TWI530724B - Image sensor module and method for adjusting focus of image sensor module - Google Patents

Description

Image sensing module and method for adjusting focal length of image sensing module

The invention relates to an image sensing module, in particular to an image sensing module and a method for adjusting the focal length of the image sensing module.

Please refer to FIG. 1 . FIG. 1 is a flow chart of assembling the image sensing module and adjusting the focal length of the image sensing module in the prior art. In the first step, an adhesive 112 is used to secure the image sensor 120 on the printed circuit board 110, and a thermal hardener 122 is applied over the printed circuit board 110 using a dispenser. Then, in the second step, the fixing base 130 having a lens module 132 is placed on the thermal curing adhesive 122 and the printed circuit board 110, wherein the lens module 132 can have a plurality of lenses; In the three steps, the entire image sensing module is placed in the oven for the curing process, that is, the thermosetting adhesive 122 is cured to stabilize the mount 130 on the printed circuit board 110; finally, in the fourth step The modulation transfer function (MTF) test is performed, and the focal length of the image sensing module is adjusted by adjusting the distance between the lens module 132 and the image sensor 120.

However, since the amount of the heat-hardening adhesive 122 coated on the printed circuit board 110 sometimes cannot be precisely controlled, the shape of the heat-hardening adhesive 122 may be changed due to the curing process, The fixing seat 130 may be tilted for the above reasons, thereby causing the image sensed by the image sensor 120 to become blurred. In addition, since the lens module 132 has a plurality of lenses, when the tilting phenomenon of the fixing base 130 occurs, the focal length of some of the lenses may be absent. The method is precisely adjusted.

Therefore, one of the objects of the present invention is to provide an image sensing module and a method for adjusting the focal length of the image sensing module to solve the above problems.

According to an embodiment of the invention, an image sensing module includes a substrate, an image sensor mounted on the substrate, a mounting seat disposed on the substrate, and a mounting on the mounting base. a plurality of lens barrels and a plurality of elastic members, wherein each of the lens barrels is used for fixing one lens module, and each elastic element is disposed between the fixing base and the corresponding lens barrel, and is configured to apply an elastic force The fixing seat is above the corresponding lens barrel.

According to another embodiment of the present invention, a method for adjusting a focal length of an image sensing module includes: providing a substrate; providing an image sensor mounted on the substrate; and providing a substrate disposed on the substrate a plurality of elastic members are respectively disposed in the plurality of holes of the fixing base; a plurality of lens barrels are respectively disposed in the plurality of holes of the fixing seat, so that each elastic element is located in the fixing seat and Between the corresponding lens barrels, wherein each of the elastic members is configured to apply an elastic force on the fixing base and the corresponding lens barrel, and each of the lens barrels fixes a lens module; and the plurality of lens barrels Sliding relative to the fixing seat to adjust a distance between the plurality of lens barrels and the image sensor to adjust a focal length of the image sensing module.

110, 210‧‧‧ Printed circuit boards

112, 212‧‧‧ adhesive

120, 220‧‧‧ image sensor

122, 222‧‧‧ Thermal hardening adhesive

130, 230‧‧‧ fixed seat

132‧‧‧ lens module

242‧‧‧UV adhesive

250_1, 250_2‧‧‧pressure coil spring

260_1, 260_2‧‧ ‧ tube

FIG. 1 is a flow chart of assembling the image sensing module and adjusting the focal length of the image sensing module in the prior art.

2A and 2B are flow charts of assembling an image sensing module and adjusting a focal length of the image sensing module according to an embodiment of the invention.

Please refer to FIG. 2A and FIG. 2B , which illustrate a flow chart of assembling an image sensing module and adjusting a focal length of the image sensing module according to an embodiment of the invention. It should be noted that, in the case of substantially the same result, the flow steps of the present invention are not limited to the order shown in FIGS. 2A and 2B, and the flow is described below with reference to FIGS. 2A and 2B.

In the first step, an adhesive 212 is used to fix the image sensor 220 on a substrate (in this embodiment, the substrate is a printed circuit board 210), and a thermal hardening adhesive is used using a coater. 222 is coated on the printed circuit board 210; in the second step, the mount 230 is placed on the thermosetting adhesive 222, and the mount 230 is placed in the oven together with the printed circuit board 210 for curing. The procedure, that is, curing of the thermosetting adhesive 222, also secures the mount 230 over the printed circuit board 210. In the present embodiment, the fixing base 230 shown in FIG. 2A has four holes, (the second drawing shows a top view and a side view of the fixing base 230), but this is not a limitation of the present invention. As such, the number of holes in the mount 230 can vary depending on the designer's considerations.

After the fixing base 230 is fixed to the printed circuit board 210, in the third step, an adhesive is applied to the inner wall of each of the holes on the fixing base 230 using a coater, in this embodiment, coated on the inner wall. The upper adhesive is an ultraviolet light adhesive (UV adhesive) 242, but the adhesive may also be another adhesive such as a heat hardening adhesive.

In the fourth step, a plurality of elastic members are respectively placed in the plurality of holes of the fixing base 230. In the embodiment, each of the elastic members is a pressure coil spring 250_1, 250_2, and each of the fixing seats 230 Only one pressure coil spring is placed in one hole. However, in other embodiments of the present invention, the pressure coil springs 250_1, 250_2 shown in FIG. 2A may be replaced with any other suitable elastic members, such as spring tabs, and the like.

In the fifth step, the plurality of lens barrels 260_1, 260_2 are respectively placed in the plurality of holes of the fixing base 230, and the pressure coil springs 250_1 / 250_2 are respectively located between the fixing base 230 and the lens barrel 260_1 / 260_2. In the present embodiment, each of the barrels 260_1, 260_2 contains only one lens.

In the sixth step, a modulation transfer function (MTF) test is performed to adjust the focal length of the lens barrel 260_1. In detail, when the focal length of the lens barrel 260_1 is adjusted, the lens barrel 260_1 is slid relative to the fixed seat 230 (for example, the lens barrel 260_1 can be slid downward by pressing the lens barrel 260_1, and the pressure coil spring 250_1 at this time) A spring force is applied to the mount 230 and the lens barrel 260_1 to adjust the distance between the lens barrel 260_1 and the image sensor 220. After the lens barrel 260_1 is slid to the optimum position, ultraviolet light is irradiated to harden the UV adhesive 242 between the holder 230 and the lens barrel 260_1 to fix the lens barrel 260_1 and the holder 230.

In the seventh step, a modulation transfer function (MTF) test is performed to adjust the focal length of the lens barrel 260_2. In detail, when the focal length of the lens barrel 260_2 is adjusted, the lens barrel 260_2 is slid relative to the fixing base 230 (for example, the lens barrel 260_2 can be slid downward by pressing the lens barrel 260_2, and the pressure coil spring 250_2 at this time) A spring force is applied to the mount 230 and the lens barrel 260_2 to adjust the distance between the lens barrel 260_2 and the image sensor 220. After the lens barrel 260_2 is slid to the optimum position, ultraviolet light is irradiated to harden the UV adhesive 242 between the holder 230 and the lens barrel 260_2 to fix the lens barrel 260_2 and the holder 230.

In the next step, the other lens barrels are placed in the remaining holes of the holder 230, and the focal lengths of the barrels are adjusted in the manner described in the sixth and seventh steps above.

As described above, since each of the lens barrels independently adjusts its own focal length, When the tilting of the mount 230 with respect to the printed circuit board 210 occurs, the focus of the lens barrels 260_1, 260_2 can be accurately dropped on the image sensor 220 by independently adjusting the positions of the lens barrels 260_1, 260_2. For example, assuming that the mounting seat 230 has a tilting phenomenon with respect to the printed circuit board 210, and the left side of the fixing base 230 is higher than the right side, the depth of the lens barrel 260_1 is greater than the depth of the lens barrel 260_2, that is, the pressure. The degree of compression of the coil spring 250_1 is greater than the degree of compression of the pressure coil spring 250_2. As described above, the image sensed by the image sensing module of the present invention is clearer than the prior art focus adjustment method shown in FIG.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

242‧‧‧UV adhesive

260_1, 260_2‧‧ ‧ tube

Claims (11)

An image sensing module includes: a substrate; an image sensor mounted on the substrate; a fixing base disposed on the substrate; and a plurality of lens barrels disposed in the fixing seat, wherein each The lens barrel is used for fixing a lens module, and each of the lens barrels is fixed to the fixing base through an adhesive; and a plurality of elastic elements, wherein each of the elastic elements is disposed on the fixing base and the corresponding lens barrel And between the fixing bracket and the corresponding lens barrel. The image sensing module of claim 1, wherein the lens module in each of the lens barrels comprises only one lens. The image sensing module of claim 1, wherein each of the elastic members is a spring. The image sensing module of claim 1, wherein each of the elastic elements is a pressure coil spring. The image sensing module of claim 1, wherein the lens barrel is fixed to the fixing seat by an ultraviolet light adhesive. The image sensing module of claim 1, wherein when the fixing seat is inclined with respect to the substrate, the degree of compression of one of the elastic members is different from the degree of compression of the other elastic member. A method for adjusting a focal length of an image sensing module includes: providing a substrate; providing an image sensor mounted on the substrate; providing a fixing seat disposed on the substrate; The components are respectively disposed in the plurality of holes of the fixing base; the plurality of lens barrels are respectively disposed in the plurality of holes of the fixing seat, such that each elastic element is located between the fixing seat and the corresponding lens barrel Each of the elastic members is configured to apply an elastic force on the fixing base and the corresponding lens barrel, and each of the lens barrels fixes a lens module; and the plurality of lens barrels are respectively slid relative to the fixing base Adjusting a distance between the plurality of lens barrels and the image sensor to adjust a focal length of the image sensing module; and the method further includes: providing the plurality of lens barrels on the fixed seat Prior to the holes, an ultraviolet light adhesive is applied to the inner walls of the plurality of holes of the mount; and when the plurality of barrels are slid to their optimum positions, ultraviolet light is used to harden the ultraviolet light adhesive To fix the mount and the Barrel. The method of claim 7, wherein the lens module in each of the lens barrels comprises only one lens. The method of claim 7, wherein each of the lens barrels is independently slid to adjust a distance between the lens barrel and the image sensor. The method of claim 7, wherein each of the elastic members is a spring. The method of claim 7, wherein each of the elastic elements is a pressure spiral spring.