Single-group laser light source and miniature LCOS projection optical structure

Abstract

The utility model provides a single-group laser light source and a miniature LCOS projection optical structure, and belongs to the technical field of laser projectors. A single-group laser light source comprises a group of three-primary-color laser light sources, a half-wave plate and a dichroic mirror are sequentially arranged on a light path of a red light source, the half-wave plate is perpendicular to an incident optical axis of the light path, an angle of 45 degrees is formed between the dichroic mirror and the incident optical axis of the light path, and the dichroic mirror is a red-reflecting and blue-transmitting dichroic mirror. A spectroscope and a first reflector are sequentially arranged on blue light paths and green light paths of the blue light source and the green light source, the spectroscope and the first reflector respectively form an angle of 45 degrees with incident optical axes of the blue light paths and the green light paths, and the spectroscope is parallel to the first reflector and parallel to the dichroic mirror. The emergent optical axis of the dichroic mirror is parallel to the emergent optical axis of the first reflector. According to the utility model, the cost is low, the light path structure of light splitting is fully utilized, the angle, the space and the main light are optimized, side lobes generated by light spots are improved, and the light source efficiency loss is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of laser projectors, and in particular relates to a single-group laser light source and a micro LCOS projection optical structure. Background Art

[0002] With the continuous development of various projector products on the market, user selection is increasingly influenced by price. LCD projectors have a clear advantage in terms of price, but they suffer from short lifespans, low color saturation, and overly large display chips, resulting in a bulky overall optical architecture and hindering miniaturization. DLP projectors are also expensive and have poor contrast. Therefore, new LCOS projectors offer a balanced combination of price, color, and contrast to meet users' daily needs.

[0003] However, for LCOS projection systems, LED light sources have a wide divergence angle, generally low light utilization efficiency, limited brightness compared to laser light sources, and a much shorter lifespan than laser light sources. Dual-laser light source solutions are expensive due to the high price of the lasers and the large size of the entire lens set, making it difficult to strike a balance between price and performance, and thus failing to meet market demand for low-end projectors.

[0004] In summary, how to make the single-laser light source LCOS solution meet the requirements of low cost, miniaturization, high color saturation and high contrast has become one of the technical problems that technicians in this field urgently need to solve. Utility Model Content

[0005] In view of this, the first technical problem to be solved by the present invention is to provide a single-group laser light source that is low in cost while making full use of the splitting optical path structure, optimizing the angle, space and main light, improving the side lobes generated by the light spot, and reducing the efficiency loss of the light source.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is: a single-group laser light source, comprising: a group of three-primary-color laser light sources, wherein the optical paths of the red light source, the blue light source, and the green light source of the group of three-primary-color laser light sources are parallel, a half-wave plate and a dichroic mirror are sequentially arranged on the optical path of the red light source, the half-wave plate is perpendicular to the incident light axis of the optical path, the dichroic mirror is at an angle of 45° to the incident light axis of the optical path, the dichroic mirror is a dichroic mirror that reflects red and transmits blue and green, a beam splitter and a first reflector are sequentially arranged on the blue and green light paths of the blue and green light sources, the beam splitter and the first reflector are respectively at an angle of 45° to the incident light axes of the blue and green light paths, the beam splitter is parallel to the first reflector and to the dichroic mirror, and the output optical axis of the dichroic mirror is parallel to the output optical axis of the first reflector.

[0007] In this way, the red light emitted by the three-primary-color laser light source changes its polarization direction through a half-wave plate, making its polarization direction consistent with that of the blue and green light, so that the light beams are converged together to avoid the lack of red in the entire optical system. The red light is then reflected by a dichroic mirror; the blue and green light of the three-primary-color laser light source are divided into two parts by a beam splitter, half of the blue and green light pass through the dichroic mirror and converge with the red light; the other half of the blue and green light are reflected by the first reflector, so that the blue and green light paths are expanded, effectively improving the side lobes generated by the light spot, reducing the efficiency loss of the light source, and finally outputting red, green and blue lasers.

[0008] The second technical problem to be solved by the present invention is to provide a micro LCOS projection optical structure, which adopts the above-mentioned single group of laser light sources, optimizes the structure and improves the projection effect on the basis of low cost.

[0009] A micro LCOS projection optical structure includes the above-mentioned single group laser light source, and also includes a light homogenizing part, an illumination part and an imaging part arranged in sequence along the incident direction of the light source.

[0010] Optionally, the light homogenizing unit includes a diffuser, a first fly-eye lens, a first lens, and a second lens, which are sequentially arranged and perpendicular to the incident light axis of the light path, and the diffuser receives the output light of the dichroic mirror and the first reflector.

[0011] Optionally, the illumination unit includes a second fly-eye lens, a second reflector, a third lens, a fourth lens, a metal wire grid, a delay plate, an LCOS chip and a polarizer arranged in sequence along the optical path, the second fly-eye lens, the second reflector, the third lens, the metal wire grid, the delay plate, the LCOS chip and the polarizer are respectively perpendicular to the incident light axis of the optical path, and the second reflector and the metal wire grid are respectively at 45° to the incident light axis of the optical path.

[0012] Optionally, the imaging unit receives the emitted light of the illumination unit, and the imaging unit includes an imaging lens.

[0013] Optionally, the imaging unit further includes a pixel dither, which is perpendicular to the incident light axis of the optical path and is arranged between the analyzer and the imaging lens.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] The utility model uses a set of three-primary-color laser light sources for optimization and improvement. Taking into account the short optical path of red light, the larger image after laser diffusion, and the larger emitting angle of red light than blue and green light, a beam splitter is used to split the blue and green light paths, thereby expanding the blue and green light paths, effectively avoiding the generation of side lobes in the light spot, reducing the efficiency loss of the entire light source, reducing costs, and making the overall optical architecture arrangement more reasonable.

[0016] The micro LCOS projection optical structure of this utility model is a "U-shaped" architecture. Each part of the structure is in a single horizontal direction, which reduces energy loss and wide-edge volume. It is compatible with the architecture of other solutions in the same series to avoid repeated mold opening, thereby ensuring that the projection color, contrast and price are better than those of common projection optical structures while reducing the cost of the entire optical machine.

[0017] In summary, the utility model adopts a single-group laser light source micro LCOS projection optical structure, which adopts a group of three-primary color lasers as the light source, and can effectively avoid the side lobes of the light spot, so that the efficiency loss of the entire lighting group is smaller, the cost is low, the color saturation is high, and the contrast is high. At the same time, it can be compatible with other solution architectures, avoid repeated mold opening, and facilitate mass production implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described 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.

[0019] Figure 1 : A schematic structural diagram of a single-group laser light source of the utility model;

[0020] Figure 2 : A schematic structural diagram of a micro LCOS projection optical structure of the utility model;

[0021] Figure 3 : A schematic diagram of the light beam of a micro LCOS projection optical structure of the utility model;

[0022] Among them, 11, three-primary color laser light source; 12, half-wave plate; 13, dichroic mirror; 14, beam splitter; 15, first reflector;

[0023] 21. Diffuser; 22. First fly-eye lens; 23. First lens; 24. Second lens;

[0024] 31. Second fly-eye lens; 32. Second reflector; 33. Third lens; 34. Fourth lens; 35. Metal wire grid; 36. Retardation plate; 37. LCOS chip; 38. Analyzer;

[0025] 41. Pixel ditherer; 42. Imaging lens. DETAILED DESCRIPTION

[0026] To better understand the present invention, the following examples further illustrate the present invention. However, the present invention is not limited to the following examples. In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be practiced without one or more of these details.

[0027] In this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0028] Unless otherwise specified, the relative arrangement of components, numerical expressions, and numerical values ​​described in these embodiments do not limit the scope of the present invention. It should also be understood that for ease of description, the dimensions of the various parts shown in the drawings are not drawn to scale. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be considered part of the specification.

[0029] In the description of the present invention, it needs to be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0030] It should be noted that the use of words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this utility model.

[0031] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and are not to be construed as limiting the present invention.

[0032] like Figure 1As shown, a single-group laser light source includes: a group of three-primary-color laser light sources 11, wherein the optical paths of the red light source, the blue light source, and the green light source of the group of three-primary-color laser light sources 11 are parallel, a half-wave plate 12 and a dichroic mirror 13 are sequentially arranged on the optical path of the red light source, the half-wave plate 12 is perpendicular to the incident light axis of the optical path, the dichroic mirror 13 is at a 45° angle to the incident light axis of the optical path, and the dichroic mirror 13 is a red-reflecting and blue-green-transmissive dichroic mirror 13, a beam splitter 14 and a first reflector 15 are sequentially arranged on the blue and green light paths of the blue and green light sources, respectively, the beam splitter 14 and the first reflector 15 are at a 45° angle to the incident light axes of the blue and green light paths, the beam splitter 14 is parallel to the first reflector 15, and is also parallel to the dichroic mirror 13, and the output optical axis of the dichroic mirror 13 is parallel to the output optical axis of the first reflector 15.

[0033] In this way, the red light from the three-primary laser source 11 is polarized by a half-wave plate 12, aligning it with the blue and green light. It is then reflected by a dichroic mirror 13. The blue and green light from the three-primary laser source 11 is split into two parts by a beam splitter 14. Half of the blue and green light passes through the dichroic mirror 13, where it converges with the red light. The other half of the blue and green light is reflected by a first reflector 15, expanding the blue and green light paths, thereby outputting red, green, and blue laser light. The red beam has a large angle and a short optical path, resulting in a large image. The blue and green beams have small angles and long optical paths, resulting in small images. Therefore, the beam splitter 14 is needed to expand both the blue and green angles and images. The diffuser 21 dithers the point-like light from the source, changing its trajectory and diffusing it. This creates a planar beam, thus converging the red, green, and blue colors.

[0034] like Figure 1 As shown, a group of three-primary-color laser light sources 11 includes a substrate (not shown) and a red light source, a blue light source, and a green light source arranged on the substrate. The left side is a green light source and a blue light source, which respectively excite green light and blue light, and the right side is a red light source, which excites red light. The polarization direction of the red light changes through a half-wave plate 12 to be consistent with the blue and green light, and is reflected by a dichroic mirror 13; the left side of the three-primary-color laser light source 11 excites green light and blue light, and the blue and green light are further evenly separated by a spectroscope 14. Half of the blue and green light passes through the dichroic mirror 13 and converges with the red light of the three-primary-color laser light source 11. The other half of the blue and green light is reflected by a first reflector 15, so that the blue and green light paths are expanded, and the final light is emitted as nearly parallel light.

[0035] like Figure 2 and Figure 3 As shown, a micro LCOS projection optical structure includes the above-mentioned single group laser light source, and also includes a light uniforming part, an illumination part and an imaging part arranged in sequence along the incident direction of the light source.

[0036] In some preferred embodiments, the light homogenizing unit receives the output light of a single group of laser light sources, and includes a diffuser 21, a first fly-eye lens 22, a first lens 23, and a second lens 24, which are arranged in sequence and perpendicular to the incident light axis of the light path, wherein the diffuser 21 simultaneously receives the output light of the dichroic mirror 13 and the first reflector 15.

[0037] like Figure 2 As shown, the diffusion sheet 21, the first fly-eye lens 22, the first lens 23 and the second lens 24 are arranged in parallel.

[0038] Exemplarily, the first fly-eye lens 22 is a hexagonal fly-eye lens.

[0039] In view of the problem of laser speckle in laser light sources, the red light and the blue and green light of the light source converge and enter the light homogenizing part. The diffuser 21 in the light homogenizing part receives the incident light from the light source, so that the light is evenly diffused, reducing the visual impact of speckle; the evenly diffused light enters the first fly-eye lens 22, passes through the first fly-eye surface of the first fly-eye lens 22, is focused on the second fly-eye surface, and then is emitted through the first lens 23 and incident on the second lens 24 to concentrate the light.

[0040] In some preferred embodiments, the illumination unit receives the output light of the light homogenizing unit, and includes a second fly-eye lens 31, a second reflector 32, a third lens 33, a fourth lens 34, a metal wire grid 35, a delay plate 36, an LCOS chip 37 and an analyzer 38 arranged in sequence along the optical path. The second fly-eye lens 31, the second reflector 32, the third lens 33, the metal wire grid 35, the delay plate 36, the LCOS chip 37 and the analyzer 38 are respectively perpendicular to the incident light axis of the optical path, and the second reflector 32 and the metal wire grid 35 are respectively at 45° to the incident light axis of the optical path.

[0041] like Figure 2 As shown, the second fly-eye lens 31 is arranged parallel to the second lens 24 of the light homogenizing part, the second reflector 32 and the metal wire grid 35 are arranged at 45° to the second fly-eye lens 31, the third lens 33, the fourth lens 34, the delay plate 36, and the LCOS chip 37 are respectively arranged perpendicular to the second fly-eye lens 31, and the polarizer 38 is arranged parallel to the second fly-eye lens 31.

[0042] Exemplarily, the second fly-eye lens 31 is a rectangular fly-eye lens.

[0043] like Figure 2As shown, the light passes through the second fly-eye lens 31, which homogenizes the laser beam to produce uniform light, and then is reflected by the second reflector 32. The second reflector 32 also has the function of adjusting the light field and color band; the light is incident on the lens group of the third lens 33 and the fourth lens 34, which reduces the image to a size close to that of the LCOS chip 37. The metal wire grid 35 (WG) is between the fourth lens 34 and the delay plate 36, which acts as a PBS, transmitting parallel P light and reflecting S light. The light passes through the delay plate 36, and after polarization purification, the polarization direction of the laser beam is adjusted and corrected, thereby improving the contrast and color uniformity of the projected image; the adjusted and corrected laser beam enters the LCOS chip 37, is reflected by the metal wire grid 35 and enters the analyzer 38, which modulates the S light, allowing the laser beam to enter the imaging unit.

[0044] In some preferred embodiments, the imaging unit receives the light emitted by the illumination unit, and the imaging unit includes an imaging lens 42 .

[0045] like Figure 2 As shown, the imaging unit further includes a pixel dither 41 , which is perpendicular to the incident light axis of the optical path. The pixel dither 41 is arranged between the analyzer 38 and the imaging lens 42 , and the pixel dither 41 is arranged parallel to the analyzer 38 .

[0046] Exemplarily, the pixel ditherer 41 dithers 1 pixel from 1080P to 4K, and the light is then imaged on the screen through the imaging lens 42.

[0047] like Figure 1-3As shown, the present invention employs a three-primary laser light source 11 placed on a flat surface. A half-wave plate 12 is positioned parallel to and behind the red light path of the three-primary laser light source 11. A dichroic mirror 13 is tilted at a 45° angle to the half-wave plate 12. A beam splitter 14 is tilted at a 45° angle above the blue and green light paths of the three-primary laser light source 11 and is positioned parallel to the dichroic mirror 13 on the red light path. A first reflector 15 is parallel to the beam splitter 14. The hexagonal fly-eye lens is located behind the diffuser 21 and between the diffuser 21 and the first lens 23. The second lens 24 is located behind the first lens 23. The rectangular fly-eye lens is located behind the second lens 24 and between the second lens 24 and the second reflector 32. The third lens 33 is located between the second reflector 32 and the fourth lens 34. The wire grid 35 is tilted at a 45° angle after the fourth lens 34. The retarder 36 is located between the wire grid 35 and the LCOS chip 37. The analyzer 38 is located above the wire grid 35. The imaging lens 42 is located behind the pixel ditherer 41. The optical structure of the present invention is a "U-shaped" structure, with each component oriented in a single horizontal direction. This reduces energy loss and wide-edge volume of the reflector, and is compatible with the architecture of other solutions in the same series to avoid repeated mold opening. This ensures that the projection color, contrast, and price are superior to those of common projection optical structures while reducing the overall optical machine cost.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model and are not limiting. Other modifications or equivalent substitutions made to the technical solution of the utility model by ordinary technicians in this field should be included in the scope of the claims of the utility model as long as they do not depart from the spirit and scope of the technical solution of the utility model.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A single-group laser light source, characterized in that: include: A group of three-primary-color laser light sources (11), wherein the optical paths of a red light source, a blue light source, and a green light source in the group of three-primary-color laser light sources (11) are parallel, a half-wave plate (12) and a dichroic mirror (13) are sequentially arranged on the optical path of the red light source, the half-wave plate (12) is perpendicular to the incident optical axis of the optical path, the dichroic mirror (13) is at an angle of 45° to the incident optical axis of the optical path, and the dichroic mirror (13) is a red-reflecting and blue-transmitting dichroic mirror (13), A beam splitter (14) and a first reflector (15) are sequentially arranged on the blue and green light paths of the blue light source and the green light source, respectively. The beam splitter (14) and the first reflector (15) are 45 degrees to the incident light axes of the blue and green light paths, respectively. The beam splitter (14) is parallel to the first reflector (15) and is also parallel to the dichroic mirror (13). The output light axis of the dichroic mirror (13) is parallel to the output light axis of the first reflector (15).

2. A micro LCOS projection optical structure, characterized by: It comprises a single-group laser light source as claimed in claim 1, and further comprises a light homogenizing part, an illumination part and an imaging part arranged in sequence along the incident direction of the light source.

3. The micro LCOS projection optical structure according to claim 2, wherein: The light homogenizing section comprises a diffuser (21), a first fly-eye lens (22), a first lens (23), and a second lens (24) which are sequentially arranged and perpendicular to the incident light axis of the light path; the diffuser (21) receives the output light from the dichroic mirror (13) and the first reflector (15).

4. The micro LCOS projection optical structure according to claim 3, wherein: The illumination unit comprises a second fly-eye lens (31), a second reflector (32), a third lens (33), a fourth lens (34), a metal wire grid (35), a delay plate (36), an LCOS chip (37) and an analyzer (38) which are sequentially arranged along the optical path. The second fly-eye lens (31), the second reflector (32), the third lens (33), the metal wire grid (35), the delay plate (36), the LCOS chip (37) and the analyzer (38) are respectively perpendicular to the incident optical axis of the optical path, and the second reflector (32) and the metal wire grid (35) are respectively at an angle of 45° to the incident optical axis of the optical path.

5. The micro LCOS projection optical structure according to claim 4, wherein: The imaging unit receives the emitted light from the illumination unit, and the imaging unit includes an imaging lens (42).

6. The micro LCOS projection optical structure according to claim 5, wherein: The imaging unit further includes a pixel dither (41), the pixel dither (41) is perpendicular to the incident light axis of the optical path, and the pixel dither (41) is arranged between the polarizer (38) and the imaging lens (42).

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