CN112099296B

CN112099296B - Two-color laser light source and laser projector

Info

Publication number: CN112099296B
Application number: CN202010962470.1A
Authority: CN
Inventors: 田有良
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2017-08-18
Filing date: 2017-08-18
Publication date: 2021-11-05
Anticipated expiration: 2037-08-18
Also published as: CN112099295A; CN112099295B; CN109407451A; CN112099296A; CN109407451B

Abstract

The invention discloses a bicolor laser light source and a laser projector, and belongs to the field of projection display. The laser light source comprises a first blue laser, a second blue laser and a red laser, and respectively emits a first blue laser, a second blue laser and a red laser; the light emitting directions of the first blue laser and the second blue laser are vertical and parallel to the light emitting direction of the red laser; the fluorescent wheel is provided with a green fluorescent area and a transmission area, and when the fluorescent wheel rotates to the green fluorescent area, the fluorescent wheel receives the irradiation of the first blue laser to generate green fluorescent light and reflects the green fluorescent light to the dichroic filter; transmitting the red laser light to the dichroic filter when the fluorescent wheel rotates to the transmission region; the dichroic sheet transmits the second blue laser light, reflects the red laser light, and reflects the green fluorescence to the light collecting member. The invention solves the problems that the light path system of the bicolor laser light source is more complex and the volume of the bicolor laser light source is larger in the prior art. The invention is used for designing the bicolor laser light source.

Description

Two-color laser light source and laser projector

The application is based on Chinese invention application 201710712834.9 (2017-8-18), and the invention name is as follows: the application of the division of bicolor laser light source and laser projector.

Technical Field

The invention relates to the field of projection display, in particular to a bicolor 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. Compared with the traditional monochromatic laser light source, the bicolor laser light source can improve the color purity, the color brightness and the color gamut of the light source and better meet the color requirement of laser projection.

In the related art, as shown in fig. 1, a two-color laser light source generally includes a blue laser 101, a red laser 102, a fluorescent wheel 103, a beam shaping device 104, a light combining member 105, and a light collecting member 106. The light-emitting principle of the bicolor laser light source comprises the following steps: the blue laser light emitted by the blue laser 101 passes through the beam shaping device 104, is reflected to the fluorescent wheel 103 by the light combining part 105, passes through the fluorescent wheel 103, passes through the relay circuit optical path, reaches the light combining part 105 again, and is reflected and output by the light combining part 105; the blue laser is irradiated on the fluorescent wheel 103, so that the fluorescent wheel 103 can be excited to emit green fluorescent light, and the green fluorescent light is transmitted and output by the light combining part 105; the red laser emitted by the red laser 102 is reflected and output by the light combining part 105 after passing through the beam shaping device 104; after the light of the three colors enters the light collecting component, the lighting function of the laser light source is realized.

However, in the related art, in order to excite the fluorescent wheel to emit green fluorescent light, the optical path transmission path of the blue laser is complicated, so that the optical path system of the two-color laser light source is complicated, and the volume of the two-color laser light source is large.

Disclosure of Invention

In order to solve the problems that an optical path system of a bicolor laser light source is complex and the volume of the bicolor laser light source is large in the related art, the embodiment of the invention provides the bicolor laser light source and a laser projector. The technical scheme is as follows:

in one aspect, the invention provides a two-color laser light source, which comprises a first blue laser, a second blue laser, a red laser, a fluorescent wheel and a light combining component, wherein the fluorescent wheel is provided with a green fluorescent area and a transmission area;

the light combining component is used for transmitting the first blue laser emitted by the first blue laser to the fluorescence wheel, and transmitting the green fluorescence to the light collecting component after receiving the green fluorescence generated by the irradiation of the green fluorescence area by the first blue laser;

the light combining component is also used for receiving second blue laser emitted by the second blue laser and transmitting the second blue laser to the light collecting component;

the light combining component is also used for receiving the red laser emitted by the red laser and transmitted by the transmission area and transmitting the red laser to the light collecting component.

In another aspect, the present invention provides a laser projector comprising the two-color laser light source of any one of the above aspects.

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

according to the two-color laser light source and the laser projector provided by the embodiment of the invention, the blue laser emitted by the first blue laser can excite the fluorescent wheel to emit green fluorescent light, and the green fluorescent light, the blue laser emitted by the second blue laser and the red laser emitted by the red laser are collected by the light combining component and then transmitted to the light collecting component.

Drawings

Fig. 1 is a schematic structural diagram of a two-color laser light source in the related art;

fig. 2 is a schematic structural diagram of a two-color laser light source according to an embodiment of the present invention;

FIG. 3-1 is a schematic view of a fluorescence wheel provided in accordance with embodiments of the present invention;

FIG. 3-2 is a schematic view of another fluorescence wheel provided by embodiments of the present invention;

fig. 4 is a schematic structural diagram of another two-color laser light source provided by the embodiment of the invention;

fig. 5 is a schematic diagram of a color filter wheel according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

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.

As an example, the laser light source may be applied to a laser projector. The laser projector may emit light of at least one color to effect display of an image. The primary colors are "basic colors" that cannot be obtained by mixing and blending other colors. Other new colors can be produced by mixing the primary colors in different proportions. Laser projectors typically produce primary color light to effect the display of graphics. The colors generated by a general laser projector are three primary colors, i.e., red, green, and blue, and with the development of technology, the laser projector can also generate two primary colors or five primary colors, which is not limited in the embodiments of the present invention.

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 can emit light of at least one color. Typically the laser light source may further comprise: a fluorescent wheel (also called a fluorescent color wheel) may be used as the wavelength conversion device. The laser light source can be a monochromatic laser light source (that is, including a laser and the laser produces a color), can also be double-colored laser light source (that is, including two lasers and every laser produces a color), thus send out the laser of one or two kinds of colors, be provided with phosphor powder on the fluorescence wheel, can be excited out the fluorescence of corresponding color, be used for forming three primary colors with the color of the laser that the laser sent out of laser together, as the projection light source provides the illumination for the ray apparatus part.

Compared with a monochromatic laser light source, the bicolor laser light source can improve the color purity, the color brightness and the color gamut of the light source and better meet the color requirement of laser projection.

An embodiment of the present invention provides a two-color laser light source, as shown in fig. 2, the laser light source includes a first blue laser 21a, a second blue laser 21b, a red laser 22, a fluorescent wheel 23, and a light combining member 24, and the fluorescent wheel 23 is provided with a green fluorescent region and a transmissive region.

The light combining member 24 is configured to transmit the first blue laser light emitted by the first blue laser 21a to the fluorescent wheel 23, and transmit the green fluorescent light to the light collecting member 25 after receiving the green fluorescent light generated by the first blue laser light irradiating the green fluorescent region.

The light combining member 24 is further configured to receive the second blue laser light emitted by the second blue laser 21b, and transmit the second blue laser light to the light collecting member 25.

The light combining member 24 is also configured to receive the red laser light emitted by the red laser 22 and transmitted through the transmission region, and transmit the red laser light to the light collecting member 25.

As shown in fig. 2, the first blue laser 21a, the second blue laser 21b, the light combining member 24 and the light collecting member 25 are disposed on a first side of the luminescent wheel 23, the red laser 22 is disposed on a second side of the luminescent wheel 23, the light combining member 24 is disposed between the first blue laser 21a and the luminescent wheel 23, and the light combining member 24 is disposed between the second blue laser 21b and the light collecting member 25.

It should be noted that the laser provided by the embodiment of the present invention may be a laser array.

Optionally, as shown in fig. 2, the two-color laser light source may further include a plurality of beam shaping devices and a reflection device E, and the plurality of beam shaping devices include a first beam shaping device a, a second beam shaping device B, a third beam shaping device C, and a fourth beam shaping device D.

The first beam shaping device a, the third beam shaping device C, and the fourth beam shaping device D may be a telescope system (in practical applications, the telescope system may include a convex lens and a concave lens) for compressing the parallel laser light emitted by the laser device to reduce the area of the beam, and the compressed laser light is still parallel laser light, which may improve the transmittance of the parallel laser light in the rear-end optical device.

The second beam shaping device B can be composed of two lenses, the first blue laser is focused by the two lenses and then irradiates the fluorescent wheel, the green fluorescent light emitted by the fluorescent wheel and the red laser emitted by the red laser can enter the light combining component after being collimated by the two lenses, and the uniformity of the emergent light is improved.

The second beam shaper B may also be composed of one, three or four lenses, and the number of lenses that make up the second beam shaper B is not limited in the embodiments of the present invention.

The optical path transmission process of the bicolor laser light source provided by the embodiment of the invention comprises the following steps: the first blue laser transmits from the light combining part 24 after passing through the first beam shaping device a, and then irradiates on the fluorescent wheel 23 through the second beam shaping device B to excite the green fluorescent powder to emit green fluorescent light, and the green fluorescent light is reflected and output by the light combining part 24 after passing through the second beam shaping device B; the second blue laser passes through the third beam shaper C and is transmitted and output from the light combining part 24; the red laser beam emitted from the red laser 22 passes through the fourth beam shaper D, is reflected by the reflector E to the fluorescent wheel 23, and after being transmitted from the fluorescent wheel 23, is reflected by the light combining part 24 and is output through the second beam shaper B. The light of the three colors can be mixed to form white light after entering the light collecting part 25, and the illumination function of the bicolor laser light source is realized.

Wherein, reflect meter E can be the reflector plate, and this reflector plate can be 45 contained angles with red laser instrument and place to make the red laser that the red laser instrument of level placement sent reflect the back by this reflector plate, can kick into the fluorescence wheel perpendicularly, make red laser can transmit according to predetermined light path, thereby guaranteed laser transmission's stability.

Alternatively, the light collecting member may be a light bar.

In summary, in the two-color laser light source provided in the embodiments of the present invention, the first blue laser can excite the fluorescence wheel to emit green fluorescence, and the light combining component collects and transmits the green fluorescence, the second blue laser, and the red laser emitted by the red laser to the light collecting component.

In the embodiment of the invention, the first blue laser, the second blue laser and the red laser are all lighted in time sequence. Optionally, the lighting time of the first blue laser, the second blue laser and the red laser are different.

Optionally, as shown in fig. 3-1, the fluorescent wheel may include a green fluorescent region Y and a transmission region K, a surface of the green fluorescent region Y is provided with green phosphor, a surface of the transmission region Y is provided with a first diffuser, the green fluorescent region and the transmission region are both arranged in a fan shape, and the fluorescent wheel can emit green fluorescent light and transmit red laser light in a time-sequential manner when rotating.

Wherein the first diffuser may be micron-sized particles.

In practical application, the fluorescent wheel can rotate at a preset rotating speed, when a green fluorescent area of the fluorescent wheel is aligned with the second beam shaping device (the green fluorescent area is an irradiation area of laser light), the first blue laser is lightened, and the second blue laser and the red laser are not lightened; when the transmission area of the fluorescent wheel is aligned with the second beam shaping device (the transmission area is the irradiation area of the laser), the red laser is lightened, and the first blue laser and the second blue laser are not lightened.

Since the central area of the fluorescent wheel cannot be aligned with the second beam shaping device, that is, the central area of the fluorescent wheel cannot become the irradiation area of the laser at any time, as shown in fig. 3-2, the fluorescent wheel may further include a blank area Q, the blank area Q is located in the central area of the fluorescent wheel, the green fluorescent area Y is located at the periphery of the blank area Q, the green fluorescent area Y is arranged in a sector ring shape, and the transmission area K is arranged in a sector shape.

As shown in fig. 4, the light combining part may include: and a dichroic plate 241, the dichroic plate 241 being disposed on the light incident side of the light collecting member 25, the dichroic plate 241 being configured to transmit the first blue laser light and the second blue laser light, reflect the green fluorescence, and reflect the red laser light emitted from the red laser 22.

Optionally, as shown in fig. 4, the light combining component may further include a fixed diffusion sheet 242, where the fixed diffusion sheet is used to homogenize the first blue laser, and since the first blue laser is an excitation light of the fluorescent wheel, if the light beam is not homogenized, the light spot intensity of the laser is not uniformly distributed, and the energy is concentrated, and when the light beam directly enters the surface of the fluorescent wheel, the laser spot with concentrated energy may burn the surface of the fluorescent wheel, damage the fluorescent wheel, and cause that the laser cannot normally excite the fluorescent wheel to emit fluorescence.

Further, as shown in fig. 4, the laser light source may further include: a color filter wheel 26, the color filter wheel 26 being disposed between the dichroic sheet 241 (light combining part) and the light incident side of the light collecting part 25, as shown in fig. 5, may include a red light diffusion region R, a blue filter region Z, and a green filter region G. The color filter wheel can transmit blue laser, red laser and green fluorescence in a time sequence when rotating.

Specifically, when the color filter wheel rotates, when the irradiation area of the color filter wheel is a blue filter area, the second blue laser is lightened, and the first blue laser and the red laser are not lightened at the same time; when the irradiation area of the color filter wheel is a red light diffusion area, a red laser is lightened, and meanwhile, the first blue laser and the second blue laser are not lightened; when the irradiation area of the color filter wheel is a green filter area, the first blue laser is lightened, and the second blue laser and the red laser are not lightened at the same time, so that the blue laser, the red laser and the green fluorescence are transmitted in a time sequence manner.

Further, as shown in fig. 4, the light combining component may further include a focusing lens 243, and the focusing lens 243 is disposed between the dichroic sheet 241 and the color filter wheel 26. When the light beam diffusion angle of the light transmitted or reflected by the dichroic sheet is larger than the collection angle of the light collection component, the collection efficiency of the light is low, and the brightness of the projection light source is affected.

Optionally, in the color filter wheel provided in the embodiment of the present invention, a second diffuser is disposed on a surface of the red light diffusion region, and a third diffuser is disposed on a surface of the blue light filter region. The second diffuser and the third diffuser may be micron-sized particles, and the particle diameter of the third diffuser may be the same as that of the second diffuser. Wherein the particle diameter of the second diffuser is different from the particle diameter of the first diffuser arranged on the surface of the transmission area of the fluorescent wheel.

Due to the high coherence of the laser light, a speckle effect is inevitably generated. The speckle is that when a coherent light source irradiates a rough object, scattered light has a constant phase due to the same wavelength, and generates interference in a space, and some of the interference in the space is long and some of the interference is cancelled, so that the final result is that granular light and dark spots appear on a screen, that is, some unfocused spots flicker, and a dizzy feeling is easily generated after long-time viewing, which undoubtedly causes the reduction of the quality of a projected image and reduces the viewing experience of a user. Compared with blue laser, the red laser has longer coherence length and higher coherence, so the speckle phenomenon is more serious.

In the embodiment of the invention, when red laser light emitted by a red laser passes through a fluorescent wheel, the red laser light is firstly diffused for the first time by a first diffuser on a transmission area of the fluorescent wheel and enters a light combining component, and then the red laser light is diffused for the second time by a second diffuser on a red light diffusion area of a color filter wheel in the light combining component; furthermore, because the fluorescent wheel and the color filter wheel are all rotating, the moving diffuser can further increase random phase, and can better destroy the coherence of the red laser, so that the laser light source for projection can form more independent random phase patterns on a projection image, and the number of the independent random phase patterns is more, the phenomenon of bright and dark spots is weaker under the integration action of human eyes, the speckle effect of the red laser can be effectively weakened, and the optical quality of the bicolor laser light source is improved.

For example, the particle diameter of the first diffuser may be larger than the particle diameter of the second diffuser, e.g., the particle diameter of the first diffuser is 100 microns, and the particle diameters of the second and third diffusers are 30 microns. The first diffuser can scatter the red laser light first, and then the second diffuser can precisely rearrange the phase of the red laser light.

It should be noted that the particle diameter of the first diffuser may also be smaller than the particle diameter of the second diffuser, for example, the particle diameter of the first diffuser is 30 micrometers, and the particle diameters of the second diffuser and the third diffuser are 100 micrometers.

In addition, the third diffuser on the blue filter area of the color filter wheel is used for homogenizing the second blue laser and playing a role in eliminating speckles on the blue laser; the green filter area on the filter wheel is used for filtering green fluorescence, so that green light entering the light collecting part is purer.

In summary, in the two-color laser light source provided in the embodiments of the present invention, the first blue laser light can excite the fluorescence wheel to emit green fluorescence, and the light combining component collects the green fluorescence, the second blue laser light, and the red laser light emitted by the red laser device and transmits them to the light collecting component, compared with the prior art, the blue laser emitted by the blue laser does not need to be transmitted in the optical path of the relay loop, therefore, a relay loop light path is not needed to be arranged in the bicolor laser light source, the light path system of the bicolor laser light source is simplified, meanwhile, the volume of the bicolor laser light source is reduced, and in addition, the first diffuser is arranged on the surface of the transmission area of the fluorescent wheel, the second diffuser is arranged on the surface of the red light diffusion area of the color filter wheel, so that the red laser with high coherence is diffused twice, the laser has good speckle eliminating effect on red laser, thereby improving the optical quality of the bicolor laser light source.

Embodiments of the present invention provide a laser projector that may include a two-color laser light source as shown in fig. 2 or fig. 4.

The invention is not to be considered as limited to the particular embodiments shown and described, but is to be understood that various modifications, equivalents, improvements and the like can be made without departing from the spirit and scope of the invention.

Claims

1. A bicolor laser light source is characterized in that the laser light source comprises a first blue laser, a second blue laser and a red laser, and the first blue laser, the second blue laser and the red laser are respectively emitted; the light emitting directions of the first blue laser and the second blue laser are vertical and parallel to the light emitting direction of the red laser;

the dichroic sheet is arranged at the intersection of the first blue laser, the second blue laser and the red laser;

a fluorescent wheel provided with a green fluorescent region and a transmissive region, the fluorescent wheel being located between the dichroic sheet and the red laser;

the first blue laser is used for transmitting the first blue laser through the dichroic plate and then emitting the first blue laser to the fluorescent wheel after passing through a first beam shaping device, and the first beam shaping device is used for reducing the area of a light beam;

the fluorescent wheel is also used for receiving the irradiation of the first blue laser to generate green fluorescent light when the fluorescent wheel rotates to the green fluorescent area, and reflecting the green fluorescent light to the dichroic sheet; and transmitting the red laser light to the dichroic plate when the fluorescent wheel rotates to the transmission region;

the dichroic sheet is also used for transmitting the second blue laser light, reflecting the red laser light, and reflecting the green fluorescence light to a light collection component.

2. The laser light source of claim 1, wherein the first blue laser light is transmitted through the dichroic plate and then passes through a second beam shaping device to irradiate the fluorescent wheel, and the second beam shaping device is configured to focus the first blue laser light.

3. The laser light source of claim 1, wherein the first blue laser light also passes through a fixed diffuser before being incident on the fluorescent wheel, the fixed diffuser for homogenizing the first blue laser light.

4. The laser light source of claim 1, wherein the light emitting directions of the first blue laser light and the red laser light are opposite.

5. The laser light source of claim 1, wherein a surface of the transmission region of the fluorescent wheel is provided with a first diffuser for first diffusing the red laser light.

6. The laser light source of any one of claims 1 to 5, further comprising a rotating color filter wheel disposed between the dichroic sheet and the light entrance side of the light collection component, the color filter wheel comprising a red light diffusion zone, a blue filter zone, and a green filter zone.

7. The laser light source of claim 6, wherein the surface of the red light diffusion region is provided with a second diffuser for diffusing the red laser light for a second time.

8. The laser light source of claim 7, wherein the particle diameter of the second diffuser is different from the particle diameter of the first diffuser disposed on the surface of the transmission region of the fluorescence wheel, or,

the particle diameter of the first diffuser is larger than the particle diameter of the second diffuser.

9. The laser light source of claim 6, wherein the surface of the blue filter is provided with a third diffuser for homogenizing the second blue laser light.

10. A laser projector comprising the two-color laser light source according to any one of claims 1 to 9.