WO2023216145A1

WO2023216145A1 - Display panel and display apparatus comprising same

Info

Publication number: WO2023216145A1
Application number: PCT/CN2022/092231
Authority: WO
Inventors: 胡巍浩; 倪恩伟; 赵楠; 兰博骁; 程金辉; 陈伟雄
Original assignee: 北京奕斯伟计算技术股份有限公司
Priority date: 2022-05-11
Filing date: 2022-05-11
Publication date: 2023-11-16

Abstract

The present disclosure relates to a display panel and a display apparatus comprising same. The display panel comprises a plurality of pixel units. Each pixel unit comprises: a light-emitting device, which comprises a light-emergent face and a back face arranged opposite the light-emergent face; a pixel circuit, which provides, in response to a scanning drive signal, to the light-emitting device a drive current corresponding to a target display grayscale; a reflection structure, which is used for reflecting light that is emitted along the back face of the light-emitting device and transmitting the light by means of the light-emergent face; and a transmission structure, which is located between the back face of the light-emitting device and the reflection structure, and controls the magnitude of the transmittance of the transmission structure itself according to the target display grayscale, so as to control the rate of effective utilization, by the pixel unit, of the light that is emitted along the back face of the light-emitting device. In the present disclosure, the transmittance of light that is emitted along a back face of a light-emitting device is controlled on the basis of a target display grayscale, such that the contrast ratios of a display panel and a display apparatus comprising same are increased by means of controlling the rate of effective utilization, by a pixel unit, of the light that is emitted along the back face of the light-emitting device.

Description

Display panel and display device thereof

Technical field

The present disclosure relates to the field of display technology, and in particular to a display panel and a display device thereof.

Background technique

With the continuous development and progress of modern display technology, display devices have also developed from informatization to intelligence, and play an irreplaceable and important role in the information interaction process of modern society. Among the various display technologies currently available, Micro-LED (micro-light-emitting diode) display technology is one of the next-generation display technologies that is considered disruptive. Micro-LED applications will expand from flat panel displays to AR (Augmented Reality, augmented reality)/VR (Virtual Reality, virtual display)/MR (Mixed Reality, mixed reality), spatial display, flexible transparent display, wearable/implantable Optoelectronic devices, optical communications/optical interconnection, medical detection, smart car lights and many other fields.

However, the current Micro-LED display technology still has some shortcomings. For example, the lack of reflective structure in its product structure will cause only part of the light emitted by Micro-LED to be utilized, and ultimately fail to achieve higher brightness and higher contrast. The existing technology generally improves the luminous efficiency of the display device by adding a reflective sheet at the Micro-LED device level or by changing part of the contact metal to reflective metal. However, the above method only improves the display brightness during grayscale display, and fails to improve the contrast of the display device (referring to the measured values of different brightness levels between the brightest white and the darkest black in the light and dark areas of an image, the greater the ratio) The greater the contrast, the smaller the ratio, the smaller the contrast), which may even reduce the contrast of the display device.

Contents of the invention

In order to solve the above technical problems, the present disclosure provides a display panel and a display device thereof to improve the contrast of the display panel and the display device thereof.

In a first aspect, embodiments of the present disclosure provide a display panel, including a plurality of pixel units, where the pixel units include: a light emitting device including a light emitting surface and a back surface opposite to the light emitting surface;

a pixel circuit that responds to the scan drive signal to provide a drive current corresponding to the target display grayscale to the light-emitting device;

a reflective structure for reflecting the light emitted along the back of the light-emitting device and emitting it through the light-emitting surface; and

A transmissive structure is located between the backside of the light-emitting device and the reflective structure, and controls its own transmittance according to the target display grayscale to control the pixel unit's response to the light emitted along the backside of the light-emitting device. effective utilization rate.

Optionally, when the target display gray scale is a black gray scale, the transmittance of the transmission structure is a first preset value; when the target display gray scale is a white gray scale, the transmittance of the transmission structure is a first preset value; The transmittance of the transmission structure is a second preset value, and the first preset value is smaller than the second preset value.

Optionally, when the target display gray scale is a black gray scale, the light emitted along the back side of the light emitting device cannot pass through the transmission structure; when the target display gray scale is a white gray scale, The light emitted along the back side of the light-emitting device passes through the transmission structure and reaches the reflective structure. The light reaching the reflective structure is reflected by the reflective structure and then emitted through the light-emitting surface.

Optionally, when the target display gray level is between a black gray level and a white gray level, the transmittance of the transmission structure is a first preset value, a second preset value, or is between a first preset value and a first preset value. between the preset value and the second preset value.

Optionally, the permeable structure includes:

The first electrode receives the control voltage;

The second electrode receives the common voltage;

Liquid crystal molecules are located between the first electrode and the second electrode and rotate according to the electric field formed between the first electrode and the second electrode; and

A control circuit, connected to the first electrode, responds to the scan drive signal and provides the corresponding control voltage according to the target display grayscale.

Optionally, the control circuit controls the state of the liquid crystal molecules according to the control voltage so that the transmittance of the transmission structure corresponds to the target display gray scale.

Optionally, the control circuit includes:

A transistor, a control terminal receives the scan driving signal, a first terminal receives the control voltage, and a second terminal is connected to the first electrode; and

One end of the storage capacitor is connected to the second end of the transistor, and the other end is connected to the first electrode.

Optionally, the reflective structure has an uneven surface facing the back side of the light-emitting device.

Optionally, the reflective structure at least includes:

an insulating layer, one of which has an uneven surface; and

The reflective layer is located on the undulating surface of the insulating layer, has an undulating topography, and is opposite to the back surface of the light-emitting device.

In a second aspect, embodiments of the present disclosure provide a display device, including the display panel as described above.

The display panel and its display device provided by the present disclosure are provided with a reflective structure for reflecting the light emitted along the back of the light-emitting device and emitting it through the light exit surface, and is located between the back of the light-emitting device and the reflective structure and according to the target Displays a transmission structure whose grayscale controls its own transmittance. Controlling the transmittance of light emitted along the backside of the light-emitting device based on the target display grayscale improves the contrast of the display panel and its display device by controlling the effective utilization of the light emitted along the backside of the light-emitting device by the pixel unit.

It should be noted that the above general description and the following detailed description are only exemplary and explanatory, and do not limit the present disclosure.

Description of the drawings

Figure 1 shows a schematic structural diagram of a display unit in a display device;

Figure 2 shows a schematic structural diagram of a display device provided according to an embodiment of the present disclosure;

Figure 3 shows a schematic structural diagram of a pixel unit in a display device according to an embodiment of the present disclosure;

Figure 4 shows a schematic cross-sectional view of a pixel unit in a display device according to an embodiment of the present disclosure;

FIG. 5 shows a schematic diagram of partial signal waveforms when the display device displays a picture according to an embodiment of the present disclosure.

Detailed ways

To facilitate understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. Preferred embodiments of the present disclosure are shown in the accompanying drawings. However, the present disclosure may be implemented in different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough understanding of the disclosure will be provided.

Figure 1 shows a schematic structural diagram of a display unit in a display device.

Referring to FIG. 1 , the display device includes a plurality of display units, and each display unit includes a substrate 110 , a light-emitting device 130 , and a thin film transistor located on the surface of the substrate 110 and connected to the light-emitting device 130 .

The thin film transistor includes a gate layer 121 located on the surface of the substrate 110, a gate insulating layer 125 located on the surface of the substrate 110 and covering the gate layer 121, an active layer 122 located on the surface of the gate insulating layer 125 away from the substrate 110, The drain layer 123 is located on the surface of the gate insulating layer 125 away from the substrate 110 and in contact with part of the active layer 122 , and the source layer is located on the surface of the gate insulating layer 125 away from the substrate 110 and in contact with part of the active layer 122 Layer 124 , wherein the source layer 124 is not in contact with the drain layer 123 and is located on both sides of the active layer 122 . The light emitting device 130 includes a first contact layer 131, a multi-quantum well layer 132 and a second contact layer 133. The first contact layer 131 is located on a surface of the gate insulating layer 125 away from the substrate 110 and is at least partially in contact with the drain layer 123 to receive a driving current through the thin film transistor. The multi-quantum well layer 132 is located on the surface of the first contact layer 131 away from the gate insulating layer 125 . The second contact layer 133 is located on the surface of the multi-quantum well layer 132 away from the first contact layer 131 and receives the reference voltage.

For example, the first contact layer 131 is a P-type ohmic contact layer, and the second contact layer 133 is an N-type ohmic contact layer. The first contact layer 131 is connected to the thin film transistor through the first electrode (the anode of the light-emitting device 130, not shown in the figure) that is electrically connected to itself to receive the driving current, and the second contact layer 133 is electrically connected to itself through the second electrode ( The cathode (not shown in the figure) of the light emitting device 130 receives the reference voltage.

The light emitting device 130 is controlled and driven based on a thin film transistor to be lit. The light-emitting device 130 is top-emitting (the surface of the second contact layer 133 away from the multi-quantum well 132 layer serves as the light-emitting surface of the display device), and some ambient light and the light emitted in the opposite direction along the light-emitting surface of the light-emitting device 130 cannot be effectively utilized. , ultimately leading to loss of display brightness and low luminous efficiency.

The prior art often solves the above technical problems by directly using a reflective metal layer as the first contact layer 131 so that ambient light and light emitted in the opposite direction along the light emitting surface of the light emitting device 130 are reflected and emitted along the light emitting surface. Alternatively, the above technical problem can be solved by arranging a reflective layer on the surface of the first contact layer 131 away from the multi-quantum well layer 132 so that the ambient light and the light emitted from the light-emitting device 130 in the opposite direction along the light-emitting surface are reflected and emitted along the light-emitting surface. The above two methods not only improve the display brightness of the display device when displaying white grayscale, but also improve the display brightness of the display device when displaying black grayscale, thereby improving the contrast of the display device.

FIG. 2 shows a schematic structural diagram of a display device provided according to an embodiment of the present disclosure. FIG. 3 shows a schematic structural diagram of a pixel unit in a display device according to an embodiment of the present disclosure. FIG. 4 shows a schematic cross-sectional view of a pixel unit in a display device according to an embodiment of the present disclosure. FIG. 5 shows a schematic diagram of partial signal waveforms when the display device displays a picture according to an embodiment of the present disclosure.

Referring to FIG. 2 , the display device includes a display panel 2000 , a scan driving circuit 3000 and a data driving circuit 4000 . The display device in this embodiment is, for example, a Micro-LED (micro light-emitting diode) display device. In other embodiments, the display device may also be other types of LED display devices. Micro-LED display technology integrates micro-sized (less than 100 microns) LEDs at a high density, where individual pixels and pixel spacing are reduced to the micron level, and each pixel can be independently addressed and emit light alone. At present, micro-LED full-color display will be achieved through chip mass transfer technology or the use of short-wavelength micro-LED. Chip mass transfer technology refers to growing epitaxial materials of a single luminous wavelength, then preparing micro-LED chips, and finally transferring single micro-LED chips of various colors to the target substrate for multi-color integration and combining them with drive circuits Achieve full color display. Display technology that uses short-wavelength micro-LEDs (such as blue light or ultraviolet) can radiate high-energy photons that can excite color conversion materials such as green and red light quantum dots, thereby obtaining RGB three-primary color light sources. The present disclosure mainly solves the technical problem of improving the contrast of a display device. To facilitate understanding, the display device in this embodiment uses a second display technology to achieve full-color display, for example. In other embodiments, the display device can also use the first display technology to achieve full-color display.

The display panel 2000 includes a plurality of pixel units 2100 arranged in an array. The scan driving circuit 3000 is, for example, used to control scanning of each pixel unit 2100 during screen display. The data driving circuit 4000 is used to provide driving current when scanning the pixel unit 2100 to achieve picture display. Further, the pixel units 2100 located in the same row share, for example, one scan drive unit in the scan drive circuit 3000 and are driven by it. The pixel units 2100 located in the same column share, for example, one data driving unit in the data driving circuit 4000 and are driven by it.

Referring to FIG. 3 , the circuit structure of the pixel unit 2100 is shown. The pixel unit 2100 includes a pixel circuit 2110, a light emitting device 2120, a reflective structure 2130 and a transmissive structure 2140.

The pixel circuit 2110 responds to the scan driving signal to provide the light emitting device 2120 with a driving current corresponding to the target display gray scale. The equivalent circuit of the pixel circuit 2110 includes a transistor T1 and a storage capacitor C1. The control terminal of the transistor T1 receives the scan driving signal provided by the scan driving circuit 3000. The first path terminal of the transistor T1 provides the data voltage Vdd. The second path terminal of the transistor T1 is connected to the anode of the light emitting device 2120 to provide a driving current. One end of the storage capacitor C1 is connected to the second path end of the transistor T1, and the other end of the storage capacitor C1 is connected to the anode of the light emitting device 2120. Wherein, the gray scale displayed by the corresponding light-emitting device 2120 is also different if the magnitude of the data voltage Vdd is different. In other embodiments, the pixel circuit 2110 may include, for example, a driving transistor, a switching transistor, and a storage capacitor. Among them, the control end of the switch tube receives the scan control signal, the first channel end of the switch tube receives the data voltage, the second channel end of the switch tube is connected to the control end of the drive tube, the first channel end of the drive tube receives the power supply voltage, and the driver The second via end of the tube is connected to the anode of the light emitting device 2120 to provide a driving current. One end of the storage capacitor is connected to the first path end of the drive tube, and the other end is connected to the control end of the drive tube.

The light-emitting device 2120 is a micro light-emitting diode, the anode of which receives a driving current, and the cathode of which receives a reference voltage VSS to display under the driving of the pixel circuit 2110. The light emitting device 2120 includes a light emitting surface and a back surface opposite to the light emitting surface (please refer to the subsequent description for details).

The reflective structure 2130 is used to reflect the light emitted along the back of the light-emitting device 2120 and emit it through the light emitting surface, so that the light emitted along the back is effectively utilized and the display brightness is improved.

The transmissive structure 2140 is located between the backside of the light-emitting device 2120 and the reflective structure 2130, and controls its transmittance according to the target display grayscale to control the effective utilization of the light emitted along the backside of the light-emitting device 2120 by the pixel unit 2100. The transmission structure 2140 includes a transmission layer 2141 and a control circuit 2142. The transmission layer 2141 has adjustable transmittance characteristics, which can be controlled to present an opaque, fully transparent, or partially transparent state. The control circuit 2142 selectively controls the transmittance of the transmission layer 2141 based on the target display gray scale, thereby controlling the effective utilization of light emitted along the back surface of the light emitting device 2120.

Further, when the target display gray scale is a black gray scale, the transmittance of the transmission structure 2140 is a first preset value; when the target display gray scale is a white gray scale, the transmittance of the transmission structure 2140 is the second default value. Among them, the first preset value is smaller than the second preset value, that is, the light emitted along the backside of the light-emitting device 2120 through the transmission structure 2140 during the black-state grayscale display is less than the light emitted through the transmission structure during the white-state grayscale display. 2140 transmits the light emitted along the back of the light-emitting device 2120, that is, the effective utilization rate of the light emitted along the back of the light-emitting device 2120 during black-state grayscale display is lower than that of the light emitted along the back of the light-emitting device 2120 during white-state grayscale display. Effective utilization of light. Furthermore, the contrast of the display device is improved by controlling the display brightness to be enhanced during white grayscale display and the display brightness to be reduced during black grayscale display.

Illustratively, the first preset value is selected from any value within the first range (illustratively [0%, 5%]). The second preset value is, for example, selected from the second range (schematically, any value within (5%, 100%)). Further, when the target display grayscale is between the black grayscale and the white grayscale , the transmittance of the transmission structure 2140 is a first preset value, a second preset value, or is between the first preset value and the second preset value.

Furthermore, when the target display gray scale is a black gray scale, the light emitted along the back of the light emitting device 2120 cannot pass through the transmission structure 2140; when the target display gray scale is a white gray scale, the light emitted along the back of the light emitting device 2120 is transparent. Through the transmissive structure 2140 to the reflective structure 2130. The light reaching the reflective structure 2130 is reflected by the reflective structure 2130 and then emitted through the light exit surface of the light emitting device 2120 . Furthermore, the contrast of the display device is improved by controlling the display brightness to be enhanced during white grayscale display and the display brightness to be reduced during black grayscale display. That is, when the black gray scale is displayed, the transmissive structure 2140 is controlled to be in an opaque state, and when the white gray scale is displayed, the transmissive structure 2140 is controlled to be in a fully transparent state. For example, when the target display gray level is between the black gray level and the white gray level, for example, when the target display gray level is any value in (0,64), the corresponding light emitted along the back of the light emitting device 2120 Light cannot pass through the transmission structure 2140; when the target display gray level is any value in (192, 255), correspondingly the light emitted along the back of the light-emitting device 2120 passes through the transmission structure 2140; the target display gray level is [64 , 192], the light emitted along the back of the light-emitting device 2120 is partially transmitted through the transmission structure 2140. Furthermore, when the target display grayscale is any value among [64, 192], it is correspondingly transparent. The transmittance of the passing structure 2140 is, for example, 50%. It should be noted that when the target display gray level is between the black gray level and the white gray level, the transmittance of the transmission structure 2140 may also be a first preset value, a second preset value, or a third preset value. between a preset value and a second preset value.

Referring to FIG. 4 , a schematic cross-sectional view of the pixel unit 2100 at the semiconductor device level is shown. In order to clearly illustrate the positional relationship between the reflective structure 2130, the transmissive structure 2140 and the light-emitting device 2120, the pixel circuit, part of the insulating layer, the functional layer and the control circuit 2142 in the transmissive structure 2140 are omitted in FIG. 4 .

The reflective structure 2130, the transmissive structure 2140, and the light-emitting device 2120 are, for example, stacked in sequence on the surface of the substrate (not shown in the figure).

The side of the reflective structure 2130 away from the substrate, that is, the surface facing the back of the light-emitting device 2120, is undulating to increase the overall reflectivity of the reflective structure 2130 through diffuse reflection, thereby increasing the display brightness of the Micro-LED panel. Further, the reflective structure 2130 at least includes an insulating layer 2131 and a reflective layer 2132. The insulating layer 2131 is prepared, for example, using a bump processing process, and one surface thereof (the surface far away from the substrate) is undulating. The reflective layer 2132 is formed on the uneven surface of the insulating layer 2131 using a deposition process to have an uneven topography. The reflective layer 2132 is an aluminum layer, a silver layer, or an aluminum-silver alloy layer.

The transmission layer 2141 includes, for example, a first electrode 2144, liquid crystal molecules 2143, and a second electrode 2145. The first electrode 2144 is located on the surface of the reflective layer 2132 and covers the reflective layer 2132. For example, there is direct contact between the two or an insulating layer is provided therebetween. The liquid crystal molecules 2143 are located between the first electrode 2144 and the second electrode 2145 and are covered by the second electrode 2145, and are controlled to rotate according to the electric field formed between them. The first electrode 2144 receives the control voltage provided by the control circuit 2142, and the second electrode 2145 receives the common voltage Vcom. The control circuit 2142 responds to the scan driving signal and provides a corresponding control voltage according to the target display gray scale to control the state of the liquid crystal molecules 2143 so that the transmittance of the transmission structure 2140 corresponds to the target display gray scale.

With reference to Figure 3, the control circuit 2142 includes a transistor T2 and a storage capacitor C2. The control end of the transistor T2 receives the scan drive signal provided by the scan drive circuit 3000, the first pass end of the transistor T2 receives the control voltage Vt, and the second pass end of the transistor T2 is connected to the first electrode 2144 to provide the control voltage. One end of the storage capacitor C2 is connected to the second path end of the transistor T2, and the other end of the storage capacitor C2 is connected to the first electrode 2144. Wherein, when the light emitted along the back side of the light-emitting device 2120 cannot pass through the transmission structure 2140, the control voltage Vt provided by the control circuit 2142 is, for example, an inactive level state. When the light emitted along the back side of the light-emitting device 2120 passes through the transmissive structure 2140 and reaches the reflective structure 2130, the control voltage Vt provided by the control circuit 2142 is, for example, an active level state. When the light emitted along the back side of the light emitting device 2120 is partially transmitted through the transmission structure 2140, the control voltage Vt provided by the control circuit 2142 is positively related to the data voltage Vdd and includes a plurality of states.

Among them, the scanning driving signal received by the control circuit 2142 and the pixel circuit 2110 in a pixel unit 2100 is the same signal.

The light emitting device 2120 includes a first contact layer 2121, a multi-quantum well layer 2122 and a second contact layer 2123. The first contact layer 2121 is located on the side of the second electrode 2145 away from the liquid crystal molecules 2143 via the insulating layer. The multi-quantum well layer 2122 is located on the side of the first contact layer 2121 away from the insulating layer, and the second contact layer 2123 is located on the side of the multi-quantum well layer 2122 away from the first contact layer 2121 . The light-emitting device 2120 is, for example, vertically disposed on one side of the transmission layer 2141, with an insulating layer (not shown in the figure) disposed between the two. The side of the second contact layer 2123 away from the multi-quantum well layer 2122 is the light-emitting surface, and the backlight surface and the light-emitting surface opposite to the light-emitting surface are located on different sides of the multi-quantum well layer 2122 .

It should be noted that both the transistor T1 and the transistor T2 are, for example, N-type thin film transistors.

Referring to FIG. 5 , a certain pixel unit 2100 realizes white grayscale display in the nth frame and black grayscale display in the n+1th frame as an example, where n is a positive integer.

In the n-th frame Frame n picture display stage, the scan driving signal received by a certain pixel unit 2100 in the display panel 2000 is an active level state (high level) during the t1 period, and the pixel circuit 2110 in the pixel unit 2100 The transistor T1 is turned on, and then the pixel circuit 2110 provides the driving current corresponding to the data voltage Vdd (high level, indicating white gray scale) to the light emitting device 2120 to achieve white gray scale display. Correspondingly, the transistor T2 in the control circuit 2142 in the pixel unit 2100 is turned on, and then provides the control voltage Vt in the effective level state (high level) to the first electrode 2144 to control the deflection of the liquid crystal molecules 2143 and cause the liquid crystal molecules 2143 to deflect along the The light emitted from the back of the light-emitting device 2120 passes through the transmissive structure 2140 and reaches the reflective structure 2130, and is reflected by the reflective structure 2130 and then emitted through the light-emitting surface of the light-emitting device 2120, thereby improving the display brightness of the white grayscale display. Exemplarily, the liquid crystal molecules 2143 are aligned along the direction of the electric field formed within the first electrode 2144 and the second electrode 2145 (eg, perpendicular to the first electrode 2144 and the second electrode 2145 respectively) to pass through the light emitted along the back side of the light emitting device 2120 Light reaches reflective structure 2130. During the t2 period, the scan driving signal received by a certain pixel unit 2100 in the display panel 2000 is in an inactive level state (low level), the transistor T1 in the pixel circuit 2110 in the pixel unit 2100 is turned off, and the pixel circuit 2110 is based on The function of the storage capacitor C1 enables the light-emitting device 2120 to maintain a white-state grayscale display. Correspondingly, the transistor T2 in the control circuit 2142 in the pixel unit 2100 is turned off, and the control circuit 2142 maintains the control voltage Vt in the effective level state (high level) to the first electrode 2144 based on the action of the storage capacitor C2, so as to The liquid crystal molecules 2143 are maintained in the state during the t1 period, and then the light emitted along the back of the light-emitting device 2120 reaches the reflective structure 2130 and is reflected by the reflective structure 2130 and then emitted through the light-emitting surface of the light-emitting device 2120, thus improving the white gray level. The display brightness of the display.

In the frame n+1 frame display stage, the scan driving signal received by a certain pixel unit 2100 in the display panel 2000 is an active level state (high level) during the t3 period, and the pixel unit 2100 in the pixel unit 2100 The transistor T1 in the pixel circuit 2110 is turned on, and the pixel circuit 2110 provides the driving current corresponding to the data voltage Vdd (low level, indicating black gray scale) to the light emitting device 2120 to achieve black gray scale display. The corresponding transistor T2 in the control circuit 2142 in the pixel unit 2100 is turned on, and then provides the control voltage Vt in the inactive level state (low level) to the first electrode 2144 to control the deflection of the liquid crystal molecules 2143 and cause the light to emit light along the The light emitted from the back side of the device 2120 cannot pass through the transmission structure 2140, thereby reducing the display brightness of the black-state grayscale display. Illustratively, the liquid crystal molecules 2143 are, for example, parallel to the first electrode 2144 and the second electrode 2145 respectively so that the light emitted along the back side of the light emitting device 2120 cannot pass through the transmission structure 2140 . During the t4 period, the scan driving signal received by a certain pixel unit 2100 in the display panel 2000 is in an inactive level state (low level), the transistor T1 in the pixel circuit 2110 in the pixel unit 2100 is turned off, and the pixel circuit 2110 is based on The function of the storage capacitor C1 enables the light-emitting device 2120 to maintain a black-state grayscale display. Correspondingly, the transistor T2 in the control circuit 2142 in the pixel unit 2100 is turned off, and the control circuit 2142 maintains the control voltage Vt in the inactive level state (low level) to the first electrode 2144 based on the action of the storage capacitor C2, so as to The liquid crystal molecules 2143 are maintained in the state during the t3 period, so that the light emitted along the back of the light-emitting device 2120 cannot pass through the transmission structure 2140, thereby reducing the display brightness of the black-state grayscale display.

In the above embodiment, the liquid crystal molecules 2143 in the transmission structure 2140 are controlled to at least make the transmittance of the transmission structure 2140 a first preset value when the target display gray level is a black gray level. When the level is a white gray level, the transmittance of the transmission structure 2140 is a second preset value.

Finally, it should be noted that: obviously, the above-mentioned embodiments are only examples to clearly illustrate the present disclosure, and are not intended to limit the implementation. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. An exhaustive list of all implementations is neither necessary nor possible. The obvious changes or changes derived therefrom are still within the protection scope of the present disclosure.

It should also be understood that the terms and expressions used herein are for description only, and one or more embodiments of this specification should not be limited to these terms and expressions. The use of these terms and expressions does not mean to exclude equivalent features of any illustrations and descriptions (or parts thereof), and it should be recognized that various possible modifications should also be included within the scope of the claims. Other modifications, changes and substitutions may exist. Accordingly, the claims should be deemed to cover all such equivalents.

Claims

A display panel includes a plurality of pixel units, the pixel units include:

A light-emitting device includes a light-emitting surface and a back surface opposite to the light-emitting surface;

a pixel circuit that responds to the scan drive signal to provide a drive current corresponding to the target display grayscale to the light-emitting device;

a reflective structure for reflecting the light emitted along the back of the light-emitting device and emitting it through the light-emitting surface; and

A transmissive structure is located between the backside of the light-emitting device and the reflective structure, and controls its own transmittance according to the target display grayscale to control the pixel unit's response to the light emitted along the backside of the light-emitting device. effective utilization rate.
The display panel according to claim 1, wherein when the target display gray level is a black state gray level, the transmittance of the transmission structure is a first preset value; when the target display gray level is In the white gray scale, the transmittance of the transmission structure is a second preset value, and the first preset value is smaller than the second preset value.
The display panel according to claim 1, wherein when the target display gray level is a black gray level, the light emitted along the back side of the light emitting device cannot pass through the transmission structure; when the target display gray level When the level is a white gray level, the light emitted along the back of the light-emitting device passes through the transmission structure and reaches the reflective structure. The light reaching the reflective structure is reflected by the reflective structure and then emitted through the light exit surface. .
The display panel according to claim 2, wherein when the target display gray level is between a black gray level and a white gray level, the transmittance of the transmission structure is a first preset value, a third preset value, and a first preset value. The two preset values may be between the first preset value and the second preset value.
The display panel according to claim 1, wherein the transmission structure includes:

The first electrode receives the control voltage;

The second electrode receives the common voltage;

Liquid crystal molecules are located between the first electrode and the second electrode and rotate according to the electric field formed between the first electrode and the second electrode; and

A control circuit, connected to the first electrode, responds to the scan drive signal and provides the corresponding control voltage according to the target display gray scale.
The display panel of claim 5, wherein the control circuit controls the state of the liquid crystal molecules according to the control voltage so that the transmittance of the transmission structure corresponds to a target display gray scale.
The display panel of claim 5, wherein the control circuit includes:

a transistor, a control terminal receiving the scan driving signal, a first terminal receiving the control voltage, and a second terminal connected to the first electrode; and

One end of the storage capacitor is connected to the second end of the transistor, and the other end is connected to the first electrode.
The display panel according to claim 1, wherein a surface of the reflective structure facing the back side of the light-emitting device is undulated.
The display panel of claim 8, wherein the reflective structure at least includes:

an insulating layer, one of which has an uneven surface; and

The reflective layer is located on the undulating surface of the insulating layer, has an undulating topography, and is arranged opposite to the back surface of the light-emitting device.
A display device, comprising the display panel according to any one of claims 1-9.