Lens unit

Abstract

To prevent a power supply line for supplying electric power to a heater part from being completely broken even when a flexible printed board is folded.SOLUTION: A lens unit 1 comprises: a lens holder 2 for holding a plurality of lenses including a first lens L1 and a second lens L2; and a flexible print board 3 that is arranged between the first lens L1 and the second lens L2 and is provided with a heater part 6. The flexible print board 3 includes: an annular part 31 having an annular shape and being in contact with an image-side flange surface 13 of the first lens L1; and an extension part 32 extending from the annular part 31 to the outside in a radial direction. The annual part 31 is arranged with the heater part 6 extending in a circular arc shape in a circumferential direction. The extending part 32 is provided with a plurality of first power supply lines 81 connected to one end of the heater part 6 and a plurality of second power supply lines 82 connected to the other end of the heater part 6.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a lens unit in which a plurality of lenses are arranged on an optical axis.

[0002] Patent Document 1 describes a lens unit used in an optical device. The lens unit in this document includes a plurality of lenses and a lens holder that holds the plurality of lenses. Further, the lens unit includes a flexible printed circuit board having a heater unit for suppressing the occurrence of dew condensation in the lens holder during outdoor use.

[0003] The flexible printed circuit board is disposed between a first lens disposed on the most object side and a second lens disposed on the image side with respect to the first lens. The flexible printed circuit board includes an annular plate-like portion that abuts against the first lens and an extending portion that extends radially outward from the plate-like portion. Further, the conductor layer constituting the heater unit includes a circumferential portion disposed on the plate-like portion, a first extending portion that extends along the extending portion from one end of the circumferential portion, and a second extending portion that extends along the extending portion from the other end of the circumferential portion. By supplying power to the circumferential portion via the first extending portion and the second extending portion, the circumferential portion generates heat. As a result, the temperature around the first lens rises.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, when the flexible printed circuit board is incorporated into the lens holder, the extending portion is bent at a right angle with respect to the plate-like portion and routed to the image side. At this time, by bending the extending portion, the first extending portion and the second extending portion may be disconnected.

[0006] In view of the above problems, an object of the present invention is to suppress the complete disconnection of the power supply wiring for supplying power to the heater portion even when the flexible printed circuit board provided with the heater portion is bent in a lens unit using the flexible printed circuit board.

Means for Solving the Problems

[0007] In order to solve the above problems, the lens unit of the present invention includes a first lens, a second lens disposed on the image side with respect to the first lens, a lens holder that holds a plurality of lenses including the first lens and the second lens, and a flexible printed circuit board disposed between the first lens and the second lens and provided with a heater portion made of a conductor layer. The first lens includes an image-side lens surface and an image-side flange surface surrounding the image-side lens surface. The flexible printed circuit board includes an annular portion overlapping the image-side flange surface and an extending portion extending radially outward from the annular portion. A heater portion extending in an arc shape in the circumferential direction is disposed in the annular portion, and a plurality of first power supply wirings connected to one end of the heater portion and a plurality of second power supply wirings connected to the other end of the heater portion are provided in the extending portion.

[0008] According to the present invention, a plurality of first power supply wirings and second power supply wirings for supplying power to the heater portion are provided respectively. Thereby, when the flexible printed circuit board is incorporated into the lens holder and the extending portion is bent with respect to the annular portion, even if a part of the first power supply wiring and the second power supply wiring is disconnected, the other first power supply wiring and second power supply wiring are connected to the heater portion, so that it is possible to suppress the heater portion from completely losing its function.

[0009] In the present invention, it is preferable that the extending portion includes a first extending portion where the first power supply wiring is disposed and a second extending portion where the second power supply wiring is disposed. With this configuration, since the first extending portion and the second extending portion are provided separately, it is possible to suppress a part of the first power supply wiring and the second power supply wiring from being disconnected simultaneously.

[0010] In the present invention, it is preferable that a plurality of the first extension portions and a plurality of the second extension portions are provided respectively. With such a configuration, since a plurality of the first extension portions and a plurality of the second extension portions are provided respectively, even when the first power supply wiring disposed in some of the first extension portions and the second power supply wiring disposed in some of the second extension portions are completely disconnected, the first power supply wiring disposed in other first extension portions and the second power supply wiring disposed in other second extension portions are connected to the heater portion, so that it is possible to suppress the heater portion from completely losing its function.

[0011] In the present invention, the extension portion includes a first extension portion in which a part of the first power supply wirings among the plurality of first power supply wirings and a part of the second power supply wirings among the plurality of second power supply wirings are disposed, and a second extension portion in which another part of the first power supply wirings among the plurality of first power supply wirings and another part of the second power supply wirings among the plurality of second power supply wirings are disposed. It is preferable that the other part of the first power supply wirings and the other part of the second power supply wirings extend in an arc shape in the circumferential direction outside the heater portion in the radial direction in the annular portion and are disposed up to the second extension portion. With such a configuration, since the first power supply wiring and the second power supply wiring are disposed in the first extension portion and the second extension portion respectively, even if the first power supply wiring and the second power supply wiring disposed in either one of the first extension portion and the second extension portion are completely disconnected, the first power supply wiring and the second power supply wiring disposed in the other one are connected to the heater portion, so that it is possible to suppress the heater portion from completely losing its function.

[0012] In the present invention, it is preferable that the first extension part and the second extension part are arranged at positions that are point-symmetrical about the optical axis of the plurality of lenses. Here, the heat generation amount of the heater part tends to decrease as the distance from the connection part connecting to the first power supply wiring and the second power supply wiring increases in the circumferential direction. Therefore, with such a configuration, since the first power supply wiring and the second power supply wiring are separated from each other in the circumferential direction, the circumferential length of the heater part between the first power supply line and the second power supply line becomes short. As a result, compared with the case where the first power supply wiring and the second power supply wiring are not separated from each other in the circumferential direction, the heater part can be heated uniformly, so that dew condensation generated on the first lens can be removed more efficiently.

[0013] In the present invention, the heater part can adopt a mode composed of heater wires folded back a plurality of times in the circumferential direction. In this case, in the present invention, it is preferable that the line width of the heater wire is narrower than the line widths of the first power supply wiring and the second power supply wiring. Here, when the conductive wire becomes thinner, the electrical resistance becomes higher, and the heat generation amount when power is supplied to the conductive wire becomes larger. Therefore, with such a configuration, it is possible to efficiently generate heat in the heater part.

Advantages of the Invention

[0014] According to the present invention, since a plurality of first power supply wirings and second power supply wirings for supplying power to the heater part are provided respectively, when the flexible printed circuit board is incorporated into the lens holder, even if the extension part is bent with respect to the annular part, it is possible to suppress the complete disconnection of the power supply wiring for supplying power to the heater part.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of a lens unit to which the present invention is applied will be described with reference to the drawings.

[0017] FIG. 1 is a cross-sectional view of a lens unit according to an embodiment of the present invention. FIG. 2 is a cross-sectional perspective view of the lens unit of FIG. 1. In FIG. 1, L is the optical axis of the lens unit 1. La is one side in the optical axis direction and is the object side of the lens unit 1. Lb is the other side in the optical axis direction and is the image side of the lens unit 1. As shown in FIGS. 1 and 2, the lens unit 1 includes a plurality of lenses, a lens holder 2 that holds the plurality of lenses, and a flexible printed circuit board 3 including a heater section 6 made of a conductor layer.

[0018] (A plurality of lenses) The plurality of lenses include, in order from the object side La toward the image side Lb, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. Therefore, the first lens L1 is located closest to the object side La, and the sixth lens L6 is located closest to the image side Lb. A light shielding plate L7 is disposed between the second lens L2 and the third lens L3, and a diaphragm L8 is disposed between the third lens L3 and the fourth lens L4.

[0019] The first lens L1 and the fourth lens L4 are glass lenses. The first lens L1 includes a convex object-side lens surface 11 on the object side La, a concave image-side lens surface 12 on the object side La, an image-side flange surface 13 surrounding the outer peripheral side of the image-side lens surface 12, and an annular stepped portion 14 that is concave on the object side La on the outer peripheral side of the image-side flange surface 13. The image-side flange surface 13 is an annular flat surface perpendicular to the optical axis L. An O-ring 7 is disposed in the annular stepped portion 14.

[0020] The fourth lens L4 is disposed inside the lens holder 2 while being fixed to a frame-shaped holder 5. The second lens L2, the third lens L3, the fifth lens L5, and the sixth lens L6 are plastic lenses. The sixth lens L6 and the fifth lens L5, which are located closest to the image side Lb, constitute a cemented lens L9. Note that the number and configuration of the lenses held by the lens holder 2 are not limited to the above number and configuration.

[0021] (Lens Holder) The lens holder 2 is made of resin. The lens holder 2 includes a first housing portion 21 that holds the first lens L1, a second housing portion 22 disposed on the image side Lb of the first housing portion 21, and a lens case 23 that surrounds the outer peripheral side of the second housing portion 22. The lens case 23 extends from the outer peripheral end of the first housing portion 21 toward the image side Lb. The second lens L2, the third lens L3, the fourth lens L4, and the cemented lens L9 are held in the second housing portion 22.

[0022] As shown in FIGS. 1 and 2, the first lens L1 is disposed in the lens holder 2 with reference to the inner peripheral surface of the first housing portion 21. Also, the second lens L2, the third lens L3, the fourth lens L4, and the cemented lens L9 are disposed with reference to the inner peripheral surface of the second housing portion 22.

[0023] As shown in FIGS. 1 and 2, the first housing portion 21 includes an annular bottom portion 24 facing the La direction and a peripheral wall portion 25 surrounding the first lens L1. The first lens L1 is housed in the first housing portion 21 and fixed by a caulking portion 27 provided at the tip of the peripheral wall portion 25. The gap between the first lens L1 and the first housing portion 21 is sealed by the O-ring 7.

[0024] As shown in FIGS. 1 and 2, the second housing portion 22 includes a cylindrical portion 28 connected to the bottom portion 24 of the first housing portion 21 and a bottom portion 29 provided at the image-side Lb end of the cylindrical portion 28 extending in the optical axis L direction. The second lens L2, the third lens L3, the fourth lens L4, and the cemented lens L9 are positioned in the optical axis L direction with reference to a lens seating surface 29a formed on the bottom portion 29 of the second housing portion 22.

[0025] The cemented lens L9 is positioned in the optical axis L direction by the outer peripheral portion of the fifth lens L5 coming into contact with the lens seating surface 29a. The fourth lens L4 located on the object side La of the cemented lens L9 is held by a holder 5, and the holder 5 comes into contact with the outer peripheral portion of the fifth lens L5 in the optical axis L direction. Also, the outer peripheral portion of the third lens L3 located on the object side La of the fourth lens L4 comes into contact with the outer peripheral portion of the holder 5 in the optical axis L direction via a diaphragm L8. Further, the outer peripheral portion of the second lens L2 located on the object side La of the third lens L3 comes into contact with the outer peripheral portion of the third lens L3 in the optical axis L direction via a light shield plate L7. Therefore, the second lens L2, the third lens L3, and the fourth lens L4 are all positioned in the optical axis L direction with reference to the lens seating surface 29a. The second lens L2 is caulked and fixed by a caulking portion 28a provided at the object-side La end of the cylindrical portion 28.

[0026] Also, the lens holder 2 includes a through hole 26 that penetrates the bottom portion 24 of the first housing portion 21 in the optical axis L direction. The through hole 26 communicates with a gap between the cylindrical portion 28 of the second housing portion 22 and the lens case 23. As will be described later, the flexible printed circuit board 3 is inserted into the through hole 26 and drawn out to the image side Lb of the lens holder 2 through a gap between the inner peripheral surface of the lens case 23 and the outer peripheral surface of the cylindrical portion 28. Note that the number, size, and position of the through holes 26 are configured according to the shape of the flexible printed circuit board 3.

[0027] (Flexible Printed Circuit Board) (First Embodiment) FIG. 3 is a plan view of the flexible printed circuit board 3 according to the first embodiment. As shown in FIG. 1, the flexible printed circuit board 3 is disposed between the first lens L1 and the second lens L2. As shown in FIG. 3, on the flexible printed circuit board 3, a heater portion 6 and a power supply wiring 8 for electrically connecting to the heater portion 6 and supplying power to the heater portion 6 are disposed.

[0028] As shown in FIGS. 2 and 3, the flexible printed circuit board 3 includes an annular portion 31 that overlaps the image-side flange surface 13, and an extension portion 32 that extends radially outward from the annular portion 31. An opening hole 33 is formed at the center of the annular portion 31 so that the lens surface of the second lens L2 is exposed. The annular portion 31 is disposed in a state of being sandwiched between the bottom portion 24 of the first housing portion 21 and the image-side flange surface 13 of the first lens L1.

[0029] As shown in FIG. 2, the extension portion 32 is bent at a right angle with respect to the annular portion 31 and inserted into the through hole 26. The extension portion 32 inserted into the through hole 26 is drawn out to the image side Lb of the lens holder 2 through the gap between the inner peripheral surface of the lens case 23 and the outer peripheral surface of the cylindrical portion 28.

[0030] A conductor layer 9 is provided on the flexible printed circuit board 3, and the conductor layer 9 includes the heater portion 6 and the power supply wiring 8. The heater portion 6 is composed of heater wires 61 formed on the surface of the flexible printed circuit board 3. The heater wires 61 are disposed on the annular portion 31. The heater wires 61 extend in an arc shape in the circumferential direction along the periphery of the opening hole 33 and are folded back a plurality of times in the circumferential direction. The power supply wiring 8 is disposed on the extension portion 32. The power supply wiring 8 includes a first power supply wiring 81 connected to one end of the heater wire 61 and a second power supply wiring 82 connected to the other end of the heater wire 61. One of the first power supply wiring 81 and the second power supply wiring 82 is connected to the positive electrode, and the other of the first power supply wiring 81 and the second power supply wiring 82 is connected to the negative electrode. A plurality of the first power supply wiring 81 and the second power supply wiring 82 are provided respectively. In this embodiment, the first power supply wiring 81 and the second power supply wiring 82 are each provided in three.

[0031] The flexible printed circuit board 3 includes a flexible substrate 30 made of a resin film such as polyimide. A heater wire 61 and a power supply wiring 8 are formed on the surface of the flexible substrate 30 by a conductor layer 9 such as Cu. An overcoat layer that covers the heater wire 61 and the power supply wiring 8 is formed on the surface of the flexible substrate 30. In this embodiment, the line width of the heater wire 61 is narrower than the line widths of the first power supply wiring 81 and the second power supply wiring 82 when viewed from the direction of the optical axis L.

[0032] The flexible printed circuit board 3 is electrically connected to a substrate. When power is supplied from the substrate to the first power supply wiring 81 and the second power supply wiring 82, the heater wire 61 generates heat. When the heater wire 61 generates heat, the first lens L1 that contacts the annular portion 31 is heated. Therefore, when the lens unit is used at a low outside air temperature, since the first lens L1 is heated by the heater unit 6, it is possible to suppress dew condensation on the image-side lens surface 12 of the first lens L1.

[0033] (Operation and Effect of this Embodiment) According to this embodiment, three first power supply wirings 81 and three second power supply wirings 82 for supplying power to the heater unit 6 are provided respectively. Thereby, when the flexible printed circuit board 3 is incorporated into the lens holder 2 and the extension portion 32 is bent with respect to the annular portion 31, even if a part of the first power supply wiring 81 and the second power supply wiring 82 is disconnected, the other first power supply wirings 81 and second power supply wirings 82 are connected to the heater unit 6, so that it is possible to prevent the heater unit 6 from completely malfunctioning.

[0034] (Second Embodiment) Next, the flexible printed circuit board 3 of the second embodiment will be described. FIG. 4 is a plan view of the flexible printed circuit board 3 according to the second embodiment. In some cases, the same components as those in the first embodiment may be denoted by the same reference numerals and the description thereof may be omitted.

[0035] As shown in FIG. 4, the flexible printed circuit board 3 includes an annular portion 31 that overlaps the image-side flange surface 13, and an extension portion 32 that extends radially outward from the annular portion 31. An opening hole 33 is formed at the center of the annular portion 31 so that the lens surface of the second lens L2 is exposed. The annular portion 31 is disposed in a state of being sandwiched between the bottom portion 24 of the first housing portion 21 and the image-side flange surface 13 of the first lens L1.

[0036] The extension portion 32 includes a first extension portion 36 and a second extension portion 37. The first extension portion 36 and the second extension portion 37 are provided at positions that are point-symmetrical about the optical axis L. Similar to the flexible printed circuit board 3 of the first embodiment, the extension portion 32 of this embodiment is bent at a right angle with respect to the annular portion 31 and inserted into the through hole 26.

[0037] A conductor layer 9 is provided on the flexible printed circuit board 3, and the conductor layer 9 includes a heater portion 6 and a power supply wiring 8. The heater portion 6 is composed of a heater wire 61 formed on the surface of the flexible printed circuit board 3. The heater wire 61 is disposed on the annular portion 31. The heater wire 61 extends in an arc shape in the circumferential direction along the periphery of the opening hole 33 and is folded back a plurality of times in the circumferential direction. The power supply wiring 8 includes a first power supply wiring 81 connected to one end of the heater wire 61 and a second power supply wiring 82 connected to the other end of the heater wire 61. The first power supply wiring 81 is disposed on the first extension portion 36. The second power supply wiring 82 is disposed on the second extension portion 37. A plurality of the first power supply wiring 81 and the second power supply wiring 82 are provided respectively. In this embodiment, three of the first power supply wiring 81 and the second power supply wiring 82 are provided respectively. That is, the three first power supply wiring 81 are disposed on the first extension portion 36. The three second power supply wiring 82 are disposed on the second extension portion 37. In this embodiment, the line width of the heater wire 61 is narrower than the line widths of the first power supply wiring 81 and the second power supply wiring 82 when viewed from the direction of the optical axis L. The line width of the power supply wiring 81 and the second power supply wiring 82.

[0038] (Operational effects of this embodiment) According to this embodiment, the three first power supply wirings 81 are arranged in the first extension part 36. The three second power supply wirings 82 are arranged in the second extension part 37. Therefore, since the first extension part 36 and the second extension part 37 are provided separately, it is possible to suppress a part of the first power supply wiring 81 and the second power supply wiring 82 from being disconnected simultaneously. Further, the first extension part 36 and the second extension part 37 are provided at positions that are point-symmetrical about the optical axis L. Therefore, since the first power supply wiring 81 and the second power supply wiring 82 are separated in the circumferential direction, the circumferential length of the heater wire 61 between the first power supply wiring 81 and the second power supply wiring 82 becomes shorter. As a result, compared with the case where the first power supply wiring 81 and the second power supply wiring 82 are not separated in the circumferential direction, the heater wire 61 can be heated uniformly, so that dew condensation generated on the first lens can be removed more efficiently.

[0039] (Third Embodiment) Next, the flexible printed circuit board 3 of the third embodiment will be described. FIG. 5 is a plan view of the flexible printed circuit board 3 according to the third embodiment. Note that the same components as those in the first embodiment may be denoted by the same reference numerals and the description thereof may be omitted.

[0040] As shown in FIG. 4, the flexible printed circuit board 3 includes an annular portion 31 that overlaps the image-side flange surface 13, and an extension portion 32 that extends radially outward from the annular portion 31. An opening hole 33 is formed at the center of the annular portion 31 so that the lens surface of the second lens L2 is exposed. The annular portion 31 is arranged in a state of being sandwiched between the bottom portion 24 of the first housing portion 21 and the image-side flange surface 13 of the first lens L1.

[0041] The extension portion 32 includes a first extension portion 36 and a second extension portion 37. A plurality of the first extension portions 36 and the second extension portions 37 are provided respectively. In this embodiment, three first extension portions 36 and three second extension portions 37 are provided respectively. The first extension portion 36 and the second extension portion 37 are provided at positions that are point-symmetrical about the optical axis L. Similar to the flexible printed circuit board 3 of the first embodiment, the extension portion 32 of this embodiment is bent at a right angle with respect to the annular portion 31 and inserted into the through hole 26.

[0042] A conductor layer 9 is provided on the flexible printed circuit board 3, and the conductor layer 9 includes a heater section 6 and a power supply wiring 8. The heater section 6 is composed of heater wires 61 formed on the surface of the flexible printed circuit board 3. The heater wires 61 are arranged in the annular portion 31. The heater wires 61 extend in an arc shape in the circumferential direction along the periphery of the opening hole 33 and are folded back a plurality of times in the circumferential direction. The power supply wiring 8 includes a first power supply wiring 81 connected to one end of the heater wire 61 and a second power supply wiring 82 connected to the other end of the heater wire 61. The first power supply wiring 81 is arranged in the first extension portion 36. The second power supply wiring 82 is arranged in the second extension portion 37. A plurality of the first power supply wiring 81 and the second power supply wiring 82 are respectively provided. In this embodiment, three of the first power supply wiring 81 and three of the second power supply wiring 82 are respectively provided. Specifically, the three first power supply wiring 81 are respectively arranged, one by one, in the three first extension portions 36. The three second power supply wiring 82 are respectively arranged, one by one, in the three second extension portions 37. In this embodiment, the line width of the heater wire 61 is narrower than the line widths of the first power supply wiring 81 and the second power supply wiring 82 when viewed from the direction of the optical axis L.

[0043] (Operation and effect of this embodiment) According to this embodiment, the three first power supply wiring 81 are respectively arranged, one by one, in the three first extension portions 36. The three second power supply wiring 82 are respectively arranged, one by one, in the three second extension portions 37. Therefore, since three of the first extension portions 36 and three of the second extension portions 37 are respectively provided, the first power supply wiring 81 arranged in some of the first extension portions 36 and the Even when the second power supply wiring 82 is completely disconnected, since the first power supply wiring 81 arranged in the other first extension portion 36 and the second power supply wiring 82 arranged in the other second extension portion 37 are connected to the heater wire 61, it is possible to suppress the complete malfunction of the heater unit 6. Further, the first extension portion 36 and the second extension portion 37 are provided at positions that are point-symmetrical about the optical axis L. Therefore, since the first power supply wiring 81 and the second power supply wiring 82 are separated in the circumferential direction, the circumferential length of the heater wire 61 between the first power supply wiring 81 and the second power supply wiring 82 becomes short. As a result, compared with the case where the first power supply wiring 81 and the second power supply wiring 82 are not separated in the circumferential direction, the heater wire 61 can be heated uniformly, so that dew condensation generated on the first lens can be removed more efficiently.

[0044] (Fourth Embodiment) Next, the flexible printed circuit board 3 of the fourth embodiment will be described. FIG. 6 is a plan view of the flexible printed circuit board 3 according to the fourth embodiment. In addition, the same components as those in the first embodiment may be denoted by the same reference numerals and the description thereof may be omitted.

[0045] As shown in FIG. 6, the flexible printed circuit board 3 includes an annular portion 31 that overlaps the image-side flange surface 13, and an extension portion 32 that extends radially outward from the annular portion 31. An opening hole 33 is formed at the center of the annular portion 31 so that the lens surface of the second lens L2 is exposed. The annular portion 31 is disposed in a state of being sandwiched between the bottom portion 24 of the first housing portion 21 and the image-side flange surface 13 of the first lens L1.

[0046] The extension portion 32 includes a first extension portion 36 and a second extension portion 37. In this embodiment, the first extension portion 36 and the second extension portion 37 are provided at positions that are point-symmetrical about the optical axis L. Similar to the flexible printed circuit board 3 of the first embodiment, the extension portion 32 of this embodiment is bent at a right angle with respect to the annular portion 31 and inserted into the through hole 26.

[0047] The flexible printed circuit board 3 is provided with a conductor layer 9, and the conductor layer 9 includes a heater section 6 and a power supply wiring 8. The heater section 6 is composed of heater wires 61 formed on the surface of the flexible printed circuit board 3. The heater wires 61 are arranged in the annular portion 31. The heater wires 61 extend in an arc shape in the circumferential direction along the periphery of the opening hole 33 and are folded back a plurality of times in the circumferential direction. The power supply wiring 8 includes a first power supply wiring 81 connected to one end of the heater wire 61 and a second power supply wiring 82 connected to the other end of the heater wire 61. Two of each of the first power supply wiring 81 and the second power supply wiring 82 are provided.

[0048] Among the two first power supply wirings 81, a part of the first power supply wiring 81a is arranged in the first extension portion 36. Among the two first power supply wirings 81, the other part of the first power supply wiring 81b is arranged in the second extension portion 37. The first power supply wiring 81b includes an arc portion 811 arranged on the radially outer side of the heater wire 61 in the annular portion 31. The arc portion 811 extends in an arc shape in the circumferential direction on the radially outer side of the heater wire 61. Therefore, the first power supply wiring 81b extends in an arc shape in the circumferential direction on the radially outer side of the heater wire 61 in the annular portion 31 and is arranged up to the second extension portion 37.

[0049] Among the two second power supply wirings 82, a part of the second power supply wiring 82a is arranged in the first extension portion 36. Among the two second power supply wirings 82, the other part of the second power supply wiring 82b is arranged in the second extension portion 37. The second power supply wiring 82b includes an arc portion 821 arranged on the radially outer side of the heater wire 61 in the annular portion 31. The arc portion 821 extends in an arc shape in the circumferential direction on the radially outer side of the heater wire 61. Therefore, the second power supply wiring 82b extends in an arc shape in the circumferential direction on the radially outer side of the heater wire 61 in the annular portion 31 and is arranged up to the second extension portion 37.

[0050] In this embodiment, the line width of the heater wire 61 is narrower than the line widths of the first power supply wiring 81 including the arc portion 811 and the second power supply wiring 82 including the arc portion 821 when viewed from the direction of the optical axis L.

[0051] (Operation and effect of this embodiment) According to this embodiment, the first power supply wiring 81a and the second power supply wiring 82a are arranged in the first extension portion 36. The first power supply wiring 81b and the second power supply wiring 82b are arranged in the second extension portion 37. Therefore, even if the first power supply wiring 81 and the second power supply wiring 82 arranged in either one of the first extension portion 36 and the second extension portion 37 are completely disconnected, since the first power supply wiring 81 and the second power supply wiring 82 arranged in the other are connected to the heater wire 61, it is possible to suppress the heater unit 6 from completely losing its function.

[0052] In this embodiment, the line width of the heater wire 61 is narrower than the line widths of the first power supply wiring 81 including the arc portion 811 and the second power supply wiring 82 including the arc portion 821 when viewed in the direction of the optical axis L. In other words, the line widths of the arc portion 811 and the arc portion 821 are wider than the line width of the heater wire 61. Therefore, when the flexible printed circuit board 3 is incorporated into the lens holder 2, even if the outer peripheral side of the annular portion 31 comes into contact with the lens holder 2, it is possible to suppress the first power supply wiring 81 and the second power supply wiring 82 from being disconnected.

[0053] (Modified example of heater unit) In the above embodiment, the heater unit 6 is composed of the heater wire 61 folded back a plurality of times in the circumferential direction, but the heater unit 6 is not limited to this configuration. As shown in FIG. 7, the heater unit 6 may be arc-shaped with a width wider than the line widths of the first power supply wiring 81 and the second power supply wiring 82 and not folded back a plurality of times in the circumferential direction.

Explanation of reference numerals

[0054] 1... lens unit, 2... lens holder, 3... flexible printed circuit board, 5... holder, 5... first, 6... heater section, 7... O-ring, 8... power supply wiring, 9... conductor layer, 11... object-side lens surface, 12... image-side lens surface, 13... image-side flange surface, 14... annular stepped portion, 21... first accommodating portion, 22... second accommodating portion, 23... lens case, 24... bottom, 25... peripheral wall portion, 26... through hole, 27... caulking portion, 28... cylindrical portion, 28a... caulking portion, 29... bottom, 29a... lens seating surface, 30... flexible substrate, 31... annular portion, 32... extension portion, 33... opening hole, 36... first extension portion, 37... second extension portion, 61... heater wire, 81, 81a, 81b... first power supply wiring, 82, 82a, 82b... second power supply wiring, 811... arc portion, 821... arc portion, L1... first lens, L2... second lens, L3... third lens, L4... fourth lens, L5... fifth lens, L6... sixth lens, L7... light shield, L9... joining lens, L... optical axis

Claims

1. a first lens; a second lens disposed on the image side with respect to the first lens; a lens holder that holds a plurality of lenses including the first lens and the second lens; a flexible printed circuit board disposed between the first lens and the second lens and having a heater portion made of a conductor layer; characterized by having the first lens includes an image-side lens surface and an image-side flange surface surrounding the image-side lens surface; the flexible printed circuit board includes an annular portion overlapping the image-side flange surface, and an extension portion extending radially outward from the annular portion and bent toward the image side; a heater portion extending in an arc shape in the circumferential direction is disposed in the annular portion; the extension portion is provided with a plurality of first power supply wirings connected to one end of the heater portion and a plurality of second power supply wirings connected to the other end of the heater portion; the extension portion includes a first extension portion on which a part of the plurality of first power supply wirings and a part of the plurality of second power supply wirings are disposed, and a second extension portion on which another part of the plurality of first power supply wirings and another part of the plurality of second power supply wirings are disposed. A lens unit characterized by comprising.

2. In the lens unit according to claim 1, the lens unit is characterized in that a plurality of the first extension portions and the second extension portions are respectively provided.

3. A first lens; a second lens disposed on the image side with respect to the first lens; a lens holder that holds a plurality of lenses including the first lens and the second lens; a flexible printed circuit board disposed between the first lens and the second lens and having a heater portion made of a conductor layer; characterized by having the first lens includes an image-side lens surface and an image-side flange surface surrounding the image-side lens surface; the flexible printed circuit board includes an annular portion overlapping the image-side flange surface, and an extension portion extending radially outward from the annular portion and bent toward the image side; a heater portion extending in an arc shape in the circumferential direction is disposed in the annular portion; the extension portion is provided with a plurality of first power supply wirings connected to one end of the heater portion and a plurality of second power supply wirings connected to the other end of the heater portion; the extension portion includes a first extension portion on which a part of the plurality of first power supply wirings and a part of the plurality of second power supply wirings are disposed, and another part of the plurality of first power supply wirings and the plurality of second power supply wirings. A second extension portion on which another part of the second power supply wirings are disposed. The other part of the first power supply wiring and the other part of the second power supply wiring are arranged in an arc shape in the circumferential direction on the radially outer side of the heater part in the annular part and extend to the second extension part. A lens unit characterized by this.

4. In the lens unit according to any one of claims 1 to 3, The first extension part and the second extension part are arranged at point-symmetrical positions around the optical axis of the plurality of lenses. A lens unit characterized by this.

5. In the lens unit according to any one of claims 1 to 4, The heater part is composed of heater wires folded back a plurality of times in the circumferential direction. A lens unit characterized by this.

6. In the lens unit according to claim 5, The line width of the heater wire is narrower than the line widths of the first power supply wiring and the second power supply wiring. A lens unit characterized by this.

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