JP2005221640A - Light source device and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device or the like capable of efficiently radiating heat by making a liquid for cooling flow near a light emitting part and supplying bright illuminating light. <P>SOLUTION: The light source device is provided with the light emitting part 201 supplying the illuminating light L, a base plate 210 on which the light emitting part 201 is mounted, and bonded parts 202 and 203 supplying a current to the light emitting part 201 by bonding the electrode of the light emitting part 201 and an electrode on the base plate 210 side. By making the fluid for cooling flow near the light emitting part 201, the light emitting part 201 is cooled. The 1st bonded part 202 has annular shape surrounding the 2nd bonded part 203, and has nearly the same potential as the fluid for cooling. By hermetically enclosing the 1st bonded part 202 and the light emitting part 201, the 2nd bonded part 203 is electrically insulated from the fluid for cooling. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a light source device and a projector, and more particularly to a technology of a light source device using a solid light emitting element.

  In recent years, a light source device using a solid light emitting element has attracted attention as a light source device of a projector. Among solid-state light emitting devices, the progress of development and improvement of light emitting diodes (hereinafter referred to as “LEDs”) is remarkable. In addition to small output LEDs for display, products have also been developed for high output LEDs for illumination. LEDs have the characteristics of being ultra-compact, ultra-light, and long-life. For this reason, the LED is suitable for use in a light source device of a projector, particularly a small portable projector.

  Thus, although it is suitable LED used for the light source device of a projector, the luminous efficiency of the present LED is about 1/2 to 1/3 of the ultrahigh pressure mercury lamp used for a projector conventionally. This is because the amount of light obtained is still small even when a rated current is passed through the LED. For this reason, in order to increase the amount of light, it is conceivable to arrange a plurality of LEDs in an array. When the LEDs are arrayed, the light emission area of the light source device increases. In a projector, in an optical system including a light source device and a spatial light modulation device, a spatial spread in which a light beam that can be effectively handled exists can be expressed as a product of an area and a solid angle (Etendue, Geometric Extent). The product of the area and the solid angle is stored in the optical system. There is a limit to the angle at which light can be effectively modulated by the spatial light modulator. For this reason, when the spatial spread of the light source is increased, it becomes difficult to effectively use the light flux from the light source, which leads to a decrease in illumination efficiency.

  Therefore, it is desirable to increase the light emission amount of the LED itself. The value of the current flowing through the LED is limited to the rated current. The maximum light quantity of the LED is determined by the rated current and efficiency. The rated current of the LED depends on the amount of heat generated. For this reason, if the heat dissipation efficiency is increased, the rated current can be increased. A large amount of light can be obtained by increasing the rated current. Heat dissipation is performed by finally releasing heat to the atmosphere. Conventionally, LEDs radiate heat using heat transfer by a metal member or the like. In order to further improve the heat dissipation efficiency, it is conceivable to perform heat dissipation using heat transfer by liquid. Techniques for cooling an LED using a liquid are proposed in Patent Documents 1 and 2 below.

JP-A-6-5923 JP-A-8-116138

  The technique proposed in Patent Document 1 is to flow a cooling liquid outside the package. In LEDs, heat of several watts or more is generated from a chip of only 1 to 2 mm square which is a light emitting part. In order to increase the heat dissipation efficiency, it is desirable to directly extract the heat from the light emitting part by flowing the cooling liquid in the vicinity of the light emitting part instead of outside the package. The technique proposed in Patent Document 2 exposes the light emitting part directly to the cooling liquid. In consideration of environmental compatibility and ease of maintenance, it is most desirable to use water as the cooling liquid. In general, since water has electrical conductivity, when water is directly exposed to the light emitting part, there is a possibility that problems such as short-circuit and electric leakage occur due to water entering the electrode.

  In order to prevent short circuit and electric leakage in the light emitting part, it is conceivable to prevent water from entering by covering the light emitting part with an insulating film. The insulating film needs to be provided also on the light emission side of the light emitting portion. The insulating film is made of a transparent member so as not to block the illumination light from the light emitting unit. However, when an insulating film of a transparent member is provided, light may be confined due to total reflection of light at the interface of the insulating film. When such light confinement occurs, the light utilization efficiency is greatly reduced. In addition to using an insulating film made of a transparent member, it is also conceivable to waterproof the light emitting part using a packing case. However, if packing is provided in the vicinity of the light emitting portion, it is considered that deformation of the packing due to heat occurs. When the packing is deformed, it is difficult to maintain a waterproof state inside the case. Thus, it is difficult to flow the cooling liquid in the vicinity of the light emitting unit to cool the light emitting unit, which causes a problem in improving the heat dissipation efficiency of the LED and supplying brighter illumination light. .

  The present invention has been made in view of the above-described problems. A light source device that can efficiently dissipate heat by flowing a cooling fluid in the vicinity of a light emitting unit and can supply bright illumination light, and the light source device. An object is to provide a projector to be used.

  In order to solve the above-described problems and achieve the object, according to the present invention, a light emitting unit that supplies illumination light, a substrate on which the light emitting unit is mounted, an electrode of the light emitting unit, and an electrode on the substrate side are joined. And at least two or more joints that supply current to the light emitting part, and the light emitting part is cooled by flowing a cooling fluid in the vicinity of the light emitting part, and one of the joints is The joint portion has an annular shape surrounding the other joint portion, and has substantially the same potential as the cooling fluid. The other joint portion is for cooling by closely contacting one joint portion and the light emitting portion. A light source device characterized in that it is electrically insulated from a fluid can be provided.

  Of the two or more joints, one joint is formed into an annular shape and surrounds the other joints. The annular joint portion is provided in close contact with the light emitting portion. Even if the cooling fluid is caused to flow in the vicinity of the light emitting portion in order to closely contact the light emitting portion and the annular joint portion, the cooling fluid does not enter the space surrounded by the annular joint portion. In this way, the joint surrounded by the annular joint and the cooling fluid can be electrically insulated with a simple configuration.

  When the cooling fluid is caused to flow in the vicinity of the light emitting portion, only one of the joints having an annular shape comes into contact with the cooling fluid. Here, one annular joint has substantially the same potential as the cooling fluid. In order to set the cooling fluid and the ring-shaped joint portion to substantially the same potential, for example, all the portions that are in contact with the cooling fluid including the ring-shaped joint portion may be connected to the ground electrode. And the junction part surrounded by the annular shape junction part is electrically connected with the drive part of the light source device. Since the joint surrounded by the annular joint and the cooling fluid are electrically insulated, conduction between the electrodes does not occur even if a conductive cooling fluid flows near the light emitting part. . Since conduction between the electrodes does not occur, it is possible to reliably prevent leakage and short circuit in the light emitting section, and to use the light source device safely.

  Since it is not necessary to provide an insulating film made of a transparent member in the light emitting portion, unnecessary light is not taken in by the insulating film, and illumination light can be extracted efficiently. In addition to the insulating film, a member such as a packing for waterproofing is unnecessary, so that the vicinity of the light emitting portion can be configured with excellent heat resistance. Further, since the light emitting part can be directly exposed to the cooling liquid, the heat from the light emitting part can be directly taken out by the cooling liquid, and the heat radiation efficiency of the light source device can be improved. By improving the heat dissipation efficiency of the light source device, the rated current of the light source device can be increased and bright illumination light can be obtained. Thereby, it is possible to obtain a light source device that can efficiently dissipate heat by supplying a cooling fluid in the vicinity of the light emitting unit and can supply bright illumination light. In addition, since a conductive cooling fluid can be used, water can be used as the cooling liquid. By using water, the light source device can be configured with excellent environmental compatibility, and the light source device can be easily maintained.

  Moreover, according to the preferable aspect of this invention, another junction part can be further provided in the space sealed by one junction part, a light emission part, and a board | substrate by closely_contact | adhering one junction part and a board | substrate. desirable. By providing the other joint in a space sealed by one annular joint, the light emitting part, and the substrate, the other joint and the cooling fluid can be insulated.

  Moreover, according to the preferable aspect of this invention, it is desirable for a board | substrate to have further the heat-transfer member which propagates the heat | fever from a light emission part in the annular shape inner peripheral side. In addition to allowing the cooling fluid to flow in the vicinity of the light emitting portion, the heat dissipation efficiency of the light source device can be further improved by providing a heat transfer member on the substrate. Thereby, a light source device capable of supplying brighter illumination light can be obtained.

  Moreover, as a preferable aspect of the present invention, the substrate further includes an opening on the inner peripheral side of the annular shape, and further includes a cooling gas supply unit that cools the light emitting unit by supplying a cooling gas to the opening. It is desirable. In addition to causing the cooling fluid to flow in the vicinity of the light emitting part, the cooling gas is supplied to the opening of the substrate by the cooling gas supply part. For this reason, the heat dissipation efficiency of the light source device can be further improved. Thereby, a light source device capable of supplying brighter illumination light can be obtained.

  Furthermore, according to the present invention, a light source device that supplies illumination light, a spatial light modulation device that modulates illumination light from the light source device according to an image signal, and a projection that projects light modulated by the spatial light modulation device A projector, wherein the light source device is the light source device described above. By using the light source device described above, bright illumination light can be obtained. Thereby, a projector with a bright projected image can be obtained.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a projector 100 according to Embodiment 1 of the present invention. In this embodiment, first, the schematic configuration of the entire projector 100 will be described, and then the configuration of the light source device will be described in detail. The projector 100 includes an R light LED 101R that is an R light source device, a G light LED 101G that is a G light source device, and a B light LED 101B that is a B light source device.

  The R light from the R light LED 101R passes through the λ / 4 phase plate 102R and enters the reflective polarizing plate 103R. The reflective polarizing plate 103R transmits polarized light in a specific vibration direction, for example, p-polarized light, and reflects polarized light in another vibration direction different from the specific vibration direction, for example, s-polarized light. The p-polarized light that has passed through the reflective polarizing plate 103 </ b> R enters the cross dichroic prism 104. The light reflected by the reflective polarizing plate 103R travels in the opposite direction on substantially the same optical path as that incident on the reflective polarizing plate 103R. Of the light reflected by the reflective polarizing plate 103R, the s-polarized light is converted into circularly polarized light by passing through the λ / 4 phase plate 102R. The light transmitted through the λ / 4 phase plate 102R returns to the R light LED 101R.

  The light returning to the R light LED 101R is reflected by the chip of the R light LED 101R, etc., and becomes circularly polarized in the reverse direction to that of the previous light and travels again in the direction of the λ / 4 phase plate 102R. Then, the circularly polarized light incident on the λ / 4 phase plate 102R is converted to p-polarized light. The p-polarized light from the λ / 4 phase plate 102R passes through the reflective polarizing plate 103R and enters the cross dichroic prism 104. In this way, R light converted into p-polarized light is incident on the cross dichroic prism 104.

  Similarly to the R light, the G light from the G light LED 101G and the B light from the B light LED 101B are converted into polarized light having a specific vibration direction, for example, p-polarized light, and enter the cross dichroic prism 104. . The cross dichroic prism 104 is configured by arranging two dichroic films 104a and 104b orthogonal to the X shape. The dichroic film 104a reflects R light and transmits B light and G light. The dichroic film 104b reflects B light and transmits R light and G light. As described above, the cross dichroic prism 104 combines the R light, the G light, and the B light.

  A liquid crystal spatial light modulator 106 that is a spatial light modulator includes polarizing plates 105 and 107. The liquid crystal spatial light modulator 106 is a so-called transmissive liquid crystal display device that transmits light to a liquid crystal layer in accordance with an image signal. The polarizing plate 105 is provided on the incident side of the liquid crystal type spatial light modulator 106. The polarizing plate 107 is provided on the emission side of the liquid crystal type spatial light modulator 106. As described above, R light, G light, and B light incident on the cross dichroic prism 104 are all converted to p-polarized light that is polarized light in a specific vibration direction. The R light, G light, and B light converted to p-polarized light are incident on the polarizing plate 105 as they are. The polarizing plate 105 transmits p-polarized light and makes it incident on the liquid crystal type spatial light modulator 106. The p-polarized light incident on the liquid crystal type spatial light modulator 106 is converted into s-polarized light by modulation according to the image signal, and is incident on the polarizing plate 107.

  The polarizing plate 107 transmits the s-polarized light and advances it in the direction of the projection lens 108. The projection lens 108 projects the light modulated by the liquid crystal spatial light modulator 106 onto the screen 109. By converting the light incident on the cross dichroic prism 104 into p-polarized light having a specific vibration direction, the light absorbed by the polarizing plate 105 is reduced and the light incident on the liquid crystal spatial light modulator 106 is increased. Can do. By increasing the light incident on the liquid crystal type spatial light modulator 106, the light from the LEDs 101R, 101G, and 101B for each color light can be used efficiently.

  Next, lighting times and timings of the R light LED 101R, the G light LED 101G, and the B light LED 101B will be described. The projector 100 modulates each color light by using a single liquid crystal type spatial light modulator 106. The liquid crystal type spatial light modulator 106 sequentially performs different modulation for each color light within one frame of an image. In order to perform different modulation for each color light within one frame of the image, one frame of the image is divided into an R lighting time, a G lighting time, and a B lighting time.

  Each of the color light LEDs 101R, 101G, and 101B is sequentially turned on for each color light in accordance with the modulation of the liquid crystal type spatial light modulator 106. The LED has a feature that it can be easily turned on, turned off, and modulated (adjustment of the amount of emitted light) on the order of milliseconds by controlling the drive current. With this feature, it is possible to illuminate by sequentially turning on LEDs for each color light within one frame of an image. For this reason, it is possible to perform color sequential driving with a simple configuration using the respective color light LEDs 101R, 101G, and 101B without using a configuration such as a color wheel.

  In order to sequentially project R light, G light, and B light and obtain a white projected image as a whole, it is necessary that the light flux amount of G light is 60 to 80% of the total light flux amount. When the output amounts of the respective color light LEDs 101R, 101G, and 101B are the same, the light flux amount of the G light is insufficient. The shortage of the amount of G light flux can be earned by making the lighting time of the G color LED 101G longer than both the lighting time of the R light LED 101R and the lighting time of the B light LED 101B. In the projector 100, one LED is provided for each color light, but a plurality of LEDs may be provided for each color light. When a plurality of LEDs are provided for each color light, the amount of G light beam 101G is increased by increasing the number of G light LEDs 101G than the number of R light LEDs 101R and the number of B light LEDs 101B. Also good.

  Next, the configuration of each of the color light LEDs 101R, 101G, and 101B as the light source device will be described. In the present invention, the structures of the characteristic portions of the respective color light LEDs 101R, 101G, and 101B are the same. Accordingly, in the present embodiment and the following embodiments, the configuration of the R light LED will be described as an example. FIG. 2 shows a cross-sectional configuration of the R-light LED 101R. The chip 201 which is a light emitting unit is mounted on the substrate 210 via the first bonding unit 202 and the second bonding unit 203. The LED 101R for R light supplies the illumination light L by supplying a current.

  The LED for R light 101R has a so-called flip chip structure in which the chip 201 is provided so that the light emitting layer faces downward. In the flip chip structure, it is not necessary to connect the chip 201 and the lead electrode with a wire. For this reason, the LED 101R for R light can be made small and thin. In addition, since the chip 201 can be directly mounted on the substrate 210 without using a radiator, the R light LED 101R can be configured to have a low thermal resistance. The chip 201 is configured by forming a light emitting layer on an insulating transparent substrate. By providing the transparent substrate, light from the light emitting layer can be extracted efficiently. In addition, the light emitted from the light emitting layer toward the substrate 210 is reflected by the p-electrode made of a metal member, so that the light can be used more efficiently.

  The first bonding portion 202 and the second bonding portion 203 electrically connect the p electrode and the n electrode of the chip 201 and an electrode (not shown) on the substrate 210 side, whereby the chip 201 and the substrate 210 are connected to each other. Join. The first joint 202 and the second joint 203 are formed by, for example, solder layers formed by soldering the electrodes of the chip 201 and the electrodes on the substrate 210 side or by joining with silver wax. A silver wax layer can be used. Further, the electrode of the chip 201 and the electrode on the substrate 210 side may be directly bonded at high temperature and high pressure.

  FIG. 3 shows a planar configuration of the first joint 202 and the second joint 203. The first joint 202 has a circular annular shape. The second joint portion 203 is provided in a region surrounded by the annular shape of the first joint portion 202. Thus, the first joint 202 has an annular shape surrounding the second joint 203. As shown in FIGS. 2 and 3, a space is provided between the first joint portion 202 and the second joint portion 203. By providing a space between the first joint 202 and the second joint 203, the first joint 202 and the second joint 203 are configured not to contact each other.

  Further, the first bonding portion 202 is provided in close contact with the chip 201 and the substrate 210. In this way, the second bonding portion 203 is provided in a space sealed by the first bonding portion 202, the chip 201, and the substrate 210. The first joint 202 is electrically connected to the ground electrode 209. The second bonding portion 203 is electrically connected to the light source driving portion 208. The second bonding portion 203 can be connected to the light source driving portion 208 by providing a through hole for wiring through the substrate 210. In addition, the 1st junction part 202 should just be a shape with an empty center area | region, and is not restricted to a circular annular shape. Moreover, the 2nd junction part 203 should just be surrounded by the 1st junction part 202, and a shape is not restricted circularly.

  The LED for R light 101 </ b> R has a cap portion 205 on the emission side of the light L from the chip 201. The cap unit 205 is composed of an optically transparent member such as a glass member or a transparent resin member. The cap part 205 seals the chip 201 and the joint parts 202 and 203. The light exit side surface of the cap portion 205 has a spherical shape or an aspherical shape. The cap unit 205 has a spherical or aspherical surface on the light emission side, thereby reducing total reflection of the illumination light L at the interface of the cap unit 205 and efficiently emitting light from the chip 201 to the outside. . Further, by providing a lens action to the tip position of the cap portion 205, the R light LED 101R has a high intensity light L in the Z-axis direction, which is a direction substantially perpendicular to the surface of the substrate 210 on which the chip 201 is provided. Inject.

  A space 204 is provided between the substrate 210 and the cap unit 205. The space 204 is filled with cooling water that is a cooling fluid. The space 204 is connected to a pump 207 via a coolant transport pipe 206. By operating the pump 207, the cooling water in the space 204 circulates in the direction of arrow W through the coolant transport pipe 206. The cooling water flows through the space 204 by circulating through the coolant transport pipe 206. In this way, the cooling water can flow in the vicinity of the chip 201.

  The heat generated in the chip 201 is transferred to the cooling water. The heat from the chip 201 transmitted to the cooling water is finally released to the atmosphere in the process of flowing the cooling water. When the cooling water is circulated, the heat-radiated cooling water can always be passed near the chip 201. In this way, by flowing the cooling water in the vicinity of the chip 201, the heat from the chip 201 can be efficiently removed.

  Note that the coolant transport pipe 206 and the pump 207 may be provided with a heat exchanger. By providing the heat exchanger, the heat transmitted to the cooling water can be actively released to the atmosphere. In addition, if the heat from the chip 201 can be sufficiently dissipated only by the thermal convection of the cooling water in the space 204, the cooling water is flowed only by the space 204 without being configured to circulate the cooling water by the pump 207. It is also good. In this case, the cooling water may be sealed in the space 204, and the pump 207 and the coolant transport pipe 206 can be omitted.

  The substrate 210 is made of, for example, a metal member. By configuring the substrate 210 with a metal member, the substrate 210 can be configured to have a low thermal resistance and efficiently radiate heat. Furthermore, the substrate 210 can dissipate heat more efficiently by providing a layer made of a ceramic member on the surface on which the chip 201 is mounted. Further, the substrate 210 may be provided with a heat sink. By providing the heat sink, heat transmitted to the substrate 210 can be actively released to the atmosphere. Note that the second bonding portion 203 electrically connects only the electrode of the chip 201 and the electrode on the substrate 210 side, and is electrically insulated from the substrate 210 itself.

  As described above, the second joint 203 is provided in a space sealed by the first joint 202, the chip 201, and the substrate 210. By closely contacting the chip 201 and the first joint portion 202, the cooling water does not enter the space surrounded by the first joint portion 202 even if it flows in the vicinity of the chip 201. In this way, the second joint 203 is electrically insulated from the cooling water.

  When the cooling water is caused to flow in the vicinity of the chip 201, only the first joint 202 of the joints contacts the cooling water. Thus, only the 1st junction part 202 is exposed to cooling water among junction parts. In addition, there is a case where a gap is generated in the joint portion between the first joint portion 202, the chip 201, and the substrate 210. By setting the gap generated at this time to a length equal to or less than water molecules, it is possible to prevent the cooling water from entering the space where the second joint portion 203 is provided.

  As described above, the first bonding portion 202 is electrically connected to the ground electrode 209. In general, in addition to the first joint portion 202, a portion that is contacted with cooling water, such as the coolant transport pipe 206 and the substrate 210, is finally connected to the ground electrode 209. For this reason, both the cooling water and all the parts that are touched by the cooling water are at ground potential. In this way, the first joint 202 has substantially the same potential as the cooling water. The second joint 203 is electrically connected to the light source driver 208.

  FIG. 4 shows a circuit example of the R light LED 101R. The chip 201 connects the anode electrode to the second joint 203 and the cathode electrode to the first joint 202. A current for causing the chip 201 to emit light is supplied to the chip 201 from an external power source (not shown) via the second bonding unit 203 and the light source driving unit 208. Since the second joint 203 and the cooling water are electrically insulated, no conduction occurs between the electrodes. In contrast to the configuration shown in FIG. 4, the chip 201 may have a configuration in which the cathode electrode is connected to the second bonding portion 203 and the anode electrode is connected to the first bonding portion 202. In this case, the first joint portion 202 can be connected to the ground electrode 209 via an external power source.

  In general, water has conductivity. The LED 101R for R light according to the present embodiment has a configuration in which only the first joint 202 having substantially the same potential as that of the coolant is in contact with the coolant. The second joint 203 is electrically insulated from the cooling water. With such a configuration, even if conductive cooling water flows in the vicinity of the chip 201, conduction between the electrodes does not occur. Since the LED 101R for R light has a flip chip structure, there is no exposure of a conductive portion having the same potential as the second bonding portion 203 such as a bonding wire. Since conduction between the electrodes does not occur and other conductive portions are not exposed, the leakage and short circuit in the chip 201 can be reliably prevented, and the R light LED 101R can be used safely.

  For example, when the insulating film is provided on the surface of the chip 201 without adopting the configuration of the present embodiment, the light may be confined by the total reflection of light by the insulating film. Further, the insulating film needs to be formed of a member that can withstand the heat from the chip 201. For example, when using a case with packing for waterproofing, it is difficult to keep the chip 201 waterproof since the packing is vulnerable to heat. If the waterproof state of the chip 201 cannot be maintained, it may cause a leakage or a short circuit in the chip 201.

  The R light LED 101R of this embodiment does not need to be provided with such an insulating film or packing. Since the insulating film is unnecessary, the LED 101R for R light can efficiently take out the illumination light by eliminating unnecessary taking-in of light by the insulating film. Further, it is possible to eliminate the need for an insulating film on the chip 201 in the manufacturing process of the R light LED 101R. Since a member such as packing is not required in addition to the insulating film, the vicinity of the chip 201 can be configured with excellent heat resistance.

  Further, since the chip 201 can be directly exposed to the cooling water, the heat from the chip 201 can be directly taken out by the cooling water, and the heat radiation efficiency of the R light LED 101R can be improved. By improving the heat dissipation efficiency of the LED 101R for R light, the rated current of the LED 101R for R light can be increased, and bright illumination light L can be obtained. Thereby, it is possible to efficiently dissipate heat by flowing the cooling water in the vicinity of the chip 201 and to supply bright illumination light.

  The LED for R light 101R of the present embodiment can use water as a cooling liquid. By using water as the cooling liquid, the R light LED 101R can be configured to have excellent environmental compatibility, and the R light LED 101R can be easily maintained. The cooling liquid is not limited to water, and other conductive liquids or non-conductive liquids may be used.

  Regarding the G light LED 101G and the B light LED 101B, the configuration for efficiently dissipating heat and supplying bright illumination light is the same as that of the R light LED 101R. Thereby, also in the LED 101G for G light and the LED 101B for B light, similarly to LED 101R for R light, it can thermally radiate efficiently and can supply bright illumination light. Thereby, a bright projected image can be obtained using the projector 100.

  5 and 6 show a planar configuration of a modified example of the joint portion. The first joint portion 502 shown in FIG. 5 has a shape in which a circular region is removed from the approximate center of a rectangular region. For example, the first joint portion 502 may be provided so that the rectangular shape of the outer periphery of the first joint portion 502 is substantially the same as the rectangular shape of the substrate 210 (see FIG. 2). In this case, the chip 501 can be provided so as to cover the second bonding portion 203 and a part of the first bonding portion 502.

  3 and 5 show a configuration in which two joint portions are provided, but a configuration in which three or more joint portions are provided corresponding to the electrodes of the chip may be employed. For example, the second joint portion 203 illustrated in FIG. 5 may also have an annular shape, and another joint portion may be provided in a region surrounded by the second joint portion 203. Thus, by providing a plurality of joint portions so that the annular shape is double or triple, it is possible to supply current to a chip having three or more electrodes. Furthermore, the joint part surrounded by the first joint part 202 is not limited to an annular shape or a circular shape, and may be, for example, a dot shape.

  Conventionally, there is an LED in which a plurality of strip-shaped chips are arranged and dot-shaped joint portions are provided corresponding to the respective chips. FIG. 6 shows a configuration in which an annular first joint portion 602 is provided so as to surround the conventional dot-like joint portions 603 and 613. The first joint portion 602 has an annular shape whose outer periphery and inner periphery are both rectangular. The strip-shaped chip 601 is provided on the dot-shaped joint portions 603 and 613. The plurality of chips 601 are electrically insulated from each other. In FIG. 6, eight joint portions are provided in a region surrounded by the first joint portion 602 corresponding to the four chips 601. In this configuration, the four chips 601 can be driven separately. In this manner, by providing a plurality of joint portions in addition to the first joint portion 602, the LED can be driven separately for each chip.

  FIG. 7 shows a cross-sectional configuration of an R light LED 701 </ b> R that is a light source device according to a second embodiment of the present invention. The LED 701R for R light can be applied to the projector 100 of the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. The LED 701R for R light of this embodiment is characterized in that a heat transfer member 712 is provided on a substrate 710.

  The heat transfer member 712 is provided on the inner peripheral side of the annular shape of the first joint 202 in the substrate 710. The heat transfer member 712 releases the heat H1 generated at the chip 201 and propagating from the second joint 203 to the outside air. On the other hand, the heat H2 generated in the chip 201 and propagated from the first joint portion 202 is released to the outside air through the substrate 710. As the heat transfer member 712, for example, a metal member can be used. Here, if a member having a lower thermal resistance than the substrate 710 is used as the heat transfer member 712, heat can be radiated more efficiently than when the substrate 710 is formed of a single member.

  Further, by providing a gap between the substrate 710 and the heat transfer member 712, the heat H1 and H2 can be released to the outside air from the gap between the substrate 710 and the heat transfer member 712. Thereby, the heat radiation efficiency of the LED 701R for R light can be further improved, and the bright illumination light L can be supplied. Although not shown in FIG. 7, the R light LED 701 </ b> R can be provided with the coolant transport pipe 206 and the pump 207, similarly to the R light LED 101 </ b> R of the first embodiment. The first joint 202 is connected to the light source driver 208, and the second joint 203 is connected to the ground electrode 209.

  FIG. 8 shows a cross-sectional configuration of an R light LED 801 </ b> R that is a light source device according to a third embodiment of the present invention. The same parts as those of the R light LED 101R of the first embodiment are denoted by the same reference numerals, and redundant description is omitted. The LED for R light 801 </ b> R of this embodiment is characterized in that a cooling gas is supplied to an opening 812 provided in the substrate 810.

  The substrate 810 has an opening 812 on the inner peripheral side of the first bonding portion 202. The nozzle 813 serving as a cooling gas supply unit is provided with the cooling gas injection port directed from the opening 812 toward the second joint 203. As the cooling gas, a vaporizable refrigerant can be used in addition to air. When a vaporizable refrigerant is used, the chip 201 can be efficiently cooled by removing heat of vaporization from the chip 201 when the refrigerant vaporizes, in addition to heat transfer due to a temperature difference between the chip 201 and the refrigerant.

  The cooling gas flows from the inlet 814 to the nozzle 813. The opening 812 is provided with cooling gas outlets 815 and 816. When the cooling gas is blown from the nozzle 813 in the direction of the arrow C1, the gas in the opening 812 flows out of the outlets 815 and 816 in the direction of the arrow C2. In this way, the cooling gas flows in the opening 812. The cooling gas injected from the nozzle 813 takes heat from the chip 201 and flows out from the outlets 815 and 816.

  Thereby, the heat radiation efficiency of the LED 801R for R light is further improved, and the effect that the bright illumination light L can be supplied is achieved. Note that the nozzle 813 is not limited to the configuration in which the injection port is provided in the opening 812, and the nozzle 813 may have a configuration in which the injection port is provided outside the opening 812. Although not shown in FIG. 8, the R light LED 801 </ b> R can be provided with the coolant transport pipe 206 and the pump 207, similarly to the R light LED 101 </ b> R of the first embodiment. The first joint 202 is connected to the light source driver 208, and the second joint 203 is connected to the ground electrode 209.

  The projector 100 is not limited to a configuration using a single liquid crystal spatial light modulator as the spatial light modulator. For example, a configuration using three liquid crystal spatial light modulators may be used. Further, the configuration is not limited to a configuration in which a transmissive liquid crystal display device is provided as a spatial light modulation device, and a configuration in which a reflective liquid crystal display device is provided or a configuration in which a tilt mirror device is used.

  As described above, the light source device according to the present invention is suitable for use as a light source device for a projector.

1 is a schematic configuration diagram of a projector according to a first embodiment of the invention. The cross-sectional block diagram of a light source device. The plane block diagram of a junction part. The figure which shows the circuit example of a light source device. Explanatory drawing of the modification of a junction part. Explanatory drawing of the modification of a junction part. The cross-sectional block diagram of the light source device of Example 2 of this invention. The cross-sectional block diagram of the light source device of Example 3 of this invention.

Explanation of symbols

100 projector, 101R R light LED, 101G G light LED, 101B B light LED, 102R, 102G, 102B λ / 4 phase plate, 103R, 103G, 103B reflective polarizing plate, 104 cross dichroic prism, 104a dichroic film 104b Dichroic film, 105, 107 Polarizing plate, 106 Liquid crystal type spatial light modulator, 108 Projection lens, 109 Screen, 201 Chip, 202 First joint, 203 Second joint, 204 Space, 205 Cap part, 206 Coolant Transport Pipe, 207 Pump, 208 Light Source Drive Unit, 209 Ground Electrode, 210 Substrate, 501 Chip, 502 First Joint, 601 Chip, 602 First Joint, 603, 613 Joint, 701R R Light LED, 7 0 substrate, 712 a heat transfer member, 801R for R light LED, 810 substrate, 812 opening, 813 nozzles, 814 inlet, 815 and 816 outlet, L illumination light, H1, H2 heat

Claims (5)

A light emitting unit for supplying illumination light;
A substrate on which the light emitting unit is mounted;
Having at least two or more joining parts that supply current to the light emitting part by joining the electrode of the light emitting part and the electrode on the substrate side;
The light emitting part is cooled by flowing a cooling fluid in the vicinity of the light emitting part,
One of the joints has an annular shape surrounding the other joint, and has substantially the same potential as the cooling fluid,
The light source device according to claim 1, wherein the other joint portion is electrically insulated from the cooling fluid by closely contacting the one joint portion and the light emitting portion.   The said other junction part is further provided in the space sealed by said one junction part, the said light emission part, and the said board | substrate by closely_contact | adhering the said one junction part and the said board | substrate. 2. The light source device according to 1.   The light source device according to claim 1, wherein the substrate further includes a heat transfer member that propagates heat from the light emitting unit on an inner peripheral side of the annular shape. The substrate has an opening on the inner peripheral side of the annular shape,
The light source device according to claim 1, further comprising a cooling gas supply unit that cools the light emitting unit by supplying a cooling gas to the opening. A light source device for supplying illumination light;
A spatial light modulator that modulates the illumination light from the light source device according to an image signal;
A projection lens for projecting light modulated by the spatial light modulator,
The projector according to claim 1, wherein the light source device is the light source device according to claim 1.

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