JP6262962B2 - Lens unit and imaging device - Google Patents

Description

  The present invention relates to a lens unit and an imaging apparatus in which a lens is fixed inside using an adhesive.

  In order to form a subject image on the light receiving surface of the image sensor while suppressing aberration, the lens unit is provided with a plurality of optical elements such as a lens and a diaphragm. In order to exhibit the required optical performance, it is necessary to fix each optical element in a predetermined position at a predetermined position.

  Conventionally, in manufacturing a lens unit, an adhesive is used to fix the lens to a lens frame or a holder. In order to suppress the inflow of excess adhesive into the effective diameter of the lens, a structure in which an adhesive reservoir is provided is known (see, for example, Patent Document 1).

JP 2001-245186 A

  However, since the adhesive generates gas (outgas) when it hardens, the outgas fills the adhesive reservoir. When exposed to the adhesive outgas for a long time, the surface and inside of the lens may corrode and whiten. In addition, the imaging performance may be deteriorated regardless of whether the generated whitening is within the effective diameter of the lens.

  An object of the present invention made in view of such circumstances is to provide a lens unit and an imaging apparatus that suppress whitening of a lens due to an adhesive outgas.

In order to solve the above problems, the lens unit according to the present invention is:
A lens,
An inner peripheral surface that faces at least a part of the outer surface of the lens and is bonded to the lens by an adhesive , a groove that is continuous from a contact surface that contacts the lens and is recessed from the contact surface, and the lens A vent part for discharging gas generated from an adhesive that can flow into a space defined by the lens and the groove part in a state of contact with the contact surface; and a position away from the vent part in the circumferential direction of the lens. A lens holder having an injection part for injecting the adhesive so that the adhesive can be introduced into the groove part through a gap between the outer side surface of the lens and the inner peripheral surface. To do.
The lens unit according to the present invention is
The lens holder has a plurality of the vent portions and the injection portion is located between the plurality of vent portions, or the lens holder has a plurality of the injection portions and the plurality of the injection portions. It is preferable that the vent part is located between the two.

The lens unit according to the present invention is
It is preferable that the vent hole portion communicates with the outside from the groove portion toward a radially inner side of the lens holder or toward a recess direction of the groove portion.

The lens unit according to the present invention is
It is preferable that the lens holder has an inflow suppressing portion that suppresses inflow of the adhesive flowing into the groove portion into the vent portion.

In addition, an imaging apparatus according to the present invention includes:
Generated from a lens, a groove that is continuous with a contact surface that is in surface contact with the lens, and a groove that is recessed from the contact surface, and an adhesive that can flow into the space defined by the lens and the groove when the lens is in contact with the contact surface A lens having a vent part for discharging the gas to be discharged, and an injection part for injecting the adhesive so that the adhesive can flow into the groove part at a position away from the vent part in the circumferential direction of the lens A lens unit comprising a holder;
An image pickup device for picking up a subject image formed by the lens unit is provided.

  According to the lens unit and the imaging apparatus according to the present invention, whitening of the lens due to the outgas of the adhesive can be suppressed.

1 is a cross-sectional view along an optical axis showing a schematic configuration of an imaging apparatus according to a first embodiment of the present invention. It is a figure which shows the lens holder which concerns on the 1st Embodiment of this invention. It is the elements on larger scale of the lens holder for demonstrating the mechanism which discharges the outgas of an adhesive agent. It is a figure which shows the lens holder which concerns on the 2nd Embodiment of this invention. It is a figure which shows the lens holder which concerns on the 3rd Embodiment of this invention. It is a figure which shows the lens holder which concerns on the modification of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, the lens unit according to the first embodiment of the present invention will be described. FIG. 1 is a cross-sectional view along an optical axis showing a schematic configuration of an imaging apparatus having a lens unit according to the first embodiment.

  As shown in FIG. 1, the imaging device 10 includes a lens unit 11 and an imaging element 12. The lens unit 11 forms a subject image. The image sensor 12 captures a subject image formed through the lens unit 11.

  The lens unit 11 includes a lens barrel 13, a plurality of lenses including a lens 14, and a lens holder 15a. The lens 14 is supported in the lens barrel 13 via the lens holder 15a. The other lens is directly supported by the lens barrel 13 or is supported in the lens barrel 13 via another lens holder.

  As shown in FIG. 2, the lens holder 15 a is configured to include a support portion 16 and a cylindrical wall portion 17 having the axis cx as a central axis. 2A is a front view of the lens holder 15a, and FIG. 2B is a cross-sectional view taken along the line AA of the lens holder 15a.

  The support portion 16 protrudes radially inward from the inner peripheral surface 18 of the wall portion 17 and is formed in an annular shape. The support portion 16 includes a seat surface portion 19, a groove portion 20, and a vent portion 21a.

  The seat surface portion 19 is an annular plane that is formed radially inward on the object side of the support portion 16 and is perpendicular to the axis cx. The seat surface portion 19 can contact or be in surface contact with the lens 14 in a state where the lens 14 is fitted into the cylindrical inner hole h of the wall portion 17, and functions as a contact surface that supports the lens 14.

  The groove portion 20 is a groove formed to be recessed from the seat surface portion 19, is provided continuously on the radially outer side with the seat surface portion 19, and has an annular shape. As will be described later, the groove portion 20 functions as an adhesive reservoir into which an excess of the adhesive that fixes the lens 14 and the lens holder 15a can flow.

  The vent portion 21 a is formed in a groove shape that is recessed from the seat surface portion 19 so as to communicate with the inner peripheral surface side of the support portion 16 from the groove portion 20 toward the radially inner side of the support portion 16. The vent portion 21a discharges the outgas of the adhesive flowing into the groove portion 20 from the inner peripheral surface side of the support portion 16 from the space defined by the lens 14 and the groove portion 20 with the lens 14 fitted in the inner hole h. .

  A D-cut portion 22 and an injection portion 23 are formed in the wall portion 17.

  The D cut portions 22 are flat surfaces formed on the inner peripheral surface 18 of the wall portion 17 and parallel to the axis cx direction, and are formed on the inner peripheral surface 18 at equal intervals in the circumferential direction. For example, in the present embodiment, six D-cut portions 22 are formed along the inner peripheral surface 18 at 60 ° intervals. The D-cut portion 22 is formed so that the distance from the axis cx is equal to the radius of the lens 14 and holds the lens 14 with the lens 14 fitted in the inner hole h.

  The injection portion 23 has a step shape in which a part on the inner diameter side of the end surface 24 on the object side of the wall portion 17 is recessed, and is formed at the same position on at least a part of the D-cut portion 22 and the inner peripheral surface 18. . For example, in this embodiment, the three injection | pouring parts 23 are formed every other with respect to the six D cut parts 22 which continue in the circumferential direction. The injection portion 23 functions as an injection port for injecting an adhesive that fixes the outer diameter side surface of the lens 14 and the inner peripheral surface 18 of the lens holder 15a. Preferably, the injection part 23 is formed at a position away from the vent part 21a. For example, the injection part 23 is formed at a position at an equal distance from the two vent holes 21a adjacent in the circumferential direction (see FIG. 2A). In this way, the vent portion 21a is blocked by the excess adhesive flowing into the groove portion 20 from the injection portion 23, and the adhesive agent is provided to the outside from the space defined by the lens 14 and the groove portion 20 via the vent portion 21a. Leakage can be suppressed.

  Next, the adhesive injected from the injection part 23 will be described. FIG. 3A is an enlarged view around the injection part 23. FIG.3 (b) is BB sectional drawing of Fig.3 (a).

  An outer diameter side surface 25 of the lens 14 is in contact with the D-cut portion 22. In the vicinity of the contact portion, there is a gap between the outer diameter side surface 25 of the lens 14 and the D-cut portion 22 (see FIG. 3A). The adhesive 26 dripped onto the injection portion 23 flows into the gap between the outer diameter side surface 25 and the D-cut portion 22 and then hardens to fix the lens 14 and the lens holder 15a. When an unnecessary amount of adhesive 26 drops on the injection portion 23, the excess adhesive 26 passes through the gap between the outer diameter side surface 25 and the D-cut portion 22 toward the image side, and the lens 14 and the groove portion 20 are defined. It flows into the space (see FIG. 3B). When the curing of the adhesive 26 starts, outgas is generated in the space defined by the lens 14 and the groove 20. The generated outgas is discharged to the outside through the vent portion 21a.

  As described above, according to the lens unit of the first embodiment, the vent portion 21a discharges the adhesive outgas from the space defined by the lens 14 and the lens holder 15a to the outside, thereby suppressing the whitening of the lens 14. Is possible.

  Further, according to the lens unit of the first embodiment, since the vent portion 21a is formed at a position away from the injection portion 23, the vent portion 21a is prevented from being blocked by excess adhesive, and the outgas is vented. The certainty discharged from the portion 21a can be improved, and the whitening of the lens 14 can be further suppressed.

(Second Embodiment)
Next, a lens unit according to a second embodiment of the present invention will be described. Hereinafter, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The lens unit 11 according to the second embodiment is different from the first embodiment in that an inflow suppression unit 27 is provided. 4A is a front view of the lens holder 15b, and FIG. 4B is a cross-sectional view taken along the line C-C of the lens holder 15b.

  The support portion 16 includes a seat surface portion 19, a groove portion 20, a vent hole portion 21 a, and an inflow suppression portion 27. The structure of the seat surface part 19 and the groove part 20 is the same as that of 1st Embodiment. The inflow suppressing portion 27 is a step formed by pulling up the groove-shaped bottom surface 28 of the vent portion 21 a from the bottom surface 29 of the groove portion 20 toward the object side. The inflow suppressing part 27 suppresses the inflow of excess adhesive flowing into the groove part 20 into the vent part 21a.

  Thus, according to the lens unit of the second embodiment, the inflow suppressing portion 27 suppresses the flow of excess adhesive into the vent portion 21a, so that outgas is reliably discharged from the vent portion 21a. Therefore, the whitening of the lens 14 can be further suppressed.

(Third embodiment)
Next, a lens unit according to a third embodiment of the present invention will be described. Hereinafter, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The lens unit 11 according to the third embodiment is different from the first embodiment in the shape of the vent portion 21b. FIG. 5A is a front view of the lens holder 15c, and FIG. 5B is a sectional view taken along the line DD of the lens holder 15c.

  The support portion 16 includes a seat surface portion 19, a groove portion 20, and a vent portion 21b. The structure of the seat surface part 19 and the groove part 20 is the same as that of 1st Embodiment. The vent portion 21 b is formed through the support portion 16 so as to communicate with the outside from the groove portion 20 in a direction in which the groove portion 20 is recessed from the seat surface portion 19.

  As described above, according to the lens unit of the third embodiment, since the vent 21b is formed through the support portion 16, the contact of the outgas discharged through the vent 21b with the lens 14 is suppressed. In addition, the whitening of the lens 14 can be further suppressed.

  Further, according to the lens unit of the third embodiment, since the vent portion 21b is formed through the support portion 16, after the lens 14 and the lens holder 15c are fixed, additional adhesion from the vent portion 21b. Agent injection is also possible.

(Modification)
Next, a lens unit according to a modification of the third embodiment of the present invention will be described. Hereinafter, the same components as those in the third embodiment are denoted by the same reference numerals, and description thereof is omitted. The lens unit 11 according to the modified example is different from the third embodiment in that the inflow suppressing unit 27 is provided. 6A is a front view of the lens holder 15d, and FIG. 6B is an EE cross-sectional view of the lens holder 15d.

  The support part 16 includes a seat surface part 19, a groove part 20, a vent part 21 b, an inflow suppressing part 27, and a vent part forming part 30. The structure of the seat surface part 19 and the groove part 20 is the same as that of 3rd Embodiment. The vent hole forming portion 30 is formed in the seat surface portion 19 on the outer side in the radial direction of the lens holder 15 d, is continuous with the groove portion 20, and has a stepped shape that is shallower than the groove portion 20 from the seat surface portion 19. In the cross section including the vent hole forming part 30 and the axis cx (the paper surface of FIG. 6B), the groove part 20, the vent hole forming part 30, and the seat surface part 19 are continuous. The inflow suppressing portion 27 is a step formed between the bottom surface 29 of the groove portion 20 and the bottom surface 31 of the vent hole forming portion 30. The vent portion 21 b is formed through the support portion 16 so as to communicate with the outside from the vent formation portion 30 in the direction in which the groove portion 20 is recessed from the seat surface portion 19.

  Thus, according to the lens unit of the modified example, the inflow suppression unit 27 suppresses the flow of excess adhesive into the vent portion 21b, so that the reliability with which outgas is discharged from the vent portion 21b is improved. Thus, the whitening of the lens 14 can be further suppressed.

  In addition, since the inflow suppressing part 27 suppresses leakage of the adhesive to the outside via the vent part 21b, it is possible to reduce deterioration in the assembly accuracy of the lens unit 11 due to the adhesive that is cured outside the lens holder 15d.

  Although the present invention has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various changes and modifications based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention.

  For example, the groove 20 may be formed in an arbitrary shape such as a plurality of arcs in addition to the annular shape. Further, any number of vent holes 21 may be formed for one groove 20.

  Further, the vent portion 21 can adopt any shape that communicates with the outside from the space defined by the lens 14 and the groove portion 20. For example, the vent portion 21 may be formed through the wall portion 17 of the lens holder 15 from the groove portion 20 toward the radially outer side of the lens holder 15.

  Moreover, the inflow suppression part 27 can employ | adopt the arbitrary shapes which can suppress the inflow to the vent part 21a of the excess adhesive agent which flows in the groove part 20, such as forming in the groove part 20 in a rib shape.

DESCRIPTION OF SYMBOLS 10 Image pick-up device 11 Lens unit 12 Image pick-up element 13 Lens tube 14 Lens 15, 15a, 15b, 15c, 15d Lens holder 16 Support part 17 Wall part 18 Inner peripheral surface 19 Seat surface part 20 Groove part 21, 21a, 21b Vent part 22D Cut portion 23 Injection portion 24 Object side end surface 25 Outer diameter side surface 26 Adhesive 27 Inflow suppressing portion 28 Bottom surface of vent portion 29 Bottom surface of groove portion 30 Vent portion forming portion 31 Bottom surface of vent portion forming portion

Claims (5)

A lens,
An inner peripheral surface that faces at least a part of the outer surface of the lens and is bonded to the lens by an adhesive , a groove that is continuous from a contact surface that contacts the lens and is recessed from the contact surface, and the lens a vent portion for discharging the lens and the gas generated from the adhesive may flow into the space defining the groove in a state of being in contact with the contact surface, at a distance from the vent portion in the circumferential direction of the lens A lens holder having an injection portion for injecting the adhesive so that the adhesive can flow into the groove through a gap between the outer side surface of the lens and the inner peripheral surface. Lens unit. The lens unit according to claim 1,
The lens holder has a plurality of the vent portions and the injection portion is located between the plurality of vent portions, or the lens holder has a plurality of the injection portions and the plurality of the injection portions. The lens unit is characterized in that the vent part is located between the two. The lens unit according to claim 1 or 2,
The lens unit, wherein the vent portion communicates with the outside from the groove portion toward a radially inner side of the lens holder or toward a recess direction of the groove portion. The lens unit according to any one of claims 1 to 3,
The lens holder includes an inflow suppressing portion that suppresses inflow of the adhesive flowing into the groove into the vent portion. An imaging apparatus comprising: the lens unit according to claim 1; and an imaging element that captures a subject image formed by the lens unit.

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