TW202235989A - Imaging lens - Google Patents

Abstract

An imaging lens including an optical lens group, a lens barrel and a heating element is disclosed. The optical lens group includes at least a first lens, wherein the first lens includes an effective optical area and a non-effective optical area, which includes an opaque film. The lens barrel includes an accommodating space, and the optical lens group is arranged in the accommodating space such that the first lens faces toward the outside of the lens barrel; an upper end of the lens barrel includes an abutting surface, and the non-effective optical area of the first lens abuts the abutting surface. The heating element is used to heat the first lens and includes a heating sheet and a wire. The heating sheet includes a heating part and an electrical connection part, wherein the electrical connection part extends outward from the heating part. The heating part is positioned between the first lens and the abutting surface of the lens barrel. The wire connects the electrical connection part of the heating sheet to an external power supply.

Description

imaging lens

The present invention relates to an imaging lens, in particular to an imaging lens with defogging (or defrosting) function.

The influence of ambient temperature on optical imaging lenses usually needs to consider the environmental adaptability of lens materials under various temperature conditions. For example, in terms of optical imaging lenses used outdoors, such as car photography lenses, sports photography lenses or aerial photography For camera lenses, etc., it is usually necessary to use several glass lenses to reduce the influence of temperature changes on the shape of the lens, so as to maintain stable imaging quality. In contrast, optical imaging lenses used indoors, such as surveillance camera lenses used at home, can use plastic lenses to reduce cost and weight because the indoor environment is usually maintained at a certain temperature range.

In addition, when the optical imaging lens is in an environment with a large temperature difference, such as entering the room from the outside, or encountering low temperature and humid weather, the optical imaging lens is also prone to damage due to condensation of saturated water vapor in the air on the surface of the lens. Cause fogging or frosting, so as to affect the clarity of imaging. However, since optical imaging lens products have precisely set the position of each optical lens inside the lens after assembly, it is generally not easy for consumers to deal with lens fogging or frosting on their own.

Therefore, how to provide an optical imaging lens that can defog (or defrost) is one of the goals that people in this technical field strive for.

Therefore, in order to solve the above problems, the present invention provides an imaging lens, which includes an optical lens group, a lens barrel and a heating element. The optical lens group at least includes a first lens, wherein the first lens includes an optically effective area and a non-optically effective area, and the non-optically effective area has an opaque film. The lens barrel includes an accommodating space for arranging the optical lens group and making the first lens face the outside of the lens barrel, and the upper edge of the lens barrel includes an abutment surface, and the non-optically effective area of the first lens abuts against the abutment surface . The heating element is used to heat the first lens; the heating element includes a heating sheet and a wire, wherein the heating sheet includes a heating part and an electrical connection part, and the heating part of the heating sheet is arranged between the first lens and the contact surface, and is electrically connected The part extends outward from the heating part and is set outside the contact surface of the lens barrel; the wire is used to connect the electrical connection part of the heating chip to an external power supply source.

According to an embodiment of the present invention, the imaging lens further includes a front cover with a central opening, which is used to be sleeved on the upper edge of the lens barrel, to fix the first lens to the contact surface of the lens barrel and to expose the optics of the first lens. valid area.

According to an embodiment of the present invention, the heating sheet includes polyimide and metal alloy.

According to another embodiment of the present invention, the heating chip includes carbon black and metal particles.

According to an embodiment of the present invention, the opaque film includes a light-absorbing coating; preferably, the light-absorbing coating includes carbon black.

According to another embodiment of the present invention, the opaque film includes a metal layer.

According to yet another embodiment of the present invention, the opaque film includes carbon black and a metal composite film.

According to an embodiment of the present invention, the imaging lens further includes a heat insulating sheet disposed between the contact surface of the heating sheet and the lens barrel.

According to an embodiment of the present invention, the thermal conductivity of the heat insulating sheet is less than 0.5 W/m·k.

According to an embodiment of the present invention, the imaging lens further includes a temperature sensing element connected to the heating plate.

According to an embodiment of the present invention, the temperature sensing element includes a negative temperature coefficient thermistor (NTC).

According to an embodiment of the present invention, the heating portion of the heating plate further covers the side edge of the first lens.

According to an embodiment of the present invention, the heating portion of the heating sheet includes an annular sheet structure.

According to an embodiment of the present invention, the electrical connection portion of the heating sheet is protruded from the periphery of the ring-shaped sheet structure.

According to an embodiment of the present invention, the lens barrel further includes a through hole through which the wire extends to the outer wall of the lens barrel.

According to an embodiment of the present invention, the wires include metal wires.

According to an embodiment of the present invention, the material of the wire includes conductive glue.

Several embodiments will be listed below, and the aforementioned and other technical contents, features and effects of the present invention will be described in detail with reference to the drawings. The directional terms mentioned in the text description of the following embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only referring to the directions of the attached drawings. Therefore, the directional terms used in the embodiments are used to illustrate the relative positions of various components, rather than to limit the present invention.

FIG. 1 is a front view of an imaging lens 100 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the imaging lens 100 of the first embodiment of the present invention drawn along line A-A of FIG. 1 . As shown in FIGS. 1 and 2 , the imaging lens 100 includes an optical lens group 10 , a lens barrel 20 and a heating element 30 . Wherein, the optical lens group 10 is assembled in the lens barrel 20; the heating element 30 is arranged between the optical lens group 10 and the lens barrel 20; the heating element 30 includes a heating sheet 31 and a wire 32; the heating sheet 31 is at least connected to the optical lens group 10 One lens, and the lens can be heated to increase the temperature of the lens surface to prevent water vapor from condensing on the lens surface or to remove the condensed fog or surface frost on the lens surface; the wire 32 is used to connect the heating chip 31 to an external power source of supply (not shown).

The optical imaging lens group 10 of the imaging lens 100 of the first embodiment includes a first lens 11 , a second lens 12 , a third lens 13 and a fourth lens 14 in sequence from the object side to the image side. Materials of the first lens 11 to the fourth lens 14 include plastic lenses or glass lenses. Referring to FIG. 3 , the first lens 11 of the optical lens group 10 includes an optically effective area 11a and a non-optically effective area 11b. The optical effective area 11a is a light-transmitting portion, and the light passing through this area is transmitted to the imaging end. The non-optical effective area 11b is an opaque portion. Preferably, an opaque film 11c is formed on the non-optical effective area 11b of the first lens 11, such as a light-absorbing coating, a metal layer, or made of carbon black and Carbon black made of metal and metal composite film, etc. Wherein, the light-absorbing coating can absorb stray light and prevent image quality from being affected, and its material is, for example, carbon black. When the opaque film 11c is made of a metal layer, it has the effect of uniform heat conduction. When the opaque film 11c is carbon black or a metal composite film composed of carbon black and metal, it has the effect of matting and uniform heat conduction. The present invention does not limit the number of lenses of the optical lens group 10, although in the first embodiment, the optical lens group 10 of the imaging lens 100 includes four optical lenses, but in other embodiments, it can also include two, three or Other quantities of optical lenses.

The lens barrel 20 includes an accommodating space 21 surrounding the optical axis I of the optical lens group 10 . The optical lens groups 10 are sequentially disposed in the accommodating space 21 of the lens barrel 20 at an appropriate distance. As shown in FIG. 2 , the accommodating space 21 in the lens barrel 20 includes a first accommodating area 21 a and a second accommodating area 21 b, and the first lens 11 is arranged in the first accommodating area 21 a, and its object side faces the lens barrel The light entrance of 20, the second lens 12 to the fourth lens 14 are arranged in the second accommodating area 21b. In this embodiment, the optical lens 100 further includes a front cover 40 , the front cover 40 is used to sleeve on the upper edge of the lens barrel 20 and fix the first lens 11 on the abutting surface 22 of the lens barrel 20 . The front cover 40 is a casing with an open rear end, and its top includes a central opening 41. The central opening 41 surrounds the optical axis I of the optical lens group 10 and allows light to enter the object side of the first lens 11. In this embodiment, the diameter of the opening 41 of the front cover 40 is smaller than the diameter of the first lens 11 ; however, in other embodiments, the diameter of the opening 41 of the front cover 40 may be greater than or equal to the diameter of the first lens 11 . The upper edge of the lens barrel 20 includes a contact surface 22 , and the contact surface 22 is substantially a plane. In the first embodiment, the abutting surface 22 is recessed on the upper edge of the lens barrel 20 . When the first lens 11 is mounted on the lens barrel 20 , the first lens 11 abuts against the abutting surface 22 of the lens barrel 20 with its non-optically effective area 11 b. The material of the lens barrel 20 is, for example, plastic or metal, or a composite material composed of plastic and inorganic materials (such as silicon dioxide).

As shown in FIG. 2 , the lens barrel 20 further includes a plurality of spacer rings 23 , and a spacer ring 23 is arranged between every two adjacent lenses to properly control the distance between the optical lenses. The material of the spacer ring 23 is, for example, metal. A sealing ring 24 is further included between the front cover 40 and the first lens 11 to prevent external moisture from entering the imaging lens 100 . The material of the sealing ring 24 is, for example, elastic plastic or silicon rubber.

The heating sheet 31 is disposed between the first lens 11 and the contact surface 22 of the lens barrel 20 . Referring to FIG. 4A , the heating sheet 31 includes a heating portion 31a and an electrical connection portion 31b. The heating portion 31a has, for example, a ring-shaped sheet structure, and the electrical connection portion 31b is protruded from the edge of the heating portion 31a. The perimeter extends outwardly. Referring to FIG. 2 , when the heating sheet 31 is disposed in the lens barrel 20 , the electrical connection portion 31 b is bent along the axial direction of the lens barrel 20 . The heating part 31a is formed under the non-optically effective region 11b of the first lens 11 by, for example, bonding, coating or transfer printing, or is arranged on the contact surface 22 of the lens barrel 20 The space between the non-optically effective area 11b of the first lens 11 and the abutting surface 22 of the lens barrel 20 is used to heat the first lens 11, increase the temperature of the lens surface, prevent moisture condensation or remove fog or frost. Through the heating effect of the heating plate 31 , the temperature of the first lens of the optical lens group 10 can be controlled to be greater than 0 degrees. The electrical connection part 31b is used to connect to a wire 32, and connect to an external power supply source (not shown) through the other end of the wire 32; Electric energy can be converted into thermal energy to produce a heating effect. In this embodiment, the heating sheet 31 includes one electrical connection portion 31b, but in other embodiments, it may also include two or more electrical connection portions. As shown in FIG. 4B, the heating sheet 31 may also include two an electrical connection portion 31b. Although in this embodiment, the heating portion 31a of the heating plate 31 is an annular plate structure, the heating plate can also be designed in a semi-arc or other shape, and the present invention is not limited thereto.

The wire 32 of the heating element 30 passes through the through hole 25 on the wall of the lens barrel 20 , extends to the outside of the lens barrel 20 through the through hole 25 , and extends along the outer wall of the lens barrel 20 .

The heater 31 is made of materials with good thermal conductivity, including polyimide (PI) film heaters, silicone heaters, or printed heaters. In this embodiment, the heating sheet 31 is, for example, a polyimide film heating sheet composed of polyimide, metal alloy and polyimide; In a manner, it is formed under the non-optically effective area of the first lens. In other embodiments, the heating plate 31 can also be made of carbon black and metal particles; the manufacturing method is, for example, coating and forming under the non-optically effective area of the first lens. The wire 32 is mainly made of a conductive material, which may include a metal wire, such as a copper wire; or, the wire 32 may also be made of a conductive glue; the outer side of the metal wire or the conductive glue can be coated with an insulating material to provide an external insulation effect .

With the structure disclosed above, the imaging lens of the present invention can heat the optical lens disposed at the front of the lens to increase the temperature of the optical lens, prevent condensation of water vapor or remove fog or frost condensed on the surface of the lens. Since the heating sheet used in the imaging lens of the present invention is disposed under the non-optically effective area of the first lens, it does not affect the imaging range of the original optical lens group. In addition, an opaque film is formed on the non-optical effective area of the first lens; when the opaque film is a metal layer, it can provide the effect of uniform heat conduction; when the opaque film is made of carbon black (light absorption layer), or a metal composite film composed of carbon black and metal, it has the effect of extinction and uniform heat conduction, so that the heat energy provided by the heating sheet can be transferred to the first lens more quickly. The imaging lens of the present invention can provide the function of defogging or defrosting the lens, and has the advantages of simple structure and easy manufacture.

Referring to FIG. 5 , it shows an imaging lens 200 according to a second embodiment of the present invention. The main difference between the imaging lens 200 of the second embodiment and the imaging lens 100 of the first embodiment is that the imaging lens 200 of the second embodiment further includes a heat insulating sheet 50, and the heat insulating sheet 50 is arranged between the heating sheet 31 and the mirror. Between barrels 20.

。在本實施例中，隔熱片50例如是具有和加熱片31的加熱部31a相同之形狀。隔熱片50之材質例如是中空微奈米球、氣凝膠複合材料、超細玻璃棉、聚苯乙烯或泡沫塑料等。隔熱片50的設置方式例如是以塗佈、貼合或轉印等方式製作至加熱片31的底部表面，再組裝至成像鏡頭200中；或者，隔熱片50可以直接抵靠在鏡筒20的抵接面22上的方式，設置於加熱片31與鏡筒20的抵接面22之間。 More specifically, the heat insulating sheet 50 is disposed between the heating portion 31 a of the heating sheet 31 and the abutting surface 22 of the lens barrel 20 . The heat insulating sheet 50 can block the thermal energy of the heating sheet 31 from being transferred to the lens barrel, so as to avoid thermal deformation and material deterioration of the lens barrel 20. Furthermore, the heat insulating sheet 50 has the effect of heat preservation, which helps to make the heating sheet 31 and the first lens 11 maintain in an appropriate temperature range, providing the effect of heat preservation. Energy consumption can be reduced due to the thermal insulation effect provided by the thermal insulation sheet 50 . The thermal insulation sheet 50 has a low thermal conductivity, for example, the thermal conductivity is less than 0.5

. In this embodiment, the heat insulating sheet 50 has, for example, the same shape as the heating portion 31 a of the heating sheet 31 . The material of the thermal insulation sheet 50 is, for example, hollow micro-nanospheres, airgel composite materials, ultra-fine glass wool, polystyrene or foamed plastics. The heat insulating sheet 50 is arranged, for example, by coating, laminating or transferring to the bottom surface of the heating sheet 31, and then assembled into the imaging lens 200; or, the heat insulating sheet 50 can directly abut against the lens barrel The contact surface 22 of the lens barrel 20 is disposed between the heating sheet 31 and the contact surface 22 of the lens barrel 20 .

Referring to FIG. 6A to FIG. 6C , several variant embodiments of the heating plate of the imaging lens of the present invention are shown. FIG. 6A is a partially enlarged view of the rectangular dashed area 60 in FIG. 2 . As shown in FIG. 6A , the heating sheet 31 of the first embodiment of the present invention includes a heating portion 31 a and an electrical connection portion 31 b, wherein the heating portion 31 a is disposed on the non-optically effective area 11 b of the first lens 11 and the upper edge of the lens barrel 20 Between the abutment surfaces 22. Referring to FIG. 6B , a heating sheet 131 according to another embodiment of the present invention includes a heating portion 131a and an electrical connection portion 131b, wherein, the heating portion 131a is provided except at the contact between the non-optically effective area 11b of the first lens 11 and the lens barrel 20 Between the surfaces 22 further extends to the first lens side surface 11d, so that the non-optically effective region 11b of the first lens 11 and the first lens side surface 11d can be heated at the same time. Referring to FIG. 6C , a heating chip 231 according to another embodiment of the present invention includes a heating portion 231 a and an electrical connection portion 231 b, wherein the heating portion 231 a covers the periphery of the first lens 11 , that is, the image side of the first lens 11 The non-optically active area 11b extends upward to the side surface 11d of the first lens 11, and extends forward to the object-side edge 11e of the first lens. In this embodiment, the heating sheet 31 provides heating to the first lens 11 in a manner of covering the edge of the first lens 11 .

Referring to FIG. 7 , it is a cross-sectional view of an imaging lens according to a third embodiment of the present invention. The difference between the imaging lens 300 of the third embodiment of the present invention and the imaging lenses of the aforementioned first and second embodiments is that the imaging lens 300 of the third embodiment further includes a temperature sensing element 70 for detecting the temperature of the lens internal temperature. The temperature sensing element 70 is, for example, connected to the heating chip 31 . The temperature sensing element 70 is, for example, a negative temperature coefficient thermistor (Negative Temperature Coefficient Thermistor, NTC thermistor). Using the temperature sensing element 70 to actively detect the temperature, the heating element 30 can be activated when the temperature is too low, and the optical lens group 10 can be heated in a timely manner, so as to prevent the lens from fogging in the imaging lens 100, or to remove the surface of the lens. Fog or frost. In this embodiment, the temperature sensing element 70 is disposed above the heating portion 31 a of the heating plate 31 , that is, the temperature sensing element 70 is located between the first lens 11 and the heating plate 31 . However, in other embodiments, the temperature sensing element can also be disposed at other positions. FIG. 8 is a cross-sectional view of an imaging lens according to a fourth embodiment of the present invention. As shown in Figure 8, the temperature sensing element 170 of the imaging lens 400 of the fourth embodiment of the present invention is arranged below the heating portion 31a of the heating plate 31, that is, the temperature sensing element 170 is located between the heating plate 31 and the lens barrel 20 between the abutment surfaces 22. Also refer to FIG. 9 , which is a cross-sectional view of an imaging lens according to a fifth embodiment of the present invention. As shown in FIG. 9 , the temperature sensing element 270 of the imaging lens 500 according to the fifth embodiment of the present invention is disposed on one side of the electrical connection portion 31 b of the heating plate 31 .

Although the present invention has been described using the preceding several examples, these examples are not intended to limit the scope of the present invention. For those skilled in the technical field of the present invention, without departing from the spirit and scope of the present invention, various changes in form and details can still be made with reference to the disclosed embodiments of the present invention. Therefore, what needs to be understood here is that the present invention is defined by the scope of the following patent application, and any changes made within the scope of the patent application or its equivalent scope should still fall into the application within the scope of the patent.

10: Optical lens group 100: imaging lens 11: First lens 11a: Optically effective part 11b: Non-optically effective part 11c: Opaque film 11d: Lens side 11e: Object-side edge of the first lens 12: Second lens 13: Third lens 131: heating sheet 131a: heating part 131b: electrical connection part 132: wire 14: Fourth lens 170: temperature sensing element 20: lens barrel 200: imaging lens 21:Accommodating space 21a: First Containment Area 21b: Second storage area 22: Contact surface 23: spacer ring 231: Heating sheet 231a: heating part 231b: electrical connection part 24: sealing ring 25: Through hole 270: temperature sensing element 30: heating element 31: Heating sheet 31a: heating part 31b: electrical connection part 32: wire 40: front cover 41: central opening 50: heat shield 60: rectangle dotted line area 70: Temperature sensing element A-A: hatching I: Optical axis of optical lens group

Fig. 1 is the front view of the imaging lens of the first embodiment of the present invention; Fig. 2 is the sectional view of the imaging lens of the first embodiment drawn along the line A-A of Fig. 1 of the present invention; 3 is a schematic diagram of the optically effective area and the non-optically effective area of a single lens; 4A is a schematic diagram of a heating plate of an imaging lens according to the first embodiment of the present invention; 4B is a schematic diagram of a heating plate of an imaging lens according to another embodiment of the present invention; 5 is a cross-sectional view of an imaging lens according to a second embodiment of the present invention; FIG. 6A is a partially enlarged view of the heating plate in the region of the rectangular dotted line in the first embodiment shown in FIG. 2; Fig. 6B is a partially enlarged view of a heating chip according to another embodiment of the present invention; Fig. 6C is a partially enlarged view of a heating chip according to another embodiment of the present invention; 7 is a cross-sectional view of an imaging lens according to a third embodiment of the present invention; 8 is a cross-sectional view of an imaging lens according to a fourth embodiment of the present invention; and FIG. 9 is a cross-sectional view of an imaging lens according to a fifth embodiment of the present invention.

10: Optical lens group

100: imaging lens

11: First lens

11c: Opaque film

12: Second lens

13: Third lens

14: Fourth lens

20: lens barrel

21:Accommodating space

21a: First Containment Area

21b: Second storage area

22: Contact surface

23: spacer ring

24: sealing ring

25: Through hole

30: heating element

31: Heating sheet

32: wire

40: front cover

41: central opening

60: rectangle dotted line area

I: optical axis

Claims (18)

An imaging lens comprising: An optical lens group, including at least a first lens, wherein the first lens includes an optically effective area and a non-optical effective area, and the non-optical effective area has an opaque film; A lens barrel includes an accommodating space for arranging the optical lens group and making the first lens face to the outside of the lens barrel, and the upper edge of the lens barrel includes an abutment surface, and the first lens uses the non-optically effective the region abuts against the abutment surface; and A heating element for heating the first lens, comprising: A heating sheet, including a heating portion and an electrical connection portion, the heating portion of the heating sheet is arranged between the first lens and the contact surface, the electrical connection portion extends outward from the heating portion and is positioned outside the abutment surface of the lens barrel; and A wire is used to connect the electrical connection part of the heating chip to an external power supply source. The imaging lens of Item 1 of the scope of the patent application, wherein the imaging lens further includes a front cover, the front cover has a central opening, and the front cover is used to be sleeved on the upper edge of the lens barrel to fix the first lens to the The abutting surface of the lens barrel exposes the optically effective area of the first lens. For example, the imaging lens of item 1 of the scope of the patent application, wherein the heating sheet includes polyimide and metal alloy. For example, the imaging lens of item 1 of the scope of the patent application, wherein the heating sheet contains carbon black and metal particles. For example, the imaging lens of claim 1, wherein the opaque film includes a light-absorbing coating. For example, the imaging lens of claim 5, wherein the light-absorbing coating includes carbon black. As for the imaging lens set forth in claim 1 of the patent application, wherein the opaque film includes a metal layer. For example, the imaging lens of item 1 of the scope of the patent application, wherein the opaque film includes carbon black and a metal composite film. As for the imaging lens of item 1 of the scope of the patent application, wherein the imaging lens further includes a heat insulating sheet disposed between the contacting surface of the heating sheet and the lens barrel. Such as the imaging lens of item 9 of the scope of the patent application, wherein the thermal conductivity coefficient of the heat shield is less than 0.5

. As for the imaging lens of item 1 or item 9 of the scope of the patent application, wherein the imaging lens further includes a temperature sensing element connected to the heating plate. For example, the imaging lens of item 11 of the scope of the patent application, wherein the temperature sensing element includes a negative temperature coefficient thermistor (NTC). In the imaging lens according to claim 1 of the patent application, the heating part of the heating plate further covers the side surface of the first lens. As for the imaging lens set forth in item 1 of the scope of the patent application, wherein the heating part of the heating sheet includes an annular sheet structure. For example, the imaging lens of item 14 of the scope of the patent application, wherein the electrical connection part of the heating sheet is protruded on the periphery of the ring-shaped sheet structure. For example, the imaging lens of item 1 of the scope of the patent application, wherein the lens barrel further includes a through hole, and the wire extends to the outer wall of the lens barrel through the through hole. For example, the imaging lens of item 16 of the scope of the patent application, wherein the wires include metal wires. For example, the imaging lens of item 16 of the scope of application, wherein, the material of the wire includes conductive glue.

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