TWI399567B - Lens module and camera module - Google Patents

Description

Lens module and camera module

The invention relates to a lens module, in particular to a lens module with a temperature compensation mechanism and a camera module using the lens module.

With the development of camera technology, camera modules have been widely used in various types of camera devices. The combination of camera modules and various portable electronic devices such as mobile phones, video cameras, computers, etc., has been favored by many consumers.

For lens modules with a wide temperature range during use, for example, a vehicle lens module, since the temperature range of the automobile is relatively large, the lens for the vehicle naturally needs to work in the same temperature range. However, the current lens is generally sensitive to temperature. When the temperature rises, since each part in the module is thermally expanded, the volume changes, and the refractive index of the lens changes with temperature. Therefore, the distance from the lens to the optimal imaging surface will change relatively, resulting in good imaging at low temperatures and poor imaging quality at high temperatures. This situation is usually compensated by means of autofocus.

However, the autofocus mechanism often takes up a large space, so that the lens module and the camera module with the autofocus mechanism are large in size and complicated in structure, and cannot meet the requirements of lightness and thinness, and the cost thereof is also large.

In view of the above, it is necessary to provide a lens module with a temperature compensation mechanism that is small in size and low in cost, and a camera module using the lens module.

The invention provides a lens module comprising a lens holder, a lens barrel and at least one compensation piece. The lens holder has a top receiving cavity for accommodating the lens barrel. The lens barrel has at least one lens. The compensation piece is connected between the lens barrel and the lens holder. The compensation piece can be bent and driven by temperature changes. The lens barrel moves in the optical axis direction to maintain the imaging surface of the lens module in a predetermined plane.

The invention also provides a camera module comprising a lens holder, a lens barrel, an image sensor and at least one compensation sheet. The lens holder has a top receiving cavity for accommodating the lens barrel. The lens barrel has at least one lens. The compensation piece is connected between the lens barrel and the lens holder. The compensation piece can be bent and driven by temperature changes. The lens barrel moves along the optical axis to maintain the imaging surface of the lens module on the plane where the image sensor is located.

The lens module and the camera module have at least one compensation piece, and the compensation piece is bent by the change of the ambient temperature, thereby driving the lens barrel with the optical lens to move along the optical axis direction, thereby achieving the lens module and the camera module. The purpose of temperature compensation. The lens module and camera module avoid the use of autofocus and other mechanisms, thereby simplifying the overall structure, reducing overall size and reducing costs.

100‧‧‧ camera module

10‧‧‧Mirror seat

11‧‧‧ Protective cover

12‧‧‧Transparent board

13‧‧‧Top cavity

14,22‧‧‧ Groove

15,23‧‧‧ dispensing holes

20‧‧‧Mirror tube

21‧‧‧ lenses

30‧‧‧Image Sensor

31‧‧‧ glass plate

40‧‧‧Compensation film

41,42‧‧‧metal pieces

50‧‧‧Lens module

FIG. 1 is a schematic cross-sectional view of a camera module according to an embodiment of the present invention.

2 is a schematic cross-sectional view showing a compensating piece in a camera module according to an embodiment of the present invention when it is bent.

3 is a cross-sectional view of the camera module of FIG. 1 taken along the III-III direction.

The invention will be further described in detail below with reference to the accompanying drawings.

Please refer to FIG. 1 , which illustrates a camera module 100 according to an embodiment of the present invention. The camera module 100 includes a lens holder 10 , a lens barrel 20 , at least one compensation sheet 40 , and an image sensor 30 . The lens holder 10, a lens barrel 20 and at least one compensation sheet 40 constitute a lens module 50.

The lens holder 10 has a top receiving cavity 13 for receiving the lens barrel 20. Preferably, the top of the lens holder 10 has a protective cover 11 for preventing dust and the like from entering the optical element in the lens holder 10 contaminating the lens holder 10. The protective cover 11 is made of a transparent material facing a portion of the lens barrel 20. In this embodiment, a portion of the protective cover 11 facing the lens barrel 20 is a transparent plate 12.

The lens barrel 20 is provided with at least one lens 21, and the outer diameter of the lens barrel 20 is equivalent to the diameter of the top receiving cavity 13, so that the lens barrel 20 can be moved in the optical axis direction while ensuring that the central axis of the lens barrel 20 does not deviate. Optical axis. The material of the lens barrel 20 may be one of or a mixture of polycarbonate or acrylonitrile-butadiene-styrene.

The image sensor 30 can be a charge coupled device or a complementary metal oxide semiconductor. Preferably, the image sensor 30 uses a ceramic leaded chip carrier (CLCC), a plastic leaded chip carrier (PLCC) or a chip scale package (CSP). There is a glass plate 31 for protecting the image sensor 30.

Referring to FIG. 2 and FIG. 3 , the at least one compensation sheet 40 is disposed between the lens holder 10 and the lens barrel 20 , wherein each of the compensation sheets 40 is fixed to the lens barrel 20 at one end and fixed to the lens holder 10 for driving. The lens barrel 20 is moved in the optical axis direction to maintain the imaging surface of the lens module 50 at a predetermined plane, that is, the plane in which the image sensor 30 is located. Preferably, the plurality of compensating sheets 40 are located on a plane perpendicular to the optical axis, and the plurality of compensating sheets 40 are equally spaced outside the lens barrel 20. In this embodiment, the number of the compensation sheets is two, and they may also be one, three, four or more, and are equally spaced outside the lens barrel 20.

The compensation sheet 40 includes at least two metal sheets having different expansion coefficients, and the multi-metal sheet can be bent in the optical axis direction by the change of the temperature, thereby driving the lens barrel 20 to move in the optical axis direction. Specifically, in the embodiment, the compensation sheet 40 includes two metal sheets having different expansion coefficients, and the expansion coefficient of the metal piece 41 of the bimetal of the compensation sheet 40 near the bottom of the lens holder 10 is closer to the top of the lens holder 10. The metal piece 42 has a large expansion coefficient. This is because, at a high temperature, the optimal imaging surface of the lens module 50 is offset from the lens 20 by the plane of the image sensor 30, so the lens barrel 20 should be enlarged to the image sensor 30. The distance between the two can make the image clear. Therefore, the compensation piece should be bent away from the image sensor 30 to move the lens barrel 20 away from the image sensor 30, thereby increasing the distance between the lens barrel 20 and the image sensor 30. So that the imaging does not shift. When the temperature rises, the metal piece 41 and the metal piece 42 are deformed. Since the thermal expansion coefficient of the metal piece 41 is larger than the thermal expansion coefficient of the metal piece 42, the shape of the metal piece 41 is changed greatly, in order to match the displacement at the interface. The metal piece 41 will be subjected to compressive stress, and the metal piece 42 will be subjected to tensile stress, so the bimetal will be oriented One side of the metal piece 42 is bent. Accordingly, when the temperature is lowered, the bimetal is bent toward one side of the metal piece 41. Correspondingly, the compensator can also be composed of three, four or more metal sheets, which also satisfy the condition that the expansion coefficient of the metal sheet near the bottom of the lens holder is larger than the expansion coefficient of the metal sheet near the top of the lens holder. .

The material of the multi-metal piece may be a metal such as copper, nickel, aluminum, tin, titanium or the like and an alloy of at least two of them, or a combination of brass, stainless steel, ordinary steel or the like. In the present embodiment, the material of the metal piece 41 is selected from brass (90% copper and 10% zinc), and the material of the metal piece 42 is selected from stainless steel. The coefficient of thermal expansion of brass is 23×10-6/°C, and the coefficient of thermal expansion of stainless steel is 16×10-6/°C, so that the expansion coefficient of the metal piece 41 is larger than that of the metal piece 42. The thickness of the two metal sheets may be equal or unequal, and the thickness thereof may be determined according to the specific material. Here, the metal piece 41 and the metal piece 42 are equal in thickness, and each is about 1 to 1.5 mm.

In order to improve the stability of the compensation piece 40 fixed to the lens holder 10 and the lens barrel 20, in the embodiment, a plurality of grooves 14 and grooves 22 are respectively formed on the lens holder 10 and the lens barrel 20 for respectively The two ends of the compensation sheet 40 are provided. The compensator 40 can be further fixedly coupled to the inner walls of the recess 14 and the recess 22 by glue. In this embodiment, the lens holder 10 and the lens barrel 20 are further provided with a plurality of dispensing holes 15 and 23, respectively communicating with the groove 14 and the groove 22, thereby facilitating the inner wall of the groove 14 and the groove 22. Dispensing.

The lens module and the camera module have a plurality of compensating pieces, and the compensation piece is bent by the change of the ambient temperature, thereby driving the lens barrel with the optical lens along the optical axis The direction is moved so that the imaging surface of the lens module is always maintained at a predetermined plane, that is, the plane of the image sensor, thereby achieving temperature compensation for the lens module and the camera module. The lens module and camera module avoid the use of autofocus and other mechanisms, thereby simplifying the overall structure, reducing overall size and reducing costs.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and equivalent modifications or variations made by those skilled in the art in accordance with the spirit of the present invention are It should be covered by the following patent application.

100‧‧‧ camera module

10‧‧‧Mirror seat

11‧‧‧ Protective cover

12‧‧‧Transparent board

13‧‧‧Top cavity

14,22‧‧‧ Groove

15,23‧‧‧ dispensing holes

20‧‧‧Mirror tube

21‧‧‧ lenses

30‧‧‧Image Sensor

31‧‧‧ glass plate

40‧‧‧Compensation film

41,42‧‧‧metal pieces

50‧‧‧Lens module

Claims (16)

A lens module includes a lens holder and a lens barrel, wherein the lens holder has a top receiving cavity for accommodating the lens barrel, and the lens barrel has at least one lens therein. The improvement is that the lens module further a plurality of compensating sheets are disposed at equal intervals between the lens barrel and the lens barrel and the lens holder. The plurality of compensating sheets can be bent due to temperature changes and drive the lens barrel to move along the optical axis direction. The imaging surface of the lens module is maintained on a predetermined plane, and a side of the lens holder opposite to the lens barrel is provided with a groove, and a side of the lens barrel opposite to the lens holder is provided with another groove, the lens holder The upper groove corresponds to the groove on the lens barrel and cooperates to clamp both ends of one of the compensation sheets. The lens module of claim 1, wherein each of the compensation sheets is located on a plane perpendicular to the optical axis. The lens module of claim 1, wherein each of the compensation sheets comprises at least two metal sheets having different expansion coefficients. The lens module of claim 3, wherein the metal sheet of the at least two metal sheets of each of the compensation sheets near the bottom of the lens holder has a larger expansion coefficient than the metal sheet near the top of the lens holder. The lens module of claim 3, wherein the material of the at least two metal sheets of each of the compensation sheets may be selected from the group consisting of copper, nickel, aluminum, tin, titanium, and alloys of at least two of them, or brass , stainless steel, ordinary steel composition. The lens module of claim 1, wherein the outer diameter of the lens barrel is equal to the diameter of the top receiving cavity. The lens module of claim 1, wherein the lens holder and the lens barrel are further provided with a plurality of dispensing holes respectively communicating with the grooves. A camera module includes a lens holder, a lens barrel and an image sensor, the lens holder having a top receiving cavity for receiving the lens barrel, the lens barrel having at least one lens therein, wherein The camera module further includes a plurality of compensating sheets disposed at equal intervals between the lens barrel and the lens barrel and the lens holder. The plurality of compensating sheets can be bent due to temperature changes and drive the lens barrel along the optical axis. The direction of movement is such that the imaging surface of the lens module is maintained on the plane of the image sensor, and a side of the lens holder opposite to the lens barrel is provided with a groove, and the side of the lens barrel opposite to the lens holder is opened. There is another groove, the groove on the lens holder corresponds to the groove on the lens barrel, and cooperates to clamp both ends of one of the compensation pieces. The camera module of claim 8, wherein each of the compensation sheets is located on a plane perpendicular to the optical axis. The camera module of claim 8, wherein each of the compensation sheets is equidistantly disposed outside the lens barrel. The camera module of claim 8, wherein each of the compensation sheets comprises at least two metal sheets having different expansion coefficients. The camera module of claim 11, wherein the metal sheet of the at least two metal sheets of each of the compensation sheets near the bottom of the lens holder has a larger expansion coefficient than the metal sheet near the top of the lens holder. The camera module of claim 11, wherein the material of the at least two metal sheets of each of the compensation sheets may be selected from the group consisting of copper, nickel, aluminum, tin, titanium, and alloys of at least two of them, or brass , stainless steel, ordinary steel composition. The camera module of claim 8, wherein the outer diameter of the lens barrel is equal to the diameter of the top receiving cavity. The camera module of claim 8, wherein the lens holder and the lens barrel are provided with a plurality of grooves for clamping both ends of the compensation sheet. The camera module of claim 15, wherein the lens holder and the lens barrel are further provided with a plurality of dispensing holes respectively communicating with the grooves.