JP2000147346A - Fitting mechanism for mold lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the fitting mechanism of a mold lens constituted so that flare and ghost are prevented from occurring and the mold lens can be precisely positioned by forming a lens supporting part of a low-reflectivity material or providing at least one out of the groove of the mold lens and the first positioning part of the lens supporting part with the low-reflective material. SOLUTION: The mold lens 21 is supported in the cylindrical lens supporting part 22 by engaging a ring-like projection part 22a being the positioning part formed along the inside circumferential surface of the supporting part 22 with the groove 21a of the lens 21. Then, one out of the groove 21a of the lens 21 and the projection part 22a of the supporting part 22 is provided with the low-reflectivity material 28. Thus, when a light beam is made incident by a possible angle which is regulated by a diaphragm hole 23a and which is outside the range of the prescribed angle θ with respect to the center line (a) of the optical axis of a printed wiring board 25, the abnormal light beam is absorbed by the low-reflectivity material 28 so as to be prevented from being irregularly reflected on a solid image pickup element. Therefore, the flare and the ghost are prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aspherical molded lens used in, for example, a small-sized image pickup device, and more particularly to an improvement in a mounting mechanism thereof.

[0002]

2. Description of the Related Art As is well known, in recent years, small-sized imaging devices using an aspherical molded lens have been actively developed. The material used for the molded lens has been changed from glass to plastic. Plastic is lightweight and low cost, with excellent aspherical formability, mass productivity and impact resistance.

As a resin material, acryl, polycarbonate, polystyrene or the like is used. At present, C
It is widely used in various fields such as a D (Compact Disk) objective lens, a camera lens, a projection TV (Television) lens, glasses, and a finder lens.

FIG. 8 shows a conventional compact image pickup apparatus using an aspherical molded lens (see Japanese Patent Application Laid-Open No. 9-284617). The aspheric mold lens 11 is housed in a cylindrical lens support 12. A top plate 12a is formed at the upper end of the lens support unit 12, and a stop hole 12a for taking in external light is formed at the center of the top plate 12a.

The lower end of the lens support 12 is open and faces the image pickup unit 13. The imaging unit 13 includes a cover glass 15 on one surface of the printed wiring board 14 in which the light passage holes 14a are formed.
And the solid-state imaging device 16 is installed on the other surface. A lens leg 11 a is formed on the periphery of the molded lens 11, and the tip of the lens leg 11 a is brought into contact with the cover glass 15 to regulate the distance between the molded lens 11 and the solid-state imaging device 16.

Ordinary light that enters the lens support portion 12 through the aperture hole 12b, that is, enters the printed wiring board 14 within a range of a predetermined angle θ with respect to the center line a of the optical axis.
Light having a brightness suitable for imaging is received on the solid-state imaging device 16 through the mold lens 11, the cover glass 15, and the light passage hole 14a of the printed wiring board 14, and is converted into an electric signal.

[0007]

An extraordinary ray, such as sunlight or direct light from an illumination lamp, which is very bright with respect to ordinary light, as shown by an arrow b, has a center line a of the optical axis of the printed wiring board 14 as shown by an arrow b. Aperture 12b outside the range of a predetermined angle θ with respect to
When the light is incident at a very small angle defined by the formula (1), the extraordinary ray is irregularly reflected on the end face of the mold lens 11, and unnecessary light is received by the solid-state imaging device 16 to generate a flare ghost.

Since it is practically difficult to manufacture the molded lens 11 so that the coefficients of thermal expansion of the lens body portion and the lens leg 11a are exactly the same,
The lens body of the molded lens 11 and the solid-state imaging device 1
It is difficult to accurately set the distance to 6.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mold lens mounting mechanism capable of preventing occurrence of flare ghost and accurately positioning the mold lens.

[0010]

A mounting mechanism for a molded lens according to the present invention includes an aspherical molded lens formed in a disk shape having a predetermined thickness and having positioning grooves formed along a peripheral side surface. A first lens positioning portion that fits into the groove of the molded lens and supports the molded lens includes a cylindrical lens supporting portion formed along the inner peripheral surface;
At one end of the lens support portion, a second positioning portion for supporting a stop portion having a stop hole for guiding external light to the molded lens is formed, and at the other end side of the lens support portion, a mold lens and the mold are formed. Forming a third positioning portion for determining a distance from the imaging portion where light incident through the lens is received, forming the lens support portion with a low-reflectance material, or forming a groove of the molded lens and the lens support portion; A low-reflectance material is provided on at least one of the first positioning portions.

According to the above arrangement, a positioning groove is formed on the peripheral side surface of the disk-shaped molded lens, and the molded lens is fitted into the groove of the molded lens on the inner peripheral surface of the cylindrical lens support. Since the first positioning portion for supporting the lens is formed, the molded lens can be accurately positioned and supported.

[0012] Whether the lens support is made of a low-reflectance material,
Since the low-reflectance material is provided in at least one of the groove of the molded lens and the first positioning portion of the lens support, the occurrence of flare ghost can be prevented.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. In FIG.
The mold lens 21 has a predetermined thickness, is formed in an aspherical disk shape whose central part is thinner than the peripheral part, and has a substantially V-shaped groove 21a for positioning along the peripheral side surface. Form.

The molded lens 21 has a groove 21a,
A ring-shaped convex portion 22 a serving as a positioning portion formed along the inner peripheral surface of the cylindrical lens support portion 22 is fitted and supported in the lens support portion 22. A stop hole 23 a for guiding external light to the molded lens 21 is provided at the upper end of the lens support 22.
Form a support portion 22b serving as a positioning portion that supports the plate-shaped throttle portion 23 formed in the central portion.

The lower end of the lens support portion 22 includes an imaging unit 24
Oppose. The imaging unit 24 includes a cover glass 26 on one surface of the printed wiring board 25 in which the light passage holes 25a are formed,
The solid-state imaging device 27 is provided on the other surface. Lens support 2
A ring-shaped guide portion 22c serving as a positioning portion is formed along the inner peripheral surface of the lower end of 2. Guide part 22c
Contacts the cover glass 26 to define the focal position of the imaging unit 24 with respect to the mold lens 21.

A low-reflectance material 28 is provided on one of the groove 21a of the molded lens 21 and the projection 22a of the lens support 22. The low reflectance material 28 is, for example, a black paint. The entire lens support portion 22 is formed of aluminum,
The projection 22a may be subjected to a black matte alumite treatment.

According to the above configuration, the ordinary light entering the lens support portion 22 through the aperture 23a, that is, within the range of the predetermined angle θ with respect to the center line a of the optical axis to the printed wiring board 25. Incident on the solid-state imaging device 27 via the mold lens 21, the cover glass 26, and the light passage hole 25a of the printed wiring board 25, and converted into an electric signal. .

An extraordinary ray, which is very bright with respect to ordinary light, is, as shown by an arrow b, a center line a of the optical axis of the printed wiring board 25.
Incident at an angle just outside the range of the predetermined angle θ with respect to the aperture 23a, the extraordinary ray is absorbed by the low-reflectance material 28 and is not irregularly reflected by the solid-state imaging device 16, so that the flare ghost Occurrence can be prevented.

Convex part 22 formed on lens support part 22
a, the mold lens 21, the aperture unit 23, and the imaging unit 24 are positioned by the support unit 22b and the guide unit 22c, so that it is possible to accurately determine the position of each member and also determine the position between the members. Be accurate. Since the groove 21a of the mold lens 21 is simultaneously molded with a mold that forms an aspheric surface, eccentricity with respect to the optical axis can be prevented.

FIGS. 2A and 2B show the structure of the lens support 22.
The details are shown below. The lens support portion 22 is a pair of half support portions 22 each formed substantially in the same shape by vertically dividing a cylinder in half.
1, 222 are abutted with each other, united, and bonded. As shown in FIG. 3, the molded lens 21 is sandwiched between the pair of half-split support portions 221 and 222 from the peripheral side surface thereof, thereby forming the lens support portion 22.
The mold lens 21 is housed therein.

FIGS. 4A to 4E show a manufacturing process of the imaging section 24. FIG. As shown in FIG. 4A, the printed wiring board 2
5, a light passing hole 25a is formed, and an electrode 25b is formed on one surface thereof. As shown in FIG.
An ultraviolet curing adhesive 25c is applied to the other surface of the printed wiring board 25, and as shown in FIG. 4C, a cover glass 26 is adhered to close the light passage hole 25a.

As shown in FIG. 4D, the printed wiring board 2
5 electrode 25b is coated with an anisotropic conductive paste adhesive 25d, and the gold ball bump 2
7a is thermocompression-bonded. Thus, the electrode 2 of the printed wiring board 25
5b and the solid-state imaging device 27 are electrically connected. FIG.
As shown in (e), the periphery of the solid-state imaging device 27 is solidified with an ultraviolet curing resin 25e to form the imaging unit 24 .

The imaging unit 24 is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-9921.
As disclosed in Japanese Patent Application Publication No. 4 (1993) -204, etc., it is possible to realize the present technology with extremely high dimensional accuracy. Since the cover glass 26 is mounted with a precision of several microns at the same time as the solid-state imaging device (bare chip imaging device) 27, the guide portion 22c of the lens support portion 22 is provided.
This is convenient for contacting and positioning.

FIG. 5 shows a modification of the above embodiment.
The camera module unit 30 is configured by connecting the solid-state imaging device 27 and various circuit devices 29 for signal processing to the printed wiring board 25. Camera module 30
Is surrounded by a housing 31 fixed to the printed wiring board 25 by screws 31a. The housing 31 is integrated with the throttle unit 23.

FIG. 6 shows another modification. A thread 21b is formed in the molded lens 21 along the peripheral side surface. The lens support portion 22 is formed with a screw portion 22d which is screwed with the screw groove 21b of the molded lens 21 along the inner peripheral surface. When the mold lens 21 is rotated, it is moved in the direction of the optical axis, and its position can be finely adjusted.

FIG. 7 shows still another modification. A diaphragm 23 is formed integrally with the lens support 22. The lens support 22 has a thread groove 22e formed along the outer peripheral surface thereof. The printed wiring board 25 of the imaging section 24 supports a cylindrical fixing section 32 having a screw section 32a that is screwed into the screw groove 22e of the lens support section 22 along the inner peripheral surface. When the lens support 22 is rotated, the mold lens 2 is rotated.
1 is moved in the direction of the optical axis, and its position can be finely adjusted.

[0027]

According to the present invention, the occurrence of flare ghosts can be prevented, and the mold lens can be accurately positioned.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIGS. 2A and 2B show details of a lens support unit in FIG. 1, wherein FIG. 2A is a plan view and FIG.

FIG. 3 is a cross-sectional view showing the assembly of the lens support unit of FIG. 1;

FIG. 4 is an explanatory diagram illustrating a manufacturing process of the imaging unit in FIG. 1;

FIG. 5 is a sectional view showing a modification of FIG. 1;

FIG. 6 is a sectional view showing another modification of FIG. 1;

FIG. 7 is a sectional view showing still another modified example of FIG. 1;

FIG. 8 is a cross-sectional view showing a conventional compact imaging device.

[Explanation of symbols]

Reference numeral 21 denotes a molded lens, 22 denotes a lens support portion, 23 denotes a diaphragm portion, 24 denotes an image pickup portion, and 28 denotes a low reflectance material.

Claims (6)

[Claims] 1. A disk having a predetermined thickness,
An aspherical molded lens having a positioning groove formed along the peripheral side surface, and a first positioning portion that fits into the groove of the molded lens and supports the molded lens is formed along the inner peripheral surface. And a second positioning portion for supporting a diaphragm portion formed with a diaphragm hole for guiding external light to the molded lens is formed on one end side of the lens support portion. On the other end side of the lens support, the molded lens,
Forming a third positioning portion for determining a distance from an imaging portion where light incident through the molded lens is received; forming the lens support portion with a low-reflectance material; A mounting mechanism for a molded lens, wherein a low-reflectance material is provided on at least one of the first positioning portions of the lens support portion. 2. The lens support section is formed by abutting and uniting a pair of half support sections formed in substantially the same shape, and the pair of half support sections causes the mold lens to be positioned on a peripheral side surface thereof. The mounting mechanism for a molded lens according to claim 1, wherein the molded lens is supported inside by being sandwiched from a side. 3. The image pickup section includes a substrate having a light passage hole formed therein, a cover glass provided on one surface of the substrate so as to close the light passage hole, and a cover glass provided on the other surface of the substrate. A solid-state imaging device installed so as to close the light passage hole; and a third positioning portion of the lens supporting portion is in contact with the cover glass to allow the mold lens and the solid-state imaging device to be in contact with each other. The mounting mechanism for a molded lens according to claim 1, wherein the distance is set. 4. The camera according to claim 1, wherein the diaphragm is formed integrally with a housing of the camera module.
A mounting mechanism for the molded lens described in the above. 5. A groove formed on a peripheral side surface of the molded lens is a screw groove, and a first positioning portion formed on the lens support is screwed into a screw groove of the molded lens. The mounting mechanism according to claim 1, wherein the mounting mechanism is a screw part. 6. It is formed in a disk shape having a predetermined thickness,
An aspherical molded lens having a positioning groove formed along the peripheral side surface, and a positioning portion which fits into the groove of the molded lens and supports the molded lens is formed along the inner peripheral surface; A cylindrical lens support portion having a stop portion formed with a stop hole on one end side for guiding external light to the mold lens; and screwed into the screw groove of the lens support portion. A fixing portion having an imaging portion formed on the inner peripheral surface of the screw portion and receiving light incident through the molded lens on the other end side of the lens supporting portion; A mounting mechanism for a molded lens, wherein the molded lens is formed of a reflective material, or a low-reflective material is provided in at least one of a groove of the molded lens and a positioning portion of the lens support portion.