JP2008287121A - Lens unit for far-infrared camera and its manufacture method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens unit for a far-infrared camera whose cost is low and which has good optical characteristics by quickly fixing a component member such as a lens inserted in a lens barrel with a photosetting adhesive. <P>SOLUTION: The lens unit for the far-infrared camera is equipped with at least one or more far infrared transmission lens and a holding member which holds the lens inside. The holding member has a transmission part which transmits ultraviolet light or visible light for photosetting the photosetting adhesive. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens unit for a far-infrared camera having a lens in a lens barrel.

FIG. 1 is a cross-sectional view showing an example of the configuration of a typical camera lens unit. The lens unit 9 includes three lenses, a lens 1a, a lens 1b, and a lens 1c, a lens barrel 2 that fixes these lenses and blocks light from the side surface, and a fastening member 3 for fastening the lens 1a. For example, the lens 1 a is fastened and fixed by the lens barrel 2 and the fastening member 3 by the screw portion 4. Similarly, the lens 1b and the lens 1c are fixed (not shown).
As shown in FIG. 1, components such as a lens are arranged inside a lens barrel. For example, an in-vehicle camera is used in a severe environment where vibration resistance is required. It is necessary to fix with adhesive.

FIG. 2 is a cross-sectional view of the vicinity of the lens 1a and the fastening member 3 in FIG. 1, and a conventional method for bonding and fixing the lens and the lens barrel will be described with reference to FIG. The lens unit includes a lens 1a that transmits visible light and ultraviolet light 6, a lens barrel 2 that fixes the lens 1a and blocks unnecessary light from the outside, and a fastening member 3 that fastens the lens 1a.
In order to fix the lens 1 a, a light curable adhesive is applied to the lens 1 a or the lens barrel 2, and ultraviolet light or visible light 6 that is light for curing the adhesive 7 is irradiated from the light source 5 through the lens 1. Therefore, it can be cured in a short time and positioned with high accuracy.

  However, far-infrared camera lenses are made of germanium, zinc selenide, zinc sulfide, chalcogenide glass, etc. Generally, these materials do not transmit ultraviolet light or visible light, and therefore cannot be irradiated through the lens. Since the fastening member is made of a metal such as an aluminum alloy for reasons of accuracy and weight reduction, there is a problem in that it cannot be irradiated through the lens barrel or the fastening member and a photo-curing adhesive cannot be used.

  Therefore, in the case of a lens unit for a far-infrared camera, a lens or the like is generally bonded and fixed using a thermosetting adhesive or an anaerobic adhesive.

On the other hand, as a method of using a photocurable adhesive, there has been proposed a method of providing a through hole in a part of a lens fixing member in order to make light to be cured enter (Patent Document 1). FIG. 3 is an enlarged cross-sectional view of the vicinity of a portion where the lens barrel and the lens are in contact with each other in the lens aligning device using the method. A lens barrel 101 is fitted on the cradle 100, and a lens 102 is further fitted thereon, and a weight member 103 is placed on the cradle 100. The weight member 103 has an open portion 104 having substantially the same shape as the effective diameter of the lens 102 at the center and a hollow portion 105 having a diameter larger than that of the open portion 104 on the side in contact with the cradle 100. Further, when the weight member 103 is placed on the cradle 100 in which the lens barrel 101 is fitted, the lens 102 is exposed from the opening 104. Further, one end of the leaf spring 108 is fixed to the upper surface 105a of the hollow portion 105, and the free end of the leaf spring 108 is bent toward the lens 102 side. Since the free end of the leaf spring 108 is in contact with the edge 102 a of the lens 102 when the weight member 103 is placed, the lens 102 is fixed to the lens barrel 101 by the elastic force of the leaf spring 108. It is urged downward. A plurality of leaf springs 108 are attached to the weight member 103 in the circumferential direction around the central axis 106 of the lens 102. Further, the weight member 103 is provided with a through-hole 107 for dropping an adhesive into a gap portion between the lens barrel 101 and the lens 102. When the weight member 103 is placed on the cradle 100 in which the lens barrel 101 is fitted, a gap portion between the lens barrel 101 and the lens 102 is exposed from the through-hole 107.
Thus, the weight member 103 is vibrated by an actuator (not shown), thereby aligning the lens 102 while pressing the lens 102 in its own weight direction with an appropriate load. Thereafter, a photocurable adhesive is dropped from the through-hole 107 provided in the weight member 103, and further, the adhesive is cured by irradiating ultraviolet light from the through-hole 107, and the lens is bonded and fixed to the lens barrel. A method has been proposed. The weight member 103 is removed after the lens is fixed.
JP 2004-177422 A

  When heat-curing using a heat-curable adhesive, there is a problem that the curing speed is slow and it takes too much time to cure. Furthermore, since components such as the lens barrel and the lens are thermally expanded by heating, the lens and the lens barrel are decentered due to the influence, and there is a problem that the optical performance is deteriorated in the heat curing process.

  In addition, in the lens adjustment device described in Patent Document 1, a method has been proposed in which when a lens is aligned and fixed, a weighting member that fixes the lens is provided with a through-hole, and ultraviolet light is irradiated from there. However, it is necessary to provide a weight member and remove the weight member after fixing the lens, which complicates the process.

  The present invention has been proposed in view of such a conventional situation, and a component such as a lens inserted in a holding member is quickly and accurately aligned and bonded with a photo-curing adhesive. An object of the present invention is to provide a far infrared camera lens unit.

  In order to achieve the above object, a far-infrared camera lens unit according to the first invention is a far-infrared camera lens unit comprising at least one far-infrared transmitting lens and a holding member for holding the lens inside. The holding member has a transmission part that transmits ultraviolet light or visible light for curing the photocurable adhesive.

Here, the holding member is a structure that is a frame for holding and fixing the lens in a predetermined arrangement, and is made of a material that does not substantially transmit far infrared rays corresponding to the purpose of use of the lens. ing.
If a part of the lens holding member has a transmissive part that transmits ultraviolet light or visible light, the adhesive can be cured by irradiating the light through the transmissive part to a portion requiring adhesion. A lens unit for a far-infrared camera with high accuracy in time can be realized.

  A far-infrared camera lens unit according to a second invention is characterized in that, in the first invention, the holding member includes a lens barrel, and the transmitting portion is all or a part of the lens barrel.

If the entire lens barrel is made of a material that transmits ultraviolet light or visible light, the far-infrared rays can be obtained with high accuracy in a short time by irradiating the light through the lens barrel to cure the adhesive. A camera lens unit can be realized.
Furthermore, even if the transmission part through which the light is transmitted is provided only in a part of the lens barrel necessary for adhering and fixing a component such as a lens, high accuracy is achieved in a short time as in the case where the entire lens barrel is transparent. A lens unit for far infrared cameras can be realized.

  The far-infrared camera lens unit according to a third aspect of the invention is characterized in that, in the first aspect, the holding member includes a lens fastening member, and the transmitting portion is all or a part of the lens fastening member. .

The lens fastening member is used to fasten and fix the lens to the lens barrel with screws or the like provided on the lens barrel. If the lens fastening member is made of a material that transmits ultraviolet light or visible light necessary for curing the photo-curing adhesive, the adhesive is applied by irradiating the spot through the fastening portion to the place that requires adhesion. By curing, it is possible to realize a highly accurate far-infrared camera lens unit in a short time.
In addition, the transmission part through which the light passes may be only a part of the fastening member necessary for bonding and fixing the structural member such as a lens. An accurate far-infrared camera lens unit can be realized.
Furthermore, even if both the fastening member and the lens barrel have a transmission part through which the light passes, a highly accurate far-infrared camera lens unit can be realized in a short time.

  The far infrared camera lens unit according to a fourth aspect of the present invention is the lens unit according to any one of the first to third aspects, wherein the material constituting the transmission part is glass, fluorite, polystyrene, acrylic resin, polyvinyl chloride, polycarbonate. , Polyethylene terephthalate, polyethylene naphthalate or polypropylene.

  These amorphous resin materials transmit ultraviolet light or visible light, and pass light that cures the photo-curing adhesive, but do not transmit far infrared light. For example, a mirror of a lens unit for a far infrared camera. Even when used as a material for a tube, it can cut far-infrared rays from the outside and exhibit its original function as a lens barrel.

  According to a fifth aspect of the present invention, there is provided a far-infrared camera that captures an image formed by the far-infrared camera lens unit according to any one of the first to fourth aspects and the far-infrared camera lens unit. It is composed of elements. As a result, a highly accurate far-infrared camera can be obtained.

  An in-vehicle far-infrared camera system according to a sixth aspect of the invention includes the far-infrared camera according to the fifth aspect of the invention and an image sensor that picks up an image formed by the far-infrared camera lens unit. As a result, a highly accurate in-vehicle far infrared camera system can be obtained.

  The far infrared camera lens unit manufacturing method according to the seventh aspect of the invention includes a step of preparing a far infrared ray transmitting lens, a step of preparing a barrel having a transmission part that transmits ultraviolet light or visible light, A step of applying a photocurable adhesive to at least one of an infrared lens and the lens barrel; and curing the photocurable adhesive by irradiating ultraviolet light or visible light through a transmission portion of the lens barrel, thereby far infrared rays. And fixing the lens to the lens barrel, whereby the far-infrared camera lens unit is manufactured.

  Furthermore, the manufacturing method of the far-infrared camera lens unit according to the eighth invention includes a step of preparing a far-infrared transmitting lens, a step of preparing a lens barrel, and a lens fastening having a transmission part that transmits ultraviolet light or visible light. A step of preparing a member, a step of applying a photocurable adhesive to at least one of the far-infrared lens, the lens barrel, and the lens fastening member, and ultraviolet light or visible light through a transmission part of the lens fastening member. Irradiating to cure the photo-curing adhesive and fixing the far-infrared lens to the lens barrel or the lens clamping member, whereby the far-infrared camera lens unit is manufactured. The

  According to the present invention, a lens unit for a far-infrared camera, a far-infrared camera, and a vehicle-mounted far-field camera that can fix a component such as a lens in a lens barrel in a short time using a photocurable adhesive, and have high-precision optical characteristics. An infrared camera system can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described by way of examples. In addition, an Example does not limit the scope of the present invention.

(Embodiment 1)
FIG. 4 is a sectional view of the lens unit in the vicinity of the lens and the fastening member. In the present embodiment, the lens 1a is a far infrared lens having a transmission wavelength of 8 to 12 μm. For this reason, germanium, zinc selenide, zinc sulfide, chalcogenide glass, or the like is used as the lens material, and hardly transmits ultraviolet light or visible light.
Further, since the lens barrel 2 is made of a material that transmits ultraviolet light and visible light but does not transmit far-infrared light, the original function of suppressing the entry of far-infrared light from the outside can be exhibited. Examples of the material constituting the lens barrel include amorphous resin materials such as glass, polystyrene, methacrylic resin, polyvinyl chloride, and polycarbonate, and materials that do not transmit far infrared rays but transmit ultraviolet light or visible light. For example, other materials may be used as long as the effect of the present invention is obtained.

Here, in order to fix the lens, the photocurable adhesive 7 is applied to the lens barrel 2 or the lens 1a, and then the ultraviolet light or the visible light 6 emitted from the light source 5 is irradiated from the outside of the lens barrel 2. Thus, the photocurable adhesive 7 can be cured to fix the lens 1 a to the lens barrel 2.
In addition, as a photocurable adhesive used, what is generally marketed, such as an acrylic adhesive, can be used.

  FIG. 5 is a cross-sectional view of the lens unit and the vicinity of the fastening member when the photocurable adhesive is applied to the upper part of the lens end surface. In this way, even if the position where the photocurable adhesive 7 is applied is different, it can be fixed in the same manner as long as the light can reach from the lens barrel 2. The lens 1 a is normally fixed to the lens barrel 2, but may be fixed to the clamping member 3 or may be fixed to both the lens barrel 2 and the clamping member 3.

  Although Embodiment 1 is an example of fixing a lens, it goes without saying that other optical components other than the lens, such as a spacer for adjusting the distance between a plurality of lenses, can be similarly fixed. Furthermore, the lens barrel and the lens may be similarly bonded and fixed via an inclusion.

(Embodiment 2)
FIG. 6 is a cross-sectional view of the vicinity of a lens and a fastening member in a lens unit when a part of the lens barrel has a transmission part. In the present embodiment, the material of the lens barrel 2 is based on an aluminum alloy, and has a transmission part 8 when the light is transmitted only to a part that irradiates light for curing the photocurable adhesive 7. .
The transmitting portion 8 may be a minimum area necessary for fixing the lens 1 a with the adhesive 7, and may be provided in the circumferential direction of the lens barrel 2 or in spots.
As described above, in the far-infrared camera lens according to the second embodiment, even if a part of the lens barrel through which the light used for curing the photo-curing adhesive is transmitted is a part, the function and effect are the same as those of the first embodiment. This is the same as the function and effect of the far infrared camera lens unit.

(Embodiment 3)
FIG. 7 is a cross-sectional view of the lens unit and the vicinity of the fastening member when the fastening member is transparent to ultraviolet light or visible light. In this embodiment, the fastening member 3 of the lens 1a only needs to be made of a material that transmits ultraviolet light or visible light. Examples of the material constituting the lens barrel include glass, polystyrene, methacrylic resin, polyvinyl chloride, and polycarbonate. If the material does not transmit far infrared rays but transmits ultraviolet light or visible light, the effect of the present invention is achieved. Other materials may be used as long as there is. By using such a material, it can be similarly fixed by irradiating the light source 5 with ultraviolet light or visible light 6 for curing the photocurable adhesive 7 through the fastening member 3.

  Further, even if the fastening member 3 is not entirely made of a transparent material, for example, an aluminum alloy is used as a base, and ultraviolet light or light is irradiated only on a portion that is irradiated with light for curing the photocurable adhesive as described above. It may have a transmission part made of a material that transmits visible light.

  Furthermore, if the transmittance of ultraviolet light or visible light of the transmission part of the lens barrel or the fastening member is 1%, curing can be performed by adjusting the energy density and time of the irradiation light.

(Embodiment 4)
Next, the case where the far-infrared camera lens unit according to this embodiment is applied to a far-infrared camera will be described. FIG. 8 is a schematic diagram showing the structure of a far-infrared camera according to Embodiment 4 of the present invention. The far-infrared camera includes a far-infrared camera lens unit 9, an image sensor 10, a signal processing unit 11, an image memory 12, and a communication interface 13.

  By constructing a far-infrared camera using the far-infrared camera lens unit 9 that is aligned and fixed with high accuracy according to the present embodiment as described above, an object in front of the vehicle at night or the like can be used as an in-vehicle camera, for example. By receiving far-infrared rays emitted by (people etc.), a far-infrared image in front of the vehicle can be taken with high accuracy.

(Embodiment 5)
Next, the case where the far-infrared camera lens unit according to the present embodiment is applied to an in-vehicle in-vehicle far-infrared camera system will be described. FIG. 9 is a schematic plan view of a vehicle equipped with an in-vehicle far-infrared camera system according to Embodiment 5 of the present invention as viewed from above. The in-vehicle far-infrared camera system is visible from a far-infrared camera 14 installed at the front end of a vehicle, a control unit 15 that displays an image captured by the far-infrared camera on a display unit, and a driver's seat in the passenger compartment. And a display unit 16 including a liquid crystal display device provided at a position.

  In this way, by constructing an in-vehicle far-infrared camera system using the lens unit for far-infrared camera that is aligned and fixed with high accuracy according to the present embodiment, an image having high resolution and bright and high contrast can be obtained. It is done. This makes it possible to recognize a person in the image even in the summer when the image is bright in summer (even in the case of a summer image, the luminance difference between the background and a person (pedestrian, etc.) is small). .

  Although the embodiments and examples of the present invention have been described above, the embodiments and examples of the present invention disclosed above are merely examples, and the scope of the present invention is the implementation of these inventions. It is not limited to the form. The scope of the present invention is defined by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  The far-infrared camera lens unit of the present invention can be used for a far-infrared camera for confirming an obstacle at night or a vehicle-mounted far-infrared camera system of an automobile.

It is sectional drawing which shows the structure of a typical camera lens unit. It is sectional drawing which shows the structure of the typical camera lens unit, and is sectional drawing of the lens 1a and the fastening member 3 vicinity in FIG. It is an expanded sectional view of the vicinity of a portion where a lens barrel and a lens are in contact in a conventional lens alignment device. It is sectional drawing of the lens of the far-infrared lens unit in Embodiment 1 of this invention, and the fastening member vicinity. It is sectional drawing of the lens of the far-infrared lens unit in Embodiment 1 of this invention, and the fastening member vicinity. It is sectional drawing of the lens and fastening member vicinity of the lens unit for far infrared rays in Embodiment 2 of this invention. It is sectional drawing of the lens and fastening member vicinity of the lens unit for far infrared rays in Embodiment 3 of this invention. It is a schematic diagram showing the structure of the far-infrared camera in Embodiment 4 of this invention. It is the plane schematic diagram which looked at the vehicle carrying the vehicle-mounted far-infrared camera system in Embodiment 5 of this invention from the upper part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens 2 Lens barrel 3 Fastening member 4 Screw part 5 Light source 6 Ultraviolet light or visible light 7 Photocurable adhesive 8 Transmission part 9 Lens unit for far-infrared cameras 10 Imaging element 11 Signal processing part 12 Image memory 13 Communication interface part 14 Far-infrared camera 15 Control unit 16 Display unit 100 Receiving base 101 Lens tube 102 Lens 102a Lens peripheral portion 103 Weight member 104 Opening portion 105 Hollow portion 105a Hollow portion upper surface 106 Center shaft 107 Through port 108 Leaf spring

Claims (8)

A far-infrared camera lens unit comprising at least one or more far-infrared transmitting lenses and a holding member for holding the lens therein,
The lens unit for a far-infrared camera, wherein the holding member has a transmission part that transmits ultraviolet light or visible light for curing the photocurable adhesive. The far-infrared camera lens unit according to claim 1,
The holding member includes a lens barrel,
The far-infrared camera lens unit, wherein the transmission part is all or a part of the lens barrel. The far-infrared camera lens unit according to claim 1,
The holding member includes a lens fastening member,
The far-infrared camera lens unit, wherein the transmission part is all or part of the lens fastening member. The far-infrared camera lens unit according to any one of claims 1 to 3,
A far infrared camera lens unit, characterized in that the material constituting the transmission part is glass, fluorite, polystyrene, acrylic resin, polyvinyl chloride, polycarbonate, polyethylene terephthalate, polyethylene naphthalate or polypropylene. The far-infrared camera lens unit according to any one of claims 1 to 4,
An image sensor that captures an image formed by the far-infrared camera lens unit;
A far-infrared camera comprising: A far-infrared camera according to claim 5;
Display means for displaying an image captured by the far-infrared camera;
A vehicle-mounted far-infrared camera system comprising: Preparing a far infrared transmission lens;
Preparing a lens barrel having a transmission part that transmits ultraviolet light or visible light;
Applying a photocurable adhesive to at least one of the far-infrared lens and the lens barrel;
Irradiating ultraviolet light or visible light through the transmission part of the lens barrel to cure the photocurable adhesive and fixing the far-infrared lens to the lens barrel;
For manufacturing a lens unit for a far-infrared camera. Preparing a far infrared transmission lens;
Preparing a lens barrel; and
Preparing a lens clamping member having a transmission part that transmits ultraviolet light or visible light;
Applying a photocurable adhesive to at least one of the far-infrared lens, the lens barrel, and the lens clamping member;
Irradiating ultraviolet light or visible light through the transmission part of the lens fastening member to cure the photocurable adhesive and fixing the far-infrared lens to the lens barrel or the lens fastening member;
For manufacturing a lens unit for a far-infrared camera.

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