Lens unit

Abstract

To reduce a harmful influence when fixing an optical filter to a lens holder by an adhesive.SOLUTION: A lens unit includes: a lens; an optical filter as a filter in a flat plate-like shape; and a lens holder for holding the lens and the optical filter. The optical filter is disposed on one end face in a direction of the optical axis of the lens holder. The end face includes: an opening in which a lens surface of the lens is exposed; and a mounting surface as a plane part for supporting the optical filter. An adhesive is filled to a side of a side face so as to be adhered to the side face of the optical filter. A stepped part for forming a gap between a plate surface of the optical filter and an end face is provided between the opening of the end face and the mounting surface.SELECTED DRAWING: Figure 3

Claims

[Claim 1] Lens and, Optical filters, which are flat-plate shaped filters, The system includes a lens holder that holds the lens and the optical filter, The optical filter is positioned on one end face of the lens holder in the direction of its optical axis. The aforementioned end face is An opening through which the lens surface of the aforementioned lens is exposed, It has a mounting surface which is a flat portion that supports the optical filter, The mounting surface is filled with adhesive on the sides of the optical filter so as to adhere to the sides of the optical filter, and the optical filter is prevented from moving in the planar direction by the hardening of the adhesive attached to its sides. Between the opening on the end face and the mounting surface described above, a stepped portion is provided that forms a gap between the plate surface of the optical filter and the end face. An annular slope surface is provided around the opening on the end face, with a downward slope toward the opening. The stepped portion is provided between the slope surface and the aforementioned surface, An air groove, which is a groove that connects the opening to the outside air, is formed on the end face. The air groove extends from inside the periphery of the optical filter to the outside of the optical filter when viewed from above. Lens unit. [Claim 2] The end face has a claw portion to prevent the optical filter from lifting up. The aforementioned claw portion is bent toward the optical filter by heating and pressurizing after the optical filter is placed, and is hooked onto its edge. The lens unit according to claim 1. [Claim 3] The optical filter is a filter with a rectangular plate surface, The adhesive is attached to two sides that form one of the four corners of the optical filter. The lens unit according to claim 1. [Claim 4] The adhesive is attached to each side surface that forms the corner of the four corners of the optical filter. The lens unit according to claim 3. [Claim 5] The mounting surface is formed such that its surface position is stepped lower than the outer edge of the end face. The mounting surface has an extended portion which is an area that the optical filter cannot reach. The stepped surface between the extended portion and the outer edge portion, and the side surface of the optical filter, form an adhesive reservoir, which is a concave space in which the adhesive is held. The lens unit according to claim 1. [Claim 6] The aforementioned lens unit is an injection-molded part. Pin marks from the mold are formed on the portion of the air groove that is outside the optical filter. The lens unit according to claim 1. [Claim 7] The portion where the pin marks are formed is formed to be thicker than the other portions of the air groove. The lens unit according to claim 6. [Claim 8] The stepped portion has multiple steps, the surface level of which decreases in a step-like manner as it approaches the opening. The lens unit according to claim 1. [Claim 9] The adhesive has UV curing and moisture curing properties. The lens unit according to claim 1. [Claim 10] The system comprises a plurality of lenses arranged in the direction of the optical axis, The optical filter is a filter with a rectangular plate surface, The mounting surface is provided at positions corresponding to the four corners of the optical filter. The adhesive is attached to each side surface that forms the corner of the four corners of the optical filter. The end face has a plurality of claws to prevent the optical filter placed on each mounting portion from lifting up. Each of the aforementioned claw portions is bent toward the optical filter by heating and pressurizing after the optical filter is placed and then hooked onto its edge. The end face has a plurality of air grooves formed therein, which are grooves that allow the opening to communicate with the outside air. Each of the aforementioned air grooves, when viewed from above, extends from inside the periphery of the optical filter to the outside of the optical filter. The aforementioned air channels are provided between each set of adjacent mounting surfaces described above. The lens unit according to claim 1.

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