JP2019168619A - Infrared-lens module - Google Patents

Abstract

To provide an infrared lens module that consumes less power.SOLUTION: A lens module 1 comprises a lens 10 for transmitting infrared rays, a lens barrel body 30 for holding the lens 10, and a temperature adjuster 61 for adjusting a temperature of the lens 10. The lens barrel body 30 comprises a cylindrical portion 31 contacting the lens 10, and a coating layer 35 arranged so as to cover a first inner peripheral surface 36 being an inner peripheral surface of the cylindrical portion 31, and having a second inner peripheral surface 37 having a lower emissivity than the first inner peripheral surface 36.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an infrared lens module.

  Infrared lens modules that include a lens that transmits infrared rays are used in infrared cameras for imaging with infrared rays. When the infrared camera is used in an environment where the temperature is low, condensation or freezing may occur on the surface of the infrared lens.

  As a countermeasure when the infrared camera is used in a low temperature environment, the infrared camera is stored in a case having a window that transmits infrared rays, and the window is heated by a heater to prevent condensation and freezing. It has been proposed (see, for example, Patent Document 1).

  There has been proposed a structure in which a temperature adjusting device is arranged on an infrared lens provided in an infrared lens module, thereby adjusting the temperature of the infrared lens to prevent dew condensation and freezing (see, for example, Patent Document 2).

JP 2001-57642 A JP 2017-167504 A

  For an infrared camera equipped with an infrared lens module, a device that adjusts the temperature, such as a heater, is used to prevent condensation and freezing. The lens is heated by the heater, and the temperature of the lens is adjusted to a desired temperature. When the lens is heated, power is supplied to the heater. If the heater can be driven efficiently, the power consumption of the infrared lens module can be reduced.

  Therefore, an object of the present invention is to provide an infrared lens module capable of reducing power consumption.

  An infrared lens module according to the present invention includes a lens that transmits infrared rays, a lens barrel body that holds the lens, and a temperature adjustment device that adjusts the temperature of the lens. The lens barrel body is disposed so as to cover the cylindrical portion that contacts the lens and the first inner peripheral surface that is the inner peripheral surface of the cylindrical portion, and the emissivity is lower than the emissivity of the first inner peripheral surface. And a coating layer having two inner peripheral surfaces.

  According to such an infrared lens module, power consumption can be reduced.

2 is a schematic cross-sectional view showing a structure of an infrared lens module according to Embodiment 1. FIG. 6 is a schematic cross-sectional view showing a structure of an infrared lens module according to Embodiment 2. FIG. 6 is a schematic cross-sectional view showing a structure of an infrared lens module according to Embodiment 3. FIG. 6 is a schematic cross-sectional view showing a structure of an infrared lens module according to Embodiment 4. FIG. FIG. 10 is a schematic cross-sectional view showing the structure of an infrared lens module in a fifth embodiment. FIG. 10 is a schematic cross-sectional view showing the structure of an infrared lens module in a sixth embodiment. FIG. 10 is a schematic cross-sectional view showing the structure of an infrared lens module in a seventh embodiment. FIG. 10 is a schematic cross-sectional view showing the structure of an infrared lens module in an eighth embodiment. FIG. 10 is a schematic cross-sectional view showing the structure of an infrared lens module in a ninth embodiment. FIG. 10 is a schematic cross-sectional view showing the structure of an infrared lens module in a tenth embodiment. FIG. 22 is a schematic cross-sectional view showing the structure of an infrared lens module in an eleventh embodiment. FIG. 22 is a schematic cross-sectional view showing the structure of an infrared lens module according to Embodiment 12.

[Description of Embodiment of Present Invention]
First, embodiments of the present invention will be listed and described. The infrared lens module of the present application includes a lens that transmits infrared rays, a barrel main body that holds the lens, and a temperature adjustment device that adjusts the temperature of the lens. The lens barrel body is disposed so as to cover the cylindrical portion that contacts the lens and the first inner peripheral surface that is the inner peripheral surface of the cylindrical portion, and the emissivity is lower than the emissivity of the first inner peripheral surface. And a coating layer having two inner peripheral surfaces.

  When adjusting the temperature of the lens, if the lens is heated by the temperature adjusting device, the heat is also transmitted to the cylindrical portion that is included in the lens barrel body that holds the lens and contacts the lens. If the amount of heat released to the inner peripheral side of the lens barrel body is large, the amount of heat transferred to the cylindrical portion increases. As a result, the temperature adjustment of the lens becomes inefficient, and the power consumption in the infrared lens module increases. In the infrared lens module, the covering layer is disposed so as to cover the first inner peripheral surface which is the inner peripheral surface of the cylindrical portion, and has a second inner peripheral surface whose emissivity is lower than the emissivity of the first inner peripheral surface. Therefore, it is possible to reduce the amount of heat released to the inner peripheral side of the barrel main body. Therefore, when adjusting the temperature of the lens, the temperature adjustment device can be driven efficiently to reduce power consumption. As a result, such an infrared lens module can reduce power consumption.

  In the lens module, the emissivity of the second inner peripheral surface may be 0.7 or less. By doing so, power consumption can be reduced more efficiently. In order to further suppress the amount of heat released from the second inner peripheral surface, the emissivity of the second inner peripheral surface may be 0.5 or less, and the emissivity of the second inner peripheral surface is 0. .3 or less.

  In the infrared lens module, the cylindrical portion may be made of resin. By doing so, heat conduction to the cylindrical portion made of resin having a lower thermal conductivity than that of metal is suppressed, and adjustment of the temperature of the lens becomes easy.

  In the infrared lens module, the covering layer may be a cylindrical layer. By carrying out like this, a cylindrical layer can be prepared as a separate body and can be arranged so as to cover the first inner peripheral surface.

  In the infrared lens module, the coating layer may be made of metal. By doing so, it becomes easy to lower the emissivity of the second inner peripheral surface, and the amount of heat radiation to the inner peripheral side of the barrel main body can be efficiently suppressed.

  In the infrared lens module, the metal is aluminum, nickel, tin, chromium, copper, zinc, silver, gold, platinum, palladium, titanium, tungsten and iron, or a single metal, or aluminum, nickel, An alloy mainly composed of one of tin, chromium, copper, zinc, silver, gold, platinum, palladium, titanium, tungsten, and iron may be used. As a result, the emissivity of the second inner peripheral surface can be lowered more easily. Here, a main component means containing more than 50 mass% with respect to the whole.

  In the infrared lens module, the coating layer may be a vapor deposition layer. By carrying out like this, a coating layer can be arrange | positioned so that a 1st internal peripheral surface may be covered more easily.

  In the infrared lens module, the coating layer may be a plating layer. By doing so, the coating layer can be disposed so as to cover the first inner peripheral surface.

  In the infrared lens module, the coating layer may be made of a resin. Such a coating layer can also be employed.

  In the infrared lens module, the resin is a fluororesin, a nylon resin, a polyolefin resin, a styrene resin, a liquid crystal polymer, a PBT (Polybutylene terephthalate) resin, a polyamide resin, a PPS (Polyphenylene sulfide) resin, and a modified PPE (modified-polyphenylene ether) resin. At least one of the above may be included. More specifically, the resin to be used includes a fluororesin, a nylon resin, a polyolefin resin, a styrene resin, a liquid crystal polymer, a PBT (Polybutylene phthalate) resin, a polyamide resin, a PPS (Polyphenylene sulfide) resin, and a modified PPE (modified-polyphenylene ether) resin. Or a composite resin containing these as main components.

[Details of the embodiment of the present invention]
Next, an infrared lens module according to an embodiment of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
1 is a schematic cross-sectional view showing a cross section including the optical axis of the lens module according to Embodiment 1. FIG. Referring to FIG. 1, the lens module 1 according to the first embodiment includes a lens 10, a lens barrel 50, and a heater 61.

  The lens 10 is an infrared lens that transmits infrared light, more specifically, light having a wavelength of 8 μm to 14 μm. The material constituting the lens 10 is, for example, ZnS. The lens 10 includes a first lens surface 11, a second lens surface 12, and an outer peripheral surface 13. The first lens surface 11 includes a central region 11A that is a convex surface that is located at the center and intersects the optical axis C, and an outer edge region 11B that is a plane surrounding the central region 11A. The second lens surface 12 includes a central region 12A that is a concave surface that is located at the center and intersects the optical axis C, and an outer edge region 12B that is a plane surrounding the central region 12A.

  The lens barrel 50 includes a cap 20 and a lens barrel body 30. The cap 20 is cylindrical and has a shape in which a protruding portion 21 that protrudes radially inward is formed at one end. The cap 20 is made of a metal such as an aluminum alloy. A gap is formed between the inner peripheral surface 22 of the cap 20 and the outer peripheral surface 13 of the lens 10. Further, the lens holding surface 27 located at the end of the portion extending along the optical axis C from the protruding portion 21 of the cap 20 and the outer edge region 11B of the first lens surface 11 are in contact with each other. A gap is formed between the outer peripheral side of the region in contact with the outer edge region 11B in the protruding portion 21 and the outer edge region 11B. The cap 20 is fixed to the barrel main body 30 in a state where the end of the barrel main body 30 is fitted at the end opposite to the side on which the protruding portion 21 is formed.

  The lens barrel body 30 includes a cylindrical portion 31. The cylindrical part 31 has a cylindrical shape. The cylindrical portion 31 holds the lens 10 in contact with the outer edge region 12B and the outer peripheral surface 13 of the second lens surface 12 at the end. In the present embodiment, the cylindrical portion 31 is made of resin. Examples of the resin constituting the cylindrical portion 31 include a fluororesin, a nylon resin, a polyolefin resin, a styrene resin, a liquid crystal polymer, a PBT (Polybutylene terephthalate) resin, a polyamide resin, a PPS (Polyphenylene sulfide) resin, and a modified PPE (modified-polyphenylene ether). ) Resin or a composite resin containing these as main components. The lens 10 is held by the lens barrel 50 including the cap 20 and the lens barrel body 30 described above.

  A heater 61 as a temperature adjusting device for adjusting the temperature of the lens 10 is fixed to the outer peripheral surface 13 of the lens 10. A heater 61 is disposed in an annular space 28 that is inside a gap formed between the outer peripheral surface 13 of the lens 10 and the inner peripheral surface 22 of the cap 20. The heater 61 is disposed on the outer peripheral surface 13 of the lens 10 so as to extend along the circumferential direction. The heater 61 may be disposed so as to contact the outer peripheral surface 13 over the entire circumference. A wiring 62 is connected to the heater 61. The wiring 62 is connected to a power source (not shown). A heater 61 driven by electric power supplied from the power source via the wiring 62 adjusts the temperature of the lens 10 by heating the lens 10. The heater 61 is a film heater, for example.

  The lens barrel body 30 includes a coating layer 35 disposed so as to cover the first inner peripheral surface 36 that is the inner peripheral surface of the cylindrical portion 31. The covering layer 35 is made of metal. More specifically, the covering layer 35 is made of any one single metal of aluminum, nickel, tin, chromium, copper, zinc, silver, gold, platinum, palladium, titanium, tungsten, and iron, or aluminum, It consists of an alloy mainly composed of one of nickel, tin, chromium, copper, zinc, silver, gold, platinum, palladium, titanium, tungsten and iron. Here, a main component means containing more than 50 mass% with respect to the whole. Examples of the alloy include nichrome. The coating layer 35 is a vapor deposition layer. That is, the coating layer 35 is formed so as to contact the first inner peripheral surface 36 and cover the first inner peripheral surface 36 by vapor deposition. Note that in FIG. 1 to FIG. 12 below, the thickness of the covering layer 35 is greatly exaggerated for easy understanding.

  A second inner peripheral surface 37 that is an inner peripheral surface of the coating layer 35 is exposed to the inner peripheral side of the barrel main body 30. The emissivity of the second inner peripheral surface 37 is lower than the emissivity of the first inner peripheral surface 36. That is, the covering layer 35 has a second inner peripheral surface 37 having a lower emissivity than that of the first inner peripheral surface 36. The emissivity of the second inner peripheral surface 37 of the coating layer 35 is 0.7 or less.

  In the lens module 1 that is the infrared lens module according to the present embodiment, when the lens 10 is heated by the heater 61 when adjusting the temperature of the lens 10, it is included in the lens barrel body 30 that holds the lens 10. Heat is also transmitted to the cylindrical portion 31 that is in contact with the lens 10. If the amount of heat released to the inner peripheral side of the lens barrel body 30 is large, the amount of heat transferred to the cylindrical portion 31 increases. As a result, the temperature adjustment of the lens 10 becomes inefficient, and the power consumption in the lens module 1 increases. In the lens module 1, the lens barrel body 30 is disposed so as to cover the first inner peripheral surface 36 that is the inner peripheral surface of the cylindrical portion 31, and has a lower emissivity than the emissivity of the first inner peripheral surface 36. Since the covering layer 35 having the second inner peripheral surface 37 is included, it is possible to reduce the amount of heat released to the inner peripheral side of the barrel main body 30. Therefore, when the temperature of the lens 10 is adjusted, the heater 61 can be efficiently driven to reduce power consumption. As a result, such a lens module 1 can reduce power consumption.

  In the present embodiment, since the emissivity of the second inner peripheral surface 37 is 0.7 or less, the power consumption can be more efficiently reduced. In order to further suppress the amount of heat released from the second inner peripheral surface 37, the emissivity of the second inner peripheral surface 37 may be 0.5 or less, and the emissivity of the second inner peripheral surface 37 is further increased. May be 0.3 or less.

  In this Embodiment, since the cylindrical part 31 is resin, the heat conduction to the resin-made cylindrical part 31 with a small heat conductivity compared with a metal is suppressed. Therefore, the temperature of the lens 10 can be easily adjusted.

  In the present embodiment, since coating layer 35 is made of metal, it is easy to reduce the emissivity of second inner peripheral surface 37. Therefore, the amount of heat released to the inner peripheral side of the barrel main body 30 can be efficiently suppressed.

  In addition, about the coating layer 35, you may arrange | position not only to cover the 1st internal peripheral surface 36 of the cylindrical part 31, but to cover the whole exposed surface which the cylindrical part 31 exposes outside. Specifically, the covering layer 35 may be disposed so as to cover the outer peripheral surface of the cylindrical portion 31, the end portion of the cylindrical portion 31, the region in contact with the lens 10, and the region exposed to the annular space 28.

  In the present embodiment, since the coating layer 35 is a vapor deposition layer, the coating layer 35 can be arranged so as to cover the first inner peripheral surface 36 more easily.

  In the present embodiment, a heater 61 that adjusts the temperature of the lens 10 is fixed to the outer peripheral surface 13 of the lens 10. The heater 61 is installed outside the lens module 1, and the temperature of the lens 10 is heated by the heater 61 fixed to the lens 10 instead of adjusting the temperature of the lens 10 from the outside. It is easy to adjust. In the present embodiment, a gap is formed between the lens 10 and the lens barrel 50 (cap 20). Thereby, heat conduction with the cap 20 is suppressed, and adjustment of the temperature of the lens 10 is further facilitated.

  In the present embodiment, in the lens module 1, the emissivity of the surface of the cap 20 other than the surface exposed to the outside is preferably 0.7 or less. In the cap 20 of the present embodiment, a black alumite layer is formed on the inner peripheral surface 26 of the protruding portion 21, the end surface 25 on the protruding portion 21 side, and the outer peripheral surface 24, which are the surfaces exposed to the outside. The black alumite layer can be formed by introducing a black dye into the pores of the alumite layer (oxidized layer) formed by the alumite treatment after the alumite treatment (anodic oxidation treatment). By forming the black alumite layer, the emissivity of these surfaces, which are surfaces exposed to the outside, exceeds 0.7. On the other hand, at least a part of the lens holding surface 27 that is a surface that contacts the lens 10 of the protrusion 21 that is a surface other than the surface exposed to the outside in the cap 20, at least a part of the inner peripheral surface 22, and at least the inner surface 39. In some cases, the black alumite layer is not formed. In the lens holding surface 27, the inner peripheral surface 22 and the inner side surface 39, a metal such as an aluminum alloy which is a material constituting the cap 20 may be exposed, or a surface treatment layer having a lower emissivity than the black alumite layer. May be exposed. As a result, the emissivities of the lens holding surface 27, the inner peripheral surface 22 and the inner side surface 39 are 0.7 or less. Thereby, the amount of heat released from the cap 20 is reduced, and the adjustment of the temperature of the lens 10 is further facilitated. From the viewpoint of further facilitating the adjustment of the temperature of the lens 10, the emissivity is preferably 0.5 or less, and more preferably 0.3 or less.

(Embodiment 2)
Next, a second embodiment which is another embodiment will be described. FIG. 2 is a schematic cross-sectional view showing a cross section including the optical axis of the lens module according to the second embodiment.

  Referring to FIG. 2, the lens module 1 according to the second embodiment includes a lens 10, a lens barrel 50, and a heater 61.

  The lens 10 is an infrared lens that transmits infrared rays. The material constituting the lens 10 is, for example, ZnS. The lens 10 includes a first lens surface 11, a second lens surface 12, and an outer peripheral surface 13. The first lens surface 11 includes a central region 11A that is a concave surface that is located at the center and intersects the optical axis C, and an outer edge region 11B that is a plane surrounding the central region 11A. The second lens surface 12 includes a central region 12A that is a convex surface that is located at the center and intersects the optical axis C, and an outer edge region 12B that is a plane surrounding the central region 12A.

  The lens barrel 50 includes a cap 20 and a lens barrel body 30. The lens barrel body 30 includes a cylindrical portion 31. The cylindrical part 31 has a cylindrical shape. In the present embodiment, the cylindrical portion 31 is made of a metal such as an aluminum alloy. Between the first inner peripheral surface 36 of the cylindrical portion 31 and the outer peripheral surface 13 of the lens 10, there is a region where a gap is formed. In a region closer to the second lens surface 12 than a region where a gap is formed between the first inner peripheral surface 36 of the cylindrical portion 31 and the outer peripheral surface 13 of the lens 10, the first inner peripheral surface of the cylindrical portion 31. 36 and the outer peripheral surface 13 of the lens 10 are in contact with each other. The cylindrical portion 31 is formed with a protruding portion 31A that protrudes toward the inner peripheral side. The protruding portion 31A of the cylindrical portion 31 and the outer edge region 12B of the second lens surface 12 are in contact with each other. The cylindrical portion 31 holds the lens 10 in contact with the outer edge region 12B and the outer peripheral surface 13 of the second lens surface 12 at the end.

  The cap 20 has a cylindrical shape. The cap 20 is made of a metal such as an aluminum alloy. The cap 20 contacts the outer edge region 11B of the first lens surface 11 at one end surface. A gap is formed between the outer peripheral side of the region of the cap 20 that contacts the outer edge region 11B and the outer edge region 11B. In the cap 20, the cap 20 is fixed to the cylindrical portion 31 in a state where the cap 20 fits with the end of the cylindrical portion 31 in a region on the outer peripheral side of a region where a gap is formed between the outer edge region 11B. In this way, the lens 10 is held by the lens barrel 50.

  The lens barrel 50 includes a first outer peripheral portion 32 surrounding the outer periphery of the cylindrical portion 31 and a second outer peripheral portion 33 surrounding the outer periphery of the first outer peripheral portion 32. The 1st outer peripheral part 32 consists of resin, for example. The 2nd outer peripheral part 33 consists of metals, such as an aluminum alloy, for example.

  A heater 61 as a temperature adjusting device for adjusting the temperature of the lens 10 is fixed to the outer peripheral surface 13 of the lens 10. A heater 61 is disposed in an annular space 28 that is inside a gap formed between the outer peripheral surface 13 of the lens 10 and the inner peripheral surface 22 of the cap 20. The heater 61 is disposed on the outer peripheral surface 13 of the lens 10 so as to extend along the circumferential direction. The heater 61 may be disposed so as to contact the outer peripheral surface 13 over the entire circumference. A wiring 62 is connected to the heater 61. The wiring 62 is connected to a power source. A heater 61 driven by electric power supplied from the power source via the wiring 62 adjusts the temperature of the lens 10 by heating the lens 10. The heater 61 is a film heater, for example.

  The lens barrel body 30 includes a coating layer 35 disposed so as to cover the first inner peripheral surface 36 of the cylindrical portion 31. The covering layer 35 is made of metal. More specifically, the covering layer 35 is made of any one single metal of aluminum, nickel, tin, chromium, copper, zinc, silver, gold, platinum, palladium, titanium, tungsten, and iron, or aluminum, It consists of an alloy mainly composed of one of nickel, tin, chromium, copper, zinc, silver, gold, platinum, palladium, titanium, tungsten and iron. Examples of the alloy include nichrome. The coating layer 35 is a vapor deposition layer.

  The second inner peripheral surface 37 of the covering layer 35 is exposed on the inner peripheral side of the barrel main body 30. The emissivity of the second inner peripheral surface 37 is lower than the emissivity of the first inner peripheral surface 36. That is, the covering layer 35 has a second inner peripheral surface 37 having a lower emissivity than that of the first inner peripheral surface 36. The emissivity of the second inner peripheral surface 37 of the coating layer 35 is 0.7 or less.

  In the lens module 1 that is the infrared lens module according to the present embodiment, when the lens 10 is heated by the heater 61 when adjusting the temperature of the lens 10, it is included in the lens barrel body 30 that holds the lens 10. Heat is also transmitted to the cylindrical portion 31 that is in contact with the lens 10. If the amount of heat released to the inner peripheral side of the lens barrel body 30 is large, the amount of heat transferred to the cylindrical portion 31 increases. As a result, the temperature adjustment of the lens 10 becomes inefficient, and the power consumption in the lens module 1 increases. In the lens module 1, the second inner peripheral surface 37 is disposed so as to cover the first inner peripheral surface 36 that is the inner peripheral surface of the cylindrical portion 31, and has a lower emissivity than the emissivity of the first inner peripheral surface 36. Therefore, the amount of heat radiation to the inner peripheral side of the lens barrel body 30 can be reduced. Therefore, when the temperature of the lens 10 is adjusted, the heater 61 can be efficiently driven to reduce power consumption. As a result, such a lens module 1 can reduce power consumption.

  In the present embodiment, since the emissivity of the second inner peripheral surface 37 is 0.7 or less, the power consumption can be more efficiently reduced. In order to further suppress the amount of heat released from the second inner peripheral surface 37, the emissivity of the second inner peripheral surface 37 may be 0.5 or less, and the emissivity of the second inner peripheral surface 37 is further increased. May be 0.3 or less.

  In the present embodiment, since the cylindrical portion 31 is made of metal, high durability can be obtained.

  In the present embodiment, since coating layer 35 is made of metal, it is easy to reduce the emissivity of second inner peripheral surface 37. Therefore, the amount of heat released to the inner peripheral side of the barrel main body 30 can be efficiently suppressed.

  In the present embodiment, since the coating layer 35 is a vapor deposition layer, the coating layer 35 can be arranged so as to cover the first inner peripheral surface 36 more easily.

  In the lens module 1 that is the infrared lens of the present embodiment, a heater 61 that adjusts the temperature of the lens 10 is fixed to the outer peripheral surface 13 of the lens 10. It is easy to adjust the lens 10 to a desired temperature by heating the temperature of the lens 10 with a heater 61 fixed to the lens 10. In the present embodiment, since there is a region where a gap is formed between the lens 10 and the cylindrical portion 31, heat conduction between the lens 10 and the cylindrical portion 31 is suppressed, and the temperature of the lens 10 is adjusted. It has become even easier. Thus, the lens module 1 of the present embodiment is an infrared lens module in which the temperature of the lens 10 can be easily adjusted.

  In addition, in Embodiment 2, although the case where the cylindrical part 31 consists of metal was demonstrated, the cylindrical part 31 may consist of resin. By adopting a resin having a thermal conductivity smaller than that of the metal as a material constituting the cylindrical portion 31 that contacts the lens 10, the heat conduction with the cylindrical portion 31 is suppressed, and the temperature of the lens 10 is adjusted. Is even easier.

(Embodiment 3)
Next, Embodiment 3 which is another embodiment will be described. FIG. 3 is a schematic cross-sectional view showing a cross section including the optical axis of the lens module according to the third embodiment. With reference to FIG. 3, the lens module 1 according to the third embodiment includes a lens 10, a lens barrel 50, and a heater 61.

  The lens 10 is an infrared lens that transmits infrared light, more specifically, light having a wavelength of 8 μm to 14 μm. The material constituting the lens 10 is, for example, ZnS. The lens 10 includes a first lens surface 11, a second lens surface 12, and an outer peripheral surface 13. The first lens surface 11 includes a central region 11A that is a convex surface that is located at the center and intersects the optical axis C, and an outer edge region 11B that is a plane surrounding the central region 11A. The second lens surface 12 includes a central region 12A that is a concave surface that is located at the center and intersects the optical axis C, and an outer edge region 12B that is a plane surrounding the central region 12A.

  The lens barrel 50 includes a cap 20 and a lens barrel body 30. The lens barrel body 30 includes a cylindrical portion 31. The cylindrical part 31 has a cylindrical shape. The cylindrical portion 31 holds the lens 10 in contact with the outer edge region 12B and the outer peripheral surface 13 of the second lens surface 12 at the end. The lens 10 is held by the lens barrel 50 including the cap 20 and the lens barrel body 30.

  The lens barrel body 30 includes a coating layer 35 disposed so as to cover the first inner peripheral surface 36 of the cylindrical portion 31. The covering layer 35 is made of metal. More specifically, the covering layer 35 is made of any one single metal of aluminum, nickel, tin, chromium, copper, zinc, silver, gold, platinum, palladium, titanium, tungsten, and iron, or aluminum, It consists of an alloy mainly composed of one of nickel, tin, chromium, copper, zinc, silver, gold, platinum, palladium, titanium, tungsten and iron. Examples of the alloy include nichrome. The coating layer 35 is a vapor deposition layer.

  The second inner peripheral surface 37 of the covering layer 35 is exposed on the inner peripheral side of the barrel main body 30. The emissivity of the second inner peripheral surface 37 is lower than the emissivity of the first inner peripheral surface 36. That is, the covering layer 35 has a second inner peripheral surface 37 having a lower emissivity than that of the first inner peripheral surface 36. The emissivity of the second inner peripheral surface 37 of the coating layer 35 is 0.7 or less.

  The cap 20 is cylindrical and has a shape in which a protruding portion 21 that protrudes radially inward is formed at one end. The cap 20 is made of a metal such as an aluminum alloy. The inner peripheral surface 22 of the cap 20 and the outer peripheral surface of the lens 10 are in contact with each other. The protruding portion 21 of the cap 20 and the outer edge region 11B of the first lens surface 11 are in contact with each other. The cap 20 is disposed on one end side of the cylindrical portion 31. The cap 20 is fixed in contact with the cylindrical portion 31 at the end opposite to the side where the protruding portion 21 is formed. In this manner, the lens 10 is held by the lens barrel 50 while being sandwiched between the cylindrical portion 31 and the cap 20.

  An annular groove portion 23 is formed in the cap 20 so as to enter the axial direction from the end surface on the side opposite to the side on which the protruding portion 21 is formed. A heater 61 that controls the temperature of the lens 10 is installed inside the groove 23. The heater 61 is fixed in contact with the side wall of the groove 23. The heater 61 is disposed so as to extend along the circumferential direction of the annular groove 23. The heater 61 may be disposed so as to contact the entire circumference of the side wall of the groove 23. A wiring 62 is connected to the heater 61. The wiring 62 is connected to a power source. A heater 61 driven by electric power supplied from the power source via the wiring 62 adjusts the temperature of the lens 10 by heating the lens 10. The heater 61 is a film heater, for example.

  In the lens module 1 that is the infrared lens module according to the present embodiment, when the lens 10 is heated by the heater 61 when the temperature of the lens 10 is adjusted, the lens module 1 is included in the lens barrel body 30 that holds the lens 10. The heat is also transmitted to the cylindrical portion 31 that is in contact with the lens 10. If the amount of heat released to the inner peripheral side of the lens barrel body 30 is large, the amount of heat transferred to the cylindrical portion 31 increases. As a result, the temperature adjustment of the lens 10 becomes inefficient, and the power consumption in the lens module 1 increases. In the lens module 1, the second inner peripheral surface 37 is disposed so as to cover the first inner peripheral surface 36 that is the inner peripheral surface of the cylindrical portion 31, and has a lower emissivity than the emissivity of the first inner peripheral surface 36. Therefore, the amount of heat radiation to the inner peripheral side of the lens barrel body 30 can be reduced. Therefore, when the temperature of the lens 10 is adjusted, the heater 61 can be efficiently driven to reduce power consumption. As a result, such a lens module 1 can reduce power consumption.

  In the present embodiment, since the emissivity of the second inner peripheral surface 37 is 0.7 or less, the power consumption can be more efficiently reduced. In order to further suppress the amount of heat released from the second inner peripheral surface 37, the emissivity of the second inner peripheral surface 37 may be 0.5 or less, and the emissivity of the second inner peripheral surface 37 is further increased. May be 0.3 or less.

  In the present embodiment, since the cylindrical portion 31 is made of resin, heat conduction to the cylindrical portion 31 made of resin having a lower thermal conductivity than metal is suppressed, and the temperature of the lens 10 is adjusted. It becomes easy.

  In the present embodiment, a heater 61 that adjusts the temperature of the lens 10 is fixed in a groove 23 formed in the cap 20. By heating the temperature of the lens 10 with the heater 61 fixed to the cap 20, it is easy to adjust the lens 10 to a desired temperature.

  In the present embodiment, in the lens module 1, the emissivity of the surface of the cap 20 other than the surface exposed to the outside is preferably 0.7 or less. In the cap 20 of the present embodiment, a black alumite layer is formed on the inner peripheral surface 26 of the protruding portion 21, the end surface 25 on the protruding portion 21 side, and the outer peripheral surface 24, which are the surfaces exposed to the outside. The black alumite layer can be formed by introducing a black dye into the pores of the alumite layer (oxidized layer) formed by the alumite treatment after the alumite treatment (anodic oxidation treatment). By forming the black alumite layer, the emissivity of these surfaces, which are surfaces exposed to the outside, exceeds 0.7. On the other hand, a black alumite layer is formed on at least a part of the lens holding surface 27 and at least a part of the inner peripheral surface 22 of the cap 20 that is a surface other than the surface exposed to the outside. Is not formed. In the lens holding surface 27 and the inner peripheral surface 22, a metal such as an aluminum alloy that is a material constituting the cap 20 may be exposed, or a surface treatment layer having an emissivity lower than that of the black alumite layer is exposed. May be. As a result, the emissivities of the lens holding surface 27 and the inner peripheral surface 22 are 0.7 or less. Thereby, the amount of heat released from the cap 20 is reduced, and the adjustment of the temperature of the lens 10 is further facilitated. From the viewpoint of further facilitating the adjustment of the temperature of the lens 10, the emissivity is preferably 0.5 or less, and more preferably 0.3 or less.

(Embodiment 4)
Next, Embodiment 4 which is another embodiment will be described. FIG. 4 is a schematic cross-sectional view showing a cross section including the optical axis of the lens module in the fourth embodiment. Referring to FIGS. 4 and 3, lens module 1 in the fourth embodiment basically has the same configuration as in the third embodiment, and has the same effects. However, the lens module 1 according to the fourth embodiment is different from the third embodiment in the structure of the cylindrical portion 31.

  Referring to FIG. 4, cylindrical portion 31 of the fourth embodiment includes a protruding portion 34 that protrudes radially outward from an end portion on the side facing cap 20. Projection 34 covers the opening of groove 23 in the third embodiment (see FIGS. 3 and 4). As a result, the annular space 28 is formed by the groove 23 and the protrusion 34. In the present embodiment, the heater 61 is installed in the annular space 28. It is easy to adjust the lens 10 to a desired temperature by heating the temperature of the lens 10 with the heater 61 installed in the cap 20 in such a manner. In addition, since the protrusion 34 is formed, it is possible to prevent the heater 61 from dropping off.

(Embodiment 5)
Next, Embodiment 5 which is another embodiment will be described. FIG. 5 is a schematic cross-sectional view showing a cross section including the optical axis of the lens module according to the fifth embodiment. Referring to FIGS. 5 and 3, lens module 1 in the fifth embodiment basically has the same configuration as that in the third embodiment and has the same effects. However, the lens module 1 according to the fifth embodiment is different from the third embodiment in the structure of the cap 20.

  Referring to FIG. 5, cap 20 of the fifth embodiment includes a holding member 29A. In the present embodiment, a protruding portion that protrudes radially outward is formed at the end of the main body portion of the cap 20 opposite to the cylindrical portion 31. On the other hand, on the outer peripheral side of the main body portion, a holding member 29A having a hollow cylindrical shape and having a protruding portion that protrudes radially inward at the end portion on the cylindrical portion 31 side is disposed. Thereby, an annular space 28 is formed between the main body portion of the cap 20 and the holding member 29A. In the present embodiment, the heater 61 is installed in the annular space 28. The heater 61 is held from the outer peripheral side by the holding member 29A. It is easy to adjust the lens 10 to a desired temperature by heating the temperature of the lens 10 with the heater 61 installed in the cap 20 in such a manner. The holding member 29A may be made of a metal such as an aluminum alloy, or may be made of a resin. By adopting a metal as the material constituting the holding member 29A, high durability can be obtained. By adopting a resin having a low thermal conductivity as a material constituting the holding member 29A, it is easy to suppress heat dissipation from the cap 20 and adjust the lens 10 to a desired temperature.

(Embodiment 6)
Next, Embodiment 6 which is another embodiment will be described. FIG. 6 is a schematic cross-sectional view showing a cross section including the optical axis of the lens module in the sixth embodiment. Referring to FIGS. 6 and 5, lens module 1 in the sixth embodiment has basically the same configuration as in the fifth embodiment, and has the same effects. However, the lens module 1 of the sixth embodiment is different from that of the fifth embodiment in the structure of the cylindrical portion 31 and the cap 20 (holding member 29A).

  Referring to FIG. 6, lens barrel body 30 of the sixth embodiment includes a protruding portion 34 that protrudes radially outward from an end portion on the side facing cap 20. Further, the holding member 29A is not formed with a protruding portion as in the fifth embodiment, and the holding member 29A has a hollow cylindrical shape. Thereby, an annular space 28 is formed between the main body portion of the cap 20 and the holding member 29A. In the present embodiment, the heater 61 is installed in the annular space 28. The heater 61 is supported from the outer peripheral side by the holding member 29A. It is easy to adjust the lens 10 to a desired temperature by heating the temperature of the lens 10 with the heater 61 installed in the cap 20 in such a manner.

(Embodiment 7)
Next, Embodiment 7 which is another embodiment will be described. FIG. 7 is a schematic cross-sectional view showing a cross section including the optical axis of the lens module according to the seventh embodiment. 7 and 3, the lens module 1 according to the seventh embodiment has basically the same configuration as that of the third embodiment and has the same effects. However, the lens module 1 according to the seventh embodiment is different from the third embodiment in the structure of the cap 20.

  Referring to FIG. 7, cap 20 of the seventh embodiment includes a holding member 29B. In the present embodiment, a groove is formed on the inner peripheral surface of the cap 20, and a holding member 29B having a hollow cylindrical shape is disposed so as to cover the opening of the groove. Thereby, an annular space 28 is formed between the main body portion of the cap 20 and the holding member 29B. In the present embodiment, the heater 61 is installed in the annular space 28. The heater 61 is supported from the inner peripheral side by the holding member 29B. It is easy to adjust the lens 10 to a desired temperature by heating the temperature of the lens 10 with the heater 61 installed in the cap 20 in such a manner. The holding member 29B may be made of a metal such as an aluminum alloy, for example.

(Embodiment 8)
Next, an eighth embodiment, which is another embodiment, will be described. FIG. 8 is a schematic sectional view showing a section including the optical axis of the lens module according to the eighth embodiment. Referring to FIGS. 8 and 7, the lens module 1 according to the eighth embodiment basically has the same configuration as that of the seventh embodiment and has the same effects. However, the lens module 1 of the eighth embodiment is different from that of the seventh embodiment in the structure of the cylindrical portion 31 and the cap 20.

  Referring to FIG. 8, cylindrical portion 31 of the eighth embodiment includes a protruding portion 34 that protrudes radially outward from an end portion on the side facing cap 20. The cap 20 is not formed with a wall on the cylindrical portion 31 side of the groove as in the seventh embodiment. The holding member 29B has a hollow cylindrical shape as in the case of the seventh embodiment. Thereby, the annular space 28 surrounded by the main body portion of the cap 20, the holding member 29 </ b> B and the protruding portion 34 of the cylindrical portion 31 is formed. In the present embodiment, the heater 61 is installed in the annular space 28. The heater 61 is supported from the inner peripheral side by the holding member 29B. It is easy to adjust the lens 10 to a desired temperature by heating the temperature of the lens 10 with the heater 61 installed in the cap 20 in such a manner.

(Embodiment 9)
Next, Embodiment 9 which is another embodiment will be described. FIG. 9 is a schematic sectional view showing a section including the optical axis of the lens module according to the ninth embodiment. Referring to FIGS. 9 and 1, the lens module 1 according to the ninth embodiment basically has the same configuration as that of the first embodiment and has the same effects. However, the lens module 1 according to the ninth embodiment is different from the first embodiment in the arrangement of the heater 61.

  Referring to FIG. 9, the heater 61 of the ninth embodiment is installed on the inner peripheral surface 22 of the cap 20. It is easy to adjust the lens 10 to a desired temperature by heating the temperature of the lens 10 with the heater 61 installed in the cap 20 in such a manner.

(Embodiment 10)
Next, Embodiment 10 which is another embodiment will be described. FIG. 10 is a schematic cross-sectional view showing a cross section including the optical axis of the lens module according to the tenth embodiment. Referring to FIGS. 10 and 9, lens module 1 in the tenth embodiment has basically the same configuration as in the ninth embodiment and has the same effects. However, the lens module 1 of the tenth embodiment differs from the ninth embodiment in the arrangement of the heater 61.

  Referring to FIG. 10, heater 61 of the tenth embodiment is installed on the surface facing annular space 28 in protrusion 21 of cap 20 (the surface opposite to outer edge region 11 </ b> B as viewed from annular space 28). ing. It is easy to adjust the lens 10 to a desired temperature by heating the temperature of the lens 10 with the heater 61 installed in the cap 20 in such a manner.

(Embodiment 11)
Next, Embodiment 11 which is another embodiment will be described. FIG. 11 is a schematic sectional view showing a section including the optical axis of the lens module according to the eleventh embodiment. Referring to FIGS. 11 and 3, lens module 1 according to the eleventh embodiment has basically the same configuration as that of the third embodiment and has the same effects. However, the lens module 1 according to the eleventh embodiment is different from the third embodiment in the structure of the cap 20.

  Referring to FIG. 11, cap 20 of the eleventh embodiment includes a holding member 29C. In the present embodiment, the groove portion 23 is not formed in the cap 20. An annular holding member 29 </ b> C having an annular groove that opens toward the end surface is disposed on the end surface side opposite to the cylindrical portion 31 of the main body portion of the cap 20. The holding member 29C is disposed so that the opening of the groove of the holding member 29C is covered by the main body portion of the cap 20. Thereby, an annular space 28 is formed between the main body portion of the cap 20 and the holding member 29C. In the present embodiment, the heater 61 is installed in the annular space 28. Rather than installing the heater 61 outside the lens module 1 and adjusting the temperature of the lens 10 from the outside, the temperature of the lens 10 is heated by the heater 61 installed in the cap 20 in this manner. It is easy to adjust the lens 10 to a desired temperature. The holding member 29C may be made of a metal such as an aluminum alloy, or may be made of a resin. By adopting a metal as a material constituting the holding member 29C, high durability can be obtained. By adopting a resin having a low thermal conductivity as a material constituting the holding member 29C, it is easy to suppress heat dissipation from the cap 20 and adjust the lens 10 to a desired temperature.

  In the first to eleventh embodiments, an intermediate layer that contacts each other member may be formed between the cylindrical portion 31 and the covering layer 35 in the radial direction. Examples of the material of the intermediate layer include a single metal such as nickel, chromium, tin, zinc, titanium, and tungsten, or an alloy containing one of these as a main component. That is, when aluminum, copper, silver, gold, platinum, palladium, iron, or an alloy containing these as a main component is adopted as the covering layer 35, the first inner peripheral surface 36 of the cylindrical portion 31 made of resin is used. First, a layer made of a single metal of nickel, chromium, tin, zinc, titanium, tungsten, or an alloy containing one of these as a main component is first formed as an intermediate layer serving as a base. And on the surface of this intermediate layer, that is, on the inner peripheral surface side, the coating layer 35 is mainly composed of a single metal of aluminum, copper, silver, gold, platinum, palladium, iron, or one of these. An alloy may be formed.

  In Embodiments 1 to 11, the coating layer 35 is a vapor deposition layer. However, the present invention is not limited to this, and the coating layer 35 may be a plating layer. The plating layer is formed by, for example, electroless plating. By forming such a plating layer, the covering layer 35 can be disposed so as to cover the first inner peripheral surface 36. Examples of the material used for electroless plating include simple metals such as nickel, tin, copper, zinc, silver, gold, and palladium, or alloys containing one of these as a main component.

  In the first to eleventh embodiments, the coating layer 35 is made of metal. However, the invention is not limited thereto, and the coating layer may be made of resin. Such a coating layer can also be employed.

  As the resin to be adopted, at least one of a fluororesin, a nylon resin, a polyolefin resin, a styrene resin, a liquid crystal polymer, a PBT (Polybutylene terephthalate) resin, a polyamide resin, a PPS (Polyphenylene sulfide) resin, and a modified PPE (modified-Polyphenylene ether) resin. Or one of them. More specifically, the resin to be used includes a fluororesin, a nylon resin, a polyolefin resin, a styrene resin, a liquid crystal polymer, a PBT (Polybutylene phthalate) resin, a polyamide resin, a PPS (Polyphenylene sulfide) resin, and a modified PPE (modified-polyphenylene ether) resin. Or a composite resin containing these as main components.

(Embodiment 12)
Next, Embodiment 12 which is another embodiment will be described. FIG. 12 is a schematic sectional view showing a section including the optical axis of the lens module according to the twelfth embodiment. Referring to FIGS. 12 and 3, lens module 1 according to the twelfth embodiment has basically the same configuration as that of the third embodiment and has the same effects. However, the lens module 1 according to the twelfth embodiment is different from the third embodiment in the structure of the covering layer 35.

  Referring to FIG. 12, the lens barrel main body 30 is disposed so as to cover the first inner peripheral surface 36 that is the inner peripheral surface of the lens barrel main body 30, and has an emissivity higher than that of the first inner peripheral surface 36. A covering layer 35 having a low second inner peripheral surface 37 is included. The covering layer 35 is a cylindrical layer. The covering layer 35 is made of metal. The covering layer 35 forms, for example, a cylindrical layer made of an aluminum alloy as a separate body. The diameter of this cylindrical layer is slightly smaller than the diameter of the cylindrical portion 31. And the cylindrical layer manufactured separately is arrange | positioned at the inner peripheral side of the 1st inner peripheral surface 36. FIG. In this way, the coating layer 35 is formed.

  According to the present embodiment, a cylindrical layer can be prepared as a separate body and disposed so as to cover the first inner peripheral surface 36. Here, a radial gap may be formed between the outer peripheral surface 38 of the covering layer 35 and the first inner peripheral surface 36 of the cylindrical portion 31.

  In the twelfth embodiment, the covering layer 35 may be made of resin. Such a coating layer 35 can also be used. Examples of the separate cylindrical layer made of resin include non-colored resin.

(Embodiment 13)
Next, Embodiment 13 which is another embodiment will be described. Referring to FIG. 5, lens module 1 according to the thirteenth embodiment has basically the same configuration as that of the fifth embodiment and has the same effects. However, the lens module 1 according to the thirteenth embodiment is different from the fifth embodiment in the structure of the covering layer 35. The covering layer 35 in the thirteenth embodiment is a cylindrical layer. That is, the coating layer 35 in the thirteenth embodiment is the same as that shown in the twelfth embodiment. The covering layer 35 that is a cylindrical layer may be made of metal or resin. The specific metal employed is the same as that described in the first embodiment. The specific resin employed is the same as that described in the first embodiment.

(Embodiment 14)
Next, Embodiment 14, which is another embodiment, will be described. Referring to FIG. 6, lens module 1 according to the fourteenth embodiment has basically the same configuration as that of the sixth embodiment and has the same effects. However, the lens module 1 according to the fourteenth embodiment is different from the sixth embodiment in the structure of the covering layer 35. The covering layer 35 in the fourteenth embodiment is a cylindrical layer. That is, the covering layer 35 in the fourteenth embodiment is the same as that shown in the twelfth embodiment. The covering layer 35 that is a cylindrical layer may be made of metal or resin. The specific metal employed is the same as that described in the first embodiment. The specific resin employed is the same as that described in the first embodiment.

  In Embodiments 4 to 14 described above, the emissivity of the second inner peripheral surface 37 may be 0.5 or less in order to suppress the amount of heat released from the first inner peripheral surface 36. Further, the emissivity of the second inner peripheral surface 37 may be 0.3 or less.

(Modification)
In the above embodiment, the case where a heater (film heater) is adopted as the temperature adjustment device has been described. However, the temperature adjustment device that can be adopted is not limited to this, for example, a thin surface such as a rubber heater or a seat heater. A linear heater or a linear heater may be used. 1 to 12 each show only one lens 10, other lenses may exist behind the lens 10 (side facing the second lens surface 12). In the first and second embodiments, the case where the heater 61 as a temperature adjusting device is disposed (fixed) on the outer peripheral surface 13 of the lens 10 has been described. The apparatus may be arranged (fixed) in the outer edge region (outer edge region 11B, outer edge region 12B) of the lens surface.

  Further, in the above embodiment, the heater 61 as the temperature adjustment device is arranged so as to contact the lens 10 or the cap 20, but the temperature adjustment device is not limited to this. For example, a heater 61 as a temperature adjusting device may be disposed at a position separated from the lens 10 and the cap 20 without contacting both the lens 10 and the cap 20.

  It should be understood that the embodiments disclosed herein are illustrative in all respects and are not restrictive in any aspect. The scope of the present invention is defined by the scope of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the scope of the claims.

  The infrared lens module of the present application can be particularly advantageously applied when reduction of power consumption is required.

DESCRIPTION OF SYMBOLS 1 Lens module 10 Lens 11 1st lens surface 11A Central area | region 11B Outer edge area | region 12 2nd lens surface 12A Central area 12B Outer edge area | region 13 Outer peripheral surface 20 Cap 21 Protrusion part 22 Inner peripheral surface 23 Groove part 24 Outer peripheral surface 25 End surface 26 Inner peripheral surface 27 Lens holding surface 28 Annular space 29A Holding member 29B Holding member 29C Holding member 30 Lens barrel body 31 Cylindrical portion 31A Protruding portion 32 First outer peripheral portion 33 Second outer peripheral portion 34 Protruding portion 35 Cover layer 36 First inner peripheral surface 37 Second inner peripheral surface 38 Outer peripheral surface 39 Inner side surface 50 Lens barrel 61 Heater 62 Wiring

Claims (10)

A lens that transmits infrared rays;
A lens barrel body for holding the lens;
A temperature adjusting device for adjusting the temperature of the lens,
The lens barrel body is
A cylindrical portion in contact with the lens;
Including a coating layer that is disposed so as to cover the first inner peripheral surface that is the inner peripheral surface of the cylindrical portion and has a second inner peripheral surface that has a lower emissivity than the emissivity of the first inner peripheral surface; Infrared lens module. The infrared lens module according to claim 1, wherein the emissivity of the second inner peripheral surface is 0.7 or less. The infrared lens module according to claim 1, wherein the cylindrical portion is made of resin. The infrared lens module according to any one of claims 1 to 3, wherein the coating layer is a cylindrical layer. The infrared lens module according to claim 1, wherein the coating layer is made of metal. The metal is aluminum, nickel, tin, chromium, copper, zinc, silver, gold, platinum, palladium, titanium, tungsten, or iron alone, or aluminum, nickel, tin, chromium, copper The infrared lens module according to claim 5, which is an alloy mainly composed of one of zinc, silver, gold, platinum, palladium, titanium, tungsten and iron. The infrared lens module according to claim 5, wherein the coating layer is a vapor deposition layer. The infrared lens module according to claim 5, wherein the coating layer is a plating layer. The infrared lens module according to claim 1, wherein the coating layer is made of a resin. The resin is at least one of a fluororesin, a nylon resin, a polyolefin resin, a styrene resin, a liquid crystal polymer, a PBT (Polybutylene terephthalate) resin, a polyamide resin, a PPS (Polyphenylene sulfide) resin, and a modified PPE (modified-Polyphenylene ether) resin. The infrared lens module according to claim 9, including one.

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