Lens unit, lens barrel, and adjustment method

Abstract

The invention relates to a lens unit, a lens barrel and an adjustment method. A lens unit including a plurality of lenses includes: a holder configured to hold a first lens of the plurality of lenses; a first adjusting frame configured to hold a first adjusting lens in the plurality of lenses, and adjust the first adjusting lens relative to the holding frame in a direction orthogonal to an optical axis; and a second adjustment frame configured to hold a second adjustment lens of the plurality of lenses and adjust the second adjustment lens relative to the holding frame in the direction orthogonal to the optical axis, the first adjusting frame and the second adjusting frame are arranged on the object side in the optical axis direction relative to the holding frame.

Description

Technical Field

[0001] The present invention relates to a lens unit and the like. Specifically, the present invention relates to a lens unit and the like used in an imaging device. Background Art

[0002] Currently, network cameras (i.e., surveillance cameras) are installed in various places such as cities and factories. In recent years, due to the increase in the number of pixels and the reduction in size, high optical performance is required for surveillance cameras. In order to achieve high optical performance, in some cases, decentering adjustment is performed to correct lens variations and position deviations between lenses that occur during the manufacturing process.

[0003] According to Japanese Patent Application Laid-Open No. 2004-219608, a technique for decentering adjustment of a lens is discussed. Specifically, according to Japanese Patent Application Laid-Open No. 2004-219608, a plurality of lens holders in a housing move in a direction orthogonal to the optical axis of the lens for decentering adjustment and are fixed using a retaining ring. However, according to the technique discussed in Japanese Patent Application Laid-Open No. 2004-219608, the lens holder to be adjusted is placed on the image side in the optical axis direction with respect to the lens holder holding the reference lens. Various components are arranged on the image side in the optical axis direction. Therefore, the adjustment mechanism for adjusting the lens holder and various components are arranged close to each other, and it is necessary to provide space to prevent interference between them, which may lead to an increase in the size of the entire device. Summary of the Invention

[0004] The present invention solves the problem of improving optical performance without increasing the size of the device.

[0005] According to one aspect of the present invention, there is provided a lens unit including a plurality of lenses, the lens unit including: a holder configured to hold a first lens among the plurality of lenses; a first adjustment holder configured to hold a first adjustment lens among the plurality of lenses and adjust the first adjustment lens with respect to the holder in a direction orthogonal to the optical axis; and a second adjustment holder configured to hold a second adjustment lens among the plurality of lenses and adjust the second adjustment lens with respect to the holder in the direction orthogonal to the optical axis, wherein the first adjustment holder and the second adjustment holder are arranged on the object side in the optical axis direction with respect to the holder.

[0006] Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Brief Description of the Drawings

[0007] Figure 1 is a perspective view of an imaging device according to an exemplary embodiment.

[0008] Figure 2 is an exploded perspective view of an imaging device according to this exemplary embodiment.

[0009] Figure 3 is an exploded perspective view of a second lens unit according to this exemplary embodiment.

[0010] Figure 4 is a cross-sectional view of a second lens unit according to this exemplary embodiment.

[0011] Figure 5 is a perspective view illustrating a state in which decentering adjustment is performed on a first adjustment lens.

[0012] Figure 6 is a cross-sectional view of a second lens unit according to this exemplary embodiment.

[0013] Figure 7 is a perspective view illustrating a state in which decentering adjustment is performed on a second adjustment lens.

[0014] Figure 8 is a perspective view illustrating the configuration of a second lens unit according to a first modification.

[0015] Figure 9 is a cross-sectional perspective view illustrating the configuration of a second lens unit according to a second modification.

[0016] Figure 10 is a cross-sectional perspective view illustrating the configuration of a second lens unit according to a third modification. Detailed Description

[0017] Various exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0018] Figure 1 is a perspective view of the imaging device 1. In each drawing including Figure 1 alternating long and short dashed lines indicate the optical axis O of the imaging device 1. In the optical axis direction, one side of the following first lens unit 10 is referred to as the object side (or front side), and one side of the following imaging element unit 300 is referred to as the image side (or rear side). Figure 2 is an exploded perspective view of the imaging device 1.

[0019] The imaging device 1 includes a lens barrel 100 and an imaging element unit 300.

[0020] The lens barrel 100 according to this exemplary embodiment includes three lens units. Specifically, the lens barrel 100 includes a front side housing member 50, a rear side housing member 51, and an imaging optical system including a first lens unit 10, a second lens unit 20, and a third lens unit 30.

[0021] The first lens unit 10 (the first group of lens units) includes a first lens group 11 and a first lens holder 12. The first lens group 11 is held by the first lens holder 12.

[0022] The first lens holder 12 is engaged with the shaft-like guide rod 52 and is supported so as to be movable in the optical axis direction. The first lens holder 12 is also engaged with the shaft-like guide rod 53 and is restricted from rotating about the guide rod 52. In addition, the first lens holder 12 rotatably holds the first group of frames 13. The first group of frames 13 is engaged with the lead screw portion of the first group of drive units 56 including an actuator such as a stepping motor. Therefore, if the lead screw portion of the first group of drive units 56 rotates, the first lens holder 12 moves in the optical axis direction together with the first group of frames 13.

[0023] Figure 3 is an exploded perspective view of the second lens unit 20 (optical adjustment group).

[0024] The second lens unit 20 includes a second lens group 21. The second lens group 21 is a zoom lens group including a plurality of lenses. Specifically, the second lens group 21 includes a reference lens 25, a first adjustment lens 24, and a second adjustment lens 23.

[0025] The reference lens 25 is held by the second lens holder 22.

[0026] The first adjustment lens 24 includes two lenses (see the following Figure 4 ) and is held by the first adjustment frame 26. The first adjustment frame 26 is held by the second lens holder 22. The first adjustment frame 26 is located on the object side in the optical axis direction with respect to the second lens holder 22. In addition, the first adjustment frame 26 can be adjusted in a direction orthogonal to the optical axis with respect to the second lens holder 22.

[0027] The second adjustment lens 23 is held by the second adjustment frame 27. The second adjustment frame 27 is held by the second lens holder 22 via the first adjustment frame 26. The second adjustment frame 27 is located on the object side in the optical axis direction with respect to the second lens holder 22 and the first adjustment frame 26. In addition, the second adjustment frame 27 can be adjusted in a direction orthogonal to the optical axis with respect to the second lens holder 22.

[0028] In the second lens unit 20, the second lens holder 22, the first adjustment frame 26, and the second adjustment frame 27 are arranged in order from the image side in the optical axis direction.

[0029] Here, the holding methods of the second adjustment lens 23, the first adjustment lens 24, and the reference lens 25 are thermal caulking, but other holding methods such as adhesive fixing and pressure fixing using a pressing member can also be used and are not limited. In addition, the second adjustment lens 23, the first adjustment lens 24, and the reference lens 25 can each be one or more lenses, and the lens configuration is not limited.

[0030] The second lens holder 22 is engaged with the shaft-like guide rod 54 and is supported so as to be movable in the optical axis direction. The second lens holder 22 is also engaged with the shaft-like guide rod 55 and is restricted from rotating around the guide rod 54. In addition, the second lens holder 22 rotatably holds the second set of frames 28. The second set of frames 28 is engaged with the lead screw portion of the second set of drive units 57 including an actuator such as a stepping motor. Therefore, if the lead screw portion is rotated by the second set of drive units 57, the second lens holder 22 moves in the optical axis direction together with the second set of frames 28.

[0031] This exemplary embodiment is not limited to the case where the second lens holder 22 holds the second set of frames 28, but may include a configuration in which the first adjustment frame 26 or the second adjustment frame 27 holds the second set of frames 28 and is engaged with the guide rods 54 and 55.

[0032] The detailed configurations of the second lens holder 22, the first adjustment frame 26, and the second adjustment frame 27, and the optical adjustment mechanism using these frames will be described below.

[0033] The third lens unit 30 includes a third lens group 31 and a third lens holder 32.

[0034] The third lens group 31 is held by the third lens holder 32. The third lens holder 32 is engaged with the shaft-like guide rod 54 and is supported so as to be movable in the optical axis direction. The third lens holder 32 is also engaged with the shaft-like guide rod 55 and is restricted from rotating around the guide rod 54. In addition, the third lens holder 32 rotatably holds the third set of frames 33. The third set of frames 33 is engaged with the lead screw portion of the third set of drive units 58 including an actuator such as a stepping motor. Therefore, if the lead screw portion is rotated by the third set of drive units 58, the third lens holder 32 moves in the optical axis direction together with the third set of frames 33.

[0035] The front-side housing member 50 and the rear-side housing member 51 function as the housing of the lens barrel 100. Specifically, the front-side housing member 50 and the rear-side housing member 51 accommodate the first lens unit 10, the second lens unit 20, and the third lens unit 30, and protect each lens unit from external impacts. The front-side housing member 50 and the rear-side housing member 51 are fixed together by screws or the like. The guide rods 52, 53, 54, and 55 are supported by the front-side housing member 50 and the rear-side housing member 51. In addition, the first set of driving units 56, the second set of driving units 57, and the third set of driving units 58 are fixed to the rear-side housing member 51 by screws or the like.

[0036] The imaging element unit 300 includes an imaging element 301 and an imaging substrate 302. The imaging element 301 is mounted on the imaging substrate 302. The imaging substrate 302 is fixed to the rear-side housing member 51 by screws or the like. The present exemplary embodiment is not limited to the form of fixing the imaging substrate 302 to the rear-side housing member 51. For example, the imaging substrate 302 may be fixed to the rear-side housing member 51 via another member.

[0037] According to the imaging device 1 configured as described above, the first lens unit 10, the second lens unit 20, and the third lens unit 30 move in the optical axis direction of the imaging optical system while maintaining a predetermined positional relationship to perform zooming and focusing. The light collected by the first lens unit 10, the second lens unit 20, and the third lens unit 30 is focused on the imaging element 301, thereby enabling acquisition of a desired image.

[0038] Next, the decentering adjustment in the second lens unit 20 will be described. In the case of performing decentering adjustment on the second lens unit 20, the second lens unit 20 is arranged such that the optical axis O is oriented in the vertical direction, the second lens holder 22 is located on the lower side, and the second adjustment holder 27 is located on the upper side.

[0039] First, the method of adjusting the eccentricity of the first adjustment lens 24 and the method of fixing the first adjustment holder 26 will be described.

[0040] Figure 4 is a cross-sectional view of the second lens unit 20. Figure 4 The left side of is a cross-section passing through the following first bonding portion 223 and second bonding portion 263. On the other hand, Figure 4 the right side of is a cross-section passing through the following screw 233.

[0041] Figure 5 is a perspective view showing the state of decentering adjustment of the first adjustment lens 24.

[0042] Figure 6 is a cross-sectional view of the second lens unit 20. Figure 6On the left side is a cross-section passing through the adjusting member 62 arranged during the decentering adjustment of the first adjusting lens 24. On the other hand, Figure 6 On the right side is a cross-section of the first bonding portion 223 and the second bonding portion 263 after the decentering adjustment and bonding of the second adjusting lens 23.

[0043] In the case of decentering the first adjusting lens 24, the side portion of the first adjusting holder 26 is pressed by a first adjusting jig 61 such as at least one pin. For example, the first adjusting jig 61 can be configured to adsorb the first adjusting holder 26. Figure 5 An example is illustrated in which adjustment is performed by pressing the surrounding portion 225 of the first adjusting holder 26 from three directions using the first adjusting jig 61.

[0044] When the first adjusting jig 61 moves back and forth, the first adjusting holder 26 moves in a direction orthogonal to the optical axis with respect to the second lens holder 22. The first adjusting holder 26 holding the first adjusting lens 24 is moved to move the first adjusting lens 24 to a desired position and perform decentering adjustment.

[0045] Ideally, in a state where the first lens unit 10 and the third lens unit 30 are arranged, the first adjusting lens 24 is decentered to cancel the sum of the minute decentering deviations of each lens. Decentering adjustment can be performed so that the optical axes of the reference lens 25 held by the second lens holder 22 and the first adjusting lens 24 coincide with each other. In this case, the minute decentering deviations of each lens can be canceled in the second lens unit 20.

[0046] The second lens holder 22 has a fastening portion 221 formed near the outer peripheral edge of the second lens holder 22. The fastening portion 221 extends in the optical axis direction and is formed with an internal threaded portion 222 into which a screw 233 as a fastening member is screwed. A plurality of fastening portions 221 (three in this example) are arranged at substantially equal intervals on a circumference centered on the optical axis O.

[0047] The first adjusting holder 26 has a fastening portion 261 formed near the outer peripheral edge of the first adjusting holder 26. The fastening portion 261 is an example of a first fixing portion and is a portion for fixing the first adjusting holder 26 to the second lens holder 22. The fastening portion 261 is formed with a through hole 262 into which the screw 233 is inserted in the optical axis direction. A plurality of fastening portions 261 (three in this example) are arranged at substantially equal intervals on a circumference centered on the optical axis O.

[0048] The second adjustment frame 27 has a fastening portion 271 formed near the outer peripheral edge of the second adjustment frame 27. The fastening portion 271 is an example of the second fixing portion and is a portion for fixing the second adjustment frame 27 to the first adjustment frame 26 or the second lens holder 22. The fastening portion 271 is formed with a through hole 272 into which the screw 233 is inserted in the optical axis direction. A plurality of fastening portions 271 (three in this example) are arranged at substantially equal intervals on a circumference centered on the optical axis O.

[0049] When viewed from the optical axis direction, the fastening portion 221 of the second lens holder 22, the fastening portion 261 of the first adjustment frame 26, and the fastening portion 271 of the second adjustment frame 27 are arranged to partially overlap each other. In addition, the internal thread portion 222 of the second lens holder 22, the through hole 262 of the first adjustment frame 26, and the through hole 272 of the second adjustment frame 27 communicate with each other in the optical axis direction. The inner diameter of the through hole 262 formed in the first adjustment frame 26 and the inner diameter of the through hole 272 of the second adjustment frame 27 are somewhat larger than the inner diameter of the internal thread portion 222 of the second lens holder 22. Therefore, even when the first adjustment frame 26 moves relative to the second lens holder 22 in a direction orthogonal to the optical axis, the screw 233 can be fastened to the internal thread portion 222 without disturbing the through holes 262 and 272.

[0050] In the case of performing decentration adjustment of the first adjustment lens 24, a shaft-shaped adjustment member 62 such as a pin is used to adjust the movement of the second adjustment frame 27 relative to the first adjustment frame 26 so that the second adjustment frame 27 moves together with the first adjustment frame 26. The adjustment member 62 is used as a jig. Specifically, in the case of performing decentration adjustment of the first adjustment lens 24, as Figure 6 shown, the screw 233 has not been fastened yet, and the adjustment member 62 is inserted into the through hole 272 of the second adjustment frame 27 and the through hole 262 of the first adjustment frame 26. The adjustment member 62 has a shaft diameter that engages with the through holes 272 and 262 and has a length that does not contact the internal thread portion 222. In other words, the shaft diameter of the adjustment member 62 is larger than the shaft diameter of the screw 233. As Figure 5As shown, a plurality of adjusting members 62 are respectively inserted into the through holes 272 and 262 so that the first adjusting lens 24 can be eccentrically adjusted in a state where the optical axis of the first adjusting lens 24 and the optical axis of the second adjusting lens 23 are substantially coincident with each other. The first adjusting lens 24 and the second adjusting lens 23 are respectively responsible for improving different optical performances. However, if the second adjusting lens 23 moves freely during the eccentric adjustment of the first adjusting lens 24, the deviation of the optical axis cannot be properly corrected. Therefore, the second adjusting bracket 27 moves together with the first adjusting bracket 26, and thus high optical performance can be achieved. According to the present exemplary embodiment, the inner diameters of the through holes 272 and 262 are the same, but in the case of using a stepped adjusting member 62, the inner diameter of the through hole 272 may be larger than the inner diameter of the through hole 262.

[0051] When the eccentric adjustment of the first adjusting lens 24 is completed, the first adjusting bracket 26 is fixed to the second lens holder 22. For example, the first adjusting bracket 26 is fixed to the second lens holder 22 by an adhesive method.

[0052] The second lens unit 20 has a first bonding portion 223 formed near the outer peripheral edge of the first adjusting bracket 26. The first bonding portion 223 is an example of the first fixing portion and is a portion for fixing the first adjusting bracket 26 to the second lens holder 22. A plurality of first bonding portions 223 (three in this example) are arranged at substantially equal intervals on a circumference centered on the optical axis O.

[0053] The first bonding portion 223 is constructed by a part of the second lens holder 22 and a part of the first adjusting bracket 26. As Figure 4 and Figure 6 shown, the first bonding portion 223 has a bottom surface 224a perpendicular to the optical axis O and side surfaces 224b, 224c (see Figure 4 ) and 224d (see Figure 6 ) extending from the bottom surface 224a in the optical axis direction and is formed in a concave shape that is recessed toward the image side in the optical axis direction. According to the present exemplary embodiment, the bottom surface 224a is formed by a part of the second lens holder 22. In addition, the side surface 224b is located at a position away from the optical axis O and is constructed by the second lens holder 22 extending from the bottom surface 224a toward the object side in the optical axis direction. The side surface 224c is located on the optical axis O side and is constructed by a part of the first adjusting bracket 26. In addition, as Figure 6 shown, a pair of opposite side surfaces 224d are constructed by an enclosing portion 225 integrally formed with the first adjusting bracket 26 and have a substantially C-shaped shape when viewed from the optical axis direction. In other words, among the side surfaces 224b to 224d of the first bonding portion 223 according to the present exemplary embodiment, the side surfaces other than the side surface 224b located at a position away from the optical axis O side are formed by the first adjusting bracket 26.

[0054] The first bonding portion 223 is filled with an adhesive (AH1) so as to fix the first adjustment holder 26 to the second lens holder 22 via the adhesive (AH1). After the first adjustment holder 26 is fixed to the second lens holder 22, the first adjustment jig 61 and the adjustment member 62 are removed, thereby completing the eccentricity adjustment of the first adjustment lens 24 and the fixation (temporary fixation) of the first adjustment holder 26.

[0055] Next, a method for adjusting the eccentricity of the second adjustment lens 23 and a method for fixing the second adjustment holder 27 will be described.

[0056] Figure 7 is a perspective view showing a state in which the second adjustment lens 23 is eccentrically adjusted.

[0057] In the case of eccentrically adjusting the second adjustment lens 23, the side portion of the second adjustment holder 2 is pressed using a second adjustment jig 63 such as at least one pin. For example, the second adjustment jig 63 can be configured to adsorb the second adjustment holder 27. Figure 7 An example of adjustment by pressing the outer peripheral side surface of the second adjustment holder 27 from three directions using the second adjustment jig 63 is illustrated.

[0058] When the second adjustment jig 63 moves back and forth, the second adjustment holder 27 moves relative to the second lens holder 22 and the first adjustment holder 26 in a direction orthogonal to the optical axis. The second adjustment holder 27 holding the second adjustment lens 23 moves, thereby moving the second adjustment lens 23 to a desired position and performing eccentricity adjustment.

[0059] Ideally, in a state where the first lens unit 10 and the third lens unit 30 are arranged, the second adjustment lens 23 is eccentrically adjusted to cancel the sum of the minute eccentricity deviations of each lens. Since the eccentricity of the first adjustment lens 24 has been adjusted, eccentricity adjustment can be performed so that the optical axis of the second adjustment lens 23 coincides with the optical axes of the first adjustment lens 24 and the reference lens 25 whose optical axes coincide with each other. In this case, the minute eccentricity deviations of each lens can be canceled within the second lens unit 20.

[0060] After the eccentricity adjustment of the second adjustment lens 23 is completed, the second adjustment holder 27 is fixed to the first adjustment holder 26. For example, the second adjustment holder 27 is fixed to the first adjustment holder 26 using an adhesion method.

[0061] The second lens unit 20 has a second bonding portion 263 formed near the outer peripheral edge of the second holder 27. The second bonding portion 263 is an example of the second fixing portion and is a portion for fixing the second holder 27 to the second lens holder 22 or the first holder 26. A plurality of second bonding portions 263 (three in this example) are arranged at substantially equal intervals on a circumference centered on the optical axis O. When viewed from the optical axis direction, the second bonding portion 263 and the first bonding portion 223 are arranged to partially overlap each other.

[0062] The first bonding portion 223 and the second bonding portion 263 are arranged such that they do not overlap with the fastening portions 261, 271, and 221 in phase on the circumference. Further, when viewed from the optical axis direction, the first bonding portion 223 and the second bonding portion 263 are arranged adjacent to the fastening portions 261, 271, and 221. Further, when viewed from the optical axis direction, the first bonding portion 223, the second bonding portion 263, the fastening portions 261, 271, and 221, and the guide rods 52, 53, 54, and 55 are arranged so as not to overlap with each other.

[0063] The second bonding portion 263 is constructed of a part of the adhesive (AH1) filled in the first bonding portion 223, a part of the second holder 27, and a part of the first holder 26. As Figure 4 and Figure 6 shown, the second bonding portion 263 has a bottom surface 264a perpendicular to the optical axis O and side surfaces 264b, 264c (see Figure 4 ) and 264d (see Figure 6 ) extending in the optical axis direction from the bottom surface 264a, and is formed in a concave shape that is recessed toward the image side in the optical axis direction. According to the present exemplary embodiment, the bottom surface 264a is constructed of a part of the adhesive (AH1) filled in the first bonding portion 223. The side surface 264b is located away from the optical axis O and is constructed of an enclosing portion 225 integrally formed with the first holder 26. Further, as Figure 6 shown, a pair of opposing side surfaces 264d are constructed of the enclosing portion 225. This pair of side surfaces 264d is formed to continuously extend from the pair of side surfaces 224d. Further, this pair of side surfaces 264d and this pair of side surfaces 224d are integrally formed by the same member (specifically, the first holder 26). Therefore, among the side surfaces 264b to 264d of the second bonding portion 263 according to the present exemplary embodiment, the side surfaces other than the side surface 264c located on the optical axis O side are formed by a part of the first holder 26.

[0064] The second bonding portion 263 is filled with an adhesive (AH2) so as to fix the second adjustment holder 27 to the first adjustment holder 26 via the adhesive (AH2). After the second adjustment holder 27 is fixed to the first adjustment holder 26, the second adjustment jig 63 is removed, thereby completing the decentering adjustment of the first adjustment lens 24 and the fixation (temporary fixation) of the first adjustment holder 26.

[0065] Finally, using the screw 233 as a common fastening member, the first adjustment holder 26 and the second adjustment holder 27 are fixed to the second lens holder 22. In other words, the screw 233 is inserted into the through holes 272 of the fastening portion 271 of the second adjustment holder 27 and the through holes 262 of the fastening portion 261 of the first adjustment holder 26 in the optical axis direction. The screw 233 inserted into the through holes 272 and 262 is fastened to the internal thread portion 222 of the fastening portion 221 of the second lens holder 22 from the object side, thereby fixing the first adjustment holder 26 and the second adjustment holder 27 to the second lens holder 22. In this way, fastening with the screw 233 can prevent the first adjustment holder 26 or the second adjustment holder 27 from changing due to the expansion and contraction of the adhesive, and thus can improve the reliability of the optical performance.

[0066] As Figure 6 shown, the side surface 264d of the second bonding portion 263 is formed by extending the side surface 224d of the first bonding portion 223 in the optical axis direction. In other words, the side surface 264d of the second bonding portion 263 and the side surface 224d of the first bonding portion 223 are common continuous surfaces. With this configuration, when viewed from the optical axis direction, the first bonding portion 223 and the second bonding portion 263 have portions that completely overlap each other, so that the space for the fixing structure can be reduced.

[0067] In addition, in the case of filling a low-viscosity adhesive, the side surfaces 264d of the continuous second bonding portion 263 and the side surfaces 224d of the first bonding portion 223 serve as guides to fill the adhesive into the first bonding portion 223.

[0068] As described above, according to the present exemplary embodiment, the first adjustment holder 26 and the second adjustment holder 27 that can be adjusted in a direction orthogonal to the optical axis with respect to the second lens holder 22 are arranged on the object side in the optical axis direction with respect to the second lens holder 22. Various components for forming an image and driving the lens are arranged on the image side in the optical axis direction. The first adjustment holder 26 and the second adjustment holder 27 are arranged on the object side, so that the adjustment mechanism and various components can be arranged without interfering with each other, thereby suppressing the lens unit and the barrel from becoming larger.

[0069] In addition, according to the present exemplary embodiment, when viewed from the optical axis direction, the first bonding portion 223 and the second bonding portion 263 are arranged to partially overlap each other. In addition, when viewed from the optical axis direction, the fastening portions 261 and 271 are arranged to partially overlap each other. Therefore, when viewed from the optical axis direction, lens driving-related structures such as a frame holding structure and a guide rod engaging structure can be arranged in a space where the first bonding portion 223, the second bonding portion 263, the fastening portions 261 and 271 are not arranged. Therefore, compared with the case of holding a lens using a retaining ring or the like in the conventional art, lens driving-related structures can be arranged near the optical axis O, thereby preventing the lens unit and the lens barrel from becoming larger.

[0070] In addition, according to the present exemplary embodiment, when viewed from the optical axis direction, the first bonding portion 223 and the second bonding portion 263 are arranged to partially overlap each other. Therefore, the first adjustment frame 26 and the second adjustment frame 27 can be bonded at substantially the same position in a direction perpendicular to the optical axis.

[0071] In addition, according to the present exemplary embodiment, when assembling the second lens unit 20, the second lens holder 22, the first adjustment frame 26, and the second adjustment frame 27 are arranged in order from the lower side in the direction of gravity.

[0072] Therefore, when adjusting the first adjustment frame 26 and the second adjustment frame 27 relative to the second lens holder 22, bonding them using an adhesive, and fastening them with screws 233, operations can be performed from above in the direction of gravity. Therefore, the configuration allows for simple adjustment and assembly of the first adjustment frame 26 and the second adjustment frame 27.

[0073] In addition, according to the present exemplary embodiment, when performing decentration adjustment of the first adjustment lens 24, the adjustment member 62 is inserted into the through holes 272 of the second adjustment frame 27 and the through holes 262 of the first adjustment frame 26 so that the second adjustment frame 27 can move together with the first adjustment frame 26. In addition, the through holes 262 and 272 into which the adjustment member 62 is inserted also serve as holes for fastening the second adjustment frame 27 and the first adjustment frame 26 to the second lens holder 22. Therefore, there is no need to provide a new structure for inserting the adjustment member 62, and the space of the second lens unit 20 can also be reduced. In the case of providing a new structure for inserting the adjustment member 62, a structure for blocking the holes passing through the first adjustment frame 26 and the second adjustment frame 27 to prevent stray light is required, but the present exemplary embodiment does not require prevention of stray light.

[0074] Figure 8FIG. is a perspective view showing a state in which the first adjustment lens 24 is eccentrically adjusted according to the first modification. According to this modification, in the case of eccentrically adjusting the first adjustment lens 24, instead of the first adjustment jig 61, the second adjustment jig 63 is used to press the outer peripheral side surface of the second adjustment frame 27 for adjustment. If the adjustment member 62 is used, the first adjustment frame 26 can be moved together with the second adjustment frame 27, so that the second adjustment jig 63 can be moved back and forth to adjust the first adjustment frame 26, and the second adjustment frame 27 can be moved in a direction orthogonal to the optical axis.

[0075] Figure 9 FIG. is a cross-sectional perspective view showing the structures of the first bonding portion 226 and the second bonding portion 266 according to the second modification.

[0076] The first bonding portion 226 is formed in a concave shape that is recessed toward the image side in the optical axis direction by a bottom surface 227a perpendicular to the optical axis O and side surfaces 227b and 227c extending from the bottom surface 227a in the optical axis direction. The bottom surface 227a is formed by a part of the second lens holder 22. The side surface 227b located at a position away from the optical axis O is formed by a part of the second lens holder 22, and the side surface 227c on the optical axis O side is formed by a part of the first adjustment frame 26. In addition, a pair of side surfaces (not shown) are formed by a part of the second lens holder 22. Therefore, the side surfaces other than the side surface 227c on the optical axis O side are formed by a part of the second lens holder 22.

[0077] The second bonding portion 266 is formed in a concave shape that is recessed toward the image side in the optical axis direction by a bottom surface 267a perpendicular to the optical axis O and side surfaces 267b and 267c extending from the bottom surface 267a in the optical axis direction. The bottom surface 267a is formed by a part of the adhesive (AH1) filled in the first bonding portion 226. The side surface 267b located at a position away from the optical axis O is formed by a part of the second lens holder 22, and the side surface 267c on the optical axis O side is formed by a part of the second adjustment frame 27. In addition, a pair of side surfaces (not shown) are formed by a part of the second lens holder 22. Therefore, the side surfaces other than the side surface 227c are formed by a part of the second lens holder 22.

[0078] According to this modification, the side surfaces of the second bonding portion 266 other than the side surface 267c are formed to continuously extend from the side surfaces of the first bonding portion 226 other than the side surface 227c. In addition, the side surfaces of the second bonding portion 266 other than the side surface 267c and the side surfaces of the first bonding portion 226 other than the side surface 227c are integrally formed by the same member (specifically, the second lens holder 22). Therefore, the first bonding portion 226 and the second bonding portion 266 can be bonded to a common surface, and thus the same effect as in the first exemplary embodiment can be achieved.

[0079] Figure 10 FIG. is a cross-sectional perspective view showing the configuration of the first bonding portion 228 and the second bonding portion 268 according to the third modification.

[0080] The first bonding portion 228 is formed by a bottom surface 229a perpendicular to the optical axis O and side surfaces 229b and 229c extending in the optical axis direction from the bottom surface 229a into a concave shape that is recessed toward the image side in the optical axis direction. The bottom surface 229a is formed by a part of the second lens holder 22. The side surfaces 229b and 229c and a pair of side surfaces (not shown) are formed by a part of the first adjuster 26.

[0081] The second bonding portion 268 is formed by a bottom surface 269a perpendicular to the optical axis O and side surfaces 269b and 269c extending in the optical axis direction from the bottom surface 269a into a concave shape that is recessed toward the image side in the optical axis direction. The bottom surface 269a is formed by a part of the adhesive (AH1) filled into the first bonding portion 228. The side surface 269c on the optical axis O side is formed by a part of the second adjuster 27, and the side surfaces other than the side surface 269c on the optical axis O side are formed by a part of the first adjuster 26.

[0082] According to this modification example, the side surfaces of the second bonding portion 268 other than the side surface 269c are formed to continuously extend from the side surfaces of the first bonding portion 228 other than the side surface 229c. In addition, the side surfaces of the second bonding portion 268 other than the side surface 269c and the side surfaces of the first bonding portion 228 other than the side surface 229c are integrally formed by the same member (specifically, the first adjuster 26). Therefore, the first bonding portion 228 and the second bonding portion 268 can be bonded to a common surface, and thus the same effect as in the first exemplary embodiment can be achieved.

[0083] The ideal exemplary embodiments of the present invention have been described above, but the present invention is not limited to these exemplary embodiments, and various modifications and changes can be made within the scope of the gist of the present invention. In addition, there is no limitation as long as the configuration takes the design function into consideration.

[0084] According to the above exemplary embodiments, the following is described: the first adjustment holder 26 is fixed to the second lens holder 22 via an adhesive, and the second adjustment holder 27 is fixed to the first adjustment holder 26 or the second lens holder 22 via an adhesive. However, the present invention is not limited to this case. For example, a screw 233 can be used as a fastening member to fix the first adjustment holder 26 and the second adjustment holder 27 together to the second lens holder 22. In this case, after the eccentric adjustment of the first adjustment lens 24, without removing the first adjustment jig 61, the eccentric adjustment of the second adjustment lens 23 is performed, and the screw 233 is fastened to the fastening portion 221 of the second lens holder 22. After fastening the screw 233, the first adjustment jig 61 and the second adjustment jig 63 are removed. In addition, the first adjustment holder 26 and the second adjustment holder 27 can be fixed to the second lens holder 22 only using an adhesive without using the fastening screw 233.

[0085] According to the above exemplary embodiments, the internal thread portion 222 is not limited to the case where the thread is pre-formed, but can be formed by screwing the screw 233 therein. In addition, the fastening member is not limited to the screw 233, and can also be a rivet or the like.

[0086] Although the present invention has been described with reference to the exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such variations as well as equivalent structures and functions.

Claims

1. A lens unit comprising a plurality of lenses, the lens unit comprising: a holding frame configured to hold a first lens among the plurality of lenses; a first adjustment frame, the first adjustment frame being configured to hold a first adjustment lens among the plurality of lenses and to adjust the first adjustment lens along a direction orthogonal to the optical axis relative to the holding frame; as well as a second adjustment frame configured to hold a second adjustment lens among the plurality of lenses and to adjust the second adjustment lens along the direction orthogonal to the optical axis relative to the holding frame, The first adjustment frame and the second adjustment frame are arranged on the object side along the optical axis direction relative to the holding frame.

2. The lens unit according to claim 1, further comprising: a first fixing portion, the first fixing portion being configured to fix the first adjustment frame to the holding frame; as well as A second fixing portion is configured to fix the second adjustment frame to the holding frame or the first adjustment frame.

3. The lens unit according to claim 2, wherein: When viewed from the optical axis direction, the first fixing portion and the second fixing portion at least partially overlap each other.

4. The lens unit according to claim 2 or 3, wherein: The first fixing portion and the second fixing portion are each filled with an adhesive.

5. The lens unit according to claim 4, in, The first fixing portion and the second fixing portion are each formed in a concave shape that is recessed toward the image side in the optical axis direction, and A portion of the side surface of the first fixing portion and a portion of the side surface of the second fixing portion are continuously and integrally formed.

6. The lens unit according to claim 4, in, The first fixing portion and the second fixing portion are each formed in a concave shape that is recessed toward the image side in the optical axis direction, and The bottom surface of the second fixing portion is constructed by the adhesive filled in the first fixing portion.

7. The lens unit according to claim 2 or 3, in, The first fixing portion and the second fixing portion have through holes for inserting a fastening member along the optical axis direction, and The holding frame is fastened using the fastening member inserted into the through hole of the first fixing portion and the through hole of the second fixing portion.

8. The lens unit according to claim 7, wherein: An inner diameter of the through hole of the second fixing portion is the same as or larger than an inner diameter of the through hole of the first fixing portion.

9. The lens unit according to claim 1, further comprising: a first bonding portion, the first bonding portion being configured to bond the first adjustment frame to the holding frame using an adhesive; a second bonding portion, the second bonding portion being configured to bond the second adjustment frame to the holding frame or the first adjustment frame using an adhesive; a first fastening portion configured to fasten the first adjustment frame to the holding frame using a fastening member; as well as A second fastening portion is configured to fasten the second adjustment frame to the holding frame or the first adjustment frame using the fastening member.

10. The lens unit according to claim 9, in, When viewed from the optical axis direction, the first bonding portion and the second bonding portion at least partially overlap each other. Wherein, when viewed from the optical axis direction, the first fastening portion and the second fastening portion at least partially overlap each other, and Wherein, when viewed from the optical axis direction, the first bonding portion and the second bonding portion as well as the first fastening portion and the second fastening portion are arranged adjacent to each other.

11. The lens unit according to claim 1, wherein: The holding frame is moved along the optical axis direction by a guide rod.

12. A lens barrel, comprising: The lens unit according to claim 2; as well as a plurality of guide rods configured to engage with the retaining frame, Wherein, when viewed from the optical axis direction, the plurality of guide rods, the first fixing portion, and the second fixing portion are arranged to overlap with each other.

13. A method for adjusting a lens unit comprising a plurality of lenses, in, The lens unit comprises: a holding frame configured to hold a first lens among the plurality of lenses; a first adjustment frame configured to hold a first adjustment lens among the plurality of lenses and adjust the first adjustment lens in a direction orthogonal to the optical axis relative to the holding frame; and a second adjustment frame configured to hold a second adjustment lens among the plurality of lenses and to adjust the second adjustment lens along the direction orthogonal to the optical axis relative to the holding frame, wherein the first adjustment frame and the second adjustment frame are arranged on the object side along the optical axis direction relative to the holding frame, and Wherein, when the first adjustment frame is adjusted relative to the holding frame along the direction orthogonal to the optical axis, the adjustment is performed in a state where the movement of the second adjustment frame relative to the first adjustment frame is restricted.

14. The method according to claim 13, in, The first adjustment frame includes a first fastening portion, and the first fastening portion is configured to fasten the first adjustment frame to the holding frame. The second adjustment frame includes a second fastening portion, the second fastening portion is configured to fasten the second adjustment frame to the holding frame or the first adjustment frame, and The adjusting member is inserted into the through hole of the first fastening portion and the through hole of the second fastening portion to limit the movement of the second adjusting frame relative to the first adjusting frame.

15. The method according to claim 14, wherein: A fastening member having a shaft diameter smaller than that of the adjustment member is inserted into the through hole of the first fastening portion and the through hole of the second fastening portion, thereby fastening the fastening member to the holding frame.

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