CN212516389U - Display panel and micro display - Google Patents

Abstract

The utility model discloses a display panel and micro-display, this display panel includes: a pixel unit layer including a plurality of pixel units; the filter comprises a waveguide grating structure, a buffer layer and a waveguide layer which are sequentially stacked and have preset slit widths. The embodiment of the utility model provides a technical scheme has reduced the pollution degree to the environment in display panel and the display device manufacture process.

Description

Display panel and micro display

Technical Field

The embodiment of the utility model provides a relate to semiconductor technology field, especially relate to a display panel and micro display.

Background

With the rapid development of the information technology era, the display panel is more and more widely applied to display devices such as smart phones and smart wearable displays.

A conventional display panel includes a pixel unit and a filter, wherein light emitted from the pixel unit is converted into light of a specific color through the filter. The existing optical filter includes an organic dye, which causes serious environmental pollution.

SUMMERY OF THE UTILITY MODEL

In view of this, the embodiment of the present invention provides a display panel and a micro display, which reduce the pollution degree to the environment in the manufacturing process of the display panel and the display device.

An embodiment of the utility model provides a display panel, include:

a pixel unit layer including a plurality of pixel units;

the optical filter is positioned on the surface of the pixel unit, and comprises a waveguide grating structure, a buffer layer and a waveguide layer which are sequentially stacked and are provided with preset slit widths.

Optionally, the filter comprises one or more of a red filter, a green filter, and a blue filter.

Optionally, the width of the slit of the waveguide grating structure is proportional to the filtering wavelength of the optical filter.

Optionally, the preset slit width of the waveguide grating structure of the red optical filter is 395 nm, the preset slit width of the waveguide grating structure of the green optical filter is 355 nm, and the preset slit width of the waveguide grating structure of the blue optical filter is 285 nm.

Optionally, the dielectric constant of the waveguide layer is greater than the dielectric constant of the buffer layer.

Optionally, the waveguide layer comprises a silicon nitride waveguide layer; and/or, the buffer layer comprises a silicon oxide buffer layer; and/or the waveguide grating structure comprises a metal waveguide grating structure.

Optionally, the pixel unit layer includes a silicon substrate and a light emitting device layer on a surface of the silicon substrate.

Optionally, the display device further comprises a printed circuit board, wherein the printed circuit board is located on the surface of the pixel unit layer on the side far away from the optical filter.

Optionally, the packaging structure further comprises a thin film packaging layer and a cover plate;

the thin film packaging layer is positioned between the pixel unit and the optical filter;

the cover plate is positioned on one side of the optical filter, which is far away from the pixel unit.

The embodiment of the utility model provides a microdisplay is still provided, including arbitrary among the above-mentioned technical scheme display panel.

In the technical solution provided in this embodiment, the optical filter includes a waveguide layer, a buffer layer, and a waveguide grating structure with a preset slit width, which are sequentially stacked, so that light with a filtering wavelength in light emitted by the pixel unit can be allowed to propagate in the waveguide layer in a resonant state, and the filtering wavelength of the optical filter can be adjusted by adjusting the slit width of the waveguide grating structure. The waveguide layer, the buffer layer and the waveguide grating structure with the preset slit width do not relate to organic dye, so that the pollution degree of the display panel to the environment in the manufacturing process can be reduced. Compared with the optical filter comprising organic dye, the optical filter formed by the waveguide layer, the buffer layer and the waveguide grating structure with the preset slit width still keeps stable physicochemical properties along with the change of the environmental temperature, so that the optical filter has stable optical filtering properties along with the change of the environmental temperature.

Drawings

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

fig. 2 is a schematic structural diagram of another display panel according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of another display panel according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

As described in the background art, the existing manufacturing process of the optical filter in the display panel has serious environmental pollution. For this reason, the conventional color filter used in the display panel is an absorption-type color filter including an organic dye, and the organic dye absorbs incident light with different wavelengths to show a specific color. And the preparation process of the organic dye has serious environmental pollution.

To the above technical problem, the embodiment of the utility model provides a following technical scheme:

fig. 1 is a schematic structural diagram of a display panel according to an embodiment of the present invention. Referring to fig. 1, the display panel includes: a pixel unit layer 10, the pixel unit layer 10 including a plurality of pixel units 10A; a plurality of filters 20, a filter 20 is located on the surface of a pixel unit 10A, wherein the filter 20 includes a waveguide grating structure 21 with a predetermined slit width, a buffer layer 22 and a waveguide layer 23 which are sequentially stacked.

Illustratively, it is known that the waveguide layer 23 and the buffer layer 22 may be prepared by plasma enhanced chemical vapor deposition. The waveguide grating structure 21 with a predetermined slit width may be fabricated using a thermal evaporation technique.

In the technical solution provided in this embodiment, the optical filter 20 includes the waveguide grating structure 21, the buffer layer 22 and the waveguide layer 23 stacked in sequence and having a preset slit width, which can allow light with a filtering wavelength in light emitted by the pixel unit 10A to propagate in the waveguide layer 23 in a resonant state, and can adjust the filtering wavelength of the optical filter 20 by adjusting the slit width of the waveguide grating structure 21. The waveguide grating structure 21, the buffer layer 22 and the waveguide layer 23 with the preset slit width do not relate to organic dyes, so that the pollution degree to the environment in the manufacturing process of the display panel can be reduced. And compared with the optical filter comprising the organic dye, the optical filter formed by the waveguide grating structure 21 with the preset slit width, the buffer layer 22 and the waveguide layer 23 still maintains stable physicochemical properties along with the change of the ambient temperature, so that the optical filter 20 has stable filtering properties along with the change of the ambient temperature.

In order to enable the display panel to display a color picture, the present embodiment provides the following technical solutions:

fig. 2 is a schematic structural diagram of another display panel according to an embodiment of the present invention. Alternatively, referring to fig. 2, the filter 20 includes one or more of a red filter 20A, a green filter 20B, and a blue filter 20C.

Specifically, the light emitted from the pixel unit 10A passes through the red filter 20A and exits as red light. The light emitted from the pixel unit 10A passes through the green filter 20B to be emitted as green light. The light emitted from the pixel unit 10A passes through the blue filter 20C and exits as blue light. Illustratively, the pixel units 10A included in the pixel unit layer 10 emit white light uniformly, and the positions and the numbers of the red filters 20A, the green filters 20B, and the blue filters 20C are configured appropriately, so that the display panel can display a color picture.

Since the slit width of the waveguide grating structure 21 is related to the filtering wavelength of the filter 20, the following describes a technical scheme for adjusting the filtering wavelength of the filter 20 by adjusting the slit width of the waveguide grating structure 21:

alternatively, the slit width of the waveguide grating structure 21 is proportional to the filtering wavelength of the filter 20.

Referring to fig. 2, in the red filter 20A, the green filter 20B, and the blue filter 20C, the width of the slit of the waveguide grating structure 23 of the red filter 20A is greater than the width of the slit of the waveguide grating structure 23 of the green filter 20B, and the width of the slit of the waveguide grating structure 23 of the green filter 20B is greater than the width of the slit of the waveguide grating structure 23 of the blue filter 20C.

Specifically, the slit width of the waveguide grating structure 21 is in direct proportion to the filtering wavelength of the optical filter 20, and the optical filter with the preset filtering wavelength can be conveniently and simply prepared by controlling the variation of the slit width of the waveguide grating structure 21.

Alternatively, the preset slit width of the waveguide grating structure 21 of the red filter 20A is 395 nm, the preset slit width of the waveguide grating structure 21 of the green filter 20B is 355 nm, and the preset slit width of the waveguide grating structure 21 of the blue filter 20C is 285 nm.

Specifically, when the width of the predetermined slit of the waveguide grating structure 21 is 395 nm, light emitted from the pixel unit 10A passes through the red filter 20A and is emitted as red light. When the width of the predetermined slit of the waveguide grating structure 21 is 355 nm, the light emitted from the pixel unit 10A passes through the green filter 20B and is emitted as green light. When the width of the predetermined slit of the waveguide grating structure 21 is 285 nm, the light emitted from the pixel unit 10A passes through the blue filter 20C and exits as blue light. Illustratively, the pixel units 10A included in the pixel unit layer 10 emit white light uniformly, and the positions and the numbers of the red filters 20A, the green filters 20B, and the blue filters 20C are configured appropriately, so that the display panel can display a color picture.

Alternatively, the dielectric constant of the waveguide layer 23 is greater than that of the buffer layer 22, which may allow light of the filtered wavelength to propagate within the waveguide layer 23 without entering the buffer layer 22.

Alternatively, referring to fig. 2, the thickness of the waveguide layer 23 is about 100 nanometers. The buffer layer 22 has a thickness of about 100 nm. The thickness of the waveguide grating structure 21 of the predetermined slit width is about 40 nm.

Optionally, the waveguide layer 23 comprises a silicon nitride waveguide layer; and/or buffer layer 22 comprises a silicon oxide buffer layer; and/or, the waveguide grating structure 21 comprises a metal waveguide grating structure.

In particular, a silicon nitride waveguide layer having a dielectric constant greater than that of the silicon oxide buffer layer may allow light of the filtered wavelength to propagate within the waveguide layer 23 without entering the buffer layer 22. The metal waveguide grating structure ensures that light of the filter wavelength propagates in the layer of the waveguide layer 23 in a resonant state. Illustratively, the metal waveguide grating structure may comprise a metallic silver waveguide grating structure. Specifically, the metal silver has good light transmittance within a preset thickness range, so that light emitted by the pixel unit 10A can pass through the metal silver, the material price is low, and the production cost of the optical filter is reduced. And the waveguide grating structure 21, the buffer layer 22 and the waveguide layer 23 with preset slit width do not relate to organic dye, so that the pollution degree to the environment in the manufacturing process of the display panel can be reduced. Compared with the optical filter comprising organic dye, the optical filter formed by the waveguide grating structure 21 with the preset slit width, the buffer layer 22 and the waveguide layer 23 still keeps stable physicochemical properties along with the change of the ambient temperature, so that the optical filter 20 has stable optical filtering properties along with the change of the ambient temperature.

It should be noted that the waveguide grating structure 21, the buffer layer 22 and the waveguide layer 23 provided by the embodiments of the present invention include, but are not limited to, films made of the above materials.

In the above technical solution, light emitted by the pixel unit 10A in the pixel unit layer 10 is converted into light of a specific color by the optical filter 20, so as to complete the image display of the display panel. The specific structure of the inside of the pixel unit layer 10 will be described in detail below.

Fig. 3 is a schematic structural diagram of a display panel for an embodiment of the present invention. Referring to fig. 3, the pixel unit layer 10 includes a silicon substrate 11 and a light emitting device layer 12, and the light emitting device layer 12 is located on a surface of the silicon substrate 11.

It should be noted that the light-emitting device layer 12 includes a plurality of discrete anodes 120, light-emitting layers 121, and cathode layers 122, and each anode 120, and the light-emitting layer 121 and the cathode layer 122 corresponding to the anode 120 constitute one pixel unit 10A. The light emitting layer 121 may include a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer, which are sequentially stacked, wherein the hole injection layer contacts the anode 120, and the electron injection layer contacts the cathode layer 122. The carriers reach the organic light-emitting layer from the hole injection layer and the electron injection layer through the transmission of the hole transport layer and the electron transport layer to carry out compound light emission. A driving circuit for driving the pixel unit 10A is provided on the silicon substrate 11. Wherein the silicon substrate is provided with a via 11A for conducting an electrical signal from the side of the silicon substrate 11 adjacent to the anode 120 to the surface of the silicon substrate 11 remote from the anode 120.

A driving circuit is formed on the silicon substrate 11 by using a silicon material as an active layer through a CMOS integrated circuit process, wherein the driving circuit includes a thin film transistor having a high carrier mobility and a threshold voltage with less drift. The preparation of the driving circuit on the silicon substrate 11 adopts the CMOS integrated circuit instead of the thin film transistor process, and has the advantages that: 1. in the production process of the thin film transistor, the characteristic dimension of the thin film transistor is relatively large, usually several to tens of micrometers, while the silicon material is used as an active layer to form a driving circuit through the CMOS integrated circuit process, the size of the prepared driving transistor can be reduced to be below micrometers, correspondingly, pixel units 10A with a spacing of about ten micrometers can be formed on the surface of the silicon substrate 11, and the size of the whole display panel is greatly reduced. 2. The CMOS integrated circuit technology is mature, and can be produced by an integrated circuit foundry, so that the product yield is high. 3. The CMOS integrated circuit process has low energy consumption. Therefore, the display panel including the silicon substrate 11 has advantages of long lifetime, small volume, light weight, high product yield, low power consumption, and the like.

The display panel including the silicon substrate 11 is referred to as a silicon-based display panel. Silicon-based display panels are increasingly widely used in display devices such as smart phones and smart wearable displays due to their advantages of long service life, small size, light weight, high product yield, low energy consumption, etc.

The embodiment of the utility model provides a still provide a preparation method of pixel unit layer, this method includes: providing a silicon substrate, defining a plurality of pixel unit areas on the silicon substrate, and preparing a light-emitting device layer in the pixel unit areas. The preparation process of the light-emitting device layer comprises the following steps: an anode, a light emitting layer and a cathode layer are prepared in the pixel unit area.

Optionally, referring to fig. 3, the display panel further includes a printed circuit board 30, and the printed circuit board 30 is located on a surface of the pixel unit layer 10 on a side away from the filter 20.

The printed circuit board 30 is provided with a pad, which is electrically connected to the driving circuit on the silicon substrate 11 through the via 11A and is used for providing a driving signal to the driving circuit to display a picture on the display panel.

Optionally, referring to fig. 3, the display panel further includes a thin film encapsulation layer 40 and a cover plate 50; the thin film encapsulation layer 40 is positioned between the pixel unit 10A and the filter 20; the cover plate 50 is located on a side of the filter 20 away from the pixel unit 10.

Specifically, the thin film encapsulation layer 40 may be an organic film layer, an inorganic film layer, or a stacked structure formed by the organic film layer and the inorganic film layer, and is used for preventing external water and oxygen from invading into the pixel unit layer 10. The thin film encapsulation layer 40 may be a stack structure of alumina/titania/silica, for example. The cover plate 50 illustratively comprises a glass cover plate. Wherein an adhesive layer 60 is disposed between the cover plate 50 and the thin film encapsulation layer 40 for fixing the cover plate 50 to the surface of the thin film encapsulation layer 40. Illustratively, the adhesive layer 60 may be selected from an Ultraviolettrays (UV) adhesive. The shadowless adhesive is also called photosensitive adhesive and ultraviolet light curing adhesive, and is a kind of adhesive which can be cured only by ultraviolet light irradiation.

It should be noted that, in the display panel shown in the present invention, 3 pixel units 10A are exemplarily shown.

The embodiment of the utility model provides a microdisplay is still provided, microdisplay includes the display panel in the above-mentioned embodiment. The embodiment of the utility model provides a microdisplay includes above-mentioned display panel, consequently has the beneficial effect that above-mentioned display panel had, no longer gives unnecessary details here. The microdisplay may be adaptable for use in a VR/AR display device.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims (10)

1. A display panel, comprising:

a pixel unit layer including a plurality of pixel units;

the optical filter is positioned on the surface of the pixel unit, and comprises a waveguide grating structure, a buffer layer and a waveguide layer which are sequentially stacked and are provided with preset slit widths.

2. The display panel of claim 1, wherein the filter comprises one or more of a red filter, a green filter, and a blue filter.

3. The display panel of claim 1, wherein the slit width of the waveguide grating structure is proportional to the filtering wavelength of the filter.

4. The display panel of claim 2, wherein the predetermined slit width of the waveguide grating structure of the red filter is 395 nm, the predetermined slit width of the waveguide grating structure of the green filter is 355 nm, and the predetermined slit width of the waveguide grating structure of the blue filter is 285 nm.

5. The display panel of claim 1, wherein the dielectric constant of the waveguide layer is greater than the dielectric constant of the buffer layer.

6. The display panel of claim 1, wherein the waveguide layer comprises a silicon nitride waveguide layer; and/or, the buffer layer comprises a silicon oxide buffer layer; and/or the waveguide grating structure comprises a metal waveguide grating structure.

7. The display panel of claim 1, wherein the pixel cell layer comprises a silicon substrate and a light emitting device layer on a surface of the silicon substrate.

8. The display panel according to claim 1, further comprising a printed circuit board on a surface of the pixel unit layer on a side away from the filter.

9. The display panel according to claim 1, further comprising a thin film encapsulation layer and a cover plate;

the thin film packaging layer is positioned between the pixel unit and the optical filter;

the cover plate is positioned on one side of the optical filter, which is far away from the pixel unit.

10. A microdisplay comprising the display panel of any of claims 1-9.

Images