JP2006178236A - Plastic lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic lens preventing stress generated in holding from being transmitted to a lens main body side. <P>SOLUTION: In the plastic lens 2, a projection 8 projected in a radial direction is integrally molded on the circumference of the lens main body 5. An insertion hole 8a through which a machine screw 12 is inserted is formed on the edge side of the projection 8 and an aperture 8b is formed on the base side thereof. The machine screw 12 is inserted through the insertion hole 8a and is screwed in the machine screw hole 10a of a lens frame 10 to mount the plastic lens 2 in the lens frame 10. The stress is exerted on the edge side of the projection 8 of the plastic lens 2 by screwing the machine screw. The stress tres to get to the lens main body 5 side passing through the base side of the projection 8, but it hardly transmits to the lens main body 5 because the aperture 8b is formed on the base side of the projection 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plastic lens used in an optical apparatus such as a camera or an optical disk device.

  Optical devices such as film units with lenses and digital cameras are injected with plastic because they are easier to form an aspheric shape, are lighter and harder to break, and are easier to manufacture than glass lenses. Opportunities are increasing for plastic lenses that are molded and manufactured.

Among plastic lenses, there is one in which an edge that does not function as an optical lens is formed on the outer periphery of a lens body that functions as an optical lens, and is used while being held in a case. A leaf spring is provided in the case, and the leaf spring presses the edge surface to hold the plastic lens in the case (see Patent Document 1).
JP 2001-209118 A

  However, when the plastic lens is held in the case as described above, the stress generated on the edge surface due to the pressing of the leaf spring is transmitted to the lens body side, so that the lens body is distorted and the lens performance is affected. It was.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a plastic lens that prevents the stress generated during holding from being transmitted to the lens body side.

  In order to solve the above-described problems, the plastic lens of the present invention is formed by integrally forming a protrusion protruding in the radial direction on the outer periphery of the lens body, the tip end side of the protrusion being fixed to the lens frame, and the protrusion on the base side of the protrusion. It is characterized in that a stress absorbing portion for preventing stress generated when the front end side is fixed from reaching the lens body side is integrally formed.

  Further, a protrusion protruding in the radial direction is integrally formed on the outer periphery of the lens body, and a cam follower that engages with a cam groove formed on the lens barrel is fixed on the outer periphery of the protrusion, and the cam follower is attached to a base side of the protrusion. A stress absorbing portion that prevents stress generated when the lens is fixed from reaching the lens body side is integrally formed.

  Also, an elastically deforming projecting piece protruding in the radial direction is integrally formed on the outer periphery of the lens body, the tip side of the projecting piece is fixed to the front surface of the lens frame, and the outer peripheral portion on the back side of the lens body is contacted with the front surface of the lens frame. A positioning surface for positioning the lens body in the optical axis direction in contact is formed, and by fixing the tip end side of the projecting piece to the front surface of the lens frame, the tip end side of the projecting piece is elastically deformed to the back side, and the elasticity of the projecting piece The stress absorbing portion that integrally presses the positioning surface against the front surface of the lens frame and prevents the stress accompanying deformation of the protruding piece from reaching the lens body side is integrally formed on the base side of the protruding piece. To do.

  According to the plastic lens of the present invention, the stress absorbing portion for preventing the stress generated when the tip end side of the protrusion is fixed to the lens body side is integrated with the base side of the protrusion protruding in the radial direction on the outer periphery of the lens body. Therefore, it is possible to prevent the stress generated by the fixing when the lens frame is held from being transmitted to the lens body.

  Also, a protrusion that protrudes in the radial direction is integrally formed on the outer periphery of the lens body, and a stress absorbing portion that prevents the stress generated when the cam follower is fixed from reaching the lens body side is integrally formed on the base side of the protrusion. Therefore, it is possible to prevent the stress generated when the cam follower is fixed from being transmitted to the lens body.

  Also, by fixing the tip end side of the projecting piece to the base side of the projecting piece projecting in the radial direction on the outer periphery of the lens body, the stress that causes the tip end side of the projecting piece to elastically deform to the back side is prevented from reaching the lens body side. By integrally forming the stress absorbing portion, it is possible to prevent the stress accompanying the deformation of the projecting piece from being transmitted to the lens body when held by the lens frame. In addition, a positioning surface that positions the lens body in the optical axis direction by contacting the front surface of the lens frame is formed on the outer peripheral portion on the back side of the lens body, so that positioning in the optical axis direction when the plastic lens is assembled to the lens frame Can be done easily.

  It is also conceivable that another member such as rubber is employed as the stress absorbing portion, and this separate member is disposed between the projection or the projecting piece and the lens frame. However, using such another member increases the number of parts and the number of man-hours for adjustment work and the like, leading to an increase in cost. Therefore, in the present invention, a stress absorbing portion is integrally formed on the base side of the protrusion or the projecting piece with the intention of excluding such another member.

  In FIG. 1 showing the first embodiment of the present invention, a plastic lens 2 is a convex lens made by injection molding of plastic. In the plastic lens 2, four protrusions 8 projecting in the radial direction are integrally formed on the outer periphery of a lens body 5 having a function as an optical lens at equal intervals. An insertion hole 8 a through which the screw 12 is inserted is formed on the tip end side of the protrusion 8. A rectangular opening 8b is formed on the base side of the protrusion 8 as a stress absorbing portion according to the present invention formed integrally therewith. In addition, a spacer receiver 5a that contacts a spacer (not shown) is formed on the lens surface.

  In FIG. 2 showing a state in which the plastic lens 2 is held on the lens frame, a screw hole 10 a into which the tip of the screw 12 is screwed is formed on the front surface of the lens frame 10. The plastic lens 2 is assembled to the lens frame 10 while adjusting the position, and the screw hole 10a is screwed through the screw 12 and the insertion hole 8a. As a result, the tip end side of the protrusion 8 is fixed to the lens frame 10 with screws, and the plastic lens 2 is held by the lens frame 10.

  The operation of this embodiment will be described. Stress due to fixing with screws is applied to the tip side of the protrusion 8 of the plastic lens 2 held by the lens frame 10. This stress is transmitted to the lens body 5 side through the root side of the protrusion 8, but is prevented from being transmitted to the lens body 5 because the opening 8 b is formed on the root side of the protrusion 8.

  In FIG. 3 showing the second embodiment of the present invention, a plastic lens 15 is integrally formed with three projections 20 projecting in the radial direction on the outer periphery of a lens body 18 having the function of an optical lens at equal intervals. A rectangular opening 20a is integrally formed on the root side of the projection 20 as a stress absorbing portion, and a loose insertion hole 20b is formed at the tip of the projection 20 into which the shaft portion 24 of the cam follower 23 is loosely inserted. A screw hole 20c into which the tip of the screw 25 is screwed is formed in the back of the loose insertion hole 20b.

  The cam follower 23 is formed with a through hole 23a through which the screw 25 passes. The cam follower 23 is rotatably fixed to the plastic lens 15 by screwing the screw 25 passed through the through hole 23a into the screw hole 20c.

  In FIG. 4 showing the zoom cam barrel and the fixed barrel to which the plastic lens 15 is attached, the zoom cam barrel 27 is formed with zoom cam grooves 27a and zoom cam grooves 27b having different shapes, and the cam follower 23 of the cam follower 23 is formed in the zoom cam grooves 27a and 27b. The root side is engaged. A plastic lens 15 is housed inside the zoom cam barrel 27. The fixed cylinder 30 is formed with a rectilinear cam groove 30a with which the distal end side of the cam follower 23 is engaged, and the zoom cam barrel 27 is accommodated therein.

In order to mount the plastic lens 15 in the zoom cam barrel 27, first, the plastic lens 15 is accommodated in the zoom cam barrel 27 so that each loose insertion hole 20b is exposed from the zoom cam groove 27a, and the zoom cam barrel 27 is moved straight. It accommodates in the fixed cylinder 30 so that each loose insertion hole 20b may be exposed from the cam groove 30a. Next, the shaft portion 24 of the cam follower 23 is inserted into each loose insertion hole 20b and engaged with the zoom cam groove 27a and the straight cam groove 30a. Thereafter, the assembly position of the plastic lens 15, the zoom cam barrel 27a, and the fixed barrel 30 is adjusted, the screw 25 is passed through the through hole 23a and screwed into the screw hole 20c, and the cam follower 23 is fixed to the plastic lens 15 with screws. Thereby, the plastic lens 15 is attached in the zoom cam barrel 27 via the cam follower 23. The plastic lens 15 moves in the optical axis direction when the zoom cam barrel 27 is rotated.

  Further, a plastic lens 32 configured in the same manner as the plastic lens 15 is accommodated in the zoom cam barrel 27 so that each loose insertion hole 20b is exposed from the zoom cam groove 27b and the straight cam groove 30a. Next, the cam follower 23 is fixed to the plastic lens 32 with screws while adjusting the assembly position of the plastic lens 32. As a result, the plastic lens 32 is mounted in the zoom cam barrel 27 via the cam follower 23 in the same manner as the plastic lens 15. The plastic lens 32 moves in the optical axis direction when the zoom cam barrel 27 is rotated. The amount of movement of the plastic lenses 15 and 32 in the optical axis direction with the rotation of the zoom cam barrel 27 is different.

  The operation of this embodiment will be described. Stress is applied to the distal ends of the projections 20 of the plastic lenses 15 and 32 attached to the zoom cam barrel 27 by screwing. This stress tends to be transmitted to the lens body 18 side, but is prevented from being transmitted to the lens body 18 because the opening 20 a is formed on the base side of the protrusion 20.

  Further, since the plastic lenses 15 and 32 are attached to the zoom cam barrel 27 and the fixed barrel 30 by fixing the cam follower 23 with screws, a lens holding frame is not necessary. When the zoom cam barrel 27 is rotated, the distance between the plastic lenses 15 and 32 in the optical axis direction is changed, and the magnification of the optical system is changed.

  In FIG. 5 showing the third embodiment of the present invention, the plastic lens 34 has four projecting pieces 37 projecting in the radial direction along the outer periphery at substantially the middle position of the outer peripheral edge of the lens body 35 in the optical axis direction. It is arrayed at regular intervals. The projecting piece 37 is thin and elastically deformable, and a rectangular opening 37a as a stress absorbing portion formed integrally is formed on the base side, and a screw 38 (see FIG. 6) is inserted on the tip side. An insertion hole 37b is formed. In addition, a positioning surface 35a (see FIG. 6) that contacts the lens frame 39 (see FIG. 6) and positions the lens body 35 in the optical axis direction is formed on the outer peripheral portion on the back side of the lens body 35.

  In FIG. 6 showing a state in which the plastic lens 34 is held by the lens frame 39, a screw hole 39a into which the tip of the screw 38 is screwed and a lens receiving surface 39b that contacts the positioning surface 35a are formed on the front surface of the lens frame 39. Yes. The positioning surface 35a is brought into contact with the lens receiving surface 39b, and the screw 28 inserted through the loose insertion hole 20b is screwed into the screw hole 39a to fix the plastic lens 34 to the lens frame 39 with screws.

  The operation of this embodiment will be described. By screwing the plastic lens 34 to the lens frame 39, the tip end side of the projecting piece 37 is elastically deformed toward the lens frame 39 side, and the stress generated on the tip end side of the projecting piece 37 tends to be transmitted to the lens body 35 side. Since the opening 37a is formed on the base side of the projecting piece 37, it is prevented from being transmitted to the lens body 35.

  In the embodiment described above, the rectangular opening is adopted as the stress absorbing portion integrally formed on the base side of the protrusion or the protruding piece of the plastic lens, but the present invention is not limited to this, and the plastic lens For example, a U-shaped groove may be used as long as it absorbs stress generated during holding. Further, the shape of the lens body is not limited to a circular shape, and may be a plastic lens having various shapes such as a square shape.

1 is an external perspective view showing a first embodiment of the present invention. It is sectional drawing which shows the state which attached the plastic lens to the lens frame. It is explanatory drawing which shows 2nd Embodiment of this invention. It is explanatory drawing which shows a fixed cylinder and a zoom cam barrel. It is an external appearance perspective view which shows 3rd Embodiment of this invention. It is sectional drawing which shows the state which attached the plastic lens of 3rd Embodiment to the lens frame.

Explanation of symbols

2, 15, 32, 34 Plastic lens 5, 18, 35 Lens body 8, 20 Protrusion 8a, 37b Insertion hole 8b, 20a, 37a Opening 10, 39 Lens frame 12, 25, 38 Screw 20b Free insertion hole 27 Zoom cam barrel 30 Fixed cylinder

Claims (3)

In a plastic lens in which a protrusion protruding in the radial direction is integrally formed on the outer periphery of the lens body, and the tip side of this protrusion is fixed to the lens frame,
A plastic lens, wherein a stress absorbing portion is integrally formed on a base side of the protrusion to prevent a stress generated when the tip end side of the protrusion is fixed from reaching the lens body side. In a plastic lens in which a protrusion protruding in the radial direction is integrally formed on the outer periphery of the lens body, and a cam follower that is engaged with a cam groove formed in a lens barrel is fixed to the tip end side of the protrusion.
A plastic lens, wherein a stress absorbing portion for preventing stress generated when the cam follower is fixed from reaching the lens body side is integrally formed on a base side of the protrusion. In a plastic lens in which an elastically deforming protruding piece protruding in the radial direction is integrally formed on the outer periphery of the lens body, and the tip side of the protruding piece is fixed to the front surface of the lens frame,
A positioning surface for positioning the lens body in the optical axis direction is formed on the outer peripheral portion on the back side of the lens body so as to position the lens body in the optical axis direction, and the tip of the protruding piece is fixed to the front surface of the lens frame. The front end side is elastically deformed to the back side, and the elastic surface of the projecting piece presses the positioning surface against the front surface of the lens frame, and projects a stress absorbing portion that prevents stress accompanying deformation of the projecting piece from reaching the lens body side A plastic lens formed on the base side of a piece.

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