Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/20—Filters
  • G02B5/201—Filters in the form of arrays
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B5/00—Optical elements other than lenses
  • G02B5/20—Filters
  • G02B5/22—Absorbing filters
  • G02B5/223—Absorbing filters containing organic substances, e.g. dyes, inks or pigments
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
  • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
  • H01L27/144—Devices controlled by radiation
  • H01L27/146—Imager structures
  • H01L27/14601—Structural or functional details thereof
  • H01L27/14625—Optical elements or arrangements associated with the device
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B2207/00—Coding scheme for general features or characteristics of optical elements and systems of subclass G02B, but not including elements and systems which would be classified in G02B6/00 and subgroups
  • G02B2207/123—Optical louvre elements, e.g. for directional light blocking
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B3/00—Simple or compound lenses
  • G02B3/0006—Arrays

Definitions

• TITLE Optical angular filter
• This description relates to an angular optical filter.
• the present description relates to an angular filter intended to be used within an optical system, for example an imaging system.
• An angular filter is a device making it possible to filter incident radiation as a function of the incidence of this radiation and thus block the rays whose incidence is greater than a maximum incidence.
• Angle filters are frequently used in conjunction with image sensors.
• One embodiment overcomes all or part of the drawbacks of known angular filters.
• One embodiment provides an angular filter comprising an array of microlenses, a first array of apertures in a layer of a first resin and a second array of apertures in a layer of a second resin, the first resin blocking at least one first and the second resin blocking a second radiation, different from the first radiation.
• the first radiation corresponds to radiation whose wavelength is between 700 nm and 1700 nm, preferably between 820 nm and 870 nm or between 910 nm and 970 nm.
• the second radiation corresponds to radiation whose wavelength is between 400 nm and 600 nm, preferably between 470 nm and 600 nm.
• the second radiation corresponds to radiation whose wavelength is between 600 nm and 700 nm, preferably between 600 nm and 680 nm.
• the openings of the first die are, in the direction perpendicular to the axis of the openings, of larger area than the openings of the second die, in said direction.
• first wavelength or first radiation e.g. visible + infrared
• second wavelength wave or second radiation for example visible only
• each opening of the first matrix has its center aligned with an opening of the second matrix and with the optical axis of a microlens.
• the angular filter comprises a protective layer between the first matrix of apertures and the second matrix of apertures.
• the first resin blocks the first radiation.
• the first resin blocks the second radiation.
• the openings of the first matrix are holes, for example filled with a material transparent to the second radiation and/or to the first radiation.
• the openings of the second matrix are holes, for example filled with a material transparent to the second radiation and/or to the first radiation.
• One embodiment provides a manufacturing method comprising the following steps: a. forming, on one face of an array of microlenses, a layer of a first resin so that the first resin and the planar faces of the microlenses face each other; b. irradiating the first resist layer with light through the array of microlenses and developing to form a first array of apertures in the first resist; vs. forming a layer of a second resin on the first array of apertures, on a face opposite the array of microlenses; and D. irradiating the layer of the second resin with light radiation through the array of microlenses and developing so as to form a second matrix of openings in the second resin, so as to obtain an angular filter as described above.
• the method comprises the following steps: a. forming, on one face of an array of microlenses, a layer of a transparent resin so that the transparent resin and the planar faces of the microlenses face each other; b. irradiating the layer of transparent resin with light radiation through the network of microlenses, developing so as to form a first matrix of pads in the transparent resin and filling the spaces between the pads with a first resin; vs . forming another layer of transparent resin on the first matrix, on a face opposite the array of microlenses; and D .
• the light radiation from step d) is collimated radiation.
• the light radiation from step b) is less collimated radiation than the light radiation from step d).
• the light radiation is identical and collimated in steps b) and d).
• the light radiation in steps b) and d) are ultraviolet radiation.
• the method comprises a step e), between step b) and step c), of forming a protective layer on and in contact with the first matrix.
• One embodiment provides an image sensor comprising at least: an image sensor consisting of a matrix of photodetectors; and an angular filter as described above.
• Figure 1 illustrates, by a block diagram, partial and schematic, an embodiment of an image acquisition system
• FIG. 2 shows, in a partial and schematic sectional view, an embodiment of an image acquisition device comprising an angular filter
• Figure 3 shows, in a sectional view, a step of a method of producing the image acquisition device illustrated in Figure 2;
• Figure 4 shows, in a sectional view, another step of a method of producing the image acquisition device illustrated in Figure 2;
• Figure 5 shows, in a sectional view, yet another step of a method of producing the image acquisition device illustrated in Figure 2;
• Figure 6 shows, in a sectional view, yet another step of a method of producing the image acquisition device illustrated in Figure 2;
• Figure 7 shows, in a sectional view, yet another step of a method of producing the image acquisition device illustrated in Figure 2;
• Figure 8 shows, in a sectional view, yet another step of a method for producing the image acquisition device illustrated in Figure 2.
• the expressions “all the elements”, “all the elements”, “each element”, mean between 95% and 100% of the elements.
• a layer or a film is said to be opaque to radiation when the transmittance of the radiation through the layer or the film is less than 10%.
• a layer or a film is said to be transparent to radiation when the transmittance of the radiation through the layer or the film is greater than 10%.
• all the elements of the optical system which are opaque to radiation have a transmittance which is less than half, preferably less than a fifth, more preferably less than a tenth, of the transmittance the weakest of the elements of the optical system transparent to said radiation.
• useful radiation is used to refer to the electromagnetic radiation passing through the optical system in operation.
• optical element of micrometric size refers to an optical element formed on one face of a support whose maximum dimension, measured parallel to said face, is greater than 1 ⁇ m and less than 1 mm.
• each micrometric-sized optical element corresponds to a micrometric-sized lens, or microlens, composed two diopters.
• each optical element of micrometric size being able to correspond, for example, to a Fresnel lens of micrometric size, to a micron-sized gradient index lens or to a micron-sized diffraction grating.
• visible light is electromagnetic radiation whose wavelength is between 400 nm and 700 nm
• green light is electromagnetic radiation whose wavelength is between 400 nm and 600 nm, more preferably between 470 nm and 600 nm.
• Infrared radiation is electromagnetic radiation with a wavelength between 700 nm and 1 mm. In infrared radiation, a distinction is made in particular between near-infrared radiation, the wavelength of which is between 700 nm and 1.7 ⁇ m, more preferably between 850 nm and 940 nm.
• Figure 1 illustrates, by a block diagram, partial and schematic, an embodiment of an image acquisition system 11.
• the image acquisition system 11, illustrated in FIG. 1, comprises: an image acquisition device 13 (DEVICE); and a processing unit 15 (PU).
• DEVICE image acquisition device 13
• PU processing unit 15
• the processing unit 15 preferably comprises signal processing means provided by the device 11, not shown in Figure 1.
• the processing unit 15 comprises, for example, a microprocessor.
• the device 13 and the processing unit 15 are preferably connected by a connection 17.
• the device 13 and the processing unit 15 are, for example, integrated in the same circuit.
• Figure 2 shows, in a sectional view, partial and schematic, an embodiment of an image acquisition device 19 comprising an angular filter.
• the image acquisition device 19 shown in Figure 2 comprises, from bottom to top in the orientation of the figure: an image sensor 21; and an angular filter 23, covering the image sensor 21.
• the embodiments of the devices of FIGS. 2 to 8 are represented in space according to a direct orthogonal XYZ frame, the Y axis of the XYZ frame being orthogonal to the upper face of the image sensor. 21.
• the image sensor 21 comprises an array of photon sensors 25, also called photodetectors.
• the photodetectors 25 are preferably arranged in matrix form.
• the photodetectors 25 may be covered with a protective coating, not shown.
• the photodetectors 25 all have the same structure and the same properties/characteristics. In other words, all the photodetectors 25 are substantially identical within manufacturing tolerances.
• the photodetectors 25 do not all have the same characteristics and may be sensitive to different wavelengths.
• photodetectors 25 can be sensitive to infrared radiation and photodetectors 25 can be sensitive to green radiation.
• the image sensor 21 further comprises conductive tracks and switching elements, in particular transistors, not shown, allowing the selection of the photodetectors 25.
• the photodetectors 25 are preferably made of organic materials.
• the photodiodes 25 are, for example, organic photodiodes (OPD, Organic Photodiode) integrated on a substrate with CMOS transistors (Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor) or a substrate with thin film transistors (TFT or Thin Film Transistor).
• OPD organic photodiodes
• CMOS transistors Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor
• TFT or Thin Film Transistor Thin Film Transistor
• the channel, source and drain regions of TFT transistors are for example made of amorphous silicon (a-Si or amorphous Silicon), indium, gallium, zinc and oxide (IGZO Indium Gallium Zinc Oxide) or low temperature polycrystalline silicon ( LTPS or Low Temperature Polycrystalline Silicon)
• the photodiodes 25 of the image sensor 21 comprise, for example, a mixture of organic semiconductor polymers such as poly (3-hexylthiophene) or poly (3-hexylthiophene-2, 5-diyl), known under the name P3HT, mixed with methyl [6,6]-phenyl-C61-butanoate (N-type semiconductor), known as PCBM.
• the photodiodes 25 of the image sensor 21 comprise, for example, small molecules, that is to say molecules having molar masses of less than 500 g/mol, preferably less than 200 g/mol .
• the photodiodes 25 can be inorganic photodiodes, for example, made from amorphous silicon or crystalline silicon.
• the photodiodes 25 are composed of quantum dots.
• each photodetector 25 is suitable for detecting visible radiation and/or near-infrared radiation.
• the angular filter 23 comprises: an array 27 of microlenses 29 of micrometric size, for example plano-convex; a first matrix 31 or layer of holes or openings 33, for example filled with a material transparent to a first radiation 203 and/or to a second radiation 201, delimited by walls 35 of a first resin opaque to the first radiation 203 and optionally opaque to the second radiation 201; and a second matrix 37 or layer of holes or openings 39, for example filled with a material transparent to the second 201 and/or first 203 radiation, delimited by walls 41 of a first resin opaque to the second radiation 201.
• the radiation 201 preferably comprises at least one or more wavelengths in the green and/or in the blue, that is to say one or more wavelengths of wave between 400 nm and 600 nm, preferably between 470 nm and 600 nm.
• the wavelengths that make up the radiation 201 are, for example, all between 400 nm and 600 nm, preferably between 470 nm and 600 nm.
• the radiation 201 preferably comprises at least one or more wavelengths in the red, that is to say one or more wavelengths between 600 nm and 700 nm, preferably between 600 nm and 680 nm.
• the wavelengths that make up the radiation 201 are, for example, all between 600 nm and 700 nm, preferably between 600 nm and 680 nm.
• the radiation 203 preferably comprises at least one or more wavelengths in the near-infrared, that is to say one or more wavelengths between 700 nm and 1700 nm, preferably between 820 nm and 870 nm and/or between 910 nm and 970 nm.
• the wavelengths that make up the radiation 203 are, for example, all between 700 nm and 1700 nm, preferably between 820 nm and 870 nm and/or between 910 nm and 970 nm.
• the array 27 of microlenses 29 is formed on a substrate or support 30 and in contact with the latter, the substrate 30 then being interposed between the microlenses 29 and the matrix 31.
• the substrate 30 may be made of a transparent polymer which does not absorb, at least, the wavelengths considered, here in the visible and near-infrared range.
• This polymer may in particular be poly (ethylene terephthalate) PET, poly (methyl methacrylate) EMMA, cyclic olefin polymer (COP), polyimide (PI), polycarbonate (PC).
• the thickness of the substrate 30 can vary between 1 ⁇ m and 100 ⁇ m, preferably between 10 ⁇ m and 100 ⁇ m.
• the substrate 30 can correspond to a colored filter, to a polarizer, to a half-wave plate or to a quarter-wave plate.
• the microlenses 29 can be made of silica, of PMMA, of a positive photosensitive resin, of PET, of poly(ethylene naphthalate) (PEN), of COP, of polydimethylsiloxane (PDMS)/silicone, of epoxy resin or in acrylate resin.
• the microlenses 29 can be formed by creeping blocks of a photosensitive resin.
• the microlenses 29 can additionally be formed by molding on a layer of PET, PEN, COP, PDMS/silicone, epoxy resin or acrylate resin.
• the microlenses 29 are converging lenses each having a focal distance f of between 1 ⁇ m and 100 ⁇ m, preferably between 1 ⁇ m and 70 ⁇ m. According to one embodiment, all the microlenses 29 are substantially identical.
• the microlenses 29 and the substrate 30 are preferably made of transparent or partially transparent materials, that is to say transparent in part of the spectrum considered for the targeted domain. , for example, imaging, over the range of wavelengths corresponding to the wavelengths used when exposing an object to be imaged.
• the flat faces of the microlenses 29 face the openings 33.
• the microlenses 29 are organized in the form of a grid of rows and columns.
• the microlenses 29 are, for example, aligned.
• the repeating pattern of the microlenses 29 is, for example, a square in which microlenses 29 are located at the four corners of the square.
• the microlenses 29 are organized in the form of a grid of rows and staggered columns.
• the repeating pattern of the microlenses 29 is, for example, a square in which the microlenses 29 are located at the four corners and in the center of the square.
• the thickness of the walls 35 is called "hl".
• the walls 35 are, for example, opaque to radiation 203 and optionally to radiation 201, for example absorbing and/or reflecting to radiation 203 and optionally to radiation 201.
• the upper face 31s of the layer 31 is called the face of the layer 31 located at the interface between the layer 31 and the substrate 30. Also referred to as the lower face 31i of the layer 31 the face of the layer 31 located opposite the upper face 31s.
• each opening 33 can have a trapezoidal, rectangular or funnel-shaped shape.
• Each opening 33 seen from above (that is to say in the XZ plane), can have a circular, oval or polygonal shape, for example triangular, square, rectangular or trapezoidal.
• Each opening 33 viewed from above, has a preferably circular shape.
• the width of an opening 33 is defined as the characteristic dimension of the opening 33 in the plane XZ. For example, for an opening 33 having a square section in the XZ plane, the width corresponds to the dimension of one side and for an opening 33 having a circular section in the XZ plane, the width corresponds to the diameter of opening 33.
• the center of an opening is called 33 the point located at the intersection of the axis of symmetry of the openings 33 and the lower face 31i of the layer 31.
• the center of each opening 33 is located on the axis of aperture revolution 33.
• the openings 33 of the layer 31, respectively the openings 39 of the layer 37 are organized in the form of a grid of rows and columns.
• the openings 33, respectively the openings 39 are, for example, aligned.
• the repeating pattern of the openings 33, respectively of the openings 39 is, for example, a square in which the openings 33, respectively the openings 39, are located at the four corners of the square.
• the openings 33 of the layer 31, respectively the openings 39 of the layer 37 are organized in the form of a grid of rows and staggered columns.
• the repeating pattern of the openings 33, respectively of the openings 39 is, for example, a square in which the openings 33, respectively the openings 39, are located at the four corners and in the center of the square.
• the openings 33 can all have substantially the same dimensions.
• the width of the openings 33 is called “wl” (measured at the base of the openings, that is to say at the interface with the substrate 30).
• wl the repetition pitch of the openings 33, that is to say the distance, along the X axis or the Z axis, between the centers of two successive openings 33 of a row or a column.
• the pitch pl can be between 5 ⁇ m and 50 ⁇ m, for example be equal to about 12 ⁇ m.
• the height hl can be between 1 ⁇ m and 1 mm, preferably between 2 p.m. and 3 p.m.
• the width wl is preferably between 0.5 ⁇ m and 25 ⁇ m, for example approximately equal to 10 ⁇ m.
• Each aperture 33 is preferably associated with a single microlens 29 of the array 27.
• the optical axes of the microlenses 29 are preferably aligned with the centers of the apertures 33 of the matrix 31.
• the diameter of the microlenses 29 is , preferably greater than the maximum section (measured perpendicular to the optical axes) of the openings 33.
• the structure associating the network 27 of microlenses 29 and the matrix 31 is adapted to filter the incident radiation according to its wavelength and the incidence of the radiation with respect to the optical axes of the microlenses 29 of the network 27.
• the structure is adapted to filter the incident rays, arriving on the microlenses, according to their incidences and their wavelengths.
• the structure associating the network 27 of microlenses 29 and the matrix 31 is adapted to block the rays of the first radiation 203 and optionally of the second radiation 201 whose respective incidences with respect to the optical axes of the microlenses 29 of the filter 23 are greater than maximum first incidence.
• This structure is adapted to only let through, in the range of wavelengths considered, rays whose incidence relative to the optical axes of the microlenses 29 is less than the first maximum incidence.
• the structure only lets through incident rays having an incidence of less than 15°, preferably less than 10°.
• the openings 33 are, for example, filled with air, a partial vacuum or a material at least partially transparent to the first 203 and second 201 radiation.
• Layer 31 and layer 37 can optionally be separated by a protective layer 43.
• Layer 43 covers the underside 31i of layer 31.
• Layer 43 is, for example, a plastic layer such as a PET layer. , COP, PEN, PI, a layer of an epoxy or acrylate resin or an inorganic layer such as silicon nitride deposited by a PVD or PECVD technique.
• Layer 43 has, for example, a thickness of between 0.2 ⁇ m and 50 ⁇ m, preferably of the order of 2 ⁇ m.
• the thickness of the walls 41 is called "h2".
• the walls 41 are, for example, opaque to the radiation 201, for example absorbing and/or reflecting the radiation 201.
• the upper face 37s of the layer 37 is called the face of the layer 37 located at the interface between the layer 37 and the layer 43. Also referred to as the lower face 37i of the layer 37 the face of the layer 37 located opposite the upper face 37s.
• each opening 39 can be trapezoidal, rectangular or funnel-shaped.
• Each opening 39, seen from above can have a circular, oval or polygonal shape, for example triangular, square, rectangular or trapezoidal.
• Each opening 39, seen from above preferably has a shape similar to the shape of an opening 33.
• the width of an opening 39 defines the characteristic dimension of the opening 39 in the XZ plane. For example, for an opening 39 having a square section in the XZ plane, the width corresponds to the dimension of one side and for an opening 39 having a section of circular shape in the XZ plane, the width corresponds to the diameter of the opening 39.
• the center of an opening 39 is called the point located at the intersection of the axis of symmetry of the openings 39 and of the lower face 37i of the layer 37.
• the center of each opening 39 is located on the axis of revolution of the opening 39.
• the openings 39 are arranged in rows and in columns.
• the openings 39 can all have substantially the same dimensions.
• the width of the openings 39 is called “w2" (measured at the base of the openings, that is to say at the interface with the layer 43).
• w2 the width of the openings 39
• p2 the repetition pitch of the openings 39, that is to say the distance, along the X axis or the Z axis, between the centers of two successive openings 39 of a row or a column.
• the pitch p2 is preferably equal to the pitch pl and can thus be between 5 ⁇ m and 50 ⁇ m, for example be equal to approximately 12 ⁇ m.
• the height h2 is, for example, between 1 ⁇ m and 1 mm, and preferably between 2 ⁇ m and 10 ⁇ m.
• the width w2 is preferably less than the width wl and can thus be between 5 ⁇ m and 50 ⁇ m, for example be equal to approximately 6 ⁇ m.
• Each aperture 39 is preferably associated with a single microlens 29 of the array 27.
• the optical axes of the microlenses 29 are preferably aligned with the centers of the apertures 39 of the matrix 31.
• the diameter of the microlenses 29 is , preferably greater than the maximum section (measured perpendicular to the optical axes) of the openings 39.
• the structure associating the network 27 of microlenses 29 and the matrix 37 is adapted to filter the radiation incident as a function of its wavelength and the incidence of the radiation with respect to the optical axes of the microlenses 29 of the grating 27.
• the structure is adapted to filter the incident rays, arriving on the microlenses, by according to their incidences and their wavelengths.
• the structure associating the network 27 of microlenses 29 and the matrix 37 is adapted to block the rays of the second radiation 201 whose respective incidences relative to the optical axes of the microlenses 29 of the filter 23 are greater than a second maximum incidence, lower than the first incidence maximum.
• This structure is adapted to only let through, in the range of wavelengths considered, rays whose incidence relative to the optical axes of the microlenses 29 is less than the second maximum incidence.
• the structure only lets through incident rays having an incidence of less than 5°, preferably less than 3.5°.
• the openings 39 are, for example, filled with air, a partial vacuum or a material at least partially transparent to the first 203 and second 201 rays.
• the material filling the openings 39 preferably forms a layer 47 on the lower face 37i of the matrix 37 so as to cover the walls 41 and planarize said lower face 37i of the matrix 37.
• each photodetector 25 is associated with four openings 33 (it is for example associated with two openings 33 along the X axis and with two openings 33 along the Z axis) and four openings 39.
• the resolution of the angular filter 23 can be more than four times higher than the resolution of the image sensor 21.
• the microlenses 29 are preferably covered by a layer 45 of planarization.
• Layer 45 is made of a material that is at least partially transparent to first 203 and second 201 radiation.
• a color filter is deposited on the surface of the device 19 or inside it, for example, between the angular filter 23 and the image sensor 21.
• An advantage of this embodiment is that it makes it possible to capture the radiation 201 only for incidences below 5°, preferably below 3.5° and the radiation only for incidences below 15°, preferably less than 10°. This filtration by incidence and by wavelength allows the image sensor 21 to capture images in the green or in the infrared having optimal resolutions.
• Figure 3 shows, in a sectional view, a step of a method for producing the image acquisition device illustrated in Figure 2.
• FIG. 3 illustrates a structure 49 comprising the array 27 of microlenses 29 surmounted, optionally by the layer 45.
• Figure 4 shows, in a sectional view, another step of a method for producing the image acquisition device illustrated in Figure 2.
• FIG. 4 illustrates a structure 51 obtained at the end of a step of depositing layer 31 of the first resin on the underside of structure 49 illustrated in FIG. 3.
• the layer 31 of the first resin absorbing at least in the first radiation 203, is deposited, full plate, on the underside of the structure 49, for example, by a spin coating technique.
• the layer 31 is deposited over a thickness hl equivalent to the thickness of the walls 35 made subsequently.
• Figure 5 shows, in a sectional view, yet another step of a method for producing the image acquisition device illustrated in Figure 2.
• FIG. 5 illustrates a structure 53 obtained at the end of a step of exposure of layer 31 of structure 51 illustrated in FIG. 4.
• layer 31 of structure 51 is exposed to radiation, for example ultraviolet (UV) radiation.
• radiation for example ultraviolet (UV) radiation.
• the exposure is carried out through the array 27 of microlenses 29, that is to say that the rays of said radiation pass through the array 27 of microlenses 29 before reaching the layer 31 via its upper face 31s.
• the insolation radiation is non-collimated, that is to say that the rays of the radiation do not all arrive parallel to each other at the surface of the microlenses 29.
• Each ray of the insolation radiation will thus pass through a microlens 29 and come out without necessarily passing through the image focal point of this microlens.
• the rays will then pass through the layer 31 over widths substantially equal to the width wl.
• the layer 31 After development, that is to say following rinsing with a developer solution, the layer 31 comprises the openings 33 delimited by the walls 35. Each opening 33 thus has a width wl. The repetition pitch pl between two openings 33 is equal to the repetition pitch of the microlenses 29. At the end of the development step, the openings 33 can be filled with a planarization layer, for example, in PDMS.
• a layer of resin transparent to radiation 201 and 203 is deposited on the surface of the lower face of the structure 49 illustrated in FIG. 3, that is to say on the surface of the underside of the substrate 30.
• the transparent resin layer can then be exposed by UV radiation and then developed so as to form studs similar to the openings 33 illustrated in FIG. 5 when they are filled with a transparent resin.
• the spaces between two pads are then filled with a material opaque at least to radiation 203 so as to form the walls 35.
• Figure 6 shows, in a sectional view, yet another step of a method for producing the image acquisition device illustrated in Figure 2.
• FIG. 6 illustrates a structure 55 obtained at the end of an optional step of depositing layer 43 on the underside of structure 53 illustrated in FIG. 5.
• the openings 33 of the structure 53 illustrated in FIG. 5 are preferably filled with a transparent material, with air, a gas or a vacuum. semi-partial.
• the optional layer 43 is produced by full plate deposition, for example by centrifugation, on the lower face of the structure 53 illustrated in FIG. 5, more precisely on the lower face 31i of the layer 31.
• FIG. 7 shows, by a sectional view, yet another step of a method for producing the image acquisition device illustrated in Figure 2. More particularly, FIG. 7 illustrates a structure 57 obtained at the end of a step of depositing layer 37 of the second resin on the underside of structure 55 illustrated in FIG. 6.
• the layer 37 of the first resin, absorbing at least in the second radiation 201 but not absorbing in the first radiation 203, is deposited, full plate, on the lower face of the structure 55, for example, by a spin coating technique. Layer 37 is deposited over a thickness h2 equivalent to the thickness of the walls 41 made subsequently.
• Figure 8 shows, in a sectional view, yet another step of a method for producing the image acquisition device illustrated in Figure 2.
• FIG. 8 illustrates a structure 59 obtained at the end of a step of exposure of layer 37 of structure 57 illustrated in FIG. 7.
• layer 37 of structure 57 is exposed to radiation, for example ultraviolet (UV) radiation.
• radiation for example ultraviolet (UV) radiation.
• the exposure is carried out through the array 27 of microlenses 29, that is to say that the rays of said radiation pass through the array 27 of microlenses 29 before reaching the layer 37 via its upper face 37s.
• the insolation radiation is collimated, that is to say that the rays of the radiation all arrive parallel to each other at the surface of the microlenses 29.
• Each ray of the insolation radiation will thus pass through a microlens 29 and come out of it while passing by the image focal point of this microlens located, preferably, near the lower face of the layer 37, that is to say the face of the layer 37 opposite the layer 43.
• layer 37 After development, that is to say following rinsing with a developer solution, layer 37 comprises openings 39 delimited by walls 41. Each opening 39 thus has a width w2.
• the repetition pitch pl between two openings 39 is equal to the repetition pitch of the microlenses 29.
• the difference between the width wl and the width w2 comes from the fact that the respective apertures are made with radiation whose collimation is different. Indeed on the one hand the openings 33 are made using a slightly divergent radiation therefore more extensive at the output of the microlenses 29 and on the other hand the openings 39 are made using a collimated radiation therefore less extended at the output of the microlenses 29.
• the difference between the width wl and the width w2 comes from the fact that the respective openings are made with the same microlenses 29. Indeed, the distance between the image focal points of the microlenses 29 and the layer 31 is greater. than the distance between the image foci of the microlenses 29 and the layer 37. Thus, the width of the cone of radiation of each microlens 29 passing through the layer 31 will be greater than the width of the same cone of radiation passing through the layer 37, the width of the radiation cone being substantially zero at the image focus of this same microlens 29.
• layer 37 may alternatively be formed by depositing a layer of radiation-transparent resin 201 and 203 on the surface of the underside of structure 55 illustrated in FIG. that is to say on the surface of the lower face of the layer 43.
• the transparent resin layer can then be exposed by UV radiation and then developed so as to form studs similar to the openings 39 illustrated in figure 8 when they are filled with a transparent resin
• the spaces between two pads are then filled with a material opaque to radiation 201 so as to form the walls 41.
• An advantage of the embodiments and modes of implementation described is that they make it possible to filter the incident radiation both angularly, but also according to the wavelengths.

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• 2020
  • 2020-12-14 FR FR2013145A patent/FR3117613A1/fr active Pending
• 2021
  • 2021-11-22 WO PCT/EP2021/082406 patent/WO2022128339A1/fr active Application Filing
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  • 2021-11-22 JP JP2023536172A patent/JP2023553660A/ja active Pending
  • 2021-11-22 EP EP21815508.3A patent/EP4260105A1/de active Pending
  • 2021-11-22 US US18/266,559 patent/US20240053519A1/en active Pending

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