JP3088166U - Auxiliary tool for optical lens barrel with vignetting prevention function - Google Patents

Abstract

(57) [Problem] To prevent the occurrence of vignetting due to a holding frame portion having a small effective diameter for mounting and holding it on a lens barrel, and to improve the operability of attaching and detaching to and from the optical lens barrel. SOLUTION: A holding frame 2 having an effective diameter larger than that of the lens barrel P for mounting and holding it on the front surface of a lens barrel P is provided on a peripheral portion of an optical element 3 such as a glass plate or a lens. The holding frame 2 is provided with an optical element 3
Cylindrical portion 5 for holding and fixing the flat cylindrical portion 5, a flat annular portion 6 extending radially from the peripheral edge of the fixed cylindrical portion 5, and a forward direction (optical axis direction) from the outer peripheral edge of the flat annular portion 6. And a female screw for screwing a male screw portion on the outer periphery of the accessory 9 to the inner peripheral side of the hood cylinder 7 so that the accessory 9 can be attached to the flat annular portion 6. Or a caulking portion for fitting the outer periphery of the accessories 9.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention is a camera having a wide-angle lens that is detachably mounted on an optical lens barrel and can be widely used as a protector, a polarizing filter, a UV filter, and other accessories for accessories as a lens cover. The present invention relates to an auxiliary tool for an optical lens barrel having a function of preventing vignetting when applied to a lens.

[0002]

[Prior art]

 Conventionally, as shown in FIG. 4, for example, a filter device 101 for general photography used for color matching photographing, natural color photographing and the like has a cylindrical holding frame portion 102 having an opening diameter substantially the same as that of a lens barrel. A peripheral edge of an optical element 103 such as a glass plate or a lens is hooked to a stepped peripheral groove 105 formed in the above-described manner, and screwed and fixed by a holding ring 104 from the front side. This adjusts the quality and quantity of light reaching the photosensitive film of the film, and plays a role in blocking light that hinders photographing and passing the required light by the required amount. In addition, it is often used as a protector for protecting a front surface of a wide-angle lens having a large angle of view or a wide / tele-conversion lens, which has recently become mainstream. In the figure, the diameter of the external thread 111 of the filter 101 and the internal thread 115 of another filter (for double use) are equal to those of the filter.

[0003]

[Problems to be solved by the invention]

 However, such a conventional filter device has a small effective diameter. Therefore, in a camera using a wide-angle lens, such as a digital camera, when a light beam enters the filter device obliquely, the filter device is not used. There is a possibility that so-called vignetting may occur due to the holding frame for mounting and holding the peripheral portion of the optical element such as the glass plate or the lens provided on the front surface of the lens barrel of the camera body. Further, vignetting is remarkable when another filter is used for the screw in front of the filter (so-called double use). In addition, since the holding frame of the filter device and the camera body (lens barrel) have substantially the same diameter, the camera body (lens barrel) is used to mount the filter device on the camera body (lens barrel). ) And the holding frame are almost simultaneously grasped, so that the holding frame itself cannot be easily screwed into the front surface of the camera body (lens barrel).

Accordingly, the present invention has been made in view of the above-described various existing circumstances, and it has been proposed that the occurrence of vignetting due to a holding frame portion having a small effective diameter to be mounted and held on a lens barrel of a camera body. In addition to making it easy to attach and detach to and from the optical lens barrel, it also has a vignetting prevention function that can be widely used as a protector as a lens cover, a polarizing filter, a UV filter, and other accessory adapters. It is an object of the present invention to provide an auxiliary tool for an optical lens barrel.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, the holding frame 2 having an effective diameter larger than that of the lens barrel P for mounting and holding it on the front surface of the lens barrel P is provided by an optical element such as a glass plate or a lens. 3 is provided at the peripheral edge of the holding frame portion 2, and a female screw 15 for double use is provided on the inner diameter of the holding frame portion 2. The holding frame portion 2 includes a fixed cylindrical portion 5 for holding and fixing the optical element 3 by screwing the holding ring 4, a flat annular portion 6 extending radially from the peripheral edge of the distal end of the fixed cylindrical portion 5, A hood tube portion 7 extending forward (in the optical axis direction) from the outer peripheral edge of the flat annular portion 6 can be provided. The holding frame portion 2 has a fixed cylindrical portion 5 for holding and fixing the optical element 3 by screwing the holding ring 4, and has either a positive or negative curvature in a radial direction from a distal end portion of the fixed cylindrical portion 5. And a curved annular portion 8 extending in a curved shape. The outer peripheral edge of the curved annular portion 8 may be provided with a hood tube portion 7 extending forward (in the optical axis direction). A female screw part for screwing a male screw part on the outer periphery of the accessory 9 on the inner peripheral side of the hood tube or an outer periphery of the accessory 9 so that the annular accessory 9 can be attached to the flat annular part 6. It can be provided with a caulking portion or the like.

In the optical lens barrel auxiliary device having the vignetting prevention function according to the present invention configured as described above, the holding frame 2 having an effective diameter larger than that of the lens barrel P is the holding frame 2. The entire front surface of the lens barrel P is covered by the optical element 3 which is held and fixed, thereby preventing vignetting caused when a light beam enters the holding frame 2 obliquely. The flat annular portion 6 extending radially from the peripheral edge of the fixed cylindrical portion 5 enables the effective diameter of the holding frame portion 2 itself to be set sufficiently larger than the lens barrel P, and has a reliable vignetting prevention function. Make it available. The hood tube portion 7 extending forward (in the optical axis direction) from the outer peripheral edge has a diameter larger than the opening diameter of the lens barrel P via the flat annular portion 6, and is thus held. The operability of screwing when the frame 2 is mounted on the front surface of the lens barrel P is improved. By providing a female screw portion for screwing a male screw portion on the outer periphery of the accessory 9 or a caulking portion for fitting the outer periphery of the accessory 9 on the inner peripheral side of the hood tube portion 7, a protector as a lens cover is provided. It improves convenience and fashionability, such as making it possible to attach overlapping accessories to the flat annular portion 6 when used as a tool, polarizing filter tool, UV filter tool, or other accessory adapter tool.

[0007]

[Embodiment of the invention]

 An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1 shown in the drawings denotes a filter tool as an auxiliary tool for an optical lens barrel having a vignetting prevention function. The following describes, as an example, various filter devices 1 such as a polarizing filter device and a UV filter device that play a role of blocking light that hinders photographing and transmitting a necessary amount of light. In addition, besides employing various filter devices 1 such as a polarizing filter device and a UV filter device as an auxiliary device for the optical lens barrel in the present invention, for example, a protector device as a lens cover, an adapter device for other accessories, and the like. Of course, it can be widely used.

The filter device 1 has a holding frame 2 having an effective diameter larger than that of the lens barrel P for mounting and holding the filter in front of the lens barrel P, and a colored glass mounted on the holding frame 2, for example. An optical element 3 such as a flat plate (blue plate glass) or a lens. As shown in FIG. 1, a fixed cylindrical portion 5 for screwing the holding frame 2 itself to the front surface of the lens barrel P is provided on one end opening side of the holding frame 2. That is, a step-shaped peripheral groove portion 10 is formed on the inner peripheral wall surface of the fixed cylindrical portion 5, and a peripheral edge portion of the optical element 3 such as a colored transparent glass plate or a lens is suspended and arranged therein. For example, a screw-in type retaining ring 4 for firmly holding and fixing the peripheral portion of the element 3 from the front side is screwed. An external thread for attaching the holding frame 2 itself to the front surface of the lens barrel P is screwed onto an outer peripheral surface of the fixed cylindrical portion 5 with a female thread portion PA formed on the inner peripheral wall surface of the lens barrel P. The part 11 is formed.

A flat annular portion 6 having a small thickness extends radially outward from a peripheral edge portion of the fixed cylindrical portion 5, and further extends forward from an outer peripheral edge portion of the flat annular portion 6. A hood tube portion 7 having a length of, for example, about 5 to 6 mm extends toward the (optical axis direction). At this time, for example, the opening diameter of the hood tube portion 7 is about 36 mmφ, and the opening diameter of the lens barrel P and the fixed tube portion 5 is about 28 mmφ, so that the width of the flat annular portion 6 in the radial direction is 36 mmφ−28 mmφ = 4 mm. It can be. Of course, the opening diameter of the hood tube part 7 can be larger than 36 mmφ, and can be changed as required.

On the inner peripheral side of the hood cylinder 7, there is provided an internal thread 15 for screwing an external thread on the outer periphery of the accessory 9. Alternatively, for example, an engagement protrusion-shaped caulking portion for fitting and holding the outer periphery of the accessory 9 can be provided. The flat annular portion 6 can be provided with a flat annular accessory 9 having a width of, for example, about 4 mm. For example, the country of manufacture and the name of the manufacturer, the type of camera compatible with the filter device 1 (for example, a digital wide camera is displayed as a digital wide filter, etc.), an ultraviolet cut filter Alternatively, it indicates whether the optical element 3 is a polarizing filter or the like, and the width and thickness of the optical element 3 attached to the holding frame 2.

As described above, the auxiliary tool according to the present invention can be widely used as a protector tool as a lens cover, a polarizing filter tool, a UV filter tool, an adapter tool for other accessories, and the like. However, the vignetting prevention function is sufficiently performed by the holding frame portion 2 larger than the lens barrel P.

Next, an example of use and assembly of the embodiment configured as described above will be described. As shown in FIG. 1, first, as shown in FIG. The peripheral edge of the optical element 3 such as a colored transparent glass plate or a lens, for example, is suspended in the peripheral groove, and the retaining ring 4 is screwed from above so that the peripheral edge of the optical element 3 is exposed from the front side. Hold firmly. Next, an external thread portion on the outer periphery of the accessory 9 is screwed into the female thread portion on the inner peripheral side of the hood cylinder portion 7 or an accessory tool is attached to the inner peripheral side of the hood cylinder portion 7, for example, by a caulking portion having an engagement protrusion shape. By fitting and holding the outer circumference of the class 9, the flat annular portion 6 is provided with accessory accessories 9 having a flat annular shape. Thus, the filter device 1 is formed as an auxiliary device in the present invention. Then, the holding frame 2 itself is attached and fixed to the front surface of the lens barrel P by screwing the male screw part on the outer peripheral surface of the fixed cylindrical part 5 to the female screw part formed on the inner peripheral wall surface of the lens barrel P. I do. As shown in FIG. 2, for example, a wide trumpet-shaped hood body 12 may be screwed into the female screw portion of the hood tube portion 7 if necessary.

FIG. 3 shows a second embodiment of the present invention, and the same components as those in FIG. 1 showing the first embodiment are denoted by the same reference numerals. The detailed description is omitted. In the second embodiment, the holding frame 2 in the first embodiment comprises a fixed cylindrical portion 5 for holding and fixing the optical element 3 by screwing the holding ring 4, and a fixed cylindrical portion 5. It extends in a curved shape such as a trumpet type (see FIG. 3 (a)) or a bowl type (see FIG. 3 (b)) having either a positive or negative curvature in the radial direction from the tip edge of the And a curved annular portion 8. That is, the flat annular portion 6 and the hood cylinder 7 are replaced with a curved annular portion 8. The outer peripheral edge of the curved annular portion 8 is provided with a hood tube portion 7 extending forward (in the optical axis direction), and accessories 9 are provided on the inner surface side of the curved annular portion 8. You may do it.

[0014]

[Effect of the invention]

 Since the present invention is configured as described above, occurrence of vignetting due to the holding frame portion 2 having a small effective diameter for mounting and holding the lens barrel P of the camera body is prevented, and the optical lens barrel is also provided. The optical lens barrel P has a vignetting prevention function that makes it easy to attach and detach to and from the P, and that can be widely used as a protector as a lens cover, a polarizing filter, a UV filter, and an adapter for other accessories. Auxiliary tools can be provided.

That is, this is because the present invention is provided with a holding frame 2 having a larger effective diameter than the lens barrel P at the periphery of the glass disk (lens) for mounting and holding the lens barrel P in front of the lens barrel P. The entire front surface of the lens barrel P can be reliably covered by the optical element 3 held and fixed by the holding frame 2, depending on the case where a light beam enters the holding frame 2 obliquely. Vignetting can be prevented beforehand.

The holding frame 2 is provided with a fixed cylindrical portion 5 for holding and fixing a glass disk (lens) by screwing a holding ring 4, and a radially extending portion from a peripheral edge of a distal end of the fixed cylindrical portion 5. The flat annular portion 6 and the hood cylindrical portion 7 extending forward (in the optical axis direction) from the outer peripheral edge of the flat annular portion 6. The flat annular portion 6 extending in the direction allows the effective diameter of the holding frame portion 2 itself to be set sufficiently larger than the lens barrel P, thereby providing a reliable vignetting prevention function. Further, the hood tube portion 7 extending forward (in the optical axis direction) from the outer peripheral edge has a diameter larger than the opening diameter of the lens barrel P via the flat ring-shaped portion 6, Thereby, the screwing operability when mounting the holding frame portion 2 on the front surface of the lens barrel P is improved.

The holding frame 2 is provided with a fixed cylindrical portion 5 for holding and fixing a glass disk (lens) by screwing a press ring 4, and a radial direction from a distal end edge of the fixed cylindrical portion 5. And a curved annular portion 8 extending in a curved shape having either a positive or negative curvature, so that when a light beam enters the holding frame 2 obliquely, vignetting is prevented by the curved annular portion 8. be able to.

Since the outer peripheral edge of the curved annular portion 8 is provided with a hood tube portion 7 extending forward (in the optical axis direction), the holding frame portion 2 is mounted on the front surface of the lens barrel P. The operability of screwing when performing is improved.

A female screw portion or an accessory component for screwing a male screw portion on the outer periphery of the accessory component 9 to the inner peripheral side of the hood tube portion 7 so that the annular accessory component 9 can be attached to the flat annular portion 6. 9 Because it has a caulking part for fitting the outer circumference, when used as a protector tool as a lens cover, a polarizing filter tool, a UV filter tool, and other accessory adapter tools, etc. It can be easily attached to the flat annular portion 6, thereby improving the convenience and the fashionability.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a filter device according to a first embodiment of the present invention.

FIG. 2 is a partial sectional view showing another example of use.

FIG. 3 shows a second embodiment of the present invention.
(A) is a partial cross-sectional view of a holding frame portion provided with a trumpet type curved annular portion, and (b) is a partial cross-sectional view of a holding frame portion provided with a bowl-shaped type curved annular portion.

FIG. 4 is a partial sectional view of a filter device showing a conventional technique.

[Explanation of symbols]

 P: Lens barrel PA: Female screw part 1: Filter device 2: Holding frame unit 3: Optical element 4: Pressing ring 5: Fixed cylindrical unit 6: Flat annular unit 7: Hood cylindrical unit 8: Curved annular unit 9: Accessories Class 10: Peripheral groove portion 11: Male screw 12: Hood body 15: Double use female screw 101: Filter device 102: Holding frame 103: Optical element 104: Pressing ring 105: Peripheral groove portion 111: Male screw 115: Female screw

Claims (6)

[Utility model registration claims] 1. A holding frame portion having an effective diameter larger than that of the lens barrel for mounting and holding it on the front surface of the lens barrel is provided on the periphery of an optical element such as a glass plate or a lens. An auxiliary tool for an optical lens barrel having a vignetting prevention function, which is provided with a female screw for heavy use. 2. The holding frame portion includes: a fixed cylindrical portion for holding and fixing an optical element by screwing a holding ring; a flat annular portion extending radially from a peripheral edge of a distal end of the fixed cylindrical portion; 2. The auxiliary tool for an optical lens barrel having a vignetting prevention function according to claim 1, further comprising a hood cylinder portion extending forward (in the optical axis direction) from an outer peripheral edge of the annular portion. 3. The holding frame portion has a fixed cylindrical portion for holding and fixing the optical element by screwing a holding ring, and has either a positive or negative curvature in a radial direction from a tip edge of the fixed cylindrical portion. 2. The auxiliary tool for an optical lens barrel having a vignetting prevention function according to claim 1, comprising a curved annular portion extending in a curved shape. 4. A hood cylindrical portion extending forward (in the optical axis direction) at an outer peripheral edge of the curved annular portion.
An auxiliary tool for an optical lens barrel having the vignetting prevention function described in the above. 5. A female screw portion for screwing a male screw portion on the outer periphery of the accessory to the inner peripheral side of the hood tube portion or a caulking portion for fitting the outer periphery of the accessory so that accessories can be attached to the flat annular portion. 3. The auxiliary tool for an optical lens barrel having a vignetting prevention function according to claim 1 or 2, further comprising: 6. An optical device having a vignetting prevention function in which a holding frame portion having an effective diameter larger than that of the lens barrel for mounting and holding it on the front surface of the lens barrel is provided on the periphery of an optical element such as a glass plate or a lens. An auxiliary tool for a lens barrel, wherein the holding frame portion includes a fixed cylindrical portion for holding and fixing an optical element by screwing a holding ring, and a flat plate extending in a radial direction from a peripheral edge of a distal end of the fixed cylindrical portion. An annular portion, and a hood tube portion extending forward (in the optical axis direction) from the outer peripheral edge of the flat annular portion, and an inner peripheral side of the hood tube portion so that accessories can be attached to the flat annular portion. An auxiliary tool for an optical lens barrel having a vignetting prevention function, comprising a female screw portion for screwing a male screw portion on an outer periphery of an accessory or a caulking portion for fitting the outer periphery of an accessory.