JP7085083B2 - Light irradiation device - Google Patents

Description

The present invention relates to a light irradiation device.

As this type of light irradiation device, a discharge tube that emits ultraviolet rays and a concave-curved reflective member that reflects the ultraviolet rays from the discharge tube toward a band-shaped irradiation position are known (for example, Patent Documents). See 1.).
Further, there is also known a light irradiation device in which a plurality of ultraviolet LEDs are arranged in the X direction and the Y direction instead of the discharge tube, and the irradiation position is irradiated by the plurality of ultraviolet LEDs (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2009-107190 Japanese Unexamined Patent Publication No. 2006-136859

Since the former light irradiation device uses a discharge tube having an output of several hundred W per 1 cm, it is excellent in increasing the curing speed of an ultraviolet curable resin (hereinafter, also simply referred to as "resin"). The life of the discharge tube is short. Since the light irradiation device is often located deep in the resin curing process, it takes time and effort to replace the discharge tube. Further, since the curing speed of the resin may change due to the replacement of the discharge tube, it may be necessary to reset the resin curing process every time the discharge tube is replaced. In addition, there is a restriction that the discharge tube must be separated from the irradiation position because the temperature becomes high.

On the other hand, the latter light irradiation device uses an ultraviolet LED, and the ultraviolet LED has a life of ten to several tens of times that of a discharge tube. However, even an LED called a power LED has an output of several watts per LED, so simply arranging the ultraviolet LEDs in the X and Y directions as in the latter light irradiation device is equivalent to a light irradiation device using a discharge tube. It is not possible to obtain the curing rate of the resin.

For example, as shown in FIG. 7, a plurality of light irradiation devices 100 are provided, and in each light irradiation device 100, an LED array 110 in which ultraviolet LEDs called power LEDs are arranged in the X direction and an LED array 110 are arranged along the LED array 110. A columnar lens 120 made of quartz or the like that collects the light from the LED array 110 in the Y direction orthogonal to the X direction is provided, and the light from the plurality of light irradiation devices 100 is overlapped at one band-shaped irradiation position. Can also be considered. This makes it possible to increase the energy density of the light at the band-shaped irradiation position.

Here, since ultraviolet rays are significantly attenuated by a lens made of ordinary glass or transparent plastic, it is necessary to use quartz or the like, which has a small attenuation, as the material of the lens. Even if quartz is used, attenuation of about 10% occurs.
Further, the light emitted from the LED spreads radially, and the cylindrical lens 120 does not collect light in the X direction. Therefore, in order to prevent light loss, it is necessary to make the distance between the light irradiation device and the irradiation position as close as possible, and specifically, it is often required to bring the distance as close as possible to about 50 mm.

On the other hand, since such a power LED generates a large amount of heat, it is necessary to bring the substrate on which the LED array 110 is mounted into contact with a water-cooled heat sink. That is, since it is necessary to provide each light irradiation device 100 with a water-cooled heat sink, the dimension of each light irradiation device in the Y direction becomes large. Specifically, since the ultraviolet power LED has a considerable amount of heat generation, the dimension of the heat sink in the Y direction is often about 50 mm or more. Therefore, when the three light irradiation devices 100 are arranged in the Y direction as shown in FIG. 7, there is a light irradiation device 100 that incidents light obliquely from an angle of about 45 ° with respect to the irradiation position. Air-cooled heat sinks may be used instead of water-cooled heat sinks, but the heat sinks tend to be larger due to the large amount of heat generated.

The shape, color, and surface condition of the resin to be cured are various, but in the case of curing the resin in resin printing, since it is difficult for light to enter the inside of black, the curing tends to be slower than other colors. That is, when light is obliquely incident on the irradiation position, reflection tends to occur and the incident depth tends to be shallow. Therefore, in order to allow light to enter the inside of the resin so as not to cause such loss, light is applied to the irradiation position. Is preferably incident from a direction as close to 90 ° as possible.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a light irradiation device capable of increasing the amount of light irradiated to an irradiation position and reducing light loss.

The light irradiation device according to the first aspect of the present invention is a rod lens extending in the X direction, has a convex curved surface having a curvature in the Y direction orthogonal to the X direction, and irradiates the convex curved surface with light. A rod lens that collects light in the Y direction, a first LED array in which LEDs are arranged in the X direction and irradiates light in a first predetermined range in the Y direction on the convex curved surface, and an LED in the X direction. A second LED array that irradiates a second predetermined range in the Y direction on the convex curved surface, and a reflecting member that reflects light from the second LED array that has passed through the rod lens. The reflecting member comprises light from the second LED array that has passed through the rod lens at a predetermined irradiation position where the light from the first LED array that has passed through the rod lens is irradiated in a band shape. It can be irradiated in a band shape.

In the first aspect, the same rod lens is irradiated with the light from the first LED array and the light from the second LED array, and the light from the first LED array is irradiated at the irradiation position in a band shape. , The light from the second LED array is reflected by the reflecting member and irradiated in a band shape. Therefore, the light from the first and second LED arrays is irradiated to the band-shaped irradiation position, and the amount of light emitted to the irradiation position can be increased.

Further, for example, by bringing the distance between the first LED array and the second LED array in the Y direction closer, or by bringing the distance between the rod lens and the reflecting member in the Y direction closer, the first one that has passed through the rod lens. The difference in angle between the optical axis of the light from the LED array and the optical axis of the light from the second LED array reflected by the reflecting member can be reduced.

The light irradiation device according to the second aspect of the present invention is a rod lens extending in the X direction, has a convex curved surface having a curvature in the Y direction orthogonal to the X direction, and irradiates the convex curved surface with light. A rod lens that collects light in the Y direction, a first ultraviolet LED array that is aligned in the X direction and irradiates a first predetermined range in the Y direction around the convex curved surface, and a first ultraviolet LED array that is aligned in the X direction. The light from the second ultraviolet LED array that irradiates the second predetermined range in the Y direction on the convex curved surface and the first ultraviolet LED array that has passed through the rod lens is reflected and formed into a band at a predetermined irradiation position. It includes a first reflecting member to irradiate, and a second reflecting member capable of reflecting light from the second ultraviolet LED array that has passed through the condensing rod lens and irradiating the predetermined irradiation position in a band shape.

In the second aspect, the same rod lens is irradiated with the light from the first LED array and the light from the second LED array, and the light from the first LED array is formed into a band by the first reflecting member. The light from the second LED array is irradiated to the irradiated position in a band shape by the second reflecting member. Therefore, the light from the first and second LED arrays is irradiated to the band-shaped irradiation position, and the amount of light emitted to the irradiation position can be increased.

Further, for example, by reducing the distance between the first LED array and the second LED array in the Y direction, or by reducing the distance between the rod lens and the first and second reflecting members in the Y direction, the first method is performed. The difference in angle between the optical axis of the light from the first LED array reflected by the reflecting member and the optical axis of the light from the second LED array reflected by the second reflecting member can be reduced. ..

According to the present invention, it is possible to increase the amount of light irradiated to the irradiation position and reduce the loss of light.

It is a schematic block diagram of the light irradiation apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the distribution of the light irradiated by the light irradiation apparatus of 1st Embodiment. It is a figure which shows the distribution of the light irradiated by the light irradiation apparatus of 1st Embodiment. It is a schematic block diagram of the light irradiation apparatus of the 1st modification of 1st Embodiment. It is a schematic block diagram of the light irradiation apparatus of the 2nd modification of 1st Embodiment. It is a schematic block diagram of the light irradiation apparatus which concerns on 2nd Embodiment of this invention. It is a schematic block diagram of the conventional light irradiation apparatus.

The light irradiation device according to the first embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, this light irradiation device has a rod lens 10 which is a cylindrical lens extending in the X direction (paper surface thickness direction in FIG. 1). The rod lens 10 is preferably made of a material such as quartz or borosilicate glass that does not attenuate ultraviolet rays.

In the light irradiation device, the ultraviolet LEDs are arranged in the X direction, and the first LED array 21 irradiates the first predetermined range A1 in the Y direction (left-right direction in FIG. 1) on the upper surface (convex curved surface) of the rod lens 10. The second LED array 22 in which the ultraviolet LEDs are arranged in the X direction and irradiate the second predetermined range A2 in the Y direction on the upper surface of the rod lens 10 with light, and the ultraviolet LEDs are arranged in the X direction and the rod lens 10 is arranged. It has a third LED array 23 that irradiates a third predetermined range A3 in the Y direction on the upper surface with light.

In the present embodiment, the X direction coincides with the parallel direction of the LEDs of each LED array 21, 22, 23, and the direction orthogonal to the X direction and the Y direction is the Z direction. Further, the rod lens 10 collects the light radiated on its upper surface in the Y direction, and as an example, refracts the light radiating from the LED in the Y direction so as to be substantially parallel light as shown in FIG. do. Condensing here means refracting the light from the LED toward the optical axes L1, L2, L3 of the LED in the Y direction, and the light after passing through the rod lens 10 may travel while spreading slightly. include. The broken line shown in FIG. 1 shows an image of a ray trajectory, and does not show a completely accurate ray trajectory.

This light irradiation device has substrates 21a, 22a, 23a on which the first to third LED arrays 21, 22, 23 are mounted, respectively. Further, a heat sink 31 to which the substrates 21a, 22a, 23a are fixed, a pair of side plates 32 having one ends attached to both ends of the heat sink 31 in the Y direction and extending in the Z direction, and a transparent side plate 32 attached to the other ends of the side plates 32. The irradiation device main body 30 includes a cover 33 and a pair of end members (not shown) that close the space formed between the pair of side plates 32 at one end and the other end in the X direction. The heat sink 31 is provided with a cooling water passage (not shown) through which the cooling water passes, and the cooling water is supplied to the cooling water passage from the cooling water supply device. Further, both ends of the rod lens 10 are supported by, for example, a pair of end members of the irradiation device main body 30.

In the present embodiment, the optical axis L1 of the first LED array 21 is parallel to the Z axis, and the optical axes L2 and L3 of the second and third LED arrays 22 and 23 are in the Y direction with respect to the optical axis L1. It is tilted 45 °.
The light irradiation device includes a reflecting member 42 that reflects light from the second LED array 22 that has passed through the rod lens 10, and a reflecting member 43 that reflects light from the third LED array 23 that has passed through the rod lens 10. Have.

The reflecting members 42 and 43 are attached to the irradiation device main body 30. Specifically, one end of each reflecting member 42, 43 in the Z direction (the side closer to each LED array 21, 22, 23) is fixed to the irradiation device main body 30, and the other end of each reflecting member 42, 43 in the Z direction. The side is positioned in the Y direction by the screw members (adjustment mechanism) 42b and 43b.

A planar reflecting surface 42a that reflects light from the second LED array 22 is provided on the surface of the reflecting member 42 on the rod lens 10 side, and a third LED is provided on the surface of the reflecting member 43 on the rod lens 10 side. A planar reflecting surface 43a that reflects light from the array 23 is provided. Each of the reflective surfaces 42a and 43a is, for example, a white reflective surface formed by depositing aluminum on the surface of the base material or a mirror surface formed by polishing the surface of the base material. The base material is glass, metal, plastic or the like. The reflecting members 42 and 43 are formed so that the distance between the reflecting surfaces 42a and 43a gradually increases from one end side to the other end side in the Z direction.

A plurality of screw members 42b and 42b are provided at intervals in the X direction, respectively. Further, the screw members 42b and 43b are screwed into the side plate 32 and are in contact with the other end side of each of the reflective members 42 and 43 in the Z direction in the Y direction. With this structure, the screw members 42b and 43b are elastically deformed in the Y direction so that the other ends of the reflective members 42 and 43 in the Z direction are close to each other, and the angle α of the inclination of the reflective surfaces 42a and 43a in the Y direction is adjusted. can do. For example, when the screw member 42b is rotated to increase the amount of protrusion of the screw member 42b in the irradiation device main body 30, the amount of elastic deformation of the reflection member 42 becomes large and the angle α becomes small.

The light from the first LED array 21 is collected in the Y direction by the rod lens 10 and is irradiated in a band shape at a predetermined irradiation position on the resin P transported in the predetermined transport direction A. Further, the light from the second LED array 22 is collected in the Y direction by the rod lens 10 and reflected by the reflecting member 42, and is irradiated on the resin P in a band shape. The light from the third LED array 23 is collected in the Y direction by the rod lens 10 and reflected by the reflecting member 43, and is irradiated on the resin P in a band shape.

As described above, according to the present embodiment, the same rod lens 10 has the light from the first LED array 21, the light from the second LED array 22, and the light from the third LED array 23. The light from the second LED array 22 is reflected by the reflecting member 42 and irradiated in a band shape at the irradiation position where the light from the first LED array 21 is irradiated in a band shape, and the third LED is also irradiated. The light from the array 23 is also reflected by the reflecting member 43 and irradiated in a band shape. Therefore, the light from the first, second, and third LED arrays 21, 22, and 23 is irradiated to the band-shaped irradiation position, and the amount of light emitted to the irradiation position can be increased.

Further, by bringing the position of the first LED array 21 and the position of the second LED array 22 closer to each other in the Y direction, and bringing the position of the rod lens 10 and the position of the reflecting member 42 closer to each other in the Y direction, the first position is obtained. The angle β formed by the optical axis L1 of the light from the LED array 21 and the optical axis L2 of the light reflected by the reflecting member 42 from the second LED array 22 can be reduced. The same applies to the third LED array 23 and the reflective member 43.

Further, in the state of FIG. 1, the LED substrates 22a and 23a are attached to the heat sink 31 so that the optical axis L2 and the optical axis L3 are tilted by 45 ° in the Y direction, and the first to third LED arrays 21, 22, 23 are attached. Although the angle β is about 15 ° in a state where the light from the light is irradiated to the same irradiation position, the inclination of the optical axes L2 and L3 in the Y-axis direction is reduced, and the positions of the LED substrate 22a and the LED substrate 23a are reduced. By bringing the position of the LED substrate 21a and the position of the LED substrate 21a closer to each other in the Y direction, the angle β can be made smaller.

Further, the screw members 42b and 43b are provided as an adjustment mechanism for adjusting the inclination of the reflection members 42 and 43 on the other end side in the Z direction (reflection surfaces 42a and 43a) in the Y direction. Therefore, the inclination of the reflecting surfaces 42a and 43a in the Y direction is adjusted by the screw members 42b and 43b, and the band-shaped irradiation position of the light from the second LED array 22 is moved to the upstream side in the transport direction A, for example. The band-shaped irradiation position of the light from the third LED array 23 can be moved, for example, to the downstream side in the transport direction A.

For example, in FIG. 1, since the band-shaped irradiation positions of the first, second, and third LED arrays 21, 22, and 23 are the same, the amount of light at each position in the irradiation position is large as shown in FIG. However, when the light irradiation position of the second LED array 22 is moved to the upstream side of the transport direction A by the width thereof and the light irradiation position of the third LED array 23 is not moved, the figure is shown in the figure. As shown in No. 3, the irradiation position becomes wider in the transport direction A, and the amount of light at each position in the irradiation position changes. When the light irradiation position of the second LED array 22 is moved to the upstream side of the transport direction A and the light irradiation position of the third LED array 23 is moved to the downstream side of the transport direction A, the irradiation width is increased. It can be expanded and at the same time the angle β can be made smaller.

In this way, by adjusting the inclination of the reflecting members 42, 43 in the Y direction on the other end side in the Z direction, the irradiation width of the irradiation position and the distribution of the amount of light can be adjusted. Since the optimum conditions for the width of the irradiation position and the amount of light differ depending on the type, shape, characteristics, transfer speed in the transfer direction A, etc. of the resin to be cured, the configuration is extremely advantageous in dealing with various situations.

Further, for example, it is possible to make the type of the ultraviolet LED of the first LED array 21 different from the type of the ultraviolet LED of the second LED array 22. For example, an ultraviolet LED having a light intensity peak in the vicinity of 405 nm can be used in the first LED array 21, and an ultraviolet LED having a light intensity peak in the vicinity of 365 nm can be used in the second LED array 22. In this case, in the state of FIG. 3, the resin P transported in the transport direction A is first irradiated with the light of the second LED array 22, and then the light of the first and third LED arrays 21 and 23 is emitted. It will be irradiated. Depending on the type, shape, characteristics, etc. of the resin, the wavelength of the ultraviolet rays that triggers curing and the wavelength of ultraviolet rays that promote curing may differ. In such a situation, it is effective to make different types of ultraviolet LEDs in each LED array 21, 22, 23.

In addition, in this embodiment, it is also possible to make the specification that the third LED array 23 is not provided. On the other hand, as shown in FIG. 4, for example, it is also possible to provide further other LED arrays such as the fourth LED array 24 and the fifth LED array 25. In this case, the light from the fourth LED array 24 and the light from the fifth LED array 25 are also irradiated on the resin P along the optical axes L4 and L5, respectively.

Further, the reflective surfaces 42a and 42b may be a concavely curved reflective surface, a reflective surface composed of a plurality of planes, or the like. For example, as shown in FIG. 5, the reflective surfaces 42a and 42b may be concave curved surfaces. By adjusting the degree of concave curvature, it is possible to bring the optical axes L2 and L3 and the optical axes L4 and L5 at the irradiation position closer to each other as shown in FIG. 5, and it is also possible to make them match.

The light irradiation device according to the second embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 6, this light irradiation device is a specification in which the first LED array 21 is not provided in the first embodiment. Further, in the second embodiment, since the first LED array 21 is not provided, the second LED array 22 is referred to as a first LED array, and the third LED array 23 is referred to as a second LED array. .. Further, the reflective member 42 is referred to as a first reflective member, and the reflective member 43 is referred to as a second reflective member.

Also in the present embodiment, as in the first embodiment, the same rod lens 10 is irradiated with the light from the first LED array 22 and the light from the second LED array 23, and the first LED array The light from the second LED array 23 is reflected by the reflecting member 43 and irradiated in a band shape at the irradiation position where the light from the 22 is irradiated in a band shape by the first reflecting member 42. Therefore, the light from the first and second LED arrays 22 and 23 is irradiated to the band-shaped irradiation position, and the amount of light emitted to the irradiation position can be increased.

Further, as in the first embodiment, the position of the first LED array 22 and the position of the second LED array 23 are brought closer to each other in the Y direction, and the position of the rod lens 10 and the positions of the reflecting members 42 and 43. And can be brought closer to the Y direction, and the inclination of the optical axes L2 and L3 in the Y axis direction can be reduced.
Further, as in the first embodiment, the inclination of the other end side (reflection surface 42a, 43a) in the Z direction of the reflection members 42, 43 in the Y direction is adjusted by the screw members 42b, 43b, and each LED array 22 is adjusted. , The irradiation position of the light from 23 can be adjusted in the transport direction A.

Further, as in the first embodiment, it is possible to make the type of the ultraviolet LED of the first LED array 22 different from the type of the ultraviolet LED of the second LED array 23, and the LED array 24 and the LED array 25 can be different. It is also possible to provide the reflective surfaces 42a and 42b as a concavely curved reflective surface, a reflective surface composed of a plurality of planes, and the like.

In the first embodiment, the position of each ultraviolet LED of the first LED array 21 and the position of each ultraviolet LED of the second LED array 22 are shifted in the X direction, and the second LED array 22 is used. It is also possible to shift the position of each ultraviolet LED of the third LED array 23 and the position of each ultraviolet LED of the third LED array 23 in the X direction. As a result, unevenness in the amount of light at the irradiation position is reduced.
Similarly, in the second embodiment, it is possible to shift the position of each ultraviolet LED of the first LED array 22 and the position of each ultraviolet ray of the second LED array 23 in the X direction.

Further, in the first and second embodiments, in order to reduce unevenness in the amount of light at the irradiation position, a diffuser lens that diffuses light is arranged between the rod lens 10 and the reflection members 42, 43 and the irradiation position. Is also possible. As the diffuser lens, for example, a fly-eye lens can be used, and a diffuser lens can be provided in the vicinity of the cover 33 or in place of the cover 33.

Further, in the first and second embodiments, the screw members 42b and 43b counteract the reaction force of the elastic deformation of the reflective members 42 and 43, and the other end side of the reflective members 42 and 43 in the Z direction is in the Y direction. Shown what to move to. On the other hand, an urging member such as a spring that urges the other ends of the reflecting members 42 and 43 in the Z direction away from each other is provided, and the screw members 42b and 43b reflect against the urging force of the urging member. The other end side of the members 42, 43 in the Z direction may be configured to move in the Y direction. In this case, even if the reflective members 42, 43 themselves are not elastically deformed, the other end of the reflective members 42, 43 in the Z direction is changed by changing the amount of protrusion of the screw members 42b, 43b in the irradiation device main body 30. The tilt of the side can be adjusted. It is also possible to configure an adjusting mechanism for adjusting the inclination of the reflecting members 42 and 43 in the Y direction by using other mechanisms such as a motor and gears instead of the screw members 42b and 43b.

Further, in the first and second embodiments, the positions of the reflective members 42 and 43 on the other end side in the Z direction in the Y direction can be adjusted, but the one end side of the reflective members 42 and 43 in the Z direction is adjustable. It may be configured to adjust the position of the above in the Y direction.
Further, in the first and second embodiments, the LEDs of the LED arrays 21, 22, 23, 24, and 25 are LEDs that emit visible light, and the light irradiating device irradiates the inspection target with light in a band shape. It may be configured. In this case, the band-shaped irradiation position can be observed using an inspection sensor, and the inspection can be speeded up by increasing the amount of light.

Further, each LED array 21, 22, 23, 24, 25 may be an LED array that irradiates different colors. For example, in FIG. 1, the first LED array 21 is an LED array that irradiates blue light, the second LED array 22 is an LED array that irradiates green light, and the third LED array 23 is red light. It can be an LED array to illuminate. As a result, it is possible to irradiate the irradiation position with blue, green, or red light, and it is also possible to irradiate light in which blue, green, and red light are mixed.

10 ... rod lens, 21 ... first LED array, 22 ... second LED array, 23 ... third LED array, 30 ... irradiation device main body, 31 ... heat sink, 32 ... side plate, 42, 43 ... reflective member, 42a, 43a ... Reflective surface, 42b, 43b ... Screw member, P ... Resin

Claims (5)

A rod lens extending in the X direction, having a convex curved surface having a curvature in the Y direction orthogonal to the X direction, and condensing the light radiated to the convex curved surface in the Y direction.
A first LED array in which LEDs are arranged in the X direction and irradiates a first predetermined range in the Y direction on the convex curved surface.
A second LED array in which LEDs are arranged in the X direction and irradiates a second predetermined range in the Y direction on the convex curved surface.
A reflecting member that reflects light from the second LED array that has passed through the rod lens is provided.
The reflective member forms a band of light from the second LED array that has passed through the rod lens at a predetermined irradiation position where the light from the first LED array that has passed through the rod lens is irradiated in a band shape. A light irradiation device that can irradiate. A rod lens extending in the X direction, having a convex curved surface having a curvature in the Y direction orthogonal to the X direction, and condensing the light radiated to the convex curved surface in the Y direction.
A first LED array that is aligned in the X direction and illuminates a first predetermined range in the Y direction on the convex curved surface.
A second LED array that is aligned in the X direction and illuminates a second predetermined range in the Y direction on the convex curved surface.
A first reflecting member that reflects light from the first LED array that has passed through the rod lens and irradiates a predetermined irradiation position in a band shape.
A light irradiation device including a second reflection member that can reflect light from the second LED array that has passed through the rod lens and irradiate the predetermined irradiation position in a band shape. A third LED array that is aligned in the X direction and irradiates a third predetermined range in the Y direction on the convex curved surface.
It comprises another reflective member that reflects light from the third LED array that has passed through the rod lens.
The light irradiation device according to claim 1, wherein the other reflective member can irradiate the predetermined irradiation position with light from the third LED array that has passed through the rod lens in a band shape. The light irradiation device according to any one of claims 1 to 3, further comprising an adjusting mechanism for adjusting the inclination of each reflecting member in the Y direction. The light irradiation device according to any one of claims 1 to 4, wherein the LED of the second LED array has a peak of the amount of light at a different wavelength with respect to the LED of the first LED array.

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