Organic light-emitting diode display panel and display apparatus

Abstract

An OLED display panel includes a substrate and a pixel array on the substrate, each pixel includes a group of subpixels, and each subpixel includes a light-emitting element and a color filter element. Among the color filter elements in the subpixel group, there is a first color filter element which is substantially transparent for light of the longest wavelength. Except a periphery of the pixel array, every M first color filter elements from M adjacent pixels abut against each other to form a seamless color filter block, where M≥2.

Claims

1. An OLED display panel, comprising: a substrate; and a pixel array comprising a plurality of pixels located on the substrate, wherein each of the plurality of pixels comprises a group of N subpixels representing N kinds of colors, respectively, and each subpixel comprises a light-emitting element and a color filter element covering the light-emitting element, and wherein the pixel array comprises a plurality of pixel clusters, and each pixel cluster of the plurality of pixel clusters is formed by tiling M adjacent pixels in a manner that M subpixels from the M adjacent pixels, respectively, share a seamless color filter block, where 2≤M≤N, and the seamless color filter block is in a same color without an inner boundary.

2. The OLED display panel according to claim 1, wherein the N colors comprise red, green and blue.

3. The OLED display panel according to claim 1, wherein the N colors comprise cyan, magenta and yellow.

4. The OLED display panel according to claim 1, wherein the N kinds of color filter elements further comprise color filter elements that are transparent to all visible light.

5. The OLED display panel according to claim 1, wherein each of the subpixels is in a quadrilateral shape, wherein each subpixel has a first side that is parallel to a direction in which rows of the subpixels in the pixel array extend, and a second side that is parallel to a direction in which columns of the subpixels in the pixel array extend, wherein the first side intersects with the second side.

6. The OLED display panel according to claim 1, wherein each of the subpixels is in a regular hexagon shape, and the subpixels in the pixel array are arranged in a honeycomb pattern.

7. The OLED display panel according to claim 1, wherein a number of light-emitting elements covered by the color filter elements with the average wavelength of λ.sub.1 is P.sub.1, a number of light-emitting elements covered by the color filter elements with the average wavelength of λ.sub.2 is P.sub.2, and a number of light-emitting elements covered by the color filter elements with the average wavelength of λ.sub.3 is P.sub.3, where P.sub.1:P.sub.2:P.sub.3 is 2:2:2, 2:3:3, 3:3:1, 3:3:2, 3:3:3, 4:4:4 or 4:6:6.

8. The OLED display panel according to claim 1, further comprising a black matrix located at a side of light-emitting elements of the subpixels facing away from the substrate and formed with a plurality of openings, wherein an orthographic projection of each of the plurality of opening on the substrate overlaps with an orthographic projection of a respective subpixel of the subpixels on the substrate.

9. A display apparatus, comprising the OLED display panel according to claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 illustrates a cross-sectional view of a pixel in an OLED display panel in the related art;

(2) FIG. 2 illustrates an optical system in an AR or VR glasses comprising an OLED display panel as illustrated in FIG. 1;

(3) FIG. 3 illustrates an aperture size dependence of an optical diffraction in the related art;

(4) FIG. 4 illustrates a pixel layout in an OLED display panel according to an embodiment of the present disclosure;

(5) FIG. 5 shows a cross-sectional view of the pixel along line A-A′ as shown in FIG. 4;

(6) FIG. 6 illustrates a pixel layout of another OLED display panel according to an embodiment of the present disclosure;

(7) FIG. 7 illustrates a cross-sectional view along line B-B′ as shown in FIG. 6;

(8) FIG. 8 illustrates a pixel layout of a further another OLED display panel according to an embodiment of the present disclosure;

(9) FIG. 9 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure;

(10) FIG. 10 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure;

(11) FIG. 11 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure;

(12) FIG. 12 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure;

(13) FIG. 13 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure;

(14) FIG. 14 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure;

(15) FIG. 15 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure;

(16) FIG. 16 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure; and

(17) FIG. 17 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

(18) The present disclosure is described below in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended to explain the present disclosure, rather than limiting the present disclosure. In addition, it should also be noted that, for ease of description, only a partial structure related to the present disclosure, rather than the entire structure thereof, is shown in the accompanying drawings.

(19) In view of the technical problems as described above, the present disclosure discloses an OLED display panel in various embodiments. FIG. 4 illustrates a pixel layout in an OLED display panel according to an embodiment of the present disclosure, and FIG. 5 shows a cross-sectional view of the pixel along line A-A′ as shown in FIG. 4. As shown in FIGS. 4 and 5, the OLED display panel includes a substrate 10 and a plurality of pixels 100A and 100B forming pixel array which is located on the substrate 10. Each pixel 100A or 100B includes a group of subpixels 110, each subpixel 110 includes a light-emitting element 20 and a color filter element covering the light-emitting element 20. Each color filter element is made approximately transparent for light of a certain color. Subpixels 110 of the plurality of pixels 100A and 100B include N kinds of color filter elements that are transparent for light of N different colors, respectively, where N≥2. FIG. 5 illustrates an example in which each subpixel group includes a first color filter element among the N kinds of the color filter elements, and except a periphery of the pixel array, every M color filter elements of the first color filter element are abutted against each other to form a seamless color filter block, where M≥2.

(20) For convenience of description, color filter element or color filter block that is made transparent for light of a first color is hereinafter referred to as color filter element or color filter block of the first color, or first color filter element or first color filter block. For example, color filter elements that are transparent for light of the first color are hereinafter referred to as color filter elements of the first color, color filter elements that are made transparent for light of N colors are hereinafter referred to as color filter elements of the N colors, color filter block that are made transparent for light of a first color is hereinafter referred to as color filter block of the first color, and color filter blocks that are made transparent for light of K colors are hereinafter referred to as color filter blocks of the K colors. For example, a color filter element or block that is made transparent for light of a red color may also be referred to as a red color filter element or a red color filter block hereinafter; and color filter elements or blocks that are made transparent for light of other colors are hereinafter referred in a similar manner.

(21) FIGS. 4 and 5 exemplarily illustrate that each pixel includes a red subpixel, a green subpixel, and a blue subpixel; in the pixel 100A, the red subpixel is denoted by R.sub.1, the green subpixel is denoted by G.sub.1, and the blue subpixel is denoted by B.sub.1; and in the pixel 100B, the red subpixel is denoted by R.sub.2, the green subpixel is denoted by G.sub.2, and the blue subpixel is denoted by B.sub.2. Further, a red color filter element 30R is provided on the light-emitting element in the red subpixel, a blue color filter element 30B is provided on the light-emitting element in the blue subpixel, and a green color filter element 30G is provided on the light-emitting element in the green subpixel. Furthermore, color filter elements of red subpixels of two adjacent pixels 100A and 100B are merged together. In this way, on the one hand, an effective aperture ratio of the red subpixels of two adjacent pixels can be improved, and on the other hand, a light transmission aperture of the red subpixel is increased by at least one fold, which can effectively reduce the optical diffraction occurring in the red subpixel, thereby protecting the adjacent pixels from being affected by diffracted light of the red subpixel.

(22) It should be noted that FIGS. 4 and 5 exemplarily illustrate that the color filter elements of the red subpixels in the adjacent pixels are merged together. Although merged together, the color filter elements of the red subpixels in the adjacent pixels are different from each other in a driving voltage of the light-emitting element. Therefore, the red subpixels in different pixels can emit light of different intensities according to their respective driving voltage signals, so that the red subpixels in different pixels have different brightness and lightness while subpixels that include different light-emitting elements sharing a color filter block of one color emit light of the same color, thus achieving the desired display effect.

(23) Since a minimum width of a black matrix between adjacent color filter elements depends on an accuracy of a patterning process of the color filter elements, including an alignment accuracy of an exposed mask, collimation of the exposure light and an accuracy at which patterns of the color filter elements are developed. For the color filter elements with a thickness close to 1 μm, the minimum width is about 1 μm. Therefore, when the minimum width of one subpixel is close to 4 μm, the aperture ratio of the subpixel is only about 50%. If no black matrix is present between the adjacent pixels, i.e., the red subpixel R.sub.1 of the pixel 100A and the red subpixel R.sub.2 of the pixel 100B sharing a seamless color filter block, then the effective aperture ratio of the red subpixel is increased to 75%.

(24) It should be noted that, in the embodiment of the present disclosure, the pixels may be the same as or different from each other in terms of the number, the color and the arrangement of the subpixels.

(25) Further, FIGS. 4 and 5 exemplarily illustrate that the color filter elements of the first color are red color filter elements, and every two red color filter elements are abutted together to form a seamless color filter block without black matrix between them. In addition, there could be multiple seamless color filter blocks in different colors. For example, the first color is a red color, the second color is a green color, every two red color filter elements are abutted together to form a seamless first color filter block, and every two green color filter elements are abutted together to form a seamless second color filter block.

(26) In the OLED display panel of the embodiment of the present disclosure, the color filter elements of the subpixels of the same color in the adjacent pixels are abutted together without black matrix between them. Therefore, the effective light transmission aperture of the subpixel is increased, and the optical diffraction and associated detrimental effects on image resolution and color gamut are minimized.

(27) In an embodiment of a general format, the pixel array includes K kinds of seamless color filter blocks in K kinds of different colors, wherein 1≤K≤N. Assume an average transmission wavelength of color filter elements of an i-th color is λ.sub.i, a ranking for the N kinds of color filter elements based on their average transmission wavelengths satisfies: λ.sub.1≥λ.sub.2≥ . . . ≥λ.sub.K≥λ.sub.K+1≥ . . . ≥λ.sub.N, where the subscripts i, K and N are positive integers and 1≤i≤N.

(28) Because the color filter blocks have relatively large apertures for light in longer wavelengths, the optical diffraction is reduced and the associated detrimental effects on image resolution and color gamut are reduced as well.

(29) The relevant descriptions and analysis in the embodiments as described above are specific embodiments for a typical chromaticity space of three primary colors RGB. The same concept is also applicable to other chromaticity spaces, such as a chromaticity space constructed by supplementary colors of the three primary colors RGB, which is commonly used in the dye industry, i.e., CMYK chromaticity coordinates. Specifically, the CMYK chromaticity space is constructed by cyan (CYAN), yellow (YELLOW), magenta (MAGENTA) and black, and a CMY chromaticity system will be formed if the chromaticity coordinates of a black dye is removed from the electronic display screen. In the RGB chromaticity coordinates, CYAN=G128+B128, MAGENTA=R228+B127, and YELLOW=R247+G171. These relationships also represent a mapping from the RGB chromaticity space to the CMY chromaticity space. Among the supplementary colors of RGB, the magenta color is a mixture of most of the red color and a small part of the blue color and has a longest average wavelength, the cyan color is a mixture of a half of the green color and a half of the blue color and has a shortest average wavelength, and the yellow color has a moderate average wavelength. In fact, there are few pure red, green, and blue colors in the nature, and most of the colors are the supplementary colors of the three primary colors of red, green, and blue, and the supplementary colors include cyan, magenta, yellow, and a mixture thereof (also known as intermediate colors). Among these supplementary colors, the yellow color occupies a considerable component. Furthermore, in existing broadcast television signals, yellow signals appear at a high frequency in addition to cyan signals. Therefore, when considering various types of light of different colors in the nature, the subpixels in which every two adjacent color filter elements are abutted together to form a seamless color filter block are not limited to the red subpixels. Thus, in the following embodiments, a description will be set forth in which a composition of the subpixels in the pixel are constructed according to different chromaticity spaces.

(30) When the subpixels of the display panel are in the chromaticity space of the three primary colors RGB, then in the pixel, the red subpixel is denoted by R, the green subpixel is denoted by G, and the blue subpixel is denoted by B. In addition, when the subpixels of the display panel are in the CMY chromaticity space of supplementary colors of the three primary colors RGB, then in the pixel, the cyan subpixel is denoted by C, the yellow subpixel is denoted by Y, and the magenta subpixel is denoted by M. Further, subscripts are used to distinguish different pixels. For example, R.sub.1 represents a red subpixel of the first pixels in the RGB chromaticity space, R.sub.2 represents a red subpixel of the second pixels in the RGB chromaticity space, C.sub.1 represents a cyan subpixel of the first subpixels in the chromaticity space of supplementary colors of RGB, and C.sub.2 represents a cyan subpixel of the second subpixels in the chromaticity space of supplementary colors of RGB. The arrangements of the subpixels in different pixels when the subpixels are in different chromaticity spaces will be described below.

(31) In an embodiment, with continued reference to FIG. 5, the color filter elements include red color filter elements, green color filter elements and blue color filter elements.

(32) On the basis of the embodiments as described above, FIG. 6 illustrates a pixel layout of another OLED display panel according to an embodiment of the present disclosure, and FIG. 7 illustrates a cross-sectional view along line B-B′ as shown in FIG. 6. As shown in FIGS. 6 and 7, the color filter elements include cyan color filter elements, magenta color filter elements and yellow color filter elements.

(33) When the pixels include red, green and blue subpixels in the chromaticity space of the three primary colors RGB, as shown in FIG. 5, the color filter elements include red color filter elements that transmit visible light with a spectral band from 590 nm to 780 nm, green color filter elements that transmit visible light with a spectral band from 495 nm to 590 nm, and blue color filter elements that transmit visible light with a spectral band from 430 nm to 495 nm. When the pixels include cyan, magenta, and yellow subpixels in the chromaticity space constructed by supplementary colors of the three primary colors RGB, as shown in FIGS. 6 and 7, the color filter elements in the pixel array include cyan color filter elements 30C, magenta color filter elements 30M and yellow color filter elements 30Y. Each of the pixels 100A includes a cyan subpixel C.sub.1, a yellow subpixel Y.sub.1 and a magenta subpixel M.sub.1, and each of the pixels 100B includes a cyan subpixel C.sub.2, a yellow subpixel Y.sub.2 and a magenta subpixel M.sub.2. Further, color filter elements of magenta subpixels in two adjacent pixels are merged together, i.e., the color filter element of the magenta subpixel M.sub.1 and the color filter element of the magenta subpixel M.sub.2 are merged together.

(34) On the basis of the embodiments as described above, FIG. 8 illustrates a pixel layout of a further another OLED display panel according to an embodiment of the present disclosure. As shown in FIG. 8, the color filter elements further include white color filter elements which are made approximately transparent to white light (i.e., all visible light), but non-transparent to infrared light and ultraviolet light.

(35) When the color filter elements include the white color filter elements, as shown in FIG. 8, each of the pixels 100A includes a red subpixel R.sub.1, a green subpixel G.sub.1, a blue subpixel B.sub.1 and a white subpixel W.sub.1, and each of the pixels 100B includes a red subpixel R.sub.2, a green subpixel G.sub.2, a blue subpixel and a white subpixel W.sub.2. Further, light-emitting elements of red subpixels of two adjacent pixels 100A and 100B share one seamless color filter block.

(36) On the basis of the embodiments as described above, FIG. 9 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure. As shown in FIG. 9, each of the subpixels is in a quadrilateral shape. Further, a direction in which rows of subpixels in the pixel array extend is parallel to a first side of each subpixel, a direction in which columns of subpixels in the pixel array extend is parallel to a second side of each subpixel, and the first side and the second side of each subpixel intersects with each other.

(37) As shown in FIG. 9, when each of the subpixels is in the quadrilateral shape, red subpixels in two adjacent pixels are adjacent to each other. Further, in one and the same pixel, the green subpixel and the blue subpixel surround the red subpixel; and in two adjacent pixels, the green subpixels is not adjacent to each other, and the blue subpixels are not adjacent to each other.

(38) It should be noted that FIG. 9 illustrates an arrangement of the adjacent subpixels when the subpixels are in the quadrilateral shape. However, the adjacent subpixels may be arranged in other manners. As shown in FIGS. 10, 11 and 12, a direction in which the subpixel columns of the pixel array extend (i.e., subpixel column direction) is perpendicular to a direction in which the rows of the pixel array extend (i.e., subpixel row direction). Alternatively, as shown in FIG. 13, the subpixel column direction of the pixel array is not perpendicular to the subpixel row direction of the pixel array. Instead, two adjacent rows of subpixels are offset with each other by a sampling space of a half-length of one subpixel in the row direction, which equivalently doubles a sampling density in a horizontal direction, thereby suppressing Moore interference stripe to a certain extent.

(39) On the basis of the embodiments as described above, FIG. 14 illustrates a pixel layout of still another OLED display panel according to an embodiment of the present disclosure. As shown in FIG. 14, each of the subpixels is in a regular hexagon shape, and the subpixels in the pixel array are arranged in a honeycomb shape.

(40) As shown in FIG. 14, because each of the subpixels is in the regular hexagon shape and the subpixels in the pixel array are arranged in the honeycomb pattern, a boundary between the subpixels occupies the smallest area, so that that the subpixels have a higher aperture ratio and improving the extraction rate of the light emitted by the light-emitting elements (i.e., the light source).

(41) It should be noted that FIG. 14 exemplarily illustrates an example in which each of the subpixels is in a regular hexagon shape, and the subpixels of the pixel array are arranged in a honeycomb pattern. Alternatively, when the subpixels are in the regular hexagon shape, the subpixels of the pixel array may be arranged in other honeycomb patterns as shown in FIGS. 15 to 17.

(42) In an embodiment, average wavelengths of transmission spectra of the color filter elements of three different colors are λ.sub.1, λ.sub.2 and λ.sub.3, where λ.sub.1≥λ.sub.2≥λ.sub.3, and the number of light-emitting elements covered by the color filter elements of a first color with the average wavelength of λ.sub.1 is P.sub.1, the number of light-emitting elements covered by the color filter elements of a second color with the average wavelength of λ.sub.2 is P.sub.2, and the number of light-emitting elements covered by the color filter elements of a third color with the average wavelength of λ.sub.3 is P.sub.3. P.sub.1:P.sub.2:P.sub.3 is 2:2:2, 2:3:3, 3:3:1, 3:3:2, 3:3:3, 4:4:4 or 4:6:6.

(43) In an embodiment, as shown in FIGS. 9 and 14, P.sub.1:P.sub.2:P.sub.3 is 2:2:2.

(44) Alternatively, as shown in FIG. 10, P.sub.1:P.sub.2:P.sub.3 is 2:2:3.

(45) Alternatively, as shown in FIG. 15, P.sub.1:P.sub.2:P.sub.3 is 3:3:1.

(46) Alternatively, as shown in FIGS. 13 and 16, P.sub.1:P.sub.2:P.sub.3 is 3:3:2.

(47) Alternatively, as shown in FIG. 16, P.sub.1:P.sub.2:P.sub.3 is 3:3:3.

(48) Alternatively, as shown in FIG. 11, P.sub.1:P.sub.2:P.sub.3 is 4:4:4.

(49) Alternatively, as shown in FIG. 12, P.sub.1:P.sub.2:P.sub.3 is 4:6:6.

(50) It should be noted that FIGS. 9-17 exemplarily illustrate the embodiments of the present disclosure in which the color filter elements include the red, green and blue color filter elements, the color filter elements with the wavelength of λ.sub.1 are the red color filter elements, the color filter elements with the wavelength of λ.sub.2 are the green color filter elements, and the color filter elements with the wavelength of λ.sub.3 are the blue color filter elements. When the color filter elements include cyan, magenta and yellow color filter elements, the ratio of the numbers of light-emitting elements covered by color filter elements of the respective colors is the same as that when the color filter elements include the red, green and blue color filter elements, the description of which is not repeated here.

(51) Further, the ratio of the numbers of light-emitting elements covered by the color filter elements of the respective colors with the average wavelengths of λ.sub.1, λ.sub.2 and λ.sub.3 may be other values, as long as the light-emitting elements of adjacent pixels are adjacent to each other and share one seamless color filter block of the same color, thereby reducing the optical diffraction occurring in the subpixels and the detrimental effect thereof on the display effect of the display panel.

(52) In an embodiment, with continued reference to FIG. 10, the number of subpixels of each color is negatively correlated with the average wavelength of the transmission spectrum of the color filter elements that cover the light-emitting elements of the subpixels of the color.

(53) According to optical diffraction theory, when the number of subpixels of a color decreases with the increase of the average wavelength of the transmission spectrum of the color filter elements that cover the light-emitting elements of the subpixels of the color, the optical diffraction may be further suppressed to obtain a higher spatial resolution. Therefore, when the subpixels include the red, green and blue subpixels, the number of the red subpixels is the smallest, thereby reducing the influence of the optical diffraction occurring in the red subpixels on the display effect of the display panel. Further, in order to compensate for the greenish or bluish color deviation of the screen due to fewer red subpixels, a white balance of the images may be re-obtained by appropriately increasing the brightness of the red subpixels and reducing the brightness of the green or blue subpixels. According to a visual response curve of the human eyes, the green light has the highest responsivity. Therefore, in the pixel array of the display panel shown in FIG. 11, it is completely feasible to appropriately reduce the brightness of the green subpixels.

(54) In an embodiment, with continued reference to FIG. 5, the OLED display panel further includes a black matrix 40 located at a side of the light-emitting elements 20 facing away from the substrate 10 and formed with a plurality of openings 41. An orthographic projection of each of the openings 41 on the substrate 10 overlaps with an orthographic projection of the corresponding subpixel 110 on the substrate 10.

(55) In this embodiment, because the black matrix 40 is formed with the openings 41, and the orthographic projection of each opening 41 on the substrate 10 overlaps with an orthographic projection of the corresponding subpixel 110 on the substrate 10, it is possible to reduce the diffraction occurring in the subpixels of the respective colors when light emitted from the subpixels passes through the color filter elements by changing sizes of the openings 41 in the black matrix 40.

(56) It should be noted that, in the above descriptions, each of the openings of the black matrix 50 is treated as circular aperture, in which Fraunhofer circular aperture diffraction occurs. However, other geometric shapes of the openings of the black matrix are feasible as well. In addition, a black matrix can be formed by superimposing two adjacent color filters in different color bands along their border, so as to block all visible light. Therefore, in all of the drawings of the present disclosure, the black matrix mentioned in the description and claims represents any structure or material constituting the structure defining light passing windows. Phrases such as “opening of the black matrix”, “light transmission aperture”, and “light transmission area” represent the light passing windows equivalently.

(57) An embodiment of the present disclosure provides a display apparatus including the OLED display panel according to any one of the embodiments as described above. It should be noted that the display apparatus of the embodiment of the present disclosure may be a computer monitor, a television screen, a smart wearable display or the like, including circuits and devices to support a normal operation of the display apparatus.

(58) It should be noted that the foregoing embodiments are merely some preferred embodiments of the present disclosure, based on the disclosed technical concept. It should be understood by those skilled in the art that the present disclosure is not limited to the specific embodiments described herein, and various modifications, combinations and substitutions may be made by those skilled in the art without departing from the scope of the present disclosure. Therefore, although the present disclosure has been described with reference to the embodiments herein, the present disclosure is not limited thereto, many other embodiments may be derived without departing from the technical concept of the present disclosure, and the scope of the present disclosure is defined by the appended claims.