Light-emitting device, backlight module and display device

Abstract

The invention provides a light-emitting device, a backlight module and a display device, and relates to the technical field of display. The light-emitting device comprises a light-emitting chip and a fluorescent part; the fluorescent part is located on one side of the light-emitting surface of the light-emitting chip, and the light-emitting chip excites the fluorescent part to The power-off duration of the light-emitting chip is larger than or equal to the extinction duration of the fluorescent part. According to the invention, the power-off time of the light-emitting chip is longer than or equal to the extinction time of the fluorescent part by prolonging the time from stable conduction to complete power-off of the light-emitting chip, so that the time when the light-emitting chip is completely powered off is close to the extinction time of the fluorescent part, and human eyes can be prevented from perceiving the light independently emitted by the fluorescent part, and therefore, the light-emitting efficiency is improved. The problem that the light-emitting device flashes red or is abnormal in color is solved, so that the reliability of the light-emitting device is improved, and the user experience is improved. In addition, when the light-emitting device is applied to the display device, the color of light emitted by the light-emitting device is more stable, and the display effect can be improved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a light-emitting device, a backlight module and a display device. Background Art

[0002] With the advancement of display technology, demand for higher-quality displays is growing across various industries. In some display products, the light-emitting devices (LEDs) excite phosphors to emit white light. However, these devices can flash red or exhibit color distortion during power-off, impacting display quality and user experience. Therefore, improving these issues has become a pressing technical challenge. Summary of the Invention

[0003] In order to solve the above technical problems, the present application provides a light-emitting device, a backlight module and a display device to improve the red flash or color problem under the light-emitting device, improve the display effect and enhance the user experience.

[0004] The present application provides a light-emitting device, comprising:

[0005] Light-emitting chip and fluorescent part;

[0006] The fluorescent portion is located on the light emitting surface side of the light emitting chip, and the light emitting chip excites the fluorescent portion to emit light;

[0007] The power-off time of the light-emitting chip is greater than or equal to the extinction time of the fluorescent portion;

[0008] The power-off duration is the time it takes for the light-emitting chip to switch from stable conduction to complete power-off, and the extinction duration is the time it takes for the phosphor in the fluorescent part to return from the excited state to the ground state and stop emitting light after the light-emitting chip is powered off.

[0009] Based on the same inventive concept, the present application also provides a backlight module including a light-emitting device.

[0010] Based on the same inventive concept, the present application also provides a display device including a backlight module.

[0011] The technical solution provided by the embodiments of the present application has the following advantages compared with the prior art:

[0012] The present application provides a light-emitting device, a backlight module, and a display device. The light-emitting device includes a light-emitting chip and a fluorescent portion. The fluorescent portion is located on the light-emitting surface of the light-emitting chip, and the light-emitting chip excites the fluorescent portion to emit light. The power-off duration of the light-emitting chip is greater than or equal to the extinction duration of the fluorescent portion. The power-off duration is the time it takes for the light-emitting chip to transition from stable conduction to complete power-off, and the extinction duration is the time it takes for the phosphor in the fluorescent portion to return from an excited state to a ground state and cease emitting light after the light-emitting chip is powered off. The present application extends the time it takes for the light-emitting chip to transition from stable conduction to complete power-off, thereby ensuring that the power-off duration of the light-emitting chip is greater than or equal to the extinction duration of the fluorescent portion. This arrangement allows the moment when the light-emitting chip is completely powered off to be close to the moment when the fluorescent portion extincts, which helps prevent the human eye from perceiving the light emitted solely by the fluorescent portion. Adjusting the power-off duration allows for more precise control of the light-emitting chip's light-emission duration. This helps alleviate issues with red flashing or abnormal color when the light-emitting device is powered off, thereby improving the reliability of the light-emitting device and enhancing the user experience. In addition, when the light-emitting device is applied to a display device, the color of the light emitted by the light-emitting device is more stable, which is also beneficial to improving the display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0015] Figure 1 FIG2 is a schematic diagram of a film layer of a light-emitting device provided in an embodiment of the present application;

[0016] Figure 2 Shown is a schematic diagram of the relative light intensity of the light-emitting chip and various phosphors provided by this application;

[0017] Figure 3 FIG2 is another schematic diagram of a film layer of a light-emitting device provided in an embodiment of the present application;

[0018] Figure 4 FIG2 is a planar schematic diagram of a backlight module provided by an embodiment of the present application;

[0019] Figure 5 FIG2 is another planar schematic diagram of the backlight module provided in an embodiment of the present application;

[0020] Figure 6FIG2 is a schematic diagram showing a method for adjusting a driving signal of a light-emitting chip provided in an embodiment of the present application;

[0021] Figure 7 FIG2 is a schematic diagram showing another method for adjusting the driving signal of the light-emitting chip provided in an embodiment of the present application;

[0022] Figure 8 Shown is a planar schematic diagram of a display device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to more clearly understand the above-mentioned objectives, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0024] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application can also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present application, not all of the embodiments.

[0025] The inventors discovered in their research that in the light-emitting devices of some display products, white light is emitted by emitting light from a light-emitting chip to excite phosphors. Different colors of phosphors react for different lengths of time after being excited. After the light-emitting chip is powered off, the time it takes for the light-emitting chip to completely power off is different from the time it takes for the phosphor to completely extinct from stable luminescence. After the light from the light-emitting chip completely disappears, the light emitted by the phosphor due to excitation has not yet disappeared. For example, when the phosphor is red, the reaction time for the red phosphor to convert from an excited state to a ground state after being excited is longer. When the light-emitting chip is powered off, the light from the light-emitting chip disappears first, while the red phosphor still has a period of luminescence. Therefore, the light-emitting device may exhibit an abnormal red flashing problem. When the phosphor is other colors, color anomalies may also occur, affecting the user experience.

[0026] In view of this, the present application provides a light-emitting device, a backlight module and a display device to improve the red flicker or color problem under the light-emitting device, improve the display effect and enhance the user experience.

[0027] Figure 1 The figure shows a film layer diagram of the light emitting device provided in the embodiment of the present application. Please refer to Figure 1 The present application provides a light-emitting device 100, comprising: a light-emitting chip 10 and a fluorescent portion 20; the fluorescent portion 20 is located on the light-emitting surface side of the light-emitting chip 10, and the light-emitting chip 10 excites the fluorescent portion 20 to emit light.

[0028] The power-off time of the light-emitting chip 10 is greater than or equal to the extinction time of the fluorescent part 20; the power-off time is the time it takes for the light-emitting chip 10 to go from stable conduction to complete power-off, and the extinction time is the time it takes for the phosphor in the fluorescent part 20 to return from the excited state to the ground state and stop emitting light after the light-emitting chip 10 is powered off.

[0029] It should be noted that this application Figure 1 The different film layers are only indicated by rectangles, which do not represent the actual structure of the light-emitting device 100. The core principle of the light-emitting device 100 provided in the present application is photoluminescence, that is, the light emitted by a light-emitting chip 10 is used to excite the phosphor in the fluorescent part 20, so that it emits light of different wavelengths, thereby achieving light output of a specific color. Exemplarily, the light from the light-emitting chip 10 excites the fluorescent part 20 to emit light, thereby enabling the light-emitting device 100 to emit white light or other composite color light. Optionally, the light-emitting chip 10 can be a light-emitting diode based on semiconductor materials. When current passes through the PN junction (a junction formed by combining a P-type semiconductor (P-type semiconductor) and an N-type semiconductor (N-type semiconductor)) of the light-emitting chip 10, electrons and holes recombine in the PN junction region, releasing energy, which is emitted in the form of photons. The light emitted by the light-emitting chip 10 is usually monochromatic light, such as a light-emitting chip that emits blue light. The fluorescent portion 20 includes one or more phosphors. When the light-emitting chip 10 emits light, the light emitted by the light-emitting chip 10 irradiates the phosphors in the fluorescent portion 20. The phosphors absorb photons, and the absorbed photons cause the electrons in the phosphors to transition from a ground state to an excited state. These excited electrons return to a lower energy level through non-radiative (such as heat) and radiative (i.e., luminescence) means. The energy released by the radiative means is emitted in the form of photons, thereby achieving luminescence of the fluorescent portion 20. The fluorescent portion 20 is located on the light-emitting surface side of the light-emitting chip 10. A portion of the light emitted by the light-emitting chip 10 is used to excite the phosphors in the fluorescent portion 20 to emit light, and another portion is used to mix with the light emitted by the fluorescent portion 20 to form the final light. For example, the light-emitting chip 10 is a light-emitting chip that emits blue light, and the fluorescent portion 20 includes yellow phosphor, which can emit yellow light when excited. A portion of the blue light emitted by the light-emitting chip 10 is used to excite the yellow phosphor to emit yellow light, and the other portion is mixed with the yellow light emitted by the fluorescent portion 20, and the human eye perceives it as white light.

[0030] Specifically, the light-emitting chip 10 emits light by receiving current. The power-off duration of the light-emitting chip 10 refers to the time it takes for the light-emitting chip 10 to complete the power-off process. The power-off process of the light-emitting chip 10 is the process by which the light-emitting chip 10 transitions from a stable on state to a completely off state. When the light-emitting chip 10 is powered off, the phosphor in the phosphor portion 20 gradually returns from an excited state to a ground state, eventually ceasing to emit light.

[0031] Figure 2 The figure shows the relative light intensity of the light emitting chip and various phosphors provided by this application. Please refer to Figure 2 , Figure 2 Five curves are shown in the figure. Curve 1 represents a power-off curve of the blue light-emitting chip during power-off. Curve 2 represents the extinction curve of the YAG phosphor (Yttrium Aluminum Garnet) during the conversion from the excited state to the ground state. Curve 3 represents the extinction curve of the CASN phosphor (CaAlSiN3:Eu 2+ The extinction curve of the phosphor powder) is converted from the excited state to the ground state. Curve 4 represents the extinction curve of the β-SiAlON phosphor (β-type silicon aluminum oxynitride phosphor) from the excited state to the ground state. Curve 5 represents the extinction curve of the KSF phosphor (K2SiF6:Mn 4+ The extinction curve of the phosphor) in the process of converting from the excited state to the ground state. It can be seen from the curve in the figure that the power-off time of the blue light emitting chip is less than the extinction time of the phosphor. It should be noted that in the related art, after the light emitting chip is powered off, its light disappears first, while the light emitted by the excited phosphor has not completely disappeared. Therefore, there will be a situation where the phosphor is still emitting light after the light emitting device is powered off, and the color that finally appears to the human eye is different from the actual expected color. For example, when the phosphor includes red phosphor, the red phosphor still emits light for a period of time after the light emitting chip is completely powered off, and the light emitting device flashes red after being powered off, affecting the display effect and user experience.

[0032] Therefore, the present application sets the power-off time of the light-emitting chip 10 to be greater than or equal to the extinction time of the fluorescent portion 20. Since the extinction time of the fluorescent portion 20 is generally determined by the material of the phosphor, the time taken for the light-emitting chip 10 to go from stable conduction to complete power-off can be extended to achieve a power-off time of the light-emitting chip 10 that is greater than or equal to the extinction time of the fluorescent portion 20. With this arrangement, the moment when the light-emitting chip 10 is completely powered off is close to the moment when the fluorescent portion 20 extincts, which helps prevent the human eye from perceiving the light emitted solely by the fluorescent portion 20. For the light-emitting duration of the light-emitting chip 10, more precise control can be achieved by adjusting the power-off time. Therefore, it helps to improve the problem of red flashing or abnormal color when the light-emitting device 100 is powered off, thereby improving the reliability of the light-emitting device 100 and improving the user experience. In addition, when the light-emitting device 100 is used in a display device, the color of the light emitted by the light-emitting device 100 is more stable, which also helps to improve the display effect.

[0033] The present application provides a light-emitting device 100 for use in a touch button. The light-emitting device 100 includes a light-emitting chip 10 that emits blue light and a fluorescent portion 20 that includes red and green phosphors. The light from the light-emitting chip 10 and the fluorescent portion 20 is mixed to emit white light. When the touch button is powered off, the power-off time of the light-emitting chip 10 is longer than the extinction time of the fluorescent portion 20. This helps prevent the human eye from perceiving the light emitted by the fluorescent portion 20 alone, thereby improving the phenomenon of the touch button flashing red after powering off, enhancing the reliability of the touch button, and improving the user experience.

[0034] Please continue to refer to Figure 1 and Figure 2 In some optional embodiments, the power-off duration of the light-emitting chip 10 can be adjusted by adjusting the light-emitting duty cycle of the light-emitting chip 10. In some other optional embodiments, the power-off duration of the light-emitting chip 10 can also be adjusted by adjusting the driving current of the light-emitting chip 10. This application only uses the above embodiment as an example to illustrate that the power-off duration of the light-emitting chip 10 can be adjusted in different ways, and the present invention is not limited to this.

[0035] Figure 3 FIG. 1 is another schematic diagram of a light emitting device according to an embodiment of the present application. Figure 3 In an optional embodiment of the present application, in the same light-emitting device 100, the fluorescent portion 20 includes a first color fluorescent portion 201 and a second color fluorescent portion 202, and the extinction time of the first color fluorescent portion 201 is greater than the extinction time of the second color fluorescent portion 202; the power-off time of the light-emitting chip 10 is greater than or equal to the extinction time of the first color fluorescent portion 201.

[0036] It should be noted that Figure 2 The figure only illustrates that the fluorescent portion 20 contains phosphors of different colors, and does not limit the specific positions of the first color fluorescent portion 201 and the second color fluorescent portion 202 in the light-emitting device 100. The first color fluorescent portion 201 and the second color fluorescent portion 202 represent that the light-emitting device 100 includes phosphors of different colors. The phosphors corresponding to the first color fluorescent portion 201 and the second color fluorescent portion 202 may be located in the same film layer or in different film layers. This application does not make any specific limitations.

[0037] Specifically, in the same light-emitting device 100, the fluorescent portion 20 includes a first color fluorescent portion 201 and a second color fluorescent portion 202 having different phosphor colors. Different colors of the fluorescent portions 20 use different phosphors, and thus the extinction time of the different colors of the fluorescent portions 20 is different. When the light-emitting device 100 is in operation, the light-emitting chip 10 is energized, and the light-emitting chip 10 excites the phosphor corresponding to the first color fluorescent portion 201 and the phosphor corresponding to the second color fluorescent portion 202 to emit light. The light emitted by the light-emitting chip 10, the first color fluorescent portion 201, and the second color fluorescent portion 202 is mixed to produce light. The present application provides an optional embodiment in which the light-emitting chip 10 is a blue light-emitting chip 10, the first color fluorescent portion 201 includes red phosphor, and the second color fluorescent portion 202 includes yellow phosphor. The blue light-emitting chip 10 excites the yellow phosphor and the red phosphor to produce white light of a specific color temperature. During the initial power-off phase of the light-emitting device 100, the light-emitting chip 10 has just been powered off but not yet completely powered off. Due to its shorter extinction period, the second-color fluorescent portion 202 ceases emitting light first compared to the first-color fluorescent portion. However, due to its longer extinction period, the first-color fluorescent portion 201 continues to emit light for a period of time. During this phase, the light emitted by the light-emitting device 100 gradually transitions from the mixed color of the light-emitting chip 10, the first-color fluorescent portion 201, and the second-color fluorescent portion 202 during stable conduction to a mixed color of the light-emitting chip 10 and the first-color fluorescent portion 201, and finally to the color of only the light-emitting chip 10. This allows for a gradual transition in the color of the light-emitting device 100 until the light-emitting chip 10 is completely extinguished at the later stage of power-off. This configuration helps prevent the phosphor in the fluorescent portion 20 from continuing to emit light after the light-emitting chip 10 is powered off, causing the light-emitting device 100 to exhibit an undesirable color. This helps alleviate issues with color anomalies in the light-emitting device 100. In addition, the gradual transition process of the light-emitting device 100 is also conducive to achieving richer lighting effects and improving the use scenarios of the light-emitting device 100.

[0038] Please continue to refer to Figure 3 In an optional embodiment of the present application, the power-off duration of the light-emitting chip 10 is equal to the extinction duration of the first color fluorescent portion 201. Specifically, in this embodiment, when the light-emitting chip 10 is completely powered off, the first color fluorescent portion 201 has also transitioned from an excited state to a ground state and stopped emitting light. This configuration helps prevent the first color fluorescent portion 201 from emitting light alone after the light-emitting chip 10 is completely powered off, thus avoiding unnecessary light residue. This helps to more accurately control the light output effect and light color of the light-emitting device 100, improve the reliability of the light-emitting device 100, and enhance the user experience and display effect.

[0039] Please continue to refer to Figure 3In an optional embodiment of the present application, the light-emitting chip 10 emits blue light, and the first color fluorescent portion 201 includes red and green phosphors. Specifically, in this embodiment, the first color fluorescent portion 201 with a longer extinction time includes red and green phosphors, at least part of the red and green phosphors emits green light, and at least part of the red and green phosphors emits red light. The light of the light-emitting device 100 is a mixture of the blue light emitted by the light-emitting chip 10 and the light emitted by the red and green phosphors, forming white light. The extinction time of the red and green phosphors is relatively long. If the power-off time of the light-emitting chip 10 is less than the power-off time of the first color fluorescent portion 201, when the light-emitting chip 10 is completely powered off, the light-emitting chip 10 stops emitting light, but the red and green phosphors have not yet completely converted from the excited state to the ground state, and have not stopped emitting light. At this time, the red light emitted from the first color fluorescent portion 201 has a strong temporary effect in the human eye, and is thus detected by the human eye. The light-emitting device 100 will flash red, affecting the user experience. Therefore, in this embodiment, the power-off time of the light-emitting chip 10 is greater than or equal to the extinction time of the first color fluorescent portion 201. With this setting, the light of the fluorescent portion 20 disappears first, which is beneficial to avoid the red flashing phenomenon of the light-emitting device 100, and is beneficial to improving the reliability of the light-emitting device 100 and improving the user experience.

[0040] Please refer to Figure 3 In an optional embodiment of the present application, the power-off time of the light-emitting chip 10 is T, 150ms≤T≤300ms.

[0041] Specifically, when the power-off time T of the light-emitting chip 10 is less than 150ms, the phosphor in the fluorescent portion 20 may not be able to completely convert from the excited state to the ground state and stop emitting light. At this time, the light-emitting chip 10 has stopped emitting light, which may cause the color of the light-emitting device 100 to be abnormal, affecting the reliability of the light-emitting device 100. When the power-off time T of the light-emitting chip 10 is greater than 300ms, the power-off time of the light-emitting chip 10 is too long, which may cause a ghosting phenomenon and affect the user experience. Therefore, the present application sets the power-off time of the light-emitting chip 10 to 150ms≤T≤300ms. This is conducive to keeping the power-off time of the light-emitting chip 10 and the extinction time of the phosphor in the fluorescent portion 20 as consistent or close as possible, thereby helping to improve the problem of color abnormality when the light-emitting device 100 is powered off, and at the same time, it is also conducive to improving the ghosting phenomenon. The present application provides an optional implementation manner, in which the power-off time of the light-emitting chip 10 is T=160ms; the present application provides another optional implementation manner, in which the power-off time of the light-emitting chip 10 is T=200ms; the present application provides yet another optional implementation manner, in which the power-off time of the light-emitting chip 10 is T=230ms; the present application provides yet another optional implementation manner, in which the power-off time of the light-emitting chip 10 is 180ms≤T≤220ms; the present application provides yet another optional implementation manner, in which the power-off time of the light-emitting chip 10 is 170ms≤T≤280ms.

[0042] Please refer to Figure 1 and Figure 2 In an optional embodiment of the present application, at the same moment, the tangent slope of the power-down curve of the light-emitting chip 10 is the same as the tangent slope of the extinction curve of the phosphor in the fluorescent portion 20 .

[0043] Specifically, during the power-off process of the light-emitting chip 10, the relative light intensity at different times varies. The power-off curve of the light-emitting chip 10 is a curve showing the relative light intensity changing over time. During the process of the phosphor in the phosphor portion 20 transitioning from an excited state to a ground state, the relative light intensity at different times also varies. The extinction curve of the phosphor in the phosphor portion 20 is a curve showing the relative light intensity changing over time. In this embodiment, the power-off curve of the light-emitting chip 10 and the extinction curve of the phosphor in the phosphor portion 20 have the same tangent slope at the same time. That is, the power-off curve of the light-emitting chip 10 and the extinction curve of the phosphor in the phosphor portion 20 are close in shape or tend to be consistent. This arrangement ensures, to a certain extent, that the relative light intensity of the light-emitting chip 10 and the phosphor in the phosphor portion 20 decrease in the same direction. During the power-off process, the relative light intensities of the light-emitting chip 10 and the phosphor portion 20 are close in shape or tend to be consistent at the same time, which helps to improve the color shift phenomenon during the power-off process and thus improves the user experience.

[0044] Please continue to refer to Figure 1 and Figure 2 In an optional embodiment of the present application, the tangent slope of the power-down curve of the light-emitting chip 10 is k, -5≤k≤-2.

[0045] Specifically, the luminescence of the fluorescent portion 20 in the light-emitting device 100 depends on the phosphor contained therein. If the phosphor is determined, the extinction curve can be roughly determined. Therefore, the power-off curve of the light-emitting chip 10 can be adjusted to ensure that the relative light intensity decrease rates of the light-emitting chip 10 and the fluorescent portion 20 during the power-off process are close or consistent. This helps improve the color shift problem of the light-emitting device 100 during the power-off process and enhances the reliability of the light-emitting device 100. When the tangent slope k of the power-off curve of the light-emitting chip 10 is less than -5, the relative light intensity of the light-emitting chip 10 relative to the relative light intensity of the fluorescent portion 20 decreases too quickly, which is not conducive to improving the color shift problem of the light-emitting device 100 during the power-off process. When the tangent slope k of the power-off curve of the light-emitting chip 10 is greater than -2, the relative light intensity of the light-emitting chip 10 relative to the relative light intensity of the fluorescent portion 20 decreases too slowly, which is also not conducive to improving the color shift problem of the light-emitting device 100 during the power-off process. Therefore, the present application sets the tangent slope of the power-off curve of the light-emitting chip 10 to -5≤k≤-2. With this setting, the power-off curve of the light-emitting chip 10 is closer to the extinction curve of the phosphor in the fluorescent portion 20, which is beneficial to improving the color shift problem of the light-emitting device 100 during the power-off process and improving the reliability of the light-emitting device 100. The present application provides an optional embodiment in which the tangent slope of the power-off curve of the light-emitting chip 10 is -4≤k≤-2; the present application provides another optional embodiment in which the tangent slope of the power-off curve of the light-emitting chip 10 is -4≤k≤-1; the present application provides another optional embodiment in which the tangent slope of the power-off curve of the light-emitting chip 10 is -4.5≤k≤-1.5; the present application provides another optional embodiment in which the tangent slope of the power-off curve of the light-emitting chip 10 is -3≤k≤-1; and the present application provides another optional embodiment in which the tangent slope of the power-off curve of the light-emitting chip 10 is -3.5≤k≤-2.

[0046] Figure 4 The figure shows a plan view of a backlight module provided by the embodiment of the present application. Please refer to Figure 4 Based on the same inventive concept, the present application provides a backlight module 200, including any one of the light-emitting devices 100 provided in the embodiments of the present application.

[0047] Specifically, the present application also provides a backlight module 200, which is used to provide backlight for a display panel. The backlight module 200 includes a light-emitting device 100, which is any of the light-emitting devices 100 provided in the embodiments of the present application. The light-emitting device 100 provided in the present application includes a light-emitting chip 10 and a fluorescent portion 20 located on the side of the light-emitting surface of the light-emitting chip 10. The light-emitting chip 10 excites the fluorescent portion 20 to emit light. The power-off time of the light-emitting chip 10 is greater than or equal to the extinction time of the fluorescent portion 20. The moment when the light-emitting chip 10 is completely powered off is close to the extinction time of the fluorescent portion 20, which helps to prevent the human eye from perceiving the light emitted by the fluorescent portion 20 alone. For the power-off time of the light-emitting chip 10, more precise control can be achieved by adjusting the power-off time. Therefore, it helps to improve the problem of red flashing or abnormal color when the light-emitting device 100 is powered off, thereby improving the user experience. The backlight module 200 provided in the present application includes the above-mentioned light-emitting device 100. The color of the light emitted by the light-emitting device 100 is more stable, which also helps to improve the display effect.

[0048] It should be noted that the embodiments related to the light emitting device 100 in the backlight module 200 provided in the embodiment of the present application can refer to the embodiments of the light emitting device 100 described above, and the repeated parts will not be repeated.

[0049] Figure 5 FIG. 1 is another planar schematic diagram of a backlight module provided in an embodiment of the present application. Figure 6 FIG2 is a schematic diagram showing a method for adjusting the driving signal of the light emitting chip provided in an embodiment of the present application. Please refer to FIG2 for details. Figure 1 、 Figure 5 and Figure 6 In an optional embodiment of the present application, the backlight module 200 further includes a driver chip 210 ; the light-emitting device 100 includes a light-emitting chip 10 , and the driver chip 210 is at least configured to adjust the light-emitting duty cycle of the light-emitting chip 10 .

[0050] Specifically, the backlight module 200 includes a driver chip 210 and a light-emitting device 100, and the driver chip 210 is at least used to control the light-emitting chip 10 in the light-emitting device 100 to emit light. Optionally, the light-emitting duty cycle of the light-emitting chip 10 can be adjusted to control the power-off time of the light-emitting chip 10. It should be noted that the light-emitting duty cycle of the light-emitting chip 10 refers to the ratio of the light-emitting time to the entire working cycle under the pulse drive mode. The present application can adjust the light-emitting duty cycle of the light-emitting chip 10 during the power-off period, that is, by adjusting the pulse width W of the driving signal received by the light-emitting chip 10, to adjust the power-off time of the light-emitting chip 10, thereby achieving the power-off time of the light-emitting chip 10 being greater than or equal to the extinction time of the fluorescent part 20, and then achieving the moment when the light-emitting chip 10 is completely powered off, which is close to the extinction moment of the fluorescent part 20, which is beneficial to avoid the human eye from perceiving the light emitted by the fluorescent part 20 alone, and is beneficial to improving the problem of red flashing or abnormal color when the light-emitting device 100 is powered off, thereby improving the display effect. It should be noted that the present application Figure 6 Only the pulse width W of the driving signal of the light-emitting chip 10 is not illustrated, and does not represent the actual timing diagram of the driving signal of the light-emitting chip 10 .

[0051] In some usage scenarios, such as vehicle-mounted display products, the light-emitting duty cycle of the light-emitting chip 10 can be adjusted to achieve a power-off time greater than or equal to the extinction time of the fluorescent part 20. This application only uses this as an example for illustration and is not limited to this.

[0052] Figure 7 FIG2 is a schematic diagram showing another adjustment method of the driving signal of the light emitting chip provided in the embodiment of the present application. Please refer to FIG2 Figure 1 、 Figure 5 and Figure 7 In an optional embodiment of the present application, the backlight module 200 further includes a driving chip 210 , the light-emitting device 100 includes a light-emitting chip 10 , and the driving chip 210 is at least configured to adjust the driving current of the light-emitting chip 10 .

[0053] Specifically, the present embodiment provides a method of adjusting the power-off duration of the light-emitting chip 10 by adjusting the driving current of the light-emitting chip 10. Specifically, the pulse amplitude A of the driving signal received by the light-emitting chip 10 is adjusted to adjust the power-off duration of the light-emitting chip 10, thereby achieving the power-off duration of the light-emitting chip 10 to be greater than or equal to the extinction duration of the fluorescent portion 20, and then achieving the moment when the light-emitting chip 10 is completely powered off to be close to the extinction moment of the fluorescent portion 20, which is beneficial to avoiding the human eye from perceiving the light emitted by the fluorescent portion 20 alone, and is beneficial to improving the problem of red flashing or abnormal color when the light-emitting device 100 is powered off, thereby improving the display effect.

[0054] In some usage scenarios, for example, display products such as mobile phones and tablet computers, the power-off time of the light-emitting chip 10 can be adjusted to be greater than or equal to the extinction time of the fluorescent part 20 by adjusting the driving current of the light-emitting chip 10. This application only uses this as an example for illustration and is not limited to this.

[0055] Please refer to Figure 1 and Figure 5 In an optional embodiment of the present application, the light-emitting device 100 includes a light-emitting chip 10 , and the power-off time of the light-emitting chip 10 is T, where 150ms≤T≤200ms.

[0056] Specifically, when the power-off time T of the light-emitting chip 10 is less than 150ms, the phosphor in the fluorescent portion 20 may not be able to completely convert from the excited state to the ground state and stop emitting light. At this time, the light-emitting chip 10 has stopped emitting light, which may cause the color of the light-emitting device 100 to be abnormal, affecting the reliability of the light-emitting device 100. When the color of the light-emitting device 100 is abnormal, it will also affect the display effect. When the power-off time T of the light-emitting chip 10 is greater than 200ms, the power-off time of the light-emitting chip 10 is too long. When the light-emitting device 100 serves as the backlight source of the backlight module 200 to provide backlight for the display panel, it may cause a display ghosting phenomenon, affecting the display effect. Therefore, the present application sets the power-off time of the light-emitting chip 10 to be 150ms≤T≤200ms. This is conducive to keeping the power-off time of the light-emitting chip 10 and the extinction time of the phosphor in the fluorescent portion 20 as consistent or close as possible, thereby helping to improve the problem of color abnormality when the light-emitting device 100 is powered off. At the same time, it is also conducive to improving the ghosting phenomenon of the display product. The present application provides an optional implementation manner, in which the power-off time of the light-emitting chip 10 is T=170ms; the present application provides another optional implementation manner, in which the power-off time of the light-emitting chip 10 is T=180ms; the present application provides yet another optional implementation manner, in which the power-off time of the light-emitting chip 10 is T=190ms; the present application provides yet another optional implementation manner, in which the power-off time of the light-emitting chip 10 is 155ms≤T≤185ms; the present application provides yet another optional implementation manner, in which the power-off time of the light-emitting chip 10 is 150ms≤T≤175ms.

[0057] Based on the same inventive concept, the present application also provides a display device, Figure 8 FIG2 is a schematic diagram of a plan view of a display device provided in an embodiment of the present application. Please refer to FIG2 Figure 8 The display device 300 includes a backlight module 200 , and the backlight module 200 is any one of the backlight modules 200 provided in the embodiments of the present application.

[0058] It should be noted that the embodiment of the display device 300 provided in the present application can refer to the embodiment of the backlight module 200 described above, and the repeated parts will not be repeated. The device provided in the present application can be embodied as: a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigation system, or any other product or component with a display function.

[0059] It can be seen from the above embodiments that the light emitting device, backlight module, and display device provided by the present application achieve at least the following beneficial effects:

[0060] The present application provides a light-emitting device, a backlight module, and a display device. The light-emitting device includes a light-emitting chip and a fluorescent portion. The fluorescent portion is located on the light-emitting surface of the light-emitting chip, and the light-emitting chip excites the fluorescent portion to emit light. The power-off duration of the light-emitting chip is greater than or equal to the extinction duration of the fluorescent portion. The power-off duration is the time it takes for the light-emitting chip to transition from stable conduction to complete power-off, and the extinction duration is the time it takes for the phosphor in the fluorescent portion to return from an excited state to a ground state and cease emitting light after the light-emitting chip is powered off. The present application extends the time it takes for the light-emitting chip to transition from stable conduction to complete power-off, thereby ensuring that the power-off duration of the light-emitting chip is greater than or equal to the extinction duration of the fluorescent portion. This arrangement allows the moment when the light-emitting chip is completely powered off to be close to the moment when the fluorescent portion extincts, which helps prevent the human eye from perceiving the light emitted solely by the fluorescent portion. Adjusting the power-off duration allows for more precise control of the light-emitting chip's light-emission duration. This helps alleviate issues with red flashing or abnormal color when the light-emitting device is powered off, thereby improving the reliability of the light-emitting device and enhancing the user experience. In addition, when the light-emitting device is applied to a display device, the color of the light emitted by the light-emitting device is more stable, which is also beneficial to improving the display effect.

[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0062] The foregoing description is intended only to provide specific embodiments of the present application, which will enable those skilled in the art to understand and implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments described herein, but is intended to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. A light emitting device, characterized in that: include: Light-emitting chip and fluorescent part; The fluorescent portion is located on the light emitting surface side of the light emitting chip, and the light emitting chip excites the fluorescent portion to emit light; The power-off time of the light-emitting chip is greater than or equal to the extinction time of the fluorescent portion; The power-off duration is the time it takes for the light-emitting chip to switch from stable conduction to complete power-off, and the extinction duration is the time it takes for the phosphor in the fluorescent part to return from the excited state to the ground state and stop emitting light after the light-emitting chip is powered off.

2. The light emitting device according to claim 1, wherein In the same light-emitting device, the fluorescent portion includes a first color fluorescent portion and a second color fluorescent portion, and the extinction time of the first color fluorescent portion is longer than the extinction time of the second color fluorescent portion; The power-off time of the light-emitting chip is greater than or equal to the extinction time of the first color fluorescent portion.

3. The light emitting device according to claim 2, wherein: The power-off time of the light-emitting chip is equal to the extinction time of the first color fluorescent portion.

4. The light emitting device according to claim 2, wherein: The light emitting chip emits blue light, and the first color fluorescent portion includes red and green fluorescent powders.

5. The light emitting device according to claim 1, wherein The power-off time of the light-emitting chip is T, 150ms≤T≤300ms.

6. The light emitting device according to claim 1, wherein At the same time, the tangent slope of the power-down curve of the light-emitting chip is the same as the tangent slope of the extinction curve of the phosphor in the phosphor portion.

7. The light emitting device according to claim 1, wherein: The tangent slope of the power-down curve of the light-emitting chip is k, where -5≤k≤-2.

8. A backlight module, characterized in that: A light-emitting device comprising the light-emitting device according to any one of claims 1 to 7.

9. The backlight module according to claim 8, wherein: Also includes driver chip; The light-emitting device includes a light-emitting chip, and the driving chip is at least configured to adjust the light-emitting duty cycle of the light-emitting chip.

10. The backlight module according to claim 8, wherein: Also includes driver chips, The light-emitting device includes a light-emitting chip, and the driving chip is at least configured to adjust a driving current of the light-emitting chip.

11. The backlight module according to claim 8, wherein: The light emitting device includes a light emitting chip, and the power-off time of the light emitting chip is T, 150ms≤T≤200ms.

12. A display device, characterized in that: The backlight module comprises the backlight module according to any one of claims 8 to 11.

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