JP5864183B2 - Glass lens and manufacturing method thereof - Google Patents

Description

  The present invention relates to a glass lens fixed to a plastic lens frame by thermal caulking and a method for manufacturing the same.

  In a CCTV lens for monitoring, the lens itself is glass, but the lens barrel is made of plastic for cost reduction, mass production, and multifunctional shape. In order to fix a glass lens to a lens frame in a plastic lens barrel, thermal caulking, in which the glass lens is fixed by thermally deforming the end surface of the lens frame, is widely used.

  Also, if you want to cut unnecessary rays on the glass or lens at the end, or if you want to prevent flare from occurring, if the glass lens is fixed with a presser ring, you can change the shape of the presser ring. it can. However, since the shape of the end of the lens frame is determined by heat caulking, fixing the glass lens by heat caulking requires the addition of a molded part that requires an initial cost. For example, it is assumed that the glass lenses L1 and L2 are fixed to the lens frame 80A via the spacing ring 14 as shown in the partial cross-sectional view of FIG. A mask member 83 extending from the upper surface of the lens frame 80A to the rear end surface of the lens frame 80A and extending from the rear end surface to the lens L2 is required. Further, as shown in the partial cross-sectional view of FIG. 5, the lens frame 80B is divided into two parts at the end of the lens frame 80B, and a mask member 85 extending from the branched part toward the glass lens L2 is provided. is there.

  In addition, the lens material and the type of thermoplastic resin of the holding frame are not limited (Patent Document 1), the one that forms a black coating for preventing stray light (Patent Document 2), and obtains a high precision core accuracy There is also a thing (patent document 3).

JP 2011-13532 A JP2009-40642 JP 2009-9168

  However, in the case shown in FIG. 4, a new mask member 83 is required. In the case shown in FIG. 5, there is not always a space for attaching such a mask member 85. 4 and 5 increase the size, and the camera cannot be reduced in size. Further, since it is necessary to attach the mask member 83 or 85, not only the cost increases, but also the manufacturing process cannot be simplified. Also in Patent Documents 1 to 3, the cost increases and the manufacturing process cannot be simplified.

  The object of the present invention is not only to simplify the manufacturing process, but also to reduce the cost and reduce the size of the camera.

The present invention is a glass lens fixed to a plastic lens frame by heat caulking, and includes a light-shielding step formed along the periphery of the lens surface of the glass lens and the peripheral surface of the glass lens. And a heat caulking slope formed continuously toward the light shielding step .

  The present invention also provides a method for manufacturing a glass lens. That is, a method of manufacturing a glass lens fixed to a plastic lens frame by heat caulking, wherein the processing means includes a light shielding step formed along the periphery of the lens surface of the glass lens, and a glass lens. The heat caulking slope formed continuously from the peripheral surface toward the light shielding step is formed by one process, and the assembling apparatus is formed with the light shading step and the heat caulking slope.・ The lens is attached to a plastic lens frame, and the heat caulking device heat caulks the peripheral surface of the glass lens to the plastic lens frame.

According to the present invention, the light shielding step portion is formed along the periphery of the lens surface of the glass lens, and the heat caulking slope is continuously formed from the peripheral surface of the glass lens toward the light shielding step portion. From these light-blocking step portion and the thermal caulking for slope than Ru is formed in one process, the manufacturing process is simplified. In addition, since there is no need to attach a new mask member for light shielding, the camera can be miniaturized and the cost can be reduced.

  The shading step and the thermal caulking slope are formed by a single cutting process using a processing member, for example.

  The light shielding step portion is shielded from light by, for example, sanitization or a light shielding sheet.

  The glass lens is, for example, the lens closest to the solid-state electronic image sensor among the lenses included in the lens barrel, and is also used in other places.

It is sectional drawing of a lens barrel. It is a flowchart which shows the process sequence which fixes a glass lens to a lens frame. (A) to (D) are processing steps for fixing the glass lens to the lens frame. It is sectional drawing of the conventional lens barrel. It is sectional drawing of the conventional lens barrel.

  FIG. 1 shows an embodiment of the present invention and is a cross-sectional view of a lens barrel 10 to which a CCD holder 20 is attached.

  The lens barrel 10 includes a plastic barrel body 11. The lens barrel body 11 is substantially cylindrical. A first glass lens L1 and a second glass lens L2 each having a circular shape are fixed to a plastic lens frame 12 inside the lens barrel body 11. The lens frame 12 is also substantially cylindrical. A spacing ring 14 is arranged between the first glass lens L1 and the second glass lens L2, and in the direction of the optical axis L, it is opened by a distance of the spacing ring 14 and the first glass lens L1. The lens L1 and the second glass lens L2 are fixed to the lens frame 12. The second lens L2 is disposed closest to the CCD 24 in the optical axis direction. As will be described in detail later, the second lens L2 is fixed to the lens frame 12 by thermal caulking. A light shielding step 31 is formed around the rear surface of the second lens. The shading step 31 is painted with black, so that unnecessary rays are cut and flare is prevented.

  A rotatable operation ring 13 is provided around the lens barrel body 11. The operation ring 13 is formed with a cam groove (not shown), and a pin (not shown) fixed to the lens frame 12 enters the cam groove. When the operation ring 13 is rotated, the pin entering the cam groove formed in the operation ring 13 moves in the direction of the optical axis, and the first glass lens L1 and the second glass lens L2 are turned into light. Move in the axial direction.

  An engaging recess 11 </ b> A is formed on the upper surface of the lens barrel body 11. The cylinder 15A extending from the connecting frame 15 to the distal end side is formed with an engaging convex portion 15B protruding in the center. The connecting frame 15 is attached to the lens barrel body 11 by the engaging convex portion 15B entering the engaging concave portion 11A.

  A cylindrical portion 21 of the CCD holder 20 is fixed around the rear end surface of the mounting frame 15.

  Inside the CCD holder 20, a CCD mounting arm 22 extends in the center direction. A CCD 24 is fixed to the arm 22. The opening 23 of the arm 22 and the light receiving surface of the CCD 24 are positioned. An optical image obtained by condensing light by the second lens L2 or the like is formed on the light receiving surface of the CCD 24.

  FIG. 2 is a flowchart showing a processing procedure for fixing the second glass lens L2 to the lens frame 12 described above. FIGS. 3A to 3D show processing steps for fixing the second glass lens 2 to the lens frame 12.

  First, the chamfering process of the second glass lens L2 is performed (step 71 in FIG. 2).

  FIG. 3A shows a chamfering process of the second glass lens L2.

  The cutting tool (processing tool) 40 is L-shaped, and is formed with a flat blade 41 and an oblique blade 42 obliquely facing the flat blade 41. In a state where the second glass lens L2 is rotated around the optical axis L, the cutting tool 40 attached to the processing apparatus (not shown) is moved in the direction of the second glass lens L2. When the cutting tool 40 contacts the second glass lens L2, the second glass lens L2 is cut by the blades 41 and 42 of the cutting tool 40. A light shielding step 31 is formed along the periphery of the second glass lens L2 by the blade 41 of the cutting tool 40. In addition, the blade 42 of the cutting tool 40 forms an inclined surface (thermal caulking inclined surface) 32 from the peripheral surface of the second glass lens L2 toward the light shielding step portion 31.

  The light shielding surface step 31 and the heat caulking slope 32 are formed by a single cutting process (one process) by the cutting tool 40. The one-time cutting process is a process from when the cutting tool 40 is brought into contact with the second glass lens L2 to start cutting and after the cutting is finished, the cutting is finished and the second glass lens L2 is separated from the cutting tool 40.

  Subsequently, sanitization is performed (step 72 in FIG. 2).

  FIG. 3B shows a sanitizing process.

  Ink is applied to the brush tip 51 of the brush 50, and the brush tip 51 with the black ink is in contact with the light shielding step portion 31, whereby the light shielding step portion 31 is painted with black ink. The ink blocks the unnecessary light beam.

  Subsequently, an assembly process is performed (step 73 in FIG. 2).

  FIG. 3C shows an assembly process.

  The outer peripheral surface of the second glass lens L2 is attached to the rear end portion of the inner peripheral surface of the lens frame 12. The second glass lens L2 is attached to the lens frame 12 by an assembling device (not shown) so that the rear end surface 12A of the lens frame 12 and the step portion 31 of the second glass lens L2 are substantially flush with each other. .

  Subsequently, heat caulking is performed (step 73 in FIG. 2).

  FIG. 3D shows a heat caulking process.

  The heat caulking jig 60 is heated by the heater. The heat caulking jig 60 has a slope 60A. The inclined surface 60A is pressed against the rear end surface 12A of the lens frame 12 by a heat caulking device (not shown). The front end surface 12A of the lens frame 12 is deformed by heat, and a part of the lens frame 12 enters and is fixed to the inclined surface 32 formed in the second glass lens L2. The lens frame 12 and the second glass lens L2 are firmly fixed. Further, the lens frame 12 is continuously formed as one surface from the rear end surface 12B of the lens frame 12 to the step portion 31 of the second glass lens L2.

  The ink can be painted before heat caulking, and the manufacturing process of fixing the second glass lens L2 to the lens frame 12 with heat caulking can be completed. If there is a sanitization defect, the defect can be found before heat caulking, so that the second glass lens L2 can be fixed to the lens frame 12 by replacing it with a new lens. If the ink is painted after heat caulking, if a defective ink is found, the second glass lens L2 fixed to the lens frame 12 must be removed from the lens frame 12 by destroying the lens frame 12. However, it is not necessary to destroy the lens frame 12 by sanitizing before heat caulking. However, it goes without saying that it may be painted after heat caulking.

  In the above-described embodiment, the light shielding step 31 is shielded by applying black ink. However, instead of applying black ink, a light shielding sheet or the like may be attached.

10 Lens barrel
12 Lens frame
31 Shading step
32 Thermal caulking slope
40 bytes (work material)

Claims (5)

A method of manufacturing a glass lens that is fixed to a plastic lens frame by heat caulking,
A light shielding step formed along the periphery of the lens surface of the glass lens by an L-shaped cutting tool formed with a flat blade and an oblique blade obliquely directed to the flat blade ; a thermal caulking slope from the peripheral surface of the glass lens is formed continuously toward the light shielding step portion, it was formed by a single cutting,
Assembling apparatus, fitted with a glass lens which the light-blocking step portion and the said heat caulking slope is formed on the plastic lens frame,
Heat staking apparatus, thermally caulking the peripheral surface of the glass lens in a plastic lens frame,
Glass lens manufacturing method. Apply black ink to the shading step
The above assembly equipment
A glass lens on which the shading step with ink and the slope for heat caulking are formed is attached to the plastic lens frame.
The method for producing a glass lens according to claim 1. A light shielding sheet is pasted on the light shielding step,
The above assembly equipment
A glass lens on which the light shielding step with the light shielding sheet and the slope for heat caulking are formed is attached to the plastic lens frame;
The method for producing a glass lens according to claim 1. The above assembly equipment
The glass lens having the light shielding step and the thermal caulking slope formed on the plastic lens frame so that the rear end surface of the plastic lens frame and the light shielding step are substantially flush with each other. Install,
The method for producing a glass lens according to claim 1. The above heat caulking device
The inclined surface of the thermal caulking device is pressed against the rear end surface of the plastic lens frame, and a part of the plastic lens frame enters the inclined surface for thermal caulking formed on the glass lens, and the glass lens The caulking surface is caulked to a plastic lens frame.
The method for producing a glass lens according to claim 1.

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