Light combination module and projection device

Abstract

The application provides a light combination module and a projection device. The light combination module comprises an excitation light source, a condenser lens with a first lens part and a second lens part, a wavelength conversion unit and a light combination unit with a reflecting surface and a light splitting surface. The reflecting surface is arranged obliquely and opposite to the second lens part. The light splitting surface is arranged obliquely between the reflecting surface and the condenser lens and opposite to the first lens part and the second lens part. The light splitting surface allows the first color light of the excitation light source to penetrate. The reflecting surface reflects the first color light from the second lens part to penetrate the light splitting surface and to be emitted from the light combination unit. The wavelength conversion unit is arranged on one side of the condenser lens and is used to partially reflect the first color light to penetrate the second lens part and the light splitting surface and to be incident on the reflecting surface, and to partially convert the first color light into second color light and reflect the second color light back to the light splitting surface, so that the second color light is reflected by the light splitting surface and combined with the first color light reflected by the reflecting surface.

Description

Technical Field

[0001] This invention relates to a light combining module and a projection device, and more particularly to a light combining module and a projection device that uses the beam-splitting surface and the reflective surface of the light combining unit to perform uniaxial light combining of the first color light of the excitation light source and the second color light formed by the wavelength conversion unit. Background Technology

[0002] Generally, in the architecture of existing laser projectors, the light-combining design typically uses a blue laser to excite phosphors to produce red and green light, which, together with the blue laser, forms multi-color imaging light for subsequent projection imaging. Common configurations can be found in [reference needed]. Figure 1 This is a simplified diagram of a prior art laser projection device 10. (As shown...) Figure 1 As shown, the laser projection device 10 includes a laser light source 12 and a light combining module 14, so that the colored light emitted by the laser light source 12 can be combined through the light combining module 14 to provide multi-color imaging light (such as red light, blue light, and green light) for subsequent projection imaging by the laser projection device 10.

[0003] In short, taking laser source 12 as an example, which is a blue laser source, such as Figure 1 As shown, the light combining module 14 includes a beam splitter 16, a phosphor color wheel 18, and multiple reflectors 20. When blue light emitted from the laser source 12 enters the light combining module 14 and is incident on the beam splitter 16, the beam splitter 16 allows the blue light to penetrate and be incident on the phosphor color wheel 18. At this time, the phosphor layer on the phosphor color wheel 18 is excited by the blue light to generate imaging colors different from blue light (such as red and green light) and is reflected back to the beam splitter 16. In addition, some of the blue light that penetrates the phosphor color wheel 18 is also reflected by the multiple reflectors 20 in sequence and is incident on the beam splitter 16 again. In this way, after the blue light is guided by the reflection of the multiple reflectors 20 and penetrates the beam splitter 16 again, and the aforementioned imaging colors different from blue light are reflected by the beam splitter 16, the light combining module 14 can provide the laser projection device 10 with multiple imaging colors required for subsequent projection imaging.

[0004] However, by Figure 1 As can be seen, the light combining module 14 must be equipped with a variety of optical elements to combine the light to form multi-color imaging light. Therefore, the above design not only significantly increases the cost of optical element configuration, but also increases the overall weight and volume of the laser projection device, which is not conducive to the miniaturization design of the laser projection device.

[0005] Therefore, it is necessary to design a new type of light combining module and projection device to overcome the above-mentioned defects. Summary of the Invention

[0006] The purpose of this invention is to provide a light combining module and a projection device, which can use the beam-splitting surface and the reflective surface of the light combining unit to perform uniaxial light combining of the first color light of the excitation light source and the second color light formed by the wavelength conversion unit, thereby reducing the number of optical components while improving the uniformity of image color.

[0007] To achieve the above objectives, the present invention provides a beam combining module for providing a combined beam to a projection device. The beam combining module includes: an excitation light source emitting a first color light; at least one first condensing lens having a first lens portion and a second lens portion; and a beam combining unit disposed between the excitation light source and the first condensing lens, having a reflective surface and a beam-splitting surface. The reflective surface is obliquely disposed at a position opposite to the second lens portion, and the beam-splitting surface is obliquely disposed between the reflective surface and the first condensing lens, opposite to the first lens portion and the second lens portion. The beam-splitting surface allows the first color light to pass through. The light penetrates and enters the first lens portion, and the reflective surface reflects the first color light transmitted from the second lens portion, so that the first color light penetrates the beam splitting surface and is emitted from the beam combining unit; and a wavelength conversion unit is disposed on the other side of the first condensing lens opposite to the beam combining unit, for reflecting a portion of the first color light to sequentially penetrate the second lens portion and the beam splitting surface and enter the reflective surface, and converting a portion of the first color light into at least one second color light and reflecting it back to the beam splitting surface, so that the at least one second color light is reflected by the beam splitting surface and combines with the first color light reflected by the reflective surface to generate a combined beam.

[0008] Preferably, the beam combining unit is a beam splitter, the reflective surface is formed on the first surface of the beam splitter facing the excitation light source, and the beam splitting surface is formed on the second surface of the beam splitter facing the first condensing lens.

[0009] Preferably, the beam combining unit includes a first beam splitter and a second beam splitter. The first beam splitter is obliquely disposed between the excitation light source and the first lens portion. The second beam splitter is connected to one side of the first beam splitter and obliquely opposite to the second lens portion. The beam splitting surface is formed on a first surface of the first beam splitter facing the first lens portion and on a second surface of the second beam splitter facing the second lens portion. The reflective surface is formed on a third surface of the second beam splitter. The second and third surfaces are opposite to each other. The thickness of the first beam splitter is less than the thickness of the second beam splitter.

[0010] Preferably, the beam combining unit includes a reflector and a beam splitter. The reflector is tilted opposite to the second lens portion, and the beam splitter is tilted between the reflector and the first condenser lens. The beam splitting surface is formed on the surface of the beam splitter facing the first condenser lens, and the reflecting surface is formed on the surface of the reflector facing the beam splitter.

[0011] Preferably, the wavelength conversion unit is a fluorescent color wheel, which is rotatably disposed on the other side and has at least one phosphor layer and a reflective layer arranged sequentially around the periphery of the fluorescent color wheel. The at least one phosphor layer excites the first color light to be converted into the at least one second color light, and the reflective layer reflects the first color light to the second lens portion.

[0012] Preferably, the reflective surface of the reflective layer is at or above the surface of the phosphor layer on the phosphor color wheel, and the height difference between the reflective surface of the reflective layer and the surface of the phosphor layer is between 0 and 0.2 mm.

[0013] Preferably, the fluorescent color wheel also has a diffusion structure formed in the reflective layer to diffuse the first color light.

[0014] Preferably, it further includes: a light homogenizing element disposed between the excitation light source and the light combining unit, used to receive the first color light for light homogenization and superposition.

[0015] Preferably, it further includes: a color filter wheel for receiving the combined light beam to generate multiple projected colored lights; and a second focusing lens disposed between the color filter wheel and the combined light unit for focusing the combined light beam to be incident on the color filter wheel.

[0016] Preferably, the beam combining unit is a beam splitter, the wavelength conversion unit is a fluorescent color wheel, and the beam combining module further includes a homogenizing element, a filter color wheel, and a second condensing lens; the reflective surface is formed on the first surface of the beam splitter facing the excitation light source, and the beam splitting surface is formed on the second surface of the beam splitter facing the first condensing lens, wherein the thickness of the beam splitter is between 9 mm and 11 mm, and the refractive index of the beam splitter is between 1.4 and 1.6; the fluorescent color wheel is rotatably disposed on the other side and has at least one phosphor layer and a reflective layer sequentially arranged around the periphery of the fluorescent color wheel. The at least one phosphor layer excites the first color light to convert it into the at least one second color light, and the reflective layer reflects the first color light to the second lens portion; the light homogenizing element is disposed between the excitation light source and the light combining unit, and the optical surface of the light homogenizing element facing one of the excitation light source and the light combining unit has a lens array to homogenize and superimpose the first color light; the color filter wheel is used to receive the combined light beam to generate multiple projected color lights, and the second condensing lens is disposed between the color filter wheel and the light combining unit to focus the combined light beam to be incident on the color filter wheel.

[0017] Preferably, the beam combining unit includes a first beam splitter and a second beam splitter, the wavelength conversion unit is a fluorescent color wheel, and the beam combining module also includes a homogenizing element, a filter color wheel, and a second focusing lens; the first beam splitter is obliquely disposed between the excitation light source and the first lens portion, the second beam splitter is connected to one side of the first beam splitter and obliquely opposite to the second lens portion, the beam splitting surface is formed on a first surface of the first beam splitter facing the first lens portion and on a second surface of the second beam splitter facing the second lens portion, the reflecting surface is formed on a third surface of the second beam splitter, the second surface and the third surface are opposite to each other, the thickness of the first beam splitter is less than the thickness of the second beam splitter, wherein the thickness of the second beam splitter is between 9mm and 11mm, and the first beam splitter... The refractive index of the second beam splitter is between 1.4 and 1.6; the fluorescent color wheel is rotatably disposed on the other side and has at least one phosphor layer and a reflective layer arranged sequentially around the periphery of the fluorescent color wheel, the at least one phosphor layer excites the first color light to convert it into the at least one second color light, and the reflective layer reflects the first color light to the second lens portion; the homogenizing element is disposed between the excitation light source and the light combining unit, and the optical surface of the homogenizing element facing one of the excitation light source and the light combining unit has a lens array to homogenize and superimpose the first color light; the filter color wheel is used to receive the combined light beam to generate multiple projected color lights, and the second condensing lens is disposed between the filter color wheel and the light combining unit to focus the combined light beam to be incident on the filter color wheel.

[0018] Preferably, the light combining unit includes a reflector and a beam splitter, the wavelength conversion unit is a phosphor color wheel, and the light combining module also includes a homogenizing element, a filter color wheel, and a second condensing lens; the reflector is obliquely positioned opposite the second lens portion, the beam splitter is obliquely positioned between the reflector and the first condensing lens, the beam splitting surface is formed on the surface of the beam splitter facing the first condensing lens, and the reflective surface is formed on the surface of the reflector facing the beam splitter; the phosphor color wheel is rotatably positioned on the other side and has at least one phosphor layer and a reflective layer sequentially arranged around the phosphor color wheel. The at least one phosphor layer excites the first color light to convert it into the at least one second color light at the periphery of the first lens portion; the reflective layer reflects the first color light to the second lens portion; the light homogenizing element is disposed between the excitation light source and the light combining unit, and the optical surface of the light homogenizing element facing one of the excitation light source and the light combining unit has a lens array formed to homogenize and superimpose the first color light; the color filter wheel is used to receive the combined light beam to generate multiple projected color lights, and the second condensing lens is disposed between the color filter wheel and the light combining unit to focus the combined light beam to be incident on the color filter wheel.

[0019] The present invention also provides a projection device, comprising: a light combining module as described above, providing a light combining beam; and a projection device, receiving and projecting the light combining beam.

[0020] Compared with existing technologies, the light combining module and projection device provided by this invention can provide a multi-color combined beam with appropriate color distribution using only a simple configuration of a light combining unit (faceted light guide design) and a wavelength conversion element (color light conversion and reflection design). This significantly reduces the cost of optical component configuration and effectively reduces the overall weight and volume of the laser projection device, thus facilitating miniaturization. Furthermore, by appropriately controlling the thickness of the light combining unit structure to extend the optical path distance of the first color light, this invention can accurately guide the first color light emitted by the excitation light source and the second color light excited by the wavelength conversion element to perform coaxial light combining. This reduces the number of optical components in the light combining module, lowers assembly tolerances, and improves the image projection quality and color uniformity of the laser projection device. It also avoids the problem of uneven beam energy caused by the first color light incident at a large angle on the first focusing lens, and the mismatch between the beam energy and the beam energy of the second color light excited by the wavelength conversion element, resulting in uneven projected image color. Attached Figure Description

[0021] Figure 1 This is a simplified diagram of a prior art laser projection device.

[0022] Figure 2 This is a simplified diagram of a light-combining module according to an embodiment of the present invention.

[0023] Figure 3 This is a simplified diagram of a wavelength conversion unit proposed according to another embodiment of the present invention.

[0024] Figure 4 This is a simplified diagram of a light-combining module according to another embodiment of the present invention.

[0025] Figure 5 This is a simplified diagram of a light-combining module according to another embodiment of the present invention. Detailed Implementation

[0026] To provide a further understanding of the purpose, structure, features and functions of the present invention, detailed descriptions are provided below with reference to embodiments.

[0027] The following description, accompanied by illustrations, illustrates the technical content of the present invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different embodiments. Various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention. In particular, the structural design and positional relationships of the various elements in the drawings (such as the structural proportions and arrangement of the various optical elements in the light combining module and the presentation of their related color light paths) are for illustrative purposes only and do not represent the actual implementation of the present invention.

[0028] Please see Figure 2 This is a simplified diagram of a light-combining module 100 according to an embodiment of the present invention. Figure 2 As shown, the beam combining module 100 is suitable for providing a combined beam required for subsequent projection imaging to a laser projection device. The beam combining module 100 includes an excitation light source 102 and at least one first focusing lens 104 (in... Figure 2 (Two are shown in the image, but not limited to this), light combining unit 106, and wavelength conversion unit 108.

[0029] The excitation light source 102 is preferably a laser light source that emits a first color light L1 of blue light, but it is not limited thereto. The type of light and the number of light sources can vary depending on the actual light combining application of the light combining module 100. The first focusing lens 104 is preferably a collimator and has a first lens section 110 and a second lens section 112 for collimating and focusing the first color light L1. The beam combining unit 106 is disposed between the excitation light source 102 and the first condenser lens 104 and has a reflective surface 114 and a beam splitting surface 116. The reflective surface 114 is obliquely disposed at a position opposite to the second lens section 30. The beam splitting surface 116 is obliquely disposed between the reflective surface 114 and the first condenser lens 104 and is opposite to the first lens section 110 and the second lens section 112. The beam splitting surface 116 allows the first color light L1 to penetrate and be incident on the first lens section 110. The reflective surface 114 reflects the first color light L1 transmitted from the second lens section 112, so that the first color light L1 penetrates the beam splitting surface 116 and is emitted from the beam combining unit 106. A wavelength conversion unit 108 is disposed on the other side of the first condensing lens 104 opposite to the beam combining unit 106. It is used to reflect a portion of the first color light L1 transmitted from the first lens section 110 so that it sequentially passes through the second lens section 112 and the beam splitting surface 116 and is incident on the reflecting surface 114. It also converts a portion of the first color light L1 into second color light L2 and reflects it back to the beam splitting surface 116, so that the second color light L2 is reflected by the beam splitting surface 116. Thus, as... Figure 2As shown, the second color light L2 reflected by the beam splitter 116 can be combined with the first color light L1 reflected by the reflector 114 to produce a combined light beam B.

[0030] More specifically, in this embodiment, the beam combining unit 106 can be a beam splitter and is relatively tilted relative to the excitation light source 102 (its tilt angle is preferably equal to 45°, but not limited thereto). The reflective surface 114 is formed on the first surface S1 of the beam combining unit 106 facing the excitation light source 102, and the beam splitting surface 116 is formed on the second surface S2 of the beam combining unit 106 facing the first condenser lens 104. The reflective surface 114 and the beam splitting surface 116 formed on the two opposing surfaces of the beam combining unit 106 can avoid assembly tolerances and reduce costs. The thickness of the beam combining unit 106 is preferably between 9 mm and 11 mm, and the refractive index of the beam combining unit 106 is preferably between 1.4 and 1.6. This avoids the first color light L1 from being incident on the first condenser lens 104 at a large angle, which would cause uneven light spot energy.

[0031] In this embodiment, the wavelength conversion unit 108 may be a phosphor wheel, and the wavelength conversion unit 108 is rotatably disposed and has at least one phosphor layer 118 (in Figure 2 Two are shown in the image, but not limited to this) and a reflective layer 120 (preferably formed by coating an aluminum disk or by embedding blue reflective glass, but not limited to this) are sequentially arranged around the periphery of the wavelength conversion unit 108. In practical applications, the wavelength conversion unit of the present invention can further employ a diffusion structure design. For example, please refer to [reference needed]. Figure 3 This is a simplified diagram of a wavelength conversion unit 108' according to another embodiment of the present invention. Elements in this embodiment that have the same number as those mentioned in the above embodiments represent elements with the same or similar structures and functions. Their related descriptions can be deduced by analogy from the above embodiments and will not be repeated here. Figure 3 As shown, the wavelength conversion unit 108' may have a phosphor layer 118, a reflective layer 120, and a diffusion structure 122. The diffusion structure 112 may preferably be formed on the reflective layer 120 in the form of an irregular structure produced by an aluminum disk or by embedding a diffusion glass sheet to diffuse the first color light L1, thereby further diffusing and homogenizing the energy and directionality of the first color light L1.

[0032] In addition, the light combining module 100 can also adopt a uniform light design, for example, such as Figure 2As shown, the light combining module 100 further includes a light homogenizing element 124, which is disposed between the excitation light source 102 and the light combining unit 106 to homogenize and superimpose the first color light L1 emitted by the excitation light source 102. The light homogenizing element 124 can preferably be a fly eye lens or have other similar functions (but is not limited thereto). In this embodiment, a lens array 125 can be formed on the optical surface of the light homogenizing element 124 facing one of the excitation light source 102 and the light combining unit 106. Figure 2 The image shows that the homogenizing element 124 has a lens array 125 formed on the optical surface of the excitation light source 102. However, it is not limited to this; it can also be a single-sided lens array design where the lens array 125 is formed on the optical surface of the homogenizing element 124 facing the light combining unit 106. Therefore, compared to the prior art using diffusers (which leads to uneven colored light energy) or double-sided compound eye lens designs (which are too costly), the single-sided lens array design of this invention not only makes the colored light spot energy uniform to improve the excitation efficiency of the phosphor layer, but also reduces the lens cost of the light combining module. The description of the array structure design of the homogenizing element 124 is common in the prior art and can vary depending on the actual application of the light combining module 100, and will not be repeated here. Figure 2 Limited to.

[0033] Through the above design, as the phosphor wheel rotates, the first color light L1, which passes through the beam-splitting surface 116 and the first lens section 110, can be excited by the phosphor layer 118 during its incidence on the wavelength conversion unit 108, resulting in a wavelength conversion phenomenon. It can also be reflected by the reflective layer 120 to sequentially pass through the second lens section 112 and the beam-splitting surface 116 before being incident on the reflective surface 114. For example, the excitation light source 102 can emit the first color light L1, which is blue. The phosphor layer 118 can correspondingly be a green phosphor layer and a yellow phosphor layer. Thus, the phosphor layer 118... The first color light L1 can be sequentially converted into a second color light L2 of green and yellow light, so that the second color light L2 can mix with the first color light L1 reflected by the reflective surface 114 to form white light. Alternatively, the phosphor layer 118 can be a red-green phosphor layer, thereby converting the first color light L1 into a second color light L2 of red and green light, so that the second color light L2 can mix with the first color light L1 reflected by the reflective surface 114 to form white light. However, this is not a limitation, and the types of light colors and the colors of the phosphor layer can vary according to the actual light combining requirements of the light combining module 100. In specific implementation, the blue light in this design is a forward incident light guide to avoid uneven light spot energy caused by the large-angle symmetrical incident light guide of the blue light when using a semi-transparent and semi-reflective mirror. In addition, in order to improve the reflection efficiency of the first color light L1 on the reflective layer 120, the reflective surface of the reflective layer 120 can be preferably equal to or higher than the phosphor layer surface of the phosphor layer 118 on the phosphor color wheel. For example, the height difference between the reflective surface of the reflective layer 120 and the phosphor surface of the phosphor layer 118 can be between 0 and 0.2 mm, but is not limited to this. To avoid the decrease in blue light efficiency due to color difference, its surface height design can vary according to the actual color uniformity of the combined light module 100.

[0034] In this way, through the above-mentioned split-beam light guide design, the light combining unit 106 can guide the first color light L1 to pass through the split-beam surface 116 and be reflected sequentially by the wavelength conversion unit 108 and the reflective surface 114, and then perform uniaxial light combining with the second color light L2 formed by the wavelength conversion unit 108 to generate a combined light beam B, thereby providing multiple imaging colors required for subsequent projection imaging of the laser projection device.

[0035] It should be noted that, such as Figure 2As shown, the beam combining module 100 further includes a color wheel 126 and a second focusing lens 128. The color wheel 126 receives the combined beam B to generate multiple projected colored lights. The second focusing lens 128 is preferably a collimating lens (but not limited thereto) and is disposed between the color wheel 126 and the beam combining unit 106 to focus the combined beam B onto the color wheel 126. More specifically, in this embodiment, the color wheel 126 may have radially arranged red filter blocks 130, green filter blocks 132, and blue filter blocks 134 to filter the combined beam B to generate corresponding projected colored lights (i.e., red, green, and blue light) for subsequent projection imaging by the laser projection device.

[0036] In this embodiment of the invention, compared to the prior art light combining module which requires multiple optical elements to combine light to form multi-color imaging light, the present invention only uses a simple configuration of a light combining unit (faceted light guide design) and a wavelength conversion element (color light conversion and reflection design) to provide a multi-color combined light beam with appropriate color distribution. In this way, the present invention can not only significantly reduce the cost of optical element configuration, but also effectively reduce the overall weight and volume of the laser projection device, thus facilitating the miniaturization design of the laser projection device. Furthermore, through the aforementioned design of appropriately controlling the thickness of the light combining unit structure to extend the optical path distance of the first color light, the present invention can reliably guide the first color light emitted by the excitation light source and the second color light excited by the wavelength conversion element to perform coaxial light combining. This reduces the number of optical elements in the light combining module, lowers assembly tolerances, and improves the image projection quality and color uniformity of the laser projection device. It also avoids the problem of uneven light spot energy caused by the first color light incident at a large angle on the first focusing lens, and the mismatch between the light spot energy and the second color light excited by the wavelength conversion element, resulting in uneven projected image color.

[0037] It is worth mentioning that the beam combining unit of the present invention can also adopt a beam-splitting reflector design with unequal thickness. For example, please refer to [link to relevant documentation]. Figure 4 This is a simplified diagram of a light-combining module 150 according to another embodiment of the present invention. Elements in this embodiment that have the same number as those mentioned in the above embodiments represent elements with the same or similar structures and functions. Their related descriptions can be deduced by analogy from the above embodiments and will not be repeated here. Figure 4As shown, the light combining module 150 includes a light combining unit 152, an excitation light source 102, a first condensing lens 104, a wavelength conversion unit 108, a light homogenizing element 124, a color filter wheel 126, and a second condensing lens 128. In this embodiment, the light combining unit 152 may include a first beam splitter 154 and a second beam splitter 156. The first beam splitter 154 is obliquely disposed between the excitation light source 102 and the first lens portion 110 (its oblique angle is preferably equal to 45°, but not limited thereto). The second beam splitter 156 is connected to one side of the first beam splitter 154 and is obliquely opposite to the second lens portion 112 (its oblique angle is preferably equal to 45°, but not limited thereto). (equal to 45°, but not limited to this), the beam splitting surface 116 is formed on the first surface S3 of the first beam splitter 154 facing the first lens portion 110 and on the second surface S4 of the second beam splitter 156 facing the second lens portion 112, the reflecting surface 114 is formed on the third surface S5 of the second beam splitter 156, the second surface S4 and the third surface S5 are opposite to each other, and the thickness of the first beam splitter 154 is less than the thickness of the second beam splitter 156, wherein the thickness of the second beam splitter 156 is preferably between 9 mm and 11 mm, and the refractive index of the first beam splitter 154 and the second beam splitter 156 is preferably between 1.4 and 1.6.

[0038] Through the above design, as the phosphor color wheel rotates, the first color light L1, which passes through the beam-splitting surface 116 of the first beam splitter 154 and the first lens section 110, can be excited by the phosphor layer 118 during its incidence on the wavelength conversion unit 108, resulting in a wavelength conversion phenomenon. It can also be reflected by the reflective layer 120 to sequentially pass through the second lens section 112 and the beam-splitting surface 116 of the second beam splitter 156, and then be incident on the reflective surface 114 of the second beam splitter 156. In this way, through the above-mentioned beam-guiding design, the beam-combining unit 152 can guide the first color light L1 to pass through the beam-splitting surface 116 and be sequentially reflected by the wavelength conversion unit 108 and the reflective surface 114, thereby performing uniaxial beam combination with the second color light L2 formed by the wavelength conversion unit 108, thus generating a combined beam B. This provides the laser projection device with multiple imaging colors required for subsequent projection imaging.

[0039] In addition, the beam combining unit of the present invention can also adopt a design in which the beam splitter and the reflector are arranged alternately. For example, please refer to Figure 5 This is a simplified diagram of a light-combining module 200 according to another embodiment of the present invention. Elements in this embodiment that have the same number as those mentioned in the above embodiments represent elements with the same or similar structures and functions. Their related descriptions can be deduced by analogy from the above embodiments and will not be repeated here. Figure 5As shown, the light combining module 200 includes a light combining unit 202, an excitation light source 102, a first condensing lens 104, a wavelength conversion unit 108, a light homogenizing element 124, a color filter wheel 126, and a second condensing lens 128. In this embodiment, the light combining unit 202 may include a reflector 204 and a beam splitter 206. The reflector 204 is tilted relative to the second lens portion 112 (its tilt angle is preferably equal to 45°, but not limited thereto). The beam splitter 206 is tilted between the reflector 204 and the first condensing lens 104 (its tilt angle is preferably equal to 45°, but not limited thereto) and is spaced apart from the reflector 204. A beam splitting surface 116 is formed on the surface of the beam splitter 206 facing the first condensing lens 104, and a reflecting surface 114 is formed on the surface of the reflector 206 facing the beam splitter 204.

[0040] Through the above design, as the phosphor color wheel rotates, the first color light L1, which passes through the beam-splitting surface 116 of the beam splitter 206 and the first lens section 110, can be excited by the phosphor layer 118 during its incident on the wavelength conversion unit 108, resulting in a wavelength conversion phenomenon. It can then be reflected by the reflective layer 120 to sequentially pass through the second lens section 112 and the beam-splitting surface 116 of the beam splitter 206 before being incident on the reflective surface 114 of the reflector 204. In this way, through the above-mentioned spaced light guiding design and by appropriately controlling the structural thickness of the beam splitter 206 and the air gap between the beam splitter 206 and the reflector 204, the beam combining unit 202 can guide the first color light L1 to pass through the beam-splitting surface 116 and be sequentially reflected by the wavelength conversion unit 108 and the reflective surface 114, thereby performing uniaxial beam combining with the second color light L2 formed by the wavelength conversion unit 108 to generate a combined beam B. This provides the laser projection device with multiple imaging colors required for subsequent projection imaging.

[0041] The present invention also proposes a projection device, which includes light combining modules 100, 150, and 200 and a projection device. The light combining modules 100, 150, and 200 provide a light combining beam B. The projection device receives the influence projected by the light combining beam B. Thus, the projection device has fewer optical elements and simultaneously improves the uniformity of image color.

[0042] In summary, the light combining module and projection device provided by the present invention include an excitation light source, a condensing lens having first and second lens portions, a wavelength conversion unit, and a light combining unit having a reflective surface and a beam-splitting surface. The reflective surface is inclined and opposite to the second lens portion, and the beam-splitting surface is inclined between the reflective surface and the condensing lens and opposite to the first and second lens portions. The beam-splitting surface allows the first color light from the excitation light source to pass through. The reflective surface reflects the first color light transmitted from the second lens portion, which passes through the beam-splitting surface and exits from the light combining unit. The wavelength conversion unit is disposed on one side of the condensing lens and is used to partially reflect the first color light to pass through the second lens portion and the beam-splitting surface and be incident on the reflective surface, and to convert a portion of the first color light into second color light and reflect it back to the beam-splitting surface, so that the second color light is reflected by the beam-splitting surface and combines with the first color light reflected by the reflective surface.

[0043] Although the invention has been described in conjunction with the accompanying drawings, the embodiments disclosed in the drawings are intended to illustrate preferred embodiments of the invention and should not be construed as limiting the invention. The scale in the schematic drawings does not represent the actual proportions of the components, in order to clearly describe the required parts.

[0044] The present invention has been described in the above-described embodiments; however, these embodiments are merely examples for implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the present invention. Conversely, any modifications and refinements made without departing from the spirit and scope of the present invention are within the scope of patent protection of the present invention.

Claims

1. A beam combining module for providing a combined beam to a projection device, characterized in that, The light-combining module includes: The light source is excited, emitting the first color of light; At least one first condenser lens, having a first lens portion and a second lens portion; A beam combining unit is disposed between the excitation light source and the first condensing lens and has a reflective surface and a beam splitting surface. The reflective surface is obliquely disposed opposite to the second lens portion, and the beam splitting surface is obliquely disposed between the reflective surface and the first condensing lens and opposite to both the first and second lens portions. The beam splitting surface allows the first color light to penetrate and enter the first lens portion, while the reflective surface reflects the first color light transmitted from the second lens portion, so that the first color light penetrates the beam splitting surface and exits from the beam combining unit; and A wavelength conversion unit is disposed on the other side of the first condensing lens opposite to the beam combining unit. It is used to reflect a portion of the first color light so that it passes through the second lens portion and the beam splitting surface in sequence and is incident on the reflecting surface. It also converts a portion of the first color light into at least one second color light and reflects it back to the beam splitting surface, so that the at least one second color light is reflected by the beam splitting surface and combines with the first color light reflected by the reflecting surface to generate a combined beam.

2. The light combining module as described in claim 1, characterized in that, The beam combining unit is a beam splitter. The reflective surface is formed on the first surface of the beam splitter facing the excitation light source, and the beam splitting surface is formed on the second surface of the beam splitter facing the first condensing lens.

3. The light combining module as described in claim 1, characterized in that, The beam combining unit includes a first beam splitter and a second beam splitter. The first beam splitter is obliquely disposed between the excitation light source and the first lens portion. The second beam splitter is connected to one side of the first beam splitter and obliquely opposite to the second lens portion. The beam splitting surface is formed on a first surface of the first beam splitter facing the first lens portion and on a second surface of the second beam splitter facing the second lens portion. The reflective surface is formed on a third surface of the second beam splitter. The second and third surfaces are opposite to each other. The thickness of the first beam splitter is less than the thickness of the second beam splitter.

4. The light combining module as described in claim 1, characterized in that, The beam combining unit includes a reflector and a beam splitter. The reflector is tilted and faces the second lens. The beam splitter is tilted and disposed between the reflector and the first condenser lens. The beam splitting surface is formed on the surface of the beam splitter facing the first condenser lens, and the reflective surface is formed on the surface of the reflector facing the beam splitter.

5. The light combining module as described in claim 1, characterized in that, The wavelength conversion unit is a fluorescent color wheel, which is rotatably disposed on the other side and has at least one phosphor layer and a reflective layer arranged sequentially around the periphery of the fluorescent color wheel. The at least one phosphor layer excites the first color light to be converted into the at least one second color light, and the reflective layer reflects the first color light to the second lens portion.

6. The light combining module as described in claim 5, characterized in that, The reflective surface of the reflective layer is at or above the surface of the phosphor layer on the phosphor color wheel, and the height difference between the reflective surface of the reflective layer and the surface of the phosphor layer is between 0 and 0.2 mm.

7. The light combining module as described in claim 5, characterized in that, The fluorescent color wheel also has a diffusion structure formed in the reflective layer to diffuse the first color light.

8. The light combining module as described in claim 1, characterized in that, Also includes: A light homogenizing element is disposed between the excitation light source and the light combining unit to receive the first color light for light homogenization and superposition.

9. The light combining module as described in claim 1, characterized in that, Also includes: A color filter wheel is used to receive the combined light beam to produce multiple projected colored lights; and A second focusing lens is disposed between the color filter wheel and the light combining unit to focus the combined light beam onto the color filter wheel.

10. The light combining module as described in claim 1, characterized in that, The beam combining unit is a beam splitter, the wavelength conversion unit is a fluorescent color wheel, and the beam combining module also includes a homogenizing element, a filter color wheel, and a second condensing lens. A reflective surface is formed on the first surface of the beam splitter facing the excitation light source, and a beam splitting surface is formed on the second surface of the beam splitter facing the first condensing lens. The thickness of the beam splitter is between 9 mm and 11 mm, and its refractive index is between 1.4 and 1.

6. The fluorescent color wheel is rotatably disposed on the other side and has at least one phosphor layer and a reflective layer sequentially arranged around the periphery of the fluorescent color wheel. The at least one phosphor layer excites the first color light to convert it into the at least one second color light, and the reflective layer reflects the first color light to the second lens portion; the homogenizing element is disposed between the excitation light source and the light combining unit, and the optical surface of the homogenizing element facing one of the excitation light source and the light combining unit has a lens array formed to homogenize and combine the first color light; the color filter wheel is used to receive the combined light beam to generate multiple projected color lights, and the second condensing lens is disposed between the color filter wheel and the light combining unit to focus the combined light beam to be incident on the color filter wheel; Alternatively, the beam combining unit includes a first beam splitter and a second beam splitter, the wavelength conversion unit is a fluorescent color wheel, and the beam combining module also includes a homogenizing element, a filter color wheel, and a second focusing lens; the first beam splitter is obliquely disposed between the excitation light source and the first lens portion, the second beam splitter is connected to one side of the first beam splitter and obliquely opposite the second lens portion, the beam splitting surface is formed on a first surface of the first beam splitter facing the first lens portion and on a second surface of the second beam splitter facing the second lens portion, the reflecting surface is formed on a third surface of the second beam splitter, the second surface and the third surface are opposite each other, the thickness of the first beam splitter is less than the thickness of the second beam splitter, wherein the thickness of the second beam splitter is between 9mm and 11mm, and the first beam splitter... The refractive index of the second beam splitter is between 1.4 and 1.6; the fluorescent color wheel is rotatably disposed on the other side and has at least one phosphor layer and a reflective layer arranged sequentially around the periphery of the fluorescent color wheel; the at least one phosphor layer excites the first color light to convert it into the at least one second color light; the reflective layer reflects the first color light to the second lens portion; the homogenizing element is disposed between the excitation light source and the beam combining unit; the homogenizing element has a lens array formed on its optical surface facing one of the excitation light source and the beam combining unit to homogenize and superimpose the first color light; the filter color wheel is used to receive the combined beam to generate multiple projected color lights; and the second condensing lens is disposed between the filter color wheel and the beam combining unit to focus the combined beam to be incident on the filter color wheel; Alternatively, the light combining unit includes a reflector and a beam splitter, the wavelength conversion unit is a phosphor color wheel, and the light combining module also includes a homogenizing element, a filter color wheel, and a second condensing lens; the reflector is tilted opposite to the second lens portion, the beam splitter is tilted between the reflector and the first condensing lens, the beam splitting surface is formed on the surface of the beam splitter facing the first condensing lens, and the reflective surface is formed on the surface of the reflector facing the beam splitter; the phosphor color wheel is rotatably disposed on the other side and has at least one phosphor layer and a reflective layer sequentially arranged around the phosphor color wheel. Peripherally, the at least one phosphor layer excites the first color light to convert it into the at least one second color light, and the reflective layer reflects the first color light to the second lens portion; the light homogenizing element is disposed between the excitation light source and the light combining unit, and the light homogenizing element has a lens array formed on the optical surface facing one of the excitation light source and the light combining unit to homogenize and superimpose the first color light; the color filter wheel is used to receive the combined light beam to generate multiple projected color lights, and the second condensing lens is disposed between the color filter wheel and the light combining unit to focus the combined light beam to be incident on the color filter wheel.

11. A projection device, characterized in that, include: The light combining module as described in any one of claims 1 to 10 provides a light combining beam; as well as The projection device receives and projects the combined light beam.

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