JP2008076698A - Lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a lens barrel where a lens and a filter member are arranged, and to facilitate positioning of the filter member. <P>SOLUTION: The lens barrel 3 is equipped with: a lens tube 10 holding the lens G and having an axial center in an optical axis direction L; a filter frame 30 attachably/detachably coupled with the end of the lens tube; and the sheet type filter member 40 fixed by the filter frame. The filter frame 30 is attachably/detachably fit to the lens tube 10 and holds the filter member 40 in cooperation with the lens tube 10, and is notched to expose a part (non-circular arc part 42) of the filter member 40. Thus, the filter member is easily positioned relative to the lens tube while achieving the simplification and miniaturization of the lens barrel, and it is easily mounted on a compact scanner for reading a printed matter or the like. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens barrel in which lenses and filter members are arranged in the optical axis direction, and in particular, a lens barrel arranged in the middle of an optical path bent by a reflection mirror or the like in a scanner or the like that reads a paper surface of a printed matter or the like. About.

With the recent spread of personal computers and the like, scanners that read the surface of printed matter and the like are generally widely used. This scanner includes a lens optical system that guides light emitted from an object (subject) to a lens barrel and an imaging element (imaging plane) by bending the light from the object (subject) using a reflecting mirror or the like. .
On the other hand, recent printed materials are often formed with a glossy reflection or special reflection by applying a vinyl coat or hologram on the surface of paper. The reflected light due to these glossy reflections and special reflections overlaps the original print information (contents) and interferes with reading, so it is desirable to remove the reflected light.

Therefore, in order to cope with this, a technique such as changing the irradiation angle of the illumination light beam or arranging a polarizing filter in the optical path is employed. When the polarizing filter is disposed in the optical path, the polarizing filter is generally disposed at the front end of the taking lens, that is, the front end of the lens barrel so that the polarizing filter may be small.
As a method for attaching the polarizing filter to the lens barrel, for example, a polarizing filter formed in a circular shape from the optical axis direction is fitted into an annular filter frame and fixed or sandwiched, and the inner peripheral surface of the filter frame or There is known a method of forming a male screw or a female screw on the outer peripheral surface, and screwing and assembling a filter frame holding the polarizing filter into a lens barrel (for example, Patent Document 1, Patent Document 2, Patent Reference 3).
However, in these methods, it is not easy to position a polarizing filter having directionality in particular, and in a scanner or the like, the tip of the lens barrel and the reflecting mirror that bends the optical path are arranged close to each other. It is difficult to apply a conventional filter frame.

JP 2004-264555 A JP-A-2005-301172 JP 2005-301173 A

  The present invention has been made in view of the above circumstances, and the object of the present invention is to easily and accurately direct a filter member such as a polarizing filter while simplifying the structure and reducing the size. It is to provide a lens barrel that can be attached and incorporated, and in particular, to provide a lens barrel that is suitable for being mounted on a small scanner (in which the internal space is limited) that reads the surface of printed matter and the like. There is to do.

The lens barrel of the present invention includes a lens barrel that holds a lens and has an axis in the optical axis direction, a filter frame that is detachably coupled to an end of the lens barrel, and a thin plate-like filter that is fixed by the filter frame A filter barrel, wherein the filter frame is detachably fitted to the lens barrel, and sandwiches the filter member in cooperation with the lens barrel and exposes a part of the filter member. It is characterized by being cut out to allow it to.
According to this configuration, the filter member is sandwiched between the filter frame and the lens tube and is firmly fixed by fitting the filter frame to the lens tube after fitting into the filter frame so that a part of the filter member is exposed. The
Further, when the filter member has directionality, the exposed part of the filter member is used as positioning (for example, the exposed part is used as positioning itself, or a mark or the like for displaying the direction is provided on the exposed part, The filter member can be easily positioned with respect to the lens tube by fitting the filter frame to the lens tube while confirming the mark.
Furthermore, when this lens barrel is mounted on a scanner or the like, the cutout region of the filter frame is incorporated so as to face an adjacent optical component (for example, a reflection mirror), so that it does not interfere with the optical component. It can be easily mounted on a scanner or the like.

In the above configuration, the lens tube is formed in a cylindrical shape having an axial center in the optical axis direction, and the filter frame includes an annular fitting portion that is detachably fitted to the outer peripheral surface of the lens tube from the optical axis direction. A notch so that a part of the outer edge area of the filter member is brought into contact with the inner side in the optical axis direction and held in cooperation with the end surface of the lens cylinder, and the other part of the outer edge area of the filter member is exposed. It is possible to adopt a configuration including an end surface portion that is contacted from the outside in the optical axis direction.
According to this configuration, a part of the outer edge area of the filter member is brought into contact with the clamping part from the inner side, and the other part (except for a part) of the outer edge area of the filter member is brought into contact with the end face part from the outer side. In addition, the filter member is fitted into the filter frame, and the annular fitting portion of the filter frame is fitted to the outer peripheral surface (of the end portion) of the lens cylinder, so that the filter member is separated by the clamping portion of the filter frame and the end surface of the lens cylinder. It is pinched and fixed firmly.
Further, the other part of the outer edge area of the filter member that is in contact with the end face part and exposed to the outside is used as positioning (for example, the other part of the exposed outer edge area is used as positioning itself, or the other part of the exposed outer edge area is used as the other part of the exposed outer edge area. By providing a mark or the like and locating the filter member while confirming the mark), the filter frame in which the filter member is positioned is rotated with respect to the lens tube (around the optical axis). Orientation of the filter member (positioning of the mounting angle) can be performed easily and with high accuracy.

In the above configuration, the filter member is formed so as to demarcate an arc portion sandwiched by the sandwiching portion and a non-arc portion other than the arc abutting against the end surface portion in the outer edge region. Can be adopted.
According to this configuration, since the filter member is formed so as to define an outer edge region (outer contour) having an arc portion and a non-arc portion, the direction of the filter member with respect to the filter frame when the filter member is incorporated into the filter frame. The attachment of the filter frame with respect to the lens barrel can be adjusted, and the orientation of the filter member with respect to the lens barrel (positioning of the mounting angle) can be performed with high accuracy.

In the above configuration, the filter frame may be configured to be fixed with screws in a state of being fitted to the lens tube.
According to this configuration, the filter frame can be firmly and easily fixed to the lens tube by tightening the screw. When a directional filter member is incorporated, the filter frame can be fixed to the lens tube. After adjusting the angular position of the filter frame, the filter frame can be fixed to the lens cylinder with high accuracy by holding the screw so as not to deviate.

In the above configuration, the filter member may be a polarizing filter.
According to this configuration, it can be easily applied to an optical apparatus that requires a lens optical system including a polarizing filter, for example, a scanner that reads a printed material or the like.

  According to the lens barrel having the above-described configuration, a filter member (for example, a color filter, a polarizing filter, etc.) is easily and highly accurately oriented and incorporated while achieving simplification and downsizing of the structure. In particular, it is possible to obtain a lens barrel that is suitable for being mounted on a small scanner or the like that reads a paper surface such as a printed material.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
1 to 5 show an embodiment in which the lens barrel according to the present invention is applied to a small-sized scanner used for reading a printed matter or the like. FIG. 1 is a side sectional view showing an optical path of the scanner. 2 is a front view showing the optical path of the scanner, FIG. 3 is a side view and a front view of the lens barrel, FIG. 4 is a front view, a side view and a sectional view of the filter frame incorporating the filter member, and FIG. It is a front view.

As shown in FIGS. 1 and 2, this scanner reflects the subject light (light rays) emitted upward from the object OBJ by a first reflecting mirror 1 and a first reflecting mirror 1 that reflect the subject light in a substantially horizontal direction. A second reflecting mirror 2 that reflects the reflected light beam in the opposite horizontal direction, a lens barrel 3 that causes the light beam reflected by the second reflecting mirror 2 to enter the optical axis direction L, and subject light that has passed through the lens barrel 3 An image pickup device having an image forming plane P for forming an image of the light beam.
Here, as shown in FIG. 1, the first reflection mirror 1 is disposed at a position close to the tip of the lens barrel 3.

  As shown in FIGS. 1 to 3, the lens barrel 3 is fitted into the lens barrel 10 that holds the lens G, the pressing member 20 that holds the lens G, the filter frame 30 that is coupled to the lens barrel 10, and the filter frame 30. The filter member 40, the screw B etc. which fix the filter frame 30 to the lens cylinder 10 are provided.

As shown in FIGS. 1, 3A, and 3B, the lens tube 10 is formed in a cylindrical shape having an axial center in the optical axis direction L, an outer peripheral surface 11, an inner wall 12 that holds the lens G, and a predetermined shape. And an end face 15 defined at one end in the optical axis direction L, and the like.
Then, the lens G is fitted into the inner wall 12 from both sides in the optical axis direction L, and the holding member 20 is fitted into the inner wall 14 so as to press the lens G from both outer sides.
Further, an outer edge region (an arc portion 41 described later) of the filter member 40 is brought into contact with the end surface 15.

As shown in FIGS. 1, 3 (a), 3 (b), 4 (a), 4 (b), (c), the filter frame 30 is against the outer peripheral surface 11 located at the end of the lens tube 10. An annular fitting portion 31 that is detachably fitted from the optical axis direction L and a part of an outer edge region of the filter member 40 described later are brought into contact with the end surface 15 of the lens tube 10 by abutting from the inner side in the optical axis direction L. A clamping part 32 that works and clamps, an end face part 33 that is notched so as to expose the other part of the outer edge region of the filter member 40 to be described later, and is brought into contact with the outside in the optical axis direction L, and a screw B are screwed together 2 Two screw holes 34 and the like are provided.

The annular fitting portion 31 is formed in a cylindrical shape, and is formed so as to have an inner diameter dimension that is in close contact with the outer peripheral surface 11 of the lens tube 10 and is rotatably fitted around the optical axis L. Yes.
The annular fitting portion 31 is detachably fitted to the lens tube 10 in the optical axis direction L.
In addition, two screw holes 34 are formed in the annular fitting portion 31 so as to penetrate from the outer peripheral surface in the radial direction. The two screw holes 34 define a female screw into which the screw B is screwed.
That is, the filter frame 30 is formed so as to be fixed by the screw B while being fitted to the lens tube 10.
Therefore, after adjusting the angular position of the filter frame 30 with respect to the lens tube 10, the filter frame 30 can be firmly and easily fixed to the lens tube 10 by tightening the screws B.

  The sandwiching portion 32 is formed so as to extend in an arc shape radially inward from the inner peripheral surface 31a of the annular fitting portion 31, and an opening portion 32a that exposes the central region of the filter member 40, an optical axis An inner end face 32b that is formed so as to face the inside of the lens tube 10 in the direction L and abuts an arc portion 41 of the filter member 40 described later from the inner side in the optical axis direction L is defined.

  The end surface portion 33 is formed continuously above the clamping portion 32 by cutting out the upper region of the annular fitting portion 31 to expose a non-arc portion 42 of the filter member 40 described later and in the optical axis direction L. It comes to contact from the outside.

  As shown in FIG. 5, the filter member 40 is a thin plate-shaped polarizing filter having a polarization transmission axis in the direction of the arrow. In the outer edge region (outer contour), the filter member 40 is formed in an arc shape so as to hold the holding portion 32 ( The arc portion 41 as a part of the outer edge region sandwiched by the inner end face 32b), is formed in a substantially rectangular shape (that is, in a shape other than the arc shape) in the region above the arc portion 41, and is exposed to the outside, and the optical axis A non-circular arc portion 42 is defined as the other portion of the outer edge region in contact with the end surface portion 33 of the filter frame 30 from the outside in the direction L.

  As described above, the filter member 40 is formed so as to define the outer edge region (outer contour) having the arc portion 41 and the non-arc portion 42, and therefore, when the filter member 40 is incorporated in the filter frame 30, the filter with respect to the filter frame 30 is filtered. The orientation of the member 40 can be reliably performed, and the orientation of the filter member 40 relative to the lens barrel 10 can be performed with high accuracy by adjusting the assembly angle of the filter frame 30 relative to the lens barrel 10.

A procedure for assembling the lens barrel 3 having the above configuration will be described.
First, the filter member 40 is assembled into the filter frame 30. That is, the non-arc portion 42 is fitted while being appropriately elastically deformed (curved) so as to protrude from the inside of the filter frame 30 to the outside, the non-arc portion 42 is opposed to the end surface portion 33 from the outside in the optical axis direction L, and the arc The part 41 is brought into contact with the inner end surface 32 b of the clamping part 32.
As a result, as shown in FIGS. 3A and 4A, the filter member 40 is held with respect to the filter frame 30, and its central region is exposed by the opening 32a. The arc portion 42 is exposed by a portion cut out so as to define the end surface portion 33.

  Subsequently, the lens G is fitted into the lens tube 10 and the pressing member 20 is attached to fix the lens G. The lens tube 10, the lens G, and the pressing member 20 may be assembled before the filter member 40 is assembled into the filter frame 30.

Subsequently, the filter frame 30 holding the filter member 40 is coupled to the lens barrel 10 in which the lens G is incorporated. That is, the annular fitting portion 31 is brought close to one end portion of the lens tube 10 from one side in the optical axis direction L and is fitted on the outer peripheral surface 11.
In this fitted state, the annular fitting part 31 (filter frame 30) can be rotated around the optical axis L with respect to the lens tube 10 to finely adjust the angle.

Therefore, the annular fitting portion 31 (filter frame 30) is appropriately rotated so that the polarization transmission axis of the filter member 40 is oriented in a predetermined direction with respect to the lens cylinder 10 (lens G), and the lens cylinder 10 Finely adjust the mounting angle with respect to.
By this fine adjustment, the filter member 40 is oriented with its mounting angle positioned with high accuracy.

  Thereafter, the filter frame 30 (filter member 40) is firmly fixed to the lens tube 10 while maintaining a highly accurate position by screwing the screw B into the screw hole 34 of the annular fitting portion 31. The Thereby, the lens barrel 3 is completed.

  As described above, after fitting into the filter frame 30 so as to expose the other part (non-arc part 42) of the central region and outer edge region of the filter member 40, the filter frame 30 is adjusted to the lens while finely adjusting the assembly angle. The filter member 40 can be clamped between the filter frame 30 and the lens tube 10 and firmly assembled while positioning (orienting) the filter member 40 only by coupling to the tube 10.

  As described above, according to the lens barrel 3, the filter member 40 can be easily and highly accurately oriented and assembled while achieving simplification and downsizing of the structure. Since part of the filter frame 30 is cut out so that part of 40 is exposed, as shown in FIG. 1, the lens cylinder 3 is mounted on a small scanner that reads a paper surface such as a printed matter. Further, by incorporating the notched region of the filter frame 30 so as to face the adjacent first reflection mirror 1 (in a non-contact state), the filter frame 30 can be easily mounted on the scanner.

  In the above embodiment, the case where the filter member 40 is formed so as to define the arc portion 41 and the non-arc portion 42 is shown, but the present invention is not limited to this, and the direction of the filter member 40 is exposed to the exposed portion. If the mark etc. which display is provided, the filter member 30 can be easily positioned by fitting the filter frame 30 to the lens tube 10 while confirming the mark.

  In the above embodiment, the case where the filter frame 30 is fitted to the lens tube 10 and then fixed by tightening the screw B is shown. However, if it is not necessary to disassemble the filter frame 30, the filter frame 30 is fitted to the lens tube 10. After positioning together, it may be fixed using an adhesive or the like.

  In the above embodiment, a polarizing filter having directionality is shown as a filter member applied to the lens barrel. However, the polarizing member is not limited to this, and has no directionality such as a color filter or an ND filter. A filter member may be applied.

  As described above, the lens barrel of the present invention can easily and precisely incorporate a filter member while achieving simplification of the structure, downsizing, etc. Needless to say, the present invention can be applied to a small scanner for reading and the like, and is not limited to a scanner, and is useful in other optical devices as long as it is a lens optical system that requires a lens barrel in which lenses and filter members are arranged.

1 is a side sectional view showing an optical path of an embodiment of a scanner equipped with a lens barrel according to the present invention. It is a front view which shows the optical path which looked at the scanner carrying the lens-barrel shown in FIG. 1 from the optical axis direction. 2 shows a lens barrel mounted on the scanner shown in FIG. 1, wherein (a) is a side view of the lens barrel, and (b) is a front view of the lens barrel. FIG. FIG. 4 shows a filter frame and a filter member included in the lens barrel shown in FIG. 3, (a) is a front view thereof, (b) is a side view thereof, and (c) is an E1-E1 in (a). It is sectional drawing. FIG. 4 is a front view showing a filter member included in the lens barrel shown in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st reflective mirror 2 2nd reflective mirror 3 Lens barrel P Imaging surface L Optical axis OBJ Object 10 Lens cylinder 11 Outer peripheral surface 12 Inner wall 13 Aperture stop 14 Inner wall 15 End surface G Lens 20 Pressing member 30 Filter frame 31 Ring fitting Part 31a Inner peripheral surface 32 Clamping part 32a Opening part 32b Inner end face 33 End face part 34 Screw hole 40 Filter member 41 Arc part (a part of outer edge area)
42 Non-arc part (other part of outer edge area)

Claims (5)

A lens tube that holds the lens and has an axis in the optical axis direction; a filter frame that is detachably coupled to an end of the lens tube; and a thin plate-like filter member that is fixed by the filter frame. A lens barrel,
The filter frame is detachably fitted to the lens cylinder, and is cut out so as to sandwich the filter member in cooperation with the lens cylinder and expose a part of the filter member.
A lens barrel characterized by that. The lens tube is formed in a cylindrical shape having an axis in the optical axis direction,
The filter frame has an annular fitting portion that is detachably fitted to the outer peripheral surface of the lens tube from the optical axis direction, and a part of an outer edge region of the filter member abutted from the inner side in the optical axis direction. And an end surface part that is notched so as to expose the other part of the outer edge region of the filter member and abuts from the outside in the optical axis direction. ,
The lens barrel according to claim 1. The filter member is formed in an outer edge region so as to delimit an arc portion held by the holding portion and a non-arc portion other than the arc abutted on the end surface portion.
The lens barrel according to claim 2, wherein: The filter frame is formed to be fixed by screws in a state of being fitted to the lens tube.
The lens barrel according to claim 2 or 3, wherein The filter member is a polarizing filter.
The lens barrel according to any one of claims 1 to 4, wherein:

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