JP2006235575A - Lens barrel module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel module which has a high anti-dust property for an imaging device and allows a satisfactory white picture to be obtained. <P>SOLUTION: A base frame which is opened to front and rear end faces along an axial direction and has a peripheral wall demarcating a cavity connecting both end openings and has a screw part provided on an inner peripheral surface on the front opening side of the peripheral wall and has an annular flange portion formed in a boundary between the screw part and the rear opening projectingly from the inner peripheral surface toward a center, a lens support cylinder which holds a lens in a cylindrical body thereof and has a screw part which is engaged with the screw part of the base frame, formed on an outer peripheral surface thereof, and seal which is made of an elastically deformable member and is attached to annular surface on the front opening side of the flange part so as to close a gap between the lens support cylinder and the annular flange part are integrally assembled into one body, whereby the lens barrel module is obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lens barrel module mounted on a digital camera or the like.

  As a lens barrel module mounted on a digital camera, mobile phone, etc., it has a single focal point that is fixed with respect to an image sensor such as a CCD, that is, a single focal point that is in focus when a subject that is more than a predetermined distance away is photographed. A lens barrel module is known.

  The structure of a conventional lens barrel module will be described with reference to FIG. In FIG. 3, the cylindrical interior of the base frame 1 has a cavity 102 in which the circumference on the front opening 106 side is smaller in diameter than the circumference on the rear opening 107 side in the axis (L1) direction, and the axis L1 is placed on the front surface 103 side. A lens support tube 2 is fitted in the center, and the lens support tube 2 holds a focusing lens set 202. A female screw 105 is formed on the inner peripheral surface of the cavity 102 of the base frame 1 on the front opening 106 side, and is screwed into a male screw 205 provided on the outer peripheral surface 201 of the lens support tube 2. The rear opening 107 of the base frame 1 has, for example, a CCD image sensor having an imaging surface that photoelectrically converts an image formed by the lens set 202, and holds and drives the imaging device 3. The circuit board 4 is held. As shown in the figure, in the cavity 102 of the base frame 1, a plate-like color filter 5 for cutting light in a predetermined wavelength region is provided at a step portion 108 formed at the boundary between the small diameter side 101 and the large diameter side 104. Although attached so as to cover the opening, a color filter film may be formed on one lens in the lens set 202 without providing the plate-like color filter 5 in some cases. In this lens barrel module, the base frame 1, the lens support cylinder 2 holding the lens set 202, and the circuit board 4 form a substantially sealed space.

  In assembling the lens barrel module, first, the lens set 202 is appropriately moved back and forth in the direction of the axis L1 by screwing into the imaging surface of the stationary image pickup device 3 and turning the lens support tube 2. Adjust the focus (focus adjustment). And it is unitized by fixing with respect to the base frame 1 so that the lens support cylinder 2 may not move.

  In focusing of the lens barrel module, focusing is performed by moving the lens support cylinder 2 back and forth while rotating with respect to the base frame 1. When the lens support cylinder 2 is screwed into the base frame 1, The dust generated when the mating part is screwed or dust from the outside is mixed in from the screwing part and accumulates on the light receiving surface of the color filter 5 or the imaging surface of the image pickup device 3 to form an imaging spot (black spot). The screen cannot be obtained. The white screen is obtained by installing the lens barrel module vertically in the white light box and performing imaging by adjusting the color of the subject until fight balance is achieved.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lens barrel module that has a high dustproof property with respect to an image pickup device and can obtain a good white screen.

  In order to achieve the above object, the lens barrel module of the present invention has a peripheral wall that opens inside the front and rear end surfaces along the axial direction and defines a cavity that communicates with both end openings. A threaded portion is provided on the inner peripheral surface of the side, a base frame formed with an annular flange projecting from the inner peripheral surface of the peripheral wall toward the center at the boundary between the screw portion and the rear opening, and a lens inside the cylindrical body A lens support cylinder in which a threaded portion that is screwed to the threaded portion of the base frame is formed on the outer peripheral surface; And a seal that is attached so as to close the gap between them.

  Moreover, the said structure WHEREIN: It is preferable that the said annular flange part protrudes at right angles to a radial direction from the internal peripheral surface of a trunk | drum.

  In addition, the inner peripheral surface of the peripheral wall of the base frame is formed by reducing the diameter of a part of the cavity so that the front opening side is smaller in diameter than the rear opening side, and an annular step portion for the rear opening is formed at the boundary. It is preferable to be formed at the position of the stepped portion.

  According to the above configuration, according to the present invention, the elastically deformable seal is in close contact with the bottom end surface of the lens support tube between the screw threaded portion of the base frame and the lens support tube and the annular flange portion in the base frame. It is attached so as to close the gap between the ring flange part and the dust or dust from the outside when both screw parts are screwed together, and even if the dust from the screw screw part is mixed in, it is blocked by the seal. A good white screen can be obtained without entering the imaging plane of the image sensor.

  In addition, the lens support tube can be positioned at the axial focus position by the seal.

  Further, the annular flange portion is formed by extending perpendicularly in the radial direction from the circumferential surface of the fuselage, and the dust-proof effect is further improved by stably fixing the seal to the front annular surface on the front opening side of the annular flange portion. be able to.

  In addition, the seal is provided on the annular surface on the front opening side of the annular flange portion, thereby preventing dust from contaminating the light receiving surface of the color filter or the imaging surface of the image sensor through the threaded portion of the screw portions. It is possible to improve the dustproof effect.

  Hereinafter, embodiments of a lens barrel module according to the present invention will be described with reference to the drawings.

  FIG. 1 is an assembled longitudinal sectional view of a lens barrel module according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view schematically showing the lens barrel module in an exploded manner. The lens barrel module of the present invention has a configuration in which the base frame 10, the lens support tube 20, and the buffer seal 30 are assembled integrally. When used in a digital camera, the lens barrel module is preferably integrally assembled as a unit together with an image sensor unit including an image sensor 50 such as a CCD image sensor and a circuit board 60.

  The base frame 10 has a peripheral wall 11 that opens to the front and rear end surfaces 111 and 112 along the axial (L2) direction and defines a cavity 12 that communicates with both end openings 121 and 122 in the cylindrical interior. 11 is provided with a threaded portion 113 on the inner peripheral surface on the front opening 111 side. An annular flange portion 13 is formed at the boundary between the screw portion 113 and the rear opening 122 so as to protrude from the inner peripheral surface of the peripheral wall 11 into the cavity 12. On the inner peripheral surface of the peripheral wall 11 of the base frame 10, a part of the cavity 12 is reduced in diameter so that the front opening 121 side is smaller in diameter than the rear opening side, and a step portion facing the rear opening 122 is formed at the boundary. The annular flange portion 13 projects from the inner peripheral surface of the peripheral wall 11 in a radial direction perpendicular to the axis (L2) direction at a substantially boundary position between the step portion, that is, the small diameter portion and the large diameter portion of the cavity 12.

  The lens support tube 20 has a plurality of stepped cavities 212 having different inner diameters on the inner surface of the body 21, and each lens of the lens set 22 is a predetermined step portion along the axis (L2) direction in the cavity 212. And a screw portion 213 that is screwed into the screw portion 113 of the base frame 10 is formed on the outer peripheral surface 211 thereof, and is screwed from the front opening 121 side in the base frame 10. In this embodiment, a ring-shaped spacer 23 interposed between two lenses and a lens set 22 are fixed to be screwed into, for example, a rear opening of the lens support frame 20 so as to be localized at a predetermined focusing position in the axial direction. The plurality of lenses are localized at predetermined in-focus positions by the ring 24.

  The seal 30 is made of an elastically deformable material such as rubber, for example, abuts against the annular rear end surface of the lens support cylinder 20, and a gap between the annular flange portion 13 in the cavity 12 of the base frame 10 and the lens support cylinder 20. Is attached to the annular surface 131 on the front opening side of the flange portion 13 so as to localize the lens support cylinder 20 to a predetermined focusing position.

  The color filter 40 is attached to the rear annular surface 132 of the annular flange portion 13 with, for example, an adhesive so as to cover the opening of the annular flange portion 13 in the base frame 10. In this embodiment, the plate-like color filter 40 is used to cut light in a predetermined wavelength range, but a color filter film may be formed on the lens as in the prior art.

  In this embodiment, on the rear opening 122 side of the base frame 10, an image sensor 50 such as a CCD image sensor that photoelectrically converts an image formed by the lens set 22, and the image sensor 50 are held. An image sensor unit composed of a circuit board 60 for driving is held. As described above, the space between the color filter 40 and the circuit board 60 holding the image sensor 50 is hermetically sealed in the base frame 10, and the seal 30 is provided between the lens support cylinder 20 and the color filter 40. Can keep. In this embodiment, the image pickup device unit has been described as being incorporated in a digital camera or the like in combination with the base frame 10 and the lens support cylinder 20 using the CCD image sensor 50, the circuit board 60, and the like. Needless to say, a lens barrel module that has a dust-proof structure and includes only the base frame 10, the seal 30, and the lens support cylinder 20 as a unit without using an element unit may be used in a film camera.

  With the above configuration, the lens support cylinder 20 holding the lens set 22, the seal 30, the color filter 40, and the circuit board 60 on which the imaging element 50 is mounted are arranged in the base frame 10 in the axial (L2) direction. The lens barrel module shown in FIG. 1 is obtained by assembling a unit at a predetermined in-focus position into a unit.

  The lens barrel module of the present invention is attached so that the elastically deformable seal 30 is in contact with the bottom end face of the lens support tube 20 between the screwed portion of the base frame 10 and the lens support tube 20 and the annular flange portion 13. Therefore, even if dust generated from both screw portions 113 and 213 are screwed together or dust from the outside is mixed into the screw screw portion, the seal 30 prevents the dust and the image from the light receiving surface of the color filter 40 or the image sensor. Since it does not fall to the surface, a good white screen can be obtained. Further, since the gap between the lens support tube 20 and the annular flange portion 13 is airtightly closed by the seal 30, the lens support tube 20 is in the axial (L2) focusing position even if there is some vibration. It can also be localized.

  Further, since an elastically deformable material such as rubber is used as the seal 30, in addition to the dustproof effect, relative displacement between the base frame and the lens support tube 20 can be prevented even with slight vibration.

  Further, the annular flange portion 13 is formed by extending in a radial direction perpendicular to the projecting axis (L2) direction from the annular stepped portion in the base frame 10, thereby screwing the screw portions (113, 213). There is also an effect of preventing the contamination of dust on the light receiving surface of the color filter 40 or the imaging surface of the image sensor (CCD image sensor, silver salt film).

  In the embodiment described above, a plurality of lenses are used as focusing lenses. However, depending on circumstances, only one lens or two or more lens sets may be used.

  As described above, according to the present invention, the gap between the flange portion in the base frame and the lens support tube is hermetically closed by the elastic seal, so that the dust generated from the screwed portion between the screw portions can be reduced. It is possible to provide a lens barrel module that can prevent dust from entering the image pickup surface of the image pickup device and obtain a good white screen.

It is an assembly longitudinal cross-sectional view of the lens-barrel module of one Embodiment concerning this invention. It is a longitudinal cross-sectional view which decomposes | disassembles and shows schematically the lens-barrel module. It is a longitudinal cross-sectional view which schematically shows the structure of the conventional lens barrel module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Base frame 11 Perimeter wall 111,112 End surface 113,213 Screw part 12 Cavity 121,122 Opening 13 Annular flange part 131,132 Annular surface 20 Lens support cylinder 211 Outer surface 212 Cavity 22 Lens set 23 Spacer 24 Fixing ring 30 Seal 40 Color Filter 50 Image sensor 60 Circuit board

Claims (6)

The inner wall has a peripheral wall that opens to the front and rear end surfaces along the axial direction and defines a cavity that communicates with both end openings, and a threaded portion is provided on the inner peripheral surface of the peripheral wall on the front opening side. A base frame in which an annular flange portion is formed to project from the inner peripheral surface toward the center at the boundary between the portion and the rear opening;
A lens support cylinder in which a lens is held inside the cylindrical body, and a screw portion that is screwed to the screw portion of the base frame is formed on the outer peripheral surface;
A seal made of an elastically deformable material and attached to the annular surface on the front opening side of the flange portion so as to close a gap between the lens support tube and the annular flange portion;
A lens barrel module, which is assembled and integrated as a unit.   The lens barrel module according to claim 1, wherein the annular flange portion protrudes in a radial direction perpendicular to the inner peripheral surface of the barrel.   2. The lens barrel module according to claim 1, wherein a color filter is attached to a rear annular surface of the annular flange portion so as to cover an opening of the annular flange portion in the base frame.   The image pickup device for photoelectrically converting an image formed by the lens and a circuit board for holding and driving the image pickup device are held on the rear opening side of the base frame. The lens barrel module according to 1.   The inner peripheral surface of the peripheral wall of the base frame is formed by reducing the diameter of a part of the cavity so that the front opening side is smaller in diameter than the rear opening side, and a step portion facing the rear opening is formed at the boundary. The lens barrel module according to claim 1, wherein is formed at the position of the stepped portion. The lens is plural,
In the lens support cylinder, a spacer interposed between at least two lenses in the plurality of lenses and a rear opening side of the cavity to position the plurality of lenses along the axial direction The lens barrel module according to claim 1, wherein a fixing ring is provided.

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