BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an alignment module, and more particularly, to an alignment module applied for a projection apparatus and having fewer optical components for cost reduction.
2. Description of the Prior Art
The conventional laser projector utilizes the blue light laser source to provide the illumination beam. The illumination beam is transformed into an excitation beam with different color via the wavelength conversion device (such as the color wheel partly covered by phosphor powder or quantum dot material); then, the excitation beam can be mixed with the illumination beam for related application. The conventional alignment module utilizes the dichroic component to reflect the illumination beam toward the color wheel. A portion of the color wheel made by wavelength conversion material generates the excitation beam accordingly, and the excitation beam can pass through the dichroic component. Besides, a part of the illumination beam passes through another portion of the color wheel without the wavelength conversion material and moves back the dichroic component via reflecting components, and then is reflected by the dichroic component to mix with the excitation beam. Therefore, the conventional alignment module has drawbacks of expensive hardware cost and heavy weight due to a large number of optical components.
SUMMARY OF THE INVENTION
The present invention provides an alignment module applied for a projection apparatus and having fewer optical components for cost reduction for solving above drawbacks.
According to the claimed invention, an alignment module includes a light source module, a collimator lens, a wavelength transformation module, a polarizing beamsplitter, a quarter wave plate and a dichroic mirror. The light source module is adapted to provide a first illumination beam with a first polarization state in a first direction. The collimator lens has a first part, a second part, and an axle located between the first part and the second part. The wavelength transformation module is adapted to receive the first illumination beam from the first part of the collimator lens, and alternately generate an actuation beam and reflect the first illumination beam. The actuation beam is transmitted towards the first part and the second part of the collimator lens in a second direction, and the first illumination beam is reflected towards the second part of the collimator lens in the second direction, and the second direction is perpendicular to the first direction. The polarizing beamsplitter is disposed on position corresponding to the first part, and the polarizing beamsplitter is adapted to reflect the first illumination beam with the first polarization state, and further allow passing of the actuation beam and a second illumination beam with a second polarization state. The quarter wave plate is disposed on a rear optical path relative to the polarizing beamsplitter, and the first illumination beam with the first polarization state is transformed into the second illumination beam with the second polarization state via the quarter wave plate. The dichroic mirror is disposed on position corresponding to the second part, and further on a rear optical path relative to the quarter wave plate. The dichroic mirror is adapted to allow passing of the actuation beam and further to reflect the first illumination beam from the quarter wave plate.
According to the claimed invention, the quarter wave plate is disposed on a rear optical path relative to the collimator lens and further on position corresponding to the second part, or the quarter wave plate is disposed on a front optical path relative to the collimator lens and further on position corresponding to the first part, or the quarter wave plate is disposed between the collimator lens and the wavelength transformation module and further on position corresponding to the first part or the second part.
The alignment module of the present invention can utilize feature of the illumination beam with a specific polarization state passing through the quarter wave plate twice to transform into the illumination beam with another polarization state, and feature of the quarter wave plate that allows passing of the actuation beam with the small-sized polarizing beamsplitter (which only corresponds to the left portion or a right portion of the collimator lens) to pass the illumination beam through the quarter wave plate back and forth for the double transformation, so as to provide light splitting and mixing functions via the polarizing beamsplitter for decreasing a number of optical components and manufacturing cost of the projection apparatus.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 to FIG. 4 are diagrams of an alignment module in several types according to different embodiments of the present invention.
FIG. 5 is a diagram of the wavelength transformation module according to the embodiment of the present invention.
FIG. 6 is a wavelength diagram of the polarizing beamsplitter cooperated with the wavelength transformation module according to the embodiment of the present invention.
FIG. 7 is a diagram of the wavelength transformation module according to another embodiment of the present invention.
FIG. 8 is a wavelength diagram of the polarizing beamsplitter cooperated with the wavelength transformation module according to another embodiment of the present invention.
FIG. 9 is a diagram of the wavelength transformation module according to another embodiment of the present invention.
FIG. 10 is a wavelength diagram of the polarizing beamsplitter cooperated with the wavelength transformation module according to another embodiment of the present invention.
DETAILED DESCRIPTION
Please refer to FIG. 1 to FIG. 4. FIG. 1 to FIG. 4 are diagrams of an alignment module 10 in several types according to different embodiments of the present invention. The alignment module 10 can include a light source module 12, a collimator lens 14, a wavelength transformation module 16, a polarizing beamsplitter 18, a quarter wave plate 20, a dichroic mirror 22 and an optical diffusor 23. The light source module 12 can emit a first illumination beam B1 with a first polarization state transmitted in a first direction D1 toward the polarizing beamsplitter 18. The first illumination beam B1 can be set in a first waveband (such as the blue light waveband). The collimator lens 14 can have a first part 24, a second part 26, and an axle Ax located between the first part 24 and the second part 26. The axle Ax can be a central axle of the collimator lens 14. The collimator lens 14 can be disposed between the polarizing beamsplitter 18 and the wavelength transformation module 16. The polarizing beamsplitter 18 can be disposed between the light source module 12 and the collimator lens 14, and further disposed on position corresponding to the first part 24 of the collimator lens 14.
The quarter wave plate 20 can be disposed on a rear optical path relative to the polarizing beamsplitter 18, which means the light beam is reflected by the polarizing beamsplitter 18 towards the quarter wave plate 20. The quarter wave plate 20 can be further optionally disposed on a front optical path or the rear optical path relative to the collimator lens 14. For example, the quarter wave plate 20 can be disposed between the collimator lens 14 and the dichroic mirror 22, and further disposed on position corresponding to the second part 26 of the collimator lens 14, as shown in FIG. 1; the light beam can pass through the collimator lens 14 and then be transmitted towards the quarter wave plate 20, so the quarter wave plate 20 can be interpreted as being disposed on the rear optical path relative to the collimator lens 14; moreover, the quarter wave plate 20 can be disposed between the collimator lens 14 and the polarizing beamsplitter 18, and further disposed on position corresponding to the first part 24 of the collimator lens 14, as shown in FIG. 2; the light beam can pass through the quarter wave plate 20 and then be transmitted towards the collimator lens 14, so the quarter wave plate 20 can be interpreted as being disposed on the front optical path relative to the collimator lens 14.
In addition, the quarter wave plate 20 can be disposed between the collimator lens 14 and the wavelength transformation module 16, and further disposed on position corresponding to the second part 26 of the collimator lens 14, as shown in FIG. 3; the light beam can pass through the first part 24 of the collimator lens 14, and then be reflected by the wavelength transformation module 16, and further pass through the quarter wave plate 20 and the second part 26 of the collimator lens 14 sequentially. Or, the quarter wave plate 20 can be disposed between the collimator lens 14 and the wavelength transformation module 16, and further disposed on position corresponding to the first part 24 of the collimator lens 14, as shown in FIG. 4; the light beam can pass through the first part 24 of the collimator lens 14, and then pass through the quarter wave plate 20 to arrive the wavelength transformation module 16, and can be further reflected by the wavelength transformation module 16 to pass through the second part 26 of the collimator lens 14.
Position of the quarter wave plate 20 is not limited to the embodiments shown in FIG. 1 to FIG. 4; it should be mentioned that the quarter wave plate 20 has to be disposed on the position corresponding to the first part 24 or the second part 26 of the collimator lens 14. Besides, the dichroic mirror 22 can be disposed on the position corresponding to the second part 26 of the collimator lens 14, and further disposed on the rear optical path relative to the quarter wave plate 20, which means the light beam can pass through the quarter wave plate 20 and then be transmitted towards the dichroic mirror 22. The dichroic mirror 22 can be used to reflect the first illumination beam B1 in the first waveband (such as the blue light waveband) and allow passing of the light beam in other waveband.
Please refer to FIG. 5 to FIG. 10. FIG. 5 is a diagram of the wavelength transformation module 16 according to the embodiment of the present invention. FIG. 6 is a wavelength diagram of the polarizing beamsplitter 18 cooperated with the wavelength transformation module 16 according to the embodiment of the present invention. FIG. 7 is a diagram of the wavelength transformation module 16′ according to another embodiment of the present invention. FIG. 8 is a wavelength diagram of the polarizing beamsplitter 18 cooperated with the wavelength transformation module 16′ according to another embodiment of the present invention. FIG. 9 is a diagram of the wavelength transformation module 16″ according to another embodiment of the present invention. FIG. 10 is a wavelength diagram of the polarizing beamsplitter 18 cooperated with the wavelength transformation module 16″ according to another embodiment of the present invention.
As shown in FIG. 5 and FIG. 6, the wavelength transformation module 16 can have a reflection region 28 and a first region 30 adjacent to each other. The reflection region 28 can be used to reflect the first illumination beam B1 incident from the first part 24 of the collimator lens 14 towards the second part 26 of the collimator lens 14. The first region 30 can include a first wavelength transformation layer 32 (such as yellow wavelength transformation material made of the yellow phosphor layer) used to receive the first illumination beam B1 and generate the actuation beam Ba in the second waveband (such as the yellow light waveband). The polarizing beamsplitter 18 that is cooperated with the wavelength transformation module 16 can provide penetration curves C11 and C12 that allow passing of the blue light and the yellow light, and the color wheel 25 can be further applied to decompose the yellow light into the green light and the red light, so that the three-color light effect of the blue light, the red light and the green light can be achieved by using one kind of phosphor powder.
As shown in FIG. 7 and FIG. 8, the wavelength transformation module 16′ can have the reflection region 28, the first region 30 and a second region 34 adjacent to each other. Functions of the reflection region 28 and the first region 30 are similar to ones of the foresaid embodiment shown in FIG. 5 and FIG. 6, and a detailed description is omitted herein for simplicity. The first wavelength transformation layer 32 of the first region 30 can be the yellow wavelength transformation material made of the yellow phosphor layer. The second region 34 can include a second wavelength transformation layer 36 (such as green wavelength transformation material made of the green phosphor layer). The first wavelength transformation layer 32 and the second wavelength transformation layer 36 can be used to receive the first illumination beam B1 and generate the actuation beam Ba in the second waveband (such as the yellow light waveband and the green light waveband). The polarizing beamsplitter 18 that is cooperated with the wavelength transformation module 16′ can provide penetration curves C21 and C22 that allow passing of the blue light, the green light and the yellow light, and the color wheel 25 can be further applied to decompose the yellow light into the red light, so that the three-color light effect of the blue light, the red light and the green light can be achieved accordingly.
As shown in FIG. 9 and FIG. 10, the wavelength transformation module 16″ can have the reflection region 28, the first region 30 and the second region 34 adjacent to each other. Functions of the reflection region 28 are similar to ones of the foresaid embodiment shown in FIG. 5 to FIG. 8, and the detailed description is omitted herein for simplicity. The first wavelength transformation layer 32 of the first region 30 can include the green wavelength transformation material used to generate the actuation beam Ba in the second waveband for providing the green light beam. The second region 34 can be divided into two sub-regions 341 and 342, and the sub-regions 341 and 342 respectively has the second wavelength transformation layer 36 with the red wavelength transformation material, and/or the second wavelength transformation layer 36 with the orange wavelength transformation material, so as to generate the actuation beam Ba in the second waveband for providing the red light beam or the orange light beam. The polarizing beamsplitter 18 that is cooperated with the wavelength transformation module 16″ can provide penetration curves C31, C32 and C33 that allow passing of the blue light, the green light and the red light (or the orange light), and the three-color light effect of the blue light, the red light and the green light can be achieved without the color wheel (which means the color wheel can be removed in the embodiments shown in FIG. 1 to FIG. 4), and further have advantages of economizing the component cost and the configuration space. Generally, the first illumination beam B1 can be set in the first waveband (such as the blue light waveband) for providing the blue light beam with the first polarization state (such as the S polarization state). The first illumination beam B1 can be transformed into the second illumination beam B2 with the second polarization state (such as the P polarization state) and still in the first waveband via double transformation of the quarter wave plate 20. The foresaid second waveband can be interpreted as other color light different from the first waveband (which means the blue light beam).
As the embodiments shown in FIG. 1 to FIG. 4, the first illumination beam B1 emitted from the light source module 12 can be reflected by the polarizing beamsplitter 18 and pass through the first part 24 of the collimator lens 14 to project onto the wavelength transformation module 16. The wavelength transformation module 16 can be a rotatable phosphor wheel or a static phosphor layer. When the first illumination beam B1 is projected onto the reflection region 28 of the wavelength transformation module 16, the first illumination beam B1 can be reflected by the reflection region 28 in the second direction D2; meanwhile, the second direction D2 can be preferably perpendicular to the first direction D1. The first illumination beam B1 reflected by the reflection region 28 can pass through the second part 26 of the collimator lens 14 to arrive the dichroic mirror 22. The first illumination beam B1 in the first waveband (such as the blue light waveband) can be reflected by the dichroic mirror 22 to pass through the second part 26 of the collimator lens 14, and further be reflected by the reflection region 28 of the wavelength transformation module 16 to pass through the first part 24 of the collimator lens 14.
The quarter wave plate 20 can be optionally disposed on the front optical path or the rear optical path relative to collimator lens 14, or disposed between the collimator lens 14 and the wavelength transformation module 16, so that the first illumination beam B1 can be transformed into the second illumination beam B2 with the second polarization state transmitted in the second direction D2 via the double transformation of the quarter wave plate 20 before arriving the polarizing beamsplitter 18; the second illumination beam B2 can be still in the first waveband. The polarizing beamsplitter 18 can allow passing of other color light and the blue light beam with the second polarization state, and therefore the second illumination beam B2 can pass through the polarizing beamsplitter 18 and be received by the optical diffusor 23. The optical diffusor 23 can be disposed on position corresponding to the wavelength transformation module 16. The optical diffusor 23 can be a light pipe, a light guide or a lens array used to homogenize energy of the received light beam (such as the second illumination beam B2). The color wheel 25 can be disposed in front of the optical diffusor 23, and used to decompose the light beam in the specific waveband (such as the yellow light) into the light beam in other wavebands (such as the green light and the red light); position and a waveband transformation function of the color wheel 25 are not limited to the foresaid embodiment.
If the first illumination beam B1 is projected onto the actuation region (which may be the first region 30 or the second region 34) of the wavelength transformation module 16, 16′ or 16″, the first illumination beam B1 can be transformed into the actuation beam Ba via the wavelength transformation module 16, and the actuation beam Ba can be transmitted towards the first part 24 and the second part 26 of the collimator lens 14 in the second direction D2 (or in a direction slightly tilted relative to the second direction D2). The actuation beam Ba can pass through the polarizing beamsplitter 18 and the dichroic mirror 22, and further optionally pass through the color wheel 25 (which depends on features of the second wavelength transformation layer 36 for determining whether to filter the actuation beam Ba by the color wheel 25), and then be received by the optical diffusor 23. Therefore, the alignment module 10 can alternately reflect the first illumination beam B1 and generate the actuation beam Ba in accordance with rotation of the wavelength transformation module 16; the optical diffusor 23 can accordingly receive and homogenize the second illumination beam B2 passing through the polarizing beamsplitter 18 from the first part 24 of the collimator lens 14, and the actuation beam Ba passing through the polarizing beamsplitter 18 and the dichroic mirror 22 from the first part 24 and the second part 26 of the collimator lens 14.
In conclusion, the alignment module of the present invention can utilize feature of the illumination beam with a specific polarization state passing through the quarter wave plate twice to transform into the illumination beam with another polarization state, and feature of the quarter wave plate that allows passing of the actuation beam with the small-sized polarizing beamsplitter (which only corresponds to the left portion or a right portion of the collimator lens) to pass the illumination beam through the quarter wave plate back and forth for the double transformation, so as to provide light splitting and mixing functions via the polarizing beamsplitter for decreasing a number of optical components and manufacturing cost of the projection apparatus.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Patent Application
20240384857
