JP5381590B2 - Plug-in filter holder - Google Patents

Description

  The present invention relates to an insertion filter holder that can be inserted into and removed from a lens barrel.

  8 and 9 show a conventional insertion filter holder 1. This conventional insertion filter holder 1 closes the holder body 4 having an opening 2 through which a light beam passes when inserted into a lens barrel, and a filter holding recess 3 positioned around the opening 2, and the opening 2. A filter holding frame 5 for holding the gelatin filter (optical filter) GF on the filter holding recess 3 is provided.

  The filter holding frame 5 is made of a single spring member having a substantially U-shape, and both ends thereof are fixed to the holder body 4 with fixing screws P. Contact protrusions 5A, 5B, and 5C that contact the gelatin filter GF held between the holder body 4 and the filter pressing frame 5 are formed on each side of the U-shape.

JP 2000-298228 A Japanese Utility Model Publication No. 61-1224026

  The gelatin filter GF is usually used in a plurality of layers depending on the usage mode (adjustment of hue and brightness), and the thickness d varies depending on the number of the layers. For this reason, it is difficult to suitably hold the gelatin filter GF regardless of its thickness d.

  That is, as shown in FIG. 9, when the thickness d of the gelatin filter GF is large (when a large number of sheets are used), one side of the filter holding frame 5 that is located farthest from the fixing screw P is lifted and formed on this side. The abutting convex portion 5C cannot abut on the gelatin filter GF, and the strength for sandwiching the gelatin filter GF is lowered, so that the stability of the gelatin filter GF cannot be maintained.

  On the other hand, it may be possible to secure the contact between the contact protrusion 5C and the gelatin filter GF by making the contact protrusion 5C higher than the contact protrusions 5A and 5B, but the thickness d of the gelatin filter GF is small. (For example, when only one sheet is used), the two sides on which the contact protrusions 5A and 5B are formed are lifted by the height of the contact protrusion 5C, and these contact protrusions 5A and 5B are formed on the gelatin filter GF. The strength of sandwiching the gelatin filter GF is lowered, and the stability of the gelatin filter GF cannot be maintained.

  The present invention has been made on the basis of the above awareness of problems, and provides an insertion filter holder capable of maintaining the stability of a gelatin filter by suitably sandwiching and holding the gelatin filter regardless of its thickness. With the goal.

  The insertion filter holder of the present invention is a holder main body that is detachable from the lens barrel, has an opening through which the light beam passes when inserted into the lens barrel, and a filter holding recess positioned around the opening; and An insertion filter holder having a filter pressing frame made of a single spring member that holds and holds the optical filter that closes the light beam passage opening on the filter holding recess. One end of the filter pressing frame is a holder. A pair of elastic legs fixed to the main body and extending along both sides of the light beam passage opening; an inner frame located inside the pair of elastic legs and extending to the outer periphery of the light beam passage opening; A connecting portion that connects the elastic leg portion and the inner frame, and at least three of the inner frame abut on the optical filter held between the holder body and the filter pressing frame. It is characterized in that the contact convex portion of the upper is formed.

  The connecting portion is provided on an extension of the force-applying frame that has a force-applying portion for connecting the free ends of the pair of elastic legs to elastically deform the filter pressing frame in a direction away from the filter holding recess. At the same time, the force applying frame can be a combined frame that also serves as a part of the inner frame.

  The dual-purpose frame can also be formed with at least one abutment convex portion that abuts on the optical filter held between the holder body and the filter pressing frame.

  The spring constant of the inner frame other than the dual-purpose frame is preferably set smaller than the spring constant of the pair of elastic legs and the force applying frame. In this case, the filter holding frame is made of a leaf spring material having the same thickness, and the magnitude of the spring constant can be set by the magnitude of the width of the leaf spring material.

  It is preferable that at least two of the contact protrusions are arranged in parallel on a straight line that is substantially orthogonal to an extension line of the pair of elastic leg portions.

  In another aspect, the connection portion can be configured by a rotation (twist) connection portion that supports a plane including the inner frame so as to be swingable with respect to the plane including the pair of elastic legs.

  In this case, the filter holding frame is made of a leaf spring material having the same thickness, and the width of the spring material of the rotational connection portion is set smaller than the width of the spring material constituting the pair of elastic legs and the inner frame. It is preferable.

  In still another aspect, the insertion filter holder of the present invention can be inserted into and removed from the lens barrel, and has an opening through which the light beam passes when inserted into the lens barrel, and a filter holding recess positioned around the opening. A filter body made of a single spring member that sandwiches and holds an optical filter that closes the light beam passage opening on the filter holding recess; Is a first U-shape comprising a pair of elastic leg portions each having one end portion fixed to the holder body and extending along both sides of the light beam passage opening, and a dual-purpose connection portion connecting the pair of elastic leg portions. Alternatively, a U-shaped holding frame and a second connecting portion extending from the joint portion of the first U-shaped or U-shaped holding frame toward the inside of the pair of elastic legs to the outer periphery of the light beam passage opening. U-shaped Alternatively, the spring constant of the second U-shaped or U-shaped pressing frame is smaller than the spring constant of the first U-shaped or U-shaped pressing frame. It is characterized by being set.

  ADVANTAGE OF THE INVENTION According to this invention, the insertion filter holder which can hold | maintain a gelatin filter suitably regardless of the thickness, and can maintain the stability of a gelatin filter can be provided.

It is a front view which shows the structure of the insertion filter holder which concerns on Embodiment 1 of this invention. It is a front view which shows the independent structure of the filter holding frame of the insertion filter holder of FIG. It is a schematic sectional drawing which shows the state which pinched | interposed and hold | maintained the optical filter in the insertion filter holder of FIG. It is a front view which shows the structure of the 1st modification of the insertion filter holder of FIG. It is a front view which shows the structure of the 2nd modification of the insertion filter holder of FIG. It is a front view which shows the independent structure of the filter holding frame of the insertion filter holder which concerns on Embodiment 2 of this invention. It is a schematic sectional drawing which shows the state which pinched | interposed and hold | maintained the optical filter in the insertion filter holder which has the filter holding frame of FIG. It is a front view which shows the structure of the conventional insertion filter holder. It is a schematic perspective view which shows the problem of the conventional insertion filter holder.

(Embodiment 1)
1 to 3 show an insertion filter holder 100 according to Embodiment 1 of the present invention. The insertion filter holder 100 has a holder main body 10 and a filter pressing frame 20 fixed to the holder main body 10 with a pair of fixing screws P.

  The holder body 10 has a partially cylindrical exterior plate 11 along the outer peripheral surface of a lens barrel (not shown), and is formed in the lens barrel via a knob portion 11 a provided on the exterior plate 11. It can be inserted into and removed from the cutout portion (not shown).

  The holder main body 10 has an opening (light beam transmission opening) 12 through which a light beam passes when inserted into the lens barrel, and a filter holding recess 13 positioned around the opening 12. Reference symbol O indicates the photographing optical axis of the lens barrel (that is, the center of the circular opening 12). The gelatin filter GF is stored in the filter holding recess 13 in a state where the opening 12 is closed and the movement in the direction perpendicular to the optical axis is restricted. The gelatin filter GF is an optical filter made of a gelatin material that changes the light transmittance in order to adjust the color and brightness of an image.

  The filter holding frame 20 is made of a single spring member (plate spring material), and has a pair of elastic legs 21 each having one end fixed to the holder body 10 by a fixing screw P and extending along both sides of the opening 12. A rectangular inner frame 22 located inside the pair of elastic legs 21 and positioned around the opening 12, and a connecting portion 23 connecting the pair of elastic legs 21 and the rectangular inner frame 22. ing. The end of the rectangular inner frame 22 on the side away from the fixing screw P constitutes a force applying frame 24 extending on the extension of the connecting portion 23, and the filter holding frame 20 is connected to the filter holding recess 13 in the force applying frame 24. An attachment force knob (attachment portion) 24a for elastically deforming in a direction away from the attachment is formed. The attachment frame 24 is a dual-purpose frame that also serves as a part of the rectangular inner frame 22 (one side portion away from the fixing portion of the pair of elastic legs 21).

  Further, the rectangular inner frame 22 has a spring constant of the left and right side portions 22a and the upper side portion 22b excluding the force applying frame (lower side portion) 24, which is larger than the spring constant of the pair of elastic leg portions 21 and the force applying frame 24 (connecting portion 23). It is set small. That is, the filter holding frame 20 is made of a leaf spring material having the same thickness, and the rectangular inner frame 22 other than the force application frame 24 is a plate spring more than the pair of elastic legs 21 and the force application frame 24 (connection portion 23). The width of the material is small.

  The rectangular inner frame 22 is formed with four contact convex portions 22A, 22B, 22C, and 22D that are positioned at the four corners of the force application frame (lower side portion) 24, the left and right side portions 22a, and the upper side portion 22b. The contact protrusions 22A and 22D and the contact protrusions 22B and 22C are respectively arranged in parallel on a straight line (left and right direction in the drawing) substantially orthogonal to the extension line of the pair of elastic legs 21.

In order to sandwich the gelatin filter GF in the insertion filter holder 100 having the above-described configuration, the filter holding recess 24 is lifted in a state in which the attachment force knob 24 a is lifted and elastically deformed in a direction to separate the filter holding frame 20 from the filter holding recess 13. Insert gelatin filter GF 13. As a result, the gelatin filter GF closes the opening 12, and the movement of the gelatin filter GF in the direction perpendicular to the optical axis is restricted. When the attaching force knob 24a is released, the filter holding frame 20 is elastically restored, and the contact protrusions 22A and 22D arranged in parallel on the side close to the fixing screw P first contact the gelatin filter GF, and then the gelatin filter GF The left and right side portions 22a of the rectangular inner frame 22 are bent by an amount corresponding to the thickness d, and the contact protrusions 22B and 22C arranged in parallel on the side far from the fixing screw P contact the gelatin filter GF. In this way, the four abutting convex portions 22A-22D abut against the gelatin filter GF, and the gelatin filter GF is sandwiched and held between the holder body 10 (filter holding concave portion 13) and the filter pressing frame 20. That is, the movement of the gelatin filter GF in the optical axis direction is restricted. The lens barrel is mounted by inserting the insertion filter holder 100 into a notch (not shown) formed in the lens barrel via a knob portion 11a provided on the exterior plate 11.

  Here, as described above, the gelatin filter GF is usually used in a plurality of layers depending on the usage mode (adjustment of hue and brightness), and the thickness d varies depending on the number of the layers. For this reason, it has been difficult for the conventional product to suitably hold the gelatin filter GF regardless of its thickness d.

On the other hand, in the present embodiment, the filter holding frame 20 includes a pair of elastic legs 21 each having one end fixed to the holder body 10 and extending along both sides of the opening 12, and the inside of the pair of elastic legs 21. A rectangular inner frame 22 that extends to the outer periphery of the opening 12, and a connection portion 23 that connects the pair of elastic legs 21 and the rectangular inner frame 22. Since the four contact protrusions 22A-22D that contact the gelatin filter GF held between the holder main body 10 and the filter pressing frame 20 are formed, the rectangular inner frame 22 has an amount corresponding to the thickness d of the gelatin filter GF . The left and right side portions 22a are bent, and the gelatin filter GF can be suitably clamped and held regardless of the thickness d.

That is, since the spring constant of the left and right side portions 22a of the rectangular inner frame 22 is smaller than the spring constant of the pair of elastic legs 21, the left and right side portions 22a of the rectangular inner frame 22 having a small spring constant are shown in FIG. The angle formed by the pair of elastic legs 21 and the rectangular inner frame 22 can be changed according to the thickness d of the gelatin filter GF. Therefore, when the thickness of the gelatin filter GF is large, the angle formed by the pair of elastic legs 21 and the rectangular inner frame 22 is increased (the amount of bending of the left and right side portions 22a of the rectangular inner frame 22 is increased ), and the thickness of the gelatin filter GF is increased. Is small, the angle formed by the pair of elastic legs 21 and the rectangular inner frame 22 is small (the amount of bending of the left and right side portions 22a of the rectangular inner frame 22 is small ). As a result, the gelatin filter GF and the four contact convex portions 22A −22D can always be suitably contacted.

  In other words, a U-shaped presser frame (first presser frame) formed by the pair of elastic legs 21 and the force applying frame 24 (connecting portion 23), and a pair of elastic legs from the force applying frame 24 (connecting portion 23). The U-shaped presser frame (second presser frame) composed of the side portions 22a and 22b extending toward the inside of the portion 21 presses the surface of the gelatin filter GF in a well-balanced manner, and the four contact convex portions 22A-22D. Can be brought into contact with each other.

  In particular, the spring constants of the rectangular inner frames 22 (side portions 22a and 22b) other than the force applying frame (combined frame) 24 are set smaller than the spring constants of the pair of elastic leg portions 21 and the force applying frame 24 (connecting portion 23). The gelatin filter GF is firmly pressed by the pair of elastic legs 21 and the force applying frame 24 (connecting portion 23), while the rectangular inner frame 22 (side portions 22a and 22b) other than the force applying frame (combined frame) 24 is reinforced. As a result of pressing the gelatin filter GF, the surface of the gelatin filter GF can be pressed uniformly.

  FIG. 4 shows a first modified example of the insertion filter holder 100, a U-shaped inner frame 25 that is positioned inside the pair of elastic legs 21 and extends to the outer periphery of the opening 12, and a linear shape The inner frame 22 ′ is closed by a force applying frame (combined frame) 24. In this embodiment, the spring constant of the U-shaped inner frame 25 is set lower (the width is narrower) than the spring constants of the other parts. In the modification of FIG. 4A, three contact protrusions 25 </ b> A, 25 </ b> B, and 25 </ b> C are formed on the U-shaped inner frame 25. In the modification of FIG. 4B, two abutting convex portions 25D and 25E are formed on the U-shaped inner frame 25, and one abutting convex portion 24A is formed on the force-applying frame 24 as a dual-purpose frame. . Also in this modified example, all of the three contact protrusions (25A, 25B, and 25C, or 25D, 25E, and 24A) can preferably contact the gelatin filter GF and stably hold the gelatin filter GF. be able to. Particularly, since the contact protrusions 25B and 25C and the contact protrusions 25D and 25E arranged in parallel contact the gelatin filter GF at the same time (only one contact protrusion does not float), the stability of the gelatin filter GF is improved. High nature.

  FIG. 5 shows a second modification of the insertion filter holder 100. In this modification, a U-shaped inner frame 26 positioned inside the pair of elastic legs 21 and extending to the outer periphery of the opening 12, and an inner frame 22 ″ closed by an inverted U-shaped attachment frame 27 are provided. It is composed. In this embodiment, the spring constant of the U-shaped inner frame 26 is set lower (the width is narrower) than the spring constants of the other parts. In addition, the filter holding recess 13 ′ has a U shape that matches the inverted U-shaped attachment frame 27. In the modification of FIG. 5A, one abutting convex portion 26 </ b> A is formed on the U-shaped inner frame 26, and two abutting convex portions 27 </ b> A and 27 </ b> B are formed on the inverted U-shaped attachment frame 27. . 5B, the U-shaped inner frame 26 has two contact projections 26B and 26C, and the inverted U-shaped application force frame 27 has one contact projection 27C. . Also in this modification, all of the three abutment convex portions (26A and 27A and 27B, or 26B and 26C and 27C) can preferably abut against the gelatin filter GF and stably hold the gelatin filter GF. be able to. In particular, since the contact protrusions 27A and 27B and the contact protrusions 26B and 26C arranged in parallel contact the gelatin filter GF at the same time (only one contact protrusion does not rise), the stability of the gelatin filter GF is stabilized. High nature.

(Embodiment 2)
6 and 7 show an insertion filter holder 200 according to Embodiment 2 of the present invention. The insertion filter holder 200 of the second embodiment has a filter pressing frame 30 instead of the filter pressing frame 20 of the first embodiment. Since the structure of the holder body 10 is the same as that of the first embodiment, the illustration and the description thereof are omitted.

  The filter holding frame 30 has one end fixed to the holder main body 10 and extending along both sides of the opening 12. The filter holding frame 30 is positioned inside the pair of elastic legs 31 and outside the opening 12. It has a hollow rectangular inner frame 32 extending to the enclosure, and a rotation connecting portion (twist connecting portion) 33 that connects the pair of elastic leg portions 31 and the hollow rectangular inner frame 32. The rotation connecting portion 33 supports the plane (surface) including the hollow rectangular inner frame 32 so as to be swingable with respect to the plane (surface) including the pair of elastic leg portions 31.

The spring constant of the rotation connecting portion 33 is set smaller than the spring constant of the pair of elastic leg portions 31 and the hollow square inner frame 32. That is, the filter pressing plate 30 is made of a leaf spring material having the same thickness, and the rotational connection portion 33 has a width of the leaf spring material smaller than that of the pair of elastic leg portions 31 and the hollow rectangular inner frame 32. ing. Four contact protrusions 32A, 32B, 32C, and 32D are formed at the four corners of the hollow rectangular inner frame 32. On one side of the hollow square inner frame 32 that is farthest from the fixing screw P, an attachment force knob (attachment portion) 32a is formed.

  According to this embodiment, as shown in FIG. 7, the hollow connecting portion 33 is twisted according to the thickness d of the gelatin filter GF, so that the hollow rectangular inner frame 32 is opposed to the pair of elastic legs 31. Since it oscillates, the hollow rectangular inner frame 32 can be maintained parallel to the gelatin filter GF. As a result, the gelatin filter GF and the four abutting convex portions 32A-32D can always be suitably abutted.

  In the above embodiment, the case where a gelatin filter is used as an optical filter has been described as an example. However, the present invention is also applicable to the case where other optical filters are used.

  Moreover, in the above embodiment, the number, position, size, and the like of the contact protrusions formed on the inner frame and the force application frame can be variously changed within the scope of the technical idea of the present invention.

100 Plug filter holder 10 Holder body 11 Exterior plate 11a Knob portion 12 Opening (light beam transmission opening)
13 13 ′ Filter holding recess 20 Filter holding frame 21 Pair of elastic legs 22 Rectangular inner frame 22 ′ 22 ″ Inner frame 22a, 22b Sides 22A, 22B, 22C, 22D Abutment convex part 23 Connection part 24 Adhesive frame ( Combined frame)
24a Power knob (force part)
24A Abutting convex part 25 U-shaped inner frame 25A, 25B, 25C, 25D, 25E Abutting convex part 26 U-shaped inner frame 26A, 26B, 26C Abutting convex part 27 Reverse U-shaped attachment frame (combined frame)
27A, 27B, 27C Abutment convex portion 200 Insert filter holder 30 Filter holding frame 31 A pair of elastic leg portions 32 Hollow square inner frame 32a Force knob (force portion)
33 Rotation (twist) connection GF Gelatin filter (optical filter)
O Optical axis P Fixing screw

Claims (9)

A holder body that can be inserted into and removed from the lens barrel, and has an opening through which the light beam passes when inserted into the lens barrel; and a filter holding recess positioned around the opening; and an optical filter that closes the light beam passage opening An insertion filter holder having a filter holding frame made of a single spring member, which is sandwiched and held on the filter holding recess.
The filter holding frame has a pair of elastic leg portions each having one end fixed to the holder main body and extending along both sides of the light beam passage opening, and is positioned on the inner side of the pair of elastic leg portions. An inner frame extending to the outer periphery, and a connecting portion that connects the pair of elastic legs and the inner frame;
The insertion filter holder, wherein the inner frame is formed with at least three or more abutment projections that abut against an optical filter held between the holder body and the filter holding frame. The insertion filter holder according to claim 1,
The connecting portion is provided on an extension of the force-applying frame that has a force-applying portion for connecting the free ends of the pair of elastic legs to elastically deform the filter pressing frame in a direction away from the filter holding recess. The insertion filter holder is a dual-purpose frame that simultaneously serves as a part of the inner frame. The insertion filter holder according to claim 2,
An insertion filter holder in which the dual-purpose frame is formed with at least one abutting convex portion that abuts on an optical filter held between the holder main body and the filter pressing frame. The insertion filter holder according to claim 2 or 3,
An insertion filter holder in which a spring constant of an inner frame other than the dual-purpose frame is set to be smaller than a spring constant of the pair of elastic legs and the force applying frame. The insertion filter holder according to claim 4,
The filter holding frame is made of a leaf spring material having the same thickness, and the spring constant is set according to the width of the leaf spring material. In the insertion filter holder according to any one of claims 1 to 5,
At least two of the contact protrusions are insertion filter holders arranged in parallel on a straight line substantially orthogonal to an extension line of the pair of elastic leg portions. The insertion filter holder according to claim 1,
The insertion filter holder, wherein the connection portion includes a rotation connection portion that supports a plane including the inner frame so as to be swingable with respect to a plane including the pair of elastic legs. The insertion filter holder according to claim 7,
The filter holding frame is made of a leaf spring material having the same thickness, and the width of the spring material of the rotational connection portion is set smaller than the width of the spring material constituting the pair of elastic legs and the inner frame. Plug-in filter holder. A holder body that can be inserted into and removed from the lens barrel, and has an opening through which the light beam passes when inserted into the lens barrel; and a filter holding recess positioned around the opening; and an optical filter that closes the light beam passage opening An insertion filter holder having a filter holding frame made of a single spring member, which is sandwiched and held on the filter holding recess.
The filter holding frame is
A first U-shape or U comprising a pair of elastic legs each having one end fixed to the holder main body and extending along both sides of the light beam passage opening, and a dual-purpose connecting part connecting the pair of elastic legs. Character-shaped presser frame,
A second U-shape or U-shape extending from the joint portion of the first U-shaped or U-shaped presser frame toward the inside of the pair of elastic legs toward the outer periphery of the light beam passage opening. A holding frame,
A spring constant of the second U-shaped or U-shaped holding frame is set to be smaller than a spring constant of the first U-shaped or U-shaped holding frame. Filter holder.

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