Display device, display panel and manufacturing method thereof, driving circuit and driving method

Abstract

A display device, a display panel and a manufacturing method thereof, a driving circuit and a driving method, wherein the display panel (100) comprises a driving backplane (2) and a light-emitting device layer (4), wherein: the driving backplane (2) comprises a plurality of pixel driving circuits (21); the light-emitting device layer (4) comprises a plurality of light-emitting units distributed in an array, the light-emitting units comprising a plurality of light-emitting devices (41) stacked and arranged in a direction away from the driving backplane (2); in a direction perpendicular to the driving backplane (2), the light-emitting devices (41) other than the light-emitting device (41) closest to the driving backplane (2) are transparent devices; in the same light-emitting unit, at least part of the light-emitting devices (41) are connected to the pixel driving circuit (21) for emitting light under the drive of the pixel driving circuit (21), and at least two light-emitting devices (41) in the same light-emitting unit have different light-emitting materials.

Description

[0001] Cross-references

[0002] The present disclosure claims priority to Chinese patent application No. 202110101413.9, filed on January 26, 2021, and entitled “Display device, display panel and manufacturing method thereof”, the entire contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates to the field of display technology, and in particular, to a display device, a display panel and a manufacturing method thereof, a driving circuit and a driving method. Background Art

[0004] With the development of display technology, OLED (Organic Light Emitting Diode) display panels are widely used in display technology due to their advantages of lightness, high contrast, flexibility, and short response time. However, existing display panels achieve full color by tiling RGB pixels, which results in low pixel density and low image resolution.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field.

[0006] Public Content

[0007] The purpose of the present disclosure is to overcome the above-mentioned deficiencies of the prior art and to provide a display device, a display panel and a manufacturing method thereof, a driving circuit and a driving method, which can improve the display resolution.

[0008] According to one aspect of the present disclosure, there is provided a display panel, comprising:

[0009] A driving backplane, including a plurality of pixel driving circuits;

[0010] a light-emitting device layer, comprising a plurality of light-emitting units distributed in an array, wherein the light-emitting units include a plurality of light-emitting devices stacked in a direction away from the driving backplane; in a direction perpendicular to the driving backplane, the light-emitting devices other than the light-emitting devices closest to the driving backplane are transparent devices;

[0011] In the same light-emitting unit, at least part of the light-emitting devices are connected to the pixel driving circuit for emitting light under the drive of the pixel driving circuit, and at least two of the light-emitting devices in the same light-emitting unit have different light-emitting materials.

[0012] In an exemplary embodiment of the present disclosure, the light emitting device comprises:

[0013] A first electrode layer is formed on one side of the driving backplane and connected to one of the pixel driving circuits;

[0014] A light-emitting functional layer is formed on a surface of the first electrode layer away from the driving backplane;

[0015] A second electrode layer is formed on a surface of the light-emitting functional layer away from the driving backplane;

[0016] In two adjacent light-emitting devices in a direction perpendicular to the driving backplane, the second electrode layer of the light-emitting device close to the driving backplane and the first electrode layer of the light-emitting device away from the driving backplane are the same electrode layer.

[0017] In an exemplary embodiment of the present disclosure, the number of light-emitting devices of the same light-emitting unit is three, and includes a first light-emitting device, a second light-emitting device and a third light-emitting device distributed in a direction away from the driving backplane, and the first light-emitting device, the second light-emitting device and the third light-emitting device have different light-emitting materials for emitting light of different colors.

[0018] In an exemplary embodiment of the present disclosure, the first electrode layer of the first light emitting device is disposed on one side of the driving backplane, and the display panel further includes:

[0019] A pixel definition layer, which is disposed on the same side of the driving backplane as the first electrode layer of the first light-emitting device, and the pixel definition layer is provided with a plurality of openings exposing the first electrode layer of each of the first light-emitting devices;

[0020] The light-emitting functional layer of the first light-emitting device is at least partially disposed in the opening;

[0021] The second electrode layer of the first light-emitting device is arranged on the surface of the pixel definition layer away from the driving backplane, and its orthographic projection in the opening at least partially overlaps with the orthographic projection of the light-emitting function layer of the first light-emitting device in the opening; the second electrode layer of the first light-emitting device is connected to the pixel driving circuit through a via hole penetrating the pixel definition layer;

[0022] The light-emitting functional layer of the second light-emitting device covers the surface of the second electrode layer of the first light-emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the second electrode layer of the first light-emitting device on the driving backplane;

[0023] The second electrode layer of the second light-emitting device covers the light-emitting function layer of the second light-emitting device and the surface of the pixel definition layer, and its orthographic projection in the opening at least partially overlaps with the orthographic projection of the light-emitting function layer of the first light-emitting device in the opening, and is connected to the pixel driving circuit through a via hole penetrating the pixel definition layer;

[0024] The light-emitting functional layer of the third light-emitting device includes a hole transport layer, a light-emitting material layer and an electron transport layer stacked in sequence, the hole transport layer is located on the side of the first electrode layer of the third light-emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the second electrode layer of the second light-emitting device on the driving backplane; the light-emitting material layer is located on the side of the hole transport layer away from the driving backplane, and its orthographic projection in the opening at least partially overlaps with the orthographic projection of the second electrode layer of the second light-emitting device in the opening; the electron transport layer covers the surface of the structure jointly constituted by the light-emitting material layer and the hole transport layer;

[0025] The second electrode layer of the third light-emitting device is located on a side of the electron transport layer away from the driving backplane, and its orthographic projection in the opening at least partially overlaps with the orthographic projection of the light-emitting material layer in the opening.

[0026] In an exemplary embodiment of the present disclosure, the third light-emitting devices of the light-emitting units share the hole transport layer and the electron transport layer.

[0027] In an exemplary embodiment of the present disclosure, the light emitting color of the first light emitting device is blue, the light emitting color of the second light emitting device is green, and the light emitting color of the third light emitting device is red.

[0028] In an exemplary embodiment of the present disclosure, the driving backplane further includes connecting leads, the connecting leads include a first lead and a second lead spaced apart from the first electrode layer, the first lead and the second lead are respectively connected to different pixel driving circuits;

[0029] The display panel further includes:

[0030] A first pixel definition layer is disposed on the same side of the driving backplane as the first electrode layer of the first light-emitting device, the first pixel definition layer is provided with a plurality of first openings exposing the first electrode layers of the first light-emitting devices, and the sidewalls of the first openings are contracted toward the driving backplane;

[0031] A second pixel definition layer is disposed on the same side of the driving backplane as the first pixel definition layer, and is located in the first opening, and has a first gap with the sidewall of the first opening, and the second lead is at least partially exposed in the first gap; the second pixel definition layer includes a second opening, the first electrode layer of the first light-emitting device is located in the second opening, and has a second gap with the sidewall of the second opening, and the first lead is at least partially exposed in the second gap; in a direction perpendicular to the driving backplane, the thickness of the second pixel definition layer is less than the thickness of the first pixel definition layer;

[0032] The light-emitting functional layer of the first light-emitting device is at least partially disposed in the second opening and is disconnected at a boundary of the second opening;

[0033] The second electrode layer of the first light emitting device is at least partially disposed in the second opening and at least partially covers the first lead, and the second electrode layer of the first light emitting device is disconnected at a boundary of the second opening;

[0034] The light-emitting functional layer of the second light-emitting device covers the surface of the second electrode layer of the first light-emitting device away from the driving backplane, is continuous in the second opening, and is disconnected at the boundary of the first opening; the light-emitting functional layer of the second light-emitting device exposes the second lead;

[0035] The second electrode layer of the second light-emitting device at least partially covers the surface of the light-emitting functional layer of the second light-emitting device and at least partially covers the second lead, the second electrode layer of the second light-emitting device is disconnected at the boundary of the first opening, and its orthographic projection on the driving backplane at least partially overlaps with the orthographic projection of the light-emitting functional layer of the first light-emitting device on the driving backplane;

[0036] The light-emitting functional layer of the third light-emitting device is located on a side of the first electrode layer of the third light-emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the first electrode layer of the third light-emitting device on the driving backplane;

[0037] The second electrode layer of the third light emitting device covers the surface of the light emitting functional layer of the third light emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the light emitting functional layer of the third light emitting device on the driving backplane.

[0038] In an exemplary embodiment of the present disclosure, the driving backplane further includes connecting leads, the connecting leads include a first lead and a second lead spaced apart from the first electrode layer, the first lead and the second lead are respectively connected to different pixel driving circuits;

[0039] The display panel further includes:

[0040] A first pixel definition layer is provided on the same side of the driving backplane as the first electrode layer of the first light-emitting device, and the first pixel definition layer is provided with a plurality of first openings exposing the first electrode layer of each of the first light-emitting devices and at least partially exposing the first lead; the sidewalls of the first openings shrink toward the driving backplane; the second lead can pass through the first pixel definition layer and be exposed to the top surface of the first pixel definition layer;

[0041] A second pixel definition layer is disposed on a surface of the first pixel definition layer away from the driving backplane and has a plurality of second openings exposing the first openings and at least partially exposing the second lead wires, and sidewalls of the second openings shrink toward the driving backplane;

[0042] The light-emitting functional layer of the first light-emitting device is at least partially disposed in the first opening and is disconnected at a boundary of the first opening or the second opening;

[0043] The second electrode layer of the first light emitting device is at least partially disposed in the first opening and at least partially covers the first lead, and the second electrode layer of the first light emitting device is disconnected at a boundary of the second opening;

[0044] The light-emitting functional layer of the second light-emitting device covers the surface of the second electrode layer of the first light-emitting device away from the driving backplane, and is at least partially located in the first opening and is disconnected at the boundary of the second opening;

[0045] The second electrode layer of the second light-emitting device at least partially covers the surface of the light-emitting functional layer of the second light-emitting device and at least partially covers the second lead, the second electrode layer of the second light-emitting device is disconnected at the boundary of the second opening, and its orthographic projection on the driving backplane at least partially overlaps with the orthographic projection of the light-emitting functional layer of the first light-emitting device on the driving backplane;

[0046] The light-emitting functional layer of the third light-emitting device is located on a side of the first electrode layer of the third light-emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the first electrode layer of the third light-emitting device on the driving backplane;

[0047] The second electrode layer of the third light emitting device covers the surface of the light emitting functional layer of the third light emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the light emitting functional layer of the third light emitting device on the driving backplane.

[0048] In an exemplary embodiment of the present disclosure, the display panel further includes:

[0049] The light-shielding layer is arranged on the side of the light-emitting device layer away from the driving backplane, and has a plurality of light-transmitting holes, each of the light-transmitting holes is arranged in one-to-one correspondence with each of the openings, and the orthographic projection of each light-transmitting hole on the driving backplane and the orthographic projection of each light-emitting device in the corresponding opening on the driving backplane at least partially overlap.

[0050] In an exemplary embodiment of the present disclosure, the display panel further includes:

[0051] The encapsulation layer is located on a side of the light-emitting device layer away from the driving backplane.

[0052] According to one aspect of the present disclosure, a display device is provided, comprising any one of the display panels described above.

[0053] According to one aspect of the present disclosure, there is provided a method for manufacturing a display panel, comprising:

[0054] forming a driving backplane, the driving backplane comprising a plurality of pixel driving circuits;

[0055] A light-emitting device layer is formed on one side of the driving backplane, the light-emitting device layer includes a plurality of light-emitting units distributed in an array, the light-emitting unit includes a plurality of light-emitting devices stacked in a direction away from the driving backplane; in a direction perpendicular to the driving backplane, the light-emitting devices other than the light-emitting device closest to the driving backplane are transparent devices;

[0056] In the same light-emitting unit, at least part of the light-emitting devices are connected to the pixel driving circuit for emitting light under the drive of the pixel driving circuit, and at least two of the light-emitting devices in the same light-emitting unit have different light-emitting materials.

[0057] According to one aspect of the present disclosure, there is provided a pixel driving circuit for driving a plurality of light emitting devices connected in series between a first power supply terminal and a second power supply terminal to emit light;

[0058] The pixel driving circuit includes a plurality of driving units, each of which includes a driving transistor, a data writing unit and an energy storage unit;

[0059] The driving transistor has a control terminal, a first terminal and a second terminal, and the second terminal of the driving transistor is used to connect to the first terminal of the light emitting device;

[0060] The data writing unit is used to be turned on in response to a writing control signal to transmit the data signal to the first end of the driving transistor;

[0061] The first end of the energy storage unit is connected to the first power supply end, and the second end of the energy storage unit is connected to the control end of the driving transistor;

[0062] The first end of each of the light emitting devices is connected to the second end of a driving transistor of the driving unit.

[0063] In an exemplary embodiment of the present disclosure, the plurality of driving units include a first driving transistor, a second driving transistor, and a third driving transistor; the plurality of light emitting devices include a first light emitting device, a second light emitting device, and a third light emitting device;

[0064] The second terminal of the first driving transistor is connected to the first light emitting device;

[0065] The second end of the second driving transistor is connected between the first light emitting device and the second light emitting device;

[0066] The second end of the third driving transistor is connected between the second light emitting device and the third light emitting device, and the second end of the third light emitting device is connected to the second power supply end.

[0067] According to one aspect of the present disclosure, a pixel driving circuit is provided for driving a first light-emitting device, a second light-emitting device and a third light-emitting device connected in series between a first power supply terminal and a second power supply terminal to emit light, the pixel driving circuit comprising:

[0068] A driving transistor having a control end, a first end, and a second end, wherein the second end of the driving transistor is used to be connected to the first end of the first light emitting device;

[0069] a data writing unit, configured to be turned on in response to a writing control signal so as to transmit a data signal to the first end of the driving transistor;

[0070] An energy storage unit, wherein a first end of the energy storage unit is connected to the first power supply end, and a second end of the energy storage unit is connected to the control end of the driving transistor;

[0071] A first switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the first switch unit is connected between the driving transistor and the first light emitting device, and a second end of the first switch unit is connected between the first light emitting device and the second light emitting device;

[0072] a second switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the second switch unit is connected between the driving transistor and the first light emitting device, and a second end of the second switch unit is connected between the second light emitting device and the third light emitting device;

[0073] A third switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the third switch unit is connected between the first light emitting device and the second light emitting device, and a second end of the third switch unit is connected to the second power supply end;

[0074] The fourth switch unit is used to be turned on in response to the light-emitting control signal, wherein the first end of the fourth switch unit is connected between the second light-emitting device and the third light-emitting device, and the second end of the fourth switch unit is connected to the second power supply end.

[0075] According to one aspect of the present disclosure, a pixel driving circuit is provided for driving a first light-emitting device, a second light-emitting device and a third light-emitting device connected in series between a first power supply terminal and a second power supply terminal to emit light, the pixel driving circuit comprising:

[0076] A driving transistor having a control end, a first end, and a second end, wherein the second end of the driving transistor is used to be connected to the first end of the first light emitting device;

[0077] a data writing unit, configured to be turned on in response to a writing control signal so as to transmit a data signal to the first end of the driving transistor;

[0078] An energy storage unit, wherein a first end of the energy storage unit is connected to the first power supply end, and a second end of the energy storage unit is connected to the control end of the driving transistor;

[0079] A first switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the first switch unit is connected between the driving transistor and the first light emitting device, and a second end of the first switch unit is connected between the first light emitting device and the second light emitting device;

[0080] a second switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the second switch unit is connected between the first light emitting device and the second light emitting device, and a second end of the second switch unit is connected between the second light emitting device and the third light emitting device;

[0081] The third switch unit is used to be turned on in response to the light-emitting control signal, wherein the first end of the third switch unit is connected between the second light-emitting device and the third light-emitting device, and the second end of the third switch unit is connected to the second power supply end.

[0082] According to one aspect of the present disclosure, a pixel driving circuit is provided for driving a first light-emitting device, a second light-emitting device and a third light-emitting device connected in series between a first power supply terminal and a second power supply terminal to emit light, the pixel driving circuit comprising:

[0083] A driving transistor having a control end, a first end, and a second end, wherein the second end of the driving transistor is used to be connected to the first end of the first light emitting device;

[0084] a data writing unit, configured to be turned on in response to a writing control signal so as to transmit a data signal to the first end of the driving transistor;

[0085] An energy storage unit, wherein a first end of the energy storage unit is connected to the first power supply end, and a second end of the energy storage unit is connected to the control end of the driving transistor;

[0086] A first switch unit, configured to be turned on in response to a light emitting control signal, wherein the first switch unit is connected between the second end of the driving transistor and the first light emitting device;

[0087] a second switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the first switch unit is connected between the driving transistor and the first light emitting device, and a second end of the first switch unit is connected between the second light emitting device and the third light emitting device;

[0088] A connecting wire has one end connected between the first light emitting device and the second light emitting device, and the other end connected to the second power supply terminal.

[0089] According to one aspect of the present disclosure, a driving method of a pixel driving circuit is provided, which is used for the pixel driving circuit described in any one of the above;

[0090] The driving method comprises:

[0091] In the data writing stage, the data writing unit of each driving unit is turned on to transmit the data signal to the control end of the driving transistor through the data writing unit and the driving transistor, and to charge the energy storage unit so that multiple light-emitting devices emit light simultaneously.

[0092] According to one aspect of the present disclosure, a driving method of a pixel driving circuit is provided, which is used for the pixel driving circuit described in any one of the above;

[0093] The driving method comprises:

[0094] In the data writing stage, the data writing unit is turned on to transmit the data signal to the control end of the driving transistor through the data writing unit and the driving transistor, and to charge the energy storage unit;

[0095] In the light-emitting stage, a first power supply signal is input to the driving transistor through the energy storage unit to turn on the driving transistor so that the signal at the second end of the driving transistor is transmitted to the first end of the first light-emitting device; the first switch unit and the second switch unit are turned off, and the third switch unit and the fourth switch unit are turned on to make the first light-emitting device emit light; or, the first switch unit and the fourth switch unit are turned on, and the second switch unit and the third switch unit are turned off to make the second light-emitting device emit light; or, the first switch unit and the second switch unit are turned on, and the third switch unit and the fourth switch unit are turned off to make the third light-emitting device emit light.

[0096] According to one aspect of the present disclosure, a driving method of a pixel driving circuit is provided, which is used for the pixel driving circuit described in any one of the above;

[0097] The driving method comprises:

[0098] In the data writing stage, the data writing unit is turned on to transmit the data signal to the control end of the driving transistor through the data writing unit and the driving transistor, and to charge the energy storage unit;

[0099] In the light-emitting stage, a first power supply signal is input to the driving transistor through the energy storage unit to turn on the driving transistor, so that the signal at the second end of the driving transistor is transmitted to the first end of the first light-emitting device; the first switch unit is turned off, and the second switch unit and the third switch unit are turned on, so that the first light-emitting device emits light; or, the second switch unit is turned off, and the first switch unit and the third switch unit are turned on, so that the second light-emitting device emits light; or, the third switch unit is turned off, and the first switch unit and the second switch unit are turned on, so that the third light-emitting device emits light.

[0100] According to one aspect of the present disclosure, a driving method of a pixel driving circuit is provided, which is used for the pixel driving circuit described in any one of the above;

[0101] The driving method comprises:

[0102] In the data writing stage, the data writing unit is turned on to transmit the data signal to the control end of the driving transistor through the data writing unit and the driving transistor, and to charge the energy storage unit;

[0103] In the light-emitting stage, a first power supply signal is input to the driving transistor through the energy storage unit to turn on the driving transistor, so that the signal at the second end of the driving transistor is transmitted to the first end of the first light-emitting device; the second switch unit is turned off and the first switch unit is turned on to make the first light-emitting device emit light; or, the first switch unit is turned off and the second switch unit is turned on, and when the voltage value at the first power supply end is lower than the voltage value at the second power supply end, the second light-emitting device emits light; or, the first switch unit is turned off and the second switch unit is turned on, and when the voltage value at the first power supply end is higher than the voltage value at the second power supply end, the third light-emitting device emits light.

[0104] The display device, display panel and its manufacturing method, driving circuit and driving method disclosed in the present invention can increase the number of light-emitting devices in each light-emitting unit by stacking multiple light-emitting devices, thereby increasing the number of light-emitting devices in the display area and improving the utilization rate of the display area; at the same time, since the light-emitting materials of at least two light-emitting devices in the same light-emitting unit are different, they can emit light of multiple colors, which can make the light of multiple colors superimposed to achieve full color, thereby doubling the display resolution; in this process, since the pixel driving circuit is connected to the light-emitting device, each light-emitting device can be driven separately by each pixel driving circuit, so that each light-emitting device emits light independently without interfering with each other; in addition, since the light-emitting devices other than the light-emitting device closest to the driving backplane in the direction perpendicular to the driving backplane are all transparent devices, the light emitted by each light-emitting device can be emitted in a direction away from the driving backplane, thereby avoiding the light from irradiating the pixel driving circuit and ensuring the stability of the pixel driving circuit.

[0105] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0106] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0107] Figure 1 A schematic diagram of a tiled display panel in the related art.

[0108] Figure 2 It is a schematic diagram of a display panel in the first embodiment of the present disclosure.

[0109] Figure 3 FIG. 4 is a schematic diagram of a display panel in a second embodiment of the present disclosure.

[0110] Figure 4 Schematic diagram of a display panel in a third embodiment of the present disclosure.

[0111] Figure 5 It is a schematic diagram of a driving backplane in the first embodiment of the present disclosure.

[0112] Figure 6 Schematic diagram of a planarization layer in the first embodiment of the present disclosure.

[0113] Figure 7 This is a schematic diagram of the spectrum in the first embodiment of the present disclosure.

[0114] Figure 8 Schematic diagram of the color gamut of the display panel in the first embodiment of the present disclosure.

[0115] Fig. 9 Schematic diagram of the structure of the second electrode layer in an embodiment of the present disclosure.

[0116] Fig.10 Schematic diagram of a pixel definition layer in the first embodiment of the present disclosure.

[0117] Fig.11 Schematic diagram of the light-emitting functional layer in the first embodiment of the present disclosure.

[0118] Fig.12 Schematic diagram of the second electrode layer in the first embodiment of the present disclosure.

[0119] Fig.13 It is a schematic diagram of the light-emitting functional layer of the second light-emitting device in the first embodiment of the present disclosure.

[0120] Fig.14 Schematic diagram of the second electrode layer of the second light-emitting device in the first embodiment of the present disclosure.

[0121] Fig.15 It is a schematic diagram of the light-emitting functional layer of the third light-emitting device in the first embodiment of the present disclosure.

[0122] Fig.16 Schematic diagram of the second electrode layer of the third light-emitting device in the first embodiment of the present disclosure.

[0123] Fig.17 Schematic diagram of a pixel definition layer in a second embodiment of the present disclosure.

[0124] Fig.18 This is a schematic diagram of the light-emitting functional layer of the first light-emitting device in the second embodiment of the present disclosure.

[0125] Fig.19 Schematic diagram of the second electrode layer of the first light-emitting device in the second embodiment of the present disclosure.

[0126] Fig. 20 It is a schematic diagram of the light-emitting functional layer of the second light-emitting device in the second embodiment of the present disclosure.

[0127] Fig.21 Schematic diagram of the second electrode layer of the second light-emitting device in the second embodiment of the present disclosure.

[0128] Fig. 22 It is a schematic diagram of the light-emitting functional layer of the third light-emitting device in the second embodiment of the present disclosure.

[0129] Fig.23 Schematic diagram of a pixel definition layer in the third embodiment of the present disclosure.

[0130] Fig.24 This is a schematic diagram of the light-emitting functional layer of the first light-emitting device in the third embodiment of the present disclosure.

[0131] Fig.25 This is a schematic diagram of the second electrode layer of the first light-emitting device in the third embodiment of the present disclosure.

[0132] Fig.26 It is a schematic diagram of the light-emitting functional layer of the second light-emitting device in the third embodiment of the present disclosure.

[0133] Fig. 27 Schematic diagram of the second electrode layer of the second light-emitting device in the third embodiment of the present disclosure.

[0134] Fig.28 Schematic diagram of the first electrode layer in one embodiment of the present disclosure.

[0135] Fig.29 Schematic diagram of an encapsulation layer in one embodiment of the present disclosure.

[0136] Fig.30 The figure is a flow chart of a method for manufacturing a display panel in an embodiment of the present disclosure.

[0137] Fig.31 Schematic diagram of a pixel driving circuit in the first embodiment of the present disclosure.

[0138] Fig.32 This is a timing diagram of the working principle of the pixel driving circuit in the first embodiment of the present disclosure.

[0139] Fig.33 RGB spectrum of the pixel driving circuit in the first embodiment of the present disclosure.

[0140] Fig.34 FIG. 4 is a schematic diagram of a pixel driving circuit in a second embodiment of the present disclosure.

[0141] Fig.35 This is a timing diagram of the working principle of the pixel driving circuit in the second embodiment of the present disclosure.

[0142] Fig.36 Spectrum of the first light-emitting device (R) in one embodiment of the present disclosure.

[0143] Fig.37 Spectrum of the first light-emitting device (G) in one embodiment of the present disclosure.

[0144] Fig.38 Spectrum of the first light-emitting device (B) in one embodiment of the present disclosure.

[0145] Fig.39 Schematic diagram of a pixel driving circuit in a third embodiment of the present disclosure.

[0146] Fig.40 This is a timing diagram of the working principle of the pixel driving circuit in the third embodiment of the present disclosure.

[0147] Fig.41 Schematic diagram of a pixel driving circuit in a fourth embodiment of the present disclosure.

[0148] Fig.42 This is a timing diagram of the working principle of the pixel driving circuit in the fourth embodiment of the present disclosure.

[0149] Fig.43 The flowchart is a driving method of a pixel driving circuit disclosed in the present invention.

[0150] Fig.44 The flowchart is a driving method of a pixel driving circuit disclosed in the present invention.

[0151] Fig.45 The flowchart is a driving method of a pixel driving circuit disclosed in the present invention.

[0152] Description of reference numerals:

[0153] 100, display panel; 101, pixel; 1, substrate; 12, first light shielding layer; 13, buffer layer; 2, driving backplane; 21, pixel driving circuit; 211, active layer; 212, gate insulating layer; 2121, first gate insulating layer; 2122, second gate insulating layer; 213, first source and drain layer; 214, second source and drain layer; 2141, first lead; 2142, second lead; 215, gate; 22, protective layer; 3, planarization layer; 4, light-emitting device layer; 41, light-emitting device; 411, first electrode layer; 412, light-emitting functional layer; 413, second electrode layer; 413a, first electrode modification layer; 413b, electrode layer; 413c, second electrode modification layer; 42, light-emitting functional layer of second light-emitting device; 43, The second electrode layer of the second light-emitting device; 44, the light-emitting functional layer of the third light-emitting device; 441, the light-emitting material layer; 45, the second electrode layer of the third light-emitting device; 5, the pixel definition layer; 51, the opening; 510, the first pixel definition layer; 520, the second pixel definition layer; 501, the first gap; 502, the second gap; 52, the via hole; 6, the second light-shielding layer; 61, the light-transmitting hole; 7, the encapsulation layer; 300, the driving unit; 301, the data writing unit; DT1, the first driving transistor; DT2, the second driving transistor; DT3, the third driving transistor; Data, the data writing unit; C, the energy storage unit; ST1, the first switch unit; ST2, the second switch unit; ST3, the third switch unit; ST4, the fourth switch unit. DETAILED DESCRIPTION

[0154] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0155] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0156] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second", "third" and "fourth" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0157] In the related art, the display panel 100 mainly includes a driving backplane and a plurality of light-emitting units arranged in an array and laid out on one side of the driving backplane. In order to realize full-color display, three laid out sub-pixels are usually used to form a pixel 101, and the display area utilization rate is relatively low. Figure 1 As shown, a is the length of the display panel 100, b is the width of the display panel 100, and c is the diagonal length of the display panel 100. The resolution of the pixel 101 is Furthermore, during the manufacturing process, due to the limitation of the fine mask process for vapor deposition, the PPi of a common display panel 100 is around 600, and the display resolution is relatively low.

[0158] The present disclosure provides a display panel, which may be an AMOLED display panel. Figure 2-Figure 4 As shown, the display panel may include a driving backplane 2 and a light emitting device layer 4, wherein:

[0159] The driving backplane 2 includes a plurality of pixel driving circuits 21;

[0160] The light emitting device layer 4 includes a plurality of light emitting units distributed in an array, and the light emitting units include a plurality of light emitting devices 41 stacked and arranged in a direction away from the driving backplane 2; in a direction perpendicular to the driving backplane 2, the light emitting devices 41 other than the light emitting device 41 closest to the driving backplane 2 are transparent devices;

[0161] In the same light-emitting unit, at least some of the light-emitting devices 41 are connected to the pixel driving circuit 21 for emitting light under the drive of the pixel driving circuit 21 . In the same light-emitting unit, at least two of the light-emitting devices 41 have different light-emitting materials.

[0162] In the display panel disclosed in the present invention, by stacking multiple light-emitting devices 41, the number of light-emitting devices 41 in each light-emitting unit can be increased, thereby increasing the number of light-emitting devices 41 in the display area and improving the utilization rate of the display area; at the same time, since the light-emitting materials of at least two light-emitting devices 41 in the same light-emitting unit are different, they can emit light of multiple colors, which can make the light of multiple colors superimposed to achieve full color, thereby doubling the display resolution; in this process, since the pixel driving circuit 21 is connected to the light-emitting device 41, each light-emitting device 41 can be driven separately by each pixel driving circuit 21, so that each light-emitting device 41 emits light independently without interfering with each other; in addition, since the light-emitting devices 41 other than the light-emitting device 41 closest to the driving backplane 2 in the direction perpendicular to the driving backplane 2 are all transparent devices, the light emitted by each light-emitting device 41 can be emitted in a direction away from the driving backplane 2, thereby avoiding the light from irradiating the pixel driving circuit 21 and ensuring the stability of the pixel driving circuit 21.

[0163] Figure 2-Figure 4 The structure diagram of the display panel according to the embodiment of the present disclosure is shown below. Figure 2-Figure 4 The light-emitting principle of the display panel in the embodiment of the present disclosure is explained. The display panel mainly includes a driving backplane 2 and a light-emitting device layer 4, wherein the driving backplane 2 can be arranged on one side of the substrate 1, and it can include a pixel driving layer arranged on one side of the substrate 1, and the pixel driving layer includes a plurality of pixel driving circuits 21 arranged side by side. The light-emitting device layer 4 is arranged on the side of the pixel driving layer away from the substrate 1, and includes a plurality of light-emitting units distributed in an array, each light-emitting unit includes a plurality of light-emitting devices 41 stacked and arranged in a direction away from the driving backplane 2, and the light-emitting materials of each light-emitting device 41 are different, and different colors of light can be emitted respectively. In the same light-emitting unit, at least part of the light-emitting devices 41 are connected to the pixel driving circuit 21, and each pixel driving circuit 21 can be powered on to each light-emitting device 41, and each light-emitting device 41 can be controlled to emit light independently in a timing manner, thereby displaying an image. For example, multiple light-emitting devices 41 in the same light-emitting unit can be powered on at the same time, and multiple light-emitting devices 41 can be controlled to emit light at the same time, so that multiple colors of light are superimposed, which can improve the utilization rate of the display area and improve the resolution of the display area.

[0164] In an exemplary embodiment of the present disclosure, the substrate 1 may be a flat plate structure, which may be made of hard materials such as glass, or flexible materials such as PI (polyimide). The substrate 1 may be a single-layer or multi-layer structure, which is not particularly limited here.

[0165] like Figure 2-Figure 4 As shown, the pixel driving circuit 21 may include a transistor, which may be electrically connected to the light-emitting device 41 so as to control each light-emitting device 41 one by one through each transistor, thereby displaying an image. In this process, each light-emitting device 41 emits light independently without interfering with each other.

[0166] The transistor may include an active layer 211, a gate insulating layer 212, a gate 215 and a first source-drain layer 213. The gate insulating layer 212 may include a first gate insulating layer 2121 and a second gate insulating layer 2122. The active region may be doped multiple times to form the active layer 211. The active layer 211 may be located on a side of the substrate 1 close to the light-emitting device layer 4. The first gate insulating layer 2121 covers the active layer 211. The gate 215 is located on a side of the first gate insulating layer 2121 away from the substrate 1. The second gate insulating layer 2122 covers the gate. 215 and the first gate insulating layer 2121, the first gate insulating layer 2121 and the second gate insulating layer 2122 can be opened to form a via hole connecting the active area, and the orthographic projection of the via hole on the substrate 1 does not overlap with the orthographic projection of the gate 215 on the substrate 1; the first source-drain layer 213 is formed on the side of the second gate insulating layer 2122 away from the substrate 1, and includes a source and a drain, and the source and the drain can be connected to the two ends of the active layer 211 through a via hole penetrating the second gate insulating layer 2122 and / or the first gate insulating layer 2121.

[0167] In addition, if Figure 5 As shown, the driving backplane 2 may also include a protective layer 22 covering the first source-drain layer 213 and a second source-drain layer 214 formed on the side of the protective layer 22 facing away from the substrate 1, wherein the protective layer 22 may cover the surface of the first source-drain layer 213 facing away from the substrate 1, and may be used to prevent the hydrogen plasma generated in the subsequent process from diffusing to each transistor; the protective layer 22 may be perforated to form a via hole connecting the first source-drain layer 213, and the second source-drain layer 214 may be formed on the side of the protective layer 22 facing away from the substrate 1, and may be connected to the first source-drain layer 213 of the transistor through a via hole penetrating the protective layer 22. Figure 6 As shown, the display panel of the present disclosure may further include a planarization layer 3 , and the planarization layer 3 may cover the protection layer 22 and the second source-drain layer 214 to eliminate the device step of the second source-drain layer 214 .

[0168] In one embodiment, if Figure 3 and Figure 4 As shown, the second source-drain layer 214 may include connecting leads, which may include first leads 2141 and second leads 2142 distributed at intervals. The first leads 2141 and the second leads 2142 may be respectively connected to different pixel driving circuits 21 through vias penetrating the planarization layer 3 and the protective layer 22.

[0169] In an exemplary embodiment of the present disclosure, the driving backplane 2 may further include a first light shielding layer 12 and a buffer layer 13, wherein:

[0170] The first light shielding layer 12 may be located between the driving backplane 2 and the substrate 1. Figure 3 and Figure 4As shown, the first light shielding layer 12 may be located on a side of the substrate 1 close to the driving backplane 2 , and the first light shielding layer 12 may block external ambient light from being incident on the active layer 31 of the transistor, thereby protecting the stability of the transistor.

[0171] For example, the first light-shielding layer 12 can be formed on the side of the substrate 1 close to the driving backplane 2 by vacuum evaporation, magnetron sputtering, chemical vapor deposition or physical vapor deposition. For example, the first light-shielding layer 12 can be formed by photolithography. A light-shielding film layer can be deposited on the side of the substrate 1 close to the driving backplane 2, and a photoresist can be formed on the side of the light-shielding film layer away from the substrate 1. The photoresist is exposed and developed using a mask to form a developing area. The pattern of the developing area can be the same as the pattern required for the first light-shielding layer 12, and its size can be equal to the size of the pattern required for the first light-shielding layer 12. The light-shielding film layer can be anisotropically etched in the developing area to form the first light-shielding layer 12. Finally, the photoresist remaining on the surface of the first light-shielding layer can be stripped off to expose the first light-shielding layer 12 formed by photolithography.

[0172] The buffer layer 13 may be located on the side of the first light shielding layer 12 away from the substrate 1, and may be formed on the surface of the first light shielding layer 12 away from the substrate 1 by chemical vapor deposition, physical vapor deposition, or atomic layer deposition. The buffer layer 13 may be used to block impurities in the substrate 1 from diffusing into the driving backplane 2, thereby protecting the stability of the driving backplane 2. For example, the pixel driving layer may be formed on the surface of the buffer layer 13 away from the substrate 1.

[0173] In an exemplary embodiment of the present disclosure, the light-emitting devices 41 in the same light-emitting unit can be stacked in a direction perpendicular to the driving backplane 2, and each light-emitting device 41 can emit light of one color. The light-emitting devices 41 in the same light-emitting unit can emit light of multiple different colors. The light emitted by each light-emitting device 41 in the direction perpendicular to the driving backplane 2 can be superimposed together, and each light-emitting device 41 can be controlled to emit light independently in a timing manner, thereby realizing light color regulation.

[0174] For example, in the same light-emitting unit, the number of light-emitting devices 41 may be two or three. In one embodiment, the number of light-emitting devices 41 in the same light-emitting unit is three, namely, a first light-emitting device, a second light-emitting device and a third light-emitting device, wherein the first light-emitting device is located on the side of the pixel driving layer away from the substrate 1, the second light-emitting device is located on the surface of the first light-emitting device away from the substrate 1, and the third light-emitting device is located on the surface of the second light-emitting device away from the substrate 1, and the first light-emitting device, the second light-emitting device and the third light-emitting device are respectively connected one-to-one with different pixel driving circuits 21 in the driving backplane 2.

[0175] The light-emitting materials of the three light-emitting devices 41 may be different, and different light-emitting materials may be used to emit light of different colors, which may be any combination of RGB. In order to improve the resolution and balance the light intensity of the light emitted by each light-emitting device 41, the light intensity of the light emitted by the light-emitting device 41 close to the driving backplane 2 in the direction perpendicular to the driving backplane 2 may be greater than the light intensity of the light emitted by the light-emitting device 41 far from the driving backplane 2. When in use, even if the light of the light-emitting device 41 located below is weakened due to the transmittance, it will not affect the overall display effect. For example, in the direction perpendicular to the driving backplane 2, the light intensity of the light emitted by the first light-emitting device may be greater than the light intensity of the light emitted by the second light-emitting device, and the light intensity of the light emitted by the second light-emitting device may be greater than the light intensity of the light emitted by the third light-emitting device.

[0176] It should be noted that the light emitted by the three light emitting devices 41 may also be the same, which can help to extend the service life of the light emitting devices.

[0177] Figure 7 It is a spectrum diagram of the three colors of red, green and blue. The horizontal axis in the figure is the wavelength range, the vertical axis is the light intensity, and the peak position in the curve is the light intensity of each color. It can be seen from the figure that the light intensity of blue light (B) is greater than the light intensity of green light (G), and the light intensity of green light (G) is greater than the light intensity of red light (R). Therefore, it can be seen that the preferred solution is: the color of the light emitted by the first light-emitting device is blue (B), the light emitted by the second light-emitting device is green (G), and the color of the light emitted by the third light-emitting device is red (R). The first light-emitting device, the second light-emitting device and the third light-emitting device can emit light at the same time, thereby increasing the display resolution by three times. Figure 8 This is a color gamut diagram of a display panel in one embodiment of the present disclosure. In the diagram, both the horizontal and vertical axes represent chromaticity. After testing, the color gamut of the display panel in this embodiment is 96.8%.

[0178] In an exemplary embodiment of the present disclosure, the light emitting device 41 may include a first electrode layer 411, a light emitting functional layer 412, and a second electrode layer 413, wherein:

[0179] The first electrode layer 411 may be disposed on one side of the driving backplane 2, for example, it may be disposed on the side of the pixel driving layer away from the substrate 1, and may be connected to the pixel driving circuit 21. The first electrode layer 411 may serve as an anode layer of the light emitting device 41, and its material may be a transparent conductive material or a light shielding material, which is not particularly limited here. For example, it may be ITO or AZO.

[0180] The light-emitting functional layer 412 may be disposed on the surface of the first electrode layer 411 away from the driving backplane 2, and may provide a recombination site for the excitons to emit light. The light-emitting functional layer 412 may be a single-layer film layer or a multi-layer film layer, which is not particularly limited here; taking a multi-layer film layer as an example, it may include a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer and an electron injection layer, wherein:

[0181] The hole injection layer covers the surface of the first electrode layer 411 away from the driving backplane 2, which helps to enhance the electron injection ability of the device; the hole transport layer covers the surface of the hole injection layer away from the first electrode layer 411, which can provide a transmission channel for holes, improve hole mobility, and help improve luminous efficiency; the electron blocking layer covers the surface of the hole transport layer away from the first electrode layer 411, which can be used to block electrons from passing through the light-emitting layer and moving to the hole transport layer, avoiding exciton recombination in the hole transport layer, and ensuring that the luminescence center is always located in the light-emitting layer; the light-emitting layer covers the surface of the electron blocking layer away from the first electrode layer 411, which can The light-emitting layer provides a place for electrons and holes to recombine and emit light; the hole blocking layer covers the surface of the light-emitting layer away from the first electrode layer 411, which can be used to block holes from passing through the light-emitting layer and moving to the electron transport layer, avoiding the recombination of excitons in the electron transport layer, and further ensuring that the light-emitting center is always located in the light-emitting layer; the electron transport layer covers the surface of the hole blocking layer away from the first electrode layer 411, which can provide a transmission channel for electrons and improve electron mobility; the electron injection layer covers the surface of the electron transport layer away from the first electrode layer 411, which can provide a transmission channel for electrons, improve electron mobility, and further improve the light-emitting efficiency. Each film layer in the light-emitting functional layer 412 can be a transparent material to improve the light transmittance and thus improve the light extraction rate.

[0182] The second electrode layer 413 may be disposed on the surface of the light-emitting functional layer 412 away from the driving backplane 2, and may be a metal oxide electrode, a metal electrode, a metal alloy electrode, or a composite electrode formed by a combination of a metal and a metal oxide, which is not specifically limited here. The second electrode layer 413 may serve as a cathode layer of the light-emitting device 41, and a voltage may be applied to the first electrode layer 411 and the second electrode layer 413, so that the light-emitting functional layer 412 emits light.

[0183] In one embodiment of the present disclosure, the material of the second electrode layer 413 may be IZO with high light transmittance, and the second electrode layer 413 may be formed on the surface of the light-emitting functional layer 412 away from the first electrode layer 411 by a sputtering process; in another embodiment of the present disclosure, Fig. 9As shown, the second electrode layer 413 includes a first electrode modification layer 413a, an electrode layer 413b and a second electrode modification layer 413c that are stacked and distributed. The first electrode modification layer 413a is located on the surface of the light-emitting functional layer 412 away from the driving backplane 2, the second electrode modification layer 413c is located on the side of the first electrode modification layer 413a away from the driving backplane 2, and the electrode layer 413b is located between the first electrode modification layer 413a and the second electrode modification layer 413c. The conductivity of the electrode layer 413b is greater than the conductivity of the first electrode modification layer 413a and the second electrode modification layer 413c. The first electrode modification layer 413a, the electrode layer 413b and the second electrode modification layer 413c can form a DMD structure, which can improve light transmittance. For example, the first electrode modification layer 413a, the electrode layer 413b and the second electrode modification layer 413c can all be light-transmitting materials. For example, the material of the first electrode modification layer 413a can be molybdenum oxide, the material of the electrode layer 413b can be aluminum-silver alloy, and the material of the second electrode modification layer can be molybdenum oxide. Of course, it can also be other light-transmitting materials, which are not listed here one by one.

[0184] In the same light-emitting unit, in two adjacent light-emitting devices 41 in a direction perpendicular to the driving backplane 2, the second electrode layer 413 of the light-emitting device close to the driving backplane 2 and the first electrode layer 411 of the light-emitting device 41 away from the driving backplane 2 can be the same electrode layer, thereby reducing the number of electrodes in the light-emitting unit and reducing the reduction in device efficiency due to electrode transmittance.

[0185] In an exemplary embodiment of the present disclosure, all light emitting devices 41 other than the light emitting device 41 closest to the driving backplane 2 may be transparent light emitting devices, and the light emitting device 41 closest to the driving backplane 2 may have a light shielding design on the side close to the driving backplane 2, thereby ensuring that the light emitted by all light emitting devices 41 can be emitted in the direction away from the driving backplane 2, avoiding the light from irradiating the driving backplane 2, and ensuring the stability of the pixel driving circuit 21 in the driving backplane 2. It should be noted that the light emitting device 41 closest to the driving backplane 2 may also be a transparent device, which is not particularly limited here.

[0186] In order to define the range of each light-emitting unit in the light-emitting functional layer 412, the display panel of the present disclosure further includes a pixel definition layer 5, such as Figure 10-12 As shown, it can be arranged on one side of the driving backplane 2, for example, it can be located on the side of the pixel driving layer away from the substrate 1, and the first electrode layer 411 of the first light-emitting device can be arranged on the same side of the driving backplane 2 as the pixel definition layer 5.

[0187] The structure and specific details of the pixel definition layer 5 are described in detail below through various implementations:

[0188] In the first embodiment of the present disclosure, Fig.10As shown, the pixel definition layer 5 may be provided with a plurality of openings 51, and each opening 51 may expose a first electrode layer 411 of a first light emitting device. Fig.11 As shown, the light-emitting functional layer 412 of the first light-emitting device may be formed on the surface of the first electrode layer 411 of the first light-emitting device away from the driving backplane 2, and may be at least partially located in the opening 51; Fig.12 As shown, the second electrode layer 413 of the first light-emitting device can be arranged on the surface of the pixel definition layer 5 away from the driving backplane 2, and connected to the pixel driving circuit 21 through the via 52 penetrating the pixel definition layer 5, so as to energize the second electrode layer 413 of the first light-emitting device through the pixel driving circuit 21. The orthographic projection of the second electrode layer 413 of the first light-emitting device in the opening 51 at least partially overlaps with the orthographic projection of the light-emitting function layer 412 of the first light-emitting device in the opening 51, and contacts with the light-emitting function layer 412 of the first light-emitting device. The light-emitting function layer 412 of the first light-emitting device and the second electrode layer 413 of the first light-emitting device within the range of the opening 51 and the first electrode layer 411 of the first light-emitting device exposed by the opening 51 can together constitute the first light-emitting device.

[0189] The second light emitting device may share an electrode with the first light emitting device. For example, the first electrode layer of the second light emitting device may be the second electrode layer 413 of the first light emitting device. Fig.13 As shown, the light-emitting functional layer 42 of the second light-emitting device covers the surface of the second electrode layer 413 of the first light-emitting device away from the driving backplane 2, and its positive projection on the driving backplane 2 covers the positive projection of the second electrode layer 413 of the first light-emitting device on the driving backplane 2. For example, it can at least cover the opening 51 area, and its two ends can extend outward from the opening 51 area and respectively cover the two ends of the second electrode layer 413 of the first light-emitting device to prevent the second electrode layer 43 of the second light-emitting device formed subsequently from contacting and short-circuiting with the second electrode layer 413 of the first light-emitting device. Fig.14 As shown, the second electrode layer 43 of the second light-emitting device can cover the surface of the light-emitting function layer 42 and the pixel definition layer 5 of the second light-emitting device, and its orthographic projection in the opening 51 at least partially overlaps with the orthographic projection of the light-emitting function layer 412 of the first light-emitting device in the opening 51. For example, it extends at least into the opening 51 area and can be connected to the pixel driving circuit 21 through the via 52 that passes through the pixel definition layer 5. The second electrode layer 413 of the first light-emitting device, the light-emitting function layer 42 of the second light-emitting device, and the second electrode layer 43 of the second light-emitting device can together constitute a second light-emitting device.

[0190] The third light emitting device may share an electrode with the second light emitting device. For example, the first electrode layer of the third light emitting device is the second electrode layer 43 of the second light emitting device. Fig.15As shown, the light-emitting functional layer 44 of the third light-emitting device covers the surface of the second electrode layer 43 of the second light-emitting device away from the driving backplane 2, and its orthographic projection on the driving backplane 2 covers the orthographic projection of the second electrode layer 43 of the second light-emitting device on the driving backplane 2. For example, it can at least cover the opening 51 area, and its two ends can respectively cover the two end portions of the second electrode layer 43 of the second light-emitting device to prevent the second electrode layer 45 of the third light-emitting device formed subsequently from contacting and short-circuiting with the second electrode layer 43 of the second light-emitting device.

[0191] like Fig.16 As shown, the second electrode layer 45 of the third light-emitting device can cover the surface of the light-emitting functional layer 44 of the third light-emitting device, and can extend at least to the opening 51 area, or can cover the surface of the light-emitting functional layer 44 of the third light-emitting device, which is not particularly limited here. The second electrode layer 45 of the third light-emitting device can be connected to an external power source through a circuit outside the light-emitting unit for powering on. The second electrode layer 43 of the second light-emitting device, the light-emitting functional layer 44 of the third light-emitting device, and the second electrode layer 45 of the third light-emitting device can together constitute a third light-emitting device.

[0192] In one embodiment, the light-emitting functional layer 44 of the third light-emitting device may include a hole transport layer, a light-emitting material layer 441 and an electron transport layer stacked in sequence, wherein the hole transport layer may be located on the side of the second electrode layer 43 of the second light-emitting device away from the driving backplane 2, and its orthographic projection on the driving backplane 2 covers the orthographic projection of the second electrode layer 43 of the second light-emitting device on the driving backplane 2. For example, the hole transport layer may at least cover the opening 51 area, and its two ends may extend outward from the opening 51 area and respectively cover the two ends of the second electrode layer 43 of the second light-emitting device. For example, it can cover the entire surface of the second electrode layer 43 of the second light-emitting device, and at the same time cover the surface of the light-emitting functional layer 42 and the pixel definition layer 5 of the second light-emitting device that are not covered by the second electrode layer 43 of the second light-emitting device. The light-emitting material layer 441 is located on the side of the hole transport layer away from the driving back plate 2, and its orthographic projection in the opening 51 overlaps at least partially with the orthographic projection of the second electrode layer 43 of the second light-emitting device in the opening 51. For example, the light-emitting material layer 441 may be at least arranged in the opening 51 area so as to emit light in the opening 51 area. The electron transport layer may cover the surface of the structure jointly formed by the light-emitting material layer 441 and the hole transport layer. For example, it may at least completely cover the light-emitting material layer 441 located in the opening 51. Of course, it may also completely cover the structure jointly formed by the light-emitting material layer 441 and the hole transport layer of the third light-emitting device. The second electrode layer 45 of the third light-emitting device may be located on the side of the electron transport layer away from the driving back plate 2, and its orthographic projection in the opening 51 overlaps at least partially with the orthographic projection of the light-emitting material layer 441 in the opening 51, so as to ensure that the light-emitting material layer 441 located in the opening 51 emits light normally.

[0193] It should be noted that the light-emitting functional layer 44 of the third light-emitting device may also include a hole injection layer and an electron injection layer. The hole injection layer may be located between the second electrode layer 43 of the second light-emitting device and the hole transport layer, and may be used to improve the hole injection capability of the third light-emitting device, thereby improving the hole mobility; the electron injection layer may be located between the second electrode layer 45 of the third light-emitting device and the electron transport layer, and may be used to improve the electron injection capability of the third light-emitting device, thereby improving the electron mobility.

[0194] In one embodiment, the third light-emitting devices of each light-emitting unit may share a hole transport layer and an electron transport layer, and the hole transport layer of the third light-emitting devices of each light-emitting unit may be formed simultaneously through a single process, and the electron transport layer of the third light-emitting devices of each light-emitting unit may also be formed simultaneously through a single process. In addition, when the third light-emitting devices each include an electron injection layer and a hole injection layer, the third light-emitting devices of each light-emitting unit may share an electron injection layer and a hole injection layer, and the electron injection layer of the third light-emitting devices of each light-emitting unit may be formed simultaneously through a single process, and the hole injection layer of the third light-emitting devices of each light-emitting unit may also be formed simultaneously through a single process, thereby simplifying the process and reducing manufacturing costs.

[0195] In the second embodiment of the present disclosure, Figure 17-Figure 22 As shown, the pixel definition layer 5 may include a first pixel definition layer 510 and a second pixel definition layer 520, wherein:

[0196] like Fig.17 As shown, the first pixel definition layer 510 and the first electrode layer 411 of the first light-emitting device can be disposed on the same side of the driving backplane 2, for example, it can be disposed on the surface of the planarization layer 3 facing away from the substrate 1. The first pixel definition layer 510 can be provided with a plurality of first openings exposing the first electrode layer 411 of each first light-emitting device, and the sidewall of the first opening can shrink from the side close to the driving backplane 2 to the side away from the driving backplane 2.

[0197] The second pixel definition layer 520 and the first pixel definition layer 510 may be disposed on the same side of the driving backplane 2, that is, the second pixel definition layer 520 may also be disposed on the surface of the planarization layer 3 facing away from the substrate 1. The second pixel definition layer 520 may be located in the first opening and have a first gap 501 with the sidewall of the first opening. The second lead 2142 may be at least partially exposed in the first gap 501, and the orthographic projection of the side of the first opening facing away from the driving backplane 2 on the driving backplane 2 does not overlap with the second lead 2142.

[0198] The second pixel definition layer 520 may be provided with a second opening, and the side wall of the second opening may shrink from the side close to the driving back plate 2 to the side away from the driving back plate 2; at the same time, the side wall of the second pixel definition layer 520 close to the first gap 501 may also shrink from the side close to the driving back plate 2 to the side away from the driving back plate 2. For example, the second pixel definition layer 520 may be an annular structure formed in the first opening of the first pixel definition layer 510, and the cross-section of the annular structure in the direction perpendicular to the driving back plate 2 may be an inverted trapezoid, T-shaped or I-shaped.

[0199] In the direction perpendicular to the driving backplane 2, the height of the second pixel definition layer 520 can be lower than the height of the first pixel definition layer 510, so that when subsequent film layers are formed, each film layer can break by itself at the opening of the first pixel definition layer 510 or the second pixel definition layer 520, avoiding the use of a fine mask and thereby reducing production costs.

[0200] The specific heights of the first pixel definition layer 510 and the second pixel definition layer 520 can be set according to the thickness of each film layer in each light-emitting unit, so that each film layer can be broken at the corresponding position through the first pixel definition layer 510 and the second pixel definition layer 520, avoiding the use of a fine mask, reducing the requirements for the mask alignment accuracy, simplifying the process, and reducing manufacturing costs.

[0201] For example, the height of the first pixel definition layer 510 may range from 1um to 2um, and the height of the second pixel definition layer 520 may range from 0.2um to 1um. Preferably, the height of the first pixel definition layer 510 may be 0.7um, and the height of the second pixel definition layer 520 may be 1.4um.

[0202] It should be noted that the first electrode layer 411 of the first light emitting device may be located in the second opening and may have a second gap 502 with the sidewall of the second opening, and the first lead 2141 may be at least partially exposed in the second gap 502 .

[0203] like Fig.18 As shown, the light-emitting functional layer 412 of the first light-emitting device can be formed on the surface of the first electrode layer 411 of the first light-emitting device away from the driving backplane 2, and can be at least partially arranged in the second opening. The light-emitting functional layer 412 of the first light-emitting device can be continuously distributed in the second opening, and can be coated on the end of the first electrode layer 411 of the first light-emitting device to avoid the second electrode layer 413 of the first light-emitting device formed subsequently contacting it and short-circuiting. In the manufacturing process, it can be automatically disconnected at the boundary of the second opening, avoiding the use of a fine mask and reducing the manufacturing cost.

[0204] like Fig.19As shown, the second electrode layer 413 of the first light-emitting device can be arranged on the side of the light-emitting functional layer 412 of the first light-emitting device away from the driving backplane 2, and can be at least partially arranged in the second opening, and can at least partially cover the first lead 2141, and then the second electrode layer 413 of the first light-emitting device can be connected to the pixel driving circuit 21 through the first lead 2141, so that the second electrode layer 413 of the first light-emitting device can be powered through the pixel driving circuit 21. During the manufacturing process, the second electrode layer 413 of the first light-emitting device can be automatically disconnected at the boundary of the second opening, avoiding the use of a fine mask, and further reducing the manufacturing cost.

[0205] The orthographic projection of the second electrode layer 413 of the first light-emitting device in the second opening at least partially overlaps with the orthographic projection of the light-emitting functional layer 412 of the first light-emitting device in the second opening 5, and the light-emitting functional layer 412 of the first light-emitting device and the second electrode layer 413 of the first light-emitting device within the second opening can together constitute the first light-emitting device with the first electrode layer 411 of the first light-emitting device exposed by the second opening.

[0206] The second light emitting device may share an electrode with the first light emitting device. For example, the first electrode layer of the second light emitting device may be the second electrode layer 413 of the first light emitting device. Fig. 20 As shown, the light-emitting functional layer 42 of the second light-emitting device covers the surface of the second electrode layer 413 of the first light-emitting device away from the driving backplane 2, and the light-emitting functional layer 42 of the second light-emitting device can be continuously distributed in the second opening and can fill the second gap. During the manufacturing process, it can be disconnected at the boundary of the first opening. In this process, since the positive projection of the side of the first opening away from the driving backplane 2 on the driving backplane 2 has no overlap with the second lead 2142, the light-emitting functional layer 42 of the second light-emitting device formed will not cover the second lead 2142 after the boundary of the first opening is disconnected, and the second lead 2142 can be exposed.

[0207] like Fig.21 As shown, the second electrode layer 43 of the second light-emitting device may at least partially cover the surface of the light-emitting functional layer 42 of the second light-emitting device away from the driving backplane 2, and may at least partially cover the second lead 2142, and then the second electrode layer 43 of the second light-emitting device may be connected to the pixel driving circuit 21 through the second lead 2142, so that the second electrode layer 43 of the second light-emitting device is energized through the pixel driving circuit 21. During the manufacturing process, the second electrode layer 43 of the second light-emitting device may be automatically disconnected at the boundary of the first opening, avoiding the use of a fine mask, thereby reducing the requirements for the mask alignment accuracy and reducing the manufacturing cost.

[0208] The light-emitting functional layer 42 of the second light-emitting device and the second electrode layer 43 of the second light-emitting device and the first electrode layer of the second light-emitting device can together constitute the second light-emitting device. The orthographic projection of the second electrode layer 43 of the second light-emitting device on the driving backplane 2 at least partially overlaps with the orthographic projection of the light-emitting functional layer 412 of the first light-emitting device on the driving backplane 2, so that the light emitted by the first light-emitting device is superimposed with the light emitted by the second light-emitting device, which can improve the display panel utilization and display resolution.

[0209] The third light emitting device may share an electrode with the second light emitting device. For example, the first electrode layer of the third light emitting device is the second electrode layer 43 of the second light emitting device. Fig. 22 As shown, the light-emitting functional layer 44 of the third light-emitting device is located on the side of the first electrode layer 43 of the third light-emitting device away from the driving backplane 2, and its orthographic projection on the driving backplane 2 can cover the orthographic projection of the first electrode layer 43 of the third light-emitting device on the driving backplane 2; for example, it can at least cover the first opening area, and can fill the first gap 501, and then cover the end of the light-emitting functional layer 44 of the third light-emitting device to prevent the subsequently formed second electrode layer 45 of the third light-emitting device from contacting and short-circuiting with the second electrode layer 43 of the second light-emitting device.

[0210] The second electrode layer 45 of the third light-emitting device can cover the surface of the light-emitting functional layer 44 of the third light-emitting device away from the driving backplane 2, and its orthographic projection on the driving backplane 2 can cover the orthographic projection of the light-emitting functional layer 44 of the third light-emitting device on the driving backplane 2. The second electrode layer 45 of the third light-emitting device can be connected to an external power source through a circuit outside the light-emitting unit for powering on. The second electrode layer 43 of the second light-emitting device, the light-emitting functional layer 44 of the third light-emitting device, and the second electrode layer 45 of the third light-emitting device can together constitute a third light-emitting device.

[0211] In the third embodiment of the present disclosure, Figure 23-Figure 27 As shown, the pixel definition layer 5 may include a first pixel definition layer 510 and a second pixel definition layer 520, wherein:

[0212] like Fig.23 As shown, the first pixel definition layer 510 and the first electrode layer 411 of the first light-emitting device can be arranged on the same side of the driving backplane 2, for example, it can be arranged on the surface of the planarization layer 3 away from the substrate 1. The first pixel definition layer 510 can be provided with a plurality of first openings that expose the first electrode layer 411 of each first light-emitting device and at least partially expose the first lead 2141, and the sidewall of the first opening can shrink from the side close to the driving backplane 2 to the side away from the driving backplane 2. It should be noted that the second lead 2142 can pass through the first pixel definition layer 510 and be exposed on the surface of the first pixel definition layer 510 away from the driving backplane 2, so as to be connected with other electrode layers or connecting wires.

[0213] The second pixel definition layer 520 can be arranged on the surface of the first pixel definition layer 510 away from the driving back plate 2, and has a plurality of second openings exposing the first openings, and the side walls of the second openings shrink from the side close to the driving back plate 2 to the side away from the driving back plate 2; in one embodiment, the bottom of the second opening can at least partially expose the second lead 2142, and the orthographic projection of the top of the second opening on the first pixel definition layer 510 does not overlap with the second lead 2142.

[0214] like Fig.24 As shown, the light-emitting functional layer 412 of the first light-emitting device can be formed on the surface of the first electrode layer 411 of the first light-emitting device away from the driving backplane 2, and can be at least partially disposed in the first opening. The light-emitting functional layer 412 of the first light-emitting device can be coated on the end of the first electrode layer 411 of the first light-emitting device in the first opening to prevent the second electrode layer 413 of the first light-emitting device formed subsequently from contacting it and short-circuiting. In the manufacturing process, it can be automatically disconnected at the boundary of the first opening or the second opening, avoiding the use of a fine mask and reducing manufacturing costs.

[0215] like Fig.25 As shown, the second electrode layer 413 of the first light-emitting device can be arranged on the surface of the light-emitting functional layer 412 of the first light-emitting device away from the driving backplane 2, and can be at least partially arranged in the first opening, and can at least partially cover the first lead 2141, and then the second electrode layer 413 of the first light-emitting device can be connected to the pixel driving circuit 21 through the first lead 2141, so that the second electrode layer 413 of the first light-emitting device can be powered through the pixel driving circuit 21. During the manufacturing process, the second electrode layer 413 of the first light-emitting device can be automatically disconnected at the boundary of the second opening, avoiding the use of a fine mask, and further reducing the manufacturing cost.

[0216] The orthographic projection of the second electrode layer 413 of the first light-emitting device within the first opening at least partially overlaps with the orthographic projection of the light-emitting functional layer 412 of the first light-emitting device within the first opening, and the light-emitting functional layer 412 of the first light-emitting device and the second electrode layer 413 of the first light-emitting device within the range of the first opening and the first electrode layer 411 of the first light-emitting device exposed by the first opening may together constitute the first light-emitting device.

[0217] The second light emitting device may share an electrode with the first light emitting device. For example, the first electrode layer of the second light emitting device may be the second electrode layer 413 of the first light emitting device. Fig.26As shown, the light-emitting functional layer 42 of the second light-emitting device covers the surface of the second electrode layer 413 of the first light-emitting device away from the driving backplane 2, and the light-emitting functional layer 42 of the second light-emitting device can be continuously distributed in the second opening, and can fill the gap between the first electrode layer of the second light-emitting device and the side wall of the first opening. During the manufacturing process, it can be disconnected at the boundary of the second opening. In this process, since the positive projection of the top of the second opening on the first pixel definition layer 510 has no overlap with the second lead 2142, the light-emitting functional layer 42 of the second light-emitting device formed will not cover the second lead 2142 after the boundary of the second opening is disconnected, thereby exposing the second lead 2142.

[0218] like Fig. 27 As shown, the second electrode layer 43 of the second light-emitting device may at least partially cover the surface of the light-emitting functional layer 42 of the second light-emitting device away from the driving backplane 2, and it may at least partially cover the second lead 2142, and then the second electrode layer 43 of the second light-emitting device may be connected to the pixel driving circuit 21 through the second lead 2142, so that the second electrode layer 43 of the second light-emitting device may be energized through the pixel driving circuit 21. During the manufacturing process, the second electrode layer 43 of the second light-emitting device may be automatically disconnected at the boundary of the second opening 521, avoiding the use of a fine mask, which can reduce the requirements for the alignment accuracy of the mask and reduce the manufacturing cost. The light-emitting functional layer 42 of the second light-emitting device and the second electrode layer 43 of the second light-emitting device and the first electrode layer of the second light-emitting device may together constitute the second light-emitting device. The orthographic projection of the second electrode layer 43 of the second light-emitting device on the driving backplane 2 at least partially overlaps with the orthographic projection of the light-emitting functional layer 412 of the first light-emitting device on the driving backplane 2, so that the light emitted by the first light-emitting device is superimposed on the light emitted by the second light-emitting device, which can improve the display panel utilization rate and display resolution.

[0219] The third light-emitting device may share an electrode with the second light-emitting device. For example, the first electrode layer of the third light-emitting device is the second electrode layer 43 of the second light-emitting device. The light-emitting functional layer 44 of the third light-emitting device is located on the side of the first electrode layer 43 of the third light-emitting device away from the driving backplane 2, and its orthographic projection on the driving backplane 2 may cover the orthographic projection of the first electrode layer 43 of the third light-emitting device on the driving backplane 2; for example, it may at least cover the second opening area and may fill the gap between the first electrode layer 43 of the third light-emitting device and the side wall of the second opening, thereby preventing the subsequently formed second electrode layer 45 of the third light-emitting device from contacting and short-circuiting with the second electrode layer 43 of the second light-emitting device.

[0220] The second electrode layer 45 of the third light-emitting device can cover the surface of the light-emitting functional layer 44 of the third light-emitting device away from the driving backplane 2, and its orthographic projection on the driving backplane 2 can cover the orthographic projection of the light-emitting functional layer 44 of the third light-emitting device on the driving backplane 2. The second electrode layer 45 of the third light-emitting device can be connected to an external power source through a circuit outside the light-emitting unit for powering on. The second electrode layer 43 of the second light-emitting device, the light-emitting functional layer 44 of the third light-emitting device, and the second electrode layer 45 of the third light-emitting device can together constitute a third light-emitting device.

[0221] The formation process of the light-emitting unit in the embodiment of the present disclosure is described in detail below:

[0222] A plurality of vias connected to different pixel driving circuits 21 can be formed on the driving backplane 2 by photolithography, and each via can be arranged at intervals. For example, when a light-emitting unit includes three light-emitting devices, at least three vias can be formed in a region corresponding to a light-emitting unit. A plurality of first electrode layers 411 of first light-emitting devices distributed in an array can be formed on the surface of the driving backplane 2 by chemical vapor deposition, physical vapor deposition, vacuum evaporation, magnetron sputtering or atomic layer deposition, and each first electrode layer 411 can be connected to the pixel driving circuit 21 through a via, such as Fig.28 As shown; subsequently, a pixel definition layer 5 can be formed on the surface of the driving backplane 2 and the first electrode layer 411 of each first light-emitting device by using processes such as chemical vapor deposition, physical vapor deposition or atomic layer deposition.

[0223] The specific details of the formation process of the light-emitting unit in different embodiments of the present disclosure are described in detail below:

[0224] In the first embodiment of the present disclosure, a photolithography process can be used to form an opening 51 on the pixel definition layer 5 to expose the first electrode layer 411 of each first light-emitting device. Fig.10 As shown; a mask having a first mask pattern may be used for masking, and the first mask pattern may be the same as the pattern of each opening 51 of the pixel definition layer 5, and then the light-emitting function layer 412 of the first light-emitting device may be formed in each opening 51, such as Fig.11 shown.

[0225] The pixel definition layer 5 and the planarization layer 3 can be photolithographically formed into a via hole 52 penetrating the pixel definition layer 5 and the planarization layer 3, and the via hole 52 can be connected to a pixel driving circuit 21. A mask having a second mask pattern can be used for masking, and the opening of the second mask pattern can be larger than the opening of the first mask pattern. Then, according to the second mask pattern, a light-emitting functional layer 412 of the first light-emitting device and a part of the pixel definition layer 5 can be formed. In this process, the second electrode layer 413 of the first light-emitting device can be connected to a pixel driving circuit 21 through the via hole 52 penetrating the pixel definition layer 5 and the planarization layer 3, as shown in FIG. Fig.12 shown.

[0226] A mask having a third mask pattern may be used for masking, and the opening of the third mask pattern may be larger than the opening of the second mask pattern, and then the light-emitting functional layer 42 of the second light-emitting device may be formed according to the third mask pattern. Fig.13 shown.

[0227] A mask having a fourth mask pattern may be used for masking, and the opening of the fourth mask pattern may be larger than the opening of the third mask pattern, and then the second electrode layer 43 of the second light-emitting device may be formed according to the fourth mask pattern. In this process, the second electrode layer 43 of the second light-emitting device may be connected to a pixel driving circuit 21 through a via 52 penetrating the pixel definition layer 5 and the planarization layer 3, such as Fig.14 shown.

[0228] In order to reduce the manufacturing cost, an open mask can be used for masking, and then the light-emitting functional layer 44 of the third light-emitting device and the second electrode layer 45 of the third light-emitting device are sequentially formed on the surface of the second electrode layer 43 of the second light-emitting device. Fig.16 In this process, a mask having a fifth mask pattern can be used to form the light-emitting material layer 441 of the third light-emitting device, and an open mask can be used to form other film layers of the light-emitting function layer 44 of the third light-emitting device and the second electrode layer 45 of the third light-emitting device.

[0229] It should be noted that the first electrode layer 411 of each light emitting device is respectively connected to different pixel driving circuits 21 in the driving backplane 2 , so that the corresponding light emitting devices 41 are respectively controlled to emit light through different pixel driving circuits 21 .

[0230] In the second embodiment of the present disclosure, Fig.17 As shown, while forming the first electrode layer 411 of the first light-emitting device, a first lead 2141 and a second lead 2142 can be respectively formed in different via holes spaced apart from the first electrode layer 411 of the first light-emitting device, and then the pixel driving circuit 21 in the driving backplane 2 can be electrically led out through the first lead 2141 and the second lead 2142.

[0231] In this embodiment, the pixel definition layer 5 may include a first pixel definition layer 510 and a second pixel definition layer 520. When forming the pixel definition layer 5, the first pixel definition layer 510 may be formed first. For example, the first pixel definition layer 510 may be formed on the surface of the driving backplane 2 and the first electrode layer 411 of each first light-emitting device by chemical vapor deposition, physical vapor deposition, or atomic layer deposition, and then a first opening may be formed in the first pixel definition layer 510 by a photolithography process. The first opening may expose the first electrode layer 411, the first lead 2141, and the second lead 2142 of the first light-emitting device. In this process, the sidewall of the first opening may be shrunk toward the driving backplane 2 by controlling the photolithography rate. Subsequently, a second pixel definition layer 520 may be formed in the first opening, and the thickness of the second pixel definition layer 520 is less than that of the first pixel definition layer 510. For example, the second pixel definition layer 520 may be formed in the first opening by a chemical vapor deposition process, a physical vapor deposition process, or an atomic layer deposition process, and then a second opening may be formed in the second pixel definition layer 520 by a photolithography process. The second opening may expose the first electrode layer 411 of the first light-emitting device, and at least partially expose the first lead 2141. In this process, the sidewall of the second opening may be contracted toward the driving backplane 2 by controlling the photolithography rate.

[0232] In order to reduce the manufacturing cost, an open mask can be used for masking, and then the light-emitting functional layer 412 of the first light-emitting device, the second electrode layer 413 of the first light-emitting device, the light-emitting functional layer 42 of the second light-emitting device, the second electrode layer 43 of the second light-emitting device, the light-emitting functional layer 44 of the third light-emitting device and the second electrode layer 45 of the third light-emitting device are sequentially formed on the surface of the first electrode layer 411 of the first light-emitting device. In this process, different film layers are disconnected at corresponding positions by setting pixel definition layers of different thicknesses and the first opening and the second opening, avoiding the use of a fine mask, which can reduce the requirements for the alignment accuracy of the mask and reduce the manufacturing cost.

[0233] In the third embodiment of the present disclosure, the method for forming the first lead 2141 and the second lead 2142 is similar to the method for forming the first lead 2141 and the second lead 2142 in the second embodiment of the present disclosure, and therefore, it is not repeated here. It should be noted that the second lead 2142 may protrude from the surface of the driving backplane 2.

[0234] In this embodiment, if Fig.23As shown, the pixel definition layer 5 may include a first pixel definition layer 510 and a second pixel definition layer 520. When forming the pixel definition layer 5, the first pixel definition layer 510 may be formed first. For example, the first pixel definition layer 510 may be formed on the surface of the driving backplane 2, the second lead 2142 and the first electrode layer 411 of each first light-emitting device by chemical vapor deposition, physical vapor deposition or atomic layer deposition, and then a first opening may be formed in the first pixel definition layer 510 by a photolithography process. The first opening may expose the first electrode layer 411, the first lead 2141 and the second lead 2142 of the first light-emitting device. At the same time, the surface of the first pixel definition layer 511 away from the driving backplane 2 may also expose the second lead 2142. In this process, the side wall of the first opening may be shrunk toward the driving backplane 2 by controlling the photolithography rate. Subsequently, a second pixel definition layer 520 may be formed on the side of the first pixel definition layer 510 away from the driving backplane 2, and then a second opening may be formed in the second pixel definition layer 520 by a photolithography process, and the second opening may expose the first opening, and at the same time, may at least partially expose the second lead 2142 located on the surface of the first pixel definition layer 511. In this process, the sidewall of the second opening may be contracted toward the driving backplane 2 by controlling the photolithography rate.

[0235] In order to reduce the manufacturing cost, an open mask can be used for masking, and then the light-emitting functional layer 412 of the first light-emitting device, the second electrode layer 413 of the first light-emitting device, the light-emitting functional layer 42 of the second light-emitting device, the second electrode layer 43 of the second light-emitting device, the light-emitting functional layer 44 of the third light-emitting device and the second electrode layer 45 of the third light-emitting device are sequentially formed on the surface of the first electrode layer 411 of the first light-emitting device. In this process, different film layers are disconnected at corresponding positions by setting the pixel definition layer with different thicknesses and the first opening 511 and the second opening 522, avoiding the use of a fine mask, which can reduce the requirements for the mask alignment accuracy and reduce the manufacturing cost.

[0236] In an exemplary embodiment of the present disclosure, the display panel may further include a second light shielding layer 6, such as Figure 2 As shown, the second light shielding layer 6 can be arranged on the side of the light emitting device layer 4 away from the driving backplane 2, and has a plurality of light-transmitting holes 61 distributed in an array, each of which can be a through hole, and its shape can be rectangular, circular, elliptical or other shapes, which are not listed one by one here. The light-transmitting holes 61 can be arranged one by one with each opening in the pixel definition layer 5, and each light-transmitting hole 61 at least partially overlaps with each opening in the pixel definition layer 5, and the overlapping area can be the area where all the film layers in each light-emitting unit overlap, and the light emitted from the light-emitting unit can be emitted from the light-transmitting hole 61, and then the light-emitting area of ​​each light-emitting unit can be defined through the light-transmitting hole 61.

[0237] In one embodiment, the material of the second light shielding layer 6 may be a metal or an organic material, which is not particularly limited here. A light shielding film layer may be formed on the side of the light emitting device layer 4 away from the driving backplane 2 by vacuum evaporation, magnetron sputtering, chemical vapor deposition or physical vapor deposition, and a light-transmitting hole 61 may be formed in the light shielding film layer by photolithography, thereby forming the second light shielding layer 6. For example, a light shielding film layer may be deposited on the side of the light emitting device layer 4 away from the driving backplane 2, and a photoresist may be formed on the side of the light shielding film layer away from the driving backplane 2. The photoresist may be exposed and developed using a mask to form a developing area. The pattern of the developing area may be the same as the pattern required for the second light shielding layer 6, and its size may be equal to the size of the light-transmitting hole 61. The light shielding film layer may be anisotropically etched in the developing area to form the second light shielding layer 6. Finally, the remaining photoresist on the surface of the second light shielding layer 6 may be stripped to expose the second light shielding layer 6 formed by photolithography.

[0238] In an exemplary embodiment of the present disclosure, the display panel may further include an encapsulation layer 7, such as Fig.29 As shown, the encapsulation layer 7 can be located on the side of the light-emitting device layer 4 away from the driving backplane 2, and can be used to block external water and oxygen, prevent the light-emitting device layer 4 from being corroded by external water and oxygen, and extend the service life of the device. For example, the encapsulation layer 7 can be located between the light-emitting device layer 4 and the second light-shielding layer 6, or on the side of the second light-shielding layer 6 away from the light-emitting device layer 4, and no special limitation is made here.

[0239] The encapsulation layer 7 may be composed of an organic material or an inorganic material, or may be a composite film layer of alternating organic and inorganic layers. For example, the material of the encapsulation layer 7 may be an acrylic material, or may be a composite film layer composed of materials such as silicon nitride, silicon oxide, or silicon oxynitride, and no special limitation is made here.

[0240] In one embodiment, the encapsulation layer 7 can be a composite film layer structure of alternating organic layers and inorganic layers. For example, it may include a first inorganic layer, an organic layer, and a second inorganic layer. The first inorganic layer can be formed on the surface of the light-emitting device layer 4, and the second inorganic layer is formed on the side of the first inorganic layer away from the light-emitting device layer 4. The organic layer is located between the first inorganic layer and the second inorganic layer. Water and oxygen can be blocked by the inorganic layer, and the stress of the inorganic layer can be released by the organic layer, thereby preventing the light-emitting device layer 4 and the first inorganic layer from being peeled off due to pulling caused by stress.

[0241] The present disclosure also provides a method for manufacturing a display panel. The display panel may be a display panel of any of the above embodiments, and its structure will not be described in detail herein. Fig.30 As shown, the manufacturing method may include steps S110 to S120, wherein:

[0242] Step S110, forming a driving backplane, wherein the driving backplane includes a plurality of pixel driving circuits;

[0243] Step S120, forming a light-emitting device layer on one side of the driving backplane, the light-emitting device layer includes a plurality of light-emitting units distributed in an array, the light-emitting unit includes a plurality of light-emitting devices stacked in a direction away from the driving backplane; in a direction perpendicular to the driving backplane, light-emitting devices other than the light-emitting device closest to the driving backplane are transparent devices; in the same light-emitting unit, at least part of the light-emitting devices are connected to the pixel driving circuit for emitting light under the drive of the pixel driving circuit, and at least two of the light-emitting devices in the same light-emitting unit have different light-emitting materials.

[0244] The specific details and beneficial effects of the manufacturing method of the embodiment of the present disclosure have been described in the above embodiment of the display panel, and therefore, will not be repeated here.

[0245] It should be noted that, although the steps of the method for manufacturing a display panel in the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0246] The present disclosure also provides a display device, which may include the display panel of any of the above embodiments. The structure and beneficial effects thereof may refer to the embodiments of the above display panel, which will not be described in detail here. The display device of the present disclosure may be a mobile phone, a display screen, a tablet computer, a television, a micro display device, or other device for displaying images, which will not be listed here.

[0247] The present disclosure also provides a pixel driving circuit for a display panel in any of the above embodiments, the display panel may be an AMOLED display panel, the display panel may include a driving backplane and a plurality of light-emitting units arrayed and distributed on one side of the driving backplane, each light-emitting unit may include a plurality of light-emitting devices connected in series between a first power supply terminal VDD and a second power supply terminal VSS to emit light. The display panel may be divided into a display area and a peripheral area outside the display area.

[0248] The driving backplane may include a substrate and a driving circuit disposed on the substrate, the driving circuit may include a pixel driving circuit located in the display area and a peripheral circuit located in the peripheral area, the peripheral circuit is connected to the pixel driving circuit, and includes a light emitting control circuit, a gate driving circuit, and a source driving circuit, etc. Among them, the light emitting control circuit can be used to output a light emitting control signal to the pixel driving circuit, the gate driving circuit can be used to output a write control signal to the pixel driving circuit, the source driving circuit can be used to output a data signal to the pixel driving circuit, and in addition, the driving circuit can also be used to output a first power supply signal to a first power supply terminal VDD of the pixel driving circuit, and output a second power supply signal to a second power supply terminal VSS.

[0249] Each light emitting device may be an OLED light emitting element, i.e. an organic light emitting diode, which may have a first end and a second end, the first end may be an anode, and the second end may be a cathode. The first end of the light emitting device may be connected to the pixel driving circuit, and the second end is used to input a second power supply signal.

[0250] By controlling the peripheral circuit to input a light emitting control signal, a write control signal, a data signal, a first power supply signal and a second power supply signal to the pixel driving circuit and the light emitting device, the light emitting device can emit light to display an image.

[0251] like Fig.31 As shown, in the first embodiment of the present disclosure, the pixel driving circuit includes a plurality of driving units, each of which includes a driving transistor, a data writing unit 301 and an energy storage unit C, wherein:

[0252] The driving transistor has a control terminal, a first terminal and a second terminal, and the second terminal of the driving transistor is used to be connected to the first terminal of the light emitting device;

[0253] The data writing unit 301 is used to be turned on in response to a writing control signal to transmit the data signal to the first end of the driving transistor;

[0254] A first end of the energy storage unit C is connected to the first power supply terminal VDD, and a second end of the energy storage unit C is connected to the control terminal of the driving transistor;

[0255] The first end of each light emitting unit is connected to the second end of a driving transistor of a driving unit.

[0256] It should be noted that there can be three driving units, namely a first driving unit 310, a second driving unit 320 and a third driving unit 330. The transistor of the first driving unit 310 is a first driving transistor DT1, the transistor of the second driving unit 320 is a second driving transistor DT2, and the transistor of the third driving unit 330 is a third driving transistor DT3.

[0257] There may also be three light emitting devices, namely a first light emitting device, a second light emitting device and a third light emitting device. In the embodiment of the present disclosure, the light emitted by the first light emitting device may be red (R), the light emitted by the second light emitting device may be green (G), and the light emitted by the third light emitting device may be blue (B).

[0258] A second terminal of the first driving transistor DT1 is connected to the first light emitting device (R);

[0259] The second end of the second driving transistor DT2 is connected between the first light emitting device (R) and the second light emitting device (G);

[0260] A second end of the third driving transistor DT3 is connected between the second light emitting device (G) and the third light emitting device (B), and a second end of the third light emitting device (B) is connected to the second power supply terminal VSS for inputting a second power supply signal.

[0261] like Fig.31 and Fig.32 As shown, the working process of the pixel driving circuit of the first embodiment of the present disclosure is as follows:

[0262] In the data writing stage, the data writing unit 301 of each driving unit is turned on to transmit the data signal to the control end of the driving transistor through the data writing unit 301 and the driving transistor, and to charge the energy storage unit C, so that the multiple light-emitting devices emit light simultaneously;

[0263] In the light-emitting stage, the first power supply signal is input to the first driving transistor DT1, the second driving transistor DT2 and the third driving transistor DT3 through the energy storage unit C of each driving unit, so as to turn on the first driving transistor DT1, the second driving transistor DT2 and the third driving transistor DT3 respectively, so that the signal at the second end of the first driving transistor DT1 is transmitted to the first end of the first light-emitting device (R), the signal at the second end of the second driving transistor DT2 is transmitted to the first end of the second light-emitting device (G), and the signal at the second end of the third driving transistor DT3 is transmitted to the first end of the third light-emitting device (B), thereby driving the first light-emitting device (R), the second light-emitting device (G) and the third light-emitting device (B) to emit light at the same time.

[0264] In the above process, if Fig.32As shown, T1 to T5 are continuous stages. In the T1 stage, the data signal Gate, the first power signal Data1 input by the first driving transistor, the first power signal Data2 input by the second driving transistor and the first power signal Data3 input by the third driving transistor are all high levels; in the T2 stage, the data signal Gate, the first power signal Data1 input by the first driving transistor, the first power signal Data2 input by the second driving transistor and the first power signal Data3 input by the third driving transistor are all low levels; in the T3 stage, the data signal Gate, the first power signal Data1 input by the first driving transistor, the first power signal Data2 input by the second driving transistor and the first power signal Data3 input by the third driving transistor are all high levels; in the T4 stage, the data signal Gate, the first power signal Data1 input by the first driving transistor, the first power signal Data2 input by the second driving transistor and the first power signal Data3 input by the third driving transistor are all low levels; in the T5 stage, the data signal Gate, the first power signal Data1 input by the first driving transistor, the first power signal Data2 input by the second driving transistor and the first power signal Data3 input by the third driving transistor are all high levels. The voltage through the third light emitting device (B) is Data3, the voltage through the second light emitting device (G) is Data2-Data3, and the voltage through the first light emitting device (R) is Data1-Data2. Data1 is greater than Data2 and greater than Data3. The specific values ​​of Data1, Data2 and Data3 can be controlled according to the required light intensity of each light emitting device. Therefore, in the T1 stage, the T3 stage and the T5 stage, RGB can emit light at the same time.

[0265] When the three RGB light-emitting devices emit light at the same time, the voltage value at both ends of each light-emitting device can be adjusted to produce a spectrum of any color. Fig.33 As shown in the figure, the horizontal axis is wavelength and the vertical axis is light intensity.

[0266] like Fig.34 As shown, in the second embodiment of the present disclosure, the pixel driving circuit is used to drive a plurality of light-emitting devices connected in series between a first power supply terminal VDD and a second power supply terminal VSS to emit light, and the plurality of light-emitting devices may include a first light-emitting device (R), a second light-emitting device (G) and a third light-emitting device (B). The pixel driving circuit includes a driving transistor DT, a data writing unit 301, an energy storage unit C, a first switch unit ST1, a second switch unit ST2, a third switch unit ST3 and a fourth switch unit ST4, wherein:

[0267] A driving transistor DT having a control terminal, a first terminal and a second terminal, wherein the second terminal of the driving transistor DT is used to be connected to the first terminal of the first light emitting device (R);

[0268] The data writing unit 301 is used to be turned on in response to a writing control signal to transmit the data signal to the first end of the driving transistor DT;

[0269] An energy storage unit C, a first end of the energy storage unit C is connected to the first power supply end VDD, and a second end of the energy storage unit C is connected to the control end of the driving transistor DT;

[0270] A first switch unit ST1, used to be turned on in response to a light emitting control signal, wherein a first end of the first switch unit ST1 is connected between the driving transistor DT and the first light emitting device (R), and a second end of the first switch unit ST1 is connected between the first light emitting device (R) and the second light emitting device (G);

[0271] A second switch unit ST2, used to be turned on in response to the light emitting control signal, wherein a first end of the second switch unit ST2 is connected between the driving transistor DT and the first light emitting device (R), and a second end of the second switch unit ST2 is connected between the second light emitting device (G) and the third light emitting device (B);

[0272] a third switch unit ST3, configured to be turned on in response to a light emitting control signal, wherein a first end of the third switch unit ST3 is connected between the first light emitting device (R) and the second light emitting device (G), and a second end of the third switch unit ST3 is connected to a second power supply terminal VSS;

[0273] The fourth switch unit ST4 is used to be turned on in response to the light emitting control signal. The first end of the fourth switch unit ST4 is connected between the second light emitting device (G) and the third light emitting device (B). The second end of the fourth switch unit ST4 is connected to the second power supply terminal VSS.

[0274] like Fig.34 and Fig.35 As shown, the working process of the pixel driving circuit of the second embodiment of the present disclosure is as follows:

[0275] In the data writing phase, the data writing unit 301 is turned on to transmit the data signal to the control end of the driving transistor DT through the data writing unit 301 and the driving transistor DT, and to charge the energy storage unit C;

[0276] In the light-emitting stage, a first power supply signal is input to the driving transistor DT through the energy storage unit C to turn on the driving transistor DT so that the signal at the second end of the driving transistor DT is transmitted to the first end of the first light-emitting device (R); the first switch unit ST1 and the second switch unit ST2 are turned off, and the third switch unit ST3 and the fourth switch unit ST4 are turned on to make the first light-emitting device (R) emit light; or, the first switch unit ST1 and the fourth switch unit ST4 are turned on, and the second switch unit ST2 and the third switch unit ST3 are turned off to make the second light-emitting device (G) emit light; or, the first switch unit ST1 and the second switch unit ST2 are turned on, and the third switch unit ST3 and the fourth switch unit ST4 are turned off to make the third light-emitting device (B) emit light.

[0277] In the above process, if Fig.35 As shown, T1 to T5 are continuous stages. In the T1 stage, the data signal Gate and the first power signal Data are both high levels, the first switch unit ST1 and the second switch unit ST2 are turned off, and the third switch unit ST3 and the fourth switch unit ST4 are turned on; in the T2 stage, the data signal Gate and the first power signal Data are both low levels, the first switch unit ST1, the second switch unit ST2, the third switch unit ST3 and the fourth switch unit ST4 are all turned off; in the T3 stage, the data signal Gate and the first power signal Data are both high levels, the second switch unit ST2 and the third switch unit ST3 are turned off, and the first switch unit ST1 and the fourth switch unit ST4 are turned on; in the T4 stage, the data signal Gate and the first power signal Data are both low levels, the first switch unit ST1, the second switch unit ST2, the third switch unit ST3 and the fourth switch unit ST4 are all turned off; in the T5 stage, the data signal Gate and the first power signal Data are both high levels, the first switch unit ST1 and the second switch unit ST2 are turned on, and the third switch unit ST3 and the fourth switch unit ST4 are turned off. Therefore, R display is performed in stage T1, G display is performed in stage T3, and B display is performed in stage T5, thereby realizing RGB time-sharing display.

[0278] When the three RGB light-emitting devices emit light in time, the spectrum of the first light-emitting device (R) is as follows: Fig.36 As shown, the spectrum of the second light emitting device (G) is as follows Fig.37 As shown, the spectrum of the third light emitting device (B) is as follows Fig.38 shown, and in Figure 36-Figure 38 In the figure, the horizontal axis is wavelength and the vertical axis is light intensity. After calculation, when RGB is time-sharing, the color gamut is greater than NTSC 117%.

[0279] like Fig.39As shown, in the third embodiment of the present disclosure, the pixel driving circuit is used to drive a plurality of light-emitting devices connected in series between a first power supply terminal VDD and a second power supply terminal VSS to emit light, and the plurality of light-emitting devices may include a first light-emitting device (R), a second light-emitting device (G) and a third light-emitting device (B). The pixel driving circuit includes a driving transistor DT, a data writing unit 301, an energy storage unit C, a first switch unit ST1, a second switch unit ST2 and a third switch unit ST3, wherein:

[0280] A driving transistor DT having a control terminal, a first terminal and a second terminal, wherein the second terminal of the driving transistor DT is used to be connected to the first terminal of the first light emitting device (R);

[0281] The data writing unit 301 is used to be turned on in response to a writing control signal to transmit the data signal to the first end of the driving transistor DT;

[0282] An energy storage unit C, a first end of the energy storage unit C is connected to the first power supply end VDD, and a second end of the energy storage unit C is connected to the control end of the driving transistor DT;

[0283] A first switch unit ST1, used to be turned on in response to a light emitting control signal, wherein a first end of the first switch unit ST1 is connected between the driving transistor DT and the first light emitting device (R), and a second end of the first switch unit ST1 is connected between the first light emitting device (R) and the second light emitting device (G);

[0284] A second switch unit ST2, used to be turned on in response to the light-emitting control signal, wherein a first end of the second switch unit ST2 is connected between the first light-emitting device (R) and the second light-emitting device (G), and a second end of the second switch unit ST2 is connected between the second light-emitting device (G) and the third light-emitting device (B);

[0285] The third switch unit ST3 is used to be turned on in response to the light emitting control signal, a first end of the third switch unit ST3 is connected between the second light emitting device (G) and the third light emitting device (B), and a second end of the third switch unit ST3 is connected to the second power supply terminal VSS.

[0286] like Fig.39 and Fig.40 As shown, the working process of the pixel driving circuit of the third embodiment of the present disclosure is as follows:

[0287] In the data writing phase, the data writing unit 301 is turned on to transmit the data signal to the control end of the driving transistor DT through the data writing unit 301 and the driving transistor DT, and to charge the energy storage unit C;

[0288] In the light-emitting stage, a first power supply signal is input to the driving transistor DT through the energy storage unit C to turn on the driving transistor DT so that the signal at the second end of the driving transistor DT is transmitted to the first end of the first light-emitting device (R); the first switch unit ST1 is turned off, and the second switch unit ST2 and the third switch unit ST3 are turned on to make the first light-emitting device (R) emit light; or, the second switch unit ST2 is turned off, and the first switch unit ST1 and the third switch unit ST3 are turned on to make the second light-emitting device (G) emit light; or, the third switch unit ST3 is turned off, and the first switch unit ST1 and the second switch unit ST2 are turned on to make the third light-emitting device (B) emit light.

[0289] In the above process, if Fig.40 As shown, T1 to T5 are continuous stages. In the T1 stage, the data signal Gate and the first power signal Data are both high level, the first switch unit is turned off, and the second switch unit and the third switch unit are turned on; in the T2 stage, the data signal Gate and the first power signal Data are both low level, and the first switch unit, the second switch unit and the third switch unit are all turned off; in the T3 stage, the data signal Gate and the first power signal Data are both high level, the first switch unit and the third switch unit are turned on, and the second switch unit is turned off; in the T4 stage, the data signal Gate and the first power signal Data are both low level, and the first switch unit, the second switch unit and the third switch unit are all turned off; in the T5 stage, the data signal Gate and the first power signal Data are both high level, the first switch unit and the second switch unit are turned on, and the third switch unit is turned off. Therefore, R is displayed in the T1 stage, G is displayed in the T3 stage, and B is displayed in the T5 stage, thereby realizing RGB time-sharing display.

[0290] like Fig.41 As shown, in the fourth embodiment of the present disclosure, the pixel driving circuit is used to drive a plurality of light-emitting devices connected in series between a first power supply terminal VDD and a second power supply terminal VSS to emit light, and the plurality of light-emitting devices may include a first light-emitting device (R), a second light-emitting device (G) and a third light-emitting device (B). The pixel driving circuit includes a driving transistor DT, a data writing unit 301, an energy storage unit C, a first switch unit ST1, a second switch unit ST2 and a connecting line, wherein:

[0291] A driving transistor DT having a control terminal, a first terminal and a second terminal, wherein the second terminal of the driving transistor DT is used to be connected to the first terminal of the first light emitting device (R);

[0292] The data writing unit 301 is used to be turned on in response to a writing control signal to transmit the data signal to the first end of the driving transistor DT;

[0293] An energy storage unit C, a first end of the energy storage unit C is connected to the first power supply end VDD, and a second end of the energy storage unit C is connected to the control end of the driving transistor DT;

[0294] a first switch unit ST1, configured to be turned on in response to a light emitting control signal, wherein the first switch unit ST1 is connected between the second end of the driving transistor DT and the first light emitting device (R);

[0295] A second switch unit ST2, used to be turned on in response to the light emitting control signal, wherein a first end of the second switch unit ST2 is connected between the driving transistor DT and the first light emitting device (R), and a second end of the second switch unit ST2 is connected between the second light emitting device (G) and the third light emitting device (B);

[0296] A connecting line has one end connected between the first light emitting device (R) and the second light emitting device (G), and the other end connected to the second power supply terminal VSS.

[0297] like Fig.41 and Fig.42 As shown, the working process of the pixel driving circuit of the fourth embodiment of the present disclosure is as follows:

[0298] In the data writing phase, the data writing unit 301 is turned on to transmit the data signal to the control end of the driving transistor DT through the data writing unit 301 and the driving transistor DT, and to charge the energy storage unit C;

[0299] In the light-emitting stage, the first power supply signal is input to the driving transistor DT through the energy storage unit C to turn on the driving transistor DT, so that the signal at the second end of the driving transistor DT is transmitted to the first end of the first light-emitting device (R); the second switch unit ST2 is turned off, and the first switch unit ST1 is turned on to make the first light-emitting device (R) emit light; or, the first switch unit ST1 is turned off, the second switch unit ST2 is turned on, and when the voltage value of the first power supply signal is lower than the voltage value of the second power supply signal, the second light-emitting device (G) emits light; or, the first switch unit ST1 is turned off, the second switch unit ST2 is turned on, and when the voltage value of the first power supply signal is higher than the voltage value of the second power supply signal, the third light-emitting device (B) emits light.

[0300] In the above process, if Fig.42As shown, when the first power signal Data is a positive voltage, the first light-emitting device (R) and the third light-emitting device (B) are controlled to display, and when the first power signal Data is a negative voltage, the second light-emitting device (G) is controlled to display. Specifically, T1 to T5 are continuous stages. In the T1 stage, the data signal Gate is a high level, the first power signal Data is a positive voltage, the first switch unit ST1 is turned on, the second switch unit ST2 is turned off, the first power signal Data is transmitted to the first end of the first light-emitting device (R), and the second power signal is transmitted to the second end of the first light-emitting device (R) through the connecting line, thereby forming a voltage difference between the two ends of the first light-emitting device (R), and the first light-emitting device (R) emits light; in the T2 stage, the data signal Gate and the first power signal Data are both low levels, and the first switch unit ST1 and the second switch unit ST2 are both turned off; in the T3 stage, the data signal Gate is a high level, the first power signal Data is a negative voltage, The first switch unit ST1 is turned off, the second switch unit ST2 is turned on, the first power signal Data is transmitted to the second end of the second light-emitting device (G), and the second power signal is transmitted to the first end of the second light-emitting device (G) through the connecting line, thereby forming a voltage difference between the two ends of the second light-emitting device (G), and the second light-emitting device (G) emits light; in the T4 stage, the data signal Gate and the first power signal Data are both high level, the first switch unit ST1 is turned off, the second switch unit ST2 is turned on, the first power signal Data is transmitted to the first end of the third light-emitting device (B), and the second power signal is transmitted to the second end of the third light-emitting device (B), thereby forming a voltage difference between the two ends of the third light-emitting device (B), and the third light-emitting device (B) emits light. Therefore, R is displayed in the T1 stage, G is displayed in the T3 stage, and B is displayed in the T5 stage, thereby realizing RGB time-sharing display.

[0301] The present disclosure also provides a driving method of a pixel driving circuit, wherein the pixel driving circuit is a pixel driving circuit of any of the above embodiments, and its structure is not described in detail here.

[0302] With respect to the pixel driving circuit in the first embodiment of the present disclosure, the driving method of the present disclosure may include:

[0303] In the data writing stage, the data writing unit of each driving unit is turned on to transmit the data signal to the control end of the driving transistor through the data writing unit and the driving transistor, and to charge the energy storage unit so that multiple light-emitting devices emit light simultaneously.

[0304] like Fig.43 As shown, for the pixel driving circuit in the second embodiment of the present disclosure, the driving method of the present disclosure may include steps S310 to S320, wherein:

[0305] Step S310, in the data writing stage, turning on the data writing unit to transmit the data signal to the control end of the driving transistor through the data writing unit and the driving transistor, and charging the energy storage unit;

[0306] Step S320, in the light-emitting stage, input a first power supply signal to the driving transistor through the energy storage unit to turn on the driving transistor, so that the signal at the second end of the driving transistor is transmitted to the first end of the first light-emitting device; turn off the first switch unit and the second switch unit, turn on the third switch unit and the fourth switch unit, so that the first light-emitting device emits light; or, turn on the first switch unit and the fourth switch unit, turn off the second switch unit and the third switch unit, so that the second light-emitting device emits light; or, turn on the first switch unit and the second switch unit, turn off the third switch unit and the fourth switch unit, so that the third light-emitting device emits light.

[0307] like Fig.44 As shown, for the pixel driving circuit in the third embodiment of the present disclosure, the driving method of the present disclosure may include steps S410 to S420, wherein:

[0308] Step S410, in the data writing phase, turning on the data writing unit to transmit the data signal to the control end of the driving transistor through the data writing unit and the driving transistor, and charging the energy storage unit;

[0309] Step S420, in the light-emitting stage, input a first power supply signal to the driving transistor through the energy storage unit to turn on the driving transistor, so that the signal at the second end of the driving transistor is transmitted to the first end of the first light-emitting device; turn off the first switch unit, turn on the second switch unit and the third switch unit, so that the first light-emitting device emits light; or, turn off the second switch unit, turn on the first switch unit and the third switch unit, so that the second light-emitting device emits light; or, turn off the third switch unit, turn on the first switch unit and the second switch unit, so that the third light-emitting device emits light.

[0310] like Fig.45 As shown, for the pixel driving circuit in the fourth embodiment of the present disclosure, the driving method of the present disclosure may include steps S510 to S520, wherein:

[0311] Step S510, in the data writing stage, turning on the data writing unit to transmit the data signal to the control end of the driving transistor through the data writing unit and the driving transistor, and charging the energy storage unit;

[0312] Step S520, in the light-emitting stage, input a first power supply signal to the driving transistor through the energy storage unit to turn on the driving transistor, so that the signal at the second end of the driving transistor is transmitted to the first end of the first light-emitting device; turn off the second switch unit, turn on the first switch unit, so that the first light-emitting device emits light; or, turn off the first switch unit, turn on the second switch unit, and when the voltage value at the first power supply end is lower than the voltage value at the second power supply end, the second light-emitting device emits light; or, turn off the first switch unit, turn on the second switch unit, and when the voltage value at the first power supply end is higher than the voltage value at the second power supply end, the third light-emitting device emits light.

[0313] The details and beneficial effects of the above driving method have been described in detail in the implementation of the pixel driving circuit above. For details, please refer to the structure and working process of the pixel driving circuit, which will not be repeated here.

[0314] It should be noted that, although the steps of the driving method in the present disclosure are described in a specific order in the drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0315] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A display panel, wherein: include: A driving backplane, including a plurality of pixel driving circuits; A light emitting device layer, comprising a plurality of light emitting units distributed in an array, wherein the light emitting unit comprises a plurality of light emitting devices stacked and arranged in a direction away from the driving backplane; In a direction perpendicular to the driving backplane, the light-emitting devices other than the light-emitting device closest to the driving backplane are transparent devices; In the same light-emitting unit, at least part of the light-emitting devices are connected to the pixel driving circuit and are used to emit light under the drive of the pixel driving circuit, and at least two of the light-emitting devices in the same light-emitting unit have different light-emitting materials; The light emitting device comprises: A first electrode layer is formed on one side of the driving backplane and is connected to one of the pixel driving circuits; A light-emitting functional layer is formed on a surface of the first electrode layer away from the driving backplane; A second electrode layer is formed on a surface of the light-emitting functional layer away from the driving backplane; In two adjacent light-emitting devices in a direction perpendicular to the driving backplane, the second electrode layer of the light-emitting device close to the driving backplane and the first electrode layer of the light-emitting device away from the driving backplane are the same electrode layer; the number of light-emitting devices in the same light-emitting unit is three, and includes a first light-emitting device, a second light-emitting device and a third light-emitting device distributed in a direction away from the driving backplane, and the first light-emitting device, the second light-emitting device and the third light-emitting device have different light-emitting materials for emitting light of different colors; The driving backplane further comprises connecting leads, wherein the connecting leads comprise a first lead and a second lead spaced apart from the first electrode layer, wherein the first lead and the second lead are respectively connected to different pixel driving circuits; The display panel further includes: A first pixel definition layer is disposed on the same side of the driving backplane as the first electrode layer of the first light-emitting device, the first pixel definition layer is provided with a plurality of first openings exposing the first electrode layers of the first light-emitting devices, and the sidewalls of the first openings are contracted toward the driving backplane; A second pixel definition layer is disposed on the same side of the driving backplane as the first pixel definition layer, and is located in the first opening, and has a first gap with the sidewall of the first opening, and the second lead is at least partially exposed in the first gap; the second pixel definition layer includes a second opening, the first electrode layer of the first light-emitting device is located in the second opening, and has a second gap with the sidewall of the second opening, and the first lead is at least partially exposed in the second gap; in a direction perpendicular to the driving backplane, the thickness of the second pixel definition layer is less than the thickness of the first pixel definition layer; The light-emitting functional layer of the first light-emitting device is at least partially disposed in the second opening and is disconnected at a boundary of the second opening; The second electrode layer of the first light emitting device is at least partially disposed in the second opening and at least partially covers the first lead, and the second electrode layer of the first light emitting device is disconnected at a boundary of the second opening; The light-emitting functional layer of the second light-emitting device covers the surface of the second electrode layer of the first light-emitting device away from the driving backplane, is continuous in the second opening, and is disconnected at the boundary of the first opening; the light-emitting functional layer of the second light-emitting device exposes the second lead; The second electrode layer of the second light-emitting device at least partially covers the surface of the light-emitting functional layer of the second light-emitting device and at least partially covers the second lead, the second electrode layer of the second light-emitting device is disconnected at the boundary of the first opening, and its orthographic projection on the driving backplane at least partially overlaps with the orthographic projection of the light-emitting functional layer of the first light-emitting device on the driving backplane; The light-emitting functional layer of the third light-emitting device is located on a side of the first electrode layer of the third light-emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the first electrode layer of the third light-emitting device on the driving backplane; The second electrode layer of the third light emitting device covers the surface of the light emitting functional layer of the third light emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the light emitting functional layer of the third light emitting device on the driving backplane.

2. The display panel according to claim 1, wherein: The first electrode layer of the first light emitting device is disposed on one side of the driving backplane, and the display panel further includes: A pixel definition layer, which is disposed on the same side of the driving backplane as the first electrode layer of the first light-emitting device, and the pixel definition layer is provided with a plurality of openings exposing the first electrode layer of each of the first light-emitting devices; The light-emitting functional layer of the first light-emitting device is at least partially disposed in the opening; The second electrode layer of the first light-emitting device is arranged on the surface of the pixel definition layer away from the driving backplane, and its orthographic projection in the opening at least partially overlaps with the orthographic projection of the light-emitting function layer of the first light-emitting device in the opening; the second electrode layer of the first light-emitting device is connected to the pixel driving circuit through a via hole penetrating the pixel definition layer; The light-emitting functional layer of the second light-emitting device covers the surface of the second electrode layer of the first light-emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the second electrode layer of the first light-emitting device on the driving backplane; The second electrode layer of the second light-emitting device covers the light-emitting function layer of the second light-emitting device and the surface of the pixel definition layer, and its orthographic projection in the opening at least partially overlaps with the orthographic projection of the light-emitting function layer of the first light-emitting device in the opening, and is connected to the pixel driving circuit through a via hole penetrating the pixel definition layer; The light-emitting functional layer of the third light-emitting device includes a hole transport layer, a light-emitting material layer and an electron transport layer stacked in sequence, the hole transport layer is located on the side of the first electrode layer of the third light-emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the second electrode layer of the second light-emitting device on the driving backplane; the light-emitting material layer is located on the side of the hole transport layer away from the driving backplane, and its orthographic projection in the opening at least partially overlaps with the orthographic projection of the second electrode layer of the second light-emitting device in the opening; the electron transport layer covers the surface of the structure jointly constituted by the light-emitting material layer and the hole transport layer; The second electrode layer of the third light-emitting device is located on a side of the electron transport layer away from the driving backplane, and its orthographic projection in the opening at least partially overlaps with the orthographic projection of the light-emitting material layer in the opening.

3. The display panel according to claim 2, wherein: The third light-emitting devices of the light-emitting units share the hole transport layer and the electron transport layer.

4. The display panel according to claim 1, wherein: The light emitting color of the first light emitting device is blue, the light emitting color of the second light emitting device is green, and the light emitting color of the third light emitting device is red.

5. The display panel according to claim 2, wherein: The display panel further includes: The light-shielding layer is arranged on the side of the light-emitting device layer away from the driving backplane, and has a plurality of light-transmitting holes, each of the light-transmitting holes is arranged in one-to-one correspondence with each of the openings, and the orthographic projection of each light-transmitting hole on the driving backplane and the orthographic projection of each light-emitting device in the corresponding opening on the driving backplane at least partially overlap.

6. The display panel according to any one of claims 1 to 5, wherein: The display panel further includes: The encapsulation layer is located on a side of the light-emitting device layer away from the driving backplane.

7. A display device, wherein: A display panel comprising any one of claims 1 to 5.

8. A method for manufacturing a display panel, wherein: include: forming a driving backplane, the driving backplane comprising a plurality of pixel driving circuits; A light-emitting device layer is formed on one side of the driving backplane, the light-emitting device layer includes a plurality of light-emitting units distributed in an array, the light-emitting unit includes a plurality of light-emitting devices stacked in a direction away from the driving backplane; in a direction perpendicular to the driving backplane, the light-emitting devices other than the light-emitting device closest to the driving backplane are transparent devices; In the same light-emitting unit, at least part of the light-emitting devices are connected to the pixel driving circuit and are used to emit light under the drive of the pixel driving circuit, and at least two of the light-emitting devices in the same light-emitting unit have different light-emitting materials; The light emitting device comprises: A first electrode layer is formed on one side of the driving backplane and is connected to one of the pixel driving circuits; A light-emitting functional layer is formed on a surface of the first electrode layer away from the driving backplane; A second electrode layer is formed on a surface of the light-emitting functional layer away from the driving backplane; In two adjacent light-emitting devices in a direction perpendicular to the driving backplane, the second electrode layer of the light-emitting device close to the driving backplane and the first electrode layer of the light-emitting device away from the driving backplane are the same electrode layer; the number of light-emitting devices in the same light-emitting unit is three, and includes a first light-emitting device, a second light-emitting device and a third light-emitting device distributed in a direction away from the driving backplane, and the first light-emitting device, the second light-emitting device and the third light-emitting device have different light-emitting materials for emitting light of different colors; The driving backplane further comprises connecting leads, wherein the connecting leads comprise a first lead and a second lead spaced apart from the first electrode layer, wherein the first lead and the second lead are respectively connected to different pixel driving circuits; The manufacturing method further comprises: forming a first pixel definition layer, wherein the first pixel definition layer and the first electrode layer of the first light-emitting device are arranged on the same side of the driving backplane, the first pixel definition layer is provided with a plurality of first openings exposing the first electrode layers of the first light-emitting devices, and the sidewalls of the first openings shrink toward the driving backplane; A second pixel definition layer is formed, wherein the second pixel definition layer and the first pixel definition layer are arranged on the same side of the driving backplane, and are located in the first opening, and have a first gap with the side wall of the first opening, and the second lead is at least partially exposed in the first gap; the second pixel definition layer includes a second opening, the first electrode layer of the first light-emitting device is located in the second opening, and have a second gap with the side wall of the second opening, and the first lead is at least partially exposed in the second gap; in a direction perpendicular to the driving backplane, the thickness of the second pixel definition layer is less than the thickness of the first pixel definition layer; The light-emitting functional layer of the first light-emitting device is at least partially disposed in the second opening and is disconnected at a boundary of the second opening; The second electrode layer of the first light emitting device is at least partially disposed in the second opening and at least partially covers the first lead, and the second electrode layer of the first light emitting device is disconnected at a boundary of the second opening; The light-emitting functional layer of the second light-emitting device covers the surface of the second electrode layer of the first light-emitting device away from the driving backplane, is continuous in the second opening, and is disconnected at the boundary of the first opening; the light-emitting functional layer of the second light-emitting device exposes the second lead; The second electrode layer of the second light-emitting device at least partially covers the surface of the light-emitting functional layer of the second light-emitting device and at least partially covers the second lead, the second electrode layer of the second light-emitting device is disconnected at the boundary of the first opening, and its orthographic projection on the driving backplane at least partially overlaps with the orthographic projection of the light-emitting functional layer of the first light-emitting device on the driving backplane; The light-emitting functional layer of the third light-emitting device is located on a side of the first electrode layer of the third light-emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the first electrode layer of the third light-emitting device on the driving backplane; The second electrode layer of the third light emitting device covers the surface of the light emitting functional layer of the third light emitting device away from the driving backplane, and its orthographic projection on the driving backplane covers the orthographic projection of the light emitting functional layer of the third light emitting device on the driving backplane.

9. A pixel driving circuit, wherein: Used to drive a plurality of light-emitting devices connected in series between a first power supply terminal and a second power supply terminal to emit light, wherein the plurality of light-emitting devices are a plurality of light-emitting devices in the light-emitting unit in the display panel according to any one of claims 1 to 6; The pixel driving circuit includes a plurality of driving units, each of which includes a driving transistor, a data writing unit and an energy storage unit; The driving transistor has a control terminal, a first terminal and a second terminal, and the second terminal of the driving transistor is used to connect to the first terminal of the light emitting device; The data writing unit is used to be turned on in response to a writing control signal to transmit the data signal to the control terminal of the driving transistor; The first end of the energy storage unit is connected to the first power supply end, and the second end of the energy storage unit is connected to the control end of the driving transistor; The first end of each of the light emitting devices is connected to the second end of a driving transistor of the driving unit.

10. The pixel driving circuit according to claim 9, wherein: The plurality of driving units include a first driving transistor, a second driving transistor and a third driving transistor; the plurality of light emitting devices include a first light emitting device, a second light emitting device and a third light emitting device; The second terminal of the first driving transistor is connected to the first light emitting device; The second end of the second driving transistor is connected between the first light emitting device and the second light emitting device; The second end of the third driving transistor is connected between the second light emitting device and the third light emitting device, and the second end of the third light emitting device is connected to the second power supply end.

11. A pixel driving circuit, wherein: Used to drive a first light-emitting device, a second light-emitting device and a third light-emitting device connected in series between a first power supply terminal and a second power supply terminal to emit light, wherein the first light-emitting device, the second light-emitting device and the third light-emitting device are all the light-emitting devices in the light-emitting unit according to any one of claims 1 to 6, and the pixel driving circuit comprises: A driving transistor having a control end, a first end, and a second end, wherein the second end of the driving transistor is used to be connected to the first end of the first light emitting device; a data writing unit, configured to be turned on in response to a writing control signal so as to transmit a data signal to a control terminal of the driving transistor; An energy storage unit, wherein a first end of the energy storage unit is connected to the first power supply end, and a second end of the energy storage unit is connected to the control end of the driving transistor; A first switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the first switch unit is connected between the driving transistor and the first light emitting device, and a second end of the first switch unit is connected between the first light emitting device and the second light emitting device; a second switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the second switch unit is connected between the driving transistor and the first light emitting device, and a second end of the second switch unit is connected between the second light emitting device and the third light emitting device; A third switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the third switch unit is connected between the first light emitting device and the second light emitting device, and a second end of the third switch unit is connected to the second power supply end; The fourth switch unit is used to be turned on in response to the light-emitting control signal, wherein the first end of the fourth switch unit is connected between the second light-emitting device and the third light-emitting device, and the second end of the fourth switch unit is connected to the second power supply end.

12. A pixel driving circuit, wherein: Used to drive a first light-emitting device, a second light-emitting device and a third light-emitting device connected in series between a first power supply terminal and a second power supply terminal to emit light, wherein the first light-emitting device, the second light-emitting device and the third light-emitting device are all the light-emitting devices in the light-emitting unit according to any one of claims 1 to 6, and the pixel driving circuit comprises: A driving transistor having a control end, a first end, and a second end, wherein the second end of the driving transistor is used to be connected to the first end of the first light emitting device; a data writing unit, configured to be turned on in response to a writing control signal so as to transmit a data signal to a control terminal of the driving transistor; An energy storage unit, wherein a first end of the energy storage unit is connected to the first power supply end, and a second end of the energy storage unit is connected to the control end of the driving transistor; A first switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the first switch unit is connected between the driving transistor and the first light emitting device, and a second end of the first switch unit is connected between the first light emitting device and the second light emitting device; a second switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the second switch unit is connected between the first light emitting device and the second light emitting device, and a second end of the second switch unit is connected between the second light emitting device and the third light emitting device; The third switch unit is used to be turned on in response to the light-emitting control signal, wherein the first end of the third switch unit is connected between the second light-emitting device and the third light-emitting device, and the second end of the third switch unit is connected to the second power supply end.

13. A pixel driving circuit, wherein: Used to drive a first light-emitting device, a second light-emitting device and a third light-emitting device connected in series between a first power supply terminal and a second power supply terminal to emit light, wherein the first light-emitting device, the second light-emitting device and the third light-emitting device are all the light-emitting devices in the light-emitting unit according to any one of claims 1 to 6, and the pixel driving circuit comprises: A driving transistor having a control end, a first end, and a second end, wherein the second end of the driving transistor is used to be connected to the first end of the first light emitting device; a data writing unit, configured to be turned on in response to a writing control signal so as to transmit a data signal to a control terminal of the driving transistor; An energy storage unit, wherein a first end of the energy storage unit is connected to the first power supply end, and a second end of the energy storage unit is connected to the control end of the driving transistor; A first switch unit, configured to be turned on in response to a light emitting control signal, wherein the first switch unit is connected between the second end of the driving transistor and the first light emitting device; a second switch unit, configured to be turned on in response to a light emitting control signal, wherein a first end of the first switch unit is connected between the driving transistor and the first light emitting device, and a second end of the first switch unit is connected between the second light emitting device and the third light emitting device; A connecting wire has one end connected between the first light emitting device and the second light emitting device, and the other end connected to the second power supply terminal.

14. A driving method for a pixel driving circuit, wherein: A pixel driving circuit according to claim 9 or 10; The driving method comprises: In the data writing stage, the data writing unit of each driving unit is turned on to transmit the data signal to the control end of the driving transistor through the data writing unit, and to charge the energy storage unit so that multiple light-emitting devices emit light simultaneously.

15. A driving method for a pixel driving circuit, wherein: A pixel driving circuit as claimed in claim 11; The driving method comprises: In the data writing phase, the data writing unit is turned on to transmit the data signal to the control end of the driving transistor through the data writing unit, and to charge the energy storage unit; In the light-emitting stage, a first power supply signal is input to the driving transistor through the energy storage unit to turn on the driving transistor so that the signal at the second end of the driving transistor is transmitted to the first end of the first light-emitting device; the first switch unit and the second switch unit are turned off, and the third switch unit and the fourth switch unit are turned on to make the first light-emitting device emit light; or, the first switch unit and the fourth switch unit are turned on, and the second switch unit and the third switch unit are turned off to make the second light-emitting device emit light; or, the first switch unit and the second switch unit are turned on, and the third switch unit and the fourth switch unit are turned off to make the third light-emitting device emit light.

16. A driving method for a pixel driving circuit, wherein: A pixel driving circuit as claimed in claim 12; The driving method comprises: In the data writing phase, the data writing unit is turned on to transmit the data signal to the control end of the driving transistor through the data writing unit, and to charge the energy storage unit; In the light-emitting stage, a first power supply signal is input to the driving transistor through the energy storage unit to turn on the driving transistor, so that the signal at the second end of the driving transistor is transmitted to the first end of the first light-emitting device; the first switch unit is turned off, and the second switch unit and the third switch unit are turned on, so that the first light-emitting device emits light; or, the second switch unit is turned off, and the first switch unit and the third switch unit are turned on, so that the second light-emitting device emits light; or, the third switch unit is turned off, and the first switch unit and the second switch unit are turned on, so that the third light-emitting device emits light.

17. A driving method for a pixel driving circuit, wherein: A pixel driving circuit as claimed in claim 13; The driving method comprises: In the data writing phase, the data writing unit is turned on to transmit the data signal to the control end of the driving transistor through the data writing unit, and to charge the energy storage unit; In the light-emitting stage, a first power supply signal is input to the driving transistor through the energy storage unit to turn on the driving transistor, so that the signal at the second end of the driving transistor is transmitted to the first end of the first light-emitting device; the second switch unit is turned off and the first switch unit is turned on to make the first light-emitting device emit light; or, the first switch unit is turned off and the second switch unit is turned on, and when the voltage value at the first power supply end is lower than the voltage value at the second power supply end, the second light-emitting device emits light; or, the first switch unit is turned off and the second switch unit is turned on, and when the voltage value at the first power supply end is higher than the voltage value at the second power supply end, the third light-emitting device emits light.

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