Projection light source

Abstract

A projection light source, comprising a laser light source (1), a wide-spectrum light source (2), and a light combining assembly. The laser light source (1) comprises laser sub-units of several colors. Light emitted from the laser light source (1) is combined with light emitted from the wide-spectrum light source (2) by means of the light combining assembly to to form a combined light beam for emission. The projection light source combines the advantages of the two light source types and has high brightness, a wide color gamut, and effective suppression of speckles.

Description

A projection light source Technical Field

[0001] The present invention relates to the technical field of projection systems, and in particular to a projection light source. Background Art

[0002] Projection light sources are a crucial component of projection systems. Traditional projection light sources include lasers, laser-excited phosphors, and broadband light sources. Lasers offer high brightness and a wide color gamut, but lasers have strong coherence and exhibit speckle, which affects projected image quality. Broadband light sources struggle to achieve high brightness and a wide color gamut, resulting in poor image quality and potentially larger projection systems. Existing projection light sources struggle to meet the increasing demand for projected image quality, impacting the viewing experience.

[0003] Summary of the Invention

[0004] The technical problem to be solved and the technical task proposed by the present invention are to improve the existing technology and provide a projection light source to solve the problem that the single type of projection light source in the current technology has defects and affects the quality of the projection picture.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A projection light source includes a laser light source, a broadband light source, and a light combining component. The laser light source includes laser subunits of several colors. A diffusion device and a first compound eye lens element are provided on the output light path of the laser light source. The light emitted by the laser light source is then combined with the light emitted by the broadband light source through the light combining component to form a combined light beam for output. A second compound eye lens element is provided on the output light path of the combined light beam. An optical component is provided on the light path from the first compound eye lens element to the second compound eye lens element so that the compound eye unit of the first compound eye lens element is imaged on the incident surface of the second compound eye lens element. The projection light source described in the present invention adopts a hybrid structure. The light emitted by the laser light source is diffused and homogenized before being combined with the light emitted by the broadband light source to ensure the uniformity and sufficiency of the combined light. It can effectively improve the brightness and color gamut of the combined light beam, effectively suppress speckle, and improve the quality of the projected image. It has a compact structure, occupies a small volume, and has good overall performance. Moreover, the optical component is equivalent to a simple imaging system. The position of the first fly-eye lens element is the object image position point. The first fly-eye lens element performs light homogenization on the laser, so that the light emitted by the laser light source is effectively homogenized and then combined with the light emitted by the wide-spectrum light source. The fly-eye unit of the first fly-eye lens element is imaged on the incident surface of the second fly-eye lens element through the optical component. The first fly-eye lens element cooperates with the second fly-eye lens element so that the second fly-eye lens element can effectively perform light homogenization on the combined light beam, so that the combined light beam can be better shaped and homogenized and imaged onto the light modulator, thereby improving the quality of the projection picture.

[0007] Furthermore, the color of the broadband light source is the same as the color of at least one of the laser sub-units, which effectively reduces the speckle caused by the narrow-bandwidth colored light emitted by the laser sub-unit and improves the light output quality.

[0008] Furthermore, the temporal proportion of the light from the wide-spectrum light source in the combined light beam is the same as the temporal proportion of the light from the laser sub-units of the same color in the combined light beam, which improves the brightness while also better eliminating speckles, thereby improving image quality.

[0009] Furthermore, at least two different colored laser subunits are integrated and packaged into a single structure to form a mixed-color component, and at least one other color laser subunit is separately packaged to form a monochromatic component. The light from the monochromatic component is combined with the light from the mixed-color component to form a combined laser beam, which is then combined with the light from the broad-spectrum light source. The light emitted by the laser subunits in the mixed-color component propagates along the same optical path, that is, the at least two different colored lasers propagate along the same optical path from the moment they are emitted. This can reduce the number of lenses used for light combining, improve the compactness of the structure, and reduce the occupied volume. The corresponding laser subunits of the color light that accounts for a larger proportion in the combined light beam are separately formed into monochromatic components, ensuring that the proportion of each color light can accurately meet the light combining requirements.

[0010] Furthermore, the diffusion device includes a static diffusion element disposed in the light path of the mixed-color component and / or the monochromatic component. The static diffusion element diffuses the light emitted by the mixed-color component and / or the monochromatic component, thereby ensuring that the spot size of the light emitted by the mixed-color component is substantially consistent with the spot size of the light emitted by the monochromatic component. This allows for more uniform light combination of the various colors of laser light, and further ensures that the energy distribution of the laser light spots of various colors is uniform when the laser light of various colors is irradiated on the first compound-eye lens element. In other words, the number of compound-eye units covered by the laser light of various colors remains substantially consistent, thereby improving the uniformity of the light uniformity of the various colors of laser light by the first compound-eye lens element and facilitating the correction of aberrations of the various colors of laser light.

[0011] Furthermore, the diffusion device includes a dynamic diffusion element arranged on the outgoing light path of the combined laser beam, which performs dynamic diffusion processing on the combined laser beam, better destroys the phase coherence of the laser beam, improves the speckle elimination effect, and thus improves the projection image effect.

[0012] Furthermore, the polarization states of the light emitted by the different colored laser subunits in the mixed-color assembly are consistent and different from the polarization states of the light emitted by the laser subunits in the monochromatic assembly. This prevents interference between the light emitted by the mixed-color assembly and the light emitted by the monochromatic assembly, effectively suppressing speckle.

[0013] Furthermore, the compound-eye unit of the first compound-eye lens element is a regular polygon with three or more sides, and the compound-eye unit of the second compound-eye lens element is a rectangle. The light emitted by the laser light source forms a larger spot after being diffused by the diffuser. The compound-eye unit, which is a regular polygon with three or more sides, can better homogenize the laser light and better correct the homogenization of the edges of the object image, so that the light emitted by the laser light source can be more evenly combined with the light emitted by the broadband light source, improving the light output quality. The second compound-eye lens element is used to better shape and homogenize the combined light beam and image it onto the light modulator, thereby improving the quality of the projected image.

[0014] Furthermore, the optical assembly includes at least one lens. The structure is simple, easy to implement, and takes up little space. The optical assembly forms a simple imaging system so that the compound eye unit of the first compound eye lens element serves as an object and is imaged on the incident surface of the second compound eye lens element.

[0015] Furthermore, the spectral band of the broadband light source includes at least the spectral band of one of the laser sub-units, and the light combining component includes a light combining element 1, which reflects light with a wavelength in the light combining band 1 and transmits light with a wavelength in the light combining band 2, or transmits light with a wavelength in the light combining band 1 and reflects light with a wavelength in the light combining band 2. The light combining band 1 covers the spectral bands of all laser sub-units, and the light combining band 2 covers a portion of the spectral band of the broadband light source. The light from the laser light source and the light from the broadband light source are emitted from the light combining element together for light combining. The structure is simple, easy to implement, and occupies a small volume, which is conducive to improving the compactness of the projection system.

[0016] Furthermore, the range endpoint of the second combined light band approaches the spectral band of the laser sub-unit, reducing the loss of light emitted by the wide-spectrum light source during light combination, so that as much light emitted by the wide-spectrum light source as possible is combined into the combined light beam, thereby improving the utilization rate of the wide-spectrum light source and the overall output brightness of the combined light beam.

[0017] Furthermore, the difference between the end point of the combined light band 2 and the spectral band of the laser sub-unit is in the range of 2 to 20 nm.

[0018] Furthermore, the diffusion device and the light-combining component are integrated into a combined element. One surface of the combined element is a diffusion layer, and the other surface is a coating layer. Light from the laser light source is incident at an angle from one side of the diffusion layer and is transmitted through the coating layer. Light from the broadband light source is incident at an angle from one side of the coating layer and is reflected or partially reflected by the coating layer to combine with the light from the laser light source. The combined element moves dynamically to dynamically diffuse the light from the laser light source. The combined element integrates the functions of diffusion and light combining. After the light from the laser light source is diffused by the diffusion layer, it is immediately combined with the light from the broadband light source at the coating layer. This makes the structure more compact and occupies less space, which helps to reduce the overall volume of the projection system.

[0019] Furthermore, the invention further includes a first lens and a second lens eccentrically disposed on the output light path of the second fly-eye lens element. The first lens and the second lens are respectively tilted relative to the optical axis, with the tilt direction of the first lens relative to the optical axis being opposite to the tilt direction of the second lens relative to the optical axis. The first lens and the second lens are used to bias and guide the optical path of the combined light beam, so that the combined light beam can be more accurately emitted to the light modulator as required. The combined light beam, serving as illumination light, is modulated by the light modulator to form image light, which is then projected from the lens to form a projection image.

[0020] Furthermore, the first lens and / or the second lens can be moved or rotated in a plane perpendicular to the optical axis to adjust the color edge. Taking the assembly tolerance into consideration, the color edge can be adjusted in the structural design. The adjustable structure also reduces the difficulty of assembly.

[0021] Furthermore, it also includes a polarization conversion element 1 set on the outgoing light path of the combined light beam, and the polarization conversion element 1 phase shifts part of the combined light beam to better eliminate phase coherence and thus more effectively suppress speckle.

[0022] Furthermore, the first polarization conversion element includes a polarization conversion region for phase shifting light, and also includes a non-polarization region. The non-polarization region includes at least one of a light-transmitting region and a diffusion region, and the polarization conversion region and the non-polarization region are arranged separately. This structure is simple and compact, with a high degree of integration. While partially phase shifting the combined light beam, the remaining portion of the combined light beam passes directly or can also be diffused.

[0023] Furthermore, the polarization conversion zone is a half-wave plate, which has a simple structure, is easy to use, and has low cost. The light emitted by the laser light source is linearly polarized light. After passing through the polarization conversion element, the polarization angle of the linearly polarized light changes, which better eliminates phase coherence and improves the speckle elimination effect.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The projection light source of the present invention adopts a hybrid structure, taking into account the advantages of two types of light sources, with high brightness and wide color gamut, effectively suppressing speckle, improving the quality of the projected image, compact structure, small footprint, and good overall performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a schematic structural diagram of a projection light source according to the present invention;

[0027] FIG2 is a schematic diagram of a top view of the structure of a laser light source of the present invention;

[0028] FIG3 is a schematic structural diagram of another projection light source of the present invention;

[0029] FIG4 is a schematic structural diagram of another projection light source of the present invention;

[0030] FIG5 is a schematic structural diagram of another projection light source of the present invention;

[0031] FIG6 is a schematic diagram of a top view of another laser light source of the present invention;

[0032] FIG7 is a schematic structural diagram of another projection light source of the present invention;

[0033] FIG8 is a schematic diagram of the spectral characteristics of the light combining element 1;

[0034] FIG9 is a schematic structural diagram of a polarization conversion element 1;

[0035] FIG10 is another schematic structural diagram of a polarization conversion element 1;

[0036] FIG11 is another structural schematic diagram of a polarization conversion element 1;

[0037] FIG12 is another structural schematic diagram of the polarization conversion element 1.

[0038] In the figure: laser light source 1, mixed color component 11, monochromatic component 12, broadband light source 2, first fly-eye lens element 3, static diffusion element 41, dynamic diffusion element 42, light combining element 1 5, combination element 6, diffusion layer 61, coating layer 62, second fly-eye lens element 7, lens 1 81, lens 2 82, prism 9, DMD 10, polarization conversion element 1 20, polarization conversion zone 201, non-polarization zone 202, polarization conversion element 2 21, lens element 1 101, lens element 2 102. DETAILED DESCRIPTION

[0039] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] A projection light source disclosed in an embodiment of the present invention adopts a hybrid light source to achieve high brightness and high color gamut, and effectively solve the speckle problem. It has low cost, small size, good overall performance, and effectively improves the quality of the projected image.

[0041] Example 1

[0042] As shown in Figures 1 and 2, a projection light source mainly includes a laser light source 1, a broadband light source 2 and a light combining component. The laser light source 1 includes laser sub-units of several colors. A diffusion device and a first compound eye lens element 3 are provided on the output light path of the laser light source 1. The compound eye unit of the first compound eye lens element is a regular polygon. The light emitted by the laser light source 1 is first diffused by the diffusion device to effectively eliminate the phase coherence of the laser beam, thereby effectively improving the effect of eliminating speckle. The light emitted by the laser light source 1 is also homogenized by the first compound eye lens element 3 to improve the uniformity of the light spot formed by the laser light source 1, which is conducive to more uniform light combining, improving the light output quality, and thus improving the quality of the projection picture. The light emitted by the laser light source 1 can be diffused first and then homogenized, or can be homogenized first and then diffused. After diffusion and homogenization, the light emitted by the laser light source 1 is combined with the light emitted by the broadband light source 2 through the light combining component. The combined light beam is emitted. The broad-spectrum light source 2 can specifically be an LED light source. The light-emitting chip emits excitation light to illuminate the fluorescent layer to obtain broad-spectrum light. The spectrum of the light emitted by the broad-spectrum light source 2 is wide and the divergence angle and spot size are large. The light emitted by the broad-spectrum light source 2 will not have serious speckle. The light emitted by the broad-spectrum light source 2 does not need to be diffused. Therefore, the light emitted by the laser light source 1 is diffused and homogenized and then combined with the light emitted by the broad-spectrum light source 2 through the light combining component to obtain a combined light beam, thereby ensuring the uniformity and sufficiency of the combined light, effectively improving the brightness and color gamut of the combined light beam, effectively suppressing speckle, and improving the quality of the projection picture. A second fly-eye lens element 7 is provided on the output light path of the combined light beam. The fly-eye unit of the second fly-eye lens element 7 is rectangular. The second fly-eye lens element 7 is used to further perform homogenization on the combined light beam. The homogenized combined light beam is then emitted to the light modulator to be modulated into an image beam. Finally, the image beam is projected through the lens to form a projection picture.

[0043] As shown in FIG2 , at least two different colored laser subunits are integrated and packaged into a single structure to form a mixed-color component 11, and at least one other colored laser subunit is separately packaged to form a monochromatic component 12. This means that the color of the laser light emitted by monochromatic component 12 is different from the color of the laser light emitted by mixed-color component 11. The light from monochromatic component 12 is combined with the light from mixed-color component 11 to form a combined laser beam, which is then combined with the light from broadband light source 2. Specifically, mixed-color component 11 is integrated from two different colored laser subunits, specifically a blue laser subunit and a green laser subunit, while monochromatic component 12 is specifically composed of a red laser subunit. The blue laser subunit and the green laser subunit are arranged side by side, and the light emitted by the blue laser subunit and the green laser subunit propagates along the same optical path, which can reduce the number of lenses used for light combination, improve the compactness of the structure, and reduce the occupied volume. There are specifically three green laser subunits, and three collimating lenses are used to collimate the light output of each green laser subunit respectively. There are specifically two blue laser subunits, and two collimating lenses are used to collimate the light output of each blue laser subunit respectively. The blue laser subunit and the green laser subunit are packaged on the same structure to emit light in the same direction, so that the light emitted by the mixed color component 11 contains green and blue. The green laser subunit and the green laser subunit are smaller chips. Since the green laser subunit and the green laser subunit are arranged side by side, to a certain extent, the two colors of laser are mixed to form combined light at the beginning of light emission, that is, the light emitted by the mixed color component 11 is a mixture of green laser and blue laser, which can reduce the number of lenses used for light combination, improve the compactness of the structure, and reduce the occupied volume. The eight red laser subunits in the monochromatic component 12 are arranged side by side, and the light emitted by the eight red laser subunits is collimated by four collimating lenses. More preferably, as shown in FIG2 , the mixed-color component 11 and the monochromatic component 12 are arranged side by side to form an integrated laser light source 1. This structure is compact and easy to arrange. The light emitted by the mixed-color component 11 and the monochromatic component 12 is emitted in the same direction, and there is a certain distance between the mixed-color component 11 and the monochromatic component 12. Therefore, the light beams emitted by the two components are parallel to each other and have a certain distance between them. The light beams emitted by the two components cannot be directly combined, and light combining processing is required. Specifically, as shown in Figure 2, the light emitted by the mixed color component 11 is guided to the dichroic mirror through the reflector, and the light emitted by the monochromatic component 12 is emitted to the dichroic mirror. The light emitted by the mixed color component 11 and the light emitted by the monochromatic component 12 are combined by the dichroic mirror. The dichroic mirror reflects the light emitted by the mixed color component 11 and transmits the light emitted by the monochromatic component 12. That is, the dichroic mirror reflects green light and blue light and transmits red light. More specifically, the spectrum of the dichroic mirror is set to reflect light of 465nm and 525nm, and transmit light greater than 630nm.Of course, the light combining method can also be changed to other methods. For example, the light emitted by the mixed color component 11 is emitted to the dichroic mirror, and the light emitted by the monochromatic component 12 is guided to the dichroic mirror through the reflector. The light emitted by the mixed color component 11 and the light emitted by the monochromatic component 12 are also combined by the dichroic mirror. At this time, the dichroic mirror transmits the light emitted by the mixed color component 11 and reflects the light emitted by the monochromatic component 12, that is, the dichroic mirror transmits green light and blue light and reflects red light.

[0044] The light emitted by the laser subunit of the laser light source 1 is usually linearly polarized light. Specifically, the polarization state of the light emitted by the blue laser subunit and the green laser subunit in the mixed color component 11 is consistent and is in the P state, and the light emitted by the red laser subunit in the monochromatic component 12 is in the S state, which is opposite to the polarization state of the former. Therefore, the light emitted by the mixed color component 11 and the light emitted by the monochromatic component 12 will not interfere with each other, effectively suppressing the speckle phenomenon.

[0045] Furthermore, the number of blue laser subunits and the number of green laser subunits differ from the number of red laser subunits, resulting in different sizes of the blue, green, and red light spots. When the light emitted by the mixed-color component 11 is directly combined with the light emitted by the monochromatic component 12, the combined light uniformity is poor, affecting the output light quality. Preferably, the diffusion device includes a static diffusion element 41 disposed in the output light path of the mixed-color component 11. The static diffusion element 41 diffuses the light emitted by the mixed-color component 11, dissipating speckle while expanding the light emitted by the mixed-color component 11. This ensures that the blue and green light spots formed by the mixed-color component 11 are substantially the same size as the red light spot, improving combined light uniformity. Furthermore, the number of fly-eye units covered by the blue, green, and red light spots on the first fly-eye lens element 3 is substantially consistent. This ensures that the energy distribution of the three colors of laser light is uniform when irradiated on the first fly-eye lens element 3, enabling better light homogenization and more advantageously correcting aberrations of the various colors of light. The diffusion angle of the static diffusion element 41 can be one of Gaussian 1°, 2°, 2.5° and 3° to ensure the diffusion effect.

[0046] Furthermore, the diffusion device includes a dynamic diffusion element 42 disposed in the outgoing optical path of the combined laser beam. Specifically, the dynamic diffusion element 42 is used to dynamically diffuse the combined laser beam. The diffusion angle of the dynamic diffusion element 42 includes one of Gaussian 1.5°, 2°, and 2.5°. The dynamic diffusion element 42 further enhances refraction, reflection, and scattering, further disrupting the phase coherence of the laser beam, improving speckle reduction, and thereby enhancing the projection image quality. The dynamic diffusion element 42 can perform diffusion processing by rotating, linearly reciprocating, or vibrating, and can be specifically configured as needed. Preferably, the dynamic diffusion element 42 is combined with the static diffusion element 41, that is, a combination of dynamic and static diffusion processing, to further eliminate phase coherence and improve speckle reduction.

[0047] Preferably, an optical component is provided on the optical path from the first fly-eye lens element 3 to the second fly-eye lens element 7. The optical component is equivalent to a simple imaging system, so that the fly-eye unit of the first fly-eye lens element 3 is imaged on the incident surface of the second fly-eye lens element 7 as an object. The position of the first fly-eye lens element 3 is the object-image position point. The light is homogenized by the first fly-eye lens element 3 and then imaged on the second fly-eye lens element 7 through the optical component. The light is further homogenized by the second fly-eye lens element 7 and then emitted to the light modulator to be modulated into an image beam. A simple imaging system is also formed between the second fly-eye lens element 7 and the light modulator. The fly-eye unit of the second fly-eye lens element 7 is imaged on the surface of the light modulator as an object, so that the combined light beam is better shaped and homogenized and imaged on the light modulator. In this embodiment, the compound-eye unit of the first compound-eye lens element 3 is a regular hexagon, and of course it can also be a regular polygon with other numbers of sides. The hexagonal compound-eye unit presents a hexagonal image of the incident light spot. It is difficult to ensure the effect of eliminating speckle by relying solely on the diffuser. The first compound-eye lens element 3 is used to homogenize the laser. The light spot formed after the light emitted by the laser light source 1 is diffused by the diffuser is larger. The regular polygonal compound-eye unit can better homogenize the laser. The first compound-eye lens element 3 is the object image position point. The hexagonal field of view setting inscribed in the spot size can better perform homogenization correction on the edge of the object image. The distance from the center of the spot to the edge is as uniform as possible to avoid affecting the imaging quality of the second compound-eye lens element 7 to the light modulation device, including distortion, chromatic aberration, uniformity, etc. Furthermore, the compound-eye unit of the second fly-eye lens element 7 is rectangular, and the second fly-eye lens element 7 is used to further homogenize the combined light beam, improving the uniformity of the combined light beam, so that the combined light beam can be evenly illuminated on the light modulator, thereby ensuring that the modulated image light is uniform and improving the quality of the projected image. In this embodiment, the compound-eye unit of the second fly-eye lens element 7 is rectangular to better match the light modulator, which is typically a rectangular DMD or LCD panel, so as to better shape and homogenize the combined light beam and image it on the light modulator. As shown in Figure 1, the optics include a lens element, namely lens element 101. Lens element 101 is located on the outgoing light path of the first fly-eye lens element 3, and lens element 101 is located on the incident light path of the light combining component. That is, only the light from the laser light source 1 passes through lens element 101, while the light from the broadband light source 2 does not pass through lens element 101. The light from the laser light source 1 is homogenized by the first fly-eye lens element 3 and then collimated and focused by lens element 101. Then, the light from the laser light source 1 and the light from the broadband light source 2 are combined by the light combining component to obtain a combined light beam, which is finally homogenized by the second fly-eye lens element 7.

[0048] In this embodiment, the light emitted by the broadband light source 2 is specifically green, that is, the color of the broadband light source 2 is the same as the color of the green laser sub-unit, but the spectral range of the light emitted by the broadband light source 2 is a broadband that is larger than the spectral range of the green laser sub-unit. The broadband light source 2 can compensate and increase the proportion of green light in the combined light beam, so that the green light meets the light combining requirements, can better improve the brightness of the combined light beam, effectively reduce the speckle caused by a simple laser, and improve the projection image effect. Furthermore, the temporal proportion of the light of the broadband light source 2 in the combined light beam is the same as the temporal proportion of the light of the same color laser sub-unit in the combined light beam, which not only improves the brightness of the light output, but also helps to improve the image quality.

[0049] In this embodiment, the light-combining component mainly includes a light-combining element 5, which can specifically be a dichroic mirror. The spectral band of the broadband light source 2 includes at least the spectral band of one of the laser sub-units. The light-combining element 5 reflects light with a wavelength in the light-combining band 1 and transmits light with a wavelength in the light-combining band 2, or the light-combining element 5 transmits light with a wavelength in the light-combining band 1 and reflects light with a wavelength in the light-combining band 2. The light-combining band 1 covers the spectral bands of all laser sub-units, and the light-combining band 2 covers a part of the spectral band of the broadband light source 2. Thus, the light from the laser light source 1 and the light from the broadband light source 2 are emitted in the same direction from the light-combining element 5 for light combining. Specifically, the light emitted by the laser light source 1 is incident on the light combining element 5 at an angle and then transmitted out from the light combining element 5. The light emitted by the broadband light source 2 passes through the focusing collimating lens assembly and then is incident on the light combining element 5 at an angle from the other side. Then, the light emitted by the broadband light source 2 is reflected by the light combining element 5 and is emitted out. The light of the laser light source 1 and the light of the broadband light source 2 are emitted in the same direction for light combining. The structure is simple, easy to implement, and takes up little space.

[0050] As shown in Figure 8, in one embodiment, the light combining element 15 reflects light with a wavelength in the light combining band 1 and transmits light with a wavelength in the light combining band 2 for illustration. The light combining band 1 covers the spectral bands of the blue laser sub-unit, the green laser sub-unit and the red laser sub-unit, that is, the light combining element 15 reflects the laser light emitted by the blue laser sub-unit, the green laser sub-unit and the red laser sub-unit. The light emitted by the broadband light source 2 is green or yellow as a whole. The spectral band of the broadband light source 2 includes the spectral band of the green laser sub-unit. Since the light combining band 2 covers a part of the spectral band of the broadband light source 2, the light combining element 15 transmits a part of the light from the broadband light source 2 and reflects a part of the light from the broadband light source 2 at the same time. In other words, not all the light emitted by the broadband light source 2 can be merged into the light combining beam. A part of the light emitted by the broadband light source 2 will be lost. The specific lost part of the light emitted by the broadband light source 2 includes the band part that overlaps with the spectral band of the green laser sub-unit. In order to improve the utilization rate of the broadband light source 2, reduce the loss of the broadband light source 2 and increase the output brightness of the combined light beam, the range endpoint of the combined light band two is close to the spectral band of the green laser sub-unit, so that as much light emitted by the broadband light source 2 as possible is transmitted to be merged into the combined light beam. Preferably, the difference between the range endpoint of the combined light band two and the spectral band of the laser sub-unit is in the range of 2 to 20 nm. Specifically, as shown in FIG8 , the light combining band 1 includes a spectral band range of 450 nm to 540 nm and greater than 630 nm, which specifically includes spectral bands of 465 nm, 525 nm and 650 nm, 465 nm is the spectral band of the blue laser sub-unit, 525 nm is the spectral band of the green laser sub-unit, and 650 nm is the spectral band of the red laser sub-unit. The light combining band 2 includes a spectral band range of 550 nm to 600 nm, and the spectral band of the broadband light source 2 includes 480 nm to 610 nm, so that when light is combined by the light combining element 1 5, the broadband light source 2, only the light in the range of 550nm to 600nm of the light emitted by the wide-spectrum light source 2 is merged into the combined light beam, while the light in the 480nm to 550nm band and the 600nm to 610nm band of the light emitted by the wide-spectrum light source 2 will be lost. In order to better improve the brightness of the projection screen, it is more preferred that the range of the combined light band 2 can be set to 532nm to 620nm, so that the left range end point of the combined light band 2 is closer to the spectral band of the green laser sub-unit, and the right range end point is closer to the spectral band of the red laser sub-unit, thereby reducing the loss of the wide-spectrum light source 2 during light combining and improving the output brightness of the combined light beam.

[0051] Furthermore, the projection light source can be switched between pure laser mode and mixed light mode by controlling the on / off of the laser light source 1 and the broadband light source 2. In pure laser mode, only the laser light source 1 is working, while the broadband light source 2 is turned off.

[0052] The mixed light mode is that the laser light source 1 works, that is, the blue laser subunit, the green laser subunit and the red laser subunit in the laser light source 1 all work, and the broadband light source 2 works;

[0053] The mixed light mode can also be that the blue laser subunit and the red laser subunit in the laser light source 1 are working, while the green laser subunit is turned off, and the broadband light source 2 is working at the same time.

[0054] Example 2

[0055] As shown in Figure 3, the difference from Example 1 is that the diffusion device and the light combining component are integrated into a combination element 6, one side surface of the combination element 6 is a diffusion layer 61, and the other side surface is a coating layer 62. The light of the laser light source 1 is obliquely incident from one side of the diffusion layer 61 and transmitted out from the coating layer 62, and the light of the broadband light source 2 is obliquely incident from one side of the coating layer 62 and reflected by the coating layer 62 to be combined with the light of the laser light source 1. The combination element 6 moves dynamically to dynamically diffuse the light of the laser light source 1. For example, the combination element 6 is disc-shaped and rotates to achieve dynamic diffusion.

[0056] When using the combined element 6, there's no need for a dynamic diffusion element. The combined element 6 integrates both diffusion and light combining functions. Light from the laser light source 1, after being diffused by the diffusion layer 61, is immediately combined with the light from the broadband light source 2 at the coating layer 62. This results in a more compact structure and smaller footprint, helping to reduce the overall size of the projection system. Because the light from the broadband light source 2 is incident obliquely from the coating layer 62, it is directly reflected by the coating layer 62, preventing it from entering the diffusion layer 61. This means that the light from the broadband light source 2 is not diffused, ensuring that only the light from the laser light source 1 is diffused, and that it is only after this diffusion that the light from the laser light source 1 is combined with the light from the broadband light source 2. Alternatively, the coating layer 62 can reflect the light from the laser light source 1 while transmitting or partially transmitting the light from the broadband light source 2. In this approach, the light from the broadband light source 2 that passes through the coating layer 62 is diffused by the diffusion layer 61.

[0057] Example 3

[0058] As shown in FIG4 , this embodiment is described using the optical modulation device DMD10 as an example. The combined light beam, serving as the illumination light, is guided to the DMD10 through the prism 9. The illumination light is modulated by the DMD10 to become image light. The image light has a certain deviation angle relative to the illumination light. The image light is reflected from the DMD10 into the prism 9 and is emitted from the prism 9 to the lens for projection along an optical path different from the illumination light. In this embodiment, the combined light beam enters the prism 9, and the angle of incidence of the combined light beam at the interface in the prism 9 is greater than the critical angle. As a result, the combined light beam undergoes total internal reflection at the interface and then exits from the prism 9 to the DMD10. The image light modulated by the DMD10 has a deviation angle relative to the incident combined light beam. The image light returns to the prism 9, and the angle of incidence of the image light at the interface in the prism 9 is less than the critical angle. As a result, the image light is transmitted through the interface and is emitted from the other side of the prism 9 to the lens, and is then projected through the lens into a projection screen.

[0059] In order to facilitate the control of the angle of the combined light beam incident on the prism 9, lens one 81 and lens two 82 are eccentrically arranged on the output light path of the second compound eye lens element 7. Lens one 81 and lens two 82 are respectively inclined to the optical axis, and the inclination direction of lens one 81 relative to the optical axis is opposite to the inclination direction of lens two 82 relative to the optical axis. Lens one 81 and lens two 82 are used to deflect the light path so that the combined light beam can be precisely matched with the prism 9, ensuring the incident angle of the combined light beam incident on the DMD10 and the sharpness of the imaging, and ensuring that the combined light beam can be totally reflected at the interface in the prism 9, and the image light modulated by the DMD10 can be transmitted through the interface in the prism 9. Specifically, the tilt axis of lens 1 81 and lens 2 82 relative to the optical axis is perpendicular to the plane of the optical path, that is, the tilt axis of lens 1 81 and lens 2 82 relative to the optical axis is perpendicular to the paper direction in Figure 4. Lens 1 81 and lens 2 82 are double convex lenses with positive refractive power. The inclination angle of lens 1 81 and lens 2 82 relative to the optical axis is initially set to 0~45°, and the adjustable range is 0~20°.

[0060] Furthermore, lens 1 81 and / or lens 2 82 are movable or rotatable in a plane perpendicular to the optical axis, allowing for adjustable color fringing in the structural design to account for assembly tolerances. Taking lens 1 81 as an example, lens 1 81 is movable and adjustable in two mutually perpendicular directions in a plane perpendicular to the optical axis. Specifically, lens 1 81 is movable and adjustable in the x-direction shown in FIG4 , with an adjustment range of approximately ±0.34 mm, thereby adjusting the upper and lower color fringing of the projected image. Lens 1 81 is movable and adjustable in the z-direction shown in FIG4 , with an adjustment range of approximately ±0.3 mm, thereby adjusting the left and right color fringing of the projected image. This allows for flexible adaptation to meet needs and improves projected image quality.

[0061] Furthermore, in this embodiment, the optics include two lens elements, namely lens element 1 101 and lens element 2 102. Lens element 101 is located on the outgoing light path of the first fly-eye lens element 3 and on the incident light path of the light-combining element 1, while lens element 2 102 is located between the light-combining element 1 and the second fly-eye lens element 7. Only the light from the laser light source 1 passes through lens element 1 101, while the light from the broadband light source 2 does not pass through lens element 1 101. The combined light beam passes through lens element 2 102 and then is emitted to the second fly-eye lens element 7. Lens element 1 101 plays a collimating role, and lens element 2 102 plays a focusing role, so that the fly-eye unit of the first fly-eye lens element 3 is imaged as an object on the incident surface of the second fly-eye lens element 7, thereby ensuring the imaging of the second fly-eye lens element 7 to the DMD 10. The elements between the second fly-eye lens element 7 and the DMD 10 also form a simple imaging system, so that the fly-eye unit of the second fly-eye lens element 7 is imaged as an object on the surface of the optical modulator, so that the combined light beam is better shaped and homogenized and imaged on the DMD 10.

[0062] Example 4

[0063] As shown in Figure 5, the difference from Example 1 is that the projection light source also includes a polarization conversion element 20 arranged on the outgoing light path of the combined light beam, and the polarization conversion element 20 performs phase shift on part of the combined light beam. Specifically, the polarization conversion element 20 can adopt a half-wave plate, and the polarization conversion element 20 only performs phase shift on half of the combined light beam, that is, only half of the combined light beam is blocked by the polarization conversion element 20, so that only half of the combined light beam passes through the polarization conversion element 20 for phase shift, and the other half of the combined light beam is not phase shifted to directly propagate along the light path. The light emitted by each laser sub-unit is linearly polarized light, and the half-wave plate changes the polarization direction of the linearly polarized light, specifically converting P light into S light, or converting S light into P light, so as to better eliminate phase coherence, effectively suppress speckle, and do not affect the light efficiency benefit of the wide-spectrum light source 2.

[0064] Furthermore, the polarization conversion element 20 includes a polarization conversion zone 201 and a non-polarization zone 202. The polarization conversion zone 201 is used to phase shift the light. The polarization conversion zone 201 is specifically a half-wave plate. The non-polarization zone 202 includes at least one of a light-transmitting zone and a diffusion zone. The polarization conversion zone 201 and the non-polarization zone 202 are arranged in partitions. Specifically, as shown in FIG9 , the polarization conversion area 201 and the non-polarization area 202 are distributed on the left and right, and half of the light spot formed by the combined light beam is irradiated on the polarization conversion area 201, and the other half is irradiated on the non-polarization area 202. The non-polarization area 202 can be entirely a light-transmitting area, and the light-transmitting area can be composed of a light-transmitting sheet (such as glass, etc.), or can be a directly vacant area without any obstruction (for the polarization conversion element 20 shown in FIG9 , the polarization conversion element 20 as a whole can be a half-wave plate, which constitutes the polarization conversion area 201, and the light-transmitting area is a virtually defined area, and half of the light spot is irradiated on the half-wave plate to constitute "half of the light spot is irradiated on the polarization conversion area 201" , the other half is irradiated on the non-polarization zone 202″). The non-polarization zone 202 may be entirely a diffusion zone, and the diffusion zone is used to further diffuse the combined light beam. The non-polarization zone 202 may also be composed of a light-transmitting zone and a diffusion zone. As shown in FIG10 , the polarization conversion zone 201 and the non-polarization zone 202 are distributed in a grid pattern, which can more evenly phase shift a portion of the combined light beam and better suppress speckle. As shown in FIG11 and FIG12 , the polarization conversion zone 201 and the non-polarization zone 202 may also be distributed alternately in concentric rings or along a circumference, which can also effectively phase shift only a portion of the combined light beam, eliminate phase coherence, and effectively suppress speckle.

[0065] To address the poor speckle effect of a monochromatic field, as shown in FIG6 , a second polarization conversion element 21 can be added to the outgoing light path of the laser main unit of the corresponding color of the laser light source 1. The second polarization conversion element 21 is specifically a half-wave plate. The light emitted by the laser main unit is linearly polarized light. After passing through the second polarization conversion element 21, the polarization direction of the linearly polarized light changes, which can better eliminate speckle in the monochromatic field.

[0066] As shown in FIG7 , no static diffusion element is provided on the outgoing light paths of the mixed color component 11 and the monochromatic component 12. The light emitted by the mixed color component 11 and the light emitted by the monochromatic component 12 are combined to obtain a combined laser beam. A dynamic diffusion element 42 is provided on the outgoing light path of the combined laser beam to perform dynamic diffusion processing on the combined laser beam. The combined laser beam is then homogenized by the first fly-eye lens element 3. After the dynamic diffusion processing and homogenization processing, the combined laser beam is combined with the light emitted by the broadband light source 2 by the light combining element 1-5. The light combining element 1-5 is specifically a dichroic mirror. The light combining element 1-5 may transmit the light of the laser light source 1 and reflect the light of the broadband light source 2 to combine the light. Alternatively, the light combining element 1-5 may reflect the light of the laser light source 1 and transmit the light of the broadband light source 2 to combine the light. The combined light beam is then emitted to the polarization conversion element 1-20. The polarization conversion element 1-20 only performs phase shift on half of the combined light beam. That is, the polarization conversion element 1-20 only causes the polarization state of half of the combined light beam to be converted, thereby effectively eliminating phase coherence and improving the effect of eliminating speckle.

[0067] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. Persons skilled in the art will appreciate that improvements and modifications may be made without departing from the spirit and scope of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A projection light source, characterized in that: It includes a laser light source, a wide-spectrum light source and a light combining component, wherein the laser light source includes laser sub-units of several colors, a diffusion device and a first compound eye lens element are arranged on the output light path of the laser light source, the light emitted by the laser light source is then combined with the light emitted by the wide-spectrum light source through the light combining component to form a combined light beam for output, a second compound eye lens element is arranged on the output light path of the combined light beam, and an optical component is arranged on the light path from the first compound eye lens element to the second compound eye lens element, so that the compound eye unit of the first compound eye lens element is imaged on the incident surface of the second compound eye lens element.

2. The projection light source according to claim 1, characterized in that: The color of the broad spectrum light source is the same as the color of at least one of the laser sub-units.

3. The projection light source according to claim 1, characterized in that: The time-sequential proportion of the light from the wide-spectrum light source in the combined light beam is the same as the time-sequential proportion of the light from the laser sub-units of the same color in the combined light beam.

4. The projection light source according to claim 1, characterized in that: At least two laser subunits of different colors are integrated and packaged in one structure to form a mixed color component, and at least another laser subunit of another color is separately packaged to form a monochromatic component. The light of the monochromatic component and the light of the mixed color component are combined into a combined laser beam, which is then combined with the light of the wide-spectrum light source.

5. The projection light source according to claim 4, characterized in that: The diffusion device comprises a static diffusion element arranged on the outgoing light path of the mixed color component and / or the single color component.

6. The projection light source according to claim 4, characterized in that: The diffusion device comprises a dynamic diffusion element arranged on the outgoing optical path of the combined laser beam.

7. The projection light source according to claim 4, characterized in that: The polarization states of the lights emitted by the laser sub-units of different colors in the mixed color component are consistent and different from the polarization states of the lights emitted by the laser sub-units in the monochromatic component.

8. The projection light source according to claim 1, characterized in that: The compound eye unit of the first compound eye lens element is a regular polygon with three sides or more, and the compound eye unit of the second compound eye lens element is a rectangle.

9. The projection light source according to claim 1, characterized in that: The optical assembly includes at least one lens element.

10. The projection light source according to claim 1, characterized in that: The spectral band of the broadband light source at least includes the spectral band of one of the laser sub-units, and the light combining component includes a light combining element 1, which reflects light with a wavelength in the light combining band 1 and transmits light with a wavelength in the light combining band 2, or transmits light with a wavelength in the light combining band 1 and reflects light with a wavelength in the light combining band 2. The light combining band 1 covers the spectral bands of all the laser sub-units, and the light combining band 2 covers a part of the spectral band of the broadband light source.

11. The projection light source according to claim 10, characterized in that: The end point of the range of the second combined light band is close to the spectral band of the laser sub-unit.

12. The projection light source according to claim 10, characterized in that: The difference between the end point of the combined light band 2 and the spectrum band of the laser sub-unit is in the range of 2 to 20 nm.

13. The projection light source according to claim 1, characterized in that: The diffusion device and the light combining component are integrated into a combined element, one surface of the combined element is a diffusion layer, and the other surface is a coating layer. The light of the laser light source is obliquely incident from one side of the diffusion layer and transmitted from the coating layer, and the light of the wide-spectrum light source is obliquely incident from one side of the coating layer and is reflected or partially reflected by the coating layer to combine with the light of the laser light source. The combined element moves dynamically to dynamically diffuse the light of the laser light source.

14. The projection light source according to claim 1, characterized in that: It also includes lens 1 and lens 2 which are eccentrically arranged on the output light path of the second compound eye lens element. Lens 1 and lens 2 are respectively inclined to the optical axis. The inclination direction of lens 1 relative to the optical axis is opposite to the inclination direction of lens 2 relative to the optical axis.

15. The projection light source according to claim 14, characterized in that: The first lens and / or the second lens can be moved or rotated in a plane perpendicular to the optical axis.

16. The projection light source according to claim 1, characterized in that: It also includes a polarization conversion element 1 arranged on the outgoing light path of the combined light beam, and the polarization conversion element 1 performs phase shift on part of the combined light beam.

17. The projection light source according to claim 16, characterized in that: The polarization conversion element 1 includes a polarization conversion zone for phase shifting of light, and the polarization conversion element 1 also includes a non-polarization zone, the non-polarization zone includes at least one of a light-transmitting zone and a diffusion zone, and the polarization conversion zone and the non-polarization zone are arranged separately.

18. The projection light source according to claim 17, characterized in that: The polarization conversion region is a half-wave plate.

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