Light path structure of LCOS projection light machine using laser fluorescent ceramic light source

Abstract

The invention provides a light path structure of an LCOS projection light machine using a laser fluorescent ceramic light source, which is applied to the technical field of projection display, and is characterized in that a blue excitation light source array emits blue excitation light to excite static fluorescent ceramic to generate red-green mixed light; the blue laser light source emits blue laser for supplementing the blue laser, and then high-brightness red light, green light and blue laser can be emitted to the LCOS through processing of the light combining element, the polarization processing optical element, the color control optical group, the polarization light splitting element and the like and then emitted out from the projection lens after being modulated by the LCOS. The fluorescent material has the technical effects that wavelength conversion can be stably carried out on exciting light, the heat dissipation performance and the laser damage resistance threshold value of the fluorescent material are improved, and the output luminous flux of a light source is increased; and moreover, the projection picture of the projection light machine has the characteristic of high brightness, and the projection light machine can also perform clear imaging in a bright environment, so that the problem that the picture is not clear when the projection light machine is used in the bright environment is solved.

Description

Technical Field

[0001] The present invention relates to the field of projection display technology, and in particular to an optical path structure of an LCOS projection optical machine using a laser fluorescent ceramic light source. Background Art

[0002] Projector optical machine refers to the core component that converts input signals into images, which includes components such as light source, lens group, optical engine and display element; its function is to convert input signals into projected images through optical technology; with the continuous development of optical projection technology, projector optical machine is becoming an indispensable and important tool for people's work, study and life; among them, laser light source is a commonly used light source type for projector optical machine, which has the advantages of high brightness, wide color gamut and vivid image; its disadvantage is that the highly coherent laser will produce speckle phenomenon when reflected on the projection surface, affecting the viewing experience; using short-wavelength laser to excite fluorescence and then combining fluorescence with three-color laser is a common technical means to supplement brightness and reduce laser speckle.

[0003] At present, a Chinese invention with publication number CN117850141A discloses a wavelength conversion device, a light source system and a projection device, including a driving device, a substrate, a wavelength conversion element and a diffusion element, wherein: the driving device is transmission-connected to the substrate, and the driving device is configured to drive the substrate to rotate around its axis; the diffusion element is arranged on the substrate, and the diffusion element is in a circular ring shape; the wavelength conversion element is arranged on the substrate in a circular ring shape, and the wavelength conversion element is arranged on the inner side of the diffusion element, or the wavelength conversion element is arranged on the outer side of the diffusion element, and the center of the diffusion element, the center of the substrate and the center of the wavelength conversion element correspond to each other, and the wavelength conversion device converts the wavelength of the excitation light through the wavelength conversion element to obtain the converted light.

[0004] In existing projection equipment, a driving device drives the substrate and drives the wavelength conversion element to rotate. The rotating wavelength conversion element converts the wavelength of the excitation light. However, the rotating wavelength conversion element is unstable and easily interfered by external factors. For example, vehicle-mounted projectors are mostly used when the vehicle is moving. The bumps of the vehicle will interfere with the rotation of the wavelength conversion element, thereby affecting the wavelength conversion of the excitation light by the wavelength conversion element. Summary of the invention

[0005] The purpose of the present invention is to provide an optical path structure of an LCOS projection optical machine using a laser fluorescent ceramic light source, which has the advantage of being able to stably convert the wavelength of the excitation light, thereby increasing the laser power resistance threshold of the phosphor, thereby increasing the output luminous flux of the optical machine and having the characteristic of high brightness.

[0006] To achieve the above objectives and other related objectives, the present invention provides the following technical solutions: Optical path structure of an LCOS projection optical machine using a laser fluorescence ceramic light source, including A blue excitation light source array for emitting blue excitation light; a blue laser light source for emitting blue laser light; A static fluorescence ceramic, with a focusing and collimating lens group arranged between the blue excitation light source array and the static fluorescence ceramic. The focusing and collimating lens group is used to focus the blue excitation light on the static fluorescence ceramic. After the blue excitation light is converted into red - green mixed light by the static fluorescence ceramic, it is emitted and collimated and expanded by the focusing and collimating lens group; A light combining element for combining the blue laser and the red - green mixed light into a mixed light and then emitting it; A polarization processing optical element for converting the mixed light into polarized light; A color control optical group for splitting the polarized light into red light, green light, and blue laser light, then respectively controlling the passing or blocking of the red light, green light, and blue laser light, and finally synthesizing the red light, green light, and blue laser light into one path for output without changing their polarization states and polarization directions during incidence; A polarization beam splitting element for reflecting red light, green light, and blue laser light with a vertical polarization direction and transmitting red light, green light, and blue laser light with a horizontal polarization direction; An LCOS for modulating the polarization state of red light, green light, and blue laser light with the same polarization direction and then reflecting them to a projection lens.

[0007] In an embodiment of the present invention, it further includes a collimating lens array for collimating the blue excitation light and a first dichroic mirror for reflecting the blue excitation light and transmitting the red - green mixed light. The collimating lens array is located between the blue excitation light source array and the focusing and collimating lens group; the first dichroic mirror is located between the collimating lens array and the focusing and collimating lens group and between the focusing and collimating lens group and the light combining element.

[0008] In an embodiment of the present invention, the static fluorescence ceramic is a copper - based fluorescence ceramic.

[0009] In an embodiment of the present invention, it further includes a collimating and expanding lens group for collimating and expanding the blue laser to the required size. The collimating and expanding lens group is located between the blue laser light source and the light combining element.

[0010] In an embodiment of the present invention, the light combining element is a second dichroic mirror for transmitting the blue laser and reflecting the red - green mixed light.

[0011] In an embodiment of the present invention, the polarization processing optical element is a linear polarizer.

[0012] In an embodiment of the present invention, the color control optical group includes a dichroic X prism, a color combining X prism, a first reflector, a second reflector, a third reflector, a fourth reflector, and three liquid crystal light valves; The dichroic X prism is disposed opposite to the linear polarizer, and the color combining X prism is disposed opposite to the dichroic X prism; The first reflector and the second reflector are respectively disposed on both sides of the dichroic X prism and inclined toward the color combining X prism; The third reflector and the fourth reflector are disposed on both sides of the color combining X prism and inclined toward the dichroic X prism; The first reflector and the fourth reflector are disposed opposite to each other, and the second reflector and the third reflector are disposed opposite to each other; The three liquid crystal light valves are respectively disposed between the first reflector and the fourth reflector, between the dichroic X prism and the color combining X prism, and between the second reflector and the third reflector.

[0013] In an embodiment of the present invention, it further includes a fifth reflector disposed opposite to the color combining X prism, and a microlens array and a relay lens group are disposed between the fifth reflector and the polarization beam splitter element.

[0014] In an embodiment of the present invention, the polarization beam splitter element is a polarization beam splitting prism, and a compensating film is disposed between the polarization beam splitting prism and the LCOS.

[0015] As described above, the optical path structure of the LCOS projection optical machine using a laser fluorescence ceramic light source of the present invention has the following beneficial effects: The static fluorescence ceramic has higher stability compared with the dynamic wavelength conversion elements in the prior art; the static fluorescence ceramic is a copper-based fluorescence ceramic, and the copper-based fluorescence ceramic has good laser resistance and heat dissipation performance, which can improve the utilization rate of converting blue excitation light into red-green mixed light; and because the copper-based fluorescence ceramic has good laser resistance and heat dissipation performance, the light energy of the blue excitation light can be increased by increasing the number of blue excitation light sources in the blue excitation light source array and increasing the energy of a single blue excitation light source, so that the copper-based fluorescence ceramic can convert high-energy red-green mixed light; the blue laser is supplemented by a blue laser light source, and then the blue laser and the red-green mixed light are combined into a mixed light by a light combining element and then emitted. The polarization processing optical element converts the mixed light into polarized light, and the color control optical group divides the polarized light into red light, green light, and blue laser and then emits them. The liquid crystal light valve controls the passing and blocking of red light, green light, and blue laser. Through the synergistic effect of the microlens array and the relay lens, the light spot is homogenized; the homogenized light spot reflects the red light, green light, and blue laser in the same direction through the polarization beam splitter element, and the high-brightness red light, green light, and blue laser are incident on the LCOS in a time-sharing manner. Then, the LCOS modulates the polarization state of the light incident on each pixel point thereon and reflects and emits it. The reflected light passes through the polarization beam splitter element, and the polarization beam splitter element transmits the light in a certain polarization direction and reflects the light perpendicular to the polarization direction of the transmitted light, so as to control the intensity of the light emitted from each LCOS pixel point. The intensity of the light emitted from each pixel is different, thus forming an image. Finally, the image is projected by the projection lens; thus, the projection screen of the projection optical machine has the characteristic of high brightness, and the projection optical machine can also clearly image in a bright environment, thus solving the problem that the projection screen of the projection optical machine is not clear when used in a bright environment. Brief Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the overall optical path structure of an embodiment of the present invention.

[0017] Reference numerals: 1. Blue excitation light source array; 2. Blue laser light source; 3. Collimating lens array; 4. Collimating and beam expanding lens group; 5. Focusing and collimating lens group; 6. Static fluorescence ceramic; 7. First dichroic mirror; 8. Light combining element; 9. Polarization processing optical element; 10. Dichroic X prism; 11. Color combining X prism; 12. First liquid crystal light valve; 13. Second liquid crystal light valve; 14. Third liquid crystal light valve; 15. First reflecting mirror; 16. Second reflecting mirror; 17. Third reflecting mirror; 18. Fourth reflecting mirror; 19. Fifth reflecting mirror; 20. Microlens array; 21. Relay lens group; 22. Polarization beam splitter element; 23. Compensation film; 24. LCOS; 25. Projection lens. Detailed Embodiments

[0018] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in this technology can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0019] Please refer to Figure 1 . It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented. Therefore, they do not have substantial technical significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration, and are not used to limit the scope under which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope under which the present invention can be implemented.

[0020] Please refer to Figure 1 , the present invention provides an optical path structure of an LCOS projection optical machine using a laser fluorescence ceramic light source, including a blue excitation light source array 1, a blue laser light source 2, a static fluorescence ceramic 6, a focusing and collimating lens group 5, a light combining element 8, a polarization processing optical element 9, a color control optical group, a polarization beam splitter element 22, an LCOS 24 (Liquid Crystal on Silicon), and a projection lens 25; Among them, the blue excitation light source array 1 is used to emit blue excitation light, and the blue laser light source 2 is used to emit blue laser light. In this embodiment, the blue laser light source 2 is a blue laser diode or a blue laser diode array, and the blue excitation light source array 1 is a blue laser diode array composed of several blue laser diodes; A collimating lens array 3 is oppositely arranged relative to the blue excitation light source array 1. Each blue laser diode in the blue excitation light source array 1 corresponds to a collimating lens. The blue excitation light emitted by the blue excitation light source array 1 passes through the collimating lens array 3, and the collimating lens array 3 is used to collimate the blue excitation light; A first dichroic mirror 7 for reflecting blue excitation light and transmitting red - green mixed light is oppositely arranged relative to the collimating lens array 3; the first dichroic mirror 7 is located between the collimating lens array 3 and the focusing and collimating lens group 5 and between the focusing and collimating lens group 5 and the light combining element 8; the blue excitation light collimated by the collimating lens array 3 is incident on the first dichroic mirror 7, and the first dichroic mirror 7 reflects the blue excitation light onto the focusing and collimating lens group 5. The blue excitation light passes through the focusing and collimating lens group 5, and the focusing and collimating lens group 5 focuses the blue excitation light on the static fluorescence ceramic 6; Blue excitation light irradiates the static fluorescent ceramic 6 to excite the generation of radiative fluorescence, where the radiative fluorescence is a mixed red and green light; the static fluorescent ceramic 6 in this embodiment is a copper-based fluorescent ceramic, and the copper-based fluorescent ceramic has good laser resistance and heat dissipation performance, which can improve the utilization rate of converting blue excitation light into mixed red and green light; the mixed red and green light reflected by the copper-based fluorescent ceramic is collimated and expanded through the focusing and collimating lens group 5; the mixed red and green light collimated and expanded through the focusing and collimating lens group 5 irradiates the light combining element 8 through the first dichroic mirror 7; A collimating and expanding lens group 4 is oppositely arranged relative to the blue laser light source 2, and the collimating and expanding lens group 4 is used to collimate and expand the blue laser to have the same beam width as the expanded mixed red and green light; The blue laser light source 2 emits blue laser light, and the blue laser light is expanded through the collimating and expanding lens group 4 and then incident on the light combining element 8; the light combining element 8 in this embodiment is a second dichroic mirror for transmitting blue laser light and reflecting the mixed red and green light. The blue laser light incident on the second dichroic mirror passes through the second dichroic mirror, and the mixed red and green light incident on the second dichroic mirror is reflected. Then, the second dichroic mirror combines the blue laser light and the mixed red and green light into a mixed light and emits it.

[0021] The polarization processing optical element 9 is oppositely arranged relative to the light combining element 8; the polarization processing optical element 9 in this embodiment is a linear polarizer; since the mixed light contains blue laser light and the mixed red and green light excited by the static fluorescent ceramic 6, where the blue laser light is polarized light, and the mixed red and green light is natural light and non-polarized light, and has a polarization direction of 360°; the polarization direction of the blue laser light in this embodiment is parallel to the transmission direction of the linear polarizer, and the blue laser light can directly pass through the linear polarizer; while the mixed red and green light passes through the linear polarizer, and the linear polarizer can filter the light with a polarization direction different from its transmission direction in the mixed red and green light, and only allow the mixed red and green light parallel to the transmission direction of the linear polarizer to pass through, thereby converting the mixed light passing through the linear polarizer into polarized light with the same polarization direction.

[0022] The color control optical group is used to separate the polarized light into red light, green light, and blue laser light and then propagate them separately; the color control optical group includes a dichroic X prism 10, a combining X prism 11, a first reflector 15, a second reflector 16, a third reflector 17, a fourth reflector 18, and three liquid crystal light valves; the three liquid crystal light valves are respectively a first liquid crystal light valve 12, a second liquid crystal light valve 13, and a third liquid crystal light valve 14; The dichroic X prism 10 is oppositely arranged relative to the linear polarizer, and the combining X prism 11 is oppositely arranged relative to the dichroic X prism 10; The first reflector 15 and the second reflector 16 are respectively arranged on both sides of the dichroic X prism 10 and are inclined towards the side of the combining X prism 11; The third reflector 17 and the fourth reflector 18 are arranged on both sides of the color-combining X prism 11 and are inclined towards the dichroic X prism 10; The first reflector 15 and the fourth reflector 18 are arranged opposite to each other, and the second reflector 16 and the third reflector 17 are arranged opposite to each other; Wherein the first liquid crystal light valve 12 is arranged between the first reflector 15 and the fourth reflector 18, the second liquid crystal light valve 13 is arranged between the dichroic X prism 10 and the color-combining X prism 11, and the third liquid crystal light valve 14 is arranged between the second reflector 16 and the third reflector 17; For example, when polarized light enters the beam-splitting X prism, it is split into red light, green light, and blue laser light. The blue laser light is reflected by the beam-splitting X prism onto the second reflector 16, then reflected by the second reflector 16 and passes through the third liquid crystal light valve 14 and is projected onto the third reflector 17, and then enters the color-combining X prism 11 after being reflected by the third reflector 17; the red light passes through the beam-splitting X prism and the second liquid crystal light valve 13 and enters the color-combining X prism 11; the green light is also reflected by the beam-splitting X prism onto the first reflector 15, then reflected by the second reflector 16 and passes through the first liquid crystal light valve 12 and is projected onto the fourth reflector 18, and then enters the color-combining X prism 11 after being reflected by the fourth reflector 18; Wherein the first liquid crystal light valve 12, the second liquid crystal light valve 13, and the third liquid crystal light valve 14 are used to respectively control the presence or absence of red light, green light, and blue laser light passing through and to adjust the amount of red light, green light, and blue laser light passing through.

[0023] A fifth reflector 19 is arranged opposite to the color-combining X prism 11, and a microlens array 20 is arranged opposite to the fifth reflector 19; the light beam passing through the color-combining X prism 11 is reflected by the fifth reflector 19 onto the microlens array 20, and the microlens array 20 is used to uniform the light spot, so as to make the brightness of the projection image projected by the projection lens 25 uniform; A relay lens group 21 is arranged opposite to the microlens array 20, and a polarization beam splitter 22 is arranged opposite to the relay lens group 21; the polarization beam splitter 22 in this embodiment is a polarization beam splitting prism; the polarization beam splitting prism is used to separate the horizontal polarization and vertical polarization of a beam of light (red light or green light or blue laser light), that is, it is divided into horizontally polarized P light and vertically polarized S light, and the polarization beam splitting prism can reflect the S light and transmit the P light; A compensating sheet 23 is oppositely arranged on the polarization beam splitting prism. The compensating sheet 23 in this embodiment can be an achromatic quarter-wave plate, which is used to compensate for the phase deviation caused by the pretilt angle of the liquid crystal molecules in the LCOS 24, so as to improve the contrast of the image output by the optical engine; the compensating sheet 23 is oppositely arranged with the LCOS 24; the projection lens 25 is arranged on one side of the polarization beam splitting prism far away from the compensating sheet 23, and the projection lens 25 is oppositely arranged with the polarization beam splitting prism. The light beam (red light or green light or blue laser) is incident on the LCOS 24 after being compensated by the compensating sheet 23. The LCOS 24 modulates the polarization state of the light incident on each pixel point thereon and reflects it; the reflected light passes through the polarization beam splitting prism. Since the polarization beam splitting prism transmits P light and reflects S light, the intensity control of the light emitted from each LCOS pixel point can be realized. The intensity of the light emitted from each pixel is different, thus forming an image, and finally the image is projected by the projection lens 25.

[0024] In summary, the static fluorescent ceramic 6 in the present invention is a copper-based fluorescent ceramic. Since the copper-based fluorescent ceramic has good laser resistance and heat dissipation performance, the light energy of the blue excitation light can be increased by increasing the number of blue laser diodes in the blue excitation light source array 1 and increasing the power of a single blue laser diode. Furthermore, the copper-based fluorescent ceramic can convert high-energy red-green mixed light; the blue laser is supplemented by the blue laser light source 2, and then the high-brightness red light, green light, and blue laser can be incident on the LCOS through the conversion and processing of the light combining element 8, the polarization processing optical element 9, the color control optical group, the polarization beam splitting element 22, etc. After being modulated by the LCOS, it is emitted from the projection lens 25, so that the projection screen of the projection optical engine has the characteristic of high brightness, and the projection optical engine can also clearly image in a bright environment. In addition, all the components used in the present invention are static devices, avoiding the use of a rotating phosphor as a wavelength conversion device and a rotating color wheel as a color control device. The static device has higher structural reliability and is suitable for scenarios with high reliability requirements where rotating elements are not allowed, such as in-vehicle and airborne applications.

[0025] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. An optical path structure of an LCOS projection optical machine using a laser fluorescence ceramic light source, characterized in that: including a blue excitation light source array (1) for emitting blue excitation light; a blue laser light source (2) for emitting blue laser light; a static fluorescent ceramic (6), with a focusing and collimating lens group (5) arranged between the blue excitation light source array (1) and the static fluorescent ceramic (6). The focusing and collimating lens group (5) is used to focus the blue excitation light on the static fluorescent ceramic (6). After the blue excitation light is converted into red-green mixed light by the static fluorescent ceramic (6), it is emitted and collimated and expanded by the focusing and collimating lens group (5); a light combining element (8) for combining the blue laser light and the red-green mixed light into mixed light and then emitting it; a polarization processing optical element (9) for converting the mixed light into polarized light; a color control optical group for splitting the polarized light into red light, green light, and blue laser light, then respectively controlling the passing or blocking of the red light, green light, and blue laser light, and finally combining the red light, green light, and blue laser light into one path for output without changing their polarization states and polarization directions when incident; a polarization beam splitter element (22) for reflecting red light, green light, and blue laser light with a vertical polarization direction and transmitting red light, green light, and blue laser light with a horizontal polarization direction; an LCOS (24) for modulating the polarization state of red light, green light, and blue laser light with the same polarization direction and then reflecting it to a projection lens (25).

2. The optical path structure of an LCOS projection optical machine using a laser fluorescent ceramic light source according to claim 1, characterized in that: It further includes a collimating lens array (3) for collimating the blue excitation light and a first dichroic mirror (7) for reflecting the blue excitation light and transmitting the red-green mixed light. The collimating lens array (3) is located between the blue excitation light source array (1) and the focusing and collimating lens group (5); the first dichroic mirror (7) is located between the collimating lens array (3) and the focusing and collimating lens group (5) and between the focusing and collimating lens group (5) and the light combining element (8).

3. The optical path structure of an LCOS projection optical machine using a laser fluorescent ceramic light source according to claim 2, characterized in that: The static fluorescent ceramic (6) is a copper-based fluorescent ceramic.

4. The optical path structure of an LCOS projection optical machine using a laser fluorescence ceramic light source according to claim 3, characterized in that: It further includes a collimating and expanding lens group (4) for collimating and expanding the blue laser light to the required size. The collimating and expanding lens group (4) is located between the blue laser light source (2) and the light combining element (8).

5. The optical path structure of an LCOS projection optical machine using a laser fluorescent ceramic light source according to any one of claims 1 to 4, characterized in that: The light combining element (8) is a second dichroic mirror for transmitting the blue laser light and reflecting the red-green mixed light.

6. The optical path structure of an LCOS projection optical machine using a laser fluorescent ceramic light source according to claim 5, characterized in that: The polarization processing optical element (9) is a linear polarizer.

7. The optical path structure of an LCOS projection optical machine using a laser fluorescence ceramic light source according to claim 6, characterized in that: The color control optical group includes a dichroic X prism (10), a combining X prism (11), a first reflecting mirror (15), a second reflecting mirror (16), a third reflecting mirror (17), a fourth reflecting mirror (18), and three liquid crystal light valves; The dichroic X prism (10) is arranged opposite to the linear polarizer, and the combining X prism (11) is arranged opposite to the dichroic X prism (10); The first reflecting mirror (15) and the second reflecting mirror (16) are respectively arranged on both sides of the dichroic X prism (10) and inclined towards the side of the combining X prism (11); The third reflecting mirror (17) and the fourth reflecting mirror (18) are arranged on both sides of the combining X prism (11) and inclined towards the side of the dichroic X prism (10); The first reflector (15) and the fourth reflector (18), and the second reflector (16) and the third reflector (17) are oppositely arranged; The three liquid crystal light valves are respectively arranged between the first reflector (15) and the fourth reflector (18), the dichroic X prism (10) and the combining X prism (11), and the second reflector (16) and the third reflector (17).

8. The optical path structure of an LCOS projection optical machine using a laser fluorescence ceramic light source according to claim 7, characterized in that: It further includes a fifth reflector (19) oppositely arranged with the combining X prism (11), and a microlens array (20) and a relay lens group (21) are arranged between the fifth reflector (19) and the polarization beam splitting element (22).

9. The optical path structure of an LCOS projection optical machine using a laser fluorescence ceramic light source according to claim 8, characterized in that: The polarization beam splitting element (22) is a polarization beam splitting prism, and a compensating film (23) is arranged between the polarization beam splitting prism and the LCOS (24).

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