locking piece 58, the linear expansion of the lens barrel 62, the subject side lens 70, and the image forming surface side lens 72 described above. When interference with the lens barrel 62 due to radial expansion due to the difference in coefficients occurs, the inner diameter of the lens barrel 62 is made larger than the outer diameter of the subject side lens 70 and the imaging surface side lens 72 so as not to interfere. It becomes possible to.

  That is, as described in the first embodiment, for example, the contact portion of the lens locking piece 58 with the outer peripheral portion of the subject-side lens 70 is an imaging surface side corner, and the lens locking piece 58 is the subject-side lens. Even if the lens 70 is pushed in a direction away from the optical axis due to the radial expansion of the lens 70, the force of pushing the outer peripheral corner of the imaging plane side lens 72 obliquely in the optical axis direction is not extremely reduced so that the lens locking piece 58 does not become extremely small. By selecting the degree of curvature, the subject side lens 70 can be evenly pressed from at least three directions in the same manner as the imaging plane side lens 72 even if the subject side lens 70 expands in the radial direction, thereby shifting the optical axis. Can be prevented.

  Therefore, when interference with the lens barrel 62 due to radial expansion occurs due to the difference in the linear expansion coefficient between the lens barrel 62, the subject side lens 70, and the imaging surface side lens 72, the inner diameter of the lens barrel 62 is It is possible to configure larger than the outer diameters of the subject-side lens 70 and the imaging surface-side lens 72, so that even in a high-temperature environment or a low-temperature environment, the optical axis shifts, deformation of the lens due to interference between components, and optical performance due to deformation. , Degradation of optical performance due to changes in lens spacing, etc., can be fixed to the lens, for example, in-vehicle or surveillance lens units that may become hot due to solar heat, It is possible to provide a lens holding body suitable for use in an FA lens unit for photographing the operating state of a machine that becomes high temperature when operated.

  FIG. 5 shows another example of the lens configuration of the lens holder according to the second embodiment of the present invention. FIG. 5A shows a case where an interval ring is provided between the subject side lens 70 and the imaging plane side lens 72. (B) is a cross-sectional view when the subject-side lens 70 and the imaging plane-side lens 82 are applied to the respective flat portions and fixed to the lens barrel.

  In the case of these configurations as well, as described with reference to FIGS. 3 and 4, the subject side lens (first lens) 70 is replaced with an annular lens pressing member 52 (first lens pressing member), and the image plane side. The lenses (second lenses) 72 and 82 are pressed from the imaging surface side by the lens locking pieces 58 (second lens pressing members) having the engaging claws 60, and the subject side lens 70, the imaging surface side lens 72, As shown in FIG. 3B, 82 is fixed to the lens barrel 62 while being integrally held.

  In the case of FIG. 5A, a spacing ring 80 is inserted between both lenses in order to maintain the distance between the subject side lens 70 and the imaging plane side lens 72, and in the case of FIG. The imaging surface side lens 82 is also a concave lens, and is held so as to be in contact with the flat portions 84 and 86 provided respectively. The other configuration is the same as that of the second embodiment described with reference to FIGS.

  In the second embodiment, the engagement claw portion 60 that presses the imaging surface side lenses 72 and 82 is formed in a V shape or a curved shape so that the engagement claw portion 60 is opened when the lens is incorporated into the lens holder 50. Therefore, it is possible to incorporate the lens by simply pressing the lens against the engaging claws. Thereby, it can be easily incorporated into the lens holder without damaging the lens.

  As described above, according to the present invention, even when the lenses 32, 72, and 82 located on the imaging plane side are expanded in the radial direction, the engaging claws of the lens locking pieces 18 and 58 as the second lens pressing members are provided. Since 20 and 60 hold the lens equally from at least three directions, the optical axis shift can be prevented. In addition, the subject side lenses 30 and 70 also have the subject side lenses evenly spaced from at least three directions in the same manner as the imaging surface side lens even if there is radial expansion due to the lens locking pieces 18 and 58 as the second lens pressing members. I can hold it down. Therefore, even if a plastic lens with a large linear expansion coefficient is used without restricting the degree of freedom of lens shape, even when expansion or contraction occurs due to environmental changes such as temperature, the optical axis shifts, lens deformation due to interference between parts, deformation The lens can be fixed with minimal degradation of optical performance due to the lens, degradation of optical performance due to the change in lens spacing, etc., and suitable for use in lens units used in places with large environmental changes such as temperature The body can be provided.

  According to the present invention, an inexpensive plastic lens or lens barrel is used, and even when expansion or contraction occurs due to environmental changes such as temperature, the deterioration of optical performance can be minimized, and it is used for a lens unit for in-vehicle use or monitoring. And a suitable lens holder can be provided.

In Example 1 of the lens holder according to the present invention, (A) is a perspective view of a lens holder that fixes a plurality of lenses to a lens barrel, and (B) is a lens using the lens holder shown in (A). FIG. 5C is a view of the lens holder fixed to the lens barrel, FIG. 7C is a cross-sectional view of the lens holder shown in FIG. The perspective view of the state which fixed the lens to the lens-barrel using the lens holding body shown to (E) is the state seen from the aa direction of (B) in the state which fixed the lens shown to (D) to the lens-barrel. FIG. 2A is a cross-sectional view of a lens held by Example 1 of a lens holder according to the present invention in a normal state at normal temperature, and FIG. 3B is a cross-sectional view in a state where the lens is expanded due to high temperature. In Example 2 of the lens holder according to the present invention, (A) is a perspective view of the lens holder 50 for fixing the lens to the lens barrel 62, and (B) is a lens 70 on the lens holder 50 shown in (A). , 72 is a perspective view of a state in which the lenses 70 and 72 are held, and FIG. 8C is a cross-sectional view of the state in which the lenses 70 and 72 are fixed to the lens barrel 62. It is a disassembled perspective view explaining the state which incorporates the lens holding body 50 and the lenses 70 and 72 in the lens-barrel 62 in Example 2 of the lens holding body 50 which becomes this invention. It is another example of the lens structure in Example 2 of the lens holding body which becomes this invention, (A) shows the case where a space | interval ring is provided between the to-be-photographed object side lens 70 and the imaging surface side lens 72, (B) FIG. 6 is a cross-sectional view of a case where an object side lens 70 and an imaging surface side lens 82 are applied to each of the plane portions provided and fixed to a lens barrel. (A) is the figure seen from the to-be-photographed object side, (B) is sectional drawing of the state which accommodated the lens in the lens barrel of the conventional lens unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lens holder 12 Lens pressing member 14 Lens barrel engaging member 16 Engagement hole 18 Lens locking piece 20 Engagement claw part 22 Lens barrel 24 Projection 26, 28 Lens fixing part 30 Subject side lens 32 Imaging surface side lens 34 Lens Side slope

Claims (9)

A lens holder that presses and holds a plurality of lenses on a lens barrel;
The lens holding body is formed of an elastic member, engages with the lens barrel, and presses and fixes the first lens peripheral edge, and an annular first lens pressing member;
A second lens pressing member having an engaging claw that extends while contacting the outer periphery of the first lens and presses and fixes the second lens outer peripheral corner in the optical axis direction and the radial direction. A lens holder characterized by.   2. The lens holder according to claim 1, wherein the lens holder is formed of a leaf spring-shaped elastic member, and the first lens pressing member and the second lens pressing member are integrally formed. .   3. The lens holding body according to claim 1, wherein a lens contact portion in the engaging claw portion of the second lens pressing member has a V shape or a curved shape.   The lens holder according to any one of claims 1 to 3, wherein the engaging claw portion presses and fixes the second lens from the first lens side.   The lens holding body according to any one of claims 1 to 3, wherein the engaging claw portion integrally holds the second lens by pressing the second lens toward the first lens side.   6. The lens holder according to claim 1, wherein a spacing ring is provided between the plurality of lenses.   7. The first lens pressing member is provided with an engaging portion that engages with a convex portion provided on the lens barrel and fixes the first lens pressing member to the lens barrel. The lens holder described in any of the above.   The lens holding body according to any one of claims 1 to 7, wherein the engaging claws are provided at three or more positions at substantially equal angular positions around the optical axis.   The lens holder according to any one of claims 1 to 8, wherein the lens holder is used in a vehicle-mounted or monitoring lens unit.

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