Method for manufacturing display panel

The present disclosure provides a display panel. The light-emitting layers within a same sub-pixel have different thicknesses, and emit light that overlap with each other at the same time, resulting in that the peak of the overall microcavity characteristic curve has a wide range. Thus, the position of the peak of the overall microcavity characteristic curve produced by the sub-pixel can overlap with the position of the peak of the inherent brightness characteristic curve of the light-emitting layer within a wider range of angles, such that the electroluminescence spectrum changes less with change of viewing angles. Therefore, the color shift at different viewing angles is reduced, and there is no substantial difference for visual sensation for color when viewing the OLED display panel including such sub-pixels at different viewing angles.

FIELD OF INVENTION

The present disclosure relates to a field of display technology, and more particularly, to a display panel, a method for manufacturing the same, and an electronic device including the same.

BACKGROUND

Because organic light emitting diode (OLED) display devices, compared to current mainstream thin film transistor liquid crystal displays (TFT-LCDs), have advantages, such as wide viewing angles, high brightness, high contrast, low power consumption, light weight, and thin thickness, OLED display devices attract user attention among various types of flat panel displays. OLED display devices are categorized to include passive matrix OLED (PM-OLED) and active matrix OLED (AM-OLED) based on a driving mode thereof. In comparison with PM-OLED, AM-OLED have advantages including large quantity of display information, low power consumption, long lifespan of devices, high contrast of displayed images.

FIG. 1Ashows a cross-sectional view of a structure of a sub-pixel of an OLED display panel according to prior art. A light-emitting layer10of the OLED display panel has a uniform thickness.FIG. 1Bshows an inherent brightness characteristic curve of a light-emitting layer of a sub-pixel and a microcavity characteristic curve of a light-emitting area according to a current OLED display panel, wherein the curve pointed at by the arrow A1is the inherent brightness characteristic curve of the light-emitting layer of the sub-pixel, and the curve pointed at by the arrow A2is the microcavity characteristic curve of the light-emitting area.FIG. 1Cshows electroluminescence spectrum at different viewing angles according to the current OLED display panel. Please refer toFIGS. 1B and 1C.FIG. 1Cshows electroluminescence spectrum at viewing angles of 0 degrees, 30 degrees, 45 degrees, and 60 degrees. Obviously, the electroluminescence spectrum changes a lot at different viewing angles. This results in color shift and reduction in brightness, which makes the color images composed of RGB have color shift because of visual difference, and thus users have different visual sensation for color when viewing the OLED display panel at different viewing angles.

SUMMARY OF DISCLOSURE

Technical Problems

The objective of the present disclosure is to provide a display panel, a method for manufacturing the same, and an electronic device including the same, where the electroluminescence spectrum changes less with change of viewing angles, the color shift at different viewing angles is reduced, and there is no substantial difference for visual sensation for color when viewing the OLED display panel including such sub-pixels at different viewing angles.

Technical Solutions

To solve the aforementioned problems, the present disclosure provides a display panel including a plurality of sub-pixels, wherein at least one of the sub-pixels comprises at least one first light-emitting area and at least one second light-emitting area, the first light-emitting area and the second light-emitting area are sequentially arranged in a direction perpendicular to a light-emitting direction of the sub-pixel, a first light-emitting layer is disposed in the first light-emitting area, a second light-emitting layer is disposed in the second light-emitting area, and a thickness of the second light-emitting layer is greater than a thickness of the first light-emitting layer.

In one embodiment, the sub-pixel further comprises a pixel defining layer, the pixel defining layer includes at least one first opening and at least one second opening, the first opening is positioned to correspond to the first light-emitting area, the first light-emitting layer is disposed in the first opening, the second opening is positioned to correspond to the second light-emitting area, and the second light-emitting layer is disposed in the second opening.

In one embodiment, the sub-pixel further comprises a pixel defining layer, the pixel defining layer includes at least one first opening, the first opening is positioned to correspond to the first light-emitting area and the second light-emitting area, and the first light-emitting layer and the second light-emitting layer are disposed in a same first opening.

In one embodiment, the sub-pixel further comprises one first light-emitting area and one second light-emitting area, and the first light-emitting area and the second light-emitting area are sequentially arranged in the direction perpendicular to the light-emitting direction of the sub-pixel.

The present disclosure further provides a method for manufacturing the above-said display panel, comprising steps of:providing a first mask having at least one first deposition hole, positioning the first deposition hole to correspond to the first opening, and depositing the first light-emitting layer in the first opening; andproviding a second mask having at least one second deposition hole, positioning the second deposition hole to correspond to the second opening, and depositing the second light-emitting layer in the second opening such that thickness of the second light-emitting layer is greater than the thickness of the first light-emitting layer.

In one embodiment, the first mask and the second mask are same, and in the step of providing the second mask, the first mask is moved to position the first deposition hole to correspond to the second opening, and the second light-emitting layer is deposited in the second light-emitting area.

The present disclosure further provides a method for manufacturing the above-said display panel, comprising steps of:providing a first mask having at least one first deposition hole, positioning the first deposition hole to correspond to the first opening, and depositing a bottom light-emitting layer in the first opening; andproviding a second mask having at least one second deposition hole, positioning the second deposition hole to correspond to a portion of the first opening, and depositing a top light-emitting layer in the first opening such that the bottom light-emitting layer overlaps with the top light-emitting layer to constitute the second light-emitting layer, and the bottom light-emitting layer constitutes the first light-emitting layer in a non-overlapping region.

In one embodiment, the first mask and the second mask are same, and in the step of providing the second mask, the first mask is moved to position the first deposition hole to correspond to a portion of the first opening, and the top light-emitting layer is deposited in the first opening.

In addition, the present disclosure provides an electronic device, comprising the above-said display panel.

In one embodiment, the display panel includes a first type of sub-pixel, a second type of sub-pixel, and a third type of sub-pixel, wherein at least one type of the sub-pixels has a structure that is the same as that of the above-said sub-pixel.

Beneficial Effects

The present disclosure provides the following beneficial effects. Different light-emitting layers having different thickness produce different microcavity characteristic curve, and the peaks thereof have different positions. The light-emitting layers within the same sub-pixel have different thicknesses, and emit light that overlap with each other at the same time, resulting in that the peak of the overall microcavity characteristic curve has a wide range. Thus, the position of the peak of the overall microcavity characteristic curve produced by the sub-pixel can overlap with the position of the peak of the inherent brightness characteristic curve of the light-emitting layer within a wider range of angles, such that the electroluminescence spectrum changes less with change of viewing angles, the color shift at different viewing angles is reduced, and there is no substantial difference for visual sensation for color when viewing the OLED display panel including such sub-pixels at different viewing angles.

DETAILED DESCRIPTION

A further description of the implementation of a display panel, a method for manufacturing the same, and an electronic device including the same of the present disclosure are provided below in detail, in conjunction with the drawings and the embodiments. Because the present invention is characterized in structure of the sub-pixels, the drawings merely show the structure of the sub-pixels. The structures of other portions of the display panel are commonly used structures.

Please refer toFIGS. 2 and 3.FIG. 2shows a top view of a sub-pixel of a display panel according to a first embodiment of the present disclosure.FIG. 3shows a cross-sectional view ofFIG. 2cut along line C-C. The display panel of the present disclosure includes a plurality of sub-pixels2, wherein at least one of the sub-pixels2includes at least one first light-emitting area A and at least one second light-emitting area B. The sub-pixels include a red sub-pixel, a green sub-pixel, a blue sub-pixel, or a white sub-pixel. However, the sub-pixels are not limited thereto. In the present embodiment, the sub-pixels2include one first light-emitting area A and one second light-emitting area B. In other embodiments of the present disclosure, the sub-pixels2can include a plurality of first light-emitting areas A and a plurality of second light-emitting areas B, which are alternated with each other.

The first light-emitting area A and the second light-emitting area B are sequentially arranged in a direction perpendicular to a light-emitting direction of the sub-pixel2. For example, in the present embodiment, the light-emitting direction of the sub-pixel2is the Y direction shown inFIG. 3, and the first light-emitting area A and the second light-emitting area B are sequentially arranged in the X direction perpendicular to the Y direction.

A first light-emitting layer21is disposed in the first light-emitting area A. A second light-emitting layer22is disposed in the second light-emitting area B. Both the first light-emitting layer21and the second light-emitting layer22are an organic light emitting diode (OLED) layer, where a structure thereof is well-known by any person having ordinary skill in the art. Because the first light-emitting layer21and the second light-emitting layer22are disposed within a same sub-pixel, the first light-emitting layer21and the second light-emitting layer22emit a same color of light. For example, if the sub-pixel2is a red sub-pixel, both the first light-emitting layer21and the second light-emitting layer22emit a red light. And, if the sub-pixel2is a green sub-pixel, both the first light-emitting layer21and the second light-emitting layer22emit a green light.

A thickness of the second light-emitting layer22is greater than a thickness of the first light-emitting layer21. That is, the thickness of the light-emitting layer varies within a same sub-pixel. Because the thickness of the second light-emitting layer22is different from the thickness of the first light-emitting layer21, the microcavity characteristic curve produced by the second light-emitting layer22is different from the microcavity characteristic curve produced by the first light-emitting layer21. Specifically, a position of a peak of the microcavity characteristic curve produced by the second light-emitting layer22is different from a position of a peak of the microcavity characteristic curve produced by the first light-emitting layer21.

With reference toFIGS. 4 and 5, advantages provided by the present disclosure are detailed below.FIG. 4shows an inherent brightness characteristic curve of a light-emitting layer of a sub-pixel and a microcavity characteristic curve of a light-emitting area according to a display panel of the present disclosure, wherein the curve pointed at by the arrow B1is the inherent brightness characteristic curve of the light-emitting layer of the sub-pixel, the curve pointed at by the arrow B2is the microcavity characteristic curve of the first light-emitting area, the curve pointed at by the arrow B3is the microcavity characteristic curve of the second light-emitting area, and the curve pointed at by the arrow B4is the overall microcavity characteristic curve of a combined light-emitting area consisting of the first light-emitting area and the second light-emitting area.FIG. 5shows electroluminescence spectrum of a sub-pixel at different viewing angles according to a display panel of the present disclosure. Different light-emitting layers having different thickness produce different microcavity characteristic curve, and the peaks thereof have different positions. The light-emitting layers within the same sub-pixel have different thicknesses, and emit light that overlap with each other at the same time, resulting in that the peak of the overall microcavity characteristic curve has a wide range. Specifically, please seeFIG. 4. The microcavity characteristic curve produced by the first light-emitting layer21overlaps over with the microcavity characteristic curve produced by the second light-emitting layer22. This makes the peak of the overall microcavity characteristic curve produced by the sub-pixel have a wider width W. Thus, the position of the peak of the overall microcavity characteristic curve produced by the sub-pixel can overlap with the position of the peak of the inherent brightness characteristic curve of the light-emitting layer within a wider range of angles, such that the electroluminescence spectrum changes less with change of viewing angles. Please refer toFIGS. 1C and 5.FIG. 5shows electroluminescence spectrum of a sub-pixel of according to the present disclosure at viewing angles of 0 degree, 30 degrees, 45 degrees, and 60 degrees. Compared withFIG. 1Cwhich shows the electroluminescence spectrum of a sub-pixel according to prior art,FIG. 5shows that the electroluminescence spectrum of a sub-pixel according to the present disclosure changes less with change of viewing angles. Therefore, the color shift at different viewing angles is reduced, and there is no substantial difference for visual sensation for color when viewing the OLED display panel including such sub-pixels at different viewing angles.

Further, please refer toFIG. 3. In the present embodiment, the sub-pixel2further includes a pixel defining layer23. The pixel defining layer23includes at least one first opening231and at least one second opening232. The first opening231is positioned to correspond to the first light-emitting area A, and the first light-emitting layer21is disposed in the first opening231. The second opening232is positioned to correspond to the second light-emitting area B, and the second light-emitting layer22is disposed in the second opening232. In other words, different light-emitting layers having different thicknesses are formed in different openings of the pixel defining layer23. Specifically, in the present embodiment, the pixel defining layer23includes one first opening231and one second opening232. The first opening231is positioned to correspond to the first light-emitting area A. The second opening232is positioned to correspond to the second light-emitting area B. The first light-emitting layer21and the second light-emitting layer22having different thicknesses are respectively formed in the first opening231and the second opening232of the pixel defining layer23. That is, the light-emitting area of a single one sub-pixel2is defined by two different openings of the pixel defining layer23, ie., the first opening231and the second opening232, where the first light-emitting layer21and the second light-emitting layer22are independent from each other, and they together constitute the light-emitting layer of the sub-pixel2.

Moreover, the sub-pixel2further includes an anode24. The anode24extends from the first light-emitting area A to the second light-emitting area B. The pixel defining layer23is disposed on the anode24. Both the first light-emitting layer21and the second light-emitting layer22are formed on the anode24, and share a same anode24. The structures and materials of the pixel defining layer23and the anode, and connections thereof to other components are well-known by any person having ordinary skill in the art, and thus description thereof are omitted.

In addition, the present disclosure provides a method for manufacturing the above-said sub-pixel. The method for forming the first light-emitting layer21and the second light-emitting layer22can include but is not limited to ink-jet printing (UP) technique, use of metal mask or other masks, or other methods that can form the light-emitting layer having varied thickness. Two embodiments are provided as examples of the present invention for forming the light-emitting layers. In the first embodiment, the first light-emitting layer21and the second light-emitting layer22are formed using different masks. In the second embodiment, the first light-emitting layer21and the second light-emitting layer22are formed using a same mask. Detailed description thereof is provided below.

FIGS. 6A and 6Bshow each stage in a process flow of a method for manufacturing a sub-pixel of a display panel according to a first embodiment of the present disclosure. In the present embodiment, the method includes the following steps.

InFIG. 6A, a first mask60having at least one first deposition hole601is provided. The first deposition hole601is a through-hole of the first mask60which allows deposition material to pass therethrough. Next, the first deposition hole601is positioned to correspond to the first opening231of the pixel defining layer23. Then, the first light-emitting layer21is deposited in the first opening231. The method used to deposit the first light-emitting layer21includes but is not limited to evaporation.

InFIG. 6B, after the first light-emitting layer21is formed, a second mask61having at least one second deposition hole610is provided. Thereafter, the second deposition hole610is positioned to correspond to the second opening232, and the second light-emitting layer22is deposited in the second opening232. The method used to deposit the second light-emitting layer22includes but is not limited to evaporation. The deposition leads to the result that thickness of the second light-emitting layer22is greater than the thickness of the first light-emitting layer21, and therefore a structure of the above-said sub-pixel is formed.

In the present embodiment, the first mask60and the second mask61are different. The first light-emitting layer21and the second light-emitting layer22are formed using different masks.

FIGS. 7A and 7Bshow each stage in a process flow of a method for manufacturing a sub-pixel of a display panel according to a second embodiment of the present disclosure. In the present embodiment, the method includes the following steps.

InFIG. 7A, a first mask70having at least one first deposition hole701is provided. The first deposition hole701is a through-hole of the first mask70which allows deposition material to pass therethrough. Next, the first deposition hole701is positioned to correspond to the first opening231of the pixel defining layer23. Then, the first light-emitting layer21is deposited in the first opening231. The method used to deposit the first light-emitting layer21includes but is not limited to evaporation.

InFIG. 7B, after the first light-emitting layer21is formed, the first mask70is moved to position the first deposition hole701to correspond to the second opening232, and the second light-emitting layer22is deposited in the second opening232. The method used to deposit the second light-emitting layer22includes but is not limited to evaporation. The deposition leads to the result that thickness of the second light-emitting layer22is greater than the thickness of the first light-emitting layer21, and therefore a structure of the above-said sub-pixel is formed.

In the present embodiment, the first mask70is moved, and is used to form the first light-emitting layer21and the second light-emitting layer22. The first light-emitting layer21and the second light-emitting layer22are formed using a same mask.

Please refer toFIGS. 8 and 9. The present disclosure further provides a sub-pixel of a display panel according to a second embodiment of the present disclosure.FIG. 8shows a top view of a sub-pixel of a display panel according to a second embodiment of the present disclosure.FIG. 9shows a cross-sectional view ofFIG. 8cut along line C-C. The present embodiment differs from the first embodiment in that, in the present embodiment, the pixel defining layer23includes at least one first opening231, the first opening231is positioned to correspond to the first light-emitting area A and the second light-emitting area B, and the first light-emitting layer21and the second light-emitting layer22are disposed in a same first opening231. That is, a light-emitting layer having varied thickness is formed in a same opening of the pixel defining layer23. Specifically, in the present embodiment, the pixel defining layer23includes one first opening231. The first opening231is positioned to correspond to the first light-emitting area A and the second light-emitting area B. The first light-emitting layer21and the second light-emitting layer22having different thicknesses are formed in the same first opening231. That is, the first light-emitting area A and the second light-emitting area B of a single one sub-pixel2are defined by one first opening231, such that the light-emitting layers in the same first opening have different thicknesses in different areas, and the light-emitting layers in the same first opening having different thicknesses together constitute the light-emitting layer of the sub-pixel2.

In addition, the present disclosure provides a method for manufacturing the above-said sub-pixel. The method for forming the first light-emitting layer21and the second light-emitting layer22can include but is not limited to ink-jet printing (IF) technique, use of metal mask or other masks, or other methods that can form the light-emitting layer having varied thickness. Two embodiments are provided as examples of the present invention for forming the light-emitting layers. In the third embodiment, the first light-emitting layer21and the second light-emitting layer22are formed using different masks. In the fourth embodiment, the first light-emitting layer21and the second light-emitting layer22are formed using a same mask. Detailed description thereof is provided below.

FIGS. 10A and 10Bshow each stage in a process flow of a method for manufacturing a sub-pixel of a display panel according to a third embodiment of the present disclosure. In the present embodiment, the method includes the following steps.

InFIG. 10A, a first mask100having at least one first deposition hole1001is provided. The first deposition hole1001is a through-hole of the first mask100which allows deposition material to pass therethrough. Next, the first deposition hole1001is positioned to correspond to the first opening231of the pixel defining layer23. Then, a bottom light-emitting layer1002is deposited in the first opening231. The method used to deposit the bottom light-emitting layer1002includes but is not limited to evaporation.

InFIG. 10B, a second mask101having at least one second deposition hole1010is provided. The second deposition hole1010is a through-hole of the second mask101which allows deposition material to pass therethrough. Thereafter, the second deposition hole1010is positioned to correspond to a portion of the first opening231, and a top light-emitting layer1011is deposited in the first opening231. Specifically, in the present embodiment, a width of the second deposition hole1010is less than a width of the first opening231. This makes that the top light-emitting layer1011is deposited in the first opening231at position corresponding to the second deposition hole1010, and there is no the top light-emitting layer1011being deposited in the first opening231at position that does not correspond to the second deposition hole1010. For the portion where the top light-emitting layer1011is deposited, the bottom light-emitting layer1002overlaps with the top light-emitting layer1011to constitute the second light-emitting layer22. In the non-overlapping region, the bottom light-emitting layer1002serves as the first light-emitting layer21.

In the present embodiment, the first light-emitting layer21and the second light-emitting layer22are disposed in the same first opening231. The first mask100and the second mask are different. That is, the first light-emitting layer21and the second light-emitting layer22are formed using different masks.

FIGS. 11A and 11Bshow each stage in a process flow of a method for manufacturing a sub-pixel of a display panel according to a fourth embodiment of the present disclosure. In the present embodiment, the method includes the following steps.

InFIG. 11A, a first mask110having at least one first deposition hole1101is provided. The first deposition hole1101is a through-hole of the first mask110which allows deposition material to pass therethrough. Next, the first deposition hole1101is positioned to correspond to the first opening231of the pixel defining layer23. Then, a bottom light-emitting layer1102is deposited in the first opening231. The method used to deposit the bottom light-emitting layer1102includes but is not limited to evaporation.

InFIG. 11B, after the bottom light-emitting layer1102is formed, the first mask110is moved to position the first deposition hole1101to correspond to a portion of the first opening231. Specifically, the first mask110is moved, such that a portion of the first opening231is shielded, and a top light-emitting layer1111is deposited in the non-shielded portion of the first opening231. The method used to deposit the top light-emitting layer1111includes but is not limited to evaporation. For the portion where the top light-emitting layer1111is deposited, the bottom light-emitting layer1102overlaps with the top light-emitting layer1111to constitute the second light-emitting layer22. In the non-overlapping region, the bottom light-emitting layer1102serves as the first light-emitting layer21.

In the present embodiment, the first light-emitting layer21and the second light-emitting layer22are disposed in the same first opening231. The first mask110is moved, and is used to form the first light-emitting layer21and the second light-emitting layer22. The first light-emitting layer21and the second light-emitting layer22are formed using a same mask.

Furthermore, the display panel includes a plurality of sub-pixels, wherein at least one sub-pixel has a structure that is the same as that of the above-said sub-pixel. In other words, the display panel includes a plurality of red sub-pixels, a plurality of green sub-pixels, a plurality of blue sub-pixels, and a plurality of white sub-pixels, wherein at least one sub-pixel has a structure that is the same as that of the above-said sub-pixel. Additionally, the display panel includes a first type of sub-pixel, a second type of sub-pixel, and a third type of sub-pixel, wherein at least one type of the sub-pixels has a structure that is the same as that of the above-said sub-pixel. In other words, in the display panel, all the sub-pixels of a same type have a structure that is the same as that of the above-said sub-pixel. For example, all the red sub-pixels have a structure that is the same as that of the sub-pixel of the present disclosure, or two or over two types of sub-pixels have a structure that is the same as that of the sub-pixel of the present disclosure.

In addition, the present disclosure provides an electronic device including the above-said display panel. It is understood that the electronic device can include but is not limited to a mobile phone, a flat panel computer, a calculating device, a game device, a television, a display screen, a wearable device, and other appliances or household appliances having display function.

While the present disclosure has been described with the aforementioned preferred embodiments, it is preferable that the above embodiments should not be construed as limiting of the present disclosure. Anyone having ordinary skill in the art can make a variety of modifications and variations without departing from the spirit and scope of the present disclosure as defined by the following claims.

INDUSTRIAL APPLICABILITY

The inventions provided by the present disclosure can be made and used in industry, and thus possess industrial applicability.