JP2016184081A - Lens unit and camera module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens unit capable of reducing assembling failures when assembled into a lens barrel by mounting an O-ring on a glass lens closest to an object side, and a camera module.SOLUTION: In this lens unit, while a groove 15 for an O-ring of a lens (glass lens) 2 closest to an object side has a cross-sectional form formed in a rectangular shape, an O-ring 16 has a cross-sectional form formed in a "D" shape. A linear portion on an inner diameter side of the O-ring 16 is in surface contact with a bottom surface of the groove 15 for the O-ring.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lens unit and a camera module that are preferably used for a camera disposed outdoors so that at least a part of the camera is exposed.

  In recent years, since a monitor is mounted on a car for car navigation or the like, for example, as a back monitor system, an image taken by a vehicle-mounted camera mounted on the back of the vehicle is displayed on the monitor. Also, a system has been developed in which this camera is provided not only in the back but also in the front, rear, left, and right sides of the vehicle, and an image overlooking the periphery of the vehicle is synthesized and displayed on a monitor in substantially real time.

Such an in-vehicle camera lens unit is a wide-angle lens unit, and the tip on the object side is out of the vehicle, so strength, waterproofness, chemical resistance, high temperature resistance, etc. are required. Is done. In addition, it is necessary to prevent the lens from fogging with respect to temperature changes.
For example, a lens unit for an in-vehicle camera having a sealed structure for preventing the lens from fogging has been proposed (see, for example, Patent Document 1).

In this lens unit, as a group of lenses in a cylindrical barrel, for example, four lenses are arranged substantially in the optical axis direction in the barrel, and the gap between the most object side lens and the barrel is Sealed by an O-ring as a sealing material. On the most imaging side (imaging device side), the optical filter or the lens disposed on the most imaging side and the lens barrel are fixed with an adhesive, so that the cured adhesive functions as a sealing material. Yes.
Accordingly, the inside of the lens barrel is hermetically sealed by the object-side seal and the imaging-side seal of the lens barrel, and the occurrence of fogging of the lens in the lens barrel due to a temperature change is prevented.

  By the way, when the gap between the glass lens closest to the object side and the resin lens barrel is sealed with an O-ring as a sealing material, an O-ring 92 having a circular cross-sectional shape is conventionally used as shown in FIG. . For this reason, when the O-ring 92 is mounted in the O-ring groove 94 on the outer peripheral surface of the glass lens 93 and is press-fitted into the holding portion 96 of the lens barrel 95, the O-ring 92 is in the press-fitting process because the sectional shape is circular. Rotates, and the O-ring 92 may be caught between the outer peripheral surface of the glass lens 93 and the inner peripheral surface of the holding portion 96, or the O-ring 92 may be twisted. There exists a problem that the manufacturing cost of a lens unit becomes high.

Japanese Patent No. 4999508

  The present invention has been made in view of the above circumstances, and provides a lens unit and a camera module that can reduce assembly failure when an O-ring is attached to the glass lens closest to the object side and incorporated into a lens barrel. The purpose is to do.

  The lens unit of the present invention includes a lens barrel and a plurality of lenses arranged in the axial direction of the lens barrel inside the lens barrel, and is located at least on the most object side of the plurality of lenses. The lens to be is a glass lens, and an annular holding portion that opens to the object side and radially inward is formed at the object side end of the inner peripheral surface of the lens barrel, and the inner peripheral surface of the holding portion and the glass A lens unit in which an O-ring is interposed between an annular O-ring groove formed on the outer peripheral surface of the lens, and the glass lens is fitted to the holding portion. At least a part of the outer peripheral surface is formed in a shape in surface contact with a part of the inner peripheral surface of the groove for O-ring.

  According to such a configuration, since at least a part of the outer peripheral surface of the O-ring is formed in a shape in surface contact with a part of the inner peripheral surface of the O-ring groove, the O-ring is formed on the outer peripheral surface of the glass lens. Even when the O-ring groove is mounted and press-fitted into the holding portion of the lens barrel, the O-ring has a large frictional force between the outer peripheral surface of the O-ring and the inner peripheral surface of the O-ring groove. The movement of the O-ring from the groove is suppressed. For this reason, it is possible to reduce an assembly failure in which the O-ring is caught between the outer peripheral surface of the glass lens and the inner peripheral surface of the holding portion or the O-ring is twisted.

  In the above configuration of the present invention, the O-ring groove opens to the bottom surface side and the radially outer side of the holding portion at an end portion of the outer peripheral surface of the glass lens on the bottom surface side of the holding portion of the lens barrel. It is preferably formed in an annular shape. Further, it is more preferable that the O-ring groove has a square cross-sectional shape having sides along the axis of the lens barrel. Furthermore, it is more preferable that the O-ring has a wedge-shaped end portion on the bottom surface side of the holding portion of the lens barrel.

  Moreover, the said structure of this invention WHEREIN: It is preferable that the said groove | channel for O-rings is formed in the outer peripheral surface of the said glass lens in the cyclic | annular form opened to a radial direction outer side.

In the above configuration of the present invention, the inner peripheral surface of the holding portion of the lens barrel includes a tapered portion that gradually increases in diameter toward the object-side end portion at the object-side end portion. The depth dimension from the object side end is preferably set to 1/5 to 1/3 of the width dimension t of the outer peripheral surface portion of the glass lens fitted to the inner peripheral surface of the holding portion. .
If it does in this way, it will become easy to insert the glass lens which attached the O-ring in the groove for O-rings in the holding part of a lens-barrel, preventing the fall of a glass lens. It is possible to further reduce assembly failures such as being caught between the inner peripheral surface and the O-ring being twisted.

The camera module of the present invention includes the lens unit having the above-described configuration, and further includes an imaging element that captures an image formed by the lens unit.
According to such a configuration, the camera module can achieve the same functions and effects as the lens units described above.

  According to the present invention, it is possible to provide a lens unit and a camera module in which an O-ring is attached to the glass lens closest to the object side and assembly failure when being assembled into a lens barrel can be reduced.

It is a figure which shows the lens unit which concerns on the 1st Embodiment of this invention, Comprising: The lens of the most object side is in the state before insertion, and is a schematic sectional drawing which abbreviate | omits and shows each lens surface shape. It is a figure which shows the lens unit which concerns on the 2nd Embodiment of this invention, Comprising: The lens of the most object side is in the state before insertion, and is a schematic sectional drawing which abbreviate | omits and shows each lens surface shape. . It is a figure which shows the lens unit which concerns on the 3rd Embodiment of this invention, Comprising: The lens of the most object side is in the state before insertion, and is a schematic sectional drawing which abbreviate | omits and shows each lens surface shape. . It is a figure which shows the lens unit which concerns on the 4th Embodiment of this invention, Comprising: It is a principal part sectional drawing in which the lens of the most object side is in the state before insertion. It is a figure which shows the lens unit which concerns on the 5th Embodiment of this invention, Comprising: It is a principal part sectional drawing in which the lens of the most object side is in the state before insertion. It is a figure which shows the lens unit which concerns on the 6th Embodiment of this invention, Comprising: The lens of the most object side is in the state before insertion, and is a schematic sectional drawing which abbreviate | omits and shows each lens surface shape. . FIG. 10 is a diagram showing a lens unit according to a seventh embodiment of the present invention, and the most object side lens is a schematic cross-sectional view showing a state before insertion and a state after insertion, and omitting the shape of each lens surface; It is. FIG. 6 is a cross-sectional view of the main part illustrating the lens closest to the object side after insertion. It is a figure which shows the conventional lens unit, Comprising: The lens of the most object side is in the state before insertion, and is a schematic sectional drawing which abbreviate | omits and shows each lens surface shape.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
First, a first embodiment of the present invention will be described.
As shown in FIG. 1, the lens unit of this embodiment includes a lens barrel 1 and a plurality of lenses 2, 3, 4, 5, and 6 arranged in the lens barrel 1.
In addition to this, the light shielding filters 7 and 9 and the lenses 2, 3, 4, 5, 6 interposed between the lenses form an image forming side (image forming element side). The optical filter etc. which are arrange | positioned at one edge part of this are provided.

This lens unit is, for example, a wide-angle camera used in an in-vehicle camera that is disposed in a state in which at least the object-side lens 2 is exposed to the outside of the automobile in order to photograph the rear side and front side of the automobile and the surroundings of the automobile. It is a lens unit.
The lens barrel 1 is made of a nylon resin reinforced with glass fibers. This nylon resin is generally a polyamide containing an aliphatic skeleton. This resin is excellent in chemical resistance, exhibits excellent toughness, impact resistance, and flexibility, and has high affinity with a composite material such as glass fiber and can be handled as an engineering plastic. However, since it has a high water absorption rate and expands when it absorbs water, it is preferable to use a polyamide resin having a low water absorption rate as much as possible. Therefore, for example, Reny (manufactured by Mitsubishi Engineering Plastics Co., Ltd.), which is a polyamide resin with reduced water absorption, may be used.
The lens barrel 1 may be made of other resin, or may be made of metal such as stainless steel or aluminum alloy.

The lens barrel 1 has a plurality (four in this example) of lenses 2, 3, 4, 5, and 6 that constitute one lens group along the axial direction of the lens barrel 1 inside. The Further, the lenses 2, 3, 4, 5 and 6 are arranged in the optical axis direction so as to substantially coincide with the axial direction of the lens barrel 1. One end of the lens barrel 1 is disposed on the imaging side as the imaging side, and the other end is disposed on the object side toward the photographing target. In the case of this example, the lens 2 side is the object side.
The lens 2 that is positioned closest to the object side is a glass lens (glass lens). The other lenses 3, 4, 5, and 6 may be glass lenses or resin lenses (resin lenses).
A plurality of lenses 2, 3, 4, 5, and 6 and the light shielding filters 7, 9 are inserted and installed in order from the object side to the image forming side.

An annular holding portion (stepped portion) 12 that opens to the object side and radially inward is formed on the inner peripheral surface of the object side end of the lens barrel 1, and the lens 2 is fitted to the holding portion 12. Yes. The lens 2 is slightly separated from the bottom surface 13 of the holding unit 12 after being fitted into the holding unit 12.
An annular O-ring groove 15 that opens to the imaging side and radially outward is formed at the imaging side end of the outer peripheral surface of the lens 2. The cross-sectional shape of the O-ring groove 15 is a square. The O-ring groove 15 includes a surface that is substantially parallel to the axis of the lens 2 and a surface that is substantially orthogonal to the axis of the lens 2. An O-ring 16 is mounted in the O-ring groove 15. The cross-sectional shape of the O-ring 16 is formed in a “D” shape in which the inner diameter side is a straight line parallel to the axis of the O-ring 16. The plane on the inner diameter side of the O-ring 16 includes a case where the draft may be slightly inclined when a draft is required during molding for manufacturing. The O-ring is mounted in an O-ring groove 15 in a state where the O-ring 16 is expanded and elastically deformed. In the O-ring 16, the linear portion on the inner diameter side is in surface contact with the bottom surface of the O-ring groove 15 (a surface defining the groove depth; a surface parallel to the axis of the lens 2). The O-ring 16 is slightly larger than the depth of the O-ring groove 15 in the depth direction of the O-ring groove 15 and slightly protrudes from the O-ring groove 15 when mounted in the O-ring groove 15. In the width direction of the ring groove 15, it is slightly smaller than the width of the O ring groove 15 and is located in the O ring groove 15.

In this lens unit, in order to fix the lens (glass lens) 2 to which the O-ring 16 is attached to the holding portion 12 of the lens barrel 1, for example, first, the lens barrel 1 is placed with its end on the object side facing up. While standing, the lens 2 is lightly pushed into the holding portion 12 of the lens barrel 1.
Next, the range 2 is fixed to the lens barrel 1 by, for example, crimping the end of the lens barrel 1 on the object side.

  Such a lens unit is attached to a holder (mount) as a pedestal, and constitutes a camera module together with an imaging device, a wiring board, a signal processing circuit, a flexible wiring sheet, a connector, and the like. Note that the camera module (imaging device) is a device including at least a lens unit and an imaging element.

  The camera module operates as follows. Light incident from the object side enters the image sensor through the lens of the lens unit. The image sensor converts an incident image into an electric signal. The signal processing circuit performs signal processing (A / D conversion, image correction processing, etc.) on the electrical signal from the image sensor. An electrical signal output from the signal processing circuit is connected to an external electronic device via a flexible wiring sheet and a connector.

In the lens unit and the camera module configured as described above, the cross-sectional shape of the O-ring groove 15 of the lens (glass lens) 2 is square, while the cross-sectional shape of the O-ring 16 is “D”. Since the linear portion on the inner diameter side of the O-ring 16 is in surface contact with the bottom surface of the O-ring groove 15, the lens 2 to which the O-ring 16 is attached is placed in the holding portion 12 of the lens barrel 1. Even if it fits in, since the frictional force of the said surface contact part is large, the movement of the O-ring 16 from the O-ring groove | channel 15 is suppressed. Therefore, it is possible to reduce an assembly failure in which the O-ring 16 is caught between the outer peripheral surface of the lens 2 and the inner peripheral surface of the holding portion 12 or the O-ring 16 is twisted.
In addition, since the O-ring 16 has a D shape, the O-ring 16 is not attached in a twisted state when the O-ring 16 is attached to the lens 2. It is hard to drop off.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.
As shown in FIG. 2, in the lens unit according to the second embodiment, the cross-sectional shape of the O-ring 16A is a straight line whose inner diameter side is parallel to the axis of the O-ring 16A, and the groove 15 for the O-ring. The first side only in that the surface on the side in contact with the side surface (the surface defining the groove width; the surface on the object side) is formed in a ¼ (¼) circular shape that is linear. Unlike the first embodiment, the other configuration is the same as that of the first embodiment.

  In the second embodiment, since the O-ring 16A and the O-ring groove 15 are in surface contact with each other on two surfaces, the frictional force of the surface contact portion is more than that in the case of the first embodiment. Therefore, the movement of the O-ring 16A from the O-ring groove 15 is further suppressed. That is, the object-side surface of the O-ring 16A and the side surface (object-side surface) of the O-ring groove 15 are in surface contact with each other, so that an O-line force applied to the O-ring 16A during press-fitting is reduced. The occurrence of twisting of the ring 16A can be suppressed.

(Third embodiment)
Next, a third embodiment of the present invention will be described.
As shown in FIG. 3, in the lens unit according to the third embodiment, the cross-sectional shape of the O-ring 16B is a straight line whose inner diameter side is parallel to the axis of the O-ring 16B, and the O-ring groove 15 is provided. The surface that contacts the side surface (the surface that defines the groove width; the object-side surface) is a straight line, and the outer diameter side is a straight line parallel to the axis of the O-ring 16B. The second embodiment is different from the second embodiment only in that the image forming side (the bottom surface 13 side of the holding portion 12 of the lens barrel 1) is formed in a wedge shape and is formed in a home base shape. It is comprised similarly to the form of. The planes on the inner diameter side and the outer diameter side of the O-ring 16B include a case where the draft may be slightly inclined when a draft is required at the time of molding for manufacturing.

  In the third embodiment, since the image forming side of the O-ring 16B is formed in a wedge shape, the O-ring 16B can be fitted into the holding portion 12 of the lens barrel 1 more smoothly without resistance.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described.
As shown in FIG. 4, in the lens unit according to the fourth embodiment, the O-ring groove 15 </ b> A is the end of the outer peripheral surface of the lens 2 on the image forming side (the bottom surface 13 side of the holding portion 12 of the lens barrel 1). The O-ring 16 is formed in an annular groove having a flat rectangular cross-sectional shape having an inclined bottom surface, and the O-ring 16 has a linear portion on the inner diameter side that defines the bottom surface (groove depth) of the O-ring groove 15A. Surface contact).
Others are configured in the same manner as in the first embodiment.
Also in the fourth embodiment, the movement of the O-ring 16 from the O-ring groove 15A is suppressed.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described.
As shown in FIG. 5, in the lens unit of the fifth embodiment, the O-ring groove 15B is the end of the outer peripheral surface of the lens 2 on the imaging side (the bottom surface 13 side of the holding portion 12 of the lens barrel 1). Is formed in an annular groove having a quarter (¼) circular cross-sectional shape, while the O-ring 16C has a circular cross-sectional shape. Is approximately in contact with the entire surface of the O-ring groove 15A.
Others are configured in the same manner as in the fourth embodiment.
Also in the fifth embodiment, the movement of the O-ring 16C from the O-ring groove 15B is suppressed.

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described.
As shown in FIG. 6, in the lens unit of the sixth embodiment, the O-ring groove 15 </ b> C is formed at the substantially central portion in the thickness direction of the outer peripheral surface of the lens 2, and the annular groove having a semicircular cross section. In the circular O-ring 16C, approximately one half of the outer peripheral surface on the inner diameter side is in surface contact with the entire surface of the O-ring groove 15C.
The other configuration is the same as that of the fifth embodiment.
Also in the sixth embodiment, the movement of the O-ring 16C from the O-ring groove 15C is suppressed.

(Seventh embodiment)
Next, a seventh embodiment of the present invention will be described.
As shown in FIGS. 7 and 8, in the lens unit of the seventh embodiment, the inner peripheral surface 22 of the holding portion 12A of the lens barrel 1 gradually increases toward the object side end portion toward the object side end portion. The taper part 23 which expands is provided. As shown in FIG. 8, the depth dimension from the object-side end of the tapered portion 23 is the width dimension t of the outer peripheral surface portion (edge surface) of the lens 2 fitted to the inner peripheral surface 22 of the holding portion 12. 1/5 to 1/3.
Others are configured in the same manner as in the first embodiment.

  In the seventh embodiment, the lens 2 in which the O-ring 16 is mounted in the O-ring groove 15 can be easily fitted into the holding portion 12A of the barrel 1 while preventing the lens 2 from falling. For this reason, it is possible to further reduce an assembly failure in which the O-ring 16 is caught between the outer peripheral surface of the lens 2 and the inner peripheral surface 22 of the holding portion 12A or the O-ring 16 is twisted.

1 Lens barrel 2 Lens (glass lens)
3, 4, 5, 6 Lens 12, 12A Holding portion 13 Bottom surface 15, 15A, 15B, 15C O-ring groove 16, 16A, 16B, 16C O-ring t A portion of the outer peripheral surface of the lens fitted to the holding portion (edge Surface) width dimension

Claims (7)

A lens barrel and a plurality of lenses provided inside the lens barrel along the axial direction of the lens barrel, and a lens that is positioned at least most on the object side among the plurality of lenses is a glass lens An annular holding portion that opens to the object side and radially inward is formed at the object side end of the inner peripheral surface of the lens barrel, and is formed on the inner peripheral surface of the holding portion and the outer peripheral surface of the glass lens. A lens unit in which an O-ring is interposed between the annular O-ring groove and the glass lens is fitted to the holding portion,
The O-ring is formed in a shape in which at least a part of an outer peripheral surface thereof is in surface contact with a part of an inner peripheral surface of the O-ring groove.   The O-ring groove is formed in an annular shape that opens to the bottom surface side and the radially outer side of the holding portion at an end portion of the outer peripheral surface of the glass lens on the bottom surface side of the holding portion. The lens unit according to claim 1.   3. The lens unit according to claim 2, wherein the O-ring groove has a square cross-sectional shape having sides along the axis of the lens barrel. 4.   The lens unit according to claim 3, wherein the O-ring has a wedge-shaped end portion on the bottom surface side of the holding portion of the lens barrel.   The lens unit according to claim 1, wherein the O-ring groove is formed in an annular shape that opens radially outward on an outer peripheral surface of the glass lens.   The inner peripheral surface of the holding portion of the lens barrel includes a tapered portion that gradually increases in diameter toward the object-side end at the object-side end portion, and the depth dimension of the tapered portion from the object-side end. Is set to 1/5 to 1/3 of the width dimension t of the outer peripheral surface portion of the glass lens fitted to the inner peripheral surface of the holding portion. The lens unit according to any one of the above.   A camera module comprising the lens unit according to any one of claims 1 to 6 and an imaging device that captures an image formed by the lens unit.

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