JP6832588B2 - Optical system equipment - Google Patents

Description

The present invention relates to a technique for parallelizing and homogenizing the irradiation light emitted from a light source.

Conventionally, an ultraviolet light irradiation device using an ultraviolet light emitting element such as a large number of ultraviolet LEDs has been used for curing an ultraviolet curable resin, etc., so that the curing of the ultraviolet curable resin does not cause unevenness in curing. Therefore, it is required to have uniform illuminance on the irradiated surface. Further, when exposure is performed by LED light using a mask, a gap is generated between the exposure target and the mask, and the radiation angle of the LED light is about 120 °. Therefore, in order to improve the accuracy, the irradiation surface It is necessary to parallelize the irradiation light so that the irradiation light is perpendicular to the light. Generally, a parabolic mirror or the like is used for parallelizing the irradiation light.

A fly array lens or the like is generally used to make the illuminance uniform on the irradiation surface, and as a technique related to this, an LED array light source in which a plurality of light emitting elements are arranged on a plane and light emitted from each light emitting element are emitted. It has a first illumination optical system that collimates the light, a second illumination optical system that collects the light emitted from the first illumination optical system at the focal position, and a plurality of lenses arranged on a plane. 2 It is equipped with a fly-eye integrator that injects light emitted from the illumination optical system on the incident surface of each lens to improve the uniformity of illuminance, and the incident surface of the fly-eye integrator is the focal position of the second illumination optical system. The light emitting surface of each light emitting element has a conjugate relationship with the incident surface of the flyeye integrator, and an image of each light emitting element is formed on the incident surface of the flyeye integrator. An irradiation device is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-200787

When parallelizing the irradiation light and making the illuminance on the irradiation surface by the irradiation light uniform, both a device for making the illuminance uniform and a device for making the irradiation light parallel are required, which increases the size of the device. There was a problem.

The present invention has been made to solve the above-mentioned problems, and provides an optical system device and a biconvex lens that make the irradiation light parallel in a more space-saving manner and make the illuminance on the irradiation surface by the irradiation light uniform. With the goal.

In order to solve the above-mentioned problems, one aspect of the present invention is an optical system device that parallelizes the irradiation light emitted from the light source and makes the illumination on the irradiation surface by the irradiation light uniform, and irradiates the irradiation light. A biconvex lens provided in a direction, having a first surface located on the incident side in the irradiation direction and a second surface located on the exit side in the irradiation direction, and the second surface is incident. A biconvex lens formed with a radius of curvature that parallelizes the irradiation light, and the first surface has a radius of curvature that equalizes the illuminance on the irradiation surface due to the irradiation light emitted by the second surface, and the light source and both of the above. It is provided with an aperture that is arranged between the convex lens and allows a part of the irradiation light to pass through.

Further, one aspect of the present invention is a biconvex lens that parallelizes the incident irradiation light and equalizes the illuminance on the irradiation surface by the irradiation light, and has a first surface located on the incident side in the irradiation direction. Irradiation that has a second surface located on the emission side in the irradiation direction, the second surface is formed with a radius of curvature that parallelizes the incident irradiation light, and the first surface is emitted by the second surface. It is characterized in that it is formed with a radius of curvature that equalizes the illuminance on the surface irradiated by light.

According to the present invention, it is possible to parallelize the irradiation light in a more space-saving manner and to make the illuminance on the irradiation surface by the irradiation light uniform.

It is a schematic perspective view which shows the structure of the optical system apparatus which concerns on embodiment. It is a schematic side view which shows the structure of an optical system apparatus. It is a figure which shows the simulation result of ray tracing. It is a graph which shows the incoherent irradiance with respect to the X-axis coordinate of the irradiation surface. It is a graph which shows the relationship between the radius of curvature of the incident side on the 1st plane, and the lens diameter. It is a figure which shows the radius of curvature of the incident side corresponding to the lens diameter in the 1st surface.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, the optical system apparatus according to the present embodiment will be described. FIG. 1 is a schematic perspective view showing an optical system device according to the present embodiment. Further, FIG. 2 is a schematic side view showing the configuration of the optical system device. Note that FIG. 2 shows a cross section of the aperture and the light absorbing portion cut by a plane passing through the optical axis and parallel to the optical axis.

As shown in FIGS. 1 and 2, in the optical system device 1 according to the present embodiment, both the irradiation unit 10 which is an ultraviolet LED light source for irradiating ultraviolet light and the irradiation light by the irradiation unit 10 are arranged so as to be incidental. It includes a convex lens 20, an aperture 30 arranged on the irradiation unit 10 side between the irradiation unit 10 and the biconvex lens 20, and a light absorption unit 40 arranged on the biconvex lens 20 side between the irradiation unit 10 and the biconvex lens 20. .. According to the optical system device 1, the irradiation light emitted by the irradiation unit 10 forms an irradiation surface orthogonal to the optical axis direction of the biconvex lens 20.

The aperture 30 is a plate-shaped member having a plane orthogonal to the optical axis direction of the biconvex lens 20, and a hole portion 31 penetrating in the optical axis direction is formed. The hole portion 31 is formed in a circular shape so that the center of the circle coincides with the optical axis of the biconvex lens 20. According to such an aperture 30, a part of the irradiation light emitted by the irradiation unit 10 is emitted from the hole portion 31, and as a result, the size of the light source of the incident light with respect to the biconvex lens 20 is defined.

The light absorption unit 40 is a member formed in a hollow square cylinder shape and a light absorption surface is formed on the inner wall surface thereof, and is an incident side, that is, an irradiation unit 10 and an aperture 30 side, and an emission side, that is, a biconvex lens 20 side. Each of these openings is formed as an incident side opening 41 and an outgoing side opening 42. An aperture 30 is arranged in the light absorbing portion 40 so that only the irradiation light that has passed through the hole 31 is incident on the incident side opening 41. Further, the irradiation light emitted from the exit side opening 42 is incident on the biconvex lens 20. Further, the inner wall surface of the light absorption unit 40, that is, the light absorption surface has a remarkably low reflectance, preferably 4% or less, whereby the inner wall of the irradiation light incident on the light absorption unit 40 is irradiated. Most of the irradiated light is absorbed by the inner wall surface and is not emitted from the exit side opening 42. The light absorbing unit 40 is not limited to a hollow square tubular member, but as a tubular member opened on the incident side and the outgoing side, only the irradiation light incident at an angle that can be parallelized by the biconvex lens 20 is opened on the outgoing side. It suffices if it is formed so that it can be emitted from the portion 42. The length of the light absorbing portion 40 in the optical axis direction, that is, the distance from the incident side opening 41 to the emitting side opening 42 is a length based on the focal length of the biconvex lens 20.

The biconvex lens 20 is a biconvex lens, has a curved surface of a first surface 21 facing the incident side of the irradiation light and a second surface 22 facing the exit side, and the shapes of the first surface 21 and the second surface 22 are It's different. In the present embodiment, the first surface 21 and the second surface 22 are both formed to be aspherical in order to improve accuracy, but they may be formed to be spherical. The first surface 21 mainly has a function of equalizing the illuminance on the irradiation surface by the irradiation light emitted from the biconvex lens 20, and the second surface 22 has a function of parallelizing the irradiation light incident on the biconvex lens 20. Mainly has.

The radius of curvature r ₂ of the second surface 22, assuming the optical angle theta, the size of the light source (diameter of the hole 31) X, if the focal length of the biconvex lens 20 is f, the first surface 21 and flat and a f _{= r} 2/2 and also on the formation of the hole portion 31 so that X = 2, the formula of X × f × tanθ, i.e., from the equation _{r 2} × tan .theta, light angle θ Determined to stipulate. Here, the light angle θ is an angle formed by a perpendicular line orthogonal to the irradiation surface and the irradiation light emitted from the biconvex lens 20, and is ideal parallel light when θ = 0, but in practice. , For example, 1 °, which is set to a value as close to 0 as possible.

The radius of curvature r ₁ of the first surface 21, for light emitted from the second surface 22 formed to the radius of curvature r ₂ which is determined as described above, the illuminance portion distribution in the plane on which perpendicular to the optical axis and uniform Is determined to be. In other words, the radius of curvature r ₁ of the first surface 21 is to be based on the curvature radius r ₂ of the second surface.

Here, the relationship between the radius of curvature and the lens diameter on the first surface will be described. FIG. 5 is a graph showing the relationship between the radius of curvature on the incident side on the first surface and the lens diameter. FIG. 6 is a diagram showing the radius of curvature on the incident side corresponding to the lens diameter on the first surface.

As shown in FIG. 5, in the first surface 21 that equalizes the illuminance on the irradiation surface by the irradiation light emitted from the biconvex lens 20, r1 = between the radius of curvature r1 on the incident side and the lens diameter d. The formula 5.64 × d holds, and if this is a specific value, it will be shown in FIG. In practice, it is preferable that the radius of curvature r1 is such that the linear coefficient 5.64 in the above equation falls within the range of ± 15% on the first surface 21 having a certain lens diameter d.

Next, the effect of the optical system device will be described. FIG. 3 is a diagram showing a simulation result of ray tracing. Further, FIG. 4 is a graph showing the incoherent irradiance with respect to the X-axis coordinates of the irradiation surface. The X coordinate value in FIG. 4 is a value of one axis on the irradiation surface as a plane.

As shown in FIG. 3, according to the simulation result of ray tracing for the irradiation light in the optical system device 1, in the irradiation light irradiated by the irradiation unit, only the irradiation light that does not go toward the inner wall of the light absorption unit 40 is a biconvex lens. It can be seen that it is incident on 20 and parallelized.

Further, as shown in FIG. 4, according to the optical system device 1, it can be seen that the illuminance on the irradiation surface is made uniform by the first surface 21 of the biconvex lens 20.

The present invention can be practiced in various other forms without departing from its gist or main features. Therefore, the above embodiments are merely exemplary in all respects and should not be construed in a limited way. The scope of the present invention is shown by the scope of claims, and is not bound by the text of the specification. Moreover, all modifications, modifications, substitutions and modifications that fall within the equivalent scope of the claims are all within the scope of the present invention.

1 Optical system device 10 Irradiation unit 20 Biconvex lens 30 Aperture 40 Light absorption unit

Claims (2)

An optical system device that parallelizes the irradiation light emitted from a light source and makes the illuminance on the irradiation surface by the irradiation light uniform.
A biconvex lens arranged in the irradiation direction of the irradiation light, and a biconvex lens for chromatic a first surface located on the incident side in the irradiation direction, and a second surface located on the exit side in the radiation direction,
It is provided with an aperture that is arranged between the light source and the biconvex lens and allows a part of the irradiation light to pass through the hole.
The first surface is formed with a _{radius of curvature r 1} obtained by multiplying the diameter of the biconvex lens by a linear coefficient in the range of 4.794 to 6.486.
For the second surface, the radius of curvature of the second surface is r ₂ , the optical angle formed by the perpendicular line orthogonal to the emission surface of the light source and the emitted light emitted from the biconvex lens is θ, and the diameter of the hole is defined as θ. X, wherein when the focal length of the biconvex lens and the f = r _2/2, in terms of X × f was formed the size of the hole so that the r _2, in the formula of r ₂ × tanθ θ is An optical system device characterized in that it is formed with a radius of curvature of 1 or less. It is arranged between the aperture and the biconvex lens, and has an incident side opening on which the irradiation light passing through the aperture is incident and an exit side opening on which the irradiation light incident from the incident side opening is emitted. The optical system device according to claim 1 , further comprising a light absorber that is formed in a tubular shape that penetrates from the entrance side opening to the exit side opening and absorbs light on the inner wall surface.

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