Lens device adjustment mechanism

Abstract

To prevent backlashes in an adjustment mechanism 1 by displacing a lens Lf1, etc., in only an optical axis direction Fc without displacing it by pivoting in a circumferential direction Ff, and reduce man-hours and cut back manufacturing costs.SOLUTION: The present invention comprises: an outer fixed tube 3 that supports an operation ring 2 so as to be pivotable by circumferential surface; a pivoting cam tube 4 which is disposed radially inward Fd of the outer fixed tube 3 and which forms inclined groove cams 4s, etc., on circumferential surface; a transmission unit 5 that transmits the pivotal displacement of the operation ring 2 to the pivoting cam tube 4; an inner fixed tube 6 which is disposed radially inward Fd of the pivoting cam tube 4 and fixed in position, and which forms vertical grooves 6s, etc., on circumferential surface and in an optical axis direction Fc; and a lens frame 7 that supports at least one lens Lf1, etc., and which is disposed radially inward Fd of the inner fixed tube 6, with a follower 7r, etc., fixed in place that engages with both vertical grooves 6s, etc., and inclined groove cams 4s, etc., on circumferential surface.SELECTED DRAWING: Figure 1

Description

【Technical Field】 【0001】 The present invention relates to an adjustment mechanism for a lens device that adjusts the lens position by displacing the lens in the optical axis direction by a rotational operation of an operation ring. 【Background Art】 【0002】 Conventionally, as an adjustment mechanism for a lens device, an adjustment mechanism provided in a lens barrel device described in Patent Document 1 proposed by the present applicant is known. 【0003】 The lens barrel device disclosed in the same Document 1 aims to solve conflicting problems by ensuring good rotational operability and preventing sufficient play in the radial direction between the fixed barrel portion and the cam barrel portion. Specifically, when constructing a lens barrel device including a lens barrel portion having a cam barrel portion rotatably assembled with respect to the fixed barrel portion, at least one roller contact mechanism portion provided with a roller that contacts the other peripheral surface and a shaft portion having an axis in the optical axis direction that rotatably supports the center of this roller is provided on the peripheral portion of one of the fixed barrel portion or the cam barrel portion. A cam barrel holding mechanism is provided, and as a focusing adjustment mechanism, a guide slit in a predetermined range along the circumferential direction is formed through the outer peripheral surface located on the front side of the fixed barrel portion, and an engaging disk portion screwed to the outer peripheral surface of the cam barrel portion is passed through the guide slit and locked to the hole portion of an adjustment ring (focusing adjustment ring) rotatably attached to the outer peripheral surface of the fixed barrel portion. Thereby, when the adjustment ring is rotated automatically or manually, the cam barrel portion can be integrally rotated and displaced, and a lens frame (lens) engaged with the cam slit can be converted into displacement in the optical axis direction. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2021-162606 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 However, the lens device adjustment mechanism provided in the lens barrel device described in Patent Document 1 above had the following problems that needed to be solved. 【0006】 Specifically, the adjustment mechanism described in Document 1 is configured to rotate and displace a cam cylinder, which is located radially inward of the fixed cylinder, by an adjustment ring, thereby displacing the engaging part of the lens frame that holds the lens, which is engaged with an inclined cam slit formed in the fixed cylinder and a vertical groove formed in the cam cylinder, in the direction of the optical axis. 【0007】 Therefore, when the adjustment ring is rotated circumferentially, the lens rotates circumferentially while also being displaced in the optical axis direction, and a certain amount of clearance must be maintained between the fixed cylinder and the cam cylinder, resulting in looseness. In the same document 1, a means of preventing looseness is adopted by holding the circumferential surface of the fixed cylinder with multiple roller contact mechanisms. However, adjusting the position of each roller contact mechanism is not easy, and this position adjustment must be done early in the manufacturing process. Therefore, if adjustment is needed at a stage close to the final stage, reassembly and readjustment are required, leading to a significant increase in man-hours. Moreover, since manual adjustment work is required, there are limitations in terms of completely eliminating looseness, and further improvements remain. 【0008】 The present invention aims to provide an adjustment mechanism for a lens device that solves the problems present in the background technology described above. [Means for solving the problem] 【0009】 To solve the above-mentioned problems, the adjustment mechanism 1 of the lens device according to the present invention includes, as a basic configuration, an adjustment mechanism that adjusts the lens position by displacing the lenses Lf1... in the optical axis direction Fc by rotating the operating ring 2. 【0010】 Furthermore, the present invention has a characteristic configuration in which a zoom lens is applied to the lens device M, and has a focus adjustment operating ring 2f that can be rotated electrically or manually, and an outer fixing cylinder 3 that rotatably supports this focus adjustment operating ring 2f by its circumferential surface, an outer cam cylinder portion 12 that is arranged radially inward Fd of the outer fixing cylinder 3 and rotates in the circumferential direction Ff, and an inclined groove cam 4s... that is arranged radially inward Fd of the outer cam cylinder portion 12 and follows the displacement of the outer cam cylinder portion 12 in the circumferential direction Ff, and has an inner cam cylinder portion 13 that has an inclined groove cam 4s... and a second guide slit 15 formed in the circumferential direction Ff, and this rotation The system includes an inner fixed cylinder 6 positioned radially inward Fd of the moving cam cylinder 4 and fixed in position, having vertical grooves 6s... formed on its circumferential surface in the optical axis direction Fc, and a follower 14 fixed to its circumferential surface and engaging with a second guide slit 15; a lens frame 7 positioned radially inward Fd of the inner fixed cylinder 6 and supporting at least one lens Lf1... having a follower 7r... fixed to its circumferential surface that engages with both the vertical grooves 6s... and the inclined groove cams 4s...; and a transmission unit 5 formed on the circumferential surface of the outer fixed cylinder 3 and having a first guide slit 3s in the circumferential direction Ff, and a link shaft 11 that engages with the first guide slit 3s and connects the rotating cam cylinder 4 to the focus adjustment operation ring 2f, thereby transmitting the rotational displacement of the focus adjustment operation ring 2f to the rotating cam cylinder 4. [Effects of the Invention] 【0011】 The adjustment mechanism 1 of the lens device according to the present invention, having such a configuration, produces the following remarkable effects. 【0012】 (1) The device includes a rotating cam cylinder 4 having inclined groove cams 4s… which are rotated by an operating ring 2, an inner fixing cylinder 6 which is positioned and fixed inside the radial Fd of the rotating cam cylinder 4 and has vertical grooves 6s… formed on its circumferential surface in the optical axis direction Fc, and a lens frame 7 which supports at least one lens Lf1… which is positioned inside the radial Fd of the inner fixing cylinder 6 and has a follower 7r… fixed on its circumferential surface that engages with both the vertical grooves 6s… and the inclined groove cams 4s…. Therefore, when adjusting the lens position in the optical axis direction Fc, the lens Lf1… can be adjusted by displacing it only in the optical axis direction Fc without rotating it in the circumferential direction Ff. This makes it possible to reduce the number of steps in the manufacturing process and reduce manufacturing costs while preventing rattling of the adjustment mechanism 1. 【0013】 (2) In constructing the transmission unit 5, a first guide slit 3s is formed on the circumferential surface of the outer fixing cylinder 3 and is aligned with the circumferential direction Ff, and a link shaft 11 engages with the first guide slit 3s and connects the operating ring 2 and the rotating cam cylinder 4. As a result, the displacement of the operating ring 2 can be transmitted to the rotating cam cylinder 4 by a simple mechanism, which contributes to miniaturization and cost reduction of the adjustment function 1. 【0014】 (3) The rotating cam cylinder 4 is configured with an outer cam cylinder portion 12 fixed to the inner end of the link shaft 11 and positioned radially outward Fd, and an inner cam cylinder portion 13 positioned radially inward Fd of the outer cam cylinder portion 12, which follows the displacement of the outer cam cylinder portion 12 in the circumferential direction Ff and has inclined groove cams 4s... formed on it. Therefore, for example, it is possible to form a vertical groove in the outer cam cylinder portion 12 and provide a follower that engages with this vertical groove in the inner cam cylinder portion 13. This makes it possible to add other adjustment functions (for example, a zooming adjustment mechanism) without impairing the original adjustment function of the rotating cam cylinder 4, thereby increasing its multifunctionality and potential for future development. 【0015】 (4) The inner cam cylinder portion 13 engages with the follower 14 fixed to the circumferential surface of the inner fixing cylinder 6, and a second guide slit 15 is provided formed along the circumferential direction Ff. Therefore, when displacing the inner cam cylinder portion 13 in the circumferential direction Ff, unnecessary rattling in the optical axis direction Fc can be prevented, and accurate guidance can be achieved. 【0016】 (5) By applying a focus adjustment operating ring 2f that can be rotated electrically or manually to the operating ring 2, the effects of the present invention in particular in the focus adjustment mechanism, namely the realization of rattle prevention, and furthermore, the reduction of man-hours in the manufacturing process and the reduction of manufacturing costs can be achieved. In addition, smooth operation can be ensured when electrically operated, and operability can be improved when manually operated, so that the advantages corresponding to each operating method can be enjoyed in either the case of electric or manual operation. 【0017】 (6) By including straight grooves and / or curved grooves 4se... in all or part of the inclined groove cam 4s..., the change in the displacement adjustment amount in the optical axis direction Fc with respect to the lens Lf1... is not limited to linear characteristics, but can easily accommodate changes in non-linear characteristics as well. That is, since the shape (change pattern) of the inclined groove cam 4s... can be formed into any shape, more advanced adjustments can be made, such as being able to trace the adjustable optical characteristics with high precision, and the versatility and potential for development of the adjustment mechanism 1 can be further enhanced. 【0018】 (7) As the lens device M is applied to the zoom lens of an optical instrument, for example, it is possible to prevent rattling of the adjustment mechanism 1 in a zoom lens used in an optical instrument such as a projector, while reducing the number of man-hours in the manufacturing process and the manufacturing cost. As a result, it can be used as the optimal adjustment mechanism 1 in an optical instrument such as a projector. [Brief explanation of the drawing] 【0019】 [Figure 1] A cross-sectional side view of the front part of a lens device equipped with an adjustment mechanism according to a preferred embodiment of the present invention. [Figure 2] An enlarged extracted view of the dashed-dotted circle B part in FIG. 1 of the adjustment mechanism in the same lens device, [Figure 3] An end view of A-A in FIG. 1 of the same lens device, [Figure 4] A schematic cross-sectional configuration diagram showing the extraction of the main part of the adjustment mechanism, [Figure 5] A cross-sectional side view of the inner cam cylinder part shown in FIG. 4, [Figure 6] A cross-sectional side view of the adjustment ring in the image plane correction mechanism shown in FIG. 4, [Figure 7] An outer peripheral surface development view of the inner cam cylinder part shown in FIG. 5, [Figure 8] An outer peripheral surface development view of the adjustment ring shown in FIG. 6, [Figure 9] A flowchart for explaining the operation of the adjustment mechanism, [Figure 10] An outer peripheral surface development view of a part of the inner cam cylinder part showing a modification example of the adjustment mechanism, 【Best Mode for Carrying Out the Invention】 【0020】 Next, preferred embodiments according to the present invention will be given and described in detail based on the drawings. 【0021】 First, the configuration of the lens device M provided with the adjustment mechanism 1 according to the present embodiment will be described with reference to FIGS. 1 to 8. 【0022】 FIG. 1 shows a cross-sectional side configuration of the lens device M, particularly on the front side (other parts including the rear side are omitted). The illustrated lens device M is assumed to be a zoom lens (projection optical system) in a projector that is an optical device. Thus, if the lens device M is applied to the zoom lens of an optical device such as a projector, it can be used as an optimal adjustment mechanism 1 in an optical device such as a projector because it can prevent looseness of the adjustment mechanism 1 in this type of zoom lens and can reduce the man-hours and manufacturing costs in the manufacturing process. 【0023】 On the other hand, in the lens device M, an operating ring 2, i.e., a focus adjustment operating ring 2f constituting the focus adjustment mechanism 1f, is rotatably mounted on the outer peripheral surface 3f of the outer fixed cylinder (lens barrel) 3. As shown in Figure 4, the focus adjustment operating ring 2f has a driven gear 2g formed over the entire circumference or a required predetermined angle in the circumferential direction on the outer peripheral surface, and a drive gear 21g attached to the output shaft of a focus adjustment drive motor 21 fixed at another position on the outer peripheral surface 3f is engaged with this driven gear 2g. Although the example focus adjustment operating ring 2f is electrically operated by the drive motor 21, it is also possible to configure it as a manual system in which the focus adjustment operating ring 2f is rotated by hand. 【0024】 Thus, by applying a focus adjustment operating ring 2f, which can be rotated electrically or manually, to the operating ring 2, the effects of the present invention, particularly in the focus adjustment mechanism, can be achieved, namely, the prevention of rattling, and furthermore, the reduction of man-hours in the manufacturing process and the reduction of manufacturing costs. In addition, smooth operation can be ensured in the case of electric operation, and operability can be improved in the case of manual operation, so that the advantages corresponding to each operating method can be enjoyed in either electric or manual operation. 【0025】 As shown in Figure 1, the lens device M is sequentially equipped with an image plane correction mechanism 1i for adjusting the first lens group G1, a focus adjustment mechanism 1f for adjusting the second lens group G2 and the third lens group G3, starting from the magnification side (front end). The first lens group G1 includes lens Li1, the second lens group G2 includes lenses Ls1 and Ls2 from the magnification side, and the third lens group G3 includes lenses Lf1 and Lf2 from the magnification side. Each lens group G1, G2, and G3 is supported by lens frames 22, 23, and 7, respectively. Each lens Li1, Ls1, Lf1, etc. is composed of either a single lens or a cemented lens. 【0026】 Next, the focus adjustment mechanism 1f (adjustment mechanism 1), which constitutes the main part of the present invention, will be described with reference to the figures. 【0027】 As shown in Figures 1 and 2, the focus adjustment mechanism 1f includes an outer fixing cylinder 3 that rotatably supports the focus adjustment operating ring 2f by its outer circumferential surface, a rotating cam cylinder 4 positioned radially inward Fd of the outer fixing cylinder 3 and having inclined groove cams 4s... formed on its circumferential surface, and a transmission unit 5 that transmits the rotational displacement of the operating ring 2 to the rotating cam cylinder 4. 【0028】 As shown in Figure 1, the transmission unit 5 is formed on the circumferential surface of the outer fixing cylinder 3 and comprises a first guide slit 3s along the circumferential direction Ff, and a link shaft 11 that engages with the first guide slit 3s and connects the operating ring 2 and the rotating cam cylinder 4. This configuration allows the displacement of the operating ring 2 to be transmitted to the rotating cam cylinder 4 by a simple mechanism, thus contributing to the miniaturization and cost reduction of the adjustment function 1. 【0029】 Furthermore, as shown in Figure 1, the rotating cam cylinder 4 is composed of a combination of an outer cam cylinder portion 12 fixed to the inner end of the link shaft 11 and positioned radially outward Fd, and an inner cam cylinder portion 13 positioned radially inward Fd of the outer cam cylinder portion 12, which follows the displacement of the outer cam cylinder portion 12 in the circumferential direction Ff and has inclined groove cams 4s... formed therein. In this embodiment, a vertical groove 12s is formed in the outer cam cylinder portion 12, and a follower 13s that engages with this vertical groove 12s is provided in the inner cam cylinder portion 13. As a result, when adjusting the focusing, the follower 13s can be displaced along the vertical groove 12s. 【0030】 In this way, when constructing the rotating cam cylinder 4, by combining the outer cam cylinder portion 12 and the inner cam cylinder portion 13, it becomes possible to provide the inner cam cylinder portion 13 with a follower 13s that engages with the vertical groove 12s. This makes it possible to add other adjustment functions (such as a zooming adjustment mechanism) without impairing the original adjustment function of the rotating cam cylinder 4, thereby increasing its multi-functionality and potential for future development. 【0031】 Furthermore, as shown in Figure 2, the inner cam cylinder portion 13 is provided with a second guide slit 15 formed along the circumferential direction Ff, which engages with a follower 14 fixed to the circumferential surface of the inner fixing cylinder 6, described later. Figure 5 shows a cross-sectional side view of the inner cam cylinder portion 13, and Figure 7 shows an unfolded view of the outer circumferential surface of the inner cam cylinder portion 13. In this way, by providing the inner cam cylinder portion 13 with a follower 14 engaging and a second guide slit 15 along the circumferential direction Ff, it is possible to prevent unnecessary rattling in the optical axis direction Fc when displacing the inner cam cylinder portion 13 in the circumferential direction Ff, and to provide accurate guidance. 【0032】 On the other hand, an inner fixed cylinder 6 is provided radially inward Fd of the rotating cam cylinder 4, that is, radially inward Fd of the inner cam cylinder portion 13, with its position fixed and a vertical groove 6s formed on its circumferential surface in the direction of the optical axis Fc. Then, a lens frame 7 is arranged radially inward Fd of this inner fixed cylinder 6, supporting at least one lens Lf1... (in this embodiment, two lenses Lf1, Lf2), and having a follower 7r fixed to its circumferential surface that engages with both the vertical groove 6s and the inclined groove cam 4s. 【0033】 In this case, as shown in Figure 2, the follower 7r has a configuration in which a cylindrical roller 7rm is rotatably supported by a pivot shaft 7rs, and the tip of the pivot shaft 7rs is screwed onto the outer surface of the lens frame 7. Note that 7rc indicates a collar interposed between the pivot shaft 7rs and the roller 7rm. The shape of the inclined groove cam 4s ​​is as shown in Figures 5 and 7, and when the inner cam cylinder portion 13 is rotated clockwise when viewed from the front (left side in Figure 5), the follower 7r can be displaced axially Fc forward. 【0034】 Furthermore, as shown in Figure 3 (Figures 5 and 7), the configuration including the inclined groove cams 4s…, longitudinal grooves 6s… and followers 7r…, the configuration including the longitudinal grooves 12s… and followers 13s…, and the configuration including the second guide slits 15… and followers 14… are each arranged in three sets at equal intervals at three locations in the circumferential direction Ff. Note that the circumferential position of the follower 14… in Figure 3 does not represent its exact position. Thus, the focus adjustment mechanism 1f is constructed. 【0035】 Next, the components other than the focus adjustment mechanism 1f (adjustment mechanism 1) will be explained with reference to the respective diagrams. 【0036】 As shown in Figure 1, an image plane correction mechanism 1i is provided in front of the focus adjustment mechanism 1f described above, at the front end of the lens device M, and a second lens group G2 is provided between this image plane correction mechanism 1i and the focus adjustment mechanism 1f. In this case, the second lens group G2 includes a lens frame 23 fixed to the outer fixing cylinder 3, and the lenses Ls1 and Ls2 are supported by this lens frame 23. 【0037】 On the other hand, as shown in Figures 1 and 4, the image plane correction mechanism 1i comprises a front fixing cylinder 25 fixed to the front end of the outer fixing cylinder 3 and having a vertical groove 25s formed on its circumferential surface along the optical axis direction Fc; an image plane adjustment operation ring 26 rotatably supported on the outer circumferential surface of the front fixing cylinder 25 and having an inclined groove cam 26s for image plane correction formed on its circumferential surface and having its displacement in the optical axis direction Fc restricted; a front cover 27 covering the image plane adjustment operation ring 26 and fixed to the front fixing cylinder 25; a lens frame 22 positioned radially inward Fd of the front fixing cylinder 25; and a follower 28 fixed to the outer circumferential surface of the lens frame 22 and engaged with both the vertical groove 25s and the inclined groove cam 26s for image plane correction. The lens Li1 constituting the first lens group G1 described above is supported by this lens frame 22. 【0038】 Figures 6 and 8 show a cross-sectional side view and an external view of the image plane adjustment ring 26, respectively. The follower 28 can be configured in the same way as the follower 7r described above. The configuration including the longitudinal grooves 25s..., the inclined groove cams 26s... for image plane correction, and the follower 28... is arranged at equal intervals at three locations in the circumferential direction Ff. 【0039】 In this case, the image plane adjustment ring 26 can be rotated through an operating opening window (not shown in the figure) formed in the front cover 27. The image plane adjustment ring 26 can be operated either electrically or manually. In the case of the electric operation, it is rotated by a drive motor (not shown), and in the case of the manual operation, the image plane adjustment ring 26 can be rotated by hand. Thus, the image plane correction mechanism 1i is configured. 【0040】 As a result, in Figure 4, when the image plane adjustment operation ring 26 of the image plane correction mechanism 1i is rotated, the followers 28... are displaced in the optical axis direction Fc. That is, since the circumferential displacement of the followers 28... is restricted by the vertical groove 25s formed in the front fixing cylinder 25, they are displaced in the optical axis direction Fc in accordance with the amount of circumferential displacement Ff of the inclined groove cam 26s for image plane correction. As a result, the lens frame 22 to which the followers 28... are fixed is displaced in the optical axis direction Fc, and the first lens group (lens Li1) supported by the lens frame 22 is also displaced together with the lens frame 22, thereby performing image plane adjustment. In Figure 4, Z2 shows an example of the displacement range in the displacement direction (optical axis direction Fc) of the followers 28 shown by the solid line and the dashed line. 【0041】 Next, the operation (function) of the adjustment mechanism 1 (focus adjustment mechanism 1f) of the lens device M according to this embodiment will be explained in accordance with the flowchart shown in Figure 9, with reference to Figures 1 to 8, and in particular to Figure 4. 【0042】 When a control signal (drive signal) is applied to the focus adjustment drive motor 21, the drive gear 21g rotates, and the driven gear 2g rotates, causing the focus adjustment operating ring 2f to rotate electrically (step S1). As a result, the transmission links 11... of the transmission unit 5 fixed to the focus adjustment operating ring 2f are pivotally displaced in the circumferential direction Ff along the first guide slit 3s formed in the outer fixed cylinder 3 (step S2). In addition, the displacement of the transmission links 11... causes the outer cam cylinder portion 12 of the rotating cam cylinder 4 to rotate and displace in accordance (step S3), and the inner cam cylinder portion 13 also rotates and displaces in accordance (step S4). In this case, the inner cam cylinder portion 13 is displaced in the circumferential direction along the second guide slit 15 because the second guide slit 15 engages with the follower 14 fixed to the inner fixed cylinder 6. 【0043】 On the other hand, since inclined groove cams 4s... are formed on the circumferential surface of the inner cam cylinder portion 13, the rotational displacement of the inner cam cylinder portion 13 causes the inclined groove cams 4s... to rotate and displace together with it (step S5). As a result, when the inclined groove cams 4s... rotate and displace in the circumferential direction, the followers 7r... that engage with the inclined groove cams 4s... also engage with the vertical grooves 6s... formed in the inner fixing cylinder 6, so the followers 7r... are displaced in the optical axis direction Fc along the vertical grooves 6s... formed in the inner fixing cylinder 6 (step S6). 【0044】 As a result, the lens frame 7 fixed to the follower 7r... is displaced in the optical axis direction Fc along the vertical groove 6s..., and its circumferential displacement is restricted by the vertical groove 6s... (step S7). That is, the third lens group G3 (lenses Lf1, Lf2) supported by the lens frame 7 is displaced in the optical axis direction Fc without rotating in the circumferential direction Ff, and the lens position of the third lens group G3 is adjusted (step S8). In Figure 4, Z1 shows an example of the displacement range in the displacement direction (optical axis direction Fc) of the follower 7r shown by the solid line and the follower 7r shown by the dashed line. 【0045】 Therefore, according to the adjustment mechanism 1 of the lens device M according to this embodiment, the basic configuration includes an outer fixing cylinder 3 that rotatably supports the operating ring 2 by its circumferential surface, a rotating cam cylinder 4 disposed radially Fd inward of the outer fixing cylinder 3 and having inclined groove cams 4s... formed on its circumferential surface, a transmission unit 5 that transmits the rotational displacement of the operating ring 2 to the rotating cam cylinder 4, an inner fixing cylinder 6 disposed radially Fd inward of the rotating cam cylinder 4 and fixed in position, and having vertical grooves 6s... formed on its circumferential surface in the optical axis direction Fc, and a lens frame 7 disposed radially Fd inward of the inner fixing cylinder 6 and supporting at least one lens Lf1... with a follower 7r... fixed on its circumferential surface that engages with both the vertical grooves 6s... and the inclined groove cams 4s... Therefore, when adjusting the lens position in the optical axis direction Fc, the lens Lf1... can be adjusted by displacing it only in the optical axis direction Fc without rotating it in the circumferential direction Ff. This makes it possible to prevent rattling of the adjustment mechanism 1 while reducing the number of man-hours and manufacturing costs in the manufacturing process. 【0046】 Figure 10 shows an example of modifications to the inclined groove cam 4s... and the second guide slit 15... in the lens device M according to this embodiment. 【0047】 The inner cam cylinder portion 13 shown in Figure 7 above shows a case where the inclined groove cam 4s... is formed so that the change in the displacement adjustment amount of the third lens group G3 has linear characteristics. However, the modified example shown in Figure 10 shows an example in which a curved groove 4se... can be included in a part of the inclined groove cam 4s... when forming the inner cam cylinder portion 13. That is, the intermediate part of the inclined groove cam 4s... and one end thereof can be formed as a straight groove shown by a solid line, and the other end of this straight groove can be formed as a curved groove 4se... shown by a dashed line. 【0048】 Thus, when forming the inclined groove cam 4s..., if straight grooves and / or curved grooves 4se... are included in all or part of the inclined groove cam 4s..., the change in the displacement adjustment amount in the optical axis direction Fc relative to the lens Lf1... is not limited to linear characteristics, but can easily accommodate changes in non-linear characteristics as well. In other words, since the shape (change pattern) of the inclined groove cam 4s... can be formed into any shape, more advanced adjustments can be made, such as being able to trace the adjustable optical characteristics with high precision, and the versatility and potential for development of the adjustment mechanism 1 (focus adjustment mechanism 1f) can be further enhanced. 【0049】 Furthermore, the modified inner cam cylinder portion 13 also shows an example in which a similar curved groove 15e can be included in the second guide slit 15.... In the case of the second guide slit 15..., it is also possible to include a curved groove 15e... as needed. For example, if the curved groove 4se... of the inclined groove cam 4s... is limited due to space constraints, the curved groove 15e... shown by the dashed line can be used to add the limited portion. 【0050】 Although preferred embodiments, including modified examples, have been described in detail above, the present invention is not limited to these embodiments, and the details of the configuration, shape, materials, quantity, etc., can be arbitrarily changed, added, or deleted without departing from the spirit of the present invention. 【0051】 For example, the lens device M may be interchangeable or non-interchangeable for optical equipment such as a projector. Furthermore, while the example given illustrates the adjustment of the third lens group G3 as the lens group to which the adjustment mechanism 1 is applied, the configuration may also involve adjusting two or more lens groups, including other lens groups. [Industrial applicability] 【0052】 The adjustment mechanism 1 of the lens device M according to the present invention can be used in various optical devices, including projectors, still cameras, and video cameras, and can also be used in other adjustment mechanisms besides focus adjustment mechanisms. [Explanation of Symbols] 【0053】 1: Adjustment mechanism, 2: Operating ring, 2f: Focus adjustment operating ring, 3: Outer fixed cylinder, 3s: First guide slit, 4: Rotating cam cylinder, 4s...: Inclined groove cam, 4se...: Curved groove, 5: Transmission part, 6: Inner fixed cylinder, 6s...: Vertical groove, 7: Lens frame, 7r...: Follower, 11: Link axis, 12: Outer cam cylinder section, 13: Inner cam cylinder section, 15: Second guide slit, 14: Follower, M: Lens device, Lf1: Lens, Lf2: Lens, Fc: Optical axis direction, Ff: Circumferential direction, Fd: Radial direction

Claims

[Claim 1] In an adjustment mechanism for a lens device that adjusts the lens position by displacing the lens in the optical axis direction by rotating an operating ring, the lens device is applied to a zoom lens and has a focus adjustment operating ring that can be rotated electrically or manually, an outer fixed cylinder that rotatably supports this focus adjustment operating ring by its circumferential surface, an outer cam cylinder portion disposed radially inward of the outer fixed cylinder and rotating in the circumferential direction, and a rotating cam cylinder disposed radially inward of the outer cam cylinder portion and following the circumferential displacement of the outer cam cylinder portion, and having an inclined groove cam that includes straight grooves and / or curved grooves on all or part of its circumferential surface, and having an inner cam cylinder portion that has an inclined groove cam and a second guide slit in the circumferential direction, An adjustment mechanism for a lens device, comprising: an inner fixed cylinder positioned radially inward of the rotating cam cylinder and fixed in position, having a vertical groove in the optical axis direction formed on its circumferential surface, and having a follower fixed to the circumferential surface and engaging with the second guide slit; a lens frame positioned radially inward of the inner fixed cylinder and supporting at least one lens having a follower fixed to its circumferential surface that engages with both the vertical groove and the inclined groove cam; and a transmission unit formed on the circumferential surface of the outer fixed cylinder and oriented in the circumferential direction, and having a link shaft that engages with the first guide slit and connects the rotating cam cylinder to the focus adjustment operation ring, thereby transmitting the rotational displacement of the focus adjustment operation ring to the rotating cam cylinder.

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