TWI231402B - 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 angle 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

1231402 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a device for a projector, and more 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. Its application range has been expanding, such as in large-scale conference speeches to enlarge the projection object with a projection system. Or it can be applied to commercial projection screens or televisions to match the contents of the presentation to real-time graphical day-to-day presentation. FIG. 1 is a schematic diagram of a lighting system and a light guide device in a conventional projector. Please refer 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 reflection cover 104, and then passes through the color wheel 106 and enters the light channel ( light tunnel). 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 relay lens 110 composed of several lenses and an optical path turning device Π2 to project the light onto a digital microiirror device (DMD) chip 114. In this example, the optical path turning device 112 is a total reflection prism (TIR prism). The image signal generated on the DMD chip 11 4 will be turned by the optical path turning device 112 and then passed through the projection lens. (Projection lens) ll 6 is projected on the screen 11 8. The lens group 110 in FIG. 1 is a light guiding device, and serves as light from the light channel 108.

1231402 V. Description of the invention (2) Transfer device between D M D wafer 1 1 4 The conventional light guide device is a lens group 110 composed of multiple lenses and mirrors, which is used to adjust the square-band transmission from the light channel 108 to meet the required angle and area dimensions of the DMD chip 114. ^ ^ Mirror group 110 is usually made up of lenses with more than three sides. However, the lens itself has a problem of aberration, which will distort or blur the edges of the square light passing through it, causing uneven light spots. In addition, because the light of the light source 102 is composed of light of different wavelengths, these different wavelengths of light may cause chromatic aberration when passing through the lens. Although the problems of aberration and chromatic aberration can be reduced through optical design, and the imaging quality is improved to a certain extent, the design of multiple lenses is more complicated and the cost is higher. Moreover, if it is in the lens group 11 〇 Adding more lenses that compensate for aberrations or chromatic aberrations will inevitably cause loss of light intensity, 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 for an illumination system. To solve the problems of aberration and chromatic aberration of the light guide device of the lighting system in the conventional projector.

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 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.

1231402 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, and 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 spherical reflectors are used to guide light. By adjusting the relative angle and eccentricity of the ellipsoidal reflector, the asymmetrical aberration is reduced to achieve uniform light. The purpose of the point. And because of this

The embodiment uses an ellipsoidal reflector to reflect light, so 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 above two spherical spherical reflectors is used, a light spot distribution with no chromatic aberration and minimum aberration can be obtained.

The light 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.

1231402 V. Description of Invention (4) Question. The present invention uses an ellipsoidal reflector to replace the conventional lens group 110 °, and places the exit of the light channel on a focal point of the ellipsoidal reflector, and the light channel itself and the long axis of the ellipsoidal reflector cover Form an angle. 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 light channel 108 is located at the first focal point 2 2 2 of the ellipsoidal reflection cover 210, and the light channel 108 is reflected by the ellipsoidal surface. The major axis 2 1 2 of the cover 2 10 forms an included angle 214. Utilizing the optical reflection characteristics of the ellipsoidal surface, the ellipsoidal reflection cover 210 will collect and reflect the light emitted from the light channel 1 08 located at the first focus 2 2 2 to the receiving end of the other focus of the ellipsoidal reflection cover 2 10. However, the light must pass through the light path turning device 11 2 before reaching another focal point. This light path turning device 11 2 will slightly change the light path, so the dmd chip 11 4 responsible for receiving the light is not the same as the other of the ellipsoidal reflector. The focus overlaps.

The divergence angle 216 and the opening area of the exit end of the optical channel 108 are fixed numbers. In this embodiment, the eccentricity of the included angle 2 丨 4 and the ellipsoidal reflector 2 丨 〇 is used to ^ light the light emitted from the optical channel 108 to make it Meet the shell required for DMD chip 114, 1 degree and active area. The ellipsoidal reflector 2 1 0 is a part of the ellipsoidal reflector 2. The area of Γη must be larger than that of the light projected from the divergence angle 2 1 6 to the spherical surface. In the embodiment, the "area" allows the light to be completely reflected. Here, it is preferable that the other type of #optical path turning device is 11 2 which is a total reflection chirp. However, its "road turning device can also be applied to the present invention and is not subject to this implementation.

1231402 V. Description of invention (5).

The present invention uses an ellipsoidal reflector 2 1 0 to replace the conventional lens group 11 0 (as shown in FIG. 1). Since the light is directly reflected by the ellipsoidal reflector 2 1 0, light of different wavelengths can be avoided. The problem of chromatic aberration when passing through the lens medium and reducing the loss of light intensity after passing through multiple lenses. However, since the light rays of the light channel 108 are imaged off-axis (of f-ax is) to the ellipsoidal reflector 210, and are not incident through the symmetry axis of the ellipsoidal reflector 210, the light spot projected on the DMD wafer 114 There will be asymmetrically distributed aberrations. At this time, an optical compensation element can be added between the ellipsoidal reflector 210 and the optical path of the DMD wafer 114 to make the light spot 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 reflecting cover 210, and then reaches the wedge 稜鏡 302. The light travels at different speeds in different media. The thickness of the wedge 稜鏡 302 is used to compensate for the path, and the path length of the light in different regions of the wedge 稜鏡 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 and the asymmetry of the two axial directions of the compensation lens 304 is used for compensation. The light is adjusted in the compensation lens 3 The path taken in 0 4 is long to eliminate the error caused by the ellipsoidal reflector 21

Page 10 1231402 V. Description of the invention (6) The aberrations are called scale. The two preferred embodiments described above use an optical compensation element, such as a wedge 稜鏡 3 0 2 or a compensation lens 3 0 4, between the optical path of the optical channel 108 and the light path of the DMD chip 114, and use the light in the medium of the optical compensation element. The length of the path taken in the process is different to compensate for the asymmetrical aberration caused by the ellipsoidal reflector 2 10. Although the addition of optical compensation elements will still cause chromatic aberration, the thickness of the monolithic optical compensation element used here is very thin (wedge 稜鏡 300) and its curvature is small (compensating lens 304). The effect is much smaller than the conventional multi-lens combination lens group 1 1 0. Referring to Fig. 4 in May, a schematic diagram of a margin which does not follow 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 asymmetrical 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 ι〇8 is located at the first focus 422 of the first ellipsoidal reflector 210, the second focus 424 of the first ellipsoidal reflector 21, and the second ellipsoidal reflector 402 The first focus overlaps. The light is emitted by the light channel 108. 'First collected by the first ellipsoidal reflector 210 and reflected to the second focus 4 2 4' After passing through the second focus 4 2 4 and then received by the second ellipsoidal reflector 4 〇2 = and reflected To the receiving end of the other focus of the second ellipsoidal reflector 402. As in the embodiment of FIG. 2, there is a light path turning point 11 2 at the receiving end. The light path turning device 2 will slightly change the light path. Therefore, the D M of the receiving friend is not connected with the second ellipse. Another focus of the spherical reflector 40 2 1231402 V. Description of the invention (7) Overlapping. The light channel 108 and the first major axis 412 of the first ellipsoidal reflector 210 will form a first included angle 404. The first major axis 412 and the main light path 41 6 form a second included angle 406 at the second focal point 424. A long axis 41 2 forms a third included angle 408 with the second long axis 41 4 of the second ellipsoidal reflector 40 2. 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 2 10 and the eccentricity of the second ellipsoidal reflector 4 002 to adjust the light channel 108. The emitted light conforms to the required entry angle and active area of the DMD chip 114. The first and second ellipsoidal reflectors 21 and 402 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 reflected by the ellipsoidal reflector. 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 40 and the second included angle 406. Under this condition, the aberration of the light spot received by the DMD chip 114 is the smallest. As can be seen from the above-mentioned preferred embodiments of the present invention, 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 eliminate 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 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. In the conventional method of using the lens group, the light must pass through the lens, which will inevitably lose light intensity 'and produce aberrations and chromatic aberrations. The present invention uses the principle of reflection

Page 12 1231402 V. Description of the invention (8) The principle of light guide can greatly increase the light intensity and improve 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.

On page 13, the point-type excellent picture and attached, the special combination, and the combination, the purpose of his practice I and Jia 2 is more clear than the previous statement. As shown in Fig. T, it is easy to say, clear and detailed, and it is updated as 1231402. 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 illustrating a preferred embodiment of the present invention.

[A brief description of the symbol of the component] 102 light source 104 ellipsoidal reflector 106 color wheel 108 light channel 110 lens group 112 optical path turning device 114 DMD wafer 116 projection lens 118 screen 210 ellipsoidal reflector 212 long axis 214 angle

Page 141231402 Brief description of the drawing 2 1 6: Divergence angle 2 2 2 · First focus 3 0 2: Wedge prism 3 0 4: Compensation lens 402: Ellipsoidal reflector 404: First included angle 40 6: Second Angle 408: third angle 4 1 2: first major axis 4 1 4: second major axis 4 1 6: light path 4 2 2: first focus 424: second focus

Page 15

Claims (1)

1231402 VI. Scope of patent application 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 a spherical shell ; 77 an optical channel 'wherein the light emitted by the optical channel is reflected by the first spherical spherical reflector and focused on a DMD chip, and the optical channel forms a first angle with the vehicle of the first spherical spherical reflector , Adjusting the light emitted from the optical channel by the first missing angle and the eccentricity of the first ellipsoidal reflector = in accordance with the required entry angle and active area of the DMD chip; and an optical compensation element mounted on the In the light path between the first ellipsoidal reflector and the dmd wafer. 0 2. The light guiding device as described in item 1 of the scope of patent application, the light guiding device in 1 further includes an optical path turning device, which is mounted on the second ellipsoidal reflector and the DMD chip. The light path between the images produced by the DMD chip. ° 3 · The light guide device described in item 2 of the patent application scope, wherein the optical path folding device includes at least a total reflection 稜鏡 〃 4. The light guide device described in item 丨 of the patent application scope, wherein the optical compensation device The element includes at least one wedge-shaped ridge. 5. The light guiding device according to item 1 of the scope of patent application, wherein the optical compensation Page 16 1231402 6. Scope of patent application The compensation element includes at least one compensation lens. 6. The light guiding device according to item 1 of the scope of patent application, wherein the optical compensation element is a second ellipsoidal reflector, the second ellipsoidal reflector is a part of an ellipsoidal shell, and the second ellipsoid A third focal point of the spherical reflection cover overlaps with a second focal point of the first ellipsoidal reflection cover. A long axis of the first ellipsoidal reflection cover and the path of the light form a second angle at the third focal point. The long axis of the first ellipsoidal reflector and the long axis of the second ellipsoidal reflector form a third included angle. The first included angle, the second included angle, the third included angle, and the first ellipsoidal reflective cover form a third included angle. The eccentricity of the second ellipsoidal reflector and the eccentricity of the second ellipsoidal reflector adjust the light emitted by the light channel to meet the required entry angle and active area of the DMD chip. 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 an 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 171231402 6. The first focal point of one of the reflectors covered by the patent application overlaps, and the light emitted by the light channel is sequentially reflected by the first ellipsoidal reflector and the second ellipsoidal 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 cool 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 second cool angle, the eccentricity of the first ellipsoidal reflector, and the second ellipsoidal surface. The eccentricity of the reflecting 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 guide device according to item 8 in the scope of the patent application, wherein the light guide device further includes a light path turning device installed between the second ellipsoidal reflector and the]) MD wafer. In the light path, it is used to turn the image produced by the DMD chip. 10. The light guiding device according to item 9 in the scope of the patent application, wherein the light path turning device includes at least a total reflection chirp. 11. The light guiding device according to item 8 of the scope of the patent application, wherein the third included angle is equal to the sum of the first included angle and the second missing angle.