Lens unit

Abstract

The purpose of the present invention is to reduce the drawbacks when an optical filter is fixed to a lens holder by means of an adhesive. The above problem is solved by a lens unit which is provided with: a lens; an optical filter which is a flat plate-shaped optical filter; and a lens holder that holds the lens and the optical filter, the optical filter being disposed on one end surface of the lens holder in the optical axis direction. The end surface has an opening part for exposing the lens surface of the lens and a carrying surface serving as a plane part for supporting the optical filter. The mounting surface is filled with an adhesive on the side of the side surface of the optical filter so that the adhesive is adhered to the side surface of the optical filter. A step portion forming a gap between the plate surface of the optical filter and the end surface is provided between the opening of the end surface and the mounting surface.

Description

Technical Field

[0001] The present invention relates to a lens unit, and more particularly to a fixing structure of an optical filter relative to a lens holder. Background Art

[0002] Patent document 1 disclosed below discloses a lens unit that fixes an optical filter by heating and pressurizing a resin claw to plastically deform the resin claw. Patent document 2 disclosed below discloses a lens unit that fixes a glass lens by using the same claw and adhesive. Patent document 3 disclosed below discloses a lens unit that fixes an optical filter by adhesive and has a groove that connects the inside of a lens barrel with the outside air.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-54735

[0006] Patent Document 2: Japanese Patent Application Publication No. 2019-179076

[0007] Patent Document 3: Japanese Patent Application Publication No. 2015-31926 Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] In the storage space of the lens holder or the like in which the optical filter is provided, a clearance is of course required for providing the optical filter. In the case where the optical filter is fixed only by the claws of the above-mentioned patent documents, the optical filter is not completely fixed and sometimes shakes within the range of the clearance due to the vibration of the lens unit or the like. On the other hand, in the case where the optical filter is fixed by an adhesive, if the adhesive adheres to the lens, the optical performance of the lens unit may be impaired.

[0010] In view of the above problems, an object of the present invention is to provide a lens unit capable of securely fixing an optical filter of the lens unit by an adhesive.

[0011] Technical solutions adopted to solve technical problems

[0012] In order to solve the above-mentioned problems, the lens unit of the present invention is mainly composed of: a lens; an optical filter which is a flat plate-shaped filter; and a lens holder which holds the lens and the optical filter, wherein the optical filter is arranged on one end face of the lens holder in the optical axis direction. The end face has: an opening portion which exposes the lens surface of the lens; and a mounting surface which is a flat surface portion which supports the optical filter. An adhesive is filled on the side of the side surface of the optical filter on the mounting surface so that the adhesive adheres to the side surface of the optical filter. A step portion which forms a gap between the plate surface of the optical filter and the end face is provided between the opening portion of the end face and the mounting surface.

[0013] By filling the side of the optical filter with adhesive and making the adhesive adhere to the side of the optical filter, the optical filter is prevented from moving to the side by the cured adhesive. That is, after the optical filter is set, the gap set in the setting space of the optical filter can be removed. In addition, the adhesive is infiltrated between the plate surface and the mounting surface of the optical filter by capillary force, but the capillary force is blocked by the step portion, and the seeped adhesive is also retained by the step portion. In this way, the adhesive can be prevented from adhering to the lens, and the optical filter can be safely fixed by the adhesive.

[0014] In this case, an annular inclined surface with a downward slope toward the opening may be provided around the opening in the end surface, and the step portion may be provided between the inclined surface and the mounting surface. By providing a dedicated step portion for blocking the capillary force between the plate surface of the optical filter and the mounting surface and retaining the adhesive that has seeped out, the lens can be more reliably protected from damage by the adhesive.

[0015] In addition, it is preferred that the end surface of the lens unit of the present invention has a claw portion for preventing the optical filter from floating, and the claw portion is bent toward one side of the optical filter by heating and pressurizing after the optical filter is arranged, and is hooked on the edge of the optical filter. By fixing the optical filter with both the adhesive and the claw portion, it is possible to more reliably prevent the optical filter from falling off.

[0016] In addition, it is preferred that the optical filter is a filter having a rectangular plate surface, and the adhesive is attached to two side surfaces of any of the four corners constituting the optical filter. Thus, the movement of the optical filter on the mounting surface in the XY directions (two directions parallel to the mounting surface and orthogonal to each other) is restricted, and the shaking of the optical filter can be effectively suppressed.

[0017] In this case, it is preferable that the adhesive is attached to the side surfaces constituting the four corners of the optical filter in order to more reliably suppress the shaking of the optical filter.

[0018] In addition, it is preferred that the placement surface is formed so that the surface position is lowered in a step shape than the outer edge of the end surface. The placement surface has an expansion portion as a range that the optical filter cannot reach. The step surface between the expansion portion and the outer edge and the side surface of the optical filter form an adhesive reservoir, and the adhesive reservoir is a concave space for the adhesive to be retained. As a result, the filling operation of the adhesive becomes easy, the operation quality is stable, and a sufficient amount of adhesive can be filled to restrict the lateral movement of the optical filter.

[0019] In addition, the lens unit of the present invention is preferably formed with an air groove on the end face, the air groove being a groove that connects the opening to the outside air. When the end face is viewed from above, the air groove extends from a position inside the periphery of the optical filter to the outside of the optical filter. In the case of sealing the lens holder with an optical filter, the method of airtightness inspection becomes complicated, and outgassing of the adhesive may reduce the optical performance of the lens. By providing the air groove, such an undesirable situation can be eliminated.

[0020] In this case, it is preferred that the lens unit is an injection molded component, and a mold pin mark is formed in the portion of the air groove that is outside the optical filter. By making the ejector pin contact the air groove that only serves as an air passage, even if burrs are generated during removal, the influence thereof can be suppressed. In addition, in this case, it is preferred that the portion where the pin mark is formed is formed to be thicker than other portions of the air groove. This is to avoid damaging the component strength of the lens holder.

[0021] In addition, it is preferred that the step portion has a plurality of steps, and the surface positions of the plurality of steps decrease in a step-like manner as they go toward one side of the opening portion, in order to more reliably prevent the adhesive from adhering to the lens.

[0022] In addition, it is preferred that the adhesive has ultraviolet curing properties and moisture curing properties. When the adhesive has ultraviolet curing properties, the time required for curing of the adhesive can be shortened. On the other hand, in the adhesive that is infiltrated between the optical filter and the mounting surface, ultraviolet rays may not be able to fully reach the optical filter. Therefore, by making the adhesive also have moisture curing properties, the portion that is not cured by ultraviolet rays can be cured over time.

[0023] In addition, the lens unit of the present invention may be configured as follows: the lens unit comprises: a plurality of the lenses arranged in the optical axis direction. The optical filter is a filter having 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, and the side surfaces constitute the four corners of the optical filter. The end surface has: a plurality of claws for preventing the optical filter mounted on each mounting portion from floating, and each claw is bent toward one side of the optical filter by heating and pressurizing after the optical filter is arranged, and hooked on the edge of the optical filter. A plurality of air grooves are formed on the end surface, and the air grooves are grooves for connecting the opening to the outside air. When the end surface is viewed from above, each of the air grooves extends from a position inside the periphery of the optical filter to the outside of the optical filter. The air grooves are provided between each group of adjacent mounting surfaces.

[0024] Effects of the Invention

[0025] As described above, according to the lens unit of the present invention, it is possible to reduce the adverse effects when the optical filter is fixed to the lens holder using an adhesive. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] [ Figure 1 ] is a side sectional view showing the internal structure of the lens unit of this embodiment.

[0027] [ Figure 2 ] is a top view showing the image side end surface of the lens unit.

[0028] [ Figure 3 ]yes Figure 2 A local enlarged view (a) of the portion surrounded by the single-dot chain line and a stereoscopic view (b) of the portion.

[0029] [ Figure 4 ] is shown Figure 3 The portion shown is a partially enlarged view (a) and a perspective view (b) of a state before an infrared cut filter is arranged.

[0030] [ Figure 5 ]yes Figure 3 (a) is a NN cross-sectional view of the image side end surface.

[0031] [ Figure 6 ]yes Figure 3 (a) is a MM cross-sectional view of the image side end surface. DETAILED DESCRIPTION

[0032] Embodiments of the lens unit of the present invention will be described below with reference to the drawings. The lens unit 90 of this embodiment is a general-purpose small lens unit used in various imaging devices.

[0033] The lens unit 90 of this embodiment has its own characteristics in the fixing structure of the optical filter relative to the lens holder. Specifically, the lens unit 90 not only chemically bonds the flat optical filter to the lens holder by means of an adhesive, but also prevents the optical filter from shaking in structure by arranging the cured adhesive adjacent to the side of the optical filter and removing the gap of the installation space of the optical filter afterwards. In addition, a special gap (step portion) is provided on the end surface of the lens holder where the optical filter is installed to prevent the adhesive that has infiltrated by capillary force from adhering to the lens, thereby reducing the disadvantages of using an adhesive in fixing the optical lens. These characteristics and their accompanying characteristics are described in detail below.

[0034] (Overall structure)

[0035] Figure 1 1 is a side cross-sectional view showing the internal structure of the lens unit 90 of this embodiment. Figure 1 The overall structure of the lens unit 90 will be described.

[0036] Figure 1 The dashed line L1-L2 shown in the figure indicates the optical axis of the lens unit 90, the L1 side is the object side (subject side), and the L2 side is the image side. The lens unit 90 has six lenses arranged along the optical axis L1-L2, namely, the first lens 11 to the sixth lens 16, and a lens holder 30 that holds these lenses. A light shielding plate 17 is arranged between the second lens 12 and the third lens 13, and an aperture 18 is arranged between the third lens 13 and the fourth lens 14. In addition, an infrared cut filter 20 (hereinafter referred to as "IRCF 20") as an optical filter is arranged on the end surface of the lens holder 30 closest to the image side.

[0037] Among these lenses, the first lens 11 and the fourth lens 14 located closest to the object side are glass lenses. The fourth lens 14 is supported on the lens holder 30 in a state of being held in a holder 141 as a ring-shaped frame. The second lens 12, the third lens 13, the fifth lens 15 and the sixth lens 16 are plastic lenses. The sixth lens and the fifth lens 15 located closest to the image side constitute a cemented lens. In addition, the number and type of lenses held on the lens holder 30 are not limited to the structure of this method, and can be appropriately changed according to the purpose of the lens unit or the subject.

[0038] The lens holder 30 of this embodiment is a lens barrel / lens frame of a double-tube structure consisting of an inner tube 31 and an outer tube 32. The first lens 11 is supported by the outer tube 32 of the lens holder 30, and the other lenses, the light shielding plate 17, and the aperture 18 are accommodated in the inner tube 32. The structure of the lens holder 30 is not limited to this embodiment, and any structure of the lens holder may be used as long as an optical filter is arranged at one end of the optical axis direction.

[0039] (IRCF fixed structure)

[0040] Figure 2 It is a plan view showing an end surface on the image side of the lens unit 90 (hereinafter referred to as “image side end surface 40 ”). Figure 3 yes Figure 2 A local enlarged view (a) of the portion surrounded by the single-dot chain line and a stereoscopic view (b) of the portion. Figure 4 It is shown Figure 3 The partially enlarged view (a) and the stereoscopic view (b) of the state before the IRCF 20 is arranged are shown. Figures 2 to 4 , the fixing structure of IRCF 20 is described.

[0041] As described above, the IRCF 20 is disposed on the image side end surface 40 of the lens holder 30. The IRCF 20 is a flat plate-shaped optical filter having a square plate surface. Figures 2 to 4 As shown, the image side end surface 40 is provided with a mounting surface 44 for mounting the four corners of the IRCF 20. Figure 3 and Figure 4 This is an enlarged view of a portion corresponding to one of the four corners of the IRCF 20 , and the fixing structure described below is common to all the four corners of the IRCF 20 .

[0042] The mounting surface 44 is a planar portion formed in a manner that the surface position is stepped down from the outer edge portion 49 of the image side end surface 40. An opening portion 41 is formed in the center of the image side end surface 40 to expose the lens surface of the sixth lens 16, and an annular inclined surface 42 is provided around the opening portion 41 and is downwardly sloping toward the opening portion 41. A step portion 43 described later is provided between the inclined surface 42 and the mounting surface 44.

[0043] The IRCF 20 of this embodiment is fixed to the mounting surface 44 by the adhesive G and the claws 45 described later. Figure 2 and Figure 3 In the figure, for the sake of convenience, the adhesive G is shaded to indicate its application range. Figure 3As shown in (b), on the mounting surface 44, adhesive G is filled on the sides of the side surfaces 21 and 22 in the XY direction (two directions horizontally orthogonal to each other) constituting the four corners of the IRCF 20. The adhesive G is infiltrated between the plate surface of the IRCF 20 and the mounting surface 44 by capillary force, and the adhesive G that seeps out from the mounting surface 44 to the opening 41 side is retained by the step portion 43.

[0044] In the space where the IRCF 20 is disposed on the image side end surface 40, a clearance C ( Figure 3 (a)). In the lens unit 90 of this embodiment, the side of the IRCF 20 is filled with adhesive G, which is attached to the side surfaces 21 and 22 of the IRCF 20 in the XY direction, and the IRCF 20 is prevented from moving to the side thereof by the cured adhesive G. That is, the gap C provided in the installation space of the IRCF 20 is removed after the installation thereof, thereby suppressing the shaking of the IRCF 20. In particular, in this embodiment, the cured adhesive G is suppressed on the side of all the side surfaces of the four corners constituting the IRCF 20, and the shaking suppression effect is maximized.

[0045] like Figure 3 As shown, the placement surface 44 has an expansion portion 441 as a range that the IRCF 20 cannot reach, and the step surface 491 between the expansion portion 441 and the outer edge portion 49 and the X-side side surface 21 of the IRCF 20 form an adhesive reservoir 44a as a concave space for retaining the adhesive G. This makes it easy to fill the adhesive G and the work quality is stable. In addition, a sufficient amount of adhesive can be filled to restrict the lateral movement of the IRCF 20.

[0046] The adhesive reservoir 44a of this embodiment is Figure 3 (a) is formed to bulge out in a tongue shape on the X-direction side of the IRCF 20. In this embodiment, since the claw portion 45 is arranged on the Y-direction side of the mounting surface 44, such a structure is adopted, but the adhesive reservoir 44a may be located on the Y-direction side of the IRCF 20, or on both the X-direction side and the Y-direction side. Furthermore, if it does not affect the filling operation or filling amount of the adhesive G, the adhesive reservoir 44a may not be provided. In this case, the gap C of the mounting surface 44 may be filled with the adhesive G.

[0047] Moreover, the adhesive G of this embodiment has ultraviolet curing properties and moisture curing properties. Since the adhesive G has ultraviolet curing properties, the time required for curing of the adhesive G is shortened. On the other hand, in the adhesive G infiltrated between the IRCF 20 and the mounting surface 44, the ultraviolet rays are reflected and attenuated by the IRCF 20, so that the ultraviolet rays may not be able to fully reach. Therefore, by making the adhesive G also have moisture curing properties, the part that is not cured by ultraviolet rays can be cured over time. In addition, as will be described in detail later, an air groove 46 that connects the opening portion 41 to the outside air is provided on the image side end surface 40, and the moisture of the outside air also affects the adhesive G retained in the step portion 43 and the adhesive G that seeps out from the mounting surface 44.

[0048] In addition, the image side end surface 40 of this embodiment has a claw portion 45 for preventing the IRCF 20 from floating. Figure 4 and Figure 3 As shown, after the IRCF 20 is arranged, the claw 45 is bent toward one side of the IRCF 20 by heating and pressurizing, and is hooked on the edge of the IRCF 20. By fixing the IRCF 20 with both the adhesive G and the claw 45, it is possible to more reliably prevent the IRCF 20 from falling off. In addition, when the adhesive G has sufficient bonding strength, or when the lens unit 90 is used in an environment where it is stationary (no vibration), the claw 45 may be omitted.

[0049] (Structure of the step portion)

[0050] Figure 5 yes Figure 3 (a) is a schematic diagram of the NN cross section of the image side end surface 40. Figures 3 to 5 The structure of the step portion 43 will be described.

[0051] like Figure 5 As shown in the figure, a step portion 43 is provided between the inclined surface 42 of the image side end surface 40 and the mounting surface 44 to form a gap between the plate surface of the IRCF 20 and the image side end surface 40. The step portion 43 of this embodiment is composed of two steps, namely, a first step portion 431 and a second step portion 432, whose surface position decreases in a step-like manner as it moves from the mounting surface 44 side toward the inclined surface 42 side (opening portion 41 side).

[0052] The adhesive G infiltrates between the plate surface of the IRCF 20 and the mounting surface 44 due to the capillary force, but when it seeps out toward the opening 41, the adhesive G adheres to the sixth lens 16, which may impair the optical performance of the lens unit 90. The lens holder 30 of this embodiment includes the step portion 43 (the first step portion 431 and the second step portion 432), so that the capillary force is blocked by the step portion 43, and the seeping adhesive G is also held by the step portion 43. Thus, the adhesive G can be prevented from adhering to the lens, and the IRCF 20 can be securely fixed with the adhesive G.

[0053] In addition, even if it is assumed that the step portion 43 is not provided, if the inclined surface 42 exists, a gap is formed between the plate surface of the IRCF 20 and the image side end surface 40 through the inclined surface 42. Therefore, it can be considered that the capillary force is blocked and the infiltration of the adhesive G is also stopped. On the other hand, the step portion 43 is formed in a step shape, and the step surface (upper surface) of each step is a plane. When the adhesive G is filled and cured, these step surfaces are arranged horizontally. Moreover, the adhesive G is pulled toward the lower end of the step surface of each section (that is, the depth of the step surface of each section) due to its surface tension. In this way, the lens unit 90 has a step portion 43, which improves the effect of keeping the adhesive G away from the opening portion 41 compared with a lens unit with a structure in which the adhesive G directly flows into the inclined surface 42. In addition, the second step portion 432 is a prepared step portion, and the effect of the step portion 43 can be obtained only by the first step portion 431.

[0054] (Structure of air tank)

[0055] The lens holder 30 has a plurality of air grooves 46 as four grooves that connect the opening 41 to the outside air on the image side end surface 40. The air grooves extend from the inner side of the periphery of the IRCF 20 to the outer side of the IRCF 20, and are respectively provided between each group of adjacent mounting surfaces 44. When the lens holder 30 is sealed with the IRCF 20, the method of airtightness inspection becomes complicated, and the outgassing of the adhesive G or other adhesive used inside the lens holder 2 may reduce the optical performance of the lens. The lens unit 90 eliminates such a problem by having the air grooves 2.

[0056] In addition, the air groove 46 of this embodiment has the effect of blocking the capillary force between the plate surface of the IRCF 20 and the mounting surface 44. In addition, the second step portion 432 of this embodiment is formed in an annular shape so as to surround the entire outer periphery of the inclined surface 42, and also acts as a preliminary step portion to prevent the adhesive G from invading the air groove 46.

[0057] Figure 6 Observed from the MM direction Figure 3(a) is a schematic cross-sectional view of the image side end surface 40. The lens unit 90 of this embodiment is an injection molded component, and a mold pin mark is formed in the portion of each air groove 46 that is outside the IRCF 20. By making the ejector pin contact the air groove 46 that only serves as a passage for air, even if burrs are generated during removal, their influence can be suppressed. In addition, as Figure 6 As shown, the portion where the pin mark is formed is formed thicker than the other portion of the air groove 46. Thus, the component strength of the lens holding frame 30 is maintained.

[0058] Furthermore, the present technology can adopt the following structures. (1)

[0060] A lens unit, comprising:

[0061] lens;

[0062] Optical filters are flat plate-shaped filters; and

[0063] a lens holder for holding the lens and the optical filter,

[0064] The optical filter is arranged on one end surface of the lens holder in the optical axis direction, wherein the end surface has:

[0065] an opening portion exposing a lens surface of the lens; and

[0066] The mounting surface is a flat surface that supports the optical filter.

[0067] An adhesive is filled on the mounting surface at the side of the side of the optical filter so that the adhesive adheres to the side of the optical filter.

[0068] A step portion is provided between the opening portion of the end surface and the placement surface so as to form a gap between the plate surface of the optical filter and the end surface. (2)

[0070] The lens unit according to (1), wherein:

[0071] An annular slope that slopes downward toward the opening is provided around the opening in the end surface. (3)

[0073] The lens unit according to (1) or (2), wherein:

[0074] The end surface has a claw portion for preventing the optical filter from floating.

[0075] After the optical filter is disposed, the claw portion is bent toward one side of the optical filter by heating and pressurizing, and is hooked on the edge of the optical filter. (4)

[0077] The lens unit according to any one of (1) to (3), wherein:

[0078] The optical filter is a filter with a rectangular plate surface.

[0079] The adhesive is attached to two side surfaces, and the two side surfaces constitute any one of the four corners of the optical filter. (5)

[0081] The lens unit according to (4), wherein:

[0082] The adhesive is attached to the side surfaces, and the side surfaces constitute four corners of the optical filter. (6)

[0084] The lens unit according to any one of (1) to (5), wherein:

[0085] The placement surface is formed so that the surface position is lower than the outer edge of the end surface in a step shape.

[0086] The mounting surface has an expansion portion as a range that the optical filter cannot reach,

[0087] The step surface between the expansion portion and the outer edge portion and the side surface of the optical filter form an adhesive reservoir, and the adhesive reservoir is a concave space for holding the adhesive. (7)

[0089] The lens unit according to any one of (1) to (6), wherein:

[0090] An air groove is formed on the end surface, and the air groove is a groove that allows the opening to communicate with external air.

[0091] The air groove extends from a position inside the periphery of the optical filter to the outside of the optical filter when the end surface is viewed in plan. (8)

[0093] The lens unit according to (7), wherein:

[0094] The lens unit is an injection molded component,

[0095] A pin mark of a mold is formed in a portion of the air groove that is located outside the optical filter. (9)

[0097] The lens unit according to (8), wherein:

[0098] The portion where the pin mark is formed is formed thicker than other portions of the air groove. (10)

[0100] The lens unit according to any one of (1) to (9), wherein:

[0101] The step portion has a plurality of steps, and the surface positions of the plurality of steps decrease in a step-like manner as they go toward one side of the opening. (11)

[0103] The lens unit according to any one of (1) to (10), wherein:

[0104] The adhesive is ultraviolet curable and moisture curable. (12)

[0106] The lens unit according to any one of (1) to (11), wherein:

[0107] The lens unit comprises: a plurality of lenses arranged along the optical axis direction,

[0108] The optical filter is a filter with a rectangular plate surface.

[0109] The mounting surface is provided at positions corresponding to the four corners of the optical filter.

[0110] The adhesive is attached to each side surface, and the side surfaces constitute the four corners of the optical filter.

[0111] The end surface has a plurality of claws for preventing the optical filter placed on each of the placement portions from floating.

[0112] After the optical filter is arranged, each claw is bent toward one side of the optical filter by heating and pressurizing, and is hooked on the edge of the optical filter.

[0113] A plurality of air grooves are formed on the end surface, wherein the air grooves are grooves for connecting the opening to the outside air.

[0114] When the end surface is viewed from above, each of the air grooves extends from a position inside the periphery of the optical filter to the outside of the optical filter.

[0115] The air grooves are respectively provided between the groups of adjacent mounting surfaces.

[0116] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments, and various changes can be made within the scope of the present invention. For example, in the above embodiments, the IRCF 20 is used as the optical filter, but other optical filters can also be used. In addition, the plate shape of the IRCF 20 is square, but it can also be circular.

[0117] Description of Reference Numerals

[0118] 90…lens unit; 16…sixth lens (lens); 20…infrared cut filter (IRCF) (optical filter); 21…X side; 22…Y side; 30…lens holder; 31…inner cylinder; 32…outer cylinder; 40…image side end surface (end surface); 41…opening; 42…inclined surface; 43…step portion; 431…first step portion; 432…second step portion; 44…loading surface; 441…expansion portion; 45…claw portion; 46…air groove; 461…pin mark; 49…outer edge portion; 491…step surface; G…adhesive.

Claims

1. A lens unit, characterized in that: include: lens; Optical filter is a filter in the shape of a flat plate; as well as a lens holder holding the lens and the optical filter, The optical filter is arranged on one end surface of the lens holder in the optical axis direction. The end surface has: an opening portion exposing a lens surface of the lens; and The mounting surface is a flat surface that supports the optical filter. An adhesive is filled on the mounting surface at the side of the side of the optical filter so that the adhesive adheres to the side of the optical filter. A step portion is provided between the opening portion of the end surface and the placement surface so as to form a gap between the plate surface of the optical filter and the end surface.

2. The lens unit according to claim 1, characterized in that: An annular slope which slopes downward toward the opening is provided around the opening in the end surface. The step portion is provided between the inclined surface and the placement surface.

3. The lens unit according to claim 1, characterized in that: The end surface has a claw portion for preventing the optical filter from floating. After the optical filter is disposed, the claw is bent toward one side of the optical filter by heating and pressurizing, and is hooked on the edge of the optical filter.

4. The lens unit according to claim 1, characterized in that: The optical filter is a filter with a rectangular plate surface. The adhesive is attached to two side surfaces, and the two side surfaces constitute any one of the four corners of the optical filter.

5. The lens unit according to claim 4, characterized in that: The adhesive is attached to the side surfaces, and the side surfaces constitute four corners of the optical filter.

6. The lens unit according to claim 1, characterized in that: The placement surface is formed so that the surface position is lower than the outer edge of the end surface in a step shape. The mounting surface has an expansion portion as a range that the optical filter cannot reach, The step surface between the expansion portion and the outer edge portion and the side surface of the optical filter form an adhesive reservoir, and the adhesive reservoir is a concave space for holding the adhesive.

7. The lens unit according to claim 1, characterized in that: An air groove is formed on the end surface, and the air groove is a groove that connects the opening portion with external air. The air groove extends from a position inside the periphery of the optical filter to the outside of the optical filter when the end surface is viewed in plan.

8. The lens unit according to claim 7, characterized in that: The lens unit is an injection molded component, A pin mark of a mold is formed in a portion of the air groove that is located outside the optical filter.

9. The lens unit according to claim 8, characterized in that: The portion where the pin mark is formed is formed thicker than other portions of the air groove.

10. The lens unit according to claim 1, wherein: The step portion has multiple steps. The surface positions of the plurality of steps are lowered in a step-like manner toward one side of the opening.

11. The lens unit according to claim 1, characterized in that: The adhesive is ultraviolet curable and moisture curable.

12. The lens unit according to claim 1, wherein: The lens unit comprises: a plurality of lenses arranged along the optical axis direction, 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, and the side surfaces constitute the four corners of the optical filter. The end surface has a plurality of claws for preventing the optical filter placed on each of the placement portions from floating. After the optical filter is arranged, each of the claws is bent toward one side of the optical filter by heating and pressurizing, and is hooked on the edge of the optical filter. A plurality of air grooves are formed on the end surface, wherein the air grooves are grooves for connecting the opening to the outside air. When the end surface is viewed from above, each of the air grooves extends from a position inside the periphery of the optical filter to the outside of the optical filter. The air grooves are respectively provided between the groups of adjacent mounting surfaces.

Images