JP2024024447A - lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel which enables both alignment work for shift alignment and tilt alignment and lens spacing adjustment work, and offers superior workability in the alignment work and adjustment work and a minimized increase in outer diameter thereof by devising an arrangement.

SOLUTION: A lens barrel is provided, comprising a lens holding member for holding lenses, a base member for fixing the lens holding member, and an adjustment member for adjusting a positional relationship between the lens holding member and the base member, where the adjustment member comprises a first adjustment part that enables adjustment in a direction perpendicular to an optical axis of the lenses, and a second adjustment part that enables adjustment in a direction along the optical axis.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a lens barrel made up of a plurality of lenses, which has an alignment mechanism for adjusting optical performance.

In recent years, imaging devices have been required to have higher performance and be smaller. As an example, imaging devices that can obtain higher resolution images are now being used in imaging devices. As a result, the optical performance required of a lens barrel used in combination with such an image sensor has been increasing along with the performance of the image sensor.

The lens barrel has a plurality of lens chambers each consisting of one or more lenses. When assembling such a lens barrel, simply assembling the lens chamber to the lens barrel does not allow the assembled lens barrel to achieve optical performance as designed. This is because errors occur during the manufacturing of each member constituting the lens barrel, such as the lens chamber, resulting in a shift in the positional relationship between the lens chambers, which has an adverse effect on resolution.

Therefore, an adjustment step is provided in the manufacturing process of the lens barrel to suppress deterioration of optical performance due to manufacturing errors of the lens barrel.

In the adjustment process, the lens barrel is attached to the MTF measurement device, and while observing the image formation through the lens, the position of the lens barrel held within the lens barrel is adjusted to find the optimal position for demonstrating lens performance. When the lens chamber is located, an adhesive or the like is applied to the engagement portion between the lens barrel and the lens chamber to fix the lens chamber.

Patent Document 1 discloses a lens barrel that performs shift alignment in which the lens is moved on a plane perpendicular to the optical axis and tilt alignment in which the lens is moved in a plane perpendicular to the optical axis toward the object side or the image side.

Patent No. 4817876

However, the lens barrel described in Patent Document 1 has a problem in that it is not possible to perform shift alignment, tilt alignment, and lens spacing adjustment that adjusts the lens group or the lens spacing within the lens group.

The present invention has been made in view of these circumstances, and it is possible to achieve both shift alignment and tilt alignment and lens spacing adjustment work, and to improve the alignment and adjustment work by devising the arrangement. The object of the present invention is to provide a lens barrel that has excellent workability and suppresses an increase in the outer diameter of the product.

A first invention, which is a means for solving the above problems, provides a lens holding member that holds a lens, a base member that fixes the lens holding member, and a positional relationship between the lens holding member and the base member that is adjusted. A lens barrel comprising: a first adjustment section adjustable in a direction perpendicular to the optical axis of the lens; and a first adjustment section adjustable in a direction along the optical axis. A lens barrel characterized by having two adjustment parts.

According to the present invention, the alignment work of shift alignment and tilt alignment and the lens spacing adjustment work are compatible, and by devising the arrangement, workability in alignment work and adjustment work is excellent, and the product outer diameter It is possible to provide a lens barrel that suppresses an increase in .

A perspective view showing main parts of a lens barrel adjustment mechanism according to an embodiment of the present invention An exploded perspective view of a lens barrel adjustment mechanism according to an embodiment of the present invention A cross-sectional perspective view of the first lens group of the lens barrel according to the embodiment of the present invention

DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. Furthermore, the present invention is not limited to this embodiment.

FIG. 1 is a perspective view showing essential parts of a lens barrel according to an embodiment of the present invention. Note that FIG. 1 is simplified to show only the essential parts of the adjustment mechanism in order to explain the adjustment steps of shift alignment, tilt alignment, and lens interval adjustment of a lens barrel according to the present invention. FIG. 2 is an enlarged exploded perspective view of the adjustment mechanism and its vicinity in FIG. 1. FIG. 3 is a cross-sectional perspective view of the first lens group of the lens barrel. In this example, based on the optical axis of the lens barrel, that is, the optical axis of the first lens group constituting the lens barrel, the direction along the optical axis is called the thrust direction, and the direction perpendicular to the optical axis is called the radial direction. direction. In all drawings, the left side in the thrust direction is the object side, the right side is the image side, the optical axis side in the radial direction is the inner circumference, and the opposite side is the outer circumference.

As shown in each drawing, the lens barrel of the present invention has an adjustment mechanism that is an adjustment member, and the adjustment mechanism includes a fitting part 111 of a base member 110, a spacer shaft engaging part 122 of a lens chamber 120, and an eccentricity. It includes a roller 130, an adjustment washer 140, and a spacer shaft 150. The base member 110 and the lens chamber 120 correspond to a first lens group located closest to the object side among the lens groups forming the lens barrel. Therefore, in the lens barrel of the embodiment of the present application, the first lens group is an adjustment group that is subject to shift alignment, tilt alignment, and lens spacing adjustment. In addition, a front ring is placed on the outer diameter side of the first lens group in the radial direction, a name ring, a light shielding member, etc. are placed on the object side in the thrust direction, and the second and third lens groups and the imaging device are placed on the image side in the thrust direction. The mounts etc. that are connected to these are placed respectively.

Furthermore, the configuration of the first lens group will be explained in detail. In addition to the lenses held by the lens chamber 120, the first lens group includes a second lens and a third lens (not shown) on the image side in the thrust direction.

The base member 110 is a fixed barrel that constitutes a lens barrel. It is fixed to the front ring with a screw (not shown) in a screw hole 112 at the bottom right of FIG. In the embodiment of the present application, a fixed barrel is used, but there is no problem if a cam groove is formed in the base member 110 and the base member 110 is a linear barrel that moves along the optical axis. Furthermore, the base member 110 has a fitting portion 111 having a long hole shape into which the eccentric roller 130 is fitted.

The lens mirror chamber 120 is a member that holds a glass material (not shown), and corresponds to a lens holding member. Tilt alignment is performed by adjusting the degree of inclination of the lens chamber 120 with respect to the optical axis. Shift alignment is performed by moving the lens chamber 120 on a plane perpendicular to the optical axis. Further, the lens chamber 120 is provided with a fitting hole 121 into which an eccentric roller 130 which is fitted into the fitting part 111 of the base member 110 is fitted. Furthermore, a spacer shaft engaging portion 122 into which the spacer shaft 150 fits is provided. The spacer shaft engaging portion 122 has a concave shape with an open outer peripheral side in the radial direction.

The eccentric roller 130 fits into the fitting portion 111 of the base member 110 and into the fitting hole 121 of the lens chamber 120. By rotating the eccentric roller 130 with an adjustment jig, the lens chamber 120 moves on a plane perpendicular to the optical axis, thereby performing shift alignment.

The adjustment washer 140 is located between the spacer shaft engaging portion 122 of the lens chamber 120 and the base member 110, and is fixed to the base member 110 together with the lens chamber 120 by the spacer shaft 150. By changing the number and thickness of the adjusting washers 140, the positional relationship between the lens chamber 120 and the base member 110 in the direction along the optical axis is changed. In other words, the lens interval can be adjusted. Further, the adjustment washer 140 has a shape having an open through hole. As a result, the adjustment washer 140 can be inserted into and removed from the screw portion of the spacer shaft 150 from the outer peripheral side in the radial direction using an adjustment jig. Although a washer is used in this embodiment, a spacer or the like may be used as long as it has a function of maintaining the distance between the base member 110 and the lens chamber 120 and has a shape that can be inserted and removed.

The spacer shaft 150 is composed of a screw and a spacer. The spacer engages with the spacer shaft engaging portion 122 of the lens chamber 120 and fixes the spacer shaft 150 to the base member 110, thereby fixing the positional relationship between the base member 110 and the lens chamber 120 in the thrust direction. Specifically, the spacer shaft 150 in FIG. 2 is fixed by fitting into a hole on the base member 110 located beyond the dotted line extending from the tip of the screw.

FIG. 2 is an enlarged exploded perspective view of the vicinity of the adjustment mechanism of the lens barrel of the present invention. The adjustment process will be explained using FIG. 2.

In the adjustment process, the lens barrel is mounted on an adjustment jig such as an MTF measuring device, and the adjustment group is adjusted while observing the resolution performance of the image formed by the light that has passed through the lens barrel. In the lens barrel of the present invention, by performing tilt alignment, shift alignment, and lens spacing adjustment in the adjustment process of the glass material (not shown) held in the lens barrel chamber 120, the lens barrel can achieve optical performance according to the designed values. We will obtain performance.

To perform tilt alignment, the number and thickness of adjustment washers 140 to be inserted between the base member 110 and the spacer shaft engaging portions 122 provided at three locations on the outer periphery of the base member 110 and the lens chamber 120 are determined. Change each. By changing the number and thickness of the adjustment washers 140, the glass material held in the lens chamber can be tilted and aligned by adjusting the inclination with respect to the optical axis.

In addition, by adjusting the adjusting washers 140 inserted between all the spacer shaft engaging parts 122 provided on the outer periphery and the base member 110 in the same way, the distance between the base member 110 and the lens chamber 120 can be adjusted. It becomes possible to adjust. In other words, since the glass material can be moved in the thrust direction without changing its inclination with respect to the optical axis, it is possible to adjust the distance between the lenses, which are glass materials.

Finally, in order to perform shift alignment, the eccentric roller 130 that fits into the fitting part 111 and the fitting hole 121 is rotated using an adjustment jig, so that the eccentric roller 130 aligns with the fitting hole 121. Since the lens chamber 120 is moved on a plane perpendicular to the optical axis through the lens chamber 120, the lens glass material held in the lens chamber 120 can also be adjusted by adjusting the eccentric rollers 130 provided at three locations on the outer periphery. It is possible to move on a plane perpendicular to the optical axis. In other words, shift alignment of the glass material becomes possible. Note that after the adjustment, the radial positional relationship between the base member 110 and the lens chamber 120 is fixed.

The adjustment process using the MTF measuring device is generally performed while observing the resolution performance as described above. Therefore, it is desirable that a jig can be inserted from the radial direction for rotating the eccentric roller 130 and inserting and removing the adjusting washer 140 for alignment and spacing adjustment. Since the jig can be inserted from the radial direction, the jig can be operated without interfering with observation of resolution performance, so the present invention has excellent workability.

Furthermore, since the adjustment is possible from the radial direction by inserting a jig, the first lens group, which is the adjustment group shown in FIGS. 1 and 2, includes a second lens and a third lens that are further adjustable. It becomes possible to configure the lens barrel as shown in FIG. 3. A specific explanation will be given below using FIG. 3.

Although only one second adjustment mechanism for adjusting the second lens chamber 220 and the third lens chamber 320 is shown in FIG. 3, the adjustment mechanism for adjusting the first lens chamber Needless to say, they are arranged at 120° intervals around the outer periphery of the lens chamber, which is adjusted in the same way as the mechanism.

FIG. 3 is a cross-sectional perspective view of the first lens group of the lens barrel of the present invention, cut in the thrust direction. As described above, the first lens group has the second lens and the third lens, and the second lens chamber 220 and the third lens chamber 320 hold respective glass materials. Further, the lens chamber 120 has a second fitting part 123 having a long hole shape similar to the fitting part 111, and the eccentric roller 230, adjustment washer 240, and spacer shaft 250 are connected to the eccentric roller 130, adjustment washer 240, and spacer shaft 250, respectively. It plays the same role as the washer 140 and the spacer shaft 150. An adjustment member for adjusting these second and third lenses is referred to as a second adjustment mechanism.

The relationship between each lens chamber will be explained. Similar to the engagement relationship between the spacer shaft 150 and the spacer shaft engaging portion 122, the spacer portion of the spacer shaft 250 and the third lens chamber 320 are engaged, and the spacer shaft 250 is fixed to the second lens chamber 220. has been done. In addition, since the adjustment washer 240 is located between the second lens mirror chamber 220 and the third lens mirror chamber 320, the distance between the second lens and the third lens can be adjusted by adjusting the number and thickness of the adjustment washers 240. Adjustment and tilt alignment of the third lens are possible, and the third lens chamber 320 is fixed to the second lens chamber 220. Next, the eccentric roller 230 fits into the second fitting portion 123 of the lens chamber 120 and is fitted into the second lens chamber 220 . That is, the lens chamber 120 holds the second lens chamber 220, and by rotating the eccentric roller 230 using an adjustment jig, the second lens chamber 220 moves on a plane perpendicular to the optical axis. Therefore, the second lens can be shifted and aligned.

The fitting part 111 shown in FIG. 2 and the second fitting part 123 shown in FIG. and the maximum thickness of the adjustment washer expected to be inserted when adjusting the lens spacing.

From the above, the lens barrel shown in FIG. It becomes possible to adjust the centering between the first lens and the third lens included in the lens group. Next, for the first lens group whose centering has been adjusted, by performing the adjustment process on the first lens as explained using FIG. 2, it becomes possible for the lens barrel to obtain the optical performance as designed. .

Further, the adjustment mechanism of the present invention is arranged at three locations on the outer periphery of the base member 110 at intervals of 120°. A fitting part 111 of the base member 110, which is an adjustment mechanism for performing shift alignment, tilt alignment, and interval adjustment, a spacer shaft engagement part 122 of the lens chamber 120, an eccentric roller 130, an adjustment washer 140, and a spacer shaft. 150 are collectively arranged on the outer periphery of the base member 110. The second adjustment mechanism is similarly arranged on the outer periphery of the second lens chamber 220 and the third lens chamber 320, thereby suppressing an increase in the outer diameter of the product toward the outer periphery of the base member 110 in the radial direction. is possible.

Next, since the adjustment mechanisms for adjusting the first lens are arranged at 120° intervals on the outer circumference of the base member 110, the adjustment mechanisms for adjusting the second lens and the third lens as shown in FIG. The second adjustment mechanism is arranged out of phase with the adjustment mechanism that adjusts the first lens group, and the adjustment jig is attached to the corresponding location of the base member 110 so that the adjustment jig can access the second adjustment mechanism from the radial direction. By forming a groove for access, the lens barrel can have two adjustment mechanisms. As a result, as described above, it becomes possible to perform alignment adjustment and lens spacing adjustment with higher precision, and it becomes possible to manufacture a lens barrel with excellent optical performance.

Further, it is desirable that the eccentric rollers and adjustment washers in each adjustment mechanism are arranged in series so as to be adjacent to each other. Excellent workability is achieved by reducing the amount of movement during adjustment, and since the base member 110 is located on the outer peripheral side like the second adjustment mechanism, when providing a groove for inserting a jig, the groove is made smaller. becomes possible.

110 Fixed cylinder 111 Fitting part 112 Screw hole 120 Lens chamber 121 Fitting hole 122 Spacer shaft engaging part 123 Second fitting part 130 Eccentric roller 140 Adjusting washer 150 Spacer shaft 220 Second lens chamber 230 Eccentric roller 240 Adjustment washer 250 Spacer shaft 320 Third lens mirror chamber

Claims (5)

a lens holding member that holds the lens;
a base member for fixing the lens holding member;
an adjustment member that adjusts the positional relationship between the lens holding member and the base member;
A lens barrel having:
The adjustment member is
a first adjustment section adjustable in a direction perpendicular to the optical axis of the lens;
a second adjustment section adjustable in a direction along the optical axis;
A lens barrel characterized by having The first adjustment part is an eccentric roller,
The lens barrel according to claim 1, wherein the second adjustment part is an adjustment washer. The adjustment member is
The lens barrel according to claim 1, wherein the lens barrel is provided at at least three locations on the outer periphery of the base member. 3. The lens barrel according to claim 1, wherein a jig can be inserted from a direction perpendicular to the optical axis when adjusting the first adjustment section and the second adjustment section. The base member is
having a fitting part through which the eccentric roller is inserted;
3. The lens barrel according to claim 2, wherein the fitting portion has a long hole shape that is a combination of the eccentricity of the eccentric roller and the adjustment washer.

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