TWI617059B - Illumination system and wavelength-converting deivce thereof - Google Patents

Abstract

The present invention relates to a light source system including a solid state light emitting device and a wavelength conversion device. The solid state light emitting element is configured to emit a first band of light to the light path. The wavelength conversion device is disposed in the light path and includes a fluorescent plate. The fluorescent plate is a solid mixture having a phosphor powder and a binder, wherein the phosphor powder has a weight percentage of 10 to 70% by weight, and the first band light is converted into the second band light. Thereby, the heat conduction of the fluorescent plate can be effectively improved, thereby improving the conversion efficiency of the wavelength conversion device, and the rigidity is sufficient for the rotation. At the same time, in addition to reducing space requirements, hot spots and thermal diffusion can be avoided, and the manufacturing cost and manufacturing difficulty of the wavelength conversion device are greatly reduced.

Description

Light source system and wavelength conversion device thereof

The present invention relates to a light source system, and more particularly to a light source system and a wavelength conversion device thereof.

In recent years, high-order projectors mainly use a laser light source in combination with a wavelength conversion device as a light source system. Traditional wavelength conversion devices can be mainly divided into two types: one is a rotating fluorescent pink wheel (Phosphor Wheel), and the other is a fixed fluorescent pink plate module (Phosphor Plate Module).

Please refer to FIG. 1 and FIG. 2 , wherein FIG. 1 is a schematic view showing a conventional rotary fluorescent pink wheel, and FIG. 2 is a schematic view showing a conventional fixed fluorescent pink plate module. In general, the rotary fluorescent pink wheel 1 is attached to a circular high-reflection substrate 10, and is coated with a cemented mixed phosphor (or phosphor) 11 at a specific position of the highly reflective substrate 10, and then high. The center of the reflective substrate 10 is mounted on the motor 12, whereby the fluorescent pink wheel 1 can be rotated to dissipate heat during wavelength conversion. Since the fixed fluorescent pink panel module 2 cannot be radiated in a rotating manner, the fluorescent pink panel 21 is fixed on one surface of the high reflection substrate 20 and disposed on the opposite surface of the high reflection substrate 20 The heat sink 22 dissipates the high temperature generated by the laser light source.

However, in the rotary fluorescent pink wheel 1, since the reliability of the adhesive is low and the thermal conductivity is poor, the heat conduction between the fluorescent powder 11 and the highly reflective substrate 10 is lowered, thereby causing the phosphor powder 11 to convert the wavelength. The conversion efficiency is not good, and the rigidity of the highly reflective substrate 10 may also be insufficient to cope with the sloshing caused by the rotation; in addition, in the fixed fluorescent pink panel module 2, the heat sink 22 is mainly used for conduction and convection. In the manner of heat dissipation, the highly reflective substrate 20 and the heat sink 22 must use components having a relatively large surface area, which often causes space requirements to exceed expectations, and at the same time, due to hot spots and thermal diffusion, the fixed fluorescent pink plate mold is fixed. Group 2's manufacturing costs and technical difficulties remain high.

The main purpose of the present invention is to provide a light source system and a wavelength conversion device thereof, which solve the aforementioned conventional technical problems.

Another object of the present invention is to provide a light source system and a wavelength conversion device thereof, which are formed by using a phosphor plate with 10 to 70 weight percent of phosphor powder and a binder to convert the first wavelength band into the second band light. The heat conduction of the fluorescent plate can be effectively improved, thereby improving the conversion efficiency of the wavelength conversion device, and the rigidity is sufficient for the rotation.

Another object of the present invention is to provide a light source system and a wavelength conversion device thereof. Although the wavelength conversion device is applied in a rotary manner, it is not necessary to use a heat sink, and in addition to reducing space requirements, hot spots and heat diffusion can be avoided. The manufacturing cost and manufacturing difficulty of the wavelength conversion device are greatly reduced.

Another object of the present invention is to provide a light source system and a wavelength conversion device thereof. Since the light-emitting surface of the fluorescent plate is polished to form a polished surface, the light-receiving efficiency of the fluorescent plate can be better, and the wavelength conversion device is coupled. The conversion efficiency is effectively improved.

In order to achieve the above object, a preferred embodiment of the present invention provides a light source system including: a solid state light emitting device configured to emit a first band of light to a light path; and a wavelength conversion device disposed on the light path And comprising a fluorescent plate, wherein the fluorescent plate is a solid mixture having a fluorescent powder and a binder, wherein the fluorescent powder has a weight percentage of 10 to 70% by weight, and the first wavelength band is converted into light A second band of light.

In some embodiments, the binder is glass or alumina. Further, the binder further comprises a ceramic additive. Further, the chemical formula of the glass is SiO _x , 0 < x ≦ 2, and the refractive index n value of the glass is less than or equal to 1.5.

In some embodiments, the fluorescent plate is an annular fluorescent plate or a sheet fluorescent plate.

According to the concept of the present invention, the wavelength conversion device further includes an optical coating formed on one surface of the fluorescent plate. The optical coating is deposited or coated on the surface of the fluorescent plate, and the optical coating is disposed on the other side of the light emitting surface of one of the fluorescent plates.

According to the concept of the present invention, the wavelength conversion device further includes a substrate and an optical coating, and the optical coating is formed on the substrate.

In some embodiments, the optical coating is disposed on the other side of one of the light-emitting surfaces of the fluorescent plate, and the light-emitting surface is a polished surface.

In some embodiments, an air gap is formed between the phosphor plate and the optical coating on the substrate. Wherein, the air gap is formed by adhesive or sandwiching.

According to the concept of the present invention, the wavelength conversion device further includes a substrate, and the substrate is provided with an optical coating, and the fluorescent plate of the wavelength conversion device is an annular fluorescent plate, wherein the fluorescent plate is disposed on the substrate. In addition, an air gap is formed between the fluorescent plate and the substrate, and the fluorescent plate and the substrate are concentric circles.

According to the creative thinking of the present invention, the thickness of the fluorescent plate is greater than or equal to 50 microns and less than or equal to 1000 microns.

In order to achieve the above object, another preferred embodiment of the present invention provides a wavelength conversion device, which is adapted to emit a light source system of a first wavelength band to a light path, comprising: a fluorescent plate disposed on the light path; For receiving the first wavelength band light, wherein the fluorescent plate is a solid mixture having a phosphor powder and a binder, wherein the phosphor powder is 10 to 70 weight percent by weight, and the first wavelength band is The light is converted into a second band of light.

According to the concept of the present invention, the wavelength conversion device further includes an optical coating formed on one surface of the fluorescent plate. The optical coating is deposited or coated on the surface of the phosphor plate, and the optical coating is disposed on the other side of the light-emitting surface of the fluorescent plate, and the light-emitting surface is a polished surface.

According to the concept of the present invention, the wavelength conversion device further includes a substrate and an optical coating, wherein the optical coating is formed on the substrate. The optical coating is disposed on the other side of the light-emitting surface of one of the fluorescent plates, and the light-emitting surface is a polished surface.

1‧‧‧Rotary Fluorescent Pink Wheel

10‧‧‧Highly reflective substrate

11‧‧‧Fluorescent powder

12‧‧‧ motor

2‧‧‧Fixed fluorescent pink board module

20‧‧‧Highly reflective substrate

21‧‧‧Fluorescent pink board

22‧‧‧ Heat sink

3‧‧‧Light source system

31‧‧‧Solid light-emitting elements

32‧‧‧wavelength conversion device

321‧‧‧Fluorescent plate

322‧‧‧Optical coating

323‧‧‧Substrate

324‧‧‧ motor

325‧‧‧ joint layer

A‧‧‧air gap

C‧‧‧ fixture

G‧‧‧Viscos

L1‧‧‧ first band light

L2‧‧‧second band light

L20‧‧‧scattered light

L21‧‧‧ Large angle scattered light

L22‧‧‧Small angle scattered light

P‧‧‧Light path

Figure 1 is a schematic diagram showing a conventional rotary fluorescent pink wheel.

Figure 2 is a schematic diagram showing a conventional fixed fluorescent pink panel module.

Figure 3A is a block diagram showing the light source system of the preferred embodiment of the present invention.

Figure 3B is a block diagram showing the light source system of another preferred embodiment of the present invention.

Figure 4 is a schematic view showing a wavelength conversion device of the preferred embodiment of the present invention.

Figure 5 is a schematic view showing a wavelength conversion device of another preferred embodiment of the present invention.

Figure 6 is a schematic view showing a wavelength conversion device of still another preferred embodiment of the present invention.

Figure 7 is a schematic view showing a wavelength conversion device of still another preferred embodiment of the present invention.

Figure 8 is a schematic view showing the formation of an air gap in an adhesive manner.

Figure 9 is a schematic view showing the formation of an air gap in a sandwiched manner.

Figure 10 is a schematic diagram showing the reflection of scattered light by an optical coating of a transmissive wavelength conversion device.

Figure 11 is a schematic diagram showing the reflection of scattered light by an optical coating of a reflective wavelength conversion device.

Fig. 12 is a view showing the reflection of scattered light by an optical coating of a transmissive wavelength conversion device having a substrate.

Figure 13 is a schematic diagram showing the reflection of scattered light by an optical coating of a reflective wavelength conversion device having a substrate.

Fig. 14 is a graph showing the performance voltage-pulse width of the wavelength conversion device and the conventional wavelength conversion device of the present invention.

Figure 15 is a graph showing the peak area-power map of the wavelength conversion device of the present invention.

Some exemplary embodiments embodying the features and advantages of the present invention are described in detail in the following description. It is to be understood that the present invention is capable of various modifications in various aspects, and is not to be construed as a limitation.

Please refer to FIG. 3A and FIG. 3B , which are respectively a structural diagram of a light source system of a preferred embodiment of the present invention and a schematic diagram of a light source system of another preferred embodiment of the present invention. As shown in FIGS. 3A and 3B, the light source system 3 of the present invention includes a solid-state light-emitting element 31 and a wavelength conversion device 32. The solid-state light-emitting element 31 is configured to emit the first-wavelength light L1 to the optical path P, and the wavelength conversion device 32 is disposed on the optical path P. The wavelength conversion device 32 includes a fluorescent plate 321 , and the fluorescent plate 321 is a solid mixture having a fluorescent powder and a binder, wherein the weight percentage of the fluorescent powder is 10 to 70% by weight based on the total weight of the fluorescent plate 321 , and the bonding material The glass may be, for example, but not limited to, 30 to 90% by weight based on the total weight of the fluorescent plate 321 The glass, or aluminum oxide, is not limited thereto to convert the first wavelength band light L1 into the second band light L2. According to the concept of the present invention, the wavelength conversion device 32 can be a transmissive wavelength conversion device (as shown in FIG. 3A) or a reflective wavelength conversion device (as shown in FIG. 3B), but is not limited thereto. In other words, in the embodiment shown in FIG. 3A, the incident direction of the first-band light L1 is the same as the outgoing direction of the second-band light L2; in the embodiment shown in FIG. 3B, the incident of the first-band light L1 The direction is opposite to the direction in which the second-band light L2 is emitted. Thereby, the wavelength conversion device 32 of the light source system 3 of the present invention can effectively improve the heat conduction of the fluorescent plate, thereby improving the conversion efficiency of the wavelength conversion device 32, and the rigidity is sufficient for the rotation.

In some embodiments, the binder may be glass or alumina as described above, and may further include ceramic additives such as BaSO ₄ , AlN, BN, etc. to enhance heat dissipation. Wherein, the chemical formula of the glass is SiO _x , 0<x≦2, and the refractive index n of the glass is less than or equal to 1.5; the chemical formula of the alumina is Al ₂ O ₃ . Compared with the glass and phosphor powder combination used in the LED field, since the LED field needs to have a refractive index n value of at least 2 or more, the invention spirit of the present invention is opposite to the application in the LED field. . In other words, the research and development direction of the wavelength conversion device 32 of the present invention is different from the research and development direction of the LED field, and the technical problems to be overcome are also different.

Please refer to FIG. 4 and FIG. 5 , wherein FIG. 4 is a schematic diagram showing a wavelength conversion device according to a preferred embodiment of the present invention, and FIG. 5 is a schematic diagram showing a wavelength conversion device according to another preferred embodiment of the present invention. In some embodiments, the wavelength conversion device 32 of the present invention adopts a substrateless design, and may further include an optical coating 322 formed on one surface of the fluorescent plate 321 and the fluorescent plate 321 is in the form of a sheet. Fluorescent plates (as shown in Figure 4) or ring-shaped fluorescent plates (as shown in Figure 5) are not limited to this. Specifically, the optical coating 322 is deposited or applied on the surface of the fluorescent plate 321 , and the optical coating 322 is oppositely disposed on the other side of the light emitting surface of the fluorescent plate 321 , that is, the surface is disposed on and emitted. The opposite side of the face is set.

Please refer to FIG. 6 and FIG. 7 , wherein FIG. 6 is a schematic diagram showing a wavelength conversion device according to still another preferred embodiment of the present invention, and FIG. 7 is a schematic diagram showing a wavelength conversion device according to still another preferred embodiment of the present invention. In these embodiments, the phosphor plate 321 of the wavelength conversion device 32 of the present invention is a sheet-like phosphor plate (as shown in FIG. 6) or a ring-shaped phosphor plate (as shown in FIG. 7). The wavelength conversion device 32 can further include an optical coating 322 and a substrate 323, and the optical coating 322 is formed on the substrate 323. More specifically, the optical coating 322 is disposed opposite to the other side of the light-emitting surface of the fluorescent plate 321 . On the other hand, the wavelength conversion device 32 may further include a bonding layer 325 disposed between the optical coating layer 322 and the substrate 323, and the bonding layer 325 is preferably cerium oxide (SiO ₂ ) or titanium dioxide (TiO ₂ ). .

In the embodiment shown in FIG. 4 to FIG. 7 above, when applied to the transmissive wavelength conversion device, the optical coating 322 is preferably a spectral coating so that the first wavelength light L1 penetrates and reflects. The two-band light L2; conversely, when applied to the reflective wavelength conversion device, the optical coating 322 is preferably a total reflection coating or a spectral coating to totally reflect the first-band light L1 and the second-band light L2 or only reflect The second band of light L2.

Please refer to FIG. 8 and FIG. 9 , wherein FIG. 8 is a schematic view showing the formation of an air gap in an adhesive manner, and FIG. 9 is a schematic view showing the formation of an air gap in a sandwich manner. As shown in FIG. 8 and FIG. 9 , an air gap A is formed between the phosphor plate 321 and the optical coating layer 322 to enhance the optical properties, for example, the refractive index n value is changed, but not limited thereto. Wherein, the air gap A can be formed by using the adhesive G to be partially glued (as shown in FIG. 8), or the fluorescent plate 321 and the optical coating 322 can be tightly arranged and sandwiched. The surface of the air gap A is naturally formed, but the manner of forming the air gap A is not limited thereto.

Please refer to Figures 3A through 9 again. According to the concept of the present invention, the wavelength conversion device 32 of the present invention can be mounted on the axis of the motor 324 to be configured for rotating applications. Therefore, although the wavelength conversion device 32 of the present invention is applied in a rotary manner, the heat sink is not required, and in addition to reducing the space requirement, hot spots and thermal diffusion phenomena can be avoided, and the manufacturing cost and manufacturing difficulty of the wavelength conversion device 32 can be avoided. significantly reduce.

Please refer to FIG. 10 and FIG. 11 , wherein FIG. 10 is a schematic diagram showing the optical coating of the transmissive wavelength conversion device, and FIG. 11 is a view showing the optical coating of the reflective wavelength conversion device. schematic diagram. As shown in FIG. 10 and FIG. 11, after the fluorescent plate 321 of the wavelength conversion device 32 receives the first band light L1, the first band light L1 is excited to be converted into the second band light L2, wherein the second band of light The L2 system is a full-angle scattering. When the scattered light L20 is back-scattered to the optical coating 322, the scattered light L20 is reflected by the optical coating 322 to the light-emitting surface and output, so that the reflection efficiency of the optical coating 322 is higher. At the same time, the wavelength conversion efficiency of the wavelength conversion device 32 is also improved.

Please refer to FIG. 12 and FIG. 13 , wherein FIG. 12 is a schematic diagram showing the optical coating reflective scattering light of the transmissive wavelength conversion device with a substrate, and FIG. 13 is a view showing the optical of the reflective wavelength conversion device with the substrate. A schematic representation of the coating reflecting scattered light. As shown in FIG. 12 and FIG. 13, after the fluorescent plate 321 of the wavelength conversion device 32 receives the first band light L1, the first band light L1 is excited to be converted into the second band light L2, wherein the second band of light The L2 system is a full-angle scattering. When the large-angle scattered light L21 is backscattered to the air gap A, the large-angle scattered light L21 is totally reflected by the air gap A and is output to the light exit surface. Further, when the small-angle scattered light L22 is back-scattered to the optical coating layer 322, the small-angle scattered light L22 is reflected by the optical coating layer 322 to the light-emitting surface and is output. In other words, by forming the air gap A between the phosphor plate 321 and the optical coating layer 322, the large-angle scattered light L21 can be reflected and outputted by the principle of total reflection to enhance the wavelength conversion efficiency of the wavelength conversion device 32 of the present invention.

According to the concept of the present invention, the phosphor powder may be a single crystal phosphor or a polycrystalline phosphor. In addition, functional additives such as BN, AlN or BaSO ₄ may be added to the process of the fluorescent plate 321 , but not limited thereto. In addition, the composition of the optical coating 322 is preferably selected from at least one of a group of gold, silver, aluminum or a combination thereof, and may also be selected from dielectric coating materials to provide good optical reflection. ability. In some embodiments, the substrate 323 can be a metal substrate, a ceramic substrate, a wafer substrate, or a composite substrate. The metal substrate may be gold, silver, aluminum or an alloy thereof, the ceramic substrate may be AlN, BN or Al ₂ O ₃ , and the wafer substrate may be a germanium wafer, a diamond coated germanium wafer, a tantalum carbide wafer, or the like. The tantalum carbide and graphene wafers or any of the III-V semiconductor wafers, and the composite substrate may be graphite substrates, aluminum and graphite substrates, or tantalum carbide and graphite substrates, but are not limited thereto.

In some embodiments, the thickness of the phosphor plate 321 of the wavelength conversion device 32 of the present invention is preferably greater than or equal to 50 micrometers and less than or equal to 1000 micrometers. In other embodiments, the phosphor plate 321 is made of 20% by weight of phosphor powder and 80% by weight of glass, and the thickness and diameter of the phosphor plate 321 are preferably 540 micrometers and 10 centimeters, but not This is limited to this. According to the experimental results of the present embodiment, the phosphor powder of the fluorescent plate 321 of the present invention accounts for only 20% by weight of the total weight, but it can be at least 70% by weight of the fluorescent powder in the prior art. With a gain of 15%, since the proportion of the phosphor powder in the present case can be practically 10 to 70% by weight, and the thickness of the fluorescent plate 321 can be 50 to 1000 μm, the maximum gain is not limited to this.

On the other hand, in order to improve the optical properties of the wavelength conversion device 32 of the present invention, in this case, the light-emitting surface of the fluorescent plate 321 is polished to form the light-emitting surface as a polished surface. Thereby, the light receiving efficiency of the fluorescent plate 321 can be further improved, and the conversion efficiency of the wavelength conversion device 32 can be effectively improved.

Please refer to Fig. 14, which is a graph showing the performance voltage-pulse width of the wavelength conversion device and the conventional wavelength conversion device of the present invention. As shown in FIG. 14, when the solid-state light-emitting element 31 is a laser light source, and the driving current of the laser light source is 2.3 amps and the output power is 3.5 watts, the heat dissipation effect of the conventional glue-type fluorescent pink wheel is the worst. Therefore, its performance is the fastest, and the performance of the traditional adhesive fluorescent pink wheel is the worst. In addition, if the YAG fluorescent powder is used to make a pure fluorescent pink wheel, its performance is normal, but the degradation problem is smaller than the traditional traditional fluorescent fluorescent pink wheel, and the performance is significantly higher than the traditional adhesive fluorescent pink wheel. . On the other hand, testing with the wavelength conversion device 32 of the foregoing embodiments of the present invention clearly shows that not only the performance is higher than that of the pure fluorescent pink wheel, but also the decay speed and amplitude are the smallest among the three, which is the wavelength of the present case. The conversion device 32 has the best performance compared to the conventional adhesive fluorescent pink wheel and the pure fluorescent pink wheel.

Please refer to Fig. 15, which shows the peak area-power map of the wavelength conversion device of the present invention. As shown in Fig. 15, when the wavelength conversion device 32 of the present invention is applied to a high-energy light source system, when the output power of the solid-state light-emitting element 31 is continuously increased, the overall peak performance generally increases linearly, and according to experimental results, the case is shown. The wavelength conversion device 32 can be applied to at least a 60 watt high power environment.

In summary, the present invention provides a light source system and a wavelength conversion device thereof, which are made of a phosphor plate with 10 to 70 weight percent of phosphor powder and a binder, and are configured to convert the first band of light into the second band of light. The heat conduction of the fluorescent plate can be effectively improved, thereby improving the conversion efficiency of the wavelength conversion device, and the rigidity is sufficient for the rotation. In addition, although the wavelength conversion device is applied in a rotary manner, it is not necessary to use a heat sink. In addition to reducing space requirements, hot spots and heat diffusion can be avoided, and the manufacturing cost and manufacturing difficulty of the wavelength conversion device are greatly reduced. Further, since the light-emitting surface of the fluorescent plate is polished to form a polished surface, the light-receiving efficiency of the fluorescent plate can be better, and the conversion efficiency of the wavelength conversion device can be effectively improved.

The present invention has been described in detail by the above-described embodiments, and may be modified by those skilled in the art, without departing from the scope of the appended claims.

Claims (17)

A light source system comprising: a solid state light emitting device configured to emit a first band of light to a light path; and a wavelength conversion device disposed in the light path and comprising: a substrate; an optical coating formed on the And a phosphor plate, and an optical gap is formed between the optical coating and the optical coating on the substrate, wherein the fluorescent plate has a fluorescent powder and a combined solid mixture, wherein the fluorescent powder The weight percentage is 10 to 70% by weight, and the first wavelength band light is converted into a second wavelength band light; wherein the bonding material is glass, the chemical formula of the glass is SiO _x , 0<x≦2, and the glass The refractive index n value is less than or equal to 1.5. The light source system of claim 1, wherein the binder further comprises a ceramic additive. The light source system of claim 1, wherein the fluorescent plate is a ring-shaped fluorescent plate or a sheet-shaped fluorescent plate. The light source system of claim 1, wherein the optical coating is formed on one surface of the fluorescent plate. The light source system of claim 4, wherein the optical coating is deposited or coated on the surface of the fluorescent plate, and the optical coating is disposed opposite to one of the light emitting surfaces of the fluorescent plate. side. The light source system of claim 1, wherein the optical coating is disposed opposite to the other side of the light emitting surface of the fluorescent plate. The light source system of claim 6, wherein the light exiting surface is a polished surface. The light source system of claim 1, wherein the air gap is formed by gluing or sandwiching. The light source system of claim 1, wherein the wavelength conversion device further comprises a bonding layer disposed between the optical coating and the substrate. The optical system of claim 9, wherein the bonding layer is cerium oxide or titanium dioxide. The light source system of claim 1, wherein the thickness of the phosphor plate is greater than or equal to 50 microns and less than or equal to 1000 microns. A wavelength conversion device, which is suitable for emitting a light source system of a first wavelength band to a light path, comprising: a substrate; an optical coating formed on the substrate; and a fluorescent plate disposed on the light path, Receiving the first band of light and forming an air gap with the optical coating on the substrate, wherein the phosphor plate is a solid mixture having a phosphor powder and a binder, wherein the phosphor powder The weight percentage is 10 to 70% by weight, and the first wavelength band light is converted into a second wavelength band light; wherein the bonding material is glass, and the chemical formula of the glass is SiO _x , 0<x≦2, and the The refractive index n of the glass is less than or equal to 1.5. The wavelength conversion device of claim 12, wherein the optical coating is formed on one surface of the fluorescent plate. The wavelength conversion device of claim 13, wherein the optical coating is deposited or coated on the surface of the fluorescent plate, and the optical coating is disposed opposite to a light emitting surface of the fluorescent plate. One side. The wavelength conversion device of claim 14, wherein the light exiting surface is a polished surface. The wavelength conversion device of claim 12, wherein the optical coating is disposed on the other side of one of the light-emitting surfaces of the fluorescent plate, and the light-emitting surface is a polished surface. The wavelength conversion device of claim 12, further comprising a bonding layer disposed between the optical coating and the substrate, and the bonding layer is cerium oxide or titanium dioxide.