LCD projection light machine

Abstract

The utility model relates to a kind of LCD projection light machine, belong to projection light machine technical field.The LCD projection light machine includes light source and the light cone being set on the emergent light path of light source, and light source includes the excitation light device and wavelength conversion layer of phase combination, wherein excitation light device generates excitation light, excitation light excites wavelength conversion layer to generate excited light, at least one of dichroic mirror and reflective polarizer is equipped in light cone, dichroic mirror reflects or partially reflects the residual excitation light of light source emission to wavelength conversion layer, while transmitting excited light of light source emission, reflective polarizer reflects the light of first polarization to wavelength conversion layer, while transmitting the light of second polarization.The LCD projection light machine excites the excited light of wavelength conversion layer emission by dichroic mirror reflection, reflective polarizer reflects the light of first polarization, wavelength conversion layer emits light twice, reduces the loss of light source in projection process, improves the brightness of wavelength conversion layer emergent light.

Description

Technical Field

[0001] This utility model belongs to the field of projection optical engine technology, and specifically relates to an LCD projection optical engine. Background Technology

[0002] LCD projectors utilize the photoelectric effect of liquid crystals, where the arrangement of liquid crystal molecules changes under the influence of an electric field, affecting the transmittance or reflectance of the liquid crystal cells, thereby affecting their optical properties and producing images with different gray levels and colors.

[0003] Currently, most high-brightness optical engines in LCD projectors use a light source and a light cone architecture. The light source is an LED chip that excites phosphors to emit white light. However, after the LED excites the phosphors, there is some residual light (i.e., LED excitation light that does not fully excite the phosphors). Simultaneously, LCD projectors must have a polarizer, which is usually attached to heat-insulating glass or the light-incident surface of the LCD. The light source formed by the excitation of phosphors lacks polarization, meaning that only polarization components parallel to the polarizer's transmission axis can pass through, while orthogonal components are usually reflected or absorbed. During projection, some light is lost and cannot be utilized, leading to reduced LCD brightness and affecting the user experience and visual effect. Utility Model Content

[0004] This invention provides an LCD projection optical engine that solves the technical problem that some light is lost during the projection process of current LCD projectors, resulting in reduced LCD brightness.

[0005] This utility model is achieved through the following technical solution: an LCD projection optical engine, comprising a light source and a light cone disposed on the light path of the light source, the light source comprising a combined excitation device and a wavelength conversion layer, wherein the excitation device generates excitation light, the excitation light excites the wavelength conversion layer to generate stimulated light, the light cone is provided with at least one of a dichroic mirror and a reflective polarizer, the dichroic mirror reflects or partially reflects the residual excitation light emitted from the light source to the wavelength conversion layer, and transmits the stimulated light emitted from the light source, the reflective polarizer reflects light of a first polarization to the wavelength conversion layer, and transmits light of a second polarization.

[0006] Optionally, the dichroic mirror and / or reflective polarizer fills the cross-section of the light cone or covers a portion of the cross-section of the light cone.

[0007] Optionally, the side wall of the light cone is provided with an insertion port, through which the dichroic mirror and / or the reflective polarizer are inserted and installed into the light cone.

[0008] Optionally, the cross-section of the light cone is rectangular, and slots are provided on the sidewalls corresponding to the long and short sides of the rectangle. The dichroic mirror and the reflective polarizer are respectively installed into the light cone through different slots.

[0009] Optionally, the dichroic mirror is located near the incident end of the light cone.

[0010] Optionally, the reflective polarizer is an inorganic polarizer, and the reflective polarizer is located near the incident end of the light cone.

[0011] Optionally, the reflective polarizer is an organic polarizer, and the reflective polarizer is located near the light-emitting end of the light cone.

[0012] Optionally, the system also includes an LCD disposed on the outgoing light path of the light cone, wherein an analyzer is disposed on the light-emitting side of the LCD at a distance from the LCD.

[0013] Optionally, the system also includes an LCD disposed on the outgoing light path of the light cone, and a polarizer disposed between the light cone and the LCD. The optical axis of the polarizer is along the vibration direction of the second polarized light, and the polarizer and the LCD are disposed at intervals.

[0014] Optionally, the excitation light device includes an LED light source or a laser light source.

[0015] Compared with the prior art, this utility model has the following advantages:

[0016] The present invention provides an LCD projection optical engine comprising a light source and a light cone disposed in the light path of the light source. The light source comprises an excitation device and a wavelength conversion layer combined therewith. The excitation device generates excitation light, which excites the wavelength conversion layer to generate stimulated light. The light cone is provided with at least one of a dichroic mirror and a reflective polarizer. The dichroic mirror reflects or partially reflects the residual excitation light emitted from the light source to the wavelength conversion layer, while transmitting the stimulated light emitted from the light source. The reflective polarizer reflects light of a first polarization to the wavelength conversion layer, while transmitting light of a second polarization.

[0017] With the above structure, the LCD projection optical engine provided by this utility model, when projecting, generates excitation light from the excitation light device to excite the wavelength conversion layer into stimulated light of other colors. Part of the excitation light passes through the wavelength conversion layer and is emitted into the light cone as stimulated light of other colors. Part of the excitation light does not undergo excitation conversion but passes through the wavelength conversion layer and is emitted into the light cone. The stimulated light emitted from the wavelength conversion layer and part of the excitation light transmitted by the wavelength conversion layer are emitted to a dichroic mirror. The dichroic mirror transmits all the stimulated light emitted from the wavelength conversion layer and reflects all or part of the residual excitation light transmitted by the wavelength conversion layer back to the wavelength conversion layer, thus exciting the wavelength conversion layer to emit light again, improving the utilization rate of the excitation light and increasing the brightness of the light emitted from the wavelength conversion layer. The light emitted by the light source is emitted into the light cone. When the light emitted by the light source reaches the reflective polarizer, the reflective polarizer transmits the second polarized light and reflects the first polarized light back to the wavelength conversion layer, thus exciting the wavelength conversion layer to emit light again, increasing the brightness of the light emitted from the wavelength conversion layer. Therefore, the optical engine of this LCD projector reflects the excited light emitted from the wavelength conversion layer through a dichroic mirror, and reflects the first polarized light through a reflective polarizer to excite the wavelength conversion layer to emit light a second time. This reduces the loss of light source during the projection process, increases the brightness of the light emitted from the wavelength conversion layer, and reduces the impact on the user's experience and visual effects. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of an LCD projector optical engine provided by this utility model;

[0020] Figure 2 This is another structural schematic diagram of an LCD projection optical engine provided by this utility model;

[0021] Figure 3 This is another structural schematic diagram of an LCD projection optical engine provided by this utility model;

[0022] Figure 4 This is another structural schematic diagram of an LCD projection optical engine provided by this utility model.

[0023] In the picture:

[0024] 1-Light source, 2-Light cone, 3-Reflective polarizer, 4-Dichroic mirror, 5-First lens, 6-Polarizer, 7-LCD, 8-Analyzer, 9-Second lens, 10-Lens. Detailed Implementation

[0025] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0026] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] This invention provides an LCD projection optical engine, solving the technical problem of reduced LCD brightness due to partial light source loss during projection in current LCD projectors. The LCD projection optical engine includes a light source 1 and a light cone 2 disposed along the light path emitted from the light source 1. The light source 1 includes a combined excitation device and a wavelength conversion layer, wherein:

[0030] Light source 1 is used to emit light, which is modulated and focused by the optical system to form a visible image projected onto the screen. The excitation device of light source 1 is used to generate excitation light, which excites the wavelength conversion layer to become excited light of other colors and emits it into light cone 2. The excitation light source can be an LED light source or a laser light source, etc. The wavelength conversion layer is phosphor. The excitation device of light source 1 generates excitation light to excite the phosphor to emit light. The cross-sectional area of ​​light cone 2 gradually increases along the outgoing light path. After the light emitted by light source 1 enters light cone 2, it is reflected by the inner wall of light cone 2, which causes light source 1 to focus on the outgoing light path, reducing the light source brightness loss caused by light source 1 emitting to other places.

[0031] The light cone 2 contains at least one of a dichroic mirror 4 or a reflective polarizer 3, such as Figure 1-3 As shown, Figure 1 This is a schematic diagram of an LCD projection optical engine that simultaneously uses a dichroic mirror 4 or a reflective polarizer 3. Figure 2 This is a schematic diagram of an LCD projection optical engine that uses only a dichroic mirror 4. Figure 3 This is a schematic diagram of an LCD projection optical engine using only a reflective polarizer 3. A dichroic mirror 4 reflects or partially reflects residual excitation light emitted from the light source 1 to the wavelength conversion layer of the light source 1, thus re-exciting the wavelength conversion layer and increasing the brightness of the light emitted from the wavelength conversion layer. The dichroic mirror 4 transmits the excited light emitted from the light source 1 to form the illumination light for the projected image. The wavelength range and reflectivity of the light transmitted and reflected by the dichroic mirror 4 can be adjusted according to spectral design and usage requirements, allowing the use of different dichroic mirrors 4 to suit different application scenarios. The reflective polarizer 3 reflects light with the first polarization. The wavelength conversion layer of the light source 1 is excited a second time to emit light, increasing the brightness of the light emitted from the wavelength conversion layer. The reflective polarizer 3 transmits light with a second polarization to form the light of the projected image. The first polarization state and the second polarization state are P state and S state or S state and P state, respectively. The reflective polarizer 3 can be an HCR film, an inorganic grid, etc. Using either the dichroic mirror 4 or the reflective polarizer 3 can increase the brightness of the light emitted from the wavelength conversion layer. Using both the dichroic mirror 4 and the reflective polarizer 3 can further increase the brightness of the light source 1 and improve the visual effect of the projection.

[0032] An optional implementation method of this embodiment is as follows: Figures 1-4As shown, the dichroic mirror 4 and / or the reflective polarizer 3 fill the cross-section of the light cone 2. All light emitted from the light source 1 needs to pass through the dichroic mirror 4 and / or the reflective polarizer 3. This allows more light to pass through the dichroic mirror 4 and / or the reflective polarizer 3, thus enabling the dichroic mirror 4 to reflect more residual excitation light and the reflective polarizer 3 to reflect more first-polarized light, thereby maximizing the brightness of the light source 1. The dichroic mirror 4 and / or the reflective polarizer 3 can also cover a portion of the cross-section of the light cone 2, such as nine-tenths, one-half, or one-quarter of the cone's cross-section. This creates an airflow channel between the dichroic mirror 4 and / or the reflective polarizer 3 and the inner wall of the light cone 2, allowing air to circulate within the light cone 2. During use, components such as the light source 1 generate heat, and the airflow can carry away heat. The heat within the light cone 2 is reduced, minimizing heat buildup and extending the lifespan of the LCD projector's optical engine. Simultaneously, the proportion of emitted blue light can be adjusted by controlling the area of ​​the dichroic mirror 4 and / or the reflective polarizer 3 covering the cone's cross-section, thereby controlling the color coordinates. Optionally, the angles of the dichroic mirror 4 and the reflective polarizer 3 can be set according to usage requirements; they can be perpendicular to the optical axis, or at an obtuse or acute angle. The dichroic mirror 4 and the reflective polarizer 3 can be installed inside the light cone 2 from its light-emitting end, or they can be inserted into the light cone 2 through a hole opened on its periphery. During use, the positions of the dichroic mirror 4 and the reflective polarizer 3 are fixed to reduce image problems caused by movement during operation.

[0033] An optional implementation method of this embodiment is as follows: Figures 1-4 As shown, the side wall of the light cone 2 is provided with an insertion port. The dichroic mirror 4 and / or the reflective polarizer 3 are inserted into the light cone 2 through the insertion port. This allows the insertion depth of the dichroic mirror 4 and the reflective polarizer 3 to be adjusted according to product requirements during trial production. This adjusts the ratio of the residual excitation light emitted from the light source 1 reflected by the dichroic mirror 4 to the first polarized light reflected by the reflective polarizer 3, thereby controlling the color coordinates. Optionally, the insertion depth of the dichroic mirror 4 and the reflective polarizer 3 can be through the light cone 2, or only half or a quarter of it can be inserted. When using the dichroic mirror 4 and the reflective polarizer 3 simultaneously, their insertion depths can be the same or different. During projection, the depth, position, and angle of the dichroic mirror 4 and the reflective polarizer 3 are not adjustable.

[0034] An optional implementation method of this embodiment is as follows: Figures 1-4As shown, the cross-section of the light cone 2 is rectangular. Insertions are provided on the sidewalls corresponding to the long and short sides of the rectangle. The dichroic mirror 4 and the reflective polarizer 3 are installed into the light cone 2 through different inserts. The inserts can be all on the long side, all on the short side, or both sides. The specific inserts for the dichroic mirror 4 and the reflective polarizer 3 can be used according to requirements. When the dichroic mirror 4 or the reflective polarizer 3 is inserted through the insert on the short side, it ensures that there is no break in the surface of the light cone 2 along its long side, which is beneficial for the light input end of the light cone 2. The high temperature generated by the light source 1 is transferred to the light-emitting end of the light cone 2, reducing the temperature near the light source 1 and improving the service life of the light source 2. Since the short side of the light cone 2 is usually surrounded by the projection optical engine, when the dichroic mirror 4 or the reflective polarizer 3 is inserted from the long side of the socket, the long side of the light cone 2 is usually located on the upper side of the optical engine, which facilitates the assembly of the projection optical engine. After the dichroic mirror 4 or the reflective polarizer 3 is adjusted, the dichroic mirror 4 and the reflective polarizer 3 are fixed with adhesive to seal the socket of the light cone 2 and reduce the light emitted from the socket.

[0035] An optional implementation method of this embodiment is as follows: Figures 1-3 As shown, the dichroic mirror 4 is placed close to the light-incident end of the light cone 2 to reduce the impact of high temperatures generated by the light source 1 when the dichroic mirror is placed at the light-outcident end of the light source 1, which would affect the lifespan of the dichroic mirror and reduce the light-gathering capacity of the light cone 2. At the same time, if the dichroic mirror 4 is placed at the light-outcident end of the light cone 2, the size of the light-outcident end of the light cone 2 is larger than that of the light-incident end, so the size of the dichroic mirror 4 needs to be increased, which increases the cost of the dichroic mirror 4. Therefore, installing the dichroic mirror 4 in the light cone 2 has a smaller impact on the light-gathering efficiency of the light cone 2 and the heat dissipation of the light source 1, and the cost is lower. Similarly, installing the reflective polarizer 3 close to the light-incident end of the light cone 2 can also reduce the impact on the light-gathering efficiency of the light cone 2 and the heat dissipation of the light source 1, and reduce the cost.

[0036] An optional implementation of this embodiment is as follows: the reflective polarizer 3 is an inorganic polarizer. Figure 1 and Figure 3 As shown, the reflective polarizer 3 is positioned close to the light-incident end of the light cone 2 to reduce the size of the reflective polarizer 3 and lower the cost.

[0037] An optional implementation of this embodiment is as follows: the reflective polarizer 3 is an organic polarizer, such as an HCR film, a DLRP film, an APF-V3 film, etc. Figure 4 As shown, since organic polarizers are not resistant to high temperatures, and since the light source 1 generates heat during operation, the reflective polarizer 3 is placed close to the light-emitting end of the light cone 2 to reduce the impact of excessive temperature on the reflective polarizer 3.

[0038] An optional implementation method of this embodiment is as follows: Figures 1-4As shown, it also includes an LCD7 disposed on the light path of the light cone 2. The LCD7 is used to modulate the illumination light to obtain image light. An analyzer 8 is disposed on the light-emitting side of the LCD7 at a distance from the LCD7. Since the LCD7 generates heat when emitting light, if the analyzer 8 is directly attached to the light-emitting end of the LCD7, the heat of the LCD7 will be transferred to the analyzer 8. At the same time, the heat dissipation effect of the LCD7 is reduced due to the obstruction of the analyzer 8. During long-term use, this will affect the performance and lifespan of the LCD7, resulting in decreased transmittance, uneven grayscale illumination, blue light leakage of LCD7 pixels, and yellowing of the analyzer. By distributing the LCD7 and the analyzer 8 at a distance, the direct conduction of heat from the LCD7 to the analyzer 8 is reduced. Specifically, a duct glass is disposed on the light-emitting end of the analyzer 8. The analyzer 8 is attached to the light-incident surface of the duct glass, and a heat dissipation duct is formed between the LCD7 and the analyzer 8. The air flow in the heat dissipation duct can reduce the temperature of both the LCD7 and the analyzer 8, thus extending the lifespan of the LCD7 and the analyzer 8.

[0039] An optional implementation method of this embodiment is as follows: Figures 1-4 As shown, it also includes an LCD7 positioned on the outgoing light path of the light cone 2. A polarizer 6 is also positioned between the light cone 2 and the LCD7. The optical axis of the polarizer 6 is along the vibration direction of the second polarized light. The polarizer 6 further filters the polarization state of the light, so that the light emitted to the LCD7 has a better degree of polarization, thereby better displaying the desired image. The polarizer 6 and the LCD7 are spaced apart, similar to the analyzer 8. If the polarizer 6 is directly attached to the light-emitting end of the LCD7, the temperature of the LCD7 will be transferred to the polarizer 6. At the same time, the heat dissipation effect of the LCD7 is reduced due to the obstruction of the polarizer 6. The LCD7 and polarizer 6 are spaced apart, which reduces the direct heat transfer from the LCD7 to the polarizer 6. Specifically, a duct glass is provided at the light-incident end of the polarizer 6, and the polarizer 6 is attached to the light-outceasing surface of the duct glass. A heat dissipation duct is formed between the polarizer 6 and the LCD7. The airflow in the heat dissipation duct can reduce the temperature of both the LCD7 and the polarizer 6, extending their service life. If the polarization degree of the reflective polarizer 3 is high enough, or the contrast requirement of the projection is not high, the polarizer 6 and the duct glass attached to the polarizer 6 can be used in the LCD7 projector.

[0040] An optional implementation of this embodiment is as follows: the excitation light source can be an LED light source or a laser light source, etc., so as to use different excitation light devices according to different usage requirements and adapt to different usage scenarios.

[0041] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope described in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An LCD projection engine, characterized by, Includes a light source and a light cone disposed in the light path of the light source, wherein the light source includes a combined excitation device and a wavelength conversion layer, wherein: The excitation light device generates excitation light, which excites the wavelength conversion layer to generate stimulated light. The light cone contains at least one of a dichroic mirror and a reflective polarizer. The dichroic mirror reflects or partially reflects the residual excitation light emitted from the light source to the wavelength conversion layer, while transmitting the stimulated light emitted from the light source. The reflective polarizer reflects light with a first polarization to the wavelength conversion layer, while transmitting light with a second polarization.

2. The LCD projection engine of claim 1, wherein the light source is a light emitting diode (LED) light source. The dichroic mirror and / or reflective polarizer fills the cross-section of the light cone or covers a portion of the cross-section of the light cone.

3. The LCD projection optical engine according to claim 1, characterized in that, The light cone has a slot on its side wall, through which the dichroic mirror and / or the reflective polarizer are inserted and installed into the light cone.

4. An LCD projection optical engine according to claim 3, characterized in that, The cross-section of the light cone is rectangular, and there are slots on the sidewalls corresponding to the long and short sides of the rectangle. The dichroic mirror and the reflective polarizer are respectively installed into the light cone through different slots.

5. An LCD projection optical engine according to any one of claims 1-4, characterized in that, The dichroic mirror is located near the incident end of the light cone.

6. An LCD projection optical engine according to any one of claims 1-4, characterized in that, The reflective polarizer is an inorganic polarizer, and the reflective polarizer is located near the incident end of the light cone.

7. An LCD projection optical engine according to any one of claims 1-4, characterized in that, The reflective polarizer is an organic polarizer, and the reflective polarizer is located near the light-emitting end of the light cone.

8. An LCD projection optical engine according to any one of claims 1-4, characterized in that, It also includes an LCD disposed on the outgoing light path of the light cone, wherein an analyzer is disposed on the light-emitting side of the LCD at a distance from the LCD.

9. An LCD projection optical engine according to any one of claims 1-4, characterized in that, It also includes an LCD disposed on the outgoing light path of the light cone, and a polarizer disposed between the light cone and the LCD. The optical axis of the polarizer is along the vibration direction of the second polarized light, and the polarizer and the LCD are disposed at intervals.

10. An LCD projection optical engine according to any one of claims 1-4, characterized in that, The excitation device includes an LED light source or a laser light source.

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