Display Devices

Abstract

The present invention discloses a display device having a light spectrum. The light spectrum is generated when displaying a white image with the highest gray scale. The integral value of the light spectrum from 415 nanometers to 455 nanometers is defined as a third integral, and the integral value from 400 nanometers to 500 nanometers is defined as a fourth integral. The ratio of the third integral to the fourth integral is less than 50%.

Description

[0001] This application is a divisional application of the invention patent application with the application date of March 19, 2019, application number 201910209217.6, and invention name “Display device and manufacturing method thereof”. Technical Field

[0002] The present invention relates to a display device, and in particular to a display device for protecting users' eyes from being harmed by blue light. Background Art

[0003] As display devices are widely used in various types of digital products, people spend more time watching screens. Therefore, reducing the harm of blue light to the user's eyes is an important research topic, especially for people who must watch the screen continuously or frequently, such as doctors or radiologists who need to watch radiological images on the screen. The traditional method of blocking blue light is to attach an anti-blue light filter to the display device to suppress the intensity of blue light. Alternatively, another traditional method of blocking blue light is to use software embedded in the display device to adjust the intensity of blue light generated by the display device. Although these methods can protect the user's eyes, they may reduce the overall brightness of the display device, or the displayed image may become yellowish, thereby reducing the display quality of the display device. Summary of the invention

[0004] According to one embodiment, the present invention provides a display device. The display device has a light spectrum, which is generated when displaying a white image with the highest gray scale. The integral value of the light spectrum from 415 nanometers to 455 nanometers is defined as a third integral, and the integral value from 400 nanometers to 500 nanometers is defined as a fourth integral. The ratio of the third integral to the fourth integral is less than 50%.

[0005] According to another embodiment, the present invention provides a display device. The display device has a light spectrum, which is generated when displaying a white image with the highest grayscale. The light spectrum has a maximum peak wavelength greater than or equal to 453 nanometers, wherein the intensity of the peak between 480 nanometers and 580 nanometers is defined as a first intensity, and the intensity of the maximum peak of the maximum peak wavelength is defined as a second intensity. The ratio of the first intensity to the second intensity is between 40% and 70%. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 Schematic diagrams showing light emission spectra, a blue light hazard weighting function and a photopic vision function respectively generated by display devices according to an embodiment of the present invention and a comparative embodiment are shown.

[0007] Figure 2Shown are the white coordinate point of the present invention in the CIE 1931xy chromaticity diagram, the area where the white coordinate point is located, and the black body curve in the CIE 1931 color space.

[0008] Figure 3 FIG. 1 is a schematic flow chart of a method for manufacturing a display device according to a first embodiment of the present invention.

[0009] Figure 4A FIG. 1 is a schematic cross-sectional view of a display device according to a first embodiment of the present invention.

[0010] Figure 4B FIG. 1 is a schematic cross-sectional view of a display device according to another variant embodiment of the first embodiment of the present invention.

[0011] Figure 5A It is a schematic diagram showing the luminous spectrum of the outgoing light and the luminous spectrum of the incident light of the comparative example.

[0012] Figure 5B FIG. 1 is a schematic diagram showing a luminous spectrum of an outgoing light and a luminous spectrum of an incident light in a first example of the first embodiment of the present invention.

[0013] Figure 5C Schematic diagram showing the emission spectrum of the outgoing light and the emission spectrum of the incident light in the second example of the first embodiment of the present invention

[0014] Figure 6 FIG. 1 is a schematic cross-sectional view of a display device according to a second variation of the first embodiment of the present invention.

[0015] Figure 7 Shown are the emission spectrum of the output light and the transmission spectrum of the blue filter of the third variation example of the first embodiment of the present invention and another comparative example.

[0016] Figure 8 FIG. 1 is a schematic flow chart of a method for manufacturing a display device according to a second embodiment of the present invention.

[0017] Fig. 9 FIG. 1 is a schematic cross-sectional view of a display device according to a second embodiment of the present invention.

[0018] Fig.10 FIG. 1 is a schematic cross-sectional view of a display device according to a variation of the second embodiment of the present invention.

[0019] Description of reference numerals: AE-anode; B C11 -First trough; B C21 -Second trough; B C12 -Third wave valley; B C22- the fourth wave valley; BCF- blue filter; BLE, BLE'- blue light emitting element; BS- lower surface; BS1- lower substrate; BS2- upper substrate; BS3, BS4- substrate; BU, BU'- backlight unit; CE- cathode; CF- color filter layer; CL, CL', CL"- light conversion layer; DD1, DD1', DD1", DD2, DD2'- display device; DP- display panel; ES- light emitting surface; GCF- green filter; GLE, GLE'- green light emitting element; IL, IL'- incident light; L1, L11, L2, L21- maximum peak wavelength; LC- liquid crystal layer; LE, LE'- light emitting element; LGP-light guide plate; LL-light-emitting layer; M0, M1, M2-light conversion materials; OL-output light; OS-output surface; P1, P2, P3, P4-maximum peak; RCF-red filter; RE-reflector; RLE, RLE'-red light-emitting element; S1-first sub-light-emitting spectrum; S2-second sub-light-emitting spectrum; SPX1-red sub-pixel; SPX2-green sub-pixel; SPX3-blue sub-pixel; SS-side; T1, T2, T3, T4-white coordinate points; TFT-circuit layer; W1-first band; W2-second band; W3-third band; W4-fourth band; W5-fifth band; W6-sixth band. DETAILED DESCRIPTION

[0020] The present invention can be understood by referring to the following detailed description in conjunction with the accompanying drawings. In order to enable those skilled in the art to further understand the present invention, the embodiments of the present invention are listed below, and the components of the present invention and the effects to be achieved are described in detail with the accompanying drawings. It should be noted that, in order to clearly illustrate and enable those skilled in the art to easily understand, the various drawings of the present invention illustrate part of the display device, and the components shown therein may not be drawn according to the actual scale. In addition, the number, size and angle of each component in the figure are only for illustration and are not intended to limit the scope of the present invention.

[0021] Certain words are used throughout the specification and claims of the present invention to refer to specific components. It should be understood by those skilled in the art that electronic equipment manufacturers may refer to the same components by different names. This document does not intend to distinguish between components that have the same function but different names. In the following specification and claims, the words "including" and "comprising" are open-ended words and should therefore be interpreted as "including but not limited to..."

[0022] It should be understood that when an element or film layer is referred to as being "on another element or film layer" or "connected to another element or film layer", it may be directly on another element or film layer or directly connected to another element or film layer, or other elements or film layers may exist between the two. On the other hand, when an element is referred to as being "directly on another element or film layer" or "directly connected to another element or film layer", there are no elements or film layers between the two.

[0023] In the following embodiments, different features in several different embodiments may be reorganized, replaced or mixed to implement other embodiments without departing from the spirit of the present invention.

[0024] In the present invention, the display device has a luminous spectrum, which is generated when displaying a white image of the highest grayscale, that is, the color of the luminous spectrum is white. Specifically, the luminous spectrum of the present invention is the spectrum of the outgoing light emitted by the display device, and in all embodiments, the outgoing light is defined as the final optical result produced by the display device presented in front of the observer (user), so the measurement of the luminous spectrum is performed on the outgoing light emitted by the display device. In addition, the white image is generated by the display device under the operation of the highest grayscale. For example, for 8-bit grayscale color, the highest grayscale can be 255, but is not limited to this. Alternatively, the operation of the highest grayscale can be performed by using a corresponding driving voltage to drive the corresponding circuit of the display device.

[0025] Figure 1 FIG. 1 is a schematic diagram showing the light emission spectrum, a blue light hazard weighting function and a photopic vision function generated by a display device of an embodiment of the present invention and a comparative embodiment. Figure 1 As shown, the luminous spectrum C1 of the present embodiment includes a first sub-luminous spectrum S1 from 380 nanometers to 478 nanometers, and a second sub-luminous spectrum S2 from 479 nanometers to 780 nanometers. The first sub-luminous spectrum S1 has a maximum peak wavelength L1 greater than or equal to 453 nanometers. For example, the first sub-luminous spectrum S1 may have a first band W1 for forming blue light, and the first band W1 of the first sub-luminous spectrum S1 has a maximum peak P1 with maximum intensity at the maximum peak wavelength L1. The first sub-luminous spectrum S1 of the present invention is not limited to having one band. In one embodiment, the maximum peak wavelength L1 of the first sub-luminous spectrum S1 may be less than or equal to 478 nanometers.

[0026] Furthermore, the second sub-luminous spectrum S2 may, for example, have a second band W2 and a third band W3, which are used to form green light and red light respectively, wherein the second band W2 may have a peak P2 between 480 nanometers and 580 nanometers, and the third band W3 may have a peak P3 between 580 nanometers and 780 nanometers. The second sub-luminous spectrum S2 of the present invention is not limited thereto. It is worth noting that the color of the luminous spectrum C1 is white, and the white image displayed by the display device may have a white coordinate point, and this white coordinate point is located in the white area required by the CIE 1931xy chromaticity diagram. In one embodiment, the x value of the white coordinate point in the CIE 1931xy chromaticity diagram is between 0.29 and 0.34, and the y value of the white coordinate point in the CIE 1931xy chromaticity diagram is between 0.305 and 0.355, so that when the display device operates at the highest grayscale, it can display a white image with a normal white coordinate point.

[0027] Specifically, refer to Figure 2 , Figure 2 The white coordinate point of the present invention in the CIE 1931xy chromaticity diagram, the region where the white coordinate point is located, and the black body curve in the CIE 1931 color space are shown. Region TR is the region where the normal white coordinate point of the present invention is located. Region TR can be defined and formed by x values ​​of 0.29 and 0.34 and y values ​​of 0.305 and 0.355. Accordingly, the luminous spectrum C1 of the present embodiment can be designed to have any white coordinate point located in region TR. For example, Figure 2 As shown, the white coordinate points T1, T2, T3 and T4 set on the black body curve BB can correspond to the color temperatures of 5000K, 5500K, 6500K and 7000K respectively. Since the white coordinate points T2, T3 and T4 are set in the region TR, and the white coordinate point T1 is set outside the region TR, the luminous spectrum C1 can be designed to have any one of the white coordinate points T2, T3 and T4 to have any one of the color temperatures of 5500K, 6500K and 7000K. In other words, the color temperature of the white coordinate point generated by the luminous spectrum C1 of the present invention can be between 5500K and 7000K, but is not limited thereto.

[0028] In addition, when the intensity of the blue light is adjusted too low, the image displayed by the display device is likely to be yellowish. On the contrary, when the intensity of the blue light is adjusted too high, the user's eyes are likely to be damaged. Therefore, the present invention provides an evaluation method that balances this dilemma. This evaluation method is used to provide a first ratio. Figure 1Specifically, the integral value of the product of the first sub-luminous spectrum S1 and the blue light hazard weighting function B(λ) from 380 nanometers to 478 nanometers is defined as the first integral. That is, the first integral is calculated by integrating the inner product of the first sub-luminous spectrum S1 and the blue light hazard weighting function B(λ) from 380 nanometers to 478 nanometers. The blue light hazard weighting function B(λ) is as follows: Figure 1 As shown. The integral value of the product of the second sub-luminous spectrum and the human eye function from 479 nanometers to 780 nanometers is defined as the second integral. That is, the second integral is calculated by integrating the inner product of the second sub-luminous spectrum S2 and the human eye function from 479 nanometers to 780 nanometers. The human eye function can be, for example, a photopic vision function Y(λ) which describes the spectral sensitivity of the brightness vision of the human eye under bright lighting conditions, such as Figure 1 The first ratio is defined as the ratio of the first integral to the second integral. The equation for calculating the first ratio is shown below.

[0029]

[0030] In the above equation, K is the first ratio, λ is the wavelength, Φ(λ) is the luminous spectrum, which is a function of the wavelength, B(λ) is the blue light hazard weighting function, which is also a function of the wavelength, and Y(λ) is the photopic vision function, which is also a function of the wavelength. It is worth noting that the first ratio is calculated when the luminous spectrum C1, the blue light hazard weighting function B(λ) and the photopic vision function Y(λ) are normalized respectively. That is, the maximum intensity of the luminous spectrum C1 is normalized to 1 by dividing it by itself, the maximum intensity of the blue light hazard weighting function B(λ) is normalized to 1 by dividing it by itself, and the maximum intensity of the photopic vision function Y(λ) is normalized to 1 by dividing it by itself. In the present invention, the first ratio of the first integral to the second integral is between 40% and 65%, so that when the yellowish image displayed by the display device under the highest grayscale operation is reduced, the blue light hazard to the user's eyes can be reduced as much as possible. Accordingly, it is possible to simultaneously reduce the blue light hazard and increase the display quality.

[0031] Specifically, since the first integral is calculated by integrating the inner product of the first sub-luminous spectrum S1 and the blue light hazard weighting function B(λ) from 380 nanometers to 478 nanometers, the first integral can represent the degree of blue light hazard to the user's eyes. The second integral is calculated by integrating the inner product of the second sub-luminous spectrum S2 and the human eye function from 479 nanometers to 780 nanometers, so the second integral can represent the degree of yellow light intensity seen by the user's eyes. By designing the first ratio to be between 40% and 65%, the degree of blue light hazard and the degree of yellow light intensity can be balanced, thereby, when operating at the highest grayscale, the display device can not only display a white image with a normal white coordinate point, but also reduce the intensity of blue light hazard. For example, when a user, such as a doctor or a radiologist, is viewing a radiological image (such as an X-ray image or a nuclear magnetic resonance image) displayed by the display device, the displayed radiological image will not have a color shift (yellowish) to affect the judgment of a suspected case, and can reduce the blue light hazard to the doctor's or radiologist's eyes when viewing the radiological image for a long time. Alternatively, in another case, when the user is viewing a web page on a display device, since most areas in the web page are set to white and the display device of the present invention can display a white image with normal white coordinate points, the user will not feel that the web page is too yellowish when viewing the web page.

[0032] In some embodiments, the luminous spectrum C1 may selectively comply with another standard for evaluating blue light hazards, namely, TUV's low blue light test standard. This standard provides a second ratio, which is defined as the ratio of the integral value of the luminous spectrum from 415 nanometers to 455 nanometers to the integral value of the luminous spectrum from 400 nanometers to 500 nanometers, and the second ratio is defined as less than 50%. Since light with wavelengths between 415 nanometers and 455 nanometers is more harmful to the user's eyes, the blue light hazard can be further reduced by having the luminous spectrum C1 comply with the second ratio standard.

[0033] Compared with the luminous spectrum C1, the luminous spectrum C2 of the comparative embodiment has a maximum peak P4 of the maximum peak wavelength L2 less than 453 nanometers, for example, equal to 440 nanometers. Taking the maximum peak wavelength L1 of the luminous spectrum C1 as 453 nanometers and the maximum peak wavelength L2 of the luminous spectrum C2 of the comparative embodiment as 440 nanometers as an example, when the luminous spectrum C1 and the luminous spectrum C2 have the same color temperature of 5500K and are generated by a blue light emitting diode and a yellow phosphor, the first ratio and the second ratio of the luminous spectrum C1 can be 43.8% and 49.5% respectively, which meet the standards of the first ratio and the second ratio, but the first ratio and the second ratio of the luminous spectrum C2 are 50.0% and 76.8% respectively, which do not meet the standards of the first ratio and the second ratio at the same time. Specifically, since the maximum peak wavelength of the blue light hazard weighting function B(λ) is 440 nanometers, the luminous spectrum C2 of the comparative embodiment having a maximum peak wavelength of 440 nanometers will cause more damage to the eyes of the user. As described above, since the maximum peak wavelength L1 of the luminous spectrum C1 is designed to be equal to or greater than 453 nanometers, that is, the peak of the luminous spectrum C1 between 380 nanometers and 480 nanometers is shifted from the maximum peak P4 to the maximum peak P1, the luminous spectrum C1 can meet the standards of the first ratio and the second ratio at the same time, thereby reducing the blue light hazard and providing better display quality. Although the blue light hazard can be reduced by designing the maximum peak wavelength of the luminous spectrum to be less than 440 nanometers, the luminous spectrum with a maximum peak wavelength less than 440 nanometers may further face the problem of ultraviolet light hazard.

[0034] In some embodiments, the light spectrum C1 may have a first valley B C11 , between the first waveband W1 and the second waveband W2. Since the maximum wave peak wavelength L1 is designed to be greater than the maximum wave peak wavelength L2, the first wave valley B C11 It may have a second valley B greater than the corresponding luminous spectrum C2 C21 For example, the first trough B C11 The ratio of the intensity of the first trough B to the intensity of the maximum peak P1 may be less than 0.3 and greater than or equal to 0. In another embodiment, taking a light source using an RGB chip as an example, the first trough B C11 The ratio of the intensity of the first trough B to the intensity of the maximum peak P1 may be less than 0.1 and greater than or equal to 0. Moreover, as the maximum peak wavelength L1 increases, the first trough B C11 The larger the wavelength can be.

[0035] In some embodiments, the light spectrum C2 may have a fourth band W4, a fifth band W5, and a sixth band W6, wherein the fourth band W4 corresponds to the first band W1 of the light spectrum C1 and has a maximum peak P4, the fifth band W5 corresponds to the second band W2 of the light spectrum C1, and the sixth band W6 corresponds to the third band W3 of the light spectrum C1. The sixth band W6 may be almost the same as the third band W3, but the present invention is not limited thereto. Furthermore, the light spectrum C1 may have a third trough B C12 , between the second band W2 and the third band W3, and the light spectrum C2 may have a fourth trough B C22 , where the third trough B C12 The intensity is almost the same as that of the fourth trough B C22 The fifth band W5 may have a maximum peak substantially the same as the maximum peak P2 of the second band W2, but the present invention is not limited thereto.

[0036] In some embodiments, when the maximum peak wavelength L1 is designed to be equal to or greater than 453 nanometers, the ratio of the intensity of the peak P2 between 480 nanometers and 580 nanometers to the intensity of the maximum peak P1 located at the maximum peak wavelength L1 is defined as a third ratio, and this third ratio may be between 40% and 70%, so that the light spectrum C1 can still have a white coordinate point located in the region TR. Based on different light-emitting elements, the third ratio may be different, which will be described in detail in the following embodiments.

[0037] The following description further describes the method of manufacturing the display device to clearly show the method of adjusting or forming the light emission spectrum to meet the standards of the first ratio and the second ratio. Figure 3 and Figure 4A . Figure 3 FIG. 1 is a flow chart of a method for manufacturing a display device according to a first embodiment of the present invention. Figure 4A: is a schematic cross-sectional view of a display device according to a first embodiment of the present invention. The manufacturing method of the display device according to the first embodiment may include the following steps. In the present embodiment, the display device DD1 is a non-self-luminous display device, such as a liquid crystal display device, but the present invention is not limited thereto. First, step S10 is performed to provide a backlight unit BU. The backlight unit BU includes at least one light-emitting element LE for generating a blue light. In the present embodiment, the backlight unit BU may include a plurality of light-emitting elements LE and a light conversion layer CL disposed on the light-emitting element LE. The light conversion layer CL of the present embodiment may cover the light-emitting element LE and be used to convert the blue light from the light-emitting element LE into yellow light, so that the blue light penetrating the light conversion layer CL may be mixed with the yellow light to form the incident light IL emitted by the backlight unit BU, but the present invention is not limited thereto. In one embodiment, the light conversion layer CL may include a light conversion material M0 to convert the blue light into a yellow light, so that the blue light and the yellow light may be mixed into the incident light IL, and the incident light IL may be white light. The x value and y value of the white coordinate point of the incident light IL in the CIE 1931xy chromaticity diagram may be the same as or different from the x value and y value of the white coordinate point of the outgoing light OL measured from the display device DD1. The x value of the incident light IL may be smaller than the x value of the outgoing light OL, and a difference between the x value of the incident light IL and the x value of the outgoing light OL may be less than or equal to 0.020. In another embodiment, the difference between the x value of the incident light IL and the x value of the outgoing light OL may be less than or equal to 0.010. The y value of the incident light IL may be smaller than the y value of the outgoing light OL, and a difference between the y value of the incident light IL and the y value of the outgoing light OL may be less than or equal to 0.020.

[0038] For example, the light conversion material M0 may include a quantum dot material, a phosphor material, a color filter material, or a pigment material, but is not limited thereto. In another embodiment, the light conversion layer CL may directly cover and contact the light emitting element. In another embodiment, the light conversion layer CL may be included in each light emitting element LE. In another embodiment, the backlight unit BU may not include the light conversion layer CL.

[0039] After step S10, step S12 is performed to provide a display panel DP on the backlight unit BU to form the display device DD1 of the present embodiment. The display panel DP includes a color filter layer CF to convert the incident light IL into the outgoing light OL having the above-mentioned luminous spectrum C1 that meets the first ratio standard. In the present embodiment, the luminous spectrum C1 may also meet the second ratio standard, but is not limited thereto. In addition, the display panel DP may also include a lower substrate BS1, an upper substrate BS2, a liquid crystal layer LC and a circuit layer TFT, wherein the liquid crystal layer LC is disposed between the lower substrate BS1 and the upper substrate BS2, the circuit layer TFT is disposed between the lower substrate BS1 and the liquid crystal layer LC, and the color filter layer CF is disposed between the liquid crystal layer LC and the upper substrate BS2. The lower substrate BS1 and the upper substrate BS2 may be a hard substrate or a flexible substrate. For example, when the display device DD1 is a liquid crystal display device, the material of the lower substrate BS1 and the material of the upper substrate BS2 may include glass, plastic, quartz, sapphire, polyimide (PI), polyethylene terephthalate (PET) or other suitable materials, but the present invention is not limited thereto. For example, the color filter layer CF may include a red filter RCF corresponding to a red sub-pixel SPX1, a green filter GCF corresponding to a green sub-pixel SPX2 and a blue filter BCF corresponding to a blue sub-pixel SPX3, wherein the red sub-pixel SPX1, the green sub-pixel SPX2 and the blue sub-pixel SPX3 may form a pixel, and this pixel is used to generate an output light OL having a white color, but the formation method of the sub-pixels of the present invention is not limited thereto. Those skilled in the art should understand that the display panel DP may also have other layers, elements or devices, such as a polarizer, an alignment layer, a black matrix, a shared electrode and an optical film, and the circuit layer TFT may include multiple elements, such as pixel electrodes, thin film transistors, scan lines, data lines and shared lines, for driving the display panel, so it will not be repeated below. Furthermore, the shift effect of the light spectrum caused by the lower substrate BS1, the upper substrate BS2, the liquid crystal layer, the circuit layer, and other film layers, components, or devices in the present invention can be ignored. The position of the color filter layer CF of the present invention is not limited here, and it can be set at any position in the display panel DP. For example, the color filter layer CF can be set between the lower substrate BS1 and the liquid crystal layer LC. In another embodiment, the light conversion layer CL can be set in the display panel DP and between the lower substrate BS1 and the color filter layer CF.

[0040] The backlight unit of the present invention is not limited to the above-mentioned embodiments. Figure 4B , Figure 4B FIG. 1 is a cross-sectional schematic diagram of a display device according to a first variation of the first embodiment of the present invention. Figure 4BAs shown, the difference between the display device DD1' of the first variant embodiment and the display device DD1 of the first embodiment is that the backlight unit BU' of this variant embodiment is an edge-type backlight unit. Specifically, the backlight unit BU' includes at least one light-emitting element LE' and a light guide plate LGP, wherein the at least one light-emitting element LE' is arranged on at least one side of the light guide plate LGP, and a light-emitting surface ES of the light-emitting element LE' faces a side surface SS of the light guide plate LGP. Accordingly, the light generated by the light-emitting element LE' can enter the side surface SS and be guided to be emitted from the exit surface OS of the light guide plate LGP to become incident light IL', wherein the exit surface OS can be connected to or adjacent to the side surface SS. In this variant embodiment, the backlight unit BU' may also include a light conversion layer CL', and the light conversion layer CL' includes a light conversion material M0 for converting blue light into yellow light. The light conversion layer CL' may cover the light-emitting surface ES of the light-emitting element LE'. In some embodiments, the backlight unit BU' may not include the light conversion layer CL', and the light conversion material M0 may be dispersed in the light guide plate LGP. In some embodiments, the backlight unit BU' may further include a reflective sheet RE for reflecting the light in the light guide plate LGP toward the exit surface OS. The reflective sheet RE may be disposed on a lower surface BS of the light guide plate LGP opposite to the exit surface OS.

[0041] The following also compares the luminous spectra of different maximum peak wavelengths generated by the display device of the first embodiment and the luminous spectrum of a comparative embodiment using the structure of the display device of the first embodiment, wherein the difference between the luminous spectrum of the first embodiment and the luminous spectrum of the comparative embodiment is that the luminous spectrum of the emitted light of the comparative embodiment has a maximum peak wavelength less than 453 nanometers. Figure 5A , Figure 5B and Figure 5C , Figure 5A FIG. 1 is a schematic diagram showing the luminous spectrum of the outgoing light and the luminous spectrum of the incident light of the comparative embodiment. Figure 5B FIG. 1 is a schematic diagram showing the luminous spectrum of the outgoing light and the luminous spectrum of the incident light in the first example of the first embodiment of the present invention. Figure 5C FIG. 1 is a schematic diagram showing the emission spectrum of the outgoing light and the emission spectrum of the incident light according to the second example of the first embodiment of the present invention. Figure 5A As shown, the luminous spectrum BL440 represents the luminous spectrum of the incident light generated by the backlight unit of the comparative embodiment, and the luminous spectrum C440 represents the luminous spectrum of the outgoing light generated by the display device of the comparative embodiment, and the luminous spectrum C440 is formed by the luminous spectrum BL440. The maximum peak wavelength of the luminous spectrum C440 of the incident light may be substantially the same as the maximum peak wavelength L2 of the luminous spectrum C440 of the outgoing light, for example, about 440 nanometers. The maximum peak wavelength of the incident light and the corresponding maximum peak wavelength of the outgoing light may differ by less than or equal to 2 nanometers. Figure 5B As shown, in the first example of the first embodiment, the luminous spectrum BL453 represents the luminous spectrum of the incident light generated by the backlight unit, and the luminous spectrum C453 represents the luminous spectrum of the outgoing light generated by the display device, and the luminous spectrum C453 is formed by the luminous spectrum BL453. The maximum peak wavelength of the luminous spectrum BL453 of the incident light may be substantially the same as the maximum peak wavelength L11 of the luminous spectrum C453 of the outgoing light, for example, about 453 nanometers. The difference between the maximum peak wavelength of the incident light and the corresponding maximum peak wavelength L11 of the outgoing light may be less than or equal to 2 nanometers. Figure 5C As shown, in the second example of the first embodiment, the luminous spectrum BL460 represents the luminous spectrum of the incident light generated by the backlight unit, and the luminous spectrum C460 represents the luminous spectrum of the outgoing light generated by the display device, and the luminous spectrum C460 is formed by the luminous spectrum BL460. The maximum peak wavelength of the luminous spectrum BL460 of the incident light may be substantially the same as the maximum peak wavelength L12 of the luminous spectrum C460 of the outgoing light, and is greater than the maximum peak wavelength L11, for example, about 460 nanometers. Since the difference between the maximum peak wavelength of each incident light and the corresponding maximum peak wavelength of the outgoing light may be less than or equal to 2 nanometers, the maximum peak wavelength of the outgoing light may be adjusted by the maximum peak wavelength of the incident light, that is, the maximum peak wavelength of the outgoing light may be adjusted by the design of the backlight unit. For example, the difference between the display device of the comparative embodiment and the display device DD1 of the first embodiment is that the light-emitting element of the comparative embodiment has a different maximum peak wavelength from the light-emitting element of the first embodiment, but is not limited thereto. Furthermore, in the comparative embodiment, the second trough B C21 The relative intensity is less than the peak of the fourth band W4 and the peak of the fifth band W5, such as Figure 5A As shown; in the first example of the first embodiment, the first valley B C11 The relative intensity is less than the maximum peak P1 and the maximum peak P2, such as Figure 5B and the first trough B of the second example of the first embodiment C11 The relative intensity is greater than the first trough B of the first example C11 In another embodiment, when the maximum peak wavelength of the light emitting spectrum is larger, the wavelength of the valley between the maximum peak and the peak between 480 nanometers and 580 nanometers may be larger.

[0042] Refer to Table 1 and Table 2, and Figure 4A , Figure 5A , Figure 5B and Figure 5C. Table 1 lists the first ratios calculated according to the comparative embodiment and the first embodiment at different maximum peak wavelengths and different color temperatures, and Table 2 lists the second ratios calculated according to the comparative embodiment and the first embodiment at different maximum peak wavelengths and different color temperatures. It can be seen from Tables 1 and 2 that, with respect to the luminous spectrum of the display device DD1 of the first embodiment, when the color temperature is between 5500K and 7000K and the maximum peak wavelength is between 453 nanometers and 478 nanometers, the first ratio of the luminous spectrum can be between 40% and 65%. Moreover, the second ratio of the luminous spectrum can be almost less than 50%. Therefore, through the light-emitting element, the emitted light of the light-emitting element can be adjusted to meet the standards of the first ratio and the second ratio.

[0043] Table 1

[0044]

[0045]

[0046] Table 2

[0047]

[0048] In some embodiments, refer to Table 3 and Figure 4A , Figure 5A , Figure 5B and Figure 5C Table 3 lists the third ratios calculated at different maximum peak wavelengths and different color temperatures according to the comparative embodiment and the first embodiment. When the color temperature is between 5500K and 7000K and the maximum peak wavelength is between 453 nanometers and 478 nanometers, the third ratio of the luminous spectrum can be selectively between 40% and 60%. In addition, the greater the color temperature, the smaller the third ratio.

[0049] Table 3

[0050]

[0051] The structure of the display device is not limited to the above-mentioned embodiment, and may have other different variant embodiments or embodiments. For the sake of simple description, the same components in the following variant embodiments or embodiments will be marked with the same reference numerals. In order to simply compare the differences between the first embodiment and its variant embodiments, and the differences between the first embodiment and other embodiments, the differences between different embodiments or variant embodiments will be described below, and the features of the same parts will not be repeated.

[0052] refer to Figure 6 , Figure 6Shown is a cross-sectional schematic diagram of a display device of a second variant embodiment of the first embodiment of the present invention. The difference between the display device DD1" of the second variant embodiment and the display device DD1 of the first embodiment is that the light conversion layer CL" of the second variant embodiment may include two light conversion materials M1 and M2, which are respectively used to convert blue light into red light and convert blue light into green light, whereby the blue light, red light and green light generated by the light-emitting element can be mixed into incident light IL. The incident light IL can be white light. In this embodiment, the light conversion materials M1 and M2 may include quantum dot materials, phosphor materials, a color filter material or a pigment material, but are not limited thereto. In some embodiments, the light conversion materials M1 and M2 may also be applied to the light conversion layer or light guide plate of the first variant embodiment.

[0053] Refer to Table 4 and Table 5 and Figure 6 . Table 4 lists the first ratios calculated according to another comparative embodiment and the second variation embodiment at different maximum peak wavelengths and different color temperatures, and Table 5 lists the second ratios calculated according to the comparative embodiment and the second variation embodiment at different maximum peak wavelengths and different color temperatures. The difference between the display device of the comparative embodiment and the display device DD1" of the second variation embodiment is that the light-emitting element of the comparative embodiment and the light-emitting element of the second variation embodiment may have different maximum peak wavelengths, but is not limited to this. It can be seen from Tables 4 and 5 that, with respect to the luminous spectrum of the display device DD1" of the second variation embodiment of the first embodiment, when the color temperature is between 5500K and 7000K and the maximum peak wavelength is between 453 nanometers and 478 nanometers, the first ratio of the luminous spectrum may be between 40% and 65%. Furthermore, the second ratio of the luminous spectrum may be less than 50%.

[0054] Table 4

[0055]

[0056] Table 5

[0057]

[0058]

[0059] In some embodiments, refer to Table 6 and Figure 6 Table 6 lists the third ratios calculated at different maximum peak wavelengths and different color temperatures according to the comparative embodiment and the second variation embodiment. When the color temperature is between 5500K and 7000K and the maximum peak wavelength is between 453 nanometers and 478 nanometers, the third ratio of the luminous spectrum can be selectively between 45% and 70%. In addition, the greater the color temperature, the smaller the third ratio.

[0060] Table 6

[0061]

[0062] refer to Figure 7 as well as Figure 4A . Figure 7 The third variation of the first embodiment of the present invention and another comparative embodiment show the emission spectrum of the outgoing light and the transmission spectrum of the blue filter. In the comparative embodiment, the transmission spectrum CCF1 is the transmission spectrum of the blue filter that allows light to pass through, and the emission spectrum C450 is the spectrum of the outgoing light formed by the incident light passing through the blue filter having the transmission spectrum CCF1. The transmission spectrum CCF1 may have a maximum peak wavelength less than 453 nanometers, for example, the transmission spectrum CCF1 has a maximum peak P5 at a wavelength of about 450 nanometers. That is, the maximum peak P5 is close to the maximum peak of the emission spectrum C450, so the emission spectrum C450 formed by the light passing through the blue filter having the transmission spectrum CCF1 may have a maximum peak wavelength of, for example, 450 nanometers. In the third variation of the first embodiment, the transmission spectrum CCF2 is the transmission spectrum of the blue filter BCF, and the emission spectrum C455 is the spectrum of the outgoing light formed by the incident light passing through the blue filter BCF having the transmission spectrum CCF2. The transmission spectrum CCF2 may have a maximum peak value P6, and the wavelength of the maximum peak P6 is equal to or greater than 453 nanometers. Therefore, the luminous spectrum C455 formed by transmitting the light through the blue filter BCF having the transmission spectrum CCF2 may have a maximum peak wavelength of, for example, 456 wavelengths. Accordingly, by adjusting the transmission spectrum CCF2 of the blue filter BCF, the maximum peak wavelength of the luminous spectrum of the emitted light can be shifted to be equal to or greater than 453 nanometers.

[0063] refer to Figure 8 and Fig. 9 . Figure 8 FIG. 1 is a flow chart of a method for manufacturing a display device according to a second embodiment of the present invention. Fig. 9The figure shows a cross-sectional schematic diagram of a display device according to a second embodiment of the present invention. The manufacturing method of the display device DD2 according to the second embodiment may include the following steps. First, step S20 is performed to provide a substrate BS3. Then, a plurality of light-emitting elements are formed on the substrate BS3 to form the display device DD2 (step S22). After the light-emitting elements are formed, a substrate BS4 may also be formed to cover the light-emitting elements, thereby protecting the light-emitting elements. The display device DD2 may be a self-luminous display device. The display device DD2 may be an inorganic light-emitting diode display device (such as QLED) or an organic light-emitting display device (such as OLED), but is not limited thereto. The substrate BS3 and the substrate BS4 may be a hard substrate or a flexible substrate. For example, when the display device DD2 is a self-luminous display device, the material of the substrate BS3 and the material of the substrate BS4 may include at least one of glass, plastic, quartz, sapphire, polyimide (PI), polyethylene terephthalate (PET) or other suitable materials, but the present invention is not limited thereto. The substrate BS4 may be a protective layer. The protective layer can be used as an encapsulation layer, a barrier film or a barrier layer to protect the light-emitting diode from being oxidized by moisture or oxygen. The encapsulation layer, barrier film and barrier layer can include organic materials, inorganic materials or a stack of organic and inorganic materials (e.g., an inorganic layer, a stack of an organic layer and an inorganic layer).

[0064] The light-emitting elements may include a red light-emitting element RLE for generating red light, a green light-emitting element GLE for generating green light, and a blue light-emitting element BLE for generating blue light. Each light-emitting element may include an anode AE, a light-emitting layer LL, and a cathode CE, which are stacked in sequence on the circuit layer TFT. The red light, the green light, and the blue light may form an output light OL, which has a light spectrum CL1 of a white image, so by adjusting the maximum peak wavelength of the blue organic light-emitting element BLE, the light spectrum of the display device DD2 may meet the standard of the first ratio, wherein the white image of the light spectrum CL1 is formed when the red light-emitting element RLE, the green light-emitting element GLE, and the blue light-emitting element BLE are driven at the highest grayscale. In some embodiments, the light spectrum of the display device DD2 may also meet the standard of the second ratio, or meet the standard of the second ratio and the third ratio. In the present embodiment, the circuit layer TFT for driving the light-emitting element may be formed between providing the substrate BS3 and forming the light-emitting element, but is not limited thereto. In another embodiment, the display device DD2 may further include at least one color filter layer CF and the light conversion layer of the first embodiment, which are disposed on the light emitting element to adjust the light emission spectrum of the display device DD2.

[0065] In another embodiment, the light emitting element can generate white light, and the display device can further include a color filter on the light emitting element, whereby the light generated by the light emitting element can be used as incident light, and the light generated by the light emitting element can pass through the color filter to form outgoing light, that is, the light emitted by the color filter can be used as outgoing light. With this design, the color filter can be used to adjust the outgoing light of the light emission spectrum.

[0066] refer to Fig.10 , Fig.10 The figure shows a cross-sectional schematic diagram of a display device of a variation of the second embodiment of the present invention. The difference between the display device DD2' of the variation and the display device DD2 of the second embodiment is that each light-emitting element is a light-emitting diode chip or a light-emitting diode package. In one embodiment, the light-emitting element may include a red light-emitting element RLE' for generating red light, a green light-emitting element GLE' for generating green light, and a blue light-emitting element BLE' for generating blue light. For example, the light-emitting element may be a general light-emitting diode, whose chip size is between 300 microns and 2 mm, a mini-LED, whose chip size is between 100 microns and 300 microns, or a micro-LED, whose chip size is between 1 micron and 100 microns, or a quantum dot light-emitting diode (QLED) including quantum dot material. Therefore, by adjusting the maximum peak wavelength of the light-emitting spectrum of the blue light-emitting element BLE', the light-emitting spectrum of the display device DD2' can meet the standards of the first ratio, the second ratio, and the third ratio.

[0067] In another embodiment, the display device DD2 ′ may further include at least one color filter layer CF and the light conversion layer of the first embodiment, which are disposed on the light emitting element to adjust the light emission spectrum of the display device DD2 ′.

[0068] As described above, the light emission spectrum of the display device of the present invention has a maximum peak wavelength greater than or equal to 453 nanometers and has a first ratio between 40% and 65%, whereby the display device can reduce the blue light hazard to the user's eyes and can also display a white image with a normal white coordinate point when operating at the highest grayscale. Accordingly, it is possible to simultaneously reduce the blue light hazard and increase the display quality.

[0069] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A display device having a light emission spectrum, characterized in that: This luminous spectrum is generated when displaying a white image with the highest grayscale. The integral value of the luminous spectrum from 415 nanometers to 455 nanometers is defined as the third integral, and the integral value from 400 nanometers to 500 nanometers is defined as the fourth integral, wherein the ratio of the third integral to the fourth integral is less than 50%, The luminous spectrum includes a first sub-luminous spectrum from 380 nanometers to 478 nanometers and a second sub-luminous spectrum from 479 nanometers to 780 nanometers, the first sub-luminous spectrum multiplied by the blue light hazard weighting function is defined as the first integral value of the product from 380 nanometers to 478 nanometers, and the second sub-luminous spectrum multiplied by the photopic vision function is defined as the second integral value of the product from 479 nanometers to 780 nanometers, wherein the ratio of the first integral to the second integral is between 40% and 65%, and The white image has a white coordinate point, wherein the x value of the white coordinate point in the CIE 1931xy chromaticity diagram is between 0.29 and 0.34, and the y value of the white coordinate point in the CIE 1931xy chromaticity diagram is between 0.305 and 0.

355.

2. The display device according to claim 1, characterized in that The display device includes a backlight unit and a display panel.

3. The display device according to claim 2, characterized in that The backlight unit includes at least one light emitting element and a light guide plate, wherein the at least one light emitting element is arranged on at least one side of the light guide plate.

4. The display device according to claim 1, characterized in that The display device includes a blue light emitting element for generating blue light, and a light conversion layer for converting the blue light.

5. The display device according to claim 4, characterized in that The light conversion layer includes a light conversion material, and the light conversion material includes a quantum dot material, a fluorescent material, a color filter material or a pigment material.

6. The display device according to claim 1, characterized in that The display device includes a plurality of inorganic light emitting elements.

7. The display device according to claim 1, characterized in that The display device includes a plurality of organic light emitting elements.

8. The display device according to claim 1, characterized in that The first sub-light emission spectrum has a maximum peak wavelength greater than or equal to 453 nanometers.

9. The display device according to claim 8, characterized in that The maximum peak wavelength of the first sub-light emitting spectrum is less than or equal to 478 nanometers.

10. A display device having a light emission spectrum, characterized in that: This luminous spectrum is generated when displaying a white image with the highest grayscale. wherein the luminescence spectrum has a maximum peak wavelength greater than or equal to 453 nanometers, The intensity of the peak between 480 nanometers and 580 nanometers is defined as the first intensity, and the intensity of the maximum peak of the maximum peak wavelength is defined as the second intensity. wherein the ratio of the first intensity to the second intensity is between 40% and 70%, The luminous spectrum includes a first sub-luminous spectrum from 380 nanometers to 478 nanometers and a second sub-luminous spectrum from 479 nanometers to 780 nanometers, the first sub-luminous spectrum multiplied by the blue light hazard weighting function is defined as the first integral value of the product from 380 nanometers to 478 nanometers, and the second sub-luminous spectrum multiplied by the photopic vision function is defined as the second integral value of the product from 479 nanometers to 780 nanometers, wherein the ratio of the first integral to the second integral is between 40% and 65%, and The white image has a white coordinate point, wherein the x value of the white coordinate point in the CIE 1931xy chromaticity diagram is between 0.29 and 0.34, and the y value of the white coordinate point in the CIE 1931xy chromaticity diagram is between 0.305 and 0.

355.

11. The display device according to claim 10, characterized in that The display device includes a backlight unit and a display panel.

12. The display device according to claim 11, characterized in that The backlight unit includes at least one light emitting element and a light guide plate, wherein the at least one light emitting element is arranged on at least one side of the light guide plate.

13. The display device according to claim 10, characterized in that The display device includes a blue light emitting element for generating blue light, and a light conversion layer for converting the blue light.

14. The display device according to claim 13, characterized in that The light conversion layer includes a light conversion material, and the light conversion material includes a quantum dot material, a fluorescent material, a color filter material or a pigment material.

15. The display device according to claim 10, characterized in that The display device includes a plurality of inorganic light emitting elements.

16. The display device according to claim 10, characterized in that The display device includes a plurality of organic light emitting elements.

17. The display device according to claim 10, characterized in that The first sub-light emission spectrum has a maximum peak wavelength greater than or equal to 453 nanometers.

18. The display device according to claim 17, characterized in that The maximum peak wavelength of the first sub-light emitting spectrum is less than or equal to 478 nanometers.

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