CN112305842B

CN112305842B - Illumination system and projection device

Info

Publication number: CN112305842B
Application number: CN202010305143.9A
Authority: CN
Inventors: 黄冠达; 徐若涵; 谢启堂; 谢裕华
Original assignee: Coretronic Corp
Current assignee: Coretronic Corp
Priority date: 2019-07-30
Filing date: 2020-04-17
Publication date: 2022-02-18
Anticipated expiration: 2040-04-17
Also published as: CN112305842A

Abstract

The invention provides an illumination system which comprises an excitation light source module, a light splitting and combining module, a light filtering module and a wavelength conversion module. The excitation light source module is used for providing an excitation light beam. The light splitting and combining module is arranged on a transmission path of the excitation light beam. The excitation light beam comprises a first excitation light beam and a second excitation light beam, and the first excitation light beam and the second excitation light beam have different polarization states or different wavelength ranges. The filtering module is arranged on a transmission path of the excitation light beam and is provided with a light passing area for the excitation light beam to pass through and a filtering area. The wavelength conversion module is arranged on a transmission path of the excitation light beam reflected by the filter area. The wavelength conversion module is used for converting the excitation light beam reflected by the filter area into a conversion light beam. The invention also provides a projection device comprising the illumination system. The illumination system and the projection device provided by the invention have the advantages of better stability of the light beam transmission path, more uniform illumination light beams and better light use efficiency.

Description

Illumination system and projection device

Technical Field

The present invention relates to a display device, and more particularly, to an illumination system and a projection apparatus including the same.

Background

With the development of projection technology, the information presentation manner is also diversified. The projection device may include an illumination system, a light valve, and a projection lens. The illumination system can use an excitation light source to generate the required color light by cooperating with a fluorescent wheel (phosphor wheel), and the color purity is improved by arranging a filter wheel (filter wheel). On one hand, because the blue reflector needs to be embedded into the fluorescent wheel, the fluorescent wheel is easy to deflect when rotating, so that the light path of the reflected excitation light beam is unstable, and the light use efficiency of the projection device is influenced. In addition, the angle range of the excitation light beam emitted from the filter wheel entering the dodging element (such as the integrating rod) is small, so that the overall light emitting uniformity is poor.

The background section is only for the purpose of illustrating the present invention, and therefore the disclosure in the background section may include some prior art that does not constitute a part of the knowledge of those skilled in the art. The statements contained in the "background" section do not represent a representation or representation of the problems associated with one or more embodiments of the present invention, but are understood or appreciated by those skilled in the art prior to the present application.

Disclosure of Invention

The invention provides an illumination system with better stability of a light beam transmission path, which can generate more uniform illumination light beams.

The invention provides a projection device with better light use efficiency.

To achieve one or a part of or all of the above or other objects, an embodiment of the present invention provides an illumination system. The illumination system comprises an excitation light source module, a light splitting and combining module, a light filtering module, a wavelength conversion module and a first lens module. The excitation light source module is used for providing at least one excitation light beam. The light splitting and combining module is arranged on a transmission path of at least one excitation light beam from the excitation light source module. The at least one excitation light beam from the light splitting and combining module comprises a first excitation light beam and a second excitation light beam, and the polarization state or the wavelength range of the first excitation light beam is different from that of the second excitation light beam. The filtering module is arranged on a transmission path of at least one excitation light beam from the light splitting and combining module. The filter module has a light passing region for passing at least one excitation beam and at least one filter region for reflecting at least one excitation beam. The wavelength conversion module is arranged on a transmission path of the at least one excitation light beam reflected by the at least one filter region. The wavelength conversion module is used for converting the at least one excitation light beam reflected by the at least one filter region into a conversion light beam and reflecting the conversion light beam so that the conversion light beam is transmitted towards the at least one filter region. The first lens module is arranged on a transmission path of the at least one excitation light beam from the light splitting and combining module and is used for focusing the at least one excitation light beam from the light splitting and combining module at the filtering module, wherein the first excitation light beam from the first lens module is incident to the filtering module along a first direction, and the second excitation light beam from the first lens module is incident to the filtering module along a second direction, the first direction and the second direction are positioned on two opposite sides of the first lens module, when the light passing area of the filtering module enters the transmission path of the first excitation light beam and the second excitation light beam from the light splitting and combining module, the light path between the first excitation light beam and the second excitation light beam from the excitation light source module to the filtering module does not pass through the wavelength conversion module, and the first excitation light beam and the second excitation light beam are respectively incident to the light passing area of the filtering module from two opposite sides of the optical axis of the first lens module.

To achieve one or a part of or all of the above or other objects, an embodiment of the invention provides a projection apparatus. The projection device comprises an illumination system, a light valve and a projection lens. The illumination system comprises an excitation light source module, a light splitting and combining module, a light filtering module, a wavelength conversion module and a first lens module. The excitation light source module is used for providing at least one excitation light beam. The light splitting and combining module is arranged on a transmission path of at least one excitation light beam from the excitation light source module. The at least one excitation light beam from the light splitting and combining module comprises a first excitation light beam and a second excitation light beam. The first excitation light beam and the second excitation light beam have different polarization states or wavelength ranges. The filtering module is arranged on a transmission path of at least one excitation light beam from the light splitting and combining module. The filter module has a light passing region for passing at least one excitation beam and at least one filter region for reflecting at least one excitation beam. The wavelength conversion module is arranged on a transmission path of the at least one excitation light beam reflected by the at least one filter region. The wavelength conversion module is used for converting the at least one excitation light beam reflected by the at least one filter region into a conversion light beam and reflecting the conversion light beam so that the conversion light beam is transmitted towards the at least one filter region. The at least one excitation light beam passing through the light passing region and the converted light beam passing through the at least one filter region form an illumination light beam. The first lens module is arranged on a transmission path of at least one excitation light beam from the light splitting and combining module and is used for focusing the at least one excitation light beam from the light splitting and combining module at the light filtering module, wherein the first excitation beam from the first lens module is incident to the filter module along a first direction, and the second excitation beam from the first lens module is incident to the filter module along a second direction, wherein the first direction and the second direction are positioned at two opposite sides of the first lens module, when the light passing area of the light filtering module enters the transmission path of the first excitation light beam and the second excitation light beam from the light splitting and combining module, the optical path between the first excitation light beam and the second excitation light beam from the excitation light source module to the filtering module does not pass through the wavelength conversion module, and the first excitation light beam and the second excitation light beam are respectively incident to the light passing area of the filtering module from two opposite sides of the optical axis of the first lens module. The light valve is disposed on a transmission path of an illumination beam from the illumination system and is used for converting the illumination beam into an image beam. The projection lens is arranged on the transmission path of the image beam from the light valve.

In view of the above, in the illumination system and the projection apparatus according to the embodiments of the invention, at least one excitation light beam from the excitation light source module forms two excitation light beams with different polarization states or wavelength ranges after passing through the light splitting and combining module. The two excitation light beams form a part of the illumination light beam after passing through the light passing area of the filter module, and the part of the illumination light beam has better uniformity. On the other hand, since the two excitation light beams do not need to be transmitted to the wavelength conversion module, the stability of the light beam transmission path is better, which is helpful for improving the light use efficiency of the projection device.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic view of a projection apparatus according to an embodiment of the invention.

Fig. 2 and 3 are schematic optical path diagrams of the illumination system of fig. 1 at different timings.

Fig. 4 is a schematic diagram of the filtering module of fig. 1.

Fig. 5A is a side view schematic diagram of the wavelength conversion module of fig. 1.

Fig. 5B is a schematic front view of the wavelength conversion module of fig. 1.

Fig. 6 is a schematic diagram of a wavelength conversion module according to another embodiment of the invention.

Fig. 7 is a timing diagram of the simultaneous operation of the filtering module, the wavelength conversion module, and the light valve according to another embodiment of the present invention.

Fig. 8 and 9 are schematic optical path diagrams of an illumination system according to another embodiment of the invention at different timings.

Fig. 10 and fig. 11 are schematic optical path diagrams of an illumination system according to another embodiment of the invention at different timings.

Fig. 12 is a graph showing transmittance of light beams of different wavelengths of the polarization splitting element of fig. 10.

Detailed Description

The foregoing and other technical matters, features and effects of the present invention will be apparent from the following detailed description of preferred embodiments, which is to be read in connection with the accompanying drawings. Directional terms as referred to in the following examples, for example: up, down, left, right, front or rear, etc., are simply directions with reference to the drawings. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting.

Fig. 1 is a schematic view of a projection apparatus according to an embodiment of the invention. Fig. 2 and 3 are schematic optical path diagrams of the illumination system of fig. 1 at different timings. Fig. 4 is a schematic diagram of the filtering module of fig. 1. Fig. 5A and 5B are a side view and a front view of the wavelength conversion module of fig. 1, respectively. Fig. 6 is a schematic diagram of a wavelength conversion module according to another embodiment of the invention. Fig. 7 is a timing diagram of the simultaneous operation of the filtering module, the wavelength conversion module, and the light valve according to another embodiment of the present invention.

Referring to fig. 1, fig. 2 and fig. 3, the projection apparatus 10 includes an illumination system 100, a light valve 200 and a projection lens 300. The illumination system 100 is used for providing an illumination beam IB, wherein the illumination beam IB is composed of the excitation beams EB1 and EB2 in fig. 2 and the converted beam CB in fig. 3 in time sequence. The light valve 200 is disposed on a transmission path of the illumination beam IB from the illumination system 100, and is used for converting the illumination beam IB into the image beam ImB. The projection lens 300 is disposed on a transmission path of the image beam ImB from the light valve 200 to project the image beam ImB onto a screen, a wall, or other objects for imaging.

In some embodiments, the light valve 200 may be a digital micro-mirror device (DMD), a liquid-crystal-on-silicon (LCOS) panel, or a transmissive liquid crystal panel (transmissive liquid crystal panel), but the invention is not limited thereto.

In some embodiments, projection lens 300 may include, for example, a combination of one or more optical lenses of the same or different diopters, including, for example, a biconcave lens, a biconvex lens, a meniscus lens, a convex-concave lens, a plano-convex lens, a plano-concave lens, and various combinations thereof. On the other hand, the projection lens 300 may also include a planar optical lens. The present invention is not limited to the type and kind of the projection lens 300.

In some embodiments, the illumination system 100 includes an excitation light source module 110, a splitting and combining optical module 120, a filtering module 130, and a wavelength conversion module 140. The excitation light source module 110 is used for providing at least one excitation light beam. In this embodiment, the excitation light source module 110 may include a first excitation light source 111 and a second excitation light source 112, and the emission wavelength of the first excitation light source 111 is different from the emission wavelength of the second excitation light source 112. For example, the first excitation light source 111 is used to provide the first excitation light beam EB1, the second excitation light source 112 is used to provide the second excitation light beam EB2, and the wavelength ranges of the first excitation light beam EB1 and the second excitation light beam EB2 are different, but the invention is not limited thereto. In the present embodiment, the first excitation light source 111 and the second excitation light source 112 are, for example, laser diodes (laser diodes), light emitting diodes (light emitting diodes), or a combination thereof, which is not limited in the invention.

In some embodiments, the light splitting and combining module 120 is disposed on a transmission path of at least one excitation light beam from the excitation light source module 110. In the present embodiment, the optical splitting and combining module 120 includes a first optical film 121, a second optical film 122, and a substrate 123. The first optical film 121 and the second optical film 122 are disposed in parallel on the substrate 123. The substrate 123 is, for example, a glass substrate, a quartz substrate, or another suitable light-transmitting substrate. For example, the first optical film 121 may be disposed on a transfer path of the first excitation light beam EB1 emitted from the first excitation light source 111. For example, the second optical film 122 may be disposed on a transfer path of the second excitation light beam EB2 emitted from the second excitation light source 112.

Further, the first optical film 121 may allow the first excitation light beam EB1 to pass through and reflect the second excitation light beam EB 2. The second optical film 122 allows the second excitation light beam EB2 to pass through and reflects the first excitation light beam EB 1. For example, the first excitation light source 111 may include a blue laser diode, and the dominant wavelength of the emitted light beam is 465 nm, for example. The second excitation light source 112 may include, for example, a blue laser diode, and the dominant wavelength of the emitted light beam is 455 nm, for example. In the above-described embodiments, first optical film 121 may allow first excitation light beam EB1 having a dominant wavelength of 465 nm to pass through and reflect second excitation light beam EB2 having a dominant wavelength of 455 nm. Second optical film 122 may allow second excitation beam EB2, having a dominant wavelength of 455 nanometers to pass through and reflect first excitation beam EB1, having a dominant wavelength of 465 nanometers.

Referring to fig. 4, the filter module 130 is disposed on a transmission path of at least one excitation light beam (e.g., the first excitation light beam EB1 and the second excitation light beam EB2) from the beam splitter module 120, and has a light passing region T for passing the excitation light beam and at least one filter region F for reflecting the excitation light beam. It should be noted that the light passing region T of the filter module 130 may be provided with a diffusion sheet or form a diffusion structure, so as to effectively improve the problem of laser spot (laser spot). In the present embodiment, the filter module 130 may include three filter regions F, which are, but not limited to, a first filter region F1, a second filter region F2 and a third filter region F3. In detail, as shown in fig. 4, the first filter region F1, the second filter region F2, and the third filter region F3 may be respectively configured with filters that respectively allow light beams of a specific color (or wavelength) to pass through and reflect or absorb light beams of other colors (or wavelengths). For example, the light passing region T, the first filter region F1, the second filter region F2, and the third filter region F3 can allow the blue light beam, the red light beam, the green light beam, and the yellow light beam to pass through, respectively. However, the present invention is not limited by the disclosure of the drawings, and in other embodiments, the number of the filter regions F of the filter module, the color of each filter region F, and the arrangement of the plurality of filter regions F may be adjusted according to actual design requirements.

In the present embodiment, the filter module 130 is, for example, a combination of a filter wheel (filter wheel) and a rotation mechanism (not shown). The rotating mechanism (e.g., a motor) is configured to rotate the filter wheel around the rotation axis RA, so that the plurality of regions of the filter module 130 can sequentially enter the transmission path of the excitation light beam from the separating and combining module 120, but the invention is not limited thereto. In other embodiments, the manner in which the plurality of regions of the filter module enter the transmission path of the excitation beam may also be adjusted according to actual design requirements, for example, the plurality of regions of the filter module may be translated in a single direction to sequentially enter the transmission path of the excitation beam.

In some embodiments, when the light passing region T of the filter module 130 enters the transmission path of the excitation light beam (e.g., the first excitation light beam EB1 and the second excitation light beam EB2), the excitation light beam can pass through the filter module 130 (as shown in fig. 2). When the filter region F of the filtering module 130 enters the transmission path of the excitation light beam from the combining and combining module 120, the excitation light beam is reflected by the filter region F of the filtering module 130 (as shown in fig. 3). Further, the first excitation light beam EB1 from the first optical film 121 is reflected by the filter region F of the filter module 130, and then transmitted to the second optical film 122 of the combining and combining module 120, and the first excitation light beam EB1 is reflected by the second optical film 122. After being reflected by the filter region F of the filter module 130, the second excitation light beam EB2 from the second optical film 122 is transmitted to the first optical film 121 of the light splitting and combining module 120, and the second excitation light beam EB2 is reflected by the first optical film 121.

In some embodiments, the wavelength conversion module 140 is disposed on a transmission path of at least one excitation light beam (e.g., the first excitation light beam EB1 and the second excitation light beam EB2) reflected by the filtering module 130, and is configured to convert the at least one excitation light beam reflected by the filtering module 130 into a conversion light beam CB and reflect the conversion light beam CB such that the conversion light beam CB is transmitted toward the filter region F of the filtering module 130. As shown in fig. 5A and 5B, the wavelength conversion module 140 may include a carrier 141 and a wavelength conversion layer 142. In the embodiment, the carrier plate 141 can reflect the light beam, so that the converted light beam CB can be reflected back to the optical splitting and combining module 120. For example, the carrier 141 may be a metal carrier. Therefore, the carrier plate 141 also helps to dissipate heat. Alternatively, the carrier 141 may be a light-transmitting carrier, and a reflective layer is formed on a surface 141s of the carrier 141 facing the combining/combining optical module 120.

In a further embodiment, the wavelength conversion layer 142 is disposed on a surface 141s of the carrier plate 141 facing the optical combiner/divider module 120, and is configured to absorb a light beam with a short wavelength (e.g., an excitation light beam) and to excite a light beam with a long wavelength (e.g., a conversion light beam CB). In the embodiment, the wavelength conversion layer 142 may be disposed along the circumference of the carrier 141, but not limited thereto. The material of the wavelength conversion layer 142 may include a fluorescent material (phosphor material), a quantum dot, or a combination of the two materials. In particular, the material of the wavelength conversion layer 142 may optionally further include light scattering particles to improve the conversion efficiency.

In the present embodiment, the wavelength conversion module 140 is, for example, a combination of a fluorescent wheel (phosphor wheel) and a rotation mechanism (not shown). A rotation mechanism (e.g., a motor) configured to rotate the fluorescent wheel around the rotation axis RA' to improve the heat dissipation effect of the wavelength conversion module 140. However, the invention is not limited thereto, and according to other embodiments the wavelength conversion module may not rotate.

In this embodiment, the excitation light beam from the excitation light source module 110 may be transmitted to the light splitting and combining module 120 without being transmitted to the wavelength conversion module 140, and further transmitted to the filtering module 130. The excitation light beam may be output from the filter module 130 through the light passing region T of the filter module 130, and thus. Accordingly, in the embodiment, when the wavelength conversion module 140 rotates around the rotation axis RA', the deflection is less likely to occur, which is helpful to improve the stability of the light beam transmission paths of the excitation light beam and the conversion light beam CB.

Referring to fig. 3, the first optical film 121 and the second optical film 122 of the optical splitting and combining module 120 may also reflect the converted light beam CB. For example, a portion of the converted light beam CB from the wavelength conversion module 140 is reflected by the first optical film 121 and transmitted toward the filter region F of the filter module 130, and another portion of the converted light beam CB from the wavelength conversion module 140 is reflected by the second optical film 122 and transmitted toward the filter region F of the filter module 130. That is, the first optical film 121 of the optical splitting and combining module 120 of the present embodiment can reflect the second excitation light beam EB2 (e.g., the excitation light beam with the dominant wavelength of 455 nm) and also reflect the converted light beam CB from the wavelength conversion module 140. The second optical film 122 may reflect the first excitation light beam EB1 (e.g., an excitation light beam with a dominant wavelength of 465 nm) and may also reflect the converted light beam CB from the wavelength conversion module 140.

It should be noted that, referring to fig. 2, when the light passing area T of the filter module 130 enters the transmission path of the excitation light beams (e.g., the first excitation light beam EB1 and the second excitation light beam EB2) from the beam splitting and combining module 120, the excitation light beams can be output through the light passing area T of the filter module 130. As shown in fig. 3, when the filter regions F (e.g., the first filter region F1, the second filter region F2, or the third filter region F3) of the filter module 130 respectively enter the transmission paths of the excitation light beams from the splitting and combining module 120 at a time sequence, the first excitation light beam EB1 passing through the first optical film 121 is reflected by the filter regions F, and then reflected by the second optical film 122 and transmitted to the wavelength conversion module 140. Similarly, the second excitation light beam EB2 passing through the second optical film 122 is reflected by the filter region F, and then reflected by the first optical film 121 to be transmitted to the wavelength conversion module 140. The first excitation light beam EB1 and the second excitation light beam EB2 are incident on the wavelength conversion module 140, so that the wavelength conversion module 140 generates a converted light beam CB, and the converted light beam CB is reflected by the optical films (the first optical film 121 and the second optical film 122) of the light splitting and combining module 120 and transmitted toward the filter region F of the filter module 130. More specifically, illumination system 100 emits illumination beam IB (shown in FIG. 1) comprising the excitation beam passing through light pass region T shown in FIG. 2 and comprising converted beam CB passing through the plurality of filter regions F shown in FIG. 3.

In detail, in the present embodiment, the wavelength conversion module 140 converts the blue excitation light beam (e.g., the first excitation light beam EB1 and the second excitation light beam EB2) into the yellow conversion light beam CB, and the yellow conversion light beam CB is filtered by the plurality of filter regions F (as shown in fig. 4) of the filter module 130 to sequentially output a plurality of color light beams (e.g., red light, green light, and yellow light) required for illumination. That is, as shown in fig. 5A and 5B, in the present embodiment, only one wavelength conversion material (e.g., a wavelength conversion material for converting yellow light) may be disposed on the carrier 141 of the wavelength conversion module 140, so that the wavelength conversion layer 142 is not divided into a plurality of wavelength conversion regions having different wavelength conversion materials. In such a configuration (the wavelength conversion module has a single wavelength conversion layer), the wavelength conversion module 140 has a more uniform mass distribution, so that the deflection is less likely to occur, which is helpful to improve the stability of the beam transmission paths of the excitation beam and the converted beam CB. Further, the filtering module 130 and the wavelength conversion module 140 may not rotate synchronously.

However, the present invention is not limited thereto, and in another embodiment, a plurality of different wavelength conversion materials may be disposed on the carrier plate 141 of the wavelength conversion module 140A to output light beams with a plurality of colors. Referring to fig. 6, for example, the wavelength conversion layer 142A of the wavelength conversion module 140A may be divided into a plurality of wavelength conversion regions (e.g., a first wavelength conversion region C1, a second wavelength conversion region C2 and a third wavelength conversion region C3 shown in fig. 6) corresponding to the plurality of filter regions F (e.g., a first filter region F1, a second filter region F2 or a third filter region F3) of the filter module 130, which are respectively disposed with different wavelength conversion materials. In other embodiments, the wavelength conversion module 140A may also have a non-conversion region NC corresponding to the light passing region T of the filter module 130 (as shown in fig. 4). The non-conversion region NC does not receive the excitation beam.

As shown in fig. 6 and 7, in another embodiment, the filtering module 130 and the wavelength conversion module 140A may also rotate synchronously. For example, the positions of the non-conversion region NC, the first wavelength conversion region C1, the second wavelength conversion region C2, and the third wavelength conversion region C3 of the wavelength conversion module 140A may respectively correspond to the positions of the light passing region T, the first filter region F1, the second filter region F2, or the third filter region F3 of the filter module 130. Further, the light valve can sequentially convert the excitation beam or the plurality of converted beams into the image beam.

Referring to fig. 1, fig. 2 and fig. 3, in the present embodiment, the illumination system 100 may further optionally include other elements according to different requirements. For example, the illumination system 100 may also include a light homogenizing element 150. The light unifying element 150 is disposed on a transmission path of the light beam output from the filter module 130 to improve uniformity of the light beam. In the present embodiment, the light uniformizing element 150 is, for example, a light integrating rod (optical integrator rod), but not limited thereto. In addition, the illumination system 100 may further include a first lens module 160 and a second lens module 170. The first lens module 160 is disposed between the light splitting and combining module 120 and the filter module 130. The first lens module 160 is disposed on a transmission path of at least one excitation light beam (e.g., the first excitation light beam EB1 and the second excitation light beam EB2) from the beam combiner module 120, and is configured to focus the at least one excitation light beam from the beam combiner module 120 on the filter module 130 or near the filter module 130 (e.g., within a distance of 5mm (e.g., +/-0.5mm) from the filter module 130).

For example, as shown in fig. 2, a first excitation beam EB1 from the first optical film 121 and a second excitation beam EB2 from the second optical film 122 are incident on the filter module 130 along different directions after passing through the first lens module 160. More specifically, the first lens block 160 has an optical axis AX, and the optical path of the first excitation light beam EB1 from the first optical film 121 of the splitting and combining module 120 and the optical path of the second excitation light beam EB2 from the second optical film 122 of the splitting and combining module 120 are located on opposite sides of the optical axis AX of the first lens block 160, respectively. The first excitation beam EB1 is incident on the filter module 130 in a first direction (i.e., the direction in which the optical path of the first excitation beam EB1 extends) after passing through the first lens module 160, and the second excitation beam EB2 is incident on the filter module 130 in a second direction (i.e., the direction in which the optical path of the second excitation beam EB2 extends) after passing through the first lens module 160. In the embodiment, an included angle θ 1 between the first direction and the optical axis AX is substantially equal to an included angle θ 2 between the second direction and the optical axis AX, and the included angles θ 1 and θ 2 are acute angles, but the invention is not limited thereto.

Since the first excitation beam EB1 and the second excitation beam EB2 from the splitting and combining module 120 are respectively located at two opposite sides of the optical axis AX of the first lens module 160 and respectively enter the filter module 130 along different directions, the excitation beam enters the dodging element 150 in a preset angle range after passing through the light passing region T of the filter module 130, which is helpful for improving the overall uniformity of the excitation beam after exiting from the dodging element 150. In addition, since the excitation light beams (such as the first excitation light beam EB1 and the second excitation light beam EB2 in fig. 2) passing through the light passing region T of the filter module 130 do not pass through the wavelength conversion module 140, the wavelength conversion module 140 (e.g., on the carrier plate 141) of the present embodiment may not be provided with a reflective element. Accordingly, the wavelength conversion module 140 can be prevented from generating a deflection when rotating around the rotation axis RA', which may cause a loss of light when the light beam is incident on the light unifying element 150. The so-called yaw is that the wavelength conversion module 140 swings up and down around the rotation axis RA' at the edge of the wavelength conversion module 140 due to uneven distribution of weight when the wavelength conversion module 140 rotates. The deflection of the wavelength conversion module 140 causes a change in the size of the spot area of the excitation beam irradiated on the wavelength conversion module 140, so that a part of the excitation beam cannot be incident on the light uniformizing element 150, and a loss of the beam is generated.

In other words, the arrangement of the first excitation beam EB1 and the second excitation beam EB2 from the light splitting and combining module 120 can effectively improve the stability of the beam transmission paths of the excitation beam and the converted beam CB and the beam utilization efficiency of the projection apparatus 10.

On the other hand, the second lens module 170 is disposed between the light splitting and combining module 120 and the wavelength conversion module 140. The second lens module 170 is disposed on a transmission path of the excitation light beam reflected by the optical film of the combining and condensing module 120, and is used to focus the excitation light beam on the wavelength conversion module 140. In the present embodiment, the second lens module 170 may include a lens 171 and a lens 172. In a further embodiment, the lens 171 and the lens 172 may also be disposed on the transmission path of the converted light beam CB for converging the converted light beam CB from the wavelength conversion module 140. It should be noted that the present invention is not limited by the disclosure of the drawings, and in other embodiments, the number of the first lens module and the second lens module and the number of the lenses of the illumination system may be adjusted according to the actual design requirement.

The present invention will be described in detail below with reference to other embodiments, wherein like components are denoted by like reference numerals, and descriptions of the same technical contents are omitted, and reference is made to the foregoing embodiments for omitting details.

Fig. 8 and 9 are schematic optical path diagrams of an illumination system according to another embodiment of the invention at different timings. Referring to fig. 8 and 9, the lighting system 100A of the present embodiment is different from the lighting system 100 of fig. 2 and 3 in the composition or configuration of the splitting and combining optical module or the excitation light source module.

In the present embodiment, the excitation light source module 110A includes a first excitation light source 111A and a second excitation light source 112A, and the first excitation light beam EB1A emitted by the first excitation light source 111A and the second excitation light beam EB2A emitted by the second excitation light source 112A may have the same light emission wavelength (for example, the dominant wavelength is 455 nanometers), but the first excitation light beam EB1A from the first excitation light source 111A and the second excitation light beam EB2A from the second excitation light source 112A have different polarization states after passing through the splitting and combining optical module 120A. Further, the first excitation beam EB1A and the second excitation beam EB2A have the same polarization state (e.g., the first polarization state P) before passing through the light splitting and combining module 120A, and have different polarization states after passing through the light splitting and combining module 120A, for example, the first polarization state P and the second polarization state S, respectively. In this embodiment, the light beam having the first polarization state P means that the intensity ratio of the light beam having the first polarization state P to the light beams having other polarization states (for example, the second polarization state S) in the light beam is greater than 500: 1, but not limited thereto.

In detail, the optical splitting and combining module 120A includes a substrate 123, a first optical film 121A disposed on the substrate 123, and a half-wave plate (also referred to as a half-wave plate) 180. The first optical film 121A is disposed on a transmission path of the first excitation light beam EB1A and the second excitation light beam EB2A from the excitation light source module 110A. The half wave plate 180 is disposed on the transfer path of the first excitation light beam EB1A from the first excitation light source 111A. The half wave plate 180 is disposed outside the transmission path of the second excitation beam EB 2A. It is noted that the half-wave plate 180 may be located on a side of the first optical film 121A facing away from the excitation light source module 110A, and is used for converting the excitation light beam having the first polarization state P (e.g., the first excitation light beam EB1A) into the excitation light beam having the second polarization state S. The first optical film 121A is disposed between the substrate 123 and the half-wave plate 180.

In the present embodiment, the first excitation light beam EB1A from the first optical film 121A and the half-wave plate 180 and the second excitation light beam EB2A from the first optical film 121A pass through the first lens module 160 and then enter the filter module 130 along different directions, respectively. More specifically, the first lens module 160 has an optical axis AX, and after passing through the splitting and combining module 120A, the optical paths of the first excitation light beam EB1A and the second excitation light beam EB2A are located on opposite sides of the optical axis AX of the first lens module 160, respectively. For example, the first excitation beam EB1A may be incident on the filter module 130 in a first direction (i.e., the direction of the optical path extension of the first excitation beam EB1A) after passing through the first lens module 160, and the second excitation beam EB2A may be incident on the filter module 130 in a second direction (i.e., the direction of the optical path extension of the second excitation beam EB 2A) after passing through the first lens module 160. Since the first excitation beam EB1A and the second excitation beam EB2A from the splitting and combining module 120A are respectively located at two opposite sides of the optical axis AX of the first lens module 160 and respectively enter the filter module 130 along different directions, the excitation beam enters the dodging element 150 in a preset angle range after passing through the light passing region T of the filter module 130, which is helpful for improving the overall uniformity of the excitation beam after exiting from the dodging element 150.

In the present embodiment, as shown in fig. 9, the first optical film 121A allows the excitation light beam having the first polarization state P to pass therethrough, and reflects the excitation light beam having the second polarization state S. For example, the first excitation light beam EB1A from the first excitation light source 111A and having the first polarization state P can pass through the first optical film 121A, but after passing through the half-wave plate 180, the polarization state of the first excitation light beam EB1A is changed, for example, converted into the second polarization state S, and then transmitted to the filtering module 130. Further, the first excitation light beam EB1A with the second polarization state S may be reflected by at least one filter region of the filter module 130 and then transmitted toward the wavelength conversion module 140 by reflection of the first optical film 121A. In the present embodiment, the second excitation light beam EB2A coming from the second excitation light source 112A and having the first polarization state P can pass through the first optical film 121A and then pass through the filtering module 130. The second excitation beam EB2A with the first polarization state P can be reflected by at least one filter region of the filter module 130, and then the polarization state of the second excitation beam EB2A is changed, for example, converted into the second polarization state S after passing through the half-wave plate 180. Then, the second excitation light beam EB2A having the second polarization state S may be reflected by the first optical film 121A to pass toward the wavelength conversion module 140.

Further, the first optical film 121A may reflect the converted light beam CB, for example, the converted light beam CB from the wavelength conversion module 140 is transmitted toward the filtering module 130 via the reflection of the first optical film 121A. It is worth mentioning that the kind or the number of the excitation light sources can be simplified by the above arrangement of the light splitting and combining module 120A and the excitation light sources having the polarization characteristics. In an embodiment not shown, only one group of excitation light sources may be disposed in the excitation light source module, and the excitation light beams from the excitation light sources form a first excitation light beam and a second excitation light beam with different polarization states after being combined and combined by the light splitting and combining module. Accordingly, the design flexibility of the illumination system 100A can be increased.

Fig. 10 and fig. 11 are schematic optical path diagrams of an illumination system according to another embodiment of the invention at different timings. Fig. 12 is a graph showing transmittance of light beams of different wavelengths of the polarization splitting element of fig. 10. Referring to fig. 10 and 11, the lighting system 100B of the present embodiment is different from the lighting system 100 of fig. 2 and 3 in the composition and configuration of the excitation light source module and the splitting and combining optical module.

In this embodiment, the excitation light source module 110B can provide a polarization ratio of about 1:1, and further, the intensity ratio of the beam with the first polarization state P to the beam with the second polarization state S in the laser beam provided by the excitation light source module 110B (e.g., semiconductor laser) is about 1:1, but not limited thereto.

In the present embodiment, the light splitting/combining module 120B includes a polarization beam splitter 125 and a wavelength beam splitter 126. The polarization splitting element 125 is disposed on a transmission path of the excitation light beam EB from the excitation light source module 110B, and a part of the excitation light beam EB (for example, a light beam with a polarization state S) is reflected by the polarization splitting element 125 to form a first excitation light beam EB 1B. Another portion of the excitation light beam EB (e.g., a light beam with polarization state P) may pass through the polarization splitting element 125 to form a second excitation light beam EB 2B. It is noted that the polarization state (e.g., the second polarization state S) of the first excitation light beam EB1B reflected by the polarization beam splitter 125 is different from the polarization state (e.g., the first polarization state P) of the second excitation light beam EB2B passing through the polarization beam splitter 125.

In the present embodiment, the transmittance of the polarization splitting element 125 for the excitation light beam of the first polarization state P is different from that of the excitation light beam of the second polarization state S. For example, the excitation light source module 110B may be a blue laser with a dominant wavelength of 450 nm, and the polarization beam splitter 125 allows a portion of the excitation light beam EB of the first polarization state P to pass through and reflects another portion of the excitation light beam EB of the second polarization state S (as shown in fig. 12). The wavelength splitting element 126 is disposed on the transmission path of the second excitation light beam EB2B from the polarization splitting element 125. In the present embodiment, the wavelength splitting element 126 allows the converted light beam CB from the wavelength conversion module 140B to pass through, and reflects the second excitation light beam EB2B from the polarization splitting element 125 and reflects the first excitation light beam EB1B (having the second polarization state S) reflected by the filter region of the filter module 130B.

In detail, the first excitation light beam EB1B from the polarization beam splitter 125 is sequentially transmitted toward the wavelength conversion module 140B through the reflection of the filter region of the filter module 130B, the reflection of the wavelength beam splitter 126, and the reflection of the polarization beam splitter 125. In addition, the second excitation beam EB2B from the wavelength splitting element 126 is sequentially reflected by the filter region of the filter module 130B, passes through the polarization splitting element 125, and then is transmitted toward the wavelength conversion module 140B. On the other hand, the converted light flux CB from the wavelength conversion module 140B is transmitted from the light splitting and combining module 120B and then transmitted toward the filter module 130B. More specifically, the polarization splitting element 125 and the wavelength splitting element 126 of the present embodiment both allow the converted light beam CB from the wavelength conversion module 140B to pass through (as shown in fig. 11).

In the present embodiment, the first excitation beam EB1B from the polarization beam splitter 125 and the second excitation beam EB2B from the wavelength beam splitter 126 are incident on the filter module 130B along different directions after passing through the first lens module 160. More specifically, the first lens module 160 has an optical axis AX, and the optical path of the first excitation light beam EB1B from the polarization beam splitter 125 and the optical path of the second excitation light beam EB2B from the wavelength beam splitter 126 are located on opposite sides of the optical axis AX of the first lens module 160. The first excitation beam EB1B enters the filter module 130B in a first direction (i.e., the direction of the optical path extension of the first excitation beam EB 1B) after passing through the first lens module 160, and the second excitation beam EB2B enters the filter module 130B in a second direction (i.e., the direction of the optical path extension of the second excitation beam EB 2B) after passing through the first lens module 160. Since the first excitation beam EB1B and the second excitation beam EB2B from the splitting and combining module 120B are respectively located at two opposite sides of the optical axis AX of the first lens module 160, and respectively enter the filter module 130B along different directions, after the excitation beam passes through the light passing region of the filter module 130B, the excitation beam can enter the dodging element 150 within a preset angle range, which is helpful for improving the overall uniformity of the excitation beam after exiting from the dodging element 150. It should be noted that, in the present embodiment, the configuration of the excitation light source module 110B can be simplified through the matching relationship between the polarization beam splitter 125 and the wavelength beam splitter 126, which is helpful to improve the design flexibility of the illumination system 100B.

In summary, in the illumination system and the projection apparatus of the embodiment of the invention, the excitation light source module provides at least one excitation light beam, and the excitation light beam passes through the splitting and combining module to form at least two excitation light beams with different polarization states or at least two excitation light beams with different wavelength ranges. After the excitation light beam passes through the light passing area of the filter module, a part of the illumination light beam is formed, and the part of the illumination light beam has better uniformity. On the other hand, since the two excitation light beams do not need to be transmitted to the wavelength conversion module, the stability of the light beam transmission path is better, which is helpful for improving the light use efficiency of the projection device.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention. While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, it is not necessary for any embodiment or claim of the invention to address all of the objects, advantages, or features disclosed herein. In addition, the abstract and the title of the invention are provided for assisting the search of patent documents and are not intended to limit the scope of the invention. Furthermore, the terms "first," "second," and the like in the description or in the claims are used only for naming elements (elements) or distinguishing different embodiments or ranges, and are not used for limiting the upper limit or the lower limit on the number of elements.

Description of the symbols

10 projection device

100. 100A, 100B illumination system

110. 110A, 110B excitation light source module

111. 111A first excitation light source

112. 112A second excitation light source

120. 120A, 120B optical splitting and combining module

121. 121A first optical film

122 second optical film

123 base plate

125 polarization light splitting element

126 wavelength light splitting element

130. 130B light filtering module

140. 140A, 140B wavelength conversion module

141 carrier plate

141s surface

142. 142A wavelength conversion layer

150 light uniformizing element

160 first lens module

170 second lens Module

171. 172 lens

180 half wave plate

200 light valve

300 projection lens

AX optical axis

CB conversion of light beams

C1, C2, C3 wavelength conversion region

EB excitation beam

EB1, EB1A, EB1B first excitation light beam

EB2, EB2A, EB2B, second excitation light beam

F. F1, F2, F3, F4 filter region

IB illuminating beam

ImB image beam

NC non-conversion area

P is the first polarization

RA, RA' rotating shaft

S second polarization

Light passing area

Theta 1 and theta 2 are included angles.

Claims

1. An illumination system is characterized by comprising an excitation light source module, a light splitting and combining module, a light filtering module, a wavelength conversion module and a first lens module, wherein,

the excitation light source module is used for providing at least one excitation light beam;

the light splitting and combining module is arranged on a transmission path of the at least one excitation light beam from the excitation light source module, wherein the at least one excitation light beam from the light splitting and combining module comprises a first excitation light beam and a second excitation light beam, and the polarization states or wavelength ranges of the first excitation light beam and the second excitation light beam are different;

the filtering module is arranged on a transmission path of the at least one excitation light beam from the light splitting and combining module, and the filtering module is provided with a light passing area for allowing the at least one excitation light beam to pass and at least one filtering area for reflecting the at least one excitation light beam;

the wavelength conversion module is disposed on a transmission path of the at least one excitation light beam reflected by the at least one filter region, wherein the wavelength conversion module is configured to convert the at least one excitation light beam reflected by the at least one filter region into a conversion light beam and reflect the conversion light beam, so that the conversion light beam is transmitted toward the at least one filter region, and an illumination light beam is formed by the at least one excitation light beam of the light passing region and the conversion light beam of the at least one filter region,

the first lens module is arranged on a transmission path of the at least one excitation light beam from the light splitting and combining module and is used for focusing the at least one excitation light beam from the light splitting and combining module at the filter module, wherein the first excitation light beam from the first lens module is incident to the filter module along a first direction, and the second excitation light beam from the first lens module is incident to the filter module along a second direction, wherein the first direction and the second direction are positioned on two opposite sides of the first lens module,

when the light passing area of the filtering module enters a transmission path of the first excitation light beam and the second excitation light beam from the light splitting and combining module, a light path between the first excitation light beam and the second excitation light beam from the excitation light source module to the filtering module does not pass through the wavelength conversion module, and the first excitation light beam and the second excitation light beam are respectively incident to the light passing area of the filtering module from two opposite sides of an optical axis of the first lens module.

2. The illumination system according to claim 1, wherein the excitation light source module comprises a first excitation light source and a second excitation light source, the first excitation light source is configured to provide the first excitation light beam, the second excitation light source is configured to provide the second excitation light beam, and a light emitting wavelength of the first excitation light source is different from a light emitting wavelength of the second excitation light source.

3. The illumination system of claim 2, wherein the light splitting and combining module comprises a first optical film and a second optical film,

the first optical film is arranged on a transmission path of the first excitation light beam from the first excitation light source, wherein the first optical film allows the first excitation light beam to pass through and reflects the second excitation light beam, and the second excitation light beam is reflected by the at least one filter region and then transmitted towards the wavelength conversion module through the reflection of the first optical film;

the second optical film is disposed on a transmission path of the second excitation light beam from the second excitation light source, wherein the second optical film allows the second excitation light beam to pass through and reflects the first excitation light beam, and the first excitation light beam is reflected by the at least one filter region and then transmitted toward the wavelength conversion module via the second optical film.

4. The illumination system of claim 3, wherein the converted light beam from the wavelength conversion module passes toward the filter module via reflection by the first and second optical films.

5. The illumination system according to claim 1, wherein the excitation light source module comprises a first excitation light source and a second excitation light source, the first excitation light source is configured to provide the first excitation light beam, the second excitation light source is configured to provide the second excitation light beam, and the first excitation light beam and the second excitation light beam have the same polarization state before entering the combiner/combiner module and have different polarization states after passing through the combiner/combiner module.

6. The illumination system of claim 5, wherein the light splitting and combining module comprises a first optical film and a half wave plate,

the first optical film is arranged on a transmission path of the at least one excitation light beam from the excitation light source module;

the half-wave plate is disposed on a transmission path of the first excitation light beam from the first excitation light source and the half-wave plate is disposed outside a transmission path of the second excitation light beam from the second excitation light source,

the second excitation light beam reflected by the at least one filter region is reflected by the first optical film and transmitted toward the wavelength conversion module, and the first excitation light beam from the half-wave plate is sequentially reflected by the at least one filter region and transmitted toward the wavelength conversion module by being reflected by the first optical film.

7. The illumination system of claim 6, wherein the converted light beam from the wavelength conversion module passes toward the filter module via reflection by the first optical film.

8. The illumination system according to claim 1, wherein the light splitting and combining module includes a polarization splitting element and a wavelength splitting element,

the polarization beam splitting element is arranged on a transmission path of the at least one excitation light beam from the excitation light source module, wherein one part of the at least one excitation light beam from the excitation light source module forms the first excitation light beam through reflection of the polarization beam splitting element, and the other part of the at least one excitation light beam from the excitation light source module forms the second excitation light beam after passing through the polarization beam splitting element, and the polarization state of the first excitation light beam is different from that of the second excitation light beam;

the wavelength light splitting element is arranged on a transmission path of the second excitation light beam from the polarization light splitting element.

9. The illumination system of claim 8, wherein the first excitation beam from the polarization beam splitter passes through the wavelength conversion module by reflection of the at least one filter region, reflection of the wavelength beam splitter, and reflection of the polarization beam splitter in sequence, and the second excitation beam from the wavelength beam splitter passes through the polarization beam splitter in sequence by reflection of the at least one filter region and passes through the wavelength conversion module.

10. The illumination system of claim 9, wherein the converted light beams from the wavelength conversion module pass toward the filter module after being transmitted from the integrating and integrating module.

11. A projection device comprising an illumination system, a light valve and a projection lens, wherein

The illumination system comprises an excitation light source module, a light splitting and combining module, a light filtering module, a wavelength conversion module and a first lens module, wherein,

the wavelength conversion module is arranged on a transmission path of the at least one excitation light beam reflected by the at least one filter region, wherein the wavelength conversion module is used for converting the at least one excitation light beam reflected by the at least one filter region into a conversion light beam and reflecting the conversion light beam, so that the conversion light beam is transmitted towards the at least one filter region, and an illumination light beam is formed by the at least one excitation light beam of the light passing region and the conversion light beam of the at least one filter region; and

wherein when the light passing region of the filter module enters a transmission path of the first and second excitation light beams from the splitting and combining optical module, an optical path between the first and second excitation light beams from the excitation light source module to the filter module does not pass through the wavelength conversion module, and the first and second excitation light beams are incident to the light passing region of the filter module from opposite sides of an optical axis of the first lens module, respectively,

the light valve is arranged on the transmission path of the illumination light beam from the illumination system and is used for converting the illumination light beam into an image light beam; and

the projection lens is arranged on a transmission path of the image light beam from the light valve.

12. The projection apparatus according to claim 11, wherein the excitation light source module comprises a first excitation light source and a second excitation light source, the first excitation light source is configured to provide the first excitation light beam, the second excitation light source is configured to provide the second excitation light beam, and a light emitting wavelength of the first excitation light source is different from a light emitting wavelength of the second excitation light source.

13. The projection device according to claim 12, wherein the optical splitting and combining module includes a first optical film and a second optical film,

14. The projection device of claim 13, wherein the converted light beam from the wavelength conversion module passes toward the filter module via reflection from the first and second optical films.

15. The projection apparatus according to claim 11, wherein the excitation light source module includes a first excitation light source and a second excitation light source, the first excitation light source is configured to provide the first excitation light beam, and the second excitation light source is configured to provide the second excitation light beam, wherein the first excitation light beam and the second excitation light beam have the same polarization state before entering the combiner/combiner module and have different polarization states after passing through the combiner/combiner module.

16. The projection device of claim 15, wherein the optical splitting and combining module includes a first optical film and a half-wave plate,

the second excitation light beam reflected by the at least one filter region is reflected by the first optical film and transmitted toward the wavelength conversion module, and the first excitation light beam from the half-wave plate is sequentially reflected by the at least one filter region, reflected by the first optical film and transmitted toward the wavelength conversion module.

17. The projection device of claim 16, wherein the converted light beam from the wavelength conversion module passes toward the filter module via reflection from the first optical film.

18. The projection apparatus according to claim 11, wherein the separation/combination optical module includes a polarization splitting element and a wavelength splitting element,

19. The projection apparatus according to claim 18, wherein the first excitation beam from the polarization beam splitter passes through the wavelength conversion module by reflection of the at least one filter region, reflection of the wavelength beam splitter and reflection of the polarization beam splitter in sequence, and the second excitation beam from the wavelength beam splitter passes through the polarization beam splitter and passes through the at least one filter region in sequence.

20. The projection apparatus according to claim 19, wherein the converted light beam from the wavelength conversion module is transmitted toward the filter module after being transmitted from the light splitting and combining module.