CN111175998A

CN111175998A - Pixel structure, display panel, display method and manufacturing method

Info

Publication number: CN111175998A
Application number: CN202010010725.4A
Authority: CN
Inventors: 丘鹤元; 吴小林; 陈惠�; 王巧妮; 谢鑫; 黄艺芳; 张新宇
Original assignee: BOE Technology Group Co Ltd; Fuzhou BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Fuzhou BOE Optoelectronics Technology Co Ltd
Priority date: 2020-01-06
Filing date: 2020-01-06
Publication date: 2020-05-19
Anticipated expiration: 2040-01-06
Also published as: CN111175998B

Abstract

The invention discloses a pixel structure, a display panel, a display method and a manufacturing method. The pixel structure is arranged between a first substrate and a second substrate, and includes: a light-emitting unit; a phase modulation unit, including: a waveguide, the The light emitted by the light-emitting unit is incident into the waveguide; a first control electrode located on the first substrate; a second control electrode corresponding to the first control electrode located on the second substrate; wherein, the The waveguide changes refractive index in response to voltages applied to the first and second control electrodes to phase modulate the incident light and to exit the modulated light from the waveguide. The embodiments provided by the present invention can realize the phase modulation of the light emitted from the pixels in the pixel structure through the phase modulation unit arranged inside the pixel structure, so as to realize holographic display inside the display panel, which has a wide application prospect.

Description

Pixel structure, display panel, display method and manufacturing method

Technical Field

The invention relates to the technical field of display, in particular to a pixel structure, a display panel, a display method and a manufacturing method.

Background

The emergence of 3D holographic display technology has solved the visual display problem in the virtual reality field, can give people to a certain extent and feel personally on the scene, can reappear the scene of objective world really, the sense of depth, the sense of hierarchy and the authenticity of expression, its applied field is very extensive, such as medicine, building, scientific calculation visualization, movie & TV amusement, military training, video communication etc.. Unlike two-dimensional display, 3D holographic display requires phase control of light during the display process. The phase control technology is one of the key technologies of 3D holographic display.

In the prior art, LiNbO based on the principle of electro-optic effect is generally adopted₃The phase modulator performs phase modulation on the light emitted by the display panel due to LiNbO₃The phase modulator is disposed outside the display panel, resulting in an increase in the overall thickness of the display panel, which is not conducive to the popularization and application of portable holographic display devices.

Disclosure of Invention

In order to solve at least one of the above problems, a first embodiment of the present invention provides a pixel structure disposed between a first substrate and a second substrate, including

A light emitting unit;

a phase modulation unit comprising

A waveguide into which light emitted from the light emitting unit is incident;

a first control electrode on the first substrate;

a second control electrode on the second substrate corresponding to the first control electrode;

wherein the waveguide changes refractive index in response to the voltages applied by the first and second control electrodes to phase modulate the incident light and emit the modulated light from the waveguide.

Further, the waveguide comprises

A light incident region located at a light emitting side of the light emitting unit;

a phase modulation region between the first and second control electrodes, the phase of the incident light being modulated in the phase modulation region;

a light exit area where the modulated light exits.

Further, in the above-mentioned case,

the refractive index of the surface of the light incident area, which is close to the light emergent side of the light emitting unit, is smaller than the refractive index of the inside of the light incident area, and the refractive index of the surface of the light incident area, which is far away from the light emergent side of the light emitting unit, is smaller than the refractive index of the inside of the light incident area;

and/or

The refractive index of the surface of the light emergent area close to the light emergent is larger than that of the inside of the light emergent area, and the refractive index of the surface of the light emergent area far away from the light emergent is smaller than that of the inside of the light emergent area.

Further, the first material layer covers the surface of the light incidence area close to the light emergent side of the light emitting unit, and the first reflection layer covers the surface of the light incidence area far away from the light emergent side of the light emitting unit

The refractive index of the first material layer is smaller than that of the light incidence area;

the first reflecting layer is used for reflecting light emitted from a surface far away from the light emitting side of the light emitting unit;

and/or

A second material layer covering the surface of the light-exiting region near the light exit, and a second reflective layer covering the surface of the light-exiting region far from the light exit, wherein

The refractive index of the second material layer is greater than that of the light emergent area;

the second reflective layer is for reflecting light emitted from a surface remote from the light-emitting surface.

Further, the pixel structure further comprises a first driving circuit on the first substrate, the first driving circuit adjusting a voltage applied to the first control electrode;

the light emitting unit includes a light emitting device and a second driving circuit on the second substrate, the second driving circuit driving the light emitting device to emit light.

Further, the second control electrode is disposed in the same layer as the cathode of the light emitting device.

Further, the second control electrode is electrically connected to a cathode of the light emitting device.

Further, in the above-mentioned case,

the waveguide is made of one of LiNbO3, LiTaO3, BaTaO3 and GaAs;

and/or

the waveguide has a thickness α, α being greater than 0.1 μm and less than 5 μm.

A second embodiment of the invention provides a display panel comprising the pixel structure according to the first embodiment arranged in an array.

A third embodiment of the present invention provides a display method using the display panel according to the second embodiment, including:

controlling the light emitting unit of each pixel structure to emit light;

controlling voltages applied to the first and second control electrodes in the respective pixel structures such that the waveguide changes a refractive index in response to the voltages applied to the first and second control electrodes to phase-modulate the incident light and emit the modulated light from the waveguide.

Further, the waveguide comprises

a light exit area where the modulated light exits;

the controlling voltages applied to the first control electrode and the second control electrode in each pixel structure such that the waveguide changes a refractive index in response to the voltages applied to the first control electrode and the second control electrode to phase-modulate the incident light and emit the modulated light from the waveguide further comprises:

controlling the light emitted by the light emitting unit to be incident on the light incident region;

controlling voltages applied to the first and second control electrodes such that the phase modulation region modulates the phase of the incident light;

controlling the modulated light to exit from the light exit area.

A fourth embodiment of the present invention provides a method for manufacturing the display panel of the second embodiment, including:

forming a first control electrode on a first substrate;

forming a light emitting unit and a second control electrode on a second substrate, the second control electrode being disposed corresponding to the first control electrode;

forming a waveguide on the first substrate or the second substrate;

and the first substrate and the second substrate are oppositely arranged.

The invention has the following beneficial effects:

aiming at the existing problems, the invention provides a pixel structure, a display panel, a display method and a manufacturing method, and the phase modulation unit arranged in the pixel structure can modulate the phase of emergent light of a pixel in the pixel structure, so that holographic display is realized in the display panel, and the display panel has wide application prospect.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a pixel structure according to an embodiment of the present invention;

2a-2b show schematic structural diagrams of the phase modulation unit according to an embodiment of the present invention;

FIGS. 3a-3b are schematic structural diagrams illustrating a pixel structure according to another embodiment of the invention;

FIGS. 4a-4b are schematic structural diagrams illustrating a pixel structure according to still another embodiment of the invention;

FIGS. 5a-5b show schematic diagrams of the first configuration of an embodiment of the present invention;

FIGS. 6a-6b are schematic diagrams illustrating a second configuration according to an embodiment of the present invention;

FIG. 7 shows a flow chart of a display method according to an embodiment of the invention;

fig. 8 is a flowchart illustrating a method for manufacturing a display panel according to an embodiment of the invention.

Detailed Description

In order to more clearly illustrate the invention, the invention is further described below with reference to preferred embodiments and the accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.

It is noted that references herein to "on … …", "formed on … …" and "disposed on … …" can mean that one layer is formed or disposed directly on another layer or that one layer is formed or disposed indirectly on another layer, i.e., there is another layer between the two layers. As used herein, unless otherwise specified, the term "on the same layer" means that two layers, components, members, elements or portions can be formed by the same patterning process, and the two layers, components, members, elements or portions are generally formed of the same material. Herein, unless otherwise specified, the expression "patterning process" generally includes the steps of coating of photoresist, exposure, development, etching, stripping of photoresist, and the like. The expression "one-time patterning process" means a process of forming a patterned layer, member, or the like using one mask plate.

As shown in fig. 1, one embodiment of the present invention provides a pixel structure disposed between a first substrate 10 and a second substrate 20, including a light emitting unit 30; a phase modulation unit 40 including a waveguide 43, the light emitted from the light emitting unit 30 being incident into the waveguide 43; a first control electrode 41 on the first substrate 10; a second control electrode 42 on the second substrate 20 corresponding to the first control electrode 41; wherein the waveguide 43 changes a refractive index in response to the voltages applied to the first and

second control electrodes

41 and 42 to perform phase modulation on the incident light and to emit the modulated light from the waveguide 43.

In this embodiment, the phase modulation unit disposed inside the pixel structure performs phase modulation on light emitted by the pixels in the pixel structure, that is, the light is phase-modulated inside the display panel to realize holographic display, so that the problem that the display device is inconvenient to carry due to the increased thickness of the display device caused by the phase modulation device disposed outside the display panel in the prior art can be solved.

Specifically, in this embodiment, the electro-optic effect of the waveguide is utilized, that is, the waveguide changes the dielectric constant under the influence of the applied electric field, so as to change the refractive index of the waveguide, and the phase modulation is performed on the incident light through the changed refractive index. In other words, by applying a voltage to the first control electrode and the second control electrode of the phase modulation unit, the first control electrode and the corresponding second control electrode form an electric field to control the refractive index of the waveguide, thereby modulating the phase of the incident light. Meanwhile, the waveguide has the characteristics of low half-wave voltage, low power consumption and the like, and is further suitable for portable display devices.

In an alternative embodiment, as shown in fig. 2a and 2b, the waveguide comprises a light entrance region 431 at the light exit side of the light emitting unit; a phase modulation region 432 between the first control electrode 41 and the second control electrode 42, the phase of the incident light being modulated in the phase modulation region 432; a light exit region 433, where the modulated light exits at the light exit region 433.

In the present embodiment, the waveguide is divided into three regions, a light incident region 431 that receives light, a phase modulation region 432 that phase-modulates the light, and a light exit region 433 that exits the modulated light. Wherein the light emitted from the light emitting unit enters the waveguide from the light incident region 431 and is transmitted in the waveguide.

After the first control electrode 41 and the second control electrode 42 form the controllable electric field according to the applied voltage, the refractive index of the waveguide within the coverage of the controllable electric field is adjusted to modulate the phase of the light, that is, the phase of the light is modulated by the refractive index of the phase modulation region. In this embodiment, the phase variation of the light is:

where V is the voltage of the controllable electric field, i.e. the voltage difference between the first control electrode 41 and the second control electrode 42, and V pi is the half-wave voltage of the waveguide.

in the present embodiment, the waveguide is LiNbO3, LiTaO3, BaTaO3 or GaAs, the thickness of the waveguide is α, α is greater than 0.1 μm and less than 5 μm, and the half-wave voltage V pi of the waveguide is a fixed value when the material and thickness of the waveguide are determined, that is, the amount of phase change of the light is only related to the voltages of the first control electrode 41 and the second control electrode 42 applied thereto, that is, the phase of the light transmitted through the phase modulation region can be controlled by controlling the voltages applied to the first control electrode 41 and the second control electrode 42.

It should be noted that, in this embodiment, the voltages applied to the first control electrode and the second control electrode are adjusted when the phase of the light needs to be modulated, and the voltage V of the controllable electric field is made 0 when the phase of the light does not need to be adjusted, that is, the same voltage is applied to the first control electrode 41 and the second control electrode 42.

The light enters the light exit region 433 after being phase-modulated, and exits from the light exit region.

It is worth mentioning that, as shown in fig. 3a, the light may exit from the surface of the light exit region away from the light emitting unit; as shown in fig. 3b, the light may also exit from the light exit region near the surface of the light emitting unit, which is not limited in this application, and a person skilled in the art should set the exit direction of the light according to the actual application requirement, which is not described herein again.

In this embodiment, the area ratio of the light incident region, the phase modulation region and the light exit region is 2:1:5, that is, the light incident region occupies 25% of the waveguide area, the phase modulation region occupies 12.5% of the waveguide area, and the light exit region occupies 62.5% of the waveguide area. It should be noted that, in the present application, the area ratio of each region is not limited, and a person skilled in the art should set the area ratio of each region according to the actual application requirement, which is not described herein again.

In view of the transmission efficiency of the light emitted by the light emitting unit, in an alternative embodiment, the refractive index of the surface of the light incident region close to the light emitting side of the light emitting unit is smaller than the refractive index of the inside of the light incident region, and the refractive index of the surface of the light incident region far from the light emitting side of the light emitting unit is smaller than the refractive index of the inside of the light incident region.

In this embodiment, the surface of the waveguide is treated so that different surfaces of the light incident region of the waveguide have different refractive indices, thereby improving the light transmission efficiency. Specifically, the surface of the light incident area corresponding to the light exit side of the light emitting unit is processed, so that the refractive index of the surface is smaller than that of the inside of the light incident area, and light emitted by the light emitting unit can enter the waveguide more easily; similarly, the surface of the light-emitting side of the light-incident area, which is far away from the light-emitting unit, is processed, so that the refractive index of the surface is greater than that of the inside of the light-incident area, and therefore the light is fully emitted on the surface, the light is stably transmitted in the waveguide, the loss of the light on the surface of the light-incident area is reduced, and the transmission efficiency of the light is improved.

In order to further improve the output efficiency of the light emitted by the light emitting unit, in another alternative embodiment, the refractive index of the surface of the light exit region close to the light exit is larger than the refractive index of the inside of the light exit region, and the refractive index of the surface of the light exit region far away from the light exit is smaller than the refractive index of the inside of the light exit region.

In the present embodiment, similarly to the above-described embodiments, the light output efficiency is improved by treating the surface of the light exit region of the waveguide so that different surfaces of the light exit region have different refractive indices. Specifically, a designated light exit surface is used as an exit surface, and the surface of the exit surface of the light exit area is processed to make the refractive index of the surface larger than the refractive index inside the light exit area, so that the modulated light is easier to be emitted from the waveguide; similarly, the surface of the light exit area far from the exit surface is processed, so that the refractive index of the surface is smaller than that of the inside of the light exit area, and thus the light exiting from the opposite surface of the exit surface is totally emitted on the surface, and the light exits only from the exit surface, so that the loss of the light in the light exit area is reduced, and the output efficiency of the light is improved.

It should be noted that, the above-mentioned embodiment for improving the transmission efficiency of the light incident region and the embodiment for improving the output efficiency of the light exiting region may be used separately or simultaneously, and the application is not limited thereto. Meanwhile, the present application also does not limit how to process the surface of the waveguide to change the refractive index, and a person skilled in the art should select an appropriate manner according to the actual application requirement to change the refractive index of the waveguide surface to the design rule, which is not described herein again.

In order to improve the transmission efficiency of the light incident region, in an alternative embodiment, as shown in fig. 4a, the pixel structure further includes a first material layer 4311 covering a surface of the light incident region 41 close to the light exit side of the light emitting unit 30, and a first reflective layer 4312 covering a surface of the light incident region far from the light exit side of the light emitting unit 30, wherein a refractive index of the first material layer 4311 is smaller than a refractive index of the light incident region 431; the first reflective layer 4312 is used to reflect light emitted from a surface away from the light emitting side of the light emitting unit.

In this embodiment, a first material layer 4311 is disposed between the light emitting unit 30 and a light incident region of the waveguide, and since the refractive index of the first material layer 4311 is smaller than that of the light incident region, light emitted from the light emitting unit easily enters the light incident region from the first material layer; meanwhile, a first reflective layer is arranged on the surface of the light incident region far away from the light emitting unit 30, so that the light emitted from the surface is reflected by the first reflective layer and continues to be transmitted in the light incident region; thereby improving the transmission efficiency of light emitted from the light emitting unit through the first material layer and the first reflective layer.

In order to improve the output efficiency of the light exiting region, in an alternative embodiment, as shown in fig. 4a and 4b, the pixel structure further includes a second material layer 4331 covering the surface of the light exiting region 433 close to the light exiting, and a second reflective layer 4332 covering the surface of the light exiting region 433 far from the light exiting, wherein the refractive index of the second material layer 4331 is greater than the refractive index of the light exiting region 433; the second reflective layer 4332 is for reflecting light emitted from a surface away from the light-emitting surface.

In this embodiment, with a given light exit surface as an exit surface, a second material layer 4331 is provided on the exit surface of the light exit region of the waveguide, and the refractive index of the second material layer 4331 is set to be larger than the refractive index of the light exit region 433 of the waveguide, so that the modulated light is easily emitted from the light exit region; meanwhile, a second reflecting layer 4332 is arranged on the surface, far away from the exit surface, of the light exit region of the waveguide, and light emitted from the surface enters the light exit region and is emitted from the exit surface after being reflected by the second reflecting layer 4332; thereby improving the output efficiency of the modulated light by the second material layer and the second reflective layer.

Specifically, as shown in fig. 4a, the exit surface of the light exit region 433 is a surface far away from the light emitting unit 30, the second material layer 4331 is disposed on the surface of the light exit region far away from the light emitting unit 30, and the second reflective layer 4332 is disposed on the surface close to the light emitting unit 30. Similarly, as shown in fig. 4b, the exit surface of the light exit region 433 is a surface close to the light emitting unit 30, the second material layer 4331 is disposed on the surface close to the light emitting unit 30, and the second reflective layer 4332 is disposed on the surface far from the light emitting unit 30.

It is worth mentioning that the skilled person can specify the exit direction of the light by providing the second material layer 4331 on different surfaces of the light exit region of the waveguide.

In view of the control of the phase modulation unit in the pixel structure, in an alternative embodiment, as shown in fig. 1, the pixel structure further includes a first driving circuit 11 on the first substrate 10, and the first driving circuit 11 adjusts the voltage applied to the first control electrode; the light emitting unit 30 includes a light emitting device and a second driving circuit on the second substrate 20, the second driving circuit driving the light emitting device to emit light.

In this embodiment, the voltage on the first control electrode is controlled by a first driving circuit provided on the first substrate 10, for example, the first driving circuit is triggered by an input signal, and the voltage is applied to the first control electrode by the first driving circuit. Meanwhile, the light emitting device is driven by a second driving circuit of the light emitting unit in the pixel structure, and the second driving circuit drives the light emitting device to emit light according to the scanning signal and the data signal.

In view of simplifying the manufacturing process and making full use of existing process steps, in an alternative embodiment, the second control electrode is disposed in the same layer as the cathode of the light emitting device.

In this embodiment, the second control electrode formed on the second substrate is considered, and the second control electrode and the cathode of the light emitting device are disposed in the same layer, so that the second control electrode is fabricated at the same time of fabricating the cathode of the light emitting device, thereby effectively simplifying the fabrication process.

Further, in order to reduce the complexity of a circuit for applying a voltage to the second control electrode, in another alternative embodiment, the second control electrode is electrically connected to a cathode of the light emitting device.

In this embodiment, the second control electrode is further electrically connected to the cathode of the light emitting device based on the position of the second control electrode, and the voltage applied to the second control electrode is the same as the voltage applied to the cathode of the light emitting device. In other words, a part of the cathode of the light emitting device is multiplexed as the second control electrode of the phase modulation unit. Namely, the voltage loaded on the second control electrode of the phase modulation unit is the voltage of the cathode of the light emitting device, and since the voltage of the cathode of the light emitting device is a constant value, the modulation of the phase of the light emitted by the light emitting unit can be realized only by controlling the voltage loaded on the first control electrode of the phase modulation unit.

It should be noted that this embodiment is only an illustration of one specific embodiment of the present application. The position of the second control electrode is not limited in the present application, and a person skilled in the art should select a proper position to set the second control electrode according to the actual application requirement, so as to form a controllable electric field corresponding to the first control electrode as a design criterion, which is not described in detail herein.

In a specific example, the pixel structure may be divided into a first structure formed on a first substrate and a second structure formed on a second substrate, the first structure of the pixel structure being shown in fig. 5a, and the second structure of the pixel structure being shown in fig. 6 a.

In this embodiment, fig. 5a is a cross-sectional view of the first structure, and fig. 5b is an electron microscope scan of the first structure, where the first structure specifically includes:

the first driving circuit formed on the first substrate 10, the first driving circuit including a first thin film transistor including a first gate electrode 111, a first active layer 112, a first source electrode 113, and a first drain electrode 114; the first control electrode 41 juxtaposed with the first driving circuit, the first control electrode 41 being disposed in the same layer as the first source 113 and the first drain 114, and the first control electrode 41 being electrically connected to the first drain 114; a planarization layer 12 covering the first driving circuit and the first control electrode 41; covering the waveguide 43 on the planarization layer 12 to form the first structure.

In this embodiment, the first driving circuit uses a first thin film transistor to control the voltage applied to the first control electrode 41, the first thin film transistor is turned on in response to a first gate signal 116 input to the first gate 111 and transmits a first source signal 115 input to the first source 113 to the first control electrode 41 electrically connected to the first drain 114, and the first control electrode 41 is disposed in the same layer as the first source 113 and the first drain 114, that is, the first control electrode 41 applies the voltage in response to the input signal.

Meanwhile, a planarization layer 12 covering the first driving circuit and the first control electrode 41, and a waveguide 43 covering the planarization layer 12 are provided. It should be noted that the waveguide 43 is formed on the planarization layer 12, and the waveguide 43 is relatively flat, so as to control the refractive index of the phase modulation region 432 of the waveguide 43 and facilitate the transmission of the light ray in the waveguide 43.

In this embodiment, fig. 6a is a cross-sectional view of the second structure, and fig. 6b is an electron microscope scan of the second structure, where the second structure includes:

the second driving circuit formed on the second substrate, the second driving circuit including a second thin film transistor 31, the second thin film transistor 31 including a second gate electrode 311, a second active layer 312, a second source electrode, and a second drain electrode 313; the light emitting device 32 formed on the second driving circuit, the light emitting device 32 including an anode 321, a light emitting layer 322, and a cathode 323, the anode 321 of the light emitting device 32 being electrically connected to the second source and the second drain 313; the second control electrode 42 is juxtaposed with the second driving circuit to form a second structure, the second control electrode 42 is disposed at the same layer as and electrically connected to the cathode 323 of the light emitting device 32, and the second control electrode 42 corresponds to the first control electrode 41.

In the present embodiment, the light emitting unit controls the light emitting device 32 to emit light through the second thin film transistor 31, and the second thin film transistor 31 is turned on in response to the second gate signal 316 input to the second gate 311 and transmits the second source signal 315 input to the second source to the light emitting device 32 electrically connected to the second drain 313, thereby driving the light emitting device 32 to emit light. Meanwhile, a second control electrode of the phase modulation unit is juxtaposed with the light emitting unit, and the second control electrode and the cathode 323 of the light emitting device 32 are arranged in the same layer and electrically connected, that is, the voltage applied to the second control electrode is the voltage applied to the cathode 323 of the light emitting device 32; and the second control electrode on the second substrate is arranged corresponding to the first control electrode on the first substrate. When a voltage is applied to the first control electrode of the phase modulation unit and a voltage difference exists between the first control electrode and the second control electrode, a controllable electric field is formed, so that the refractive index of the phase modulation region of the waveguide is adjusted to realize phase modulation of light emitted by the light emitting unit.

It should be noted that this embodiment is only used to illustrate one specific embodiment of the present application, and the second driving circuit of the light emitting unit is not limited in this application, and a person skilled in the art should select an appropriate driving circuit to drive the light emitting device to emit light according to practical application requirements, and details are not repeated herein.

It should be noted that, as shown in fig. 6b, a region surrounded by the light emitting device 32 corresponding to the dashed line is a light incident region 431 of the waveguide, that is, an orthogonal projection of the light emitting device 32 on the second substrate overlaps with an orthogonal projection of the light incident region 431 on the second substrate, so that light emitted by the light emitting device 32 enters the light incident region; similarly, the area surrounded by the second control electrode 42 corresponding to the dotted line is the phase modulation area 432 of the waveguide, that is, the orthographic projection of the second control electrode 42 on the second substrate overlaps with the orthographic projection of the phase modulation area 432 on the second substrate, as shown in fig. 2a, the orthographic projection of the first control electrode 41 on the second substrate overlaps with the orthographic projection of the second control electrode 42 on the second substrate, and then the second control electrode 42 and the first control electrode 41 are correspondingly arranged to form a controllable electric field to adjust the refractive index of the phase modulation area; similarly, a region 433 enclosed by the dotted line is a position corresponding to the light exit region of the waveguide in the second structure; only for illustrating the correspondence of the first and second structures of the pixel structure.

In this embodiment, the phase modulation unit changes the refractive index of the phase modulation region of the waveguide in real time through a pixel structure formed by the first structure and the second structure which are arranged oppositely, so that the phase of the light emitted by the light emitting unit is dynamically adjusted and controlled to achieve the spatial bandwidth required by holographic display, and dynamic holographic display is realized. The embodiment solves the problems that the thickness of the display device is thicker and the carrying is not facilitated due to the fact that the phase modulation unit is arranged outside the display device in the prior art by arranging the phase modulation unit inside the display device, and has wide application prospect.

Based on the pixel structure, an embodiment of the present application further provides a display panel including the pixel structure, where the display panel is an electroluminescent diode display panel, and may be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, or a navigator.

Corresponding to the display panel provided in the foregoing embodiments, an embodiment of the present application further provides a display method using the display panel, and since the display method provided in the embodiment of the present application corresponds to the pixel structures of the display panels provided in the foregoing embodiments, the foregoing embodiments are also applicable to the display method provided in this embodiment, and detailed description is omitted in this embodiment.

Based on the above pixel structure and display panel, as shown in fig. 7, an embodiment of the present invention further provides a display method, including: controlling the light emitting unit of each pixel structure to emit light; controlling voltages applied to the first and second control electrodes in the respective pixel structures such that the waveguide changes a refractive index in response to the voltages applied to the first and second control electrodes to phase-modulate the incident light and emit the modulated light from the waveguide.

In this embodiment, the pixel structure of each sub-pixel unit of the display panel emits light in response to a driving signal of the display panel, and at the same time, the display panel applies a voltage to the first control electrode and the second control electrode of the phase modulation unit of the pixel structure of each sub-pixel unit to dynamically change the refractive index of the waveguide, thereby phase-modulating the light emitted from the light emitting unit in real time to display a dynamic holographic display image.

In an alternative embodiment, the waveguide comprises a light incident region located at a light exit side of the light emitting unit; a phase modulation region between the first and second control electrodes, the phase of the incident light being modulated in the phase modulation region; a light exit area where the modulated light exits; the controlling voltages applied to the first control electrode and the second control electrode in each pixel structure such that the waveguide changes a refractive index in response to the voltages applied to the first control electrode and the second control electrode to phase-modulate the incident light and emit the modulated light from the waveguide further comprises: controlling the light emitted by the light emitting unit to be incident on the light incident region; controlling voltages applied to the first and second control electrodes such that the phase modulation region modulates the phase of the incident light; controlling the modulated light to exit from the light exit area.

In this embodiment, the light emitted by the emission unit enters the light incident region of the waveguide according to the pixel structure and is transmitted to the phase modulation region, and the phase modulation region responds to a controllable electric field formed by the voltages applied by the first control electrode and the second control electrode to adjust the refractive index, so as to modulate the phase of the light and enter the light exit region, and the light exits through the light exit region.

It should be noted that the phase of the light emitted by the emitting unit is determined by the holographic image to be displayed, for example, the required holographic image may be divided into light intensity chromaticity data and phase distribution data, wherein the display panel controls the emitting unit to emit light according to the light intensity chromaticity data, and simultaneously controls the voltages applied to the first control electrode and the second control electrode and controls the refractive index of the waveguide according to the phase distribution data, so as to implement phase modulation of the light, thereby implementing dynamic holographic image display.

In view of improving the light extraction efficiency of the display panel, in an alternative embodiment, the pixel structure further includes a first material layer covering a surface of the light-exit side of the light-entrance region close to the light-emitting unit, and a first reflective layer covering a surface of the light-exit side of the light-entrance region far from the light-emitting unit, wherein a refractive index of the first material layer is smaller than a refractive index of the light-entrance region; the first reflecting layer is used for reflecting light emitted from a surface far away from the light emitting side of the light emitting unit; the controlling the light emitted from the light emitting unit to be incident on the light incident region further includes: and controlling the light to enter the light incidence area from the first material layer.

Similarly, the pixel structure further comprises a second material layer covering the surface of the light exit area close to the light exit, and a second reflecting layer covering the surface of the light exit area far from the light exit, wherein the refractive index of the second material layer is greater than that of the light exit area; the second reflecting layer is used for reflecting light emitted from a surface far away from the light emitting surface; the controlling the modulated light to exit the light exit area further comprises: controlling the modulated light to enter the second material layer from the light exit area.

In this embodiment, by disposing the first material layer, the second material layer, the first reflective layer, and the second reflective layer on the surface of the waveguide, a ratio of the light entering the light entrance region of the waveguide is increased, and a ratio of the light exiting from the light exit region is increased, so as to increase transmission efficiency and output efficiency of the light.

Based on the display panel, as shown in fig. 8, an embodiment of the present application further provides a manufacturing method for manufacturing the display panel, including: forming a first control electrode on a first substrate; forming a light emitting unit and a second control electrode on a second substrate, the second control electrode being disposed corresponding to the first control electrode; forming a waveguide on the first substrate or the second substrate; and the first substrate and the second substrate are oppositely arranged.

In the present embodiment, the display panel is formed by a pair of boxes of the first substrate and the second substrate, which are separately formed, respectively, so that the phase modulation of the light emitted from the light emitting unit is realized by the phase modulation unit disposed inside the display panel, thereby realizing the lightness and thinness of the pixel structure. It should be noted that the waveguide may be formed on the first substrate or the second substrate, which is not limited in this application, and those skilled in the art should set the waveguide according to actual requirements to implement the phase modulation of the light as a design criterion, which is not described herein again.

In an alternative embodiment, the pixel structure further comprises a first driving circuit on the first substrate, the first driving circuit adjusting a voltage applied to the first control electrode in response to an input signal; the light emitting unit includes a light emitting device and a second driving circuit on the second substrate, the second driving circuit driving the light emitting device to emit light in response to a scan signal and a data signal; the forming of the first control electrode on the first substrate further includes: forming the first driving circuit on the first substrate, the first driving circuit including a first thin film transistor including a first gate electrode, a first active layer, a first source electrode, and a first drain electrode; forming the first control electrode on the first substrate, wherein the first control electrode is arranged on the same layer as the first source electrode and the first drain electrode, and the first control electrode is juxtaposed with the first thin film transistor; forming a planarization layer covering the first driving circuit and the first control electrode; forming a waveguide overlying the planarization layer; the forming of the light emitting unit and the second control electrode on the second substrate, the second control electrode being disposed corresponding to the first control electrode, further includes: forming the second driving circuit on the second substrate, the second driving circuit including a second thin film transistor including a second gate electrode, a second active layer, a second source electrode, and a second drain electrode; forming the light emitting device on the second driving circuit, an anode of the light emitting device being electrically connected to the second source electrode and the second drain electrode; and forming a second control electrode which is arranged on the same layer as the cathode of the light-emitting device and is electrically connected with the cathode of the light-emitting device on the second substrate, wherein the second control electrode is juxtaposed with the second driving circuit, and the second control electrode corresponds to the first control electrode.

In a specific embodiment, fabricating the pixel structure includes:

first, the first drive circuit and the juxtaposed first control electrode are formed on the first substrate.

In this embodiment, as shown in fig. 5a, the method includes:

the first driving circuit comprises a first thin film transistor, and the first thin film transistor comprises a first grid electrode, a first active layer, a first source electrode and a first drain electrode. The first control electrode is arranged on the same layer as the first source electrode and the first drain electrode and is electrically connected with the first drain electrode.

And forming a planarization layer covering the first drive circuit and the first control electrode.

Forming a waveguide overlying the planarization layer.

In this embodiment, the planarization layer provides a relatively flat film substrate for the waveguide such that the waveguide is relatively flat, facilitates control of the refractive index of the phase modulation region of the waveguide, and facilitates transmission of the light within the waveguide.

Next, a light emitting unit and a second control electrode are formed on a second substrate, the second control electrode being disposed corresponding to the first control electrode.

In this embodiment, as shown in fig. 6a, the method includes:

the light emitting unit includes a second driving circuit including a second thin film transistor including a second gate electrode, a second active layer, a second source electrode, and a second drain electrode, and a light emitting device; and forming the light emitting device on the second driving circuit, wherein an anode of the light emitting device is electrically connected with the second source electrode or the second drain electrode.

The second control electrode is arranged on the same layer as the cathode of the light-emitting device and is electrically connected with the cathode, namely, the voltage loaded by the second control electrode is the voltage loaded by the cathode of the light-emitting device.

Finally, the first substrate and the second substrate are boxed.

In this embodiment, the first substrate and the second substrate are paired into a box to form a pixel structure, and the first control electrode and the second control electrode form a controllable electric field according to a voltage difference by controlling voltages loaded on the first control electrode and the second control electrode which are oppositely arranged, so as to adjust a refractive index of the phase modulation region of the waveguide, thereby performing phase modulation on light emitted by the light emitting unit to realize dynamic holographic image display.

It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications may be included within the scope of the present invention.

Claims

1. A pixel structure, disposed between a first substrate and a second substrate, characterized in that it comprises a light-emitting unit;

Phase modulation unit, including

a waveguide into which the light emitted by the light emitting unit is incident;

a first control electrode on the first substrate;

a second control electrode corresponding to the first control electrode on the second substrate;

Wherein, the waveguide changes a refractive index in response to a voltage applied by the first control electrode and the second control electrode to phase-modulate the incident light and emit the modulated light from the waveguide.

2. The pixel structure of claim 1, wherein the waveguide comprises

a light incident area, located on the light-emitting side of the light-emitting unit;

a phase modulation area, located between the first control electrode and the second control electrode, and the phase of the incident light is modulated in the phase modulation area;

a light exit area, where the modulated light exits.

3. The pixel structure according to claim 2, wherein,

The refractive index of the surface of the light incident area close to the light-emitting side of the light-emitting unit is smaller than the refractive index of the interior of the light-incidence area, and the refractive index of the surface of the light-incident area away from the light-emitting side of the light-emitting unit is smaller than the refractive index of the light incident area. Refractive index inside the light incident zone;

and / or

The refractive index of the surface of the light exit area close to the light exit is greater than the refractive index of the inside of the light exit area, and the refractive index of the surface of the light exit area away from the light exit is smaller than the index of refraction inside the light exit area.

4. The pixel structure according to claim 2, further comprising:

a first material layer covering the surface of the light incident area close to the light-emitting side of the light-emitting unit, and a first reflective layer covering the surface of the light-incidence area away from the light-emitting side of the light-emitting unit, wherein

The refractive index of the first material layer is smaller than the refractive index of the light incident region;

the first reflection layer is used for reflecting the light emitted from the surface away from the light-emitting side of the light-emitting unit;

and / or

a second material layer covering the surface of the light exit area close to the light exit, and a second reflective layer covering the surface of the light exit area away from the light exit, wherein

The refractive index of the second material layer is greater than the refractive index of the light exit region;

The second reflective layer is used to reflect light emitted from a surface away from the light emitting surface.

5. The pixel structure according to any one of claims 2-4, characterized in that,

The pixel structure further includes a first drive circuit on the first substrate, the first drive circuit adjusts the voltage applied to the first control electrode;

The light-emitting unit includes a light-emitting device and a second driving circuit located on the second substrate, and the second driving circuit drives the light-emitting device to emit light.

6. The pixel structure according to claim 5, wherein,

The second control electrode is disposed in the same layer as the cathode of the light-emitting device.

7. The pixel structure according to claim 6, wherein,

The second control electrode is electrically connected to the cathode of the light emitting device.

8. The pixel structure according to claim 1, wherein,

The material of the waveguide is one of LiNbO3, LiTaO3, BaTaO3 and GaAs;

and / or

The thickness of the waveguide is α, which is greater than 0.1 μm and less than 5 μm.

9 . A display panel, characterized by comprising the pixel structure according to any one of claims 1 to 8 arranged in an array. 10 .

10. A display method using the display panel according to claim 9, characterized in that, comprising:

controlling the light-emitting units of the pixel structures to emit light;

controlling the voltage applied to the first control electrode and the second control electrode in each pixel structure such that the waveguide changes refractive index in response to the voltage applied to the first control electrode and the second control electrode to respond to the incident The light is phase modulated and the modulated light is emitted from the waveguide.

11. The display method according to claim 10, wherein,

The waveguide includes

a light exit area, where the modulated light exits;

The controlling the voltage applied to the first control electrode and the second control electrode in the respective pixel structures such that the waveguide changes the refractive index in response to the voltage applied to the first control electrode and the second control electrode to adjust the The incident light is phase-modulated and the modulated light is emitted from the waveguide further comprising:

controlling the light emitted by the light emitting unit to be incident on the light incident area;

controlling the voltage applied to the first control electrode and the second control electrode so that the phase modulation region modulates the phase of the incident light;

The modulated light is controlled to exit from the light exit area.

12. A method of manufacturing the display panel according to claim 9, characterized in that, comprising:

forming a first control electrode on the first substrate;

A light-emitting unit and a second control electrode are formed on the second substrate, and the second control electrode is arranged corresponding to the first control electrode;

forming the waveguide on the first substrate or on the second substrate;

The first substrate and the second substrate are assembled.