Light source module with annular light guide plate

Abstract

A light source module with an annular light guide plate is provided, which is advantageous for reducing the volume and improving the optical uniformity. [Solution] A light source module (100) with an annular light guide plate (120) comprises an annular light guide plate and at least one light source (140). The annular light guide plate includes a light incident surface (122) and a light exit surface (124) adjacent to the light incident surface. The light exit surface has an annular shape and intersects with the light incident surface. The light source is used to emit at least one light beam toward the light incident surface of the annular light guide plate, where the light beam enters the annular light guide plate from the light incident surface and is emitted through the light exit surface.

Description

[Technical Field]

[0001] The present invention relates to a light source module, and more particularly to a light source module with an annular light guide plate. [Background technology]

[0002] With the development of optical detection devices, the number of light sources with different spectra used within the same device is also increasing. Generally, in devices employing different light wave spectra (e.g., optical biological detection devices), each light source with a different spectrum corresponds to a set of filter modules and is combined with a set of optical transmission modules to transmit the light beam emitted from the light source to a target location (e.g., a biological sample mounting stage). The more light sources with different spectra are used within the device, the more filter modules and optical transmission modules need to be installed, which makes it difficult to reduce the volume of the multi-spectral optical device. Summary of the Invention

[0003] One embodiment of the present invention provides a light source module with an annular light guide plate, which is advantageous in reducing the volume and improving the optical uniformity.

[0004] One embodiment of the present invention provides a light source module including an annular light guide plate and at least one light source. The annular light guide plate includes a light incident surface and a light exit surface adjacent to the light incident surface. The light exit surface has an annular shape and intersects with the light incident surface. The light source is used to emit at least one light beam toward the light incident surface of the annular light guide plate, where the light beam enters the annular light guide plate from the light incident surface and is emitted through the light exit surface.

[0005] In one embodiment of the present invention, the light source module further includes at least one color filter disposed between the annular light guide plate and the light source, and disposed in the transmission path of the light toward the light incident surface.

[0006] In one embodiment of the present invention, the light source module further includes a diffusion sheet and a reflective layer, the diffusion sheet being disposed on the light output surface of the annular light guide plate, and the reflective layer being disposed on the annular light guide plate, the reflective layer being disposed on the diffusion sheet and the diffusion sheet being disposed on opposite sides of the annular light guide plate.

[0007] In one embodiment of the present invention, at least one light source shares a transmission path within the annular light guide plate.

[0008] In one embodiment of the present invention, when the number of at least one light source is two or more, the light sources are displaced along a linear direction and aimed at the light-incident surface in sequence.

[0009] In one embodiment of the present invention, when the quantity of at least one light source is two or more, the light sources are displaced along a circular direction and aimed at the light-incident surface in turn.

[0010] In one embodiment of the present invention, the width of the light exit surface of the annular light guide plate is the same along the rotation direction away from the light incident surface.

[0011] In one embodiment of the present invention, the width of the light exit surface of the annular light guide plate gradually decreases along the rotation direction away from the light incident surface.

[0012] In one embodiment of the present invention, the annular light guide plate further includes a counter-light-emitting surface, an inner ring surface, and an outer ring surface. The counter-light-emitting surface faces the light-emitting surface in the thickness direction of the annular light guide plate. The inner ring surface is adjacent to the light-emitting surface and the counter-light-emitting surface, respectively. The outer ring surface is adjacent to the light-emitting surface and the counter-light-emitting surface, respectively, and faces the inner ring surface and the outer ring surface. The light-emitting surface and the counter-light-emitting surface are located between the inner ring surface and the outer ring surface.

[0013] In one embodiment of the present invention, the light source module further includes at least two color filters disposed between the light incident surface of the annular light guide plate and the light source, the color filters being aligned in a row on the light incident surface along a direction extending from the inner surface of the annular ring to the outer surface of the annular ring, and the two color filters having different colors.

[0014] In one embodiment of the present invention, when the quantity of the at least one light beam is two or more, one of the at least two light beams passes through one of the color filters close to the inner surface of the ring to enter the annular light guide plate, and another of the at least two light beams passes through another of the color filters close to the outer surface of the ring to enter the annular light guide plate, and the optical wavelength of one of the at least two light beams is smaller than the optical wavelength of the other of the at least two light beams.

[0015] In one embodiment of the present invention, when the number of at least one light source is two or more, the annular light guide plate further includes a plurality of transmission paths adjacent to the light incident surface, each extending in a rotational direction away from the light incident surface and aligned along a direction on the light incident surface, the direction extending from the inner surface of the annular ring to the outer surface of the annular ring. The light sources correspond to the transmission paths within the annular light guide plate and on the light incident surface, respectively.

[0016] In one embodiment of the present invention, the annular light guide plate has a long axis that passes through the annular center of the annular light guide plate, a light exit surface that intersects the long axis, and a light entrance surface that is polygonal, with a long side adjacent to the light exit surface and extending in a radial direction from the annular center of the annular light guide plate.

[0017] In one embodiment of the present invention, the annular light guide plate further includes a counter-light-emitting surface and an inner surface of the annular light guide plate, the counter-light-emitting surface facing the light-emitting surface in the thickness direction of the annular light guide plate, and the inner surface of the annular light guide plate adjacent to the light-emitting surface and the counter-light-emitting surface, respectively. A first distance exists between the center of the annular light guide plate and the test point on the major axis, and the value of the first distance is S1. The shortest distance between the major axis and the inner surface of the annular light guide plate is a second distance, and the value of the second distance is S2. The value of the included angle between the light-emitting surface of the annular light guide plate and the major axis is θ1, and 90°-θ1=tan -1 (S1 / S2)±10°.

[0018] In one embodiment of the present invention, the first distance is in the range of 80mm to 120mm, and the second distance is in the range of 60mm to 80mm.

[0019] Based on the above, at least one embodiment of the present invention installs an annular light guide plate in a light source module, allowing light rays of different spectra to enter the annular light guide plate through the light-input surface of the annular light guide plate and collectively emit light from the light-output surface of the annular light guide plate. In this way, the transmission of multi-spectral light sources can be achieved with just one annular light guide plate, eliminating the need for multiple light source modules for different spectral light sources, which is advantageous for reducing the volume of multi-spectral optical detection devices. [Brief explanation of the drawings]

[0020] Aspects of the present invention can be understood by reference to the following detailed description in conjunction with the drawings. It should be noted that, in accordance with industrial practice, certain features are not drawn to scale. In fact, the dimensions of certain features may be arbitrarily increased or decreased for clarity of illustration. [Figure 1A] 1 is a perspective view of a light source module with an annular light guide plate according to an embodiment of the present invention; [Figure 1B] FIG. 1B shows a side view along cross section A in FIG. 1A. [Figure 2] 1 is a perspective view of a light source module with an annular light guide plate according to an embodiment of the present invention; [Figure 3A] 1 is a perspective view of a light source module with an annular light guide plate according to an embodiment of the present invention; [Figure 3B] 3B shows a cross-sectional view taken along cross section B in FIG. 3A. [Figure 4A] 1 is a side view of a light source according to an embodiment of the present invention; [Figure 4B] 3 is a side view of a light source according to another embodiment of the present invention; [Figure 5] 1 is a perspective view showing an embodiment of the present invention applied to optical biological detection; DETAILED DESCRIPTION OF THE INVENTION

[0021] In the following description, to clearly illustrate the technical features of the present invention, the dimensions (e.g., length, width, thickness, and depth) of elements (e.g., layers, films, substrates, and regions) in the drawings may be exaggerated and the number of some elements may be reduced. Therefore, the description and interpretation of the following embodiments are not limited to the number of elements in the drawings and the dimensions and shapes of the elements, but include deviations in dimensions, shapes, and both resulting from actual manufacturing processes and / or tolerances. Therefore, the elements shown in the drawings of the present invention are mainly shown schematically and are not intended to accurately depict the actual shapes of the elements, nor do they limit the scope of the claims of the present invention. Next, terms such as "about," "approximately," or "substantially" that appear in the present application include not only explicitly stated numerical values ​​and numerical ranges, but also an acceptable deviation range that would be understandable to a person of ordinary skill in the art to which the invention pertains. This deviation range can be determined by errors that occur during measurement, and this error may be due to limitations of both the measurement system and manufacturing process conditions. Furthermore, "about" can indicate that the value is within one or more standard deviations of the aforementioned numerical value, for example, within ±5%, ±3%, or ±1%. Terms such as "about," "approximately," or "substantially" that appear in the present application can select an acceptable deviation range or standard deviation based on optical properties, etching properties, mechanical properties, or other properties, and do not uniformly apply a single standard deviation to all properties, such as the aforementioned optical properties, etching properties, mechanical properties, and other properties.

[0022] 1A , a light source module 100 with an annular light guide plate includes an annular light guide plate 120 and at least one light source 140. The annular light guide plate 120 includes a light incident surface 122 and a light exit surface 124, and the light exit surface 124 is adjacent to the light incident surface 122. As shown in FIG. 1A , the light exit surface 124 has an annular (e.g., circular) shape, and intersects with the light incident surface 122. In other words, an included angle exists between the light incident surface 122 and the light exit surface 124. The light source 140 is used to emit at least one light ray L1 toward the light incident surface 122 of the annular light guide plate 120. The light ray L1 enters the annular light guide plate 120 from the light incident surface 122 and is emitted through the light exit surface 124. In detail, the light ray L1 enters the annular light guide plate 120 from the light incident surface 122, and then travels along a transmission path P1 inside the annular light guide plate 120. During the travel of the light ray L1, a portion of the light ray L1 leaves the annular light guide plate 120 from the light exit surface 124, causing the annular light guide plate 120 to emit light.

[0023] In a device employing different light spectrums (e.g., a multi-spectral optical detection device), each light source corresponds to a set of filter modules and cooperates with a set of light transmission modules to transmit the light beam to a target location (e.g., a test sample stage). The more spectra required, the more filter modules and light transmission modules must be installed. In the present invention, the annular light guide plate 120 is installed so that light beams L1 of different spectra can all enter the annular light guide plate 120 through the light incident surface 122 of the annular light guide plate 120 and emerge collectively from the light exit surface 124 of the annular light guide plate 120. In this way, the transmission of multi-spectral light sources can be achieved with only one annular light guide plate 120, thereby reducing the volume of the multi-spectral optical device.

[0024] In some embodiments of the present invention, the light source module 100 includes only one light source 140, which may emit white light. To allow the light beam L1 entering the annular light guide plate 120 to be any color light (e.g., blue light) other than white light, the light source module 100 further includes at least one color filter 150, which is disposed between the annular light guide plate 120 and the light source 140 and disposed in a transmission path (not shown) of the light beam L1 toward the light incident surface 122. In various embodiments of the present invention, the color filter 150 may be a filter of different colors, such as a red filter, a blue filter, a green filter, and a yellow filter. The light source 140 includes, but is not limited to, at least one light-emitting element (not shown), which may be, for example, a light-emitting diode (LED). The light beam L1 may include, but is not limited to, red light, green light, blue light, or yellow light.

[0025] In this embodiment, the number of color filters 150 is four, namely, a red filter, a blue filter, a green filter, and a yellow filter, but the number and colors of the color filters 150 are not limited to the above embodiment. For example, in other embodiments, the light source module 100 may include one blue filter and two red filters, or one green filter and one yellow filter.

[0026] 1A , the annular light guide plate 120 further includes a light-returning surface 126, an annular inner surface 127, and an annular outer surface 128. The light-returning surface 126 faces the light-returning surface 124 in the thickness direction T1 of the annular light guide plate 120. In other words, the light-returning surface 126 and the light-returning surface 124 are located on opposite sides of the annular light guide plate 120 (i.e., the top and bottom sides of the annular light guide plate 120), respectively.

[0027] The annular inner surface 127 is adjacent to the light-emitting surface 124 and the light-receiving surface 126, respectively, and the annular outer surface 128 is also adjacent to the light-emitting surface 124 and the light-receiving surface 126, respectively. The annular inner surface 127 and the annular outer surface 128 are opposite each other, and the light-emitting surface 124 and the light-receiving surface 126 are located between the annular inner surface 127 and the annular outer surface 128. That is, the annular inner surface 127 and the annular outer surface 128 are located on opposite sides of the annular light guide plate 120 (i.e., the inside and outside of the annular light guide plate 120), respectively.

[0028] 1A and 1B together, Fig. 1B is a side view taken along cross section A in Fig. 1A. In some embodiments, when the light source module 100 includes at least two color filters 150, the color filters 150 are disposed between the light incident surface 122 of the annular light guide plate 120 and the light source 140. The color filters 150 are aligned on the light incident surface 122 along direction D1, which extends from the annular inner surface 127 to the annular outer surface 128. The at least two color filters 150 have different colors.

[0029] Therefore, if the number of light rays L1 is two or more (e.g., two), one of the light rays L1 passes through one color filter 150 close to the ring inner surface 127 (e.g., the color filter 150 closest to the ring inner surface 127) and enters the annular light guide plate 120. The other light ray L1 passes through another color filter 150 close to the ring outer surface 128 (e.g., the color filter 150 closest to the ring inner surface 127) and enters the annular light guide plate 120.

[0030] The annular light guide plate 120 has an annular shape, i.e., the light output surface 124 of the annular light guide plate 120 is connected head to tail. After a light ray L1 enters the annular light guide plate 120, the path length of the light ray L1 closer to the inside of the annular shape is shorter than the path length of the light ray L1 closer to the outside of the annular shape. Meanwhile, the annular light guide plate 120 has a high absorption rate for light rays with a short wavelength range and a low absorption rate for light rays with a long wavelength range. For example, the annular light guide plate 120 has a higher absorption rate for blue light (wavelength range 450 nm to 475 nm) than for red light (wavelength range 620 nm to 750 nm).

[0031] Therefore, in order to match the absorption levels of light rays L1 of different colors within the annular light guide plate 120, the optical wavelength of light ray L1 close to the inner ring surface 127 is smaller than that of light ray L1 close to the outer ring surface 128, i.e., the closer the propagation path of light ray L1 is to the inner ring surface 127, the smaller the optical wavelength of light ray L1. Taking the above-mentioned blue and red light as an example, since the blue light is closer to the inner ring surface 127, the path of light ray L1 is shortened and energy loss is reduced, thereby avoiding a decrease in brightness due to excessive absorption of the blue light by the annular light guide plate 120, while the red light is closer to the outer ring surface 128. This arrangement can improve the light output uniformity of the light output surface 124 of the annular light guide plate 120.

[0032] In the light source module 100 of the above embodiment, the light sources 140 share one transmission path within the annular light guide plate 120 (i.e., the shared transmission path P1), and the shared transmission path P1 has a notch design located near the light incident surface 122, so that when light beams L1 of various colors or wavelengths first enter the annular light guide plate 120, the air gap within the notch can prevent the light beams L1 of various colors or wavelengths from interfering with each other. However, the present invention is not limited to the above embodiment. Referring to the light source module 200 in FIG. 2 , the light source module 200 is similar to the light source module 100, except that the number of light sources 240 in the light source module 200 is two or more (e.g., four), and the annular light guide plate 220 further includes a plurality of transmission paths P2.

[0033] 2 , the transmission paths P2 are adjacent to the light incident surface 222, and each transmission path P2 extends along a rotation direction R2 away from the light incident surface 222. Additionally, the transmission paths P2 are aligned along a direction D2 on the light incident surface 222, which extends from the inner annular surface 227 toward the outer annular surface 228. The light sources 240 correspond to the transmission paths P2 within the annular light guide plate 220 and on the light incident surface 222, respectively. Specifically, the light sources 240 correspond one-to-one to the transmission paths P2 within the annular light guide plate 220. Therefore, during the transmission of light beams L1 of various colors or wavelengths within the annular light guide plate 120, the light beams L1 are isolated from one another by the air gaps formed by the cuts, and thus the light beams L1 of various colors or wavelengths are positioned and transmitted along the transmission paths P2, without interfering with one another.

[0034] 1B , the annular light guide plate 120 has a microstructure on at least its light-returning surface 126 that destroys total internal reflection, allowing light ray L1 to exit from the light-returning surface 124 of the annular light guide plate 120 as it travels through the annular light guide plate 120. The light source module 100 further includes a diffusion sheet 160 and a reflective layer 170. The diffusion sheet 160 is disposed on the light-returning surface 126 of the annular light guide plate 120, and the reflective layer 170 is disposed on the light-returning surface 126 of the annular light guide plate 120, facing the diffusion sheet 160. That is, the reflective layer 170 and the diffusion sheet 160 are disposed on opposite sides of the annular light guide plate 120, respectively. After some light rays L1 pass through the light-returning surface 124 and leave the annular light guide plate 120, these light rays L1 pass through the diffusion sheet 160, thereby improving the light output uniformity of the annular light guide plate 120.

[0035] Meanwhile, since the reflective layer 170 is provided on the light-removing surface 126, it is possible to reduce the possibility that the light ray L1 will leave the annular light guide plate 120 from the light-removing surface 126 while traveling through the annular light guide plate 120. This allows most of the light ray L1 to exit from the light-removing surface 124 of the annular light guide plate 120, thereby further improving the light output efficiency of the annular light guide plate 120.

[0036] Although the light source module 100 shown in FIG. 1A has one light source 140, the present invention is not limited thereto, and the light source module 100 may have two or more light sources 140. For example, referring to FIGS. 4A and 4B, if the light source module 100 does not have a color filter 150, it may include two or more light sources 140 of different colors (e.g., B, G, Y, and R in FIGS. 4A and 4B represent blue, green, yellow, and red, respectively). However, unlike the embodiment shown in FIG. 2, as shown in FIG. 4A, these light sources 140 may be displaced along a linear direction D1 and aimed sequentially at the light incident surface 122. Note that each light source 140 may be a light source of a different color (e.g., a red light source). However, the manner in which the light sources 140 are displaced in the present invention is not limited thereto. As shown in FIG. 4B, in another embodiment, when the number of light sources 140 is two or more, these light sources 140 may be displaced along a circular direction and aimed sequentially at the light incident surface 122.

[0037] 1A , the width W1 of the light exit surface 124 of the annular light guide plate 120 is constant along the rotation direction R1 away from the light incident surface 122. In other words, when rotating around the light incident surface 122, the width W1 of the annular light guide plate 120 is constant from the starting point to the end point. However, the present invention is not limited to this embodiment. In other embodiments, the width W1 of the light exit surface 124 of the annular light guide plate 120 in the light source module 100 can gradually decrease along the rotation direction R1 away from the light incident surface 122. That is, when rotating around the light incident surface 122, the width W1 of the annular light guide plate 120 gradually decreases from the starting point to the end point.

[0038] As the light ray L1 travels from the origin to the destination, some of the light ray L1 leaves the light output surface 124, and some of the light ray L1 is absorbed by the annular light guide plate 120. Therefore, by reducing the width W1 of the annular light guide plate 120 near the destination, the light ray can more easily come into contact with the microstructures of the light guide plate, thereby improving the proportion of the light ray L1 that exits the light output surface 124 and making the light source energy more concentrated.

[0039] 3A and 3B, FIG. 3B is a cross-sectional view of section B in FIG. 3A. The light source module 300 in this embodiment is similar to the light source module 100. The difference between the two is that the annular light guide plate 320 of the light source module 300 has a major axis X1, which passes through the ring center C1 of the annular light guide plate 320, and the light exit surface 324 of the annular light guide plate 320 intersects with the major axis X1. The light incident surface 322 of the annular light guide plate 320 is polygonal. For example, the light incident surface 322 of the annular light guide plate 320 may be a parallelogram, a rhombus, a square, or a rectangle. As shown in FIG. 3B, the polygon has a long side E1 adjacent to the light exit surface 324, and the long side E1 extends from the ring center C1 of the annular light guide plate 320 along the radial direction D3 of the ring center C1.

[0040] As shown in FIG. 3A , the annular light guide plate 320 further includes a light-returning surface 326 and an annular inner surface 327. The light-returning surface 326 faces the light-returning surface 324 in the thickness direction T2 of the annular light guide plate 320. The annular inner surface 327 is adjacent to the light-returning surface 324 and the light-returning surface 326, respectively. Specifically, the annular light guide plate 320 is inclined and has a shape resembling the outer ring of a shade or a cone. Compared with the flat annular light guide plate 120 in the light source module 100, the inclined annular light guide plate 320 can reduce the overall width of the light source module. Therefore, for the same annular radius, the width of the light source module 300 is smaller than the width of the light source module 100. In addition, the shade-shaped annular light guide plate 320 is not completely sealed (i.e., the head and tail are not completely joined), and there are some notches on the annular surface, which are used to position the light source and allow light generated by the light source to enter the annular light guide plate 320 from the light-incident surface 322.

[0041] Note that there is a first distance sp1 between the ring center C1 and the test point Y1 on the major axis X1, and the value of the first distance sp1 is S1. Meanwhile, the shortest distance between the major axis X1 and the ring inner surface 327 is a second distance sp2, and the value of the second distance sp2 is S2. The value of the included angle θ between the light output surface 324 of the annular light guide plate 320 and the major axis X1 is 90°-θ=tan -1The relationship (sp1 / sp2)±10° is satisfied, which is advantageous in that the light output direction is directed at a specific angle θ toward the test point Y1, unlike the embodiment shown in FIG. 1A, in which the light is emitted vertically and no specific angle is generated. In practice, the first spacing sp1 is in the range of 80 mm to 120 mm, and the second spacing sp2 is in the range of 60 mm to 80 mm. The included angle θ is in the range of 15° to 35°. However, in various embodiments of the present invention, the values ​​of the first spacing sp1, the second spacing sp2, and the included angle θ are not limited to the above ranges.

[0042] As described above, by installing an annular light guide plate in the light source module, light rays of different spectra can all enter the annular light guide plate through the light-input surface of the annular light guide plate and be emitted collectively from the light-output surface of the annular light guide plate. In this way, a single annular light guide plate can achieve the transmission of multispectral light sources, eliminating the need to employ multiple light source modules (including filter modules and light guide modules) for light sources of different spectra. This is advantageous for reducing the volume of the multispectral optical detection device, and can generate softer light rays, making the light intensity on the surface of the illuminated object more uniform and avoiding obvious variations in light intensity caused by the spotlight effect.

[0043] 5, particularly when an optical detection device is used to detect the biochip 502, the diameter of the annular light guide plate 120 is determined according to the size of the detection device. The central space of the annular light guide plate 120 is used to place the camera 504, and is located directly above the biochip 502. Because of its annular shape, the annular light guide plate 120 can avoid being located directly above the biochip 502, thereby avoiding interference caused by reflected light. Furthermore, the dimensions of the annular light guide plate 120 can be designed to be larger than the biochip 502, but the overall space occupation rate should be kept as small as possible.

[0044] Although the present invention has been disclosed above by way of examples, it is not intended to limit the present invention, and a person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention, and the scope of protection of the present invention shall be defined by the appended claims. [Explanation of symbols]

[0045] 100, 200, 300: Light source module with annular light guide plate 120, 220, 320: Annular light guide plate 122, 222, 322: Light entrance surface 124, 224, 324: Emission surface 126, 326: Anti-light emission surface 127, 227, 327: Ring inner surface 128, 228: Annular outer surface 140, 240: Light source 150: Color filter 160: Diffusion sheet 170: Reflective layer 502: Biochip 504: Camera A, B: Cross section C1:Ringshin D1, D2, D3: Direction E1: Long side L1: Ray of light P1, P2: Transmission pathway R1, R2: Rotation direction T1, T2: thickness direction W1: Width X1:Long axis Y1:Test point θ: included angle

Claims

1. A light source module including an annular light guide plate, an annular light guide plate including a light incident surface and a light exiting surface adjacent to the light incident surface, the light exiting surface having an annular shape and intersecting the light incident surface; and at least one light source used to emit at least one light beam toward the front light surface of the annular light guide plate, the at least one light beam entering the annular light guide plate from the light entrance surface and emitting light through the light exit surface.

2. 2. The light source module with an annular light guide plate according to claim 1, further comprising at least one color filter disposed between the annular light guide plate and the light source, the at least one color filter being disposed in a transmission path of the light ray toward the light incident surface.

3. 2. The light source module with an annular light guide plate according to claim 1, wherein the at least one light source shares a transmission path within the annular light guide plate, and when the quantity of the at least one light source is two or more, the light sources are displaced along a linear direction and aimed at the light incident surface in sequence.

4. 2. The light source module with an annular light guide plate according to claim 1, wherein the at least one light source shares a transmission path within the annular light guide plate, and when the quantity of the at least one light source is two or more, the light sources are displaced along an annular direction and aimed at the light incident surface in sequence.

5. The light source module having an annular light guide plate according to claim 1 , wherein the width of the light exit surface of the annular light guide plate gradually decreases along a rotation direction away from the light incident surface.

6. The annular light guide plate is a counter light-emitting surface facing the light-emitting surface in a thickness direction of the annular light guide plate; annular inner surfaces adjacent the light-emitting surface and the light-receiving surface, respectively; an outer ring surface adjacent to the light-emitting surface and the light-receiving surface, respectively, and facing the inner ring surface; The light source module with an annular light guide plate according to claim 1 , wherein the light-emitting surface and the light-reverse surface are located between the inner surface of the annulus and the outer surface of the annulus.

7. The light guide plate further includes at least two color filters disposed between the front writing surface of the annular light guide plate and the light source; the color filters are aligned along a line on the light entrance surface, the line extending from the inner ring surface to the outer ring surface, and at least two of the color filters have different colors; When the quantity of the at least one light ray is two or more, one of the at least two light ray passes through one of the color filters close to the inner ring surface and enters the annular light guide plate, and another of the at least two light ray passes through another of the color filters close to the outer ring surface and enters the annular light guide plate; 7. The light source module with an annular light guide plate according to claim 6, wherein the optical wavelength of one of the at least two light rays is smaller than the optical wavelength of another of the at least two light rays.

8. When the quantity of the at least one light source is two or more, the annular light guide plate has: a plurality of transmission paths adjacent to the light entrance surface, each of the transmission paths extending along a rotational direction away from the light entrance surface, and aligned along a direction at the light entrance surface, the direction extending from the inner ring surface toward the outer ring surface; 7. A light source module equipped with an annular light guide plate according to claim 6, wherein the light sources correspond to the respective transmission paths within the annular light guide plate and on the light incident surface.

9. 2. The light source module equipped with an annular light guide plate according to claim 1, wherein the annular light guide plate has a long axis, and the long axis passes through an annular center of the annular light guide plate, the light exit surface of the annular light guide plate intersects with the long axis, and the light entrance surface is polygonal, the polygon having a long side adjacent to the light exit surface, and the long side extending from the annular center of the annular light guide plate in a radial direction of the annular center.

10. The annular light guide plate further includes a light-returning surface and an annular inner surface, the light-returning surface facing the light-returning surface in a thickness direction of the annular light guide plate, the annular inner surface respectively adjacent to the light-returning surface and the light-returning surface, a first distance exists between the annular center and a test point on the major axis, and the value of the first distance is S1, the shortest distance between the major axis and the annular inner surface is a second distance, and the value of the second distance is S2, an included angle between the light-returning surface and the major axis of the annular light guide plate is θ1, and 90°-θ1=tan －１ A light source module comprising the annular light guide plate according to claim 9, which satisfies (S1 / S2)±10°.

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