CN117950260A

CN117950260A - Optical system and projection device

Info

Publication number: CN117950260A
Application number: CN202410323628.9A
Authority: CN
Inventors: 聂思永; 彭水海; 陈怡学; 刘凤; 袁敏; 杜霁轩
Original assignee: Yibin Jimi Photoelectric Co Ltd
Current assignee: Yibin Jimi Photoelectric Co Ltd
Priority date: 2024-03-21
Filing date: 2024-03-21
Publication date: 2024-04-30

Abstract

The invention discloses an optical system and a projection device, and relates to the technical field of photoelectricity. The optical system comprises a light source component, a wavelength conversion device and a light processing device, wherein the optical system is provided with a filter layer in the light processing device, the filter layer is used for transmitting the laser light and reflecting at least the light of the wave band of the first laser light, so that the light path of the first laser light reflected by the filter layer is different from the light path of the first light passing through the second region of the light processing device, and the residue of the excitation light (namely the first laser light) in the laser light can be reduced.

Description

Optical system and projection device

Technical Field

The present invention relates to the field of photoelectric technologies, and in particular, to an optical system and a projection apparatus.

Background

In the field of projection display, conventional bulbs have not been adopted due to their own defects, and new light sources such as LEDs, fluorescence and lasers have been increasingly becoming the main stream of light sources for projection display because they exhibit excellent characteristics in terms of brightness, color, lifetime, energy consumption and the like. The laser has the advantages of high brightness and high light efficiency as a light source, the optical expansion of the laser is smaller, the light spot formed on the optical element is smaller, and the energy is concentrated. At present, the fluorescence excited by monochromatic laser can obtain higher brightness, but the color is worse, and the color of the trichromatic laser is high, but the phenomenon of color edges exists, and speckle is difficult to eliminate, and the cost is high.

Disclosure of Invention

In view of the above, the present invention provides an optical system and a projection apparatus that reduce the residual excitation light in the excited light.

In a first aspect, the present invention provides an optical system comprising:

The light source assembly comprises a first laser light source, wherein the first laser light source is used for emitting first laser;

A wavelength conversion device including a wavelength conversion region for generating a lasing light under irradiation of the first laser light and a light guiding region for guiding a propagation direction of the first laser light to form first light;

The light processing device is used for providing the laser-receiving light and the first light to the light homogenizing element after being processed, and comprises a first area and a second area, wherein the first area is used for passing through the laser, the second area is used for passing through the first light, the first area comprises a filter layer, and the filter layer is used for transmitting the laser-receiving light and reflecting at least light of a wave band where the first laser is located, so that the optical path of the first laser reflected by the filter layer is different from that of the first light passing through the second area.

In a possible implementation manner, the method further includes:

The light splitting sheet is used for guiding the first laser emitted by the light source assembly to enter the wavelength conversion device and guiding at least one of the laser and the first light to enter the light combining assembly; the light splitting sheet comprises a first area and a second area, wherein the first area enables light in a wave band where the first laser is located to pass through and reflects light in the wave band where the laser is located, and the second area at least reflects light in the wave band where the laser is located;

and the light combining component is used for guiding the laser and the first light to enter the light processing device from the same direction.

In a possible implementation manner, the method further includes:

The beam shrinking lens group is positioned between the light source component and the beam splitting sheet and used for compressing the light spot of the first laser;

a diffusion element or a homogenizing element, which is positioned between the light source component and the beam splitting sheet and is used for homogenizing the light spot of the first laser;

The first laser processed by the beam shrinking lens group and the diffusion element or the homogenizing element is entirely incident to the wavelength conversion device through the first area.

In a possible implementation manner, the method further includes:

and the collimating lens group is positioned between the wavelength conversion device and the light source component and is used for collimating the laser emitted by the wavelength conversion region, and the principal ray of the first laser emitted from the first laser source is not coincident with the optical axis of the collimating lens group.

In a possible implementation manner, the light combining component comprises a first light combining element and a second light combining element, wherein,

The first light combining element is used for transmitting the first light and reflecting the laser;

The second light combining element is used for reflecting the first light, so that each light is incident to the light homogenizing element in an angle symmetrical mode.

In a possible implementation manner, the method further includes:

The focusing lens group is positioned between the light combination assembly and the light processing device and is used for focusing the light emitted by the light combination assembly into the light homogenizing element, so that more than 90% of the light emitted by the light combination assembly enters the light homogenizing element after passing through the focusing lens group and the light processing device.

In a possible implementation, the second region is provided with a diffusing element.

In a possible implementation manner, the number of the wavelength conversion regions and the number of the light guiding regions are both n, the rotation speed of the wavelength conversion device is m revolutions per second, n×m=q, where q is a picture refresh rate, the unit is HZ, n is greater than or equal to 1, and m is greater than 0.

In a possible implementation, the wavelength conversion device and the light processing device are a single device.

In a second aspect, the present invention provides a projection apparatus comprising the optical system of the first aspect.

The optical system provided by the invention is used for arranging the filter layer in the light processing device for passing through the first area of the laser receiving, and the filter layer is used for transmitting the laser receiving and reflecting at least the light of the wave band of the first laser, so that the light path of the first laser reflected by the filter layer is different from the light path of the first light passing through the second area of the light processing device, and the residue of the excitation light (namely the first laser) in the laser receiving can be reduced.

Drawings

Fig. 1 is a schematic functional block diagram of a projection apparatus according to an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a projection apparatus according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an optical system according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of an optical system according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of an optical system according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an optical system according to an embodiment of the present invention;

Fig. 7 is a schematic light combination diagram of a first laser light source according to an embodiment of the present invention;

fig. 8 is a schematic light combination diagram of a first laser light source according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a light combining component according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of an optical system according to an embodiment of the present invention;

Fig. 11 is a schematic structural diagram of a wavelength conversion device according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of a wavelength conversion device according to an embodiment of the present invention;

Fig. 13 is a schematic structural diagram of a wavelength conversion device according to an embodiment of the present invention;

fig. 14 is a schematic structural diagram of a wavelength conversion device according to an embodiment of the present invention;

fig. 15 is a schematic structural diagram of an optical system according to an embodiment of the present invention.

Detailed Description

In order to better understand the technical solutions of the present invention, the following description will clearly and completely describe the technical solutions of the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. While the present disclosure has been described in terms of an exemplary embodiment or embodiments, it should be understood that each aspect of the disclosure may be separately provided as a complete solution. The following embodiments and features of the embodiments may be combined with each other without conflict.

In the present invention, for the purpose of clearly describing the technical solutions of the embodiments of the present invention, the words "first", "second", etc. are used to distinguish identical items or similar items having substantially identical functions and actions, and those skilled in the art will understand that the words "first", "second", etc. do not limit the number and execution order, but merely serve to illustrate and distinguish between the objects to be described, without separating the order, nor do they represent that the number of devices or messages in the embodiments of the present invention is particularly limited, and cannot constitute any limitation of the embodiments of the present invention. "plurality" means two or more, and the like, means that the element or article recited in the preceding word "comprise" or "comprises", and the like, is meant to encompass the element or article listed thereafter and equivalents thereof without precluding other elements or articles.

In order that the invention may be fully understood, a detailed description will be provided below in order to illustrate the technical aspects of the invention. Preferred embodiments of the present invention are described in detail below, however, the present invention may have other embodiments in addition to these detailed descriptions.

Fig. 1 is a schematic functional block diagram of a projection apparatus according to an embodiment of the present invention. As shown in fig. 1, the projection device includes an image processor 110 and a projection light engine 120. Wherein:

The image processor 110 may be a microcontroller, a dedicated image processing chip, etc., and the microcontroller may be an ARM chip, a micro control unit (Microcontroller Unit; MCU), etc.; the dedicated image Processing chip may be an image signal processor (IMAGE SIGNAL Processing, ISP), a graphics processor (graphics Processing unit, GPU), an embedded neural Network Processor (NPU), or the like. The image processor 110 may be used for video decoding, image quality processing, etc.

The projector 120 may include a driving chip, a display chip, a light source, and the like. Wherein the light source may include a laser light source, an LED light source, a fluorescent light source, etc.; the display chip may be a digital micromirror device (Digtial Micromirror Devices, DMD), a Liquid crystal device (Liquid CRYSTAL DISPLAY, LCD), a Liquid crystal on silicon device (Liquid Crystal on Silicon, LCOS), or the like for modulating light source light to generate image light; the driving chip corresponds to the display chip, and for example, the digital micromirror device may be driven by a Digital Light Processing (DLP) element (DIGITAL LIGHT Processing). The projection light machine 120 is used for projecting an image to be projected into a projection screen.

In some embodiments, the projection device further includes a central controller 130, which may be CPU, ARM, MCU or the like, of one or more processing cores. The central controller 130 is a control center of the projection device, and may run or execute software programs and/or an operating system stored in the memory module 140 and call up data stored in the memory module 140 using various interfaces and lines to connect various parts of the entire projection device. Alternatively, the image processor 110 and the central controller 130 may be integrated as one processor.

In some embodiments, the projection device further includes a storage module 140, an input module 150, and a communication module 160, among other components, of one or more computer-readable storage media. It will be appreciated by those skilled in the art that the projection device structure shown in fig. 1 is not limiting of the projection device and may include more or fewer components than shown, or may combine certain components, or a different arrangement of components. Wherein:

The memory module 140 may be used to store software programs and an operating system, and the central controller 130 performs various functional applications and data processing by running the software programs and the operating system stored in the memory module 140. The storage module 140 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program (such as a sound playing function, an image playing function, etc.) required for at least one function, etc.; the storage data area may store data created according to the use of the projection device, etc. In addition, the storage module 140 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid-state storage device. Accordingly, the memory module 140 may also include a memory controller to provide access to the memory module 140 by the central controller 130.

The projection device may further comprise an input module 150, which input module 150 may be used to receive entered numerical or character information and to generate remote control, keyboard, mouse, joystick, optical or trackball signal inputs related to user settings and function control.

The projection device may also include a communication module 160, in some embodiments the communication module 160 may include a wireless module, and the projection device may provide wireless broadband internet access to the user by short-range wireless transmission through the wireless module of the communication module 160. For example, the communication module 160 may be used to assist a user in accessing streaming media, and the like.

Fig. 2 is a schematic structural diagram of a projection apparatus according to an embodiment of the present invention. As shown in fig. 2, the projection device includes a light source device 210, a light homogenizing element 220, an illumination system 230, and an imaging system 240. The illumination light generated by the light source device 210 is homogenized by the light homogenizing element 220, the light spot emitted by the light homogenizing element 220 is imaged on a display chip (not shown in the figure) by the illumination system 230, the display chip modulates the incident illumination light into image light, the image light enters the imaging system 240, and finally, the image light is imaged on a projection plane such as a screen to form a projection picture.

In addition, the projection device may further include a light source control module (not shown in the drawing), which may control the operation of one or more light sources in the light source device 210 such that the light source device 210 emits light of a prescribed wavelength band required when generating an image. Further, the light source device 210, the dodging element 220, the illumination system 230 and the imaging system 240 may all be included in the projector 120 (refer to fig. 1).

The light source device 210 may include one or more light sources. The light source can be a laser light source, an LED light source, a fluorescent light source, or the like. Further, the light source may be a single light emitting element or an array of light emitting elements, and the array of light emitting elements may include light emitting elements of different colors. For example, the light source may be an LD light source or an LED light source, which generates blue light or green light or red light, or the light source may be a multicolor laser, that is, an array of light emitting elements including a plurality of lasers, for example, the light source may include a blue laser and a red laser, or include a blue laser and a green laser, or include a blue laser, a red laser, and a green laser at the same time.

The light homogenizing element 220 is used for homogenizing illumination light generated by the light source device 210. Specifically, the light homogenizing element 220 includes an incident surface and an exit surface, and the light homogenizing element 220 is configured to perform a homogenization process on illumination light incident from the incident surface thereof. Illustratively, the light homogenizing element 220 may be a light bar, compound eye, or the like.

The illumination system 230 is the portion from the light homogenizing element to the display chip for imaging the spot of light exiting the light homogenizing element 220 on the display chip. For example, the illumination system 230 may include one or more lenses.

The imaging system 240 is used to image light onto a projection plane such as a screen to form a projection screen. Imaging system 240 is typically a lens system, such as a projection lens.

Fig. 3-6 are schematic structural diagrams of an optical system according to an embodiment of the present invention. As shown in fig. 3-6, the optical system, which may be the light source device shown in fig. 2, includes a light source assembly 100 and a wavelength conversion device 200. The light source assembly 100 is configured to emit light source light, where the light source light may include only laser light, or may include only LED light, or may include both laser light and LED light, and the wavelength conversion device 200 is configured to generate lasing (e.g. fluorescence) under irradiation of at least part of the light source light. In other embodiments, the illumination light emitted by the optical system may further include LED light.

The light source assembly 100 includes a first laser light source 101, the first laser light source 101 for emitting a first laser light. By way of example, the first laser light source may be a short-wave visible light source with a wavelength in the range of 440nm-480nm, preferably the first laser light source 101 is a blue laser light source. It should be appreciated that the first laser light source 101 may also be short-wave invisible light, such as UV light, etc. Further, the first laser source 101 may include one or more laser modules, and the number of light emitting chips in each laser module is not limited, and may be a single light emitting chip or an array of light emitting chips, for example, a blue laser module may be 1 column of light spots or 2 columns of light spots, and may be a mirror for combining light, or may be a polarized light combining light. In fig. 3 to 6, solid arrows indicate light rays in the wavelength band of the light emitted from the first light source 101, dotted arrows indicate light rays in the wavelength band of the laser light, and dotted arrows indicate light rays in the wavelength band of the light emitted from the second light source 102.

7-8, The first laser light source 101 includes a first sub-laser module 1011, a second sub-laser module 1012 and a light combining module 1013, wherein the first sub-laser module 1011 is used to emit a first sub-laser light having a second color, the second sub-laser module 1012 is used to emit a second sub-laser light having a second color, and wavelength bands of the first sub-laser light and the second sub-laser light may be the same or different, for example, the first sub-laser module 1011 and the second sub-laser module 1012 are both blue laser modules, the dominant wavelength of the first sub-laser module 1011 is 455nm, the dominant wavelength of the second sub-laser module 1012 is 465nm, and the speckle effect is further reduced by using blue light of two different wavelengths.

In some embodiments, the light combining module 1013 includes one or more mirrors for guiding the first sub-laser light and the second sub-laser light to exit from the same direction to form the first laser light, such that a spot size of the first laser light is greater than a spot of any one of the first sub-laser light and the second sub-laser light and less than or equal to a sum of spot sizes of the first sub-laser light and the second sub-laser light, as shown in fig. 7. In other embodiments, the light combining module 1013 includes a polarization light combining element configured to polarization-combine the first sub-laser and the second sub-laser to form a first laser, so that a spot size of the first laser is equal to a spot of a larger one of the first sub-laser and the second sub-laser, as shown in fig. 8. Alternatively, when the polarization of the first sub-laser light and the second sub-laser light are the same, a wave plate may be used to change the polarization state of one of them, thereby achieving polarization combination.

The wavelength conversion device 200 includes a wavelength conversion region for generating a lasing light under illumination of a first laser light, where the first laser light is referred to as excitation light. The wavelength-converting region may comprise one or more color-converting regions, e.g., the wavelength-converting region may comprise a green fluorescent region and/or a red fluorescent region, may also comprise an orange or yellow fluorescent region, etc. The wavelength-converting region includes, for example, a first color-converting region for producing a first sub-lasing having a first color under illumination by a first laser. Preferably, the luminous flux of the first sub-lasing in the white field is more than or equal to 20% and less than or equal to 90%, such as 20%, 30%, 50%, 70% or 90%, and the like, and preferably more than or equal to 50% and less than or equal to 90%, so as to improve the problems of speckle and color edges in a laser scheme, and simultaneously consider the efficiency and color of the lasers. Optionally, the luminous flux ratio of the first sub-lasing light in the white field is greater than or equal to 70%, and at this time, the light of the first color in the illumination light emitted by the optical system may only include the first sub-lasing light, without adding other light sources for generating the first color, so as to reduce cost. Further, the first color is preferably green, and the speckle and fringing effects on the white field are improved more significantly than for the other colors.

The illumination light emitted from the optical system includes the first sub-laser-receiving light, and the emitted laser included in the illumination light may be emitted from other laser sources (laser sources other than the first laser source 101), or may be obtained by changing the optical path of the first laser, or may include both the light obtained by changing the optical path of the first laser and the light emitted from other laser sources.

Referring to fig. 3, in some embodiments, the light source assembly further includes a second light source 102, where in this embodiment, the second light source 102 is a laser light source for emitting a second laser light, and the laser light emitted by the second laser and the wavelength conversion device 200 synthesizes illumination light emitted by the entire optical system. The second light source 102 may be integrally packaged with the first laser light source 101, for example, the light source assembly 100 may be obtained by packaging an array of LD light emitting chips, for example, a row of blue laser LD light emitting chips, a row of green laser LD light emitting chips, and a row or two rows of red laser LD light emitting chips may be integrally packaged, and the integrally packaged light source has a compact structure, so that the volume of the projection apparatus may be reduced.

In other embodiments, the wavelength conversion device 200 further includes a light transmission region for transmitting the first laser light emitted from the first laser light source 101 to form the first light, and the first light and the laser light, or the first light and the second laser light combine with the illumination light emitted from the whole optical system.

Referring to fig. 4-5, the wavelength conversion device 200 further includes a light guiding region for guiding a propagation direction of the first laser light emitted from the first laser light source 101 to form the first light, where the light guiding region may be a transmissive region (as shown in fig. 4) or a reflective region (as shown in fig. 5). In this embodiment, the optical system further includes a light combining component 300, and the light combining component 300 is used for guiding the received laser light and the emitted laser light to emit from the same direction, so as to form illumination light. Further, the optical system further includes a beam splitting component 400, where the beam splitting component 400 is configured to guide the first laser light to enter the wavelength conversion device 200, and is configured to guide one of the received laser light and the first light to enter the light combining component 300.

As shown in fig. 4, a light splitting component 400, such as a light splitting sheet, is configured to transmit a first laser light emitted from a first laser light source 101 to a wavelength conversion device 200, at a first moment, a wavelength conversion region of the wavelength conversion device 200 receives the laser light under irradiation of the first laser light, the laser light is reflected back to the light splitting component 400 by the wavelength conversion device 200, is reflected to a light combining component 300 by the light splitting component 400, and finally is guided to exit by the light combining component 300, and at a second moment, a light guiding region, such as a transmission region, of the wavelength conversion device 200 transmits the first laser light to form a first light, and then the first light is guided to exit by the light combining component 300. In this embodiment, the light splitting component 400 may be a dichroic element that transmits the first laser light and reflects the laser light, and if the first laser light is blue laser light and the laser light is green fluorescent light, the light splitting component 400 may be a dichroic element that transmits blue and reflects green. Alternatively, after the light guiding region of the wavelength conversion device 200 transmits the first laser light to form the first light, the first light may first change the propagation direction through a reflective element or the like, then enter the light splitting component 400 again, and then be transmitted to the light combining component 300 through the light splitting component 400. Further, the second light emitted from the second light source 102 can also be guided to exit through the light combining component 300.

As shown in fig. 5, a light splitting component 400, such as a light splitting sheet, is configured to transmit a first laser light emitted from a first laser light source 101 to a wavelength conversion device 200, at a first moment, a wavelength conversion region of the wavelength conversion device 200 receives the laser light under irradiation of the first laser light, the laser light is reflected back to the light splitting component 400 by the wavelength conversion device 200, is reflected to a light combining component 300 by the light splitting component 400, and finally is guided to exit by the light combining component 300, and at a second moment, a light guiding region, such as a reflection region, of the wavelength conversion device 200 reflects the first laser light to form a first light, and then the first light is guided to exit by the light combining component 300. In this embodiment, the light splitting component 400 may be a light splitting sheet including a first area a and a second area B, as shown in fig. 9, where the first area a transmits light of a wavelength band where the first laser is located, the second area B reflects the first light and light of a wavelength band where the laser is located, the first area a may be a through hole or a film coating area on a reflecting mirror, the first laser emitted from the first laser source 101 is transmitted to the wavelength conversion device 200 through the first area a, and the laser reflected by the wavelength conversion device 200 and the first light are reflected to the light combining component 300 through the second area B. Preferably, the first area a allows light in a wavelength band of the first laser to pass through and reflects light in a wavelength band of the laser, for example, the first area a is coated with a blue-transparent and green-reflecting film, and the second area B is coated with a total reflection film, so that blue light can penetrate and reflect on the same element (i.e., the light splitting assembly 400), the function of combining blue light and fluorescence is realized, damage of the reflected fluorescence can be reduced, and first laser which is not excited in the fluorescence, such as blue light, is filtered, so that the problem of blue light residue is reduced. Further, the first area a may be disposed offset from the center of the beam splitter, and the sizes of the first area a and the second area B are not particularly limited, and the area of the first area a may be greater than the second area B or may be less than or equal to the second area B.

In some embodiments, the outgoing laser light may include only the first light, and the first laser light may be redirected through the light guiding region of the wavelength conversion device 200 to form the first light, as shown in fig. 4-5, or may not be redirected through the light guiding region of the wavelength conversion device 200, as shown in fig. 6. In other embodiments, with continued reference to fig. 4-5, the light source assembly 100 further includes a second light source 102, the second light source 102 is configured to emit a second light, and the light combining assembly 300 is configured to guide the first light, the second light, and the laser light to exit from the same direction. The second light source 102 may be a laser light source or an LED light source or other type of light source, or a hybrid light source of a laser light source and an LED light source, or the like. When the second light source 102 includes a laser light source, such as a red laser light source, the emitted laser light includes the laser light emitted from the second light source 102 and the first light, and when the second light source 102 includes an LED light source, the illumination light emitted from the optical system includes three types of light, i.e., laser light, LED light, and fluorescent light.

Further, the number of wavelength conversion regions and light guiding regions included in the wavelength conversion device 200 is n, and if the rotation speed of the wavelength conversion device 200 is m rpm, n×m=q, where q is a frame refresh rate, the unit is HZ, n is greater than or equal to 1, and m is greater than 0, for example, the rotation speed of the wavelength conversion device 200 is 120 rpm, n=1, the frame refresh rate of the projection device is 120HZ, and if n=2, the frame refresh rate of the projection device is 240HZ, and when the rotation speed of the wavelength conversion device 200 is unchanged, different image quality requirements are satisfied by setting the number of wavelength conversion regions and light guiding regions. It should be understood that in other embodiments, the wavelength conversion device 200 may include only a wavelength conversion region and not include a light guiding region, and if the wavelength conversion region includes multiple color conversion regions, the number of each color conversion region also satisfies the above relationship, and the description will not be repeated here.

In the above embodiment, the first laser light source 101 may provide light sources for both the first light and the laser light, and in the prior art, the current of the first laser light source 101 in one frame of the display period is uniformly controlled, for example, one frame of the display period includes a first period for emitting the laser light and a second period for emitting the first light, and in one frame of the display period, if the current of the first laser light source 101 is adjusted, the current of the first laser light source 101 in the first period and the current of the second period are simultaneously changed, that is, the current of the first laser light source 101 in the first period and the current of the second period are always the same, so that it is difficult to balance the color gamut, the color point, and the brightness. In this embodiment of the present invention, the optical system may further include a control unit 500, as shown in fig. 10, where the control unit 500 is connected to the first laser light source 101, and the control unit 500 is configured to separately control the currents of the first laser light source 101 in the first period and the second period, that is, the control unit 500 may set the currents of the first laser light source 101 in the first period and the second period, respectively, for example, in a certain frame display period, and the control unit 500 may only increase or decrease the current of the first laser light source 101 in the first period, or only increase or decrease the current of the first laser light source 101 in the second period, or increase the current of the first laser light source 101 in the first period and simultaneously decrease the current of the first laser light source 101 in the second period, that is, the current of the first laser light source 101 in the first period and the second period may be different, so that the brightness may be higher under a certain white balance condition. In fig. 10, solid arrows indicate light rays in the wavelength band of light emitted from the first light source 101, dotted arrows indicate light rays in the wavelength band of laser light, and dotted arrows indicate light rays in the wavelength band of light emitted from the second light source 102.

Specifically, the control unit 500 may be configured to adjust the current of the first laser light source 101 in the first period and the second period according to an adjustment signal, where the adjustment signal may be a signal that the projection device automatically switches the display mode according to the display requirement, or an adjustment signal received by the projection device, for example, an adjustment instruction sent by a user to the projection device according to the self requirement, where the adjustment instruction may be a display mode switching instruction sent by the user, a brightness adjustment instruction sent by the user, or the like.

In some embodiments, the wavelength conversion region of the wavelength conversion device 200 includes a first color conversion region, the first period includes a first sub-period for emitting a first sub-lasing, and the control unit 500 is configured to increase the current of the first laser light source in the first sub-period, or decrease the current of the first laser light source in the second period while increasing the current of the first laser light source in the first sub-period, when the adjustment signal indicates that the ordinate of the white field is high, so as to increase the duty ratio of the first sub-lasing, such as that the first sub lasing is green fluorescence or yellow fluorescence, including light of the green primary spectrum, i.e. the optical system emits green primary light in the first sub-period. Accordingly, in the case where the adjustment signal indicates that the ordinate of the white field becomes low, the current of the first laser light source in the first sub-period is reduced and/or the current of the first laser light source in the second period is increased, so that the duty ratio of the first sub-lasing is reduced. The adjustment signal indicates that the ordinate of the white field is high or low, which may mean that the display mode after switching is high or low compared with the ordinate of the white field corresponding to the display mode before switching, or that the ordinate of the white field corresponding to the adjustment parameter in the adjustment command is high or low, or that the adjustment signal directly indicates that the ordinate of the white field is high or low.

In other embodiments, the wavelength conversion region of the wavelength conversion device 200 includes a second color conversion region, where the second color conversion region is used to generate a second sub-lasing light under the irradiation of the first laser light, the first period includes a second sub-period for emitting the second sub-lasing light, and the control unit 500 is used to increase the current of the first laser light source in the second sub-period, or decrease the current of the first laser light source in the second period while increasing the current of the first laser light source in the second sub-period, so as to increase the duty ratio of the second sub-lasing light, such as the second sub-lasing light being red fluorescent light or yellow fluorescent light, including the red primary spectrum, i.e. the optical system emits red primary light in the second sub-period. Accordingly, in case the adjustment signal indicates that the abscissa of the white field becomes low, the current of the first laser light source in the second sub-period is reduced and/or the current of the first laser light source in the second period is increased, while the duty ratio of the second sub-lasing is reduced. The adjustment signal indicates that the abscissa of the white field is high or low, which may mean that the display mode after switching is high or low compared with the abscissa of the white field corresponding to the display mode before switching, or that the abscissa of the white field corresponding to the adjustment parameter in the adjustment command is high or low, or that the adjustment signal directly indicates that the abscissa of the white field is high or low.

The illumination light emitted from the optical system is generally composed of three primary colors of light capable of synthesizing white light, such as red primary color light, green primary color light and blue primary color light, for example, the wavelength conversion region of the wavelength conversion device 200 includes only the first color conversion region or the second color conversion region, that is, the lasing light includes only fluorescence of one color, and then one frame of image display period includes a third period in addition to the first period and the second period, the third period is used for emitting third light, the third light may be one of the second lights emitted from the second light source 102, the first laser light source 101 is lighted in the first period and the second period, the optical system emits lasing light and the first light, the second light source 102 is lighted in the third period, the lasing light, the first light and the third light can synthesize white light, and if the second light emitted from the second light source 102 includes light of the same color as the lasing light, the light source emitting the same color in the first period is lighted. As shown in fig. 9, the wavelength conversion region of the wavelength conversion device 200 may include only a first color conversion region generating green fluorescence, the light guiding region is a reflection region, the first laser light source 101 is configured to generate blue laser light, the second light source 102 is configured to generate red laser light, and a frame display period sequentially includes a third period, a first period, and a second period, wherein the second light source 102 is illuminated in the third period, red-primary light is emitted, and the first laser light source 101 is illuminated in the first period and the second period, and green-primary light and blue-primary light are emitted, respectively. It should be understood that the wavelength conversion region of the wavelength conversion device 200 may also include the first color conversion region and the second color conversion region, where the optical system may not include the second light source 102, and the one-frame display period may include only a first period and a second period, and the first period includes a first sub-period and a second sub-period.

With continued reference to fig. 10, the optical system may further include a light processing device 600 for providing the light emitted from the light combining component 300 to a light homogenizing element (not shown in the drawing) after processing, where the light processing device 600 includes a first region for passing the laser light and a second region for passing the emitted laser light, for example, the first region is for transmitting the laser light, and the second region is for transmitting and diffusing the emitted laser light, i.e., the first region may be a highly transmissive plate element, and the second region is provided with a diffusing element. It will be appreciated that when the laser comprises fluorescence of a plurality of colours, the first region may comprise one or more different sub-regions for handling different fluorescence, when the exiting laser comprises one or more lasers, the second region may comprise one or more different sub-regions for handling different lasers, e.g. the exiting laser comprises a first light and a third light, the second region may be a complete region or may comprise two different sub-regions, one for handling the first light and one for handling the third light, and the angle of spread of the two sub-regions may be set according to the characteristics of the first light and the third light, i.e. the angle of spread of the two sub-regions may be different, e.g. the first light is blue laser, the receiving laser is green fluorescence, the angle of spread of the sub-region handling the third light may be greater than the angle of spread of the sub-region handling the first light, further reducing the speckle effect. Further, the first region may also include a diffusing element for diffusing light, such as a green laser included in the second light emitted by the second light source 102, and may also be used for passing the green laser, and if the first region is used only for passing green fluorescence, the first region may not need to be provided with a diffusing element, such as a diffusing plate. It should be noted that the first region and/or the second region of the light processing device 600 may be a reflective region.

Optionally, the first area of the light processing device 600 may further be provided with a filter layer (e.g. a dichroic film is coated on a transparent substrate), or may be a two-layer structure with one side coated with a dichroic film and the other side coated with a diffusion sheet or a diffusion sheet and a filter layer, where the filter layer is configured to transmit the laser light and reflect at least light in a wavelength band where the first laser light is located, if the laser light is green fluorescence, and the first laser light is blue laser light, the filter layer transmits the green fluorescence and reflects the blue laser light, i.e. the filter layer may filter the blue laser light that is not excited in the green fluorescence, and meanwhile, the first light (i.e. the blue laser light) is transmitted through the second area of the light processing device 600, so that the optical path of the first laser light that is not excited in the laser light is different from the optical path of the first light through the second area, and by setting of the filter layer, the optical path of the first laser light that is not excited in the laser light can be separated from the optical path of the first laser light, thereby filtering the first laser light that remains in the laser light, and improving the color gamut. Furthermore, the filter layer in the first area can reflect light of a preset wave band in the received laser besides light of the wave band of the first laser, for example, light with longer wavelength in green fluorescence is also reflected, so that green is purer.

In some embodiments, the wavelength conversion device 200 and the light treatment device 600 are integrated as a unit, and as shown in fig. 11-14, the wavelength conversion device and the light treatment device are disposed circumferentially or radially, referring to fig. 11, the wavelength conversion device and the light treatment device are disposed circumferentially, the first color conversion region PW1 of the wavelength conversion device and the first region DW1 of the light treatment device are disposed symmetrically, and the light guiding region W2 of the wavelength conversion device and the second region DW2 of the light treatment device are disposed symmetrically. Referring to fig. 12-14, the wavelength conversion region and the light guiding region of the wavelength conversion device are circumferentially disposed, and the wavelength conversion device and the light processing device are radially disposed, wherein the wavelength conversion region of the wavelength conversion device may include only the first color conversion region PW1 (as shown in fig. 12-13), and may also include the first color conversion region PW1 and the second color conversion region PW3 (as shown in fig. 14); the light processing device may include only a first area DW1 and a second area DW2 (as shown in fig. 12), at least one of the first area DW1 and the second area DW2 being used for processing two kinds of light, and the light processing device may also include a first area DW1, a second area DW2, and a third area DW3 (as shown in fig. 13 to 14), each of which is used for processing one kind of light. In the embodiments shown in fig. 12-14, the light processing device is located on the outer ring of the wavelength conversion device, and it should be noted that the light processing device may also be located on the inner ring of the wavelength conversion device.

The following description will further take, as an example, a case where the first laser light source 101 is a blue laser light source, the second light source 102 is a red laser light source, the wavelength conversion region of the wavelength conversion device 200 is a green phosphor region, and the light guiding region is a reflection region.

As shown in fig. 15, the blue laser emitted from the first laser source 101 is transmitted to the wavelength conversion device 200 through the first region of the light splitting component 400, the green phosphor region and the reflection region of the wavelength conversion device 200 are alternately located in the optical path of the blue laser, the green phosphor region generates green fluorescence under the irradiation of the blue laser, the green fluorescence is reflected back to the light splitting component 400 through the wavelength conversion device 200, is sequentially reflected to the light processing device 600 through the light splitting component 400 and the light combining component 300, and is transmitted to the light homogenizing element 700 through the first region of the light processing device 600; the reflection region reflects the first laser light to form first light, and the first light is reflected to the light processing device 600 through the second region of the light splitting component 400 and the light combining component 300 in sequence, and is transmitted to the light homogenizing element 700 through the second region of the light processing device 600. In fig. 15, solid arrows indicate light rays in the wavelength band of light emitted from the first light source 101, dotted arrows indicate light rays in the wavelength band of laser light, and dotted arrows indicate light rays in the wavelength band of light emitted from the second light source 102.

In some embodiments, the light combining assembly 300 includes a first light combining element 301 and a second light combining element 302, where the first light combining element 301 is configured to transmit a first light and reflect a laser light, and the second light combining element 302 is configured to reflect the first light, so that an angle of each light incident on the light homogenizing element 700 is symmetrical, for example, optical axes of the first light and the laser light are coincident with an optical axis of the light homogenizing element 700, so that an angle of the first light and the laser light entering the light homogenizing element 700 is symmetrical, and a light homogenizing effect is improved. Further, the second light combining element 302 is further configured to transmit the second light emitted by the second light source 102. In this embodiment, the first light combining element 301 may be a red-blue-transmitting dichroic element, and the second light combining element 302 may be a red-blue-transmitting dichroic element. The first light combining element 301 and the second light combining element 302 may have the same size or different sizes.

Optionally, the optical system further includes a beam reduction lens group 103, located between the light source assembly 100 and the beam splitting assembly 400, where the beam reduction lens group 103 may include one or more lenses, which function to compress the spot of the first laser light. Further, the optical system further includes a diffusing element 104, located between the light source assembly 100 and the beam splitting assembly 400, which is used to homogenize the light spot of the first laser, reduce the power density of the first laser irradiated to the wavelength conversion region, and make all the first laser processed by the beam shrinking lens group 103 and the diffusing element 104 enter the wavelength conversion device 200 through the first region of the beam splitting assembly 400, so as to improve the light efficiency of the first laser. The diffusing element 104 may be located between the beam-shrinking lens group 103 and the beam-splitting assembly 400, or may be located between a plurality of lenses included in the beam-shrinking lens group 103, and compared with the diffusing element 104 located between the beam-splitting assembly 400 and the wavelength conversion device 200, the diffusing element can avoid the laser passing through the diffusing element, and reduce the loss of the laser. It should be understood that the diffusing element 104 may be replaced by a light homogenizing element such as a microlens array.

Optionally, the optical system further includes a collimating lens group 105, located between the wavelength conversion device 200 and the light source assembly 100, for collimating the laser light emitted from the wavelength conversion region of the wavelength conversion device 200, and the principal ray of the first laser light emitted from the first laser light source 101 is not coincident with the optical axis of the collimating lens group 105. The optical system may also include a relay lens 106 to increase the efficiency of the laser entering the homogenizing element 700 and reduce the spot size. The collimating lens group 105 may include one or more lenses. Further, the first area of the beam splitting assembly 400 is offset from the optical axis of the collimating lens group 105, so that the chief ray of the first laser light emitted from the first laser light source 101 does not coincide with the optical axis of the collimating lens group 105, thereby separating the optical path of the first laser light incident on the wavelength conversion device 200 and the first light emitted from the wavelength conversion device 200, and improving the utilization rate of the first laser light.

Optionally, the optical system further includes a filter element 107 and a driving element (not shown in the figure), where the filter element 107 is used to filter light of a preset wavelength band in the laser light, so as to improve the purity of the laser light. The driving element is used for driving the filter element 107, so that the filter element 107 is located in a laser light path before the light combining component 300 or the filter element 107 is not located in the light path, and the function of switching the high color gamut and the low color gamut can be achieved, and the balance between the brightness and the color gamut can be achieved. When the high color gamut mode is needed, the driving element drives the filter element 107 to move or rotate or swing to the area where the light passes, so that the laser is purer; when the low color gamut mode is required, the driving element drives the filter element 107 to move or rotate or oscillate where the light does not pass, and the filter element 107 is not optically active.

In this embodiment, when the filter element 107 is located in the optical path of the first sub-laser (e.g. green fluorescence), the green fluorescence is filtered by the filter element 107 and the filter layer in the first region of the light processing device 600, so that the purity of the green light can be greatly improved, and the high color gamut function is realized, where the color coordinates (Gx, gy) of the first sub-lasing in the white field can satisfy the following conditions:

0.23≤Gx≤0.29； 0.65≤Gy≤0.74。

It should be understood that when the laser includes multiple colors of sub-lasers, the filter element 107 may process only one of the colors of sub-lasers, or multiple colors of sub-lasers, where the filter element 107 may include one or more sub-regions.

Optionally, the optical system further comprises a diffusing element 201, which functions to dissipate and homogenize the spot of the red laser light emitted by the second light source 102. Further, the optical system further includes a shaping lens group 108, which functions to perform light shaping on the red laser light.

Optionally, the optical system further includes a focusing lens group 109, located between the light combining component 300 and the light processing device 600, for focusing the light emitted from the light combining component 300 into the light homogenizing element 700, so that more than 90% of the light emitted from the light combining component 300 enters the light homogenizing element 700 after passing through the focusing lens group 109 and the light processing device 600, thereby reducing the loss of light. In this embodiment, the light homogenizing element 700 is preferably a light bar, and the light emitting surface of the light processing device is matched with the size of the incident end surface of the light bar, so that a large-sized light processing device is not required, and the system volume is reduced.

Optionally, the optical system further includes a phase conversion element 202, located between the light combining component 300 and the light homogenizing element 700, preferably located between the light combining component 300 and the light processing device 600, for changing the polarization state of the light emitted by the light combining component 300, so that at least two different polarization states exist in the light beam emitted at the same time, and further reducing the speckle effect.

It should be noted that, the corresponding transmission function in the above embodiment may be changed into reflection, and the reflection function is changed into transmission, so that the function implementation of the whole light path is not affected, and the embodiments of the present invention will not be described in detail.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An optical system, comprising:

2. An optical system as recited in claim 1, further comprising:

3. An optical system as claimed in claim 2, further comprising:

4. An optical system according to claim 1 or 2, further comprising:

5. An optical system according to claim 2, wherein the light combining means comprises a first light combining element and a second light combining element, wherein,

6. An optical system as claimed in claim 2, further comprising:

7. An optical system as claimed in claim 1, characterized in that the second zone is provided with a diffusing element.

8. An optical system according to claim 1, wherein the number of wavelength converting regions and the number of light guiding regions are each n, the rotational speed of the wavelength converting means is m revolutions per second, n x m = q, where q is the picture refresh rate in HZ, n being greater than or equal to 1, m being greater than 0.

9. An optical system according to claim 1, wherein the wavelength conversion device and the light processing device are a unitary device.

10. A projection device comprising an optical system according to any one of claims 1-9.