WO2012133552A1

WO2012133552A1 - Lens unit and image capture unit

Info

Publication number: WO2012133552A1
Application number: PCT/JP2012/058183
Authority: WO
Inventors: 佐々木　竜太; 直喜佐々木
Original assignee: 富士フイルム株式会社
Priority date: 2011-03-31
Filing date: 2012-03-28
Publication date: 2012-10-04
Also published as: JP2014115304A

Abstract

Provided are a lens unit, comprising an optical assembly which includes at least one lens and a lens barrel which houses the optical assembly, and an image capture unit which comprises the lens unit. The lens barrel further comprises a cylindrical cylinder part to which the lens is hooked. The cylinder part is formed from a polychrome mold using a first resin and a second resin which forms a site which includes at least a lens hook part to which the lens is hooked. The second resin has a smaller measurement change due to humidity than the first resin.

Description

Lens unit and imaging unit

The present invention relates to a lens unit and an imaging unit.

Currently, in-vehicle cameras used for back monitoring and forward monitoring are in widespread use.

An imaging unit used for an in-vehicle camera generally includes an imaging element such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, and a lens unit that forms an image on a light receiving surface of the imaging element. Prepare.

The lens unit includes a plurality of lenses and a lens barrel that houses these lenses. For example, Patent Document 1 and Patent Document 2 describe an imaging unit including such a lens unit.

Japanese Unexamined Patent Publication No. 2009-95000 Japanese Unexamined Patent Publication No. 2004-295119

By the way, in a lens unit used in an imaging unit, a resin excellent in heat resistance, chemical resistance, and weather resistance is used as a material of the lens barrel. For example, a polyamide resin (PA) and a prephthalamide resin (PPA) are often used. On the other hand, these resins have a large dimensional change due to the use environment, and particularly a large dimensional change due to humidity. For this reason, when a lens unit and an imaging unit including a lens barrel made of these resins are used in a hot and humid environment, a dimensional change occurs in the lens barrel, and a gap is generated between the lens and the lens barrel. is there. As a result, the lens barrel and axial displacement may occur in the lens barrel, and the optical performance of the lens unit and the imaging unit may deteriorate.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a lens unit and an imaging unit that can suppress deterioration of optical performance while ensuring resistance to heat from the outside.

(1) A lens unit including an optical system including at least one lens and a lens barrel that houses the optical system, and the lens barrel has a cylindrical tube portion into which the lens is fitted. The cylindrical portion is formed by multicolor molding using a first resin and a second resin that forms a portion including at least a lens fitting portion into which the lens is fitted, and the second resin However, the lens unit is a resin whose dimensional change according to humidity is smaller than that of the first resin.
(2) a sensor unit including an optical system including at least one lens, an image sensor that forms an image of the light of the optical system, a sensor substrate on which the image sensor is fixed, and the optical system for the sensor substrate. A lens holding member for fixing the position, wherein the lens holding member has a first resin forming a first portion exposed to the outside of the lens holding member, and a lens fitting into which the lens is fitted. A second resin forming a second part having at least one of a joint portion and an attachment portion for attaching the lens holding member to the sensor substrate, and the second resin. The imaging unit whose resin is resin with a small dimensional change according to humidity compared with the said 1st resin.

According to the present invention, it is possible to provide a lens unit and an imaging unit that can suppress deterioration of optical performance while ensuring resistance to heat from the outside.

It is a figure which shows an example of a structure of the lens unit for describing embodiment of this invention. It is a figure which shows the imaging unit provided with the lens unit of FIG. It is sectional drawing of the lens barrel of the lens unit of FIG. It is a figure which shows the modification of a structure of the imaging unit of FIG. It is a figure which shows the other modification of a structure of the imaging unit of FIG.

FIG. 1 is a diagram illustrating an example of a configuration of a lens unit.
The lens unit 10 includes an optical system 4 that includes a plurality of lenses, and a lens barrel 1 that houses the optical system 4. In the example shown in FIG. 1, the optical system 4 includes a first lens 11, a second lens 21, a third lens 31, and a fourth lens 41 that are arranged in order from the incident side (subject side). Yes.

The configuration of the optical system 4 is not limited to the illustrated example. For example, the number of lenses may be 3, or 5 or more.

The lens barrel 1 includes a cylindrical tube portion 1a into which each lens is fitted, and a bottom portion 1b provided at one end portion in the axial direction of the tube portion 1a. Further, the end of the tube portion 1a of the barrel 1 opposite to the bottom portion 1b in the axial direction is open.

The lens barrel 1 is provided with a stepped portion 7 on the inner peripheral surface of the tube portion 1a. The step portion 7 is provided in an annular shape around the central axis of the cylindrical portion 1a.

The optical system 4 is disposed in the tube portion 1a in a state where the optical axis thereof coincides with the central axis of the tube portion 1a of the lens barrel 1. An opening 3 is provided at the center of the bottom 1b through which the optical axis of the optical system 4 passes. The light transmitted through the optical system 4 passes through the opening 3 and enters an image sensor of a sensor unit (see FIG. 2) described later.

The first lens 11, the second lens 21, the third lens 31, and the fourth lens 41 are arranged in this order from the end opposite to the bottom 1b of the lens barrel 1 in this order.

The first lens 11 is composed of a lens portion 12 having optical surfaces on the front and back sides and an edge portion 13 extending around the lens portion 12.
Similarly, the second lens 21 includes a lens part 22 having optical surfaces on the front and back sides and an edge part 23 extending around the lens part 22.
Similarly, the third lens 31 includes a lens part 32 having optical surfaces on the front and back sides and an edge part 33 that spreads around the lens part 32 in a bowl shape.
Similarly, the fourth lens 41 includes a lens part 42 having optical surfaces on the front and back sides, and an edge part 43 that spreads around the lens part 42 in a bowl shape.

The first lens 11, the second lens 21, the third lens 31, and the fourth lens 41 are respectively fitted on the inner peripheral surface of the lens barrel 1. The

edge portions

13, 23, 33, and 43 of the first lens 11, the second lens 21, the third lens 31, and the fourth lens 41 are in contact with the inner peripheral surface of the lens barrel 1. The edge portion 13 of the first lens 11 is held by the tube portion 1a from the subject side by caulking the tip portion of the tube portion 1a.

The diameter of the first lens 11 is larger than the diameter of the second lens 21. The diameter of the second lens 21 is larger than the diameter of the third lens 31. The diameter of the third lens 31 is larger than the diameter of the fourth lens 41. In the following description, the first lens 11, the second lens 21, the third lens 31, and the fourth lens 41 are collectively referred to simply as a lens.

FIG. 2 is a diagram illustrating an example of a configuration of an imaging unit including the lens unit of FIG.

The imaging unit 100 includes the lens unit 10 of FIG. 1, a sensor unit 101, an outer cover part 102, a holder part 103, a connection part 108, and a wiring 110.

The sensor unit 101 includes a main body cover 105, an image sensor 106 built in the main body cover 105, and a sensor substrate 104 to which the image sensor 106 is attached. The image sensor 106 converts an image formed by the optical system 4 into an electrical signal. The image sensor 106 is, for example, a CCD image sensor or a CMOS image sensor.

The sensor substrate 104 is a plate-like member that supports the image sensor 106 so that the imaging surface of the image sensor 106 is perpendicular to the optical axis of the optical system 4.

The holder portion 103 is a frame-like member that holds the lens barrel 1 of the lens unit 10. In addition, the holder portion 103 is fixed to the sensor substrate 104. Although not shown, the holder portion 103 has an inner peripheral surface that is screw-fitted with the outer peripheral surface of the cylindrical portion 1 a of the lens barrel 1, and positions the optical system 4 in the optical axis direction with respect to the imaging element 106.

The outer cover portion 102 covers the periphery of the lens barrel 1 and the holder portion 103, and holds the outer periphery of the lens barrel 1 of the lens unit 10 on the subject side. Further, the outer cover portion 102 is fixed to the main body cover 105.

The connection unit 108 connects the wiring extending from the sensor substrate 104 in the main body cover 105 to the wiring 110 extending outward from the main body cover 105.

As shown in FIG. 2, in the lens unit 10 of the imaging unit 100, the lens barrel 1 is formed by two-color molding.

Next, a configuration example of the lens barrel 1 when the lens barrel 1 is two-color molded will be described. In the following description, the configurations of the lens unit in FIG. 1 and the imaging unit in FIG. 2 will be referred to as appropriate, and the description of the members and parts already described will be simplified or omitted.

FIG. 3 is a cross-sectional view of the lens barrel 1 of the lens unit 10. In FIG. 3, the state cut | disconnected in parallel with respect to the central axis of the cylinder part 1a of the lens barrel 1 is shown.
As shown in FIG. 3, in the lens barrel 1, a portion 1A including an outer surface is formed of a first resin. Part 1B including the inner surface is formed of the second resin.

The resin having different performance is used for the first resin and the second resin.

As an example, a resin having excellent heat resistance, chemical resistance, and weather resistance is used as the first resin. Such resins include polyamide resin (PA), polyphthalamide resin (PPA), polycarbonate resin (PC), polyphenylene sulfide resin (PPS), polybutylene terephthalate resin (PBT), and polyether sulfone resin (PES). , Polyphenylene ether resin (PPE), polyethylene resin (PE), polyarylate resin (PAR), liquid crystal polymer resin (LCP), polyether ether ketone resin (PEEK), polyimide resin (PI), polyamideimide resin (PAI), etc. It is.

Further, as the second resin, a resin whose dimensional change due to humidity is smaller than that of the first resin is used. Such a resin is a resin whose dimensional change due to humidity is smaller than that of the first resin, such as PA, PPA, PC, PPS, PBT, PES, PPE, PE, PAR, LCP, PEEK, PI, PAI, and the like. . The first resin and the second resin may be a combination of different types of resins, or may be resins of the same type and different grades.

That is, a portion 1B including a lens fitting portion that is provided on the inner surface of the barrel portion 1a of the lens barrel 1 and into which each lens of the optical system 4 is fitted is formed of the second resin. The second resin is less deformed depending on the humidity than the first resin that forms the outside of the cylindrical portion 1a. Therefore, the lens barrel 1 is less likely to undergo a dimensional change on the side that holds each lens in the lens barrel 1, and can prevent a gap from being generated between the lens and the lens barrel 1. Therefore, the imaging unit 100 including the lens unit 10 and the lens unit 10 can suppress deterioration in optical performance.

In the lens barrel 1, the portion 1B including the entire inner surface of the tube portion 1a is formed of the second resin, but is not limited thereto. By forming the portion 1B including at least the lens fitting portion in the cylindrical portion 1a with the second resin, it is possible to suppress a gap from being generated between the lens and the lens barrel 1 due to a dimensional change of the cylindrical portion 1a due to humidity.

Next, a modified example of the configuration of the imaging unit will be described.

FIG. 4 shows a modification of the configuration of the imaging unit.

In the imaging unit 100 shown in FIG. 4, a holder portion for holding the lens barrel 1 of the lens unit 10 and an outer cover portion covering the outer periphery of the lens barrel 1 of the lens unit 10 are integrally formed by two-color molding. A portion integrally formed by the two-color molding functions as the lens holding member 141.

The lens holding member 141 has a substantially cylindrical shape centered on the optical axis of the optical system 4. As shown by a dotted line in FIG. 4, the lens holding member 141 is arranged on the inner side of the outer part 141 </ b> A as an example of an outer cover part that is an exposed part of the lens holding member 141 and on the inner side of the outer part 141 </ b> A. It is divided into an inner portion 141B as an example of the holder portion. The outer portion 141A having the outer diameter of the lens holding member 141 is formed of the first resin, and the inner portion 141B on the inner diameter side is formed of the second resin. The lens holding member 141 is formed by two-color molding of the first resin and the second resin.

The lens holding member 141 holds the lens unit 10 including the optical system 4 and fixes the position of the optical system 4 with respect to the sensor substrate 104.

In the lens holding member 141, an outer portion 141A that is a portion exposed to the outside in the lens holding member 141 is formed of the first resin. As the first resin, a resin having excellent heat resistance, chemical resistance, and weather resistance is used. Examples of such a resin include PA and PPA.

In the lens holding member 141, the inner part 141B other than the outer part 141A formed of the first resin is formed of the second resin. As the second resin, a resin whose dimensional change due to humidity is smaller than that of the first resin is used as described above.

The inner portion 141B includes an attachment portion 143 for fixing the lens unit 10 and attaching the lens holding member 141 to the sensor substrate 104.

The mounting portion 143 is joined to the periphery of the surface on which the image sensor 106 of the sensor substrate 104 is mounted. The attachment portion 143 has a side wall that is substantially perpendicular to the surface of the sensor substrate 104, and is formed so as to surround the imaging element 106 by the side wall. The attachment portion 143 defines the distance between the optical system 4 held by the lens holding member 141 and the image sensor 106 of the sensor substrate 104.

Since the inner portion 141B including the attachment portion 143 in the lens holding member 141 is formed of the second resin, the dimensional deformation due to humidity is less than that of the first resin forming the outer portion 141A of the lens holding member 141. Hard to occur. On the other hand, of the lens holding member 141, the outer portion 141A constituting the outer side is superior in heat resistance, chemical resistance, and weather resistance as compared to the inner portion 141B constituting the inner side.

As described above, the imaging unit 100 including the lens holding member 141 has the outer portion 141A to ensure heat resistance, chemical resistance, and weather resistance, and to the mounting portion 143 using a resin that hardly causes dimensional deformation due to humidity. Reduces dimensional deformation due to humidity. For this reason, it can suppress that the space | interval of the optical system 4 and the image pick-up element 106 changes. That is, since the dimensional change of the attachment portion 143 affects the amount of focus shift of the subject at the time of imaging, the deterioration of the optical performance of the imaging unit 100 can be suppressed by suppressing the dimensional change due to the humidity of the attachment portion 143. it can.

FIG. 5 shows another modification of the configuration of the imaging unit.

In the imaging unit 100 shown in FIG. 5, a holder part that also functions as a lens barrel that houses the optical system 4 and an outer cover part that covers the outer periphery of the holder part are integrally formed by two-color molding. A portion integrally formed by the two-color molding functions as the lens holding member 51.

In the lens holding member 51, an outer portion 51A as an outer cover portion which is a portion exposed to the outside in the lens holding member 51 is formed of the first resin. As the first resin, a resin having excellent heat resistance, chemical resistance, and weather resistance is used. Examples of such a resin include PA and PPA.

In the lens holding member 51, the inner part 51B as the holder part other than the outer part 51A formed of the first resin is formed of the second resin. As the second resin, a resin whose dimensional change due to humidity is smaller than that of the first resin is used as described above.

The inner portion 51 </ b> B formed of the second resin includes a lens fitting portion 151 into which each lens of the optical system 4 is fitted, and an attachment portion 153 for attaching the lens holding member 51 to the sensor substrate 104. .

The attachment portion 153 is joined to the periphery of the surface on which the image sensor 106 of the sensor substrate 104 is mounted, similarly to the attachment portion 143 described above. The attachment portion 153 has a side wall that is substantially perpendicular to the surface of the sensor substrate 104, and is formed so as to surround the imaging element 106 by the side wall. The attachment portion 153 defines the distance between the optical system 4 held by the lens holding member 51 and the image sensor 106 of the sensor substrate 104.

Further, the inner portion 51B of the lens holding member 51 has a lens fitting portion 151 into which the edge portion of each lens is fitted integrally with the mounting portion 153. This lens fitting portion 151 is also formed of the second resin.

The outer portion 51A constituting the outside of the lens holding member 51 is superior in heat resistance, chemical resistance, and weather resistance compared to the inner portion 51B constituting the inside.

On the other hand, since the mounting portion 153 and the lens fitting portion 151 of the lens holding member 51 are formed of the second resin, a dimensional change due to humidity hardly occurs.

That is, by forming the attachment portion 153 with the second resin, it is possible to suppress a change in the distance between the optical system 4 and the image sensor 106.

Further, by forming the lens fitting portion 151 with the second resin, it is possible to suppress a gap from being generated between the lens fitting portion 151 of the lens holding member 51 and the lens.

As described above, according to the imaging unit 100 including the lens holding member 51, it is possible to suppress deterioration of optical performance.

In the imaging unit 100 shown in FIG. 5, the lens fitting portion 151 and the attachment portion 153 of the lens holding member 51 are both formed of the second resin, but the present invention is not limited to this. For example, by forming at least one of the lens fitting portion 151 and the attachment portion 153 with the second resin, it is possible to obtain an effect of suppressing dimensional change due to humidity and suppressing deterioration of optical performance.

However, by forming the lens fitting portion 151 and the attachment portion 153 integrally using the second resin, it is possible to suppress a relative position shift between the optical system 4 and the image sensor 106. For this reason, deterioration of optical performance can be suppressed more reliably.

The above-described lens unit and imaging unit are examples formed by two-color molding, but are not limited thereto. For example, the lens unit and the imaging unit may be formed by multicolor molding using three or more different resins.

This specification discloses the following matters.
(1) A lens unit including an optical system including at least one lens and a lens barrel that houses the optical system, and the lens barrel has a cylindrical tube portion into which the lens is fitted. The cylindrical portion is formed by multicolor molding using a first resin and a second resin that forms a portion including at least a lens fitting portion into which the lens is fitted, and the second resin However, the lens unit is a resin whose dimensional change according to humidity is smaller than that of the first resin.
(2) The lens unit according to (1), wherein the first resin is polyamide resin (PA), polyphthalamide resin (PPA), polycarbonate resin (PC), polyphenylene sulfide resin (PPS), poly Butylene terephthalate resin (PBT), polyether sulfone resin (PES), polyphenylene ether resin (PPE), polyethylene resin (PE), polyarylate resin (PAR), liquid crystal polymer resin (LCP), polyether ether ketone resin (PEEK) ), A polyimide resin (PI), or a polyamide-imide resin (PAI), wherein the second resin is the same or different kind of resin as the first resin, A lens unit that is a resin whose dimensional change due to humidity is smaller than that of resin.
(3) The lens unit according to (1) or (2), an image sensor that forms an image of the light of the optical system, a sensor unit that includes a sensor substrate on which the image sensor is fixed, and a sensor unit that is fixed to the sensor substrate. An imaging unit comprising: a holder portion that holds the lens barrel; and an outer cover portion that covers the periphery of the lens barrel and the holder portion.
(4) A sensor unit including an optical system including at least one lens, an image sensor that forms an image of light of the optical system, a sensor substrate on which the image sensor is fixed, and the optical system for the sensor substrate. A lens holding member for fixing the position, wherein the lens holding member has a first resin forming a first portion exposed to the outside of the lens holding member, and a lens fitting into which the lens is fitted. A second resin forming a second part having at least one of a joint portion and an attachment portion for attaching the lens holding member to the sensor substrate, and the second resin. The imaging unit whose resin is resin with a small dimensional change according to humidity compared with the said 1st resin.
(5) The imaging unit according to (4), including a lens unit including a lens barrel that accommodates the optical system, wherein the lens holding member includes the mounting portion and fixes the lens unit. An imaging unit in which a holder part as a second part and an outer cover part as a first part covering the periphery of the lens unit and fixed to the sensor unit are integrally formed by the multicolor molding.
(6) In the imaging unit according to (4), the lens holding member covers a holder portion as a second part having the attachment portion and the lens fitting portion, and a periphery of the optical system, An imaging unit in which an outer cover portion fixed to the sensor unit is integrally formed by the multicolor molding.
(7) The imaging unit according to (6), wherein the attachment portion and the lens fitting portion are integrally formed of the second resin.
(8) The imaging unit according to any one of (4) to (7), wherein the first resin is a polyamide resin (PA), a polyphthalamide resin (PPA), or a polycarbonate resin (PC). , Polyphenylene sulfide resin (PPS), polybutylene terephthalate resin (PBT), polyether sulfone resin (PES), polyphenylene ether resin (PPE), polyethylene resin (PE), polyarylate resin (PAR), liquid crystal polymer resin (LCP) ), Polyetheretherketone resin (PEEK), polyimide resin (PI), and polyamideimide resin (PAI), wherein the second resin is the same type or different type from the first resin. An imaging unit that is a resin and has a smaller dimensional change due to humidity than the first resin.

The lens unit and the imaging unit described above are useful when used for cameras that require resistance to environmental temperature changes and humidity. For example, it is useful for a vehicle-mounted camera provided for back monitoring or front monitoring. Further, the lens unit and the imaging unit described above are not limited to a vehicle-mounted camera, and are useful for a camera mounted on a terminal such as a mobile phone.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application filed on Mar. 31, 2011 (Japanese Patent Application No. 2011-081230), the contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1 Lens barrel 1a Tube part 10 Lens unit 11 1st lens (lens)
21 Second lens (lens)
31 Third lens (lens)
41 Fourth lens (lens)
100 Imaging unit 101 Sensor unit

Claims

An optical system comprising at least one lens;
A lens unit that houses the optical system,
The lens barrel has a cylindrical tube portion into which the lens is fitted,
The cylindrical portion is formed by multicolor molding using a first resin and a second resin that forms a portion including at least a lens fitting portion to which the lens is fitted. A lens unit that is a resin that has a smaller dimensional change in accordance with humidity than the first resin.
The lens unit according to claim 1,
The first resin is a polyamide resin (PA), a polyphthalamide resin (PPA), a polycarbonate resin (PC), a polyphenylene sulfide resin (PPS), a polybutylene terephthalate resin (PBT), or a polyether sulfone resin (PES). , Polyphenylene ether resin (PPE), polyethylene resin (PE), polyarylate resin (PAR), liquid crystal polymer resin (LCP), polyether ether ketone resin (PEEK), polyimide resin (PI), polyamideimide resin (PAI) One of them,
The lens unit, wherein the second resin is a resin of the same type or different type from the first resin, and has a smaller dimensional change due to humidity than the first resin.
The lens unit according to claim 1 or 2,
An image sensor for imaging the light of the optical system, a sensor unit including a sensor substrate to which the image sensor is fixed, and
A holder part fixed to the sensor substrate and holding the lens barrel;
An imaging unit comprising: the lens barrel and an outer cover that covers the periphery of the holder.
An optical system comprising at least one lens;
A sensor unit including an image sensor that images light of the optical system, and a sensor substrate on which the image sensor is fixed;
A lens holding member that fixes the position of the optical system with respect to the sensor substrate,
The lens holding member includes a first resin that forms a first portion exposed to the outside of the lens holding member, a lens fitting portion into which the lens is fitted, and the lens holding member. And a second resin that forms a second part having at least one of the attachment part for attaching to the first part, and the second resin is formed by comparison with the first resin. An imaging unit that is a resin with a small dimensional change according to humidity.
The imaging unit according to claim 4,
A lens unit including a lens barrel that houses the optical system;
The lens holding member has the mounting portion and has a holder portion as a second portion for fixing the lens unit, and a first portion that covers the periphery of the lens unit and is fixed to the sensor unit. An imaging unit in which an outer cover portion is integrally formed by the multicolor molding.
The imaging unit according to claim 4,
The lens holding member includes a holder part as a second part having the attachment part and the lens fitting part, and an outer cover part that covers the periphery of the optical system and is fixed to the sensor unit. An imaging unit integrally formed by molding.
The imaging unit according to claim 6,
The mounting unit and the lens fitting portion are an imaging unit formed integrally with the second resin.
The imaging unit according to any one of claims 4 to 7,
The first resin is a polyamide resin (PA), a polyphthalamide resin (PPA), a polycarbonate resin (PC), a polyphenylene sulfide resin (PPS), a polybutylene terephthalate resin (PBT), or a polyether sulfone resin (PES). , Polyphenylene ether resin (PPE), polyethylene resin (PE), polyarylate resin (PAR), liquid crystal polymer resin (LCP), polyether ether ketone resin (PEEK), polyimide resin (PI), polyamideimide resin (PAI) One of them,
The imaging unit, wherein the second resin is a resin of the same type or different type from the first resin, and has a smaller dimensional change due to humidity than the first resin.