CN113946092A - a projection system - Google Patents

Abstract

The present application discloses a projection system, which includes a color mixing light source module, a beam combining module and a light homogenizing module, wherein the color mixing light source module is used to provide three primary color LED light and yellow laser light, and three primary color LED light and yellow laser light The mixed color light is formed after the beam combining module is combined, and the mixed color light is homogenized and shaped by the homogenizing module to obtain the projection light for projection. In this system, the yellow laser light is used to make up for the problem that the three primary color LED light cannot fully traverse in the yellow part. The problem of poor color rendering capability of the projection system is solved, and at the same time, only one type of laser light is used in the system, which avoids the problem of large heat dissipation caused by using all laser light sources as working light.

Description

a projection system

technical field

The present application relates to the technical field of optical optoelectronics, and more particularly, to a projection system.

Background technique

The projection system is an optical system that images the object on the projection screen after illuminating it. The ultimate purpose of the projection system is to truly reproduce the natural colors and various scenes that the human eye can see. It is mainly divided into three types according to different light sources: light bulb, LED (Light-Emitting Diode, light-emitting diode) and laser projection. With the development of display technology, projection technology with LED and laser as light source stands out.

However, the current projection systems using LEDs or lasers as light sources have problems of poor color rendering capability or large heat dissipation.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present application provides a projection system to solve the problems of poor color rendering capability or large heat dissipation of the projection system.

To achieve the above technical purpose, the embodiments of the present application provide the following technical solutions:

A projection system includes: a color mixing light source module, a beam combining module and a uniform light module; wherein,

The color mixing light source module is used to provide three primary colors of LED light and yellow laser light;

The beam combining module is used for combining the three primary color LED lights into a first combining light, and for combining the first combining light and the yellow laser light into a mixed color light;

The homogenizing module is used for homogenizing and shaping the mixed color light to obtain projection light.

Optionally, the color mixing light source module includes: an LED light source unit and a laser light source unit; wherein,

The LED light source unit includes a plurality of LEDs, and the plurality of LEDs at least include a first LED, a second LED and a third LED, wherein the first LED is used for emitting red light, and the second LED is used for emit green light, and the third LED is used to emit blue light;

The laser light source unit includes at least one laser for emitting yellow laser light.

Optionally, it also includes: a light modulation module;

The light modulation module includes: a circuit board and a first signal controller; wherein,

the circuit board for carrying the LED light source unit and the laser light source unit;

The first signal controller is used for signal modulation and control of the LED light source unit and/or the laser light source unit.

Optionally, it also includes: a collimation module;

The collimation module includes a plurality of collimation elements, and the collimation elements are used for collimating the light emitted by the first LED, the second LED, the third LED or the laser.

Optionally, the beam combining module includes: a first beam combining element and a second beam combining element; wherein,

The first beam combining element is arranged on the common optical path of the first LED, the second LED and the third LED, and the first beam combining element is used to combine the red light, the green light and the blue light. After the color light is combined, the three primary color mixed light is obtained and transmitted along the first direction;

The second beam-combining element is arranged in the first direction of the first beam-combining element, and the second beam-combining element is used to combine the three-primary-color mixed light and the yellow laser light to obtain the The mixed color light is transmitted along the first direction.

Optionally, the beam combining module further includes: a reflective element;

The reflective element is arranged in the first direction of the second beam combining element, and the reflective element is used to reflect the mixed color light to a second direction, and the first direction and the second direction are on the same plane inside, and the first direction intersects the second direction.

Optionally, the color mixing light source module further includes: a heat sink;

The heat sink is used to transmit the heat generated by the LED light source unit and the laser light source unit to the outside.

Optionally, it also includes: an imaging module;

The imaging module is configured to obtain a projection image based on the projection light.

Optionally, the uniform light module includes: a uniform light element and a relay lens; wherein,

The homogenizing element is used for homogenizing and shaping the mixed color light to obtain the mixed color light in the shape of a rectangular spot;

The relay lens is used for imaging the mixed color light in the shape of the rectangular light spot on the imaging module.

Optionally, the imaging module includes: a spatial light modulator and a second signal controller; wherein,

The second signal controller is configured to transmit a modulation signal to the spatial light modulator, so that the spatial light modulator outputs the projection image based on the modulation signal.

It can be seen from the above technical solutions that an embodiment of the present application provides a projection system, the projection system includes a color mixing light source module, a beam combining module and a light homogenizing module, wherein the color mixing light source module is used to provide three primary colors of LED light and yellow light Laser light, three primary color LED light and yellow laser light are combined by the beam combining module to form mixed color light. After the mixed color light is homogenized and shaped by the uniform light module, the projection light is obtained for projection. In this system, the yellow laser light is used to make up for the three primary color LEDs. The problem that the light cannot be fully traversed in the yellow part solves the problem of poor color rendering capability of the projection system. At the same time, only one type of laser light is used in the system, which avoids the problem of large heat dissipation caused by using all laser light sources as working light. .

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only It is an embodiment of the present application. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a projection system according to an embodiment of the present application;

2 is a schematic structural diagram of a projection system according to another embodiment of the present application;

3 is a schematic structural diagram of a projection system according to another embodiment of the present application;

FIG. 4 is a schematic diagram of a spectrum of a first LED, a second LED, and a third LED provided by an embodiment of the present application;

5 is a schematic diagram of a spectrum of a color mixing light source module provided by an embodiment of the present application;

Fig. 6 is another one of this application;

7 is a schematic diagram of a reflection spectrum of a second beam combining element provided by an embodiment of the present application;

FIG. 8 is a schematic diagram of the spectrum of the color mixing light of the projection system shown in FIG. 2 including the second beam combining element shown in FIG. 7 provided for an embodiment of the application;

9 is a schematic diagram of a reflection spectrum of a second beam combining element provided by another embodiment of the present application;

FIG. 10 is a schematic diagram of the spectrum of the color mixing light of the projection system shown in FIG. 3 including the second beam combining element shown in FIG. 9 according to an embodiment of the present application.

Detailed ways

As described in the background art, the prior art projection systems using LEDs or lasers as light sources have problems of poor display capability or large heat dissipation.

The inventor's research found that compared with traditional light sources such as high-pressure mercury lamps and halogen lamps, LEDs have the advantages of high luminous efficiency, small size, and low cost. The monochromatic LED light source has a narrow spectral width (tens of nanometers), has higher color saturation, has a larger color gamut, and shows that the colors in nature are more real and bright, but its color rendering ability is still far away Far from reaching the color resolution limit of the human eye. In addition, the luminous energy density of LEDs (luminous flux per unit area) has reached a bottleneck. In order to improve the brightness of LEDs, the luminous area must be increased, which increases the difficulty of optical path design, increases the volume of the projection system, and leads to high costs. Therefore, the basic direction of LED projector applications lies in home theaters, small conference rooms, and the like. In addition, for the traditional red, green and blue LED projection system, limited by its conversion efficiency, it is impossible to achieve a breakthrough in the brightness of the projected image, and there is a problem that the yellow part cannot be fully traversed. , making it difficult for home projectors to meet the DCI digital cinema standard.

The laser light source has the advantages of high brightness and high monochromaticity. Compared with the LED light source, the monochromatic spectral width of the laser light source is narrower (nano-scale) and the saturation is higher. The color rendering ability of the projection system using pure laser as the light source is close to The color resolution limit of the human eye is a very promising projection technology. At present, the more mature laser projection scheme usually adopts the two-color wheel method of fluorescent wheel and filter wheel, that is, the blue semiconductor laser is irradiated on the phosphor to excite yellow-green light, and then the yellow-green light passes through the filter wheel to generate red and green light with higher saturation. The light, together with the transmitted blue laser, forms three primary colors, and the desired image is produced by the ratio between the three primary colors. This method requires the use of high-power and long-time laser irradiation on the fluorescent wheel, which will locally generate high temperature in the fluorescent wheel, resulting in a decrease in fluorescence efficiency, and the use of a color wheel increases the volume of the optical engine. The timing signal of the two-color wheel is difficult to synchronize with the timing signal of the three-primary LED, and it is inconvenient to add additional light sources for system optimization. Another solution is the projection method of three-primary pure laser, which optimizes the effect with pure laser. Another way is to use a projection system with red, green, and blue lasers as the light source. The laser has a color rendering ability close to the color resolution limit of the human eye. Its color coordinate point is closer to the MacAdam boundary, the limit of the human eye color resolution, and the color gamut triangle is larger. Due to the high directivity and high brightness of the laser, it can achieve High brightness projection effect. However, due to the large heat dissipation of the laser, it is difficult to reduce the volume of the heat dissipation system, and the volume cannot be effectively reduced.

After further research, the inventor found that for the existing red and blue LED projection light source technology, the spectral width is in the order of 20 nanometers, which is close to the color resolution capability of the human eye. However, for the existing green LED projection light source technology, the spectral width is On the order of one hundred nanometers, the saturation is low, which limits the size of the gamut in the green direction of the projection system. Therefore, for the projection system of the red, green and blue LED light sources, the yellow laser light source is added to complement the brightness and saturation of the green LED light source, and the color gamut of the yellow area is expanded, so as to obtain the projection effect of high brightness and large color gamut.

Based on the above research, an embodiment of the present application provides a projection system, the projection system includes a color mixing light source module, a beam combining module and a light homogenizing module, wherein the color mixing light source module is used to provide three primary colors of LED light and yellow laser light. The LED light and the yellow laser light are combined by the beam combining module to form mixed color light. After the mixed color light is homogenized and shaped by the uniform light module, the projected light is obtained for projection. In this system, the yellow laser light is used to make up for the three primary color LED light. Part of the problem of full traversal solves the problem of poor color rendering capability of the projection system. At the same time, only one type of laser light is used in the system, which avoids the problem of large heat dissipation caused by using all laser light sources as working light.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

An embodiment of the present application provides a projection system, as shown in FIG. 1 , including: a color mixing light source module 100 , a beam combining module 200 and a light homogenizing module 300 ; wherein,

The color mixing light source module 100 is used to provide three primary colors of LED light and yellow laser light;

The beam combining module 200 is used for combining the three primary color LED lights into a first combining light, and for combining the first combining light and the yellow laser light into a mixed color light;

The homogenizing module 300 is used for homogenizing and shaping the mixed color light to obtain projection light.

Optionally, the three primary color LED light refers to the three primary color light emitted by the LED light-emitting element, and the three primary color light may include red light, green light and blue light.

The yellow laser light refers to the yellow light emitted by a laser.

The projection system provided by this embodiment uses yellow laser light to make up for the problem that the three primary color LED light cannot fully traverse in the yellow part, and solves the problem of poor color rendering capability of the projection system. The problem of large heat dissipation caused by using a laser light source as the working light.

The projection system makes full use of the advantages of small size and low cost of LEDs, as well as high brightness, high saturation and large color gamut of laser light. Under the condition of low cost and small volume, projection with higher brightness and larger color gamut is obtained. system.

In addition, the projection system eliminates the necessary color wheel in the laser fluorescence projection system, further reduces the volume, and makes the system static, eliminating the influence caused by the high-speed rotation of the color wheel.

The feasible structure of each module of the projection system provided by the embodiment of the present application is described below.

Optionally, as shown in FIG. 2 and FIG. 3 , the color mixing light source module 100 includes: an LED light source unit and a laser light source unit; wherein,

The LED light source unit includes a plurality of LEDs 10, and the plurality of LEDs 10 include at least a first LED, a second LED and a third LED, wherein the first LED is used for emitting red light, and the second LED is used for emit green light, and the third LED is used to emit blue light;

The laser light source unit includes at least one laser 11 for emitting yellow laser light.

Referring to FIG. 4, FIG. 4 shows a schematic diagram of the spectrum of the first LED, the second LED and the third LED, the intensity of each primary color is determined by the white balance of the projection system. Certainly, in other embodiments of the present application, the spectral curves of the first LED, the second LED and the third LED can also be determined according to actual requirements.

In FIG. 2 , the color mixing light source module 100 includes one laser 11 , and in FIG. 3 , the color mixing light source module 100 includes two lasers 11 . In other embodiments of the present application, the number of lasers 11 in the color mixing light source module 100 may also be three, four, or five, etc., which is not limited in the present application, and depends on the actual situation. When the number of lasers 11 in the color mixing light source module 100 is two or more, the spectrum of the laser light emitted by each of the lasers 11 may be the same or different, which is not limited in this application.

Referring to FIGS. 5 and 6 , FIG. 5 shows a schematic diagram of a spectrum when the color mixing light source module 100 includes one laser 11 , and FIG. 6 shows a spectrum when the color mixing light source module 100 includes two lasers 11 Schematic. The intensity of each primary color is determined by the white balance of the projection system. Of course, in other embodiments of the present application, the spectral curve of the laser 11 can also be determined according to actual requirements.

Correspondingly, still referring to FIG. 2 or FIG. 3 , the beam combining module 200 includes: a first beam combining element 21 and a second beam combining element 22; wherein,

The first beam combining element 21 is arranged on the common optical path of the first LED, the second LED and the third LED, and the first beam combining element 21 is used to combine the red light, the green light and all the After the blue light is combined, the three primary color mixed light is obtained and transmitted along the first direction;

The second beam combining element 22 is arranged in the first direction of the first beam combining element 21, and the second beam combining element 21 is used to combine the three primary color mixed light and the yellow laser light, to obtain the mixed color light and transmit it along the first direction.

The number of the second beam combining elements 22 is consistent with the number of the lasers. In FIG. 2 , the number of the second beam combining elements 22 is one. The quantity is two.

Optionally, the first beam combining element 21 may be a dichroic mirror or an X prism.

The second beam combining element 22 may be a narrow bandpass filter or a narrowband rejection filter matching the wavelength of the yellow laser light, or an interference narrowbandpass filter or a holographic optical element corresponding to the wavelength of the yellow laser light.

Optionally, still referring to FIG. 2 or FIG. 3 , the projection system further includes: a light modulation module;

The light modulation module includes: a circuit board 12 and a first signal controller 13; wherein,

the circuit board 12 is used to carry the LED light source unit and the laser light source unit;

The first signal controller 13 is used for signal modulation and control of the LED light source unit and/or the laser light source unit.

The first signal controller 13 is electrically connected to the LED light source unit and/or the laser light source unit through the wiring on the circuit board, so that the first signal controller 13 can be connected to the LED light source. unit and/or the laser light source unit for signal transmission.

Optionally, the first signal controller 13 may only perform signal modulation and control on the LED light source unit, or may only perform signal modulation and control on the laser light source unit, and may also perform signal modulation and control on the LED light source unit. The signal modulation and control are performed, and the signal modulation and control are performed on the laser light source unit, which is not limited in this application, and depends on the actual situation.

Optionally, a collimation module is also shown in FIG. 2 and FIG. 3 , the collimation module includes a plurality of collimation elements, and the collimation elements are used to The light emitted by the three LEDs or the laser is collimated.

In FIG. 2 and FIG. 3 , the collimating element 41 for collimating the light emitted by the first LED, the second LED or the third LED may be a lens or a lens group, and collimating the light emitted by the laser The collimating element 42 can be an aspheric lens or a fiber coupling element.

In FIG. 2 and FIG. 3 , the beam combining module 200 further includes: a reflective element 23;

The reflective element 23 is arranged in the first direction of the second beam combining element 22, and the reflective element 23 is used to reflect the mixed color light to the second direction, the first direction and the second direction In the same plane, and the first direction intersects the second direction.

The reflective element 23 may be a reflective mirror, and the reflective element 23 is used to compress/fold the light path of the combined color-mixed light, thereby reducing the overall volume of the projection system.

In addition, the existence of the reflective element 23 can improve the robustness of the optical path, that is, in the case of some errors during the construction of the optical path of the system, the reflective element 23 can still be used to shape the light beam of the mixed color light to obtain Color mixing light that meets the requirements.

Optionally, in an embodiment of the present application, the color mixing light source module 100 further includes: a heat sink;

The heat sink is used to transmit the heat generated by the LED light source unit and the laser light source unit to the outside.

More specifically, the heat sink transmits the heat generated by the LED light source unit and the laser light source unit to the respective bases, so as to keep the working temperature of the LED light source unit and the laser light source unit at a certain working temperature. within the range.

A heat sink refers to a structure whose temperature does not change with the amount of heat energy transferred to it. Optionally, the heat sink may be a structure with better thermal conductivity such as a copper column.

Optionally, still referring to FIG. 2 or FIG. 3 , the projection system further includes: an imaging module;

The imaging module is configured to obtain a projection image based on the projection light.

Optionally, the imaging module includes: a spatial light modulator 51 and a second signal controller 52; wherein,

The second signal controller 52 is configured to transmit a modulation signal to the spatial light modulator 51, so that the spatial light modulator 51 outputs the projection image based on the modulation signal.

Optionally, the homogenizing module 300 includes: a homogenizing element 31 and a relay lens 32; wherein,

The homogenizing element 31 is used for homogenizing and shaping the mixed color light to obtain the mixed color light in the shape of a rectangular spot;

The relay lens 32 is used to image the mixed color light in the shape of the rectangular spot on the imaging module.

In the structure shown in FIG. 2 , when the second beam combining element 22 is an interference narrow bandpass filter, referring to FIG. 7 , FIG. 7 shows a schematic diagram of a reflection spectrum of the second beam combining element 22 . The yellow laser light and the three primary color LED light are coaxially combined by the second beam combining element 22. Referring to FIG. 8, the combined spectrum shows that the brightness and saturation of the wavelength portion of the yellow laser pipeline are greatly improved.

In the structure shown in FIG. 3 , when the second beam combining element 22 is an interference narrow bandpass filter, referring to FIG. 9 , FIG. 9 shows a schematic diagram of a reflection spectrum of the second beam combining element 22 , the upper and lower figures in Fig. 9 correspond to the laser light sources of the two wavelength bands respectively. The yellow laser light and the three primary color LED light are coaxially combined by the second beam combining element 22. Referring to FIG. 10, the combined spectrum shows that the brightness and saturation of the wavelength portion of the yellow laser pipeline are greatly improved.

In Figures 3 to 10, the abscissas are all wavelengths in nanometers (nm), the ordinates of Figures 5, 6, 7 and 9 are reflectance, and the vertical axes of Figures 4, 8 and 10 are all reflectances. Coordinates are normalized intensity.

To sum up, the embodiments of the present application provide a projection system, which includes a color mixing light source module 100, a beam combining module 200 and a light homogenizing module 300, wherein the color mixing light source module 100 is used to provide three primary colors of LED light and The yellow laser light, the three primary color LED light and the yellow laser light are combined by the beam combining module 200 to form a mixed color light, and the mixed color light is homogenized and shaped by the uniform light module 300 to obtain a projection light for projection. The yellow laser light is used in the system. It makes up for the problem that the three primary colors of LED light cannot be fully traversed in the yellow part, and solves the problem of poor color rendering capability of the projection system. At the same time, only one type of laser light is used in the system, which avoids the heat dissipation caused by using all laser light sources as working light. big problem.

The features described in the various embodiments in this specification can be replaced or combined with each other, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, this application is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A projection system, characterized in that, comprising: a color mixing light source module, a beam combining module and a light homogenizing module; wherein, The color mixing light source module is used to provide three primary colors of LED light and yellow laser light; The beam combining module is used for combining the three primary color LED lights into a first combining light, and for combining the first combining light and the yellow laser light into a mixed color light; The homogenizing module is used for homogenizing and shaping the mixed color light to obtain projection light. 2. The projection system according to claim 1, wherein the color mixing light source module comprises: an LED light source unit and a laser light source unit; wherein, The LED light source unit includes a plurality of LEDs, and the plurality of LEDs at least include a first LED, a second LED and a third LED, wherein the first LED is used for emitting red light, and the second LED is used for emit green light, and the third LED is used to emit blue light; The laser light source unit includes at least one laser for emitting yellow laser light. 3. The projection system according to claim 2, further comprising: a light modulation module; The light modulation module includes: a circuit board and a first signal controller; wherein, the circuit board for carrying the LED light source unit and the laser light source unit; The first signal controller is used for signal modulation and control of the LED light source unit and/or the laser light source unit. 4. The projection system according to claim 2, characterized in that, further comprising: a collimation module; The collimation module includes a plurality of collimation elements, and the collimation elements are used for collimating the light emitted by the first LED, the second LED, the third LED or the laser. 5. The projection system according to claim 2, wherein the beam combining module comprises: a first beam combining element and a second beam combining element; wherein, The first beam combining element is arranged on the common optical path of the first LED, the second LED and the third LED, and the first beam combining element is used to combine the red light, the green light and the blue light. After the color light is combined, the three primary color mixed light is obtained and transmitted along the first direction; The second beam-combining element is arranged in the first direction of the first beam-combining element, and the second beam-combining element is used to combine the three-primary-color mixed light and the yellow laser light to obtain the The mixed color light is transmitted along the first direction. 6. The projection system according to claim 5, wherein the beam combining module further comprises: a reflective element; The reflective element is arranged in the first direction of the second beam combining element, and the reflective element is used to reflect the mixed color light to a second direction, and the first direction and the second direction are on the same plane inside, and the first direction intersects the second direction. 7. The projection system according to claim 2, wherein the color mixing light source module further comprises: a heat sink; The heat sink is used to transmit the heat generated by the LED light source unit and the laser light source unit to the outside. 8. The projection system of claim 1, further comprising: an imaging module; The imaging module is configured to obtain a projection image based on the projection light. 9. The projection system according to claim 8, wherein the uniform light module comprises: a light uniform element and a relay lens; wherein, The homogenizing element is used for homogenizing and shaping the mixed color light to obtain the mixed color light in the shape of a rectangular spot; The relay lens is used for imaging the mixed color light in the shape of the rectangular light spot on the imaging module. 10. The projection system according to claim 8, wherein the imaging module comprises: a spatial light modulator and a second signal controller; wherein, The second signal controller is configured to transmit a modulation signal to the spatial light modulator, so that the spatial light modulator outputs the projection image based on the modulation signal.

Images