JP2015102821A - Finder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a finder device that enables an eyepiece lens to be held to a holding member without use of an adhesive agent or additional component, and enables display quality to be maintained without having position accuracy of the eyepiece lens deviated even when a photographer touches or cleans the eyepiece lens.SOLUTION: A finder device comprises: an eyepiece lens; and a lens holding member that holds the eyepiece lens, and the lens holding member includes: a positioning part that is for determining an optical axis direction of the eyepiece lens and a location about two directions orthogonal to the optical axis; a first spring part that moors the eyepiece lens and urges the eyepiece lens toward a finder optical axis direction; and second and third spring parts that urge the eyepiece lens toward two directions orthogonal to the finder optical axis. The eyepiece lens includes: a positioning part that corresponds to the positioning part of the lens holding member for determining the optical axis direction of the eyepiece lens and the location about two directions orthogonal to the optical axis; and a protrusion part that is for mooring to the first spring part of the lens holding member. In a state where the eyepiece lens is moored to the lens holding member, the eyepiece lens is configured to be urged from the first, second and third spring parts to abut against the positioning part.

Description

  The present invention relates to a finder device and an imaging device using the same, and more particularly to a lens holding structure used in the finder device.

  An imaging device such as a camera is provided with a finder device for a photographer to observe a subject image. The viewfinder device is an optical unit composed of a plurality of lens groups, and is generally provided with an eyepiece at the last stage in order to form a subject image at the pupil position of the photographer. The viewfinder optical system is basically protected from being touched by the photographer, but since the eyepiece is at the last stage of the lens group, the photographer has many opportunities to touch it directly. If the position of the eyepiece lens is shifted by touching the photographer, it will lead to an abnormality in the viewfinder display, so the eyepiece lens needs to be firmly attached.

  In Patent Document 1, an eyepiece lens group is fixed to a positioning portion formed on a holding member using an adhesive. Patent Document 2 discloses a method of pressing and holding with a metal leaf spring.

JP 2012-88633 A Japanese Patent Laid-Open No. 11-84475

  In Patent Document 1, an eyepiece lens is bonded and fixed to a holding member together with a lens constituting another finder device. Such a fixing method allows the lens to be firmly attached to the holding member, but in the manufacturing process, it takes time to adhere the lens.

  Further, as in Patent Document 2, there is also proposed a method in which a lens is not adhesively fixed to a holding member, but is pressed and held in a direction of an optical axis with a member having a spring property. However, this method requires an additional member for pressing and holding. Furthermore, if a load is applied in a direction other than the optical axis direction simply by pressing in the optical axis direction, there is a concern that the lens position shifts and the display quality of the viewfinder is impaired.

  In view of such circumstances, the present invention can hold an eyepiece without using an adhesive or an additional part with respect to a holding member, and even if a photographer touches or cleans the eyepiece. There is provided a finder device that can maintain the display quality without deviating the positional accuracy.

In order to achieve the above object, the present invention includes an eyepiece and a lens holding member that holds the eyepiece, and the lens holding member includes two directions perpendicular to the optical axis direction of the eyepiece and the optical axis. A positioning part for determining a position in relation to a direction; a first spring part that anchors the eyepiece lens and biases it in the finder optical axis direction; a second part that biases the eyepiece lens in two directions perpendicular to the finder optical axis; A third spring portion, and the eyepiece has a positioning portion corresponding to a positioning portion for determining a position in two directions perpendicular to the optical axis direction of the lens holding member and the optical axis,
A protrusion for anchoring with the first spring portion of the lens holding member; and being biased by the first, second, and third spring portions while being anchored to the lens holding member; A finder device that abuts against the portion.

  According to the present invention, the ocular lens can be held with respect to the holding member without using an adhesive or an additional component, and even if the photographer touches the eyepiece or performs cleaning, the positional accuracy of the ocular lens is improved. It is possible to provide a finder device that does not shift and can maintain display quality.

It is the perspective view which showed the procedure which attaches an eyepiece to the finder base in a present Example. It is a schematic sectional drawing which shows the structure of the camera system in a present Example. It is a disassembled perspective view of the finder unit in a present Example. It is sectional drawing of the finder unit in a present Example. It is a perspective view of the finder base in a present Example. It is an enlarged view of the A section in FIG. It is an enlarged view of the B section in FIG. It is a perspective view of the eyepiece in a present Example. It is a front view from the + Z direction of the finder base in a present Example. FIG. 10 is a cross-sectional view taken along line AA in FIG. 9 for explaining an eyepiece holding mechanism by a finder base bar spring portion in the present embodiment. It is the perspective view which showed the procedure which attaches an eyepiece to the finder base in a present Example. FIG. 10 is a cross-sectional view taken along the line BB in FIG. 9 for explaining an eyepiece holding mechanism by a finder base J-shaped spring portion in the present embodiment. It is a figure of the state which moored the eyepiece lens to the finder base in a present Example.

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

[Example]
As an example of an embodiment of the present invention, a configuration of a digital single lens reflex camera will be described with reference to FIG. In the following, the X, Y, and Z directions shown in each figure are defined as the X-axis and the Y-axis, respectively, in the plane perpendicular to the Z-axis, with the photographing optical axis direction being the Z-axis. .

  FIG. 2 is a schematic cross-sectional view showing the configuration of the camera system in the present embodiment, which includes a camera body (imaging device) 1 and a photographic lens 2 that is detachably attached to the camera body 1. In the photographing lens 2, a photographing optical system 2a and a diaphragm 2b for adjusting the exposure amount are provided. Although the photographing optical system 2a is represented as one lens in FIG. 2, it is actually an optical system composed of a plurality of lens groups. The taking lens 2 is electrically and mechanically connected to the camera body 1 via a known mount mechanism. By attaching the photographing lens 2 having different focal lengths to the camera body 1, it is possible to obtain photographing screens having various angles of view. In the photographing lens 2, the focus of the photographing optical system 2a is adjusted by moving a focus lens, which is a part of the photographing optical system 2a, in the optical axis direction via a drive mechanism (not shown).

  The camera described in the present embodiment is a digital camera using an image sensor 3 such as a CCD or CMOS sensor, and obtains an image signal of a still image or a moving image by driving the image sensor 3 once or continuously. . The photographer can confirm the photographing result by displaying the moving image and the still image obtained by the image sensor 3 on the display 4 provided on the back surface of the camera body 1. In addition, an optical low-pass that limits the cutoff frequency of the photographing optical system 2a so that a spatial frequency component higher than necessary of the subject image is not transmitted to the imaging element 3 in the optical path from the photographing optical system 2a to the imaging element 3. A filter 5 is provided. Reference numeral 6 provided in front of the optical low-pass filter 5 is a focal plane shutter that adjusts the amount of light incident on the image sensor 3, and has a front curtain and a rear curtain composed of a plurality of light shielding blades.

  Reference numeral 7 denotes a movable half mirror that divides one optical path into two optical paths by reflecting a part of the light beam incident through the photographing optical system 2a and transmitting the remaining part. A movable sub-mirror 8 (total reflection mirror) is provided at the tip of the half mirror, and the light beam transmitted through the half mirror 7 is reflected and guided to the focus detection unit 9. The focus detection unit 9 receives the light beam reflected by the sub mirror 8 and performs focus detection by the phase difference detection method. The half mirror 7 and the sub mirror 8 are retracted from the optical path during photographing.

  Of the optical paths divided by the half mirror 7, the light bent in the + Y direction in FIG. 2 enters a finder unit (finder apparatus) 10. A range surrounded by a dotted line in FIG. First, an image is formed on the focusing screen 11. The direction of the image formed on the focusing screen 11 is changed through the hollow pentamirror 12 and can be confirmed by the photographer through the finder optical system 13 including a plurality of lenses. The finder unit 10 is provided with an in-finder LCD (in-finder information display device) 15 for confirming information necessary for photographing even when the photographer looks into the finder. The information displayed on the LCD 15 in the viewfinder is viewed by the photographer through the triangular prism 14, the hollow pentamirror 12, and the viewfinder optical system 13 in the same manner as the image on the focusing screen 11.

  3 and 4 are views for explaining the configuration of the finder unit 10 provided in the single-lens reflex camera according to the embodiment of the present invention. 3 is an exploded perspective view of the finder unit 10, and FIG. 4 is a cross-sectional view regarding the YZ plane.

  The finder unit 10 is configured by attaching each component to a finder base (lens holding member) 100. The finder base 100 is manufactured by resin (polycarbonate) molding and has a structure for attaching each member. Details will be described later.

  A metal spring member 101 is a member for holding the focusing screen 11 against the finder base 100 by sandwiching the focusing screen 11 with the finder base member 100.

  Reference numeral 102 denotes a field frame in which a substantially rectangular opening is formed in the plate-like member. In this embodiment, the black PET sheet is manufactured by pressing. The field frame 102 is for restricting the size of the light beam incident on the hollow pentamirror 12 from the focusing screen 11 and substantially matching the size of the image obtained by the image sensor 3.

  Reference numeral 14 denotes a triangular prism, which is disposed on the front surface (−Z direction) of the LCD 15 in the finder and below the field frame 102 (−Y direction). Its role is to bend the optical path so that the photographer can confirm the information displayed on the LCD 15 in the viewfinder. In this embodiment, the optical path of the in-finder LCD 15 arranged in a direction perpendicular to the focusing screen 11 is bent at a substantially right angle so that the optical axis direction is aligned with the focusing screen 11.

  Reference numerals 301, 302, and 303 denote lenses constituting the finder optical system 13, which are referred to as first, second, and third lenses in order from the position closer to the hollow pentamirror 12. The third lens is a so-called eyepiece arranged on the most photographer side.

  Of the three lenses, the first lens 301 and the third lens 303 are directly attached to the viewfinder base 100. On the other hand, the second lens 302 is attached to the finder base 100 via the second lens holding member 103. Although description regarding the structure of the second lens holding member 103 is omitted, the second lens holding member 103 is configured to be slidable in the Z-axis direction. The second lens is a so-called diopter adjustment lens, and it is possible to adjust the diopter (image forming position) of the finder optical system 13 by moving in the Z-axis direction.

  Reference numeral 104 denotes an upper lid member, which is a member produced by resin molding like the finder base 100. The upper lid member 104 is for preventing the hollow pentamirror 12, the first lens 301, the second lens 302, and the second lens holding member 103 attached to the finder base 100 from dropping off. Furthermore, a photometric sensor, a photometric lens, and an LED optical system for instructing a distance measuring point are mounted, but detailed description thereof is omitted.

  Reference numeral 105 denotes an eyepiece frame which is attached to the finder base 100. The eyepiece frame 105 has a role of protecting the eyepiece lens 303 and a mooring mechanism of the finder base 100 and the eyepiece lens 303 described later in FIG. Further, as shown in FIG. 4, the eyepiece lens 303 has a mouth-shaped frame portion 303a, and the eyepiece frame 105 has a mouth-shaped groove portion 105a so as to correspond thereto. When the eyepiece frame 105 is attached to the viewfinder base 100, the mouth-shaped frame portion 303a of the eyepiece lens 303 and the mouth-shaped groove portion 105a of the eyepiece frame are fitted together, so that the eyepiece lens 303 and the eyepiece frame 105 are fitted. Dust and droplets are prevented from entering the finder unit 10 from the gap.

  From here, the detail of the structure for mooring the eyepiece lens 303 to the finder base 100 is demonstrated.

  FIG. 5 is a perspective view showing details of a mechanism for holding the eyepiece lens 303 of the finder base 100, and FIGS. 6 and 7 are enlarged views of a portion A and a portion B in FIG.

  On the + Z side of the finder base 100, there is an opening 100a that restricts light incident on the eyepiece lens 303. A mechanism for positioning the eyepiece lens 303 is provided at the four peripheral corners of the opening 100a, and an X-direction positioning portion 100x, a Y-direction positioning portion 100y, and a Z-direction positioning portion 100z for the eyepiece lens 303 are disposed. 6 and 7 show only two locations on the + Y side, but in reality, they are arranged at the four corners. These positioning portions have positional accuracy necessary for attaching the eyepiece lens 303.

  Reference numeral 100b denotes a leaf spring portion having a cantilever structure that biases the moored eyepiece lens 303 in the -Z direction, and 100c at a position substantially symmetrical with respect to the Y-axis of the leaf spring portion 100b also applies the eyepiece lens 303. -J-shaped spring for mooring in the Z direction. These two springs biased in the -Z direction correspond to the first spring portion in claim 1 of the present invention. Reference numerals 100d and 100e denote second and third spring portions for urging the moored eyepiece 303 in the + X and −Y directions, respectively, and the structure is a cantilever similar to that of 100b.

  FIG. 8 is a perspective view showing details of the eyepiece lens 303.

  The eyepiece 303 in this embodiment is manufactured by molding resin (PMMA). The rough shape is a substantially square shape, and a substantially spherical lens effective surface, R1 surface and R2 surface are formed at the center. A substantially mouth-shaped frame portion 303a is formed on the R2 surface side. This is provided in order to prevent dust and droplets from entering the finder unit from the R2 surface side.

  For positioning with the finder base 100, there is a Z-direction positioning portion 303z on the R1 surface side, and an X-direction positioning portion 303x and a Y-direction positioning portion 303y are disposed in the vicinity thereof. These are arranged at the four corners similarly to the X, Y, and Z direction positioning portions of the finder base 100.

  Since the Z-direction positioning portion 303z of the eyepiece and the Z-direction positioning portion of the finder base are in contact with each other, the positional accuracy is guaranteed. Further, the X-direction positioning portion 303x of the eyepiece lens and the X-direction positioning portion 100x of the finder base, and the Y-direction positioning portion 303y of the eyepiece lens and the Y-direction positioning portion 100y of the finder base have a fitting relationship having a minute gap. Yes.

  Reference numerals 303b and 303c denote protrusions for being anchored to the leaf spring portion 100b and the J-shaped spring portion 100c of the lens holding member, respectively. Reference numerals 303d and 303e denote the second and third spring portions 100d of the lens holding member, respectively. , 100e, and a protrusion that receives a load by a spring.

  From here, the detailed procedure for attaching the eyepiece lens 303 to the finder base 100 and the role of each mooring portion will be described with reference to FIGS.

  FIG. 9 is a view of the finder base 100 viewed from the + Z direction. 9 will be described as appropriate using FIG. 10 which is a cross-sectional view taken along the one-dot chain line AA of FIG. 9 and FIG. 12 which is a cross-sectional view taken along BB.

  First, as shown in FIG. 1, an eyepiece lens 303 is inserted into the finder base 100 from an oblique direction. FIG. 10A is a cross-sectional view along the line AA in the state of FIG. The projection 303b of the eyepiece is inserted in the + Z side of the finder base leaf spring 100b, and the finder base leaf spring 100b and the projection 303b of the eyepiece are not yet in contact with each other.

  From the state described above, when the eyepiece 303 is rotated in the direction of the arrow in FIG. 1 around the protrusion 303b (around the Y axis), the state shown in FIG. 11 is obtained. FIG. 10B is a cross-sectional view taken along the line AA in the state of FIG. At this time, as shown in FIG. 10B, the projection 303b of the eyepiece moves in the + Z direction and pushes up the leaf spring portion 100b of the finder base in the + Z direction. As a result, as indicated by a thick arrow in FIG. 10B, a load pressing in the −Z direction acts on the eyepiece projection 303b.

  On the other hand, the state on the opposite side with respect to the Y axis, that is, in the vicinity of the J-shaped spring portion 100c will be described with reference to FIGS.

  FIG. 12A is a BB cross-sectional view when the eyepiece 303 is in the state of FIG. From here, the eyepiece 303 is inserted into the finder base 100 from a direction substantially parallel to the Z direction. The state shown in FIG. 12B is when the eyepiece 303 is further pushed in the + Z direction from the state shown in FIG. Here, the projection 303c of the eyepiece and the J-shaped spring portion 100c of the finder base start to contact each other, and since the slope is formed on the projection 303c of the eyepiece, −X with respect to the J-shaped spring 100c. A force that pushes in the direction acts. By the action of this force, the bent portion at the base of the J-shaped spring portion 100c is deformed and is expanded in the −X direction.

  When the eyepiece 303c is further pushed in, as shown in FIG. 12 (c), the tip of the J-shaped spring portion 100c gets over the tip of the projection 303c of the eyepiece and comes into contact with the opposite slope. In this state, as shown by the thick arrow in FIG. 12C, a load that pulls in the + Z direction acts on the eyepiece lens 303. Finally, mooring is completed when the Z-direction positioning portion 303z of the eyepiece and the Z-direction positioning portion 100z of the finder base 100 abut. FIG. 13 shows a state where mooring is completed.

  Note that when the eyepiece lens 303 is removed, a load may be applied to the eyepiece lens 303 in the −Z direction from the state of FIG. When a load in the −Z direction is applied to the eyepiece 303, the projection 303c of the eyepiece is configured with an inclined surface, so that the J-shaped spring portion 100c of the finder base is pushed and spread as in the case of attachment. A force acts and the eyepiece 303 can be removed.

  As described above, on the + X side of the eyepiece lens 303, as shown in FIG. 10B, the projection 303b of the eyepiece is moored to the leaf spring portion 100b of the finder base, and on the −X side, FIG. As shown in c), the finder base J-shaped spring portion 100c and the projection 303c of the eyepiece are anchored, and a load in the -Z direction acts on the eyepiece 303 in both anchorings. As a result, the contact between the Z-direction positioning portion 303z of the eyepiece and the Z-direction positioning portion 100z of the finder base is maintained.

  Next, a displacement prevention mechanism for the eyepiece lens 303 in the X and Y directions will be described. As described above, the eyepiece lens X-direction positioning 303x and the lens holding member X-direction positioning 100x, and the eyepiece lens Y-direction positioning 303y and the lens holding member Y-direction positioning 100y are in a fitting relationship. There is a small gap of the degree.

  In the present embodiment, a mechanism for biasing the spring in the X and Y directions is also provided in order to suppress the displacement of the eyepiece lens 303 due to a minute gap. In the state of FIG. 13 where the mooring in the Z direction is completed, the second spring portion 101d of the finder base abuts on the projection 303d of the eyepiece in the X direction, and the third spring portion 101e of the finder base in the Y direction. Comes into contact with the protrusion 303e of the eyepiece. As a result, a load urging in the + X and −Y directions as shown by a thick arrow in FIG. 13 always acts on the eyepiece lens 303, and a load in the X and Y directions acts on the eyepiece lens 303. However, the displacement is suppressed.

  As described above, in order to moor the eyepiece lens 303 to the finder base 100, the finder base 100 is positioned in the X, Y, and Z directions 100x, 100y, and 100z, and the first spring portion for biasing in the Z direction. 100b and 100c, the 2nd spring part 100d and the 3rd spring part 100e for energizing to a X and Y direction were provided. The eyepiece 303 includes positioning portions 303x, 303y, and 303z in the X, Y, and Z directions, and first spring portions for biasing in the Z direction, and projections 303b and 303c corresponding to 100b and 100c in the X and Y directions. Protrusions 303d and e corresponding to the second and third spring portions for urging to are provided. Accordingly, the eyepiece lens 303 is held with respect to the finder base 100 without using an adhesive or other additional members, and even when a load is applied to the eyepiece lens 303, the positional accuracy of the eyepiece lens 303 is shifted. No display quality can be maintained.

  Note that all the portions where the eyepiece lens 303 is urged are provided with protrusions. This is to avoid the influence on the display quality by limiting the generation of distortion due to the spring bias to only the protrusion as much as possible and suppressing the generation of distortion in the lens effective surface.

   In addition, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

100 Viewfinder base (Lens holding member)
100b Bar spring part 100c J-shaped spring part 100d Second spring part 100e Third spring part 303 Eyepiece 303b Projection part 303c Projection part 303d Second projection part 303e Third projection part

Claims (4)

An eyepiece 303;
A lens holding member 100 for holding the eyepiece;
With
The lens holding member 100 includes positioning portions 100z, 100x, 100y for determining positions in the optical axis direction of the eyepiece lens 303 and two directions perpendicular to the optical axis.
First spring portions 100b and 100c for mooring the eyepiece and urging it in the direction of the viewfinder optical axis;
Second and third spring portions 100d and 100e for urging the eyepiece lens in two directions perpendicular to the viewfinder optical axis,
The eyepiece 303 is
Positioning portions 303z, 303x, and 303y corresponding to positioning portions 100z, 100x, and 100y for determining positions in the optical axis direction of the lens holding member 100 and two directions perpendicular to the optical axis;
Protruding portions 303b and 303c for mooring with the first spring portion of the lens holding member 100,
A finder device, wherein the finder device is urged by the first, second, and third spring portions and is in contact with the positioning portion while being anchored to the lens holding member. The eyepiece 303 has a frame portion 303a provided outside the optical effective area,
The viewfinder device according to claim 1, wherein the viewfinder device is covered with an eyepiece frame member 105. The viewfinder according to claim 1 or 2, wherein the eyepiece lens (303) has protrusion shapes (303d, 303e) to be pressed by the second and third springs (100d, 100e) of the holding member. apparatus. The viewfinder device according to any one of claims 1 to 3, wherein a mooring portion of the eyepiece lens by the first spring portion 100c of the lens holding member is configured by an inclined surface.