JP3030106U - Irradiation optical system - Google Patents

Abstract

(57) An object of the present invention is to provide an irradiation optical system capable of rapidly changing the irradiation area without increasing the manufacturing cost, and without changing the irradiation distance, which enables irradiation with uniform intensity. SOLUTION: In an irradiation optical system including a light source, an optical fiber, a light beam homogenizing means, and an imaging lens, a plurality of the light beam homogenizing means are arranged, and the plurality of light flux homogenizing means are used for the light of the imaging lens. It can move in the direction orthogonal to the axis.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to an optical system that uniformly and strongly illuminates a specific area. Such an optical system is used, for example, in the work of curing an adhesive using ultraviolet light. It is also used to illuminate an object in order to capture the image of the object and perform image processing.

[0002]

[Prior art]

 In the irradiation optical system used in the above fields, firstly, it is necessary to irradiate only a specific area. Irradiating an unnecessary area causes unnecessary adhesion and causes flare harmful to image processing.

Secondly, it is necessary to irradiate the specific region with uniform light. This is because if the irradiation unevenness is large, adhesion will be insufficient and the dynamic range of image processing will be reduced.

Third, it is necessary to irradiate with intense light. This is because the process can be completed in a shorter time as the irradiation light is stronger, whether it is adhesion or image input.

In order to meet such a demand, for example, an optical system as shown in FIG. 4 is conventionally known as an optical system for irradiating a rectangular area. That is, it is an irradiation optical system including a light source 1, an optical fiber 2, a light beam homogenizing means 3, and an imaging lens 4. As the light beam equalizing means 3, for example, a transparent body such as glass or quartz cut into a rectangular parallelepiped shape is used. The light beam emitted from the optical fiber 2 is repeatedly totally reflected inside the glass to uniformly illuminate the rectangular emission end. Then, the imaging lens 4 makes the exit end of the light beam homogenizing means 3 and the irradiation surface conjugate, so that the irradiation surface is also irradiated with uniform intensity. Here, the mask 9 prevents the electronic component 6 from being irradiated with useless light.

When illuminating the outer frame of the rectangular area, the configuration as shown in FIG. 5 may be used. This is such that the optical fiber emitting end 22 has a frame shape as shown in FIG. 6 and the light flux uniformizing means 3 also has a frame shape as shown in the sectional view of FIG.

[0007]

[Problems to be solved by the device]

 However, there is a case where the irradiation area needs to be changed regardless of whether the object to be irradiated is changed, whether it is adhesion or image processing. In order to cope with this with the conventional irradiation optical system, it is necessary to change the light beam homogenizing means 3 or the imaging magnification of the imaging lens 4.

However, this has the following problems. First, when changing the light beam homogenizing means 3, it is necessary not only to manufacture a new light beam homogenizing means 3 but also to replace it with a previously used one. In other words, not only is the manufacturing cost greatly increased, but also rapid changes cannot be made. Secondly, when the imaging magnification of the imaging lens 4 is changed, not only the irradiation distance changes but also the distortion aberration of the imaging lens 4 usually changes, so that irradiation with uniform intensity cannot be performed. is there. The change of the irradiation distance not only requires the moving mechanism of the imaging lens 4, but also increases the installation volume of the irradiation optical system.

Therefore, the present invention provides an irradiation optical system capable of rapidly changing the irradiation area without increasing the manufacturing cost, and also capable of performing irradiation with uniform intensity without changing the irradiation distance. It is an issue.

[0010]

[Means for Solving the Problems]

 In the irradiation optical system including the light source 1, the optical fiber 2, the light beam homogenizing means 3, and the imaging lens 4, a plurality of the light beam homogenizing means are arranged, and the plurality of light flux homogenizing means are provided in the imaging lens 4. It is movable in the direction orthogonal to the optical axis of.

[0011]

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows an irradiation optical system according to the present invention. It is used to bond electronic components with ultraviolet light. The light source 1 has a built-in ultra-high pressure mercury lamp and focuses ultraviolet light on the incident end face of the optical fiber 2. The optical fiber 2 is branched into four, and each output end face 21 thereof has a line shape of 0.5 mm × 4 mm. As a result, the ultraviolet light is guided to the four flat light beam homogenizing means 31, 32, 33, 34.

The light beam homogenizing means 31 is in the shape of a rectangular parallelepiped and can be made of quartz in order to transmit ultraviolet light without loss. Its cross section is 1 × 5 mm and its length is 50 mm. The light incident on the light beam homogenizing means 31 repeats total reflection inside the quartz. As shown in FIG. 2, the exit side 311 of the light beam homogenizing means 31 is cut at 45 °, and a thin film of aluminum is vapor-deposited on its slope. Therefore, the light is bent at a right angle on this slope and is emitted from the lower surface 312 of the light beam homogenizing means 31. By this time, the luminous flux repeats total reflection inside the luminous flux homogenizing means, and has a uniform distribution at the lower surface outlet 312. The same applies to the other light flux uniformizing means 32, 33, 34.

The imaging lens 4 projects the images of the emission end faces 312, 322, 332, 342 of the light beam homogenizing means 31, 32, 33, 34 on the irradiation surface 5. The projection lens 4 is sufficiently corrected for the distortion difference and uniformly irradiates the specific regions 51, 52, 53 and 54 of the irradiation surface 5. An electronic component 6 and a substrate 7 are installed on the irradiation surface 5, and an adhesive 8 which is cured by ultraviolet light is applied between them. Therefore, the adhesive 8 is cured by the irradiation of ultraviolet light from the irradiation optical system.

Here, since the irradiation optical system irradiates only the specific regions 51, 52, 53, 54 of the outer frame of the electronic component 6, it does not unintentionally cure the other regions. Further, the electronic component 6 is not unnecessarily damaged by the ultraviolet light.

When the size of the electronic component 6 is changed after the above bonding work is continued, the optical system according to the present invention functions as follows. Figure 3 shows the situation. That is, the light beam homogenizing means 31, 32, 33, 34 are moved in the arrow direction in FIG. 3 manually or by a motor. Then, the emission end face 312 and the like of the light beam homogenizing means 31 and the like move in the direction orthogonal to the optical axis of the imaging lens 4. As a result, the irradiation area also moves and new specific areas 55, 56, 57 and 58 are irradiated. A light-shielding plate 313 is installed on the lower surface of the light beam homogenizing means 31 to block light from the end portion of the light flux uniformizing means 32, which exits from the lower surface outlet 322. As a result, the irradiation surface is prevented from being irradiated in a cross beam shape, and is irradiated in a square shape.

[0016]

[Effect of device]

 The irradiation optical system according to the present invention can change the irradiation area by simply moving the parts without replacing the parts. Therefore, not only does the manufacturing cost of the irradiation optical system increase, but also rapid changes are possible. Moreover, since the imaging lens 4 does not need to move at all, the irradiation distance is not changed, and irradiation with uniform intensity is secured. Therefore, not only is a mechanism for changing the irradiation distance unnecessary, but the irradiation intensity per unit area does not change.

[Brief description of drawings]

FIG. 1 is a perspective view of a case where an irradiation optical system according to the present invention irradiates a large electronic component.

FIG. 2 is a side view of an irradiation optical system according to the present invention.

FIG. 3 is a perspective view of a case where the irradiation optical system according to the present invention irradiates a small electronic component.

FIG. 4 is a perspective view of a conventional irradiation optical system using a rectangular parallelepiped light beam homogenizing means.

FIG. 5 is a perspective view of a conventional irradiation optical system using a frame-shaped light beam homogenizing means.

FIG. 6 is an emission end shape of an optical fiber used for introducing light into a frame-shaped light beam homogenizing means.

FIG. 7 is a cross-section of a frame-shaped light beam homogenizing means.

[Explanation of symbols]

 1: Light source 2: Optical fiber 3: Luminous flux uniformizing means 4: Imaging lens 5: Irradiation surface

Claims (1)

[Scope of utility model registration request] 1. An irradiation optical system comprising a light source, an optical fiber, a light beam homogenizing means, and an imaging lens, wherein a plurality of the light beam homogenizing means are arranged and the plurality of light beam homogenizing means are provided in the imaging lens. An irradiation optical system characterized by being movable in a direction orthogonal to the optical axis.