TW201643485A - Light source module and manufacturing method thereof - Google Patents

Abstract

A manufacturing method of a light source module, which includes providing a light guide plate, which has a first surface, a second surface opposite to the first surface, an incident surface connecting the first surface and the second surface, and a plurality of optical diffusion micro-units; disposing a reflective sheet on the second surface and measure a light intensity distribution on the first surface while a light beam is incident on the incident surface; when the light intensity distribution on the first surface is different from a predetermined light intensity distribution, disposing a plurality of optical structures on a reflective surface, facing the second surface, of the reflective sheet, so that the light intensity distribution on the first surface approaches the predetermined light intensity distribution. A light source module is also provided.

Description

Light source module and manufacturing method thereof

The present invention relates to an optical device and a method of fabricating the same, and more particularly to a light source module and a method of fabricating the same.

The development of display technology in recent years has made various displays popular, and has gradually played an indispensable role in the daily life of modern people. The existing display technology has applied a liquid crystal display (LCD) panel to screens of electronic devices such as computer screens, smart phones, and electronic books, and in order to improve the display quality, the convenience of use can be increased. The above-mentioned displays have been trending toward a trend toward thinning.

However, since the liquid crystal display panel is a non-self-illuminating type display, the backlight module must be matched with the display. In general, the backlight module includes a linear light source and a light guide plate having a surface microstructure. With the thinning of the liquid crystal display, the backlight module is also becoming thinner, and therefore the thickness of the light guide plate is also required to be lowered. Since the thinned light guide plate is more likely to be damaged due to the negligence of the processing process when the surface microstructure is fabricated by a processing method such as screen printing, the production is improved. The instability of the surface microstructure, and the surface structure after fabrication can not be adjusted or repaired by rework. The above problems not only reduce the yield of the light guide plate manufacturing process, but also improve the difficulty of manufacturing the light guide plate and the cost of the backlight module. Therefore, how to simultaneously consider the thinning production of the light guide plate and save the manufacturing cost has become one of the problems to be solved at present.

The "previous technology" paragraph is only used to help understand the content of the present invention, so The disclosure of the "prior art" section may contain some conventional techniques that are not known to those of ordinary skill in the art. The matters disclosed in the "Prior Art" section, which do not represent the subject matter or the problems to be solved by one or more embodiments of the present invention, are known or recognized by those of ordinary skill in the art prior to the present application.

The invention provides a method for manufacturing a light source module, which can avoid the loss caused by the light guide plate during the processing, thereby improving the efficiency, the yield and the overall cost of the optical module with good optical quality.

The invention provides a light source module, which can form a good desired light source by using a relatively simplified structure.

The present invention provides a method for fabricating a light source module, including providing a light guide plate having a first surface, a second surface opposite to the first surface, and a light incident surface connecting the first surface and the second surface. And the light guide plate has a plurality of light diffusing micro-units; a reflective sheet is disposed on the second surface, and is measured when the light beam is incident on the light incident surface a light intensity distribution on the first surface; when the light intensity distribution on the first surface is different from a predetermined light intensity distribution, a plurality of optical structures are disposed on a reflective surface of the reflective sheet facing the second surface such that The light intensity distribution on the first surface approaches a preset light intensity distribution.

The invention provides a light source module, which comprises a light guide plate, a light emitting unit and a reflection sheet. The light guide plate has a plurality of uniformly distributed light diffusing micro-cells, and has a first surface, a second surface opposite to the first surface, and a light-incident surface connecting the first surface and the second surface. The light emitting unit is disposed beside the light incident surface and emits a light beam toward the light incident surface. The reflective sheet is disposed on the second surface and has a reflective surface facing the second surface. A plurality of optical structures are disposed on the reflective surface in a non-uniform manner.

In an embodiment of the invention, the optical structures described above comprise a plurality of light distribution dots, a plurality of light absorbing dots, or a combination thereof.

In an embodiment of the invention, the method of providing the optical structures described above is inkjet printing or screen printing.

In an embodiment of the invention, the light diffusing micro-units are a plurality of light-diffusing particles disposed inside the light guide plate.

In an embodiment of the invention, the light diffusing micro-units are a plurality of surface optical microstructures disposed on at least one of the first surface and the second surface.

In an embodiment of the invention, the light diffusing micro-units are uniformly distributed in the light guide plate, and the step of disposing the optical structures comprises placing the optical structures on a region of the reflecting surface close to the light incident surface or away from the light entering. The area of the face.

In an embodiment of the invention, the method for providing a light guide plate includes providing a light guide plate by an extrusion process.

In an embodiment of the invention, the above method of arranging the optical structures on the reflective surface of the reflective sheet is accomplished in a roll to roll process.

In an embodiment of the invention, when the light intensity of the local area on the first surface is greater than a corresponding preset value in the preset light intensity distribution, the optical structures are disposed on corresponding areas on the reflective surface to reduce The light intensity of the local area.

In an embodiment of the invention, when the light intensity of the local area on the first surface is smaller than a corresponding preset value in the preset light intensity distribution, the optical structures are disposed on the corresponding areas on the reflective surface to enhance The light intensity of the local area.

In an embodiment of the invention, the light intensity distribution and the light intensity in the predetermined light intensity distribution are luminance.

In an embodiment of the invention, the optical structures are disposed on a partial area of the reflective surface to suppress a phenomenon that the light guide plate is too strong in intensity corresponding to the local area.

In an embodiment of the invention, the optical structures are disposed on a partial area of the reflective surface to compensate for the phenomenon that the light intensity of the light guide plate is too low corresponding to the local area.

In an embodiment of the invention, the optical structures are arranged on the reflecting surface in a hexagonal arrangement.

In an embodiment of the invention, the optical structures described above comprise a cured white ink, a cured black ink, a cured clear ink, or a combination thereof.

In an embodiment of the invention, each of the optical structures described above is in the form of a dot.

Based on the above, the method for fabricating the light source module of the embodiment of the present invention has a plurality of optical structures disposed on the reflective sheet. Therefore, when the light beam enters the light guide plate from the light incident surface of the light guide plate, the first surface of the light guide plate may have a good surface. The required light intensity distribution. On the other hand, the light source module of the embodiment of the present invention can make the light guide plate form a good light source on the first surface by using the optical structure of the reflective sheet, thereby reducing the difficulty in fabricating the light source module and avoiding the light guide plate. The losses caused during processing, and the use of a more simplified architecture to form a good desired source.

The above described features and advantages of the invention will be apparent from the following description.

A, B, C‧‧‧ areas

L1, L2, L3, L4, L5, L6, L7‧‧‧ beams

100, 100A, 100B, 100C‧‧‧ light source module

110, 110A, 110B, 110C‧‧‧ light guide plate

112, 112A, 112B, 112C‧‧‧ first surface

114, 114B, 114C‧‧‧ second surface

116, 116A, 116B, 116C‧‧‧ into the glossy surface

117‧‧‧ surface

118, 118A, 118B‧‧‧Light diffusing microcells

120, 120A, 120B, 120C‧‧‧ reflection film

122, 122A, 122B, 122C‧‧‧ reflective surface

124, 124A, 124B, 124C‧‧‧ optical structure

125‧‧‧Light diffusion network

130, 130A, 130B, 130C‧‧‧ lighting units

140, 140A, 140B‧‧‧ optical diaphragm

1A to 1C are schematic views of a method of fabricating a light source module in accordance with a first embodiment of the present invention.

Figure 2 is a partial enlarged view of a reflecting surface and an optical structure in accordance with a first embodiment of the present invention.

3 is a schematic diagram of a light source module in accordance with a second embodiment of the present invention.

4 is a schematic diagram of a light source module in accordance with a third embodiment of the present invention.

Figure 5 is a schematic illustration of a light source module in accordance with a fourth embodiment of the present invention.

The foregoing and other technical contents, features and effects of the present invention are The detailed description of the various embodiments of the present invention will be apparent from the following description. The directional terms mentioned in the following embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only directions referring to the additional schema. Therefore, the directional terminology used is for the purpose of illustration and not limitation.

1A to 1C are schematic views of a method of fabricating a light source module in accordance with a first embodiment of the present invention. In the schematic diagram referred to in the first embodiment of the present invention, in order to clearly explain the relative relationship between the elements and the effects thereof, only the partial light beam transmission path is exemplarily illustrated in the drawings, which is not It is used to define the beam transmission mode in the light source module of the present invention. Referring to FIG. 1A, a method for fabricating a light source module according to a first embodiment of the present invention provides a light guide plate 110. The light guide plate 110 has a first surface 112, a second surface 114 opposite to the first surface 112, and a light incident surface 116 connecting the first surface 112 and the second surface 114, and the light guide plate 110 has a plurality of light diffusion micro Unit 118. In the present embodiment, the light diffusing micro-units 118 are distributed in the light guide plate 110, and when a light beam is transmitted to the light diffusing micro-units 118, the light-diffusing micro-units 118 are adapted to transmit the light beams in a plurality of directions. In other words, these light diffusing microcells 118 are adapted to diffuse the light beam.

Referring to FIG. 1B , in the method for fabricating the light source module of the embodiment, a reflective sheet 120 is disposed on the second surface 114 of the light guide plate 110 . The reflective sheet 120 is adapted to reflect the light beam from the second surface 114 (herein the light beam L2 is exemplified), so that the reflected light beam (herein the light beam L2 is exemplified) can pass through the light guide plate 110 from the first surface 112. For example, the light guide plate 110 of the present embodiment receives, for example, a light beam emitted by the light emitting unit 130 (here, the light beam L1 is taken as an example). Transmission by light guide plate 110, optical expansion The diffusion of the diffusing unit 118 and the reflection of the reflective sheet 120, the light beam (herein, the light beam L1 as an example) can enter the light guide plate 110 from the light incident surface 116 and then exit the first surface 112. In the method of fabricating the light source module of the present embodiment, when the light beam (herein, the light beam L1 is taken as an example) is incident on the light surface 116, the light formed on the first surface 112 is measured by, for example, a brightness meter. Intensity distribution.

After the correlation data of the light intensity distribution on the first surface 112 is measured by the above method, the correlation data of the light intensity distribution is compared with a predetermined light intensity distribution data. The preset light intensity distribution is, for example, the light intensity distribution of the light source module to be fabricated in an optimal state. The present invention is not limited thereto, and it can be known from the above comparison whether the first surface 112 is Some areas have problems of excessive brightness and low brightness. Referring to FIG. 1C , when the light intensity distribution on the first surface 112 is different from the preset light intensity distribution, the light source module 100 of the present embodiment is formed on a reflective surface of the reflective sheet 120 facing the second surface 114 . A plurality of optical structures 124 are disposed on the 122 such that the light intensity distribution on the first surface 112 approaches a predetermined light intensity distribution.

In other words, the reflective sheet 120 of the present embodiment can reflect the light beam from the second surface 114, and the optical structures 124 can change the light intensity distribution that is reflected by the reflective sheet 120 and enter the light guide plate 110, thereby making the first surface 112 The light intensity distribution can be approximated by a predetermined light intensity distribution by compensation of these optical structures 124.

Therefore, the fabrication method of this embodiment can form these optical structures 124 to easily produce a good light source module 100. When the light beam enters the light guide plate 110 from the light incident surface 116, the optical structure 124 formed on the reflective surface 122 can make the light intensity distribution of the first surface 112 approach the preset light intensity distribution, so the light guide plate 110 can be The additional processing and microstructure design (such as screen printing processing) is not required, thereby reducing the difficulty in fabricating the light guide plate 110. On the other hand, since the manufacturing method of the light source module 100 of the present embodiment measures the light intensity distribution on the first surface 112, the optical structure 124 can be formed on the reflective surface 122 to compensate the first surface 112. The light intensity distribution further avoids the scraping of the entire set of light source modules 110 due to poor light guiding effect of the light guide plate 110 during the manufacturing process of the light source module 100, and provides a simplified structure to form a good desired light source. The yield at the time of fabricating the light guide plate 110 is also improved.

The optical film sheet 140 such as a brightness enhancement film, a diffuser film, or the like may be formed on the first surface 112, and the present invention is not limited thereto. In detail, referring to FIG. 1C , in the embodiment, the light source module 100 includes a light guide plate 110 , a light emitting unit 130 (for example, a light emitting diode (LED)), and a reflective sheet 120 . The light guide plate 110 of the light source module 100 has a plurality of uniformly distributed light diffusion micro-units 118, and the light diffusion micro-units 118 are a plurality of light-diffusing particles disposed inside the light guide plate 110, and the light guide plate 110 transmits the light beam. The optical structure 124 disposed on the reflective surface 122 in a non-uniform manner compensates for the light intensity distribution of the local region, so that the light source module 100 can emit a light beam with a preset light intensity distribution. The light emitting unit 130 is disposed beside the light incident surface 116 and emits a light beam L toward the light incident surface 116. When the light beam L is transmitted through the light guide plate 110, it is emitted from the first surface 112 via the diffusion of the light diffusion micro-unit 118 or the reflection of the reflection sheet 120, so that the light intensity distribution on the first surface 112 approaches the preset light intensity distribution. .

Figure 2 is a partial enlarged view of a reflecting surface and an optical structure in accordance with a first embodiment of the present invention. Referring to FIG. 2, in the embodiment, the optical structures 124 described above include a plurality of light diffusion dots 125. More specifically, the light diffusion dots 125 are, for example, a cured white ink or a cured transparent ink or a combination of the two, and the light diffusion dots 125 are formed on the reflective surface 122 by, for example, inkjet printing. Therefore, the manufacturing method of the light source module of the embodiment of the present invention can easily form the optical structure 124 on the reflective surface 122, and also provides a manufacturing method that can easily form a good light source module, but the invention is not limited thereto. In other embodiments, the optical structure 124 may further comprise a plurality of light absorbing dots or a combination of the light diffusion dots and the light absorbing dots, wherein the light absorbing dots are, for example, cured black inks, and the optical structures 124 may be Screen printing is formed. Further, in other embodiments of the present invention, the method of arranging the optical structures on the reflective surface of the reflective sheet can be realized by a roll-to-roll process, thereby providing higher efficiency in, for example, mass production. Light source module production method.

Referring to FIG. 2, in the first embodiment of the present invention, the light diffusion dots 125 are, for example, dot-shaped optical structures 124 formed by inkjet printing, and the optical structures 124 can be made through the above manner. Arranged on the reflecting surface 122 in a high-density arrangement of hexagonal arrays to provide an optimum light intensity compensation effect. The optical structures of the embodiments of the present invention may be arranged on the reflective surface in other ways as needed, and are not limited to the arrangement of the optical structures 124 described above. On the other hand, in the manufacturing method of the light source module 100 of the embodiment, when the light intensity of the local area on the first surface 112 is greater than the corresponding preset value in the preset light intensity distribution, These optical structures 124 are disposed on corresponding areas on the reflective surface 122 to reduce the light intensity of the localized regions described above. In other words, the optical structures 124 of the light source module 100 of the present embodiment are disposed on a partial area on the reflective surface 122, and the light guide plate 110 is inhibited from being diffused or absorbed by the optical structure 124 to correspond to the local area. The phenomenon of excessive light intensity.

Specifically, in the first embodiment of the present invention, since the light diffusing micro-units 118 formed by, for example, a plastic material are uniformly distributed in the light guide plate 110, the optical structures 124 are disposed on the reflecting surface 122 away from the light-incident surface. Area A of 116. Since the light guide plate 110 is away from the light incident surface 116, a light beam (which is exemplified by the light beams L3, L4) passes through the second surface 114 during the transfer to the surface 117, and a light beam is reflected by the surface 117. The second surface 114 is then passed through to further increase the local light intensity of the region A of the reflective sheet 120. The light source module 100 of the present embodiment diffuses the partial light beam in the region A by the optical structure 124 (the light beam L3 is taken as an example), thereby bringing the light intensity distribution of the first surface 112 of the light guide plate 110 closer to Preset light intensity distribution.

In the embodiment of the present invention, the position of the optical structure on the reflecting surface is not limited to the partial area away from the light incident surface in the above embodiment, and the distribution area of the optical structure may further depend on the thickness, material and light diffusing micro unit of the light guide plate. The size, material, density, and preset light intensity distribution are adjusted appropriately. Other embodiments are listed below for illustration. It is to be noted that the following embodiments use the same reference numerals and parts of the above-mentioned embodiments, and the same reference numerals are used to refer to the same or similar elements, and the description of the same technical content is omitted. For a description of the omitted part, please refer to the previous The embodiments are not described again in the following embodiments.

3 is a schematic diagram of a light source module in accordance with a second embodiment of the present invention. Referring to FIG. 3, the light source module 100A is substantially similar to the light source module 100, but the main difference between the two is that, in the second embodiment of the present invention, the light diffusing micro-units 118A of the light guide plate 110A are disposed in the first embodiment. A plurality of surface optical microstructures of a surface 112A, and the optical structure 124A is disposed adjacent to the region B of the light incident surface 116A. The optical structure 124A of the present embodiment is, for example, a light absorbing mesh point. Therefore, after the light beam emitted from the light emitting unit 130A enters the light guide plate 110A from the light incident surface 116A, the optical structure 124A on the reflective surface 122A can be partially transmitted to the reflective sheet 120A. The beam of region B, in turn, causes the light intensity distribution on first surface 112A and on optical film 140A to approach a predetermined light intensity distribution.

4 is a schematic diagram of a light source module in accordance with a third embodiment of the present invention. Referring to FIG. 4, the light source module 100B is substantially similar to the light source module 100A, but the main difference between the two is that, in the third embodiment of the present invention, the light diffusing micro-units 118B of the light guide plate 110B are disposed in the first A plurality of surface optical microstructures of the two surfaces 114B, and the optical structure 124B is disposed in a region A remote from the light incident surface 116B. The optical structure 124B of the present embodiment is, for example, a combination of a light absorbing mesh point and a light diffusing mesh point. Therefore, when the light beam emitted from the light emitting unit 130B enters the light guide plate 110B from the light incident surface 116B, the optical structure 124B on the reflective surface 122B can be absorbed or The diffused portion is transmitted to the light beam of the region A of the reflective sheet 120B, so that the light intensity distribution on the first surface 112B and on the optical film 140B can approach the preset light intensity distribution.

Figure 5 is a schematic illustration of a light source module in accordance with a fourth embodiment of the present invention. in In an embodiment of the invention, the optical structure formed on the reflective surface is not limited to the optical structure 124 described above that can absorb or diffuse the beam. Referring to FIG. 5, in the fifth embodiment of the present invention, the light emitting unit 130C emits the light beam L5 to the light incident surface 116C of the light guide plate 110C. When the light intensity distribution of the local region on the first surface 112C is too low, the reflective surface On the 122C, the optical structure 124C having high reflectivity can be formed in the corresponding region (here, the region C is taken as an example), so that the reflective surface 122C and the optical structure 124C of the reflective surface of the reflective sheet 120C can reflect the light beam toward the second surface 114C. L6, L7, in turn, the light intensity of the local region where the light intensity distribution on the first surface 112C is too low is increased, and compensation is obtained. In other words, the optical structure 124C on the reflecting surface 122C can compensate for the phenomenon that the light intensity of the light guiding plate 110C at the local area corresponding to the above is too low.

In the above embodiments of the present invention, since the light guide plate has a uniform distribution The light diffusing microcell, so the above light guide plate can be produced, for example, in an extrusion process, but the invention is not limited thereto. In other words, since the optical module in the embodiment of the present invention can provide a good light source by the reflective sheet, and the light guide plate is formed of a uniform material, the embodiment of the present invention provides a simpler provision of the light guide plate. the way.

In the above embodiments of the present invention, the light intensity distribution and the preset light are The light intensity in the intensity distribution is luminance, but the present invention is not limited thereto. In other embodiments, the light intensity distribution of the first surface of the light guide plate can be appropriately adjusted according to the unit and demand of the preset light intensity distribution.

In summary, the method for fabricating the light source module of the embodiment of the present invention is first Measuring a light intensity distribution on the first surface of the light guide plate, and then providing a plurality of optical structures on the reflective sheet according to the comparison result between the light intensity distribution and the preset light intensity distribution, wherein the optical structures compensate the first surface Light intensity distribution. Since the above method does not need to additionally process the light guide plate, the loss caused by the light guide plate during the processing process can be avoided, and the production yield of the light source module is greatly improved, and a relatively simplified structure is used to form a good desired light source. . When the light beam emitted by the light emitting unit of the light source module of the embodiment of the present invention enters the light guide plate from the light incident surface of the light guide plate, the first surface of the light guide plate may have a good desired light intensity distribution, and the light source module borrows The optical structure of the reflective sheets allows the light guide plate to provide a good light source on the first surface, thereby reducing the difficulty in fabricating the light source module.

A‧‧‧ area

L1, L3, L4‧‧‧ beams

100‧‧‧Light source module

110‧‧‧Light guide plate

112‧‧‧ first surface

114‧‧‧ second surface

116‧‧‧Into the glossy surface

117‧‧‧ surface

118‧‧‧Light diffusing microcells

120‧‧‧reflector

122‧‧‧reflecting surface

124‧‧‧Optical structure

130‧‧‧Lighting unit

140‧‧‧Optical diaphragm

Claims (22)

A method for fabricating a light source module, comprising: providing a light guide plate, wherein the light guide plate has a plurality of light diffusing micro-cells, and has a first surface, a second surface opposite to the first surface, and a connection a light incident surface of the surface and the second surface; a reflective sheet disposed on the second surface; a light beam incident from the light incident surface, and measuring a light intensity distribution on the first surface; and when the first When the light intensity distribution on the surface is different from a predetermined light intensity distribution, a plurality of optical structures are disposed on a reflective surface of the reflective sheet facing the second surface such that the light intensity on the first surface The distribution approaches the predetermined light intensity distribution. The method of fabricating a light source module according to claim 1, wherein the optical structures comprise a plurality of light diffusion dots, a plurality of light absorption dots, or a combination thereof. The method for fabricating a light source module according to claim 1, wherein the method of providing the optical structures is inkjet printing or screen printing. The method for fabricating a light source module according to claim 1, wherein the light diffusing micro-units are a plurality of light-diffusing particles disposed inside the light guide plate. The method of fabricating a light source module according to claim 1, wherein the light diffusing micro-units are a plurality of surface optical microstructures disposed on at least one of the first surface and the second surface. The method of fabricating a light source module according to claim 1, wherein the light diffusing micro-units are evenly distributed in the light guiding plate, and the step of disposing the optical structures comprises setting the optical structures to the reflecting The area near the entrance surface or the area away from the light entrance surface. The method for fabricating a light source module according to claim 1, wherein the method for providing the light guide plate comprises providing the light guide plate by an extrusion process. The method of fabricating a light source module according to claim 1, wherein the method of disposing the optical structures on the reflective surface of the reflective sheet is implemented by a roll-to-roll process. The method of manufacturing the light source module of claim 1, wherein when the light intensity of the local area on the first surface is greater than a corresponding preset value in the predetermined light intensity distribution, the reflective surface is The corresponding regions are arranged to reduce the light intensity of the local region. The method of manufacturing the light source module of claim 1, wherein when the light intensity of the local area on the first surface is less than a corresponding preset value in the predetermined light intensity distribution, the reflective surface is The corresponding regions are arranged to enhance the light intensity of the local region. The method of fabricating a light source module according to claim 1, wherein the light intensity distribution and the light intensity in the predetermined light intensity distribution are luminance. A light source module includes: a light guide plate having a plurality of uniformly distributed light diffusing micro-cells, and having a first surface, a second surface opposite to the first surface, and a first surface coupled to the first surface a light incident surface of the second surface; a light emitting unit disposed adjacent to the light incident surface and emitting a light beam toward the light incident surface; a reflective sheet disposed on the second surface and having a second surface facing the second surface a reflective surface; and a plurality of optical structures disposed on the reflective surface in a non-uniform manner. The light source module of claim 12, wherein the optical structures comprise a plurality of light diffusion dots, a plurality of light absorption dots, or a combination thereof. The light source module of claim 12, wherein the light diffusing micro-units are a plurality of uniformly distributed light diffusing particles disposed inside the light guiding plate. The light source module of claim 12, wherein the light diffusing micro-units are a plurality of surface optical microstructures disposed on at least one of the first surface and the second surface. The light source module of claim 12, wherein the optical structures are disposed on a region of the reflective surface adjacent to the light incident surface or a region away from the light incident surface. The light source module of claim 12, wherein the optical structures are disposed on a partial area of the reflective surface to suppress a phenomenon that the light guide plate is too strong in intensity corresponding to the local area. The light source module of claim 17, wherein the light intensity is luminance. The light source module of claim 12, wherein the optical structures are disposed on a partial area of the reflective surface to compensate for a phenomenon in which the light intensity of the light guide plate is too low corresponding to the local area. The light source module of claim 12, wherein the optical structures are arranged on the reflective surface in a hexagonal arrangement. The light source module of claim 12, wherein the optical structures comprise a cured white ink, a cured black ink, a cured transparent ink, or a combination thereof. The light source module of claim 12, wherein each of the optical structures is in the form of a dot.