Projection light source

Abstract

The invention relates to the technical field of projection systems, in particular to a projection light source which comprises a laser light source, a wide-spectrum light source and a light combining assembly, the laser light source comprises laser subunits of multiple colors, and light emitted by the laser light source is combined with light emitted by the wide-spectrum light source through the light combining assembly to form a combined light beam to be emitted. The projection light source adopts a hybrid structure, integrates the advantages of two light source types, and is high in brightness, high in color gamut, compact in structure, small in occupied volume and good in comprehensive performance, speckles are effectively inhibited, and the quality of projection pictures is improved.

Description

Technical Field

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

[0002] The projection light source is a crucial component of a projection system. Traditional projection light sources include laser light sources, laser-excited phosphor light sources, and broadband light sources. Laser light sources offer high brightness and a wide color gamut, but their strong coherence leads to speckle problems, affecting the quality of the projected image. Broadband light sources, on the other hand, struggle to achieve high brightness and a wide color gamut, also resulting in subpar image quality and potentially larger projection system sizes. Existing projection light sources are insufficient to meet the ever-increasing demands for projected image quality, impacting the viewing experience. Summary of the Invention

[0003] The technical problem to be solved and the technical task proposed by this invention is 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 that affect the quality of the projected image.

[0004] To solve the above technical problems, the technical solution of the present invention is as follows:

[0005] A projection light source includes a laser light source, a broadband light source, and a beam combining component. The laser light source includes laser sub-units of several colors. A diffusion device and a first compound eye lens element are disposed on the output light path of the laser light source. The light emitted by the laser light source is combined with the light emitted by the broadband light source by the beam combining component to form a combined beam for output. The spectral band of the broadband light source includes at least one spectral band of the laser sub-units. The beam combining component includes a beam combining element one, which reflects light with wavelength in beam combining band one and transmits light with wavelength in beam combining band two, or transmits light with wavelength in beam combining band one and reflects light with wavelength in beam combining band two. Beam combining band one covers the spectral bands of all laser sub-units, and beam combining band two covers a portion of the spectral band of the broadband light source. The projection light source described in this invention employs a hybrid structure. Light emitted from the laser source undergoes diffusion and homogenization treatment before being combined with light emitted from the broadband source. This ensures the uniformity and sufficiency of the combined light beam, effectively improving its brightness and color gamut, suppressing speckle, and enhancing the quality of the projected image. The structure is compact, occupies little space, and offers excellent overall performance. The laser light and broadband light are emitted together from the combining element for combined projection. The structure is simple, easy to implement, and occupies little space, contributing to the compactness of the projection system.

[0006] Furthermore, the color of the broadband light source is the same as the color of at least one of the laser subunits, which effectively reduces the speckle caused by the narrow bandwidth of the colored light emitted by the laser subunit and improves the light output quality.

[0007] Furthermore, the timing ratio of the broadband light source in the combined beam is the same as the timing ratio of the light from the same color laser subunit in the combined beam, which improves brightness and also better eliminates speckle, thus improving image quality.

[0008] Furthermore, at least two different colored laser subunits are integrated and packaged in a single structure to form a mixed-color component, and at least another colored laser subunit is separately packaged to form a monochromatic component. The light from the monochromatic component and the light from the mixed-color component are combined to form a combined laser beam, which is then combined with the light from a broadband light source. The light emitted by the laser subunits in the mixed-color component propagates along the same optical path, meaning that at least two different colored lasers propagate along the same optical path from the moment of emission. This reduces the number of lenses used for combining the light, improves structural compactness, and reduces the volume occupied. The color light with a larger proportion in the combined beam has its corresponding laser subunit separately configured into a monochromatic component, ensuring that the proportion of each color light can accurately meet the requirements of combining the light.

[0009] Furthermore, the diffusion device includes a static diffusion element disposed in the output light path of the color mixing component and / or the monochromatic component. By using the static diffusion element to diffuse the light output from the color mixing component and / or the monochromatic component, the size of the light spot emitted by the color mixing component and the monochromatic component can be substantially consistent. This allows for more uniform beam combining of various colors of laser light, resulting in a more uniform energy distribution of the laser spot when various colors of laser light illuminate the first compound eye lens element. In other words, the number of compound eye units covered by each color of laser light remains substantially consistent, improving the uniformity of beam combining of various colors of laser light by the first compound eye lens element and facilitating aberration correction for various colors of laser light.

[0010] Furthermore, the diffusion device includes a dynamic diffusion element disposed in the output optical path of the combined laser beam to perform dynamic diffusion processing on the combined laser beam, thereby better destroying the phase coherence of the laser, improving the speckle elimination effect, and thus improving the projection image effect.

[0011] Furthermore, the polarization states of the light emitted by the different color laser subunits in the color mixing component are consistent and different from the polarization states of the light emitted by the laser subunits in the monochromatic component. The light emitted by the color mixing component does not interfere with the light emitted by the monochromatic component, effectively suppressing speckle phenomena.

[0012] Furthermore, a second compound eye lens element is provided in the outgoing optical path of the combined beam, and an optical component is provided in the optical 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 optical component is equivalent to a simple imaging system, the position of the first compound eye lens element is the object image position point, the first compound eye lens element performs homogenization processing on the laser, so that the light emitted by the laser source is effectively homogenized and then combined with the light emitted by the broadband source, and the compound eye unit of the first compound eye lens element is imaged on the incident surface of the second compound eye lens element through the optical component. The cooperation between the first compound eye lens element and the second compound eye lens element enables the second compound eye lens element to effectively homogenize the combined beam, so that the combined beam can be better shaped and homogenized and imaged onto the light modulation device, thereby improving the quality of the projected image.

[0013] Furthermore, the compound eye unit of the first compound eye lens element is a regular polygon with three or more sides, while the compound eye unit of the second compound eye lens element is rectangular. The light spot formed after the light emitted from the laser source is diffused by the diffusion device is relatively large. The compound eye unit, with a regular polygon of three or more sides, can better homogenize the laser beam, allowing for better homogenization correction of the image edges. This enables the light emitted from the laser source to combine more evenly with the light emitted from the broadband source, improving the output light quality. The second compound eye lens element further shapes and homogenizes the combined beam onto the light modulation device, improving the quality of the projected image.

[0014] Furthermore, the optical assembly includes at least one lens. It has a simple structure, is easy to implement, occupies little space, and forms a simple imaging system so that the compound eye unit of the first compound eye lens element is imaged onto the incident surface of the second compound eye lens element.

[0015] Furthermore, the endpoint of the combined light band two is close to the spectral band of the laser subunit, which reduces the loss of light emitted by the broadband light source during the combined light, so that as much light emitted by the broadband light source as possible is combined into the combined light beam, thereby improving the utilization rate of the broadband light source and increasing the overall output brightness of the combined light beam.

[0016] Furthermore, the difference between the endpoint of the combined light band two and the spectral band of the laser subunit is in the range of 2 to 20 nm.

[0017] 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 source is incident obliquely from the diffusion layer side and transmitted through the coating layer, while light from the broadband light source is incident obliquely from the coating layer side and reflected or partially reflected by the coating layer to combine with the laser source light. The combined element dynamically moves to dynamically diffuse the laser source light. The combined element integrates the functions of diffusion and light combining. After the laser source light is diffused by the diffusion layer, it immediately combines with the broadband light source light in the coating layer. The structure is more compact, occupies less space, and helps to reduce the overall size of the projection system.

[0018] Furthermore, the system also includes two lenses, Lens 1 and Lens 2, which are eccentrically positioned in the outgoing light path of the second compound eye lens element. Lens 1 and Lens 2 are tilted relative to the optical axis, with the tilt direction of Lens 1 relative to the optical axis opposite to that of Lens 2. Lens 1 and Lens 2 are used to bias and guide the optical path of the combined beam, allowing it to be emitted more accurately onto the light modulator as needed. The combined 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 projected image.

[0019] Furthermore, lens one and / or lens two are adjustable in movement or rotation on a plane perpendicular to the optical axis. Considering assembly tolerances, the color edge is adjustable in the structural design, and the adjustable structure also reduces the difficulty of assembly.

[0020] Furthermore, it also includes a polarization conversion element 1 disposed on the outgoing optical path of the combined beam. The polarization conversion element 1 performs phase shifting on part of the combined beam to better eliminate phase coherence and thus more effectively suppress speckle.

[0021] Furthermore, the polarization conversion element includes a polarization conversion region for phase shifting of light, and also includes a non-polarization region, which includes at least one of a transmission region and a diffusion region. The polarization conversion region and the non-polarization region are arranged separately. The structure is simple and compact, with high integration. While partially shifting the phase of the combined light beam, another part of the combined light beam can pass directly or be diffused.

[0022] Furthermore, the polarization conversion region is a half-wave plate, which has a simple structure, is easy to use, and has low cost. The light emitted by the laser 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.

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] The projection light source described in this invention adopts a hybrid structure, which combines the advantages of two light source types. It has high brightness, wide color gamut, effectively suppresses speckle, improves the quality of the projected image, has a compact structure, occupies a small volume, and has good overall performance. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a projection light source according to the present invention;

[0026] Figure 2 This is a top view of the laser light source structure of the present invention;

[0027] Figure 3 This is a schematic diagram of another projection light source according to the present invention;

[0028] Figure 4 This is a schematic diagram of another projection light source according to the present invention;

[0029] Figure 5 This is a schematic diagram of another projection light source according to the present invention;

[0030] Figure 6 This is a top view of another laser light source according to the present invention;

[0031] Figure 7 This is a schematic diagram of another projection light source according to the present invention;

[0032] Figure 8 This is a schematic diagram of the spectral characteristics of optical combining element one;

[0033] Figure 9 A schematic diagram of a polarization conversion element;

[0034] Figure 10 This is a schematic diagram of another structure for polarization conversion element one;

[0035] Figure 11 This is another schematic diagram of the structure of polarization conversion element one;

[0036] Figure 12 This is another structural schematic diagram of polarization conversion element one.

[0037] In the picture:

[0038] Laser light source 1, color mixing component 11, monochromatic component 12, broadband light source 2, first compound eye lens element 3, static diffusion element 41, dynamic diffusion element 42, light combining element 1 5, combined element 6, diffusion layer 61, coating layer 62, second compound eye lens element 7, lens 1 81, lens 2 82, prism 9, DMD 10, polarization conversion element 1 20, polarization conversion region 201, non-polarization region 202, polarization conversion element 2 21, lens element 1 101, lens element 2 102. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] The projection light source disclosed in this invention adopts a hybrid light source to achieve high brightness and high color gamut, and effectively solves the speckle problem. It is low in cost, small in size, and has good overall performance, effectively improving the quality of the projected image.

[0041] Example 1

[0042] like Figure 1 and Figure 2 As shown, 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 diffuser and a first compound eye lens element 3 are arranged in the output light path of the laser light source 1. The compound eye units of the first compound eye lens element are regular polygons. The light emitted by the laser light source 1 is first diffused by the diffuser to effectively eliminate the phase coherence of the laser beam, thereby effectively improving the speckle elimination effect. 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 projected image. The light emitted by the laser light source 1 can be diffused first and then homogenized, or 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 by the light combining component to form a combined light. The beam is emitted, and the broadband light source 2 can specifically be an LED light source. The light-emitting chip emits excitation light to irradiate the phosphor layer to obtain broadband light. The light emitted by the broadband light source 2 has a wide spectrum, a large divergence angle, and a large spot size. The light emitted by the broadband light source 2 will not have severe speckle. The light emitted by the broadband light source 2 does not need to be diffused. Thus, the light emitted by the laser light source 1 is diffused and homogenized, and then combined with the light emitted by the broadband light source 2 through the light combining component to obtain a combined beam. This ensures the uniformity and sufficiency of the combined beam, effectively improves the brightness and color gamut of the combined beam, effectively suppresses speckle, and improves the quality of the projected image. A second compound eye lens element 7 is set in the output light path of the combined beam. The compound eye unit of the second compound eye lens element 7 is rectangular. The second compound eye lens element 7 is used to further homogenize the combined beam. The combined beam after homogenization 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 projected image.

[0043] like Figure 2 As shown, at least two different colored laser subunits are integrated and packaged in one structure to form a mixed-color component 11, and at least another laser subunit of a different color is separately packaged to form a monochromatic component 12. This means that the color of the laser emitted by the monochromatic component 12 is different from the color of the laser emitted by the mixed-color component 11. The light from the monochromatic component 12 and the light from the mixed-color component 11 are combined to form a combined laser beam, which is then combined with the light from the broadband light source 2. Specifically, the mixed-color component 11 is composed of two different colored laser subunits, specifically a blue laser subunit and a green laser subunit, while the monochromatic component 12 is specifically composed of a red laser subunit. The blue and green laser subunits are arranged side by side, and the light emitted by both propagates along the same optical path. This reduces the number of lenses used for light combining, improves structural compactness, and reduces the volume occupied. Specifically, there are three green laser subunits, each collimated by a collimating lens. There are two blue laser subunits, each collimated by a collimating lens. The blue and green laser subunits are packaged on the same structure to emit light in the same direction. Thus, the light emitted by the color mixing component 11 contains both green and blue light. The green and blue laser subunits are small chips. Because they are arranged side by side, the two colors of laser light mix to a certain extent at the beginning of emission, forming a combined light. That is, the light emitted by the color mixing component 11 is a mixture of green and blue laser light, which reduces the number of lenses used for light combining, improves structural compactness, and reduces the volume occupied. The monochromatic component 12 has eight red laser subunits arranged side by side, and the light emitted by the eight red laser subunits is collimated by four collimating lenses. More preferably, as... Figure 2 As shown, the color mixing component 11 and the monochromatic component 12 are arranged side by side to form a laser light source 1. The structure is compact and easy to arrange. The light emitted by the color mixing component 11 and the monochromatic component 12 is emitted in the same direction, with a certain distance between them. Therefore, the beams emitted by the two components are parallel and spaced apart. The beams cannot be directly combined; a beam combining process is required. Specifically, as... Figure 2As shown, the light emitted by the color mixing component 11 is guided to the dichroic mirror by a reflector, and the light emitted by the monochromatic component 12 is emitted to the dichroic mirror. The light emitted by the color mixing 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 color mixing component 11 and transmits the light emitted by the monochromatic component 12. That is, the dichroic mirror reflects green and blue light and transmits red light. More specifically, the spectrum of the dichroic mirror is set to reflect light at 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 color mixing component 11 is emitted to the dichroic mirror, and the light emitted by the monochromatic component 12 is guided to the dichroic mirror by a reflector. The light emitted by the color mixing component 11 and the light emitted by the monochromatic component 12 are also combined by the dichroic mirror. In this case, the dichroic mirror transmits the light emitted by the color mixing component 11 and reflects the light emitted by the monochromatic component 12. That is, the dichroic mirror transmits green and blue light and reflects red light.

[0044] The light emitted by the laser subunit of laser source 1 is usually linearly polarized. Specifically, the light emitted by the blue laser subunit and the green laser subunit in the color mixing component 11 has the same polarization state and is in the P state. 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 color mixing component 11 and the light emitted by the monochromatic component 12 will not interfere with each other, effectively suppressing speckle phenomenon.

[0045] Furthermore, the number of blue and green laser sub-units differs from the number of red laser sub-units, resulting in different sizes of blue, green, and red light spots. When the light emitted from the color mixing component 11 is directly combined with the light emitted from the monochromatic component 12, the uniformity of the combined light 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 color mixing component 11. The static diffusion element 41 diffuses the light emitted from the color mixing component 11, expanding the beam while eliminating spots. This ensures that the blue and green light spots formed by the color mixing component 11 are approximately the same size as the red light spot, improving the uniformity of the combined light. Furthermore, it ensures that the number of compound eye units covered by the blue, green, and red light spots on the first compound eye lens element 3 is approximately consistent, resulting in a uniform energy distribution when the three colors of laser light irradiate the first compound eye lens element 3. This allows for better light homogenization and is more beneficial for aberration correction of 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 dissipation effect.

[0046] Furthermore, the diffusion device includes a dynamic diffusion element 42 disposed on the output optical path of the combined laser beam. That is, the dynamic diffusion element 42 performs dynamic diffusion processing on 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 phenomena, better disrupts the phase coherence of the laser, improves the speckle elimination effect, and thus improves the projected image quality. The dynamic diffusion element 42 can perform diffusion processing by rotating, reciprocating linear motion, or vibrating, and can be specifically configured as needed. Preferably, the dynamic diffusion element 42 is combined with a static diffusion element 41, that is, a combination of dynamic and static diffusion processing, to better eliminate phase coherence and improve the speckle elimination effect.

[0047] Preferably, an optical component is provided in the optical path from the first compound eye lens element 3 to the second compound eye lens element 7. The optical component is equivalent to a simple imaging system, so that the compound eye unit of the first compound eye lens element 3 acts as an object and is imaged on the incident surface of the second compound eye lens element 7. The position of the first compound eye lens element 3 is the object image position point. The light is homogenized by the first compound eye lens element 3 and then imaged on the second compound eye lens element 7 by the optical component. The light is then further homogenized by the second compound eye lens element 7 and then emitted to the light modulation device to be modulated into an image beam. The second compound eye lens element 7 and the light modulation device also constitute a simple imaging system. The compound eye unit of the second compound eye lens element 7 acts as an object and is imaged on the surface of the light modulation device, so that the combined beam is better shaped and homogenized and imaged onto the light modulation device. In this embodiment, the compound eye unit of the first compound eye lens element 3 is a regular hexagon, but it can also be a regular polygon with other numbers of sides. The hexagonal compound eye unit forms a hexagonal image of the incident light spot. It is difficult to guarantee the effect of eliminating speckle by relying solely on the diffusion device. The first compound eye lens element 3 is used to homogenize the laser. The light spot formed after the light emitted by the laser source 1 is diffused by the diffusion device is relatively large. 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 set inscribed in the size of the light spot can better homogenize and correct the edge of the object image. The distance from the center of the light 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 compound eye lens element 7 is rectangular. The second compound eye lens element 7 further homogenizes the combined light beam, improving its uniformity and ensuring it evenly illuminates the light modulator, thereby guaranteeing uniform image light modulation and improving the projected image quality. In this embodiment, the rectangular shape of the compound eye unit of the second compound eye lens element 7 is for better matching with the light modulator, which is typically a rectangular DMD or LCD panel, thus better shaping and homogenizing the combined light beam for imaging onto the light modulator. Figure 1 As shown, the optics includes a lens element, namely lens element 101. Lens element 101 is located in the output light path of the first compound eye lens element 3 and in the incident light path of the light combining assembly. That is, only the light from the laser source 1 passes through lens element 101, while the light from the broadband source 2 does not pass through lens element 101. The light from the laser source 1 is homogenized by the first compound eye lens element 3 and then collimated and focused by lens element 101. Then, the light from the laser source 1 and the light from the broadband source 2 are combined by the light combining assembly to obtain a combined beam. Finally, the combined beam is homogenized by the second compound 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 subunit, but the spectral range of the light emitted by the broadband light source 2 is a wider spectrum than that of the green laser subunit. The broadband light source 2 can compensate for and increase the proportion of green light in the combined beam, so that the green light meets the requirements for beam combining, which can better improve the brightness of the combined beam, effectively reduce the speckle caused by the laser alone, and improve the projection image effect. Furthermore, the temporal proportion of the light from the broadband light source 2 in the combined beam is the same as the temporal proportion of the light from the same-color laser subunit in the combined beam, which not only improves the output brightness but also helps to improve the image quality.

[0049] Example 2

[0050] In this embodiment, the light combining component mainly includes a light combining element 5, which can be a dichroic mirror. The spectral band of the broadband light source 2 includes at least one of the spectral bands of the laser subunit. The light combining element 5 reflects light with a wavelength in the first light combining band and transmits light with a wavelength in the second light combining band, or the light combining element 5 transmits light with a wavelength in the first light combining band and reflects light with a wavelength in the second light combining band. The first light combining band covers the spectral bands of all laser subunits, and the second light combining band covers a portion 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 and combined. Specifically, the light emitted by the laser source 1 is obliquely incident on the light combining element 5 and then transmitted out from the light combining element 5. The light emitted by the broadband source 2 passes through the focusing collimating lens assembly and is obliquely incident on the light combining element 5 from the other side. Then the light emitted by the broadband source 2 is reflected out by the light combining element 5. The light from the laser source 1 and the light from the broadband source 2 are emitted in the same direction to perform light combining. The structure is simple, easy to implement, and occupies little space.

[0051] like Figure 8As shown, in one embodiment, the light combining element 5 reflects light with wavelength in light combining band one and transmits light with wavelength in light combining band two. The light combining band one covers the spectral bands of the blue laser subunit, the green laser subunit, and the red laser subunit. That is, the light combining element 5 reflects the lasers emitted by the blue laser subunit, the green laser subunit, and the red laser subunit. The light emitted by the broadband light source 2 is generally green or yellow. The spectral band of the broadband light source 2 includes the spectral band of the green laser subunit. Since the light combining band two covers a part of the spectral band of the broadband light source 2, the light combining element 5 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. 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. Specifically, the lost part of the light emitted by the broadband light source 2 includes the band that overlaps with the spectral band of the green laser subunit. To improve the utilization rate of the broadband light source 2 and reduce its losses to increase the output brightness of the combined beam, the endpoint of the second combining wavelength band is close to the spectral band of the green laser subunit. This allows as much light emitted from the broadband light source 2 as possible to be transmitted and merge into the combined beam. Preferably, the difference between the endpoint of the second combining wavelength band and the spectral band of the laser subunit is in the range of 2–20 nm. Specifically, as shown... Figure 8 As shown, the first light-combining band includes a spectral range of 450nm to 540nm and greater than 630nm, specifically including spectral bands of 465nm, 525nm, and 650nm. 465nm corresponds to the spectral range of the blue laser subunit, 525nm to the green laser subunit, and 650nm to the red laser subunit. The second light-combining band includes a spectral range of 550nm to 600nm, while the broadband light source 2 includes a spectral range of 480nm to 610nm. Therefore, when light is combined by the light-combining element 5, the broadband light source 2 emits... Only light in the 550nm–600nm range is incorporated into the combined beam, while light in the 480nm–550nm and 600nm–610nm bands emitted by the broadband light source 2 is lost. To further improve the brightness of the projected image, it is preferable to set the range of the second combined beam to 532nm–620nm. This makes the left endpoint of the second combined beam closer to the spectral band of the green laser subunit, and the right endpoint closer to the spectral band of the red laser subunit, thereby reducing the loss of the broadband light source 2 during light combining and improving the output brightness of the combined beam.

[0052] Furthermore, the projection light source can switch between pure laser mode and mixed light mode by controlling the switching of laser light source 1 and broadband light source 2. In pure laser mode, only laser light source 1 is working, while broadband light source 2 is turned off;

[0053] The hybrid light mode is that laser source 1 is working, that is, the blue laser subunit, green laser subunit and red laser subunit in laser source 1 are all working, and broadband source 2 is working;

[0054] The hybrid light mode can also be that the blue laser subunit and the red laser subunit in laser source 1 are working, while the green laser subunit is off, and the broadband source 2 is working at the same time.

[0055] Example 3

[0056] like Figure 3 As shown, the difference from Embodiment 1 is that the diffusion device and the light combining component are integrated into a combined element 6. One side surface of the combined element 6 is a diffusion layer 61, and the other side surface is a coating layer 62. The light from the laser source 1 is obliquely incident from the side of the diffusion layer 61 and transmitted out through the coating layer 62. The light from the broadband source 2 is obliquely incident from the side of the coating layer 62 and reflected by the coating layer 62 to combine with the light from the laser source 1. The combined element 6 is dynamically movable to dynamically diffuse the light from the laser source 1. For example, the combined element 6 is disk-shaped and rotates to achieve dynamic diffusion.

[0057] When using the combined element 6, there is no need to set up a dynamic diffusion element. The combined element 6 integrates the functions of diffusion and light combining. After the light from the laser source 1 is diffused by the diffusion layer 61, it is immediately combined with the light from the broadband source 2 in the coating layer 62. The structure is more compact and occupies less space, which helps to reduce the overall size of the projection system. Since the light from the broadband source 2 is incident obliquely from one side of the coating layer 62, the light from the broadband source 2 is directly reflected by the coating layer 62. Therefore, the light from the broadband source 2 will not be incident on the diffusion layer 61, that is, the light from the broadband source 2 will not be diffused. This ensures that only the light from the laser source 1 is diffused, and the light from the laser source 1 is diffused before being combined with the light from the broadband source 2. Alternatively, the coating layer 62 can reflect the light from the laser source 1 and transmit or partially transmit the light from the broadband source 2. In this method, the light from the broadband source 2 transmitted through the coating layer 62 will be diffused by the diffusion layer 61.

[0058] Example 4

[0059] like Figure 4As shown, this embodiment uses a DMD10 as the optical modulation device. The combined beam of illumination light is guided to the DMD10 by a prism 9. Under the modulation of the DMD10, the illumination light becomes 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 exits from the prism 9 through a different optical path than the illumination light to the lens for projection. In this embodiment, the combined beam is incident on the prism 9, and the incident angle of the combined beam at the interface in the prism 9 is greater than the critical angle. As a result, the combined beam undergoes total internal reflection at the interface and exits from the prism 9 to the DMD10. The image light modulated by the DMD10 has a deviation angle relative to the incident combined beam. The image light returns to the prism 9, and the incident angle 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 exits from the other side of the prism 9 to the lens, and is then projected into a projected image through the lens.

[0060] To facilitate control of the angle at which the combined beam enters the prism 9, lenses 81 and 82 are eccentrically positioned on the outgoing light path of the second compound eye lens element 7. Lenses 81 and 82 are tilted relative to the optical axis, with the tilt direction of lens 81 opposite to that of lens 82. Lenses 81 and 82 deflect the light path, ensuring precise alignment of the combined beam with the prism 9. This guarantees the incident angle of the combined beam onto the DMD 10 and the sharpness of the image, ensuring total internal reflection at the interface of the prism 9, while the image light modulated by the DMD 10 is transmitted through the interface of the prism 9. Specifically, the tilt axes of lenses 81 and 82 relative to the optical axis are perpendicular to the plane of the light path, meaning the tilt axes of lenses 81 and 82 are perpendicular to... Figure 4 In the direction of the paper, lens 1 (81) and lens 2 (82) are biconvex lenses with positive diopter. The initial tilt angle of lens 1 (81) and lens 2 (82) relative to the optical axis is 0 to 45°, and the adjustable range is 0 to 20°.

[0061] Furthermore, lens 81 and / or lens 82 are adjustable in movement or rotation on a plane perpendicular to the optical axis. Considering assembly tolerances, the structural design achieves adjustable edge thickness. Taking lens 81 as an example, lens 81 is adjustable in two directions on a plane perpendicular to the optical axis, and these two directions are perpendicular to each other. Specifically, lens 81... Figure 4 The lens shown is adjustable in the x-direction, with an adjustment range of approximately ±0.34mm, thereby adjusting the top and bottom color borders of the projected image. Lens 81... Figure 4 The movement in the z-direction shown is adjustable, with an adjustment range of approximately ±0.3mm, thereby enabling adjustment of the left and right color borders of the projected image to flexibly meet needs and improve the quality of the projected image.

[0062] Furthermore, in this embodiment, the optics includes two lens elements, namely lens element one 101 and lens element two 102. Lens element one 101 is located in the outgoing light path of the first compound eye lens element 3 and in the incident light path of the light combining element one. Lens element two 102 is located between the light combining element one and the second compound eye lens element 7. Only the light from the laser source 1 passes through lens element one 101, while the light from the broadband source 2 does not pass through lens element one 101. The combined light beam passes through lens element two 102 and then strikes the second compound eye lens element 7. Lens element one 101 acts as collimator, and lens element two 102 acts as focuser, so that the compound eye unit of the first compound eye lens element 3 is imaged on the incident surface of the second compound eye lens element 7, thereby ensuring the imaging of the second compound eye lens element 7 to the DMD 10. The elements between the second compound eye lens element 7 and the DMD10 also constitute a simple imaging system, so that the compound eye unit of the second compound eye lens element 7 is imaged on the surface of the light modulation device, so that the combined light beam is better shaped and homogenized and imaged onto the DMD10.

[0063] Example 5

[0064] like Figure 5 As shown, the difference from Embodiment 1 is that the projection light source also includes a polarization conversion element 20 disposed on the outgoing light path of the combined beam. The polarization conversion element 20 performs phase shifting on part of the combined beam. Specifically, the polarization conversion element 20 can be a half-wave plate, and the polarization conversion element 20 only performs phase shifting on half of the combined beam. That is, only half of the combined beam is blocked by the polarization conversion element 20, so only half of the combined beam passes through the polarization conversion element 20 for phase shifting, while the other half of the combined beam does not undergo phase shifting and propagates directly along the light path. The light emitted by each laser subunit is linearly polarized light. The half-wave plate changes the polarization direction of the linearly polarized light, specifically converting P-light to S-light or vice versa, better eliminating phase coherence, effectively suppressing speckle, and not affecting the luminous efficiency gain of the broadband light source 2.

[0065] Furthermore, the polarization conversion element 20 includes a polarization conversion region 201 and a non-polarization region 202. The polarization conversion region 201 is used to shift the phase of light, and specifically, the polarization conversion region 201 is a half-wave plate. The non-polarization region 202 includes at least one of a light-transmitting region and a diffusion region. The polarization conversion region 201 and the non-polarization region 202 are arranged in separate sections. Specifically, as shown... Figure 9As shown, the polarization conversion region 201 and the unpolarized region 202 are distributed horizontally. Half of the light spot formed by the combined beam illuminates the polarization conversion region 201, and the other half illuminates the unpolarized region 202. The unpolarized region 202 can be entirely transparent. The transparent region can be made of a transparent sheet (such as glass) or it can be an unobstructed open area (for...). Figure 9 Regarding the polarization conversion element 20 shown, the polarization conversion element 20 as a whole can be a half-wave plate, which constitutes the polarization conversion region 201, while the light transmission region is a virtually defined area. Half of the light spot illuminates the half-wave plate, thus forming a situation where "half of the light spot illuminates the polarization conversion region 201, and the other half illuminates the non-polarization region 202". The non-polarization region 202 can also be entirely a diffusion region, used to further diffuse the combined light beam. The non-polarization region 202 can also be formed by combining the light transmission region and the diffusion region; for example... Figure 10 As shown, the polarization conversion region 201 and the unpolarization region 202 are distributed in a grid pattern, which can more uniformly shift the phase of a portion of the combined beam and better suppress speckle; as Figure 11 and Figure 12 As shown, the polarization conversion region 201 and the non-polarization region 202 can also be distributed in concentric rings or along the circumference, which can effectively shift the phase of only a part of the combined beam, eliminate phase coherence, and effectively suppress speckle.

[0066] For situations where the speckle effect is poor in a monochromatic field, such as Figure 6 As shown, a polarization conversion element 21 can be added to the output light path of the laser master unit of the corresponding color in the laser source 1. The polarization conversion element 21 is specifically a half-wave plate. The light emitted by the laser master unit is linearly polarized light. After passing through the polarization conversion element 21, the polarization direction of the linearly polarized light changes, which can better eliminate speckle in the monochromatic field.

[0067] like Figure 7As shown, no static diffusion element is provided in the output light path of the color mixing component 11 and the monochromatic component 12. The light emitted by the color mixing 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 in the output light path of the combined laser beam to perform dynamic diffusion processing on the combined laser beam. Then the combined laser beam is subjected to homogenization processing by the first compound eye lens element 3. After dynamic diffusion and homogenization processing, the combined laser beam is combined with the light emitted by the broadband light source 2 by the light combining element 5. The light combining element 5 is specifically a dichroic mirror. It can be that the light combining element 5 transmits the light of the laser light source 1 and reflects the light of the broadband light source 2 to perform light combination, or it can be that the light combining element 5 reflects the light of the laser light source 1 and transmits the light of the broadband light source 2 to perform light combination. Then the combined beam is emitted to the polarization conversion element 20. The polarization conversion element 20 only performs phase shift on half of the combined beam. That is, the polarization conversion element 20 only causes half of the combined beam to undergo polarization state conversion, effectively eliminating phase coherence and improving the speckle elimination effect.

[0068] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these 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, The system includes a laser source, a broadband light source, and a beam combining component. The laser source comprises laser sub-units of several colors. A diffusion device and a first compound eye lens element are provided in the output light path of the laser source. The light emitted by the laser source is combined with the light emitted by the broadband light source by the beam combining component to form a combined beam for output. The spectral band of the broadband light source includes at least one of the spectral bands of the laser sub-units. The beam combining component includes a beam combining element one, which reflects light with wavelength in beam combining band one and transmits light with wavelength in beam combining band two, or transmits light with wavelength in beam combining band one and reflects light with wavelength in beam combining band two. Beam combining band one covers the spectral bands of all laser sub-units, and beam combining band two covers a portion of the spectral band of the broadband light source.

2. The projection light source according to claim 1, characterized in that, The color of the broadband light source is the same as the color of at least one of the laser subunits.

3. The projection light source according to claim 1, characterized in that, The temporal proportion of the light from the broadband light source in the combined beam is the same as the temporal proportion of the light from the same color laser subunit in the combined beam.

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

5. The projection light source according to claim 4, characterized in that, The diffusion device includes a static diffusion element disposed in the outgoing light path of the mixed color component and / or the monochromatic component.

6. The projection light source according to claim 4, characterized in that, The diffusion device includes a dynamic diffusion element disposed in the output optical path of the combined laser beam.

7. The projection light source according to claim 4, characterized in that, The light emitted by the laser subunits of different colors in the color mixing component has the same polarization state, which is different from the light emitted by the laser subunits in the monochromatic component.

8. The projection light source according to claim 1, characterized in that, A second compound eye lens element is provided in the outgoing optical path of the combined beam, and an optical component is provided in the optical 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.

9. The projection light source according to claim 8, characterized in that, The optical component includes at least one lens element; 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 rectangular.

10. The projection light source according to claim 1, characterized in that, The endpoint of the combined light band two is close to the spectral band of the laser subunit; or the difference between the endpoint of the combined light band two and the spectral band of the laser subunit is in the range of 2 to 20 nm.

11. 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 side surface of the combined element is a diffusion layer and the other side surface is a coating layer. The light from the laser source is obliquely incident from the diffusion layer side and transmitted through the coating layer. The light from the broadband source is obliquely incident from the coating layer side and is reflected or partially reflected by the coating layer to combine with the light from the laser source. The combined element is dynamically active to dynamically diffuse the light from the laser source.

12. The projection light source according to claim 1, characterized in that, It also includes a lens 1 and a lens 2 that are eccentrically arranged in the outgoing light path of the second compound eye lens element. The lens 1 and the lens 2 are respectively tilted relative to the optical axis, and the tilt direction of the lens 1 relative to the optical axis is opposite to the tilt direction of the lens 2 relative to the optical axis.

13. The projection light source according to claim 12, characterized in that, Lens 1 and / or Lens 2 are adjustable in movement or rotation on a plane perpendicular to the optical axis.

14. The projection light source according to claim 1, characterized in that, It also includes a polarization conversion element 1 disposed on the outgoing optical path of the combined beam, the polarization conversion element 1 performing phase shift on a portion of the combined beam.

15. The projection light source according to claim 14, characterized in that, The polarization conversion element includes a polarization conversion region for phase shifting of light, and the polarization conversion element also includes a non-polarization region, which 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.

16. The projection light source according to claim 15, characterized in that, The polarization conversion region is a half-wave plate.

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