JP6759714B2 - Light source device and projector - Google Patents

Description

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

As a light source device for a projector, a device using a solid-state light source that emits laser light has been proposed. It is considered that it is easy to increase the output of the solid-state light source by using the end face emitting type laser element.

Usually, a solid-state light source such as a laser element is mounted on a submount provided on a base substrate. The submount is also used, for example, as a cushioning material. A solid-state light source provided on the submount emits laser light in a direction parallel to one surface of the submount. As a light source device having such an existing structure, for example, one having a reflection mirror that deflects light emitted in parallel with the surface of a substrate from a laser element by 90 degrees is known. In such a light source device, the light emitted from the laser element is reflected by the reflection mirror and reflected in the normal direction of the substrate (see, for example, Patent Document 1).

U.S. Patent Application Publication No. 2008/884905

However, many solid-state light sources such as laser elements have a large radiation angle. Of the light emitted from the laser element in the light source device having the existing structure, a part of the light emitted downward with respect to the central axis of the light beam reaches the substrate without being incident on the reflection mirror. Therefore, in the light source device, the emitted light may not be effectively used depending on the type of laser element used.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a light source device capable of effectively using light emitted from a solid-state light source by emitting it to the outside with a small loss. Another object of the present invention is to provide a projector having such a light source device.

In order to solve the above problems, one aspect of the present invention is provided on a substrate having a first surface, an auxiliary substrate provided on the first surface, and a second surface which is an upper surface of the auxiliary substrate. It has a solid light source that emits light substantially parallel to the second surface, and an optical element that deflects the light emitted from the solid light source in a direction away from the first surface, and the substrate is made of a metal material. Is used as the forming material, the auxiliary substrate is made of a material having a linear expansion coefficient smaller than that of the substrate, and the solid light source is arranged on the second surface toward the optical element with the light emitting surface facing. The second surface provides a light source device in which the optical element side has a higher inclined surface than the side opposite to the optical element.
According to this configuration, even if the solid-state light source generates heat, it can satisfactorily dissipate heat without being damaged. Further, the solid-state light source emits light diagonally upward with respect to the first surface. Therefore, even if the radiation angle of the solid-state light source is large, among the light emitted from the solid-state light source, the light that spreads downward with respect to the central axis of the light beam is likely to enter the optical element. Therefore, the light source device is highly reliable and can effectively use the light emitted from the solid-state light source by emitting it to the outside with a small loss.

According to one aspect of the present invention, the auxiliary substrate may be configured to be in thermal contact with the substrate via a heat transfer material.
According to this configuration, even if the solid-state light source generates heat, heat can be satisfactorily dissipated.

According to one aspect of the present invention, the solid-state light source may be configured to be in thermal contact with the auxiliary substrate via a heat transfer material.
According to this configuration, even if the solid-state light source generates heat, heat can be satisfactorily dissipated.

Further, one aspect of the present invention includes the above-mentioned light source device, an optical modulation device that modulates the light emitted from the light source device, and a projection optical system that projects the light modulated by the light modulation device. projector.
According to this configuration, since the light source device having high light utilization efficiency is provided, it is possible to provide a projector capable of projecting a bright image.

According to one aspect of the present invention, the light source device may further include a wavelength conversion element that converts light emitted from the solid light source into fluorescent light.
According to this configuration, since the projector is provided with a wavelength conversion element, it is possible to realize desired brightness and color tone.

The perspective view which shows the light source apparatus of this embodiment. FIG. 5 is a cross-sectional view taken along the line showing the light source device of this embodiment. FIG. 5 is a cross-sectional view taken along the line showing the light source device of this embodiment. The figure which shows the optical system of the projector which concerns on this embodiment. The figure which shows for demonstrating the rotary fluorescent plate in this embodiment.

[Light source device]
Hereinafter, the light source device according to the embodiment of the present invention will be described with reference to the drawings. In all the drawings below, the dimensions and ratios of the components are appropriately different in order to make the drawings easier to see.

FIG. 1 is a perspective view showing a light source device of the present embodiment. FIG. 2 is a cross-sectional view taken along the line segment II-II of FIG. As shown in FIGS. 1 and 2, the light source device 1 of the present embodiment includes a substrate 101, a plurality of auxiliary substrates 102, a plurality of solid-state light sources 103, and a plurality of reflection mirrors (optical elements) 104. ing. Further, the light source device 1 has a frame material 105, an electrode 106, and a cover material 70.

(substrate)
The substrate 101 is a plate material made of a metal material as a forming material. By using the metal material as the forming material for the substrate 101, the driving heat generated by the solid light source 103 can be efficiently discharged via the substrate 101. As the metal material, one having a high thermal conductivity is preferable, for example, copper or aluminum is preferable, and copper is more preferable.

(Auxiliary board)
The plurality of auxiliary substrates 102 are arranged in a matrix on the surface (first surface) 101a of the substrate 101 at predetermined intervals. The substrate 101 and the auxiliary substrate 102 are in thermal contact with each other via a heat transfer material. Examples of the heat transfer material for connecting the substrate 101 and the auxiliary substrate 102 include a solder material such as gold-tin. The separation distance of each auxiliary substrate 102 is, for example, 4 to 5 mm.

The auxiliary substrate 102 uses a material having a coefficient of linear expansion smaller than that of the substrate 101 as a forming material. Examples of such a forming material include ceramics such as aluminum nitride and alumina.

Further, as shown in FIG. 2, the upper surface (second surface) 102a of the auxiliary substrate 102 of the present embodiment is inclined with respect to the first surface 101a. That is, the second surface 102a is higher on the reflection mirror 104 side, which will be described later, than on the side opposite to the reflection mirror 104.

(Solid light source)
The solid-state light source 103 is arranged on the second surface 102a. The auxiliary substrate 102 and the solid-state light source 103 are in thermal contact with each other via a heat transfer material. Examples of the heat transfer material for connecting the auxiliary substrate 102 and the solid light source 103 include a solder material such as gold-tin.

Since the substrate 101, the auxiliary substrate 102, and the solid light source 103 are in thermal contact with each other via the heat transfer material, even if the solid light source 103 generates heat, the generated heat is satisfactorily transferred to the substrate 101. It can dissipate heat.

The solid-state light source 103 emits light substantially parallel to the second surface 102a. Further, the plurality of solid-state light sources 103 are provided on the substrate 101 so as to emit light in substantially the same direction.

In FIG. 2, the central axis of the light bundle of light emitted from the solid-state light source 103 is indicated by the alternate long and short dash line L. By arranging the solid light source 103 in such a posture, the contact area between the solid light source 103 and the auxiliary substrate 102 is increased as compared with the posture in which light is emitted from the solid light source 103 in the normal direction of the second surface 102a. Can be done. Therefore, the heat generated by the solid-state light source 103 can be efficiently transferred to the auxiliary substrate 102, and the deterioration of the solid-state light source 103 can be suppressed.

Examples of the solid-state light source 103 include a light emitting diode and a semiconductor laser. The solid-state light source 103 can be selected with an arbitrary wavelength depending on the application. For example, as a light emitting device that emits blue light having a wavelength of 430 nm to 490 nm, a nitride semiconductor (In _X Al _Y Ga _1-XY N, 0 ≦ X ≦ 1, 0 ≦ Y ≦ 1, X + Y ≦ 1) is used. Materials containing can be used. Further, in addition to this material, a material in which a boron atom is partially substituted as a group III element or a material in which a part of a nitrogen atom is substituted with a phosphorus atom or an arsenic atom as a group V element can also be used.

(Reflective mirror)
The reflection mirror 104 reflects the light emitted from the solid-state light source 103 in a direction away from the first surface 101a. That is, the solid-state light source 103 is arranged on the second surface 102a toward the reflection mirror 104 toward the light emission surface 30a, and the light emitted from the solid-state light source 103 is incident on the reflection mirror 104 and is reflected on the reflection mirror. The reflective surface of 104 is deflected in a direction away from the first surface 101a.

The reflection mirror 104 of the present embodiment extends in a strip shape along the arrangement direction of the four solid light sources 103 in each row in a plan view. The reflection mirror 104 is provided with one common to the four solid light sources 103 in each row on the light emitting side. Further, in the light source device 1, five configurations in which four solid light sources 103 and one reflection mirror 104 are paired are arranged.

Generally, the alignment of the reflection mirror 104 with respect to the solid-state light source 103 requires high accuracy. By providing one reflection mirror 104 common to the four solid light sources 103, alignment can be performed more efficiently than in the case where one reflection mirror is provided for one solid light source 103.

As the reflection mirror 104, if it has a reflection surface 104a that reflects light, a commonly known one can be used.

Further, if the light emitted from the solid-state light source 103 can be deflected, a prism can be used instead of the reflection mirror as the optical member in the present invention.

(Frame material, electrode, cover member)
The frame member 105 is provided on the first surface 101a so as to surround the plurality of auxiliary substrates 102 and the solid-state light source 103. The substrate 101 and the frame material 105 are joined by a metal wax such as silver wax.

An example of a material for forming the frame material 105 is Kovar. A plating layer is formed on the surface of the frame material 105, and for example, a plating layer made of nickel-gold is formed.

The frame member 105 is provided with a plurality of through holes. Each through hole is provided with an electrode 106 for supplying electric power to the solid-state light source 103. A bonding wire for electrically connecting to the solid-state light source 103 is provided at one end of each electrode 106 (not shown). Gold is preferable as the material for forming the bonding wire. The other end of each electrode 106 is connected to an external electrical circuit.

The through holes and the electrodes 106 are sealed with low melting point glass or the like.

As a material for forming the electrode 106, for example, Kovar is used. Further, a plating layer is formed on the surface of the electrode 106, and for example, a plating layer made of nickel-gold may be formed.

The cover member 107 is arranged at the upper end of the frame member 105. The cover member 107 has a rectangular shape along the frame member 105 and closes one opening side of the frame member 105. The cover member 107 is a plate-shaped member made of a light-transmitting material as a forming material, and has a light-transmitting property. Examples of such a forming material include glass, quartz, and transparent resin.

The cover member 107, together with the frame member 105, seals the periphery of the plurality of solid light sources 103. That is, by arranging the plurality of solid light sources 103 in a closed space surrounded by the substrate 101, the frame member 105, and the cover member 107, deterioration of the solid light source 103 due to moisture and oxygen contained in the atmosphere can be suppressed. Can be done.

In addition, a configuration such as a heat sink that enhances heat dissipation efficiency may be provided on the surface of the substrate 101 opposite to the first surface 101a.

The light source device 1 of the present embodiment has the above-described configuration.

A solid-state light source such as a laser element has a constant radiation angle. Therefore, when light is emitted from a solid light source arranged on the substrate substantially parallel to the surface of the substrate, half of the emitted light is emitted toward the substrate side.

When the light emitted from the solid-state light source is deflected by an optical element such as a reflection mirror arranged on the substrate, the optical element is arranged at a position where the light spreading at a constant radiation angle is effectively incident. That is, it is preferable that the optical element is arranged as close to the light emitting surface of the solid light source as possible.

On the other hand, when the solid-state light source is arranged on the substrate via the auxiliary substrate, the auxiliary substrate is bonded to the substrate via a material such as solder. At this time, there is usually a region around the auxiliary substrate where the solder used for joining protrudes and spreads. Therefore, the optical element cannot be arranged at the position where the protruding solder interferes, and the optical element is arranged at a position slightly separated.

In such a configuration, when the emission angle of the solid-state light source is large, a part of the light emitted from the solid-state light source toward the substrate side reaches the substrate without being incident on the optical element. .. That is, of the light emitted from the solid-state light source in the light source device having the above configuration, a part of the light emitted downward with respect to the central axis of the light bundle does not enter the optical element and is the light of the solid-state light source. It reaches the exposed substrate between the injection surface and the optical element. Therefore, in the light source device, the emitted light may not be effectively used depending on the type of solid light source used.

As one method of solving this problem, the substrate is dug down and the optical element is placed at the dug down position so that the light emitted downward can be incident on the optical element, so that the position of the lower end of the optical element and the light can be obtained. A configuration that widens the gap with the position of the injection surface can be considered. However, in this case, it is necessary to process the substrate while ensuring high processing accuracy, which leads to a decrease in price competitiveness.

Therefore, in the present invention, the upper surface (second surface) 102a of the auxiliary substrate 102 is set as an inclined surface, and light is emitted obliquely upward from the solid-state light source 103. As a result, the light emitted downward from the solid-state light source 103 with respect to the central axis L of the light beam can be effectively guided to the reflection mirror (optical element) 104, and the emitted light can be effectively used.

According to the light source device 1 having the above configuration, the light emitted from the solid-state light source 103 can be emitted to the outside with a small loss and effectively used.

In this embodiment, the plate-shaped cover member 107 is used, but as in the light source device 2 shown in FIG. 3, the declined glass prism 108 having a refraction action is used instead of the cover member 107. It may be used. According to the light source device 2 having such a configuration, the emission direction of the light emitted from the solid-state light source 103 can be adjusted by the reflection mirror 104 and the polarized glass prism 108, so that the emission direction of the light can be easily adjusted. It is controllable.

[projector]
FIG. 4 is a diagram showing an optical system of a projector according to the present embodiment. FIG. 5 is a diagram shown for explaining the rotating fluorescent plate in the present embodiment. 5 (a) is a front view of the rotating fluorescent screen, and FIG. 5 (b) is a cross-sectional view of Vb-Vb of FIG. 5 (a).

First, the configurations of the light source system 550 and the projector 1000 according to the first embodiment will be described.

As shown in the figure, the projector 1000 according to the present embodiment includes a lighting device 100, a color separation light guide optical system 200, a liquid crystal light valve (light modulator) 400R, a liquid crystal light valve (light modulator) 400G, and a liquid crystal light valve. (Optical modulator) 400B, a cross dichroic prism 500, and a projection optical system 600 are provided.

The illumination device 100 includes a light source system 550, a first lens array 120, a second lens array 130, a polarization conversion element 140, and a superimposing lens 150. The light source system 550 includes an array light source 10, a condensing optical system 20, a rotating fluorescent plate (wavelength conversion element) 30, a motor 50, and a collimating optical system 60.

The array light source 10 is composed of one or more laser light sources that emit blue light (peak of emission intensity: about 445 nm) as excitation light. A laser light source that emits blue light having a wavelength other than 445 nm (for example, 460 nm) can also be used. As the array light source 10, the light source devices 1 and 2 according to the present invention described above can be used.

The condensing optical system 20 includes a first lens 22. The condensing optical system 20 is arranged in an optical path from the array light source 10 to the rotating fluorescent plate 30, and causes blue light to enter the phosphor layer 42 in a substantially condensed state. The first lens 22 is made of a convex lens.

As shown in FIGS. 4 and 5, the rotating fluorescent plate 30 is formed with a phosphor layer 42 provided along the circumferential direction of the disk 40 on a disk 40 that can be rotated by a motor 50. The rotating fluorescent plate 30 emits fluorescent light composed of red light and green light toward the side opposite to the side on which the blue light is incident.

The disk 40 is made of a material that transmits blue light. As the material of the disk 40, for example, quartz glass, crystal, sapphire, optical glass, transparent resin and the like can be used.

The blue light from the array light source 10 is incident on the phosphor layer 42 from the disk 40 side. A dichroic film 44 that transmits blue light and reflects fluorescent light is provided between the phosphor layer 42 and the disk 40.

The phosphor layer 42 is excited by blue light having a wavelength of about 445 nm. The phosphor layer 42 converts a part of the blue light from the array light source 10 into fluorescent light, and allows the remaining part of the blue light to pass through without conversion. The phosphor layer 42 is composed of, for example, a layer containing (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, which is a YAG-based phosphor.

As shown in FIG. 4, the collimating optical system 60 includes a first lens 62 and a second lens 64, and substantially parallelizes the light from the rotating fluorescent plate 30. The first lens 62 and the second lens 64 are made of a convex lens.

The first lens array 120 has a plurality of first small lenses 122 for dividing the light from the collimating optical system 60 into a plurality of partial luminous fluxes. The plurality of first small lenses 122 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

The second lens array 130 has a plurality of second small lenses 132 corresponding to the plurality of first small lenses 122 of the first lens array 120. The second lens array 130, together with the superimposed lens 150, connects the image of each first small lens 122 of the first lens array 120 to the vicinity of the image forming region of each liquid crystal light bulb 400R, liquid crystal light bulb 400G, and liquid crystal light valve 400B. Make an image. The plurality of second small lenses 132 are arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax.

The polarization conversion element 140 converts each partial luminous flux divided by the first lens array 120 into linearly polarized light.
The polarization conversion element 140 transmits one of the polarization components contained in the light from the rotating fluorescent plate 30 as it is, and reflects the other linear polarization component in a direction perpendicular to the illumination optical axis 100ax. The other linearly polarized light component reflected by the polarization separation layer is converted into one linearly polarized light component by the reflecting layer that reflects the other linearly polarized light component in the direction parallel to the illumination optical axis 100ax and the other linearly polarized light component reflected by the reflecting layer. It has a retardation plate.

The superimposing lens 150 collects each partial luminous flux from the polarization conversion element 140 and superimposes it on the vicinity of the image forming region of each liquid crystal light bulb 400R, the liquid crystal light bulb 400G, and the liquid crystal light bulb 400B. The first lens array 120, the second lens array 130, and the superimposed lens 150 constitute an integrator optical system that makes the in-plane light intensity distribution of the light from the rotating fluorescent plate 30 uniform in the image forming region.

The color separation light guide optical system 200 includes a dichroic mirror 210, a dichroic mirror 220, a reflection mirror 230, a reflection mirror 240, a reflection mirror 250, a relay lens 260, and a relay lens 270. The color separation light guide optical system 200 separates the light from the lighting device 100 into red light, green light, and blue light, and the red light, green light, and blue light correspond to each of the liquid crystal light valve 400R and the liquid crystal light valve 400G. , Guides light to the liquid crystal light valve 400B.
A condensing lens 300R, a condensing lens 300G, and a condensing lens 300B are arranged between the color separation light guide optical system 200 and the liquid crystal light valve 400R, the liquid crystal light valve 400G, and the liquid crystal light valve 400B, respectively.

The dichroic mirror 210 is a dichroic mirror that allows a red light component to pass through and reflects a green light component and a blue light component.
The dichroic mirror 220 is a dichroic mirror that reflects a green light component and allows a blue light component to pass through.

The red light that has passed through the dichroic mirror 210 is reflected by the reflection mirror 230, passes through the condensing lens 300R, and is incident on the image forming region of the liquid crystal light valve 400R for red light.
The green light reflected by the dichroic mirror 210 is further reflected by the dichroic mirror 220, passes through the condensing lens 300G, and is incident on the image forming region of the liquid crystal light valve 400G for green light.
The blue light that has passed through the dichroic mirror 220 passes through the relay lens 260, the reflection mirror 240 on the incident side, the relay lens 270, the reflection mirror 250 on the emission side, and the condenser lens 300B, and then passes through the image forming region of the liquid crystal light valve 400B for blue light. Incident in.

The liquid crystal light bulb 400R, the liquid crystal light bulb 400G, and the liquid crystal light bulb 400B modulate the incident colored light according to the image information to form a color image. Although not shown, there are polarizing plates on the incident side between the condenser lens 300R, the condenser lens 300G, and the condenser lens 300B, and the liquid crystal light valve 400R, the liquid crystal light valve 400G, and the liquid crystal light valve 400B, respectively. A polarizing plate on the injection side is arranged between the liquid crystal light valve 400R, the liquid crystal light valve 400G, the liquid crystal light valve 400B, and the cross dichroic prism 500, respectively.

The cross dichroic prism 500 forms a color image by synthesizing the image lights emitted from each of the liquid crystal light valve 400R, the liquid crystal light valve 400G, and the liquid crystal light valve 400B. The cross dichroic prism 500 has a substantially square shape in a plan view in which four right-angled prisms are bonded together, and a dielectric multilayer film is formed at a substantially X-shaped interface in which the right-angled prisms are bonded to each other.

The color image ejected from the cross dichroic prism 500 is magnified and projected by the projection optical system 600 to form an image on the screen SCR.

According to the projector 1000 having the above configuration, since the light source device having high light utilization efficiency is provided, it is possible to provide a projector capable of projecting a bright image.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. The various shapes and combinations of the constituent members shown in the above-mentioned examples are examples, and can be variously changed based on design requirements and the like without departing from the gist of the present invention.

For example, in the projector 1000 of the present embodiment, an example in which a transmissive liquid crystal light bulb is used as the light modulation device has been shown, but the present invention is not limited to this. As another light modulation device, for example, a reflective liquid crystal light bulb or a digital mirror device may be used. Here, the "transmissive type" means that the liquid crystal light bulb including the liquid crystal panel or the like transmits light. "Reflective type" means that the liquid crystal light bulb is a type that reflects light.

1,2 ... Light source device, 30 ... Rotating fluorescent plate (wavelength conversion element), 30a ... Light emitting surface, 101 ... Substrate, 101a ... First surface, 102 ... Auxiliary substrate, 102a ... Second surface, 103 ... Solid light source, 104 ... Reflective mirror (optical element), 400R ... Liquid crystal light valve (light modulator), 600 ... Projection optical system, 1000 ... Projector

Claims (7)

A substrate having a first surface and
Auxiliary substrate provided on the first surface and
A solid light source provided on a second surface, which is the upper surface of the auxiliary substrate, and emitting light substantially parallel to the second surface.
It has an optical element that deflects the light emitted from the solid-state light source in a direction away from the first surface.
A plurality of the auxiliary substrates are provided in a matrix on the first surface.
A plurality of the solid-state light sources are provided corresponding to the plurality of the auxiliary substrates.
The substrate is made of a metal material as a forming material.
The auxiliary substrate is made of a material having a coefficient of linear expansion smaller than that of the substrate.
The plurality of solid light sources are arranged on the second surface toward the optical element so as to face the light emitting surface.
The second surface has an inclined surface on the side of the optical element higher than that on the side opposite to the optical element .
The optical element is a light source device that is a reflection mirror . The light source device according to claim 1, wherein the auxiliary substrate is in thermal contact with the substrate via a heat transfer material. The light source device according to claim 1 or 2, wherein the solid light source is in thermal contact with the auxiliary substrate via a heat transfer material. The light source device according to any one of claims 1 to 3, wherein the optical element is provided for each of the plurality of solid light sources. The light source device according to any one of claims 1 to 4, further comprising a second optical element for adjusting the emission direction of polarized light in the optical element. The light source device according to any one of claims 1 to 5 .
An optical modulator that modulates the light emitted from the light source apparatus,
A projector including a projection optical system that projects light modulated by the light modulator. The projector according to claim 6 , wherein the light source device further includes a wavelength conversion element that converts light emitted from the solid-state light source into fluorescent light.

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