JP2020086201A - Lens device and imaging apparatus - Google Patents

Abstract

To provide a lens device capable of reducing the discomfort of the shape of a blur and suppressing the decrease of a peripheral light quantity and to provide an imaging apparatus including the lens device.SOLUTION: The lens device includes a plurality of lens units which are held by holding members different from each other, a contact member for electrically connecting to the imaging apparatus, and a light-shielding member which is arranged between the end surface on the object side of a final lens unit located on the most image side among the plurality of lens units and the end surface on the image side of the contact member, in the optical axes of the plurality of lens units and is for suppressing the quantity of a luminous flux shielded by the contact member.SELECTED DRAWING: Figure 7

Description

The present invention relates to a lens device and an imaging device including the lens device.

Conventionally, in a lens barrel such as an interchangeable lens, an optical system in which a flare cut is arranged is used in order to reduce harmful light such as ghost and flare. Patent Document 1 discloses a flare cut member in which the shape of an opening through which a light flux passes is rotationally symmetrical.

International Publication No. 2016/121033

In the configuration in which the lens barrel and the camera are electrically connected to communicate with each other, the electrical connection portion provided on the lens barrel is located at a position corresponding to the short side of the rectangular imaging surface from the viewpoint of space efficiency. Will be placed. Further, the electrical connection portion is configured in the same shape as the electrical connection portion provided on another lens barrel so that the camera can attach a plurality of lens barrels. In such a state, in the configuration in which the lens diameter is large and the light beam is incident at a large angle, the peripheral light amount is reduced by the electrical connection portion, and the light beam is partially vignetted, so that the shape of the blur is uncomfortable. May take shape. When the configuration of Patent Document 1 is used, the peripheral light amount is reduced even in the phase other than the electrical connection portion.

It is an object of the present invention to provide a lens device capable of reducing a sense of discomfort in the shape of blur and suppressing a decrease in the amount of peripheral light, and an imaging device including the lens device.

A lens device according to one aspect of the present invention includes a plurality of lens units held by different holding members, a contact member for electrically connecting to an imaging device, and a plurality of lens units in the optical axis direction of the plurality of lens units. Of the last lens unit, which is located closest to the image side, of the second lens unit and the image-side end surface of the contact member, and the light blocking for suppressing the amount of light flux blocked by the contact member And a member.

According to the present invention, it is possible to provide a lens device capable of reducing a sense of discomfort in the shape of a blur and suppressing a decrease in peripheral light amount, and an imaging device including the lens device.

It is a schematic diagram of an imaging device which has a lens barrel concerning an embodiment of the present invention. It is sectional drawing of a lens barrel. It is an enlarged view of a portion of a lens barrel on a mount side. It is a rear view of a lens barrel. It is an enlarged view of the area|region A of FIG. It is a sectional view of a plurality of lens units provided in a lens barrel. It is a front view of a light shielding member. It is a figure which shows the range where the image height of an imaging surface is high. It is a figure which shows the shape of the blur in the range where the image height of the upper right of an imaging surface is high. It is a figure which shows the shape of the blur in the range where the image height of the lower left of an imaging surface is high. It is a figure which shows the shape of the blur in the range where the image height of the lower left of an imaging surface is high when a light shielding member is not arrange|positioned. It is a modification of a light shielding member.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each drawing, the same reference numerals are given to the same members, and duplicate description will be omitted.

FIG. 1 is a schematic diagram of an image pickup apparatus IA having a lens barrel (lens device) 100 according to an embodiment of the present invention. The lens barrel 100 holds the image pickup optical system IOS. The camera body CB holds an image pickup element (photoelectric conversion element) IE. The image sensor IE photoelectrically converts the optical image formed via the lens barrel 100. The lens barrel 100 may be configured integrally with the camera body CB, or may be configured to be detachably attached to the camera body CB. Further, the lens barrel 100 may hold the image pickup element IE.

FIG. 2 is a sectional view of the lens barrel 100. FIG. 3 is an enlarged view of the mount side portion of the lens barrel 100. FIG. 4 is a rear view of the lens barrel 100. FIG. 5 is an enlarged view of the area B in FIG. FIG. 6 is a sectional view of a plurality of lens units provided in the lens barrel 100.

In this embodiment, the plurality of lens units includes the first lens unit L1, the second lens unit L2, and the third lens unit (final lens unit) L3, and the distance between adjacent lens units during zooming or focusing is small. It is configured to change. Note that focusing may be performed by moving out the plurality of lens units as a whole while maintaining a distance between adjacent lens groups. Further, in the present embodiment, it is desirable that the F values of the plurality of lens units be 2.0 or less. It is more desirable that the F values of the plurality of lens units be 1.5 or less.

The first lens holding frame 1 is a holding member that holds the first lens group L1, and is fixed to the tip of the guide cylinder 5 with a screw. The second lens group L2 is a focus group that moves along the optical axis direction of the plurality of lens units, and is composed of lens groups L2a and L2b. The lens holding frame 2a is a holding member that holds the lens unit L2a, and is held by a cam ring 4 held on the outer peripheral side of the guide cylinder 5 by a roller. The lens holding frame 2b is a holding member that holds the lens unit L2b. The third lens holding frame 3 is a holding member that holds the third lens group L3 that includes the lens G1 that is arranged closest to the image side (mount side) among the lenses included in the plurality of lens units. It is fixed with screws.

The guide cylinder 5 is fixed to the exterior ring 11 with screws. The diaphragm device 6 is fixed to the lens holding frame 2a. The diaphragm device 6 includes a motor (not shown) as a drive source, and when the motor is driven, the aperture area of the diaphragm blade incorporated therein is changed to adjust the light amount. The substrate 7 is fixed to the exterior ring 11 with screws. Electronic components are mounted on the board 7, and the microcomputer mounted on the board 7 performs various drive controls. The substrate 7 is electrically connected to the diaphragm device 6 and a contact member 9 described later.

The mount 8 is fixed to the exterior ring 11 with screws. On the outer periphery of the mount 8, a claw portion that is bayonet-connected to the camera body CB is provided. In this embodiment, the lens barrel 100 is detachably attached to the camera body CB via the mount 8. The contact member 9 is arranged at a position corresponding to the short side of the image pickup surface of the image pickup element IE on the inner periphery of the mount 8 from the viewpoint of space efficiency, and is fixed to the mount 8 with a screw. The contact member 9 has a contact portion that is electrically connected to a contact portion (not shown) provided in the camera body CB when the lens barrel 100 is attached to the camera body CB. By connecting the contact portions of the lens barrel 100 and the camera body CB, the lens barrel 100 can communicate with the camera body CB and receive power supply from the camera body CB. The back cover 10 is fixed to the mount 8 with screws from the circumferential direction. In the present embodiment, the case back 10 is fixed to the mount 8 similarly to the contact member 9, and is therefore treated as a part of the contact member 9. The light blocking member 12 is arranged between the subject-side (object-side) end surface of the third lens unit L3 and the image-side end surface of the contact member 9 (range A in FIG. 2) in the optical axis direction, and the third lens It is fixed to the holding frame 3. The light blocking member 12 blocks a part of the light flux reaching the peripheral image height so as to suppress the amount of the light flux blocked by the contact member 9. By disposing the light shielding member 12, the light flux incident on the image sensor IE is determined by the light shielding member 12 instead of the member in the vicinity of the contact member 9. That is, the shape of the blur in the high image height range is determined by the shape of the inner circumference of the light shielding member 12. It is more desirable that the light blocking member 12 is disposed between the subject-side end surface of the contact member 9 and the image-side end surface of the contact member 9 in the optical axis direction.

Hereinafter, the configuration of the light shielding member 12 will be described with reference to FIG. 7. FIG. 7 is a front view of the light shielding member 12. The light shielding member 12 is formed so as to be substantially line-symmetrical to a straight line 13 that is parallel to the short side of the image pickup surface and that passes through the centers of the optical axes of the plurality of focus lenses. The inner circumference of the light shielding member 12 has a first arc of a radius (first value) R1 centered on the optical axis and a second arc of a radius (second value) R2 longer than the radius R1 centered on the optical axis. , And a connecting portion C connecting the first circular arc and the second circular arc. The connecting portion C is formed by a straight line or a curved line.

FIG. 8 is a diagram showing a range in which the image height of the imaging surface is high. FIG. 9 is a diagram showing a blur shape 16 in the lower left area 14a of the image pickup surface of FIG. 8 in which the image height is high. FIG. 10 is a diagram showing a blur shape 17 in the upper right range 15a of the imaging surface of FIG. The blurring shape 16 of the range 14a is determined by the first circular arc on the inner circumference of the light shielding member 12 and the connecting portion C. The blurring shape 17 of the range 15a is determined by the second circular arc on the inner circumference of the light shielding member 12. Note that the shape of the blur on the lower right side of the imaging surface in the high image height range 14b is bilaterally symmetrical with the shape of the blur 16. Further, the shape of the blur in the upper left area 15b of the image pickup surface where the image height is high is symmetrical with the shape of the blur 17.

If the light shielding member 12 is not arranged, for example, the shape of the blur on the lower left side of the imaging surface in the range where the image height is high is the inner peripheral shapes 18 and 19 of the case back 10 and the third lens holding frame 3. It is determined by the shape 20 of the inner circumference and becomes the blur shape shown in FIG. 11. The blur shapes 21, 22, and 23 correspond to the inner peripheral shapes 18 and 19 of the back cover 10 and the inner peripheral shape 20 of the third lens holding frame 3, respectively. The shape of the blur shown in FIG. 11 is a shape with a sense of discomfort because there are angular portions.

In the present embodiment, as described above, the shape of the blur in the high image height range is determined by the shape of the inner circumference of the light shielding member 12. Since there are no angular portions on the inner circumference of the light shielding member 12, the blurring shapes 16 and 17 have a shape that does not cause a feeling of strangeness. Further, the difference between the blur shapes 16 and 17 becomes inconspicuous. Further, as compared with the decrease in the peripheral light amount in the range 14a corresponding to the first circular arc having the radius R1, it is possible to reduce the decrease in the peripheral light amount in the range 15a corresponding to the second circular arc having the radius R2 longer than the radius R1.

Further, in the present embodiment, the inner periphery of the light shielding member 12 is configured to completely eliminate the discomfort of the shape of the blur near the contact member 9, that is, to completely shield the light flux reaching the contact member 9. However, the present invention is not limited to this. Compared with the discomfort in the shape of the blur when the light shielding member 12 is not arranged, the discomfort in the shape of the blur is lessened, that is, at least a part of the light flux reaching the contact member 9 is shielded. Good.

Further, in the present embodiment, the shape of the light shielding member 12 is a circular shape as shown in FIG. 7, but as shown in FIG. 12, the first arc and the arc on the side opposite to the connecting portion A1 side are eliminated. It may have a semicircular shape. Also in this case, the light shielding member 12 is formed so as to be substantially line-symmetric with respect to the straight line 13 which is parallel to the short side of the imaging surface and passes through the center of the optical axis. As a result, it is possible to further suppress the reduction in the amount of peripheral light while reducing the discomfort in the shape of the blur.

As described above, according to the configuration of the present embodiment, it is possible to provide a lens device that can reduce a sense of discomfort in the shape of blur and suppress a decrease in peripheral light amount, and an imaging device including the lens device.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof.

1 First lens holding frame (holding member)
2a Lens holding frame (holding member)
2b Lens holding frame (holding member)
3 Third lens holding frame (holding member)
9 Contact member 10 Back cover (contact member)
12 Light-shielding member 100 Lens barrel L1 First lens group L2 Second lens group L3 Third lens group

Claims (9)

A plurality of lens units held by different holding members,
A contact member for electrically connecting to the imaging device,
In the optical axis direction of the plurality of lens units, the plurality of lens units are arranged between the object-side end surface of the final lens unit located closest to the image side and the image-side end surface of the contact member, And a light blocking member for suppressing the amount of light flux blocked by the contact member. The inner circumference of the light shielding member has a first arc having a radius of a first value centered on the optical axes of the plurality of lens units and a second arc longer than the first value centered on the optical axes. The second circular arc having a radius as a value, and a connecting portion that connects the first circular arc and the second circular arc and is formed by a straight line or a curved line. Lens device. The lens device according to claim 1, wherein the light blocking member has a circular shape. The lens device according to claim 1, wherein the light blocking member has a semicircular shape. The lens device according to claim 1, wherein the light blocking member blocks a part of the light flux reaching the peripheral image height. 6. The light-shielding member is arranged between an object-side end surface of the contact member and an image-side end surface of the contact member in the optical axis direction. The described lens device. 7. The lens device according to claim 1, wherein the F values of the plurality of lens units are 2.0 or less. The lens device according to claim 1, wherein the F values of the plurality of lens units are 1.5 or less. The lens device according to claim 1,
An image pickup device, comprising: a camera body that holds an image pickup element that photoelectrically converts an optical image formed through the lens device.