Light source module and display device

Abstract

The invention discloses a light source module and a display device. The light source module includes a substrate, a plurality of blue light emitting diodes (LEDs), and a quantum dot film. The substrate includes a first surface. The plurality of blue light LEDs are arranged on the first surface, and the wavelength of blue light emitted by the blue light LEDs closer to the periphery of the substrate is shorter than that of blue light emitted by the blue light LEDs farther away from the periphery of the substrate. The quantum dot film is arranged on one side of the first surface of the substrate and comprises a plurality of quantum dots, and the quantum dots are excited to emit red light and green light after receiving blue light emitted by the blue light LED. The display device comprises a light source module and a liquid crystal module arranged on the other side, opposite to the substrate, of the quantum dot film.

Description

Technical Field

[0001] The invention relates to a light source module and a display device. Background Art

[0002] In recent years, liquid crystal display devices (LCD) have become the mainstream of various display devices. For example, home televisions, personal computers, laptops, monitors, mobile phones and digital cameras are all products that use a large number of LCD devices. Among the many forms of LCD devices, the sub-millimeter light-emitting diode (mini LED) backlight module with quantum dot (QD) film-type LCD device has the advantages of wider color gamut, higher display brightness, and less prone to burn-in, so it has attracted attention. However, the light source module of this type of LCD device is prone to brightness reduction and blue color in the area near the edge, which has room for improvement. Summary of the invention

[0003] An object of the present invention is to provide a light source module having more uniform brightness and color.

[0004] Another object of the present invention is to provide a display device having more uniform brightness and color.

[0005] The light source module of the present invention comprises a substrate, a plurality of blue light emitting diodes (LEDs) and a quantum dot film. The substrate comprises a first surface. A plurality of blue LEDs are arranged on the first surface, wherein the wavelength of the blue light emitted by the blue LEDs closer to the periphery of the substrate is shorter than the wavelength of the blue light emitted by the blue LEDs farther from the periphery of the substrate. The quantum dot film is arranged on one side of the first surface of the substrate, and comprises a plurality of quantum dots, which are excited to emit red light and green light after receiving the blue light emitted by the blue LEDs.

[0006] In one embodiment, a first area close to the periphery of the substrate is defined on the first surface, wherein the wavelength of blue light emitted by the blue LED disposed in the first area is shorter than the wavelength of blue light emitted by the blue LED disposed outside the first area.

[0007] In one embodiment, the wavelengths of the blue light emitted by the two rows of blue LEDs closest to the periphery of the substrate are shorter than the wavelengths of the blue light emitted by the other blue LEDs.

[0008] In one embodiment, the distance between adjacent blue LEDs is 2 to 6 times the distance between the first surface and the quantum dot film.

[0009] In one embodiment, a plurality of blue LEDs are arranged in a rectangular array, wherein: the wavelength of the blue light emitted by the blue LEDs in the first row and the second row at the ends of the long axis of the rectangular array is 4nm and 2nm less than the wavelength of the blue light emitted by the blue LEDs near the center of the substrate, respectively; the wavelength of the blue light emitted by the blue LEDs in the first row and the second row at the ends of the short axis of the rectangular array is 6nm and 3nm less than the wavelength of the blue light emitted by the blue LEDs near the center of the substrate, respectively.

[0010] In one embodiment, the spacing between the first and second rows of blue LEDs at the ends of the long axis of the rectangular array is 4.48 mm, and the spacing between the first and second rows of blue LEDs at the ends of the short axis of the rectangular array is 3.59 mm.

[0011] In one embodiment, the distance between the first surface and the quantum dot film is 1.2 mm.

[0012] In one embodiment, two adjacent blue light LEDs emitting blue light with a shorter wavelength are defined as a first blue light LED and a second blue light LED, respectively. The differences between the wavelengths of the blue light emitted by the first blue light LED and the second blue light LED and the wavelength of the blue light emitted by the blue light LED near the center of the substrate are Δλ1 and Δλ2. The energy of the blue light emitted by the first blue light LED reaching the corresponding quantum dot film directly above is W0, and the energy reaching the corresponding quantum dot film directly above the second blue light LED is W1. Then, the brightness adjustment amount of the first blue light LED at the corresponding quantum dot film directly above is expressed by the following formula: Brightness adjustment amount (%) = 0.67%*Δλ1*W0+0.67%*Δλ2*W1.

[0013] In one embodiment, two adjacent blue light LEDs emitting blue light with a shorter wavelength are defined as a first blue light LED and a second blue light LED, respectively. The differences between the wavelengths of the blue light emitted by the first blue light LED and the second blue light LED and the wavelength of the blue light emitted by the blue light LED near the center of the substrate are Δλ1 and Δλ2. The energy of the blue light emitted by the first blue light LED reaching the corresponding quantum dot film directly above is W0, and the energy reaching the corresponding quantum dot film directly above the second blue light LED is W1. Then, the chromaticity adjustment amount of the first blue light LED at the corresponding quantum dot film directly above is expressed by the following formula: Chromaticity adjustment amount (CIE_xy) = 0.00167*Δλ1*W0+0.00167*Δλ2*W1.

[0014] The display device of the present invention comprises the above light source module and a liquid crystal module arranged on the other side of the quantum dot film relative to the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1A FIG. 4 is a schematic diagram of an embodiment of a display device of the present invention.

[0016] Figure 1B This is a diagram showing the measurement results of the light divergence angle in the prior art.

[0017] Figure 2 It is a schematic diagram of an embodiment of a substrate and a blue light LED in a light source module of the present invention.

[0018] Figure 3 Schematic diagrams of different embodiments of the substrate and the blue light LED in the light source module of the present invention.

[0019] Figure 4 Schematic diagram of adjacent blue LEDs in the calculation formula of brightness adjustment amount and chromaticity adjustment amount.

[0020] Figure 5 Schematic diagram of the relationship between wavelength adjustment amount.

[0021] Description of reference numerals:

[0022] 100: Substrate

[0023] 101: First Surface

[0024] 200: Blue light emitting diode

[0025] 200': Blue LED

[0026] 200”: Blue LED

[0027] 201: The first blue LED

[0028] 202: Second blue LED

[0029] 300: Quantum dot film

[0030] 310: Quantum dots

[0031] 400: LCD module

[0032] 500: Optical film

[0033] 600: Optical film

[0034] 710: First Area

[0035] 800: Light source module

[0036] 900: Display device

[0037] D: Spacing

[0038] D1: Spacing

[0039] D2: Spacing

[0040] H: Distance

[0041] W0: Energy

[0042] W1: Energy DETAILED DESCRIPTION

[0043] The following is a specific embodiment and a drawing to illustrate the embodiment of the connection assembly disclosed in the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. However, the content disclosed below is not intended to limit the scope of protection of the present invention. Without deviating from the principle of the spirit of the present invention, those skilled in the art can implement the present invention with other different embodiments based on different viewpoints and applications. In the accompanying drawings, for the sake of clarity, the thickness of the layer, film, panel, region, etc. is magnified. Throughout the specification, the same reference numerals represent the same elements. It should be understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to another element, or an intermediate element can also exist. On the contrary, when an element is referred to as "directly on" or "directly connected to" another element, there is no intermediate element. As used herein, "connection" can refer to physical and / or electrical connection. Furthermore, "electrical connection" or "coupling" can be the presence of other elements between two elements.

[0044] It should be understood that although the terms "first", "second", "third", etc. can be used to describe various elements, components, regions, layers and / or parts in this article, these elements, components, regions, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, the "first element", "component", "region", "layer" or "part" discussed below can be referred to as a second element, component, region, layer or part without departing from the teachings of this article.

[0045] In addition, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe the relationship of one element to another element, as shown in the figures. It should be understood that relative terms are intended to include different orientations of the device in addition to the orientation shown in the figures. For example, if the device in one figure is turned over, the element described as being on the "lower" side of the other elements will be oriented on the "upper" side of the other elements. Therefore, the exemplary term "lower" can include both "lower" and "upper" orientations, depending on the specific orientation of the figure. Similarly, if the device in one figure is turned over, the element described as being "below" or "below" other elements will be oriented as being "above" other elements. Therefore, the exemplary term "below" or "below" can include both above and below orientations.

[0046] As used herein, "about", "approximately", or "substantially" includes the stated value and the average value within an acceptable deviation range of the particular value determined by one of ordinary skill in the art, taking into account the measurement in question and the particular amount of error associated with the measurement (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within ±30%, ±20%, ±10%, ±5%. Furthermore, as used herein, "about", "approximately", or "substantially" can select a more acceptable deviation range or standard deviation depending on the optical property, etching property or other property, and can apply to all properties without a single standard deviation.

[0047] like Figure 1A In the embodiment shown, the light source module 800 of the present invention comprises a substrate 100, a plurality of blue light emitting diodes (LEDs) 200, and a quantum dot film 300. Further, the light source module 800 of the present invention can be combined with a liquid crystal module 400 disposed on the other side of the quantum dot film 300 relative to the substrate 100 to form a display device 900 of the present invention. The display device 900 can further comprise optical films 500 and 600 to enhance optical properties.

[0048] like Figure 1A In the embodiment shown, the substrate 100 includes a first surface 101, and a plurality of blue LEDs 200 are disposed on the first surface 101. More specifically, the substrate 100 includes a printed circuit board, and the plurality of blue LEDs 200 are electrically connected to circuits disposed on the first surface 101. The wavelength of the blue light emitted by the blue LEDs 200 closer to the periphery of the substrate 100 is shorter than the wavelength of the blue light emitted by the blue LEDs 200 farther from the periphery of the substrate 100. The quantum dot film 300 is disposed on one side of the first surface 101 of the substrate 100, and includes a plurality of quantum dots 310. In one embodiment, the spacing between adjacent blue LEDs 200 is 2 to 6 times the distance between the first surface 101 and the quantum dot film 300. After receiving the blue light emitted by the blue LEDs 200, the quantum dots 310 are excited to emit red light and green light. Furthermore, the quantum dots 310 may include elements such as zinc, chromium, selenium, and sulfur, and may have diameters of 6 nm and 2.5 nm to be excited to emit red light and green light, respectively.

[0049] In the prior art, Figure 1BAs shown in the measurement results, the divergence angle of the blue light emitted by the blue LED is smaller, while the divergence angle of the red light and the green light emitted by the quantum dot after receiving the blue light is larger. Therefore, the area above the quantum dot film that is closer to the periphery of the substrate receives less red light and green light, resulting in lower brightness and a bluer color. However, according to the light energy principle E=hc / λ (h: Planck's constant c: speed of light λ: wavelength of light), the short-wavelength blue LED has higher energy to excite the quantum dot film to obtain higher brightness and more red and green light. In the present invention, the wavelength of the blue light emitted by the blue LED 200 that is closer to the periphery of the substrate 100 is shorter than the wavelength of the blue light emitted by the blue LED 200 that is farther away from the periphery of the substrate 100. Therefore, in the present invention, the quantum dots 310 above the blue light LED 200 closer to the periphery of the substrate 100 can emit more red light and green light, so that more red light and green light reach the area above the quantum dot film 300 closer to the periphery of the substrate 100, making the brightness and color more uniform.

[0050] More specifically, if Figure 2 In the illustrated embodiment, a first area 710 close to the periphery of the substrate 100 is defined on the first surface 101, wherein the wavelength of the blue light emitted by the blue LED 200 disposed in the first area 710 is shorter than the wavelength of the blue light emitted by the blue LED 200 disposed outside the first area 710. The wavelength of the blue light emitted by the blue LED 200 disposed in the first area 710 close to the periphery of the substrate 100 is further shorter than the wavelength of the blue light emitted by the blue LED 200 also disposed in the first area 710 but farther from the periphery of the substrate 100.

[0051] Looking at it from different angles, Figure 3 In the embodiment shown, the wavelength of the blue light emitted by the two rows of blue light LEDs 200' and 200" closest to the periphery of the substrate 100 is shorter than the wavelength of the blue light emitted by other blue light LEDs 200. Among them, the wavelength of the blue light emitted by the first row of blue light LEDs 200' closest to the periphery of the substrate 100 is further shorter than the wavelength of the blue light emitted by the second row of blue light LEDs 200" farther from the periphery of the substrate 100.

[0052] like Figure 3In the embodiment shown, a plurality of blue LEDs may be arranged in a rectangular array, wherein the spacing D1 between the blue LEDs 200' in the first row and the blue LEDs 200", located at the sides at both ends of the long axis of the rectangular array (i.e., the left and right sides in the figure) may be 4.48 mm, and the wavelength of the blue light emitted may be 4 nm and 2 nm less than the wavelength of the blue light emitted by the blue LEDs 200 near the center of the substrate, respectively; the spacing D2 between the blue LEDs 200' in the first row and the blue LEDs 200", located at both ends of the short axis of the rectangular array (i.e., the upper and lower sides in the figure) may be 3.59 mm, and the wavelength of the blue light emitted may be 6 nm and 3 nm less than the wavelength of the blue light emitted by the blue LEDs 200 near the center of the substrate, respectively. The first surface 101 and the quantum dot film 300 (see Figure 1A ) is 1.2mm.

[0053] Furthermore, if Figure 4 In the embodiment shown, two adjacent blue LEDs emitting shorter wavelength blue light are defined as the first blue LED 201 and the second blue LED 202, respectively. The wavelength differences between the blue light emitted by the first blue LED 201 and the second blue LED 202 and the blue light emitted by the blue LED near the center of the substrate are Δλ1 and Δλ2. The energy of the blue light emitted by the first blue LED 201 reaching the corresponding quantum dot film 300 directly above is W0, and the energy reaching the corresponding quantum dot film 300 directly above the second blue LED 202 is W1. Then, the brightness adjustment amount and the chromaticity adjustment amount of the first blue LED 201 at the corresponding quantum dot film 300 directly above can be expressed by the following formulas, respectively:

[0054] Brightness adjustment amount (%) = 0.67%*Δλ1*W0+0.67%*Δλ2*W1,

[0055] Chromaticity adjustment amount (CIE_xy) = 0.00167*Δλ1*W0+0.00167*Δλ2*W1,

[0056] In other words, the above formula can be used to evaluate the effect of wavelength adjustment on brightness enhancement and chromaticity improvement, which can be used as a basis for design and manufacturing.

[0057] For example, if Figure 3 The distance D2 between the first row of blue LEDs 200' and the second row of blue LEDs 200" on the upper and lower sides is 3.59 mm. Figure 1A The distance between the first surface 101 and the quantum dot film 300 is 1.2 mm. Figure 4 D≒3H. Since the benefit (energy) is defined as W being inversely proportional to the square of the distance, that is, W1=W0*H 2 / (D 2 H2 ), so W1=0.1*W0. Therefore, when the wavelength adjustment amounts of the first blue light LED 200' and the second blue light LED 200" are 4nm and 2nm respectively,

[0058] Chroma improvement effect:

[0059] The chromaticity adjustment amount of the first blue LED 200 ′=0.00167*4*1+0.00167*2*0.1=0.00668+0.00033=7 / 1000,

[0060] The chromaticity adjustment amount of the second blue light LED 200" = 0.00167*2*1 + 0.00167*4*0.1 = 0.0033 + 0.00067 = 4 / 1000,

[0061] Brightness enhancement effect:

[0062] The brightness adjustment amount of the first blue LED 200' (%) = 0.67% * 4 * 1 + 0.67% * 2 * 0.1 = 2.68% + 0.268% = 2.8%,

[0063] The brightness adjustment amount (%) of the second blue LED 200″=0.67%*2*1+0.67%*4*0.1=1.34%+0.268%=1.6%.

[0064] like Figure 3 The distance D1 between the first row of blue LEDs 200' and the second row of blue LEDs 200" on the left and right sides is 4.48 mm. Figure 1A The distance between the first surface 101 and the quantum dot film 300 is 1.5 mm. Figure 4 D≒4H, W1=0.067*W0, so when the wavelength adjustment amounts of the first blue light LED 201 and the second blue light LED 202 are 6nm and 3nm respectively,

[0065] Chroma improvement effect:

[0066] Chromaticity adjustment amount of the first blue LED 200 ′=0.00167*6*1+0.00167*3*0.067=0.01+0.00034=10 / 1000,

[0067] The chromaticity adjustment amount of the second blue light LED 200" = 0.00167*3*1 + 0.00167*6*0.067 = 0.005 + 0.00067 = 6 / 1000,

[0068] Brightness enhancement effect:

[0069] The brightness adjustment amount of the first blue LED 201 (%) = 0.67%*6*1+0.67%*3*0.067=4.02%+0.13%=4.2%,

[0070] The brightness adjustment amount (%) of the second blue LED 202 = 0.67%*3*1+0.67%*6*0.067=2.01%+0.027%=2.04%.

[0071] In one embodiment, if Figure 4 As shown, the blue LEDs emitting shorter wavelength blue light are defined as a first blue LED, and the difference between the wavelength of the blue light emitted by the first blue LED and the wavelength of the blue light emitted by the blue LEDs near the center of the substrate is Δλ1. Then, at the quantum dot film directly above the first blue LED, the brightness adjustment amount (%) = 0.67% * Δλ1, Δλ wavelength adjustment amount ≒ brightness difference (%) * 1.49, and the chromaticity adjustment amount (CIE_xy) = 0.00167 * Δλ1, Δλ wavelength adjustment amount ≒ chromaticity difference * 598.8. Figure 5 In the embodiment shown, the wavelength adjustment amount Δλ can be expressed as 1nm≦Δλ≦2*D / H-1. In one embodiment, the wavelength adjustment amount Δλ1 is equal or decreases from the outermost part of the light source module to the inner part.

[0072] The present invention has been described by the above-mentioned relevant embodiments, however, the above-mentioned embodiments are only examples for implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, modifications and equivalent settings of the concepts and scopes contained in the claims are all included in the scope of the present invention.

Claims

1. A light source module, comprising: A substrate comprising a first surface; A plurality of blue light emitting diodes (LEDs) are disposed on the first surface, wherein the wavelength of blue light emitted by the blue LEDs closer to the periphery of the substrate is shorter than the wavelength of blue light emitted by the blue LEDs farther from the periphery of the substrate; A quantum dot film is disposed on one side of the first surface of the substrate and includes a plurality of quantum dots. After receiving the blue light emitted by the blue LEDs, the quantum dots are excited to emit red light and green light.

2. The light source module as claimed in claim 1, wherein a first area close to the periphery of the substrate is defined on the first surface, wherein the wavelength of the blue light emitted by the blue light LEDs arranged in the first area is shorter than the wavelength of the blue light emitted by the blue light LEDs arranged outside the first area.

3. The light source module according to claim 1, wherein: The wavelengths of the blue light emitted by the two rows of blue LEDs closest to the periphery of the substrate are shorter than the wavelengths of the blue light emitted by the other rows of blue LEDs. 4 . The light source module as claimed in claim 2 , wherein a distance between adjacent blue LEDs is 2 to 6 times the distance between the first surface and the quantum dot film.

5. The light source module as claimed in claim 4, wherein the blue LEDs are arranged in a rectangular array, wherein: The wavelengths of the blue light emitted by the blue LEDs in the first and second rows at the two ends of the long axis of the rectangular array are respectively 4nm and 2nm shorter than the wavelengths of the blue light emitted by the blue LEDs near the center of the substrate; The wavelengths of the blue light emitted by the blue LEDs in the first and second rows at the two ends of the short axis of the rectangular array are respectively 6nm and 3nm shorter than the wavelengths of the blue light emitted by the blue LEDs near the center of the substrate.

6. The light source module as described in claim 5, wherein the spacing between the blue LEDs in the first and second rows on the sides at both ends of the long axis of the rectangular array along the long axis direction of the rectangular array is 4.48 mm, and the spacing between the blue LEDs in the first and second rows on the sides at both ends of the short axis of the rectangular array along the short axis direction of the rectangular array is 3.59 mm. 7 . The light source module as claimed in claim 6 , wherein the distance between the first surface and the quantum dot film is 1.2 mm.

8. The light source module as claimed in claim 4, wherein two adjacent blue LEDs emitting blue light of shorter wavelength are respectively defined as a first blue LED and a second blue LED, the wavelengths of the blue light emitted by the first blue LED and the second blue LED differ from the wavelengths of the blue light emitted by the blue LEDs near the center of the substrate by Δλ1 and Δλ2, the energy of the blue light emitted by the first blue LED reaching the corresponding quantum dot film directly above is W0, and the energy of the blue light emitted by the first blue LED reaching the corresponding quantum dot film directly above is W1, then the brightness adjustment amount of the first blue LED at the corresponding quantum dot film directly above is expressed by the following formula, Brightness adjustment amount (%) = 0.67%*Δλ1*W0+0.67%*Δλ2*W1.

9. The light source module as claimed in claim 4, wherein two adjacent blue LEDs emitting blue light of shorter wavelength are respectively defined as a first blue LED and a second blue LED, the wavelengths of the blue light emitted by the first blue LED and the second blue LED differ from the wavelengths of the blue light emitted by the blue LEDs near the center of the substrate by Δλ1 and Δλ2, the energy of the blue light emitted by the first blue LED reaching the corresponding quantum dot film directly above is W0, and the energy of the blue light emitted by the first blue LED reaching the corresponding quantum dot film directly above is W1, then the chromaticity adjustment amount of the first blue LED at the corresponding quantum dot film directly above is expressed by the following formula, Chromaticity adjustment amount (CIE_xy) = 0.00167*Δλ1*W0+0.00167*Δλ2*W1.

10. In the light source module as described in claim 4, the blue light LEDs that emit blue light with a shorter wavelength are defined as a first blue light LED, and the difference between the wavelength of the blue light emitted by the first blue light LED and the wavelength of the blue light emitted by the blue light LEDs close to the center of the substrate is Δλ1, then the brightness adjustment amount (%) of the first blue light LED at the corresponding quantum dot film directly above it = 0.67%*Δλ1, Δλ1 wavelength adjustment amount ≒ brightness difference (%)*1.

49.

11. The light source module as described in claim 4, wherein the blue light LEDs emitting blue light with a shorter wavelength are defined as a first blue light LED, and the difference between the wavelength of the blue light emitted by the first blue light LED and the wavelength of the blue light emitted by the blue light LEDs near the center of the substrate is Δλ1, then the chromaticity adjustment amount (CIE_xy) of the first blue light LED at the corresponding quantum dot film directly above is = 0.00167*Δλ1, Δλ1 wavelength adjustment amount ≒ chromaticity difference*598.

8.

12. The light source module as described in claim 4, wherein two adjacent blue light LEDs emitting blue light with a shorter wavelength are respectively defined as a first blue light LED at an outer edge and a second blue light LED relatively at an inner edge, the difference between the wavelength of the blue light emitted by the first blue light LED and the wavelength of the blue light emitted by the blue light LEDs close to the center of the substrate is defined as Δλ1, the difference between the wavelength of the second blue light LED relatively at the inner edge and the blue light LEDs at the center of the substrate is defined as Δλ2, and Δλ1≧Δλ2.

13. The light source module as claimed in claim 12, wherein the distance between the first blue LED and the second blue LED is D, the height from the substrate to the quantum dot film is H, and the wavelength adjustment amount Δλ1 is expressed by the following formula: 1nm≦Δλ1≦2*D / H-1≦12nm.

14. A display device, comprising: The light source module according to any one of claims 1 to 3; A liquid crystal module is arranged on the other side of the quantum dot film relative to the substrate.

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