CN111338167B

CN111338167B - Laser light source and laser projector

Info

Publication number: CN111338167B
Application number: CN201811558952.XA
Authority: CN
Inventors: 刘洪岩; 张勇; 王振
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2018-12-19
Filing date: 2018-12-19
Publication date: 2022-04-22
Anticipated expiration: 2038-12-19
Also published as: CN111338167A

Abstract

The invention relates to a laser light source and a laser projector, and belongs to the field of laser projection display. The laser light source includes: a blue laser emitting blue laser light; the fluorescent wheel is provided with a plurality of areas which are arranged along the circumferential direction, the plurality of areas of the fluorescent wheel comprise a fluorescent area and a transmission area, the fluorescent area is used for emitting fluorescent light under the excitation of blue laser, and the transmission area is used for transmitting the laser; the light emitted by the multiple regions of the fluorescent wheel has at least three colors, the multiple regions of the fluorescent wheel comprise at least one pair of first regions with the same color of the emitted light, a second region is arranged between each pair of first regions, and the colors of the emitted light of the first regions and the emitted light of the second regions are different; the fluorescent wheel rotates to provide the different colors of light required to output the three primary colors. The present invention achieves a reduction in spoke light. The invention is used for designing the laser light source.

Description

Laser light source and laser projector

Technical Field

The invention relates to the field of laser projection display, in particular to a laser light source and a laser projector.

Background

The laser light source is a light source that emits monochromatic coherent light beams with high brightness and high directivity, and has been gradually applied to the field of projection display in recent years due to many advantages of the laser light source. Current laser light sources typically include at least: laser, fluorescence wheel, filter wheel and optical wand. The working process of the laser light source comprises the following steps: the laser emits laser, the laser irradiates on the fluorescent wheel, fluorescent powder on the fluorescent wheel is excited to output fluorescent light with at least one color, the fluorescent light with at least one color is obtained through filtering processing of the color filter wheel, and the laser and the light with at least one color realize the lighting function of the laser light source after the dodging processing of the light bar. The optical-mechanical part comprises a Light valve core component, the Light valve receives the illumination Light beam of the front-end laser Light source and modulates the Light beam, a Digital Light Processing (DLP) architecture is mostly adopted at present, the color timing output by the color wheel needs to be synchronous with the Light valve, and thus the Light valve can receive the illumination Light beam emitted by the laser Light source in a timing manner according to the control signal of the color component of the image to be displayed.

The conventional fluorescent wheel and color filter wheel both have a plurality of areas, and light of different colors has an obvious boundary when being output, but in practical application, light spots have a certain size and can irradiate the boundary when passing through the boundary of the color wheel (the fluorescent wheel and the color filter wheel are collectively called), and at the moment, because the light spots are positioned on the two areas and the colors of the light emitted from the two areas are different, the colors of the light emitted from the light spots after passing through the two areas are mixed, namely, mixed light (also called wheel radiation) is generated, which is a color mixing phenomenon, and the light mixing phenomenon makes the light machine unable to distinguish the current primary color light.

One of the processing methods that is commonly used at present is: the light emitted from the color mixing region (the region for generating the mixed color light, also called the spoke region) is discarded and not utilized, but as the number of the subareas is larger, for example, as shown in fig. 14, three groups of color subareas are symmetrically arranged according to the vertex of the central angle, that is, the color wheel has 6 subareas in a circle (the 6 subareas of the fluorescent wheel are respectively a yellow fluorescent region Y1, a yellow fluorescent region Y2, a green fluorescent region G1, a transmission region B2, a transmission region B1 and a green fluorescent region G2; and the 6 subareas of the color filter wheel are respectively a red filter region r1, a red filter region r2, a green filter region G1, a transmission region B2, a transmission region B1 and a green filter region G2), so that a full time sequence of three primary colors can be provided by a half-circle of the color wheel rotation, and two three time sequence periods can be provided by a circle of the color wheel. However, it is obvious that the number of spoke regions is also increased, and there is one spoke region between every two sub-regions, and there are 6 spoke regions in total, so that this processing method can obviously lose part of the primary light, which not only results in the loss of the brightness of the projection picture, but also affects the proportion of the primary light in the original white balance, and further affects the display of the projection picture.

If fewer partitions are arranged for the color wheel, for example, only three partitions are arranged along the circumference of the color wheel, so that the spoke areas can be reduced along with the reduction of the number of the partitions, and according to the display requirement of forming a complete image by three primary colors, the color wheel can provide three primary color light components required by image display after rotating for one circle, namely, the color wheel provides one three primary color time sequence period after rotating for one circle, although an image picture can be displayed, the longer the period for providing the complete three primary color light time sequence is, or the slower the rotating speed of the color wheel is, the higher the probability of the occurrence of a rainbow phenomenon during the display of the projection picture is, and the rainbow phenomenon refers to a color stripe phenomenon observed on the projection picture by human eyes. This also reduces the viewing quality of the projected picture.

Disclosure of Invention

The embodiment of the invention provides a laser light source and laser projection equipment, which can output a plurality of primary light time sequence periods and simultaneously reduce the number of spoke areas, and adopts the following technical scheme:

in a first aspect, a laser light source is provided, which includes:

a blue laser emitting blue laser light;

the fluorescent wheel is provided with a plurality of areas which are arranged along the circumferential direction, the plurality of areas of the fluorescent wheel comprise a fluorescent area and a transmission area, the fluorescent area is used for emitting fluorescent light under the excitation of the blue laser, and the transmission area is used for transmitting the laser;

wherein the light emitted from the plurality of regions of the fluorescent wheel has at least three colors, the plurality of regions of the fluorescent wheel comprises at least one pair of first regions emitting light with the same color, a second region is spaced between each pair of the first regions, and the colors of the light emitted from the first regions and the second regions are different; the fluorescent wheel rotates to provide the different colors of light required to output the three primary colors.

In a second aspect, there is provided a laser projector, comprising:

the projection device comprises an optical machine, a projection lens and a laser light source, wherein the laser light source is the laser light source in the first aspect;

the optical machine is used for modulating the light beam to generate an image light beam when being irradiated by the light beam emitted by the laser light source;

the projection lens is used for projecting the image light beam to a projection screen.

The technical scheme provided by the embodiment of the invention can have the following beneficial effects:

the laser light source and the color wheel structure in the laser light source in the laser projector provided by the embodiment of the invention can ensure that when a light spot passes through the color wheel, the color wheel rotates for a circle to provide a plurality of time sequence period primary color lights, and only a small number of spoke lights are generated, and the reduction of the number of the spoke area lights can reduce the complexity of the light processing of the area by an electronic software program on one hand.

And more importantly, when the spoke light is processed in a manner of abandoning the spoke light area, namely the electronic software control can be relatively simple and reliable, the scheme of the spoke light with a small number can reduce the loss of various primary color lights, further reduce the loss of the brightness of the whole projection picture, reduce the influence of the lost primary color lights on the proportion in the primary white balance, and be beneficial to presenting high-quality projection picture display.

Furthermore, by arranging the multi-color-division segments, the color wheel can provide complete 3-color light with at least 2 time sequence periods in one rotation, which is also called as tricolor light (namely tricolor light components), so that the time for emitting 1 group of complete 3-color light by the color wheel is shortened, the probability of rainbow phenomenon is reduced, and the viewing quality of pictures is improved.

Drawings

In order to illustrate the embodiments of the present invention more clearly, the drawings that are needed in the description of the embodiments will be briefly described below, it being apparent that the drawings in the following description are only some embodiments of the invention, and that other drawings may be derived from those drawings by a person skilled in the art without inventive effort.

FIG. 1 is a schematic diagram of an implementation environment in which some embodiments of the invention are implemented.

Fig. 2 is a schematic structural diagram of a laser light source according to an exemplary embodiment of the present invention.

FIG. 3 is a schematic structural diagram of a fluorescent wheel according to an exemplary embodiment of the present invention.

Fig. 4 is a schematic diagram of an arrangement of fluorescent regions and transmissive regions according to an exemplary embodiment of the present invention.

Fig. 5 is a schematic diagram of an arrangement of fluorescent regions and transmissive regions according to an exemplary embodiment of the present invention.

Fig. 6 is a schematic diagram of an arrangement of fluorescent regions and transmissive regions according to an exemplary embodiment of the present invention.

FIG. 7 is a schematic diagram of a fluorescent wheel according to an exemplary embodiment of the present invention.

Fig. 8 is a schematic structural diagram of a color filter wheel according to an exemplary embodiment of the present invention.

Fig. 9 is a schematic structural diagram of a color wheel according to an exemplary embodiment of the present invention.

Fig. 10 is a schematic structural diagram of another laser light source according to an exemplary embodiment of the present invention.

Fig. 11 is a schematic structural diagram of another laser light source according to an exemplary embodiment of the invention.

Fig. 12 is a schematic structural diagram of another laser light source according to an exemplary embodiment of the invention.

Fig. 13 is a schematic structural diagram of a color wheel according to an exemplary embodiment of the present invention.

Fig. 14 is a schematic diagram of color segmentation of a color wheel of the prior art.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, a schematic diagram of an implementation environment according to some embodiments of the invention is shown. The implementation environment may include: the laser projection system comprises a laser light source 10, an optical machine 20 and a projection lens 30, wherein the laser light source 10, the optical machine 20 and the projection lens 30 are sequentially arranged along a light beam transmission direction. The laser light source 10 is configured to emit a light beam, the optical engine 20 is configured to modulate the light beam to generate an image light beam when being irradiated by the light beam emitted from the laser light source 10, and the projection lens 30 is configured to project the image light beam onto the projection screen 40.

For example, the laser light source 10, the optical engine 20, and the projection lens 30 may be applied to the laser projector 1. There are many laser light sources of the current laser projectors, and the laser light source may include: at least one laser, the laser light source is used for emitting laser light of at least one color. For example, the laser light source may be a single-color laser light source (i.e., including one laser and emitting laser light of one color), or may be a two-color laser light source (i.e., including a plurality of lasers and emitting laser light of two colors in common).

Referring to fig. 2, fig. 2 is a schematic structural diagram of a laser light source 10 according to an embodiment of the present invention. Wherein, one of the laser light sources is assumed to be a blue laser. The laser light source 10 includes:

a fluorescent wheel 110, a color filter wheel 120, and a blue laser 130.

The fluorescent wheel 110 has a plurality of regions arranged in a circumferential direction, and the number of the plurality of regions of the fluorescent wheel 110 may be 4 or 5, for example. The plurality of regions of the fluorescent wheel 110 include a fluorescent region for emitting fluorescent light under excitation of the laser light and a transmissive region for transmitting the laser light.

The light emitted from the plurality of regions of the fluorescent wheel 110 has at least three colors, the plurality of regions of the fluorescent wheel 110 includes at least one pair of first regions emitting light with the same color, the second region is spaced between each pair of first regions, the colors of the light emitted from the first regions and the light emitted from the second regions are different, the fluorescent wheel 110 rotates to provide light with different colors required for outputting three primary colors, for example, blue laser light, green fluorescent light, yellow fluorescent light, and yellow fluorescent light can be filtered to obtain red fluorescent light, thereby forming three primary colors, or blue laser light, green fluorescent light, orange fluorescent light, and orange fluorescent light can be filtered to obtain red fluorescent light, thereby forming three primary colors.

A color filter wheel 120 is further disposed in the light path of the fluorescent wheel 110, the color filter wheel 120 has a plurality of filter regions corresponding to the plurality of regions of the fluorescent wheel 110, and the color filter wheel 120 is configured to output red light, blue light, and green light in a time-sequential manner.

The blue laser 130 is used to emit blue laser light.

In summary, the color wheel structure in the laser light source provided in the embodiments of the present invention can ensure that when a light spot passes through the color wheel, a small number of spoke lights are generated while a plurality of time-sequence period primary lights are provided by a circle of the color wheel, and the reduction of the number of spoke lights can reduce the complexity of the electronic software program for processing the area lights on the one hand, for example, if the color-mixed segment is not discarded but used, the white balance needs to be recalculated, the rotation position of the color wheel is accurately controlled, the duration of the color-mixed segment is determined and used, and the reduction of the number of spoke lights inevitably reduces the complexity of the electronic software control.

Furthermore, by arranging the multi-color-division segments, the color wheel can provide complete light with 3 colors in at least 2 time sequence periods in one rotation, which is also called as tricolor light (namely tricolor light components), so that the rotating speed of the color wheel is increased, the time for the color wheel to emit 1 group of complete light with 3 colors is shortened, the probability of rainbow phenomenon can be reduced, and the viewing quality of a projection picture is improved.

As shown in fig. 3, fig. 3 is a schematic structural diagram of a fluorescence wheel according to an embodiment of the present invention. The fluorescent wheel 110 includes:

a substrate 1101. The plurality of regions of the fluorescent wheel 110 may be arranged on the substrate 1101 in the circumferential direction. The plurality of regions includes n fluorescent regions and m transmissive regions. Illustratively, 1< n <5, 0< m <3, and 3< m + n <6, wherein the plurality of regions emit light of at least three colors, and wherein each two adjacent regions emit light of a different color. For example, the light emitted from the plurality of regions has green (corresponding to the green fluorescent region G), yellow (corresponding to the yellow fluorescent region Y), and blue (corresponding to the transmissive region B). Fig. 3 is a schematic illustration of an example of a substrate 1101 having 1 yellow fluorescent region Y, 2 green fluorescent regions G and 1 transmissive region B.

Optionally, each region on the fluorescent wheel may be in a fan shape or a fan-ring shape, and the area of each region may be represented by the number of central angles of the region, so that the area of light emitted from each region is the angle of light emitted from each region. Then, the angle of the light emitted from the fluorescent wheel includes the angle of the spoke light and the angle of the pure color light, and under the condition that the angle of the light actually emitted from the fluorescent wheel is not changed, the angle of the spoke light is negatively correlated with the angle of the pure color light, that is, the angle of the spoke light is larger, and the angle of the corresponding pure color light is reduced.

In order to enable the fluorescent regions to emit fluorescent light with different colors under the excitation of blue laser, green fluorescent powder or yellow fluorescent powder is arranged on the surface of each fluorescent region, so that when the fluorescent regions are irradiated by the blue laser, the fluorescent powder with the corresponding color can be excited to emit light with the color corresponding to the fluorescent powder. For example, the colors of the light emitted from the plurality of regions include: the color of light emitted by the n fluorescent regions comprises green and yellow, the color of light emitted by the n fluorescent regions comprises a green fluorescent region and a yellow fluorescent region, and the color of light emitted by the m transmission regions is blue.

Since the user demands for the picture of the projection screen are higher and higher, for example, the display frequency is 240HZ, and for the frequency of image display, the three-color-segment fluorescent wheel (fluorescent wheel having three regions of yellow fluorescent region, green fluorescent region and transmissive region) needs to increase the frequency of emitting three colors of light (yellow light, green light and blue light) to emit light of a faster frequency to the light engine, and thus, the three-color-segment fluorescent wheel needs to increase the rotation frequency. However, a larger rotational frequency may cause a larger noise, which may result in a poorer user experience. Therefore, in order to reduce noise and improve user experience, the fluorescent wheel can emit 1 group of three-color light under the condition of rotating for half a circle, that is, emit 2 three-color light with the same time sequence period (that is, the angles of the light with the same color in the three-color light with 2 time sequence periods are the same) under the condition of rotating for a circle, so that the frequency of emitting the three-color light by the fluorescent wheel is improved under the condition of keeping the original rotating frequency.

Therefore, in order to make the fluorescent wheel rotate once to emit two groups of same three-color lights, the central angles of the first areas of the fluorescent wheel are equal.

Further, as shown in fig. 3, the arrangement order of the plurality of regions may be: a yellow fluorescent region Y, a green fluorescent region G, a transmission region B and a green fluorescent region G; as shown in fig. 4, the arrangement order of the plurality of regions may be: a transmission area B, a yellow fluorescence area Y, a green fluorescence area G and a yellow fluorescence area Y; as shown in fig. 5, the arrangement order of the plurality of regions may further be: a green fluorescence area G, a yellow fluorescence area Y, a green fluorescence area G, a yellow fluorescence area Y and a transmission area B; as shown in fig. 6, the arrangement order of the plurality of regions may be: a transmission region B, a yellow fluorescence region Y, a transmission region B and a green fluorescence region G.

The size of the areas of the plurality of regions, that is, the size of the corresponding circumferential angles of the plurality of regions, may be determined according to actual conditions.

In practical applications, the color and duration of the light emitted from the plurality of regions are related to the arrangement order of the plurality of regions, the size of the circumferential angle corresponding to the plurality of regions, and the rotation frequency of the fluorescent wheel. For example, assuming that the plurality of regions are arranged in the order of yellow phosphor region, green phosphor region, transmission region and green phosphor region, the corresponding circumferential angles of the plurality of regions may be 100 °, 80 °, 100 ° and 80 °, and the rotation frequency of the phosphor wheel is 120HZ, the duration of the yellow phosphor light emitted from the yellow phosphor region is Tr, Tr is (100/360) × (1/120) seconds, the duration of the green phosphor light emitted from each green phosphor region is Tg, Tg is (80/360) × (1/120) seconds, the duration of the blue laser light emitted from the transmission region is Tb, Tb is (100/360) × (1/120) seconds. Assuming that the luminescent wheel starts to rotate from the projection area, after Tb, the luminescent wheel emits green fluorescence, after Tg, the luminescent wheel emits yellow fluorescence, and after Tr, the luminescent wheel emits blue laser … to circulate sequentially.

Optionally, as shown in fig. 7, the fluorescent wheel 110 further includes a driving structure 1102, where the driving structure 1102 is located in a circle center region of the annular substrate 1101, and the driving structure 1102 is connected to the substrate 1101, and the driving structure 1102 is configured to drive the substrate 1101 to rotate. Illustratively, the drive structure 1102 may be a motor. The driving structure 1102 may be fixedly connected to the substrate 1101 by a ring connector (not shown in fig. 7), which may make the driving structure 1102 more tightly connected to the substrate 1101. The annular connecting piece can be an annular metal sheet, and due to the fact that metal is good in ductility, the annular connecting piece is not prone to breaking when receiving rotating force generated by rotation of the driving structure for a long time, and effective connection of the driving structure and the substrate is guaranteed.

Optionally, as shown in fig. 8, fig. 8 is a schematic structural diagram of a color filter wheel according to an embodiment of the present invention. The plurality of filter regions of the color filter wheel 120 include a red filter region r, a green filter region g, and a transparent region b. The red filter area r is used for filtering yellow fluorescence to obtain red light, the green filter area is used for filtering green fluorescence to obtain green light, and the light-transmitting area b is used for transmitting laser or fluorescence. Optionally, each filter area on the filter wheel is shaped like a sector or a sector ring. Fig. 8 schematically illustrates an example in which the plurality of filter regions of the color filter wheel 120 includes 1 red filter region r, 2 green filter regions g, and 1 light-transmitting region b.

The plurality of filter areas of the color filter wheel correspond to the plurality of areas of the fluorescent wheel, so that when the arrangement sequence of the plurality of areas of the fluorescent wheel is changed, the arrangement sequence of the plurality of filter areas of the color filter wheel is changed.

Then, when the arrangement sequence of the plurality of regions of the fluorescent wheel is YGBG as shown in fig. 3, correspondingly, the arrangement sequence of the plurality of filter regions is a red filter region, a green filter region, a transparent region and a green filter region;

when the arrangement sequence of the plurality of regions of the fluorescent wheel is BYGY as shown in FIG. 4, correspondingly, the arrangement sequence of the plurality of filter regions is a light-transmitting region, a red filter region, a green filter region and a red filter region;

when the arrangement sequence of the plurality of regions of the fluorescent wheel is gygby as shown in fig. 5, correspondingly, the arrangement sequence of the plurality of filter regions is a green filter region, a red filter region, a green filter region, a red filter region and a light-transmitting region;

when the arrangement sequence of the plurality of regions of the fluorescent wheel is BYBG as shown in fig. 6, the arrangement sequence of the plurality of filter regions is a light-transmitting region, a red filter region, a light-transmitting region, and a green filter region.

Further, as shown in fig. 2, the laser light source 10 further includes:

a beam shaping component 150, a light combining component 140, and a light collecting component 160. The beam shaping unit 150, the light combining unit 140, the color filter wheel 120, and the light collecting unit 160 are sequentially arranged along the transmission direction of the laser light.

The beam shaping unit 150 is configured to shape the laser beam and transmit the shaped laser beam to the light combining unit 140. The shaping process may include compressing the parallel laser light into a smaller area and parallel laser light. The beam shaping part 150 can increase the transmittance of the parallel laser light in the following optical devices (light combining part, fluorescent wheel, color filter wheel, and light collecting part). Illustratively, the beam shaping component 150 can be a telescopic system, which in practice can include a convex lens and a concave lens. The light combining part 140 is configured to transmit the received laser light to the fluorescent wheel 110, the light combining part 140 is further configured to transmit the laser light transmitted by the fluorescent wheel 110 to the color filter wheel 120, the laser light is transmitted by the transmission area after the laser light irradiates the transmission area, and the light combining part 140 is further configured to transmit the fluorescent light emitted by the fluorescent wheel 110 to the color filter wheel 120, and the fluorescent light is generated by the fluorescent area irradiated by the laser light. Illustratively, the light combining component 140 may include a light combining dichroic sheet. The light collection member 160 is used to homogenize the received red, blue and green light. Illustratively, the light collection member 160 may be a light wand. When the laser is a blue laser, the laser may be a blue laser.

By way of example, the light extraction process of the laser light source comprises: the blue laser emitted by the blue laser 130 is shaped by the beam shaping device 150, and then is emitted to the light combining part 140 and then is transmitted to the fluorescent wheel 110; the fluorescent wheel 110 rotates in sequence, when the blue laser beam irradiates the transmission region on the fluorescent wheel 110, the blue laser beam transmits from the fluorescent wheel 110, passes through the relay circuit optical path of the blue laser beam (referring to the optical path circuit in fig. 2 where the blue laser beam is transmitted from the fluorescent wheel 110 to the light combining part 140), then passes through the light combining part 140 again, passes through the color filter wheel 120, and enters the light collecting part 160; when the blue laser light is irradiated to the fluorescent region of the fluorescent wheel 110, the phosphor powder on the fluorescent region is excited to emit fluorescent light of at least one color (e.g., yellow fluorescent light and/or green fluorescent light in fig. 2), and the excited fluorescent light is transmitted in a reverse direction, reflected to the color filter wheel 120 by the light combining part 140, and then enters the light collecting part 160.

Optionally, since the blue laser needs to be transmitted to the fluorescent wheel 110 through the light combining part 140, and the blue laser needs to be transmitted to the color filtering wheel 120 after passing through the transmission region of the fluorescent wheel 110, the fluorescent wheel 110 and the color filtering wheel 120 are disposed on two sides of the light combining part 140, and the fluorescent wheel 110 and the color filtering wheel 120 may be disposed in different axes, which is convenient for assembling the fluorescent wheel 110 and the color filtering wheel 120 and reduces assembly complexity compared to coaxial arrangement. Further, in order to enable the fluorescent light emitted from the fluorescent wheel 110 to pass through the filtering process of the color filter wheel 120, the fluorescent wheel 110 and the color filter wheel 120 are configured to rotate synchronously.

Optionally, the fluorescent wheel 110 and the color filter wheel 120 are configured to rotate synchronously, and the ratio of the center angle of the red filter area on the color filter wheel 120 is equal to the ratio of the center angle of the yellow fluorescent area on the fluorescent wheel 110, the ratio of the center angle of the green filter area on the color filter wheel 120 is equal to the ratio of the center angle of the green fluorescent area on the fluorescent wheel 110, and the ratio of the center angle of the transparent area on the color filter wheel 120 is equal to the ratio of the center angle of the transparent area on the fluorescent wheel 110.

Because the fluorescent wheel 110 and the color filter wheel 120 rotate synchronously, by designing the circle center angles of the red filter area, the green filter area and the light transmission area on the color filter wheel 120 to be equal to the circle center angles of the yellow fluorescent area, the green fluorescent area and the light transmission area on the fluorescent wheel 110 respectively and corresponding to the arrangement sequence, it can be ensured that when the fluorescent wheel 110 emits yellow fluorescent light, the yellow fluorescent light is completely filtered to remove yellow light after passing through the red filter area of the color filter wheel 120, so that the color filter wheel emits red light; when the fluorescent wheel 110 emits green fluorescent light, the green fluorescent light passes through the green filter area of the color filter wheel 120, so that the color filter wheel emits green light; when the fluorescent wheel 110 transmits the blue laser, the blue laser passes through the light-transmitting area of the color filter wheel 120, and then the color filter wheel 120 emits the blue laser, so that the effective light emission of the laser light source is ensured, and simultaneously, the yellow fluorescent light is filtered by the color wheel to generate the red light, so that the proportion of other primary color light components except the red light component of the laser light source is improved.

It should be noted that the fluorescent wheel 110 and the color filter wheel 120 may also be coaxially disposed, as long as it is ensured that the fluorescent light and the blue laser emitted from the fluorescent wheel 110 can be transmitted to the color filter wheel 120.

When the fluorescent wheel 110 and the color filter wheel 120 are coaxially disposed, optionally, as shown in fig. 9, the fluorescent wheel and the color filter wheel are coaxial and may be disposed on the same substrate, the substrate has a fluorescent wheel region and a color filter wheel region, the fluorescent wheel region realizes functions of multiple regions of the fluorescent wheel, that is, the fluorescent wheel region includes multiple regions of the fluorescent wheel, and the color filter wheel region realizes functions of multiple color filter regions of the color filter wheel, that is, the color filter wheel region includes multiple color filter regions of the color filter wheel. The fluorescent wheel area surrounds the color wheel filtering area, the fluorescent wheel area is located on the outer side of the color wheel, and the color wheel filtering area is located on the inner side of the color wheel.

Fig. 9 schematically illustrates an example in which the fluorescent wheel region includes a yellow fluorescent region Y1, a transmission region B, a green fluorescent region G1, a yellow fluorescent region Y2, and a green fluorescent region G2, and the color filter wheel region includes a red filter region r1, a transmission region B, a green filter region G1, a red filter region r2, and a green filter region G2. When the fluorescent wheel and the color filter wheel are disposed on the same substrate, the structure may be referred to as a color wheel 180. The fluorescent wheel and the color filtering wheel are arranged on the same substrate, so that the color wheel is multifunctional, the number of system parts can be reduced, the miniaturization is facilitated, the manufacturing process can be reduced, and the manufacturing cost is reduced.

Since the optical engine is required to generate the image light beam only by the pure color light, the light collection component is required to selectively receive the pure color light, so that the laser light source only emits the pure color light. In practical applications, the angle of the spoke light that needs to be shielded by the light collection member needs to be determined by a color correction process so that the spoke light is not received by the light collection member. The color correction process is executed through software, the software corresponds to the size of a light machine in the current laser projector, and the image quality requirement of the laser projector, the rotation frequency of a fluorescent wheel under the requirement, the area arrangement sequence of the fluorescent wheel and the size of corresponding circumferential angles of a plurality of areas of the fluorescent wheel are set in the software, so that the angle for generating spoke light is determined. The color correction process is a process of determining the angle of each spoke light on the fluorescent wheel. Since the structure of the color wheel in embodiments of the invention will only produce 4 or 5 area spoke lights, the time required for the color correction process is saved.

For example, assuming that the size of the light valve of the optical machine is 0.47 inches, the image quality is required to display 4K image quality, the rotation frequency of the fluorescent wheel is 120HZ, and the areas of the fluorescent wheel are arranged in the order of yellow fluorescent area, green fluorescent area, transmission area and green fluorescent area, the circumferential angles corresponding to the areas of the fluorescent wheel may be 100 °, 80 °, 100 ° and 80 °. Based on the foregoing parameters, it was determined by software corresponding to a 0.47 inch light machine that there were 4 spoke lights and that the angle of each spoke light was 11 °.

Further, if the brightness of the laser light source needs to be improved, while the angles of the yellow fluorescent region, the green fluorescent region and the transmission region of the fluorescent wheel are changed, the angle of the red filter region on the filter wheel and the angle of the transmission region are changed in a matched manner, so that the orthographic projection of the yellow fluorescent region on the filter wheel is staggered with the red filter region by a certain region, and therefore, a part of yellow light wave band of yellow fluorescent light is reserved, namely, yellow light which does not pass through the red filter region (namely, yellow light of the staggered region) is not filtered, and further the brightness of the laser light source is improved.

Referring to fig. 10, fig. 10 is a schematic structural diagram of another laser light source 10 according to an embodiment of the invention. In fig. 10, the laser light source is described as a two-color laser light source, and fig. 10 assumes that one laser is a blue laser and the other laser is a red laser.

In fig. 10, the laser light source 10 further includes a red laser 170, and the red laser 170 is used to emit red laser light. The structure and principle of the blue laser 130, the fluorescent wheel 110 and the color filter wheel 120 in fig. 10 can refer to the aforementioned laser light source 10 shown in fig. 2, and the description of the embodiment of the present invention is omitted.

By way of example, the light extraction process of the laser light source comprises: the blue laser emitted by the blue laser 130 is shaped by the beam shaping device 150 and then emitted to the light combining part 140, the red laser emitted by the red laser 170 is shaped by the beam shaping device 150 and then emitted to the light combining part 140, and the blue laser and the red laser are transmitted to the fluorescent wheel 110; the fluorescent wheel 110 rotates in a time sequence, when the blue laser and the red laser irradiate the transmission area on the fluorescent wheel 110, the blue laser and the red laser transmit from the fluorescent wheel 110, and the blue laser and the red laser pass through the light combining part 140, are reflected to the color filter wheel 120, and then enter the light collecting part 160; when the blue laser light is irradiated to the fluorescent region of the fluorescent wheel 110, the phosphor powder on the fluorescent region is excited to emit fluorescent light of at least one color (for example, yellow fluorescent light and/or green fluorescent light in fig. 10), and the excited fluorescent light is reflected to the color filter wheel 120 through the light combining part 140 and then enters the light collecting part 160.

It should be noted that the red light entering the light collection component 160 includes red laser emitted by a red laser and red fluorescent light obtained by filtering yellow fluorescent light by a color filter wheel.

Referring to fig. 11, fig. 11 is a schematic structural diagram of another laser light source according to an embodiment of the invention. In the laser light source structure of this embodiment, the fluorescent wheel and the color filter wheel are disposed on the same substrate.

As shown in fig. 11, a first laser 130 and a second laser 170 are included. The first laser 130 and the second laser 170 may be a blue laser and a red laser, respectively, which respectively emit a blue laser and a red laser, wherein the blue laser is used as the excitation light of the fluorescence.

The structure and principle of the blue laser in fig. 11 may refer to the laser light source 10 shown in fig. 2, and the structure and principle of the red laser in fig. 11 may refer to the laser light source 10 shown in fig. 10, which is not described again in this embodiment of the present invention.

By way of example, the light extraction process of the laser light source comprises: blue laser light emitted by the blue laser 130 is beam-shaped by the beam shaping device 150 and then emitted to the light combining part 140, red laser light emitted by the red laser 170 is beam-shaped by the beam shaping device 150 and then emitted to the light combining part 140, the blue laser light is transmitted to the fluorescent wheel area of the color wheel 180 through the light combining part 140, and the red laser light is transmitted to the color filter wheel area of the color wheel 180 through the light combining part 140 and enters the light collecting part 160.

The color wheel 180 rotates in a time sequence, when the blue laser irradiates the fluorescent area on the color wheel 180, the phosphor powder on the fluorescent area is excited to emit at least one color of fluorescent light (for example, yellow fluorescent light and/or green fluorescent light in fig. 11), and the excited fluorescent light reversely passes through the light combining part 140, is reflected to the color wheel filtering area on the color wheel 180, and then enters the light collecting part 160; when the blue laser beam irradiates the transmission region in the fluorescent wheel region of the color wheel 180, the blue laser beam is transmitted to the light combining member 140 under the action of the transmission region, and is reflected to the color filter wheel region of the color wheel 180 by the light combining member 140 to enter the light collecting member 160.

In an implementation manner, the color wheel 180 is shown in fig. 13, in the color wheel structure shown in fig. 13, the substrate is a circular metal substrate, and a reflection surface is disposed on an incident side of the metal substrate facing the laser, and the reflection surface may be implemented by a plated film, or the metal substrate may be polished into a mirror surface to implement reflection of a full spectrum light beam. The filter color wheel area is fixed on the inner ring of the color wheel in an embedding or bonding mode inside the circular metal substrate, the outer ring of the circular metal substrate is a fluorescent wheel area, specifically, the fluorescent wheel area comprises a fluorescent area (a yellow fluorescent area Y and a green fluorescent area G) coated with fluorescent powder and a laser reflection area BR coated with a scattering layer, and the scattering layer is used for scattering laser passing through the layer of structure and plays a certain role in eliminating speckles. Fig. 13 schematically illustrates an example in which the fluorescent wheel region includes a yellow fluorescent region Y1, a laser reflection region BR, a green fluorescent region G1, a yellow fluorescent region Y2, and a green fluorescent region G2, and the color filter wheel region includes a red filter region r1, a light transmission region b, a green filter region G1, a red filter region r2, and a green filter region G2. Thus, the blue laser beam is reflected by the laser reflection area to the light combining member through the laser reflection area of the color wheel 180; in another implementation manner, as shown in fig. 9, the color wheel 180 is configured such that another optical path loop is disposed on a side of the color wheel away from the blue laser, and the blue laser transmits through a transmission region of the color wheel 180 and then is transmitted to the light combining component through the optical path loop.

Fig. 12 is a schematic view of a structure of another laser light source according to an embodiment of the present invention. In the architecture shown in fig. 12, including multiple sets of first lasers 130 may increase the brightness of the light source.

Wherein, the multiple groups of first lasers 130 are blue lasers, taking two groups of lasers as an example, the two groups of lasers can be vertically arranged in space and combined by a step mirror, or as shown in fig. 12, the two groups of lasers are combined by first light combining lenses 200 with reflecting films arranged at intervals, wherein the light beams of one group of lasers all irradiate the region of the reflecting film, the light beams of the other group of lasers all irradiate the region of the transmitting region, so that one group of light beams emitted by the two groups of lasers is transmitted, one group of light beams is reflected and all emits towards the same direction, and the size of the light spot can be reduced after light combination

Preferably, the combined laser beam passes through a light homogenizing unit, which may be a fly-eye lens 210, before reaching the color wheel.

After the light is homogenized, the energy distribution of the laser beam is more uniform, and the improvement of the excitation efficiency of fluorescence is facilitated.

In this example, the color wheel 180 is the color wheel structure shown in fig. 13.

Specifically, after the blue laser beam is homogenized by the fly-eye lens 210, the blue laser beam may further pass through a converging lens (not shown in the figure), further reduce the spot area, and then enter the second light combining lens 141, where the second light combining lens 141 may be a dichroic filter, and may transmit blue light, and reflect light of other colors except for the blue light, such as yellow fluorescence and green fluorescence.

The transmitted blue laser light is incident on the fluorescent regions in the plurality of regions arranged in the first circumferential direction (i.e., the outer circumferential direction in the figure) of the color wheel 180, and the arrangement of the fluorescent regions may be referred to in the above embodiments. The fluorescent area comprises a yellow fluorescent area and a green fluorescent area which are excited to generate fluorescence with corresponding colors.

The fluorescence is reflected by the metal substrate and then enters the second light combining lens 141, the second light combining lens 141 reflects the fluorescence of multiple colors to the fourth reflecting mirror 142, the fourth reflecting mirror 142 reflects the fluorescence to the filter region in multiple regions arranged along the second circumferential direction (i.e. the inner circumferential direction in the figure), and the filter region can be divided as in the above embodiments. So that the fluorescence is filtered and output by the corresponding filter region.

With the rotation of the color wheel, when laser irradiates the laser reflection area in a plurality of areas arranged along the first circumferential direction, the laser reflection area comprises a scattering layer, and multi-angle divergence and scattering can be generated on the laser. Similarly, the laser light is reflected by the metal substrate, passes through the scattering layer again, and returns to the second light combining lens 141, the second light combining lens 141 transmits the blue laser light, and the transmitted laser light enters the third light combining lens 143, wherein the third light combining lens 143 is smaller than the second light combining lens 141 in size and is only used for receiving the laser light beam.

The third reflector 143 reflects the blue laser beam to the fourth reflector 142, and the fourth reflector 142 reflects the blue laser beam to a light-transmitting area of a plurality of areas arranged along the second circumferential direction, wherein the light-transmitting area is used for transmitting the laser beam, and the light-transmitting area may be flat glass or a diffusion sheet structure.

A light collecting member 160, such as a light rod, is arranged in correspondence with the light exit position of the inner circumference of the color wheel.

Preferably, a field lens 190 is further disposed between the second light combining lens 141 and the fourth mirror 142, and is used for compressing the beam angle of the light beams reflected by the second light combining lens 141 and the third mirror 143, so that the spot size is small.

Preferably, a collimating lens (not labeled) is further disposed between the second light combining lens 141 and the color wheel 180, and the collimating lens is configured to further compress the divergence angle of the laser beam incident to the color wheel and collimate the large-angle reflected light beam emitted from the color wheel.

And, preferably, a focusing lens (not shown) may be further disposed between the light emitting position of the color wheel 180 and the light collecting member 160, so as to compress the light beam output by the color wheel, and then the compressed light beam enters the light rod.

In summary, the color wheel structure in the laser light source provided by the embodiment of the invention can ensure that when the light spot passes through the color wheel, a small amount of spoke light is generated while the color wheel rotates for one circle to provide a plurality of timing period primary color light. For example, when the plurality of regions of the fluorescent wheel are in the arrangement order as shown in fig. 3, 4 and 6, the color wheel may generate only 4 spoke lights, and when the plurality of regions of the fluorescent wheel are in the arrangement order as shown in fig. 5, the color wheel may generate only 5 spoke lights. The reduction of the number of the light in the spoke area can reduce the complexity of the electronic software program for processing the light in the area, for example, if the mixed color segment is not abandoned but used, the white balance needs to be recalculated and the ratio needs to be recalculated, the rotating position of the color wheel is accurately controlled, the duration of the mixed color segment is judged and used, and the reduction of the number of the light in the spoke area inevitably reduces the complexity of the electronic software control.

Furthermore, by arranging the multi-color-division segments, the color wheel can provide complete light with 3 colors in 2 time sequence periods in one rotation, namely three-color light (namely three-primary-color light components), so that the rotating speed of the color wheel is increased, the time for the color wheel to emit 1 group of complete light with 3 colors is shortened, the probability of rainbow phenomenon can be reduced, and the viewing quality of a projection picture is improved.

As shown in fig. 1, an embodiment of the present invention provides a laser projector, including: a laser light source 10, an optical engine 20 and a projection lens 30, wherein the laser light source 10 is any one of the above laser light sources. The optical engine 20 is located between the laser light source 10 and the projection lens 30. The optical engine 20 is configured to modulate a light beam emitted from the laser light source 10 to generate an image light beam. For example, the optical engine includes a light valve, which may be a Digital Micromirror Device (DMD), and the DMD includes a plurality of mirrors, and when the light beam is irradiated to the DMD, the DMD deflects the mirror at a position where the same color appears in an image to be displayed according to the color of the received light beam, so that the light beam is reflected by the deflected mirror to generate an image light beam. The projection lens 30 is used for projecting the image beam onto a projection screen.

Because the arrangement sequence of the areas of the fluorescent wheel is different, the sequence of the light beams with different colors emitted by the laser light source is also different. When the light valve is irradiated by the light beam emitted by the laser light source, the light beam is modulated to generate an image light beam according to the arrangement sequence of the plurality of areas in the substrate on the fluorescent wheel. For example, it is assumed that the arrangement order of the plurality of regions of the fluorescence wheel is the arrangement order shown in fig. 3. If the rotation frequency of the color wheel (the fluorescent wheel and the color filter wheel are collectively called) is the same as the frequency of the laser projector for displaying images, in the process of one rotation of the color wheel, the light beams emitted by the laser light source sequentially irradiate the light valve according to the sequence of red light, green light, blue light and green light, the light valve can sequentially generate sub-image light beams with corresponding colors according to the sequence of the received red light, green light, blue light and green light, and finally the plurality of sub-image light beams are superposed to form a complete image light beam. The light valve may also generate a first sub-image beam according to a portion of the received red light, generate a second sub-image beam according to the remaining portion of the received red light, and superimpose the first sub-image beam and the second sub-image beam to form a sub-image beam corresponding to the color. Thus, the flexibility of the light valve to generate the image beam is improved.

In summary, in the laser projector provided in the embodiments of the present invention, due to the color wheel structure of the laser light source in the laser projector, when the light spot passes through the color wheel, it is ensured that the color wheel rotates for one circle to provide multiple timing period primary color lights, and only a small amount of spoke light is generated. The reduction of the number of the light in the spoke area can reduce the complexity of the electronic software program for processing the light in the area, for example, if the mixed color segment is not abandoned but used, the white balance needs to be recalculated and the ratio needs to be recalculated, the rotating position of the color wheel is accurately controlled, the duration of the mixed color segment is judged and used, and the reduction of the number of the light in the spoke area inevitably reduces the complexity of the electronic software control.

As mentioned above, when the arrangement sequence of the plurality of regions of the fluorescent wheel is as shown in fig. 3, the sequence of the sub-image light beams generated by the optical machine is red corresponding sub-image light beams, green corresponding sub-image light beams, blue corresponding sub-image light beams and green corresponding sub-image light beams; when the arrangement sequence of the plurality of regions of the fluorescent wheel is shown in fig. 4, the sequence of the sub-image light beams generated by the optical machine is the sub-image light beam corresponding to blue, the sub-image light beam corresponding to red, the sub-image light beam corresponding to green and the sub-image light beam corresponding to red; when the arrangement sequence of the plurality of regions of the fluorescent wheel is shown in fig. 5, the sequence of the partial image light beams generated by the optical machine is the partial image light beam corresponding to green, the partial image light beam corresponding to red, the partial image light beam corresponding to green, the partial image light beam corresponding to red and the partial image light beam corresponding to blue; when the arrangement sequence of the plurality of regions of the fluorescent wheel is as shown in fig. 6, the sequence of the sub-image light beams generated by the optical engine is the sub-image light beam corresponding to blue, the sub-image light beam corresponding to red, the sub-image light beam corresponding to blue, and the sub-image light beam corresponding to green. Therefore, due to the fact that the arrangement sequence of the areas of the color wheel is different, the sequence of the light beams with different colors emitted by the laser light source is different, the sequence of the sub-image light beams generated by the optical machine is different, and the flexibility of generating the image light beams by the optical machine is improved.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims

1. A laser light source, comprising:

a blue laser emitting blue laser light;

the fluorescent wheel is provided with a plurality of areas which are arranged along the circumferential direction, the plurality of areas of the fluorescent wheel comprise a green fluorescent area, a yellow fluorescent area and a transmission area, the green fluorescent area is used for emitting green fluorescent light under the excitation of the blue laser, the yellow fluorescent area is used for emitting yellow fluorescent light under the excitation of the blue laser, and the transmission area is used for transmitting the laser;

the color filtering wheel comprises a plurality of filter zones corresponding to the plurality of areas, and the plurality of filter zones comprise a red filter zone, a green filter zone and a light-transmitting zone;

wherein the arrangement sequence of the plurality of regions of the fluorescent wheel is as follows: a yellow fluorescent region, a green fluorescent region, a transmission region and a green fluorescent region; correspondingly, the arrangement sequence of the plurality of filter areas of the color filter wheel is as follows: the light-filtering device comprises a red light-filtering area, a green light-filtering area, a light-transmitting area and a green light-filtering area; or the arrangement sequence of the plurality of regions of the fluorescence wheel is as follows: the filter device comprises a transmission area, a yellow fluorescent area, a green fluorescent area and a yellow fluorescent area, and correspondingly, the arrangement sequence of a plurality of filter areas on the filter wheel is as follows: a light-transmitting area, a red filter area, a green filter area and a red filter area; or the arrangement sequence of the plurality of regions of the fluorescence wheel is as follows: the filter wheel comprises a transmission area, a yellow fluorescent area, a transmission area and a green fluorescent area, and correspondingly, the arrangement sequence of the plurality of filter areas on the filter wheel is as follows: a light-transmitting area, a red filter area, a light-transmitting area and a green filter area;

the fluorescent wheel and the color filter wheel are configured to rotate synchronously, the red filter area is used for filtering the yellow fluorescent light to obtain red light, the green filter area is used for filtering the green fluorescent light to obtain green light, and the light-transmitting area is used for transmitting laser or fluorescent light; the fluorescent wheel rotates to provide different colors of light required for outputting three primary colors for a plurality of time sequence periods every revolution.

2. The laser light source according to claim 1,

the fluorescent wheel and the filtering color wheel are coaxial and arranged on the same substrate, the substrate comprises a fluorescent wheel area and a filtering color wheel area, and the fluorescent wheel area surrounds the filtering color wheel area.

3. Laser light source according to claim 1 or 2,

the ratio of the circle center angle of the yellow fluorescent region on the fluorescent wheel is equal to that of the circle center angle of the red filter region on the filter color wheel;

the ratio of the circle center angle of the green fluorescence area on the fluorescence wheel is equal to the ratio of the circle center angle of the green filter area on the filter color wheel;

the ratio of the circle center angle of the transmission area on the fluorescent wheel is equal to that of the circle center angle of the transmission area on the color filter wheel.

4. The laser light source according to claim 1,

each area on the fluorescent wheel is in a fan shape or a fan-ring shape, and the central angles of the areas with the same color of the emergent light of each pair are equal.

5. The laser light source of claim 1, further comprising:

the red laser emits red laser, and the red laser is emitted through a transmission area of the fluorescent wheel and then enters the color filter wheel, or the red laser directly enters the color filter wheel.

6. A laser projector, characterized in that the laser projector comprises:

an optical machine, a projection lens and a laser light source, wherein the laser light source is the laser light source of any one of claims 1 to 5;