JP2007057795A - Lens-fixing device and lens barrel using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain with high accuracy for the interval between lenses to be at a predetermined interval by surely fixing the lenses. <P>SOLUTION: The lens-fixing mechanism 130 has a third reference face 104, a first spacer 122 and an adjustment screw 131. The third reference face 104 is disposed in a direction perpendicular to an optical axis in the inside a lens barrel 100, and used for positioning the movement of a lens in the direction of the optical axis. The first spacer 122 is disposed between a pair of lenses within the lens barrel 100, has a fixed length in the direction of the optical axis corresponding to the interval between the pair of lenses, and is freely slid in the direction of the optical axis. The adjustment screw 131 is disposed within the lens barrel 100, pressed against in the direction of the spacer, and presses, via the spacer, one of the pair of lenses, which is located between a positioning part and the spacer, toward the positioning part along the optical axis. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens barrel of a lens device provided in an optical apparatus such as a camera, and more particularly to a lens fixing device for fixing a lens in the optical axis direction and a lens barrel using the same.

  Conventionally, in a lens barrel that is provided in an optical device such as a camera and in which a plurality of lenses are arranged inside in the optical axis direction, a spacer is used to install the plurality of lenses in the lens barrel direction. The distance between adjacent lenses is kept constant. A plurality of lenses are held in the lens barrel at a predetermined interval by pressing the rear surface of the final lens from the optical axis direction with a lens pressing ring coupled to the lens barrel. In such a lens barrel, there is a gap between the lens barrel members due to tolerances in the geometrical dimensions of the lens barrel members and errors caused when the lens barrel members are assembled. It was happening. As a result, the lens cannot be securely held, and the optical performance may be adversely affected by the rattling of the lens or the tilt of the lens.

  On the other hand, for example, in the lens barrel in which the intervals between the plurality of lenses arranged side by side in the lens barrel are held at a predetermined interval by the spacer, by using an elastic member such as rubber or a spring for the spacer, A lens holding structure that holds a lens by eliminating a gap between each member of the lens barrel by a reaction force when the spacer is pressed against the lens is disclosed (for example, see Patent Document 1 below).

JP 2003-1505 A

  However, in the above-described conventional technology, the use of an elastic member such as rubber or a spring as the spacer causes the spacer to undergo dimensional deformation, cracking, sag, etc. due to a temperature difference in the environment where it is used or used. In addition, when an external impact or vibration is applied to the lens barrel, a gap is temporarily generated between each member of the lens barrel due to bending of the elastic member. As a result, the lens cannot be securely fixed, causing a rattling of the lens or tilting of the lens, resulting in a problem that the predetermined lens interval cannot be maintained and the optical performance of the lens barrel is lowered. .

  In addition, in the above-described conventional technology, once the lens and the spacer are assembled to the lens barrel, it is not possible to correct the rattling of the lens, the tilt of the lens, and the like unless they are disassembled. For this reason, there has been a problem that it is not possible to easily correct the rattling of the lens or the tilt of the lens that occurs after the lens barrel is assembled.

  In order to eliminate the above-described problems caused by the prior art, the present invention provides a lens fixing device capable of adjusting the lens interval even after assembly of the lens barrel and enhancing optical performance, and a lens barrel using the same. The purpose is to provide.

  In order to solve the above-described problems and achieve the object, a lens fixing device according to the present invention is provided in a direction orthogonal to the optical axis direction inside the lens barrel, and positions the movement of the lens in the optical axis direction. Is positioned between the pair of lenses inside the lens barrel and has a certain length in the optical axis direction corresponding to the distance between the pair of lenses, and slides in the optical axis direction. A free spacer and a lens provided in the lens barrel and moving in the direction of the spacer, the lens between the positioning portion and the spacer of the pair of lenses is moved in the optical axis direction via the spacer. And a pressing member for pressing in the direction of the positioning portion.

  In the lens fixing device according to the present invention, in the invention described above, the pressing member includes an inclined surface in a portion in contact with the spacer, the spacer abuts on the inclined surface of the pressing member, It is provided with the inclined surface which changes the moving direction to the direction of the said spacer of a press member into the moving direction to the said optical axis direction of the said spacer.

  In the lens fixing device according to the present invention as set forth in the invention described above, the pressing member is formed of a screwed body and penetrates from the outer peripheral surface of the lens barrel to the inner peripheral surface of the lens barrel. It is characterized by being screwed into a provided screw hole.

  In the lens fixing device according to the present invention, a plurality of the pressing members are disposed on the same circumference in the optical axis direction centering on the optical axis of the lens barrel. It is characterized by.

  Furthermore, the lens barrel according to the present invention includes a lens fixing device for fixing the lens, and the lens fixing device is provided in a direction orthogonal to the optical axis direction inside the lens barrel, and the optical axis of the lens. A positioning part for positioning the movement in the direction and the pair of lenses inside the lens barrel, and has a certain length in the optical axis direction corresponding to the distance between the pair of lenses , A spacer slidable in the optical axis direction, and movably disposed in the direction of the spacer from the lens barrel, and the positioning allows the positioning of the pair of lenses via the spacer. And a pressing member that presses the lens between the portion and the spacer in the direction of the positioning portion along the optical axis direction.

  Further, in the lens barrel according to the present invention, a plurality of the lens fixing devices are arranged corresponding to the arrangement positions of the lenses that need to be positioned in the optical axis direction of the lens barrel. It is provided.

  The lens barrel according to the present invention is the lens barrel according to the invention described above, wherein the lens surface between the positioning portion and the spacer is in surface contact with the positioning portion. The lens surface is provided with a plane that is orthogonal to the optical axis direction.

  In the lens barrel according to the present invention as set forth in the invention described above, the lens surface between the positioning portion and the spacer is such that the lens surface that contacts the positioning portion is in point contact with the positioning portion. The lens surface is provided with a convex curved surface.

  According to the present invention, it is possible to fix the lens by adjusting the adjusting screw without disassembling the lens barrel both when the lens barrel is assembled and after the assembly. Thereby, the lens interval can be held with high accuracy, and the optical performance of the lens barrel can be enhanced.

(Embodiment 1)
Exemplary embodiments of a lens fixing device and a lens barrel using the same according to the present invention will be explained below in detail with reference to the accompanying drawings. First, the first embodiment will be described. The first embodiment is a configuration example in which the lens is moved and fixed to the object side in the optical axis direction via a spacer by adjustment from the outer peripheral surface direction of the lens barrel. 1 is a side sectional view of a lens barrel provided with a lens fixing mechanism according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing the appearance of the lens barrel shown in FIG. FIG. 3 is a partially enlarged sectional view of the lens barrel shown in FIG.

  As shown in FIG. 1, the lens barrel 100 includes a lens barrel body 101, a front lens group 110 disposed on the object side in the optical axis direction inside the lens barrel body 101, and the interior of the lens barrel body 101. And a rear lens group 120 disposed on the image plane side in the optical axis direction, and a lens fixing mechanism 130 disposed in the lens barrel body 101.

  The lens barrel main body 101 is formed in a cylindrical shape with the optical axis 100 </ b> A as an axis, and includes an outer peripheral surface 105, an inner peripheral surface 106, and an opening 107.

  As shown in FIG. 1, the inner peripheral surface 106 is formed in a step shape according to the outer diameter of each lens, each spacer, and the like disposed in the lens barrel main body 101. The inner peripheral surface 106 includes an inner peripheral surface 106A where the first spacer 122 is inserted, an inner peripheral surface 106B where the fourth lens 121 is inserted, and a portion where the second spacer 124 is inserted. An inner peripheral surface 106F is provided. Furthermore, the inner peripheral surface 106C of the portion where the screw groove is formed so that the first lens pressing ring 111 is screwed and the portion where the screw groove is formed so that the second lens pressing ring 113 is screwed. An inner peripheral surface 106D and a portion of the inner peripheral surface 106E in which a screw groove is formed so that the eighth lens pressing ring 129 is screwed are provided.

  The opening 107 includes an opening 107F on the object side in the optical axis direction and an opening 107R on the image plane side in the optical axis direction. The opening 107 includes an opening 107A where the first spacer 122 is inserted, an opening 107B where the fourth lens 121 is inserted, and between the third lens 115 and the fourth lens 121. A portion of the opening 107 </ b> C and a portion of the opening 107 </ b> D into which the second spacer 124 is inserted are provided.

  A first reference surface 102, a second reference surface 103, and a third reference surface 104 are formed inside the lens barrel body 101. The first reference surface 102 is a plane orthogonal to the optical axis 100 </ b> A formed in a protruding shape on the inner peripheral surface 106 in order to position the third lens 115 on the object side in the optical axis direction. The second reference surface 103 is a plane orthogonal to the optical axis 100 </ b> A formed by the step of the inner peripheral surface 106 in order to position the first lens 112 on the object side in the optical axis direction. The third reference plane 104 is a plane orthogonal to the optical axis 100 </ b> A formed by the step of the inner peripheral surface 106 in order to position the fourth lens 121 on the image plane side in the optical axis direction.

  The front lens group 110 includes a first lens 112, a second lens 114, and a third lens 115 in order from the object side in the optical axis direction.

  The third lens 115 and the second lens 114 are inserted from the opening 107 </ b> F and positioned by the first reference surface 102 formed inside the lens barrel main body 101. The screw groove on the inner peripheral surface 106D and the screw groove 113a formed on the outer peripheral surface of the second lens pressing ring 113 are screwed together to be pressed in the direction of the first reference surface 102.

  Further, the first lens 112 is inserted from the opening 107F and positioned by the second reference surface 103 formed inside the lens barrel main body 101. The screw groove on the inner peripheral surface 106 </ b> C and the screw groove 111 a formed on the outer peripheral surface of the first lens pressing ring 111 are screwed together to be pressed in the direction of the second reference surface 103.

  The rear lens group 120 includes, in order from the object side in the optical axis direction, a fourth lens 121, a fifth lens 123, a sixth lens 125, a seventh lens 126, and an eighth lens 128. Yes.

  In addition, the first lens 122 holds the fourth lens 121 and the fifth lens 123 at a predetermined interval. Furthermore, the second spacer 124 holds the fifth lens 123 and the sixth lens 125 at a predetermined interval. Further, the seventh lens 126 and the eighth lens 128 are held at a predetermined interval by the third spacer 127.

  The rear lens group 120 and the spacers described above are arranged in order from the opening 107R, the fourth lens 121, the first spacer 122, the fifth lens 123, the second spacer 124, the sixth lens 125, and the seventh lens. The lens 126, the third spacer 127, and the eighth lens 128 are inserted and positioned by the third reference surface 104 formed inside the lens barrel body 101. Then, the screw groove of the inner peripheral surface 106E and the screw groove 129a formed on the outer peripheral surface of the eighth lens pressing ring 129 are screwed together to be pressed in the direction of the third reference surface 104.

  In the rear lens group 120, the fourth lens 121 fixed by the lens fixing mechanism 130 is inserted into the opening 107B while the outer peripheral surface 121A of the fourth lens 121 is in contact with the inner peripheral surface 106B. It has an outer diameter that can slide along the axial direction. The fourth lens 121 includes a lens surface R1 and a lens surface R2. The lens surface R1 is a lens surface on the object side in the optical axis direction, and a circular concave curved surface portion centering on the optical axis 100A is formed inside the lens surface R1. Further, an annular flat surface portion 121 f is formed on the outer peripheral side of the curved surface portion so as to come into surface contact with the third reference surface 104 formed inside the lens barrel main body 101. The lens surface R2 is a lens surface on the image surface side in the optical axis direction, and is formed by a convex curved surface portion.

  Next, as shown in FIG. 3, the lens fixing mechanism 130 includes an adjusting screw 131 as a pressing member, a screw hole 132, and a first spacer 122.

  The screw hole 132 is formed so as to penetrate from the outer peripheral surface 105 (not shown) of the lens barrel main body 101 to the inner peripheral surface 106A in a direction orthogonal to the optical axis 100A. A screw groove 132 a that is screwed with the screw groove 131 b of the adjusting screw 131 is formed on the inner peripheral surface of the screw hole 132.

  The adjustment screw 131 is screwed into the screw hole 132 and can be adjusted from the direction of the outer peripheral surface 105 of the lens barrel main body 101. The tip of the adjustment screw 131 has a conical shape formed by the inclined surface 131a. A screw groove 131b that is screwed into the screw groove 132a of the screw hole 132 is formed on the outer peripheral surface excluding the tip of the adjustment screw 131.

  As shown in FIG. 2, a groove 131c is formed at the rear end of the adjustment screw 131, and the adjustment screw 131 is rotated by an adjustment tool or the like to advance and retract in the screw hole 132. Can do. The entire length of the adjusting screw 131 is preferably formed to be shorter than the length of the screw hole 132. The adjustment screw 131 can be made of a metal material such as stainless steel or aluminum, or a resin material.

  The first spacer 122 is formed in an annular shape, and has a predetermined length W1 in the optical axis direction in order to maintain a predetermined distance between the fourth lens 121 and the fifth lens 123. . The first spacer 122 has an outer diameter that can slide along the optical axis direction while the outer peripheral surface 122A of the first spacer 122 is in contact with the inner peripheral surface 106A when inserted into the opening 107A. have. The material of the first spacer 122 can be a metal material such as stainless steel or aluminum, or a resin material.

  An operation groove 140 is provided on the outer peripheral surface of the first spacer 122. An inclined surface 141 is formed on the object side in the optical axis direction of the operation groove 140. The inclined surface 141 is inclined toward the image plane side in the optical axis direction so that the outer diameter becomes smaller as it goes toward the image plane side in the optical axis direction. Further, the inclined surface 141 is formed at a position where the object side portion in the optical axis direction of the inclined surface 131a formed on the adjusting screw 131 comes into contact. Further, the inclination angle of the inclined surface 141 is matched with the inclination angle of the inclined surface 131 a provided in the adjusting screw 131. The inclined surface 141 has a predetermined length K1. This length K1 is longer than the length of the inclined surface 131a formed on the adjusting screw 131 by a predetermined amount toward the image plane side in the optical axis direction.

  A space 142 is formed on the image plane side of the operation groove 140 in the optical axis direction. The space portion 142 is formed further toward the image plane side in the optical axis direction with a space portion in contact with the screw hole 132 as a reference, and has a predetermined length W2. The space 142 is formed so as not to interfere with the adjustment screw 131 when the first spacer 122 is slid toward the object side in the optical axis direction.

  A protrusion 150 is formed at the front end in the optical axis direction inside the first spacer 122. The protrusion 150 presses the fourth lens 121 toward the third reference surface 104 by contacting the lens surface R <b> 2 of the fourth lens 121. Further, the protrusion 150 has a circular shape when viewed from the front, and defines an effective diameter (a diameter necessary for light to pass) of the fourth lens 121. Further, a sawtooth flare preventing groove 160 is provided on the image plane side in the optical axis direction inside the first spacer 122. The flare prevention groove 160 is formed in the first spacer 122 to prevent the occurrence of internal reflection (flare) that adversely affects the optical performance.

  Next, the operation of the lens fixing mechanism 130 configured as described above will be described with reference to FIG. First, the adjusting screw 131 is advanced in the direction of the inner peripheral surface 106 (direction A) by fitting the adjusting tool into the groove 131c formed in the adjusting screw 131 and rotating the adjusting screw 131. . As a result, the inclined surface 131a formed on the adjusting screw 131 abuts on the inclined surface 141 provided on the first spacer 122, and the adjusting screw 131 is further advanced so that the inclined surface 141 is pressed by the inclined surface 131a. Is done. The first spacer 122 generates a moving force in the object side direction (direction B) in the optical axis direction when the inclined surface 141 is pressed, and slides toward the object side along the optical axis direction. The protrusion 150 formed on the first spacer 122 contacts the fourth lens 121 and slides the fourth lens 121 toward the object side in the optical axis direction.

  As described above, the adjustment of the adjustment screw 131 causes the fourth lens 121 to slide toward the object side in the optical axis direction until the flat surface portion 121f of the lens surface R1 of the fourth lens 121 comes into surface contact with the third reference surface 104. Can be moved. Thereby, the gap 170 generated between the third reference surface 104 and the fourth lens 121 can be eliminated. Furthermore, the fourth lens 121 is pressed by the flat surface portion 121f being brought into surface contact with the third reference surface 104 via the first spacer 122 by appropriately advancing the adjusting screw 131, so that the fourth lens 121 is securely fixed. Can do.

  In the lens barrel 100, the distance D1 between the lens surface R1 of the fourth lens 121 and the lens surface R2 of the third lens 115 is a place where the light rays are concentrated, and the lens barrel 100 is caused by a slight error in the distance D1. In order to adversely affect the optical performance of the lens, it is particularly necessary to maintain the lens interval with high accuracy. Therefore, in the lens barrel 100, the fourth lens 121 is securely fixed to the third reference surface 104 by the lens fixing mechanism 130 so that D1 can be held at a predetermined interval with high accuracy. It has become.

  Further, since the adjustment screw 131 can adjust the pressing force with respect to the fourth lens 121 from the direction of the outer peripheral surface 105 of the lens barrel 100, the lens barrel 100 even after the lens barrel 100 is assembled. The fourth lens 121 can be fixed with an appropriate pressing force by adjusting the adjustment screw 131 without disassembling the distance D1, and the distance D1 can be held at a predetermined distance with high accuracy. As a result, it is possible to improve the optical performance of the lens barrel 100 without causing aberrations or shifting of the imaging position with respect to the image plane.

  FIG. 4 is a front sectional view showing the lens fixing mechanism according to the first embodiment of the present invention. In the lens barrel 100 of the example shown in FIG. 4, an adjustment screw 131 and a screw hole 132 that are components of the lens fixing mechanism 130 are 120 in the lens barrel body 101 in the circumferential direction around the optical axis 100A. It is arranged at three places with an interval of °.

  According to such a configuration, the fourth lens 121 is slid evenly from the plurality of locations to the object side in the optical axis direction via the first spacer 122 by evenly tightening the plurality of adjusting screws 131. The third reference surface 104 can be pressed. As a result, the fourth lens 121 can be reliably fixed without being inclined in a certain direction. In addition, it is preferable that the adjusting screws 131 and the screw holes 132 which are components of the lens fixing mechanism 130 are disposed at least at two or more in the circumferential direction around the optical axis 100A of the lens barrel body 101.

  As described above, according to the first embodiment, the fourth lens 121 is connected to the third lens 122 via the first spacer 122 by tightening the adjustment screw 131 from the direction of the outer peripheral surface 105 of the lens barrel 100. It is configured to be fixed with respect to the reference surface 104. Therefore, even after the lens barrel 100 is assembled, the fourth lens 121 can be reliably fixed with an appropriate pressing force by adjusting the adjustment screw 131 without disassembling the lens barrel 100. The optical performance of the lens barrel 100 can be improved by maintaining the gap between the fourth lens 121 and the third lens 115 at a predetermined interval with high accuracy.

  Note that the tip of the adjustment screw 131 has a shape that can press the inclined surface 141, for example, the inclination angle of the inclined surface 131a does not match the inclination angle of the inclined surface 141, or a hemispherical shape. Can also be used. Furthermore, the thing of the structure provided with the separate inclined surface which can rotate in the front-end | tip part of the screw 131 for adjustment can also be used. Also in this case, the tip portion is not limited to the conical shape, and may be any shape as long as it has an inclined surface 141 and an inclined surface to be pressed. For example, a quadrangular pyramid shape can be used.

(Embodiment 2)
Next, a second embodiment will be described. The second embodiment is a configuration example in which a plurality of lens fixing mechanisms are arranged in the optical axis direction of the lens barrel. FIG. 5 is a side sectional view of a lens barrel provided with a lens fixing mechanism according to Embodiment 2 of the present invention.

  As shown in FIG. 5, the lens barrel 500 has the same configuration as the lens barrel 100 described above (see FIG. 1), and in addition to the lens fixing mechanism 130 described above (FIG. 1) for fixing the fifth lens 123. This is a configuration example in which a lens fixing mechanism 530 having the same configuration as that of the reference is disposed. Since other configurations are the same as those of the lens barrel 100 described above, description thereof is omitted here.

  The lens fixing mechanism 530 includes an adjusting screw 531 as a pressing member, a screw hole 532, and a second spacer 524.

  The screw hole 532 is formed so as to penetrate from the outer peripheral surface 105 of the lens barrel main body 501 to the inner peripheral surface 106F in a direction orthogonal to the optical axis 100A.

  The adjustment screw 531 is screwed into the screw hole 532 and can be adjusted from the direction of the outer peripheral surface 105 of the lens barrel main body 501. The tip of the adjustment screw 531 has a conical shape.

  The second spacer 524 is formed in an annular shape, and has a predetermined length in the optical axis direction in order to maintain a predetermined distance between the fifth lens 123 and the sixth lens 125. The second spacer 524 has an outer diameter that can slide along the optical axis direction while the outer peripheral surface 524A of the second spacer 524 is in contact with the inner peripheral surface 106F when inserted into the opening 107D. have.

  Similar to the operation groove 140 (see FIG. 3) described in the first embodiment, the outer circumferential surface of the second spacer 524 is provided with an operation groove 540 in which an inclined surface 541 and a space 542 are formed. .

  Next, the operation of the lens barrel 500 having the above-described configuration will be described with reference to FIG. First, the fourth lens 121 is slid toward the object side in the optical axis direction until the fourth lens 121 comes into contact with the third reference surface 104 by adjusting the adjustment screw 131 provided in the lens fixing mechanism 130. . Furthermore, the fourth lens 121 can be appropriately pressed and fixed to the third reference surface 104 via the first spacer 122 by causing the adjustment screw 131 to appropriately move.

  Next, the fifth lens 123 is moved to the optical axis until the fifth lens 123 comes into contact with the first spacer 122 holding the fourth lens 121 by adjusting the adjustment screw 531 provided in the lens fixing mechanism 530. Slide to the object side in the direction. Furthermore, the fifth lens 123 can be pressed against the first spacer 122 via the second spacer 524 and can be reliably fixed by causing the adjusting screw 531 to travel appropriately.

  As described above, according to the second embodiment, by securely fixing the fourth lens 121 and the fifth lens 123, in addition to the distance D1 between the third lens 115 and the fourth lens 121, The distance D2 between the fourth lens 121 and the fifth lens 123 can also be held at a predetermined distance with high accuracy. Thereby, the optical performance of the lens barrel 500 can be further enhanced.

  In addition to the configuration of the lens barrel 500, the sixth lens 125 and the seventh lens 126 are also fixed using a lens fixing mechanism including a spacer, a screw hole, and an adjusting screw. Can do. In this case, the distance between the fifth lens 123 and the sixth lens 125 can be held at a predetermined distance with high accuracy, and the optical performance of the lens barrel 500 can be further improved.

(Embodiment 3)
Next, Embodiment 3 will be described. The third embodiment is a configuration example in which the lens is fixed by moving the lens to the image plane side in the optical axis direction by adjustment from the outer peripheral surface direction of the lens barrel. FIG. 6 is a side sectional view of a lens barrel provided with a lens fixing mechanism according to Embodiment 3 of the present invention.

  In the lens barrel 100 (see FIG. 1) described above, the fourth lens 121 of the rear lens group 120 is fixed by the lens fixing mechanism 130. On the other hand, as shown in FIG. 6, the lens barrel 600 is changed to a configuration in which the third lens 615 of the front lens group 610 is fixed by a lens fixing mechanism 630 having the same configuration as the lens fixing mechanism 130. Yes.

  The lens barrel 600 includes a lens barrel main body 601, a front lens group 610 disposed on the object side in the optical axis direction inside the lens barrel main body 601, and an image plane in the optical axis direction inside the lens barrel main body 601. A rear lens group 620 disposed on the side and a lens fixing mechanism 630 disposed on the lens barrel body 601 are configured.

  The lens barrel main body 601 is formed in a cylindrical shape with the optical axis 600A as an axis, and includes an outer peripheral surface 605, an inner peripheral surface 606, and an opening 607.

  The inner peripheral surface 606 includes an inner peripheral surface 606A where the first spacer 614 is inserted and an inner peripheral surface 606B where the third lens 615 is inserted.

  The opening 607 includes an object-side opening 607F in the optical axis direction, an image-side opening 607R in the optical axis direction, an opening 607A where the first spacer 614 is inserted, and a third lens 615. And an opening 607B of a portion to be inserted.

  In addition, a first reference surface 602 for positioning the third lens 615 and a second reference surface 603 for positioning the fourth lens 621 are formed inside the lens barrel body 601.

  The front lens group 610 includes a first lens 612, a second lens 613, and a third lens 615 in order from the object side in the optical axis direction. The second lens 613 and the third lens 615 are held at a predetermined interval by the first spacer 614. Then, the first lens pressing ring 611 is held so as to be pressed in the direction of the first reference plane 602.

  Of the front lens group 610, the third lens 615 fixed by the lens fixing mechanism 630 is inserted into the opening 607B while the outer peripheral surface 615A of the third lens 615 is in contact with the inner peripheral surface 606B. It has an outer diameter that can slide along the axial direction. The third lens 615 includes a lens surface R1 and a lens surface R2. The lens surface R1 is a lens surface on the object side in the optical axis direction, and is formed by a convex curved surface portion. The lens surface R2 is a lens surface on the image surface side in the optical axis direction, and a circular concave curved surface portion centering on the optical axis 600A is formed inside the lens surface R2. Further, an annular flat surface portion 615r is formed on the outer peripheral side of the curved surface portion.

  The rear lens group 620 includes a fourth lens 621, a fifth lens 623, a sixth lens 624, and a seventh lens 626 in order from the object side in the optical axis direction. The fourth lens 621 and the fifth lens 623 are held at a predetermined interval by the second spacer 622. Further, the sixth lens 624 and the seventh lens 626 are held at a predetermined interval by the third spacer 625. Then, it is held by the seventh lens pressing ring 627 so as to be pressed in the direction of the second reference plane 603.

  The lens fixing mechanism 630 includes an adjusting screw 631 that is a pressing member, a screw hole 632, and a first spacer 614.

  The screw hole 632 is drilled so as to penetrate from the outer peripheral surface 605 of the lens barrel main body 601 to the inner peripheral surface 606A in a direction orthogonal to the optical axis 600A.

  The adjusting screw 631 is screwed into the screw hole 632 and can be adjusted from the direction of the outer peripheral surface 605 of the lens barrel body 601. The tip of the adjustment screw 631 has a conical shape.

  The first spacer 614 is formed in an annular shape, and has a predetermined length in the optical axis direction in order to maintain a predetermined distance between the second lens 613 and the third lens 615. When the first spacer 614 is inserted into the opening 607A, the outer diameter of the first spacer 614 can slide along the optical axis direction while the outer peripheral surface 614A of the first spacer 614 contacts the inner peripheral surface 606A. have.

  Similar to the operation groove 140 (see FIG. 3) described in the first embodiment, the outer circumferential surface of the first spacer 614 is provided with an operation groove 640 including an inclined surface 641 and a space portion 642. With respect to the operation groove 140 described above, the operation groove 640 has an inclined surface 641 formed on the image plane side in the optical axis direction of the operation groove 640, and a space portion 642 on the object side in the optical axis direction of the operation groove 640. It differs in that it is formed.

  A protrusion 650 is formed at the front end in the optical axis direction inside the first spacer 614. The protrusion 650 presses the third lens 615 in the direction of the first reference surface 602 by contacting the lens surface R1 of the third lens 615. The protrusion 650 is circular when viewed from the front, and defines the effective diameter of the third lens 615. Further, a sawtooth flare prevention groove 660 is provided on the object side in the optical axis direction inside the first spacer 614. The flare prevention groove 660 is formed in the first spacer 614 to prevent the occurrence of internal reflection (flare) that adversely affects the optical performance.

  Next, the operation of the lens fixing mechanism 630 configured as described above will be described with reference to FIG. First, by rotating the adjustment screw 631 using an adjustment tool or the like, the adjustment screw 631 advances toward the inner peripheral surface 606 (direction A). As a result, the inclined surface formed on the adjusting screw 631 is brought into contact with the inclined surface 641 provided on the first spacer 614, and the adjusting screw 631 is further advanced to thereby form the inclined surface formed on the adjusting screw 631. Thus, the inclined surface 641 is pressed. The first spacer 614 slides toward the image plane along the optical axis direction when the inclined surface 641 is pressed to generate a moving force in the image plane side direction (direction B) in the optical axis direction. The protrusion 650 formed on the first spacer 614 contacts the third lens 615 and slides the third lens 615 to the image plane side in the optical axis direction.

  As described above, the adjustment of the adjustment screw 631 causes the third lens 615 to slide toward the image plane in the optical axis direction until the flat portion 615r of the lens surface R2 of the third lens 615 contacts the first reference surface 602. Can be moved. As a result, a gap generated between the first reference surface 602 and the third lens 615 can be eliminated. Furthermore, the third lens 615 can be appropriately pressed against the first reference surface 602 via the first spacer 614 and can be reliably fixed by causing the adjustment screw 631 to travel appropriately.

  In the lens barrel 600, similarly to the lens barrel 100 (see FIG. 1) described above, the distance D1 between the lens surface R1 of the fourth lens 621 and the lens surface R2 of the third lens 615 is a place where light rays concentrate. Since a slight error in the distance D1 adversely affects the optical performance of the lens barrel 600, it is particularly necessary to maintain the lens distance with high accuracy. In the lens barrel 100 described above, the fourth lens 121 is securely fixed to the third reference surface 104 by the lens fixing mechanism 130. On the other hand, the lens barrel 600 can hold D1 at a predetermined interval with high accuracy by securely fixing the third lens 615 to the first reference surface 602 by the lens fixing mechanism 630. It is like that.

  As described above, according to the third embodiment, the third lens 615 is attached to the first lens 615 via the first spacer 614 by tightening the adjustment screw 631 from the direction of the outer peripheral surface 605 of the lens barrel 600. The reference surface 602 is fixed. Therefore, even after the lens barrel 600 is assembled, the third lens 615 can be reliably fixed with an appropriate pressing force by adjusting the adjustment screw 631 without disassembling the lens barrel 600. The optical performance of the lens barrel 600 can be improved by maintaining the gap between the fourth lens 621 and the third lens 615 at a predetermined interval with high accuracy.

(Embodiment 4)
Next, a fourth embodiment will be described. The fourth embodiment is a configuration example in which the tilt of the lens is adjusted by adjustment from the outer peripheral surface direction of the lens barrel. FIG. 7 is a side sectional view of a lens barrel provided with a lens fixing mechanism according to Embodiment 4 of the present invention. FIG. 8 is a partially enlarged sectional view of the lens barrel shown in FIG.

  As shown in FIG. 7, the lens barrel 700 and the lens barrel main body 701 have the same configuration as the lens barrel 100 and the lens barrel main body 101 (see FIG. 1) described above, and the lens fixing mechanism 130. A lens fixing mechanism 730 having the same configuration as the lens fixing mechanism 130 (see FIG. 1) described above is disposed on the diagonal line of the optical axis 100A.

  And the 4th lens 121 provided with the concave lens surface R1 is changed into the 4th lens 721 provided with the convex lens surface R1. In the cross-sectional view of FIG. 8, the lens surface R1 of the fourth lens 721 is in point contact with the inner ends 104U and 104D of the third reference surface 104, but actually, the third reference surface 104 is circular. Since the aperture is open, the lens surface R1 of the fourth lens 721 is in line contact with the third reference surface 104 in a circular shape. Since other configurations are the same as those of the lens barrel 100 described above, description thereof is omitted here.

  Next, the operation of the lens barrel 700 configured as described above will be described with reference to FIG. As shown in FIG. 8, it is assumed that the axis 721A of the fourth lens 721 is inclined downward with respect to the optical axis 100A. In this case, first, the adjusting screw 131 is advanced toward the outer peripheral surface 105 (direction A) by rotating the adjusting screw 131 using an adjusting tool or the like. Thus, the upper portion of the first spacer 122 is sufficiently slid between the inclined surface 131a of the adjusting screw 131 and the inclined surface 141 provided in the operating groove 140 toward the image surface side in the optical axis direction. Leave an interval.

  Next, by rotating the adjustment screw 731 using an adjustment tool or the like, the adjustment screw 731 advances toward the inner peripheral surface 106 (direction B). As a result, the inclined surface formed on the adjusting screw 731 comes into contact with the inclined surface 141 below the first spacer 122, and the adjusting screw 731 is further advanced, so that the inclined surface formed on the adjusting screw 731 The inclined surface 141 below the first spacer 122 is pressed. The lower part of the first spacer 122 generates a moving force in the object side direction (direction C) in the optical axis direction when the inclined surface 141 of the lower part of the first spacer 122 is pressed, and the object side along the optical axis direction. To slide. Accordingly, the protrusion 150 formed on the first spacer 122 presses the lower portion of the fourth lens 721 toward the object side in the optical axis direction, and the lower portion of the fourth lens 721 toward the object side in the optical axis direction (direction D). To slide.

  At this time, the fourth lens 721 generates a rotational force toward the image plane in the optical axis direction with the inner end 104D below the third reference surface 104 as a rotational axis, and the rotational force of the fourth lens 721 is generated by the rotational force. The upper part slides to the image plane side (direction E) in the optical axis direction. As a result, the upper part of the fourth lens 721 presses the upper part of the protrusion 150 formed on the first spacer 122 and slides the upper part of the first spacer 122 to the image plane side (direction G) in the optical axis direction. . Thereby, the inclination of the axis 721A of the fourth lens 721 is corrected toward the direction of the optical axis 100A (direction F).

  As described above, by adjusting the adjustment screw 131 and the adjustment screw 731, the downward inclination of the fourth lens 721 with respect to the optical axis 100 </ b> A can be corrected.

  When the axis 721A of the fourth lens 721 is inclined upward with respect to the optical axis 100A, the adjustment screw 731 is loosened and the adjustment screw 131 is tightened, whereby the light of the fourth lens 721 is obtained. The upward tilt with respect to the axis 100A can be corrected.

  As described above, according to the fourth embodiment, the adjustment screw 131 and the adjustment screw 731 are adjusted from the direction of the outer peripheral surface 105 of the lens barrel main body 701, so that the first spacer 122 is interposed. The configuration is such that the inclination of the four lenses 721 is adjusted. Therefore, even after the lens barrel 700 is assembled, the fourth lens 721 is tilted in the vertical direction with respect to the optical axis 100A by adjusting the adjustment screw 131 and the adjustment screw 731 without disassembling the lens barrel 700. Can be easily corrected.

  In addition to the configuration of the lens barrel 700, a lens fixing mechanism having the same configuration as the lens fixing mechanism 130 (see FIG. 1) described above is provided in the left-right direction around the optical axis 100A of the lens barrel main body 701. By disposing, the inclination of the fourth lens 721 in the left-right direction with respect to the optical axis 100A can be easily corrected by adjusting the adjusting screw. As described above, the lens fixing mechanism having the same configuration as the lens fixing mechanism 130 (see FIG. 1) described above is disposed in the direction in which the inclination of the lens barrel body 701 around the optical axis 100A is desired to be adjusted. The inclination of the lens with respect to that direction can be easily corrected by adjusting the adjusting screw.

  As described above, the lens fixing device and the lens barrel using the same according to the present invention are useful for a lens device provided in an optical device such as a camera, and in particular, an industrial lens that requires high optical performance. Suitable for equipment.

It is a sectional side view of the lens barrel provided with the lens fixing mechanism concerning Embodiment 1 of this invention. It is a perspective view which shows the external appearance of the lens-barrel shown in FIG. It is a partially expanded sectional view of the lens barrel shown in FIG. It is a front sectional view showing a lens fixing mechanism according to the first embodiment of the present invention. It is a sectional side view of the lens barrel provided with the lens fixing mechanism concerning Embodiment 2 of this invention. It is a sectional side view of the lens barrel provided with the lens fixing mechanism concerning Embodiment 3 of this invention. It is a sectional side view of the lens barrel provided with the lens fixing mechanism concerning Embodiment 4 of this invention. FIG. 8 is a partially enlarged sectional view of the lens barrel shown in FIG. 7.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Lens barrel 101 Lens barrel main body 104 3rd reference surface 105 Outer peripheral surface 106 Inner peripheral surface 121 4th lens 122 1st spacer 130 Lens fixing mechanism 131 Adjusting screw 132 Screw hole

Claims (8)

A positioning unit provided in a direction orthogonal to the optical axis direction inside the lens barrel, for positioning the movement of the lens in the optical axis direction;
A spacer disposed between a pair of lenses inside the lens barrel, having a certain length in the optical axis direction corresponding to the distance between the pair of lenses, and slidable in the optical axis direction;
Positioning the lens between the positioning portion and the spacer of the pair of lenses along the optical axis direction through the spacer by moving in the direction of the spacer provided in the lens barrel. A pressing member that presses in the direction of the part;
A lens fixing device comprising: The pressing member includes an inclined surface at a portion in contact with the spacer,
The spacer includes an inclined surface that is in contact with the inclined surface of the pressing member and converts a moving direction of the pressing member in the direction of the spacer into a moving direction of the spacer in the optical axis direction. The lens fixing device according to claim 1.   2. The pressing member is made of a screwed body, and is screwed into a screw hole formed so as to penetrate from the outer peripheral surface of the lens barrel to the inner peripheral surface of the lens barrel. Alternatively, the lens fixing device according to claim 2.   4. The press member is provided in plural on the same circumference in the optical axis direction centering on the optical axis of the lens barrel. 5. The lens fixing device according to one. A lens fixing device for fixing the lens;
The lens fixing device includes:
A positioning portion that is provided in a direction orthogonal to the optical axis direction inside the lens barrel and for positioning the movement of the lens in the optical axis direction;
A spacer disposed between the pair of lenses inside the lens barrel, having a certain length in the optical axis direction corresponding to the distance between the pair of lenses, and slidable in the optical axis direction;
The lens barrel is movably disposed in the direction of the spacer, and by the movement, the lens between the positioning portion and the spacer among the pair of lenses is moved in the optical axis direction through the spacer. A pressing member that presses in the direction of the positioning portion along
A lens barrel characterized by comprising a lens barrel.   6. The lens barrel according to claim 5, wherein a plurality of the lens fixing devices are arranged corresponding to the arrangement positions of the lenses that need to be positioned in the optical axis direction of the lens barrel. .   The lens between the positioning portion and the spacer is formed with a plane orthogonal to the optical axis direction so that a lens surface in contact with the positioning portion is in surface contact with the positioning portion. The lens barrel according to claim 5, further comprising a lens surface. The lens between the positioning portion and the spacer includes the lens surface on which a convex curved surface is formed so that a lens surface that contacts the positioning portion is in point contact with the positioning portion. The lens barrel according to claim 5 or 6, wherein the lens barrel is provided.

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