Light source system and projection equipment

Abstract

This invention provides a light source system and a projection device. The light source system includes a light source device, a wavelength conversion device, optical components, and a beam splitting and combining unit. The light source device emits excitation light, and the wavelength conversion device converts the received excitation light at least partially into laser light. The light source device and the wavelength conversion device are respectively disposed on adjacent sides of the optical component. The beam splitting and combining unit is disposed inside the optical component. The excitation light enters the optical component and is incident on the beam splitting and combining unit. The beam splitting and combining unit reflects the received excitation light to the wavelength conversion device. The laser light emitted from the wavelength conversion device enters the optical component. Part of the laser light is transmitted through the beam splitting and combining unit and exits the optical component, while the remaining laser light passes through the optical components surrounding the beam splitting and combining unit and exits the optical component. The light source system provided by this invention is beneficial for improving brightness.

Description

Technical Field

[0001] This invention relates to the field of projection technology, and more specifically, to a light source system and a projection device. Background Technology

[0002] Currently, laser phosphor light sources are widely used in various projection devices due to their advantages of long lifespan, low cost, and high brightness, resulting in excellent display effects. A crucial aspect of laser phosphor technology lies in the excitation scheme of fluorescence and the combination scheme of fluorescence and laser light. Developing more efficient and compact fluorescence excitation and fluorescence-laser combination schemes is of great significance to the advancement of laser phosphor technology.

[0003] In existing fluorescence excitation and collection schemes, dichroic filters are typically used to reflect short-wavelength excitation light and transmit long-wavelength fluorescence to achieve the separation and combination of laser and fluorescence beams. To ensure the consistency of fluorescence beam translation and avoid scattering of light by the edges of the dichroic filter, the filter needs to cover the entire fluorescence area. Therefore, the area of ​​the dichroic filter needs to be relatively large. This results in an excessively long propagation distance of the fluorescence after passing through the collecting lens group, causing dilution of the optical spread of the fluorescence, which is detrimental to improving the brightness of the laser fluorescence source. Summary of the Invention

[0004] This invention proposes a light source system and a projection device to solve the above problems.

[0005] The embodiments of the present invention achieve the above objectives through the following technical solutions.

[0006] In a first aspect, embodiments of the present invention provide a light source system, the light source system including a light source device, a wavelength conversion device, an optical device, and a beam splitting and combining unit; the light source device is used to emit excitation light, and the wavelength conversion device is used to convert the received excitation light at least partially into laser light; the light source device and the wavelength conversion device are respectively disposed on adjacent sides of the optical device, and the beam splitting and combining unit is disposed inside the optical device; the excitation light enters the optical device and is incident on the beam splitting and combining unit, the beam splitting and combining unit reflects the received excitation light to the wavelength conversion device, the laser light emitted from the wavelength conversion device enters the optical device, part of the laser light is transmitted through the beam splitting and combining unit and emitted from the optical device, and the remaining part of the laser light passes through the optical device surrounding the beam splitting and combining unit and is emitted from the optical device.

[0007] In one embodiment, the light splitting and combining unit is tilted relative to the optical path of the excitation light emitted by the light source device.

[0008] In one embodiment, the optical device includes a first surface, a second surface, and a third surface connected to each other, with the first surface and the third surface arranged relatively parallel to each other. The wavelength conversion device faces the first surface, the light source device faces the second surface, and the laser light is emitted from the third surface.

[0009] In one embodiment, the area of ​​the orthographic projection of the light-splitting and light-combining unit onto the first surface is smaller than the area of ​​the first surface.

[0010] In one embodiment, the region of the orthographic projection of the light-splitting and light-combining unit on the first surface is located in the middle region of the first surface.

[0011] In one embodiment, the optical device is a hollow cuboid prism, and the beam splitting and combining unit is a beam splitter. The beam splitter is disposed inside the optical device and reflects the excitation light and transmits the laser light.

[0012] In one embodiment, the optical device is a cuboid prism formed by splicing two right-angled trapezoidal prisms, with the inclined surfaces of the two right-angled trapezoidal prisms joined together, and the beam splitting and beam combining unit is disposed at the splicing point of the two right-angled trapezoidal prisms.

[0013] In one embodiment, the beam splitting and combining unit is a beam splitter sandwiched between two right-angled trapezoidal prisms, which reflects the excitation light and transmits the laser beam.

[0014] In one embodiment, the light splitting and combining unit is an optical coating formed on the inclined surface of at least one right-angled trapezoidal prism, which reflects the excitation light and transmits the laser light.

[0015] In one embodiment, the distance between the first surface and the third surface is equal to the shortest edge length of the cuboid prism.

[0016] In one embodiment, the light source device emits excitation light of a first polarization state, the laser light is unpolarized, and the light splitting and combining unit reflects the excitation light of the first polarization state and transmits the excitation light of the laser light and the excitation light of the second polarization state.

[0017] In one embodiment, the light source system further includes a supplementary light source for emitting supplementary light of the first polarization state, the supplementary light having the same color as the excitation light; the supplementary light source is disposed on a side of the optical device opposite to the light source device, the supplementary light emitted by the supplementary light source enters the optical device and is incident on the beam splitting and combining unit, the supplementary light is reflected by the beam splitting and combining unit and exits the optical device along the same optical path as the laser beam.

[0018] In one embodiment, the optical device is a cuboid prism formed by splicing two right-angled trapezoidal prisms. The inclined surfaces of the two right-angled trapezoidal prisms are spliced ​​together, and an optical coating is provided on the inclined surfaces of the two right-angled trapezoidal prisms. The optical coating reflects the excitation light and supplementary light of the first polarization state, and transmits the excitation light of the laser and the second polarization state.

[0019] Secondly, embodiments of the present invention provide a projection device, which includes the light source system of any of the above embodiments.

[0020] In the light source system and projection device provided by the present invention, a portion of the laser light is transmitted through the beam splitting and combining unit and then emitted from the third surface, while the remaining portion of the laser light passes through the optical devices surrounding the beam splitting and combining unit and then emitted from the third surface. This reduces the volume of the optical devices, thereby reducing the dilution of the optical spread of the laser light during propagation, which is beneficial to improving the brightness of the light source system. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the light source system provided in an embodiment of the present invention.

[0023] Figure 2 yes Figure 1 A schematic diagram of the optical components and light-splitting and light-combining units of the light source system.

[0024] Figure 3 yes Figure 1 A schematic diagram of another embodiment of the optical components and light-splitting and light-combining unit of the light source system.

[0025] Figure 4 This is a schematic diagram illustrating the estimation of the offset of a dichroic color filter provided by existing technology.

[0026] Figure 5 This is a schematic diagram illustrating the estimation of the optical spread of a dichroic filter provided by existing technology.

[0027] Figure 6 yes Figure 1 A schematic diagram for estimating the optical extension of a light source system.

[0028] Figure 7 This is a schematic diagram of the structure of a light source system provided in another embodiment of the present invention.

[0029] Figure 8 yes Figure 7 A schematic diagram of the characteristics of the optical coating of the light source system.

[0030] Figure 9 yes Figure 7 A schematic diagram illustrating the characteristics of another optical coating for a light source system.

[0031] Figure 10 yes Figure 7 A schematic diagram illustrating the characteristics of another type of optical coating for a light source system.

[0032] Figure 11 This is a schematic diagram of the structure of a light source system provided in another embodiment of the present invention.

[0033] Figure 12 This is a schematic diagram of the projection device provided in an embodiment of the present invention. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0035] Please see Figure 1 This invention provides a light source system 100, which includes a light source device 10, a wavelength conversion device 40, optical components 20, and a light splitting and combining unit 30. The light source device 10 is used to emit excitation light, and the wavelength conversion device 40 is used to convert the received excitation light at least partially into laser light.

[0036] The light source device 10 and the wavelength conversion device 40 are respectively disposed on two adjacent sides of the optical device 20, and the beam splitting and combining unit 30 is disposed inside the optical device 20. The excitation light emitted by the light source device 10 enters the optical device 20 and is incident on the beam splitting and combining unit 30. The beam splitting and combining unit 30 reflects the received excitation light to the wavelength conversion device 40. The wavelength conversion device 40 converts the received excitation light into laser light at least partially. The laser light emitted from the wavelength conversion device 40 enters the optical device 20. Part of the laser light is transmitted through the beam splitting and combining unit 30 and exits the optical device 20. The remaining part of the laser light passes through the optical device 20 surrounding the beam splitting and combining unit 30 and exits the optical device 20.

[0037] Specifically, the light source device 10 refers to a light source capable of emitting light for exciting wavelength conversion materials. The light source device 10 can be a laser diode or a light-emitting diode to emit excitation light. The excitation light emitted by the light source device 10 can be blue light, violet light, red light, green light, ultraviolet light, or other types of light, which are not listed here. In this embodiment, the light source device 10 includes a blue semiconductor laser diode, and the light source device 10 emits blue laser light as excitation light. The number of blue semiconductor laser diodes can be one or more. Multiple blue semiconductor diodes can form a semiconductor diode array.

[0038] In one embodiment, the blue semiconductor laser diode is a gallium nitride-based blue laser. Gallium nitride-based blue lasers have lower luminous efficiency and manufacturing costs, and also overcome the limitations of poor thermal stability of red laser materials and low efficiency and short lifespan of green lasers. They can achieve red-green spectrum with wavelength conversion device 40.

[0039] The wavelength conversion device 40 is located on the optical path of the excitation light reflected by the beam splitting and combining unit 30 and is disposed on adjacent sides of the optical device 20, respectively, as is the light source device 10. The wavelength conversion device 40 is provided with a wavelength conversion material layer (not shown) to convert at least a portion of the received excitation light into laser light. Here, excitation light and laser light are relative concepts. Excitation light refers to light that can excite the wavelength conversion material layer, causing it to produce light of different wavelengths. Laser light refers to light produced by the wavelength conversion material layer when excited by excitation light. For example, blue light excites a yellow light conversion material layer to produce yellow light; in this case, blue light is the excitation light and yellow light is the laser light. Yellow light excites a red light conversion material layer to produce red light; in this case, yellow light is the excitation light and red light is the laser light. Blue light excites a green light conversion material layer to produce green light; in this case, blue light is the excitation light and green light is the laser light.

[0040] Wavelength conversion materials can include phosphorescent materials, such as phosphors, nanomaterials, such as quantum dots, and fluorescent materials, among others. In one embodiment, the wavelength conversion material includes a fluorescent material, and the laser emitted by the wavelength conversion device 40 is fluorescent. Thus, since fluorescence is incoherent light, the laser is free from speckle effects. By using blue light to excite the fluorescent material to produce green and red fluorescence, the speckle problem in human vision caused by the incoherence of the excitation light emitted by the light source device 10 can be avoided.

[0041] The wavelength conversion device 40 is equipped with a heat dissipation device (not shown), such as heat sink fins, for heat dissipation. The heat dissipation device can be disposed on the surface opposite the light-emitting surface of the wavelength conversion device 40. By utilizing the heat dissipation device to conduct excess heat to the surrounding environment, the temperature of the wavelength conversion material layer is prevented from rising excessively and affecting the luminous efficiency of the wavelength conversion device 40.

[0042] Optical device 20 is located at the intersection of the optical path of the excitation light emitted by the light source device 10 and the optical path of the laser emitted by the wavelength conversion device 40. Optical device 20 is spaced apart from the light source device 10 and the wavelength conversion device 40. In this embodiment, optical device 20 is a prism, which can transmit both the excitation light and the laser. Optical device 20 includes a first surface 21, a second surface 22, a third surface 23, and a fourth surface 24 connected to each other. The first surface 21 and the third surface 23 are arranged relatively parallel to each other, and the second surface 22 and the fourth surface 24 are arranged relatively parallel to each other. The light source device 10 faces the second surface 22, and the wavelength conversion device 40 faces the first surface 21. The excitation light emitted by the light source device 10 passes through the first surface 21 and enters the optical device 20 and is incident on the beam splitting and combining unit 30. The beam splitting and combining unit 30 reflects the received excitation light to the wavelength conversion device 40. The laser emitted from the wavelength device 40 passes through the first surface 21 and enters the optical device 20. Part of the laser is transmitted through the beam splitting and combining unit 30 and exits from the third surface 23. The remaining part of the laser passes through the optical device 20 around the beam splitting and combining unit 30 and exits from the third surface 23.

[0043] In one embodiment, such as Figure 2 As shown, the optical device 20 can be a one-piece molded cuboid prism, and the interior of the cuboid prism is hollow. In other embodiments, such as... Figure 3 As shown, the optical device 20 can also be a cuboid prism formed by combining two right-angled trapezoidal prisms. The distance between the first surface 21 and the third surface 23 of the optical device 20 can be equal to the shortest edge length of the cuboid prism. In this way, the laser beam is transmitted through the cuboid prism from the direction of the shortest edge length, which can reduce the propagation distance of the laser beam in the optical device 20 and help reduce the dilution of the optical spread of the light source system 100.

[0044] The beam splitting and combining unit 30 is disposed inside the optical device 10. The beam splitting and combining unit 30 can reflect excitation light and transmit laser light. Specifically, the beam splitting and combining unit 30 reflects blue light and transmits red, green, and yellow light. When the optical device 20 is a hollow cuboid prism, the beam splitting and combining unit 30 can be a beam splitter, disposed within the hollow cavity of the optical device 20. When the optical device 20 is a cuboid prism formed by joining two right-angled trapezoidal prisms, the beam splitting and combining unit 30 can be a beam splitter, sandwiched at the joining point of the two right-angled trapezoidal prisms. The beam splitting and combining unit 30 can also be an optical coating 51, which can be formed on the inclined surface of one of the right-angled trapezoidal prisms, or formed on the inclined surfaces of both right-angled trapezoidal prisms respectively.

[0045] The optical device 20 and the beam splitting and combining unit 30 are coordinated in the manner described above, so that a portion of the laser light is transmitted through the beam splitting and combining unit 30 and then emitted from the third surface 23, while the remaining portion of the laser light passes through the optical device 20 surrounding the beam splitting and combining unit 30 and then is emitted from the third surface 23. In this way, the beam splitting and combining unit 30 can maintain the consistency of the translation of the laser light after passing through the transmission optical device 20 without needing to cover all the areas of the laser light emitted by the wavelength conversion device 40. At the same time, it can also reduce the dilution of the optical extension of the light source system 100, maintain the ability of the light source system 100 to transmit light energy, and help improve the brightness of the light source system 100.

[0046] Optical spread is a geometric property in non-imaging optics used to describe a light beam with a given aperture angle and cross-sectional area. Optical spread represents the integral of the area the beam passes through and the solid angle it occupies, i.e., Etendue ≡ n. 2 ∫∫cosθdAdΩ. Where θ is the angle between the normal to the area element dA and the central axis of the solid angle element dΩ. In an ideal optical system that does not consider energy loss due to scattering and absorption, the optical spread of the beam remains conserved after passing through the system. Optical spread measures the change between the beam source area and the solid angle spread as the beam passes through the optical system. A larger beam angle or a larger beam source area results in a larger optical spread, which in turn reduces the optical system's ability to transmit light energy and is less conducive to improving its brightness.

[0047] Existing technology uses dichroic film 200 ( Figure 4 In this manner, when light is obliquely incident on a dichroic filter 200 with a refractive index of n and a thickness of t, a certain translation will occur within the incident plane, such as... Figure 4 As shown. Assuming the angle of incidence of the light ray is θ, then the translation of the light ray is... Further simplification yields: As can be seen from the above formula, when n→1, the translation Δy(0; θ)→0. For ordinary glass, the refractive index is about 1.5, so obliquely incident light will always be translated to a certain extent after passing through the dichroic filter 200.

[0048] In the prior art, the dichroic filter 200 is used to ensure the consistency of laser translation, avoid the partial displacement of laser light when obliquely incident laser light passes through the dichroic filter 200 while the partial non-displacement occurs, and avoid laser light scattering caused by the edges of the dichroic filter 200. This requires expanding the area of ​​the dichroic filter 200 to cover all areas of laser light emitted by the wavelength conversion device 40. However, this can easily lead to an increase in the optical extension of the light source system 100, which is not conducive to improving the brightness of the light source system 100.

[0049] This invention adopts Figure 5 and Figure 6 The schematic diagram is used to estimate and compare the optical expansion obtained by the prior art and the technical solution of this embodiment. The prior art uses a dichroic filter 200 (…). Figure 5 In this embodiment, optical device 20 and beam splitting and combining unit 30 are used. Figure 6 (The form of cooperation)

[0050] Please see Figure 5 Assuming the light emitted by the wavelength conversion device 40 has a spot size of D0 at position A, an exit angle of θ0, and a divergence angle of θ1, and the light spot size at position B after passing through the dichroic filter 200 is D1, the distance between positions A and B is t1, and the dichroic filter 200 is tilted at 45° relative to the incident light path, then t1 = D0 + t1tan(θ1).

[0051] Please see Figure 6 Assume the light emitted by the wavelength conversion device 40 has a spot size of D0 at position A, an exit angle of θ0, a divergence angle of θ2, and a spot size of D2 at position B after passing through the optical device 20 and the beam splitter / combiner unit 30. The distance between positions A and B is t2, the refractive index of the optical device 20 is n, and the beam splitter / combiner unit 30 is tilted at 45° relative to the incident light path. Then, D2 = D0 + 2t2tan(θ2). Then D2 = D0[1 + tan(θ2)], where sin(θ1) = nsin(θ2).

[0052] Under normal circumstances, the divergence angle of light upon emission is not very large, so θ1 can be approximated as a small angle. Therefore, θ1≈sin(θ1)≈tan(θ1), hence:

[0053]

[0054]

[0055] The degree of optical spread dilution is estimated by comparing D1 and D2. For example, the magnitude of the two values ​​can be compared by subtracting or quotienting D1 and D2.

[0056] If D1 and D2 are compared by subtraction, then Generally, n≈1.5, and substituting into the calculation yields... Therefore, when light is emitted and there is a certain divergence angle, that is, when the divergence angle θ1 > 0 and D1 - D2 > 0, it can be said that under the same conditions, the area of ​​the light spot formed by the dichroic color filter 200 scheme is larger than that of the scheme in which the optical device 20 and the beam splitting and combining unit 30 cooperate with each other in the embodiment of the present invention. This is not conducive to reducing the optical extension of the light source system 100 and not conducive to improving the brightness of the light source system 100.

[0057] If D1 and D2 are compared by quotient, then Generally, θ1≈3°, n≈1.5, substituting these values ​​into the calculation yields... Therefore, under the same conditions, the optical expansion of the scheme using the existing dichroic filter 200 is increased by 14% compared with the scheme of the optical device 20 and the beam splitting and combining unit 30 of the present invention.

[0058] Therefore, through the above two comparison methods, it can be seen that the technical solution of the present invention can reduce the volume of the optical device 20, thereby reducing the dilution of the optical spread during laser propagation, which is beneficial to improving the brightness of the light source system 100.

[0059] Please see Figure 1 In one embodiment, the light source system 100 includes a light source device 10, a wavelength conversion device 40, an optical device 20, and a light splitting and combining unit 30. The optical device 20 is a cuboid prism formed by splicing two right-angled trapezoidal prisms. The two right-angled trapezoidal prisms each have a first inclined surface 31 and a second inclined surface 32. The first inclined surface 31 and the second inclined surface 32 are spliced ​​together with optical adhesive. That is, the first inclined surface 31 and the second inclined surface 32 of the two right-angled trapezoidal prisms are placed opposite each other, and one of the right-angled trapezoidal prisms is inverted so that the upper and lower base surfaces of the one right-angled trapezoidal prism are flush with the lower and upper base surfaces of the other right-angled trapezoidal prism, respectively. Thus, the first inclined surface 31 and the second inclined surface 32 of the two right-angled trapezoidal prisms are spliced ​​together with optical adhesive to form a cuboid prism. In this way, the two right-angled trapezoidal prisms can be prevented from detaching from each other when the light source system 100 is subjected to external impact, which helps to improve the stability of the optical device 20 and ensure the normal operation of the light source system 100.

[0060] In this embodiment, the optical device 20 includes a first surface 21, a second surface 22, a third surface 23, and a fourth surface 24 connected to each other. The first surface 21 and the third surface 23 are arranged in parallel with each other, and the second surface 22 and the fourth surface 24 are arranged in parallel with each other. The first surface 21 is formed by connecting the bottom surface of one right trapezoidal prism and the top surface of another right trapezoidal prism. The third surface 23 is formed by connecting the top surface of one right trapezoidal prism and the bottom surface of another right trapezoidal prism. The second surface 22 and the fourth surface 24 are formed by the right-angled waist surfaces of the two right trapezoidal prisms, respectively. The light source device 10 faces the second surface 22, and the wavelength conversion device 40 faces the first surface 21. The excitation light emitted by the light source device 10 passes through the first surface 21 and enters the optical device 20 and is incident on the beam splitting and combining unit 30. The beam splitting and combining unit 30 reflects the received excitation light to the wavelength conversion device 40. The laser emitted from the wavelength device 40 passes through the first surface 21 and enters the optical device 20. Part of the laser is transmitted through the beam splitting and combining unit 30 and exits from the third surface 23. The remaining part of the laser passes through the optical device 20 around the beam splitting and combining unit 30 and exits from the third surface 23.

[0061] The beam splitting and combining unit 30 is disposed at the junction of two right-angled trapezoidal prisms, and is inclined relative to the optical path of the excitation light emitted by the light source device 10. Specifically, the light source device 10 and the wavelength conversion device 40 are respectively disposed on adjacent second surfaces 22 and first surfaces 21 of the optical device 20, and the light-emitting surface of the light source device 10 is perpendicular to the wavelength conversion device 40. The laser light emitted by the light source device 10 enters the optical device 20 perpendicularly from the second surface. The beam splitting and combining unit 30 is inclined at 45° relative to the optical path of the excitation light emitted by the light source device 10. After being reflected by the beam splitting and combining unit 30, the excitation light can be perpendicularly incident on the wavelength conversion device 40. In other embodiments, the light source device 10 and the wavelength conversion device 40 may also be disposed on other adjacent sides of the optical device 20, which are not listed here.

[0062] In this embodiment, the area of ​​the beam splitting and combining unit 30 projected onto the first surface 21 is smaller than the area of ​​the first surface 21. Thus, the projection of the beam splitting and combining unit 30 onto the first surface 21 does not completely cover the first surface 21. This allows a portion of the laser beam to pass through the optical devices 20 surrounding the beam splitting and combining unit 30 and exit from the third surface 23. This reduces the need for the beam splitting and combining unit 30 to be excessively large. Even without needing to cover all laser-received areas emitted by the wavelength conversion device 40, it maintains consistent laser translation, which helps reduce the processing difficulty of the beam splitting and combining unit 30 and the manufacturing cost of the light source system 100. In one embodiment, the area of ​​the projection of the beam splitting and combining unit 30 onto the first surface 21 is located in the middle region of the first surface 21, which helps to achieve a more reasonable arrangement of the beam splitting and combining unit 30 and the optical devices 20.

[0063] In this embodiment, please refer to Figure 7 The beam splitting and combining unit is an optical coating 51 formed on the inclined surface of at least one of the two right-angled isosceles trapezoidal prisms. This optical coating 51 is used to reflect excitation light and transmit received laser light. Thus, the beam splitting and combining unit 30 achieves the reflection of excitation light and the transmission of received laser light through the optical coating 51. In this embodiment, the optical coating 51 can reflect blue light and transmit red, green, and yellow light.

[0064] The optical coating 51 can have wavelength-splitting and light-combining coating characteristics, or it can have polarization-splitting and light-combining coating characteristics. When the optical coating 51 has wavelength-splitting and light-combining coating characteristics, such as... Figure 8 As shown, the optical coating 51 can reflect short-wavelength light (or excitation light) and transmit long-wavelength light (or laser light), thereby achieving the combination of light of different wavelengths. When the optical coating 51 has polarization-splitting and light-combining coating characteristics, as shown... Figure 9 As shown, the optical coating 51 can reflect S-polarized light and transmit P-polarized light, thereby achieving the combination of light with different polarizations.

[0065] When the excitation light excites the wavelength conversion device 40, because the wavelength conversion device 40 has a certain reflectivity, the excitation light cannot be completely absorbed, and the unconverted excitation light is reflected back by the wavelength conversion device 40. When the excitation light is blue light, the unconverted excitation light reflected back by the wavelength conversion device 40 can be recovered and directly used for blue light display. In this embodiment, the optical coating 51 has coating characteristics that combine wavelength splitting and combining with polarization splitting and combining, such as... Figure 10As shown, the optical coating 51 can reflect short-wavelength (λ1) excitation light and transmit long-wavelength (λ2) received laser light. Furthermore, due to the coating characteristics, the cutoff wavelength of S-polarized light is longer than that of P-polarized light, making S-polarized light more easily reflected than P-polarized light. This allows the optical coating 51 to reflect short-wavelength (excitation light) S-polarized light with wavelength λ1 and transmit short-wavelength (excitation light) P-polarized light with wavelength λ1, as well as long-wavelength (received laser light) of both S-polarized and P-polarized states with wavelength λ2. Therefore, in this embodiment, the light source device 10 can emit excitation light of the first polarization state, for example, blue laser light of the S-polarized state with a wavelength of 455 nm. The optical coating 51 reflects the excitation light of the first polarization state and transmits the received laser light emitted from the wavelength conversion device 40. The unconverted excitation light becomes disordered in polarization state after being reflected by the wavelength conversion device 40. It includes excitation light in a first polarization state and excitation light in a second polarization state. The excitation light in the second polarization state can be emitted from the optical device 20 through the optical coating 51 for blue light display, thereby improving the light utilization rate of the light source system 100 and increasing the brightness.

[0066] The above Figures 8 to 10 In the example shown, the vertical axis "T" in the line graph represents transmittance, and the horizontal axis "λ" represents wavelength.

[0067] Since high-energy-density excitation light accelerates the aging of the adhesive used to join the two right-angled trapezoidal prisms, the optical coating 51 can be placed on the first inclined surface 31 of the right-angled isosceles trapezoidal prism near the light source device 10. This makes the optical coating 52 closer to the light source device 10 than the adhesive, so that the excitation light emitted by the light source device 10 is directly reflected by the optical coating 52 to the wavelength conversion device 40, and the excitation light no longer incident on the adhesive. This effectively avoids the excitation light from accelerating the aging of the adhesive and improves the reliability and service life of the light source system 100.

[0068] Optical device 20 may include other types of films. For example, see [link to example]. Figure 7 The optical device 20 includes an excitation light antireflection film 52, which is disposed on the second surface 22 of the optical device 20. Thus, the excitation light antireflection film 52 can improve the transmittance of the excitation light emitted by the light source device 10 when it enters the optical device 20 from the second surface 22.

[0069] For example, the optical device 20 includes a white light anti-reflection film 53. The white light anti-reflection film 53 can be disposed on the first surface 21, the third surface 23, or both. In this way, the white light anti-reflection film 53 can improve the transmittance of the laser emitted by the wavelength conversion device 40 when it enters the optical device 20 from the first surface 21 and when it exits from the third surface 23. Furthermore, the white light anti-reflection film 53 can also be disposed on the second inclined surface 32 of the right-angled isosceles trapezoidal prism away from the light source device 10. In this way, the white light anti-reflection film 53 can improve the transmittance of the laser when it passes through the second inclined surface 32. It should be noted that the white light anti-reflection film 53 can be disposed on at least one of the first surface 21, the third surface 23, and the second inclined surface 32.

[0070] The light source system 100 also includes a collecting lens group 70, which can consist of multiple lenses, such as three or four lenses. In this embodiment, the collecting lens group includes three convex lenses. The wavelength conversion device 40 can receive the excitation light via the collecting lens group 70. The laser light emitted by the wavelength conversion device 40 and the excitation light reflected by the wavelength conversion device 40 can be collected, focused, and collimated by the collecting lens group 70 before being incident on the optical device 20. Thus, by setting a collecting lens group 70, the collection of excitation light and the laser light can be achieved.

[0071] Furthermore, after the laser is excited, the laser emitted by the wavelength conversion device 40 is approximately a Lambertian source. The brightness of the laser is the same in all directions. By collecting the laser through the collecting lens group 70, a large collection efficiency can be obtained.

[0072] In the above embodiment of the scheme for recovering unconverted excitation light, the optical coating 51 allows only the unconverted excitation light of the second polarization state to pass through, while the optical device 20 around the optical coating 51 allows both the unconverted excitation light of the first polarization state and the second polarization state to pass through, thereby causing the brightness of the blue spot in the light path emitted from the optical device 20 to be lower in the central region than in the outer region.

[0073] Please see Figure 11In another embodiment, the light source system 100 further includes a supplementary light source 60, which faces the fourth surface 24 of the optical device 20 and is spaced apart from the optical device 20. The supplementary light source 60 emits supplementary light, which is light of a first polarization state and has the same color as the excitation light emitted by the light source device 10, i.e., the supplementary light is blue light of the first polarization state. The supplementary light emitted by the supplementary light source 60 is incident on the beam splitting and combining unit 30 via the fourth surface 24, and is reflected by the beam splitting and combining unit 30 to the third surface 23 and then emitted via the third surface 23. In this embodiment, by setting a supplementary light source, the supplementary light and the laser light have the same polarization state and color, which can supplement the excitation light of the first polarization state polarized light missing in the central region of the light path emitted from the optical device 20, so as to make the light intensity of the light spot after exiting the optical device 20 more uniform.

[0074] Please see Figure 11 In this embodiment, the light splitting and combining unit 30 further includes an optical coating 51 disposed on the second inclined surface 32 of the right-angled isosceles trapezoidal prism near the supplementary light source 60. That is, an optical coating 51 is disposed on the inclined surface of both right-angled trapezoidal prisms. The optical coating 51 can reflect the supplementary light and transmit the excitation light subjected to the laser and the second polarization state. Since the supplementary light and the laser light have the same polarization state and color, the optical coating 51 can reflect the excitation light of the first polarization state and the supplementary light, and transmit the excitation light subjected to the laser and the second polarization state. By disposing of the optical coating 51 on the second inclined surface 32, the excitation light of the first polarization state polarized light missing in the central region of the light path emitted from the optical device 20 is supplemented, and the supplementary light does not pass through the adhesive, preventing adhesive aging and improving the reliability and service life of the light source system 100.

[0075] When the light source system 100 includes a supplementary light source 60, the optical device 20 also includes a supplementary light antireflection film 55. The supplementary light antireflection film 55 can be disposed on the fourth surface 24 of the optical device 20. In this way, the supplementary light antireflection film 55 can improve the transmittance of the supplementary light emitted by the supplementary light source 60 when it exits the optical device 20 from the fourth surface 24. The optical device 20 also includes a white light antireflection film 53. The white light antireflection film 53 can be disposed on the first surface 21 of the optical device 20, or on the third surface 23, or simultaneously on both the first surface 21 and the third surface 23. In this way, the white light antireflection film 53 can improve the transmittance of the laser emitted by the wavelength conversion device 40 when it enters the optical device 20 from the first surface 21, and the transmittance when it exits the optical device 20 from the third surface 23.

[0076] Please see Figure 12 This invention provides a projection device 200, which includes the light source system 100 of any of the above embodiments.

[0077] The projection device 200 can be a cinema projector, engineering projector, micro projector, educational projector, video wall projector, laser TV, etc. The projection device 200 may also include a housing 301, within which the light source system 100 is housed. The housing 301 protects the light source system 100 from direct impact from the external environment. In this embodiment of the projection device 200, the volume of the optical components 20 can be reduced, thereby reducing the dilution of optical spread during laser propagation and improving the brightness of the light source system 100.

[0078] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A light source system, characterized in that, include: A light source device used to emit excitation light; A wavelength conversion device for converting at least partially the received excitation light into laser light; Light splitting and combining unit; and An optical device, wherein the optical device is a cuboid prism, the cuboid prism includes a first surface, a second surface and a third surface connected together, the first surface and the third surface being opposite to each other and arranged in parallel, and the second surface being located between the first surface and the third surface; the distance between the first surface and the third surface is equal to the shortest edge length of the cuboid prism, so that the laser beam is transmitted through the cuboid prism from the direction of the shortest edge length of the cuboid prism; The light splitting and combining unit is disposed inside the optical device; The light source device faces the second surface, and the excitation light enters the optical device from the second surface and is incident on the beam splitting and combining unit. The beam splitting and combining unit reflects the received excitation light to the wavelength conversion device. The wavelength conversion device faces the first surface. The laser emitted from the wavelength conversion device enters the optical device from the first surface. A portion of the laser passes through the first surface and the beam splitting and combining unit and exits from the third surface. The remaining portion of the laser passes through the first surface and the optical device around the beam splitting and combining unit and exits from the third surface.

2. The light source system according to claim 1, characterized in that, The light-splitting and light-combining unit is inclined relative to the optical path of the excitation light emitted by the light source device.

3. The light source system according to claim 1, characterized in that, The area of ​​the beam splitting and combining unit projected onto the first surface is smaller than the area of ​​the first surface.

4. The light source system according to claim 3, characterized in that, The region of the orthographic projection of the light splitting and combining unit onto the first surface is located in the middle region of the first surface.

5. The light source system according to claim 1, characterized in that, The optical device is a hollow cuboid prism, and the beam splitting and combining unit is a beam splitter. The beam splitter is disposed inside the optical device and reflects the excitation light and transmits the laser light.

6. The light source system according to claim 1, characterized in that, The optical device is a cuboid prism formed by splicing two right-angled trapezoidal prisms, with the inclined surfaces of the two right-angled trapezoidal prisms joined together, and the beam splitting and combining unit is disposed at the splicing point of the two right-angled trapezoidal prisms.

7. The light source system according to claim 6, characterized in that, The beam splitting and combining unit is a beam splitter sandwiched between two right-angled trapezoidal prisms. The beam splitter reflects the excitation light and transmits the laser light.

8. The light source system according to claim 7, characterized in that, The light splitting and combining unit is an optical coating formed on the inclined surface of at least one of the right-angled trapezoidal prisms, which reflects the excitation light and transmits the laser light.

9. The light source system according to any one of claims 1 to 8, characterized in that, The light source device emits excitation light of the first polarization state, and the beam splitting and combining unit reflects the excitation light of the first polarization state and transmits the excitation light of the second polarization state.

10. The light source system according to claim 9, characterized in that, The light source system further includes a supplementary light source, which is used to emit supplementary light of the first polarization state. The supplementary light has the same color as the excitation light. The supplementary light source is disposed on the side of the optical device opposite to the light source device. The supplementary light emitted by the supplementary light source enters the optical device and is incident on the beam splitting and combining unit. The supplementary light is reflected by the beam splitting and combining unit and exits the optical device along the same optical path as the laser beam.

11. The light source system according to claim 10, characterized in that, The optical device is a cuboid prism formed by splicing two right-angled trapezoidal prisms. The inclined surfaces of the two right-angled trapezoidal prisms are spliced ​​together, and an optical coating is provided on the inclined surfaces of the two right-angled trapezoidal prisms. The optical coating reflects the excitation light and supplementary light of the first polarization state, and transmits the excitation light of the laser and the second polarization state.

12. A projection device, characterized in that, Includes the light source system according to any one of claims 1 to 11.

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