JP2004147032A - Small imaging module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of parts and facilitate assembling by using a method of fixing the parts in which the parts are incorporated into a case of a small imaging module from one direction, while the parts are incorporated from both above and under parts in a conventional technique which takes much troublesomeness, an aperture of a single part is not required, and bonding is not used. <P>SOLUTION: The top end of a case 2 is covered with a ceiling 2b, and an aperture hole 2c is made so as to have an aperture function. Protrusions 2d are provided on the internal surface of the case, and a lens 6 is pushed into the case so that the lens passes through the protrusions, thus the lens is held by the protrusions. An IR cut filter 7 is abutted on the step portions of the case from the lower part and is bonded. In this way, the parts are incorporated only from under. The method of fixing the lens also includes bonding, ring pressure fitting, thermal caulking of the case and others, and these fixing methods are applicable to the IR cut filter. Further, by sandwiching an IR cut filter having the same contour as that of the lens between the lens and the ceiling of the case, the two parts can be simultaneously assembled and assembling man-hours can be reduced. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small imaging module that is incorporated into a video camera, a surveillance camera, an industrial camera, a personal computer, a mobile phone, or the like and used to take a picture.
[0002]
[Prior art]
FIGS. 13A and 13B show an example of the small imaging module as described above. FIG. 13A is a top view and FIG. 13B is a cross-sectional view taken along line BB in FIG. FIG. 14 is an exploded perspective view thereof. As seen in these drawings, each component is housed in a package made up of a substrate 1 made of ceramics or epoxy resin containing glass and a plastic case 2. An IC (3) is die bonded to the substrate 1 and wire bonded with a wire 4. The IC (3) is formed with an imaging circuit in which a large number of detection elements, each of which is a combination of a photoelectric conversion element such as a photodiode and a MOS transistor or a CCD element, are arranged in a matrix.
[0003]
As shown in FIG. 14, the case 2 has a box shape on the lower side and a cylindrical shape on the upper side, and faces the IC (3) on the substrate 1 as shown in FIG. Further, an IR (infrared) cut filter 7 is fixed to prevent the image from becoming saturated due to the saturation of electric charge in an environment with a lot of infrared rays such as outdoors. A shelf 2a is provided on the inner wall of the upper cylindrical portion of the case 2, and a lens 6 is attached thereto.
[0004]
The lens 6 is made of glass or transparent plastic, and a convex lens 6b is formed on the lower surface of the disc-shaped base portion 6a, and the upper surface may be flat, concave or convex, and the outer periphery of the base portion 6a is placed on the shelf 2a, The aperture 5 is overlaid. The aperture 5 has an aperture 5a serving as an optical path. An adhesive such as epoxy is used for joining these components. With such a configuration, an image of the outside world is imaged on the surface of the IC (3) through the lens 6, and is converted into an electric signal and processed.
[0005]
As seen in these figures, there are a plurality of depressions 1a around the substrate 1, and the inner walls of the depressions 1a are covered with a conductive material, which connects the conductive patterns on both the upper and lower surfaces of the substrate 1, Although not shown, the land portion of the conductive material around the recess 1a on the lower surface of the substrate 1 serves as a terminal electrode for connection to the circuit board to be incorporated. Therefore, this small imaging module is suitable for surface mounting on a circuit board of an electronic device using the terminal electrode on the lower surface of the substrate 1.
[0006]
Patent Document 1 below discloses a small-sized imaging module similar to the above, but the actual structure of attaching an IR cut filter, a lens, a diaphragm, etc. to the lens frame is schematically illustrated rather than the main point of the invention. The details are not shown.
[0007]
[Patent Document 1]
JP 2001-245217 A (FIG. 1 to FIG. 13)
[0008]
[Problems to be solved by the invention]
FIG. 15 shows the procedure for assembling the small imaging module as described above. The IR cut filter 7, the lens 6 and the diaphragm 5 are attached to the case 2, and this is fixed to the substrate 1 on which the IC (3) is mounted. As shown in the figure, the IR cut filter is assembled to the case 2 from the lower side, while the lens 6 and the diaphragm 5 are assembled to the case 2 from the upper side. . In addition, a diaphragm means for blocking unnecessary light and improving imaging quality is essential for a small imaging module, and therefore the diaphragm 5 is used. However, if this part can be eliminated, the cost is reduced accordingly. The present invention eliminates the diaphragm 5 and facilitates assembly.
[0009]
[Means for Solving the Problems]
In the present invention, in order to solve the above-described problem, first, a ceiling is provided at the upper end of the upper cylindrical portion of the case that has been open in the past, and a throttle hole is formed in the central portion thereof to make the ceiling portion an aperture. In this way, the case and the diaphragm are integrated, and the diaphragm of another part is abolished. Since the upper end of the case is closed by the ceiling, the lens is assembled from the lower side rather than the upper side as in the prior art, and is put into the case from the lower side and abuts against the ceiling. The IR cut filter is assembled to the case from below as in the prior art. This unifies the assembly direction of the parts from the lower side of the case.
[0010]
In the conventional example described above, the lens 6 is mounted on the shelf 2a of the case 2 and bonded with an adhesive. The present invention adopts a structure in which a lens is assembled regardless of the shelf 2a as described above in connection with providing a ceiling on the case. That is, a protrusion is provided on the inner surface of the case of the lens housing portion, and the lens is pushed over and held in engagement with the protrusion, adhered to the inner surface of the case without the protrusion, and adhered to the inner surface of the case below the lens. For example, a ring is press-fitted and held thereby, and an enclosure is provided on the lower surface of the case ceiling to accommodate the lens, and an end surface of the enclosure is heat caulked to press and hold the outer periphery of the lens. These fixing methods can also be applied to attachment of an IR cut filter to the case. Furthermore, the present invention proposes a structure in which the IR cut filter and the lens are attached to the case at the same time by holding the IR cut filter between the ceiling of the case and the lens.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the embodiments, the basic structure as a small imaging module is the same as that of the prior art, so corresponding parts and portions are denoted by the same reference numerals and detailed description thereof is omitted.
[0012]
FIG. 1 shows a cross-sectional view of a first embodiment of the present invention. The diaphragm 5 used in the conventional examples of FIGS. 13 to 15 is abolished. Instead, the upper end of the case 2 is closed by the ceiling 2b, and a diaphragm hole 2c is provided at the center to perform the diaphragm action. Then, instead of the shelf 2 a as shown in FIG. 13, a protrusion 2 d is provided on the inner surface of the cylindrical portion of the case 2 to support the base portion 6 a of the lens 6.
[0013]
As shown in FIG. 2, the lens 6 is inserted into the cylindrical portion of the case 2 from below and pushed in over the protrusion 2 d on the inner surface of the case 2. As shown in FIG. 1, the lens 6 engages with the protrusion 2d and settles. Next, the IR cut filter 7 is inserted from below the case, applied to the stepped portion at the lower end of the cylindrical portion of the case 2, and fixed with an adhesive as in the conventional case. The case 2 to which the components are attached in this way is completed by joining to the upper surface of the substrate 1 on which the IC (3) is mounted. With this structure, both the lens 6 and the IR cut filter 7 have only to be assembled to the case 2 from below, and it is not necessary to perform from the top and bottom separate directions as in the prior art. It will be easy.
[0014]
When the protrusion 2d surrounds the inner periphery of the cylindrical portion of the case 2 as shown in FIGS. 1 and 2, the height of the protrusion 2d is difficult to be managed, and it is difficult to push the lens 6 in. However, if the protrusions 2d are provided not in a continuous manner on the entire circumference but in several places, this point is alleviated.
[0015]
FIG. 3 shows a cross-sectional view of the second embodiment of the present invention. Also in this case, the upper end of the cylindrical portion of the case 2 is closed by the ceiling 2b, and a throttle hole 2c is provided. Unlike the previous embodiment, no protrusion is provided on the inner surface of the case 2, and the lens 6 is bonded to the inner surface of the case with an adhesive 11.
[0016]
As shown in FIG. 4, the parts are assembled by putting the lens 6 into the cylindrical portion of the case 2 from below, abutting against the ceiling, and fixing with an adhesive. Next, the IR cut filter 7 is inserted from below the case, applied to the stepped portion at the lower end of the cylindrical portion of the case 2, and fixed with an adhesive. As a result, the lens 6 and the IR cut filter 7 can be assembled to the case 2 from below.
[0017]
FIG. 5 shows a cross-sectional view of a third embodiment of the present invention. Also in this case, a ceiling 2b is provided at the upper end of the cylindrical portion of the case 2, and a throttle hole 2c is formed. The feature here is that the lens 6 is held by fixing a ring 12 made of resin or rubber inside the cylindrical portion of the case 2.
[0018]
As shown in FIG. 6, the lens 6 is put into the cylindrical portion of the case 2 from below, the ring 12 is lightly press-fitted into the inside of the cylindrical portion from below, and the lens 6 is abutted against the ceiling. Next, an IR cut filter 7 is inserted from below the case and adhered to the case 2. As a result, the parts need only be assembled from below, and the lens 6 need not be adhered.
[0019]
FIG. 7 shows a cross-sectional view of a fourth embodiment of the present invention. Also in this case, a ceiling 2b is provided at the upper end of the cylindrical portion of the case 2, and a throttle hole 2c is formed. Further, a short cylindrical enclosure 2e surrounding the lens 6 is provided on the lower surface of the ceiling 2b, and the lower end thereof is deformed by “heat caulking”, and the base 6a of the lens 6 is pressed and held. For heat caulking, an ultrasonic wave, a heater, a laser, or the like may be used, and the heat caulking may be performed at several places on the end face of the enclosure 2e. Further, the enclosure 2e itself may be provided in a dispersed form in a number of support columns instead of a continuous shape.
[0020]
As shown in FIG. 8, the lens 6 is inserted into the enclosure 2 e on the lower surface of the ceiling 2 b of the case 2 from below, and the lower end of the enclosure 2 e is heat caulked to hold the lens 6. Next, an IR cut filter 7 is inserted from below the case and adhered to the case 2. As a result, the parts need only be assembled from below, and the lens 6 need not be adhered.
[0021]
In each of the embodiments described above, the lens 6 is attached to the case 2 by means such as a protrusion, an adhesive, a ring, and an enclosure, whereas the IR cut filter 7 is fixed solely by adhesion, but the lens 6 is attached. The same means can be used for the IR cut filter 7 as well. An example thereof is shown in FIG. 9 as a fifth embodiment. Similarly to the first embodiment (FIG. 1), the lens 6 is attached by engagement with the protrusion 2d on the inner surface of the case 2. Further, the IR cut filter 7 is attached by being engaged with the hook 2f having a protrusion integral with the case.
[0022]
FIG. 10 is a perspective view of the part assembly state from below. The lens has already been fixed to the case 2, and the IR cut filter 7 is to be attached. Also in this case, the parts are assembled only from below, and the IR cut filter 7 only needs to be engaged with the hook 2f, and the bonding step is unnecessary. In addition, although not shown in the figure, the press-fitting of the ring used for fixing the lens 6 and the heat caulking of the case portion can also be applied to the assembly of the IR cut filter 7.
[0023]
FIG. 11 shows a cross-sectional view of a sixth embodiment of the present invention. Unlike the previous embodiments, in this embodiment, the IR cut filter 7 is not attached to the case 2 alone, and the outline of the IR cut filter 7 is substantially the same shape as the lens 6, and the ceiling 2 b of the case 2 Hold between the lenses 6. Although the lens 6 is fixed with the adhesive 11 in this figure, it is needless to say that it is possible to use other means that have already been seen, such as protrusions, rings, and enclosures.
[0024]
As shown in FIG. 12, the parts are assembled by sequentially inserting the IR cut filter 7 and the lens 6 into the cylindrical portion of the case 2 from below and fixing the lens 6 to the case 2 by an appropriate method as described above. Also in this case, the parts need only be assembled from below, and the IR cut filter 7 can be assembled at the same time as the lens 6, thereby reducing the number of assembly steps.
[0025]
【The invention's effect】
According to the present invention, the diaphragm of a single component as in the past can be eliminated by integrating the diaphragm and the case in the small imaging module. This reduces the number of parts and eliminates the need for a drawing mold. Furthermore, since the lens and the IR cut filter need only be assembled to the case from only one direction, the assembling work is facilitated. However, in the third embodiment shown in FIGS. 5 and 6, since the ring 12 is introduced instead of eliminating the aperture, the number of parts does not change, but the advantage of assembling from one direction is maintained. In addition, the lens and IR cut filter can be fixed with an adhesive as in the conventional case, but the process of using the adhesive can be abolished by engaging with the protrusions and hooks, or by heat caulking part of the case. . Thus, a high-performance and inexpensive small-sized imaging module is realized.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a first embodiment of a small imaging module of the present invention.
FIG. 2 is a diagram showing an assembly procedure of the embodiment of FIG. 1;
FIG. 3 is a cross-sectional view of a second embodiment of a small imaging module of the present invention.
FIG. 4 is a diagram showing an assembly procedure of the embodiment of FIG. 3;
FIG. 5 is a cross-sectional view of a third embodiment of a small imaging module of the present invention.
6 is a diagram showing an assembly procedure of the embodiment of FIG. 5;
FIG. 7 is a cross-sectional view of a fourth embodiment of a small imaging module of the present invention.
FIG. 8 is a diagram showing an assembly procedure of the embodiment of FIG.
FIG. 9 is a cross-sectional view of a fifth embodiment of a small imaging module of the present invention.
FIG. 10 is a perspective view from below showing the assembly procedure of the embodiment of FIG. 9;
FIG. 11 is a cross-sectional view of a sixth embodiment of a small imaging module of the present invention.
FIG. 12 is a diagram showing an assembly procedure of the embodiment of FIG.
13A and 13B are drawings of a conventional small imaging module, in which FIG. 13A is a top view and FIG. 13B is a cross-sectional view taken along line BB of FIG.
14 is an exploded perspective view of the conventional example of FIG.
15 is a diagram showing an assembly procedure of the conventional example of FIG.
[Explanation of symbols]
1 Substrate 2 Case 2a Shelf 2b Ceiling 2c Restriction hole 2d Protrusion 2e Enclosure 2f Hook 3 IC
5 Aperture 6 Lens 7 IR Cut Filter 11 Adhesive 12 Ring

Claims (7)

In a small imaging module comprising a package with a substrate and a case, and containing an aperture means, a lens, an IR cut filter, an IC, etc.
A ceiling is formed integrally with the case, and a hole is made in the center thereof, which is used as a squeezing means.
A compact imaging module, wherein a lens and an IR cut filter are assembled to a case from below. The small imaging module according to claim 1,
A small imaging module characterized in that a projection is provided on the inner periphery of the case, and the lens assembled over the projection is held by the projection. The small imaging module according to claim 1,
A compact imaging module, wherein a lens is fixed to an inner periphery of a case with an adhesive. The small imaging module according to claim 1,
A compact imaging module characterized by holding a lens by press-fitting a ring into the inner periphery of the case on the lower side of the lens. The small imaging module according to claim 1,
A compact imaging module characterized in that a lens is fixed by caulking part of a case. The small imaging module according to claim 1,
A small imaging module, wherein an IR cut filter is attached to a case by any one of adhesive, protrusion, ring, or heat caulking of the case. The small imaging module according to claim 1,
A compact imaging module characterized in that an IR cut filter is held between a case ceiling and a lens.

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