JP2013045606A - Light source unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source unit capable of achieving high waterproof characteristics in a prepared section of a window member and achieving high waterproof characteristics in the prepared section of the window member for a long period.SOLUTION: In the light source unit, a light source module having an LED board for preparing a plurality of LED elements is arranged in a cylindrical casing having an integral structure with no boundary so as to emit light from the LED elements forming the light source module via a window member with a light transparency which is arranged by being fixed to block an opening on one open section in one of open sections of the cylindrical casing. An annular seal section made of a caulking material with a liquid impermeability is formed on the whole periphery of the boundary between the cylindrical casing and the window member.

Description

The present invention relates to a light source unit including a plurality of LED (Light Emitting Diode) elements, and more specifically, an LED element that emits light in the ultraviolet light region as a light source, and a light source for fixing an ink or a resin composition. The present invention relates to a light source unit that can be suitably used as a light source.

Recently, an LED element that emits light in the ultraviolet region has been developed, and conventionally, an LED element that emits light in the ultraviolet region has used a discharge lamp in which mercury is enclosed as a light source. Use in various fields is being studied.
As a certain type of light source unit including an LED element that emits light in the ultraviolet light region, an LED substrate on which a plurality of LED elements are arranged is arranged on the upper surface of a heat sink, and its external shape is a rectangular parallelepiped. The light source module is covered with an aluminum cover member having an opening in front of the light emission direction of the light source module, and light from the LED elements constituting the light source module is opened by the cover member. The thing of the structure radiated | emitted via the glass-made window members provided so that it may block | close is disclosed (for example, refer patent document 1). In this light source unit, the cover member is formed by a plurality of plate-like members that are respectively fixed to the four side surfaces of the light source module by screw members.

Specifically, the light source unit having such a configuration, for example, as shown in Patent Document 1, is for fixing photocurable ink to a printing object such as paper in a photocurable inkjet printer apparatus. In addition, it has been studied to be used as a light source for curing a resin composition containing a photocurable resin in a photocuring apparatus.
Thus, when the light source unit is used as an ink fixing light source or a resin composition curing light source, dirt may adhere to the window member.
Specifically, when used as an ink fixing light source, when ink is ejected onto a print object, a portion of the ejected ink does not adhere to the print object and scatters around. Also, it adheres to the window member of the light source unit as dirt. In addition, the photocurable ink attached to the window member in this way may be cured by being irradiated with ultraviolet light, and may be adhered as dirt in the cured state.
Further, when used as a light source for curing a resin composition, siloxane contained in the resin composition evaporates and adheres to the window member of the light source unit. Occurs.
In this way, the deposit (dirt) adhering to the window member of the light source unit may be removed by wiping the window member with a cloth to which an organic solvent such as alcohol is attached. Depending on the wiping operation, for example, it is not possible to remove deposits or the like in a state where the photocurable ink is cured. In order to remove the deposits that cannot be wiped off in this way, it is necessary to immerse the entire outer surface of the window member on which the deposits of the window member are adhered for a certain period of time to wash away.

  However, in order to immerse the entire outer surface of the window member in the organic solvent, it is necessary to immerse the portion of the light source unit where the window member is disposed. When immersed in, for example, the organic solvent enters the cover member from the gap between the window member and the cover member, or the gap between the plate members constituting the cover member in the cover member, As a result, there is a problem that the LED element disposed inside the cover member is short-circuited.

  Further, in the light source unit having a structure in which the cover member is provided with a window member, dust enters the gap between the window member and the cover member, or the light source unit is made of an ink fixing light source or a resin composition. When used as a light source for curing, etc., dirt may enter or dirt (adhered matter) removed from the window member during the wiping operation of the attached matter attached to the window member of the light source unit may enter. In this way, there is a problem that harmful effects may occur due to dust and dirt entering the gap between the window member and the cover member. In addition, particularly when the window member is fixed using an adhesive, a liquid is applied to the adhesive joint portion of the window member by, for example, immersing the portion of the light source unit in which the window member is disposed in an organic solvent. The adhesive performance of the adhesive is reduced and the cylindrical casing is deteriorated due to the penetration of the light or the light (ultraviolet light) from the LED element being irradiated to the adhesive joint portion of the window member. There is a problem that sufficient adhesion cannot be obtained over a long period between the window member and the window member.

JP 2011-103261 A

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a light source unit that can obtain high waterproofness in the portion where the window member is disposed.
Another object of the present invention is to provide a light source unit capable of obtaining a high waterproof property over a long period of time at a portion where a window member is disposed.

The light source unit of the present invention includes a light source module including an LED substrate on which a plurality of LED elements are arranged, in a cylindrical casing having an integral structure without a boundary portion, in one opening of the cylindrical casing. It is arranged so that light from the LED element constituting the light source module is radiated through a window member having light transmittance, which is fixed so as to close the opening in one opening.
An annular seal portion made of a caulking material having liquid impermeability is formed over the entire circumference of the boundary between the cylindrical casing and the window member.

  In the light source unit of the present invention, a window member supporting convex portion is provided on the inner peripheral surface of the opening in the cylindrical casing, and the LED element constituting the light source module on the surface of the window member supporting convex portion It is preferable that the window member is adhesively bonded with an adhesive to the front region in the light emission direction where light from the light is shielded.

  In the light source unit of the present invention, it is preferable that a coking groove for filling a caulking material is formed at a boundary between the cylindrical casing and the window member.

According to the light source unit of the present invention, the cylindrical casing to which the window member is fixed has an integral structure without a boundary portion, and the entire boundary of the boundary is provided at the boundary between the window member and the cylindrical casing. Since an annular seal portion made of a caulking material having liquid impermeability is provided, the outer peripheral surface of the cylindrical casing has no gap communicating with the outside and the inside of the cylindrical casing, and the window member At the boundary between the cylindrical casing and the cylindrical casing, the gap that communicates the outside formed at the boundary and the inside of the cylindrical casing is reliably liquid-tightly closed by the caulking material that forms the annular seal portion. The casing constituted by the cylindrical casing and the window member has a high waterproof structure, and high waterproofness is obtained at the portion where the window member comprising the casing is provided.
Therefore, since the light source unit of the present invention has high waterproofness in the portion where the window member is disposed, even if the portion where the window member is disposed is immersed in the liquid for a long time, the tube Liquid does not enter the inside of the casing.
In the light source unit of the present invention, since the gap formed at the boundary between the window member and the cylindrical casing is closed by the caulking material forming the annular seal portion, No adverse effects caused by dirt and dirt entering.

  In the light source unit of the present invention, a window member supporting convex portion is provided on the inner peripheral surface of the opening in the cylindrical casing, and light from the LED elements constituting the light source module on the surface of the window member supporting convex portion is shielded. By adopting a configuration in which the window member is adhesively bonded to the front side region in the light emission direction that is in the state of being formed, the adhesive bonding portion of the window member can be positioned on the inner side of the annular seal portion, and the adhesive bonding portion Can be prevented from being irradiated with ultraviolet light, so that even if the adhesive does not have light resistance and liquid impermeability to ultraviolet light, it is irradiated with ultraviolet light. Or the penetration of liquid does not deteriorate the adhesive and deteriorate the adhesion performance, and the adhesion between the cylindrical casing and the window member is maintained. The boundary between the window member and the cylindrical casing is a state sealed in a liquid-tight maintained Te, the arranged partial of the window member, a high waterproof property can be obtained over a long period of time.

It is an explanatory perspective view which shows an example of a structure of the light source unit of this invention. It is a partial expanded sectional view for description which shows the structure inside the cylindrical casing in the light source unit of FIG. FIG. 2 is an explanatory perspective view showing a light source module constituting the light source unit of FIG. 1. It is explanatory drawing which shows the cylindrical casing which comprises the light source unit of FIG. 1, (a) is a perspective view for description of a cylindrical casing, (b) is an expanded sectional view for description of a cylindrical casing. It is an expanded sectional view for description which shows the structure of the boundary of the cylindrical casing and window member in the light source unit of FIG. It is explanatory drawing which shows the window member which comprises the light source unit of FIG. 1, (a) is a perspective view for description of a window member, (b) is an expanded sectional view for description of a window member. It is explanatory drawing which shows the optical path of the light from the LED element which comprises the light source module in the light source unit of FIG.

Embodiments of the present invention will be described below.
FIG. 1 is an explanatory perspective view showing an example of the configuration of the light source unit of the present invention. FIG. 2 is an explanatory partial enlarged sectional view showing an internal configuration of a cylindrical casing in the light source unit of FIG. FIG. 3 is a perspective view for explaining a light source module constituting the light source unit of FIG.
In this light source unit 10, a rectangular LED substrate 23 in which a plurality of LED elements 22 are arranged on an upper surface (the upper surface in FIGS. 2 and 3) is an upper surface of a heat sink 25 having a rectangular parallelepiped appearance (see FIGS. The light source module 20 is configured to be disposed on the upper surface in FIG. 3, and the light source module 20 is placed in one of the cylindrical casings 30 (FIG. 1 and FIG. 1) in a rectangular cylindrical cylindrical casing 30. 2 has a configuration in which light is emitted from a plurality of LED elements 22 constituting the light source module 20 from an upper opening (hereinafter also referred to as a “light emission opening”). . In the cylindrical casing 30, the LED substrate 23 constituting the light source module 20 is configured such that an opening having a light emission opening (hereinafter also referred to as “light emission opening”) is closed. Further, a window member 35 having light transmittance for protecting the plurality of LED elements 22 is provided in a state of being received in the light emission opening, and the window member 35, the cylindrical casing 30, A rectangular annular seal portion 40 made of a caulking material having liquid impermeability is formed on the entire boundary.
In the example of this figure, a power supply mechanism (not shown) for supplying power from an external power source to the light source module 20 is arranged on the lower surface (the lower surface in FIG. 2) of the heat sink 25 constituting the light source module 20. A plurality of metal plate-like members 18 </ b> A are screwed by the screw members 19 so as to cover the power supply mechanism and to close the other opening of the cylindrical casing 30 (downward in FIGS. 1 and 2). A combined casing 18 is provided, and the casing 18 and the cylindrical casing 30 form a cover member 15. Further, the casing 18 constituting the cover member 15 is provided with a power supply connector 17 for connection to an external power source. In the present embodiment, the metal plate-like member 18A is used as the plurality of constituent members for forming the casing 18, but the plurality of constituent members related to the casing 18 is not limited to the plate-like member but is a block-like one. It may be.

  As shown in FIG. 3, a plurality (32 in the example shown in the figure) of LED elements 22 are arranged in two rows at equal intervals on the surface of the LED substrate 23. A connector (not shown) for supplying power to the plurality of LED elements 22 is provided.

  As the LED element 22, one that emits light in the ultraviolet region, specifically, one having peak emission wavelengths of 365 nm, 385 nm, and 405 nm, for example, is used.

  As a base material which comprises LED board 23, the appropriate thing according to the kind etc. of LED element 22 is used, for example, the thing made from aluminum nitride etc. can be used.

  As shown in FIG. 3, the heat sink 25 is for cooling the LED elements 22 arranged on the LED substrate 23. A flow path for flowing a cooling medium such as cooling water is formed, a supply unit (not shown) for supplying the cooling medium to the flow path, and the cooling medium from the flow path A discharge portion (not shown) for discharging the LED is provided in a region other than the region where the LED substrate 23 is located on the outer surface of the heat sink body 25A. In the present embodiment, a heat sink configured to perform cooling using a cooling medium is shown. However, the heat sink may be configured to be forcibly cooled by a fan such as a heat sink with a fan.

As shown in FIG. 4, the cylindrical casing 30 has an integral structure without a boundary portion.
Here, in this specification, the “integrated structure without a boundary portion” means a structure having no joint portion obtained by, for example, forming integrally by cutting or the like, or a plurality of members. Although the joint portion is formed by joining, for example, by welding, the joint portion is formed so that there is no gap between the joint portions.
In the example of this figure, the cylindrical casing 30 has a rectangular cylindrical shape and has four side portions, but these four side portions 30A, 30B, 30C, 30D are continuous, It does not have a joint part and a boundary part. Further, on the outer peripheral surface of the cylindrical casing 30, each of the edge angles is chamfered. The cylindrical casing 30 in the present embodiment is integrally formed by cutting a metal block, and has a joint portion and a boundary portion between the side portions adjacent to each other in the four side portions. However, the cylindrical casing is formed by joining, for example, four plate-like members by welding or the like, and the four joint portions where the plate-like members are joined together have gaps in the joint portions. The thing of the structure formed without there may be sufficient.

The cylindrical casing 30 accommodates the light source module 20 and forms a window member receiving space for receiving the window member 35 in the light emission opening.
In the example of this figure, the window member receiving space is formed by the inner peripheral surface of the light radiating opening in the cylindrical casing 30 and a window member supporting convex portion 33 which will be described later. Has a depth that allows it to be disposed below the level at which the tip surface 31 of the cylindrical casing 30 on the light emission opening side is located (downward in FIG. 2). Specifically, the depth of the window member receiving space (the separation distance between the tip surface 31 of the cylindrical casing 30 and the side surface 33A of the window member supporting convex portion 33) is 2 mm.

The cylindrical casing 30 has an appropriate shape according to the components to be accommodated therein, specifically, the light source module 20, the window member 35, and the like. In the case of being used, it is preferable to make it small (for example, 2.5 mm or less) in order to prevent the discontinuous region of light emission from becoming large by bringing the window members 35 in the light source units 10 adjacent to each other close to each other.
In the example of this figure, the cylindrical casing 30 has an inner peripheral surface that surrounds the window member receiving space, with the portion relating to the inner peripheral surface surrounding the window member receiving space having a larger thickness than the other portions. The thickness of the part which concerns on a surface is 3.4 mm. As for the thickness of the other part (the part other than the part related to the inner peripheral surface surrounding the window member receiving space), it is preferable that the thickness of the short side surfaces (side surfaces 30A, 30C) is small. Since the side surfaces (side portions 30B and 30D) need to retain mechanical strength, the thickness of the side surface of the long side is larger than the thickness of the side surface of the short side. The thickness of the side surface of the side can be 1.5 mm.

As the material of the cylindrical casing 30, a metal or a resin having chemical resistance against an organic solvent used for removing deposits (dirt) attached to the outer surface 36 of the window member 35 is used. Specifically, aluminum etc. are mentioned, for example.
In the example of this figure, the entire outer peripheral surface of the cylindrical casing 30 is subjected to black alumite treatment from the viewpoint of preventing light scattering. Moreover, the area | region (henceforth a "below,""light from the LED element 22 which comprises the light source module 20 to the window member 35 currently fixed to the light emission opening part in the internal peripheral surface of the cylindrical casing 30 (henceforth" The optical path enclosing surface is also mirror-finished from the viewpoint of radiating light from the LED element 22 constituting the light source module 20 from the window member 35 with high efficiency.

Further, the cylindrical casing 30 is provided with a window member supporting convex portion 33 on the inner peripheral surface of the light emission opening portion, and the LED constituting the light source module 20 on the surface of the window member supporting convex portion 33 is provided. A window member 35 is adhesively bonded and supported and fixed by an adhesive (hereinafter also referred to as “window member fixing adhesive”) in a light radiation direction front side region where light from the element 22 is shielded. Thus, the window member 35 is fixed at the light emission opening of the cylindrical casing 30.
The window member supporting convex portion 33 is formed of a rectangular annular flange extending along the inner peripheral edge 31A that forms the light radiation opening over the entire circumference of the inner peripheral surface of the light radiation opening. Projecting in a direction perpendicular to the peripheral surface, the cross-sectional shape is a square shape.
And as shown in FIG. 5, the light emission direction front side in the surface perpendicular | vertical to the internal peripheral surface of the cylindrical casing 30 in the surface of the convex part 33 for window member support, ie, the side surface of the convex part 33 for window member support. A peripheral portion of the inner surface 37 of the window member 35 is positioned on the side surface (hereinafter also referred to as “window member mounting surface”) 33A (the upper side in FIG. 5). A window member fixing adhesive layer 45 made of a window member fixing adhesive is formed in a gap between the peripheral edge portion of the plate and the window member mounting surface 33A. This window member fixing adhesive layer 45 is on the window member mounting surface 33 </ b> A where light from the LED elements 22 constituting the light source module 20 in the surface of the window member supporting convex portion 33 is shielded. It is formed only in the region, and is not formed in a region other than the window member mounting surface 33A, that is, a region irradiated with light from the LED element 22 constituting the light source module 20.
In the example of this figure, the window member supporting convex portion 33 is provided integrally with the cylindrical casing 30, and the window member supporting convex portion 33 and the cylindrical casing 30 have an integral structure without a boundary portion. Is. In the present embodiment, the cylindrical casing 30 provided with the window member supporting convex portion 33 integrally does not have a joint portion formed by cutting a metal block. An integral structure having no boundary portion can be formed between the window member supporting convex portion and the cylindrical casing by joining the cylindrical members by welding or the like.
Further, a region other than the window member mounting surface 33A surrounding the window member receiving space on the surface of the window member supporting convex portion 33, specifically, a side surface 33B on the rear side in the light emission direction (the lower side in FIG. 5) and the tip. Like the optical path surrounding surface of the cylindrical casing 30, the surface 33C is mirror-finished.

The dimension of the window member supporting convex portion 33 in the direction perpendicular to the inner peripheral surface of the cylindrical casing 30 (hereinafter, also referred to as “projection height”) is sufficient for the window member supporting convex portion 33 to make the window member 35 sufficient. It is preferable that the dimensions be such that the light from the plurality of LED elements 22 constituting the light source module 20 is not irradiated onto the annular seal portion 40 as needed.
In the example of this figure, the protruding height of the projection 33 for supporting the window member is 2.1 mm from the inner peripheral surface of the cylindrical casing 30 surrounding the window member receiving space, and from the optical path surrounding surface. The protruding height is 3 mm.

As the adhesive for fixing the window member for fixing the window member 35, an appropriate material according to the material of the projection 33 for supporting the window member, the material of the window member 35, and the material of the cylindrical casing 30 as necessary, etc. However, from the viewpoint of workability of applying the window member fixing adhesive to the window member mounting surface 33A of the window member supporting convex portion 33, one having a low viscosity is preferable. For example, a silicone rubber adhesive or the like is used. Can be used.
Preferable specific examples of the silicone rubber-based adhesive include thermosetting types such as “KER-2600 (A / B)” and “KER-2500 (A / B)” (both manufactured by Shin-Etsu Chemical Co., Ltd.). Things.

As shown in FIG. 6, the window member 35 is, for example, a flat plate shape having a thickness of 1.75 mm. The window member 35 is received in the window member receiving space in the light emission opening of the cylindrical casing 30 and emits light from the cylindrical casing 30. It has a shape applied to the light emission opening so that the opening can be closed.
In the illustrated example, the window member 35 is a rectangular flat plate having a vertical and horizontal dimension slightly smaller than the vertical and horizontal dimensions of the light emitting opening of the cylindrical casing 30, and as shown in FIG. Are disposed so as to be located on the inner side of the inner peripheral surface surrounding the window member receiving space of the cylindrical casing 30 over the entire circumference, and the outer peripheral surface 38 of the window member 35 and the window member receiving portion of the cylindrical casing 30. Between the inner peripheral surface surrounding the space, a gap is formed over the entire periphery. Further, in this gap, a window member fixing adhesive layer 45 is formed in a region (inner region) on the rear side in the light emission direction (lower side in FIG. 5), and on the front side in the light emission direction. In a region (outside region in FIG. 5) (a region on the outer side), a caulking material is filled as described later. In addition, the area where the window member fixing adhesive layer 45 is formed in the gap is not irradiated with direct light from the LED elements 22 constituting the light source module 20.

  As a material of the window member 35, the window member 35 has a light transmissive property capable of transmitting light from the LED elements 22 constituting the light source module 20, and deposits (dirt) adhered to the outer surface 36 of the window member 35. Glass or resin having chemical resistance against the organic solvent used for removal is used. Specific examples include borosilicate glass.

Further, the window member 35 is chamfered at the edge angle on the front side in the light emission direction (the upper side in FIG. 6B), so that the entire circumference is provided between the outer surface 36 and the outer peripheral surface 38. A chamfered surface 39 is formed, and the chamfered surface 39 and the outer peripheral surface 38 constitute a peripheral portion of the window member 35.
In the example shown in the figure, the window member 35 is chamfered at 45 °, and the thickness of the portion related to the outer peripheral surface 38 (the separation distance between the inner surface 37 and the chamfered surface 39) is 0.75 mm.

The boundary between the window member 35 and the cylindrical casing 30 is formed by the peripheral edge portion of the window member 35 and the inner peripheral surface surrounding the window member receiving space of the cylindrical casing 30, and the boundary includes The caulking groove for filling the caulking material with the gap formed between the peripheral edge of the window member 35 and the inner peripheral surface surrounding the window member receiving space of the cylindrical casing 30 over the entire circumference. 42 is formed.
By forming the coking groove 42 at the boundary between the window member 35 and the cylindrical casing 30, it is possible to control the formation position and dimensions of the annular seal portion 40, and therefore, the radiation is radiated through the window member 35. The progress of light from the LED elements 22 constituting the light source module 20 can be prevented from being obstructed by the annular seal portion 40.

The caulking groove 42 preferably has a shape in which the groove width decreases as the groove depth increases from the viewpoint of workability for filling the caulking material and positioning of the window member 35.
Moreover, it is preferable that the groove depth of the coking groove | channel 42 is 0.9-1.75 mm.
In the example of the figure, the caulking groove 42 is formed in the light emitting direction front of the inner peripheral surface surrounding the window member receiving space in the cylindrical casing 30, the chamfered surface 39 of the window member 35, and the outer peripheral surface 38 continuous to the chamfered surface 39. The groove width decreases as the groove depth increases, the cross-sectional shape is a substantially right triangle, the maximum groove width is 1 mm, and the minimum groove width. Is 0.1 mm, and the maximum groove depth (the maximum groove depth from the outer surface 36 of the window member 35) is 1.75 mm.

  The annular seal portion 40 is a gap between the boundary surface formed by the inner peripheral surface of the light emission opening in the cylindrical casing 30 and the peripheral portion of the window member 35 at the boundary between the cylindrical casing 30 and the window member 35. The window member 35 and the cylindrical casing 30 are bonded to each other so that the outside and the inside of the light source unit 10, that is, the inside of the cylindrical casing 30 do not communicate with each other through the gap. It is provided so as to surround the periphery of the window member 35 on the outer side of the portion (upper side in FIG. 5).

From the viewpoint of using the light from the LED element 22 constituting the light source module 20 radiated through the window member 35 with high efficiency, the annular seal portion 40 is a front end surface of the cylindrical casing 30 on the light radiation opening side. It is preferably located in the region below the level where 31 is located (the lower side in FIG. 5) and formed so as not to cover the outer peripheral edge 36 </ b> A on the outer surface 36 of the window member 35. . Further, from the viewpoint of unit arrangement, the outer peripheral edge 36A of the outer surface 36 of the window member 35 and the inner peripheral edge 31A of the distal end forming the light emission opening in the cylindrical casing 30 are not covered and do not protrude from the distal end surface 31. It is preferable to be formed.
In the example of this figure, the annular seal portion 40 is formed by filling the caulking groove 42 with a caulking material, and is below the level where the front end surface 31 on the light emission opening side of the cylindrical casing 30 is located. In addition, the inner peripheral edge 41A of the annular seal portion 40 is located below the level where the outer peripheral edge 36A of the outer surface 36 of the window member 35 is located, and the annular seal portion 40 The outer peripheral edge 41B is located below the level of the inner peripheral edge 31A that forms the light emission opening in the cylindrical casing 30, and the outer peripheral edge 36A of the window member 35 and the inner end of the cylindrical casing 30 The peripheral edge 31A is exposed over the entire circumference. In such a state, when a curing process or the like is performed by bringing the inner peripheral edge 31A of the cylindrical casing 30 into surface contact with a light irradiation object or the like and performing a curing process or the like, a certain distance can be ensured and a stable irradiation amount can be secured. There are advantages such as.

The caulking material for forming the annular seal portion 40 has liquid impermeability and chemical resistance against an organic solvent used to remove deposits (dirt) attached to the outer surface 36 of the window member 35. When light is emitted from the LED element 22 constituting the light source module 20 to the annular seal portion 40 due to the structure of the light source unit 10, light resistance as well as liquid impermeability and chemical resistance are used. It is preferable that it has the property (ultraviolet light resistance).
As a specific example of the caulking material, for example, a silicone-based caulking material can be used, and as a preferable specific example of the silicone-based caulking material, for example, “S-45W” (manufactured by Shin-Etsu Chemical Co., Ltd.) and “ One-component room-temperature curing type such as “TOSSEAL381W” (Mentive Performance Materials Japan GK), and one-component thermosetting type such as “TSE3261-G” (Mentive Performance Materials Japan GK) Can be mentioned.

According to the light source unit 10 having the above configuration, the cylindrical casing 30 to which the window member 35 is fixed has an integral structure without a boundary portion, and at the boundary between the window member 35 and the cylindrical casing 30, Since the annular seal portion 40 made of a caulking material having liquid impermeability is provided over the entire circumference of the boundary, the outside and the inside of the cylindrical casing 30 communicate with each other on the outer peripheral surface of the cylindrical casing 30. In addition, at the boundary between the window member 35 and the cylindrical casing 30, there is a peripheral portion formed by the outer peripheral surface 38 and the chamfered surface 39 of the window member 35 constituting the boundary, and the window member of the cylindrical casing 30. The caulking material formed between the inner peripheral surface surrounding the receiving space and communicating with the outside and the inside of the cylindrical casing 30 is a caulking material that forms the annular seal portion 40. Therefore, the casing having the window member 35 fixed to the cylindrical casing 30 has a highly waterproof structure, and the arrangement of the window member 35 made of the casing is provided. High waterproofness is obtained in the part.
Accordingly, since the light source unit 10 has a high waterproof property at the portion where the window member 35 is disposed, the portion where the window member 35 is disposed is immersed in the liquid for a long time of 2 hours. However, the liquid does not enter the inside of the cylindrical casing 30.
Further, since the light source unit 10 is in a state in which the gap formed at the boundary between the window member 35 and the cylindrical casing 30 is closed by the caulking material constituting the annular seal portion 40, No harmful effects are caused by the entry of dust and dirt.

Further, in the light source unit 10, the window member 35 is adhesively bonded to the window member mounting surface 33 </ b> A of the window member supporting convex portion 33 provided on the inner peripheral surface of the cylindrical casing 30 with a window member fixing adhesive. On the window member mounting surface 33A, as shown in FIG. 7, the light from the LED elements 22 constituting the light source module 20 is shielded by the side surface 33B and the tip surface 33C of the window member supporting convex portion 33. Therefore, the window member fixing adhesive that fixes the window member 35 is not irradiated with light (ultraviolet light). Here, in FIG. 7, an example of an optical path of light from the LED element 22 is indicated by an arrow, and the optical path L1 is an example of an optical path of light emitted in a direction from the LED element 22 toward the window member 35. The optical path L2 is an example of an optical path of light that is emitted from the LED element 22 in a direction toward the distal end surface 33C of the window member supporting convex portion 33, and reflected by the distal end surface 33C. The optical path L3 is a window from the LED element 22 to the window. This is an example of an optical path of light emitted in a direction toward the side surface 33B of the member supporting convex portion 33 and reflected by the side surface 33B.
In addition, since the bonded joint portion of the window member 35 is located on the inner side of the annular seal portion 40, the window member 35 of the light source unit 10 can be disposed even when it is immersed in the liquid. The window member fixing adhesive that fixes the member 35 does not come into contact with the liquid.
Therefore, according to the light source unit 10, even if the window member fixing adhesive does not have ultraviolet light resistance and liquid impermeability, the ultraviolet light is irradiated or the liquid penetrates. As a result, the adhesive for fixing the window member is not deteriorated, whereby the adhesive performance of the adhesive for fixing the window member is not lowered, and the adhesion between the cylindrical casing 30 and the window member 35 is maintained. Since the boundary between the window member 35 and the cylindrical casing 30 is liquid-tightly sealed by the annular seal portion 40, high waterproofness can be obtained over a long period of time at the portion where the window member is disposed.

The light source unit 10 is a fixing light source for fixing a photocurable ink to a printing object such as paper in a photocurable ink jet printer apparatus, or a resin containing a photocurable resin in a photocurable apparatus. It can be suitably used as a curing light source for curing the composition.
That is, according to the light source unit 10, even when dirt is attached to the window member 35 using it as a light source for fixing an ink or a light source for curing a resin composition, the dirt is removed from the inside of the cylindrical casing 30. The window member of the light source unit 10 is disposed in the organic solvent without adverse effects such as the LED element 22 constituting the light source module 20 being short-circuited due to the organic solvent entering. By soaking, the entire surface of the outer surface 36 to which the window member 35 is contaminated can be washed away by immersing it in an organic solvent for a certain period of time. Moreover, dirt such as dust does not enter the gap formed at the boundary between the window member 35 and the cylindrical casing 30, and the dirt attached to the window member 35 is wiped with a cloth to which an organic solvent is attached. Since the dirt removed from the window member 35 does not enter during the operation, there is no problem caused by dust and dirt entering the gap.

The light source unit of the present invention is not limited to the above embodiment, and various modifications can be made.
For example, the projection for supporting the window member may not extend over the entire circumference of the inner peripheral surface of the light emission opening as long as the window member can be sufficiently supported and fixed, and the cylindrical casing. It does not have to have an integral structure.
In addition, the caulking groove is formed by chamfering the edge angle on the front side in the light emission direction of the window member, as long as the caulking material can be filled at the boundary between the window member and the cylindrical casing. However, the inner peripheral surface surrounding the window member receiving space of the cylindrical casing may be formed into a tapered shape, and the inner surface surrounding the window member receiving space of the cylindrical casing may be formed. The peripheral surface may be tapered and formed by chamfering the edge angle on the front side in the light emission direction of the window member.

DESCRIPTION OF SYMBOLS 10 Light source unit 15 Cover member 17 Power supply connector 18 Casing 18A Plate-shaped member 19 Screw member 20 Light source module 22 LED element 23 LED board 25 Heat sink 25A Heat sink main body 30 Cylindrical casing 30A, 30B, 30C, 30D Side surface part 31 End surface 31A Front edge inner peripheral edge 33 Window member supporting convex portions 33A, 33B Side surface 33C Front end face 35 Window member 36 Outer surface 36A Outer peripheral edge 37 Inner surface 38 Outer peripheral surface 39 Chamfered surface 40 Annular seal portions 41A, 41B Peripheral 42 Caulking groove 45 Window member fixing Adhesive layer

Claims (3)

A light source module including an LED substrate on which a plurality of LED elements are arranged has an opening in the one opening in the cylindrical casing having an integral structure without a boundary portion. It is arranged so that light from the LED elements constituting the light source module is radiated through a light-transmissive window member provided so as to be closed.
An annular seal portion made of a caulking material having liquid impermeability is formed over the entire circumference of the boundary between the cylindrical casing and the window member.   A window member supporting convex portion is provided on the inner peripheral surface of the opening in the cylindrical casing, and light from the LED elements constituting the light source module on the surface of the window member supporting convex portion is shielded. The light source unit according to claim 1, wherein a window member is adhesively bonded to the front side region in the light emission direction by an adhesive. The light source unit according to claim 1, wherein a coking groove for filling a caulking material is formed at a boundary between the cylindrical casing and the window member.