TW201504681A - Light irradiation device - Google Patents

Abstract

A light irradiation device which can simultaneously irradiate an annular illumination area using only one light source is disclosed. The light irradiation device for irradiating light to the annular illumination area placed in designated position includes an LED unit emitting light; a first lens having an optical axis in common with the LED unit, narrowing the spread angle of the light emitted from the LED unit and forming into the light having a predetermined spreading angle; a second lens having an optical axis in common with the first lens, and refracting the light transmitted through the first lens to provide an annular light around the optical axis; and a third lens having an optical axis in common with the second lens and focusing the light transmitted through the second lens to the annular illumination area.

Description

Light irradiation device

The present invention relates to a light irradiation device which can illuminate an object to be irradiated with annular ultraviolet light.

In the past, ultraviolet curable resins have been widely used for attaching optical components such as plastic lenses to optical components such as lens holders. Such an ultraviolet curable resin is designed to be cured by irradiation with ultraviolet light having a wavelength of about 365 nm, and an ultraviolet light irradiation device (that is, an ultraviolet irradiation device) is used for curing the ultraviolet curable resin.

As an ultraviolet irradiation device, a lamp type irradiation device using a high-pressure mercury lamp or a mercury xenon lamp as a light source has been known. However, in recent years, in order to reduce the power consumption, the long life, and the miniaturization of the device, the ultraviolet ray irradiation device using LED (Light Emitting Diode) as a light source has been put into practical use in place of the conventional discharge lamp (for example, Patent Literature) 1-Japanese Patent No. 4303582).

Generally, when an optical component such as a plastic lens is fixed to a lens holder (lens barrel), an ultraviolet curing resin must be applied to a plurality of positions where the periphery of the plastic lens is in contact with the lens holder, and the ultraviolet curing resin at a plurality of positions is simultaneously hardened ( That is, ultraviolet light is irradiated at the same time. Therefore, the ultraviolet irradiation device described in Patent Document 1 is provided with a plurality of LED light source units (irradiation heads) that are capable of illuminating ultraviolet light, and simultaneously irradiates ultraviolet rays with ultraviolet curable resins that can be applied to a plurality of positions on the same circumference. Light way.

However, in the ultraviolet irradiation device described in Patent Document 1, since it is necessary to arrange the light source unit at each application position of the ultraviolet curable resin, a plurality of light source units are required, and thus the overall size of the device is increased. Further, in order to allow the ultraviolet light to be surely irradiated to the ultraviolet curable resin, it is necessary to perform positioning adjustment (i.e., aligning the position between the optical component and the light source unit) with respect to the ultraviolet light emitted from the light source unit at each application position of the ultraviolet curable resin.

Here, regarding the configuration in which the ultraviolet curable resin applied to a plurality of positions on the same circumference is simultaneously irradiated with ultraviolet light without requiring positioning adjustment, it is also conceivable to irradiate a large beam diameter such as a cover lens holder and an optical part (ie, a wide range). Ultraviolet light in the area irradiated area. However, in this configuration, since the ultraviolet light irradiation region is broadened, the average ultraviolet light energy per unit area becomes small, and in order to stabilize and harden the ultraviolet curable resin, it is necessary to enhance the ultraviolet light energy or increase the irradiation time. In order to enhance the ultraviolet light energy, it is necessary to use a high output type of LED, which causes a problem that the overall cost of the ultraviolet irradiation device rises. Further, once the irradiation time is increased, the work for hardening the ultraviolet curable resin will be more time consuming, and there is a problem that the production efficiency is lowered.

The present invention has been made in view of the above reasons, and an object thereof is to provide an LED that does not use a high output type, does not increase the irradiation time, does not require positioning adjustment, and can be simultaneously coated on the same by a light source unit (ie, a light source). An ultraviolet ray curing device (that is, a light irradiation device) that irradiates ultraviolet rays at a plurality of positions on the circumference of the ultraviolet curable resin (that is, an annular irradiation region).

In order to achieve the above object, the light irradiation device of the present invention is a light irradiation device that irradiates light to an annular irradiation region of an irradiation target placed at a specific position, and includes an LED (Light Emitting Diode) element that emits the light. a first lens; an optical axis having a common light with the LED element, and a divergence angle of the ultraviolet light emitted from the LED element, and forming a light having a specific divergence angle; a second lens; having a common light with the first lens a shaft that refracts light of the first lens to be annularly light centered on the optical axis; and a third lens; has a common optical axis with the second lens, and will penetrate The light of the second lens is focused in an annular shape on the irradiation region.

According to the above configuration, the light emitted from the LED element forms an annular light and is irradiated onto the annular irradiation region of the object to be irradiated. Therefore, for example, when the ultraviolet curable resin is coated in the irradiation region, the ultraviolet curable resin hardens once (i.e., simultaneously) after receiving the light.

Further, the apparatus may further include a lens moving means for relatively moving the third lens to the second lens. According to this configuration, the focus position of the light that penetrates the second lens can be changed in accordance with the position of the object to be irradiated.

Further, the second lens may be constituted by an axicon lens having a conical surface facing the first lens end or the third lens end.

Further, the second lens may be constituted by an axicon lens having a conical surface on the first lens side and the third lens side.

Further, the second lens may be constituted by a pair of axicon lenses each having a conical surface on the first lens side or the third lens side.

Further, the apex angle of the conical surface is preferably 120 to 150 degrees.

Further, the first lens may be composed of a lenticular lens, a plano-convex lens, or a convex-concave lens.

Further, the third lens may be composed of a lenticular lens, a plano-convex lens, or a convex-concave lens.

Further, the light emitted from the light irradiation device is preferably light having a wavelength of the ultraviolet light region. Further, at this time, the light of the wavelength of the ultraviolet light region is preferably light containing a wavelength which acts on the ultraviolet curable resin.

As described above, according to the light irradiation device of the present invention, the ultraviolet light emitted from one LED element forms an annular ultraviolet light and is irradiated onto the annular irradiation region. Therefore, it is not necessary to provide a plurality of light source units as in the related art, and it is possible to simultaneously irradiate the ultraviolet curable resin applied at a plurality of positions in the irradiation region. In addition, there is no need for the necessary positioning adjustments. In addition, since the light is only irradiated to the annular irradiation region, it is not necessary to use a high output type LED, and it is not necessary to increase the irradiation time.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same or corresponding portions are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

Fig. 1 is a perspective view showing a schematic configuration of a light irradiation device according to an embodiment of the present invention. In the light irradiation device 1 of the present embodiment, ultraviolet light (for example, light having a wavelength of 365 nm) of a specific irradiation intensity distribution (beam distribution) is irradiated onto the outer circumferential surface of the object to be irradiated (lens L). La device. The base end surface Lb of the flange La (the side surface indicated by oblique lines in Fig. 1) is a continuous surface, and the ultraviolet curable resin is applied to a plurality of positions on the base end surface Lb of the flange La, and is offset from the lens holder not shown in the drawing. Pick up. When ultraviolet light is applied to the flange La, the ultraviolet curable resin between the flange La and the lens holder is hardened, and the lens L is fixed to the lens holder.

As shown in Fig. 1, the light irradiation device 1 includes an optical head 100 that emits ultraviolet light, and a power supply unit 200 that supplies electric power to the optical head 100 while adjusting the irradiation intensity of the ultraviolet light emitted from the optical head 100; the cable 300, electrical The optical head 100 and the power supply unit 200 are connected. Further, the cable 300 of the present embodiment is constituted by two lead wires 300a and 300b (second drawing) which are respectively connected to the anode terminal and the cathode terminal of the LED element 12 which will be described later.

The lens L is spaced apart from the optical head 100 by a specific distance, and is positioned and arranged such that the optical axis AX of the lens L is coaxial with the optical axis O of the optical head 100. Hereinafter, the distance between the exit end surface of the optical head 100 and the base end surface Lb (the following surface) of the lens L will be referred to as "working distance WD".

Further, in the present specification, the emission direction of the ultraviolet light emitted from the optical head 100 (that is, the optical axis AX direction) is defined as the Z-axis direction, and the two directions perpendicular to the Z-axis and perpendicular to each other are defined as the X-axis direction and Y. The direction of the axis is explained by this.

Fig. 2 is a side sectional view showing the configuration of the optical head. Fig. 2a is an exploded view of the optical head 100 before assembly, and Fig. 2b and Fig. 2c are side cross-sectional views of the optical head 100 after assembly. As shown in Fig. 2, the optical head 100 of the present embodiment is composed of an LED unit 10, a first lens unit 20, a set screw 30, and a second lens unit 40. As shown in FIGS. 2b and 2c, the optical head 100 of the present embodiment is configured such that the relative positional relationship between the first lens unit 20 and the second lens unit 40 can be adjusted by adjusting the position of the set screw 30. Composition.

The LED unit 10 includes a housing 11 and an LED (Light Emitting Diode) element 12 fixed to the housing 11. The casing 11 is a bottomed cylindrical body member, and includes an opening portion 11a, a cylindrical side wall portion 11b, and a bottom portion 11c that is integrally formed by the side wall portion 11b. The cable 300 is inserted and fixed from the opening portion 11a. Further, the bottom portion 11c is formed with two through holes 11ca and 11cb extending in parallel with the optical axis O of the optical head 100, and the two wires 300a and 300b of the cable 300 are respectively pulled out from the through holes 11ca and 11cb, and are respectively connected to the LEDs. The anode terminal (not shown) of the component 12 and the cathode terminal (not shown). Further, the bottom portion 11c is formed with a projection portion 11d for fixing the LED element 12 to protrude along the optical axis O of the optical head 100.

The LED element 12 is a semiconductor light-emitting element having a substantially square light-emitting surface 12a (not shown in FIG. 2) and a cover glass 12b (not shown in FIG. 2), and a wavelength 365 nm emitted from the light-emitting surface 12a. The ultraviolet light is emitted through the cover glass 12b. The LED element 12 is adjusted in such a manner that its optical axis coincides with the optical axis O of the optical head 100 (i.e., coincides with the central axis of the casing 11), and is then fixed to the front end of the projection 11d. As described above, the anode terminal and the cathode terminal of the LED element 12 are connected to the power source unit 200 by the cable 300, and emit ultraviolet light of a specific amount of light corresponding to the driving current supplied from the power source unit 200 from the LED element 12. Further, in the present embodiment, the ultraviolet light which is emitted from the LED element 12 and which is spread around the optical axis O while being diffused into a circular shape at a divergence angle of 60° is described.

The first lens unit 20 includes a lens barrel 21, a first lens 22, and a second lens 23. The lens barrel 21 is a hollow cylindrical body member having the opening portions 21a and 21b and the cylindrical side wall portion 21c. The inner diameter of the opening portion 21a side of the lens barrel 21 is slightly larger than the outer diameter of the side wall portion 11b of the casing 11, and the casing 11 (i.e., the LED unit 10) is inserted from the opening portion 21a and fixed in the lens barrel 21. Specific location (Fig. 2b, 2c). Further, a male screw (not shown) is formed on the outer circumferential surface of the side wall portion 21c of the lens barrel 21, and can be abutted against the female screw formed on the inner circumferential surface of the set screw 30 and the inner circumferential surface of the second lens unit 40. The details will be described later.

Further, the first lens 22 and the second lens 23 are housed in the opening portion 21b side of the lens barrel 21. The first lens 22 is positioned and joined to the inner circumferential surface of the lens barrel 21 such that its optical axis coincides with the optical axis of the LED element 12 (ie, the optical axis O of the optical head 100), and the LED unit 10 is housed. In the lens barrel 21, the first lens 22 is disposed close to the LED element 12 (e.g., 0.35 mm apart). The first lens 22 of the present embodiment is a lenticular lens having a thickness of 3.75 mm, which reduces the divergence angle of the ultraviolet light emitted from the LED element 12, and causes the light to have a specific divergence angle.

The second lens 23 is spaced apart from the first lens 22 by a specific interval (e.g., an interval of 1.5 mm), and its optical axis is aligned with the optical axis of the first lens 22 (i.e., the optical axis O of the optical head 100). The method is positioned and joined to the inner circumferential surface of the lens barrel 21. The second lens 23 of the present embodiment is an axicon lens having a conical surface facing the first lens 22 side and having a thickness of 4 mm, and the ultraviolet light penetrating the first lens 22 is made to have an optical axis O. The manner of the center-shaped circular light (that is, the manner in which the light passing through the periphery of the optical axis O disappears) is refracted. Fig. 3 is an external view when the second lens 23 of the present embodiment is viewed from the X-axis direction. As shown in Fig. 3, the second lens 23 of the present embodiment is an axicon lens having a conical incident surface 23a and a planar exit surface 23b. In the present embodiment, the apex of the conical incident surface 23a The angle α (i.e., the angle between the two ridges of the section on the second lens 23Y-Z plane) is 140°.

The set screw 30 (Fig. 2) is an annular member having a screw hole 30a at the center, and the second lens unit 40, which will be described later, is fixed to the lens barrel 21. The inner diameter of the screw hole 30a is slightly larger than the outer diameter of the side wall portion 21c of the lens barrel 21, and a female screw (not shown) that abuts against the male screw on the outer peripheral surface of the side wall portion 21c of the lens barrel 21 is formed in the screw hole 30a. Therefore, by screwing the front end portion (the end portion on the opening portion 21b side) of the lens barrel 21 (i.e., the first lens unit 20) into the screw hole 30a and rotating the set screw 30 in the clockwise direction, the stopper screw 30 It can be attached to the side wall portion 21c of the lens barrel 21.

The second lens unit 40 includes a lens barrel 41 and a third lens 42. The lens barrel 41 is a hollow cylindrical body member having openings 41a and 41b and a cylindrical side wall portion 41c. The inner diameter of the opening portion 41a side of the lens barrel 41 is slightly larger than the outer diameter of the side wall portion 21c of the lens barrel 21, and the inner peripheral surface of the lens barrel 41 is formed with a female screw (not shown) which can be combined with the side wall portion of the lens barrel 21. The male thread formed on the outer peripheral surface of 21c abuts. Therefore, the lens barrel 21 (i.e., the end portion of the opening portion 21b side) of the lens barrel 21 (i.e., the first lens unit 20) is screwed into the opening portion 41a of the lens barrel 41 and rotated in the clockwise direction, and the lens barrel 21 is rotated. The inside of the lens barrel 41 is inserted. Then, the lens barrel 41 is fixed to a position where the base end portion (the end portion on the opening portion 41a side) of the lens barrel 41 is in contact with the set screw 30. Thus, the lens barrel 41 and the set screw 30 of the present embodiment are of a so-called double nut configuration, and by changing the position of the set screw 30, the lens barrel 41 can be aligned with the lens barrel 21 along the optical axis O. (ie moving in the Z-axis direction). In other words, the interval between the second lens 23 and the third lens 42 can be changed by changing the position of the set screw 30. After the lens barrel 41 is attached to the lens barrel 21, the lens barrel 41 is completely fixed to the lens barrel 21 by rotating the set screw 30 in the counterclockwise direction.

The third lens 42 is housed in the opening portion 41b side of the lens barrel 41. The third lens 42 is positioned and joined and fixed to the inner circumference of the lens barrel 41 such that its optical axis coincides with the optical axes of the first lens 22 and the second lens 23 (ie, the optical axis O of the optical head 100). surface. In the present embodiment, when the lens barrel 21 is attached to the lens barrel 41, the interval between the second lens 23 and the third lens 42 is matched with the position of the set screw 30 at 2 mm (Fig. 2b) to 25 mm ( 2c diagram) adjustment within the range. The third lens 42 of the present embodiment is a 3 mm plano-convex lens, and the ultraviolet light penetrating the second lens 23 is focused (projected) on the base end face Lb (the following surface) of the lens L disposed on the specific working distance WD. Into an annular shape.

Fig. 4 is an example of a light path diagram (i.e., on the Y-Z plane) when the optical head 100 of the present embodiment is viewed from the X-axis direction, and in order to make the working distance WD 20 mm (even a circular ultraviolet projection) The light path map when the interval between the second lens 23 and the third lens 42 is adjusted to a specific distance (for example, 19 mm) at a position 20 mm from the exit end surface of the optical head 100. Further, in the present embodiment, since the ultraviolet light which is diffused into a circular shape while being irradiated from the LED element 12 is irradiated, all the light path patterns on the plane passing through the Z-axis are the same as those in the fourth drawing. Therefore, this specification only uses the fourth diagram to illustrate the light path on the Y-Z plane.

In addition, in FIG. 4, in order to make the drawing easy to understand, a part of the structure of the optical head 100 is omitted, and only the LED element 12, the first lens 22, the second lens 23, and the third lens 42 are shown, and The position at 10° indicates the light path of the ultraviolet light emitted from the LED element 12 at a 60° divergence angle. Further, in Fig. 4, among the ultraviolet light emitted from the LED element 12, the ultraviolet light passing through the optical path of the optical axis O is expressed as light having a divergence angle of 0 (i.e., light having an emission angle of 0), toward the light. The ultraviolet light emitted from the upper side of the axis O (i.e., the Y-axis direction + side) is expressed as the ultraviolet light of the + divergence angle, and the ultraviolet light emitted toward the lower side (the Y-axis direction-side) of the optical axis O is expressed as the ultraviolet light of the divergence angle. Further, in Fig. 4, the positions where the working distance WD is 20 mm, 30 mm, and 40 mm are indicated as "WD = 20 mm", "WD = 30 mm", and "WD = 40 mm".

As shown in Fig. 4, ultraviolet light having a wavelength of 365 nm which is emitted by the light-emitting surface 12a of the LED element 12 passes through the cover glass 12b and enters the first lens 22. The ultraviolet light incident on the first lens 22 is refracted by the first lens 22, the divergence angle is reduced, and is incident on the second lens 23. In the present embodiment, almost all of the ultraviolet light having a divergence angle of ±60° emitted from the LED element 12 is incident on the second lens 23.

The ultraviolet light that has penetrated the first lens 22 is incident on the incident surface 23a of the second lens 23. As described above, the second lens 23 of the present embodiment is an axicon lens, and since the incident surface 23a has a conical surface, each optical path is curved in the direction of the optical axis O. Then, the light passing through the inner side of the second lens 23 (i.e., the light having a small divergence angle), the larger the emission angle (the angle of the optical axis O), and the ultraviolet light emitted from the exit surface 23b of the second lens 23 is At a position near the second lens 23, it is emitted so as to intersect the optical axis O. In this way, the ultraviolet light emitted from the exit surface 23b of the second lens 23 of the present embodiment is refracted at a larger angle from the optical axis O, and is refracted at a smaller angle from the optical axis O, so that it is worn. The light around the transmission axis O disappears (that is, the light that penetrates the optical axis O gradually overlaps the light that is off the optical axis O), and becomes circularly shaped with the optical axis O as the center. The way to shoot.

The ultraviolet light that penetrates the second lens 23 is further refracted by the third lens 42, and is focused in an annular shape at a position of WD = 20 mm. Thereafter, the ultraviolet light is focused in a circular shape at a position of WD=20 mm, and is gradually defocused due to the distance.

Fig. 5 is a plan showing the intensity distribution of the irradiation intensity at the position of WD = 20 mm in Fig. 4. The vertical axis of Fig. 5 shows the distance (mm) in the Y-axis direction with the optical axis O at 0, and the horizontal axis represents the distance (mm) in the X-axis direction with the optical axis O at 0, and is performed by four stages. The lightness indicates the irradiation intensity (mW/cm ² ). In addition, Fig. 6 is a graph showing the irradiation intensity distribution in the Y-axis direction at each of WD = 20 mm, WD = 30 mm, and WD = 40 mm in Fig. 4 . The vertical axis of Fig. 6 is the irradiation intensity (mW/cm ² ), and the horizontal axis is the distance (mm) in the Y-axis direction in which the optical axis O is 0.

As shown in Fig. 5 and Fig. 6, in the position of WD = 20 mm, since the ultraviolet light emitted from the optical head 100 is focused in an annular shape, a diameter of about 8 mm with a peak intensity of about 1800 mW/cm ² can be obtained. Ring-shaped ultraviolet light.

Further, as shown in Fig. 6, it can be seen that in the position of WD = 30 mm, the ultraviolet light has a stable irradiation intensity distribution with a peak intensity of about 600 mW/cm ² due to out-focus, and in the position of WD = 40 mm, ultraviolet light Since the light is further out of focus, it is impossible to form an annular light.

Thus, in the present embodiment, since the LED element 12 that emits ultraviolet light having a divergence angle of 60° is used as the light source, the parallel light does not enter the incident surface 23a of the second lens 23, and penetrates the ultraviolet light of the third lens 42. Light does not form parallel circular ultraviolet light. Therefore, once the working distance WD is different, the problem of the desired annular ultraviolet light cannot be obtained. Therefore, in the present embodiment, in order to obtain the annular ultraviolet light of the desired irradiation intensity at the desired working distance WD, the lens barrel 41 can be moved toward the lens barrel 21 along the optical axis O. The configuration is such that the interval between the second lens 23 and the third lens 42 can be adjusted.

Figs. 7 and 8 are views showing an example of a light path diagram (i.e., on the Y-Z plane) when the optical head 100 of the light-emitting device of the embodiment of the present invention is viewed from the X-axis direction. 7 is a diagram in which the working distance WD is 30 mm (that is, the annular ultraviolet light is projected at a position 30 mm from the exit end surface of the optical head 100), and the interval between the second lens 23 and the third lens 42 is Adjust the light path map to a specific distance (for example, 15mm). In addition, Fig. 8 is a view in which the working distance WD is 40 mm (i.e., the annular ultraviolet light is projected at a position 40 mm from the exit end surface of the optical head 100), and the second lens 23 and the third lens 42 are disposed. Interval, the light path map when adjusted to a specific distance (for example, 8mm). In addition, FIG. 9 shows an irradiation intensity distribution in the Y-axis direction at the position of WD=30 mm in FIG. 7 (shown as “WD=30 mm” in FIG. 9), and WD=40 mm in FIG. A graph of the irradiation intensity distribution in the Y-axis direction (shown as "WD=40 mm" in Fig. 9). The vertical axis of Fig. 9 is the irradiation intensity (mW/cm ² ), and the horizontal axis is the distance (mm) in the Y-axis direction where the optical axis O is 0.

As shown in Fig. 7 and Fig. 9, when the interval between the second lens 23 and the third lens 42 is adjusted, the annular ultraviolet light can be focused at a position of WD = 30 mm, and can be at WD = 30 mm. At the position, an annular ultraviolet light having a peak intensity of about 580 mW/cm ^{2 and} a diameter of about 10 mm was obtained.

Further, as shown in Figs. 8 and 9, when the interval between the second lens 23 and the third lens 42 is adjusted, the annular ultraviolet light can be focused at the WD = 40 mm position, and can be at WD = At a position of 40 mm, an annular ultraviolet light having a peak intensity of about 200 mW/cm ^{2 and} a diameter of about 14 mm was obtained.

As described above, according to the light irradiation device 1 of the present embodiment, the ultraviolet light emitted from one LED element 12 forms an annular ultraviolet light and is irradiated onto the object to be irradiated (ie, the lens L) disposed on the working distance WD. The annular irradiation area (ie, the base end surface Lb). Therefore, it is not necessary to provide a plurality of light source units (optical heads) as in the related art, and the ultraviolet curable resin applied to a plurality of positions in the irradiation region can be simultaneously irradiated by ultraviolet light. In addition, there is no need for the necessary positioning adjustments. In addition, since the ultraviolet light is irradiated only to the annular irradiation region, it is not necessary to use a high output type LED, and it is not necessary to increase the irradiation time.

Further, as described above, in the present embodiment, the interval between the second lens unit 23 and the third lens unit 42 can be adjusted by adjusting the position of the set screw 30. Since the interval between the second lens 23 and the third lens 42 is changed, the focus position of the ultraviolet light that penetrates the second lens 23 changes, and the working distance WD also changes. In other words, according to the configuration of the present embodiment, by changing the interval between the second lens 23 and the third lens 42, various working distances WD can be corresponding, and the annular ultraviolet light can be efficiently irradiated in correspondence. The working distance is the position of the WD (i.e., the base end face of the lens L (following surface)).

The above is the description of the embodiment, but the present invention is not limited to the above-described configuration, and various modifications are possible within the scope of the technical idea of the present invention.

For example, although the light irradiation device 1 of the present embodiment is described as curing the ultraviolet curable resin in the annular irradiation region, it is not limited to this use, and may be applied to other uses requiring annular light. (For example, an object to be irradiated that does not wish to illuminate the center portion with a circular shape is irradiated).

Further, the light irradiation device 1 of the present embodiment is described as a device that irradiates ultraviolet light having a wavelength of 365 nm, but may be irradiated with ultraviolet light of other wavelengths in the ultraviolet light region. In recent years, an LED element that illuminates light having a wavelength close to the ultraviolet region (for example, a wavelength of 405 nm) has been put to practical use, and its LED element can also be applied to the light irradiation device 1 of the present embodiment. In other words, the meaning of "ultraviolet light" and "light of the wavelength of the ultraviolet light region" in the present specification means light having a wavelength close to the ultraviolet light region, and the technical idea of the present invention is provided as long as the action and effect of the present invention can be produced. Within the scope. Further, as described above, when the light irradiation device 1 of the present embodiment is applied to other applications requiring an annular light (that is, a use other than the use of curing the ultraviolet curable resin), the light irradiation device 1 is not limited to being necessary. The means for irradiating ultraviolet rays may be a device for irradiating light of a wavelength in the visible light region or the infrared light region.

Further, although the first lens 22 of the present embodiment is described as a lenticular lens, it is not limited to this configuration, and for example, a plano-convex lens or a convex-concave lens may be applied.

Further, although the third lens 42 of the present embodiment is described by a plano-convex lens, it is not limited to this configuration, and for example, a lenticular lens or a convex-concave lens may be applied. Further, in the case of a plano-convex lens, the convex surface may be an incident surface, and the plane may be an exit surface.

Further, in the present embodiment, the angle α of the apex of the conical incident surface 23a of the second lens 23 is described as 140°, but the configuration is not limited thereto. 10 to 14 are light path diagrams in which the angle α of the apex of the incident surface 23a of the second lens 23 of the present embodiment is changed to 160°, 150°, 120°, 100°, and 80°, respectively (10a) Fig. 14A) and an irradiation intensity distribution chart (Fig. 10b to Fig. 14b) showing the X-axis direction at a specific working distance (WD = 20 mm). In addition, the vertical axis of the 10th to 14th drawings is the same as the illumination intensity (mW/cm ² ), and the horizontal axis is the distance between the X-axis direction and the Y-axis direction where the optical axis O is 0 (mm). ).

As shown in Figs. 10a and 10b, when the angle α of the apex of the incident surface 23a of the second lens 23 is 160°, the refractive power generated by the second lens 23 becomes small, so that light of about 200 mW/cm ^{2 is obtained} . It will remain on the periphery of the optical axis O (ie, the center portion), and it is impossible to obtain a completely annular ultraviolet light. As described above, if the light remains in the center portion of the irradiation region, the amount of light in the vicinity of the irradiation region is reduced, so that the peak intensity is slightly lowered. However, if the ultraviolet curing resin on the specific working distance WD can be hardened, this can be applied. Kind of structure.

As shown in Figs. 11a and 11b, when the angle α of the apex of the incident surface 23a of the second lens 23 is 150°, as in the present embodiment, a ring-shaped ultraviolet having a diameter of about 10 mm can be obtained at a specific working distance WD. Light.

As shown in FIGS. 12a and 12b, when the angle α of the apex of the incident surface 23a of the second lens 23 is 120°, since the second lens 23 becomes thick, part of the ultraviolet light that penetrates the first lens 22 is diverged. The light having a larger angle does not enter the second lens 23, and the utilization efficiency of the light is slightly lowered. However, as in the present embodiment, the annular ultraviolet light having a diameter of about 12 mm can be obtained at a specific working distance WD. . Further, in the present modification, in order to increase the light use efficiency, the outer diameter of the second lens 23 may be increased.

As shown in Figs. 13a and 13b, when the angle α of the apex of the incident surface 23a of the second lens 23 is 100°, since the thickness of the second lens 23 is changed to be thicker than the angle α of 120°, the light utilization efficiency is further improved. Lowering, but still the same as in the present embodiment, an annular ultraviolet light having a diameter of about 18 mm can be obtained at a specific working distance WD. Further, in the present modification, in order to improve the light use efficiency, the same as the case where the angle α is 120°, the outer diameter of the second lens 23 may be increased.

As shown in Figs. 14a and 14b, when the angle α of the apex of the incident surface 23a of the second lens 23 is 80°, the thickness of the second lens 23 is changed to be thicker than the angle α of 100°, so that the light utilization efficiency is It is further reduced, but still in the same manner as the present embodiment, an annular ultraviolet light having a diameter of about 24 mm can be obtained at a specific working distance WD. Further, in the present modification, in order to improve the light use efficiency, the angle α may be the same as that in the case of 120° or 100°, and the outer diameter of the second lens 23 may be increased.

Thus, the angle α of the apex of the conical incident surface 23a of the second lens 23 of the present embodiment is not limited to 140°, and as long as it is 160° or less, circular ultraviolet light can be obtained at a specific working distance WD. Further, as described above, when the angle α of the apex of the incident surface 23a of the second lens 23 is 160°, the light use efficiency is lowered by the light remaining in the center portion, and the smaller the angle α, the second lens 23 The thicker the light, the lower the efficiency of light utilization. Therefore, the angle α of the apex of the incident surface 23a of the second lens 23 is preferably 120 to 150.

Further, the second lens 23 of the present embodiment is described by an axicon lens having a conical surface facing the end of the first lens 22. However, the present invention is not limited to this configuration, and various modifications are possible.

Fig. 15 is a view showing a light path diagram (Fig. 15a) of the first modification of the second lens 23 of the present embodiment, and an irradiation intensity distribution chart showing the X-axis direction at WD = 20 mm. (Fig. 15b). The second lens 231 of the present modification is an axicon lens having a conical surface facing the end of the third lens 42, which is different from the second lens 23 of the present embodiment. Even if the conical surface is disposed on the exit surface side as described above, the same function as the second lens 23 of the present embodiment can be achieved, and annular ultraviolet light having a diameter of about 7 mm can be obtained at WD = 20 mm.

Fig. 16 is a view showing a light path diagram (Fig. 16a) of the second modification of the second lens 23 of the present embodiment, and an irradiation intensity distribution chart (Fig. 16b) showing the X-axis direction at WD = 20 mm. The second lens 232 of the present modification is an axicon lens having a conical surface on the side of the first lens 22 (ie, the incident surface side) and the third lens 42 side (ie, the exit surface side), which is the same as the embodiment. The two lenses 23 are different. Even if the incident surface and the outgoing surface are formed by a conical surface as described above, the same function as the second lens 23 of the present embodiment can be achieved, and circular ultraviolet light having a diameter of about 14 mm can be obtained at WD = 20 mm. Further, in the present modification, even if ultraviolet light is irradiated on the periphery (ie, the central portion) of the optical axis O, the lens L can be made as long as the annular ultraviolet light can be obtained at the working distance WD. The ultraviolet curable resin of the base end face Lb is hardened, so that it does not cause a problem.

Fig. 17 is a view showing a light path diagram (Fig. 17a) of the third modification of the second lens 23 of the present embodiment, and an irradiation intensity distribution chart (Fig. 17b) showing the X-axis direction at WD = 20 mm. The second lens 233 of the present modification is composed of a first axicon lens 233a having a conical surface facing the third lens 42 side and a second axicon lens 233b having a conical surface facing the first lens 22 side. The second lens 23 of this embodiment is different. Thus, the pair of axicon lenses arranged in such a manner that the conical surfaces are opposite to each other can achieve the same function as the second lens 23 of the present embodiment, and according to this structure, an annular shape having a diameter of about 15 mm can be obtained at WD=20 mm. UV light.

Fig. 18 is a view showing a light path diagram (Fig. 18a) of the fourth modification of the second lens 23 of the present embodiment, and an irradiation intensity distribution chart (Fig. 18b) showing the X-axis direction at WD = 20 mm. The second lens 234 of the present modification is composed of a first axicon lens 234a having a conical surface facing the first lens 22 side and a second axicon lens 234b having a conical surface facing the third lens 42 side. The second lens 23 of this embodiment is different. Thus, the pair of axicon lenses arranged in such a manner that the conical surface is reversed can achieve the same function as the second lens 23 of the embodiment, and according to this structure, a ring having a diameter of about 14 mm can be obtained at WD=20 mm. Shaped ultraviolet light. Further, in the present modification, as in the second modification, even if ultraviolet light is irradiated on the periphery (i.e., the center portion) of the optical axis O, as long as the circular ultraviolet light can be obtained at the working distance WD. The ultraviolet curable resin of the base end face Lb of the lens L can be hardened, and thus does not cause a problem.

Fig. 19 is a view showing a light path diagram (Fig. 19a) of the fifth modification of the second lens 23 of the present embodiment, and an irradiation intensity distribution chart (Fig. 19b) showing the X-axis direction at WD = 20 mm. The second lens 235 of the present modification is constituted by a first axicon lens 235a and a second axicon lens 235b having a conical surface facing the first lens 22, which is different from the second lens 23 of the present embodiment. Thus, the pair of axicon lenses arranged in such a manner that the conical surface faces the first lens 22 side can still achieve the same function as the second lens 23 of the present embodiment, and according to this structure, the diameter can be obtained at WD=20 mm. A ring-shaped ultraviolet light of about 14 mm. Further, in the present modification, as in the second and fourth modifications, even if there is a slight ultraviolet light irradiation around the optical axis O (that is, the central portion), as long as the working distance WD can be obtained as a ring shape. The ultraviolet light can harden the ultraviolet curable resin of the base end face Lb of the lens L, and thus does not cause a problem.

Fig. 20 is a view showing a light path diagram (Fig. 20a) of the sixth modification of the second lens 23 of the present embodiment, and an irradiation intensity distribution chart (Fig. 20b) showing the X-axis direction at WD = 20 mm. The second lens 236 of the present modification is constituted by the first axicon lens 236a and the second axicon lens 236b having the conical surface facing the third lens 42 side, which is different from the second lens 23 of the present embodiment. Thus, the pair of axicon lenses arranged in such a manner that the conical surface faces the third lens 42 side can still achieve the same function as the second lens 23 of the present embodiment, and the diameter can be obtained at WD=20 mm according to such a structure. A ring-shaped ultraviolet light of about 14 mm. Further, in the present modification, as in the second, fourth, and fifth modifications, even if there is a slight ultraviolet light irradiation around the optical axis O, as long as the annular ultraviolet light can be obtained at the working distance WD Light can harden the ultraviolet-curable resin of the base end face Lb of the lens L, and thus does not cause a problem.

The embodiments and the modifications disclosed in the present invention are all illustrative and are not intended to limit the invention. The scope of the present invention is not limited by the description, but is intended to cover all modifications within the scope and scope of the patent application.

1‧‧‧Lighting device
10‧‧‧LED unit
11‧‧‧Shell
11a‧‧‧ Opening
11b‧‧‧ Sidewall
11c‧‧‧ bottom
11ca, 11cb‧‧‧through holes
11d‧‧‧protrusion
12‧‧‧LED components
12a‧‧‧Lighting surface
12b‧‧‧Shield glass
20‧‧‧First lens unit
21‧‧‧Mirror tube
21a, 21b‧‧‧ openings
21c‧‧‧ Sidewall
22‧‧‧ first lens
23, 231, 232, 233, 234, 235, 236‧‧‧ second lens
23a‧‧‧Incoming surface
23b‧‧‧Outlet
30‧‧‧Lock screws
30a‧‧‧ screw holes
40‧‧‧second lens unit
41‧‧‧Mirror tube
41a, 41b‧‧‧ openings
41c‧‧‧ Sidewall
42‧‧‧ third lens
100‧‧‧ optical head
200‧‧‧Power unit
233a, 234a, 235a, 236a‧‧‧ first axicon lens
233b, 234b, 235b, 236b‧‧‧second axicon lens
300‧‧‧ cable
300a, 300b‧‧‧ wires
AX, O‧‧‧ optical axis
L‧‧ lens
La‧‧‧Flange
Lb‧‧‧ base end face
WD‧‧‧ working distance α‧‧‧ angle

[Fig. 1] A perspective view showing a schematic configuration of a light irradiation device according to an embodiment of the present invention. [Fig. 2a to Fig. 2c] A side sectional view showing the configuration of the optical head of the light irradiation device of the embodiment of the present invention. [Fig. 3] An external view of the second lens of the light irradiation device of the embodiment of the present invention viewed from the X-axis direction. [Fig. 4] An example of a light path diagram (i.e., on the Y-Z plane) when the optical head of the light-emitting device of the embodiment of the present invention is viewed from the X-axis direction. [Fig. 5] A shading diagram showing the irradiation intensity distribution at the position of WD = 20 mm in Fig. 4. [Fig. 6] A graph showing the irradiation intensity distribution in the Y-axis direction at each of WD = 20 mm, WD = 30 mm, and WD = 40 mm at Fig. 4. [Fig. 7] An example of an optical path diagram (i.e., on the Y-Z plane) when the optical head of the light-emitting device of the embodiment of the present invention is viewed from the X-axis direction. [Fig. 8] An example of a light path diagram (i.e., on the Y-Z plane) when the optical head of the light-emitting device of the embodiment of the present invention is viewed from the X-axis direction. [Fig. 9] A graph showing the irradiation intensity distribution in the Y-axis direction at the position of WD = 30 mm in Fig. 7 and the irradiation intensity distribution in the Y-axis direction at the position of WD = 40 mm in Fig. 8 . [Fig. 10a to 10b] The light path diagram when the angle ? of the second lens incident surface apex of the light irradiation device of the embodiment of the present invention is changed to 160, and the X axis indicating the specific working distance WD Directional illumination intensity distribution chart. [Fig. 11a to Fig. 11b] The light path diagram when the angle ? of the second lens incident surface apex of the light irradiation device of the embodiment of the present invention is changed to 150, and the X axis indicating the specific working distance WD Directional illumination intensity distribution chart. [Fig. 12a to Fig. 12b] The light path diagram when the angle ? of the second lens incident surface apex of the light irradiation device of the embodiment of the present invention is changed to 120, and the X axis indicating the specific working distance WD Directional illumination intensity distribution chart. [Fig. 13a to Fig. 13b] The light path diagram when the angle ? of the second lens incident surface apex of the light irradiation device of the embodiment of the present invention is changed to 100, and the X axis indicating the specific working distance WD Directional illumination intensity distribution chart. [Fig. 14a to Fig. 14b] The light path diagram when the angle ? of the second lens incident surface apex of the light irradiation device of the embodiment of the present invention is changed to 80, and the X axis indicating the specific working distance WD Directional illumination intensity distribution chart. [Fig. 15a to Fig. 15b] A light path diagram showing a first modification of the second lens of the light irradiation device according to the embodiment of the present invention, and an irradiation intensity distribution chart showing the X-axis direction. [16a to 16b] A light path diagram showing a second modification of the second lens of the light irradiation device according to the embodiment of the present invention, and an irradiation intensity distribution chart showing the X-axis direction. [Fig. 17a to Fig. 17b] A light path diagram showing a third modification of the second lens of the light irradiation device according to the embodiment of the present invention, and an irradiation intensity distribution chart showing the X-axis direction. [Fig. 18a to Fig. 18b] A light path diagram showing a fourth modification of the second lens of the light irradiation device according to the embodiment of the present invention, and an irradiation intensity distribution chart showing the X-axis direction. [Fig. 19a to Fig. 19b] A light path diagram showing a fifth modification of the second lens of the light irradiation device according to the embodiment of the present invention, and an irradiation intensity distribution chart showing the X-axis direction. [Figs. 20a to 20b] A light path diagram showing a sixth modification of the second lens of the light irradiation device according to the embodiment of the present invention, and an irradiation intensity distribution chart showing the X-axis direction.

10‧‧‧LED unit

11‧‧‧Shell

11a‧‧‧ Opening

11b‧‧‧ Sidewall

11c‧‧‧ bottom

11ca, 11cb‧‧‧through holes

11d‧‧‧protrusion

12‧‧‧LED components

20‧‧‧First lens unit

21‧‧‧Mirror tube

21a, 21b‧‧‧ openings

21c‧‧‧ Sidewall

22‧‧‧ first lens

23‧‧‧second lens

30‧‧‧Lock screws

30a‧‧‧ screw holes

40‧‧‧second lens unit

41‧‧‧Mirror tube

41a, 41b‧‧‧ openings

41c‧‧‧ Sidewall

42‧‧‧ third lens

300‧‧‧ cable

300a, 300b‧‧‧ wires

O‧‧‧ optical axis

Claims (10)

A light irradiation device that irradiates light to an annular irradiation region disposed at a specific position to illuminate an object, comprising: an LED element that emits the light; and a first lens that has a common function with the LED element An optical axis, and a divergence angle of the ultraviolet light emitted by the LED element is reduced, and the light is formed to have a specific divergence angle; a second lens having a common optical axis with the first lens and penetrating the first lens The light is refracted in such a manner as to form an annular light centered on the optical axis; and a third lens having an optical axis common to the second lens and penetrating the light of the second lens The illuminated area is focused in an annular shape. The light irradiation device according to claim 1, further comprising a lens moving means for relatively moving the third lens to the second lens. The light irradiation device according to the first or second aspect of the invention, wherein the second lens is an axicon lens having a conical surface facing the first lens end or the third lens end. The light irradiation device according to the first or second aspect of the invention, wherein the second lens is an axicon lens having a conical surface on the first lens side and the third lens side. The light irradiation device according to the first or second aspect of the invention, wherein the second lens is a pair of axicon lenses each having a conical surface on the first lens side or the third lens side. The light irradiation device according to any one of claims 3 to 5, wherein the angle of the apex of the conical surface is 120 to 150. The light irradiation device according to any one of claims 1 to 6, wherein the first lens is a lenticular lens, a plano-convex lens, or a convex-concave lens. The light irradiation device according to any one of claims 1 to 7, wherein the third lens is a lenticular lens, a plano-convex lens, or a convex-concave lens. The light irradiation device according to any one of claims 1 to 8, wherein the light irradiated from the light irradiation device is light of a wavelength of an ultraviolet region. The light irradiation device according to claim 9, wherein the light of the wavelength of the ultraviolet light region contains light that acts on a wavelength of the ultraviolet curable resin.