Projection device and projection system

Abstract

The present invention discloses a projection device and a projection system, comprising: at least one laser light source, including a plurality of red laser chips, a plurality of green laser chips, and a plurality of blue laser chips, wherein the number of green laser chips and the number of blue laser chips are both less than the number of red laser chips; at least one waveguide plate, wherein one waveguide plate is located on the light-emitting side of each green laser chip; the waveguide plate comprises a light input portion and a light output portion, wherein the light input portion is used to guide the incident laser into the waveguide plate, and the light output portion is used to output the conducted laser; and the width of the laser beam emitted by the light output portion is equal to the width of the laser beam emitted by the red laser chip, so that the spot size of the blue and green lasers in the emitted light is the same as the spot size of the red laser, thereby making the optical etendue of the blue and green lasers the same as the optical etendue of the red laser, and the three colors of laser light are evenly distributed after light combination.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a projection device and a projection system. Background Art

[0002] Full-color laser display technology typically uses red, green, and blue lasers as light sources. These lasers offer a wide color gamut and high color saturation, reproducing real-world colors and delivering excellent display quality. However, due to their high collimation, narrow spectrum, and high coherence, lasers also introduce the problem of laser speckle, which compromises the quality of laser display images.

[0003] In current full-color laser display products, due to the requirements of color matching and laser power, the number of red lasers is generally required to be higher than the number of blue and green lasers. Therefore, the size of the blue light and green light spots emitted by the blue and green lasers will be somewhat different from the size of the light spots emitted by the red laser, resulting in the problem of uneven output light; the optical expansion of the red light spot is greater than the optical expansion of the blue and green light spots, which will further lead to the problem that the speckle of blue light and green light is more serious than that of red light. Summary of the Invention

[0004] The present invention provides a projection device and a projection system, which are used to solve the problem of uneven emission of red, green and blue lasers in current projection devices.

[0005] In a first aspect, the present invention provides a projection device, comprising:

[0006] At least one laser light source, the at least one laser light source comprising a plurality of red laser chips, a plurality of green laser chips, and a plurality of blue laser chips, wherein the number of the green laser chips and the number of the blue laser chips are both less than the number of the red laser chips;

[0007] At least one waveguide plate, one of the waveguide plates is located on the light-emitting side of each of the green laser chips; the waveguide plate includes a light input portion and a light output portion; the light input portion is used to introduce incident laser light into the waveguide plate, and the light output portion is used to output the conducted laser light; wherein the width of the laser beam emitted by the light output portion is equal to the width of the laser beam emitted by each of the red laser chips.

[0008] In some embodiments of the present invention, the waveguide plate includes a light incident surface and a light exit surface that are arranged relatively parallel, and the light incident portion and the light exit portion are both located between the light incident surface and the light exit surface; the laser light source is arranged relative to the light incident surface of the waveguide plate.

[0009] In some embodiments of the present invention, the light incident portion is a first reflective film, the light exit portion includes a transflective film and a second reflective film, and the transflective film is located between the first reflective film and the second reflective film;

[0010] The first reflective film, the transflective film, and the second reflective film are arranged parallel to each other and are inclined at a set angle relative to the light incident surface of the waveguide plate; the set angle satisfies the condition that the laser light is totally reflected in the waveguide plate;

[0011] The distance between the transflective film and the second reflective film is equal to the width of the laser beam emitted by each red laser chip.

[0012] In some embodiments of the present invention, the reflectivity of the transflective film is 50%, and the transmittance of the transflective film is 50%.

[0013] In some embodiments of the present invention, the light incident portion is a reflective film, the light emitting portion is a prism portion, the reflective film and the prism portion are separated by a set distance, and the prism portion is located on the light incident surface of the waveguide plate;

[0014] The prism portion includes a plurality of parallel arranged strip prisms, wherein a transflective film is provided on the surface of the plurality of strip prisms close to the reflective film and facing the reflective film, and a reflective film is provided on the surface of at least one strip prism away from the reflective film and facing the reflective film;

[0015] The width of the prism portion is equal to the width of the laser beam emitted by each of the red laser chips.

[0016] In some embodiments of the present invention, the projection device includes only one waveguide plate, and the waveguide plate is located on the light-emitting side of each green laser chip;

[0017] Alternatively, the projection device includes two waveguide plates, namely a first waveguide plate and a second waveguide plate, wherein the first waveguide plate is located on the light-emitting side of each green laser chip, and the second waveguide plate is located on the light-emitting side of each blue laser chip.

[0018] In some embodiments of the present invention, the projection device includes a laser light source, which includes multiple red laser chips, multiple green laser chips, and multiple blue laser chips; and the at least one waveguide is located on the light-emitting side of the laser light source.

[0019] In some embodiments of the present invention, the projection device includes two laser light sources, namely a first laser light source and a second laser light source;

[0020] The first laser light source includes a plurality of red laser chips, and the second laser light source includes a plurality of green laser chips and a plurality of blue laser chips; the at least one waveguide plate is located on the light output side of the second laser light source.

[0021] In some embodiments of the present invention, the projection device further comprises:

[0022] a beam combining lens assembly, located on the light-emitting side of each of the laser light sources, for combining the red laser, green laser, and blue laser beams;

[0023] A light homogenizing component, located on the light-emitting side of the light-combining lens assembly;

[0024] A shaping lens group is located on the light-emitting side of the light-uniform component;

[0025] A light modulation component, located on the light-emitting side of the shaping lens group, for modulating the incident laser light;

[0026] The projection lens is located on the light-emitting side of the light modulation component.

[0027] In a second aspect, the present invention provides a projection system, comprising:

[0028] A projection device, wherein the projection device is any one of the projection devices described above;

[0029] The projection screen is located on the light-emitting side of the projection device.

[0030] The beneficial effects of the present invention are as follows:

[0031] The projection device and projection system provided by the present invention include: at least one laser light source, including multiple red laser chips, multiple green laser chips, and multiple blue laser chips, wherein the number of green laser chips and the number of blue laser chips are both less than the number of red laser chips; at least one waveguide plate, wherein one waveguide plate is located on the light-emitting side of each green laser chip; the waveguide plate includes a light input portion and a light output portion, wherein the light input portion is used to guide the incident laser into the waveguide plate, and the light output portion is used to output the conducted laser; and the width of the laser beam emitted by the light output portion is equal to the width of the laser beam emitted by the red laser chip, so that the spot size of the blue and green lasers in the emitted light is the same as the spot size of the red laser, thereby making the optical etendue of the blue and green lasers the same as the optical etendue of the red laser, and the three colors of laser light are evenly distributed after light combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings introduced below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 Schematic diagram of a light combining scheme of three-color laser light sources in the prior art;

[0034] Figure 2 Schematic diagram of the principle of array waveguide;

[0035] Figure 3 Schematic diagram of the principle of the serrated waveguide;

[0036] Figure 4 A schematic diagram of the planar structure of a laser light source provided in an embodiment of the present invention;

[0037] Figure 5 One of the structural schematic diagrams of the projection device provided in an embodiment of the present invention;

[0038] Figure 6 One of the optical path schematic diagrams provided in an embodiment of the present invention;

[0039] Figure 7 The second optical path schematic diagram provided by the embodiment of the present invention;

[0040] Figure 8 A second structural diagram of a projection device provided in an embodiment of the present invention;

[0041] Figure 9 The third optical path diagram provided by the embodiment of the present invention;

[0042] Figure 10 The fourth optical path diagram provided by the embodiment of the present invention;

[0043] Figure 11 The fifth optical path diagram provided by the embodiment of the present invention;

[0044] Figure 12 This is a schematic structural diagram of a projection system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention will be further described below with reference to the accompanying drawings and examples. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concepts of the example embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all explained with reference to the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the true proportion.

[0046] In projection equipment, the light source is the main factor affecting the projection quality. Since laser is the light source with the highest color purity at present, mixing and adjusting the three primary colors of red, green and blue lasers can restore colors close to the real world to the greatest extent. This makes the laser light source have unique advantages that traditional light sources do not have. Therefore, full-color laser display technology using red, green and blue lasers as light sources has become a major development trend in the current projection field.

[0047] Full-color laser display technology combines a specific amount of red, green, and blue laser light to create an image. This technology offers the advantages of a wide color gamut, high contrast, and excellent color rendering. When applied to projection equipment, it can achieve excellent projection effects. However, due to the high collimation, narrow spectrum, and high coherence of lasers, randomly distributed bright and dark spots, known as laser speckle, can appear in the displayed image. This phenomenon can severely affect the clarity and resolution of the displayed image, reducing display quality.

[0048] In current full-color laser display products, due to the requirements of color matching and laser power, the number of red lasers generally requires a higher number than the number of blue and green lasers. Therefore, the width of the blue laser emitted by the blue laser, the green laser emitted by the green laser, and the red laser emitted by the red laser will be different, and after the light is combined, there will be a problem of uneven output light.

[0049] Furthermore, the product of the laser spot size and the divergence angle determines the optical expansion of the laser beam, that is, the smaller the laser beam size, the smaller the optical expansion of the laser beam. Since the smaller the optical expansion, the more serious the laser speckle phenomenon will be, the optical expansion of the red laser in the current full-color laser display products is greater than that of the blue laser and the green laser, which also brings the problem that the speckle of the blue laser and the green laser is more obvious than that of the red laser.

[0050] Figure 1Schematic diagram of a three-color laser light source light combination scheme in the prior art.

[0051] like Figure 1 As shown, in currently used laser light sources, the ratio of red, green, and blue laser chips is typically 2:1:1. In the prior art, a dichroic plate is used to combine light. The projection device includes a laser light source 100, a reflective plate 04, a first dichroic plate 05, a second dichroic plate 06, and a lens 07. The laser light source 100 may include a green laser chip 01, a blue laser chip 02, and a red laser chip 03. The first dichroic plate 05 can reflect blue laser light and transmit green laser light, while the second dichroic plate 06 can reflect red laser light and transmit both blue and green laser light.

[0052] The green laser light emitted by the green laser chip 01 is incident on the reflective plate 04 and then reflected to the first dichroic plate 05. It is then transmitted by the first dichroic plate 05 and the second dichroic plate 06 before being incident on the lens 07. The blue laser light emitted by the blue laser chip 02 is incident on the first dichroic plate 05 and then reflected to the second dichroic plate 06. It is then transmitted by the second dichroic plate 06 and then is incident on the lens 07. The red laser light emitted by the red laser chip 03 is incident on the second dichroic plate 06 and then reflected to the lens 07. The red, green, and blue laser lights are then combined by the lens 07 before being emitted.

[0053] However, since the number of red laser chips in the laser light source is greater than the number of blue laser chips and green laser chips, the width of the red laser beam incident on the lens is greater than the width of the green laser beam and the blue laser beam. The solution of using a dichroic plate to combine light does not change the size of each color beam. Finally, the output light after combining through lens 07 is not uniform, which will affect the projection display effect.

[0054] In view of this, an embodiment of the present invention provides a projection device to solve the problem of uneven light output in the above-mentioned projection device.

[0055] In the embodiments of the present invention, waveguides are used to achieve beam expansion. Specifically, they are based on the principles of arrayed and serrated waveguides. Essentially, a waveguide is a transparent substrate with a high refractive index. A light beam is coupled into the substrate through a specific structure on its side. The beam then propagates through total internal reflection within the substrate, reaching a specific location before being coupled out through a specific structure.

[0056] Figure 2 Schematic diagram of the principle of array waveguide.

[0057] like Figure 2As shown, the coupling-in end of the arrayed waveguide plate A may include a coupling-in end reflective film a1, and the coupling-out end may include at least one layer of transflective film a2 and a coupling-out end reflective film a3. A light beam incident on the coupling-in end of the arrayed waveguide plate A is first reflected by the coupling-in end reflective film a1 and then propagates through the arrayed waveguide plate A through multiple total reflections. As the light beam passes through each transflective film a2, the transflective film a2 reflects a portion of the light beam out of the arrayed waveguide plate A and transmits another portion of the light beam to the next transflective film. When the light beam reaches the coupling-out end reflective film a3 at the coupling-out end of the arrayed waveguide plate A, the coupling-out end reflective film a3 reflects the remaining light beam out of the arrayed waveguide plate A.

[0058] By setting multiple film layers in the arrayed waveguide plate, the light beam in the arrayed waveguide plate can be emitted in batches, thereby achieving the effect of expanding the light beam. Furthermore, by adjusting the number and position of the transflective films in the arrayed waveguide plate, the size of the light beam can be flexibly controlled. By adjusting the reflectivity and transmittance of each transflective film, the light beam is reflected multiple times in the arrayed waveguide plate, and the emitted light can be adjusted to make it more uniform.

[0059] Figure 3 Schematic diagram of the principle of a serrated waveguide.

[0060] like Figure 3 As shown, the sawtooth waveguide plate B can include a reflective film b1 at the input end and a prism portion b2 at the output end. Each surface of the prism portion b2 can be provided with either a transflective film or a reflective film. The number of transflective and reflective films can be adjusted based on actual needs. A light beam is incident on the reflective film b1, reflected by it, and then propagates through the sawtooth waveguide plate B through multiple total reflections. As the light beam passes through each transflective film on the prism portion b2, a portion of the light is reflected out of the sawtooth waveguide plate B, while another portion is transmitted to the next transflective film. When the light beam reaches the reflective film on the prism portion b2, it is reflected out of the sawtooth waveguide plate B.

[0061] By providing a transflective film and a reflective film in the sawtooth waveguide plate B, the spot of the outgoing light can be expanded to the same width as the prism portion, thereby achieving the effect of light beam homogenization.

[0062] By applying the principles of the above-mentioned array waveguide plate and the sawtooth waveguide plate to the projection equipment, it is possible to achieve uniform distribution of laser lights of different colors emitted by the laser source.

[0063] The projection device provided by the embodiment of the present invention may include at least one laser light source and at least one waveguide.

[0064] Figure 4 A schematic diagram of the planar structure of a laser light source provided in an embodiment of the present invention.

[0065] like Figure 4As shown, the laser light source 40 includes multiple red laser chips 403, multiple green laser chips 401, and multiple blue laser chips 402, wherein the number of green laser chips 401 and the number of blue laser chips 402 are both less than the number of red laser chips 403. The red laser chips 403, green laser chips 401, and blue laser chips 402 are arranged in an array.

[0066] In specific implementation, the laser light source 40 can be a laser or a laser array. Figure 4 For example, current MCL lasers typically have 4 rows and 7 columns of laser chips. In an embodiment of the present invention, they may include 2 rows and 7 columns of red laser chips 403 , 1 row and 7 columns of green laser chips 401 , and 1 row and 7 columns of blue laser chips 402 .

[0067] In practical applications, other numbers of laser chips and lasers may be used and arranged in other arrangements. The embodiments of the present invention are only used for illustration and do not limit the specific number and arrangement of laser chips and lasers.

[0068] Since the ratio of the number of red, green, and blue laser chips in currently used lasers is generally 2:1:1, the drawings provided in the embodiments of the present invention are all described using the case where the laser light source includes two rows of red laser chips 403, one row of green laser chips 401, and one row of blue laser chips 402 as an example.

[0069] At least one waveguide plate is located on the light-emitting side of each green laser chip. Each waveguide plate includes a light input portion and a light output portion. The light input portion is used to introduce the incident laser into the waveguide plate, and the light output portion is used to output the transmitted laser. In addition, the width of the laser beam emitted by the light output portion is equal to the width of the laser beam emitted by each red laser chip.

[0070] In specific implementation, the waveguide can be made of materials with low optical transparency and transmission loss, such as glass, silicon dioxide, lithium niobate or polymer materials, and a film layer with reflection or transmission function can be formed in the light input and light output parts of the waveguide, so that the light incident on the waveguide can propagate along the set path in the waveguide.

[0071] Figure 5 This is one of the structural schematic diagrams of the projection device provided by an embodiment of the present invention.

[0072] like Figure 5 As shown, the laser light source 40 includes a green laser chip 401, a blue laser chip 402, and a red laser chip 403. The waveguide 10 includes a light incident surface I and a light output surface O that are relatively parallel. The light incident portion 20 and the light output portion 30 of the waveguide 10 are both located between the light incident surface I and the light output surface O. The laser light source 40 is disposed opposite the light incident surface I of the waveguide 10.

[0073] In an embodiment of the present invention, the projection device may include only one waveguide plate 10, and this waveguide plate 10 is located on the light-emitting side of each green laser chip 401. The waveguide plate 10 can expand the beam width of the green laser light emitted by the green laser chip 401, so that the width of the green laser beam emitted by the light-emitting portion 30 of the waveguide plate 10 is equal to the width of the red laser beam emitted by each red laser chip 403. In a specific implementation, the waveguide plate 10 can be an array-type waveguide plate or a serrated waveguide plate.

[0074] Since the human eye is not sensitive to blue light, the emitted light can be made more uniform by simply making the beam width of the green laser and the red laser the same. In addition, the optical etendue of the green laser beam is increased and made the optical etendue of the green laser beam the same as the optical etendue of the red laser beam, which can reduce the speckle phenomenon of the green laser, thereby achieving better projection display effects at a lower cost.

[0075] In embodiments of the present invention, the projection device may further include a beam combining lens assembly 50. This lens assembly 50 is located on the light-emitting side of the laser light source 40 and is used to combine the red, green, and blue laser beams. The combined beams have good uniformity. In a specific implementation, the beam combining lens assembly 50 may be composed of components such as at least one reflector and at least one dichroic mirror, and may be configured according to specific requirements.

[0076] A light homogenizing component 60 can be provided on the light-emitting side of the light-combining lens assembly 50 to further homogenize the light combined by the light-combining lens assembly 50, thereby making the laser energy distribution more uniform and improving the laser speckle. In a specific implementation, a light pipe or a fly-eye lens can be used as the light homogenizing component 60.

[0077] The light combining mirror group 50 combines the three-color laser beams emitted by the laser light source 40. Usually, the size of the combined laser spot is large, so a focusing lens group 500 can be set on the light output side of the light combining mirror group 50 to focus and shrink the laser beam, so that more light can be incident on the light homogenizing component 60.

[0078] Figure 6 This is one of the optical path schematic diagrams provided in an embodiment of the present invention.

[0079] like Figure 6 As shown, the waveguide plate 10 in the embodiment of the present invention can be an array type waveguide plate.

[0080] Specifically, the light entrance portion of the waveguide 10 may be a first reflective film 21, and the light exit portion may include a transflective film 31 and a second reflective film 32, with the transflective film 31 located between the first reflective film 21 and the second reflective film 32. The first reflective film 21, the transflective film 31, and the second reflective film 32 are arranged parallel to each other, and are tilted at a set angle relative to the light entrance surface I of the waveguide 10. The set angle should satisfy the conditions for reflecting the incident laser and causing the laser to be totally reflected in the waveguide 10. In a specific implementation, the transflective film 31 can be coated to change its transmittance and reflectance of the incident light, and the second reflective film 32 can be coated to change the wavelength of light that it can transmit and reflect. Figure 6 In the projection device shown, the transflective film 31 can transmit part of the green laser and reflect part of the green laser, and can completely transmit the red laser. The second reflective film 32 can transmit the red laser and reflect the green laser. At this time, the second reflective film 32 is equivalent to a dichroic mirror.

[0081] like Figure 6 As shown, the green laser light emitted from the green laser chip 401 is guided into the optical waveguide 10 by the first reflective film 21. Since the inclination angle of the first reflective film 21 relative to the light incident surface I satisfies the total reflection condition, after the first reflective film 21 reflects the green laser light onto the light incident surface I of the waveguide plate 10, the green laser light can be totally reflected multiple times by the light incident surface I and the light exiting surface O in the waveguide plate 10 and then incident on the transflective film 31. The portion of the green laser light reflected by the transflective film 31 is guided out of the optical waveguide 10, and the portion of the green laser light transmitted by the transflective film 31 continues to propagate in the waveguide plate 10 to the second reflective film 32, and is then completely reflected by the second reflective film 32 before being guided out of the waveguide plate 10.

[0082] In the embodiment of the present invention, the light-combining mirror assembly 50 includes a first light-combining mirror 51 and a second light-combining mirror 52. The first light-combining mirror 51 reflects blue light, while the second light-combining mirror 52 reflects red and green light and transmits blue light. The first light-combining mirror 51 and the second light-combining mirror 52 are arranged in parallel and can form a set angle with respect to the waveguide 10.

[0083] After the green laser is guided out of the waveguide plate 10, it is reflected by the second light-combining mirror 52 toward the focusing lens 500. The blue laser emitted from the blue laser chip 402 is directly transmitted by the waveguide plate 10 and then incident on the first light-combining mirror 51, then reflected by the first light-combining mirror 51 to the second light-combining mirror 52, and then transmitted by the second light-combining mirror 52 and incident on the focusing lens 500. The red laser emitted from the red laser chip 403 is transmitted by the waveguide plate 10 and then incident on the second light-combining mirror 52, and then reflected by the second light-combining mirror 52 toward the focusing lens 500. The red, green, and blue lasers incident on the focusing lens 500 are focused by the focusing lens 500.

[0084] In this embodiment of the present invention, the transflective film 31 and the second reflective film 32 are respectively disposed on the light-emitting sides of the two rows of red laser chips 403. Because the green laser light is directed out of the waveguide plate 10 twice by the transflective film 31 and the second reflective film 32, the width of the green laser beam emitted from the waveguide plate 10 is equal to the distance between the transflective film 31 and the second reflective film 32. Furthermore, because both the transflective film 31 and the second reflective film 32 transmit red laser light, the width of the red laser beam emitted from the red laser chip 403 is also equal to the distance between the transflective film 31 and the second reflective film 32. This ensures that the width of the green laser beam is equal to that of the red laser beam, resulting in more uniform light output. Furthermore, the etendue of the green laser beam is increased to the same as that of the red laser beam, reducing speckle in the green laser light.

[0085] In a specific implementation, the transmittance and reflectance of the transflective film 31 can be changed according to the design requirements of the projection equipment. In some embodiments of the present invention, the transmittance of the transflective film 31 can be 50%, and the reflectance of the transflective film 31 can be 50%, so that the energy of the green laser light emitted from the transflective film 31 and the second reflective film 32 can be equal, so that the intensity distribution of the emitted green laser beam is more uniform.

[0086] Figure 7 This is the second optical path schematic diagram provided by an embodiment of the present invention.

[0087] As shown in FIG7 , the waveguide plate 10 in the embodiment of the present invention may be a sawtooth waveguide plate.

[0088] Specifically, the light entrance portion of the waveguide sheet 10 may be a reflective film 22, and the light exit portion may be a prism portion 33. The reflective film 22 and the prism portion 33 are separated by a predetermined distance, and the prism portion 33 is located on the light entrance surface I of the waveguide sheet 10. The prism portion 33 may include a plurality of parallel strip prisms N. The plurality of strip prisms N near the reflective film 22 have transflective coatings disposed on their surfaces facing the reflective film 22, while at least one strip prism N farthest from the reflective film 22 has a reflective coating disposed on its surface facing the reflective film 22. In a specific implementation, a reflective coating may be disposed on the surface of the strip prism N farthest from the reflective film 22 facing the reflective film 22. This reflective coating can reflect all light propagating from the waveguide sheet 10 to that surface and out of the waveguide sheet 10, thereby preventing light loss.

[0089] like Figure 7As shown, the green laser light emitted from the green laser chip 401 is guided into the waveguide plate 10 by the reflective film 22, and then reflected by the reflective film 22 to the light incident surface I of the waveguide plate 10. The green laser light can be reflected multiple times by the light incident surface I and the light exiting surface O in the waveguide plate 10 and then incident on the prism portion 33. When the green laser light passes through the transflective film on each strip prism N, it can be partially transmitted and partially reflected. The transmitted light continues to propagate to the next strip prism N, and the reflected light is guided out of the waveguide plate 10. After repeating the above process multiple times, the green laser light is completely reflected by the reflective film N1 and exits the optical waveguide 10.

[0090] The green laser light emitted from the green laser chip 401 is emitted from the waveguide plate 10 in multiple times, and the width of the final light beam emitted from the optical waveguide 10 is equal to the width of the prism portion 33. In the embodiment of the present invention, the width of the prism portion 33 is set to be equal to the width of the laser beam emitted by each red laser chip 403, so that the beam widths of the green laser and the red laser can be equal. After the two are combined by the light combining lens group 50, the output light is more uniform. At the same time, the optical etendue of the green laser beam can be expanded to the same as the optical etendue of the red laser beam, thereby reducing the speckle phenomenon of the green laser.

[0091] Figure 8 This is a second structural diagram of the projection device provided in an embodiment of the present invention.

[0092] like Figure 8 As shown, in an embodiment of the present invention, the projection device may include two waveguides, namely a first waveguide 101 and a second waveguide 102. The first waveguide 101 is located on the light-emitting side of each green laser chip 401, and the second waveguide 102 is located on the light-emitting side of each blue laser chip 402. The first waveguide 101 can expand the beam width of the green laser light emitted by the green laser chip 401, and the second waveguide 102 can expand the beam width of the blue laser light emitted by the blue laser chip 402, so that the width of the green laser beam emitted by the first waveguide 101, the width of the blue laser beam emitted by the second waveguide 102, and the width of the red laser beam emitted by each red laser chip 403 are equal.

[0093] The use of two waveguides in a projection device can be used when the laser light source has a small number of blue laser chips. By increasing the width of the blue and green laser beams to match that of the red laser beam, the emitted light is evenly distributed, while also avoiding the issues of abnormal color temperature and color on the display caused by the smaller blue laser beam width. The etendue of both blue and green lasers is increased to match that of red lasers, minimizing the difference in speckle between the blue and green lasers and the red laser.

[0094] In a specific implementation, both the first waveguide plate 101 and the second waveguide plate 102 can be arrayed waveguide plates; alternatively, both the first waveguide plate 101 and the second waveguide plate 102 can be sawtooth waveguide plates; alternatively, the first waveguide plate 101 and the second waveguide plate 102 can be arrayed waveguide plates and sawtooth waveguide plates, respectively. Both of these can achieve the effect of expanding the beam width of the blue laser and the green laser. The following embodiments are described using the case where both the first waveguide plate 101 and the second waveguide plate 102 are arrayed waveguide plates as an example.

[0095] Figure 9 This is the third optical path schematic diagram provided by an embodiment of the present invention.

[0096] like Figure 9 As shown, the light incident portion of the first waveguide plate 101 may be the third reflective film 211, which is arranged on the light output side of the green laser chip 401. The light output portion of the first waveguide plate 101 may include a first transflective film 311 and a fourth reflective film 321. The first transflective film 311 is located between the third reflective film 211 and the fourth reflective film 321. The third reflective film 211, the first transflective film 311, and the fourth reflective film 321 are arranged parallel to each other and are tilted at a set angle relative to the light incident surface of the first waveguide plate 101. The set angle should meet the condition for total reflection of the laser in the first waveguide plate 101.

[0097] The light incident portion of the second waveguide 102 may be a fifth reflective film 212, which is disposed on the light-emitting side of the blue laser chip 402. The light-emitting portion of the second waveguide 102 may include a second transflective film 312 and a sixth reflective film 322. The second transflective film 312 is located between the fifth reflective film 212 and the sixth reflective film 322. The fifth reflective film 212, the second transflective film 312, and the sixth reflective film 322 are disposed parallel to each other and are tilted at a set angle relative to the light incident surface of the second waveguide 102. The set angle should satisfy the condition for total reflection of the laser light in the second waveguide 102.

[0098] The spacing between the first transflective film 311 and the fourth reflective film 321, and the spacing between the second transflective film 312 and the sixth reflective film 322 are both equal to the width of the laser beam emitted by each red laser chip 403. In a specific implementation, the first transflective film 311 and the second transflective film 312 can be arranged in parallel, and the fourth reflective film 321 and the sixth reflective film 322 can be arranged in parallel.

[0099] The green laser light emitted by the green laser chip 401 is reflected by the third reflective film 211, undergoes multiple total reflections in the first waveguide plate 101, and then enters the first transflective film 311. The green laser light is then partially transmitted and partially reflected. The transmitted portion of light continues to propagate in the first waveguide plate 101 to the fourth reflective film 321, and is completely reflected by the fourth reflective film 321 to exit the first waveguide plate 101. Therefore, the width of the green laser beam emitted from the first waveguide plate 101 is equal to the width of the red laser beam.

[0100] The blue laser light emitted by the blue laser chip 402 is reflected by the fifth reflective film 212, undergoes multiple total reflections in the second waveguide plate 102, and then enters the second transflective film 312. The blue laser light is then partially transmitted and partially reflected. The transmitted portion of light continues to propagate through the second waveguide plate 102 to the sixth reflective film 322, where it is completely reflected by the sixth reflective film 322 and exits the second waveguide plate 102. Therefore, the width of the blue laser beam emitted from the second waveguide plate 102 is equal to the width of the red laser beam.

[0101] The green laser beam output from the first waveguide plate 101 , the blue laser beam output from the second waveguide plate 102 , and the red laser beams emitted from each red laser chip 403 are directly incident on the focusing lens 500 .

[0102] Setting two waveguides in the projection device can make the beam widths of the red, green and blue lasers equal, so that the color distribution of the output light is uniform. Only one focusing lens is set to focus the light, and the light-combining lens group is omitted, which is conducive to simplifying the internal structure of the projection device and achieving a low-cost and lightweight design.

[0103] Figure 10 This is the fourth optical path schematic diagram provided by an embodiment of the present invention.

[0104] like Figure 10 As shown, in the embodiment of the present invention, the light combining mirror group may include a first light combining mirror 51. The first light combining mirror 51 can be used to reflect the green laser emitted from the first waveguide plate 101, the blue laser emitted from the second waveguide plate 102, and the red laser emitted from the red laser chip 403 in the same direction to achieve light combining and incident on the focusing lens 500, thereby achieving the purpose of steering the projection image and making the projection device suitable for more real-life scenarios.

[0105] Reference Figures 5 to 10 In some embodiments of the present invention, the projection device may include a laser light source 40, which may include multiple red laser chips 403, multiple green laser chips 401 and multiple blue laser chips 402, and at least one optical waveguide is located on the light output side of the laser light source 40.

[0106] Figure 11This is the fifth optical path schematic diagram provided by an embodiment of the present invention.

[0107] like Figure 11 As shown, in other embodiments of the present invention, the projection device may include two laser light sources, namely a first laser light source 41 and a second laser light source 42. The first laser light source 41 includes a red laser chip 403, and the second laser light source 42 includes a green laser chip 401 and a blue laser chip 402. The first waveguide plate 101 and the second waveguide plate 102 are located on the light output side of the second laser light source 42. In specific implementations, the number of red laser chip 403, green laser chip 401, blue laser chip 402, and waveguide plates can be multiple, and the number is not limited here.

[0108] In the embodiment of the present invention, the light combining mirror group may include a third light combining mirror 53 . The third light combining mirror 53 has the function of reflecting blue light, green light and transmitting red light.

[0109] The red laser beam emitted from the red laser chip 403 in the first laser light source 41 is transmitted through the third light combiner 53 and then incident on the focusing lens 500; the green laser beam emitted from the green laser chip 401 in the second laser light source 42 is expanded to the same width as the red laser beam through the first waveguide plate 101, and the blue laser beam emitted from the blue laser chip 402 in the second laser light source 42 is expanded to the same width as the red laser beam through the second waveguide plate 102. Both the green laser beam and the blue laser beam are reflected by the third light combiner 53 to the focusing lens 500, and the focusing lens 500 then combines the red, green and blue laser beams.

[0110] The solution of including two laser light sources in the projection device can also be used in a scenario where the laser light source includes 2 rows and 7 columns of red laser chips 403, 1 row and 7 columns of green laser chips 401, and 1 row and 7 columns of blue laser chips 402.

[0111] Reference Figure 5 and Figure 8 In the embodiment of the present invention, a shaping lens group 70, a light modulation component 80 and a projection lens 90 may also be included.

[0112] The shaping lens assembly 70 can be composed of multiple lenses. The specific structure of the lenses can be optically designed according to actual needs. In a specific implementation, the shaping lens assembly 70 may include at least one lens, and the specific structure and number of lenses in the shaping lens assembly 70 are not limited herein. The shaping lens assembly 70 is located on the light-emitting side of the light-uniform component 60. The shaping lens assembly 70 can not only collimate the laser light, but also ensure that the laser spot is incident on the light modulation component 80 at a suitable angle.

[0113] The light modulation component 80 is located on the light-emitting side of the shaping lens group 70 and can be used to modulate the incident laser. In specific implementation, a digital micromirror device (DMD) can be used as the light modulation component 80. The DMD surface includes many tiny mirrors, each of which can be driven individually for deflection. By controlling the deflection angle and deflection time of the DMD, the brightness of the reflected light can be modulated, and the modulated reflected light can be incident on the projection lens 90.

[0114] The projection lens 90 is located on the light-emitting side of the light modulating component 80. Its specific structure can be optically designed according to actual needs. The projection lens 90 can be an ultra-short-throw projection lens, which is not limited here. The projection lens 90 can be used to emit the laser light modulated by the light modulating component 80 and form an image.

[0115] Figure 12 This is a schematic structural diagram of a projection system provided by an embodiment of the present invention.

[0116] Based on the same inventive concept, an embodiment of the present invention further provides a projection system, such as Figure 12 As shown, the projection system includes a projection device 1 and a projection screen 2 .

[0117] Projection screen 2 is located on the light-emitting side of projection device 1. The audience faces projection screen 2. Projection device 1 emits projection light, which is incident on projection screen 2 and then reflected by projection screen 2 into the human eye, allowing the audience to view the projected image. In specific implementations, projection device 1 can employ any of the projection devices described in the aforementioned embodiments. The three-color laser light emitted by the projection device exhibits uniform light emission and minimal speckle, resulting in an image projected onto the projection screen having good contrast and clarity.

[0118] It is worth mentioning that the embodiments of the present invention can also be applied to the field of laser lighting. By providing at least one optical waveguide, the laser beam can be expanded, so that after combining the red, green and blue lasers, uniform white light can be obtained as the light source of the lighting device, achieving a good lighting effect.

[0119] According to the first inventive concept, a waveguide is provided on the light-emitting side of each green laser chip of the laser light source. By providing a transflective film and a reflective film with a set distance in the waveguide, and the specific distance is equal to the width of the red laser beam emitted by the red laser chip, the green laser is emitted from the waveguide twice. This can expand the green laser beam to be equal to the width of the red laser beam. When the number of blue laser chips is not much different from the number of green laser chips, the three-color laser can be emitted evenly.

[0120] According to the second inventive concept, a waveguide is provided on the light-emitting side of each green laser chip of the laser light source. By providing a reflective film and a prism portion including a plurality of strip prisms in the waveguide, and the prism portion has a width equal to that of the red laser beam emitted by the red laser chip, a transflective film is provided on the surface of each strip prism facing the reflective film, and a reflective film is provided on the surface of at least one strip prism facing the reflective film away from the reflective film, so that the green laser is emitted from the waveguide in multiple times, the green laser beam can be expanded to be equal to the width of the red laser beam. When the number of blue laser chips is not much different from that of green laser chips, the three-color laser can be emitted evenly.

[0121] According to the third inventive concept, a first waveguide is provided on the light-emitting side of each green laser chip, and a second waveguide is provided on the light-emitting side of each blue laser chip. This allows the widths of both the green and blue laser beams to be expanded to be equal to the width of the red laser beam emitted by each red laser chip. This allows the red, green, and blue lasers to be emitted evenly, reducing the difference in speckle between the blue and green lasers and the red laser. Furthermore, when the number of blue laser chips is small, it can avoid abnormal color temperature and color cast problems in the displayed image.

[0122] According to the fourth invention, the light-emitting side of each optical waveguide is provided with a light-combining mirror group and a light-uniform component, etc., which can combine the red, green and blue lasers to achieve uniform white light, which can be applied to the field of laser lighting.

[0123] According to the fifth inventive concept, using one or two laser light sources can realize diversified designs of the internal structure of the projection device, which are respectively applicable to situations where the ratio of the number of three-color laser chips included in the laser light source is different.

[0124] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0125] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A projection device, characterized in that: include: At least one laser light source, the at least one laser light source comprising a plurality of red laser chips, a plurality of green laser chips, and a plurality of blue laser chips, wherein the number of the green laser chips and the number of the blue laser chips are both less than the number of the red laser chips; At least one waveguide plate, one of the waveguide plates being located on the light-emitting side of each green laser chip; the waveguide plate comprising a light input portion and a light output portion; the light input portion being used to guide incident laser light into the waveguide plate for total reflection within the waveguide plate and transmitting the incident laser light to the light-emitting side of the red laser chip; and the light output portion being used to guide the transmitted laser light out and combine it with the laser light emitted by the red laser chip; The width of the laser beam emitted by the light emitting portion is equal to the width of the laser beam emitted by each red laser chip; the light emitting portion includes an array composed of a transflective film and a reflective film; or the light emitting portion includes a prism portion.

2. The projection device according to claim 1, wherein: The waveguide plate includes a light incident surface and a light exit surface which are arranged relatively parallel, and the light incident portion and the light exit portion are both located between the light incident surface and the light exit surface; the laser light source is arranged opposite to the light incident surface of the waveguide plate.

3. The projection device according to claim 2, wherein: The light incident portion is a first reflective film, the light exit portion includes a transflective film and a second reflective film, and the transflective film is located between the first reflective film and the second reflective film; The first reflective film, the transflective film, and the second reflective film are arranged parallel to each other and are inclined at a set angle relative to the light incident surface of the waveguide plate; the set angle satisfies the condition that the laser light is totally reflected in the waveguide plate; The distance between the transflective film and the second reflective film is equal to the width of the laser beam emitted by each red laser chip.

4. The projection device according to claim 3, wherein: The reflectivity of the transflective film is 50%, and the transmittance of the transflective film is 50%.

5. The projection device according to claim 2, wherein: The light incident portion is a reflective film, the light emitting portion is a prism portion, the reflective film and the prism portion are at a set distance, and the prism portion is located on the light incident surface of the waveguide plate; The prism portion includes a plurality of parallel arranged strip prisms, wherein a transflective film is provided on the surface of the plurality of strip prisms close to the reflective film and facing the reflective film, and a reflective film is provided on the surface of at least one strip prism away from the reflective film and facing the reflective film; The width of the prism portion is equal to the width of the laser beam emitted by each of the red laser chips.

6. The projection device according to claim 1, wherein: The projection device comprises only one waveguide plate, and the waveguide plate is located on the light-emitting side of each green laser chip; Alternatively, the projection device includes two waveguide plates, namely a first waveguide plate and a second waveguide plate, wherein the first waveguide plate is located on the light-emitting side of each green laser chip, and the second waveguide plate is located on the light-emitting side of each blue laser chip.

7. The projection device according to claim 6, wherein: The projection device includes a laser light source, which includes multiple red laser chips, multiple green laser chips, and multiple blue laser chips; the at least one waveguide plate is located on the light output side of the laser light source.

8. The projection device according to claim 6, wherein: The projection device includes two laser light sources, namely a first laser light source and a second laser light source; The first laser light source includes a plurality of red laser chips, and the second laser light source includes a plurality of green laser chips and a plurality of blue laser chips; the at least one waveguide plate is located on the light output side of the second laser light source.

9. The projection device according to claim 7 or 8, characterized in that: The projection device further includes: a beam combining lens assembly, located on the light-emitting side of each of the laser light sources, for combining the red laser, green laser, and blue laser beams; A light homogenizing component, located on the light-emitting side of the light-combining lens assembly; A shaping lens group is located on the light-emitting side of the light-uniform component; A light modulation component, located on the light-emitting side of the shaping lens group, for modulating the incident laser light; The projection lens is located on the light-emitting side of the light modulation component.

10. A projection system, characterized in that: include: A projection device, wherein the projection device is the projection device according to any one of claims 1 to 9; The projection screen is located on the light-emitting side of the projection device.

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