Patent Application
20090059585
This application claims the priority benefit of Taiwan application serial no. 96132000, filed on Aug. 29, 2007. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
1. Field of the Invention
The present invention relates to an illumination system. More particularly, the present invention relates to a scanning illumination system.
2. Description of Related Art
Referring to
To achieve a full color display effect of the projection apparatus 100, the red light source 112r, the green light source 112g and the blue light source 112b are turned on and then turned off in sequence. In other words, at any time point, only one light source with one color is turned on, and the light sources with the other colors are turned off. By mixing colors in a time-sequential manner, a full color display effect is then achieved. However, since each of the light sources with one color is turned on for only one third of time, the utilization efficiency of the light source of the projection apparatus 100 is poor. Accordingly, brightness of the image frames projected by the projection apparatus 100 is not high.
The present invention is directed to an illumination system having a relatively high utilization efficiency of light sources.
An embodiment of the present invention provides an illumination system capable of providing at least one light beam to a light valve. The illumination system includes at least one light source, a linearization beam shaper and an optical scanning device. The light source is capable of providing the light beam. The linearization beam shaper is disposed on a transmission path of the light beam and between the light source and the light valve to expand the light beam along a first direction. The optical scanning device is disposed on the transmission path of the light beam and between the linearization beam shaper and the light valve. The optical scanning device is capable of moving for making the light beam scan the light valve unidirectionally along a second direction or back and forth along the second direction.
In the illumination system, since a light spot formed by the light beam incident on the linearization beam shaper is changed from a circular light spot to a linear uniform light spot, and since the light beam scans the light valve with the linear light spot by the optical scanning device, the light source may be in the on state continuously, which is different from a conventional technique which requires the light sources being constantly turned on and then turned off. Therefore, the illumination system has a relative high utilization efficiency of light sources.
Other objectives, features and advantages of the present invention will be further understood from the further technological features disclosed by the embodiments of the present invention wherein there are shown and described preferred embodiments of this invention, simply by way of illustration of modes best suited to carry out the invention.
In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” etc., is used with reference to the orientation of the Figure(s) being described. The components of the present invention can be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. On the other hand, the drawings are only schematic and the sizes of components may be exaggerated for clarity. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. Similarly, the terms “facing,” “faces” and variations thereof herein are used broadly and encompass direct and indirect facing, and “adjacent to” and variations thereof herein are used broadly and encompass directly and indirectly “adjacent to”. Therefore, the description of “A” component facing “B” component herein may contain the situations that “A” component facing “B” component directly or one or more additional components is between “A” component and “B” component. Also, the description of “A” component “adjacent to” “B” component herein may contain the situations that “A” component is directly “adjacent to” “B” component or one or more additional components is between “A” component and “B” component. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
Referring to
The linearization beam shaper 220 is disposed on transmission paths of the light beams 212 and between the light sources 210 and the light valve 50 to expand the light beams 212 along a first direction D1, in which the third direction D3 is perpendicular to the first direction D1. The optical scanning device 230 is disposed on the transmission paths of the light beams 212 and between the linearization beam shaper 220 and the light valve 50. In the present embodiment, the linearization beam shaper 220 includes a lenticular lens 222. The lenticular lens 222 has a curve surface 222a facing to the optical scanning device 230. A cutaway section line of the curve surface 222a along the first direction D1 is a curve line, and the cutaway section line of the curve surface 222a along the third direction D3 perpendicular to the first direction D1 is a straight line. In other words, the curve surface 222a is only curved in one direction, and therefore the light beams 212 may be expanded along the first direction D1, namely, a cross-section view of the light beams 212 are straight lines. Moreover, in the present embodiment, the lenticular lens 222 further has a plane surface 222b facing to the light sources 210. In other embodiments, the curve surface may face to the light sources 210, or the lenticular lens 222 may have two curve surfaces respectively facing to the light sources 210 and the optical scanning device 230.
In the present embodiment, the optical scanning device 230 includes a polyhedron 232 and a reflection film 234. The polyhedron 232 is, for example, prismatical and has a bottom surface 232a, a top surface 232b and a plurality of side surfaces 232c connecting the bottom surface 232a with the top surface 232b. The reflection film 234 is disposed on the side surfaces 232c of the polyhedron 232 for reflecting the light beams 212 from the linearization beam shaper 220 to the light valve 50. Since the light-emitting groups G1, G2 and G3 are arranged along the third direction D3, and since, after passing through the linearization beam shaper 220, the cross-sectional view of the light beams 212 and the illumination beams 212′ are straight lines, the illumination beams 212′ form three paratactic linear light spots S1, S2 and S3 on the reflection film 234 respectively corresponding to the light-emitting groups G1, G2 and G3. Moreover, after being reflected by the reflection film 234, the illumination beams 212′ form three paratactic linear light spots S1′, S2′ and S3′ on the light valve respectively corresponding to the linear light spots S1, S2 and S3. In other embodiments, the light sources of each of the light-emitting groups may also be arranged along a straight line, for example, the first direction D1, so as to narrow the linear light spots formed on the reflection film to obtain a better image quality.
The optical scanning device 230 is capable of moving for making the light beams 212 and the illumination beams 212′ scan the light valve 50 unidirectionally along a second direction D2. In the present embodiment, the polyhedron 232 has an axis A extending from the bottom surface 232a to the top surface 232b, and the polyhedron 232 is capable of rotating about the axis A, such that the light beam 212 scans the light valve unidirectionally along the second direction D2. In other words, the linear light spots S1′, S2′ and S3′ scan the light valve 50 along the second direction D2 due to rotation of the polyhedron 232. In the present embodiment, the illumination beams 212′ emitted from the light-emitting groups G1, G2 and G3 are, for example, a red light, a green light and a blue light, and therefore the linear light spots S1′, S2′ and S3′ scanning on the light valve 50 are a red light spot, a green light spot and a blue light spot. Thus, based on a visual persistence effect of human eyes, the light valve 50 provides a full color image. In the present embodiment, the illumination system 200 further includes an actuator 240 connected with the optical scanning device 230 for driving the optical scanning device 230 to move around. In particular, the actuator 240 is, for example, a motor for driving the optical scanning device 230 to rotate.
To achieve a better effect for converging the light beams 212 on the reflection film 234, at least one lens 250 is disposed on the transmission paths of the light beams 212 and between the linearization beam shaper 220 and the optical scanning device 230. Moreover, to achieve a better quality of imaging formed by the light beams 212 on the light valve 50, at least one lens 260 is disposed on the transmission paths of the light beams 212 and between the optical scanning device 230 and the light valve 50.
In the illumination system 200 according to the present embodiment, since the light spots formed by the light beams 212 incident on the linearization beam shaper 220 are changed from circular light spots to linear uniform light spots, and since the light beams 212 scan the light valve 50 with the linear light spots S1′, S2′ and S3′ by the optical scanning device 230, the light sources 210 may be in an on state continuously, which is different from a conventional technique which requires the light sources being constantly turned on and then turned off. Therefore, the illumination system 200 has a relative high utilization efficiency of the light sources 210, such that extra energy consumption is saved, and brightness of the image frames projected by the projection apparatus is improved. Moreover, the price of the lenticular lens 222 is relatively low, and therefore the illumination system 200 not only improves its utilization efficiency of the light sources 210 but also has a low cost.
It should be noted that the quantity of the light sources for the illumination system is not limited by the present invention. In other embodiments, the illumination system may have only one light source, or the illumination system may have a plurality of light sources divided into a plurality of light-emitting groups, each of which has only one light source.
Referring to
Referring to
Referring to
It should be noted that, in other embodiments, the aforementioned lenticular lens plate 224 (referring to
Referring to
In summary, in the illumination system, since the light spot formed by the light beam incident on the linearization beam shaper is changed from a circular light spot to a linear uniform light spot, and since the light beam scans the light valve with the linear light spot by the optical scanning device, the light source may be in an on state continuously, which is different from a conventional technique which requires the light sources being constantly turned on and then turned off. Therefore, the illumination system of the embodiments of the present invention has a relative high utilization efficiency of the light source. Accordingly, extra energy consumption is reduced, and brightness of the image frames projected by the projection apparatus using the aforementioned illumination system is improved. Moreover, low cost accessories such as the lenticular lens, the lenticular plate and the light integration rod may be adopted, and therefore the illumination system of the embodiments of the present invention not only improves its utilization efficiency of the light sources but also has a low cost.
The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Accordingly, the foregoing description should be regarded as illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments are chosen and described in order to best explain the principles of the invention and its best mode practical application, thereby to enable persons skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Therefore, the term “the invention”, “the present invention” or the like is not necessary limited the claim scope to a specific embodiment, and the reference to particularly preferred exemplary embodiments of the invention does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is limited only by the spirit and scope of the appended claims. The abstract of the disclosure is provided to comply with the rules requiring an abstract, which will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Any advantages and benefits described may not apply to all embodiments of the invention. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the present invention as defined by the following claims. Moreover, no element and component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 96132000 | Aug 2007 | TW | national |
