A display panel and display device

Abstract

This invention provides a display module and a display device. The display module includes a display panel and an optical modulation element. The display panel includes pixel areas and non-pixel areas. The optical modulation element is located at least in the non-pixel area. The operation of the display panel includes at least one light-emitting stage and at least one non-light-emitting stage. The operating states of the optical modulation element include a first state and a second state. The transmittance of the optical modulation element in the first state is greater than the transmittance of the optical modulation element in the second state. During the light-emitting stage, the optical modulation element is in the second state. In this application, during the light-emitting stage of the display module, the transmittance state of the optical modulation element is switched to the second state with lower transmittance. This blocks stray light with a wide viewing angle from passing through the back of the display module, reducing light leakage from the backlight surface and improving the visibility of the content on the back. Simultaneously, it absorbs this light, improving the halo effect and enhancing the display performance.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more particularly to a display panel and a display device. Background Technology

[0002] Currently, transparent displays offer a unique visual experience by blending the screen content with the background, and are thinner and more space-saving than traditional displays. For example, they can be used for product displays, allowing customers to see both the product and the screen information simultaneously, attracting more attention in places like shopping malls and airports.

[0003] However, when transparent displays are used, the content displayed on the back of the screen becomes visible, which can easily lead to the leakage of personal privacy in some applications. Therefore, their display performance still needs to be improved. Summary of the Invention

[0004] This invention provides a display module and a display device. By setting an optical modulation element, during the light emission stage, the light transmission state of the optical modulation element is switched to a second state with lower light transmittance. This blocks stray light with a wide viewing angle from passing through the back of the display module, reduces light leakage from the back light surface of the display module, improves the visibility of the content on the back, and can also absorb some of the light to improve the halo phenomenon and enhance the display effect.

[0005] In a first aspect, embodiments of the present invention provide a display module, comprising:

[0006] The display panel includes pixel areas and non-pixel areas;

[0007] An optical modulation element is located at least in the non-pixel region;

[0008] The operation of the display panel includes at least one light-emitting stage and at least one non-light-emitting stage; the operating state of the optical modulation element includes a first state and a second state; the transmittance of the optical modulation element in the first state is greater than the transmittance of the optical modulation element in the second state;

[0009] During the light-emitting phase, the optical modulation element is in the second state.

[0010] Secondly, embodiments of the present invention also provide a display device, including the display module provided in the first aspect.

[0011] The display module provided in this embodiment of the invention includes a display panel and an optical modulation element. The display panel includes pixel areas and non-pixel areas; the optical modulation element is located at least in the non-pixel area; the operation of the display panel includes at least one light-emitting stage and at least one non-light-emitting stage; the operating states of the optical modulation element include a first state and a second state; the transmittance of the optical modulation element in the first state is greater than the transmittance of the optical modulation element in the second state; during the light-emitting stage, the optical modulation element is in the second state. By adopting the above technical solution, this embodiment of the invention sets the optical modulation element to include at least two states with different transmittances, namely a first state and a second state. During the light-emitting stage of the display module, the transmittance state of the optical modulation element is switched to the second state with lower transmittance. This blocks stray light with a wide viewing angle from passing through the back of the display module, reduces light leakage from the backlight surface of the display module, improves the visibility of the content on the back, and also absorbs some of the light, improving the halo effect and enhancing the display performance. Attached Figure Description

[0012] Figure 1 This is a cross-sectional schematic diagram of a transparent display screen provided by existing technology;

[0013] Figure 2 yes Figure 1 A schematic diagram illustrating the effect of a transparent display screen.

[0014] Figure 3 This is a schematic diagram of the structure of a display module provided in an embodiment of the present invention;

[0015] Figure 4 yes Figure 3 A cross-sectional schematic diagram of a display module provided along the AA' direction;

[0016] Figure 5 yes Figure 3 A cross-sectional schematic diagram of another display module provided along the AA' direction;

[0017] Figure 6 yes Figure 4 A schematic diagram illustrating the display effect of a display module is provided.

[0018] Figure 7 This is a schematic diagram of the circuit structure of a pixel circuit provided in an embodiment of the present invention;

[0019] Figure 8 yes Figure 7 A timing diagram of the scanning signal and the light emission control signal in the provided pixel circuit;

[0020] Figure 9 yes Figure 3 A cross-sectional schematic diagram of another display module provided along the AA' direction;

[0021] Figure 10 yes Figure 3 A cross-sectional schematic diagram of another display module provided along the AA' direction;

[0022] Figure 11 This invention provides a timing diagram of a light emission control signal and a modulation control signal;

[0023] Figure 12 This is a timing diagram of another light emission control signal and modulation control signal provided by the present invention;

[0024] Figure 13 yes Figure 4 A schematic diagram illustrating the display effect of another display module is provided.

[0025] Figure 14 This is a schematic diagram of the structure of an optical modulation element provided by the present invention;

[0026] Figure 15 This is a schematic diagram of another optical modulation element provided by the present invention;

[0027] Figure 16 This is a schematic diagram of another optical modulation element provided by the present invention;

[0028] Figure 17 This is a schematic diagram of the structure of a display device provided in an embodiment of the present invention. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0030] Figure 1 This is a cross-sectional schematic diagram of a transparent display screen provided by existing technology. Figure 2 yes Figure 1 A schematic diagram illustrating the effect of a transparent display screen is provided for reference. Figure 1 and Figure 2Taking the existing Micro LED (Micro Light Emitting Diode Display) transparent display screen 100 as an example, the Micro LED chips used in the Micro LED display screen 100 are currently smaller in size, with a lower pixel area ratio compared to OLED (Organic Light Emitting Diode) displays, resulting in higher transparency and promising application prospects in the field of transparent displays. However, the transparent display screen 100 typically has a transparent area. During transparent display, external light S0 can pass through the transparent area and be seen by user A. A portion of the light S emitted from the front of the Micro LED is emitted from the light-emitting surface of the transparent display screen 100 and is seen by user A. However, due to the presence of the transparent area, some of the wide-viewing-angle light S emitted from the front of the Micro LED also undergoes reflection and / or total internal reflection at various film layer interfaces within the display screen, forming stray light. This stray light leaks through the transparent area from the sides and back of the display screen, becoming visible to user B and making the content on the back visible. In some privacy displays, this can easily leak personal privacy. Simultaneously, this light leakage can also cause a halo effect on the display screen, affecting the display effect.

[0031] Transparent display refers to a display screen that allows the surrounding environment to be seen while displaying an image. The main reason for the halo effect on transparent displays is that the light emitted from the light-emitting elements undergoes total internal reflection during its lateral propagation within the display screen. This light then encounters non-transparent materials and undergoes diffuse reflection during its lateral propagation.

[0032] Based on this, embodiments of the present invention provide a display module, which includes a display panel and an optical modulation element. The display panel includes a pixel area and a non-pixel area; the optical modulation element is located at least in the non-pixel area; the operation of the display panel includes at least one light-emitting stage and at least one non-light-emitting stage; the operating state of the optical modulation element includes a first state and a second state; the transmittance of the optical modulation element in the first state is greater than the transmittance of the optical modulation element in the second state; in the light-emitting stage, the optical modulation element is in the second state.

[0033] By adopting the above technical solution, the embodiments of the present invention provide an optical modulation element in at least the non-pixel area of ​​the display module. The optical modulation element includes at least two states with different transmittances: a first state and a second state. During the light-emitting phase of the display module, the light-transmitting state of the optical modulation element is switched to the second state with lower transmittance. This blocks stray light with a wide viewing angle from passing through the back of the display module, reduces light leakage from the back light surface of the display module, improves the visibility of the content on the back, and can also absorb some of the light to improve the halo phenomenon and enhance the display effect.

[0034] The above is the core idea of ​​this invention. The technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0035] Figure 3 This is a schematic diagram of the structure of a display module provided in an embodiment of the present invention; Figure 4 yes Figure 3 A cross-sectional schematic diagram of a display module provided along the AA' direction. Figure 5 yes Figure 3 A cross-sectional schematic diagram of a display module provided along the AA' direction. Figure 6 yes Figure 4 A schematic diagram illustrating the display effect of a display module is provided. Figure 7 This is a schematic diagram of a pixel circuit structure provided in an embodiment of the present invention. Figure 8 yes Figure 7 The timing diagram of the scanning signal and the light emission control signal in the provided pixel circuit is for reference. Figures 3-5 An embodiment of the present invention provides a display module 300 including a display panel 200 and an optical modulation element 10. The display panel 200 includes a pixel area 01 and a non-pixel area 02. The optical modulation element 10 is located at least in the non-pixel area 02. The operation of the display panel 200 includes at least one light-emitting stage and at least one non-light-emitting stage. The operating states of the optical modulation element 10 include a first state and a second state. The transmittance of the optical modulation element 10 in the first state is greater than the transmittance of the optical modulation element 10 in the second state. When the display panel 200 is in the light-emitting stage, the optical modulation element 10 is in the second state. The second state can also be referred to as a privacy state.

[0036] refer to Figure 3 In this embodiment of the invention, the display panel 200 can be an organic light-emitting diode display panel (OLED), a micro light-emitting diode display panel (Micro LED), or a light-emitting diode display panel (Micro LED), etc., and this embodiment of the invention does not impose any limitations.

[0037] refer to Figures 3-5Pixel area 01 contains multiple light-emitting elements 011, such as red light-emitting element R, green light-emitting element G, and blue light-emitting element B. Non-pixel area 02 does not contain any light-emitting elements 011. The type of light-emitting element 011 can be OLED, Micro LED, LED, etc., and this embodiment of the invention is not limited thereto. In this embodiment of the invention, the display panel 200 can be a transparent display panel, and each film layer structure is formed using a transparent material. It should be noted that pixel area 01 can also be understood as the area where sub-pixels 011 are set, and non-pixel area 02 can be understood as the area where no sub-pixels 011 are set.

[0038] It needs to be explained that, Figure 4 This is merely one example of pixel area 01 and non-pixel area 02. Pixel area 01 and non-pixel area 02 can be regular or irregular areas. This embodiment of the invention does not limit the position, size, etc. of pixel area 01 and non-pixel area 02.

[0039] The light-emitting stage refers to the light-emitting element 011 emitting light to display an image, while the non-light-emitting stage refers to the light-emitting element 011 not emitting light. During the light-emitting stage, pixel areas 01 of the display panel 200 emit light, while non-pixel areas 02 do not. During the non-light-emitting stage, neither pixel areas 01 nor non-pixel areas 02 of the display panel 200 emit light.

[0040] refer to Figure 4 and Figure 5 Taking a Micro LED display panel 200 as an example, the display panel 200 typically includes a substrate 20, a driving circuit layer 30 located on one side of the substrate 20, and multiple light-emitting elements 011. The material of the substrate 20 includes, but is not limited to, rigid materials such as glass or silicon wafers, or flexible materials such as ultra-thin glass, metal foil, or polymer plastics. The flexible or rigid substrate 20 can block oxygen and moisture, preventing moisture or impurities from diffusing into the display panel 200 through the substrate 20.

[0041] The driving circuit layer 30 includes multiple pixel circuits. Figure 4 and Figure 5 (Not shown in the image), the pixel circuit is electrically connected to the light-emitting element 011 within the pixel area 01, and is used to drive a voltage to the light-emitting element 011 to drive it to emit light. The pixel circuit can be a 2T1C, 4T1C, 7T1C, 7T2C, 8T1C, 8T2C, etc. circuit structure, and includes multiple thin-film transistors (TFTs), storage capacitors, and metal traces, etc. Figure 4 and Figure 5 (Not shown in the image). Reference Figure 7The following explanation uses a pixel circuit 301, which includes seven thin-film transistors and one storage capacitor (i.e., a 7T1C circuit), as an example. Figure 7 and Figure 8 As shown, the working process of any pixel circuit is briefly explained below:

[0042] The first scan signal line, Scan1, controls the on / off state of the reset transistor T5 in the pixel circuit, and resets the gate potential of the driving transistor T3 when the reset transistor T5 is on. The second scan signal line, Scan2, controls the on / off state of the data writing transistor T2 and the threshold compensation transistor T4 in the pixel circuit. When the data writing transistor T2 and the threshold compensation transistor T4 are on, the data signal on the data signal line Vdata is written to the gate of the driving transistor T1, and the threshold voltage of the driving transistor T3 is compensated. In some optional pixel circuit designs, the scan signal Scann can also be multiplexed to control the on / off state of the initialization transistor T7 in the pixel circuit, and resets the anode potential of the light-emitting element 011 when the initialization transistor T7 is on. In this case, it is not necessary to set a separate scan signal line for the initialization transistor T7.

[0043] In other words, the first scan signal line Scan1 can be understood as the scan signal line connected to the control terminal of the reset transistor T5 in the pixel circuit 301, and the second scan signal line Scan2 can be understood as the scan signal line connected to the control terminals of the data writing transistor T2, the compensation transistor T4, and the initialization transistor T7 in the pixel circuit 301. Generally, each row of pixel circuit 301 used for display is connected to at least the first scan signal line Scan1 and the second scan signal line Scan2.

[0044] The power supply voltage signal line PVDD provides power to the driving transistor T3, and the voltage on PVDD can be positive. The voltage on the common power supply signal terminal PVEE can be negative. The initialization signal line Vref provides the reset voltage signal, and the voltage on Vref can be negative.

[0045] It should be noted that the reference Figure 7 The above embodiment uses the example where all transistors in pixel circuit 301 are P-type transistors. In other optional embodiments, all transistors in pixel circuit 301 may be N-type transistors, or some may be P-type transistors and some may be N-type transistors. Different enable levels can be provided according to different types of transistors. The enable level is the level that enables the transistor to conduct. For example, for N-type transistors, the enable level is high, and for P-type transistors, the enable level is low.

[0046] In order to meet the driving requirements of high-resolution display panels, this embodiment of the invention can use pulse amplitude modulation (PAM) to control the driving current intensity and pulse width modulation (PWM) to control the duration of the driving current. A pixel circuit combining PAM and PWM is used to control the driving current intensity and duration in a hybrid driving mode, so as to control the light emission state of the light-emitting element 011 in pixel area 01.

[0047] Specifically, in combination Figure 4 , Figure 5 , Figure 7 and Figure 8 As shown, the driving process of pixel circuit 301 can include an initialization stage, a data writing stage, and a light-emitting stage. In the initialization stage, the first scan signal line Scan1 provides a low-level signal, the reset transistor T5 is turned on, and the gate potential of the driving transistor T3 is reset. In the data writing stage, the second scan signal line Scan2 provides a low-level signal, the data writing transistor T2 and the threshold compensation transistor T4 are turned on, the data signal on the data signal line Vdata is written to the gate of the driving transistor T1, and the threshold voltage of the driving transistor T3 is compensated; and the initialization transistor T7 is turned on, resetting the anode potential of the light-emitting element 011. In the light-emitting stage, the light-emitting control signal line Emit provides a low-level signal, the light-emitting control transistors T1 and T6 are turned on, the driving current generated by the driving transistor T3 is transmitted to the light-emitting element 011, the light-emitting element 011 emits light, and the display panel 200 operates in the light-emitting stage.

[0048] During the non-light-emitting phase, the Emit signal line outputs an invalid pulse to control the light-emitting control transistors T1 and T6 to be in the off state. Therefore, the light-emitting element 011 does not emit light, and the display panel 200 operates in the non-light-emitting phase. It should be noted that... Figure 7 and Figure 8 This is merely an example and is not intended to limit this application.

[0049] It should be noted that the display panel 200 may include at least one light-emitting stage and one non-light-emitting stage within one frame of the image, and continuously works to form a display image, which will not be elaborated here.

[0050] Furthermore, considering that no light-emitting element 011 is set in the non-pixel area 02, and that the film layer of the non-pixel area 02 has high light transmittance, the backlight surface of the display panel 200 will have light leakage and halo problems when it is operating in the light-emitting stage. (Continue to refer to...) Figure 4 and Figure 5 In this embodiment of the invention, the optical modulation element 10 is at least disposed in the non-pixel area 02.

[0051] The optical modulation element 10 is an optical device with adjustable light transmittance, such as an optical film layer containing liquid crystal molecules. The light transmittance of the optical film layer is adjusted by changing the rotation angle of the liquid crystal molecules in the optical film layer. When the display panel 200 is operating in the light-emitting stage or the non-light-emitting stage, the optical modulation element 10 is controlled to switch between a first state and a second state with different light transmittances to improve the different display effects of the display panel 200 in the light-emitting and non-light-emitting stages.

[0052] For details, please refer to Figure 4 When the optical modulation element 10 switches to a first state with higher light transmittance, background light S0 and wide-viewing-angle display light S', which reaches the non-pixel area 02 after reflection and / or total internal reflection within the display panel 200, can pass through. This wide-viewing-angle display light S' is emitted by the light-emitting element 011. (Reference) Figure 5 When the optical modulation element 10 switches to the second state with lower light transmittance, the optical modulation element 10 can block the portion of the wide-viewing-angle display light S' from passing through the back of the display module 300. This can prevent light leakage from the back of the display module 300, and at the same time absorb the portion of the wide-viewing-angle display light S', improve the halo problem of the display module 300, thereby improving the display effect.

[0053] Based on this, refer to Figure 5 and Figure 6 In this embodiment of the invention, during the light-emitting phase of the display panel 200, the optical modulation element 10 is switched to a second state with lower light transmittance. In this state, the optical modulation element 10 can block and absorb the wide-viewing-angle display light S' reflected and / or totally reflected by the interfaces of various film layers within the display panel 200, reducing the amount of wide-viewing-angle display light S' passing through the back of the display module 300. In this second state, during the light-emitting phase of the display panel 200, user A can see the displayed image on the light-emitting surface (front) of the display module 300, while user B cannot see or can only vaguely see the displayed image on the light-emitting surface of the display module 300, thus improving the problem of light leakage from the back of the display module 300. Especially in applications requiring privacy protection, this can effectively prevent the leakage of personal privacy caused by light leakage from the back of the display module. Furthermore, since the optical modulation element 10 can also absorb this portion of the wide-viewing-angle display light S', it improves the halo phenomenon caused by the total internal reflection of this portion of the wide-viewing-angle display light S' within the display panel 200, thereby improving the visual effect for user A.

[0054] It should be noted that the reference Figure 4 and Figure 5This invention also includes other film layers, such as a black matrix (BM), an encapsulation layer 50, and a cover glass, which work together to achieve the display of the display panel. These details will not be elaborated further in this invention. The encapsulation layer 50 can be a thin-film encapsulation (TFE) layer, which may include, but is not limited to, a first optically clear (OC) layer OC1, a second optically clear layer OC2, and an organic layer OCA, used to isolate water and oxygen, preventing external moisture and oxygen from affecting the light-emitting element 011 material. The OCA is an optically clear adhesive (OCA).

[0055] In summary, the embodiments of the invention provide an optical modulation element in at least the non-pixel area of ​​the display module. The optical modulation element includes at least two states with different transmittances: a first state and a second state. During the light-emitting phase of the display module, the transmittance state of the optical modulation element is switched to the second state with lower transmittance. This blocks stray light with a wide viewing angle from passing through the back of the display module, reduces light leakage from the back light surface of the display module, improves the visibility of the content on the back, and also absorbs some of the light, improving the halo effect and enhancing the display effect.

[0056] Based on the above embodiments, continue to refer to Figure 4 and Figure 5 The optical modulation element 10 has a first state of transparency and a second state of opacity. In this embodiment of the invention, an optical modulation element 10 with a wide transmittance adjustment range can also be selected, allowing the optical modulation element 10 to switch between the transparent and opaque states. When the display panel 200 is operating in the light-emitting stage, the optical modulation element 10 is controlled to be in the opaque state to block and absorb the wide-viewing-angle display light inside the display panel 200, improving the problems of light leakage and halo on the back of the display module, thereby improving the transparent display effect of the display module.

[0057] Among them, combined Figure 6 According to Table 1, the transparent display of the display module refers to the situation where, when the display module 300 is working in the light-emitting stage, user A can see the displayed image and the scene behind the display module, while user B cannot see the displayed image but can see the scene in front of the display module. At this time, the display effect of the display module 300 is to protect the displayed content.

[0058] Based on the above embodiments, when the display panel 200 is in the non-light-emitting stage, the optical modulation element 10 can be in either the first state or the second state. In this embodiment of the invention, when the display panel 200 is in the non-light-emitting stage, the light-emitting element 011 does not emit light, so there is no problem of information leakage from the back of the display panel 200. Therefore, the optical modulation element 10 can be switched between the first state and the second state according to the needs of the application scenario of the display panel 200.

[0059] Based on the above embodiments, continue to refer to Figure 4 and Figure 5 The optical modulation element 10 is located on the backlight side of the display module 300. The backlight side is opposite to the light-emitting surface of the display module 300. In this embodiment, the optical modulation element 10 can be directly attached to the backlight side of the display module 300. The orthographic projection of the optical modulation element 10 onto the display panel 200 at least covers the non-pixel area 02. When the optical modulation element 10 is in its second state, it can block wide-viewing-angle display light from passing through the back of the display module 300, preventing light leakage from the backlight side of the display module 300; simultaneously, it can absorb totally internally reflected display light within the display panel 200, reducing halo effects and improving the display effect.

[0060] Based on the above embodiments, continue to refer to Figure 4 and Figure 5 The optical modulation element 10 is also located in pixel region 01. In this embodiment of the invention, the optical modulation element 10 can also completely cover pixel region 01 and non-pixel region 02 of the display module 300, as shown in the reference. Figure 5 When the optical modulation element 10 is in the second state, it blocks and absorbs the wide-view display light S' reflected and / or totally reflected from each film layer of the pixel area 01 and the non-pixel area 02, preventing this part of the wide-view display light S' from passing through the back of the display module 300, improving the problem of light leakage on the backlight side of the display module 300, and reducing the halo.

[0061] Figure 9 yes Figure 3 A cross-sectional schematic diagram of another display module provided along the AA' direction is shown in the reference diagram. Figure 9Based on the above embodiments, the optical modulation element 10 includes a modulation region 11 and a blocking region 12; the modulation region 11 is located in the non-pixel region 01, and the blocking region 12 is located in the pixel region 01. The modulation region 11 includes a first state and a second state. In this embodiment of the invention, a "patterned" structure can also be used to divide the optical modulation element 10 into zones. The blocking region 12 is set in the pixel region 01, and its transmittance is not adjustable, usually in a non-transparent state. The blocking region 12 can block light transmission during both the light-emitting and non-light-emitting phases of the display panel 200. The modulation region 11 is set in the non-pixel region 02, and its transmittance can switch between the first state and the second state. During the light-emitting phase of the display panel 200, the modulation region 11 is switched to the second state with lower transmittance to block and absorb the wide-viewing-angle display light reflected and / or totally reflected from the various film layers of the pixel region 01 and the non-pixel region 02, avoiding light leakage from the backlight side of the display module 300. During the non-light-emitting phase of the display panel 200, the modulation region 11 can be in either the first state or the second state, and this embodiment of the invention does not impose any limitations.

[0062] Based on the above embodiments, Figure 10 yes Figure 3 A cross-sectional schematic diagram of another display module provided along the AA' direction is shown in the reference diagram. Figure 10 The optical modulation element 10 can also be disposed inside the film layer of the display panel 200 in a "patterned" structure. The display module 300 also includes a substrate 20 and a driving circuit layer 30, a plurality of light-emitting elements 011 and a planarization layer (PLN) sequentially located on one side of the substrate 20. In this embodiment of the invention, the optical modulation element 10 is located between the driving circuit layer 30 and the planarization layer 40 in the non-pixel area 02.

[0063] refer to Figure 10 During the light-emitting phase of the display panel 200, the optical modulation element 10 is in a second state with low light transmittance, such as a non-transparent state, which can block and absorb the wide-viewing-angle display light S' emitted from the light-emitting element 011, preventing this portion of the wide-viewing-angle display light S' from passing through the back of the display module 300. During the non-light-emitting phase of the display panel 200, the optical modulation element 10 can be in either the first or second state, and the embodiments of the present invention are not limited thereto.

[0064] In this article, "patterning" specifically refers to non-integral structure, that is, a structure formed by first creating an integral layer of material and then carving out a specific shape during the manufacturing process.

[0065] It should be noted that continued reference is necessary. Figure 4 , Figure 5 , Figure 9 and Figure 10The non-pixel area 02 includes multiple transparent film layers, and the transmittance of the optical modulation element 10 in the first state is greater than or equal to the transmittance of the multiple transparent film layers. The first state can be a transparent state. In this embodiment of the invention, each film layer of the display panel 200 can be made of a combination of transparent materials and transparent conductive materials. Designing each film layer of the non-pixel area 012 and the pixel area 01 as a transparent film layer is beneficial to improving the transparent display effect of the display module 300.

[0066] Transparent materials include, but are not limited to, PET (polyethylene terephthalate), PMMA (polymethyl methacrylate), PC (polycarbonate), COP (cycloolefin polymer), PEN (polyethylene naphthalate), SiO2 (silicon dioxide), Si3N4 (silicon nitride), Al2O3 (alumina), MgF2 (magnesium fluoride), epoxy resin, UV-curable adhesives, and OCA (optical transparent adhesive). Transparent conductive materials include, but are not limited to, ITO (indium tin oxide), GZO (gallium-doped zinc oxide), IZO (indium-doped zinc oxide), silver nanowires, metal mesh, and graphene.

[0067] Based on the above embodiments, refer to Figures 3-10 The optical modulation frequency at which the optical modulation element 10 switches between the first and second states is the same as the refresh frequency at which it switches between the light-emitting and non-light-emitting stages. In this embodiment of the invention, the optical modulation element 10 can be added to the backlight side or inside the film layer of the display panel 200. The optical modulation element 10 has at least two optical modulation states with different transmittances, such as a transparent state and an opaque state, and the two modulation states can be electrically switched.

[0068] The refresh rate of the display panel refers to the number of times the screen updates the image per second, usually measured in Hertz (Hz). It should be noted that, in this embodiment of the invention, the optical modulation frequency of the optical modulation element 10 refers to the number of times it switches between two modulation states per second. The refresh rate of the display panel 200 switching between the light-emitting and non-light-emitting stages refers to the number of times the light-emitting element 011 switches between the light-emitting and non-light-emitting stages per second. (Continue to refer to...) Figure 7 and Figure 8 The refresh rate of the display panel 200 when switching between the light-emitting stage and the non-light-emitting stage can also be understood as the number of times the light-emitting control signal line Emit outputs an effective pulse during the driving process of the pixel circuit 301 to control the light-emitting control transistors T1 and T6 to be in the on state, and the number of times the light-emitting element 011 emits light per second.

[0069] The following example uses the first state as transparent and the second state as non-transparent. In this embodiment of the invention, PAM and PWM dimming technology are combined. During the light-emitting stage of the light-emitting element 011, the optical modulation element 10 is switched to a non-transparent state so that the display light S emitted by the light-emitting element 011 can only be emitted from the front of the display panel 200. During the non-light-emitting stage of the light-emitting element 011 (after it is turned off), the optical modulation element 10 is switched to a non-transparent state or a transparent state.

[0070] Figure 11 This invention provides a timing diagram of a light emission control signal and a modulation control signal. Based on the above embodiments, referencing... Figure 11 Emit1 is denoted as the light-emitting control signal of the light-emitting element 011; a high level indicates light emission, and a low level indicates no light emission. Emit2 is denoted as the modulation control signal of the optical modulation element 10 in the second state; a high level indicates the first state, and a low level indicates the second state. The duration of one light-emitting stage is T1, and the duration of the optical modulation element 10 in the second state is T2; where T1 < T2.

[0071] For example, combined Figures 3-11 As shown, in this embodiment of the invention, the duration T2 of the optical modulation element 10 in the non-transparent state is greater than the duration T1 of the driving current of the light-emitting element 011 in one light-emitting stage. When the light-emitting element 011 is in the light-emitting state, the optical modulation element 10 is in the non-transparent state. This can block and absorb the wide-viewing-angle display light in the display panel 200, prevent this part of the wide-viewing-angle display light from passing through the back of the display panel 200, improve the problem of light leakage and halo on the back of the display module 300, and help to make the content on the back of the display module 300 invisible.

[0072] Based on the above embodiments, refer to Figure 11 During the light-emitting phase, the optical modulation element 10 begins its second state before the start of the light-emitting phase. Figures 3-11 As shown, in this embodiment of the invention, the starting time of controlling the optical modulation element 10 to switch to the second state is earlier than the starting time of the light-emitting element 011 working in the light-emitting stage. This ensures that when the light-emitting element 011 emits light, the optical modulation element 10 has already switched to the non-transparent state, ensuring that the optical modulation element 10 can block and absorb the wide-viewing-angle display light in the display panel 200, so that the content on the back of the display module 300 is not visible.

[0073] Based on the above embodiments, refer to Figure 11 During the light-emitting phase, the end time of the second state of the optical modulation element 10 is after the end time of the light-emitting phase. Figures 3-11As shown, in this embodiment of the invention, the end time of switching the optical modulation element 10 to the second state is later than the end time of the light-emitting element 011 working in the light-emitting stage. This ensures that when the light-emitting element 011 transitions from the light-emitting stage to non-light-emitting, the optical modulation element 10 remains in a non-transparent state. This can block and absorb the residual wide-view display light in the display panel 200, making the content on the back of the display module 300 invisible.

[0074] Based on the above embodiments, refer to Figure 11 The duration of one light-emitting phase is T1. The overlap between the driving period of the optical modulation element 10 in the second state and the driving period of the light-emitting phase is greater than or equal to the duration of the light-emitting phase, T1. That is, in this embodiment of the invention, the time T2 during which the optical modulation element 10 remains in the second state completely covers the light-emitting time T1 during which the light-emitting element 011 operates in the light-emitting phase. This ensures that when the light-emitting element 011 emits light, the optical modulation element 10 remains in a non-transparent state, thus blocking and absorbing residual wide-viewing-angle display light within the display panel 200, making the content on the back of the display module 300 invisible.

[0075] Based on the above embodiments, continue to refer to Figure 11 A driving cycle consists of a light-emitting phase and a non-light-emitting phase. The duration of the driving cycle is T, and the duration of a light-emitting phase is T1, where T1 ≤ 50%T. T3 is the duration of a non-light-emitting phase, and T = T1 + T3.

[0076] It should be noted that if the optical modulation element 10 remains in the second state for a long time, it will affect the transparent display effect of the display panel. Therefore, in this embodiment of the invention, the duration T1 of the light emission phase within one driving cycle of the light-emitting element is controlled to be no greater than the duration T of half a driving cycle. This ensures that the light-emitting element has high luminous efficiency, and at the same time, while ensuring that the duration of the optical modulation element 10 in the second state covers the light emission time, the duration of the optical modulation element 10 in the second state is compressed as much as possible, so that the optical modulation element 10 can remain in the first state with higher light transmittance for a longer period of time, thereby increasing the light transmission time of the display panel and improving the transparent display effect of the display panel.

[0077] Furthermore, Figure 12 This is a timing diagram of another light emission control signal and modulation control signal provided by the present invention. Figure 13 yes Figure 4 Another display module is provided as a schematic diagram of its display effect. In this embodiment of the invention, reference is made to... Figure 12Emit1 is denoted as the light-emitting control signal for the light-emitting element 011; a high level indicates light emission, and a low level indicates no light emission. Emit2 is denoted as the modulation control signal for the optical modulation element 10 in its second state; a high level indicates a transparent state, and a low level indicates a non-transparent state. (Refer to the diagram.) Figures 1-12 According to Table 1, the display module 300 can achieve at least four modes, such as transparent display mode, non-transparent display mode, transparent non-display mode, and non-transparent non-display mode.

[0078] Table 1

[0079]

[0080]

[0081] In this context, the foreground refers to the view behind the display module as seen by user A from the light-emitting side, while the background refers to the view in front of the display module as seen by user B from the backlight side. An "×" indicates that the view is not visible, and a "√" indicates that the view is visible.

[0082] In transparent display mode: the refresh rates of the light emission control signal Emit1 and the modulation control signal Emit2 are the same. When the light emission control signal Emit1 is high, the light-emitting element emits light; when the light emission control signal Emit1 is low, the light-emitting element does not emit light. When the modulation control signal Emit2 is low, the optical modulation element 10 is in a non-transparent state; when the modulation control signal Emit2 is high, the optical modulation element 10 is in a transparent state.

[0083] The optical modulation element 10 is opaque only during the light-emitting phase and transparent during the non-light-emitting phase. The display panel 200 still has transparent periods throughout the entire driving cycle. Typically, when the display panel 200 displays one frame, there are multiple light-emitting and non-light-emitting phases. The refresh rate of the display panel 200 is usually quite high, such as 30Hz, 60Hz, or 120Hz. At such high refresh rates, the difference is almost imperceptible to the naked eye. (Continue to refer to...) Figure 5 , Figure 6 Throughout the entire light-emitting phase, the wide-view display light S' cannot pass through the back of the display panel 200, but the background light S0 (ambient light) can still be seen by user A through the display panel 200 when the optical modulation element 10 is in a non-transparent state, thus achieving a transparent display mode. (Reference) Figure 6 According to Table 1, in this transparent display mode, user A can see both the displayed image and the foreground of the display module, while user B cannot see the displayed image but can see the background of the display module. At this time, the display effect of display module 300 is the display content privacy mode.

[0084] In non-transparent display mode: the refresh rates of the emissive control signal Emit1 and the modulation control signal Emit2 are the same. When the emissive control signal Emit1 is high, the emissive element emits light; when the emissive control signal Emit1 is low, the emissive element does not emit light. The modulation control signal Emit2 remains low, and the optical modulation element 10 remains opaque. That is, the optical modulation element 10 is opaque during both the emissive and non-emissive phases, and the display panel 200 remains opaque throughout the entire driving cycle. (Reference) Figure 5 and Figure 13 In this non-transparent display mode, the light rays S' from the wide viewing angle cannot pass through the back of the display panel 200 during both the light-emitting and non-light-emitting stages. User A can see the displayed image but cannot see the foreground image of the display module 300, and User B cannot see either the displayed image or the background image of the display module 300. At this time, the display effect of the display module 300 is in high contrast mode.

[0085] In transparent non-display mode, the refresh rates of the light emission control signal Emit1 and the modulation control signal Emit2 are the same. The light emission control signal Emit1 remains low, the light-emitting element does not emit light, and the display panel 200 operates in the non-light-emitting stage, displaying no information. The modulation control signal Emit2 remains high, and the optical modulation element 10 remains transparent. (Reference) Figure 4 The optical modulation element 10 remains transparent throughout the entire driving cycle of the display panel 200. This can be understood as the display module 300 only having a transparent function at this time. Combined with... Figure 6 and Figure 13 User A cannot see the displayed image but cannot see the foreground image of display module 300. User B cannot see the displayed image but can see the background image of display module 300. The display effect of display module 300 is only transparent.

[0086] In the non-transparent, non-display mode, the refresh rates of the light-emitting control signal Emit1 and the modulation control signal Emit2 are the same. Emit1 remains low, the light-emitting element does not emit light, and the display panel 200 operates in a non-light-emitting stage, displaying no information. The modulation control signal Emit2 remains low, and the optical modulation element 10 remains opaque. The display module 300 is in the non-transparent, non-display mode. Figure 6 and Figure 13 This can be understood as the display module 300 not being a transparent display screen. User A cannot see the displayed image or the foreground image of the display module 300, and user B cannot see the displayed image or the background image of the display module 300. The display effect of the display module 300 is to provide background privacy.

[0087] Figure 14This is a schematic diagram of the structure of an optical modulation element provided by the present invention. Based on the above embodiments, refer to... Figure 14 The optical modulation element 10 includes a first electrode layer 10a, an electrochromic material 10b, and a second electrode layer 10c stacked together. The electrochromic material 10b is in an oxidized state in a first state and a reduced state in a second state.

[0088] Electrochromic material 10b is a material that undergoes reversible color changes under the influence of an applied electric field. Under the influence of an electric field, its optical properties (such as transmittance, reflectance, and absorptivity) change, thus exhibiting different colors or transparency. The redox reaction can be a metal oxide, such as WO3 (tungsten trioxide), NiO (nickel oxide), or MoO3 (molybdenum trioxide). Electrochromic phenomena typically involve redox reactions and ion insertion / extraction processes.

[0089] In this embodiment of the invention, the redox reaction of the electrochromic material 10b is utilized by applying a voltage to the first electrode layer 10a and the second electrode layer 10c. In the first state, the electrochromic material 10b is controlled to undergo an oxidation reaction and become oxidized, and the optical modulation element 10 exhibits a transparent state, such as... Figure 14 As shown in (a). In the second state, the electrochromic material 10b is controlled to undergo a reduction reaction and become a reduced state, and the optical modulation element 10 exhibits a non-transparent or semi-transparent state, such as... Figure 14 As shown in (b). In this embodiment of the invention, the non-transparent state of the electrochromic material is controlled to block and absorb light from the display panel at a wide viewing angle, thereby improving the problems of light leakage and halo on the back of the display module and enhancing the transparent display effect of the display module.

[0090] Figure 15 This is a schematic diagram of the structure of an optical modulation element provided by the present invention. Based on the above embodiments, refer to... Figure 15 The optical modulation element 10 includes a first electrode layer 10d, a liquid crystal layer 10e, and a second electrode layer 10f stacked together; the liquid crystal layer 10e is in a transparent state in a first state and in a scattering state in a second state.

[0091] In this embodiment, the liquid crystal molecules in the liquid crystal layer 10e are anisotropic and can change their alignment direction under the action of an applied electric field. The present invention applies an electric field to the liquid crystal molecules through the first electrode layer 10d and the second electrode layer 10f to control the alignment and orientation of the liquid crystal molecules, thereby adjusting the light transmittance and achieving a transparent state for the optical modulation element 10. For example, in the first state, a high voltage difference is maintained between the first electrode layer 10d and the second electrode layer 10f, causing the liquid crystal molecules in the liquid crystal layer 10e to align in the same direction. The transmittance of the liquid crystal molecules to light is low, and the optical modulation element 10 exhibits a transparent state. Figure 15As shown in (a). In the second state, a low voltage difference is maintained between the first electrode layer 10d and the second electrode layer 10f. The liquid crystal molecules in the liquid crystal layer 10e are arranged in a disordered manner, resulting in low light transmittance. The optical modulation element 10 exhibits a high scattering state, as shown in (a). Figure 15 As shown in (b). The high scattering state can disrupt and absorb the light from the display panel at a wide viewing angle, improving the problems of light leakage and halo on the back of the display module, thus enhancing the transparent display effect of the display module.

[0092] Figure 16 This is a schematic diagram of the structure of an optical modulation element provided by the present invention. Based on the above embodiments, refer to... Figure 16 The optical modulation element 10 includes a first electrode layer 10g, a microlens structure 10h, and a second electrode layer 10i stacked together; the microlens structure 10h is in a transparent state in a first state and in a highly reflective state in a second state.

[0093] In this embodiment of the invention, the microlens structure 10h is a lens array or a single lens with a tiny size (typically in the micrometer to millimeter range) that can focus, diverge or modulate light.

[0094] In this embodiment of the invention, an electric field is applied to the microlens structure 10h by the first electrode layer 10d and the second electrode layer 10f to control the arrangement angle and direction of the microlens structure 10h, thereby adjusting the light transmittance and thus adjusting the transparent state of the optical modulation element 10. For example, in the first state, by controlling the voltage of the first electrode layer 10d and the second electrode layer 10f, the shape angle of the microlens structure 10h is changed to be consistent in the horizontal direction, adjusting its light transmittance to be higher, and the optical modulation element 10 exhibits a transparent state, such as... Figure 16 As shown in (a). In the second state, by controlling the voltage of the first electrode layer 10d and the second electrode layer 10f, the shape and angle of the microlens structure 10h are changed to be consistent along the vertical direction, adjusting its reflectivity to be higher. The optical modulation element 10 exhibits a high reflectivity state, as shown in (a). Figure 16 As shown in (b). The high reflectivity state can reflect and absorb the light from the display panel at a wide viewing angle, improving the problems of light leakage and halo on the back of the display module, thus enhancing the transparent display effect of the display module.

[0095] Based on the above embodiments, refer to Figures 14-16 The first and second electrode layers can be made of transparent electrodes, such as ITO (indium tin oxide) electrodes, which is beneficial to achieving a completely transparent state for the optical modulation element 10.

[0096] Table 2 shows the adoption of Figures 14-16 The optical modulation element 10 shown in the figure displays a comparison of the differences in display effects, combined with Figure 6The viewing experience of users A and B was compared using... Figures 14-16 The optical modulation element 10 shown is switched to a second state during the light-emitting phase of the display module 300. This second state can be any one of a non-transparent state, a high-scattering state, or a high-reflection state. When the display module 300 is in transparent display mode, user A can see both the displayed image and the foreground image of the display module; user B cannot see the displayed image but can see the background image. This achieves a transparent display effect for the display module, avoiding image leakage and halo issues on the back of the display module 300.

[0097] Table 2

[0098]

[0099] Based on the same inventive concept, embodiments of the present invention also provide a display device. Figure 17 This is a schematic diagram of a display device provided in an embodiment of the present invention. (In conjunction with...) Figure 17 As shown, the display device 400 includes any of the display modules 300 provided in the above embodiments. Therefore, the display device 17 also has the beneficial effects of the display module 300 in the above embodiments. The similarities can be understood with reference to the explanation of the display module 300 above, and will not be repeated below.

[0100] The display device 400 provided in this embodiment of the invention can be Figure 17 The mobile phone shown can also be any electronic product with display function, including but not limited to the following categories: television, laptop, desktop monitor, tablet computer, digital camera, smart bracelet, smart glasses, in-vehicle display, industrial control equipment, medical display screen, touch interactive terminal, etc. The embodiments of the present invention do not make any special limitations on this.

[0101] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A display module, characterized in that, include: The display panel includes pixel areas and non-pixel areas; An optical modulation element is located at least in the non-pixel region; The operation of the display panel includes at least one light-emitting stage and at least one non-light-emitting stage; the operating states of the optical modulation element include a first state and a second state; the transmittance of the optical modulation element in the first state is greater than the transmittance of the optical modulation element in the second state; the non-pixel area includes multiple transparent film layers, and the transmittance of the optical modulation element in the first state is greater than or equal to the transmittance of the multiple transparent film layers. During the light-emitting phase, the optical modulation element is in the second state.

2. The display module according to claim 1, characterized in that, The first state is a transparent state, and the second state is a non-transparent state.

3. The display module according to claim 1, characterized in that, During the non-light-emitting phase, the optical modulation element is in either the first state or the second state.

4. The display module according to claim 1, characterized in that, The optical modulation element is located on the backlight side of the display module; wherein the backlight side is opposite to the light-emitting surface of the display module.

5. The display module according to claim 4, characterized in that, The optical modulation element is also located in the pixel area.

6. The display module according to claim 4, characterized in that, The optical modulation element includes a modulation region and a blocking region; the modulation region is located in the non-pixel region, the blocking region is located in the pixel region, and the modulation region includes a first state and a second state.

7. The display module according to claim 1, characterized in that, The display module further includes a substrate and a driving circuit layer, a plurality of light-emitting elements and a planarization layer located sequentially on one side of the substrate; the optical modulation element is located between the driving circuit layer and the planarization layer in the non-pixel area.

8. The display module according to claim 1, characterized in that, The optical modulation frequency at which the optical modulation element switches between the first state and the second state is the same as the refresh frequency at which it switches between the light-emitting stage and the non-light-emitting stage.

9. The display module according to claim 1, characterized in that, The duration of one of the light-emitting stages is T1, and the duration of the optical modulation element in the second state is T2; wherein, T1 < T2.

10. The display module according to claim 1, characterized in that, During the light emission phase, the optical modulation element begins its second state at a time prior to the start of the light emission phase.

11. The display module according to claim 1, characterized in that, During the light emission phase, the optical modulation element ends at a time after the end of the second state.

12. The display module according to claim 1, characterized in that, The duration of one of the light-emitting phases is T1, and the overlap between the driving period of the optical modulation element in the second state and the driving period of the light-emitting phase is greater than or equal to the duration of the light-emitting phase T1.

13. The display module according to claim 1, characterized in that, A driving cycle includes a light-emitting phase and a non-light-emitting phase, the duration of the driving cycle is T, the duration of a light-emitting phase is T1, and T1 ≤ 50% T.

14. The display module according to any one of claims 1 to 13, characterized in that, The optical modulation element includes a first electrode layer, an electrochromic material, and a second electrode layer stacked together; the electrochromic material is in an oxidized state in the first state and in a reduced state in the second state.

15. The display module according to any one of claims 1 to 13, characterized in that, The optical modulation element includes a first electrode layer, a liquid crystal layer, and a second electrode layer stacked together; the liquid crystal layer is in a transparent state in the first state and in a scattering state in the second state.

16. The display module according to any one of claims 1 to 13, characterized in that, The optical modulation element includes a first electrode layer, a microlens structure, and a second electrode layer stacked together; the microlens structure is transparent in the first state and highly reflective in the second state.

17. A display device, characterized in that, Includes the display module as described in any one of claims 1-16.

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