TWI403816B - Method for assembling an ir-cut filter into a lens barrel - Google Patents

Abstract

The present invention relates to a method for assembling an IR-cut filter into a lens barrel. The method includes the steps of: providing a barrel module which includes a lens barrel and a spacer received in the lens barrel; providing an IR-cut filter and disposing the IR-cut filter into the lens barrel and adjacent to the spacer; providing a laser beam having a infrared wavelength to incident on the IR-cut filter, thereby the incident beam being reflected by the IR-cut filter and then striking on and heating a sidewall of the lens barrel to a softening temperature thereof; cooling the sidewall of the lens barrel.

Description

Assembly method of infrared filter in lens barrel

The invention relates to a method for assembling a filter, in particular to an assembly method of an infrared cut filter in a lens barrel.

With the development of optical imaging technology, lens modules are widely used in various imaging devices such as digital cameras and video cameras. Generally, the lens module includes optical elements such as a plurality of lenses, an aperture plate, and an infrared cut filter housed in the lens barrel, and a spacer for controlling the distance between the optical elements. During the assembly of the lens module, the optical components such as the plurality of lenses, aperture plates, and filters are sequentially housed in a lens barrel, and the infrared cut filter is adjacent to the filter. The lens is separated by a spacer. The infrared cut filter is glued to the spacer by a dispensing process.

In the assembly process of the infrared cut filter, the optical elements such as the complex lens and the aperture plate are usually first loaded into the lens barrel in a predetermined order and separated by a spacer; then, a spacer is provided, and the spacer is loaded into the lens barrel. And abutting against the optical component in the lens barrel; using a dispenser having a needle-like injection portion to apply glue to the outer circumference of one surface of the spacer away from the optical element in the lens barrel; The sheet is used to glue the infrared cut filter to the spacer.

However, in the above assembly method, the dispensing process of the dispenser is time consuming and the dispensing accuracy is difficult to control, so that uneven dispensing or insufficient dispensing is likely to occur, resulting in insufficient adhesion between the infrared cut filter and the spacer. .

In view of the above, it is necessary to provide an assembly method of an infrared cut filter in a lens barrel, which can quickly and accurately assemble an infrared cut filter into a lens barrel.

Hereinafter, a method for assembling an infrared cut filter in a lens barrel will be described by way of a specific embodiment, which can quickly and accurately assemble an infrared cut filter in a lens barrel.

A method for assembling an infrared cut filter in a lens barrel, comprising the steps of: providing a lens barrel assembly comprising a lens barrel and a spacer received in the lens barrel; providing an infrared cut filter to cut off the infrared The filter is received on the image side of the lens barrel and abuts against the spacer; and a laser beam having a wavelength within the filtering range of the infrared cut filter is provided to be incident at an acute angle with respect to a central axis of the lens barrel. On the infrared cut filter, and reflected by the infrared cut filter to the side wall of the lens barrel for heating the side wall of the irradiated lens barrel to a softening temperature; cooling the heated side wall of the lens barrel to filter the infrared cutoff The sheets are bonded and fixed.

Compared with the prior art, the method for assembling the infrared cut filter in the lens barrel irradiates the infrared cut filter with a laser beam having a wavelength within the filtering range of the infrared cut filter, and the infrared cut filter is filtered by the infrared cut filter The sheet is reflected to the side wall of the lens barrel to heat the side wall of the irradiated lens barrel to a softening temperature, and the infrared cut filter can be bonded and fixed after the side wall of the lens barrel is cooled. The assembly method of the infrared cut filter in the lens barrel can quickly and accurately assemble the infrared cut filter into the lens barrel.

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

The method for assembling the infrared cut filter in the lens barrel provided by the embodiment of the invention includes the following steps: Referring to FIG. 1 , a lens barrel assembly 10 is provided, which includes a lens barrel 12 and a first lens received in the lens barrel 12 . 14. The aperture sheet 16, the second lens 18, and the spacer 19.

In this embodiment, the lens barrel 12 includes a lens barrel front end 122 and a cylindrical body portion 124. The front end 122 of the lens barrel is integral with the main body portion 124, and the material thereof may be selected from engineering plastics such as polyethylene, polypropylene, polyvinyl chloride, and polystyrene. The barrel front end 122 is located at an object side end of the main body portion 124, and the barrel front end 122 has a funnel-shaped light entrance hole 1220 whose diameter gradually decreases from the object side to the image side. A thread 1240 is provided outside the main body portion 124. The first lens 14, the aperture sheet 16, the second lens 18, and the spacer 19 are accommodated in order from the object side to the image side in the main body portion 124.

Referring to FIG. 2, an infrared cut filter 20 is provided. The infrared cut filter 20 is received on the image side in the lens barrel 10 and abuts against the spacer 19.

In this embodiment, the infrared cut filter 20 includes a substrate 22 and a filter film 24 formed on a surface of the substrate 22. Preferably, after the infrared cut filter 20 is placed in the main body portion 124 of the lens barrel 10, one side of the filter film 24 faces and abuts against the spacer 19.

Referring to FIG. 3, a laser beam having a wavelength within the filtering range of the infrared cut filter 20 (shown by an arrow in FIG. 3) is provided, so that the laser beam is opposite to the central axis of the lens barrel 10 (as shown by the dotted line in FIG. 3). An angle θ is incident on the edge of the infrared cut filter 20 at an angle θ.

Generally, the infrared cut filter 20 has a filtering range of 700 to 1100 nanometers (nm). This laser beam is generated by a laser 30. The laser 30 can be an ytterbium-doped aluminum garnet (Nd-YAG) laser with a working wavelength of 1064 nm and a yttrium aluminum garnet (Yd-YAG) laser with a working wavelength of 940 nm. Or a vanadium hydride (Nd-Vanadate) laser with a working wavelength of 1047~1064 nm. The included angle θ is preferably greater than 0 degrees and less than 90 degrees, that is, an acute angle. In this embodiment, a laser beam is generated by using an ytterbium-doped aluminum garnet (Nd-YAG) laser having a working wavelength of 1064 nm, and the laser beam is incident at an angle of 45 degrees with respect to the central axis of the lens barrel 10 to The infrared cut filter 20 is on.

Referring to FIG. 4, the laser beam incident on the infrared cut filter 20 can be transmitted through the substrate 22 and reach the filter film 24. The laser beam is reflected by the filter film 24 and is adjacent to the body portion 124 of the substrate 22. The circumferential side of the wall exits, and the side wall portion of the barrel adjacent to the infrared cut filter 20 absorbs the energy of the laser beam and is heated to a softening temperature.

The heated barrel side wall is cooled to bond the infrared cut filter 20 to each other. The specific steps are: turning off the laser 30 and then allowing the side wall of the lens barrel heated to a softening temperature to cool naturally. After the side wall of the lens barrel is cooled, the circumferential side surface of the substrate 22 of the infrared cut filter 20 can be bonded to the side wall of the lens barrel, so that the infrared cut filter 20 can be assembled into the lens barrel 12.

It is to be understood that the lens barrel assembly 10 provided by the above method is not limited to the structure as described above, and for example, the barrel assembly 10 can also accommodate three or more lenses for optical imaging.

The method for assembling the infrared cut filter in the lens barrel provided by the embodiment, wherein the infrared cut filter 20 is irradiated by the laser beam having the wavelength within the filtering range of the infrared cut filter 20, and the infrared cut filter is 20 is reflected to the side wall of the lens barrel to heat the side wall of the irradiated lens barrel to a softening temperature, and the infrared cut filter 20 can be bonded and fixed after the side wall of the lens barrel is cooled. The assembly method of the infrared cut filter in the lens barrel can quickly and accurately assemble the infrared cut filter into the lens barrel.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art of the present invention should be included in the following claims.

Tube assembly. . . 10

Tube. . . 12

Front end of the lens barrel. . . 122

Into the light hole. . . 1220

Main body. . . 124

Thread. . . 1240

First lens. . . 14

Aperture piece. . . 16

Second lens. . . 18

Spacer. . . 19

Infrared cut filter. . . 20

Substrate. . . twenty two

Filter film. . . twenty four

Laser device. . . 30

FIG. 1 is a schematic structural view of a lens barrel assembly according to an embodiment of the present invention.

FIG. 2 is a schematic structural view of the lens barrel shown in FIG. 1 after the infrared cut filter is received.

Figure 3 is a schematic illustration of the use of a laser beam to illuminate an infrared cut filter.

Figure 4 is a schematic diagram of the direction of light propagation after the laser beam is incident on the infrared cut filter.

Infrared cut filter. . . 20

Substrate. . . twenty two

Filter film. . . twenty four

Laser device. . . 30

Claims (5)

A method for assembling an infrared cut filter in a lens barrel, comprising the steps of: providing a lens barrel assembly comprising a lens barrel and a spacer received in the lens barrel; providing an infrared cut filter to cut off the infrared The filter is received on the image side of the lens barrel and abuts against the spacer; and a laser beam having a wavelength within the filtering range of the infrared cut filter is provided to be incident at an acute angle with respect to a central axis of the lens barrel. On the infrared cut filter, and reflected by the infrared cut filter to the side wall of the lens barrel for heating the side wall of the irradiated lens barrel to a softening temperature; cooling the heated side wall of the lens barrel to filter the infrared cutoff The sheets are bonded and fixed. The method for assembling an infrared cut filter in a lens barrel according to the first aspect of the invention, wherein the infrared cut filter comprises a substrate and a filter film formed on a surface of the substrate, the filter film Abut against the spacer. The method for assembling an infrared cut filter in a lens barrel according to the first aspect of the invention, wherein the laser beam has a wavelength range of 700 to 1100 nm. The method for assembling an infrared cut filter in a lens barrel according to claim 1, wherein the laser beam is made of a yttrium aluminum garnet laser, a yttrium aluminum garnet laser or a vanadium vanadium The acid salt generator is produced. The method for assembling an infrared cut filter in a lens barrel according to the first aspect of the invention, wherein the angle is 45 degrees.