TWI780823B - Illumination system - Google Patents

Abstract

An illumination system is provided including: a light source for emitting light; a first focusing component disposed before the light source for converging the light toward a focusing surface; a second focusing component disposed before the focusing surface for modifying the angle of the light emitted from the focusing surface; and a variable wavelength filter movably disposed between the first and second focusing components, and the distance between the variable wavelength filter and the focusing surface is less than the distance between the variable wavelength filter and the focusing component. Therefore, the illumination system can quickly change the wavelength of the projected illumination light.

Description

Lighting system

The present invention relates to an illumination system, in particular to an illumination system that can be used for applications such as optical detection.

The basic structure of a general image-type optical detection device can include an imaging system and an illumination system, and the imaging system is composed of a camera (also known as a sensor or photosensitive element) and a lens, and the imaging system mainly uses the principle of geometric optical imaging to obtain the desired The image or brightness signal of the subject (under test); the lighting system is selected or combined with optical components such as light source, light-collecting element, light-shielding element or light-homogenizing element, so as to highlight the appearance of the subject to be highlighted , size or color, etc., to provide corresponding and appropriate lighting (light projection) effects. Therefore, different lighting methods (lighting effects) are required for different subjects or different features of the same subject.

When evaluating whether the lighting is suitable for highlighting the characteristics of the object under test, for example, several points can be considered: lighting angle related to bright and dark fields, light collimation or uniformity, light source wavelength and bandwidth. For example, in order to detect objects with smooth surfaces, the bright field lighting effect of highlighting the concave and convex points of the surface to present a dark image, or conversely, the lighting effect of dark field lighting of a bright image by highlighting the concave and convex points of the surface; for For the detection of objects with rough surfaces, the image formed by the illumination with good uniformity (diffusion) is less disturbed by surface fluctuations than the illumination with good collimation, so it is beneficial to the optical detection of objects with rough surfaces . In terms of the color of the object to be tested, a brighter outline image can be obtained if the object is easy to reflect the light of the wavelength, and on the contrary, a darker or black outline image can be obtained if the object is easy to absorb the light of the wavelength.

The light source of the lighting system generally includes: fluorescent tube, halogen bulb, light emitting diode (LED), laser (LASER), etc. Difficult to be adjusted. If there are lighting requirements of multiple wavelengths (visible light is colored light or invisible light), in addition to combining light sources with different spectra, you can only use light sources with broadband spectra (such as white light) and filters with different wavelengths to switch between different wavelengths. The wavelength of the illuminating light.

In addition to detection devices that require their illumination systems to provide different spectra, other devices or applications may also have this requirement.

Therefore, how to change the wavelength of the light of the lighting system conveniently or quickly is the goal of practitioners in related technical fields.

The purpose of the present invention is to provide an illumination system that can conveniently or quickly change the wavelength of the projected illumination light. Another object of the present invention is to provide an illumination system that can change the wavelength of the projected illumination light without requiring a large-sized filter. Another object of the present invention is to provide an illumination system that can change the wavelength of the projected illumination light and change the projection range of the illumination light.

To achieve the above purpose, in the first aspect of the present invention, the lighting system includes: a light source for emitting light; a first light concentrating element arranged in front of the light source for converging the light toward the light concentrating surface; Two light concentrating elements, arranged in front of the light concentrating surface, are used to correct the angle of the light extending and diverging from the light concentrating surface; and variable wavelength filters, which are movably arranged on the first light concentrating element and the light concentrating element Between the second light concentrating elements, the distance between the variable wavelength filter and the light concentrating surface is smaller than the distance between the variable wavelength filter and the first light concentrating element, or less than the variable wavelength filter and the first light concentrating element. The distance between the variable wavelength filter and the second light concentrating element.

In the second aspect of the present invention, the variable wavelength filter is provided on the light collecting surface.

In a third aspect of the present invention, the variable wavelength filter is adjacent to the light collecting surface.

In a fourth aspect of the present invention, the variable wavelength filter includes a bandpass type linearly varying wavelength filter.

In a fifth aspect of the present invention, the variable wavelength filter includes a combination of a high-pass type linearly varying wavelength filter and a low-pass type linearly varying wavelength filter.

In the sixth aspect of the present invention, the high-pass type linearly varying wavelength filter and the low-pass type linearly varying wavelength filter are movable synchronously.

In the seventh aspect of the present invention, the high-pass linearly varying wavelength filter and the low-pass linearly varying wavelength filter are relatively movable.

In an eighth aspect of the present invention, the lighting system further includes an aperture, and the aperture is disposed on or adjacent to the light-condensing surface.

In the ninth aspect of the present invention, the lighting system further includes a lens, which is arranged in front of the second light concentrating element to define the area of the projection surface of the lighting system.

In the tenth aspect of the present invention, the lens is a lens combination structure capable of extending the light path, including a telecentric lens.

In the eleventh aspect of the present invention, the lighting system includes: a light source for emitting light; a first light concentrating element arranged in front of the light source for correcting the angle of the light; and a variable wavelength filter capable of Moveably arranged between the light source and the first light concentrating element, and the distance between the variable wavelength filter and the light source is smaller than the distance between the variable wavelength filter and the first light concentrating element distance.

By means of the above technical means, the present invention can at least achieve the following technical effects:

1. The variable wavelength filter is movable so that the light emitted by the light source can pass through different sections of the variable wavelength filter, thereby changing the wavelength of the light conveniently;

2. The variable wavelength filter is set close to the light-condensing surface or directly on the light-condensing surface, so the size and position of the variable wavelength filter are not affected by the light-condensing element, and if the size of the light-condensing surface When the design can be very small, the size of the variable wavelength filter can be further reduced;

3. Since the variable wavelength filter can have a smaller size, its movement can also be relatively fast, so as to quickly switch to the desired wavelength of light;

4. The variable wavelength filter can provide a linearly changing filtering effect, so that when the variable wavelength filter is moved, the wavelength of the projected light can be continuously changed;

5. The lighting system can include replaceable and connected lenses, such as commercial lenses such as telecentric lenses, so as to easily change the light angle and projection range of the lighting light to meet different application conditions.

The objects, features, and advantages disclosed herein will become more apparent to those skilled in the art from the description of the following embodiments with reference to the accompanying drawings.

Hereinafter, embodiments, examples, and examples of the present invention will be described with reference to the drawings. For purposes of clarity or convenience, the drawings are not necessarily drawn in accordance with the shapes and/or proportions of actual elements or structures, and thus the present invention is not limited to the shapes and/or proportions in the drawings. In addition, the details of the embodiments, examples, and examples of the present invention can be changed into different forms without departing from the overall scope of the present invention, so the present invention should not be simply limited to the embodiments, examples, and examples described below. Rather, it should include reasonable changes that do not exceed the overall scope of the present invention. In addition, the embodiments, examples, and examples of the present invention should be arbitrarily and reasonably combined.

Please refer to FIG. 1A and FIG. 1B , which are schematic diagrams of lighting systems with and without light-condensing elements and their geometric light paths, respectively. As shown in Figure 1A, the lighting system 10 includes a light source 11 and a light-condensing element 12, the light-condensing element 12 is arranged in front of the light source 11, and is optically coupled to the light source 11, and the light source 11 is used as the object of the lighting system, due to the light-condensing element 12 The light rays are focused into an image, so the image is the projection surface 13 . The light source 11 can include any one or combination of any luminous objects such as fluorescent lamps, light-emitting diodes, lasers, etc. The light source 11 can emit light (beam) 112 from its light-emitting surface 110, and the light 112 can include visible light ( That is, colored light) or invisible light (such as infrared or ultraviolet light). The light 112 diverges forward and passes to the light-condensing element 12 , and then the light-condensing element 12 converges the light 112 (corrects the angle of the light 112 ), and projects it onto the projection surface 13 outside the lighting system 10 . The light-condensing element 12 can be in any form, for example, it can include a lens (as shown in FIG. 1A ) or a combination of multiple lenses, a single Fresnel lens (Fresnel lens) or multiple combinations thereof, etc. for projection or imaging purposes. type. In addition, the light-condensing element 12 can be used as the pupil surface or the aperture diaphragm of the lighting system 10. The light 112 diverged from each light-emitting point on the light-emitting surface 110 can only converge to the corresponding light on the projection surface 13 when it passes through the pupil surface. for each point. The size of the pupil surface can limit the total passing amount of the light 112. In addition, the meaning of the pupil surface can be understood from the entire optical path, that is, no matter whether the brightness or wavelength of the light 112 at each light-emitting point of the light-emitting surface 110 is uniform or not, if From the light-emitting surface 110 to the pupil surface, or from the pupil surface to the projection surface 13, it can be seen that there is an effect of uniform light.

As used herein, "front", etc. and any other similar directional terms refer to the overall direction of travel (light path) of light ray 112 . Therefore, setting the light concentrating element 12 before the light source 11 means that the light 112 passes forward from the light source 11 to the light concentrating element 12 . In addition, other optical elements that do not change the degree of light divergence or convergence on the optical path can be arranged between the light-condensing element 12 and the light source 11 or between the light-condensing element 12 and the projection surface 13 (for example, the light path can be turned to advance perpendicularly to the original light path) The reflecting mirror, or the beam used for light splitting, etc., not shown in the figure), does not affect the object-image conjugate relationship between the original light source 11 and the projection surface 13 due to the concentrating element 12 .

As shown in FIG. 1B , the lighting system 10 without light-concentrating elements includes a light source 11, and the light 112 emitted from the light source 11 can be transmitted forward, spread evenly over a certain distance, and then transmitted to the projection surface 13. In this light path schematic diagram, the projection surface 13 Limited to the field stop due to its size.

Please refer to FIG. 2A , which is another schematic diagram of the lighting system shown in FIG. 1A . The lighting system 10 further includes a filter 14, which can be arranged in front of the light source 11 (such as at position P1 or at position P2) and optically coupled with the light source 11, and can also be arranged at the front of the light collecting element 12 (such as at position P3 or at position P4 ), and optically coupled with the light-concentrating element 12.

If the filter 14 is a filter with a general fixed wavelength and bandwidth (such as a high-pass filter, a low-pass filter or a band-pass filter, etc.), no matter whether the filter 14 is placed on the light source 11 or the projection surface 13 Any position between the light 112 and any place where the light 112 passes through the filter 14 should all receive the same filtering effect. If the optical filter 14 is a variable-wavelength person, the optical filter 14 is placed at P1 to P4 (not located on the pupil surface or not close to the pupil surface), and the light 112 emitted from different light-emitting points on the light-emitting surface 110 of the light source 11 will pass through. When the sections of the optical filter 14 have different wavelength ranges, they will receive different filtering effects. For example, if the filter 14 is placed at the position P1, the light rays 112 emitted from the positions A1, A2 and A3 of the light-emitting surface 110 toward the light-concentrating element 12 will respectively pass through the greenish-blue section and the greenish-green section of the filter 14. section and the greenish-yellow section (respectively corresponding to the dashed ellipse lines at the upper, middle and lower positions shown in the figure, these dashed lines are partially overlapped), when finally projected onto the projection surface 13 of the lighting system 10, there will be The color difference does not meet the requirements.

Please refer to FIG. 2B , which is another schematic diagram of the lighting system shown in FIG. 1A . When the wavelength-variable optical filter 14 is placed close to the light-condensing element (pupil surface) 12 or on the light-condensing element 12, the light 112 emitted from any part of the light-emitting surface 110 of the light source 11 will pass through the filter as a whole 14 of the same wavelength range, so the light 112 can have a uniform or roughly uniform color on the projection surface 13.

Please refer to FIG. 3A to FIG. 3C , which are schematic diagrams of wavelength variation of the illumination system shown in FIG. 2B . The optical filter 14 can move laterally relative to the light source 11 and the light-concentrating element 12 (as shown by the double arrows shown in the figure), so that the light 112 passes through different sections (wavelength ranges) of the optical filter 14 to change the projection to The light color on the projection surface 13. As shown in Figure 3A, the initial spectrum S of the light 112 is 400-700nm, the light 112 passes through the red section of the filter 14 (the spectrum S is 600-700nm), and the light 112 on the projection surface 13 is roughly red, as shown in the figure As shown in 3B, the light 112 passes through the green section of the filter 14 (spectrum S is 500-600nm), the light 112 on the projection surface 13 is roughly green, and as shown in Figure 3C, the light 112 passes through the green section of the filter 14 In the blue section (the spectrum S is 400-500nm), the light 112 on the projection surface 13 is roughly blue.

Although this lighting system 10 can change the light color on the projection surface 13 , it will face the following deficiency: the size of the light-condensing element 12 (pupil surface) is related to the size of the filter 14 . If the size of the pupil surface is large, the filter 14 will be made relatively large, causing the volume of the entire lighting system 10 to be too large; in addition, the size of the pupil surface is related to whether the projection surface with a narrower bandwidth can be achieved. The variable wavelength bandwidth of the optical filter 14 is discussed in the visible light range of 400~700nm. When the narrower optical filter 14 is placed on a relatively large pupil surface, the light 112 will pass through a larger bandwidth range on the pupil surface. Therefore, it is impossible to achieve a narrower bandwidth filtering effect; moreover, when wanting to change the area of the projection surface 13, it is necessary to adjust the position of the light-condensing element 12, which means that the position of the filter 14 must also be changed accordingly, which is really inconvenient.

Please refer to FIG. 4 , which is another schematic diagram of the lighting system shown in FIG. 1B . The lighting system 10 further includes a filter 14 , which can be arranged in front of the light source 11 and optically coupled with the light source 11 . Please refer to FIG. 5A to FIG. 5C , which are schematic diagrams of wavelength variation of the illumination system shown in FIG. 4 . The filter 14 can move laterally relative to the light source 11 so that the light 112 passes through different sections of the filter 14 to change the color of the light projected onto the projection surface 13 .

Although this kind of lighting system 10 can change the light color on the projection surface 13, it will face the following disadvantages: the lighting system 10 without light-collecting elements uses the light rays 112 of each light-emitting point of the light source 11 to diverge to achieve uniform filtering Therefore, there is a problem that the brightness of the light is easily insufficient; in addition, if you want to make the projection surface 13 have different areas, you can only use the distance to control it, but the farther the distance is, the larger the projection surface 13 will be, the weaker the brightness of the projection surface 13 will be. Furthermore, if only divergence is used to project light, the brightness of the projection surface 13 will attenuate as the distance from the center of the projection surface 13 increases, so that the brightness uniformity of the projection surface 13 is not good.

Based on the technical content of the lighting system 10 above, a lighting system is proposed, which can improve the above defects, so as to better achieve the technical purpose of changing the wavelength of the lighting light.

Please refer to FIGS. 6A to 6C , which are schematic diagrams of lighting systems according to preferred embodiments of the present invention. The lighting system 20 includes a light source 21, a first light concentrating element 22, a second light concentrating element 23 and a variable wavelength filter 24, wherein the technical content of the light source 21 can include the technical content of the above light source 11, and the first light concentrating element 22 and the second light concentrating element 23 may include the technical content of the light concentrating element 12 described above.

More specifically, the light source 21 emits light rays 212 from its light emitting surface 210, and the first light concentrating element 22 is arranged in front of the light source 21 and optically coupled with the light source 21 to converge the divergent light rays 212; then the light rays 212 converge to A concentrating surface 220 , which can be regarded as a second light-emitting surface, is located in front of the first concentrating element 22 , for example, outside the focal length of the first concentrating element 22 .

Afterwards, the light 212 converged on the light-concentrating surface 220 diverges again and passes forward. The second light concentrating element 23 is disposed in front of the light concentrating surface 220 to correct the angle of the diverging light 212 . According to the distance d1, d2 between the second light concentrating element 23 and the light concentrating surface 220, the light 212 can be converged by the second light concentrating element 23 (as shown in FIG. 6A, the distance d1 is greater than the equivalent of the second light concentrating element 23 focal length), or the light 212 can be corrected into parallel light by the second light concentrating element 23 (as shown in FIG. 6B, the distance d2 is equal to the equivalent focal length of the second light concentrating element 23).

The variable wavelength filter 24 is movably disposed between the first light concentrating element 22 and the second light concentrating element 23 , and is optically coupled to both. In this embodiment, the variable wavelength filter 24 can be moved laterally (for example, linearly moved by a linear motor, a piezoelectric device or a screw device, etc.), and its moving direction is parallel to the plane of the light emitting surface 210 or the light collecting surface 220; In other embodiments, the movement of the variable wavelength filter 24 may be a rotary type or the like. By moving the variable wavelength filter 24 , the light 212 can be filtered by different sections (band ranges) of the variable wavelength filter 24 . The filtered light 212 is forwarded to the second light concentrating element 23 , during which the light 212 will mix the filter bands due to divergence, so when reaching the second light concentrating element 23 , the light 212 will have a uniform color distribution as a whole.

The distance (straight-line distance or shortest distance) between the variable wavelength filter 24 (as indicated by the solid line) and the light-condensing surface 220 is smaller than the distance between the variable wavelength filter 24 and the first light-condensing element 22, Alternatively, the distance between the variable wavelength filter 24 (as indicated by the dotted line) and the light collecting surface 220 is smaller than the distance between the variable wavelength filter 24 and the second light collecting element 23 . In other words, the variable wavelength filter 24 can be selectively arranged before or after the light-condensing surface 220, and no matter where, the variable-wavelength filter 24 is closer to the light-condensing surface 220 than close to the first light-condensing element 22 and The second light concentrating element 23 .

Preferably, the variable wavelength filter 24 is adjacent to the concentrating surface 220, for example, the distance between the variable wavelength filter 24 and the concentrating surface 220 is the same as the distance between the variable wavelength filter 24 and the first concentrating element 22. The ratio of the distance between (the second light concentrating elements 23 ) is at least 1:8, 1:9 or 1:10, etc. The larger the ratio, the closer the variable wavelength filter 24 is to the light concentrating surface 220 . More preferably, the variable wavelength filter 24 is disposed on the light collecting surface 220 , and the distance between the variable wavelength filter 24 and the light collecting surface 220 is zero.

In this way, the light 212 can pass through the variable wavelength filter 24 intensively, and the irradiation area (range) of the light 212 on the incident surface 240 of the variable wavelength filter 24 is much smaller than that shown in FIG. 2A and FIG. 2B . The irradiation area is smaller than the area of each segment of the variable wavelength filter 24, that is, the light 212 can be filtered to have a desired wavelength.

In addition, the size of each segment of the variable wavelength filter 24 is equal to or slightly larger than the light-condensing surface 220, so if the design of the light-condensing surface 220 is smaller, each segment of the variable wavelength filter 24 that needs to be filtered The smaller the wavelength, the variable wavelength filter 24 does not need to be made too large as a whole. Furthermore, the variable wavelength filter 24 does not increase the overall size of the illumination system 20 when the variable wavelength filter 24 does not need to be made too large.

On the other hand, the size and position of the variable wavelength filter 24 are related to the concentrating surface 220, as long as it is confirmed that the concentrating surface 220 can meet the collocation requirements of the variable wavelength filter 24, the variable wavelength filter 24 is less affected by the size and position of the first light concentrating element 22 or the second light concentrating element 23 (pupil surface).

Please refer to FIG. 6C , the illumination system 20 may optionally further include an aperture (diaphragm) 27, which may be disposed on or adjacent to the concentrating surface 220, and may be disposed on the variable wavelength filter 24. before or after. If one of the variable wavelength filter 24 and the aperture 27 is disposed on the light-condensing surface 220 , the other is disposed before or after the light-condensing surface 220 . The aperture 27 can correct the shape and size of the light-condensing surface 220, and cover the unfavorable part of the edge of the light-condensing surface 220, because the relationship between the manufacturing quality of the first light-condensing element 22 or the aberration of the optical path may cause the edge of the light-condensing surface 220 to be damaged. Some have poor shape or contour. In addition, the aperture of the aperture 27 can also be adjustable.

Please refer to FIGS. 7A and 7B , which are schematic diagrams of an illumination system according to another preferred embodiment of the present invention. The illumination system 20 may further include a lens 25 , which may be any lens combination structure for extending the light path for imaging, or a general commercial or industrial lens available on the market. The lens 25 is arranged in front of the second light concentrating element 23 and optically coupled with the second light concentrating element 23 . The plane located at the second light concentrating element 23 can be used as the object plane of the lens 25 for projection, and the lens 25 can define the area of the projection surface 26 of the lighting system 20, and the selection of the lens 25 can adjust the range of the projection surface 26 and/or Brightness uniformity, etc. The lens 25 is preferably interchangeable, so that a lens of corresponding specifications can be selected according to the application of the lighting system 20 . As shown in Figure 7B, the lens 25 may include a telecentric lens so that the transmitted light 212 is relatively parallel; for this reason, the distance between the second light-condensing element 23 and the light-condensing surface 220 needs to be equal to the distance between the second light-condensing element 23 Equivalent focal length, so that the light 212 emitted by the second light concentrating element 23 is corrected to be parallel light.

Please refer to FIGS. 8A and 8B , which are schematic diagrams of an illumination system according to yet another preferred embodiment of the present invention. The lighting system 20 can omit the second light concentrating element 23, and the variable wavelength filter 24 is arranged between the light source 21 and the first light concentrating element 22, and the distance between the variable wavelength filter 24 and the light source 21 It is smaller than the distance between the variable wavelength filter 24 and the first light concentrating element 22 , that is, the variable wavelength filter 24 is closer to the light source 21 than to the first light concentrating element 22 . Preferably, the variable wavelength filter 24 is adjacent to the light source 21, so that the light 212 passes through the variable wavelength filter 24 (that is, the light 212 passes through the variable wavelength filter 24 on the incident surface 240 of the variable wavelength filter 24). The irradiation area is relatively small); in this way, the variable wavelength filter 24 does not need to be made too large as a whole.

The distances d1 and d2 between the first light concentrating element 22 and the light source 21 can be adjusted to change the light path of the light 212 after passing through the first light concentrating element 22 . For example, as shown in FIG. 8A, when the distance d1 between the first light concentrating element 22 and the light source 21 is relatively large, the light 212 is converged by the first light concentrating element 22; as shown in FIG. 8B, the first light concentrating element When the distance d2 between 22 and the light source 21 is equal to the focal length of the first condensing element 22, the light 212 is corrected by the first condensing element 22 to be parallel light. On the other hand, although not shown in FIGS. 8A and 8B , the lighting system 20 of this embodiment may further include a lens (as shown in FIG. 6A or 6B ).

The variable wavelength filter 24 in the above-mentioned embodiments may include filters of different mechanisms or types. For example, the variable wavelength filter 24 may include a bandpass linear variable wavelength filter or a bandpass continuously variable wavelength filter. As shown in the graph of the relationship between wavelength and transmittance in Figure 9, this variable wavelength filter 24 has linear (or continuous) changing spectral properties along one (or more) directions; Figure 10A to Figure As shown in 10E, by moving the variable wavelength filter 24 linearly, the wavelength of the light 212 projected by the illumination system 20 (including the lens (telecentric lens) 25) will also change linearly (or continuously), for example, sequentially Change to red light, yellow light, green light, blue light and purple light (indicated by different slashes).

As shown in FIGS. 11A to 11C , in other examples, the variable wavelength filter 24 may include a high-pass linear variable wavelength filter (high-pass linear variable wavelength filter) 241 and a low-pass linear variable wavelength filter. (low-pass linear variable wavelength filter) 242, the two can be arranged front and back on the light path of the light 212. The high-pass linearly varying wavelength filter 241 and the low-pass linearly varying wavelength filter 242 have a spectrum P that varies linearly along one (or multiple) directions, but can block light of a specific wavelength.

The high-pass type linearly variable wavelength filter 241 and the low-pass type linearly variable wavelength filter 242 can move synchronously to continuously and synchronously adjust the upper and lower boundaries of the wavelength range of the light 212; The through-type linear variable wavelength filter 242 can also move relatively, changing the relative position of the two, so as to adjust the wavelength range of the combination of the two. In addition, the aperture 27 shown in FIG. 6C can be disposed before, after or between the high-pass linearly varying wavelength filter 241 and the low-pass linearly varying wavelength filter 242 .

The aforementioned linear change (high-pass, low-pass or band-pass, etc.) filters can be purchased from companies such as Delta Optical Thin Film A/S, Semrock, etc., but are not limited thereto. It should also be noted that the variable wavelength filter is not limited to a linear variable filter, and may be of other types or mechanisms.

To sum up, the illumination provided by the present invention can effectively change the wavelength of the projected illumination light, and can realize the technical effects described in the above summary of the invention.

Although the invention has been described with respect to the above selected embodiments only, various changes, modifications or substitutions are possible in this case without departing from the scope of the invention as defined by the claims of the appended claims, as long as they do not materially affect intended operation or functionality. A single element shown as integrally formed may be a single component, or may be composed of several sub-components. Various features and advantages do not necessarily appear in a specific embodiment at the same time, but can be implemented in combination or independently in different embodiments. Therefore, the foregoing descriptions of the embodiments are only for illustrative purposes and not intended to limit the present invention, and the scope of the application is defined by the scope of the patent application and its equivalents.

10: Lighting system 11: Light source 110: Luminous surface 112: light 12: Concentrating element 13: Projection surface 14: Filter 20: Lighting system 21: light source 210: Luminous surface 212: light 22: The first concentrating element 220: Concentrating surface 23: The second concentrating element 24: variable wavelength filter 240: incident surface 241: Linear Variation High Pass Filter 242: Linear change low-pass filter 25: Lens 26: Projection surface 27: Aperture A1~A3: position d1: distance d2: distance S: spectrum P: spectrum P1~P4: position

[FIG. 1A and FIG. 1B] are schematic diagrams of lighting systems with and without light-condensing elements and their geometric light paths, respectively.

[Fig. 2A] is another schematic diagram of the illumination system shown in Fig. 1A and its geometric light path;

[Fig. 2B] is another schematic diagram of the illumination system shown in Fig. 1A and its geometric light path;

[FIG. 3A to FIG. 3C] are schematic diagrams of the illumination system and its wavelength variation shown in FIG. 2B, respectively;

[Fig. 4] is another schematic diagram of the illumination system shown in Fig. 1B and its geometric light path;

[FIG. 5A to FIG. 5C] are respectively schematic diagrams of the illumination system shown in FIG. 4 and its wavelength variation;

[FIG. 6A to FIG. 6C] are schematic diagrams of the lighting system and its geometric light path according to a preferred embodiment of the present invention;

[FIG. 7A and FIG. 7B] are respectively schematic diagrams of an illumination system and its geometric light path according to another preferred embodiment of the present invention;

[FIG. 8A and FIG. 8B] are respectively schematic diagrams of an illumination system and its geometric light path according to yet another preferred embodiment of the present invention;

[Fig. 9] is a graph of the relationship between the wavelength and the transmittance of the linearly varying optical filter;

[FIG. 10A to FIG. 10E] are schematic diagrams of illumination systems and their wavelength changes according to other preferred embodiments of the present invention; and

[FIGS. 11A to 11C] are schematic diagrams of illumination systems and their wavelength changes according to other preferred embodiments of the present invention.

20: Lighting system

21: light source

210: Luminous surface

212: light

22: The first concentrating element

220: Concentrating surface

23: The second concentrating element

24: variable wavelength filter

240: incident surface

d1: distance

Claims (11)

A lighting system comprising: a light source for emitting light; a first light concentrating element, arranged in front of the light source, for converging the light toward the light concentrating surface; a second light concentrating element, arranged in front of the light concentrating surface, for correcting the angle of the light extending and diverging from the light concentrating surface; and A variable wavelength filter is movably arranged between the first light concentrating element and the second light concentrating element, and the distance between the variable wavelength filter and the light concentrating surface is smaller than the variable The distance between the wavelength filter and the first light concentrating element is smaller than the distance between the variable wavelength filter and the second light concentrating element. The lighting system as claimed in claim 1, wherein the variable wavelength filter is arranged on the light collecting surface. The lighting system as claimed in claim 1, wherein the variable wavelength filter is adjacent to the light collecting surface. The lighting system according to any one of claims 1 to 3, wherein the variable wavelength filter includes a bandpass linearly variable wavelength filter. The lighting system according to any one of claims 1 to 3, wherein the variable wavelength filter includes a high-pass linearly varying wavelength filter and a low-pass linearly varying wavelength filter. The lighting system according to claim 5, wherein the high-pass linearly changing wavelength filter and the low-pass linearly changing wavelength filter can move synchronously. The lighting system according to Claim 5, wherein the high-pass linearly changing wavelength filter and the low-pass linearly changing wavelength filter are relatively movable. The lighting system according to any one of Claims 1 to 3, further comprising an aperture, and the aperture is disposed on or adjacent to the light-condensing surface. The lighting system as described in any one of Claims 1 to 3 further includes a lens, which is arranged in front of the second light concentrating element to define the area of the projection surface of the lighting system. The lighting system according to claim 9, wherein the lens is a lens combination structure capable of extending the light path, including a telecentric lens. A lighting system comprising: a light source for emitting light; the first light concentrating element is arranged in front of the light source to correct the angle of the light; and A variable wavelength filter is movably arranged between the light source and the first light concentrating element, and the distance between the variable wavelength filter and the light source is smaller than the distance between the variable wavelength filter and the The distance between the first concentrating elements.

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