CN109143744B - Light source system and projection system using same - Google Patents

Abstract

The invention relates to a light source system and a projection system, the light source system comprises a light emitting unit, a light path switching unit, a wavelength conversion unit, a first light splitting unit and a second light splitting unit, wherein, the light emitting unit emits light beams, the light path switching unit switches the light beams emitted by the light emitting unit into a first light path or a second light path, the first light splitting unit is arranged at the tail ends of the first light path and the second light path, the light splitting unit is used for splitting the incident light beam and then emitting the split light beam in a time sequence, the second light path passes through the space between the wavelength conversion unit and the first light splitting unit, and the height of the second light path in at least one dimension direction is lower than that of the wavelength conversion unit in the dimension direction. The invention has high light energy utilization rate and compact structure.

Description

Light source system and projection system using same

Technical Field

The invention relates to the field of projection display, in particular to a light source system and a projection system using the same.

Background

The current projection system adopting the monolithic spatial light modulator generally adopts an excitation light source to irradiate a rotating color wheel to form three primary colors of red, green and blue emitted in time sequence, the three primary colors of red, green and blue emitted in time sequence are projected onto the spatial light modulator to be modulated, monochromatic light images obtained by modulation are rapidly and alternately switched on a screen, and then the monochromatic light images in each time sequence are mixed together by utilizing the visual residual effect of human eyes to form a color image. The color wheel is coated with red, green and blue phosphors to obtain red, green and blue lights, but the red phosphor has a low light conversion efficiency, so that the brightness of the image in the red portion of the projection system using monolithic spatial light modulation is low, thereby affecting the overall image display effect. Because the brightness of the monolithic spatial light modulator is low, at present, the engineering projection with luminous flux more than 20000 lumens is realized by the 3-piece spatial light modulator, but a projection system adopting the 3-piece spatial light modulator has large volume, long back focal length of a projection lens, high requirement on the lens and high price.

Disclosure of Invention

In view of the above situation, the present invention provides a light source system and a projection system with high light energy utilization efficiency and compact structure.

In one aspect, the present invention provides a light source system, including a light emitting unit, a light path switching unit, a first light splitting unit, a wavelength converting unit and a second light splitting unit, wherein the light emitting unit emits a light beam, the light path switching unit is configured to switch the light beam emitted by the light emitting unit into a first light path or a second light path, the first light splitting unit is disposed at the end of the first light path and the end of the second light path, and is configured to guide the light beam incident from the first light path and the second light path to the wavelength converting unit or the second light splitting unit, respectively, the first light splitting unit is further configured to guide the light beam emitted after the wavelength conversion performed by the wavelength converting unit to the second light splitting unit, the second light splitting unit is configured to emit the incident light beam in a time sequence after the light beam is split, and the second light path passes through between the wavelength converting unit and the first light splitting unit, the height of the second optical path in at least one dimension direction is lower than the height of the wavelength conversion unit in the dimension direction.

In another aspect, the invention further provides a projection system, where the projection system includes the light source system and a spatial light modulator, and the unit spatial light modulator is configured to modulate a light beam emitted from the light source system into image light carrying image information.

The light source system and the projection system provided by the embodiment of the invention have the advantages that: because the light source system utilizes yellow light to separate and obtain red light, and because of the arrangement of the whole structure, the light energy utilization rate is improved; on the other hand, in some embodiments, a light path is multiplexed in one dimension direction of the fluorescent color wheel through proper arrangement of the optical elements, so that the structures of the light source system and the projection system using the light source system are more compact, and the difficulty of structural design of the light source system is reduced.

Drawings

Fig. 1 is a block diagram of a projection system according to a first embodiment of the present invention.

Fig. 2 is a first specific architecture diagram of a light source system of the projection system shown in fig. 1.

Fig. 3 is a schematic view of an embodiment of a beam splitting wheel of the light source system shown in fig. 2.

Fig. 4 is a schematic view of an embodiment of a color correction wheel of the light source system shown in fig. 2.

Fig. 5 is a second specific architecture diagram of the light source system of the projection system shown in fig. 1.

FIG. 6 is a schematic view of an embodiment of a color wheel of the light source system shown in FIG. 5.

Fig. 7 is a front view of a third specific architecture of the light source system of the projection system of fig. 1.

Fig. 8 is a top view of the light source system shown in fig. 7.

Fig. 9 is a block schematic diagram of a projection system according to a second embodiment of the present invention.

Fig. 10 is a perspective view of a first specific architecture of the light source system of the projection system of fig. 9.

Fig. 11 is a front view of the light source system shown in fig. 10.

Fig. 12 is a top view of the light source system shown in fig. 10.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and 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.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Fig. 1 is a block diagram illustrating a projection system according to a first embodiment of the present invention. The projection system 1 includes a light source system 2, a spatial light modulator 3, and a projection lens 4. The light beam emitted from the light source system 2 is modulated into image light carrying image information by the spatial light modulator 3, and then projected to a screen (not shown) through the projection lens 4 to form an image for displaying to a user.

In the present embodiment, the light source system 2 includes a light emitting unit 20, an optical path switching unit 21, a first light splitting unit 22, a wavelength conversion unit 23, and a second light splitting unit 24. The light path switching unit 21 switches the light beam emitted by the light emitting unit 20 into a first light path L1 or a second light path L2, the first light splitting unit 22 is disposed at the end of the first light path L1 and the end of the second light path L2, the light beams emitted from the first light path L1 and the second light path L2 reach the first light splitting unit 22, the first light splitting unit 22 respectively guides the incident light beam to the wavelength conversion unit 23 or the second light splitting unit 24 according to the difference of the light paths of the incident light beams, for example, the first light splitting unit 22 guides the light beam from the first light path L1 to the wavelength conversion unit 23 and guides the light beam from the second light path L2 to the second light splitting unit 24. Alternatively, in another embodiment, the first light splitting unit 22 directs the light beam from the first optical path L1 to the second light splitting unit 24 and directs the light beam from the second optical path L2 to the wavelength converting unit 23. The light beam subjected to wavelength conversion by the wavelength conversion unit 23 is guided to the second light splitting unit 24 by the first light splitting unit 22. The light beams are split by the second light splitting unit 24 to form light beams with a plurality of set colors, and the light beams are sequentially emitted to the light channel 25 arranged behind the second light splitting unit 24 and sequentially emitted to the spatial light modulator 3 through the light channel 25.

Referring to fig. 2, a specific architecture diagram of a first embodiment of the light source system 2 is shown, in this embodiment, the light emitting unit 20 is a blue laser module 20a emitting blue laser, the light path switching unit 21 is a light splitting wheel 21a, the first light splitting unit 22 is a blue-reflective yellow-transparent film 22a, the wavelength converting unit 23 is a fluorescent color wheel 23a, more specifically, a yellow fluorescent color wheel, and the second light splitting unit 24 is a color modifying wheel 24 a. The structure and function of each component are described in detail below.

The dichroic wheel 21a transmits or reflects the blue laser light emitted from the blue laser module 20a so that the blue laser light enters the first light path L1a or the second light path L2 a. As shown in fig. 3, the beam splitter wheel 21a is driven by a driving device 210a to rotate around its rotation axis, and the beam splitter wheel 21a is divided into a transmission region 211a and a reflection region 212a along its rotation direction, and when the beam splitter wheel 21a rotates, the transmission region 211a and the reflection region 211b alternately cut into the propagation path of the blue laser, so that the blue laser enters the first optical path L1a and the second optical path L2a at regular time intervals. In the present embodiment, since only a small amount of blue light is required for synthesizing white light by the spatial light modulator 3, the reflection region 212a occupies a smaller area than the transmission region 211 a.

In this embodiment, a relay system 26 is further disposed on the first optical path L1a, wherein the relay system 26 includes a spot relay system 261, a diffuser 262, a dodging rod 263 and a converging lens 264, which are sequentially disposed along the first optical path L1 a. The spot relay system 261 is configured to relay the focal point of the blue laser spot entering the first optical path L1a to the entrance of the dodging bar 263, and in this embodiment, in order to reduce the influence of the spoke region on the beam splitting wheel 21a on the incident spot, the laser spot incident on the beam splitting wheel 21a is controlled to be as small as possible. The spoke area refers to a boundary between the transmission area 211a and the reflection area 212a on the light splitting wheel 21a and areas on both sides of the boundary, and when the blue laser passes through the boundary and the areas on both sides of the boundary, the light spot of the blue laser covers the transmission area 211a and the reflection area 212a at the same time, so that one part of the light spot is transmitted and the other part is reflected, and the light beam emitted from the color modifying wheel 24a may be mixed color light. The light homogenizing rod 263 is used for homogenizing the incident light beam, and the light homogenizing rod 263 can be a light homogenizing square rod. The light diffuser 262 is disposed at an entrance of the light uniformizing rod 263 for diffusing the light beam entering the light uniformizing rod 263 to further improve the uniformity of the laser beam emitted from the light uniformizing rod 263. The converging lens 264 is used for converging and relaying the blue laser light emitted from the dodging rod 263 to the anti-blue transparent yellow film 22 a. The anti-blue and yellow-transmitting film 22a includes a first surface 221a and a second surface 222a opposite to each other, a blue laser beam incident from a first light path L1a is guided to the first surface 221a of the anti-blue and yellow-transmitting film 22a and reflected by the first surface 221a of the anti-blue and yellow-transmitting film 22a to the fluorescent color wheel 23a, and the blue laser is absorbed by the yellow phosphor on the fluorescent color wheel 23a and excites the yellow phosphor to generate yellow light.

In the present embodiment, a guiding system 27 is further disposed on the second light path L2a, and the guiding system 27 is configured to guide the blue laser beam reflected by the dichroic wheel 21a to the second surface 222a of the anti-blue transparent-yellow film 22 a. The guide system 27 is a mirror system in this embodiment, and includes a first mirror 271, a second mirror 272, and a third mirror 273 in this order. The first reflective mirror 271 faces the dichroic wheel 21a and is disposed substantially in parallel with the dichroic wheel 21a, the third reflective mirror 273 faces the second surface 222a of the anti-blue and anti-yellow transparent film 22a and is disposed substantially in parallel with the second surface 222a, the second reflective mirror 272 is disposed between the first reflective mirror 271 and the third reflective mirror 273 and is disposed substantially perpendicular to both the first reflective mirror 271 and the third reflective mirror 273, and the blue laser beam reflected by the dichroic wheel 21a is reflected by the first reflective mirror 271 onto the second reflective mirror 272, then reflected by the second reflective mirror 272 onto the third reflective mirror 273, and finally reflected by the third reflective mirror 273 onto the second surface 222a of the anti-blue and anti-yellow transparent film 22 a.

In this embodiment, the light splitting wheel 21a and the anti-blue yellow-transmitting membrane 22a are disposed substantially in parallel, the first light path L1a and the fluorescent color wheel 23a are located on different dimensions, so as to avoid the shielding or other influences of the fluorescent color wheel 23a and the optical instrument disposed between the fluorescent color wheel 23a and the anti-blue yellow-transmitting membrane 22a on the light beam on the second light path L2a, the guiding system 27 and the second light path L2a are disposed to surround the fluorescent color wheel 23a and the optical instrument disposed between the fluorescent color wheel 23a and the anti-blue yellow-transmitting membrane 22a, that is, the fluorescent color wheel 23a and the optical instrument disposed between the fluorescent color wheel 23a and the anti-blue yellow-transmitting membrane 22a are disposed inside the guiding system 27 and the second light path L2 a.

In the present embodiment, the fluorescent color wheel 23a is driven to rotate around its rotation axis by a driving device 230 a. In the process of rotating the fluorescent color wheel 23a, the blue laser reflected by the blue-reflecting yellow-transmitting diaphragm 22a to the fluorescent color wheel 23a is projected to different positions of the fluorescent color wheel 23a, so as to improve the efficiency of the fluorescent color wheel 23a, and in addition, in order to further improve the efficiency of the fluorescent color wheel 23a, in this embodiment, a collecting system 27 is further disposed between the fluorescent color wheel 23a and the blue-reflecting yellow-transmitting diaphragm 22a to shape and homogenize the light beam incident to the fluorescent color wheel 23a, and the collecting system 27 is a lens set in this embodiment.

The blue laser beam reaching the anti-blue and yellow-transparent membrane 22a from the first light path L1a is reflected by the first surface 221a of the anti-blue and yellow-transparent membrane 22a to the fluorescent color wheel 23a, and excites the fluorescent color wheel 23a to generate yellow light, and the yellow light returns to the anti-blue and yellow-transparent membrane 22a through the lens group 27 and is transmitted to the color modifying wheel 24a through the anti-blue and yellow-transparent membrane 22 a. On the other hand, the blue laser beam reaching the blue-reflective yellow-transmissive film 22a from the second light path L2a is reflected by the second surface 222a of the blue-reflective yellow-transmissive film 22a to the color correction wheel 24 a. Therefore, the blue laser beams sequentially emitted from the beam splitter wheel 21a to the first light path L1a and the second light path L2a, one of the blue laser beams is converted into yellow light, the other blue laser beam is still blue light, the two blue laser beams are sequentially incident on the color corrector wheel 24a, and the color corrector wheel 24a finally sequentially emits a plurality of beams with the set color to the spatial light modulator 3.

The color correction wheel 24a is driven by a driving device 240a to rotate around its rotation axis, and in the present embodiment, the color correction wheel 24a and the light splitting wheel 21a rotate synchronously. Referring to fig. 4, the color correction wheel 24a is divided into a plurality of color regions along the rotation direction, in this embodiment, a red region R, a yellow region Y, a green region G, and a blue region B. The red area R, the yellow area Y, and the green area G correspond to the transmission area 211a on the dichroic wheel 21a, and the blue area B corresponds to the reflection area 212a on the dichroic wheel 21 a. That is, when the dichroic wheel 21a rotates to make the blue laser light transmit through the transmission region 211a, the color modifying wheel 24a synchronously rotates to make the yellow light generated by the fluorescent color wheel 23a sequentially reach a red light region R, a yellow light region Y and a green light region G, wherein the red light region R separates the yellow light into red light and green light, the green light is reflected, the red light is transmitted into the light channel 25, the yellow light region Y transmits the yellow light to enter the light channel 25, the green light region G separates the yellow light into red light and green light, the red light is reflected, and the green light is transmitted into the light channel 25. When the dichroic wheel 21a rotates to reflect the blue laser light by the reflective region 212a, the color correction wheel 24a rotates synchronously to pass the blue laser light through the blue region B, which transmits the blue light into the optical channel 25. In the present embodiment, a light diffuser (not shown) is provided on the blue region B. The light-diffusing sheet is used for adjusting the angle of incident laser to enable the angle of emergent blue laser to be more uniform, and on the other hand, the light-diffusing sheet also performs decoherence on the incident laser. It is understood that, in another embodiment, a light diffuser may be disposed on the yellow region Y.

In the above embodiment, the anti-blue and yellow-transmitting film 22a and the dichroic wheel 21a are disposed substantially in parallel, but in other embodiments, the anti-blue and yellow-transmitting film 22a and the dichroic wheel 21a may be disposed substantially perpendicular to each other, the blue laser light transmitted by the dichroic wheel 21a is reflected by the anti-blue and yellow-transmitting film 22a to the color correction wheel 24a, and the blue laser light reflected by the dichroic wheel 21a is reflected by the anti-blue and yellow-transmitting film 22a to the fluorescent color wheel 23 a. In addition, other optical components may be adjusted accordingly, for example, the relay system 26 may be disposed on the second light path L2a between the guiding system 27 and the anti-blue transparent-yellow film 22 a. In addition, the ratio of the transmission area 211a to the reflection area 212a on the dichroic wheel 21a can also be changed accordingly.

It is understood that in other embodiments, the fluorescent color wheel 23a may or may not rotate synchronously with the dichroic wheel 21a and the color correction wheel 24 a.

It is understood that in other embodiments, a plurality of transmissive regions 211a and a plurality of reflective regions 212a may be disposed on the dichroic wheel 21a, and the transmissive regions 211a and the reflective regions 212a are spaced apart.

It is understood that in other embodiments, a plurality of red, yellow, green and blue regions R, Y, G and B may be disposed on the color correction wheel 24a, and the regions may be arranged in a regular array.

The light channel 25 may be an optical integrator, and in one embodiment, the light channel 25 is an optical integrator.

Referring to fig. 5, a specific architecture diagram of a second embodiment of the light source system 2 is shown, in this embodiment, the light emitting unit 20 is a combined light source 20b, the combined light source 20b sequentially emits red laser light and blue laser light, and includes a blue laser module 200b emitting blue laser light and a red laser module 201b emitting red laser light, the light path switching unit 21 is a light splitting wheel 21b, the first light splitting unit 22 is a blue-reflective yellow-transparent film 22b, the wavelength conversion unit 23 is a fluorescent color wheel 23b, more specifically, a yellow fluorescent color wheel, and the second light splitting unit 24 is a color trimming wheel 24 b.

The dichroic wheel 21b includes a transmission region (not shown) for sequentially transmitting the red laser light and the blue laser light emitted from the combined light source 20b so that the red laser light and the blue laser light sequentially enter the first light path L1b, and a reflection region (not shown) for reflecting the blue laser light emitted from the combined light source 20b so that the blue laser light enters the second light path L2 b.

In a timing when the combined light source 20b emits the red laser light, the dichroic wheel 21b turns to the front portion of the transmission area, and the red laser light reaches the first face 221b of the anti-blue and yellow-transparent film 22b via the first light path L1b, and is reflected by the first face 221b of the anti-blue and yellow-transparent film 22b to the fluorescent color wheel 23 b. In the present embodiment, a red reflecting film is disposed on the first surface 221b of the blue-reflecting and yellow-transmitting film 22b in a region corresponding to the region where the red laser beam is incident, and the red reflecting film reflects the incident red laser beam to the fluorescent color wheel 23 b. In other embodiments, the anti-reddish film sheet may also be replaced by an anti-reddish coating. The red laser beam is decohered by the fluorescent color wheel 23b, reflected to the anti-blue transparent-yellow film 22b, and transmitted to the color correction wheel 24b from the anti-blue transparent-yellow film 22 b.

In the timing sequence in which the combined light source 20b emits the blue laser light, the light splitting wheel 21 turns to the rear portion of the transparent region and continues to the reflective region, and therefore, the blue laser light emitted by the combined light source 20b in the front portion timing sequence reaches the first surface of the anti-blue and yellow-transparent film 22b via the first light path L1b, and is reflected by the first surface 221b of the anti-blue and yellow-transparent film 22b to the fluorescent color wheel 23 b. The blue laser light emitted by the combined light source 20b in the rear portion timing sequence reaches the second surface 222b of the anti-blue and yellow-transparent film 22b through the second light path L2b, and is reflected by the second surface 222b of the anti-blue and yellow-transparent film 22b to the color correction wheel 24 b.

Referring to fig. 6, the color modifying wheel 24B includes a red light region R, a green light region G and a blue light region B, the color modifying wheel 24B rotates to cut the red light region R, the green light region G and the blue light region B into the light path of the light beam emitted from the anti-blue yellow-transparent film 22B in turn, in this embodiment, in the time sequence that the combined light source 20B emits the red laser light, the red light region R of the color modifying wheel 24B cuts into the light path of the light beam emitted from the anti-blue yellow-transparent film 22B, and the red light transmitted from the anti-blue yellow-transparent film 22B is transmitted into the light channel 25 by the red light region R. In the front time sequence of the combined light source 20b emitting blue laser light, the green light region G of the color trimming wheel 24b cuts into the light path of the outgoing light beam from the anti-blue-yellow-transparent diaphragm 22b, and the yellow light transmitted from the anti-blue-yellow-transparent diaphragm 22b is separated into red light and green light by the green light region G, wherein the red light is reflected off and the green light is transmitted into the light channel 25. In the rear time sequence of the combined light source 20B emitting blue laser light, the blue light region B of the color correction wheel 24B is cut into the light path of the outgoing light beam from the anti-blue-transparent-yellow film 22B, and the blue light reflected from the anti-blue-transparent-yellow film 22B is transmitted into the light tunnel 25 by the blue light region B.

In the present embodiment, as in the first embodiment, the second light path L2b and the fluorescent color wheel 23b are respectively located in two intersecting two-dimensional planes, and the second light path L2b is also disposed around the fluorescent color wheel 23b and the optical instrument disposed between the fluorescent color wheel 23b and the blue-reflecting yellow-transmitting film 22 b. Namely, the fluorescent color wheel 23b and the optical instrument disposed between the fluorescent color wheel 23b and the blue-reflecting yellow-transmitting film 22b are disposed inside the second light path L2 b.

In the present embodiment, unlike the first embodiment, in the red light portion, since red laser light having a smaller spread is used instead of blue laser light to obtain red light necessary for image formation, the efficiency of the red light portion is made higher.

It is understood that in another embodiment, during the continuous rotation of the color-modifying wheel 24b, the combined light source 20b can emit the blue laser light all the time, but only when the red light region R of the color-modifying wheel 24b cuts into the light path of the outgoing light beam from the anti-blue yellow-transmitting film 22b, the combined light source 20b is turned on to emit the red laser light, so that, after the red light region R of the color-modifying wheel 24b cuts into the light path of the outgoing light beam from the anti-blue yellow-transmitting film 22b, on one hand, the blue laser light reaches the fluorescent color wheel 23b through the anti-blue red-transmitting film 22b, and excites the fluorescent color wheel 23b to generate yellow light, which is transmitted to the red light region R of the color-modifying wheel 24b through the anti-blue yellow-transmitting film 22b and is separated into red light and green light by the red light region R, wherein the red light is transmitted into the light channel 25, and the green light is reflected, on the, after decoherence, the red light is transmitted through the anti-blue and yellow-transmitting film 22b to the red region R of the color correction wheel 24b and further transmitted by the red region R into the light channel 25, thereby contributing to the red light separated by the yellow light and further enhancing the efficiency of the red light portion.

Other structures of the light source system 2 in the present embodiment are not described in detail, and may be the same as or appropriately changed based on the corresponding structures in the first embodiment, for example, in the present embodiment, the relay system 26b is provided on the first optical path L1b, the spot relay system 261b, the light diffuser 262b, the dodging rod 263b, and the condensing lens 264b are provided on the relay system 26b, the blue-reflecting yellow-transmitting membrane 22b is disposed at the focal point of the converging lens 264b, so that the area of the blue-reflecting yellow-transmitting membrane 22b on which the red-reflecting membrane needs to be disposed is minimized, which is more favorable for the blue laser to excite the yellow light generated by the fluorescent color wheel 23b and/or the red light reflected by the fluorescent color wheel 23b to reach the red light area of the color correction wheel 24b through the blue-reflecting yellow-transmitting membrane 22b, and further improves the efficiency of the red light portion.

Referring to fig. 7 and 8, which are specific structural diagrams of a third embodiment of the light source system 2, in this embodiment, the light emitting unit 20 is a combined light source 20c, the combined light source 20c includes a blue laser module 200c emitting blue laser and a red laser module 201c emitting red laser, the light path switching unit 21 is a light splitting wheel 21c, the first light splitting unit 22 is a blue-reflective yellow-transparent film 22c, the wavelength converting unit 23 is a fluorescent color wheel 23c, more specifically, a yellow fluorescent color wheel, and the second light splitting unit 24 is a color modifying wheel 24 c.

The working principle of the combined light source 20c, the light splitting wheel 21c, the blue-reflective yellow-transparent membrane 22c, the fluorescent wheel 23c and the color correction wheel 24c may be substantially the same as that of the corresponding components in the second embodiment, the combined light source 20c may emit red laser and blue laser in time sequence, or the combined light source 20c continuously emits blue laser in the process of continuous rotation of the color correction wheel 24c, and emits red laser when the red light region of the color correction wheel 24c enters the emergent light path of the blue-reflective yellow-transparent membrane 22c, which is not described herein again.

In the present embodiment, the greatest difference from the second embodiment is that the second light path L2c and the fluorescent color wheel 23c in the present embodiment are respectively located in two parallel two-dimensional planes, so that the second light path L2c in the present embodiment can be disposed between the fluorescent color wheel 23c and the anti-blue yellow-permeable membrane 22c, the second light path L2c passes through between the fluorescent color wheel 23c and the anti-blue yellow-permeable membrane 22c, and the height of the second light path L2c in at least one dimension direction is lower than the height of the fluorescent color wheel 23c in the dimension direction, that is, the height direction of the fluorescent color wheel 23c is multiplexed, so as to reduce the volume of the light source system 2 and reduce the difficulty of the structural design of the light source system 2.

Fig. 9 is a block diagram illustrating a projection system according to a second embodiment of the present invention. The projection system comprises a light source system 5, a spatial light modulator 6 and a projection lens 7. The light beam emitted from the light source system 5 is modulated into image light carrying image information by the spatial light modulator 6, and then projected to a screen (not shown) through the projection lens 7 to form an image for displaying to a user.

In the present embodiment, the light source system 5 includes a light emitting unit 50, a light path switching unit 51, a first light splitting unit 52, a wavelength conversion unit 53, and a second light splitting unit 54. The light path switching unit 51 switches the light beam emitted by the light emitting unit 50 into the first light path L3 or the second light path L4, the light beams emitted from the first light path L3 and the second light path L4 reach the first light splitting unit 52, and the first light splitting unit 52 guides the incident light beam to the wavelength conversion unit 53 or the second light splitting unit 54 respectively according to the light paths of the incident light beam. The light beam emitted by the light emitting unit 50 also reaches the first light splitting unit 52 via the third light path L5, and is guided by the first light splitting unit 52 to the wavelength converting unit 53. The light beam subjected to wavelength conversion by the wavelength conversion unit 53 is guided to the second light splitting unit 54 by the first light splitting unit 52. The light beams are split by the second splitting unit 54 to form light beams of a plurality of set colors, and the light beams are sequentially emitted to the light channel 55 arranged behind the second splitting unit 54 and sequentially emitted to the spatial light modulator 6 through the light channel 55.

Referring to fig. 10-12, which are specific structural diagrams of an embodiment of the light source system 5, in the embodiment, the light emitting unit 50 is a combined light source 50a, and the combined light source 50a includes a blue laser module 500a emitting blue laser and a red laser module 501a emitting red laser. The blue laser emitted from the blue laser module 500a enters the first optical path L3 and the second optical path L4 through the optical path switching unit 51, and the red laser emitted from the red laser module 501a enters the third optical path L5. The light path switching unit 51 is a dichroic wheel 51a, the first dichroic unit is a blue-reflective yellow-transparent film 52a, the wavelength conversion unit 53 is a fluorescent color wheel 53a, more specifically, a yellow fluorescent color wheel, and the second dichroic unit 54 is a color correction wheel 54 a.

The structures and operation principles of the combined light source 50a, the light splitting wheel 51a, the blue-reflecting yellow-transmitting membrane 52a, the fluorescent wheel 53a and the color modifying wheel 54a are the same as or similar to those of the other embodiments described above, and are not fully described, but only the differences from the above embodiments are mainly described.

The main difference between this embodiment and the third embodiment of the light source system 2 is that in the third embodiment of the light source system 2, the red laser beam emitted by the red laser module 201c enters the first light path L1c through the beam splitter 21c, but in this embodiment, the red laser beam emitted by the red laser module 501a does not enter the first light path L3 through the beam splitter 51a, but directly enters the third light path L5. The first optical path L3 is provided with a relay system 56, and the relay system 56 includes an integrator 561. The third light path L5 is provided with a converging lens 57 and a blue-reflective red-transmissive film 58, and the red laser light enters the blue-reflective yellow-transmissive film 52a after passing through the converging lens 57 and the blue-reflective red-transmissive film 58, and is reflected by the blue-reflective yellow-transmissive film 52a to the fluorescent color wheel 53 a. Because the red laser does not need to be homogenized by the homogenizing rod, the optical expansion of the red light part is more favorably reduced, and the efficiency of the red light part is favorably improved. In addition, the red laser light enters the anti-blue and yellow-transmitting membrane 52a after being focused by the converging lens 57, and the anti-blue and yellow-transmitting membrane 52a is disposed at the focal point of the converging lens 57, so that the area on the anti-blue and yellow-transmitting membrane 52a where the anti-red membrane needs to be disposed is minimized, which is more beneficial to the yellow light generated by the fluorescent color wheel 53a excited by the blue laser light and/or the red light reflected by the fluorescent color wheel 53a reaching the red light area (not shown) of the color correction wheel 54a through the anti-blue and yellow-transmitting membrane 52a, and further improves the efficiency of the red light portion.

The first light path L3 is further provided with a reflective mirror 59, and the reflective mirror 59 reflects the blue laser light passing through the relay system 56 onto the anti-blue red-transmitting diaphragm 58, onto the anti-blue yellow-transmitting diaphragm 52a via the anti-blue red-transmitting diaphragm 58, and onto the fluorescent color wheel 53a via the anti-blue yellow-transmitting diaphragm, so as to excite the fluorescent color wheel 53a to generate yellow light, and the generated yellow light reaches the green light region (not shown) of the color correction wheel 54a via the anti-blue yellow-transmitting diaphragm 52 a.

The second light path L4 in this embodiment is similar to the second light path L1c in the third embodiment of the light source system 2, that is, the second light path L4 is disposed between the fluorescent color wheel 53a and the blue-reflective yellow-transmissive film 52a, the second light path L4 passes through between the fluorescent color wheel 53a and the blue-reflective yellow-transmissive film 52a, and the height of the second light path L4 in at least one dimension direction is lower than that of the fluorescent color wheel 53a in the dimension direction, that is, the height direction of the fluorescent color wheel 53a is multiplexed, so that the volume of the light source system 5 is reduced, and the difficulty in designing the structure of the light source system 5 is reduced.

In summary, in the light source system and the projection system provided by the embodiment of the invention, the light source system separates the yellow light to obtain the red light, and due to the arrangement of the overall structure, the light energy utilization rate of the projection system adopting the single-chip spatial light modulator is improved, so that the display brightness of the projection system is improved; on the other hand, in some embodiments, a light path is multiplexed in one dimension direction of the fluorescent color wheel through proper arrangement of the optical elements, so that the structures of the light source system and the projection system using the light source system are more compact, and the difficulty of structural design of the light source system is reduced.

Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention.

Claims (17)

1. A light source system is characterized by comprising a light emitting unit, a light path switching unit, a first light splitting unit, a wavelength conversion unit and a second light splitting unit, wherein the light emitting unit emits light beams, the light path switching unit is used for switching the light beams emitted by the light emitting unit into a first light path and a second light path in a time-sharing manner, the first light splitting unit is arranged at the tail ends of the first light path and the second light path and is used for guiding one of the light beams incident from the first light path and the second light path to the wavelength conversion unit and guiding the other light beam to the second light splitting unit, the first light splitting unit is also used for guiding the light beams emitted after the wavelength conversion of the wavelength conversion unit to the second light splitting unit, the second light splitting unit is used for emitting the incident light beams in a time sequence after the light splitting, and the second light path and the wavelength conversion unit are respectively positioned in two parallel two-dimensional planes, the second optical path passes through a space between the wavelength conversion unit and the first light splitting unit, and the length of the second optical path in at least one direction in a plane in which the second optical path is located is smaller than the length of the wavelength conversion unit in the direction in the plane in which the second optical path is located.

2. The light source system of claim 1, further comprising a light tunnel disposed behind the second beam splitting unit for guiding the light beam exiting the second beam splitting unit to a spatial light modulator.

3. The light source system according to claim 1, wherein the first light splitting unit is configured to guide the light beam incident from the first optical path to a wavelength conversion unit and guide the light beam incident from the second optical path to a second light splitting unit, or the first light splitting unit is configured to guide the light beam incident from the first optical path to a second light splitting unit and guide the light beam incident from the second optical path to a wavelength conversion unit.

4. The light source system according to claim 3, wherein a relay system is provided on the first light path, the relay system includes an integrator rod for homogenizing an incident light beam, a diffuser provided at an entrance of the integrator rod for diffusing the light beam to be entered into the integrator rod, a spot relay system for relaying the light beam spot entered into the first light path to the entrance of the integrator rod, and a condensing lens for condensing and relaying the light beam exiting from the integrator rod to the first light splitting unit.

5. A light source system as set forth in claim 3, wherein a mirror system for guiding the light beam entering the second light path to the first light splitting unit is provided on the second light path.

6. The light source system of claim 5, wherein a relay system is further disposed on the second light path, the relay system being disposed behind the mirror system, the relay system including an integrator rod for homogenizing the incident light beam.

7. The light source system according to claim 1, wherein the light path switching unit cuts the light beam emitted from the light emitting unit into the first and second light paths in a time series by means of transmission and reflection.

8. The light source system according to claim 1, wherein the light emitting unit emits blue laser light and red laser light.

9. The light source system of claim 8, wherein the first light splitting unit is a blue-reflective yellow-transparent film, and the surface of the first light splitting unit is provided with a red-reflective film or a red-reflective coating, and the blue-reflective yellow-transparent film is used for reflecting the incident blue laser light to the wavelength conversion unit or the second light splitting unit and transmitting the incident yellow light and the red light emitted from the wavelength conversion unit to the second light splitting unit.

10. The light source system of claim 9, wherein the anti-blue and anti-yellow transparent film is provided with an anti-red film or an anti-red coating layer facing a region where the red laser light is incident, and the anti-red film or the anti-red coating layer is used for reflecting the incident red laser light to the wavelength conversion unit.

11. The light source system of claim 10, wherein the wavelength conversion unit is a yellow color wheel for absorbing blue laser light reflected by the anti-blue yellow-transparent film and generating yellow light, and the second light splitting unit is a color trimming wheel comprising a plurality of color zones sequentially cut into an exit light path of the anti-blue yellow-transparent film, so that the color trimming wheel sequentially emits light beams of set colors to a spatial light modulator.

12. The light source system of claim 11, wherein the color light area of the color trimming wheel comprises a red light area for splitting the incident yellow light into red and green light and emitting the red light to the spatial light modulator, a green light area for splitting the incident yellow light into red and green light and emitting the green light to the spatial light modulator, and a blue light area for emitting the incident blue laser light to the spatial light modulator.

13. The light source system of claim 12, wherein the blue light region is provided with a diffuser.

14. The light source system of claim 12, wherein the color light region further comprises a yellow light region for emitting incident yellow light to the spatial light modulator.

15. The light source system of claim 8, wherein the red laser beam emitted from the light emitting unit is incident on the first light splitting unit via a third light path, and the blue laser beam emitted from the light emitting unit is incident on the first light splitting unit via the first and second light paths in a time sequence.

16. The light source system according to claim 15, wherein a reverse blue-red-transmitting film is provided on the third light path, a relay system and a reflecting mirror disposed behind the relay system are provided on the first light path, the relay system includes an integrator rod, the reflecting mirror reflects the blue laser light entering the first light path to the reverse blue-red-transmitting film and to the first light splitting unit through the reverse blue-red-transmitting film, and the red laser light is transmitted to the first light splitting unit through the reverse blue-red-transmitting film.

17. A projection system comprising a light source system as claimed in any one of claims 1 to 16 and a monolithic spatial light modulator for modulating the light beam from the light source system into image light carrying image information.

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