WO2013073189A1

WO2013073189A1 - Lens barrel

Info

Publication number: WO2013073189A1
Application number: PCT/JP2012/007345
Authority: WO
Inventors: 岩崎　真一; 直樹吉川; 西村　直人
Original assignee: パナソニック株式会社
Priority date: 2011-11-17
Filing date: 2012-11-15
Publication date: 2013-05-23
Also published as: JP2015025826A

Abstract

　A lens barrel (1) is provided with a fixed frame (600) and a first shielding plate (610). A second optical axis (AX2), guided by a plurality of lenses, passes through the inside of the fixed frame (600). The first shielding plate (610) has a first inner surface (610S), which is attached to the fixed frame (600), and which is exposed to the inner-side, through which the second optical axis (AX2) passes. At least part of the first inner surface (610S) has a lower optical reflectance than a first inner surface (S2) of the fixed frame (600).

Description

Lens barrel

The technology disclosed herein relates to a lens barrel provided with an optical system.

Conventionally, a method of forming a fine groove on the inner surface of a lens barrel has been widely known for the purpose of suppressing flare and ghost (see Patent Document 1). According to this method, a part of unnecessary light emitted from the lens can be scattered in the groove.

Japanese Patent Laid-Open No. 9-15475

However, as described in Patent Document 1, simply forming grooves on the inner surface of the lens barrel limits the scattering of unnecessary light.

The technology disclosed herein has been made in view of the above situation, and an object thereof is to provide a lens barrel that can more effectively suppress flare and ghost.

The technique disclosed herein is a lens barrel that bends light incident along a first optical axis by a reflecting member into light along a second optical axis that is substantially orthogonal to the first optical axis. And a shielding member. The frame has a second optical axis guided by a plurality of lenses passing through the inside thereof. The shielding member is attached to the frame and has an inner surface exposed to the inside through which the second optical axis passes. At least a part of the inner surface has a light reflectance lower than that of the inner surface of the frame.

(The invention's effect)
According to the technique disclosed herein, a lens barrel capable of effectively suppressing flare and ghost can be provided.

1 is an exploded perspective view of a lens barrel according to the present embodiment. Sectional drawing of the lens-barrel of FIG. Sectional drawing of the lens-barrel of FIG. The figure for demonstrating the reflection of the light in the inner surface of the fixed frame contained in the lens barrel of FIG. Sectional drawing of the lens-barrel which concerns on other embodiment.

[1. Lens barrel configuration]
FIG. 1 is an exploded perspective view of a lens barrel 1 according to the embodiment. FIG. 2 is a cross-sectional view of the lens barrel 1 according to the embodiment. FIG. 2 is a cross-sectional view of the lens barrel 1 taken along a plane including the first optical axis AX1 and the second optical axis AX2.

In the following description, the direction along the first optical axis AX1 is the “first direction”, the direction along the second optical axis AX2 orthogonal to the first optical axis AX1 is the “second direction”, and the first light. A direction orthogonal to the axis AX1 and the second optical axis AX2 is referred to as a “third direction”.

As shown in FIGS. 1 and 2, the lens barrel 1 includes a first group frame 100, a second group frame 200, a zoom motor 300, a shutter unit 400, an image blur correction unit 500, a fixed frame (an example of a frame), A first shielding plate 610, a second shielding plate 620, a fourth group frame 700, a focus motor 800, and an image sensor 900 are provided.

The first group frame 100 holds the front lens group L1, the prism L2, and the fixed lens L3.

The front lens group L1 has a first optical axis AX1.
The prism L2 bends the light beam incident from the first direction along the first optical axis AX1 in the second direction along the second optical axis AX2 orthogonal to the first optical axis AX1.

The second group frame 200 holds the zoom lens group L4 having a zooming action. The second group frame 200 is held movably in the second direction inside the first group frame 100.

The zoom lens group L4 is disposed on the imaging element 900 side of the prism L2.
The zoom motor 300 is attached to the side surface of the first group frame 100. The zoom motor 300 moves the second group frame 200 in the second direction inside the first group frame 100.

The shutter unit 400 adjusts the amount of light hitting the image sensor 900 by controlling the shielding and passage of light toward the image sensor 900. The shutter unit 400 is attached to the image sensor 900 side in the first group frame 100.

The image blur correction unit 500 corrects the blur of the image formed on the image sensor 900. The image blur correction unit 500 is disposed on the image sensor 900 side of the shutter unit 400. The image blur correction unit 500 includes a movable frame 510 and a third group frame 520.

The movable frame 510 is disposed on the image sensor 900 side of the shutter unit 400 and holds the image blur correction lens L5. The movable frame 510 is supported by the third group frame 520 so as to be movable in a plane perpendicular to the second optical axis AX2.

The third group frame 520 includes hall elements and coils (not shown). The third group frame 520 is connected to the first group frame 100. The third group frame 520 is supported by the fixed frame 600.

The fixed frame 600 (an example of a frame) supports the third group frame 520 on the prism L2 side. The fixed frame 600 holds the fourth group frame 700 so as to be slidable in the second direction. The fixed lens group L7 is fixed to the lower end of the fixed frame 600 (the end on the image sensor 900 side). A focus motor 800 is attached to the side surface of the fixed frame 600.

Further, a rectangular annular light blocking portion 601 protruding toward the second optical axis AX2 is formed on the inner periphery of the lower end portion of the fixed frame 600. The light blocking portion 601 is disposed closer to the image sensor 900 than first and second through holes T1 and T2 described later. The light blocking unit 601 prevents unnecessary light emitted from the focus lens group L6 or unnecessary light reflected by first and

second shielding members

610 and 620 described later from entering the fixed lens group L7.

Here, the fixed frame 600 has first and second through holes T1 and T2 (an example of a through hole).
The first and second through holes T 1 and T 2 are formed in part of the wall surface provided along the second direction in the fixed frame 600. More specifically, the first and second through holes T 1 and T 2 are provided on the wall surfaces orthogonal to the first direction along the first optical axis AX 1 in the fixed frame 600. In other words, as shown in FIG. 2, the first through hole T1 passes through the fixed frame 600 from the first outer surface S1 side orthogonal to the first direction along the first optical axis AX1 to the first inner surface S2. The second through hole T2 passes through the fixed frame 600 from the second outer surface S3 side orthogonal to the first optical axis AX1 to the second inner surface S4.

The arrangement relationship between the first and second through holes T1, T2 and the focus lens group L6 will be described later.

The first shielding plate 610 (an example of a shielding member) is formed in a plate shape. The first shielding plate 610 is disposed on the first outer surface S1 from the outside of the fixed frame 600 so as to block the first through hole T1. More specifically, the 1st shielding board 610 is arrange | positioned and fixed in the recessed part 602 formed in 1st outer surface S1.

The second shielding plate 620 (an example of a shielding member) is formed in a plate shape. The second shielding plate 620 is disposed on the second outer surface S3 from the outside of the fixed frame 600 so as to block the second through hole T2.

Here, the light reflectance of the first inner surface 610S exposed to the inside of the fixed frame 600 in the first shielding plate 610 is lower than the light reflectance of the first inner surface S2 of the fixed frame 600. Similarly, the light reflectance of the second inner surface 620S exposed in the fixed frame 600 in the second shielding plate 620 is lower than the light reflectance of the second inner surface S4 of the fixed frame 600.

The first and second

inner surfaces

610S and 620S are subjected to a treatment for suppressing the reflectance by, for example, forming fine irregularities, grooves or flocking, forming inclined surfaces or curved surfaces, and applying black paint. ing. The first and

second shielding members

610 and 620 may be fixed to the fixed frame 600 with an adhesive or the like.

In the present embodiment, the first inner surface 610S of the first shielding plate 610 is disposed outside the first inner surface S2 of the fixed frame 600 with the second optical axis AX2 as a reference. Similarly, the second inner surface 620S of the second shielding plate 620 is disposed outside the second inner surface S4 of the fixed frame 600 with the second optical axis AX2 as a reference.

Further, as shown in FIG. 4, the first inner surface 610S of the first shielding plate 610 is disposed adjacent to a stepped portion formed by the portion of the fixed frame 600 in which the first through hole T1 is formed. Similarly, the second inner surface 620S of the second shielding plate 620 is disposed adjacent to a step portion formed by the portion of the fixed frame 600 in which the second through hole T2 is formed.

As a result, the light incident downward in the figure is hardly reflected on the first inner surface 610S than the light incident along the solid line in the figure, and is fixed even when a small amount of reflected light is generated. Since the light can be scattered at the step portion formed by the frame 600, the amount of unnecessary light incident on the image sensor 900 can be more effectively reduced.

Furthermore, the first and

second shielding plates

610 and 620 are provided between the shutter unit 400 and the image sensor 900 described above in the second direction along the second optical axis AX2.

As a result, a part of the first and second inner surfaces S2 and S4, which are likely to receive the strongest light inside the fixed frame 600, has a reflectance higher than that of the first and second inner surfaces S2 and S4. The first and second

inner surfaces

610S and 620S of the first and

second shielding members

610 and 620 having a low height can be replaced.

As a result, the amount of unnecessary light incident on the image sensor 900 can be effectively reduced.
The fourth group frame 700 holds a focus lens group L6 having a focus adjusting action. The fourth group frame 700 is slidably held in the second direction inside the fixed frame 600. The fourth group frame 700 is disposed on the image sensor 900 side of the image blur correction lens L5. The fourth group frame 700 is driven by the focus motor 800.

The focus motor 800 is attached to the side surface of the fixed frame 600. A shield plate 810 is attached to the lower end surface of the focus motor 800.

The shield plate 810 is made of a high permeability material. The shield plate 810 shields the lines of magnetic force generated from the focus motor 800 from going to the image sensor 900.

The image sensor 900 is bonded and fixed to the sheet metal 910. The sheet metal 910 is fixed to the lower end portion of the fixed frame 600 with the shielding member 930 interposed therebetween. The image sensor 900 is electrically connected to the flexible printed circuit board 920.

[2. Arrangement relationship between through hole and focus lens group]
Next, the positional relationship between the first and second through holes T1, T2 and the focus lens group L6 will be described with reference to FIG. 3 is a view taken in the direction of arrows III-III in FIG.

As shown in FIG. 3, the focus lens group L6 has a first curved face M1, a second curved face M2, a first plane N1, and a second plane N2.

The first and second planes N1, N2 are each perpendicular to the first direction along the first optical axis AX1. That is, the first plane N1 is substantially parallel to the first inner surface S2 of the fixed frame 600 and the first inner surface 610S of the first shielding plate 610. The second plane N2 is substantially parallel to the second inner surface S4 of the fixed frame 600 and the second inner surface 620S of the second shielding plate 620.

As described above, since the focus lens unit L6 includes the first and second planes N1 and N2, the focus lens unit L6 is reduced in size and the lens barrel 1 is reduced in thickness in the first direction along the first optical axis AX1. Is realized.

In general, unnecessary light emitted from the focus lens group L6 tends to be strong on the first and second inner surfaces S2 and S4 of the fixed frame 600 facing the first and second planes N1 and N2. .

[3. Summary]
(1)
The lens barrel 1 according to the embodiment includes a fixed frame 600 and a first shielding plate 610. The fixed frame 600 has a first through hole T1 formed in a wall extending in the second direction. The first shielding plate 610 is disposed so as to block the first through hole T1 from the first outer surface S1 of the fixed frame 600. The light reflectance of the first inner surface 610S exposed in the fixed frame 600 of the first shielding plate 610 is lower than the light reflectance of the first inner surface S2 of the fixed frame 600.

As described above, since the first shielding plate 610 is provided as a member different from the fixed frame 600, the material of the first shielding plate 610 is used regardless of whether or not it is suitable as the material of the lens barrel 1. Can be widely selected.

Also, it is easier to perform processing for reducing the light reflectivity on the first inner surface 610S of the first shielding plate 610 than when forming a groove or the like on the first inner surface S2 of the fixed frame 600 using a mold. Therefore, since unnecessary light emitted from the focus lens group L6 can be efficiently reduced by the first shielding plate 610, the occurrence of flare and ghost can be effectively suppressed.

In addition, since the first through hole T1 is closed by the first shielding plate 610, it is possible to suppress the entry of dust and light into the lens barrel 1 through the first through hole T1.

(2)
The first inner surface 610S of the first shielding plate 610 is disposed outside the first inner surface S2 of the fixed frame 600 with the second optical axis AX2 as a reference.

Therefore, as shown in FIG. 4, a recess 605 having the first inner surface 610S as a bottom surface is formed in the first inner surface S2. Therefore, the luminous flux P1 of unnecessary light (see solid line arrow) reflected in a small amount on the first inner surface S2 having low reflectivity is used as unnecessary light (dotted arrow in the conventional configuration in which the concave portion 605 is not formed on the first inner surface S2. Reference) light flux P2.

As a result, unnecessary light incident on the image sensor 900 can be reduced, so that occurrence of flare and ghost can be further suppressed.

(3)
The first through hole T1 is formed in the first inner surface S2 of the fixed frame 600 that is substantially parallel to the first plane N1 of the focus lens group L6.

Therefore, of the unnecessary light emitted from the focus lens group L6, particularly strong light can be received by the first inner surface 610S of the first shielding plate 610. Therefore, since unnecessary light can be reduced on the first inner surface 610S having a low reflectance, it is possible to effectively suppress the occurrence of significant flare and ghost.

(4)
The first shielding plate 610 is disposed in a recess 602 formed in the first outer surface S1 of the fixed frame 600.

Therefore, since the amount of the first shielding plate 610 attached from the outside of the fixed frame 600 protrudes from the outer peripheral surface of the fixed frame 600 can be reduced, the size of the lens barrel 1 can be reduced.

[4. Other Embodiments]
(A)
In the above embodiment, the fixed frame 600 has the first and second through holes T1 and T2. However, the present invention is not limited to this.

For example, as shown in FIG. 5, the fixed frame 600 does not have a through-hole, and the first and

second shielding members

610 and 620 are attached to the inner surfaces S2 and S4 of the fixed frame 600, respectively. May be. Even in this case, since the reflectance of the

inner surfaces

610S and 620S of the first and second shielding members 610.620 is lower than that of the inner surfaces S2 and S4 of the fixed frame 600, the same effect as in the above embodiment can be obtained.

Alternatively, there may be a configuration in which only one or three or more through holes are provided and a shielding member is provided so as to close each through hole.

(B)
In the above embodiment, the first and second through holes T1 and T2 are formed on the wall of the fixed frame 600 that is orthogonal to the first optical axis AX1, but the present invention is not limited to this.

For example, the first and second through holes T1 and T2 may be formed on the wall surfaces of the fixed frame 600 parallel to the first optical axis AX1, respectively.

(C)
In the above embodiment, the first and

second shielding members

610 and 620 are not inserted into the first and second through holes T1 and T2. However, the present invention is not limited to this.

For example, a part of the first and

second shielding members

610 and 620 may be inserted into the first and second through holes T1 and T2. In this case, the first and second

inner surfaces

610S and 620S may protrude inward from the first and second inner surfaces S2 and S4.

(D)
In the above embodiment, the first and second through holes T1 and T2 are formed in the fixed frame 600. However, the present invention is not limited to this.

For example, the first and second through holes T1 and T2 may be formed in the first group frame 100, the second group frame 200, or the third group frame 520. In this case, the first and second through holes T1 and T2 may be formed in the first group frame 100 between the front lens group L1 and the prism L2.

(E)
Although not particularly mentioned in the above embodiment, the light reflectance of the first inner surface S2 of the fixed frame 600 may not be lower than the entire surface of the first inner surface 610S of the first shielding plate 610.

That is, if at least a part of the first inner surface 610S is lower than the light reflectance of the first inner surface S2, a desired effect can be obtained.

(F)
In the above embodiment, the fixed frame 600 in which the first and second through holes T1 and T2 are formed is formed in a rectangular tube shape, but is not limited thereto.

For example, the fixed frame 600 may be formed in a cylindrical shape.
In this case, the first and second through holes T 1 and T 2 only need to be formed on the wall surface of the fixed frame 600 along the second direction.

(G)
In the said embodiment, although the through-holes T1 and T2 were formed in the side surface of the fixed frame 600, it is not limited to this.

For example, a notch or the like may be formed in a part of the fixed frame instead of the through hole, and the notch or the like may be blocked by a shielding member.

According to the technology disclosed herein, a lens barrel capable of suppressing flare and ghost can be provided, and thus can be applied to, for example, a camera, a mobile phone with a camera, a portable terminal with a camera, and the like.

DESCRIPTION OF SYMBOLS 1 Lens barrel 100 1st group frame 200 2nd group frame 300 Zoom motor 400 Shutter unit 500 Image blur correction unit 510 Movable frame 520 3rd group frame 600 Fixed frame (frame body)
601 Light blocking portion 602 Recessed portion 610 First shielding plate 610S First inner surface 620 Second shielding plate 620S Second inner surface 700 Fourth group frame 800 Focus motor 810 Shield plate 900 Imaging element 910 Sheet metal 920 Flexible printed circuit board 930 Shielding member AX1 First light Axis AX2 Second optical axis L1 Front lens group L2 Prism L3 Fixed lens L4 Zoom lens group L5 Image blur correction lens L6 Focus lens group L7 Fixed lens group M1 First curved surface M2 Second curved surface N1 First plane N2 Second plane P1 Light beam S1 First outer surface S2 First inner surface S3 Second outer surface S4 Second inner surface T1 First through hole T2 Second through hole

Claims

In a lens barrel that bends light incident along a first optical axis by a reflecting member into light along a second optical axis that is substantially orthogonal to the first optical axis.
A frame through which the second optical axis guided by a plurality of lenses passes;
A shielding member attached to the frame, having an inner surface exposed to the inside through which the second optical axis passes, wherein at least a part of the inner surface has a light reflectance lower than that of the inner surface of the frame;
Lens barrel with
The inner surface of the shielding member exposed in the frame is disposed outside the second optical axis from the inner surface of the frame;
The lens barrel according to claim 1.
The frame body has a through hole in an inner wall surface along the second optical axis,
The shielding member is attached so as to close the through-hole,
The lens barrel according to claim 1 or 2.
The shielding member is attached to the frame so as to close the through hole from the outside of the frame.
The lens barrel according to claim 3.
The inner surface of the shielding member is disposed at a position adjacent to a step portion formed in the vicinity of the through hole of the frame body.
The lens barrel according to claim 3 or 4.
The shielding member is provided at a position where strong light is incident in the frame.
The lens barrel according to any one of claims 1 to 5.
A shutter unit and an image sensor;
The shielding member is provided between the shutter unit and the imaging element in the frame.
The lens barrel according to claim 6.
The portion having low light reflectance in the shielding member is formed with fine irregularities, inclined surfaces, curved surfaces, grooves or flocks, or black paint is applied,
The lens barrel according to any one of claims 1 to 7.