TW200426489A - Light guiding apparatus for an illumination system - Google Patents

Abstract

A light guiding apparatus for an illumination system is provided. The light guiding apparatus includes at least a light tunnel and an ellipsoidal reflector. The exit of the light tunnel is place on one focal point of the ellipsoidal reflector. The light tunnel and the long axis of the ellipsoidal reflector form an angle. The angel and the eccentricity of the ellipsoidal reflector are used to modify light emitted from the light tunnel. Thus makes the light fit the entrance angle and effective area of a digital micro-mirror device when the light reaches the digital micro-mirror device.

Description

200426489 V. Description of the invention (1) " ~ --- [Technical field to which the invention belongs] The present invention relates to a device for a projector, and particularly to a light guide device for an illumination system. ^ [Previous technology] Since the invention of the projector, with the development of science and technology, it has been used in various fields, from consumer products to high-tech products, and its application range has been expanding. For example, it is used in large-scale conference lectures to enlarge the projection by the projection system. Object: Or it can be used in commercial projection screens or televisions to match the presentation of the presentation to the real-time graphical day and time presentation. FIG. 1 is a schematic diagram of a lighting system and a light guide device in a conventional projector. Referring to Figure 1, the current architecture uses the ellipsoidal optical reflection characteristics. The light from the light source 102 is collected and reflected by the ellipsoidal reflector i 04, and then passes through the color wheel 106 'to enter the light channel (Hght tunnel). ) 108. Since the exit end of the optical channel 108 is square, after a plurality of reflections of the light in the optical channel 108 within the light channel, a square light is emitted uniformly. Then, the square light passes through a lens group consisting of several lenses, the belay lens M10 and the optical path turning device 112, to project the light onto a digital micro-mirror device (DMD) chip 114. In this example, the optical path turning device 112 is a total internal reflection prism (TIR prism). The image signal generated on the chip 11 4 is turned by the optical path turning device ii 2 and then passes through the projection lens ( projection lens) 116 is projected onto the screen 118. The lens group 110 in FIG. 1 is a light guiding device, and serves as light from the light channel 108.

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V. Description of the invention (2) Transfer device between DMD chip 114 The conventional light guide device is a lens group 1 10 composed of a plurality of lenses, which is used to adjust the square-step light emitted from the optical channel 108 to meet the angle and area dimensions required by the DMD chip 1 1 4. The lens group 110 is usually composed of lenses with more than three sides. However, the lens itself has a problem of aberration, which will twist & bend or blur the edges of the square light after passing, resulting in uneven light spots. In addition, because the light of the light source 102 is composed of light of different wavelengths, the problem of chromatic aberration occurs when the light of different wavelengths passes through the lens. Although the problems of aberration and chromatic aberration can be reduced through optical design, and the image quality is improved to a certain degree, the design of multiple lenses is more complicated and the cost is higher. In addition, if more lenses for compensating aberration or chromatic aberration are added to the lens group 110, the loss of light intensity will inevitably be caused, and these losses will reduce the performance of the projector. [Summary of the Invention] Therefore, the object of the present invention is to provide a light guide device of a lighting system, which is used to solve the problem of aberration ^ of a light guide device of a lighting system in a conventional projector. /, Bazuo

According to the above object of the present invention, a light guide device of a lighting system is proposed. Place the exit of the light channel at a focal point of the ellipsoidal reflector, and an angle will be formed between the 2 channels of light itself and the long axis of the ellipsoidal reflector. By using this angle and the eccentricity of the spherical reflector, the square light X-rays' emitted from the optical channel can be adjusted so that when the light reaches the DMD chip, it can meet the required I angle and active area of the DMD chip.

200426489 V. Description of the invention (3) According to a preferred embodiment of the present invention, the ellipsoidal reflector is a part of an ellipsoidal shell. Its area must be greater than the area of the divergent angle of the light projected onto the ellipsoidal reflector, so that the light Can be completely reflected. In addition, an optical compensation element is added between the ellipsoidal reflector and the optical path of the DMD wafer. This optical compensation element includes a wedge-shaped chirp and a compensation lens to compensate for the asymmetrical aberration caused by the ellipsoidal reflector.

According to another preferred embodiment of the present invention, two pieces of ellipsoidal reflector are used to guide the light. By adjusting the relative angle and eccentricity of the ellipsoidal reflector, the asymmetrical aberration is reduced to a uniform light. The purpose of the point. Moreover, since this embodiment uses an ellipsoidal reflector to reflect light, there is no problem of chromatic aberration. The present invention uses an ellipsoidal reflector to replace the conventional lens group, which can avoid problems such as chromatic aberration caused by the conventional lens group. Adding an optical compensation element that has little effect on chromatic aberration can solve the problem of aberration together. Furthermore, if a combination of the two ellipsoidal reflectors is used, a light spot distribution with no chromatic aberration and minimal aberration can be obtained.

The invention uses the principle of reflection to guide light, which can greatly increase the light intensity and improve the efficiency of the light guide device. In addition, the light guide device of the present invention is simpler in design than a conventional lens group with a plurality of lens combinations, and has fewer components, which not only facilitates maintenance, but also reduces production costs. [Embodiment] Therefore, an object of the present invention is to provide a light guide device of a lighting system, which is used to improve aberration and chromatic aberration of a light guide device of a lighting system in a conventional projector.

Page 8 200426489 V. Explanation of the Invention (4) Problem. The present invention uses an ellipsoidal reflector to replace the conventional lens group 1 1 0. Place the exit of the light channel on a focal point of the ellipsoidal reflector, and an angle will be formed between the light channel itself and the long axis of the ellipsoidal reflector. By using this angle and the eccentricity of the ellipsoidal reflector, the square light emitted from the optical channel can be adjusted, so that when the light reaches the DMD wafer, it can meet the required angle of entry and area of the DMD wafer.

Please refer to FIG. 2 ', which illustrates a schematic diagram according to a preferred embodiment of the present invention. The exit end of the optical channel 108 is located at the first focal point 2 2 2 of the ellipsoidal reflector 21 0, and the optical channel 108 and the major axis 2 1 2 of the ellipsoidal reflector 21 0 form an included angle 214. Utilizing the optical reflection characteristics of the ellipsoidal surface, the ellipsoidal reflective cover 21o will collect and reflect the light emitted from the light channel 108 located at the first focal point 22 2 to the receiving end of the other focal point of the eaves spherical reflective cover 210. However, the light must pass through the light path turning device before reaching another focal point. This light path turning = device 11 2 will slightly change the light path. Therefore, the dmd said film 11 4 which is responsible for receiving the light is not connected with the ellipsoidal reflector. Another focus overlaps.

= The divergence angle 21 6 at the exit end of the light channel 10 8 and the opening area are fixed. This embodiment uses the eccentricity of the cool angle 2 1 4 and the spherical reflector 2 1 0 to 2 the light emitted by the light channel 108 So that it conforms to the required housing, angle and active area of the DMD chip 114. The ellipsoidal reflector 2 1 0 is a part of an ellipsoidal reflector. The area must be larger than that when the light is projected onto the ellipsoid from the divergence angle 2 丨 6. The > area on 彳 4 2 allows the light to be completely reflected. Here, it is preferred that the # ΐ 路 turning device of i = 112 is a total reflection prism, but its turning device can also be applied to the present invention and is not subject to this implementation.

200426489 V. Description of invention (5).

The present invention uses an ellipsoidal reflector 2 1 0 to replace the conventional lens group 1 10 (as shown in FIG. 1). Since the light is directly reflected by the ellipsoidal reflector 2 丨 〇, different wavelengths can be avoided. The problem of chromatic aberration caused by light passing through the lens medium and reducing the loss of light intensity after passing through multiple lenses. However, since the light of the optical channel 108 is imaged off-axis to the ellipsoidal reflector 210, and is not incident through the symmetry axis of the ellipsoidal reflector 210, the light projected on the DMD wafer 1 1 4 Points will have asymmetrical aberrations. At this time, an optical compensation element may be added between the optical paths of the ellipsoidal reflector 2 10 and the DMD wafer 114 to make the light spots uniform. Please refer to FIG. 3A, which illustrates a schematic diagram according to a preferred embodiment of the present invention. In this preferred embodiment, a wedge prism 302 is added to FIG. 2 to compensate for the asymmetrical aberration caused by the ellipsoidal reflector 210. The light is emitted from the light path 108, and is reflected by the ellipsoidal reflector 2 10, and then reaches the wedge 稜鏡 302. The light travels at different speeds in different media. The thickness of the wedge prism 302 is used to compensate for the path, and the path length of the light in different regions of the wedge 302 is adjusted. In this way, it is possible to reduce the asymmetric aberration of the light spot projected on the DMD wafer 114.

Please refer to FIG. 3B, which illustrates a schematic diagram according to another preferred embodiment of the present invention. This preferred embodiment is similar to FIG. 3A, except that a compensation lens 304 is added to FIG. 2. The asymmetry of the two axial directions of the compensation lens 304 is used to compensate, and the light is adjusted in the compensation lens. The path taken in 3 0 4 is long to eliminate the error caused by the ellipsoidal reflection force 2 1 0

Page 10 200426489 V. Explanation of the invention (6) The two preferred embodiments described above use an optical compensation element, such as a wedge 302 or a compensation lens 304, between the optical path of the optical channel 108 and the light path of the DMD chip 114, and use light in the medium of the optical compensation element. The length of the path taken is different to compensate for the asymmetric aberration caused by the ellipsoidal reflector 2 10. Although the addition of optical compensation elements will still cause the problem of chromatic aberration, the thickness of the single-chip optical compensation element used here is very thin (wedge 稜鏡 302) and its curvature is small (compensating lens 3 0 4 ), So the effect on chromatic aberration is much smaller than the conventional multiple lens combination 1 1 0.

Please refer to FIG. 4, which illustrates a schematic diagram according to another preferred embodiment of the present invention. This preferred embodiment uses two ellipsoidal reflectors to guide light, and by adjusting the relative angle and eccentricity of the ellipsoidal reflector, the asymmetric aberration is reduced 'to achieve the purpose of uniform light spot. Moreover, since this embodiment uses an ellipsoidal reflector to reflect light, there is no problem of chromatic aberration at all. ,

As shown in FIG. 4, the exit end of the light channel [〇8 is located at the first focus 422 of the first ellipsoidal reflector 2 10, the second point 424 of the first ellipsoidal reflector 210, and the second ellipsoidal reflector The first focus of 402 overlaps. The light is emitted by the ^ channel 108, collected by the first ellipsoidal reflector 210 and reflected to the second focus 424, and then passed through the second focus 424 and then reflected by the second ellipsoidal reflector 4 To the receiving end at the other focus of the second ellipsoidal reflector 402. As in the embodiment of FIG. 2, there is an optical path turning device 11 2 at this receiving end. This optical path turning device Π 2 slightly changes the path of light, so it is responsible for The DMD chip Π4 that receives light does not have another focus with the second ellipsoidal reflector 40

Page 11 200426489 V. Description of Invention (7) Overlap. The light channel 108 and the first major axis 41 2 of the first ellipsoidal reflector 210 will form a first included angle 404, and the first major axis 41 2 and the main light path 41 6 form a second included angle 40 6 at the second focus 42 4 The first major axis 412 and the second major axis 414 of the second ellipsoidal reflector 40 2 form a third included angle 408. This embodiment uses the first included angle 404, the second included angle 406, the third included angle 408, and the eccentricity of the first ellipsoidal reflector 210 and the eccentricity of the second ellipsoidal reflector 40 2 to adjust the light emitted by the light channel 108. So that it conforms to the required entry angle and active area of the DMD chip 114.

The first and second ellipsoidal reflectors 2 1 0 and 40 2 are partial ellipsoidal shells, and their areas must be larger than the area of light projected onto the ellipsoidal reflector, so that the light can be completely covered by the ellipsoidal reflector. By reflection. In a more preferred embodiment, the angle of the third included angle 408 is equal to the sum of the angles of the first included angle 404 and the second included angle 406. Under this condition, the aberration of the light spot received by the DMD chip 114 is the smallest. It can be known from the foregoing preferred embodiments of the present invention that the application of the present invention has the following advantages:

1. The present invention uses an ellipsoidal reflector to replace the conventional lens group, which can avoid problems such as chromatic aberration caused by the known lens group. Adding an optical compensation element that has little effect on chromatic aberration can solve the problem of aberration together. Furthermore, if the combination of the two ellipsoidal reflectors in the above embodiment is used, a light spot distribution with no chromatic aberration and minimal aberration can be obtained. 2. Using the loss of light intensity The light of the conventional lens group must pass through the lens, which will inevitably cause damage and produce aberrations and chromatic aberrations. The present invention uses the principle of reflection

Page 12 200426489 V. Description of the invention (8) Light guide can be used to improve the light intensity and the efficiency of the light guide device. 3. The light guide device of the present invention is simpler in design than a conventional lens group with a plurality of lens combinations, and has fewer components, which not only facilitates maintenance, but also reduces production costs. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various changes and decorations without departing from the spirit and scope of the present invention. The scope of protection of the invention shall be determined by the scope of the attached patent application.

Page 13 200426489 Brief description of the drawings [Simplified description of the drawings] In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below in conjunction with the accompanying drawings. The detailed description is as follows: FIG. 1 is a schematic diagram of a lighting system and a light guide device in a conventional projector. FIG. 2 is a schematic diagram according to a preferred embodiment of the present invention. FIG. 3A is a schematic diagram according to another preferred embodiment of the present invention. FIG. 3B is a schematic diagram according to another preferred embodiment of the present invention. FIG. 4 is a schematic diagram according to still another preferred embodiment of the present invention. [A brief description of the symbol of the component] 1 0 2: Light source 104: Ellipsoidal reflector 1 0 6: Color wheel 1 08: Light channel 11 0: Lens group 11 2: Optical path turning device 114: DMD chip 11 6: Projection lens 11 8: Screen 2 1 0: Ellipsoidal reflector 2 1 2: Long axis 214: Angle

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Claims (1)

200426489 VI. Application Patent Scope 1 · A light guide device of a lighting system, the light guide device of the lighting system at least includes: a first ellipsoidal reflector, the first ellipsoidal reflector is a part of an ellipsoidal shell; Ellipsoid-light channel, in which the light emitted by the light channel is reflected by the first radiation cover and focused to a]) MD chip, and the light channel forms a first with the long axis of the first-elevation = reflection cover The included angle is adjusted by the first included angle and the eccentricity of the second expanded spherical reflector to adjust the light emitted by the light channel to meet the required entry angle and active area of the DMD; and ΰ f two pieces, Installed in the light path between the first ellipsoidal reflector and the DMD wafer. 2 · The device described in item 丨 of the scope of patent application further includes a light path turning device, # the first device, in which the light guide i bamboo outer cover is placed on the light path, and the ellipsoidal reflection cover of the light path is extruded and the _ wafer turning device : Mounted on the first-the image generated by the DMD chip. In the 9-line circuit, it is used for turning 3. The folding device described in item 2 of the patent application scope includes at least a total reflection chirp. In particular, the light path is changed. 4. As in the light guide device described in item 丨 of the patent application scope, the compensation element includes at least one shape changer. / 、 The optical supplement 5. The light guide device as described in item 1 of the patent application scope, wherein the optical supplement 200426489 6. Scope of patent application The compensation element includes at least one compensation lens. Wherein, the optical supplementary reflector is a third angle between the third focal point and the second ellipsoidal reflector, and the long axis angle of the reflector and the third sandwich two ellipsoidal reflector are combined with the DMD wafer. The light guide device according to item 1, the compensation element is a second ellipsoidal reflector, the second ellipsoidal part of the ellipsoidal shell, one of the second ellipsoidal reflector The two focal points overlap, the first major axis and the path of the light form a first ellipsoidal reflector at the third focal point and the second ellipsoidal surface forms a third included angle. With the first included angle, The second included angle, the eccentricity of the first ellipsoidal reflector, and the eccentricity of the first cover adjust the light emitted by the light channel to meet the required entry angle and active area. 7. The light guiding device according to item 6 of the scope of patent application, wherein the third included angle is equal to the sum of the first included angle and the second included angle. 8. A light guide device of a lighting system, the light guide device of the lighting system at least includes: a first ellipsoidal reflector, the first ellipsoidal reflector is a part of an ellipsoidal shell; a light channel, the The light channel forms a first angle with the long axis of the first ellipsoidal reflector; and a second ellipsoidal reflector, the second ellipsoidal reflector is a part of an ellipsoidal shell, and the second ellipsoidal surface A second focus of the reflector and the first ellipsoid Page 17 200426489 VI. One of the patented Fanyuan reflectors has a first focal point overlap, where the light emitted by the optical channel is sequentially reflected by the first spherical reflector and the first spherical reflector and focused to A DMD wafer, and the long axis of the first ellipsoidal reflector and the path of the light form a second angle at a third focal point of the second ellipsoidal reflector, and the long axis of the first ellipsoidal reflector and The long axis of the second ellipsoidal reflector forms a third included angle. The first included angle, the second included angle, the third included angle, the eccentricity of the first ellipsoidal reflector, and the second ellipsoidal reflection. The eccentricity of the cover adjusts the light emitted by the light channel to meet the required entry angle and active area of the DMD chip. 9. The light guiding device according to item 8 in the scope of the patent application, wherein the light guiding device further includes a light path turning device, and the light path turning device is installed / mounted on the light beam between the 'ellipsoidal reflector and the DMD chip. It defeats the image produced by the mA chip. In the forward path, it is used to turn the optical path. 11. The angle included in item 8 of the scope of patent application is equal to the sum of the first included angle and the 光 light guide device, and the third included angle.