JP2006018070A - Light source device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize illuminance distribution of emitted light emitted from a light source device by eliminating stray light components.
A light source device includes a light emitting chip that emits light when energized through a first electrode and a second electrode, and emits light emitted from the light emitting chip in a front direction of the light emitting chip. The light-shielding means 5 is provided for preventing the emitted light emitted from the side surface 23 of the light-emitting chip 2 from being emitted directly in the front direction.
[Selection] Figure 1

Description

  The present invention relates to a light source device and a projector.

  In recent years, projectors have been reduced in size, increased in brightness, extended in lifetime, reduced in price, and the like. For example, with respect to miniaturization, the size of the liquid crystal panel (light modulation element) has been reduced from a diagonal of 1.3 inches to 0.5 inches, and an area ratio of slightly over 1/6.

  On the other hand, miniaturization by using a light emitting diode (LED) light source which is a solid light source as a light source of a projector has been proposed. The LED light source has a merit as a light source for a projector, such as being small in size including a power source, capable of instantaneous lighting / extinguishing, and wide color reproducibility and long life. Further, since it does not contain harmful substances such as mercury, it is preferable from the viewpoint of environmental protection.

By the way, in a light source device including an LED light source as described above, in general, in order to improve the extraction efficiency of emitted light, emitted light emitted from the light emitting chip obliquely with respect to the emission direction is emitted around the light emitting chip. Is reflected in the emission direction of the light source device (see Patent Document 1). By providing such a reflector, the emitted light emitted from the light source device can be collimated, and the light utilization efficiency can be increased.
Japanese Patent Laid-Open No. 7-7185 Japanese Patent Laid-Open No. 11-65477

  When the light source device is used as a light source for a projector, it is necessary to make the emitted light parallel and enter the light modulation element of the projector. However, as described above, the liquid crystal panel (light modulation element) has been miniaturized and the etendue of the liquid crystal panel has been reduced. Therefore, the light source device for the projector is also required to have a low etendue. Here, etendue is a parameter given by the product of the light emitting area of the light source and the solid angle of light that can be collected, and indicates the spatial extent in which there is a luminous flux that can be used effectively and is stored optically. is there.

  Since the conventional light source device reflects the emitted light emitted obliquely from the front surface of the light emitting chip by the reflector in the emission direction of the light source device, the emitted light emitted from the front surface of the light emitting chip is collimated. Can do. However, emitted light is emitted from the light emitting chip from the surface other than the front surface, and in the conventional light source device, the emitted light is also reflected by the reflector. Therefore, the conventional light source device has a large etendue and emits light. It has been difficult to make all the emitted light emitted from the side surface of the chip collimate and enter the liquid crystal panel (light modulation element) that is miniaturized. For this reason, most of the emitted light emitted from the side surface of the light emitting chip has become stray light in the projector after being emitted from the light source device.

  In the projector, it is preferable that the illuminance distribution of the emitted light incident on the light modulation element is uniform in order to improve display characteristics. However, since it is difficult to uniformly emit the light emitted from the side surface of the light emitting chip as described above together with the light emitted from the front surface of the light emitting chip, the light emitted from the light source device The illuminance distribution of light was uneven.

  The present invention has been made in view of the above-described problems. By eliminating the light emission component emitted from the side surface of the light emitting chip, the light source is reduced in etendue, and the illuminance distribution of the light emission emitted from the light source device is achieved. It aims at equalizing.

  In order to achieve the above object, a light source device of the present invention includes a light emitting chip that emits light when energized through a first electrode and a second electrode, and emits light emitted from the light emitting chip in front of the light emitting chip. A light source device that emits light in a direction includes light shielding means for preventing light emitted from a side surface of the light emitting chip from being emitted directly in the front direction.

According to the light source device of the present invention having such a feature, it is possible to prevent the emitted light emitted from the side surface of the light emitting chip by the light shielding means from being emitted directly in the front direction. For this reason, according to the light source device of the present invention, the stray light component (the emitted light emitted from the side surface of the light emitting chip) is eliminated from the emitted light emitted from the light source device (hereinafter referred to as illumination light). The etendue can be reduced, and the illuminance distribution of the illumination light can be made uniform.
It is to be noted that a reusable means for converting the emitted light shielded by the light shielding means into a component that can be collimated by reusing the light is indirectly disposed through the reusable means. Alternatively, it may be emitted outside the light source device. By arranging such reuse means, it is possible to improve the extraction efficiency of the emitted light in the light source device.

In the light source device of the present invention, the light shielding unit reflects at least a part of the emitted light emitted from the side surface of the light emitting chip, so that the emitted light emitted from the side surface of the light emitting chip is directly It is possible to employ a configuration that prevents the injection in the front direction.
In general, a light emitting chip of an LED has a lower luminous efficiency when the temperature rises. For this reason, by adopting the configuration as described above, the light shielding unit can prevent all of the emitted light emitted from the side surface of the light emitting chip from being absorbed by the light shielding unit, and the temperature of the light source device can be increased. Can be suppressed, and a larger amount of light can be obtained from the light source device.

In the light source device of the present invention, the light shielding means is a conductive member that is connected to the first electrode disposed in front of the light emitting chip and disposed along the outer peripheral portion of the light emitting chip. A configuration can be employed.
In the conventional light source device, the first electrode is generally energized via a bonding wire. However, since such a bonding wire is disposed on the optical path of the emitted light, it causes non-uniform illuminance distribution of the illumination light. For this reason, it is possible to prevent the illuminance distribution of the illumination light from becoming non-uniform by energizing the first electrode through the conductive member disposed along the outer peripheral portion of the light emitting chip.
In the light source device of the present invention, since such a conductive member is used as the light shielding unit of the present invention, light emission emitted from the side surface of the light emitting chip without newly arranging another member as the light shielding unit. It is possible to prevent light from being emitted directly in the front direction.
In addition, since the cross-sectional area of the conductive member is much wider than the cross-sectional area of the bonding wire, it is possible to secure a wide current flow path and to pass a larger current than that of the conventional light source device. it can.
In addition, when it is unavoidable to adopt a configuration in which the first electrode is energized through a bonding wire, a non-conductive member made of ceramics or the like is disposed instead of the conductive member of the present invention, and this non-conductive It is also possible to use the member as the light shielding means of the present invention.

Moreover, in the light source device of this invention, the structure provided with the optical element connected with the said electroconductive member and arrange | positioned in the front direction of the said light-emitting chip is employable.
By disposing a conductive member around the light emitting chip, the light source device can be made solid. For this reason, it is possible to directly connect an optical element, which has been conventionally arranged as a component on the projector side, to the conductive member. Thereby, the optical path of the emitted light can be shortened as compared with the case where the light source device and the optical element are arranged separately. Therefore, the projector can be downsized and the loss of emitted light can be reduced.
In addition, a rod lens, a polarizing plate, etc. can be used as an optical element.

In the light source device of the present invention, a configuration in which an insulating liquid having translucency is provided between the optical element and the light emitting chip can be employed.
By adopting such a configuration, the light emitted from the light-emitting chip can be incident on the optical element without passing through the air with a large loss. Therefore, the extraction efficiency of the emitted light in the light source device can be improved.

In the light source device of the present invention, it is possible to employ a configuration in which a cooling means for flowing a cooling medium is provided between the optical element and the light emitting chip.
By adopting such a configuration, since a cooling medium flows between the optical element and the light emitting chip, the light emitting chip and the optical element can be actively cooled via the cooling medium, and the light emission efficiency of the light emitting chip can be improved. In addition, the light emitting chip can be driven with a larger current.

In the light source device of the present invention, the first electrode may be disposed on the entire front surface of the light emitting chip and may be formed of a light-transmitting conductive material. .
By adopting such a configuration, a current is uniformly applied to the entire front surface of the light emitting chip. Therefore, illumination light with a uniform illuminance distribution can be obtained from the light emitting chip. Note that, as described above, since the first electrode is formed of a light-transmitting conductive material, light emitted from the light-emitting chip is not shielded by the first electrode.

Moreover, in the light source device of this invention, the structure of providing an insulating member between the said 1st electrode and light emitting chip in the site | part in which the said electroconductive member was connected is employable.
When the light emitting chip is in direct contact with the first electrode at the part where the conductive member is connected, for example, a large amount of current is applied to the part shielded from light by the conductive member and applied to the front surface of the light emitting chip. There is a concern that the amount of current generated will decrease. In such a case, light emission occurs at a portion shielded from light by the conductive member, and the amount of light emission in front of the light emitting chip is reduced.
For this reason, by arranging the insulating member between the first electrode and the light emitting chip at the part where the conductive member is connected as described above, the current is applied to the part shielded from light by the conductive member. It can prevent, and it can prevent that the light-emission quantity in the front of a light-emitting chip reduces.

In the light source device of the present invention, it is possible to employ a configuration in which a reflector for deriving emitted light emitted obliquely from the front surface of the light emitting chip in the front direction is employed.
By adopting such a configuration, the illumination light emitted from the light source device can be converted into parallel light.

Moreover, in the light source device of this invention, the structure that the said reflector and the said electroconductive member are integrally formed is employable.
By adopting such a configuration, the illumination light can be collimated without newly arranging another member as a reflector.

Moreover, in the light source device of this invention, while being arrange | positioned in the surface facing the front surface of the said light emitting chip, the structure provided with the reflective film formed with an electroconductive material is employable.
By adopting such a configuration, the emitted light that is guided through the light emitting chip and is emitted to the surface facing the front surface of the light emitting chip is reflected by the reflective film, and is again guided through the light emitting chip. Injected from the front of the light emitting chip. For this reason, it becomes possible to improve the extraction efficiency of the emitted light in the light source device.

In the light source device of the present invention, a configuration in which the second electrode is a base that supports the light emitting chip and is formed of a conductive material can be employed.
By adopting such a configuration, it is possible to apply a current to the light emitting chip without newly arranging another member as the second electrode.
In addition, for example, when the base is formed of a member having high heat conductivity, the light emitting chip and the base are in direct contact with each other by using the base as the second electrode. It is possible to escape to the base side. For this reason, it can suppress that a light emitting chip becomes high temperature, the fall of the light emission efficiency of a light emitting chip can be prevented, and a light emitting chip can be driven with a larger electric current.

Next, a projector according to the present invention is characterized in that the light source device according to the present invention is used as a light source.
According to the projector of the present invention having such characteristics, the illuminance distribution of the illumination light emitted from the light source device is made uniform, so that the projector has better display characteristics.

  Hereinafter, an embodiment of a light source device and a projector according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member and each layer is appropriately changed in order to make each member and each layer recognizable.

<Light source device>
(First embodiment)
FIG. 1 is a schematic configuration diagram of a light source device 1 according to the first embodiment, in which (a) is a plan view and (b) is a cross-sectional view taken along line AA ′ in (a). As shown in FIG. 1, the light source device 1 of the first embodiment includes a light emitting chip 2 that emits light when energized. And the light source device 1 inject | emits the emitted light of the light emitting chip 2 in the front direction which is the direction where the upper surface 21 (front) of the light emitting chip 2 was faced.

  The light emitting chip 2 is directly mounted (supported) on a base 3 formed of a conductive member such as copper. The base 3 is connected to the lower surface 22 of the light emitting chip 2 via a conductive adhesive such as silver paste, and is used as a lower electrode (second electrode) for applying a current to the light emitting chip 2. It is done.

  A flexible substrate 4 is arranged on the base 3 so as to surround the light emitting chip 2. The flexible substrate 4 includes an insulating layer 41 and a conductive layer 42 disposed on the insulating layer 41. The insulating layer 41 ensures an insulating state between the conductive layer 42 and the base 3. Has been.

On the flexible substrate 4, the conductive member 5 (light shielding means) is disposed along the outer peripheral portion of the upper surface 21 of the light emitting chip 2. The conductive member 5 is disposed so as to cover the outer periphery of the light emitting chip 2 and prevents emitted light emitted from the side surface 23 of the light emitting chip 2 from being directly emitted in the front direction. is there.
Further, the surface 51 of the conductive member 5 in the vicinity of the light emitting chip 2 is subjected to a surface treatment so as to reflect at least a part of the emitted light emitted from the side surface of the light emitting chip 2.
In addition, the conductive member 5 should just be formed with the material which has electroconductivity, for example, can be formed using copper and aluminum.

FIG. 2 is an enlarged view of a portion A in FIG. As shown in this figure,
On the entire upper surface 21 of the light emitting chip 2, an upper electrode 7 (first electrode) made of a light-transmitting conductive material is disposed. In addition, ITO (Indium Tin Oxide) etc. can be used as a translucent conductive material for forming the upper electrode 7. The upper electrode 7 is connected to the conductive member 5 as shown in FIG. In addition, an insulating member 6 is disposed between the upper electrode 7 and the light emitting chip 2 at a portion where the conductive member 5 is connected. Further, the conductive member 5 is connected to the conductive layer 41 of the flexible substrate 4. The light emitting chip 2 emits light by being energized through the upper electrode 7 and the base 3 that is the lower electrode.

  Returning to FIG. 1, the side surface of the conductive material 5 on the light emitting chip 2 side is an inclined surface 52 (reflector) inclined from the outside to the inside of the light emitting chip 2. The inclined surface 52 is configured as a reflecting surface formed at an angle such that the emitted light emitted obliquely from the upper surface 21 of the light emitting chip 2 is led out in the above-described front direction. Thus, in the light source device 1 of the first embodiment, the reflector of the present invention and the conductive member are integrally formed. Therefore, according to the light source device 1 of the first embodiment, it is not necessary to install a new member as the reflector of the present invention.

  Further, as shown in FIG. 2, a reflective film 8 made of a conductive material is disposed on the lower surface 22 of the light emitting chip 2 (the surface facing the upper surface 21 of the light emitting chip 2). That is, in the first embodiment, the light emitting chip 2 is connected to the base 3 that is the lower electrode via the conductive adhesive and the reflective film 8.

  The light emitting chip 2 is a diode (LED) that emits light when a current flows through the pn junction. In a homojunction type LED in which the same semiconductor material is joined, there is no barrier against carriers injected into the light emitting portion, so that the carriers spread to the diffusion distance in the semiconductor. On the other hand, in a heterojunction LED in which different semiconductor materials are joined, a barrier against carriers is created in the structure, so that the density of carriers injected into the light emitting portion can be greatly increased. In particular, in a double heterojunction LED in which a light emitting layer is sandwiched between cladding layers, the carrier density can be increased as the width of the light emitting layer is narrowed, and the internal quantum efficiency can be improved. On the other hand, in a homojunction type LED, the material in contact with the outside world and the material of the light emitting part are the same, so that the emitted light is absorbed by its own material. On the other hand, in a double heterojunction LED, a light emitting layer made of a material having a narrow band gap is sandwiched between clad layers made of a material having a wide band gap. The extraction efficiency can be improved. Therefore, it is desirable to employ a double heterojunction type LED having excellent luminous efficiency.

When a light emitting chip 2 that emits red light emission is used, the light emitting chip 2 is formed by growing an AlGaInP-based compound semiconductor crystal on a substrate such as gallium arsenide (GaAs). In addition, since the GaAs substrate absorbs visible light, there is a limit in improving the extraction efficiency of light emitted from the LED. Therefore, in the light-emitting chip 2 in the present embodiment, it is desirable to remove the GaAs substrate after growing the semiconductor crystal and attach a gallium phosphide (GaP) substrate that is transparent to the emission wavelength at a high temperature and high pressure. Then, a double heterojunction structure is employed in which an AlGaInP light emitting layer is sandwiched between an n-GaP clad layer and a p-GaP clad layer.
When a light emitting chip 2 that emits blue or green light is used, it is formed by growing a GaInN-based compound semiconductor crystal on the surface of a substrate such as sapphire (Al ₂ O ₃ ). . It is preferable to adopt a double heterojunction structure in which a light emitting layer made of InGaN is sandwiched between a clad layer made of n-GaN and a clad layer made of p-GaN.

In the light source device 1 of the first embodiment having such a configuration, light is emitted from the light emitting chip 2 by energizing the light emitting chip 2 through the base 3 and the upper electrode 7.
Here, the emitted light emitted from the side surface 23 of the light emitting chip 2 is prevented from being emitted directly in the front direction by the conductive member 5. For this reason, since the stray light component contained in the illumination light that is difficult to be collimated can be eliminated, the illuminance distribution of the emitted light (illumination light) emitted from the light source device 1 can be made uniform. .

  Further, the surface 51 of the conductive member 5 in the vicinity of the light emitting chip 2 is surface-treated so as to reflect at least a part of the emitted light emitted from the side surface of the light emitting chip 2. Therefore, the light emitted from the side surface 23 of the light emitting chip 2 in the conductive member 5 can be prevented from being absorbed in the conductive member 5, and the temperature rise of the light source device 1 can be suppressed. . For this reason, it is possible to prevent a decrease in the light emission efficiency of the light emitting chip 2 and to drive the light emitting chip 2 with a larger current, and to obtain a larger amount of light emission from the light source device 1. In addition, a mirror (reuse means) etc. that indirectly emits in the front direction as emitted light that can be collimated by reflecting the emitted light reflected on the surface 51 of the conductive member 5 near the light emitting chip 2 is installed. By doing so, the emitted light reflected on the surface 51 of the conductive member 5 in the vicinity of the light emitting chip 2 may be reused. Thereby, the extraction efficiency of the emitted light in the light source device 1 can be improved.

  Here, a current is applied to the upper electrode 7 via the conductive member 5. Since such a conductive member 5 has a much larger cross-sectional area than the bonding wire provided in the conventional light source device, a larger current can flow. Therefore, according to the light source device 1 of the first embodiment, the light emitting chip 2 can be driven with a large current, and the light source device 1 with a larger light emission amount can be obtained. In the light source device 1 of the first embodiment, as described above, a current is applied to the upper electrode 7 via the conductive member 5 instead of the bonding wire. That is, the bonding wire that has been conventionally arranged on the optical path of the emitted light is not arranged. For this reason, it is possible to prevent the illuminance distribution of the illumination light from becoming non-uniform.

  Further, as described above, the light source device 1 of the first embodiment prevents the emitted light emitted from the side surface 23 of the light emitting chip 2 from being emitted directly in the front direction using the conductive member 5. Yes. For this reason, it is possible to prevent the emitted light emitted from the side surface 23 of the light emitting chip 2 from being emitted directly in the front direction without newly arranging another member as the light shielding means of the present invention.

  Further, in the light source device 1 of the first embodiment, the base 3 is formed of a highly conductive metal material (Cu) and is used as the second electrode, so that the heat quantity of the light emitting chip 2 is efficient. Thus, heat is radiated through the base 3. For this reason, since the temperature rise of the light-emitting chip 2 can be suppressed, the light-emitting chip 2 can be driven with a large current, and the light source device 1 with a larger amount of light emission can be obtained.

  Further, according to the light source device 1 of the first embodiment, the upper electrode 7 is disposed on the entire upper surface 21 of the light emitting chip 2. For this reason, a current is uniformly applied to the upper surface 21 of the light emitting chip 2, and light emitted with a uniform illuminance distribution can be obtained from the light emitting chip 2. Therefore, the illuminance distribution of the illumination light of the light source device 1 of the first embodiment is made more uniform.

  Further, in the light source device 1 of the first embodiment, the insulating member 6 is disposed between the upper electrode 7 and the light emitting chip 2 in the portion where the conductive member 5 is connected. For this reason, the amount of current applied to the outer peripheral portion of the light-emitting chip 2 covered by the conductive member 5 (the portion shielded from light by the conductive member 5) is reduced, and the light-emitting chip 2 not covered by the conductive member 5 A larger amount of current can be applied to the central portion of the. Therefore, according to the light source device 1 of the first embodiment, the light emission amount at the outer peripheral portion of the light emitting chip 2 where the emitted light is blocked by the conductive member 2 is reduced, and the light emission used as the illumination light of the light source device 1. The emitted light emitted from the center portion of the chip 2 can be increased. Therefore, it is possible to prevent the emission light extraction efficiency from deteriorating.

Of the emitted light emitted from the light emitting chip 2, the emitted light emitted in the front direction is emitted as it is in the front direction. Of the emitted light emitted from the light emitting chip 2, the emitted light emitted obliquely is reflected by the inclined surface 52 of the conductive member 5 configured as a reflector so as to be converted into parallel light and directed in the front direction. It is injected. Of the emitted light emitted from the light emitting chip 2, the emitted light guided through the light emitting chip 2 and emitted from the lower surface of the light emitting chip is reflected by the reflective film 8 disposed on the lower surface 22 of the light emitting chip 2. The light is again guided in the light emitting chip 2 and emitted in the front direction.
As described above, in the light source device 1 according to the first embodiment, since the reflective film 8 is disposed on the lower surface 22 of the light emitting chip 2, it is possible to improve the extraction efficiency of the emitted light.

  According to the light source device 1 of the first embodiment as described above, the illuminance distribution of the illumination light is made uniform and the collimated illumination light is emitted by the various configurations described above. For this reason, it becomes a light source device suitable as a light source of a projector.

  In the first embodiment, as shown in FIG. 2, the conductive member 5 has a configuration having four inclined surfaces 52. However, the present invention is not limited to this, and for example, as shown in FIG. 3, it may be configured to have a mortar-shaped conductive member in which the planar view shape of the slope 52 is circular.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the description of the second embodiment, the description of the same parts as in the first embodiment will be omitted or simplified. In the light source device of the second embodiment, the light source device of the first embodiment further includes an optical element.

  FIG. 4 is a cross-sectional view illustrating a schematic configuration of an example of a light source device according to the second embodiment. As shown in this figure, the light source device shown in FIG. 4 includes a rod lens 20 (optical element) connected to the conductive member 5 and arranged in the front direction of the light emitting chip 2. Further, silicon oil 30 is filled between the rod lens 20 and the light emitting chip 2 as an insulating liquid having translucency.

According to the light source device 1 as shown in the first embodiment, the light source device 1 itself can be made solid by disposing the conductive member 5 around the light emitting chip 2. Therefore, it can be set as the light source device further provided with an optical element by connecting to the electroconductive member 5 like the light source device of this 2nd Embodiment.
Conventionally, such an optical element is arranged as a component on the projector side, and the light source device and the optical element are arranged apart from each other. Therefore, by using the light source device of the second embodiment in which the optical element is connected to the conductive member 5 as the light source device of the second embodiment as the light source of the projector, the optical path of the illumination light (emitted light) is changed. The projector can be shortened, and the projector can be miniaturized.
Further, since the optical path from the light emitting chip 2 to the optical element is shortened, the optical path of the emitted light (illumination light) in the air is shortened, and the loss of the emitted light can be reduced. Therefore, in the light source device including the optical element, it is possible to further improve the extraction efficiency of the emitted light.

  Then, as shown in FIG. 4, the illuminance distribution of illumination light emitted from the light source device can be further uniformized by using a rod lens 30 as an optical element. Further, by filling silicon oil 30 between the rod lens 20 and the light emitting chip 2, it is possible to further suppress the loss of the emitted light between the light emitting chip 2 and the rod lens 30, and to extract the emitted light. The efficiency can be further improved.

  FIG. 5 is a cross-sectional view illustrating a schematic configuration of another example of the light source device according to the second embodiment. As shown in this figure, the light source device shown in FIG. 5 includes an inorganic polarizing plate 40 (optical element) connected to the conductive member 5 and arranged in the front direction of the light emitting chip 2. Further, silicon oil 30 is filled between the inorganic polarizing plate 40 (optical element) and the light emitting chip 2.

According to the light source device shown in FIG. 5 having such a configuration, the light source device including the optical element as described above has an effect, and the polarizing plate 40 is used as the optical element. Only illumination light can be emitted.
In a projector that uses a light source device having such a polarizing plate 40 as a light source, for example, a polarizing plate on the incident light incident side among polarizing plates that have been conventionally installed in a liquid crystal light valve used as a light modulation element is used. It can be eliminated.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. In the description of the third embodiment, the description of the same parts as those of the second embodiment will be omitted or simplified. In addition, the light source device of the third embodiment includes a cooling unit that causes the cooling medium X to flow between the optical element (the rod lens 20 and the polarizing plate 40) and the light emitting chip 2 in the light source device of the second embodiment. It has been configured.

  As shown in FIGS. 6 and 7, in the light source device of the third embodiment, a flow path 50 is formed in the conductive member 5. The flow path 50 is connected to a heat exchanger (not shown) and a circulation pump (not shown). And the cooling medium X is circulated through the circulation path comprised by the flow path 50, the heat exchanger, the circulation pump, etc. In the third embodiment, the cooling means of the present invention includes the flow path 50, the heat exchanger, and the circulation pump.

  According to the light source device of the third embodiment having such a configuration, the light emitting chip 2 is actively cooled through the cooling medium X. For this reason, the light emitting chip 2 can be further driven with a large current, and a light source device capable of obtaining brighter illumination light can be obtained.

<Projector>
Next, the projector of the present invention will be described with reference to FIG.
FIG. 8 is a schematic configuration diagram of a projector including the light source device according to the present embodiment. In the figure, reference numerals 512, 513, and 514 denote the light source devices shown in the above embodiment, 522, 523, and 524 denote liquid crystal light valves (light modulation elements), 525 denotes a cross dichroic prism, and 526 denotes a projection lens.

  The projector of FIG. 8 includes three light source devices 512, 513, and 514 configured as in the above embodiment. Each of the light source devices 512, 513, and 514 employs LEDs that emit light in red (R), green (G), and blue (B). In addition, a condensing lens 535 corresponding to each of the light source devices 512, 513, and 514 is disposed.

  The light beam from the red light source device 512 passes through the condenser lens 535R, is reflected by the reflection mirror 517, and enters the red light liquid crystal light valve 522. Further, the light beam from the green light source device 513 passes through the condenser lens 535G and enters the liquid crystal light valve 523 for green light. The light beam from the blue light source device 514 passes through the condenser lens 535B, is reflected by the reflection mirror 516, and enters the blue light liquid crystal light valve 524.

  In addition, polarizing plates (not shown) are arranged on the incident side and the emission side of each liquid crystal light valve. Then, only linearly polarized light in a predetermined direction out of the light flux from each light source passes through the incident side polarizing plate and enters each liquid crystal light valve. Further, a polarization conversion means (not shown) may be provided behind the incident side polarizing plate. In this case, the light beam reflected by the incident side polarizing plate can be recycled and incident on each liquid crystal light valve, and the utilization efficiency of illumination light (emitted light) can be improved. In addition, when using the light source device provided with the polarizing plate as an optical element shown in FIG. 5, the polarizing plate of the incident side of a liquid crystal light valve can be eliminated.

  The three color lights modulated by the liquid crystal light valves 522, 523, and 524 are incident on the cross dichroic prism 525. This prism is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged in a cross shape on the inner surface thereof. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the projection screen 527 by the projection lens 526 which is a projection optical system, and an enlarged image is displayed.

  In the light source device of the present embodiment described above, since the emitted light emitted from the side surface of the light emitting chip is blocked, the stray light component included in the illumination light is eliminated, and the illuminance distribution of the illumination light is made uniform. For this reason, it can be set as the projector which was more excellent in the display characteristic.

  The preferred embodiments of the light source device and the projector according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above embodiment, a liquid crystal light valve is used as the light modulation means in the projector. However, the present invention is not limited to this, and it is also possible to use a micromirror array device or the like as the light modulation means.

It is a schematic block diagram of the light source device of 1st Embodiment of this invention. It is an enlarged view of the A section in FIG. It is a modification of the light source device in 1st Embodiment of this invention. It is a schematic block diagram of the light source device of 2nd Embodiment of this invention. It is a schematic block diagram of the light source device of 2nd Embodiment of this invention. It is a schematic block diagram of the light source device of 3rd Embodiment of this invention. It is a schematic block diagram of the light source device of 3rd Embodiment of this invention. It is a schematic block diagram of the projector which is one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light source device, 2 ... Light emitting chip, 3 ... Base (2nd electrode), 5 ... Conductive member (light-shielding means), 52 ... Inclined surface (reflector), 6 ... Insulating member, 7 ... ... upper electrode (first electrode), 8 ... reflective film, 500 ... projector, 20 ... rod lens (optical element), 30 ... silicon oil, 40 ... polarizing plate (optical element)

Claims (15)

A light source device that includes a light emitting chip that emits light when energized through a first electrode and a second electrode, and emits light emitted from the light emitting chip in a front direction of the light emitting chip,
A light source device comprising: a light shielding unit that prevents emitted light emitted from a side surface of the light emitting chip from being emitted directly in the front direction. The light shielding means reflects at least a part of the light emitted from the side surface of the light emitting chip, thereby preventing the emitted light emitted from the side surface of the light emitting chip from being emitted directly in the front direction. The light source device according to claim 1. The said light-shielding means is a conductive member that is connected to the first electrode disposed on the front surface of the light-emitting chip and is disposed along the outer periphery of the light-emitting chip. Light source device. The light source device according to claim 3, further comprising an optical element connected to the conductive member and disposed in a front direction of the light emitting chip. The light source device according to claim 4, wherein an insulating liquid having translucency is sealed between the optical element and the light emitting chip. 6. The light source device according to claim 4, further comprising cooling means for flowing a cooling medium between the optical element and the light emitting chip. The light source device according to claim 4, wherein the optical element is a rod lens. The light source device according to claim 4, wherein the optical element is a polarizing plate. The light source device according to claim 1, wherein the first electrode is disposed on the entire front surface of the light emitting chip and is formed of a light-transmitting conductive material. The light source device according to claim 9, further comprising an insulating member between the first electrode and the light emitting chip at a portion to which the conductive member is connected. The light source device according to any one of claims 1 to 10, further comprising a reflector for deriving emitted light emitted obliquely from the front of the light emitting chip in the front direction. The light source device according to claim 11, wherein the reflector and the conductive member are integrally formed. The light source device according to claim 1, further comprising a reflective film that is disposed on a surface facing the front surface of the light emitting chip and is formed of a conductive material. The light source device according to claim 1, wherein the second electrode is a base that supports the light emitting chip and is formed of a conductive material. A projector using the light source device according to claim 1 as a light source.

Images