JPH02170148A - Optical device - Google Patents

Abstract

PURPOSE:To improve the positioning accuracy of an auxiliary lens to an optical system and to facilitate operation by supporting the auxiliary lens rotatably so that the lens overlap with >=1 optical system. CONSTITUTION:For example, the rotary ring 40 of the optical device 37 is engaged coaxially and rotatably with a support ring which projects from the main body 10 of a single-lens reflection electronic still camera, and a macrolens 44 as the auxiliary lens is fixed to the lens frame 42 of the ring 40. When normal photography is performed by this camera, the lens 44 is rotated and used so that the lens 44 shifts from a photographic lens 26. For macrophotography, the lens 44 rotates and is positioned in front of the lens 26 in overlapping relation to make light from a object incident on the lens 26 through the lens 44. Consequently, the close-up is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an optical device equipped with an auxiliary lens, for example, an optical device for an electronic still camera equipped with an auxiliary lens.

(Prior Art) Conventionally, cameras have been known that use auxiliary lenses such as macro lenses and teleconverter lenses to change the optical characteristics of a photographing optical system. According to this main camera, the auxiliary lens is supported by a slide frame, and this slide frame is configured to move the auxiliary lens to a position where it overlaps with the photographic optical system.
It is attached to the camera body so that it can slide linearly.

Further, conventionally, an electronic still camera equipped with an auxiliary lens as described above has not been provided.

(Problem to be solved by the invention) However, in the case of a conventional mechanism that linearly moves a slide frame supporting an auxiliary lens, the sliding part between the slide frame and the camera body is processed with high precision. Therefore, it is difficult to accurately align the optical axis of the auxiliary lens and the optical axis of the photographing optical system, and the mechanism tends to be loose. In addition, the slide mechanism is
The entire mechanism is large and requires a large installation space. Therefore, when this main slide mechanism is applied to a compact camera or an electronic still camera, it becomes an obstacle to making the camera more compact. Furthermore, when the slide frame is to be slid during the camera's photographing operation, the handle body must be moved to move the slide frame, resulting in poor operability.

This invention has been made in view of the above points, and its purpose is to easily align an auxiliary optical system with high precision with respect to an optical system provided on the camera body side such as a photographic optical system. Another object of the present invention is to provide an optical device that allows the camera to be easily made compact.

[Structure of the Invention (Means for Solving the Problems) In order to achieve the above object, according to the optical device of the present invention, the auxiliary lens can be used as a photographic lens, an observation lens, a distance measuring window, It is supported so as to be able to pass through a position overlapping with at least one of the optical systems necessary for photographing, such as a white balance detection window, a finder, and a strobe.

Further, according to the present invention, the auxiliary optical system for changing the optical characteristics of a plurality of optical systems such as the photographing optical system and the finder optical system is provided on the rotatable support member, and the auxiliary optical system is linked to the rotation of the support member. It is possible to change the optical characteristics of optical systems such as a photographing optical system, a finder optical system, and other optical systems.

Further, according to the present invention, the barrier portion is rotatably supported by the support member so as to be movable along the movement path including a position overlapping with at least one optical system necessary for photographing.

(Function) According to the above configuration, by rotating the support member, the auxiliary lens moves to a position overlapping the photographing lens, for example,
It acts to change the optical characteristics of the photographic lens. Further, since the support member has a rotatable structure, the support member can be easily and accurately processed. Accordingly, it becomes possible to accurately align the auxiliary lens with respect to the photographic lens. Furthermore, for the same reason, the mechanism can be made more compact.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a single-lens reflex electronic still camera to which an optical device according to an embodiment of the present invention is applied. The electronic still camera includes a camera body 10 having a substantially rectangular box shape. One side wall of the camera body 10 has an insertion slot 12 for inserting a floppy disk (not shown) as a magnetic recording medium into a disk drive device (not shown) provided inside the camera body, and An eject button 14 is provided for ejecting a floppy disk from the disk drive. A zoom switch 16 and a release switch 18 are mounted on the earthen wall of the camera body 10.
is provided. A strobe window 20 and a white balance detection window 22 are provided on the front wall of the camera body 10.

In addition, as shown in FIGS. 1 and 2, the camera body 1
A lens barrel 24 is fixed to the front wall 10a of the camera 0 and extends into the camera body from the front wall 10a. Lens barrel 24
Inside, a photographic lens 26 consisting of three lenses, a half prism 28, an optical low-pass filter 30, and an image sensor 32 are fixed in order. Note that the image sensor 32 is attached to the lens barrel 24 via a substrate 34, and this substrate is provided so that the inclination and focal position of the image sensor with respect to the photographic lens 26 can be adjusted.

A portion of the light that enters the lens barrel 24 through the photographing lens 26 passes through the half prism 28 and the low-pass filter 30, and then forms an image on the light-receiving surface of the imaging probe 32. A part of the light passing through the photographing lens 26 is deflected by the Hough prism 28 in a direction perpendicular to the optical axis of the photographing lens, and then reflected by the mirror 36 and guided to a finder optical system (not shown).

A support ring 38 projecting outward is integrally formed on the front wall Oa of the camera body 10. The support ring 38 is formed such that its central axis is eccentric and parallel to the optical axis of the photographic lens 26, and is arranged such that the photographic lens 26 is located inside the support ring 38. ing.

As shown in FIGS. 1 to 5, an optical device 37 according to an embodiment of the present invention is attached to the support ring 38. As shown in FIGS. The optical device 37 includes a rotary ring 40 having a diameter equal to that of the support ring 38, and this rotary ring is coaxially and rotatably fitted to the support ring. Therefore, the rotating ring 40 is rotatable around an axis A that is eccentric and parallel to the optical axis of the photographic lens 26. Note that an O-ring 41 is installed between the support ring 38 and the rotation ring 40. A lens frame 42 is integrally formed with the rotating ring 40, and a macro lens 44 as an auxiliary lens is fixed to this lens frame. When the macro lens 44 rotates together with the rotating ring 40 around the axis A so that its leading axis B is parallel to the optical axis C of the photographing lens 26, the trajectory 46 of the optical axis B is the same as that of the photographing lens. It is supported by a rotating ring 40 and a lens frame 42 so as to pass through an optical axis C of the lens. Then, the rotating ring 40 is held by a holding means (not shown), such as a click mechanism, to hold the macro lens 44 as shown in FIG.
The macro lens is configured to be able to be elastically held in a non-operating position where the macro lens is positioned offset from the photographing lens 26, and an operating position where the macro lens is positioned coaxially with the photographing lens as shown in FIG.

In this way, the rotating ring 40 and the lens frame 42 constitute a support member in this invention.

Further, the tip opening of the rotating ring 40 is closed by a circular protective glass 48 fixed to the rotating ring. As can be clearly seen from FIG. 3, the peripheral edge of the protective glass 48 is pressed onto the rotating ring 40 via an O-ring 52 by an annular retaining ring 50 fitted to the tip of the rotating ring 40.

This O-ring 52 and the above-mentioned O-ring 41
The inside of the rotating ring is completely waterproof. In addition,
Support ring 38 forms part of optical device 37 .

Next, the operation of the optical device 37 configured as above will be explained.

As shown in FIG. 4, during normal photographing with an electronic still camera, the rotating ring 40 is rotated so that the macro lens 44 is in contact with the photographing lens 2.
It is rotated to a non-operating position located offset from 6. Therefore, the light from the subject enters the photographic lens 26 without passing through the macro lens 44, and is imaged on the light receiving surface of the image sensor 32 by this photographic lens.

On the other hand, during macro photography, as shown in FIG. 5, the rotating ring 40 is rotated from the non-operating position to the operating position. Thereby, the macro lens 44 is located in front of the photographic lens 26 and overlaps with the photographic lens.

In other words, the macro lens 44 is in a state where its front axis B coincides with the optical axis C of the photographic lens 26. Therefore, light from the subject passes through the macro lens 44 to the photographic lens 2.
As a result, macro photography, that is, close-up photography becomes possible.

According to the optical device configured as described above, it is possible to set a state in which macro photography is possible by simply rotating the rotary ring 40, and when photographing, the rotary ring can be rotated with only a fingertip. Operability can be improved. Furthermore, since the movement of the macro lens 44 is performed by the rotating ring 40 that is rotatably provided, the sliding contact portion that serves as a reference for positioning the macro lens, that is, the outer circumferential surface of the proximal end of the rotating ring and the support ring 38 The inner circumferential surfaces of both are formed of circumferential surfaces. Further, a circumferential surface can be processed with much higher precision and easier than a flat surface.

Therefore, it is possible to reliably prevent backlash occurring in the sliding contact portion, and to position the macro lens 44 with high precision. As a result, during macro photography, the macro lens 44
The optical axis of the photographing lens 26 can be made to coincide with the optical axis of the photographing lens 26 with high accuracy, and the capabilities of these lenses can be fully demonstrated. Furthermore, in the case of a structure in which the macro lens 44 is moved by the rotational movement of a rotating ring, compared to a conventional structure in which the macro lens is moved in a straight line,
The entire mechanism can be made smaller, and the camera can be made more compact.

In the above embodiments, the auxiliary lens is not limited to the macro lens, but other lenses such as a teleconverter lens or a wide converter lens may be used. Further, by making the rotating ring 40 detachable from the support ring 38, the optical device 37 may be treated as an optional part of the electronic still camera.

6 and 7 show an embodiment in which the optical device is adapted to a single-lens type, so-called compact electronic still camera.

Note that the same parts as in the first embodiment are given the same reference numerals and detailed explanation thereof will be omitted.

The camera body 10a is provided with a photographing lens 26, a finder lens 54, a circular strobe window 20, and a pair of distance measuring windows 56a and 56b, which are located inside the support ring 38. Photographing lens 26 and finder lens 5
4 are provided such that these optical axes are perpendicular to a circle 58 concentric with the center axis of the support ring 38 and are spaced apart by a predetermined distance along the circle 58.Similarly, the strobe window 20 is
It is provided so that its central axis is perpendicular to the circle 58 and is spaced apart from the finder lens by a predetermined distance along the circle 58. Further, the distance measuring windows 56a and 56b are arranged so that their central axes are perpendicular to a circle 60 that is concentric with the center axis of the support ring 38 and has a smaller diameter than the circle 58, and are spaced apart by a predetermined interval along the circle 60. It is provided.

Rotating ring 40 of optical device 37 acting as operating member
is fitted into the support ring 38 so as to be rotatable around the central axis. Protective glass 4 fixed to rotating ring 40
8 has a macro lens 44 as a correction lens,
Finder correction lens 62, circular strobe correction plate 64
, a pair of circular barriers 66a, 66b1, and a pair of distance measurement correction lenses 68a, 68b are attached. The macro lens 44 and the finder correction lens 62 are provided so that their optical axes are perpendicular to the circle 58, and similarly,
The strobe correction plate 74 is provided so that its central axis is orthogonal to the circle 58. Macro lens 4 along circle 58
4. The mutual spacing between the finder correction lens 62 and the strobe correction plate 64 is set to be the same as the mutual spacing between the photographing lens 26, the finder lens 54, and the strobe window 20 provided on the camera body 10 side. The barriers 66a, 66b are
These central axes are arranged perpendicular to the circle 58, and the distance between the barriers along the circle 58 is equal to the circle 58.
This corresponds to the distance between the photographing lens 26 and the finder lens 54 along the line. Note that the barrier 66b is located between the macro lens 44 and the finder correction lens 62. Further, the 11-axis distance correction lenses 68a and 68b are provided so that their optical axes are perpendicular to the circle 60 and spaced apart from each other by a predetermined distance along the circle 60. Distance correction lens 6
The distance between 8a and 68b is the distance measurement window 56a along the circle 60,
56b.

The rotating ring 40 is rotated counterclockwise by a predetermined angle from the normal photographing position E shown in FIG. They are each configured to be able to be temporarily held at a stop position G rotated clockwise by a predetermined angle from E.

Next, the operation of the second embodiment configured as above will be explained.

During normal photographing, the rotating ring 40 is held at the normal photographing position E shown in FIG. In this position, the macro lens 44, finder correction lens 62, strobe correction plate 64, barriers 66a, 66bl, and distance measurement correction lens 6
8a and 68b are the photographing lens 26, the finder lens 54, the strobe window 20, and the distance measuring windows 55a and 5, respectively.
It is located circumferentially offset from 6b. Therefore, the light from the object does not pass through the various lenses attached to the protective glass 48, but instead enters the photographic lens 26, the finder lens 54.7II, and the distance windows 56a, 56b. Further, when a strobe is used, the light emitted from the strobe is diffused to the outside without passing through the strobe correction plate 64.

During macro photography, when the rotating ring 40 is rotated to the macro photography position F, the macro lens 44 moves to a position where it overlaps with the photography lens 26, that is, to a position where its optical axis coincides with the optical axis of the photography lens. Thereby, light from the subject enters the photographing lens 26 through the macro lens 44, allowing close-up photography. Further, at the same time that the macro lens 44 overlaps with the photographing lens 26, the funda correction lens 62,
Strobe correction plate 64, nj distance correction lenses 68a, 68b
are the finder lens 54, the strobe window 20, and
It moves to a position coaxial with the distance measuring windows 56a and 56b. The finder correction lens 62 prevents variations in the finder lens 54 and corrects the field of view in accordance with macro photography. Similarly, 71III distance correction lenses 68a, 68b
This prevents variation in the distance measuring device (not shown) and enables autofocus during macro photography. Further, the strobe correction plate 64 reduces the amount of light emitted from the strobe to prevent overexposure. or,
The strobe correction plate 64 may be composed of a diffusion lens to deflect the direction of light emitted from the strobe.

When the rotating ring 40 is rotated to the stop position G, the barrier 6
6a and 66b are moved to positions overlapping with the photographing lens 26 and the finder lens 54, respectively. At the same time, a changeover switch (not shown) linked to the rotation ring 40 turns off the power of the camera. And barrier 6
6a blocks light entering the photographing lens 26, thereby preventing excessive light from entering the imaging probe when the camera is stopped, thereby protecting the imaging element. Furthermore, the barrier 66b blocks light from entering the finder lens 54. As a result, the camera operator cannot see the subject through the finder and can immediately recognize that the camera is powered off.

At the stop position G, the strobe correction plate 64 and the δ1 distance correction lenses 68a and 68b are positioned circumferentially offset from the strobe window 20 and the distance measurement windows 56a and 56b, respectively.

According to the second embodiment configured as described above, similarly to the first embodiment described above, it is possible to easily set a state in which macro photography is possible by a simple operation, and the light of the macro lens can be easily set. The axis can be precisely aligned with the optical axis of the photographing lens, and the camera can also be made more compact. Furthermore, according to the second embodiment, the finder correction lens 62, the flash correction plate 64, and the distance measurement correction lenses 68a and 68b for performing various corrections necessary for macro photography operate the macro lens 44. (a), that is, the operating member consisting of the rotating ring 40 and the protective glass 48 is attached. Therefore, the various corrections described above can be performed at the same time as turning the rotary ring 40 to set a state in which macro photography is possible. Therefore, macro lens 4
4, there is no need to independently provide an interlocking mechanism for moving various auxiliary lenses or holding plates in conjunction with 4, and it is possible to simplify the structure and reduce manufacturing costs.

Further, according to this embodiment, the burr can prevent damage to the imaging cord when the camera is stopped, and it is also possible to easily confirm whether the camera is stopped.

Note that in the second embodiment, other auxiliary lenses, such as a teleconverter lens, a wide converter lens, an inverted lens, or an AF lens, are used instead of the macro lens.
An optical system necessary for photographing, such as an auxiliary optical system for (autofocus), may be used.

Further, the protective glass 48 and various lenses and barriers provided on the protective glass may be integrally formed of resin. In this case, it becomes easier to manufacture the optical device, and the manufacturing cost can be further reduced.

Furthermore, it goes without saying that the present invention is not limited to electronic still cameras, but can be applied to silver halide cameras, video movie cameras, and the like.

(Effects of the Invention) As detailed above, according to the present invention, the auxiliary optical system can be easily aligned with high precision with respect to the optical system provided on the camera body side, such as the photographic optical system. At the same time, it is possible to provide an optical device that allows the camera to be made more compact.

[Brief explanation of the drawing]

1 to 5 show an electronic still camera equipped with an optical device according to a first embodiment of the present invention, FIG. 1 is a perspective view showing the entire electronic still camera, and FIG. 2 is a perspective view showing the entire electronic still camera. FIG. 3 is a sectional view showing the main parts of the electronic still camera; FIG. 3 is an enlarged sectional view showing the joint between the rotating ring and the protective glass;
FIG. 4 is a front view of the optical device in an inoperative position;
FIG. 5 is a front view of the optical device in the working position, FIGS. 6 and 7 show an electronic still camera equipped with the optical device according to the second embodiment of the invention, and FIG. FIG. 7 is an exploded perspective view showing essential parts of the electronic camera, and FIG. 7 is a front view of the optical device. 10... Camera body, 20... Strobe window, 26.
- Photographing lens, 32... Image pickup element, 37... Optical device, 38... Support ring, 40... Rotating ring, 42
...Lens frame, 44...Macro lens, 48...
Protective glass, 54...finder lens, 56a, 5
6b... Distance measurement window, 64... Strobe correction plate, 66a
, 66b... Barrier, 68a, 68b... Distance measurement correction lens. Applicant Agent Patent Attorney Atsushi Tsuboi 1r+1

Claims (3)

[Claims] (1) The auxiliary lens passes on a trajectory that includes a position overlapping with at least one of the optical systems necessary for photographing, such as the auxiliary lens, photographic lens, observation lens, distance measurement window, white balance detection window, finder, and strobe. and a support member rotatably supporting the auxiliary lens. (2) In an optical device that has multiple optical systems such as a photographic optical system and a finder optical system, and uses an auxiliary optical system to change the optical characteristics of the photographic optical system, other than the auxiliary optical system and the photographic optical system. An auxiliary optical system for changing the optical characteristics of the optical system is provided on a rotatable support member, and in conjunction with the rotation of the support member, the optical characteristics of the photographing optical system and the optical characteristics of the optical system other than the photographing optical system are changed. An optical device characterized in that optical characteristics can be changed. (3) The barrier section passes on a trajectory that includes a position overlapping the barrier section and at least one of the optical systems necessary for photographing, such as a photographing lens, an observation lens, a distance measurement window, a white balance detection window, a finder, and a strobe. and a support member rotatably supporting the barrier section.