Device for inhibiting scattering of light transmitted through an OLED display

Abstract

An apparatus comprising a display panel comprising a first pixel region having a first pixel density and a second pixel region having a second pixel density higher than the first pixel density, the panel configured to generate an image viewable from a front side, and a sensor located at a back side, the sensor arranged to receive incident light transmitted through the first pixel region from the front side to the back side. The first pixel region has light-emitting pixels and signal lines electrically connected to pixel circuits associated with the pixels, and the panel comprises a layer having a light-blocking material patterned to provide apertures to transmit the incident light between some of the light-emitting pixels and the signal lines, and to block the incident light from the pixel circuits and the signal lines. The apertures can have different sizes.

Description

Background Technology

[0001] This disclosure relates to displays, particularly organic light-emitting diode (OLED) displays, which include front-side sensors, such as cameras, located beneath the display panel. When a camera is placed beneath the display panel, such as in a bezel-less smartphone, the image captured by the camera through the display panel can exhibit severe haze. For example, pixel circuitry and the traces connecting the pixel circuitry can scatter light as it passes through the display panel. This effect is particularly noticeable in high-resolution displays with high pixel density, such as those used in many smartphones. Summary of the Invention

[0002] In general, in a first aspect, the present invention features an apparatus comprising a display panel including a first pixel region having a first pixel density and a second pixel region having a second pixel density higher than the first pixel density, the display panel being configured to generate an image viewable from the front side of the display panel; and a sensor located at the rear side of the display and arranged to receive incident light transmitted from the front side of the display to the rear side of the display through the first pixel region. The first pixel region has light-emitting pixels and signal lines electrically connected to pixel circuits associated with the light-emitting pixels, and the display panel includes a layer having a light-shielding material patterned to provide apertures, thereby transmitting incident light between at least some of the light-emitting pixels and the signal lines and blocking incident light from the pixel circuits and the signal lines. The apertures include a first aperture and a second aperture, the first aperture having a first size in a first direction and the second aperture having a second size in a second direction, the first size being different from the second size.

[0003] Embodiments of the device may include one or more of the following features. For example, at least some of the light-emitting pixels are arranged in a pixel cluster. A pixel cluster may include two or more pixels (e.g., four or more pixels).

[0004] The first direction can be different from the second direction. The first direction can be orthogonal to the second direction.

[0005] The spacing between luminescent pixels can vary in at least one direction. A spacing that varies in at least one direction may mean that the spacing between a first pair of adjacent pixels within a first pixel region can be different from the spacing between a second pair of adjacent pixels within the first pixel region.

[0006] The holes can be arranged non-periodically in the first direction, such as in the horizontal direction. Non-periodic arrangement may mean that the size and / or spacing of the holes in the first direction may not be constant for each hole along the first direction.

[0007] The first direction can be horizontal. At least some holes can have different dimensions in the vertical direction orthogonal to the horizontal direction. Having different dimensions may mean that at least some holes have horizontal and vertical dimensions that are not equal to each other (e.g., at least some holes are not square or circular).

[0008] The holes can be arranged non-periodically in the second direction. Non-periodic arrangement may mean that the size and / or spacing of the holes in the second direction may not be constant for each hole along the second direction.

[0009] At least some of the holes can be straight.

[0010] In some embodiments, at least some of the holes are elliptical or circular. The holes may include elliptical holes of different ellipticity. The holes may include elliptical or circular holes of different sizes.

[0011] In some embodiments, some holes may be straight, while others may be elliptical or circular.

[0012] In some embodiments, the orifices are arranged such that they introduce a haze of less than 1.9% as measured using a method conforming to ASTM D1003.

[0013] The first and second dimensions can be 50 µm or larger.

[0014] The sensor can be a camera.

[0015] The device can be a smartphone or a tablet computer.

[0016] The display can be an organic light-emitting diode (OLED) display.

[0017] A light-shielding layer may be disposed in front of the light-emitting pixels. The light-shielding layer may also include pixel apertures configured to allow light from the pixels to pass through from the front side of the display.

[0018] In some embodiments, signal lines are arranged on vertical and / or horizontal lines that extend along common vertical and / or horizontal lines between adjacent pixels and / or pixel clusters in the first pixel region. In some embodiments, signal lines are arranged on vertical and / or horizontal lines offset from each other. Alternating horizontal and / or vertical signal lines may be offset. For example, horizontal signal lines may be arranged such that a first horizontal line portion linking a first pixel cluster and a second adjacent pixel cluster is offset in the vertical direction relative to a second horizontal line portion linking a second pixel cluster and a third pixel cluster adjacent to the second pixel cluster. Furthermore, or alternatively, vertical signal lines may be arranged such that a first vertical line portion linking a fourth pixel cluster and a fifth adjacent pixel cluster is offset in the horizontal direction relative to a second vertical line portion linking a fifth pixel cluster and a sixth pixel cluster adjacent to the fifth pixel cluster.

[0019] In general, in another aspect, the present invention is characterized by an apparatus comprising a display panel including a first pixel region having a first pixel density and a second pixel region having a second pixel density higher than the first pixel density, the display panel being configured to generate an image viewable from the front side of the display panel; and a sensor located at the rear side of the display and arranged to receive incident light transmitted from the front side of the display to the rear side of the display through the first pixel region. The first pixel region includes light-emitting pixels arranged in a pixel cluster and signal lines electrically connected to pixel circuitry associated with the pixel cluster. The display panel includes a layer having a light-shielding material patterned to provide apertures for transmitting incident light between the pixel cluster and the signal lines, and for blocking incident light from the pixel cluster and the signal lines. At least some of the apertures are elliptical or circular.

[0020] Embodiments of the device may include one or more of the following features and / or other features, such as those described above in conjunction with the first aspect. For example, each hole may be the same size and shape.

[0021] Alternatively or additionally, at least some of the holes may have different sizes and / or shapes. That is, not all holes in the light-shielding material can have the same size and shape as each other.

[0022] In general, in another aspect, the present invention is characterized by an apparatus comprising a display panel including a first pixel region having a first pixel density and a second pixel region having a second pixel density higher than the first pixel density, the display panel being configured to generate an image viewable from the front side of the display panel; and a sensor located at the rear side of the display and arranged to receive incident light transmitted from the front side of the display to the rear side of the display through the first pixel region. The first pixel region includes light-emitting pixels arranged in a pixel cluster and signal lines electrically connected to pixel circuitry associated with the pixel cluster. The display panel includes a layer of light-shielding material patterned to provide apertures for transmitting incident light between the pixel cluster and the signal lines and for blocking incident light from the pixel cluster and the signal lines. These apertures are arranged such that they introduce a haze of less than 1.9% as measured using a method conforming to ASTM D1003.

[0023] Embodiments of the device may include one or more features described above in conjunction with the first aspect and / or other aspects.

[0024] According to another further aspect, the invention features an apparatus comprising a display panel including a first pixel region having a first pixel density and a second pixel region having a second pixel density higher than the first pixel density, the panel being configured to generate an image viewable from a front side, and a rear-side sensor arranged to receive incident light transmitted from the front side to the rear side through the first pixel region. The first pixel region has light-emitting pixels and signal lines electrically connected to pixel circuitry associated with the pixels, and the panel includes a layer of light-shielding material patterned to provide apertures that allow incident light to pass between some of the light-emitting pixels and the signal lines, and block incident light from the pixel circuitry and the signal lines. The apertures may have different sizes.

[0025] Embodiments of the device may include one or more features described above in conjunction with the first aspect and / or other aspects.

[0026] Among other advantages, the embodiments disclosed herein can provide high-quality images from a camera located beneath a display panel. For example, embodiments may include a mask layer to reduce scattering and / or diffraction of light reaching the camera through the display panel. The mask layer may be designed to reduce direction-dependent scattering (e.g., along the horizontal and / or vertical axes) and / or large-angle scattering (e.g., scattering at angles of 20° or greater). The mask layer may block light from pixel circuitry and / or traces connecting pixels, reducing its scattering and / or diffraction.

[0027] The embodiments may also provide borderless devices, such as smartphones or tablets, characterized by a front-facing camera capable of capturing high-quality images.

[0028] Other features and advantages will become apparent from the description, drawings and claims. Attached Figure Description

[0029] Figure 1A and Figure 1B These are plan and cross-sectional views of a smartphone, characterized by a display with a front-facing camera located below the display panel.

[0030] Figure 2A It shows a high pixel density Figure 1A The diagram shows the pixel cluster pattern of the area of ​​the display.

[0031] Figure 2B It shows a low pixel density Figure 1A The diagram shows the pixel cluster pattern of the area of ​​the display.

[0032] Figure 3A It is a cross-sectional view of a display including a mask layer for low pixel density areas.

[0033] Figure 3B It is shown Figure 3A The diagram shows a plan view of the pixel arrangement of the display.

[0034] Figure 3C It shows that it is applicable to Figure 3B A schematic diagram of the planar view of the pixel arrangement of the mask layer.

[0035] Figure 4A A photomicrograph of an example mask pattern is shown.

[0036] Figure 4B It shows Figure 4A A photograph of the point spread function (PSF) of the mask pattern shown.

[0037] Figure 4C It shows Figure 4B The intensity map of the PSF is shown.

[0038] Figure 5A A photomicrograph showing another example of a mask pattern.

[0039] Figure 5B It shows Figure 5A A photograph of the point spread function (PSF) of the mask pattern shown.

[0040] Figure 6A A photomicrograph showing another example of a mask pattern.

[0041] Figure 6B It shows Figure 6A A photograph of the point spread function (PSF) of the mask pattern shown.

[0042] Figure 6C It shows Figure 6B The intensity map of the PSF is shown.

[0043] Figure 7A A photomicrograph showing another example of a mask pattern.

[0044] Figure 7B It shows Figure 7A A photograph of the point spread function (PSF) of the mask pattern shown.

[0045] Figure 7C It shows Figure 7B The intensity map of the PSF is shown.

[0046] Figure 8A It is a schematic diagram showing a plan view of the pixel arrangement including pixel clusters.

[0047] Figure 8B It is suitable for concealment Figure 8A A planar view of the pixel arrangement of the mask layer.

[0048] Figure 8C It shows Figure 8A A photograph of the point spread function (PSF) of the mask pattern shown.

[0049] Figure 9A It is a schematic diagram showing a plan view of another pixel arrangement including pixel clusters.

[0050] Figure 9B It is suitable for concealment Figure 9A A planar view of the pixel arrangement of the mask layer.

[0051] Figure 9C It shows Figure 9A A photograph of the point spread function (PSF) of the mask pattern shown.

[0052] Figure 9D It shows Figure 9C The intensity map of the PSF is shown.

[0053] Figure 10A It is a schematic diagram showing a plan view of another pixel arrangement including pixel clusters.

[0054] Figure 10B It is suitable for concealment Figure 10A A planar view of the pixel arrangement of the mask layer.

[0055] Figure 10C It shows Figure 10A The intensity map of the point spread function (PSF) of the mask pattern shown.

[0056] Figure 11AThis is a photomicrograph of an example mask layer composed of varying elliptical apertures.

[0057] Figure 11B yes Figure 11A The micrograph shown illustrates pixel clusters and signal lines.

[0058] Figure 12 It is a graph showing the transmission intensity based on the scattering angle of several different mask layers. Detailed Implementation

[0059] refer to Figure 1A and Figure 1B The smartphone 100 includes an organic light-emitting diode (OLED) display 110, which includes a region 112 with a high pixel density and a region 114 with a low pixel density.

[0060] Camera 130 (and / or other sensors) is located behind the display below region 114. Camera 130, consisting of a lens and pixelation sensors, sees and captures images through region 114 of the display. This means that detected light is transmitted through each layer of display 110, including display panel 115, touch panel 125, and cover glass 121. Display panel 115 further comprises multiple layers, including an OLED layer 116 composed of light-emitting elements, and a layer 118 of integrated circuits forming pixel circuits and connecting metal lines to the pixel circuits. Touch panel 125 also includes metal lines 127.

[0061] refer to Figure 2A The display 110's region 112 is composed of pixel clusters 210 arranged at a high density (e.g., 100 pixels per inch (ppi) or more, 200 ppi or more, 300 ppi or more, 400 ppi or more, 500 ppi or more, such as 600 ppi or less). In the illustrated embodiment, each pixel cluster 210 consists of a first pixel 210a having a red subpixel 211 and a green subpixel 213, and a second pixel 210b having a blue subpixel 212 and a green subpixel 213. In other cases, pixels may have other combinations of RGB subpixels (e.g., one red, one green, one blue) and / or other combinations of subpixel colors (e.g., cyan, yellow, magenta). Horizontally and vertically oriented metal traces are used for electrical connections between each subpixel and a driver facilitating pixel operation.

[0062] refer to Figure 2BRegion 114 of display 110 has a lower pixel density than region 112. In this case, the pixel density of region 114 is one-quarter of the pixel density of region 112. Because regions 112 and 114 are arranged on the same metal trace array, this means there are array positions in region 114 where only horizontal traces exist (e.g., position 230), positions where only vertical traces exist (e.g., position 240), and positions where neither vertical nor horizontal traces exist (e.g., position 220). More generally, the pixel density of the low pixel density region can be 50% or less smaller than the pixel density of region 112 (e.g., 40% or less, 30% or less, 20% or less, 10% or less, 5%).

[0063] Typically, the materials that form the horizontal and vertical traces (i.e., conductive materials, such as metals) are opaque or reflective at visible light wavelengths. Furthermore, when light passes through the display and reaches the camera 130, the close spacing of the traces between adjacent pixels causes light diffraction and / or scattering.

[0064] To reduce scattering and / or diffraction caused by traces, an opaque mask layer can be formed that blocks light before it interacts with the traces and pixel circuitry. The mask layer includes holes in pixel-free and trace-free regions, allowing light to pass through low-pixel-density areas to reach the camera. An example of this is... Figures 3A to 3C As shown, the display 300 includes a mask layer 301 on the front surface of the touch panel 310. In this example, the mask layer 301 is formed between the touch panel 310 and a passivation layer 320 formed on the touch panel. The display 300 also includes a polarizer 330 located between the passivation layer 320 and a cover glass 340, the cover glass 340 providing an exposed surface for the display 300.

[0065] The display 300 also includes an OLED display panel 350, which includes a film encapsulation layer 351 encapsulating a cathode layer 352 and an OLED layer 353. The OLED layer 353 is formed of regions (e.g., columns or rows) of a light-emitting polymer to provide different regions capable of transmitting light of different wavelengths. A circuit layer 355 beneath the OLED layer 353 includes pixel circuitry 356 and traces 357. A polyimide layer 358 and a protective film 359 protect the rear side of the circuit layer 355.

[0066] Although the mask layer 301 is located on the top surface of the touch panel 310, more generally, it can be formed at other locations within the display panel. For example, the mask layer can be formed between the encapsulation film of the touch panel and the OLED display panel. Ideally, the mask layer should be formed between the circuit layer of the OLED display panel and the top of the display. However, in some embodiments, the mask layer can be formed between the circuit layer and the back side of the display. In this case, the mask layer blocks light (i.e., light scattered and / or diffracted from elements in the circuit layer) after it has interacted with the circuit layer. Alternatively or additionally, in some cases, one or more layers of the touch panel 310 itself can be patterned to form the mask layer and / or additional layers included within the touch panel 310 to provide the mask layer. For example, one or more metal layers in the touch panel 310 can be patterned to provide the mask layer.

[0067] Generally, the mask layer is formed of a material that is opaque (e.g., reflects and / or absorbs) light detected by sensors beneath the display (e.g., visible light). For example, the mask layer can be formed of a black matrix material (e.g., black resin) commonly used in displays. Metals can also be used. For example, molybdenum, silver, or aluminum can be used for opaque mask layers. Alloys or stacks of several different materials can also be used for this layer.

[0068] Figure 3B An example of OLED layer 353 and circuit layer 360 is shown, illustrating the arrangement of horizontal lines 363 and vertical lines 362 between pixels, and traces 364 connecting the pixel circuits. In this example, a pixel cluster consists of two pixels (one pixel has red and green sub-pixels, and the other pixel has blue and green sub-pixels, a traditional pixel arrangement). Here, each pixel cluster includes a transmissive area of ​​a red sub-pixel 371, a blue sub-pixel 372, and two green sub-pixels 373.

[0069] Figure 3C A mask layer 380 of circuit layer 360 is shown. Mask layer 380 includes apertures 381 and opaque regions corresponding to vertical (382) and horizontal (383) traces, as well as opaque regions (384) covering pixel circuitry. Apertures 381 are disposed in free regions without traces. Additional apertures 391-393 are included in the opaque regions 384 on the sub-pixels to allow light to be transmitted from the sub-pixels. These additional apertures may be referred to as pixel apertures.

[0070] Figure 4A A micrograph of the mask layer is shown, representing a projection map of a low-pixel-density region in an OLED display. Here, the opaque material is represented by crosshairs and defines an array of linear apertures. Each aperture has the same size and shape. This is achieved using methods such as... Figure 4AThe mask layer of the holes shown is believed to significantly reduce haze in the display panel. However, it is further argued that the shape and arrangement of the holes can cause scattering and / or diffraction, which, despite the reduction in haze, can degrade the image acquired by the image sensor beneath the display.

[0071] Figure 4B It shows from Figure 4A The point spread function (PSF) of the mask layer is shown. Measurements were performed by guiding a collimated laser beam substantially perpendicular to the mask plane through the mask. The haze of this example was measured to be 1.9% using an ASTM D1003 compatible haze meter (e.g., a Rhopoint Novo-Haze TX haze meter or a BYK Gardner Haze-Gard i (4775) haze meter). A significant amount of light is diffracted into non-zero diffraction orders. The diffracted light is particularly pronounced along the vertical and horizontal axes and includes higher orders extending to large angles. This is due to the linear characteristics of the aperture array. Figure 4C The intensity diagram in the image shows the intensity of the PSF according to the angle.

[0072] While the aforementioned examples of mask layers are characterized by a regular pattern of apertures, it is believed that reducing the periodicity of the array along each principal direction (vertical or horizontal) can reduce the diffraction effect of transmitted light. Furthermore, although the apertures in the mask layer are all of the same shape, it is also believed that changing the size and / or shape of the apertures can reduce diffraction and / or scattering effects, and thus reduce color artifacts. Therefore, examples of mask patterns are described, characterized by an aperiodic array of apertures and / or apertures of different sizes and / or shapes. Such a mask layer can reduce the haze of collimated light normally incident upon it to less than 1.9% (e.g., 1.8% or less, 1.7% or less, 1.6% or less, 1.5% or less, 1.4% or less, 1.3% or less, 1.2% or less, 1.1% or less, 1% or less, e.g., 0.5%).

[0073] For example, the mask pattern may have holes spaced at least two different periods in the horizontal and / or vertical directions. Generally, the spacing between the holes depends on the size of the pixel elements and pixel circuitry masked by the mask layer. This spacing (in the horizontal and / or vertical directions) can be 10 µm or greater (e.g., 20 µm or greater, 30 µm or greater, 40 µm or greater, 50 µm or greater, up to 1 mm, up to 500 µm, up to 250 µm, up to 100 µm, up to 75 µm).

[0074] In general, the mask layer can include apertures of different sizes, such as different horizontal widths, different vertical heights, and / or different areas. Typically, the aperture size can vary, but should be large enough to allow sufficient light transmission for sensor operation behind the display. For example, the aperture can have at least one size of 20 µm or larger (e.g., 30 µm or larger, 50 µm or larger, 75 µm or larger, 100 µm or larger, 150 µm or larger, 200 µm or larger, such as up to 400 µm, up to 350 µm, up to 300 µm, up to 250 µm). The aperture can also have a size of 50 µm. 2 Or a larger area (e.g., 100 µm) 2 or larger, 200 µm 2 or larger, 400 µm 2 or larger, 500 µm 2 or larger, 750 µm 2 Or larger, 1,000 µm 2 Or larger, up to 1,500 µm 2 Up to 1,250 µm 2 ).

[0075] The mask layer may include two or more holes of different shapes, including but not limited to straight shapes (e.g., squares, rectangles) and curved shapes (e.g., circles and ellipses).

[0076] In low pixel density areas, pixels can be arranged periodically or non-periodically in the horizontal and / or vertical directions. For example, multiple pixels (e.g., two, three, four, five, six or more) can be grouped together and separated by different distances in the horizontal and / or vertical directions.

[0077] Figure 5A An example mask pattern is shown, in which... Figure 4A Compared to the mask layer shown, the periodicity of the hole pattern is reduced. Specifically, although the holes are mostly linear, their size and shape vary. For example, the vertical range of holes in different rows differs, and the horizontal range of holes in different columns differs. The spacing between adjacent rows and columns also varies. There is a scale in the lower left corner of the image.

[0078] Figure 5B It shows from Figure 5A The PSF of the mask layer is shown. Measurements are performed by guiding a collimated laser beam substantially perpendicular to the mask plane through the mask. In this example, the haze was measured at 1.3%, which is higher than... Figure 4A The example measured a 32% increase in haze. However, a significant amount of light was scattered along both the vertical and horizontal axes. This is attributed to the linear characteristics of the aperture array. However, compared to... Figure 4B Compared to the PSF shown, the diffraction peaks along the vertical and horizontal directions are less pronounced, and the diffraction peaks away from these directions are significantly reduced.

[0079] While the aforementioned example is characterized by the mask layer including linear holes, other shapes of holes are also possible. For example, elliptical or circular holes can be used. Figure 6A A photomicrograph of an example mask layer comprising a regular array of elliptical apertures is shown. The major axis of the elliptical apertures is aligned with the horizontal direction, and the minor axis is aligned with the vertical direction. The spacing between the apertures along each row is the same, and the spacing between the apertures along each column is also the same.

[0080] Figure 6B It shows from Figure 6A The PSF of the mask layer is shown. Measurements were performed by guiding a collimated laser beam substantially perpendicular to the mask plane through the mask. The haze was measured as 1.7%, compared to... Figure 4A The mask layout shown is reduced by approximately 10% compared to the previous one. Furthermore, compared to... Figure 4B and Figure 4C Compared to the PSF shown, scattering along both the horizontal and vertical axes is reduced (i.e., directional scattering is reduced). Furthermore, there is more scattering in the vertical direction than in the horizontal direction. This is believed to be due to the elliptical shape of the aperture. The intensity of the PSF varies depending on the angle. Figure 6C The intensity diagram is shown, and with Figure 4C Compared to the intensity map, this demonstrates a reduction in large-angle scattering.

[0081] Non-linear holes can also be arranged in irregular patterns. For example, a mask can include elliptical and / or circular holes with different areas, ellipticity, and / or spacing. Figure 7A A photomicrograph of an example mask comprising an irregular array of elliptical apertures is shown. Here, each elliptical aperture in a row (in the horizontal direction) has the same vertical height, and each elliptical aperture in a column (in the vertical direction) has the same horizontal width.

[0082] Figure 7B It shows from Figure 7A The PSF of the mask layer is shown. Measurements are performed by guiding a collimated laser beam substantially perpendicular to the mask plane through the mask. Figure 6B Compared to the PSF shown, scattering at large angles is reduced. Furthermore, there is more scattering in the vertical direction than in the horizontal direction. The intensity of the PSF varies depending on the angle. Figure 7C The intensity diagram shows that, with Figure 4C Compared to the intensity map, this demonstrates a reduction in directional scattering and large-angle scattering.

[0083] Although Figure 2BThe low-density pixel arrangement shown is characterized by pixels separated from each other by a single array position in both the horizontal and vertical directions, but other arrangements are possible. For example, pixels can be separated by multiple array positions in either direction. Alternatively or additionally, pixels can be arranged in adjacent array positions to form pixel clusters. Typically, a low-density pixel region may include a regular arrangement of pixel clusters, where each cluster has the same pixel arrangement, or the pixel clusters may be different. A pixel cluster may include two, three, four, or more pixels. A pixel cluster may be square, rectangular, or other shapes. Figure 8A An example of a pixel arrangement including pixel clusters is shown. Here, each pixel cluster 810 includes four pixels 820a, 820b, 830a, and 830b arranged in a square. Figure 8B It shows a suitability for concealment Figure 8A The pixel cluster arrangement and the mask layer for the signal lines are shown. Figure 8C The PSF from this mask layer is shown.

[0084] In the previous example, each row and column of pixel clusters is connected by collinear horizontal and vertical signal lines. In other words, each pixel cluster in a row is connected by a horizontal signal line, with each horizontal signal line following a common horizontal line. Similarly, vertical signal lines along a common vertical line connect each pixel cluster in a column. This arrangement... Figure 8A The example is shown.

[0085] Figure 8B The image shows a suitable cover. Figure 8A The mask layer arranged in the middle consists of straight cross-shaped holes. Figure 8C The final PSF is shown.

[0086] However, other arrangements of the signal lines are also possible. For example, one or more signal lines linking pixel clusters can be in a column and / or a row, offset from the signal lines connecting adjacent pixel clusters. For example, see reference... Figure 9A In the example embodiment, the alternating vertical signal lines 920 are offset in the horizontal direction, causing a change in the horizontal distance between signal lines in adjacent columns. Similarly, the alternating horizontal signal lines 930 in a row are offset in the vertical direction, causing a change in the vertical distance between signal lines in adjacent rows.

[0087] Figure 9B It shows the applicable Figure 9A The mask layer 950 is arranged with pixels as shown. The mask layer 950 consists of rectangular holes arranged in rows and columns, wherein the orientation of adjacent holes is rotated at right angles relative to each other. Figure 9C A photograph showing the PSF of mask layer 950 is shown. Figure 9DAn intensity map of the PSF is shown. The PSF exhibits low light scattering in most directions away from the vertical and horizontal axes. Not wishing to be bound by theory, this is believed to be due to the mask shape being smaller than... Figure 8B The mask layer shown has fewer periodic inflection points.

[0088] Mask layers with non-linear apertures can also be used for masking. Figure 9A The circuit structure shown. For example. Figure 10A and Figure 10B An example of such a mask layer 1050 is shown, which consists of ellipses of similar size, wherein the alternating ellipses have major axes oriented horizontally (1010) and vertically (1020).

[0089] Figure 10C A PSF image of mask layer 1050 is shown. It is clear from the PSF that... Figure 8B and Figure 9B Compared to the mask layer shown, the mask layer reduces angular scattering to a greater extent.

[0090] refer to Figure 11A and Figure 11B The image shows a photomicrograph of another mask pattern 1150, in which, in some embodiments, elliptical and / or circular apertures may be used in conjunction with offset signal lines. Figure 11A A photomicrograph of mask pattern 1150 is shown. The scale in the lower right corner indicates 100 µm in both the horizontal and vertical directions. The elliptical apertures in mask 1150 are arranged aperiodically, and the spacing between adjacent apertures varies. The elliptical apertures are arranged such that their major axes extend vertically or horizontally. In both the vertical and horizontal directions...

[0091] Figure 11B It shows the relationship with Figure 11A The same photomicrographs, but with overlapping pixel clusters and signal lines. As shown, the size of the pixel clusters varies. For example, the smallest pixel cluster (e.g., 1151) consists of two pixels (each containing four sub-pixels), and the largest pixel cluster (e.g., 1152) contains eight pixels. Pixel clusters containing four pixels (e.g., 1153, 1154) form rectangles that extend vertically and horizontally. In this layout, pixel clusters are arranged in rows of constant vertical height (e.g., corresponding to one or two pixels) and columns of constant horizontal width (e.g., corresponding to one or two pixels). Other arrangements are also possible.

[0092] The bundled signal lines have different bundle widths and spacings in the horizontal and vertical directions. Each bundle of signal lines includes the signal lines required for the operation of the clustered pixels associated with the signal lines.

[0093] Figure 12The graph shows the transmitted signal intensity at diffraction angles for several different aperture arrangements, compared to a display without a mask layer. The vertical axis is logarithmic. It is clear from the graph that, compared to no mask layer, the number of cases where all mask layers scatter at angles of 20° or greater is significantly reduced. The number of cases scattering at smaller angles is also reduced, with the most significant reductions observed in mask layers with a regular array of circular apertures. Figure 7A The mask layer shown.

[0094] While some embodiments have been disclosed, other implementations are possible. For example, although the display panel described above is an OLED display, the principles disclosed herein can also be applied to other display technologies, such as microLED displays. Furthermore, the mask layer can be applied to a display characterized by multiple low-pixel-density regions. For example, when the device has more than one front-facing sensor behind the display, each sensor can be positioned behind a corresponding low-pixel-density region with a mask layer.

[0095] Other embodiments are described in the appended claims.

Claims

1. An apparatus including a display, comprising: A display panel, the display panel including a first pixel region having a first pixel density and a second pixel region having a second pixel density higher than the first pixel density, the display panel being configured to generate an image viewable from the front side of the display panel; as well as A sensor, located at the rear of the display, is arranged to receive incident light transmitted from the front of the display to the rear of the display through the first pixel region, wherein: The first pixel region includes light-emitting pixels and signal lines electrically connected to pixel circuitry associated with the light-emitting pixels, and The display panel includes a layer comprising a light-shielding material patterned to provide apertures in pixel-free and signal-line-free areas to transmit incident light between at least some of the light-emitting pixels and the signal lines and to block incident light from the pixel circuitry and the signal lines, wherein the light-shielding material is formed between the front side of the display and the first pixel area. The hole includes one or more first holes and one or more second holes, the one or more first holes having a first dimension in a first direction, and the one or more second holes having a second dimension in a second direction, wherein the first dimension is different from the second dimension. At least some of the holes are elliptical or circular, and the holes include elliptical holes with different degrees of ellipticity.

2. The apparatus of claim 1, wherein at least some of the light-emitting pixels are arranged in a pixel cluster.

3. The apparatus of claim 2, wherein the pixel cluster comprises two or more pixels.

4. The apparatus of claim 1, wherein the spacing between the light-emitting pixels varies in at least one direction.

5. The apparatus of claim 1, wherein the holes are arranged non-periodically in the first direction.

6. The apparatus of claim 1, wherein the first direction is a horizontal direction.

7. The apparatus of claim 6, wherein at least some of the holes have different dimensions in a vertical direction orthogonal to the horizontal direction.

8. The apparatus of claim 1, wherein the holes are arranged non-periodically in the second direction.

9. The apparatus of claim 1, wherein at least some of the holes are linear.

10. The apparatus of claim 1, wherein the hole comprises an elliptical hole or a circular hole of different sizes.

11. The apparatus of claim 1, wherein the first dimension and the second dimension are 50 µm or greater.

12. The apparatus of claim 1, wherein the sensor is a camera.

13. The apparatus of claim 1, wherein the apparatus is a smartphone or a tablet computer.

14. The apparatus of claim 1, wherein the display is an organic light-emitting diode (OLED) display.

15. The apparatus according to claim 1, wherein: The light-emitting pixels are arranged in a pixel cluster and the signal lines are electrically connected to the pixel circuitry associated with the pixel cluster. The light-shielding material is patterned to provide apertures to allow incident light between the pixel clusters and the signal lines to pass through and to block incident light from the pixel clusters and the signal lines. At least some of the holes are elliptical or circular.

16. The apparatus of claim 15, wherein each of the holes has the same size and shape.

17. The device of claim 15, wherein at least some of the holes have different sizes and / or shapes.

18. The apparatus according to claim 1, wherein: The light-emitting pixels are arranged in a pixel cluster and the signal lines are electrically connected to the pixel circuitry associated with the pixel cluster. The light-shielding material is patterned to provide apertures to allow incident light between the pixel clusters and the signal lines to pass through and to block incident light from the pixel clusters and the signal lines. The orifices are arranged in a non-periodic array and / or at least some of the orifices are elliptical and / or the orifices include different sizes and / or shapes such that they introduce a haze of less than 1.9% as measured using a method conforming to ASTM D1003.

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