Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
  • G06F1/16—Constructional details or arrangements
  • G06F1/1613—Constructional details or arrangements for portable computers
  • G06F1/1633—Constructional details or arrangements of portable computers not specific to the type of enclosures covered by groups G06F1/1615 - G06F1/1626
  • G06F1/1656—Details related to functional adaptations of the enclosure, e.g. to provide protection against EMI, shock, water, or to host detachable peripherals like a mouse or removable expansions units like PCMCIA cards, or to provide access to internal components for maintenance or to removable storage supports like CDs or DVDs, or to mechanically mount accessories
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
  • G06F1/16—Constructional details or arrangements
  • G06F1/1613—Constructional details or arrangements for portable computers
  • G06F1/1633—Constructional details or arrangements of portable computers not specific to the type of enclosures covered by groups G06F1/1615 - G06F1/1626
  • G06F1/1637—Details related to the display arrangement, including those related to the mounting of the display in the housing
  • G06F1/1643—Details related to the display arrangement, including those related to the mounting of the display in the housing the display being associated to a digitizer, e.g. laptops that can be used as penpads
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
  • G06F3/0412—Digitisers structurally integrated in a display
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
  • G06F3/042—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
  • G06F3/042—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means
  • G06F3/0421—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means by interrupting or reflecting a light beam, e.g. optical touch-screen
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
  • G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
  • G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
  • G06V40/12—Fingerprints or palmprints
  • G06V40/13—Sensors therefor
  • G06V40/1318—Sensors therefor using electro-optical elements or layers, e.g. electroluminescent sensing
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F2203/00—Indexing scheme relating to G06F3/00 - G06F3/048
  • G06F2203/041—Indexing scheme relating to G06F3/041 - G06F3/045
  • G06F2203/04107—Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds

Definitions

• the present description generally relates to electronic devices and, more particularly, to devices comprising a display screen and an image sensor.
• the present description applies more particularly to electronic devices in which the image sensor has a function of a fingerprint sensor.
• EP-A-2 458 482 discloses an array of pixels in which an EMI filter is provided which covers data lines and is interposed between a read line and a data line.
• the EMI filter is an open mesh.
• One embodiment provides for reducing all or part of the disadvantages of the known techniques of integrating an image sensor serving as a fingerprint sensor under a display screen.
• One embodiment provides a solution compatible with the integration of the sensor under all or part of the screen.
• One embodiment provides a solution particularly suitable for OLED screens.
• an embodiment provides a device having a display screen and an image sensor, wherein a first electromagnetic shielding light permeable layer is disposed between active portions of the screen and active portions of the sensor. image.
• the image sensor is a fingerprint sensor.
• the first layer is intended to be connected, preferably connected, to a mass of the device.
• a second electromagnetic shielding layer intended to be connected, preferably connected to a mass of the device is arranged between the image sensor and an electronic card.
• said first layer is made of metal, preferably gold, and has a thickness of less than 10 nm, preferably less than 5 nm.
• said first layer is made of metal oxide, preferably an indium tin oxide (ITO), and has a thickness of less than 100 ⁇ m.
• ITO indium tin oxide
• said first layer is made of transparent conductive polymer, preferably PEDOT: PSS, and has a thickness of less than 10 ⁇ m.
• the first transparent polymer layer is full plate.
• said first layer integrates a network of silver nanowires.
• the surface of said first layer corresponds at least to the facing surface between the screen and the sensor.
• said first layer is disposed between an optical filter and a support of the screen.
• said first layer is disposed between an optical filter and an encapsulation layer of the sensor.
• said first layer is integrated in an optical filter interposed between the sensor and the screen.
• One embodiment provides a display screen, wherein said first layer is formed between an insulating support of the screen and a substrate from which the screen components are formed.
• One embodiment provides a display screen, wherein said first layer is formed between a substrate from which the screen components are formed and a buffer layer separating said substrate from a semiconductor stack producing transistors.
• One embodiment provides an image sensor, wherein said first layer is formed between a transparent layer defining photodiode electrodes of the sensor and an overlying encapsulation layer.
• One embodiment provides a mobile phone having at least one device as described.
• One embodiment provides a connected watch comprising at least one device as described.
• One embodiment provides a touch pad having at least one device as described.
• One embodiment provides a computer comprising at least one device as described.
• Figure 1 is a schematic sectional view of an embodiment of an electronic device incorporating an image sensor behind a display screen
• FIG. 2 is a schematic and partial sectional view of an exemplary embodiment of an OLED type display screen
• Figure 3 shows, schematically and partially, in section, an embodiment of an image sensor
• FIG. 4 illustrates an embodiment of an electronic device incorporating a screen and an image sensor
• FIG. 5 illustrates another embodiment of an electronic device integrating a screen and an image sensor
• FIG. 6 illustrates another embodiment of an electronic device incorporating a screen and an image sensor
• FIG. 7 illustrates another embodiment of an electronic device incorporating a screen and an image sensor
• FIG. 8 illustrates another embodiment of an electronic device incorporating a screen and an image sensor
• Figure 9 illustrates another embodiment of an electronic device incorporating a screen and an image sensor. detailed description
• a display screen for example an organic light-emitting diode (OLED) -type screen, is generally integrated in an electronic device of the mobile phone, connected watch, tablet or computer type, and is reported on an electronic board (board) carrying the electronic components of the device.
• a copper layer is then generally attached to the back of the screen and is connected to the ground to reduce the electromagnetic interference between the screen and the electronic components.
• a particular shielding layer having the property of allowing light to pass to the image sensor.
• the layer for reducing the electromagnetic disturbances, carried by the electronic card is maintained but is offset under the image sensor.
• Figure 1 is a schematic sectional view of an embodiment of an electronic device incorporating a fingerprint sensor behind a display screen. According to this embodiment, shown in a simplified manner, the device comprises successively, from the outside (the upper face):
• a display screen 1, preferably of the OLED type; a layer 3, conductive and permeable to light, intended to be electrically connected, preferably connected, to a mass of the device;
• an electronic card 7 carrying various components (not shown), functions of the destination of the electronic device.
• the screen does not necessarily cover the entire surface of the electronic card, typically if the screen is smaller than the electronic card. The opposite is also possible (electronic card smaller than the screen).
• the presence of the layer 3 reduces the noise coming from the screen 1 and in particular the electronic elements that it contains.
• the layer 3 provides an electromagnetic shielding function between the active parts of the screen 1 and the active parts of the image sensor 5. As this layer 3 is permeable to light (the layer 3 is preferably transparent), it does not interfere with the operation of the image sensor 5.
• the layer 3 is disposed between the active elements (capturing the light) of the image sensor and the electronic components (generating switching noise) of the screen.
• the conductive layer 3 is sufficiently thin, preferably of a thickness less than 100 ⁇ m, and more preferably less than a few ⁇ m, to remain compatible with integration with an integrated footprint sensor under a flat screen, preferably of the OLED type, without increasing the overall thickness too much.
• the layer 3 is preferably made of a material chosen from:
• a metal preferably gold, which is sufficiently thin (with a thickness of less than 10 nm, preferably less than 5 nm) to be transparent while maintaining, at this small thickness, conductive properties which are sufficient for a function of shielding;
• a metal oxide for example an indium tin oxide (ITO);
• ITO indium tin oxide
• a conductive polymer having a thickness of less than 10 ⁇ m preferably of the PEDOT: PSS type (mixture of poly (3,4-ethylenedioxythiophene) and of sodium polystyrene sulphonate), which has the advantage of being already used in the manufacture of image sensors covered by this description;
• the layer transparent conductive 3 may however be integrated at different levels of the display screen 1 or the image sensor 5, especially in embodiments where it is intended to perform both (screen and sensor) separately and then postpone the screen 1 on the image sensor 5, itself reported on the electronic card 7.
• FIG. 2 is a schematic and partial cross-section of an embodiment of a screen display 1 of the OLED type.
• Figure 2 shows only one display pixel.
• Such a screen 1 generally comprises successively:
• PET polyethylene terephthalate
• a substrate 13 (generally flexible for OLED screens) made of an insulating material, for example polyimide;
• a buffer layer (insulating) between the active levels of the transistors and the underlying layers 11 and 13;
• a semiconductor stack 17 producing the individual control transistors of each pixel of the screen, this stack being, for example, symbolized in FIG. 2 by gate conductors 171, a gate dielectric layer 173, regions 175 of drain and source separated by active regions 179 (for example polysilicon or zinc-gallium-indium oxide (IGZO)) and a passivation layer 177;
• gate conductors 171 a gate dielectric layer 173, regions 175 of drain and source separated by active regions 179 (for example polysilicon or zinc-gallium-indium oxide (IGZO)) and a passivation layer 177;
• a transmission stack 19 carrying out the actual transmission, symbolized in FIG. 2 by pixelated emission zones 191 in a passivation layer 193 surmounted by a cathode 195, the drain or source layer 175 of the stack 17 defining the anode of each pixel;
• an optional tactile layer 23 (present in the touch screens);
• the transistors may be organic or inorganic (for example, amorphous silicon-based transistors based on metal oxide, for example zinc oxide -gallium-indium (IGZO), based on polycrystalline silicon, for example at low temperature (LTPS), etc.).
• IGZO zinc oxide -gallium-indium
• LTPS low temperature
• FIG. 2 is an example and other conventional screen structures, OLED or not, may be used for the implementation of the described embodiments.
• FIG. 3 is a schematic and partial sectional view of an exemplary embodiment of an image sensor 5. The case of a sensor based on organic materials as described in the aforementioned publications is assumed. Figure 3 represents only one pixel of the image sensor.
• Such a sensor 5 generally comprises:
• a substrate 51 for example glass in the case of a rigid sensor, or polyimide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN) or cycloolefin polymer (COP) or another polymer in the case of a flexible sensor, especially when the sensor 5 is derived from a manufacturing technology by printing;
• PET polyethylene terephthalate
• PEN polyethylene naphthalate
• COP cycloolefin polymer
• An active stack 53 of sensors consisting of transistors (gate 531, gate dielectric 533, active region 535, source 537, drain 539), the active region being for example based on amorphous silicon, on metal oxide, for example on zinc-gallium-indium oxide (IGZO), polycrystalline silicon for example at low temperature (LTPS), or transistors being thin-film organic transistors (OTFTs);
• transistors gate 531, gate dielectric 533, active region 535, source 537, drain 539
• the active region being for example based on amorphous silicon, on metal oxide, for example on zinc-gallium-indium oxide (IGZO), polycrystalline silicon for example at low temperature (LTPS), or transistors being thin-film organic transistors (OTFTs);
• a dielectric layer 55 isolating the stack 53 from a layer of first electrodes 57 with a rear face of photodiodes, generally connected to the drains 539 of the transistors;
• An encapsulation layer 62 An encapsulation layer 62;
• a layer 63 preferably constituting an optical filter for angular selection of the excitation signals of the image sensor.
• layers of adhesive are present between layers 61 and 62 and between layers 62 and 63.
• FIG. 3 is an example and other image sensor structures may be used for the implementation of the described embodiments.
• the optical filter 63 can be made separately from the image sensor 5.
• FIGS. 2 and 3 schematically illustrate screen structures and sensor whose operation is in itself usual and is not detailed.
• the layer 3 conductive and transparent, connected to ground, can be provided at different levels of the stacked structure of a screen and an image sensor.
• Figures 4, 5, 6, 7 and 8 illustrate different embodiments of this layer 3 according to its arrangement in the stack.
• These figures show, as specific embodiments, the structures illustrated in Figures 2 and 3 with respect to the screen and the image sensor.
• the layers taken from these structures are, for simplicity, symbolized by a single layer to which the references of the different layers of FIG. 2 or FIG. 3 it contains.
• an additional layer of metal shielding 9, preferably copper between the image sensor (under its substrate 51) and the electronic card 7.
• FIG. 4 illustrates an embodiment of an electronic device integrating a screen 1 and an image sensor 5.
• the layer 3, conductive and transparent, connected to the ground, is present between the layer 11 of transparent PET of the screen 1 and the optical filter 63.
• the embodiment of the layer 3 can then be part of manufacturing process of the screen 1, that of the sensor 5 if the filter 63 is made with the sensor, or the filter 63.
• FIG. 5 illustrates another embodiment of an electronic device integrating a screen 1 and an image sensor 5.
• the layer 3, conductive and transparent, connected to the ground, is formed between the insulating support 11 of the screen 1 and the flexible substrate 13 from which are formed the components of the screen, the substrate 13 being transparent.
• Figure 6 illustrates another embodiment of an electronic device incorporating a screen and an image sensor.
• the layer 3 conductive and transparent, connected to the ground, is formed between the substrate 13 and the buffer layer 15.
• FIG. 7 illustrates another embodiment of an electronic device integrating a screen 1 and an image sensor
• the layer 3, conductive and transparent, connected to ground, is arranged between the encapsulation layer 62 of the sensor 5 and the optical filter 63.
• a particularly simple embodiment is then to coat the encapsulation layer 62 of the sensor with a layer 3 in PEDOT: PSS, the manufacturing process of the sensor already in the technologies more particularly targeted by the present description, a step of depositing a PEDOT: PSS.
• the embodiment of the layer 3 is part of the manufacturing process of the filter 63 if this is done independently of the sensor 5.
• FIG. 8 illustrates another embodiment of an electronic device incorporating a screen 1 and an image sensor 5.
• the layer 3 conductive and transparent, connected to ground, is formed between the electrode layer 61 of photodiodes and the encapsulation layer 62 of the sensor 5.
• grounding of the shielding layer 3 may be effected by a ground connection at the display screen 1, at the image sensor 5 , and / or at the level of the electronic card 7.
• FIG. 9 illustrates yet another embodiment of an electronic device incorporating a screen 1, an optical filter 63 and an image sensor 5.
• the conductive and transparent layer 3, connected to the ground, is part of the optical filter 63 being embedded in the structure thereof.
• this mesh is connected to ground in order to carry out the shielding 3.
• the layer 3 may occupy a smaller area than the surface of the screen 1, provided that its surface covers the sensor 5 at least next to the screen 1.
• the layer 3 may therefore be of a different surface the surface of the sensor 5 and / or the surface of the screen 1 provided to cover the area between the two.
• the layer 3 is made of transparent polymer, preferably PEDOT: PSS
• PEDOT: PSS transparent polymer
• Such an embodiment is particularly interesting in the context of the realization of a fingerprint sensor where the meshed shielding structures may deteriorate the signal / noise ratio of the sensor.
• An advantage of the embodiments described is that they are compatible with the usual techniques for manufacturing the screen 1 and the image sensor 5.
• the insertion of the shielding layer 3, whether in the the manufacturing process of the screen (FIG. 5 or 6), in the manufacturing process of the image sensor (FIG. 7 or 8) or between the screen and the image sensor (FIG. 4), does not modify the active regions of the screen and the image sensor.
• Another advantage of the embodiments described is that they remain compatible with the use of a copper shield between the sensor / screen assembly and the electronic card.
• a device incorporating an image sensor 5 and a display screen 1 with the interposition of a conductive and transparent ITO shielding layer 3 has been produced in accordance with the embodiment of FIG. Figure 4 (layer 3 between the optical filter 63 and the substrate 11).
• the layer 3 has been connected to the ground of the electronic control circuits of the screen (mass of the circuits of the layer 17) and to the mass of the electronic reading circuits of the sensor (connected to the ground of the electronic card 7). Measurements were made by displaying a white image on the screen and noise and signal-to-noise measurements were made at the sensor for a black object and a reflective object placed on the screen with and without shielding layer.

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• Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Physics & Mathematics (AREA)
• Human Computer Interaction (AREA)
• Computer Hardware Design (AREA)
• Multimedia (AREA)
• Devices For Indicating Variable Information By Combining Individual Elements (AREA)
• Electroluminescent Light Sources (AREA)
• Image Input (AREA)
• Position Input By Displaying (AREA)
• User Interface Of Digital Computer (AREA)
• Solid State Image Pick-Up Elements (AREA)
• Transforming Electric Information Into Light Information (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=61224034

Family Applications (1)

Country Status (7)

Families Citing this family (4)

Family Cites Families (15)

• 2017
  • 2017-11-15 FR FR1760719A patent/FR3073648B1/fr active Active
• 2018
  • 2018-11-09 WO PCT/FR2018/052788 patent/WO2019097145A1/fr unknown
  • 2018-11-09 KR KR1020207015180A patent/KR20200086688A/ko not_active Application Discontinuation
  • 2018-11-09 CN CN201890001362.4U patent/CN212675539U/zh active Active
  • 2018-11-09 US US16/763,708 patent/US11775018B2/en active Active
  • 2018-11-09 JP JP2020526518A patent/JP7355737B2/ja active Active
  • 2018-11-09 EP EP18827149.8A patent/EP3710920A1/fr active Pending

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