JP2005062385A - Lens device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens device equipped with a click mechanism which can position an operation ring in a prescribed position, with respect to a stationary cylinder, without increasing the number of parts. <P>SOLUTION: In the lens device 10, an engaging member 60 formed integrally with the operation ring 40 is elastically engaged with a section 62 to be engaged which is formed integrally with a stationary cylinder 38, so that the clicking mechanism for positioning the operation ring 40, with respect to the stationary cylinder 40, is constituted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lens apparatus, and more particularly to a lens apparatus for a document camera that captures a document such as a document and displays it on an image display apparatus.

  In recent years, video projectors with document cameras have become widespread instead of overhead projectors as projectors used for presentations (Patent Document 1).

  A video projector with a document camera attaches a document camera to a pole of a camera stand, places a document on a table of the camera stand, and images the document with the document camera, thereby projecting a document image on a screen. There is also a device that displays a captured document image on a display device such as an LCD monitor.

  By the way, the lens device of the document camera may be used not only to image a document placed on a table but also to change the direction from that position, for example, to image a scene of a presentation venue. In such a case, if an autofocus lens device is used, it is possible to automatically focus at a close distance (foreground) for capturing an image of a document and at a distant position (distant view) for capturing an image of a presentation venue. However, since an autofocus lens device is expensive, a lens device that switches the focus by manual operation is generally used.

As a manually operated lens device, an operating ring to which a focus lens is attached is screwed and connected to a fixed cylinder, and the operating ring is rotated to move the focus lens back and forth with respect to the photographing optical axis. There is something to match. In the manually operated lens device, it is necessary to position the operation ring at the foreground in-focus position and the far-in-focus position with respect to the fixed cylinder, respectively. (For example, patent document 2).
JP 11-252454 A Japanese Utility Model Publication No.4-130917

  However, the conventional lens device having a click mechanism composed of a spring and a steel ball has a drawback that the number of parts increases due to the parts of the click mechanism, and it takes time to assemble the click mechanism which is a small part. It was.

  The present invention has been made in view of such circumstances, and provides a lens apparatus including a click mechanism that can position an operation ring at a predetermined position with respect to a fixed cylinder without increasing the number of parts. Objective.

  In order to achieve the above-mentioned object, the present invention rotates the operating ring that is rotatably attached to the fixed cylinder so that the moving lens attached to the operating ring moves relative to the photographing optical axis, or In the lens device in which the aperture member operates, an engagement member is integrally formed on the operation ring, and an engaged portion is formed integrally on the fixed cylinder, and the engagement member is elastically engaged. The rotational position of the operation ring with respect to the fixed cylinder is positioned by elastically engaging the engaging member with the engaged portion.

  According to the present invention, the click mechanism for positioning the operation ring with respect to the fixed cylinder by elastically engaging the engaging member formed integrally with the operation ring with the engaged portion formed integrally with the fixed cylinder. Configured. Accordingly, it is possible to provide a lens apparatus including a click mechanism that can position the operation ring at a predetermined position with respect to the fixed cylinder without increasing the number of parts.

  Further, when the operation object by the operation ring is a focus lens, two engaged parts are formed in the vicinity of both ends of the rotation range of the operation ring, and the engagement is performed at the two engaged parts. By engaging the members, it is possible to switch between pan focus on the foreground side and pan focus on the far side. Further, when the operation target is a diaphragm member, the aperture diameter can be switched between the minimum diameter and the maximum diameter by the operation of the diaphragm member, and when the operation target is a zoom lens, the aperture is switched between wide angle and telephoto. be able to. Further, by forming three or more engaged parts, the focal position, aperture value, and focal distance can be switched in multiple stages.

  According to the lens device of the present invention, the engagement member formed integrally with the operation ring is elastically engaged with the engaged portion formed integrally with the fixed cylinder, thereby positioning the operation ring with respect to the fixed cylinder. Since the click mechanism is configured, a lens apparatus including a click mechanism that can position the operation ring at a predetermined position with respect to the fixed cylinder without increasing the number of parts can be provided.

  Further, according to the present invention, two engaged parts are formed in the vicinity of both ends of the rotation range of the operation ring, and the engaging member is engaged with the two engaged parts. It is possible to switch between pan focus on the foreground side and pan focus on the far view side.

  Hereinafter, preferred embodiments of a lens apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view of a document camera 12 to which the lens device 10 of the embodiment is attached. The image of the document 14 captured by the document camera 12 is displayed on the LCD monitor device 20 connected to the camera body 16 of the document camera 12 via the signal cable 18.

  The document camera 12 is attached to a pole 26 erected on a table 24 of a camera stand 22 via an elevating block 28 so that the elevating position can be raised and lowered by tightening an operation knob 30 attached to the block 28. Adjusted. As a result, the document camera 12 is positioned at a position where the document 14 placed on the table 24 is in focus. The camera body 16 of the document camera 12 is attached to a bracket 32 formed on the block 28 via an operation knob 34. If the operation knob 34 is loosened, the camera body 16 can be rotated as shown by the arrow A about the shaft 35 of the operation knob 34. Thereby, the direction of the lens apparatus 10 can be changed from a downward position where the document 14 is imaged to a lateral position where the scenery of the presentation venue is imaged, for example.

  2 is a perspective view of the lens apparatus 10 with the cover 36 of the lens apparatus 10 shown in FIG. 1 removed, and a cross-sectional view thereof is shown in FIG.

  The lens device 10 includes a fixed cylinder 38, an operation ring 40, a spring 42, and the like. The fixed cylinder 38 includes a large-diameter cylinder part 44 connected to the mount part of the camera body 16 shown in FIG. 1 and a small-diameter cylinder part 50 into which a lens frame 48 holding the focus lenses 46 and 46 is inserted. Is done. The CCD 52 and the substrate thereof, which are solid-state image sensors, are fixed to the large-diameter cylindrical portion 44 in a state in which the spring washer 54 is prevented from falling off. Has been.

  The operation ring 40 has a knurled portion 41 that is manually operated formed on the surface thereof, and the above-described lens frame 48 is integrally fixed by a set screw 58 inside the operation ring 40. A male screw portion 49 is engraved on a part of the outer peripheral surface of the lens frame 48, and a female screw portion 51 that engages with the male screw portion 49 is formed on the inner peripheral surface of the small diameter cylindrical portion 50 of the fixed cylinder 38. Accordingly, when the operation ring 40 is rotated with respect to the fixed cylinder 38, the lens frame 48 moves back and forth along the optical axis P together with the operation ring 40 by the screw feeding action of the male screw portion 49 and the female screw portion 51. Thereby, the focus lens 46 moves back and forth along the optical axis P, and focusing is performed. Further, the backlash between the male screw portion 49 and the female screw portion 51 is caused by the biasing force of the spring 42 disposed between the step portion 50A of the small-diameter tube portion 50 of the fixed tube 38 and the flange portion 48A of the lens frame 48. Has been removed.

  By the way, the lens device 10 of the embodiment is provided with a click mechanism for positioning the rotation position of the operation ring 40 with respect to the fixed cylinder 38. The click mechanism includes an engaging member 60 integrally formed with the operation ring 40 and an engaged portion 62 integrally formed with the fixed cylinder 38 as shown in FIG. Are engaged with each other elastically to position the rotation position of the operation ring 40 with respect to the fixed cylinder 38.

  As shown in FIG. 3, the engaging member 60 has a beam portion 64 projecting in parallel with the optical axis P from the side surface of the operation ring 40. Thus, the claw portion 68 having a triangular cross section is formed in parallel with the optical axis P. According to the engaging member 60, an elastic force is applied to the claw portion 68 engaged with the engaged portion 62 by the elasticity of the beam portion 64 and the thin tip portion 66 that are cantilevered on the operation ring 40. ing.

  2 and 3, the engaged portion 62 has an arcuate plate 70 projecting in parallel with the optical axis P from the side surface of the large-diameter cylinder portion 44 of the fixed cylinder 38. Concave portions 72 and 74 with which the claw portion 68 is elastically engaged are formed on the inner surface as shown in FIGS. The recesses 72 and 74 are formed on both sides of the operation ring 40 in the rotational direction, and the recess 72 is a stopper 76 formed at one end of the plate 70 and a ridge formed on the inner surface of the plate 70. The concave portion 74 is formed between the stopper portion 80 formed at the other end of the plate 70 and the convex portion 82 formed on the inner side surface of the plate 70.

  When the claw portion 68 is engaged with the concave portion 72 as shown in FIG. 5, the engaging member 60 receives a force in the direction of the arrow and is elastically deformed in the same direction. Therefore, the claw portion 68 is engaged with the concave portion 72 with an elastic force, so that it is not easily detached from the concave portion 72. The same applies to the recess 74. Further, the engagement from the concave portion 72 to the concave portion 74 and the engagement from the concave portion 74 to the concave portion 72 are made possible by the claw portion 68 being elastically deformed and passing so as to ride on the ridge portions 78 and 82.

  When the operation ring 40 is rotated to engage the claw portion 68 with the recess 72, the focus lens 46 is moved backward (opposite to the subject side) by the screw feeding action of the male screw portion 49 and the female screw portion 51 shown in FIG. Therefore, it is positioned at the pan focus position where the far side is in focus. Further, when the operating ring 40 is rotated to engage the claw portion 68 with the recess 74, the focus lens 46 is moved forward (subject side) by the screw feeding action of the male screw portion 49 and the female screw portion 51. The camera is positioned at the pan focus position where the foreground is in focus.

  Since the fixed cylinder 38 is connected to the camera body 16, the fixed cylinder 38 is manufactured by a high strength polycarbonate. On the other hand, the operation ring 40 is not required to be strong like the fixed cylinder 38, and is elastic in the click mechanism. It is manufactured from polyacetal because it requires slipperiness and wear resistance.

  Next, the operation of the lens apparatus 10 configured as described above will be described.

  First, when the document 14 is imaged by the document camera 12 attached to the pole 26 of the camera stand 22, the operation ring 40 is rotated to engage the claw portion 68 with the recess 74. As a result, the focus lens 46 is moved forward by the screw feeding action of the male screw portion 49 and the female screw portion 51 shown in FIG. 3, and is positioned at the pan focus position where the foreground side is in focus. It is possible to take an image in a state in which

  Next, when the document camera 12 captures, for example, the scenery of the presentation venue, the operation ring 40 is rotated in the opposite direction to engage the claw portion 68 with the recess 72. As a result, the focus lens 46 is moved rearward by the screw feeding action of the male screw portion 49 and the female screw portion 51 and is positioned at the pan focus position where the far side is in focus, so that the scenery of the presentation venue is in focus. Images can be taken in a state. In this case, the orientation of the document camera 10 may be changed while the document camera 10 is attached to the camera stand 22, or the document camera 10 may be detached from the camera stand 22 and imaged.

  As described above, according to the lens device 10 of the embodiment, the engaging member 60 formed integrally with the operation ring 40 is elastically engaged with the engaged portion 62 formed integrally with the fixed cylinder 38. The click mechanism for positioning the operation ring 40 with respect to the fixed cylinder 38 is configured. In addition, it is preferable that the integral formation in a present Example is produced by the shaping | molding by a plastic. Of course, it may be created by bonding, joining, shaving, etc., but it is preferable to integrally form by plastic molding in consideration of the number of processing steps, the number of parts, and the like.

  Thereby, according to the lens apparatus 10, the lens apparatus provided with the click mechanism which can position the operation ring 40 with respect to the fixed cylinder 38 in a predetermined position without increasing the number of parts can be provided.

  In the embodiment, the lens apparatus 10 that moves the focus lens 46 has been described. However, the object that operates by rotating the operation ring is not limited to the focus lens 46. For example, in the case of a lens device that can change the aperture value by rotating the operation ring, the aperture diameter of the aperture member can be switched between the minimum diameter and the maximum diameter. Further, in the case of a lens device in which the zoom lens is moved by the rotation of the operation ring, it can be switched between wide angle and telephoto.

  Furthermore, by forming three or more engaged parts, the focal position, aperture value, and focal distance can be switched in multiple stages. FIG. 6 is a cross-sectional view in which concave portions 63, 63... Are continuously formed in the engaged portion 62. In this case, it is preferable that the concave portion 63 is formed in a triangular cross section in terms of engagement of the engaging member 60. Further, the engaged portion 62 may be formed on the operation ring 40 side, and the engaging member 60 may be formed on the fixed cylinder 38 side.

The perspective view which shows the structure of the document camera with which the lens apparatus of embodiment was attached The perspective view when the cover of the lens apparatus shown in FIG. 1 is removed. Sectional drawing of the lens apparatus shown in FIG. Enlarged perspective view of main parts of engaging member and engaged part Sectional drawing of the principal part of the lens apparatus seen from the 5-5 line of FIG. Sectional view in which recesses are continuously formed in the engaged part

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Lens apparatus, 12 ... Document camera, 14 ... Document, 16 ... Camera body, 20 ... LCD monitor apparatus, 22 ... Camera stand, 38 ... Fixed cylinder, 40 ... Operation ring, 42 ... Spring, 46 ... Focus lens, 48 ... Lens frame, 60 ... Engaging member, 62 ... Engaged part, 68 ... Claw part, 72, 74 ... Recessed part

Claims (3)

In the lens device in which the movable lens attached to the operation ring moves with respect to the photographing optical axis or the diaphragm member operates by rotating the operation ring attached to the fixed cylinder so as to be rotatable.
An engaging member is integrally formed on the operation ring, and an engaged portion to which the engaging member is elastically engaged is integrally formed on the fixed cylinder, and the engaged portion is engaged with the engaged portion. A lens device in which a rotation position of an operation ring with respect to a fixed cylinder is positioned by elastically engaging a member.   The engaged portions are formed at two positions near both end portions of the rotation range of the operation ring, and the engaging member is engaged with the two engaged portions so that the moving lens is light-transmitted. The lens apparatus according to claim 1, wherein the lens apparatus is moved with respect to an axis, and is switched between a foreground pan focus and a far view pan focus.   3. The lens apparatus according to claim 1, wherein the operation ring is a focus operation ring.

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