TWI451039B - Led unit - Google Patents

Description

LED unit

The invention relates to a light emitting diode (LED) unit.

Conventionally, there has been provided a light source device using a discharge lamp or a laser oscillator as a light source, but in recent years, for the purpose of low power consumption or long life, a method has been proposed. An LED unit that uses an LED (light emitting diode) as a light source instead of a discharge lamp or the like.

In order to obtain the same amount of light as the previous light source device using a discharge lamp or the like, a plurality of LEDs are used in the LED unit. Moreover, after the LED is energized to cause the LED to emit light, the LED will generate heat. At this time, if the number of LEDs is small, there is no problem. However, if a plurality of LEDs are used as in the above-described LED unit, the amount of heat generated by the LEDs increases. Moreover, since the life of the LED has a negative temperature coefficient, if the amount of heat generation increases, the life of the LED is shortened. Therefore, in the LED unit as described above, a plurality of LEDs are mounted on the heat radiating member, and a refrigerant such as cooling water flows into the heat radiating member to cool the LED (for example, Refer to Patent Document 1).

Moreover, as a use of the LED unit, for example, a light source device (ultraviolet curing device) using an LED that emits ultraviolet rays can be used. Such a light source device is used in a printing system that performs printing, and the printing system irradiates ultraviolet rays to an ultraviolet curing material that is cured by receiving ultraviolet rays. For example, an ultraviolet curable ink (ink) hardens (drys) the ultraviolet curable ink.

Fig. 7 is a view showing a schematic configuration of a conventional LED unit 10 used in the above printing system. In addition, the upper, lower, left and right sides of FIG. 7 will be described below as the up, down, left, and right directions.

The conventional LED unit 10 includes a plurality of LEDs 1 that emit ultraviolet rays, and a heat dissipating member 102 that is formed in an elongated shape having a length L1 in the left-right direction, and LEDs 1 are mounted side by side in the left-right direction on the upper surface.

Further, the heat radiating member 102 includes a flow path 103 for flowing a refrigerant (cooling water) therein, and the refrigerant (cooling water) is used for cooling the LED 1. The flow path 103 is provided along the left-right direction of the heat dissipation member 102. That is, the length of the flow path 103 in the left-right direction is also L1. Further, the heat dissipating member 102 is provided with an inflow port 105 for allowing the refrigerant to flow into the flow path 103 on the right surface, and the heat dissipating member 102 is provided with an outflow port 106 on the left surface for allowing the refrigerant to flow from the flow path. 103 out.

Further, a chiller 4 is connected to the inflow port 105 and the outflow port 106. The cooler 4 has a pump function of flowing the refrigerant into the flow path 103, and cools the refrigerant. Further, as shown by the arrow in FIG. 7, a circulation path of the refrigerant is formed, and the refrigerant circulation path means that the refrigerant discharged from the cooler 4 flows into the flow path 103 via the inflow port 105, passes through the flow path 103, and passes through the outflow port 106. On the other hand, it flows out, and then flows into the cooler 4 again, and the cooler 4 cools the refrigerant.

Further, heat generated by the lighting of the LED 1 is conducted to the refrigerant flowing through the flow path 103 via the heat radiating member 102. The heated refrigerant is cooled by the cooler 4 After cooling, it flows into the flow path 103 again. Thereby, the heat generated from the LED 1 is released.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-66387

FIG. 8 shows the distribution of the temperature of the refrigerant in the flow path 103. When the temperature of the refrigerant is compared before and after passing through the flow path 103, since the refrigerant passes through the flow path 103, heat generated by the lighting of the LED 1 is absorbed, so that the refrigerant passes through the flow path 103. The temperature is higher. That is, as the refrigerant flows from the inflow port 105 to the outflow port 106, the temperature of the refrigerant rises, so that the heat dissipation of the LED 1 decreases as it approaches the outflow port 106.

Moreover, FIG. 9(a) shows the distribution of the irradiation intensity in the irradiation area A1 of the LED unit 10, and the LED unit 10 is comprised by each LED1 attached to the heat radiating member 102. As shown in FIG. 9( a ), the irradiation intensity in the vicinity of both ends of the irradiation region A1 is insufficient and cannot be used for printing, so that the irradiation region A2 is ineffective. Therefore, the irradiation area obtained by removing the ineffective irradiation area A2 at both ends from the irradiation area A1 becomes an effective irradiation area A3 usable for printing.

Fig. 9(b) is a schematic view showing printed whole fabrics 71 to 73 which are irradiated with ultraviolet rays by the respective LEDs 1. Fig. 9(b) is a cross-sectional view showing the width of each of the entire printing sheets 71 to 73. The widths of the printed entire sheets 71 to 73 are different from each other, and the width is expanded in accordance with the order in which the entire sheets 71, 72, and 73 are printed. Further, the entire printing cloth 73 has, for example, a width dimension corresponding to the effective irradiation area A3.

Further, the above-described printing system using the light source device including the LED unit 10 includes a configuration in which ultraviolet rays are irradiated to the entire printing cloth. When printing is performed at 71 to 73, the irradiation range of the LED 1 can be changed according to the width of the entire printing cloth 71 to 73. Further, when the entire printing sheets 71 to 73 are placed in the printing system, the center P1 in the width direction of each of the entire printing sheets 71 to 73 and the center of the heat dissipation member 102 (LED unit 10) in the left-right direction are printed. In the P2 direction, the entire printing cloth 71-73 is placed in the printing system.

Therefore, when the printing full-width cloth 73 having a large width is printed, all the LEDs 1 on the heat radiating member 102 are turned on, and when the printing full-width cloth 71 having a narrow width is printed, the left and right sides of the heat radiating member 102 are attached. LED1 (hereinafter referred to as central portion LED1) near the center of the direction is turned on.

Therefore, even when the ultraviolet ray is irradiated to any one of the printing full fabrics 71 to 73 having different widths for printing, the central portion LED 1 must be turned on. Therefore, since the frequency of use of the central portion LED 1 is increased, the central portion LED 1 reaches a high temperature, and there is a problem that the life of the central portion LED 1 is shortened. Therefore, it is necessary to improve the heat dissipation of the central portion LED1.

However, since the inflow port 105 and the outflow port 106 of the refrigerant are provided at both ends of the heat dissipating member 102, the temperature of the refrigerant rises when the refrigerant reaches directly below the central portion LED1, so that the central portion LED1 cannot obtain sufficient heat dissipation. .

Further, since the LED 1 attached to the vicinity of the inflow port 105 and the outflow port 106 has a low frequency of use, the life of the LED 1 is long, and in particular, the temperature of the refrigerant of the LED 1 attached to the vicinity of the inflow port 105 is low, so that the life is further increased. Therefore, there is a problem that the unevenness of the life of the central portion LED 1 and the LED 1 attached to the vicinity of the inflow port 105 and the outflow port 106 becomes large.

The present invention has been made in view of the above circumstances, and an LED unit capable of improving heat dissipation of an LED provided near a center of an LED unit and having a high frequency of use, thereby realizing a long life of the LED, and The life of the LED as a whole is uniformized.

An LED unit according to an embodiment of the present invention includes: one or a plurality of LEDs; and a heat dissipating member formed in an elongated shape having a mounting surface on which the LED is mounted, and having a flow path inside, the flow path causing the refrigerant to follow The flow path is formed in the flow path at an approximate center in the longitudinal direction of the heat dissipating member, and an inflow port of the refrigerant is formed on one end side and the other end side in the longitudinal direction of the heat dissipating member.

Preferably, the plurality of heat dissipating units having the mounting surface and having the flow path therein are connected to each other along the longitudinal direction, thereby constituting the heat dissipating member.

According to one embodiment of the present invention, it is possible to improve the heat dissipation of the LED provided near the center of the LED unit and having a high frequency of use, thereby realizing the life of the LED and uniformizing the life of the LED as a whole. .

The objects and features of the present invention will become apparent from the following description of the preferred embodiments.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings which form a part of this specification. In the whole schema, the phase The same or similar portions are denoted by the same reference numerals and the description is omitted.

(embodiment)

The LED unit 20 of the present embodiment is used, for example, in a light source device (ultraviolet curing device) including an LED 1 that emits ultraviolet rays. Such a light source device is used in a printing system that performs printing, and the printing system irradiates ultraviolet rays to an ultraviolet curable material that is cured by ultraviolet rays, for example, an ultraviolet curable ink, and the ultraviolet curable ink is cured (dried).

Fig. 1 is a view showing a schematic configuration of an LED unit 20 of the present embodiment. In addition, the upper, lower, left and right sides of FIG. 1 will be described below in the up, down, left, and right directions.

As shown in FIG. 1 , the LED unit 20 of the present embodiment includes a plurality of LEDs 1 that emit ultraviolet rays, and a heat dissipating member 2 that is formed in a long shape having a length L1 in the left-right direction and has a mounting surface on which the LEDs 1 are mounted. Further, there are flow paths 31 and 32 inside, and the flow paths 31 and 32 flow the refrigerant in the left-right direction.

The LED 1 is an ultraviolet light emitting diode having a peak wavelength in the ultraviolet region. Further, as shown in FIG. 2, a mounting surface is formed on the upper surface of the heat radiating member 2, and a plurality of LEDs 1 are mounted in a row in the left-right direction.

The six heat radiating units 21 are coupled to each other in the left-right direction, thereby constituting the heat radiating member 2.

3 is a plan view showing the heat dissipation unit 21 and the LEDs 1 mounted on the heat dissipation unit 21. The heat dissipation unit 21 is made of high thermal conductivity The metal such as copper is formed into a rectangular plate shape, and the upper surface includes a mounting surface, and the plurality of LEDs 1 are mounted on the mounting surface in a row along the left-right direction. Further, as shown in FIG. 4, the heat radiating unit 21 includes a flow path 3 for flowing a refrigerant (cooling water) therein, and the refrigerant (cooling water) is used for cooling the LED 1. The flow path 3 is formed in a cylindrical shape and is provided along the left-right direction of the heat dissipation unit 21.

Further, when the heat radiating units 21 are connected to each other and the flow paths 3 are connected to each other, the flow path 3 is connected to each other by the pipe connecting member 8. Thereby, the flow paths 3 can be reliably connected to each other, and leakage of the refrigerant at the joint portion can be prevented.

Further, the six heat radiating units 21 are coupled in the left-right direction to constitute the heat radiating member 2. Furthermore, in order to individually recognize the heat radiating unit 21, the heat radiating units 21 are referred to as heat radiating units 211 to 216 in the order from left to right in FIG.

In the present embodiment, each of the flow paths 3 provided in the heat radiating units 211 to 213 is connected by the pipe connecting member 8, and a flow path 31 having a length L2 in the left-right direction is formed. In the same manner, each of the flow paths 3 provided in the heat radiating units 214 to 216 is connected by the pipe connecting member 8 to constitute a flow path 32 having a length L2 in the left-right direction. Further, the flow path 31 is not connected to the flow path 32, and the partition wall 22 is provided between the flow path 31 and the flow path 32. In other words, the heat radiating member 2 includes two flow paths 31 and 32 which are divided left and right at the center in the left-right direction.

Further, the inflow ports 51 and 52 for allowing the refrigerant to flow in, and the outflow ports 61 and 62 for allowing the refrigerant to flow out are connected to the flow paths 31 and 32.

The inflow ports 51 and 52 are cylindrical members having a flow path inside, and the flow path is for allowing the refrigerant to flow into the flow paths 31 and 32 from the downward direction. The inflow port 51 is disposed such that the upper surface comes into contact with the right end of the lower surface of the heat radiating unit 213, and the heat radiating unit 213 is located at the right end of the flow path 31. Further, the inflow port 52 is disposed such that the upper surface comes into contact with the left end of the lower surface of the heat radiating unit 214, and the heat radiating unit 214 is located at the left end of the flow path 32. In other words, the inflow ports 51 and 52 are provided adjacent to each other with the following portions interposed therebetween, and the portions are spaced apart from both ends of the heat dissipating unit 21 by L2 (L1/2). In the present embodiment, the inflow ports 51 and 52 are provided in the above-described position, and the inflow ports 51 and 52 are provided in the center of the heat dissipating member 2 in the left-right direction.

Further, the outflow ports 61 and 62 are cylindrical members having a flow path inside, and the flow paths are for allowing the refrigerant passing through the flow paths 31 and 32 to flow downward. The outflow port 61 is provided such that an upper portion of the right surface comes into contact with the left surface of the heat radiating unit 211, and the heat radiating unit 211 is located at the left end of the flow path 31. Further, the outflow port 62 is provided such that an upper portion of the left surface comes into contact with the right surface of the heat radiating unit 216, and the heat radiating unit 216 is located at the right end of the flow path 32.

Further, the cooler 4 is connected to the inflow ports 51 and 52 and the outflow ports 61 and 62 via a flow path (not shown). The cooler 4 has a pump function of allowing the refrigerant to flow into the two inlets of the inflow ports 51 and 52. The cooler 4 cools the refrigerant flowing out of the outflow ports 61 and 62, and flows the refrigerant again through the inflow ports 51 and 52. Flow paths 31, 32. That is, as shown by the arrow in Fig. 1, the circulation path of the refrigerant includes the circulation path "cooler 4 → flow inlet 51 → flow path 31 → flow outlet 61 → cooler 4", and the circulation path "cooler 4 → flow inlet" 52→flow path 32→flow outlet 62→cooler 4” the two circulation paths.

Fig. 5 shows the temperature distribution of the refrigerant in the flow paths 31 and 32 of the present embodiment. In the present embodiment, since the inflow ports 51 and 52 are provided in the center of the heat radiating member 2 in the left-right direction, the temperature of the refrigerant in the vicinity of the inflow ports 51 and 52 is the lowest. Therefore, the heat dissipation property of the central portion LED 1 attached to the vicinity of the center of the heat dissipation member 2 can be improved.

Further, the printing unit using the LED unit 20 of the present embodiment includes a configuration in which the irradiation range of the LED 1 can be changed in accordance with the width of the entire printing cloth. When printing a printing full-width cloth having a large width, all of the LEDs 1 on the heat radiating member 2 are turned on, and when printing a printing full-width cloth having a narrow width, only the central portion LED1 is turned on. In other words, the heat dissipation property of the central portion LED 1 having a high frequency of use is increased upward, whereby the central portion LED 1 can be extended in life.

Further, the temperature of the refrigerant in the vicinity of the outflow ports 61 and 62 rises with respect to the temperature of the refrigerant in the vicinity of the inflow ports 51 and 52. However, the temperature of the refrigerant in the vicinity of the outflow ports 61 and 62 in the present embodiment is lower than the temperature of the refrigerant in the vicinity of the previous outflow port 106. . Since the previous LED unit 10 is provided with the inflow port 105 and the outflow port 106 at both ends of the heat dissipating member 102, the length of the flow path 103 in the left-right direction is L1 (refer FIG. 7). On the other hand, in the LED unit 20 of the present embodiment, the inflow ports 51 and 52 are provided at the center in the left-right direction of the heat dissipating member 2, and the outflow ports 61 and 62 are provided at both ends of the heat dissipating member 2, so that the flow path 31, The length L2 of the left and right direction of 32 is L1/2.

Therefore, the total heat absorbed by the refrigerant when passing through the flow path 31 having the length L2 is less than the total heat absorbed by the flow path 103 having the length L1. Therefore, the temperature of the refrigerant near the outflow port 61 is lower than that of the previous flow. Exit 106 The temperature of the nearby refrigerant. Similarly, the total heat absorbed by the refrigerant when passing through the flow path 32 having the length L2 is less than the total heat absorbed by the flow path 103 having the length L1. Therefore, the temperature of the refrigerant near the outflow port 62 is lower than that of the previous one. The temperature of the refrigerant near the outflow port 106. Therefore, the heat dissipation of the LED 1 mounted near the both ends of the heat radiating member 2 is also improved as compared with the prior art.

Further, the LED 1 mounted near the both ends of the heat radiating member 2 is turned on only when the printing full width cloth is printed, and therefore, the frequency of use of the LED 1 mounted near the both ends of the heat radiating member 2 is low. Since the irradiation region is included in the ineffective irradiation region A2, the influence of the increase in the temperature of the refrigerant is small (see FIGS. 9(a) and 9(b)).

In the conventional LED unit 10, the LED 1 attached to the right end of the heat radiating member 102 has the highest heat dissipation property, the frequency of use of the LED 1 is low, and the irradiation region corresponds to the ineffective irradiation region A2. However, in the LED unit 20 of the present embodiment, the central portion LED 1 attached to the vicinity of the center of the heat radiating member 2 and having a high frequency of use has the highest heat dissipation property. Therefore, the LED unit 20 of the present embodiment reduces the unevenness of the life of the entire LED 1 .

Further, in the present embodiment, the lower surfaces of the heat radiating members 2 (heat radiating units 213, 214) are provided with inflow ports 51, 52 at both ends of the heat radiating member 2 (the left surface of the heat radiating unit 211, the right surface of the heat radiating unit 216) The flow outlets 61, 62 are provided. However, the installation positions of the inflow ports 51 and 52 and the outflow ports 61 and 62 are not limited to the above positions, and may be any positions that can be connected to both ends of the flow paths 31 and 32.

Further, in the present embodiment, the inflow ports 51 and 52 are provided at the center in the left-right direction of the heat dissipating member 2, but the above-described embodiment can be obtained. In the above-described manner, the inflow ports 51 and 52 may be provided at substantially the center of the center of the heat dissipating member 2 in the left-right direction.

Moreover, the heat radiating member 2 of this embodiment is comprised by connecting the six heat radiating elements 21. Therefore, when replacement is necessary due to the life or failure of the LED 1 mounted on the heat dissipation unit 21, only the heat dissipation unit 21 can be replaced, so that it is not necessary to replace the entire heat dissipation member 2, the work is easy, and the cost can be increased. (cost) reduction.

Further, in the heat radiating member 2 of the present embodiment, six heat radiating units 21 are connected, an inflow port 51 is provided at the right end of the heat radiating unit 213, and an inflow port 52 is provided at the left end of the heat radiating unit 214.

Further, although the heat radiating members 2 of the present embodiment are connected to the six heat radiating units 21, the present invention is not limited thereto, and an even number of heat radiating units 21 of four or eight may be connected.

However, when the odd heat radiating elements 21 are connected to each other to constitute the heat radiating member 2, as shown in FIG. 6, the inflow ports 51 and 52 are provided in the center in the left-right direction with respect to the heat radiating unit 21 located in the center in the left-right direction. Further, the partition wall 23 is provided to constitute the flow paths 31 and 32, and the partition wall 23 divides the flow path 3 of the heat radiating unit 21 in the left-right direction. According to the configuration described above, the inflow ports 51 and 52 can be provided in the center of the heat dissipating member 2 in the left-right direction, and the heat dissipation property of the central portion LED 1 having a high frequency of use can be improved, and the central portion LED 1 can be extended in life, thereby making the LED 1 The overall life span is uniform.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above, and can be applied to the subsequent patent application. Various changes and modifications are possible within the scope of the invention, and various changes and modifications are also within the scope of the invention.

1‧‧‧LED/Central LED

2, 102‧‧‧ heat dissipation components

3, 31, 32, 103‧‧ ‧ flow path

4‧‧‧ cooler

8‧‧‧Pipe connection member

10, 20‧‧‧ LED unit

21, 211~216‧‧‧ heat dissipation unit

22, 23‧‧‧ partition wall

51, 52, 105‧‧‧

61, 62, 106‧‧ ‧ outflow

71~73‧‧‧Printing the entire fabric

A1‧‧‧ illuminated area

A2‧‧‧Invalid illumination area

A3‧‧‧Effective area

L1, L2‧‧‧ length

P1, P2‧‧‧ Center

Fig. 1 is a schematic configuration diagram of an LED unit according to an embodiment of the present invention.

Fig. 2 is a view showing an upper surface of an LED unit according to an embodiment of the present invention.

3 is a plan view showing a heat radiating unit and an LED mounted on the heat radiating unit according to an embodiment of the present invention.

4 is a view showing a cross section of an LED unit according to an embodiment of the present invention.

Fig. 5 is a view showing a change in temperature of a refrigerant according to an embodiment of the present invention.

Fig. 6 is a schematic configuration diagram of a heat radiating unit according to another embodiment of the present invention.

Fig. 7 is a schematic configuration diagram of a conventional LED unit.

Fig. 8 is a view showing a change in temperature of a conventional refrigerant.

Fig. 9(a) is a view showing the irradiation intensity in the previous irradiation region, and Fig. 9(b) is a schematic configuration view showing the printing entire cloth.

1‧‧‧LED/Central LED

2‧‧‧heating components

4‧‧‧ cooler

8‧‧‧Pipe connection member

20‧‧‧LED unit

21, 211~216‧‧‧ heat dissipation unit

22‧‧‧ partition wall

31, 32‧‧‧ flow path

51, 52‧‧‧

61, 62‧‧ ‧ outflow

L1, L2‧‧‧ length

Claims (2)

An LED unit comprising: a plurality of LEDs arranged adjacent to each other; and a heat dissipating member formed in an elongated shape, having a mounting surface on which the LED is mounted, and having a flow path inside, the flow path The refrigerant flows in the longitudinal direction, and the flow path is formed at an inlet of the refrigerant in a substantially central portion of the heat dissipation member in the longitudinal direction, and the refrigerant flow is formed on one end side and the other end side in the longitudinal direction of the heat dissipation member. In the outlet, a partition wall is formed in a central portion of the flow path, and a circulation path from the inlet port to the outlet port on the one end side and a circulation path from the inlet port to the outlet port on the other end side constitute a second Loop path. The LED unit according to claim 1, wherein the plurality of heat dissipating units having the mounting surface and having the flow path therein are connected to each other along the longitudinal direction, thereby constituting the heat dissipating member.