Laser display apparatus

Abstract

A laser display apparatus (10), comprising: a light source component (110), a polarized light-transmitting component (120), and a light modulation component (130). The light source component (110) is configured to emit a laser having at least one color, and the laser passes through the polarized light-transmitting component (120) and then reaches the light modulation component (130). The polarized light-transmitting component (120) is arranged between the light source component (110) and the light modulation component (130). The polarized light-transmitting component (120) is configured to receive light incident from different directions, and emitted light comprises first polarized light and second polarized light, which are perpendicular to each other, wherein the proportions of the first polarized light and the second polarized light in the emitted light corresponding to the light incident from different directions are different. The light modulation component (130) is configured to modulate a received light beam so as to obtain a light beam containing information of an image to be displayed. The laser display apparatus (10) can ameliorate a speckle phenomenon.

Description

Laser display device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on September 26, 2023, with application number 202311251546.X, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of laser display technology, and in particular to a laser display device. Background Art

[0004] Laser-Display Technology (LDT) is an image information terminal display technology that uses lasers as light sources. Compared to traditional displays using LEDs, laser displays offer wider color gamut coverage, better color expression, and superior color reproduction. While lasers offer advantages such as a wide color gamut and high color saturation, their high collimation, narrow spectrum, and high coherence also create laser speckle, which seriously impacts the quality of laser display images.

[0005] Currently, laser speckle reduction methods primarily include reducing temporal coherence, spatial coherence, and time averaging. Temporal coherence reduction primarily involves broadening the laser spectrum, including adding lasers of different wavelengths or increasing the laser spectrum from the laser chip end. Spatial coherence reduction primarily involves increasing the system's etendue, including using diffusers to increase the laser spot's diffusion angle and increase the diversity of diffusion angles, thereby increasing etendue. The increase and diversity of diffusion angles increase the random phase of the beam space, which is detrimental to forming a constant phase difference and generating light wave interference. Alternatively, laser polarization can be changed to orthogonal polarization to eliminate speckle and reduce laser coherence. Temporal averaging primarily involves adding moving components to the system, such as diffusers or moving diffusers.

[0006] However, the above-mentioned speckle elimination method usually changes the spot size or transmission path of the laser, resulting in the need for additional optical elements to further modulate the light beam, making the overall structure of the laser display device more complicated.

[0007] Summary of the Invention

[0008] The present application exemplarily discloses a laser display device, which is used to provide a technical solution for improving speckle applicable to the laser display device.

[0009] This application provides the following technical solutions:

[0010] A laser display device includes: a light source component, a polarized light-transmitting component, and a light modulation component;

[0011] The light source component is configured to emit laser light having at least one color, and the laser light reaches the light modulation component after passing through the polar light-transmitting component;

[0012] The polarized light-transmitting component is disposed between the light source component and the light modulation component, and is configured to receive light incident from different directions, and the output light includes a first polarized light and a second polarized light, the first polarized light is perpendicular to the second polarized light, and the ratio of the first polarized light to the second polarized light in the output light corresponding to the light incident from different directions is different;

[0013] The light modulation component is configured to modulate the received light beam to obtain a light beam having image information to be displayed.

[0014] It can be seen from the above technical solution that in the laser display device provided by the present application, a polarization light-transmitting component is arranged between the light source component and the light modulation component, and the polarization light-transmitting component is configured to receive light incident from different directions, and its output light includes a first polarization light and a second polarization light, the first polarization light is perpendicular to the second polarization light, and the ratio of the first polarization light and the second polarization light of the output light corresponding to the light incident from different directions is different. The polarization light-transmitting component can be used to adjust the polarization distribution of light incident from different directions to be more diversified, thereby improving the speckle problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the implementation methods in the embodiments of the present application or related technologies, the following is a brief introduction to the drawings required for use in the embodiments or related technology descriptions. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0016] FIG1 is a schematic structural diagram of a laser display device in some embodiments;

[0017] FIG2 is a schematic diagram showing the working principle of the polar light-transmitting component in some embodiments;

[0018] FIG3 is a schematic diagram showing the structure of a crystal wave plate in some embodiments;

[0019] FIG4 is a schematic diagram showing the working principle of a crystal wave plate in some embodiments;

[0020] FIG5 is a schematic diagram showing the application principle of a crystal wave plate in some embodiments;

[0021] FIG6 is a schematic diagram showing the structure of a crystal wave plate in some embodiments;

[0022] FIG7 is a schematic diagram showing the working principle of a crystal wave plate in some embodiments;

[0023] FIG8 is a schematic diagram showing the application principle of a crystal wave plate in some embodiments;

[0024] FIG9 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0025] FIG10 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0026] FIG11 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0027] FIG12 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0028] FIG13 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0029] FIG14 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0030] FIG15 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0031] FIG16 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0032] FIG17 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0033] FIG18 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0034] FIG19 is a schematic diagram showing a partial structure of a laser display device in some embodiments;

[0035] FIG20 is a schematic structural diagram of a laser display device in some embodiments;

[0036] FIG21 is a schematic structural diagram of a laser display device in some embodiments;

[0037] FIG22 is a schematic structural diagram of a laser display device in some embodiments;

[0038] FIG23 shows a schematic structural diagram of a laser display device in some embodiments. DETAILED DESCRIPTION

[0039] In order to make the purpose and implementation of this application clearer, the exemplary implementation of this application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of this application. Obviously, the described exemplary embodiments are only part of the embodiments of this application, not all of the embodiments.

[0040] It should be noted that the brief descriptions of terms in this application are only for the purpose of facilitating the understanding of the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their ordinary and usual meanings.

[0041] The terms "comprise," "include," and "have," and any variations thereof, are intended to cover but not exclude inclusion; for example, a product or device comprising a list of components is not necessarily limited to all the components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0042] The technical solution provided in the embodiments of the present application can be applied to the field of laser display, for example, in the field of laser projection display. By providing a light source component including lasers of the three primary colors of red, green, and blue (RGB), full-color laser display can be achieved. By providing a polarized light-transmitting component for polarization conversion, the polarization distribution of light incident from different directions can be adjusted to be more diversified, thereby improving the speckle problem. At the same time, since the polarized light-transmitting component does not change the direction of the light, it can be located at any position between the light source component and the light modulation component without the need for additional optical elements. In this way, the speckle problem can be solved without changing the transmission direction of the light beam (i.e., light), which is beneficial for avoiding the complexity of the overall structure of the laser display device.

[0043] The laser display device provided in the embodiments of the present application is exemplarily described below with reference to the accompanying drawings.

[0044] For example, FIG1 shows a schematic structural diagram of a laser display device 10 in some embodiments, and FIG2 shows a schematic diagram of the working principle of a polar light-transmitting component 120 in some embodiments. As shown in Figures 1 and 2, the laser display device 10 includes: a light source component 110, a polarization transparent component 120 and a light modulation component 130; the light source component 110 is configured to emit a laser having at least one color, and the laser reaches the light modulation component 130 after passing through the polarization transparent component 120; the polarization transparent component 120 is arranged between the light source component 110 and the light modulation component 130, and the polarization transparent component 120 is configured to receive light incident from different directions (i.e., angles), and the output light includes a first polarization light and a second polarization light, the first polarization light is perpendicular to the second polarization light, and the ratio of the first polarization light and the second polarization light of the output light corresponding to the light incident from different directions is different; in some specific implementations, the polarization transparent component 120 is also configured to keep the incident direction and the output direction of the light the same; the light modulation component 130 is configured to modulate the received light beam to obtain a light beam with image information to be displayed.

[0045] The light source component 110 is a component for emitting light and may include a laser that emits initial light. The initial light may be a laser having at least one color, which may be at least one of basic colors such as red, green, and blue. Correspondingly, the laser may include a monochromatic laser, for example, for achieving a monochromatic display, or a multicolor laser, for example, for achieving a full-color display, without limitation herein.

[0046] The laser display device 10 may also include other optical elements for modulating the initial light after the light source component 110 along the light transmission direction, such as a beam combiner, focusing element, beam expander, or other elements known to those skilled in the art, without limitation herein. The laser light emitted by the light source component 110 passes through the optical elements of the laser display device 10 and the polarized light-transmitting component 120 interposed in the optical path, before reaching the light modulator 130.

[0047] The polarized light-transmitting component 120 is capable of receiving light incident from different directions and performing polarization conversion. Due to the different incident angles and deflection angles, it is possible to form output light with different polarization ratios. For example, as shown in FIG2 , the dotted and solid lines represent light incident from different directions to the polarized light-transmitting component 120 and exiting after polarization conversion. The solid lines represent light with a first ratio of two different polarization directions, while the dotted lines represent light with a second ratio of two different polarization directions, which is different from the first ratio. Thus, the polarized light-transmitting component 120 can adjust the polarization distribution of light incident from different directions to be more diverse by performing polarization conversion on light incident from different directions, thereby improving the speckle problem and providing a solution to improving speckle. In some specific implementations, since the polar light-transmitting component 120 does not change the direction of the light, that is, the light emission direction is parallel to the incident direction, it can be located at any position between the light source component 110 and the light modulation component 130 without the need for additional optical elements, thereby solving the speckle problem without changing the light beam transmission direction, which is beneficial to avoiding the complexity of the overall structure of the laser display device 10.

[0048] The light modulator 130 spatially modulates the speckle-reduced light beam to form a light beam that carries the image information to be displayed. Specifically, this modulation method can utilize an array of mirrors to reflect light at different spatial locations, or employ other methods to achieve spatial light beam modulation. Exemplarily, the light modulator 130 can be a digital micromirror device (DMD) or other spatial light modulator, though this is not limited here.

[0049] It should be noted that Figure 1 only exemplarily shows a light beam in a converging state passing through the polar light-transmitting component 120; in other embodiments, a light beam in a diverging state may also pass through the polar light-transmitting component 120. It is only necessary to ensure that light from different directions is incident on the polar light-transmitting component 120. The embodiment of the present application does not limit whether the light beam incident on the polar light-transmitting component 120 is a converging light beam or a diverging light beam.

[0050] At the same time, FIG1 only shows the light source component 110, the polarization light-transmitting component 120 and the light modulation component 130 by way of example, and does not constitute a limitation on the laser display device 10 provided in the embodiment of the present application; in other embodiments, other optical elements may be provided between the light source component 110 and the light modulation component 130, before and after the polarization light-transmitting component 120, or after the light modulation component 130, which are not limited here.

[0051] In addition, FIG2 only exemplarily shows light rays of two different incident directions, but does not constitute a limitation on the light rays incident on the polar light-transmitting component 120 in the laser display device 10 provided in the embodiment of the present application; in other embodiments, the light rays incident on the polar light-transmitting component 120 may also include light rays of multiple different directions, which are not limited here.

[0052] The laser display device 10 provided in the embodiment of the present application includes a light source component 110, a polarized light-transmitting component 120, and a light modulation component 130, wherein the laser light having at least one color emitted by the light source component 110 passes through the polarized light-transmitting component 120 and reaches the light modulation component 130, so that the light beam after the speckle improvement is spatially modulated by the light modulation component 130 to obtain a light beam having the image information to be displayed, thereby facilitating image display; wherein the polarized light-transmitting component 120 can receive light incident from different directions, emit light with different polarization ratios, and maintain the incident direction and the outgoing direction of the light. The polar light-transmitting component 120 is the same, so that the polar light-transmitting component 120 can deflect light incident from different directions at different angles, thereby emitting light with different polarization ratios, and adjusting the polarization distribution of light incident from different directions to be more diversified, thereby improving the speckle problem; at the same time, since the polar light-transmitting component 120 does not change the direction of the light, it can be located at any position between the light source component 110 and the light modulation component 130 without the need for additional optical elements, thereby solving the speckle problem without changing the transmission direction of the light beam (i.e., light), which is beneficial to avoiding the complexity of the overall structure of the laser display device 10.

[0053] In some embodiments, FIG3 shows a schematic diagram of the structure of a crystal wave plate in some embodiments. Referring to FIG3 in conjunction with FIG1 , in the laser display device 10, the polarized light-transmitting component 120 may include a crystal wave plate 121 of uniform thickness. The crystal wave plate 121 has an incident surface 1211 and an exit surface 1212 that are parallel, and is configured to refract incident light at the incident surface 1211 and then at the exit surface 1212, producing exit light with the same transmission direction as the incident light.

[0054] Specifically, in the process of passing through the crystal wave plate 121, the light beam first undergoes the first refraction at the incident surface 1211 and then undergoes the second refraction at the exit surface 1212. Since the exit surface 1212 is parallel to the incident surface 1211, the transmission direction of the light beam will not change, that is, the transmission direction of the incident light and the exit light are the same. It can also be understood that the incident angle of the light at the incident surface 1211 is the same as its exit angle at the exit surface 1212.

[0055] With this arrangement, since the light emission direction does not change, the overall viewing angle setting of the laser display device 10 will not be affected. The crystal wave plate 121 can be set at any position between the light source component 110 and the light modulation component 130.

[0056] For example, Figure 4 illustrates a schematic diagram of the operating principle of a crystal wave plate in some embodiments, and Figure 5 illustrates a schematic diagram of the application principle of a crystal wave plate in some embodiments. Based on Figure 3 and in conjunction with Figures 4 and 5 , when a parallel laser beam converges after passing through a lens component, a crystal wave plate with a birefringence effect, such as a half-wave plate, a quarter-wave plate, or other type of wave plate, with its optical axis parallel to the surface, is placed near the convergence point.

[0057] Polarization refers to the phenomenon in which the vibration vector (perpendicular to the propagation direction) of a transverse wave (light in this embodiment) is biased in certain directions. Taking the orientation shown in Figure 4 as an example, the arrow from left to right indicates the propagation direction of the light; the line segment or ellipse in that propagation direction indicates the polarization direction of the light. Taking Figure 5 as an example, the arrowed line indicates the propagation direction of the light, and the points or line segments in that direction illustrate the polarized rays of light.

[0058] For a crystal wave plate, the polarization direction can be decomposed into a part perpendicular to the optical axis (i.e., o-light) and a part parallel to the optical axis (i.e., e-light). O-light and e-light have different refractive indices in the crystal wave plate. Therefore, after passing through a wafer wave plate with a thickness of d, o-light and e-light will produce a phase difference, as shown below:

[0059] Where no represents the refractive index of o light, ne represents the refractive index of e light, and δ represents the phase, i.e., the polarization direction, with different δ values ​​representing different polarization directions. For example, when δ = π, it is linearly polarized light; when δ = nπ + 0.5π, it is elliptically polarized light.

[0060] For example, as shown in Figure 4, when a light beam enters the crystal wave plate 121 in the normal direction (i.e., perpendicular to the surface of the crystal wave plate), its polarization direction can be decomposed into two mutually perpendicular components, namely o-light and e-light. The e-light is polarized parallel to the plane formed by the optical axis and the incident light, while the o-light is perpendicular to this plane. Specifically, the light beam is shown as vector A in the figure, with P representing its polarization direction. Ae represents the e-light, and Ao represents the o-light.

[0061] For example, taking the crystal wave plate 121 as a half-wave plate (ie, a half-wave plate), if the polarization direction of the incident light forms an angle of 45° with the optical axis of the half-wave plate, the polarization direction of the outgoing light rotates 90°.

[0062] As shown in Figure 2 or Figure 5, when the light beam is incident on the surface of the crystal wave plate, its outgoing light will be divided into o light and e light, and will be emitted at different positions of the crystal wave plate, wherein the ratio of the o light and e light components is related to the incident angle and the polarization direction of the incident light. Specifically, when the incident angle is different, the ratio of the o light and e light components is different (as shown in Figure 2); when the polarization direction of the incident light is different, the ratio of the o light and e light components is also different; and the polarization direction P of the light beam formed by the different ratios of o light and e light is also different (as shown in Figure 4). Furthermore, when the crystal wave plate emits o light and e light, the two beams of light are mutually perpendicular linearly polarized light (as shown in Figure 5). In particular, regardless of whether the incident light is perpendicular to the surface of the crystal wave plate, the outgoing light will be divided into o light and e light, but when it is perpendicular to the incident light, the ratio of the o light and e light in each direction is the same, so there is only one synthesized polarization direction, and polarization diversification adjustment cannot be achieved; in the embodiment of the present disclosure, polarization diversification adjustment can be achieved by using light from different directions to be incident on the crystal wave plate, thereby improving speckle.

[0063] In the embodiments of the present application, when light incident from different directions, that is, light incident at different angles, strikes different positions on the crystal wave plate, the ratios of the O-light and E-light components are different due to the different angles between the incident light and the optical axis of the crystal wave plate. Therefore, for light incident at different angles and / or positions, the polarization of the emergent light is different, and the ratios of the O-light and E-light components are different. Thus, the polarization directions of light emitted from different positions can be divided into two types: O-light and E-light, and the ratios of O-light and E-light at different positions are different, which reduces coherence and thus reduces speckle.

[0064] In the above embodiment, after the same beam of light passes through the crystal wave plate with birefringence effect, two beams of light with different polarization directions are generated; among them, for the incident light, whether it is elliptically polarized light or linearly polarized light, it is necessary to pay attention to the angle between the polarization direction of the incident light and the optical axis of the crystal wave plate. If it is not parallel to or perpendicular to the optical axis, it can be divided into non-zero o light and e light components; if it is perpendicular to the optical axis, it will also be divided into two components, but one of the components is 0, so the polarization direction of the outgoing light will be the same as or perpendicular to the polarization direction of the incident light.

[0065] For example, in the above embodiment, if the incident light (for example, red light) is P light, the vertically incident half-wave plate will become S light, that is, the phase difference between the outgoing light and the incident light is π; if the polarization direction of the incident light is at a certain angle to the optical axis (that is, it is not parallel or perpendicular to the optical axis), it can be divided into o light and e light components.

[0066] The laser display device 10 proposed in the embodiment of the present application is a laser display device that improves speckle based on a crystal wave plate 121. The crystal wave plate 121 is located at positions in the optical path where the light beam has different angles. It can make the polarization variables of light incident at different angles different, thereby adjusting the polarization distribution of light incident from different directions to be more diversified, thereby achieving the effect of improving speckle (i.e., reducing the impact of speckle); at the same time, since the exit surface 1212 of the crystal wave plate 121 is parallel to the incident surface 1211, that is, the crystal wave plate 121 is a flat plate and does not affect the transmission direction of the light beam, it can be placed at any position in the optical path without the need for additional optical elements, thereby not increasing the overall complexity of the laser display device 10.

[0067] In some embodiments, in the laser display device 10 , the crystal wave plate 121 is a half-wave plate, a quarter-wave plate, or a three-quarter-wave plate.

[0068] With this arrangement, the polarization directions of light incident from different directions can be adjusted differently, thereby making the polarization distribution of the outgoing light more diverse and improving speckle.

[0069] In other embodiments, the crystal wave plate 121 may also be other optical elements with birefringence characteristics, which is not limited here.

[0070] In some embodiments, FIG6 shows a schematic diagram of the structure of the crystal wave plate in some embodiments, FIG7 shows a schematic diagram of the working principle of the crystal wave plate in some embodiments, and FIG8 shows a schematic diagram of the application principle of the crystal wave plate in some embodiments. As shown in any of FIG6-FIG8, the exit surface 1212 of the crystal wave plate 121 is configured as a diffusion surface 1213; in some embodiments, an irregular concave-convex structure can be formed on the diffusion surface 1213 by etching or other processes, so that the transmission direction of the light beam after passing through is more random. In some embodiments, a regular pattern can also be formed on the diffusion surface 1213, such as a regularly arranged concave-convex structure. The regularly arranged concave-convex structure can have a certain degree of controllability over the direction of light beam propagation, thereby having a high degree of controllability over the spot size, which is beneficial to the design of the back-end optical path system.

[0071] Exemplarily, the incident surface 1211 of the crystal wave plate 121 can be a smooth surface, and the exit surface 1212 can be made into an irregular diffusion surface 1213 by etching or other methods. The diffusion surface 1213 can also be called a diffusion layer; the crystal wave plate 121 can be placed at any position between the light source component 110 and the light modulation component 130.

[0072] As shown in Figures 6-8, regardless of whether the light beam is incident on the crystal wave plate 121 at different angles or at the same angle but different positions, the polarization of the outgoing light will differ due to the birefringence of the crystal wave plate 121 and the characteristics of its surface diffusion layer. In other words, regardless of the angle or position at which the light beam enters the crystal wave plate 121, the polarization will differ after passing through the crystal wave plate 121, thereby reducing laser coherence and speckle. In Figure 8, d1 and d2 represent the optical path length at different positions.

[0073] For example, the surface of the crystal wave plate 121 can be micro-machined to form an irregular surface such as a diffuser surface. Light passing through the crystal wave plate 121 will produce different polarization elimination effects due to different paths it passes through.

[0074] In some embodiments, FIG9 shows a schematic diagram of a partial structure of a laser display device in some embodiments, and FIG10 shows a schematic diagram of a partial structure of a laser display device in some embodiments. Based on FIG1 and FIG3 , with reference to FIG9 or FIG10 , the laser display device 10 further includes: a lens component 140 , wherein the lens component 140 includes a focusing lens 141 and / or a beam expander lens 142 ; the focusing lens 141 is configured to form a converging light beam, and the beam expander lens 142 is configured to form a diverging light beam; wherein the crystal wave plate 121 is disposed after the lens component 140 along the direction of light transmission.

[0075] As shown in Figure 9, the lens component 140 is a focusing lens 141, which can converge the light beam. The crystal wave plate 121 is placed behind the focusing lens 141 along the light transmission direction, and can adjust the polarization of the converged light beam, thereby adjusting the polarization of light incident from different directions in the converged light beam, so that the polarization ratio of the output light is different, achieving polarization diversification and improving speckle; at the same time, since the crystal wave plate 121 is set at the place where the light beam converges, the area of ​​the crystal wave plate 121 can be made small, which is conducive to saving space.

[0076] As shown in Figure 10, lens component 140 is a beam expander lens 142 that can diverge the light beam. A crystal wave plate 121 is placed after the beam expander lens 142 along the light transmission direction. It can adjust the polarization of the diverging light beam, thereby adjusting the polarization of light incident from different directions within the diverging light beam. This results in different polarization ratios for the outgoing light beam, achieving polarization diversification and improving speckle. Furthermore, because the crystal wave plate 121 is placed where the light beam diverges, the spot size at this location is larger, making the placement of the crystal wave plate 121 more flexible.

[0077] In some embodiments, the lens component in the laser display device 10 may simultaneously include a first focusing lens and a second focusing lens arranged along the direction of light transmission, and the first focusing lens and the second focusing lens are confocal. The polar light-transmitting component, i.e., the crystal wave plate, is located at the focal position of the two lenses. This position is the position where the light spot is the smallest, but the divergence angle is the largest, which is conducive to forming different incident angles to the crystal wave plate.

[0078] Also, in some embodiments, the lens component 140 in the laser display device 10 may simultaneously include a third focusing lens and a fourth expanding lens arranged along the light transmission direction, and the third focusing lens and the fourth expanding lens are confocal, and the polar light-transmitting component, namely the crystal wave plate, is located at the focal position to obtain incident light beams in multiple directions.

[0079] And, specifically, the crystal wave plate 121 may also be arranged in front of or behind at least one lens component 140 to meet the requirements of light rays from different directions incident on the crystal wave plate 121 , which is not limited here.

[0080] In the above examples, along the direction of light transmission, the polarity light-transmitting structure is located at least behind one lens component, and the divergence angle of the laser beam incident on the polarity light-transmitting structure is greater than the divergence angle of the laser beam incident on the lens component, so that the incident direction of the light beam received by the polarity light-transmitting structure can be multiple or diversified.

[0081] In some embodiments, FIG11 shows a schematic diagram of a partial structure of a laser display device in some embodiments, FIG12 shows a schematic diagram of a partial structure of a laser display device in some embodiments, and FIG13 shows a schematic diagram of a partial structure of a laser display device in some embodiments. Based on FIG1 and FIG3 , as shown in any of FIG11 - FIG13 , the laser display device 10 further includes: a light homogenizing component 150. In this example, the light homogenizing component 150 can be specifically a light pipe, so that the light pipe 150 is configured to receive a converged light beam and emit a light beam with uniform brightness; wherein the crystal wave plate 121 is arranged before the light pipe 150 along the light transmission direction.

[0082] For example, the crystal wave plate 121 can be placed at the entrance of the light pipe 150, as shown in Figures 11 or 12. Since the light beam at the entrance of the light pipe 150 is in a focused state, light from different angles will be incident on the crystal wave plate 121, resulting in different polarization ratios and diversified polarization directions of the corresponding outgoing light, thereby improving the speckle problem.

[0083] For example, as shown in FIG11 or FIG12 , regardless of whether the crystal wave plate 121 includes a diffusion surface 1213, the crystal wave plate 121 can be located between the lens component 140 and the light homogenizing component 150; or, as shown in FIG13 , in a structure in which the crystal wave plate 121 includes a diffusion surface 1213, the crystal wave plate 121 can also be arranged before the lens component 140. In this structure, the diffusion surface 1213 of the crystal wave plate 121 is first used to perform polarization differentiation adjustment on the light beam, and then the lens component 140 is used to focus the light beam, and the light homogenizing component 150 is used to homogenize the light beam.

[0084] In some embodiments, FIG14 shows a schematic diagram of a partial structure of a laser display device in some embodiments, and FIG15 shows a schematic diagram of a partial structure of a laser display device in some embodiments. Based on FIG1 and FIG3 , as shown in FIG14 or FIG15 , the laser display device 10 may further include: a lens component 140 configured to converge a light beam; a first telescope 161 and a second telescope 162 disposed between the light source component 110 and the lens component 140; the first telescope 161 is configured to converge a light beam, and the second telescope 162 is configured to diverge a light beam; wherein the crystal wave plate 121 is located between the first telescope 161 and the second telescope 162 along the light transmission direction, and / or located behind the lens component 140.

[0085] The first telescope 161 and the second telescope 162 can compress the light spot to obtain a light spot with a higher energy density. The light spot is further processed by the lens component 140, that is, it can be homogenized after being converged.

[0086] For example, as shown in FIG14 , the crystal wave plate 121 may be located at the focal position of the first telescope 161 , and the focal position of the first telescope 161 and the focal position of the second telescope 162 may be the same position; alternatively, the crystal wave plate 121 may be located at any position between the first telescope 161 and the second telescope 162 , and both can satisfy the requirement that light rays from different directions are incident on the crystal wave plate 121 , thereby facilitating polarization diversification adjustment and improving speckle.

[0087] For example, as shown in FIG15 , there may be two crystal wave plates 121 , wherein one crystal wave plate 121 is located between the first telescope 161 and the second telescope 162 , and the other crystal wave plate 121 is located behind the lens component 140 . Both can satisfy the requirement that light rays from different directions are incident on the crystal wave plate 121 , thereby facilitating polarization diversification adjustment and improving speckle.

[0088] In other embodiments, when there is only one crystal wave plate 121, the crystal wave plate 121 may also be located only behind the lens component 140 (not shown in Figures 14 and 15), as long as light from different directions is incident on the crystal wave plate 121, which is not limited here.

[0089] In the embodiment of the present application, the crystal wave plate 121 may be a structure in which both the incident surface and the exit surface are smooth planes, or a structure in which the exit surface is a diffusion surface, which is not limited here.

[0090] In other embodiments, a diffuser may also be placed at the location of the crystal wave plate 121 to improve speckle, which is not limited here.

[0091] In some embodiments, FIG16 shows a schematic diagram of a partial structure of a laser display device in some embodiments, and FIG17 shows a schematic diagram of a partial structure of a laser display device in some embodiments. Based on FIG14 or FIG15 , as shown in FIG16 or FIG17 , the laser display device 10 may further include: a light homogenizing component 150 , wherein the lens component 140 is disposed between the second telescope 162 and the light homogenizing component 150 . In this example, the light homogenizing component 150 is specifically a light guide.

[0092] Specifically, the second telescope 162 and the first telescope 161 form a group of telescopes to compress the light spot; the lens component 140 can converge the compressed light spot here, and the light pipe 150 receives the converged light spot and performs homogenization processing to improve the uniformity of energy distribution while increasing the energy density of the light spot.

[0093] For example, as shown in FIG16 , along the direction of light beam transmission, the first telescope 161, the crystal wave plate 121, the second telescope 162, the lens component 140 and the light pipe 150 are arranged in sequence; or, as shown in FIG17 , along the direction of light beam transmission, the first telescope 161, the crystal wave plate 121 (one), the second telescope 162, the lens component 140, the crystal wave plate 121 (the second) and the light pipe 150 are arranged in sequence.

[0094] In other embodiments, the number and arrangement order of the optical elements may be set in other ways, which are not limited here.

[0095] In some embodiments, FIG18 shows a partial structural diagram of a laser display device in some embodiments, and FIG19 shows a partial structural diagram of a laser display device in some embodiments. Based on FIG14 or FIG15 , as shown in FIG18 or FIG19 , the laser display device 10 may further include a fly-eye lens 170 disposed between the second telescope 162 and the lens component 140.

[0096] Specifically, the second telescope 162 and the first telescope 161 form a group of telescopes to compress the light spot; the reduced light spot can illuminate the compound eye lens 170, which is first used to uniform the light and then the lens component 140 is used to converge the light.

[0097] For example, as shown in FIG18 , along the direction of light beam transmission, the first telescope 161, the crystal wave plate 121, the second telescope 162, the fly-eye lens 170 and the lens component 140 are arranged in sequence; or, as shown in FIG19 , along the direction of light beam transmission, the first telescope 161, the crystal wave plate 121 (one), the second telescope 162, the fly-eye lens 170, the lens component 140 and the crystal wave plate 121 (the second) are arranged in sequence.

[0098] In other embodiments, the number and arrangement order of the optical elements may be set in other ways, which are not limited here.

[0099] In the laser display device 10 provided in the above embodiment, since the polarized light-transmitting component 120 does not change the direction of light beam transmission, it can be set at any position between the light source component 110 and the light modulation component 130, thereby meeting the application requirements of small-size design. For example, the light source component 110 may include a semiconductor laser chip. Since the number and packaging method of the semiconductor laser chips in the light source component 110 are positively correlated with the final output luminous flux, for small-sized laser TVs or laser micro-projectors, the laser chips used are getting smaller and smaller, and the light spot and optical etendue are also getting smaller and smaller. By matching the size of the polarized light-transmitting component 120 with them, it is helpful to reduce the difficulty of laser light uniformity and laser speckle elimination.

[0100] In some embodiments, Figure 20 illustrates a schematic structural diagram of a laser display device in some embodiments. In addition to Figures 1 and 3 , as shown in Figure 20 , in this laser display device 10, the polarized light-transmitting component 120 further includes a diffuser 122 and a diffuser wheel 123. The diffuser 122 and diffuser wheel 123 share the same optical axis, and the diffuser wheel 123 is configured to rotate about the optical axis relative to the diffuser 122. In other words, in this example, the use of two diffuser configurations, one static and one dynamic, facilitates generating a greater number of different spatial phases for the light beam and increases the probability of generating random phases.

[0101] The diffuser wheel 123 can also be called a vibration diffuser. Because the laser light emitted by the light source component 110 has high coherence and a Gaussian intensity distribution, resulting in poor uniformity, the polarized light-transmitting component 120, along with the diffuser 122 and diffuser wheel 123, can improve laser uniformity while reducing laser coherence and speckle.

[0102] In an embodiment of the present application, the polar light-transmitting component 120 may include a crystal wave plate 121, a diffuser 122 and a diffuser wheel 123, wherein the diffuser 122, the crystal wave plate 121 and the diffuser wheel 123 may be arranged in sequence along the light beam transmission direction; the lens component 140 may be arranged between the diffuser 122 and the crystal wave plate 121, and the light pipe 150 may be arranged behind the diffuser wheel 123.

[0103] In other embodiments, the number and arrangement order of the optical elements may be set in other ways, which are not limited here.

[0104] In some embodiments, Figure 21 shows a schematic diagram of the structure of a laser display device in some embodiments, Figure 22 shows a schematic diagram of the structure of a laser display device in some embodiments, and Figure 23 shows a schematic diagram of the structure of a laser display device in some embodiments. As shown in any of Figures 21-23, in the laser display device 10, the light source component 110 includes a laser having a preset light emission color.

[0105] Exemplarily, the light source component 110 may include a green laser 111 , a blue laser 112 , and a red laser 113 . Correspondingly, the preset light emission colors may include green, blue, and red, so as to achieve full-color display.

[0106] In other embodiments, the light source component 110 may also include a monochromatic laser, a dual-color laser, or lasers of other colors, which are not limited herein.

[0107] In some examples, a polarization-transmitting component is disposed on the light-emitting side of at least a portion of the laser, and is used to convert the laser beam emitted by at least a portion of the laser into a laser having at least two polarization directions, that is, the crystal wave plate can only act on the light beam emitted by a portion of the laser.

[0108] In other examples, a polarized light-transmitting component is disposed in at least a portion of the combined light path of multiple-color lasers to convert at least one color of laser light having a single polarization direction into laser light having at least two polarization directions. That is, the crystal wave plate can transmit all of the combined laser light beams, thereby converting the polarization directions of the combined laser light beams of multiple colors, forming a situation in which the output light includes a first polarized light and a second polarized light, the first polarized light is perpendicular to the second polarized light, and the ratio of the first polarized light to the second polarized light in the output light corresponding to light incident from different directions is different.

[0109] Alternatively, the polarization transparent component transmits only a portion of the combined light beam, thereby performing polarization conversion only on the portion of the combined light beam that passes through. The portion of the combined light beam that passes through can be a combined laser beam of three colors or a laser beam of one color.

[0110] Whether it is relative to the outgoing light beam of part of the laser or for at least part of the combined laser beam, during the operation process, the polar light-transmitting component is configured to receive light incident from different directions, and its outgoing light includes a first polarized light and a second polarized light, the first polarized light is perpendicular to the second polarized light, and the ratio of the first polarized light and the second polarized light of the outgoing light corresponding to the light incident from different directions is different. The polar light-transmitting component can be used to adjust the polarization distribution of light incident from different directions to be more diversified, thereby improving the speckle problem.

[0111] And, exemplarily, continuing to refer to any one of Figures 21 to 23, in the laser display device 10, the polarization transparent component 120 also includes: a polarization modulation element 124, which is arranged on the light-emitting side of at least part of the laser; the polarization modulation element 124 is configured to modulate the laser light with a single polarization direction into a laser light with at least two polarization directions for laser light of at least one color.

[0112] For example, the polarization modulation element 124 can be disposed between the laser and the crystal wave plate 121, and can perform polarization modulation on the three-color laser beams before beam combining, or on the multi-color laser beams after beam combining, without limitation. The polarization modulation element 124 can modulate laser beams polarized in a single direction into laser beams having different polarization directions, thereby varying the direction, incident position, and polarization orientation of the beam incident on the crystal wave plate 121. This increases the randomness of the polarization of the laser beam after passing through the crystal wave plate 121, thereby increasing its variability, improving uniformity, and reducing speckle.

[0113] For example, as shown in FIG21 , the polarization modulation element 124 may be provided corresponding to the red laser 113 to change the polarization direction of a portion of the red laser light emitted by the red laser 113 so that the red laser light may include P light and S light when incident on the crystal wave plate 121, thereby further improving polarization uniformity and improving speckle.

[0114] For example, as shown in FIG22 , a polarization modulation element 124 may be provided corresponding to the green laser 111, the blue laser 112, and the red laser 113; wherein, the polarization modulation element 124 may include a modulation area and a hollow area. For each color of light, part of the light changes its deflection direction by passing through the modulation area, and part of the light maintains its polarization direction unchanged by passing through the hollow area. Thus, each color of light includes two different polarization directions when entering the crystal wave plate 121, further increasing the clutter of the laser polarization after passing through the crystal wave plate 121, that is, increasing the difference, improving the uniformity, and improving the speckle.

[0115] In the above Figures 21 and 22, the polarization modulation element 124 corresponds to a monochromatic laser setting. In other embodiments, the polarization modulation element 124 can also correspond to a multi-color laser setting, and can perform polarization modulation on the light beam after the combination, as shown in Figure 23.

[0116] In the above-described embodiment, as shown in any of Figures 20-23 , the structure of a three-color laser display device is illustrated. Here, the red, green, and blue lasers are combined by a dichroic filter. After passing through a diffuser 122, a lens assembly 140, a crystal wave plate 121, and a diffuser wheel 123, the light is incident on a light pipe 150. The lasers are reflected back and forth within the light pipe 150, ultimately outputting a uniform white light spot. Following the light pipe 150 is an illumination system 102, typically consisting of two to four lenses. This illumination system 102 is used to direct the uniform white light output from the light pipe 150 onto a light modulator 130, such as a DMD display chip. The image formed by the light modulator 130 is then magnified by a TIR lens 104 and a lens 160, projecting the enlarged image.

[0117] The polarization modulation element 124 may be located between the laser and the dichroic plate, or at any position between the crystal wave plate 121 and the laser, which is not limited here.

[0118] The crystal wave plate 121 may adjust the entire light beam or a portion of the light beam, which is not limited here.

[0119] In the laser display device 10 provided in the embodiment of the present application, by providing the light source component 110 with a red, green, and blue laser, full-color laser display can be achieved; by providing the polarization transparent component 120 with a crystal wave plate 121, polarization conversion of different polarization ratios can be achieved for light incident from different directions without changing the light beam transmission direction, thereby improving polarization diversity and improving speckle while facilitating miniaturization; in some specific implementations, the exit surface 1212 of the crystal wave plate 121 may be a diffusion surface 1213, thereby further improving speckle; in some specific implementations, the polarization transparent component 120 may further include a diffusion plate or a diffusion wheel, thereby improving light spot uniformity and further improving speckle; in some specific implementations, the polarization transparent component 120 may further include a polarization modulation element 124 for increasing polarization diversity before the crystal wave plate 121 and further improving speckle (i.e., speckle contrast).

[0120] In other embodiments, the laser display device 10 may further include a projection screen or other components, which are not described or limited herein.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0122] For ease of explanation, the above description has been made with reference to specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations are possible. The above embodiments are selected and described to better explain the principles and practical applications, so that those skilled in the art can better utilize the embodiments and various different variations of the embodiments suitable for specific use considerations.

Claims

1. A laser display device, characterized in that: include: A light source component, a polar light-transmitting component, and a light modulation component; The light source component is configured to emit laser light having at least one color, and the laser light reaches the light modulation component after passing through the polar light-transmitting component; The polar light-transmitting component is disposed between the light source component and the light modulation component, and the polar light-transmitting component is configured to receive light incident from different directions, and the outgoing light includes a first polarized light and a second polarized light, the first polarized light is perpendicular to the second polarized light, and the proportions of the first polarized light and the second polarized light of the outgoing light corresponding to the light incident from different directions are different; The light modulation component is configured to modulate the received light beam to obtain a light beam having image information to be displayed.

2. The laser display device according to claim 1, characterized in that: The polar light-transmitting component is also configured to keep the incident direction and the emitting direction of the light the same.

3. The laser display device according to claim 1 or 2, characterized in that: The polar light-transmitting component comprises a crystal wave plate with uniform thickness; The incident surface and the exit surface of the crystal wave plate are parallel, and are configured to refract the incident light at the incident surface and then at the exit surface to obtain an exit light whose transmission direction is the same as that of the incident light.

4. The laser display device according to claim 3, characterized in that: The crystal wave plate is a half-wave plate, or a quarter-wave plate, or a three-quarter wave plate.

5. The laser display device according to claim 3, characterized in that: The exit surface of the crystal wave plate is set as a diffusion surface; The diffusion surface includes an irregular concave-convex structure.

6. The laser display device according to claim 3, characterized in that: The exit surface of the crystal wave plate is set as a diffusion surface; The diffusion surface includes regularly arranged concave-convex structures.

7. The laser display device according to claim 3, characterized in that: Also includes: A lens component, wherein the lens component comprises a focusing lens and / or a beam expanding lens; The focusing lens is configured to form a converging light beam, and the beam expanding lens is configured to form a diverging light beam; Wherein, the polar light-transmitting structure is arranged behind the lens component along the light transmission direction.

8. The laser display device according to claim 7, characterized in that: The lens component comprises a first focusing lens and a second focusing lens arranged along a light transmission direction, the first focusing lens and the second focusing lens share a common focal point, and the polar light-transmitting component is located at the focal position.

9. The laser display device according to claim 7, characterized in that: The lens component comprises a third focusing lens and a fourth expanding lens arranged along the light transmission direction, the third focusing lens and the fourth expanding lens have a common focal point, and the polar light-transmitting component is located at the focal position.

10. The laser display device according to claim 7, characterized in that: The divergence angle of the laser beam incident on the polar light-transmitting structure is greater than the divergence angle of the laser beam incident on the lens component.

11. The laser display device according to claim 3, characterized in that: Also includes: Light homogenization components; The light homogenizing component is configured to receive a convergent light beam and emit a light beam with uniform brightness; Wherein, the polar light-transmitting component is arranged before the light-homogenizing component along the light transmission direction.

12. The laser display device according to claim 3, characterized in that: Also includes: a lens assembly configured to focus the light beam; A first telescope and a second telescope are arranged between the light source component and the lens component; the first telescope is configured to converge the light beam, and the second telescope is configured to diverge the light beam; Wherein, the polar light-transmitting component is located between the first telescope and the second telescope along the light transmission direction, and / or is located behind the lens component.

13. The laser display device according to claim 12, characterized in that: Also includes: The light homogenizing component is provided between the second telescope and the light homogenizing component.

14. The laser display device according to claim 1, characterized in that: It also includes a diffusion wheel; the diffusion wheel is arranged in the light path between the polar light-transmitting component and the light modulation component.

15. The laser display device according to claim 1, characterized in that: The light source component includes a laser with a preset light output color; The polar light-transmitting component is arranged on the light-emitting side of at least part of the lasers, and is used to convert the laser light beam emitted by at least part of the lasers into laser light with at least two polarization directions.

16. The laser display device according to claim 1, characterized in that: The light source component includes a laser with a preset light output color; The polarized light-transmitting component is disposed in at least part of the light-combining optical path of the lasers of multiple colors, and is used to convert laser light of at least one color with a single polarization direction into laser light with at least two polarization directions.

17. The laser display device according to claim 1, characterized in that: The light-transmitting component further comprises: a polarization modulation element, which is arranged on the light-emitting side of at least part of the laser; The polarization modulation element is configured to modulate laser light with a single polarization direction into laser light with at least two polarization directions for laser light of at least one color.

18. The laser display device according to claim 1, characterized in that: The light modulation component is a digital micromirror device or an LCD liquid crystal light valve.

19. The laser display device according to claim 15 or 16, characterized in that: It also includes a projection lens, which is located at the light output side of the light modulator.

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