Light source module and display device

Abstract

The present invention provides a light source module and a display device, wherein the light source module includes a light-emitting component, a light guide plate, and a filter. The light-emitting component includes a light-emitting surface. The light guide plate includes a light incident surface, and the light guide plate is arranged so that the light incident surface faces the light-emitting surface. The filter is arranged between the light-emitting surface and the light incident surface, and the center wavelength of the reflection band of the filter falls within the range of 570nm to 590nm. The light-emitting component emits first light having a first color temperature from the light-emitting surface. After passing through the filter, the first light is filtered into second light having a second color temperature. The light incident surface of the light guide plate receives the second light, wherein the first color temperature is lower than the second color temperature.

Description

Technical Field

[0001] The present invention relates to an optical module and a device, and in particular to a light source module and a display device. Background Art

[0002] Light source modules are widely used in display devices, and the light-emitting diodes (LEDs) are the primary light-emitting components used in these modules. Generally speaking, to enhance the color saturation of a light source module, a hybrid LED is used as the light-emitting component, such as a blue LED paired with green and red phosphors. However, this achieves a narrow color gamut based on the NTSC (National Television System Committee) standard. Using red, blue, and green LEDs as the light-emitting components results in poor efficiency and easily produces color differences due to the varying attenuation rates of different LEDs. Therefore, achieving both optimal color saturation and a wider NTSC color gamut in a light source module is a current challenge. Summary of the Invention

[0003] The present invention is directed to a light source module and a display device, which have better color saturation and a wider NTSC color gamut.

[0004] According to an embodiment of the present invention, a light source module includes a light-emitting component, a light guide plate, and a filter. The light-emitting component includes a light-emitting surface. The light guide plate includes a light incident surface, and the light guide plate is arranged so that the light incident surface faces the light-emitting surface. The filter is arranged between the light-emitting surface and the light incident surface, and the center wavelength of the reflection band of the filter falls within the range of 570nm to 590nm. The light-emitting component emits first light having a first color temperature from the light-emitting surface. After passing through the filter, the first light is filtered into second light having a second color temperature. The light incident surface of the light guide plate receives the second light, wherein the first color temperature is lower than the second color temperature.

[0005] In the light source module according to the embodiment of the present invention, the first color temperature is between 2500K and 3800K.

[0006] In the light source module according to the embodiment of the present invention, the second color temperature is between 6000K and 7000K.

[0007] In a light source module according to an embodiment of the present invention, a filter includes a substrate and a stacked structure disposed on the substrate. The stacked structure includes (N+1) first material layers and N second material layers in an alternating stack, where N is a positive integer. Each second material layer is sandwiched between two first material layers. The first material layers have a first refractive index, and the second material layers have a second refractive index, wherein the first refractive index is greater than the second refractive index.

[0008] In the light source module according to the embodiment of the present invention, the ratio of the difference between the first refractive index and the second refractive index to the number of layers of the stack structure is between 0.049 and 0.277.

[0009] In the light source module according to the embodiment of the present invention, the material of the first material layer includes titanium dioxide, and the material of the second material layer includes silicon dioxide.

[0010] In the light source module according to an embodiment of the present invention, the thickness of each of the first material layers is 3(λ0 / 4n1) or 5(λ0 / 4n1), and the thickness of each of the second material layers is 3(λ0 / 4n2) or 5(λ0 / 4n2), where λ0 is the center wavelength of the reflection band of the filter, n1 is the first refractive index, and n2 is the second refractive index.

[0011] In the light source module according to the embodiment of the present invention, the width of the reflection band ranges from 20 nm to 120 nm.

[0012] In the light source module according to the embodiment of the present invention, the light emitting component includes silicate or yellow phosphor.

[0013] According to an embodiment of the present invention, a display device includes the light source module and a display module as described above. The display module is located under the light guide plate of the light source module.

[0014] In the light source module according to the embodiment of the present invention, the display module is a reflective display module.

[0015] In the light source module according to the embodiment of the present invention, the light source module is a front light source module.

[0016] In the light source module according to the embodiment of the present invention, the display module is bonded to the light guide plate of the light source module via an adhesive material.

[0017] Based on the above, the light source module of the present invention includes a filter arranged between the light-emitting surface and the light-incident surface, and the center wavelength of the reflection band of the filter falls within the range of 570nm to 590nm. This can filter the first light with a lower color temperature into the second light with a higher color temperature through the filter, thereby obtaining a light source module with a wider NTSC color gamut and improving the color saturation of the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a cross-sectional schematic diagram of a light source module according to an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 A schematic cross-sectional view of a light-emitting component in a display device;

[0020] Figure 3 yes Figure 1 A schematic cross-sectional view of a filter in a display device;

[0021] Figure 4 is a reflection spectrum diagram of a filter according to an embodiment of the present invention;

[0022] Figure 5 is a spectrum diagram of a first light according to an embodiment of the present invention;

[0023] Figure 6 is a spectrum diagram of a second light according to an embodiment of the present invention;

[0024] Figure 7 is a schematic cross-sectional view of a display device according to an embodiment of the present invention.

[0025] Description of Reference Numerals

[0026] 10: Display device;

[0027] 100: light source module;

[0028] 110: light-emitting component;

[0029] 111: packaged light emitting diode;

[0030] 112: light emitting diode chip;

[0031] 114: fluorescent structure;

[0032] 119: circuit board;

[0033] 110a: light-emitting surface;

[0034] 120: filter;

[0035] 122: base;

[0036] 124: stack structure;

[0037] 124a: first material layer;

[0038] 124b: second material layer;

[0039] 130: light guide plate;

[0040] 130a: light incident surface;

[0041] 200: display module;

[0042] L1: First light;

[0043] L2: Second light. DETAILED DESCRIPTION

[0044] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0045] The directional terms mentioned herein, such as "up," "down," "front," "back," "left," "right," etc., are merely references to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrative purposes only and are not intended to limit the present invention.

[0046] In the accompanying drawings, each figure illustrates the general characteristics of the methods, structures, and / or materials used in a particular embodiment. However, these figures should not be interpreted as defining or limiting the scope or nature of the embodiments. For example, the relative size, thickness, and position of various layers, regions, and / or structures may be reduced or exaggerated for clarity.

[0047] In the following embodiments, identical or similar components will be denoted by identical or similar reference numerals, and redundant descriptions will be omitted. Furthermore, features from different embodiments may be combined unless there is a conflict, and simple equivalent variations and modifications made within the scope of this specification or claims are also covered by this patent.

[0048] The terms "first," "second," and the like mentioned in this specification or claims are used only to name discrete components or to distinguish between different embodiments or scopes, and are not intended to limit the upper or lower limit on the number of components, nor to define the order in which the components may be manufactured or disposed. Furthermore, "a component / film layer disposed on (or over) another component / film layer" may encompass situations where the component / film layer is directly disposed on (or over) the other component / film layer, with the two components / film layers in direct contact; and situations where the component / film layer is indirectly disposed on (or over) the other component / film layer, with one or more components / film layers interposed between the two components / film layers.

[0049] Figure 1 is a cross-sectional schematic diagram of a light source module according to an embodiment of the present invention. Figure 2 yes Figure 1 A schematic cross-sectional view of a light-emitting component in a light source module. Figure 3 yes Figure 1 A schematic cross-sectional view of a filter in a light source module. Figure 4 FIG. 4 is a reflection spectrum diagram of a filter according to an embodiment of the present invention. Figure 5 FIG. 4 is a spectrum diagram of a first light according to an embodiment of the present invention. Figure 6 FIG. 4 is a spectrum diagram of a second light according to an embodiment of the present invention.

[0050] Please refer to Figure 1, the light source module 100 includes a light-emitting component 110, a filter 120 and a light guide plate 130. The light-emitting component 110 includes a light-emitting surface 110a, the light guide plate 130 includes a light-incident surface 130a, and the light-incident surface 130a of the light guide plate 130 is arranged to face the light-emitting surface 110a of the light-emitting component 110. The filter 120 is arranged between the light-emitting surface 110a and the light-incident surface 130a, and the center wavelength of the reflection band of the filter 120 falls within the range of 570nm to 590nm. The light-emitting component 110 emits a first light L1 with a first color temperature from the light-emitting surface 110a. After passing through the filter 120, the first light L1 is filtered into a second light L2 with a second color temperature. The light-incident surface 130a of the light guide plate 130 receives the second light L2, and the first color temperature is lower than the second color temperature. In Figure 1 In the embodiment, the light source module 100 may be further covered by a cover plate (not shown), and the light emitting element 110, the optical filter 120, and the light guide plate 130 may be attached to the cover plate (not shown) by an adhesive material (not shown), but the present invention is not limited thereto. In other embodiments, the light emitting element 110, the optical filter 120, and the light guide plate 130 of the light source module 100 may be positioned relative to each other by other mechanisms and assembled together.

[0051] The light incident surface 130a of the light guide plate 130 can receive the second light L2 and guide the second light L2 into a surface light source. The material of the light guide plate 130 may include glass, polycarbonate (PC), polymethyl methacrylate (PMMA) or other suitable organic materials or inorganic materials, but the present invention is not limited thereto. The light incident surface 130a of the light guide plate 130 is located on the side of the light guide plate 130, so the light source module 100 has a side light incident design. The light emitting component 110 can be a light bar and is arranged on the side of the light guide plate 130. In response to the side light incident and the design of the light bar, the filter 120 can be a strip-shaped optical film arranged along the light incident surface 130a.

[0052] Please refer to Figure 2 In some embodiments, the light emitting component 110 may be composed of a packaged light emitting diode 111 and a circuit board 119 carrying the light emitting diode. For example, the packaged light emitting diode 111 may include a light emitting diode chip 112 and a fluorescent structure 114. The light emitting diode chip 112 is, for example, a blue light emitting diode, but the present invention is not limited thereto. The fluorescent structure 114 may include a matrix and silicate or yellow phosphor (such as YAG) doped in the matrix, but the present invention is not limited thereto. Figure 2In some embodiments, the fluorescent structure 114 may surround the periphery and top surface of the LED chip 112. However, in other embodiments, the fluorescent structure 114 may be disposed only on the top surface of the LED chip 112. The light emitted by the LED chip 112 includes a first portion emitted directly from the light-emitting surface 110a and a second portion emitted from the light-emitting surface 110a after being converted by the fluorescent structure 114. In some embodiments, the wavelength of the second portion may be longer than the wavelength of the first portion. In addition, the first portion and the second portion of light together constitute a first light L1 having a first color temperature. For example, if the fluorescent structure 114 includes silicate or yellow phosphor (such as YAG), the first color temperature may range from 2500K to 3800K, or be lower than 6000K.

[0053] Please refer to Figure 3 The filter 120 may include a substrate 122 and a stack structure 124 disposed on the substrate 122. The substrate 122 may be a light-transmitting material, such as polycarbonate (PC), polymethylmethacrylate (PMMA) or other suitable materials, but the present invention is not limited thereto. The stack structure 124 includes (N+1) first material layers 124a and N second material layers 124b stacked in an alternating manner, where N is a positive integer, and each of the second material layers 124b is sandwiched between two of the first material layers 124a. In other words, a second material layer 124b is sandwiched between two adjacent first material layers 124a. The material of the first material layer 124a is different from the material of the second material layer 124b. The first material layer 124a has a first refractive index, the second material layer 124b has a second refractive index, and the first refractive index is greater than the second refractive index. For example, the first material layer 124a may include titanium dioxide, and the second material layer 124b may include silicon dioxide, but the present invention is not limited thereto. In other embodiments, the material of the first material layer 124a may be selected from silicon (Si), tantalum pentoxide (Ta2O5), titanium dioxide (TiO2), titanium pentoxide (Ti3O5), or niobium pentoxide (Nb2O5), while the material of the second material layer 124b may be selected from silicon dioxide (SiO2) or magnesium fluoride (MgF2). Through the design of the stacked structure 124, the center wavelength of the reflection band of the optical filter 120 can fall within the range of 570 nm to 590 nm, and the width of the reflection band can fall within the range of 20 nm to 120 nm.

[0054] Figure 4 The transmission spectrum of the stack structure in which the first material layer 124a is made of titanium dioxide and the second material layer 124b is made of silicon dioxide is shown. Figure 41 and 2 are transmission spectra of two examples of the filter 120, and the two examples have stack structures 124 with different numbers of layers. Figure 4 As shown, the center wavelength of the reflection bands exhibited by the two examples of optical filters 120 roughly falls within the range of 570nm to 590nm, and the width of the reflection bands ranges from 20nm to 120nm. Furthermore, the reflection band width of the optical filter 120 including the stack structure 124 with N being 5 is narrower than the reflection band width of the optical filter 120 including the stack structure 124 with N being 3. This shows that, given the material properties of the first material layer 124a and the second material layer 124b, the width of the reflection band of the optical filter 120 can be adjusted by adjusting the number of layers in the stack structure 124.

[0055] In some embodiments, to achieve the desired filtering effect, the smaller the difference between the first refractive index and the second refractive index, the more layers are required in the stacked structure 124. The number of layers in the stacked structure 124 refers to the sum of the number of first material layers 124a (N+1) and the number of second material layers 124b (N), that is, 2N+1. For example, the ratio of the difference between the first refractive index and the second refractive index (Δn) to the number of layers in the stacked structure 124 (2N+1) (Δn / (2N+1)) can be between 0.049 and 0.277. In some embodiments, N is at least 3. Preferably, N can be 3, 5, 7, or other odd numbers.

[0056] In some embodiments, the thickness of each first material layer 124a is 3(λ0 / 4n1) or 5(λ0 / 4n1), and the thickness of each second material layer 124b is 3(λ0 / 4n2) or 5(λ0 / 4n2), where λ0 is the center wavelength of the reflection band of the optical filter 120, n1 is the first refractive index, and n2 is the second refractive index. If the materials of the first material layer 124a and the second material layer 124b are known, the center wavelength of the reflection band of the optical filter 120 can be adjusted by adjusting the thickness of the first material layer 124a and / or the thickness of the second material layer 124b. For example, the required thickness of the first material layer 124a and / or the thickness of the second material layer 124b, as well as the total number of layers required for the stacked structure 124, can be estimated using the Bragg reflection law.

[0057] In this embodiment, the first light L1 is filtered into the second light L2 by the filter 120. The first light L1 is emitted from the light emitting surface 110a of the light emitting component 110. Its light color is yellowish and has a relatively low color temperature, for example, between 2500K and 3800K (i.e., the first color temperature). Its spectrum is shown in FIG. Figure 5 As shown in FIG. 1 . Since the filter 120 can filter out light with a wavelength of about 570nm to 590nm, the first light L1 can be filtered into the second light L2. The spectrum of the second light L2 is shown in FIG. Figure 6The second light L2 exhibits a higher color temperature than the first light L1. Its color temperature (i.e., the second color temperature) is, for example, between 6000K and 7000K and can reach approximately 82% of the NTSC color gamut. When used in display applications, the second light L2 can provide images with good color saturation.

[0058] Figure 7 is a schematic cross-sectional view of a display device according to an embodiment of the present invention. Figure 7 The display device 10 includes a light source module 100 and a display module 200. The display module 200 is located under the light guide plate 130 of the light source module 100. For example, the display module 200 can be bonded to the light guide plate 130 by adhesive material to form the display device 10, but the present invention is not limited thereto.

[0059] In an exemplary application, the display device 10 may be a reflective display device, the light source module 100 thereof may be a front light source module, and the display module 200 may be a reflective display module, but the present invention is not limited thereto. That is, when a user views the image presented by the display device 10, the light source module 100 is located between the display module 200 and the user. The light source module 100 may include a light-emitting component 110, a filter 120, and a light guide plate 130. The light-emitting component 110 includes a light-emitting surface 110a, the light guide plate 130 includes a light-incident surface 130a, and the light-incident surface 130a of the light guide plate 130 is arranged to face the light-emitting surface 110a of the light-emitting component 110. The filter 120 is arranged between the light-emitting surface 110a and the light-incident surface 130a, and the center wavelength of the reflection band of the filter 120 falls within the range of 570nm to 590nm. The light-emitting component 110 emits first light L1 having a first color temperature from its light-emitting surface 110a. After passing through the optical filter 120, the first light L1 is filtered into second light L2 having a second color temperature. The light-incident surface 130a of the light guide plate 130 receives the second light L2, where the first color temperature is lower than the second color temperature. The display module 200 reflects the second light L2 from the light guide plate 130 into an image for the user to view. Based on the aforementioned configuration of the light source module 100, a wider NTSC color gamut can be achieved. Consequently, the image reflected by the display module 200 through the light source module 100 exhibits better color saturation.

[0060] In summary, the light source module of the present invention includes a filter disposed between the light-emitting surface and the light-incident surface, and the center wavelength of the reflection band of the filter falls within the range of 570nm to 590nm. This allows first light with a lower color temperature to be filtered by the filter into second light with a higher color temperature, thereby obtaining a light source module with a wider NTSC color gamut and improving the color saturation of the display device.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A light source module, characterized in that: include: A light-emitting component, including a light-emitting surface; A light guide plate, comprising a light incident surface, wherein the light guide plate is arranged so that the light incident surface faces the light emitting surface; as well as A filter is provided between the light emitting surface and the light incident surface, wherein the center wavelength of the reflection band of the filter falls within the range of 570nm to 590nm. The light-emitting component emits first light having a first color temperature from the light-emitting surface. The first light is filtered into second light having a second color temperature after passing through the filter. The light incident surface of the light guide plate receives the second light. The first color temperature is lower than the second color temperature. The light guide plate guides the second light having the second color temperature into a surface light source. The first color temperature is between 2500K and 3800K, and the second color temperature is between 6000K and 7000K.

2. The light source module according to claim 1, wherein: The filter includes a substrate and a stack structure disposed on the substrate, wherein the stack structure includes (N+1) first material layers and N second material layers stacked alternately, where N is a positive integer. Each of the second material layers is sandwiched between two of the first material layers, and The first material layer has a first refractive index, and the second material layer has a second refractive index, wherein the first refractive index is greater than the second refractive index.

3. The light source module according to claim 2, wherein: A ratio of a difference between the first refractive index and the second refractive index to the number of layers of the stacked structure is between 0.049 and 0.

277.

4. The light source module according to claim 2, wherein: The material of the first material layer includes titanium dioxide, and the material of the second material layer includes silicon dioxide.

5. The light source module according to claim 2, wherein: N is at least 3.

6. The light source module according to claim 2, wherein: The thickness of each of the first material layers is 3(λ0 / 4n1) or 5(λ0 / 4n1), and the thickness of each of the second material layers is 3(λ0 / 4n2) or 5(λ0 / 4n2), where λ0 is the center wavelength of the reflection band of the filter, n1 is the first refractive index, and n2 is the second refractive index.

7. The light source module according to claim 1, wherein: The width of the reflection band ranges from 20 nm to 120 nm.

8. The light source module according to claim 1, wherein: The light-emitting component includes silicate or yellow phosphor.

9. A display device, characterized in that: include: The light source module according to any one of claims 1 to 8; as well as The display module is located under the light guide plate of the light source module.

10. The display device according to claim 9, wherein The display module is a reflective display module.

11. The display device according to claim 9, wherein The light source module is a front light source module.

12. The display device according to claim 9, wherein The display module is bonded to the light guide plate of the light source module through an adhesive material.

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