JP2016081024A - Imaging optical system device and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To propose enabling one interchangeable lens to be directly attached to respective cameras by preventing the occurrence of inconvenience such as the impossibility of attachment, the requirement of an intermediate device (adaptor) and changing of the maximum view angle when photographed using one interchangeable lens for a lens interchangeable camera which is different in flange back or image size.SOLUTION: There is provided an optical system device which, in an optical system, is constituted of at least two or more lens groups and in which an image forming position is made to be varied or the view angle is made to be equal by moving one or more lens groups in two or more lens groups on an optical axis and varying the distance between at least one or more lens groups before and after movement. The optical system device is directly attached to at least two or more imaging apparatuses which are different in flange back or an image size.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an imaging optical system device and an imaging device.

  Conventionally, in a lens interchangeable lens device and a camera device to which the lens device is attached, lens devices that can be mounted on the one camera device have been dedicated.

  In order to attach a lens device other than a dedicated lens to the camera device, at least an intermediate device (adapter) is required because the flange back is different, or a lens device for a short flange back camera device is a long flange back camera device. It was not possible to attach to. Alternatively, the maximum angle of view changes when mounted on camera devices having different image sizes (Non-Patent Document 1).

  Also, there is a proposal for an intermediate adapter that can automatically adjust the difference between the replacement lens and the flange back of the camera body when a replacement lens with a different mount form or flange back is mounted on the camera body (Patent Document). 1).

  Hereinafter, the conventional method will be described with reference to FIG. FIG. 1A shows a single-lens reflex camera system 100 in which an interchangeable lens 102 is attached to a camera body 103. The camera body 103 includes a quick return mirror 110 and an image sensor 120, and has a flange back FB1.

  FIG. 1B shows a mirrorless camera system 200 in which an interchangeable lens 102 and an intermediate device (adapter) are mounted on a camera body 203. The camera body 203 includes an image sensor 220 and has a flange back FB2. In general, FB1> FB2. An intermediate device (adapter) between the camera body 203 and the interchangeable lens 102 has a length AL, and has a relationship of FB1 = FB2 + AL.

  Canon Inc. EF Lens Catalog 2014.4.9 29, 30

  JP 2012-155026 A

  Conventionally, when an interchangeable lens device is mounted on a flange-back or an interchangeable lens camera having a different image size, it cannot be mounted or is mounted via an intermediate device (adapter). Or, the maximum angle of view when the lens system was attached to each camera was different.

  An object of the present invention is to eliminate the above-described problems and enable a normal camera-lens relationship.

  In the optical system, the optical system includes at least two or more lens groups, and one or more lens groups among the two or more groups move on the optical axis, and at least one or more before and after the movement. Is an optical system device that changes the imaging position by changing the lens group spacing, and directly attaches the optical system device before and after the movement to at least two or more imaging devices having different flange backs, It is something to shoot.

  More specifically, the lens unit is composed of at least three groups, and the one or more lens groups move on the optical axis. The focal length of the optical system after the movement is substantially the same.

  Or, it is composed of at least two groups, and one or more lens groups among the two or more groups move on the optical axis, and the image sizes of at least two or more imaging devices having different flange backs are different. The maximum angle of view when the optical system having the configuration before and after the movement is mounted on the imaging apparatus is substantially the same with respect to the change in the imaging position in the configuration before and after the movement.

  More specifically, the imaging devices having different flange backs are a lens interchangeable single lens reflex camera and a lens interchangeable mirrorless camera. Alternatively, the imaging devices having different flange backs are interchangeable lens cameras having different image sizes.

  In the optical system, at least two or more lens groups are formed, and one or more lens groups of the two or more groups move on the optical axis, and at least one or more lenses before and after the movement. An optical system apparatus in which the group interval changes, and the maximum angle of view when the optical system having the configuration before and after the movement is mounted on at least two imaging apparatuses having different image sizes is substantially the same. Are the same.

  In the present invention, when one lens interchangeable lens apparatus is mounted on two or more interchangeable lens cameras having different flange sizes or image sizes, the maximum image when mounted can be directly mounted on each camera. Each corner is the same.

It is a schematic diagram which shows the prior art example when attaching one interchangeable lens to two cameras with different flange backs. It is a schematic diagram which shows the relationship which mounts two cameras from which one interchangeable lens and flange back in 1st embodiment of this invention differ. It is a figure which shows the relationship which mounts two cameras from which one interchangeable lens and flange back in 2nd embodiment of this invention differ. It is a schematic diagram explaining the lens group used by this invention.

  FIG. 1A, which is the first embodiment of the present invention, shows a single-lens reflex camera system 400, in which an interchangeable lens 402 (a) is attached to a camera body 403.

  The camera body 403 includes a quick return mirror 410 and an image sensor 420, and the flange back FB1 is 50 mm.

    The interchangeable lens 402 (a) has three lens groups, a first lens group 461, a second lens group 462, and a third lens group 463, and the back focus bf1 is 169.7 mm, and the axial luminous flux 450 forms an image on the image sensor 420. The focal length f of this lens is 163.9 mm.

  FIG. 2B shows a mirrorless camera system 500 in which the interchangeable lens 402 (b) is attached to the camera body 503.

The camera body 503 includes an image sensor 520, and the flange back FB2 is 13.1 mm.

  At this time, in the interchangeable lens 402 (b), the second lens group is moved on the optical axis to the image sensor side relative to the state of FIG. The back focus bf2 is 132.8 mm, and the axial light beam 550 forms an image on the image sensor 620. The focal length f of this lens is 163.9 mm, which is the same as the state (a).

  In this case, it is desirable that the image sensor 420 and the image sensor 520 have the same size. Thereby, the maximum angle of view of (a) and (b) becomes the same.

  As described above, when the method of the present invention is used, one interchangeable lens can be directly attached to each of imaging devices having different flange backs. There is no need to install an intermediate device (adapter).

  At this time, even if the second lens group moves on the optical axis, the focal lengths of the interchangeable lenses before and after the movement are the same and do not change.

  FIG. 3A showing a second embodiment of the present invention is a single-lens reflex camera system 600, in which an interchangeable lens 602 is attached to a camera body 603.

  The camera body 603 includes a quick return mirror 610 and an image sensor 620, and the flange back FB1 is 50 mm.

  The interchangeable lens 602 (a) has three lens groups, a first lens group 661, a second lens group 662, and a third lens group 663, the back focus bf1 is 138 mm, and the axial light beam 650 is imaged. An image is formed on the element 620. The focal length f of the interchangeable lens is 140.8 mm, and the size of the image sensor 620 is a diagonal line of 43.2 mm. Therefore, the maximum field angle (2ω) of the interchangeable lens attached to the camera is 17.4 °.

  3B shows a single-lens reflex camera system 700, in which an interchangeable lens 602 (b) is attached to a small camera body 703. FIG. The small camera body 703 includes a quick return mirror 710 and an image sensor 720, and the flange back FB2 is 35.2 mm.

  At this time, in the interchangeable lens 602 (b), the first lens group moves on the optical axis to the object side relative to the state of (a), and the second lens group moves on the optical axis to the image sensor side. 680.

  The back focus bf2 is 123.2 mm, and the axial light beam 750 forms an image on the image sensor 720. The focal length f2 of the interchangeable lens is 101 mm, and the size of the image sensor 720 is a diagonal line of 31 mm. Therefore, the maximum field angle (2ω) of the interchangeable lens attached to the camera is 17.4 °, which is the same as the state of (a).

  As described above, when the system of the present invention is used, one interchangeable lens can be directly attached to each of image pickup apparatuses having different flange backs and different image pickup element sizes. There is no need to install an intermediate device (adapter).

  At this time, a part of the lens group moves on the optical axis, and the maximum angle of view when the interchangeable lens before the movement and the interchangeable lens after the movement are respectively attached to the imaging apparatus is the same.

  In addition, when each image pickup apparatus is different only in image size (size of image pickup element), it can be applied in the same way.

  The embodiment of the present invention uses a paraxial power arrangement lens system. The lens groups shown in FIGS. 2 and 3 do not define a specific number of lenses, but represent the power (1 / f) of one lens group, and the interval between the lens groups is defined by the principal point interval. doing.

Convex lens shape and concave lens shape make power easy to understand.
Therefore, the thickness is not expressed in one lens group as shown in FIG.

  The convergent lens group 901a is equivalent to the symbol 901b, and the divergent lens group 905a is equivalent to the symbol 905b.

  The system of the present invention directly attaches one interchangeable lens and two or more cameras having different flange sizes or image sizes.

  Therefore, the present invention does not prescribe the mount form on which the interchangeable lens and each of the cameras are mounted. However, if the mount form has the same structure, the mount is easy and convenient.

    Next, a paraxial arrangement that is an embodiment of the optical system will be described.

Example (1)
(1) Paraxial arrangement first lens group before lens group movement (convergence) φ1: 0.01 e1: 5
Second lens group (divergence) φ2: −0.015 e2: 20
Third lens group (convergence) φ3: 0.01
φ: Power (1 / f) (1 / mm) e: Principal point focal length f1: 163.9
Back focus bf1: 169.7
Flange back FB1: 50
(2) Paraxial arrangement after moving the lens group The second lens group moves 15 times toward the image plane side.
'e1: 20 e2: 5
Focal length f2: 163.9
Back focus bf2: 132.8
Flange back FB2: 13.1
Unit: mm

Example (2)
(1) Paraxially arranged first lens group before lens group movement (divergence) φ1: −0.01 e1: 10
Second lens group (convergence) φ2: 0.02 e2: 10
Third lens group (divergence) φ3: −0.005
φ: power (1 / f) (1 / mm) e: principal point interval focal length f1: 140.8
Back focus bf1: 138
Flange back FB1: 50
Image sensor size (diagonal): 43.2
Maximum angle of view (2ω): 17.4 (°)
{Circle around (2)} The paraxially-arranged first lens group after moving the lens group moves 15 toward the object side, and the second lens group moves 5 toward the image plane side.
'e1: 30 e2: 5
Focal length f2: 101
Back focus bf2: 123.2
Flange back FB2: 35.2
Image sensor size (diagonal line): 31
Maximum angle of view (2ω): 17.4 (°)
Unit: mm

  Since the present invention can be used in a convenient way if new development of an interchangeable lens and development with relevance to each mount on the camera side can be realized, the present invention can be used sufficiently.

402 (a) Interchangeable lens 402 (b) before moving the lens group of Example 1 Interchangeable lens 403 after moving the lens group of Example 1 single-lens reflex camera (large flange back)
461 First lens group (convergence)
462 Second lens group (divergence)
463 Third lens group (convergence)
503 Mirrorless camera (small flange back)
602 (a) Interchangeable lens 602 before moving the lens group of Example 2 (b) Interchangeable lens 603 after moving the lens group of Example 2 Single-lens reflex camera (large image size)
661 First lens group (divergence)
662 Second lens group (convergence)
663 Third lens group (divergence)
703 SLR camera (small image size)

In addition, when each image pickup apparatus is different only in image size (size of image pickup element), it can be applied in the same way. In this case, the entire first to third lens units may be moved to the image plane side by the numerical value of bf1-bf2 (14.8 mm) with reference to (2) in Example (2) . As a result, the flange back can be 50 mm, which is the same as (1).

Claims (6)

  In the optical system, the optical system includes at least two lens groups, and one or more lens groups among the two or more groups move on the optical axis, and at least one lens group interval before and after the movement. Is an optical system apparatus that makes the imaging position variable by changing the optical system apparatus, wherein the optical system apparatus configured before and after the movement is directly mounted on at least two imaging apparatuses having different flange backs, respectively. An imaging optical system device and an imaging device.   2. The structure according to claim 1, comprising at least three groups, wherein the one or more lens groups move on the optical axis, and before and after the movement with respect to a change in imaging position in a configuration before and after movement. An imaging optical system apparatus and an imaging apparatus, wherein the focal lengths of the optical system configured as described above are substantially the same.   2. The image of at least two or more image pickup devices having different flange backs according to claim 1, wherein the one or more lens groups move on the optical axis, and change in imaging position in a configuration before and after movement. An imaging optical system apparatus and an imaging apparatus having different sizes and having substantially the same maximum angle of view when the optical system apparatus having the configuration before and after the movement is mounted on the imaging apparatus. .   2. An imaging optical system apparatus and an imaging apparatus according to claim 1, wherein the imaging apparatuses having different flange backs are an interchangeable lens single-lens reflex camera and an interchangeable lens mirrorless camera.   2. The imaging optical system apparatus and the imaging apparatus according to claim 1, wherein the imaging apparatuses having different flange backs are interchangeable lens cameras having different image sizes.   In the optical system, the optical system includes at least two lens groups, and one or more lens groups among the two or more groups move on the optical axis, and at least one lens group interval before and after the movement. The maximum angle of view when the optical system apparatus having the configuration before and after the movement is mounted on at least two or more imaging apparatuses having different image sizes is substantially the same. An imaging optical system device and an imaging device,

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