EP4689774A1 - Display device and method to manufacture the display device - Google Patents

Display device and method to manufacture the display device

Info

Publication number
EP4689774A1
EP4689774A1 EP24714480.1A EP24714480A EP4689774A1 EP 4689774 A1 EP4689774 A1 EP 4689774A1 EP 24714480 A EP24714480 A EP 24714480A EP 4689774 A1 EP4689774 A1 EP 4689774A1
Authority
EP
European Patent Office
Prior art keywords
lenticular
display device
light emitting
aperture
emitting elements
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP24714480.1A
Other languages
German (de)
French (fr)
Inventor
Claude Tydtgat
Patrick Willem
Peru DHARANIPATHY
Artem SHCHEGLOV
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Barco NV
Original Assignee
Barco NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Barco NV filed Critical Barco NV
Publication of EP4689774A1 publication Critical patent/EP4689774A1/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B30/00—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images
    • G02B30/20—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images by providing first and second parallax images to an observer's left and right eyes
    • G02B30/26—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images by providing first and second parallax images to an observer's left and right eyes of the autostereoscopic type
    • G02B30/27—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images by providing first and second parallax images to an observer's left and right eyes of the autostereoscopic type involving lenticular arrays

Definitions

  • the invention relates to a display device and to a method to manufacture said display device.
  • lenticular sheets comprising parallel lenticulars or lenticular lenses are used to convert a 2D generated image into two pictures or more pictures to make multi-view, to enable 3D stereoscopic view.
  • the lenticular sheet faces a panel or substrate including a number of pixels of light separated by a pixel pitch.
  • a first example is a LCD or Liquid-Crystal Display as known by one skilled in the art.
  • the aperture ratio (or pixel aperture ratio) is high, generally higher than 90 %.
  • the aperture ratio can be defined as the ratio between the cumulated surface covered by the pixels of light and the total surface of the panel or substrate comprising said pixels of light.
  • LCDs it is possible to obtain a 3D display device by using a lenticular sheet facing the substrate or panel comprising the different pixels of lights.
  • the display device it is necessary to decrease the size of the pixels. Otherwise, the thickness of the lenticular sheet becomes too large.
  • the decrease of the size of the pixels leads to a strong decrease of the amount of light that is emitted. So, with LCDs, it is not possible to modify strongly the viewing distance, and in particular to increase it strongly.
  • Displays with a low aperture ratio exist, for instance with a aperture ratio less than 20% or even about 10% or less.
  • An example of such a display is a LED or Light-Emitting Diode display.
  • LED displays have some advantages with respect to LCDs, notably they present higher contrast. Moreover, larger viewing distance are possible with LED displays or displays with a low aperture ratio in general.
  • other problems arise when one uses a display with a low aperture ratio.
  • a major problem is that the view cone for each eye is only partially filled with such sources of light. In particular, there is typically much space between the different light emitting regions and only in a very small region the eyes with observe some light. In other words, it is hard to position exactly so that both eyes observe effectively the left and right images.
  • Inter Pupil Distance the distance between the two eyes
  • the distance between the two eyes is on average 65 mm, and varies from one user to another.
  • Inter Pupil Distance the distance between the two eyes
  • the approach used with the LCDs for designing a lenticular sheet is not applicable in the case of a display with a low aperture ratio such as a LED display. Otherwise, one has the problem of view cones only partially filled as described above.
  • lenticular thickness is proportional to the optimum viewing distance and to the display pixel pitch, this is, if one follows the classical approach for designing a lenticular sheet.
  • the pixel pitch can be quite large, for instance close to 1 mm.
  • a thickness that can be higher than 10 mm or even higher than 15 mm, whereas a thickness of about 1 -5 mm is rather wanted.
  • the typical viewing distance for LED displays is larger than for LCDs, again increasing the required lenticular thickness.
  • a thickness larger than 10 mm would result when using the state of the art. This leads to too heavy screens and can result in manufacturing difficulties. For instance, manufacturing a thick (> 10 mm) lenticular with a rol l-to-roll process is impossible requiring extra intermediate spacing layers. These extra production steps increase the risk of failures. So, it is better to have a thinner lenticular sheet.
  • An object of the invention is to provide an efficient multi-view display device presenting a low aperture ratio (or low pixel aperture ratio).
  • the invention relates to a display device comprising : a panel comprising a plurality of light emitting elements, the light emitting elements having an emitting aperture of size A along one direction D; a lenticular sheet facing the panel, the lenticular sheet comprising an array of lenticulars defined by a lenticular pitch LP along same direction D, the lenticular pitch LP being a multiple larger than 1 of the size A of the aperture, each lenticular facing a number of N zones of the panel, said N zones corresponding to N different possible views of said display device, the number N being larger than 1 , the lenticular sheet is facing at least two zones corresponding to an aperture position.
  • the zones of the panel facing it are free of any aperture.
  • the zones of the panel without or free of any aperture could be named empty regions or non-active pixels.
  • the panel comprises active pixels corresponding to positions where there are some apertures and light emitting elements able to emit light through said apertures, and non-active pixels corresponding to positions where there is no aperture and no related light emitting element.
  • the zones free of any aperture can be used to place various elements or components such as for instance electronic components (for instance a LED driver or any other driver chip).
  • These empty zones can also be used to assemble electronical components, mechanical components and/or optical components. So, with the invention, it is possible to put electronics on the front side of the panel, leading to an easier way for connecting all the components. It is another advantage with respect to LCD where electronics is put on a back side generally.
  • each lenticular of the lenticular sheet some zones of the panel facing said each lenticular are free of any aperture. Then, there is still more possibilities and flexibilities for placing electronic components and making connections on the front side of the panel.
  • all of the zones along direction D’ of the panel are free of any aperture.
  • This aperture free lenticular enables to assemble two adjacent tiles at said location without deteriorating the optical quality of the display device.
  • the arrangement of aperture free zones and occupied zones along direction D follows a periodic pattern such that there exists at least one lenticular with aperture-free zones along the direction D’.
  • the lenticular pitch LP is defined or determined from the size A of the emitting aperture. More precisely, the lenticular pitch is a multiple of that size A, said multiple being not necessarily an integer, but defined depending on the application setup. So, in the invention, the lenticular pitch is not defined from the pixel pitch (pp) which represents the distance between each light emitting element. In particular, the lenticular pitch is not a multiple of the pixel pitch.
  • the pixel aperture ratio is defined as the ratio between the cumulated surface covered by the pixels of light and the total surface of the panel or substrate comprising said pixels of light.
  • the pixel aperture ratio can be defined as the ratio between the cumulated surface of the apertures and the total surface of the panel.
  • a low pixel aperture ratio means lower than 20%, preferably lower than 15 %, and still more preferably lower than 10%.
  • the dimension used for determining the thickness of the lenticular sheet is no longer the pixel pitch pp, but rather the size A of the aperture, or a value of the order of A.
  • the thickness of the lenticular will be much smaller and acceptable. For instance, a thickness between 1 and 5 mm for the lenticular sheet is possible.
  • the display device of the invention if one increases the number of views, the lenticular pitch LP increases, but not the thickness of the lenticular sheet. In addition, a smaller thickness of the lenticular sheet leads to a lighter display device.
  • the panel comprising the different light emitting elements is planar. Then, the direction D is parallel to that planar panel. With the display device of the invention, one could also say that the panel comprises apertures of size A through which the light emitting elements can emit light. Preferably, A is constant or equal for all the apertures.
  • the lenticular sheet comprises a plurality of lenticulars or lenticular lenses. These terms are known by one skilled in the art.
  • Each lenticular is collimating light coming from each point of the aperture towards the viewer.
  • the lenticulars may form a periodic array, but this is not necessary.
  • the lenticular pitch is the width of a lenticular.
  • the lenticular pitch is the same or constant for all the lenticulars.
  • the lenticular pitch is also the distance between the centers of each adjacent lenticular.
  • a light emitting element can be e.g., a solid-state light emitting element, such as a light emitting diode (LED), an OLED, Quantum Dot Light Emitting Diodes (QD- LED), EL-QLED, AMOLED, mini-LED, micro-LED.
  • the light emitting elements are any one of LEDs, OLED, and variations thereof, QD-LED, EL-QLED, AMOLED, mini-LED, micro-LED.
  • the invention is not limited to a particular type of light emitting element, such as LED, and the advantages provided can be beneficial to any type of light emitting element, such as for LCD.
  • the light emitting elements are provided with quantum dots to generate the different colors of emission.
  • Quantum dots have the advantage of improving the brightness of a display and can also improve the color points.
  • the light emitting elements may be discrete (or punctual) light emitting elements.
  • the light emitting elements may be continuous light emitting elements.
  • the light emitting element may have an RGB structure.
  • the display of the invention comprising such light emitting elements can be named as a low aperture ratio display device.
  • the lenticular sheet is facing at least two zones corresponding to an aperture position.
  • the lenticular sheet as a whole is facing said at least two zones, i.e. , the same lenticular is facing said at least two zones or different lenticulars are facing respectively at least two zones.
  • the lenticular sheet is facing at least two zones each corresponding to a possible aperture position.
  • each lenticular faces a number of N zones of the panel.
  • the number N is larger than 1 , meaning that more than one zone is facing a given lenticular.
  • a given lenticular is facing more than one possible view.
  • the magnitude of the lenticular pitch LP can vary between 10 pm to 5 mm, even if other values are possible.
  • the lenticular pitch LP is between 1 pm and 2000pm, preferably between 80pm and 1200pm, preferably between 160pm and 600pm.
  • This magnitude allows that the light emitting elements generating the different views are shared amongst several lenticulars. In other words, this results in a small lenticular pitch resulting into shared views of the light emitting elements amongst several lenticulars.
  • the lenticular pitch LP depends on the size A of the apertures and the number N of zones of the panel corresponding to the number of views of the display device.
  • Each of the N zones of the panel has an extension of approximatively A along the direction, or each of the N zones of the panel has an extension A along the direction D.
  • Each of the N zones has an extension of less than 1 .3* A.
  • A is constant or equal for the different zones of the panel facing one lenticular.
  • the N zones correspond to N different possible views of the display device.
  • each one of the N zones of the panel has a fixed corresponding position along the direction D with respect to a lenticular of the lenticular sheet.
  • N is comprised between 2 and 200.
  • the size of the apertures can be small, while keeping high contrasts possible. Small means lower than 300 pm for instance, or still lower.
  • By reducing the size of the aperture it is possible to increase the number N of views of the display device without increasing too much the lenticular pitch LP.
  • N may be between 2 and 50.
  • N can be between 2 and 12.
  • some light emitting elements are adjacent to each other, at least two adjacent light emitting elements are on a matrix. Accordingly, multi-aperture components having at least two adjacent light emitting elements are formed. This enables to have several light emitting elements touching each other being reduced in size, and as such make different views. This makes it possible to reduce the size A of the emitting aperture of the respective light emitting elements, for instance below 10pm, for instance of 8pm. For instance, it is possible to have 40 apertures of 8 pm, that equals 320 pm total aperture per multi-aperture component. So this enables many views. Therefore, the aforementioned advantages of small size A apply here. Multi-aperture components make it possible to adapt the size A of the emitting aperture.
  • a distance between centers of each aperture along said direction D is larger than the size A of each aperture along said direction D. According, to this possible embodiment, there are no adjacent active pixels or no adjacent apertures.
  • some apertures are adjacent to each other so that a minimal distance along said direction D between their centers is substantially equal to the size A of each aperture, said adjacent apertures forming groups of apertures, said groups of apertures being separated by a distance larger than the size A along said direction D.
  • a whole space of the panel facing one lenticular is free of any aperture. So, according to that possible embodiment, a whole region or space of the panel facing one lenticular has no aperture. In other words, according to this embodiment, there is no active pixels under one lenticular in that case. It generates higher order views. Indeed, under higher angles views are repeated as light can pass from a certain pixel through an adjacent lenticular and even further through a next adjacent one. However, if the generation of higher order views is not desired, one can remove this lenticular. For instance, this specific lenticular can be made flat and/or can be covered with an absorbing coating.
  • said whole space free of any aperture comprises a camera and/or a sensor and/or an electrode and/or a LED driver.
  • each lenticular faces maximum one aperture. This possible embodiment takes full advantages of the shares of views between different lenticulars.
  • the apertures are separated by a constant pixel pitch pp that is larger than the lenticular pitch LP.
  • the light emitting elements are solid-state light emitting elements chosen in the group comprising a light emitting diode (LED), an OLED, Quantum Dot Light Emitting Diodes (QD-LED), EL-QLED, AMOLED, miniLED, micro-LED. So, the invention can be implemented with various examples of light emitting elements.
  • the panels comprising such light emitting elements generally have a low pixel aperture ratio, for instance lower than 20%, or even lower than 10%.
  • the lenticular sheet is asymmetric or symmetric with respect to the array of lenticulars. It is not necessary to have a perfectly symmetric lenticular sheet for the display device of the invention.
  • two or more lenticulars are adjacent, each separated by a lenticular pitch, and this group of lenticulars is separated by another group of lenticular by a flat region or non-active region of the lenticular sheet. Having such flat or non-active regions can present some interest.
  • the display device being a low aperture ratio display device.
  • d n.
  • A.L/VCW where n is a refractive index of a lenticular material of the lenticular sheet
  • VCW is the view cone width at the observer position.
  • said thickness d is defined as a distance between a top surface of one lenticular and the top surface of the panel; then d includes possible thicknesses of glue and/or spacing layers.
  • the observation distance L is for instance comprised between 500 and 3000mm. Preferably, it is between 600 and 900mm.
  • the view cone width at the observer position, VCW can vary from one user to another.
  • VCW is preferably between 21 mm and 65mm (which corresponds to the average interpupil distance of human being).
  • d n. .L/VCW
  • the thickness d is lower. For instance a thickness between 1 and 4 mm is possible. This allows having a display device whose weight is acceptable.
  • the invention relates to a method to design or manufacture a display device
  • the lenticulars from a multiplicity of sets of at least two lenticulars, N lighting elements being spread over a set of lenticulars such that a lenticular set is facing a total of N light emitting elements at the N possible positions, and wherein the arrangement of the N lighting elements under the set of P lenticulars forms a first structure.
  • the sets of lenticulars form a periodicity.
  • the periodicity of the set of lenticulars is related to a row of light emitting elements or is related to a set of rows of light emitting elements.
  • all of the zones along direction D’ of the panel are free of any aperture.
  • the lenticular can be flat, there can be no lenticular at said location, or it can be replaced or provided with a coating, such as an absorbing coating.
  • P>N or wherein P>N. If P N, then there is the same number of light emitting elements as lenticulars. Thus there is at least one light emitting element per lenticular. If P>N, there is at least one lenticular free of aperture.
  • the first structure is replicated in consecutive rows to provide P populated rows. This ensures consistency and uniform light distribution across the display, enhancing visual appeal and simplifying production. This approach also optimizes panel integrity and facilitates cost-effective manufacturing.
  • the first structure is replicated in consecutive columns.
  • the first structure is replicated in consecutive rows, by permutating or rearranging the light emitting elements in the first structure, in consecutive rows to provide P populated rows, resulting in a second structure.
  • the first structure is replicated in consecutive columns, by permutating or rearranging the light emitting elements of the first structure, in consecutive columns to provide a second structure.
  • the second structure is repeated in consecutive rows and/or columns, by permutating or rearranging the light emitting elements of the second structure, and provide a third structure.
  • the different structures obtained by permutation ensure a display with a uniform distribution but a reduced regularity in order to reduce Moire effects.
  • digital processing techniques can be used to detect and remove the interfering patterns causing the eventual moire effect. This can be achieved using algorithms that analyze the distribution of the lighting elements and compute a new distribution, to selectively remove or replace the unwanted patterns, while obeying to some design specifications.
  • the light emitting elements are arranged in rows and columns ensuring a substantially constant spacing between light emitting elements, or a spacing adapted to the aspect-ratio to be provided by the display.
  • Reduced Moire Effects Introducing variability in the arrangement of the lightemitting elements helps to reduce the occurrence of Moire effects, which are unwanted interference patterns that can appear when two similar, overlapping patterns interact.
  • Enhanced Optical Quality By avoiding a completely regular and repetitive pattern, the optical quality of the display can be enhanced, as regular patterns can sometimes lead to visual artifacts or distortions.
  • Permutating or rearranging the light-emitting elements allows for greater flexibility in design and customization of the display, accommodating different panel sizes, resolutions, and viewing angles.
  • This approach enables the adaptation of the display to specific panel requirements and constraints, optimizing the distribution of light-emitting elements based on the panel's characteristics and performance criteria. A more uniform, visually appealing, and high-quality display while minimizing unwanted visual artifacts such as Moire effects can be achieved.
  • the invention also relates to a method to manufacture the display device as described above, and comprising the following steps: providing a panel comprising a plurality of light emitting elements , said panel comprising apertures of size A along a direction D and through which the light emitting elements can emit light; providing a lenticular sheet comprising a plurality of lenticulars each having a lenticular pitch LP, said width LP being a multiple larger than 1 of said size A; placing the lenticular sheet such that it faces the panel and such that each lenticular is facing a number of N zones of the panel, said N zones corresponding to N different possible views of said display device, the number N being larger than 1 , the lenticular sheet is facing at least two zones corresponding to a aperture position, and wherein for at least one lenticular, some of the zones of the panel along a direction D’, perpendicular to direction D facing it are free of any aperture, wherein the zones free of any aperture follow a periodic pattern or uniform distribution along direction D.
  • N is the ratio between LP and A rounded to the nearest integer.
  • d n.
  • VCW is the view cone width at the observer position.
  • the panel comprises tiles assembled together.
  • the lenticulars from a multiplicity of sets of at least two lenticulars, N lighting elements being spread over a set of lenticulars such that a lenticular set is facing a total of N light emitting elements at the N possible positions.
  • the sets of lenticulars form a periodicity.
  • the periodicity of the set of lenticulars is related to a row of light emitting elements or is related to a set of rows of light emitting elements.
  • the thickness d is defined as a distance between a top surface of one lenticular and the top surface of the panel; then d includes possible thicknesses of glue and/or spacing layers.
  • the invention also relates to a panel for a display device according to the invention, comprising tiles assembled together.
  • the panel for the display device according to the invention comprises at least a set of identical tiles, or a plurality of sets of identical tiles.
  • a tile for a panel comprises at least a first row of N lighting elements, the N lighting elements being configured to be spread over a set of P lenticulars such that a lenticular set is facing a total of N light emitting elements at the N possible positions, and wherein the arrangement of the N lighting elements under the set of P lenticulars forms a first structure.
  • the lighting elements are configured to provide for at least one lenticular of the P lenticulars all of the zones along direction D’ of the panel free of any aperture. This ensures that the edges of the individual tiles can be provided at the locations where in the assembled display device there will be a lenticular free of any aperture.
  • the first structure is replicated in consecutive rows to provide P populated rows.
  • the first structure is replicated in consecutive columns. This maintains uniformity and visual appeal.
  • the first structure is replicated in consecutive rows, by permutating or rearranging the light emitting elements in the first structure, in consecutive rows to provide P populated rows, resulting in a second block structure.
  • the first structure is replicated in consecutive columns, by permutating or rearranging the light emitting elements of the first structure, in consecutive columns.
  • the second structure is repeated in consecutive rows and/or columns, by permutating or rearranging the light emitting elements of the second block structure, resulting in a third block structure.
  • a tile comprises at least one of a second block structure, a third block structure or a plurality of block structures being permutations or rearrangements of one another, the arrangement of the block structures determining a set of identical tiles.
  • lenticular having no apertures.
  • the light emitting elements are arranged in rows and columns ensuring a substantially constant spacing between light emitting elements, or a spacing adapted to the aperture ratio to be provided by the display.
  • an absorption layer is provided at the edges of the tile. This reduces edge reflections and improves display contrast and clarity.
  • FIG. 1 schematically illustrates a possible embodiment of the display device of the invention
  • FIG. 5 schematically illustrates a panel of the display device of the invention
  • FIG. 8 schematically illustrates a panel of the display device of the invention.
  • the drawings in the figures are not scaled. Similar elements can be assigned by similar references in the figures. In the framework of the present document, identical or analogous elements may have the same references. The presence of reference numbers in the drawings cannot be considered to be limiting, in particular if these numbers are indicated in the claims.
  • the terms "about” or “approximate” and the like are synonymous and are used to indicate that the value modified by the term has an understood range associated with it, where the range can be +20%, +15%, +10%, +5%, or +1 %.
  • the term “substantially” is used to indicate that a result (e.g., measurement value) is close to a targeted value, where close can mean, for example, the result is within 80% of the value, within 90% of the value, within 95% of the value, or within 99% of the value.
  • Lenticular refers to an optical element commonly known as a lenticular lens. It possesses a cylindrical shape and functions to manipulate light. Each lenticular lens has a curved surface, usually forming a portion of a cylinder. These lenses are utilized to create visual effects such as depth, motion, or the display of multiple images contingent on the viewing angle.
  • a lenticular sheet is an assembly comprising an array of lenticulars (or lenticular lenses). This sheet is positioned facing a panel. Each lenticular within the lenticular sheet consists of a cylindrical lens. The lenticular sheet facilitates the manipulation of light and visual effects, with each lenticular lens redirecting light in a particular direction.
  • the width of each lenticular along a specified direction (denoted as D) is termed as the lenticular pitch (LP).
  • each lenticular lens can have a variety of shapes, such as cylindrical or aspheric, or any optical shape known to the skilled person, such as an elliptic shape, parabolic shape, etc., depending on the specific design requirements and optical characteristics desired for the application.
  • Vertical Axis D When viewing the lenticular sheet from the side, the vertical axis corresponds to the direction of the cylindrical lenses or lenticular’s curvature.
  • Horizontal Axis D Perpendicular to the vertical axis, the horizontal axis is the direction in which the viewer's perspective changes, causing different images or effects to be visible depending on the viewing angle.
  • the figures schematically illustrate possible embodiments of the display device 1 of the invention. It comprises a panel 5 comprising a plurality of light emitting elements 10.
  • the panel 5 is configured such that said light emitting elements 10 have respectively an emitting aperture 11.
  • a circle depicts the aperture 11 , but the form of the aperture 11 is not necessarily a circle.
  • the panel 5 comprises such apertures 11 .
  • the size of the aperture 11 is equal to A.
  • Different values of A are possible. For instance, A is lower than 300pm or even lower than 200pm or even lower than 100pm.
  • A is comprised between 4pm and 300pm, and preferably between 10pm and 200pm. However, other values, for instance larger than 300pm are possible.
  • the figures illustrate a number of N zones 51 , 52, 53, 54, 55, 56, 57, 58, etc. of the panel 5.
  • Said N zones 51 , 52, 53, 54, 55, 56, 57, 58, etc. correspond to N different possible views of said display device 1 .
  • Zone 51 corresponds to view 1
  • zone 52 corresponds to view 2, etc.
  • Each one of the N zones - and corresponding view - has a fixed position along said direction D with respect to a lenticular 21 of the lenticular sheet.
  • the figures illustrate arrays of zones and light emitting element positions (and respective aperture position). In other words, the figures illustrate row(s) and column(s) of zones and light emitting element positions (and respective aperture position).
  • a lenticular sheet 20 faces the panel 5.
  • This lenticular sheet 20 comprises an array of lenticulars 21 (or lenticular lenses 21 ).
  • the lenticular sheet 20 comprises a number of lenticulars 21.
  • the top surface of each lenticular 21 can follow a cylindrical or aspheric shape.
  • the width of each lenticular 21 along direction D is named lenticular pitch LP.
  • LP is a multiple larger than 1 of A, but that multiple is not necessarily an integer.
  • a given lenticular covers more than one aperture.
  • the lenticular pitch LP is equal to two times A.
  • the lenticular sheet 20 faces the panel 5, with the curvature of the lenticulars 21 facing the panel.
  • the lenticulars 21 have a curvature in direction D and extend in a direction D’ perpendicular to D.
  • the lenticulars 21 are depicted in cross section above the row of light emitting element 10 to simplify the figures.
  • each lenticular 21 faces more than one zone, each zone corresponding to a position with respect to a given lenticular. Each zone corresponds to a position with respect to a lenticular, starting from an edge of the lenticular.
  • the light emitting elements are arranged in rows and columns.
  • a single row of light emitting elements is represented.
  • both the rows and columns are represented.
  • each lenticular 21 faces two zones 51 , 52 of the panel 5. And each zone 51 , 52 has a width equal to A along D. Each zone occupies a position with respect to the same lenticular facing the panel 5.
  • the example of figure 1 is a two-view display device 1 .
  • a display device 1 it is possible to have filled view cones, for instance at a viewing distance of 600 mm.
  • A 0.1875 mm
  • a viewing distance of 600 mm With an VCW parameter equal to 65 mm, the thickness of the lenticular sheet 20 is equal to 2.66 mm which is acceptable.
  • FIG. 2 schematically illustrates another possible embodiment of the display device 1 of the invention.
  • the lenticular pitch LP is equal to four times A.
  • each lenticular 21 faces four zones 51 , 52, 53, 54 of the panel 5.
  • each zone 51 , 52, 53, 54 has a width equal to A along D.
  • Each zone occupies a position with respect to the same lenticular facing the panel 5.
  • These zones 53, 54 can be referred to as aperture-free zones.
  • the next lenticular 21 has a non-active pixel (or black pixel or no aperture) at a first zone 51 followed by a aperture 11 or active pixel at a second zone 52 followed by a non-active pixel (or black pixel or no aperture) at a third zone 53 and at a fourth zone 54.
  • the next lenticular 21 has a non-active pixel (or black pixel or no aperture) at a first zone 51 and at a second zone 52 followed by an aperture 11 or active pixel at a third zone 53 followed by a non-active pixel (or black pixel or no aperture) at a fourth zone 54.
  • the next lenticular 21 has a non-active pixel (or black pixel or no aperture) at a first zone 51 , at a second zone 52 and at a third zone 53 followed by an aperture 11 or active pixel at a fourth zone 54.
  • the structure (or pattern) is repeated, signifying that these aperture-free zones showcase either a periodic pattern or a uniform distribution across the entire display.
  • FIG. 3 schematically illustrates another possible embodiment of the display device 1 of the invention.
  • the lenticular pitch LP is equal to eight times A.
  • each lenticular 21 faces eight zones 51 to 58 of the panel 5.
  • each zone 51 to 58 has a width equal to A along D.
  • Each zone occupies a position with respect to the same lenticular facing the panel 5.
  • lenticular 21 there is one active pixel at a first zone 51 , at a second zone 52, at a third zone 53 and at a fourth zone 54 and a non-active pixel (or black pixel or no aperture) at a fifth zone 55, at a sixth zone 56, at a seventh zone 57 and at a eighth zone 58.
  • the next lenticular 21 has a non-active pixel (or black pixel or no aperture) at a first zone 51 , at a second zone 52, at a third zone 53 and at a fourth zone 54 followed by an aperture 11 or active pixel at a fifth zone 55, at a sixth zone 56, at a seventh zone 57 and at a eighth zone 58.
  • a lenticular 21 facing non-active pixel (or black pixel or no aperture) there is a lenticular 21 facing non-active pixel (or black pixel or no aperture).
  • the structure (or pattern) is repeated; signifying that these aperture-free zones showcase either a periodic pattern or a uniform distribution across the entire display.
  • FIG. 4 schematically illustrates another possible embodiment of the display device 1 of the invention.
  • the lenticular pitch LP is equal to six times A.
  • each lenticular 21 faces six zones 51 , 52, 53, 54, 55, 56 of the panel 5.
  • each zone 51 to 56 has a width equal to A along D.
  • Each zone occupies a position with respect to the same lenticular facing the panel 5.
  • lenticular 21 there is one active pixel at a first zone 51 , at a second zone 52, at a fourth zone 54 and at a sixth zone 56 and a non-active pixel (or black pixel or no aperture) at a third zone 53 and at a fifth zone 55. Then moving further to the right, the next lenticular 21 has a nonactive pixel (or black pixel or no aperture) at a first zone 51 , at a second zone 52, at a fourth zone 54 and at a sixth zone 56 and an aperture 11 or active pixel at a third zone 53 and at a fifth zone 55. Then the structure (or pattern) is repeated.
  • Figure 5 schematically illustrates a panel 5 of the display device of the invention.
  • Figure 5 is according to the view of a user toward the display device.
  • Apertures 11 are visible with a size A.
  • the size A may be as mentioned above.
  • the geometric shape of the apertures 11 is not limited.
  • an aperture 11 may be a square, with an edge of the size A. It can be a rectangle; in that case, the width of the size A in the direction D is lower than the length in the direction transverse to the direction D (in the plan of the aperture in the panel 5).
  • a pixel pitch pp is depicted. With respect to the size A of an aperture, the pixel pitch pp size is much higher.
  • the aperture size is well below the pixel pitch.
  • the lenticular pitch LP is small, and possibly defined or determined from the size A of the aperture, the light emitting elements generating the different views are shared amongst several lenticulars. Also, since the dimension used in the present invention for determining the thickness of the lenticular sheet is the size A of the aperture, or a value of the order of A, the thickness of the lenticular sheet can be much smaller and acceptable.
  • Figure 5 shows groups of apertures 11 as an example, but the apertures on figure 5 may be depicted as on the other figures, such as continuously spaced apart, like on figure 1 .
  • Figure 6 schematically illustrates a panel 5 of the display device of the invention.
  • Figure 6 corresponds to the embodiment of figure 2 (the same description applies mutatis mutandis to the other embodiments).
  • Figure 6 depicts the panel 5 both in direction D and in a direction D’ perpendicular to D.
  • Figure 6 illustrates how the structure (or pattern) of active pixels and non-active pixels is repeated according to a row in the direction D and how the structure (or pattern) of active pixels and non-active pixels is repeated in direction D’ in column.
  • direction D the same structure is repeated as explained with respect to figure 2.
  • direction D’ the active pixels of a given zone are repeated in column.
  • the active pixels at the first zone 51 are repeated in column - the same other active pixels at the second zone 52, at the third zone 53 and at the fourth zone 54. All of the rows of active pixels start with the same zone (first zone 51 in the example of figure 6 - but it could be another zone at first). Thus, the active pixels of a given zone are aligned in column.
  • the embodiment of figure 6 makes it possible to obtain a “vertical” spacing (in direction D’) between the active pixels of a given zone being much smaller than the “horizontal” spacing (in Direction D). This is a possible way of increasing resolution of the display device 1 vertically, in the direction D’.
  • Figure 7 schematically illustrates a panel 5 of the display device of the invention.
  • Figure 7 depicts the panel 5 both in direction D and in a direction D’ perpendicular to D.
  • Figure 7 illustrates how the structure of active pixels and non- active pixels is repeated according to a row in the direction D and how the structure of active pixels and non-active pixels is repeated in direction D’ in column.
  • direction D the same structure is repeated similarly to the explanation of figure 2. More precisely, the series of zones populated or not by a light emitting element is repeated, but the space between the active pixels and non-active pixel is not repeated.
  • direction D’ the active pixels of a given zone are shifted towards the direction D (or opposite to direction D). For example, the active pixel corresponding to zone 51 illustrates the shift.
  • the active pixels of a given zones are disposed somehow in diagonal.
  • the active pixels of the first zone 51 are shifted in the direction D from one line to another - the same of the other active pixels at the second zone 52, at the third zone 53 and at the fourth zone 54.
  • the active pixels of a given zone are shifted in direction D from one row of pixels to another.
  • the embodiment of figure 7 makes it possible to obtain a better distribution per view.
  • the active pixels of the respective view are more uniformly spread. This is a possible way to avoid the moire effect and to have a better visual effect.
  • the embodiment of figure 7 avoids slanting the lenticular.
  • Figure 7 shows a “re-arrangement” of pixels whereas figure 6 shows how the pixels are disposed without “re-arrangement”.
  • the figures are only to be construed as possible examples of pixel arrangement for a particular number of views.
  • each lenticular 21 faces a number of N possible positions of the light emitting elements 10 (with a respective aperture) corresponding to N different possible views.
  • the lenticulars 21 form a multiplicity of sets of P lenticulars 21 , P being at least two.
  • a lenticular set is facing at least a total of N light emitting elements 10 at the N possible positions.
  • each lenticular 21 of a given set does not face N light emitting elements (or active pixels).
  • a lenticular 21 facing N zones is facing less than N light emitting elements 10 (and less than N aperture positions).
  • a lenticular of the set may even face no light emitting elements 10.
  • the N light emitting elements (and related apertures) corresponding to the N zones are spread among a set of at least two lenticulars.
  • the lenticular set is then the basic building element of the display device is repeated over the whole display device 1 .
  • the sets of lenticulars form a periodicity.
  • the lenticulars are divided in the multiple sets of P lenticulars, so that a light emitting element (and respective aperture) in a row is located in each position of the zone in a given set with respect to the nearest left lenticular edge.
  • the lenticulars 21 are spread with a periodicity along the direction D.
  • FIG 1 there is a periodicity of a set of five lenticulars facing two zones. Two lenticulars of the set of lenticulars are each facing a respective zone populated with a light emitting element (active pixel) and three lenticulars of the set is not facing any light emitting element (non-active pixel). Among one set of lenticulars, one lenticular is facing zone 51 populated with a light emitting element, one lenticular is facing zone 52 populated with a light emitting element and three lenticulars are facing no light emitting element. The set of lenticulars may be repeated in an adjacent way or not.
  • FIG. 2 and 6 there is a periodicity of a set of five lenticulars facing four zones.
  • Four lenticulars of the set of lenticulars are each facing a respective zone populated with a light emitting element (active pixel) and one lenticular of the set is not facing any light emitting element (non-active pixel).
  • one lenticular is facing zone 51 populated with a light emitting element
  • one lenticular is facing zone 52 populated with a light emitting element
  • one lenticular is facing zone 53 populated with a light emitting element
  • one lenticular is facing zone 54 populated with a light emitting element
  • one lenticular is facing no light emitting element.
  • the set of lenticulars may be repeated in an adjacent way or not.
  • FIG 3 there is a periodicity of three lenticulars, facing eight zones.
  • Two lenticulars of the set of lenticulars are each facing four respective zones populated with a light emitting element (active pixel) and one lenticular of the set is not facing any light emitting element (non-active pixel).
  • one lenticular is facing zones 51 -54 populated with a light emitting element
  • one lenticular is facing zones 55-58 populated with a light emitting element
  • one lenticular is facing no light emitting element.
  • the set of lenticulars may be repeated in an adjacent way or not.
  • One lenticular of the set of lenticulars is facing four respective zones populated with a light emitting element (active pixel) and one lenticular of the set is facing two respective zones populated with a light emitting element (active pixel).
  • one lenticular is facing zones 51 , 52, 54, 56 populated with a light emitting element and one lenticular is facing zones 53, 55 populated with a light emitting element.
  • the set of lenticulars may be repeated in an adjacent way or not.
  • the lenticulars of the set of lenticulars are each facing a zone populated with a light emitting element (active pixel). These lenticulars are facing all four zones 51 -54 populated in each row by a light emitting element (active pixel). Other lenticulars of the set are not facing any light emitting element (nonactive pixel).
  • active pixel a light emitting element
  • Other lenticulars of the set are not facing any light emitting element (nonactive pixel).
  • the active pixels of a given zone are shifted towards the direction D (or opposite to direction D).
  • a gap 28 may be positioned after group B. Then the set of lenticulars and the set of rows are repeated in directions D and D’, in an adjacent way or not.
  • the advantage of figure 7 is that the resolution loss in the horizontal direction (direction D) is evenly spread over horizontal (direction D) and vertical direction (direction D').
  • the light emitting elements under each set of lenticulars are positioned so that all possible positions with respect to the lenticular pitch, are populated.
  • a minimum number of at least two lenticulars is present in a set so that all light emitting elements under this set of lenticulars contribute to all views.
  • the result is that non light-emitting regions become available under the lenticulars which enable “blind” lenticulars allowing to tile different display panels, adding electronics (or other functionalities) in these space regions, 3D is still working.
  • the display device (1 ) is designed with a sophisticated structural arrangement to optimize its visual output and quality:
  • the first structure can be replicated in consecutive rows to produce P populated rows, enhancing the display's uniformity and brightness.
  • the first structure can be replicated in consecutive columns, ensuring a consistent and appealing visual presentation across the display.
  • the first structure can also be replicated in consecutive rows, with light emitting elements permutated within each row. This permutation results in a second structure, introducing variability and reducing visual artifacts for improved display quality. This is illustrated in figure 7.
  • the first structure is replicated in consecutive columns with permutated light emitting elements, resulting in a second structure. This approach further enhances optical quality and reduces regularity, as illustrated in figure 7.
  • the second structure is further repeated in consecutive rows and/or columns by permutating or rearranging the light emitting elements, leading to a third structure. This repetition and permutation maintain display uniformity while minimizing irregularities.
  • a tile may consist of multiple unique structures, or each tile may possess its own distinct structure, leading to diverse sets of identical tiles. These tiles are separated at an aperture-free lenticular, located at space 28, between two adjacent tiles.
  • the display device ensures that the light emitting elements are meticulously arranged in rows and columns, maintaining a consistent spacing between them or adapting to the display's aspect ratio. This meticulous arrangement optimizes light distribution and enhances overall display quality.
  • the display device 1 of the invention solves the problem of low fill factor and still has pixels in focus resulting in uniformly filled view cones (what enhance the 3D view quality, although users have different view cone width VCW) and feasible lenticular thicknesses. The smaller the width of the view cones, the more views are needed to fill-up the space in which the user still experiences a good 3D quality.
  • the advantage is that the user has a good 3D experience when his eyes move from one view cone to another because of a smooth transition between cones.
  • a super-stereo display increases the quality of the 3D impression, even closer to reality.
  • the embodiment of figure 8 is especially useful to generate super-stereo-displays.
  • Non-active pixels i.e., a lenticular 21 a facing only non-active pixels (such a lenticular can be flat - such as the dotted lines represented on the figures - and/or can be covered with an absorbing coating) as well as lenticular sections facing some pixels being non-active pixels
  • Such spaces help in the generation of higher order views. Indeed, under higher angles views are repeated as light can pass from a certain pixel through an adjacent lenticular and even further through a next adjacent one.
  • These spaces can thus be used to add one or more extra functionalities to the display like one or more functionalities among for instance: sensors (humidity, environmental light, adjustment of brightness, etc.), touch (capacitive), top electrodes for power distribution, optical high-speed link, in-cell camera, black (to enhance contrast) or background picture, transparency, hiding seams in tile-able displays (free format direct view displays, not restricted to video aspect ratio’s), extra space between light emitting elements or groups of light emitting elements can be generated to assemble electronical (high speed signaling, leddrivers, ...), mechanical (lamination spacers) or optical (high speed optical links, sensors, etc.), etc.
  • These spaces enable also tilable multiview display according to the invention.
  • these spaces facilitate the assembly of panel 5 by seamlessly interlocking individual tiles. This eases the manufacture of the display into tiles.
  • a lenticular 21 a facing a space 28 with non-active pixels. This space 28 may be the tile boundary. Because of the periodic or uniformly distributed nature of the aperture-free zones across the display, assembling the display from individual tiles at these empty locations becomes feasible.
  • the light emitting elements may be positioned individually on the panel 5.
  • Figure 8 shows another embodiment of the display device.
  • Figure 8 relates to the embodiment of figure 3. On figure 8, the light emitting elements may be positioned per group on the panel 5. As depicted, at least two adjacent light emitting elements 10 are on a matrix 24.
  • a group (or series) of light emitting elements 10 is supported by the matrix 24.
  • a multi-aperture component 26 is a single component containing multiple addressable light emitting elements.
  • the light emitting elements 10 of the multi-aperture component 26 can be controlled independently of each other. Another advantage is that the size of the light emitting elements can be reduced. This leads to a reduced size A of the aperture related to each light emitting element of the multi-aperture component 26.
  • the size A of the aperture related to a respective light emitting element of the multiaperture component 26 can be below 10pm, for instance 8pm (although larger and other sizes are possible).
  • a multi-aperture component 26 can be provided in association with a local optical component that is a lenticular 21 .
  • the multi-aperture component and the lenticular 21 form a module. This module eases the manufacturing of the display device.
  • the multi-aperture component 26 is provided independently of any associated lenticular 21. This also eases the manufacturing of the display device.
  • Figure 8 relates to the embodiment of figure 3 but is applicable to any embodiment as far as at least two pixels 10 are adjacent.
  • the multi-aperture component 26 makes it possible to adjust the optimum viewing distance.
  • the at least two adjacent light emitting elements 10 have respective emitting apertures, forming a group of apertures.
  • a minimal distance along direction D between their centers is substantially equal to the size A of each aperture 11 , said adjacent apertures 11 forming groups of apertures, said groups of apertures being separated by a distance larger than the size A along said direction D.
  • the display device 1 may be based on a fixed format and on a fixed ratio type. Alternatively, the display device 1 may be based on a panel 5 having multiple smaller boards of pixel - or sub-boards. As depicted on figures 6 and 7, in order to maintain the pixel arrangement between the sub-boards, the sub-boards have a gap 28.
  • the gap 28 of the sub-boards does not contain any active pixel (or said otherwise, the gap 28 contains non-active pixel). Neither can the gap 28 be in the middle of a ‘functional’ view. Having a gap 28 enables also some ‘tolerance correction' from sub-board-to-sub-board to keep the picture as fluent as possible.
  • the gaps 28 are arranged with respect to lenticulars 21a facing non-active pixels (“blind” lenticulars).
  • the sub-board size may vary related to the position of the ‘blind’ lenticular 21a. This help in manufacturing the display device.
  • the display device 1 of the invention can be described as follows.
  • the display device 1 has the lenticular sheet 20, the lenticular sheet facing the panel 5.
  • the lenticular sheet 20 comprises an array of lenticulars 21 that are facing the panel 5 and the panel 5 comprises a plurality of light emitting elements 10.
  • Each lenticular 21 faces a number of N possible positions of the light emitting elements 10.
  • the lenticulars 21 form sets of at least two lenticulars 21 .
  • a lenticular set is facing a total of N light emitting elements 10 at the N possible positions.
  • N light emitting elements 10 are spread within a given lenticular set to populate the N possible positions, or said otherwise, the light emitting elements 10 under each lenticular set are positioned so that all N possible positions with respect to the lenticular pitch are populated, or said otherwise, in each N positions in the lenticular set with respect to the nearest left lenticular edge a light emitting element is located.
  • the lenticulars are divided in multiple sets of P lenticulars (P being at least 2). The advantage is that there is no need to have N light emitting elements under each lenticular 21 but much less. Possibly, the lenticular set can be repeated over the whole display device.
  • each lenticular 21 of a lenticular set is facing at least one position free of light emitting elements 10. Possibly, at least one lenticular of a lenticular set is only facing N positions free of light emitting elements.
  • the light emitting elements have an emitting aperture of size A along one direction D, the lenticulars 21 defined by a lenticular pitch LP along same direction D, the lenticular pitch LP being a multiple larger than 1 of the size A of the aperture 11 .
  • the ratio of the sum of the apertures along direction D to the size P * lenticular pitch can have any value between ]0, 1], Possibly, the ratio of the total area of the pixel apertures A to the area of the panel can have any value in the range ]0,1],
  • the other features described previously and the related advantages also apply here.
  • the advantages of the display device mentioned previously also apply here. Notably, this allows that the light emitting elements generating different views are shared amongst several lenticulars instead of typically having all the light emitting elements for all views under one lenticular.
  • the present invention has been described in relation to the specific embodiments which have a value that is purely illustrative and should not be considered to be limiting.
  • the skilled person will notice that the invention is not limited to the examples that are illustrated and/or described here above.
  • the lenticular sheet may be slanted, i.e., may be rotated under a small angle such as for instance 10° or so.
  • the invention comprises each of the new technical characteristics described in the present document, and their combinations.

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Abstract

The present invention relates to a display device (1) comprising a panel (5) comprising a plurality of light emitting elements (10) and configured such that said light emitting elements (10) are able to emit light through apertures (11) of size ∆ along one direction D; a lenticular sheet (20) facing the panel (5), the lenticular sheet (20) comprising an array of lenticulars (21) defined by a lenticular pitch LP along same direction D, the lenticular pitch LP being a multiple larger than 1 of the size ∆ of the aperture (11), each lenticular (21) facing a number of N zones (51, 52) of the panel (5), said N zones (51, 52) corresponding to N different possible views of said display device (1), the number N being larger than 1, the lenticular sheet is facing at least two zones corresponding to an aperture position. The invention also relates to a method to manufacture the display device.

Description

Display device and method to manufacture the display device
Technical field
The invention relates to a display device and to a method to manufacture said display device.
Prior art
In 3D displays, lenticular sheets comprising parallel lenticulars or lenticular lenses are used to convert a 2D generated image into two pictures or more pictures to make multi-view, to enable 3D stereoscopic view. The lenticular sheet faces a panel or substrate including a number of pixels of light separated by a pixel pitch.
There exist different types of displays with different types of sources of light. A first example is a LCD or Liquid-Crystal Display as known by one skilled in the art. For such a type of display, the aperture ratio (or pixel aperture ratio) is high, generally higher than 90 %. The aperture ratio can be defined as the ratio between the cumulated surface covered by the pixels of light and the total surface of the panel or substrate comprising said pixels of light. With LCDs, it is possible to obtain a 3D display device by using a lenticular sheet facing the substrate or panel comprising the different pixels of lights. When one wants to increase the viewing distance from which a user looks to the display device, it is necessary to decrease the size of the pixels. Otherwise, the thickness of the lenticular sheet becomes too large. But, with LCDs, the decrease of the size of the pixels leads to a strong decrease of the amount of light that is emitted. So, with LCDs, it is not possible to modify strongly the viewing distance, and in particular to increase it strongly.
Displays with a low aperture ratio (or low pixel aperture ratio) exist, for instance with a aperture ratio less than 20% or even about 10% or less. An example of such a display is a LED or Light-Emitting Diode display. LED displays have some advantages with respect to LCDs, notably they present higher contrast. Moreover, larger viewing distance are possible with LED displays or displays with a low aperture ratio in general. However, other problems arise when one uses a display with a low aperture ratio. A major problem is that the view cone for each eye is only partially filled with such sources of light. In particular, there is typically much space between the different light emitting regions and only in a very small region the eyes with observe some light. In other words, it is hard to position exactly so that both eyes observe effectively the left and right images. Moreover, the distance between the two eyes (known as Inter Pupil Distance) is on average 65 mm, and varies from one user to another. According to the inventors, no solution exists until now to design a lenticular sheet for such displays with low aperture ratios, for finally obtain an efficient 3D display device. In particular, the approach used with the LCDs for designing a lenticular sheet is not applicable in the case of a display with a low aperture ratio such as a LED display. Otherwise, one has the problem of view cones only partially filled as described above.
Another problem when one wants to use such a type of display is linked to the thickness of the lenticular sheet. Indeed, in the current state of the art, lenticular thickness is proportional to the optimum viewing distance and to the display pixel pitch, this is, if one follows the classical approach for designing a lenticular sheet. In a display with a low aperture ratio such as a LED display, the pixel pitch can be quite large, for instance close to 1 mm. And so, by using the classical approach for designing a lenticular sheet, one obtains a thickness that can be higher than 10 mm or even higher than 15 mm, whereas a thickness of about 1 -5 mm is rather wanted. Next to that, the typical viewing distance for LED displays is larger than for LCDs, again increasing the required lenticular thickness. A thickness larger than 10 mm would result when using the state of the art. This leads to too heavy screens and can result in manufacturing difficulties. For instance, manufacturing a thick (> 10 mm) lenticular with a rol l-to-roll process is impossible requiring extra intermediate spacing layers. These extra production steps increase the risk of failures. So, it is better to have a thinner lenticular sheet.
So, until now, there is no efficient solution for a multi-view display device with a low aperture ratio. Summary of the invention
An object of the invention is to provide an efficient multi-view display device presenting a low aperture ratio (or low pixel aperture ratio). To this end, the invention relates to a display device comprising : a panel comprising a plurality of light emitting elements, the light emitting elements having an emitting aperture of size A along one direction D; a lenticular sheet facing the panel, the lenticular sheet comprising an array of lenticulars defined by a lenticular pitch LP along same direction D, the lenticular pitch LP being a multiple larger than 1 of the size A of the aperture, each lenticular facing a number of N zones of the panel, said N zones corresponding to N different possible views of said display device, the number N being larger than 1 , the lenticular sheet is facing at least two zones corresponding to an aperture position.
Preferably, for at least one lenticular, some of the zones of the panel facing it are free of any aperture. The zones of the panel without or free of any aperture could be named empty regions or non-active pixels. Then, the panel comprises active pixels corresponding to positions where there are some apertures and light emitting elements able to emit light through said apertures, and non-active pixels corresponding to positions where there is no aperture and no related light emitting element. The zones free of any aperture can be used to place various elements or components such as for instance electronic components (for instance a LED driver or any other driver chip). These empty zones can also be used to assemble electronical components, mechanical components and/or optical components. So, with the invention, it is possible to put electronics on the front side of the panel, leading to an easier way for connecting all the components. It is another advantage with respect to LCD where electronics is put on a back side generally.
According to an embodiment, for each lenticular of the lenticular sheet, some zones of the panel facing said each lenticular are free of any aperture. Then, there is still more possibilities and flexibilities for placing electronic components and making connections on the front side of the panel.
According to an embodiment, for at least one lenticular, all of the zones along direction D’ of the panel are free of any aperture. This aperture free lenticular enables to assemble two adjacent tiles at said location without deteriorating the optical quality of the display device.
Preferably, the arrangement of aperture free zones and occupied zones along direction D follows a periodic pattern such that there exists at least one lenticular with aperture-free zones along the direction D’.
In the display device of the invention, the lenticular pitch LP is defined or determined from the size A of the emitting aperture. More precisely, the lenticular pitch is a multiple of that size A, said multiple being not necessarily an integer, but defined depending on the application setup. So, in the invention, the lenticular pitch is not defined from the pixel pitch (pp) which represents the distance between each light emitting element. In particular, the lenticular pitch is not a multiple of the pixel pitch. As A is quite small in general (lower than 300pm or even lower than 200pm or even lower than 100pm, as low as 4pm), this allows that the light emitting elements generating the different views are shared amongst several lenticulars instead of typically having all the light emitting elements for all views under one lenticular. Indeed, in the state of the art, for instance a 2-view LCD display has approximately 2 pixels per lenticular pitch (approximately means for instance 1 .8 or 2.2 ... ). For a 4-view display, state of the art has typically in the order of 4 pixels per lenticular. By using the emitting aperture of the light emitting elements as lenticular design parameter and sharing the pixels generating the different views over multiple lenticulars, the major problem of using lenticular sheets with a panel having a low aperture ratio (view cones only partially filled) can be solved.
The pixel aperture ratio is defined as the ratio between the cumulated surface covered by the pixels of light and the total surface of the panel or substrate comprising said pixels of light. In other words, the pixel aperture ratio can be defined as the ratio between the cumulated surface of the apertures and the total surface of the panel. A low pixel aperture ratio means lower than 20%, preferably lower than 15 %, and still more preferably lower than 10%.
With the display device of the invention, one can have uniformly filled view cones. With the display device of the invention, the dimension used for determining the thickness of the lenticular sheet is no longer the pixel pitch pp, but rather the size A of the aperture, or a value of the order of A. As a consequence, the thickness of the lenticular will be much smaller and acceptable. For instance, a thickness between 1 and 5 mm for the lenticular sheet is possible. With the display device of the invention, if one increases the number of views, the lenticular pitch LP increases, but not the thickness of the lenticular sheet. In addition, a smaller thickness of the lenticular sheet leads to a lighter display device.
Preferably, the panel comprising the different light emitting elements is planar. Then, the direction D is parallel to that planar panel. With the display device of the invention, one could also say that the panel comprises apertures of size A through which the light emitting elements can emit light. Preferably, A is constant or equal for all the apertures.
The lenticular sheet comprises a plurality of lenticulars or lenticular lenses. These terms are known by one skilled in the art. Each lenticular is collimating light coming from each point of the aperture towards the viewer. The lenticulars may form a periodic array, but this is not necessary. The lenticular pitch is the width of a lenticular. Preferably, the lenticular pitch is the same or constant for all the lenticulars. When the lenticulars form a periodic array and when they are directly adjacent to each other, the lenticular pitch is also the distance between the centers of each adjacent lenticular.
A light emitting element can be e.g., a solid-state light emitting element, such as a light emitting diode (LED), an OLED, Quantum Dot Light Emitting Diodes (QD- LED), EL-QLED, AMOLED, mini-LED, micro-LED. Preferably, the light emitting elements are any one of LEDs, OLED, and variations thereof, QD-LED, EL-QLED, AMOLED, mini-LED, micro-LED. The invention is not limited to a particular type of light emitting element, such as LED, and the advantages provided can be beneficial to any type of light emitting element, such as for LCD. Advantageously, the light emitting elements are provided with quantum dots to generate the different colors of emission. Quantum dots have the advantage of improving the brightness of a display and can also improve the color points. The light emitting elements may be discrete (or punctual) light emitting elements. The light emitting elements may be continuous light emitting elements. The light emitting element may have an RGB structure. The display of the invention comprising such light emitting elements can be named as a low aperture ratio display device.
When the eyepoints of a user move in a parallel plane with respect to the lenticular sheet, or when a user looks towards the lenticular sheet under different angles, different regions or zones of the panel under the lenticular sheet are observed. These different zones of the panel correspond to different possible views provided by the display device, depending on the viewing position I angle of a user. For generating 3D content, at least two views are implemented, one for each eye. So, the lenticular sheet is facing at least two zones corresponding to an aperture position.. The lenticular sheet as a whole is facing said at least two zones, i.e. , the same lenticular is facing said at least two zones or different lenticulars are facing respectively at least two zones. The lenticular sheet is facing at least two zones each corresponding to a possible aperture position.
With the invention, each lenticular faces a number of N zones of the panel. The number N is larger than 1 , meaning that more than one zone is facing a given lenticular. A given lenticular is facing more than one possible view.
The magnitude of the lenticular pitch LP can vary between 10 pm to 5 mm, even if other values are possible. Preferably, the lenticular pitch LP is between 1 pm and 2000pm, preferably between 80pm and 1200pm, preferably between 160pm and 600pm.
This magnitude allows that the light emitting elements generating the different views are shared amongst several lenticulars. In other words, this results in a small lenticular pitch resulting into shared views of the light emitting elements amongst several lenticulars.
The lenticular pitch LP depends on the size A of the apertures and the number N of zones of the panel corresponding to the number of views of the display device.
N is the ratio between LP and A rounded to the nearest integer. For a midvalue between to integer, the N is rounded to nearest upper integer. For instance, if LP = 3.2*A, then N is equal to 3 or if LP = 5.8*A, then N is equal to 6, or if LP = 7,5*A, then N is equal to 8. Each of the N zones of the panel has an extension of approximatively A along the direction, or each of the N zones of the panel has an extension A along the direction D. Each of the N zones has an extension of less than 1 .3* A. Preferably, A is constant or equal for the different zones of the panel facing one lenticular. The N zones correspond to N different possible views of the display device. Preferably, each one of the N zones of the panel has a fixed corresponding position along the direction D with respect to a lenticular of the lenticular sheet.
According to an embodiment, N is comprised between 2 and 200. By the use of light emitting elements, for instance LEDs, the size of the apertures can be small, while keeping high contrasts possible. Small means lower than 300 pm for instance, or still lower. By reducing the size of the aperture, it is possible to increase the number N of views of the display device without increasing too much the lenticular pitch LP. This is another advantage of the invention: it allows to have efficient high multi views display devices. As a matter of other examples, N may be between 2 and 50. N can be between 2 and 12.
According to an embodiment, some light emitting elements are adjacent to each other, at least two adjacent light emitting elements are on a matrix. Accordingly, multi-aperture components having at least two adjacent light emitting elements are formed. This enables to have several light emitting elements touching each other being reduced in size, and as such make different views. This makes it possible to reduce the size A of the emitting aperture of the respective light emitting elements, for instance below 10pm, for instance of 8pm. For instance, it is possible to have 40 apertures of 8 pm, that equals 320 pm total aperture per multi-aperture component. So this enables many views. Therefore, the aforementioned advantages of small size A apply here. Multi-aperture components make it possible to adapt the size A of the emitting aperture.
According to an embodiment, a distance between centers of each aperture along said direction D is larger than the size A of each aperture along said direction D. According, to this possible embodiment, there are no adjacent active pixels or no adjacent apertures.
According to an embodiment, some apertures are adjacent to each other so that a minimal distance along said direction D between their centers is substantially equal to the size A of each aperture, said adjacent apertures forming groups of apertures, said groups of apertures being separated by a distance larger than the size A along said direction D. This is another possible design of the display device of the invention that is also particularly easy to manufacture.
According to an embodiment, a whole space of the panel facing one lenticular is free of any aperture. So, according to that possible embodiment, a whole region or space of the panel facing one lenticular has no aperture. In other words, according to this embodiment, there is no active pixels under one lenticular in that case. It generates higher order views. Indeed, under higher angles views are repeated as light can pass from a certain pixel through an adjacent lenticular and even further through a next adjacent one. However, if the generation of higher order views is not desired, one can remove this lenticular. For instance, this specific lenticular can be made flat and/or can be covered with an absorbing coating.
According to an embodiment, said whole space free of any aperture comprises a camera and/or a sensor and/or an electrode and/or a LED driver.
According to an embodiment, each lenticular faces maximum one aperture. This possible embodiment takes full advantages of the shares of views between different lenticulars.
According to an embodiment, the apertures are separated by a constant pixel pitch pp that is larger than the lenticular pitch LP.
According to an embodiment, the light emitting elements are solid-state light emitting elements chosen in the group comprising a light emitting diode (LED), an OLED, Quantum Dot Light Emitting Diodes (QD-LED), EL-QLED, AMOLED, miniLED, micro-LED. So, the invention can be implemented with various examples of light emitting elements. The panels comprising such light emitting elements generally have a low pixel aperture ratio, for instance lower than 20%, or even lower than 10%. According to an embodiment, the lenticular sheet is asymmetric or symmetric with respect to the array of lenticulars. It is not necessary to have a perfectly symmetric lenticular sheet for the display device of the invention. According to a possible embodiment, two or more lenticulars are adjacent, each separated by a lenticular pitch, and this group of lenticulars is separated by another group of lenticular by a flat region or non-active region of the lenticular sheet. Having such flat or non-active regions can present some interest.
According to an embodiment, the display device being a low aperture ratio display device.
According to an embodiment, said lenticular sheet has a thickness d equal to d = n. A.L/VCWwhere n is a refractive index of a lenticular material of the lenticular sheet
L is an observation distance
VCW is the view cone width at the observer position.
Preferably, said thickness d is defined as a distance between a top surface of one lenticular and the top surface of the panel; then d includes possible thicknesses of glue and/or spacing layers.
The observation distance L is for instance comprised between 500 and 3000mm. Preferably, it is between 600 and 900mm. The view cone width at the observer position, VCW, can vary from one user to another. For example VCW is preferably between 21 mm and 65mm (which corresponds to the average interpupil distance of human being). It appears from the formula d = n. .L/VCW, that lower thickness of the lenticular sheet are possible. Indeed, by having the thickness d of the lenticular sheet being dependent on the aperture A and not on the pixel pitch pp, the thickness d is lower. For instance a thickness between 1 and 4 mm is possible. This allows having a display device whose weight is acceptable.
According to a second aspect, the invention relates to a method to design or manufacture a display device,
According to an embodiment, the lenticulars from a multiplicity of sets of at least two lenticulars, N lighting elements being spread over a set of lenticulars such that a lenticular set is facing a total of N light emitting elements at the N possible positions, and wherein the arrangement of the N lighting elements under the set of P lenticulars forms a first structure.
According to an embodiment, the sets of lenticulars form a periodicity.
According to an embodiment, the periodicity of the set of lenticulars is related to a row of light emitting elements or is related to a set of rows of light emitting elements.
Preferably, for at least one lenticular of the P lenticulars all of the zones along direction D’ of the panel are free of any aperture.
This ensures that within a first structure of lighting elements, there is one lenticular free of apertures. This is important if for example two tiles are to be assembled together without reducing the optical quality of the display, they can be assembled at that location. Thus, the lenticular can be flat, there can be no lenticular at said location, or it can be replaced or provided with a coating, such as an absorbing coating.
Preferably, P>N or wherein P>N. If P=N, then there is the same number of light emitting elements as lenticulars. Thus there is at least one light emitting element per lenticular. If P>N, there is at least one lenticular free of aperture.
Preferably, the first structure is replicated in consecutive rows to provide P populated rows. This ensures consistency and uniform light distribution across the display, enhancing visual appeal and simplifying production. This approach also optimizes panel integrity and facilitates cost-effective manufacturing.
Advantageously, the first structure is replicated in consecutive columns.
This ensures periodicity of the light emitting elements on the panel.
Preferably, the first structure is replicated in consecutive rows, by permutating or rearranging the light emitting elements in the first structure, in consecutive rows to provide P populated rows, resulting in a second structure.
This results in a display having variability and reduced regularity in the arrangement of the light-emitting elements.
Preferably, the first structure is replicated in consecutive columns, by permutating or rearranging the light emitting elements of the first structure, in consecutive columns to provide a second structure. Advantageously, the second structure is repeated in consecutive rows and/or columns, by permutating or rearranging the light emitting elements of the second structure, and provide a third structure.
The different structures obtained by permutation ensure a display with a uniform distribution but a reduced regularity in order to reduce Moire effects.
In addition, digital processing techniques can be used to detect and remove the interfering patterns causing the eventual moire effect. This can be achieved using algorithms that analyze the distribution of the lighting elements and compute a new distribution, to selectively remove or replace the unwanted patterns, while obeying to some design specifications.
Preferably, the light emitting elements are arranged in rows and columns ensuring a substantially constant spacing between light emitting elements, or a spacing adapted to the aspect-ratio to be provided by the display.
Here are some specific advantages of providing the structures defined above:
Reduced Moire Effects: Introducing variability in the arrangement of the lightemitting elements helps to reduce the occurrence of Moire effects, which are unwanted interference patterns that can appear when two similar, overlapping patterns interact.
Improved Display Uniformity: While maintaining a uniform distribution of lightemitting elements across the panel, permutating or rearranging the elements in consecutive rows helps to distribute the light more evenly, resulting in improved display uniformity.
Enhanced Optical Quality: By avoiding a completely regular and repetitive pattern, the optical quality of the display can be enhanced, as regular patterns can sometimes lead to visual artifacts or distortions.
Flexibility in Design: Permutating or rearranging the light-emitting elements allows for greater flexibility in design and customization of the display, accommodating different panel sizes, resolutions, and viewing angles.
Adaptive to Panel Requirements: This approach enables the adaptation of the display to specific panel requirements and constraints, optimizing the distribution of light-emitting elements based on the panel's characteristics and performance criteria. A more uniform, visually appealing, and high-quality display while minimizing unwanted visual artifacts such as Moire effects can be achieved.
The invention also relates to a method to manufacture the display device as described above, and comprising the following steps: providing a panel comprising a plurality of light emitting elements , said panel comprising apertures of size A along a direction D and through which the light emitting elements can emit light; providing a lenticular sheet comprising a plurality of lenticulars each having a lenticular pitch LP, said width LP being a multiple larger than 1 of said size A; placing the lenticular sheet such that it faces the panel and such that each lenticular is facing a number of N zones of the panel, said N zones corresponding to N different possible views of said display device, the number N being larger than 1 , the lenticular sheet is facing at least two zones corresponding to a aperture position, and wherein for at least one lenticular, some of the zones of the panel along a direction D’, perpendicular to direction D facing it are free of any aperture, wherein the zones free of any aperture follow a periodic pattern or uniform distribution along direction D.
According to an embodiment, N is the ratio between LP and A rounded to the nearest integer.
According to an embodiment, said lenticular sheet has a thickness d equal to d = n. A.LA/CWwhere n is a refractive index of a lenticular material of the lenticular sheet
L is an observation distance
VCW is the view cone width at the observer position.
According to an embodiment, the panel comprises tiles assembled together.
According to an embodiment, the lenticulars from a multiplicity of sets of at least two lenticulars, N lighting elements being spread over a set of lenticulars such that a lenticular set is facing a total of N light emitting elements at the N possible positions.
According to an embodiment, the sets of lenticulars form a periodicity. According to an embodiment, the periodicity of the set of lenticulars is related to a row of light emitting elements or is related to a set of rows of light emitting elements.
The advantages presented for the display device of the invention apply to this method, mutatis mutandis.
Preferably, the thickness d is defined as a distance between a top surface of one lenticular and the top surface of the panel; then d includes possible thicknesses of glue and/or spacing layers.
The invention also relates to a panel for a display device according to the invention, comprising tiles assembled together.
This allows for modular construction and easier maintenance.
Preferably, the panel for the display device according to the invention comprises at least a set of identical tiles, or a plurality of sets of identical tiles.
This ensures simplified manufacturing and consistent display quality.
Preferably, a tile for a panel comprises at least a first row of N lighting elements, the N lighting elements being configured to be spread over a set of P lenticulars such that a lenticular set is facing a total of N light emitting elements at the N possible positions, and wherein the arrangement of the N lighting elements under the set of P lenticulars forms a first structure.
This ensures optimized light distribution and enhanced display brightness.
Preferably, the lighting elements are configured to provide for at least one lenticular of the P lenticulars all of the zones along direction D’ of the panel free of any aperture. This ensures that the edges of the individual tiles can be provided at the locations where in the assembled display device there will be a lenticular free of any aperture. Preferably, P>N or wherein P>N.
This ensures adequate light coverage for each lenticular, enhancing display uniformity.
Preferably, the first structure is replicated in consecutive rows to provide P populated rows.
This ensures consistent light distribution and simplifies production. Preferably, the first structure is replicated in consecutive columns. This maintains uniformity and visual appeal.
Preferably, the first structure is replicated in consecutive rows, by permutating or rearranging the light emitting elements in the first structure, in consecutive rows to provide P populated rows, resulting in a second block structure.
This reduces regularity and minimizes Moire effects for improved display quality.
Preferably, the first structure is replicated in consecutive columns, by permutating or rearranging the light emitting elements of the first structure, in consecutive columns.
This introduces variability, reducing visual artifacts and enhancing optical quality.
Preferably, the second structure is repeated in consecutive rows and/or columns, by permutating or rearranging the light emitting elements of the second block structure, resulting in a third block structure.
This maintains uniformity while minimizing display irregularities.
Preferably, a tile comprises at least one of a second block structure, a third block structure or a plurality of block structures being permutations or rearrangements of one another, the arrangement of the block structures determining a set of identical tiles.
This allows for versatile design options and customization. Between the block structures there is preferably a lenticular having no apertures. There can be one set of identical tiles or a plurality of sets of identical tiles.
Preferably, the light emitting elements are arranged in rows and columns ensuring a substantially constant spacing between light emitting elements, or a spacing adapted to the aperture ratio to be provided by the display.
This optimizes light distribution and enhances overall display quality.
Preferably, an absorption layer is provided at the edges of the tile. This reduces edge reflections and improves display contrast and clarity.
In the framework of this document, the use of the indefinite article “a”, “an” or the definite article “the” to introduce an element does not exclude the presence of a plurality of these elements. In this document, the terms “first”, “second”, “third” and the like are solely used to differentiate elements and do not imply any order in these elements.
In the framework of the present document, the use of the verbs “comprise”, “include”, “involve” or any other similar variant, as well as their conjugational forms, cannot exclude the presence of elements other than those mentioned. When the verb “comprise” is used for defining an interval by the terms “comprised between” two values, these two values should not be interpreted as excluded from the interval.
Brief description of the figures
Other characteristics and advantages of the present invention will appear on reading the following detailed description, for the understanding of which, it is referred to the attached figures where:
- Figure 1 schematically illustrates a possible embodiment of the display device of the invention;
- Figure 2 schematically illustrates another possible embodiment of the display device of the invention;
- Figure 3 schematically illustrates another possible embodiment of the display device of the invention;
- Figure 4 schematically illustrates another possible embodiment of the display device of the invention;
- Figure 5 schematically illustrates a panel of the display device of the invention;
- Figure 6 schematically illustrates another possible embodiment of the display device of the invention;
- Figure 7 schematically illustrates another possible embodiment of the display device of the invention;
- Figure 8 schematically illustrates a panel of the display device of the invention. The drawings in the figures are not scaled. Similar elements can be assigned by similar references in the figures. In the framework of the present document, identical or analogous elements may have the same references. The presence of reference numbers in the drawings cannot be considered to be limiting, in particular if these numbers are indicated in the claims.
Description of specific embodiments of the invention
Description of preferred embodiments of the present invention are hereafter described with references to figures, but the invention is not limited by these references. In particular, the drawings or figures described below are only schematic and are not limiting in any way.
The following definitions are hereby provided for the sake of clarity:
The terms "about" or "approximate" and the like are synonymous and are used to indicate that the value modified by the term has an understood range associated with it, where the range can be +20%, +15%, +10%, +5%, or +1 %. The term "substantially" is used to indicate that a result (e.g., measurement value) is close to a targeted value, where close can mean, for example, the result is within 80% of the value, within 90% of the value, within 95% of the value, or within 99% of the value.
Lenticular (or Lenticular Lens): A lenticular refers to an optical element commonly known as a lenticular lens. It possesses a cylindrical shape and functions to manipulate light. Each lenticular lens has a curved surface, usually forming a portion of a cylinder. These lenses are utilized to create visual effects such as depth, motion, or the display of multiple images contingent on the viewing angle.
Lenticular Sheet: A lenticular sheet is an assembly comprising an array of lenticulars (or lenticular lenses). This sheet is positioned facing a panel. Each lenticular within the lenticular sheet consists of a cylindrical lens. The lenticular sheet facilitates the manipulation of light and visual effects, with each lenticular lens redirecting light in a particular direction. The width of each lenticular along a specified direction (denoted as D) is termed as the lenticular pitch (LP). The top surface of each lenticular lens can have a variety of shapes, such as cylindrical or aspheric, or any optical shape known to the skilled person, such as an elliptic shape, parabolic shape, etc., depending on the specific design requirements and optical characteristics desired for the application.
Vertical Axis D’: When viewing the lenticular sheet from the side, the vertical axis corresponds to the direction of the cylindrical lenses or lenticular’s curvature.
Horizontal Axis D: Perpendicular to the vertical axis, the horizontal axis is the direction in which the viewer's perspective changes, causing different images or effects to be visible depending on the viewing angle.
The figures schematically illustrate possible embodiments of the display device 1 of the invention. It comprises a panel 5 comprising a plurality of light emitting elements 10. The panel 5 is configured such that said light emitting elements 10 have respectively an emitting aperture 11. For the purpose of understanding only, a circle depicts the aperture 11 , but the form of the aperture 11 is not necessarily a circle. According to a preferred example, the panel 5 comprises such apertures 11 . According to a direction D as shown in figures, the size of the aperture 11 is equal to A. Different values of A are possible. For instance, A is lower than 300pm or even lower than 200pm or even lower than 100pm. Preferably, A is comprised between 4pm and 300pm, and preferably between 10pm and 200pm. However, other values, for instance larger than 300pm are possible.
The figures illustrate a number of N zones 51 , 52, 53, 54, 55, 56, 57, 58, etc. of the panel 5. Said N zones 51 , 52, 53, 54, 55, 56, 57, 58, etc. correspond to N different possible views of said display device 1 . Zone 51 corresponds to view 1 , zone 52 corresponds to view 2, etc. Each one of the N zones - and corresponding view - has a fixed position along said direction D with respect to a lenticular 21 of the lenticular sheet. The figures illustrate arrays of zones and light emitting element positions (and respective aperture position). In other words, the figures illustrate row(s) and column(s) of zones and light emitting element positions (and respective aperture position).
A lenticular sheet 20 faces the panel 5. This lenticular sheet 20 comprises an array of lenticulars 21 (or lenticular lenses 21 ). The lenticular sheet 20 comprises a number of lenticulars 21. The top surface of each lenticular 21 can follow a cylindrical or aspheric shape. The width of each lenticular 21 along direction D is named lenticular pitch LP. Generally according to the invention, LP is a multiple larger than 1 of A, but that multiple is not necessarily an integer. Thus, a given lenticular covers more than one aperture. In the example shown in figure 1 , the lenticular pitch LP is equal to two times A.
In the figures, the lenticular sheet 20 faces the panel 5, with the curvature of the lenticulars 21 facing the panel. The lenticulars 21 have a curvature in direction D and extend in a direction D’ perpendicular to D. In a nonrestrictive way, the lenticulars 21 are depicted in cross section above the row of light emitting element 10 to simplify the figures. In the figures each lenticular 21 faces more than one zone, each zone corresponding to a position with respect to a given lenticular. Each zone corresponds to a position with respect to a lenticular, starting from an edge of the lenticular.
In the figures, the light emitting elements are arranged in rows and columns. In figures 1 to 4 and 8 a single row of light emitting elements is represented. In figures 6 and 7, both the rows and columns are represented.
For the embodiment of figure 1 , each lenticular 21 faces two zones 51 , 52 of the panel 5. And each zone 51 , 52 has a width equal to A along D. Each zone occupies a position with respect to the same lenticular facing the panel 5.
In the example of figure 1 and for the second lenticular 21 starting from left, there is a aperture 11 at a first zone 51 whereas its adjacent zone 52 under same lenticular 21 has no aperture. One could say that for that lenticular 21 , there is one active pixel at a first zone 51 and a non-active pixel (or black pixel or no aperture) at a second zone 52. Then moving further to the right, there is a lenticular 21 facing non-active pixel (or black pixel or no aperture). The next lenticular 21 further right has a non-active pixel (or black pixel or no aperture) at a first zone 51 followed by a aperture 11 or active pixel at a second zone 52. Then the structure (or pattern) is repeated.
The example of figure 1 is a two-view display device 1 . With such a display device 1 , it is possible to have filled view cones, for instance at a viewing distance of 600 mm. With a refractive index equal to 1.54, A=0.1875 mm, a viewing distance of 600 mm, and an VCW parameter equal to 65 mm, the thickness of the lenticular sheet 20 is equal to 2.66 mm which is acceptable.
Figure 2 schematically illustrates another possible embodiment of the display device 1 of the invention. In the example shown in figure 2, the lenticular pitch LP is equal to four times A. For the embodiment of figure 2, each lenticular 21 faces four zones 51 , 52, 53, 54 of the panel 5. And each zone 51 , 52, 53, 54 has a width equal to A along D. Each zone occupies a position with respect to the same lenticular facing the panel 5. In the example of figure 2 and for the first lenticular 21 starting from left, there is an aperture 11 at a first zone 51 whereas its adjacent zone 52 and the other zones 53, 54 under same lenticular 21 have no aperture. These zones 53, 54, can be referred to as aperture-free zones. One could say that for that lenticular 21 , there is one active pixel at a first zone 51 and a non-active pixel (or black pixel or no aperture) at a second zone 52, at a third zone 53 and at a fourth zone 54. Then moving further to the right, the next lenticular 21 has a non-active pixel (or black pixel or no aperture) at a first zone 51 followed by a aperture 11 or active pixel at a second zone 52 followed by a non-active pixel (or black pixel or no aperture) at a third zone 53 and at a fourth zone 54. Then moving further to the right, the next lenticular 21 has a non-active pixel (or black pixel or no aperture) at a first zone 51 and at a second zone 52 followed by an aperture 11 or active pixel at a third zone 53 followed by a non-active pixel (or black pixel or no aperture) at a fourth zone 54. Then moving further to the right, the next lenticular 21 has a non-active pixel (or black pixel or no aperture) at a first zone 51 , at a second zone 52 and at a third zone 53 followed by an aperture 11 or active pixel at a fourth zone 54. Then moving further to the right, there is a lenticular 21 facing non-active pixel (or black pixel or no aperture). Then the structure (or pattern) is repeated, signifying that these aperture-free zones showcase either a periodic pattern or a uniform distribution across the entire display.
The example of figure 2 is a four-view display device 1. With such a display device 1 , it is possible to have filled view cones, for instance at a viewing distance of 900 mm. With a refractive index equal to 1 .54, A=0.1875 mm, a viewing distance of 900 mm, and an VCW parameter equal to 65 mm, the thickness of the lenticular sheet 20 is equal to 3.998 mm which is acceptable.
Figure 3 schematically illustrates another possible embodiment of the display device 1 of the invention. In the example shown in figure 3, the lenticular pitch LP is equal to eight times A. For the embodiment of figure 3, each lenticular 21 faces eight zones 51 to 58 of the panel 5. And each zone 51 to 58 has a width equal to A along D. Each zone occupies a position with respect to the same lenticular facing the panel 5. In the example of figure 3 and for the first lenticular 21 starting from left, there is an aperture 11 at a first zone 51 , at a second zone 52, at a third zone 53 and at a fourth zone 54 whereas the other zones 55, 56, 57, 58 under same lenticular 21 have no aperture. One could say that for that lenticular 21 , there is one active pixel at a first zone 51 , at a second zone 52, at a third zone 53 and at a fourth zone 54 and a non-active pixel (or black pixel or no aperture) at a fifth zone 55, at a sixth zone 56, at a seventh zone 57 and at a eighth zone 58. Then moving further to the right, the next lenticular 21 has a non-active pixel (or black pixel or no aperture) at a first zone 51 , at a second zone 52, at a third zone 53 and at a fourth zone 54 followed by an aperture 11 or active pixel at a fifth zone 55, at a sixth zone 56, at a seventh zone 57 and at a eighth zone 58. Then moving further to the right, there is a lenticular 21 facing non-active pixel (or black pixel or no aperture). Then the structure (or pattern) is repeated; signifying that these aperture-free zones showcase either a periodic pattern or a uniform distribution across the entire display.
The example of figure 3 is a four-view display device 1. With such a display device 1 , it is possible to have filled view cones, for instance at a viewing distance of 900 mm. With a refractive index equal to 1 .54, A=0.1875 mm, a viewing distance of 900 mm, and a VCW parameter equal to 65mm, the thickness of the lenticular sheet 20 is equal to 3,998mm which is acceptable.
Figure 4 schematically illustrates another possible embodiment of the display device 1 of the invention. In the example shown in figure 4, the lenticular pitch LP is equal to six times A. For the embodiment of figure 4, each lenticular 21 faces six zones 51 , 52, 53, 54, 55, 56 of the panel 5. And each zone 51 to 56 has a width equal to A along D. Each zone occupies a position with respect to the same lenticular facing the panel 5. In the example of figure 4 and for the first lenticular 21 starting from left, there is an aperture 11 at a first zone 51 , at a second zone 52, at a fourth zone 54 and at a sixth zone 56 whereas the other zones 53, 55 under same lenticular 21 have no aperture. One could say that for that lenticular 21 , there is one active pixel at a first zone 51 , at a second zone 52, at a fourth zone 54 and at a sixth zone 56 and a non-active pixel (or black pixel or no aperture) at a third zone 53 and at a fifth zone 55. Then moving further to the right, the next lenticular 21 has a nonactive pixel (or black pixel or no aperture) at a first zone 51 , at a second zone 52, at a fourth zone 54 and at a sixth zone 56 and an aperture 11 or active pixel at a third zone 53 and at a fifth zone 55. Then the structure (or pattern) is repeated.
The example of figure 4 is a six-view display device 1. With such a display device 1 , it is possible to have filled view cones, for instance at a viewing distance of 900mm. With a refractive index equal to 1 .54, A=0.1875 mm, a viewing distance of 900mm, and a VCW parameter equal to 65mm, the thickness of the lenticular sheet 20 is equal to 3,998mm which is acceptable.
Figure 5 schematically illustrates a panel 5 of the display device of the invention. Figure 5 is according to the view of a user toward the display device. Apertures 11 are visible with a size A. The size A may be as mentioned above. The geometric shape of the apertures 11 is not limited. For instance, an aperture 11 may be a square, with an edge of the size A. It can be a rectangle; in that case, the width of the size A in the direction D is lower than the length in the direction transverse to the direction D (in the plan of the aperture in the panel 5). Also, a pixel pitch pp is depicted. With respect to the size A of an aperture, the pixel pitch pp size is much higher. The aperture size is well below the pixel pitch. Since the lenticular pitch LP is small, and possibly defined or determined from the size A of the aperture, the light emitting elements generating the different views are shared amongst several lenticulars. Also, since the dimension used in the present invention for determining the thickness of the lenticular sheet is the size A of the aperture, or a value of the order of A, the thickness of the lenticular sheet can be much smaller and acceptable. Figure 5 shows groups of apertures 11 as an example, but the apertures on figure 5 may be depicted as on the other figures, such as continuously spaced apart, like on figure 1 .
Figure 6 schematically illustrates a panel 5 of the display device of the invention. Figure 6 corresponds to the embodiment of figure 2 (the same description applies mutatis mutandis to the other embodiments). Figure 6 depicts the panel 5 both in direction D and in a direction D’ perpendicular to D. Figure 6 illustrates how the structure (or pattern) of active pixels and non-active pixels is repeated according to a row in the direction D and how the structure (or pattern) of active pixels and non-active pixels is repeated in direction D’ in column. In direction D, the same structure is repeated as explained with respect to figure 2. In direction D’, the active pixels of a given zone are repeated in column. The active pixels at the first zone 51 are repeated in column - the same other active pixels at the second zone 52, at the third zone 53 and at the fourth zone 54. All of the rows of active pixels start with the same zone (first zone 51 in the example of figure 6 - but it could be another zone at first). Thus, the active pixels of a given zone are aligned in column. The embodiment of figure 6 makes it possible to obtain a “vertical” spacing (in direction D’) between the active pixels of a given zone being much smaller than the “horizontal” spacing (in Direction D). This is a possible way of increasing resolution of the display device 1 vertically, in the direction D’.
Figure 7 schematically illustrates a panel 5 of the display device of the invention. Figure 7 depicts the panel 5 both in direction D and in a direction D’ perpendicular to D. Figure 7 illustrates how the structure of active pixels and non- active pixels is repeated according to a row in the direction D and how the structure of active pixels and non-active pixels is repeated in direction D’ in column. In direction D, the same structure is repeated similarly to the explanation of figure 2. More precisely, the series of zones populated or not by a light emitting element is repeated, but the space between the active pixels and non-active pixel is not repeated. In direction D’, the active pixels of a given zone are shifted towards the direction D (or opposite to direction D). For example, the active pixel corresponding to zone 51 illustrates the shift. In other words, the active pixels of a given zones are disposed somehow in diagonal. The active pixels of the first zone 51 are shifted in the direction D from one line to another - the same of the other active pixels at the second zone 52, at the third zone 53 and at the fourth zone 54. Thus, the active pixels of a given zone are shifted in direction D from one row of pixels to another. The embodiment of figure 7 makes it possible to obtain a better distribution per view. The active pixels of the respective view are more uniformly spread. This is a possible way to avoid the moire effect and to have a better visual effect. Also, the embodiment of figure 7 avoids slanting the lenticular.
Figure 7 shows a “re-arrangement” of pixels whereas figure 6 shows how the pixels are disposed without “re-arrangement”. The figures are only to be construed as possible examples of pixel arrangement for a particular number of views.
According to all embodiments, each lenticular 21 faces a number of N possible positions of the light emitting elements 10 (with a respective aperture) corresponding to N different possible views. The lenticulars 21 form a multiplicity of sets of P lenticulars 21 , P being at least two. A lenticular set is facing at least a total of N light emitting elements 10 at the N possible positions. Thus, each lenticular 21 of a given set does not face N light emitting elements (or active pixels). In other words, a lenticular 21 facing N zones is facing less than N light emitting elements 10 (and less than N aperture positions). A lenticular of the set may even face no light emitting elements 10. The N light emitting elements (and related apertures) corresponding to the N zones are spread among a set of at least two lenticulars. The lenticular set is then the basic building element of the display device is repeated over the whole display device 1 . The advantage is that one can reduce the presence of light emitting elements, and thus the amount of light - while keeping the same quality or even increasing the quality of the display device. This reduces the cost of the display device.
Thus, in all embodiments, the sets of lenticulars form a periodicity. There may be a periodicity of the set of lenticulars in relation to a row of light emitting elements in direction D and/or direction D’. The lenticulars are divided in the multiple sets of P lenticulars, so that a light emitting element (and respective aperture) in a row is located in each position of the zone in a given set with respect to the nearest left lenticular edge. On the figures, the lenticulars 21 are spread with a periodicity along the direction D. There may be a periodicity of the set of lenticulars in relation to a set of rows of light emitting elements. There may be also a periodicity in blocks. In other words, there may be a periodicity in both directions D and D’. There may be a periodicity in block in the direction D and direction D’. The periodicity may cover a set of lenticulars in the direction D as well as a set of rows of light emitting elements in the direction D’.
On figure 1 , there is a periodicity of a set of five lenticulars facing two zones. Two lenticulars of the set of lenticulars are each facing a respective zone populated with a light emitting element (active pixel) and three lenticulars of the set is not facing any light emitting element (non-active pixel). Among one set of lenticulars, one lenticular is facing zone 51 populated with a light emitting element, one lenticular is facing zone 52 populated with a light emitting element and three lenticulars are facing no light emitting element. The set of lenticulars may be repeated in an adjacent way or not.
On figures 2 and 6, there is a periodicity of a set of five lenticulars facing four zones. Four lenticulars of the set of lenticulars are each facing a respective zone populated with a light emitting element (active pixel) and one lenticular of the set is not facing any light emitting element (non-active pixel). Among one set of lenticulars, one lenticular is facing zone 51 populated with a light emitting element, one lenticular is facing zone 52 populated with a light emitting element, one lenticular is facing zone 53 populated with a light emitting element, one lenticular is facing zone 54 populated with a light emitting element and one lenticular is facing no light emitting element. The set of lenticulars may be repeated in an adjacent way or not.
On figure 3, there is a periodicity of three lenticulars, facing eight zones. Two lenticulars of the set of lenticulars are each facing four respective zones populated with a light emitting element (active pixel) and one lenticular of the set is not facing any light emitting element (non-active pixel). Among one set of lenticulars, one lenticular is facing zones 51 -54 populated with a light emitting element, one lenticular is facing zones 55-58 populated with a light emitting element and one lenticular is facing no light emitting element. The set of lenticulars may be repeated in an adjacent way or not. On figure 4, there is a periodicity of two lenticulars, facing six zones. One lenticular of the set of lenticulars is facing four respective zones populated with a light emitting element (active pixel) and one lenticular of the set is facing two respective zones populated with a light emitting element (active pixel). Among one set of lenticulars, one lenticular is facing zones 51 , 52, 54, 56 populated with a light emitting element and one lenticular is facing zones 53, 55 populated with a light emitting element. The set of lenticulars may be repeated in an adjacent way or not.
On figure 7, there is a periodicity in blocks, i.e. , a periodicity in both directions D and D’. As a matter of example (other numbers are possible), there is a periodicity with a set of 25 lenticulars wide (direction D) with respect to 5 light emitting rows high (direction D’). On figure 7, the 25 first lenticulars starting from the lenticular on the left form a set of lenticulars (set B) in direction D and the 5 first rows having light emitting elements starting from the top row of light emitting elements form a set of rows of light emitting elements (set B’) in the direction D’. The 25 lenticulars are facing four zones. Some of the lenticulars of the set of lenticulars are each facing a zone populated with a light emitting element (active pixel). These lenticulars are facing all four zones 51 -54 populated in each row by a light emitting element (active pixel). Other lenticulars of the set are not facing any light emitting element (nonactive pixel). On figure 7, in each row, the active pixels of a given zone are shifted towards the direction D (or opposite to direction D). A gap 28 may be positioned after group B. Then the set of lenticulars and the set of rows are repeated in directions D and D’, in an adjacent way or not. The advantage of figure 7 is that the resolution loss in the horizontal direction (direction D) is evenly spread over horizontal (direction D) and vertical direction (direction D').
The light emitting elements under each set of lenticulars are positioned so that all possible positions with respect to the lenticular pitch, are populated. A minimum number of at least two lenticulars is present in a set so that all light emitting elements under this set of lenticulars contribute to all views. As this is further explained below, the result is that non light-emitting regions become available under the lenticulars which enable “blind” lenticulars allowing to tile different display panels, adding electronics (or other functionalities) in these space regions, 3D is still working. The display device (1 ) is designed with a sophisticated structural arrangement to optimize its visual output and quality:
As shown in figure 6, the first structure can be replicated in consecutive rows to produce P populated rows, enhancing the display's uniformity and brightness.
The first structure can be replicated in consecutive columns, ensuring a consistent and appealing visual presentation across the display.
The first structure can also be replicated in consecutive rows, with light emitting elements permutated within each row. This permutation results in a second structure, introducing variability and reducing visual artifacts for improved display quality. This is illustrated in figure 7.
Similarly, the first structure is replicated in consecutive columns with permutated light emitting elements, resulting in a second structure. This approach further enhances optical quality and reduces regularity, as illustrated in figure 7.
The second structure is further repeated in consecutive rows and/or columns by permutating or rearranging the light emitting elements, leading to a third structure. This repetition and permutation maintain display uniformity while minimizing irregularities. In figure 7, P=5 or P=25, and N=4. There are 5 substructures under the 25 lenticulars, which are permutations or rearrangements of one another, or shifted with respect to each other.
Incorporating various arrangements of distinct structures facilitates the design diversity of individual tiles. A tile may consist of multiple unique structures, or each tile may possess its own distinct structure, leading to diverse sets of identical tiles. These tiles are separated at an aperture-free lenticular, located at space 28, between two adjacent tiles.
Additionally, the display device ensures that the light emitting elements are meticulously arranged in rows and columns, maintaining a consistent spacing between them or adapting to the display's aspect ratio. This meticulous arrangement optimizes light distribution and enhances overall display quality.The display device 1 of the invention solves the problem of low fill factor and still has pixels in focus resulting in uniformly filled view cones (what enhance the 3D view quality, although users have different view cone width VCW) and feasible lenticular thicknesses. The smaller the width of the view cones, the more views are needed to fill-up the space in which the user still experiences a good 3D quality. The advantage is that the user has a good 3D experience when his eyes move from one view cone to another because of a smooth transition between cones. The wider the width of the view cones, the fewer views are needed. This in turn enables multiview, super stereo displays. A super-stereo display increases the quality of the 3D impression, even closer to reality. The embodiment of figure 8 is especially useful to generate super-stereo-displays.
Spaces with non-active pixels (i.e., a lenticular 21 a facing only non-active pixels (such a lenticular can be flat - such as the dotted lines represented on the figures - and/or can be covered with an absorbing coating) as well as lenticular sections facing some pixels being non-active pixels) will be non-actively participating in the generation of the different (first order) 3D views. Such spaces help in the generation of higher order views. Indeed, under higher angles views are repeated as light can pass from a certain pixel through an adjacent lenticular and even further through a next adjacent one. These spaces can thus be used to add one or more extra functionalities to the display like one or more functionalities among for instance: sensors (humidity, environmental light, adjustment of brightness, etc.), touch (capacitive), top electrodes for power distribution, optical high-speed link, in-cell camera, black (to enhance contrast) or background picture, transparency, hiding seams in tile-able displays (free format direct view displays, not restricted to video aspect ratio’s), extra space between light emitting elements or groups of light emitting elements can be generated to assemble electronical (high speed signaling, leddrivers, ...), mechanical (lamination spacers) or optical (high speed optical links, sensors, etc.), etc. These spaces enable also tilable multiview display according to the invention. In other words, these spaces facilitate the assembly of panel 5 by seamlessly interlocking individual tiles. This eases the manufacture of the display into tiles. For instance, on figures 6 and 7 (applicable to the other embodiments), there is a lenticular 21 a facing a space 28 with non-active pixels. This space 28 may be the tile boundary. Because of the periodic or uniformly distributed nature of the aperture-free zones across the display, assembling the display from individual tiles at these empty locations becomes feasible.The light emitting elements may be positioned individually on the panel 5. Figure 8 shows another embodiment of the display device. Figure 8 relates to the embodiment of figure 3. On figure 8, the light emitting elements may be positioned per group on the panel 5. As depicted, at least two adjacent light emitting elements 10 are on a matrix 24. In other words, a group (or series) of light emitting elements 10 is supported by the matrix 24. This forms a multi-aperture component 26. A multi-aperture component 26 is a single component containing multiple addressable light emitting elements. The light emitting elements 10 of the multi-aperture component 26 can be controlled independently of each other. Another advantage is that the size of the light emitting elements can be reduced. This leads to a reduced size A of the aperture related to each light emitting element of the multi-aperture component 26. The size A of the aperture related to a respective light emitting element of the multiaperture component 26 can be below 10pm, for instance 8pm (although larger and other sizes are possible). This could enable more spaces with non-active pixels under the lenticular to create extra functionalities (such as gap for cutting, sensors, .... as mentioned above). Also a multi-aperture component 26 can be provided in association with a local optical component that is a lenticular 21 . The multi-aperture component and the lenticular 21 form a module. This module eases the manufacturing of the display device. Alternatively, the multi-aperture component 26 is provided independently of any associated lenticular 21. This also eases the manufacturing of the display device. Figure 8 relates to the embodiment of figure 3 but is applicable to any embodiment as far as at least two pixels 10 are adjacent. The multi-aperture component 26 makes it possible to adjust the optimum viewing distance.
The at least two adjacent light emitting elements 10 have respective emitting apertures, forming a group of apertures. A minimal distance along direction D between their centers is substantially equal to the size A of each aperture 11 , said adjacent apertures 11 forming groups of apertures, said groups of apertures being separated by a distance larger than the size A along said direction D. With such a display device 1 of figure 8, it is possible to have filled view cones, for instance at a viewing distance of 2700mm. With a refractive index equal to 1 .64, A=0.008 mm, a viewing distance of 3500mm, and a VCW parameter equal to 65mm, the thickness of the lenticular sheet 20 equal to 0,706mm is obtained.
The display device 1 may be based on a fixed format and on a fixed ratio type. Alternatively, the display device 1 may be based on a panel 5 having multiple smaller boards of pixel - or sub-boards. As depicted on figures 6 and 7, in order to maintain the pixel arrangement between the sub-boards, the sub-boards have a gap 28. The gap 28 of the sub-boards, does not contain any active pixel (or said otherwise, the gap 28 contains non-active pixel). Neither can the gap 28 be in the middle of a ‘functional’ view. Having a gap 28 enables also some ‘tolerance correction' from sub-board-to-sub-board to keep the picture as fluent as possible. The gaps 28 are arranged with respect to lenticulars 21a facing non-active pixels (“blind” lenticulars). Depending on the number of views, the sub-board size may vary related to the position of the ‘blind’ lenticular 21a. This help in manufacturing the display device.
The display device 1 of the invention can be described as follows. The display device 1 has the lenticular sheet 20, the lenticular sheet facing the panel 5. The lenticular sheet 20 comprises an array of lenticulars 21 that are facing the panel 5 and the panel 5 comprises a plurality of light emitting elements 10. Each lenticular 21 faces a number of N possible positions of the light emitting elements 10. The lenticulars 21 form sets of at least two lenticulars 21 . A lenticular set is facing a total of N light emitting elements 10 at the N possible positions. This last sentence said otherwise, N light emitting elements 10 are spread within a given lenticular set to populate the N possible positions, or said otherwise, the light emitting elements 10 under each lenticular set are positioned so that all N possible positions with respect to the lenticular pitch are populated, or said otherwise, in each N positions in the lenticular set with respect to the nearest left lenticular edge a light emitting element is located. Thus, in the display device, the lenticulars are divided in multiple sets of P lenticulars (P being at least 2). The advantage is that there is no need to have N light emitting elements under each lenticular 21 but much less. Possibly, the lenticular set can be repeated over the whole display device. Possibly, each lenticular 21 of a lenticular set is facing at least one position free of light emitting elements 10. Possibly, at least one lenticular of a lenticular set is only facing N positions free of light emitting elements. Possibly, the light emitting elements have an emitting aperture of size A along one direction D, the lenticulars 21 defined by a lenticular pitch LP along same direction D, the lenticular pitch LP being a multiple larger than 1 of the size A of the aperture 11 . Possibly, the ratio of the sum of the apertures along direction D to the size P * lenticular pitch can have any value between ]0, 1], Possibly, the ratio of the total area of the pixel apertures A to the area of the panel can have any value in the range ]0,1], The other features described previously and the related advantages also apply here. The advantages of the display device mentioned previously also apply here. Notably, this allows that the light emitting elements generating different views are shared amongst several lenticulars instead of typically having all the light emitting elements for all views under one lenticular.
The present invention has been described in relation to the specific embodiments which have a value that is purely illustrative and should not be considered to be limiting. The skilled person will notice that the invention is not limited to the examples that are illustrated and/or described here above. For example, the lenticular sheet may be slanted, i.e., may be rotated under a small angle such as for instance 10° or so. The invention comprises each of the new technical characteristics described in the present document, and their combinations.

Claims

Claims
1 . A display device (1 ) comprising
• a panel (5) comprising a plurality of light emitting elements (10), the light emitting elements having an emitting aperture (11 ) of size A along one direction D,
• a lenticular sheet (20) facing the panel (5), the lenticular sheet (20) comprising an array of lenticulars (21 ) defined by a lenticular pitch LP along same direction D, the lenticular pitch LP being a multiple larger than 1 of the size A of the aperture (11 ), each lenticular (21 ) facing a number of N zones (51 , 52, 53, 54, 55, 56, 57, 58, etc.) of the panel (5), said N zones (51 , 52, 53, 54, 55, 56, 57, 58, etc.) corresponding to N different possible views of said display device (1 ) along direction D, the number N being larger than 1 , the lenticular sheet is facing at least two zones corresponding to an aperture position, and wherein for at least one lenticular (21 ), some of the zones (51 , 52, 53, 54, 55, 56, 57, 58, etc.) of the panel (5) along a direction D’, perpendicular to direction D facing it are free of any aperture (11 ), wherein the zones free of any aperture follow a periodic pattern or uniform distribution along direction D.
2. The display device (1 ) according to claim 1 , wherein for each lenticular (21 ) of the lenticular sheet (20), some zones (51 , 52, 53, 54, 55, 56, 57, 58, etc.) of the panel (5) facing said each lenticular (21 ) are free of any aperture (11 ) along direction D’ of the panel (5), wherein the zones free of any aperture follow a periodic pattern or uniform distribution direction D.
3. The display device (1 ) according to any of the preceding claims, wherein for at least one lenticular (21a), all of the zones (51 , 52, 53, 54, 55, 56, 57, 58, etc.) along direction D’ of the panel (5) are free of any aperture (11 ).
4. A display device according to claim 1 , wherein the lenticular pitch LP is between 1 pm and 2000pm, preferably between 80pm and 1200pm, preferably between 160pm and 600pm.
5. A display device (1 ) according to claim 1 or 2, wherein N is the ratio between LP and A rounded to the nearest integer.
6. A display device (1 ) according to any of the preceding claims, wherein each of the N zones of the panel (5) has an extension of approximatively A along said direction D or each of the N zones of the panel (5) has an extension of A along said direction D.
7. The display device (1 ) according to any of the preceding claims, wherein N is comprised between 2 and 200.
8. The display device (1 ) according to any of the preceding claims, wherein some light emitting elements (10) are adjacent to each other, at least two adjacent light emitting elements (10) are on a matrix (24).
9. The display device (1 ) according to any of the preceding claims, wherein a distance between centers of each aperture (11 ) along said direction D is larger than the size A of each aperture (11 ) along said direction D.
10. The display device (1 ) according to any of the preceding claims, wherein some apertures (11 ) are adjacent to each other so that a minimal distance along said direction D between their centers is substantially equal to the size A of each aperture (11 ), said adjacent apertures (11 ) forming groups of apertures, said groups of apertures being separated by a distance larger than the size A along said direction D.
11. The display device (1 ) according to any of the preceding claims, wherein a whole space of the panel (5) facing one lenticular (21 ) is free of any aperture (11 ).
12. The display device (1 ) according to previous claim, wherein said whole space free of any aperture (11 ) comprises a camera and/or a sensor and/or an electrode and/or a LED driver.
13. The display device (1 ) according to any of the preceding claims, wherein each lenticular (21 ) faces maximum one aperture (11 ).
14. The display device (1 ) according to any of the preceding claims, wherein the apertures (11 ) are separated by a constant pixel pitch pp that is larger than the lenticular pitch LP.
15. The display device (1 ) according to any one of the preceding claims, wherein the light emitting elements are solid-state light emitting elements chosen in the group comprising a light emitting diode (LED), an OLED, Quantum Dot Light Emitting Diodes (QD-LED), EL-QLED, AMOLED, mini-LED, micro-LED.
16. The display device (1 ) according to any of the preceding claims, wherein the lenticular sheet (20) is asymmetric or symmetric with respect to the array of lenticulars (21 ).
17. The display device (1 ) according to any of the preceding claims, the display device (1 ) being a low aperture ratio display device.
18. The display device (1 ) according to any of the preceding claims, wherein said lenticular sheet (20) has a thickness d equal to d = n. A-LA/CI/l/where
- n is a refractive index of a lenticular material of the lenticular sheet (20)
- L is an observation distance - VCW is the view cone width at the observer position.
19. The display device (1 ) according to any of the preceding claims, the lenticulars from a multiplicity of sets of at least P lenticulars, P> 2, N lighting elements being spread over a set of P lenticulars such that a lenticular set is facing a total of N light emitting elements (10) at the N possible positions, and wherein the arrangement of the N lighting elements under the set of P lenticulars forms a first structure.
20. The display device (1 ) according to preceding claim, wherein the sets of lenticulars form a periodicity.
21 . The display device (1 ) according to preceding claim, wherein the periodicity of the set of lenticulars is related to a row of light emitting elements or is related to a set of rows of light emitting elements.
22. The display device according to any of claims 19 to 21 , wherein for at least one lenticular of the P lenticulars all of the zones (51 , 52, 53, 54, 55, 56, 57, 58, etc.) along direction D’ of the panel (5) are free of any aperture (11 ).
23. The display device according to claim 22, wherein P>N or wherein P>N.
24. Display device (1 ) according to claim 23, wherein the first structure is replicated in consecutive rows to provide P populated rows.
25. Display device (1 ) according to any of claims 19 to 24, wherein the first structure is replicated in consecutive columns.
26. Display device (1 ) according to any of claims 19 to 25, wherein the first structure is replicated in consecutive rows, by permutating or rearranging the light emitting elements in the first structure, in consecutive rows to provide P populated rows, resulting in a second structure.
27. Display device (1 ) according to any of claims 19 to 25, wherein the first structure is replicated in consecutive columns, by permutating or rearranging the light emitting elements of the first structure, in consecutive columns, and provide a second structure.
28. Display device (1 ) according to claims 26 and 27, wherein the second structure is repeated in consecutive rows and/or columns, by permutating or rearranging the light emitting elements of the second structure, and provide a third structure.
29. Display device (1 ) according to any preceding claims, wherein the light emitting elements are arranged in rows and columns ensuring a substantially constant spacing between light emitting elements, or a spacing adapted to the aperture ratio to be provided by the display.
30. A method to manufacture the display device (1 ) according to any one of the preceding claims, and comprising the following steps:
- providing a panel (5) comprising a plurality of light emitting elements (10), said panel (5) comprising apertures (11 ) of size A along a direction D and through which the light emitting elements (10) can emit light;
- providing a lenticular sheet (20) comprising a plurality of lenticulars (21 ) each having a lenticular pitch LP, said width LP being a multiple larger than 1 of said size A;
- placing the lenticular sheet (20) such that it faces the panel (5) and such that each lenticular (21 ) is facing a number of N zones (51 , 52, 53, 54, 55, 56, 57, 58, etc.) of the panel (5), said N zones (51 , 52, 53, 54, 55, 56, 57, 58, etc.) corresponding to N different possible views of said display device (1 ), the number N being larger than 1 , the lenticular sheet is facing at least two zones corresponding to an aperture position, and wherein for at least one lenticular (21 ), some of the zones (51 , 52, 53, 54, 55, 56, 57, 58, etc.) of the panel (5) along a direction D’, perpendicular to direction D facing it are free of any aperture (11 ), wherein the zones free of any aperture follow a periodic pattern or uniform distribution along direction D.
31 . The method according to the preceding claim, wherein N is the ratio between LP and A rounded to the nearest integer.
32. The method according to any of the two preceding claims, wherein said lenticular sheet (20) has a thickness d equal to d = n. A.L/VCWwhere
- n is a refractive index of a lenticular material of the lenticular sheet (20)
- L is an observation distance
- VCW is the view cone width at the observer position.
33. The method according to any of the three preceding claims, wherein the panel (5) comprises tiles assembled together.
34. The method according to any of the four preceding claims, the lenticulars from a multiplicity of sets of at least two lenticulars, N lighting elements being spread over a set of lenticulars such that a lenticular set is facing a total of N light emitting elements (10) at the N possible positions.
35. The method according to the preceding claim, wherein the sets of lenticulars form a periodicity.
36. The method according to preceding claim, wherein the periodicity of the set of lenticulars is related to a row of light emitting elements or is related to a set of rows of light emitting elements.
37. A panel (5) for a display device according to any of claims 1 to 29, wherein the panel comprises tiles assembled together.
38. A panel (5) for a display device according to claim 37, wherein the panel comprises at least a set of identical tiles, or a plurality of sets of identical tiles.
39. A tile for a panel according to claims 37 or 38, wherein each tile of a set comprises at least a first row of N lighting elements, the N lighting elements being configured to be spread over a set of P lenticulars such that a lenticular set is facing a total of N light emitting elements (10) at the N possible positions, and wherein the arrangement of the N lighting elements under the set of P lenticulars forms a first structure.
40. Tile according to claim 39, wherein the lighting elements are configured to provide for at least one lenticular of the P lenticulars all of the zones (51 , 52, 53, 54, 55, 56, 57, 58, etc.) along direction D’ of the panel (5) free of any aperture (11 ).
41 . Tile according to any of claims 39 or 40, wherein P>N or wherein P>N.
42. Tile according to claim 41 , wherein the first structure is replicated in consecutive rows to provide P populated rows.
43. Tile according to any of claims 39 to 42, wherein the first structure is replicated in consecutive columns.
44. Tile according to any of claims 39 to 43, wherein the first structure is replicated in consecutive rows, by permutating or rearranging the light emitting elements in the first structure, in consecutive rows to provide P populated rows, resulting in a second block structure.
45. Tile according to any of claims 39 to 44, wherein the first structure is replicated in consecutive columns, by permutating or rearranging the light emitting elements of the first structure, in consecutive columns.
46. Tile according to claims 44 and 45, wherein the second structure is repeated in consecutive rows and/or columns, by permutating or rearranging the light emitting elements of the second block structure, resulting in a third block structure.
47. Tile according to claim 46, comprising at least one of a second block structure, or a third block structure, or a plurality of block structures being permutations or rearrangements of one another, the arrangement of the block structures determining a set of identical tiles.
48. Tile according to any of claims 39 to 47, wherein the light emitting elements are arranged in rows and columns ensuring a substantially constant spacing between light emitting elements, or a spacing adapted to the apect ratio to be provided by the display.
49. Tile according to any of claims 39 to 48, wherein an absorption layer is provided at the edges of the tile.
EP24714480.1A 2023-03-24 2024-03-25 Display device and method to manufacture the display device Pending EP4689774A1 (en)

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