Screen for performing physiological measurements

Abstract

The invention relates to a measurement and display device comprising a first electrode and a second electrode, and a screen formed by a plurality of pixels, wherein each pixel comprises three light-emitting diodes emitting in the visible range, a light-emitting diode emitting in the near-infrared range, an infrared photodetector, and a control electronics unit. The first and second electrodes are transparent, are at least partially arranged on the plurality of pixels, and connected to at least one control electronics unit of a pixel in the plurality of pixels. Advantageously, the device is configured to group the pixels according to a measurement zone for a physiological parameter by means of a plurality of programmable control blocks arranged within each pixel.

Description

[0001]

[0002] The present invention relates to the fields of optoelectronics and biomedical devices. It can be implemented for the production of so-called smart screens, equipped with display, detection and measurement functions. It finds a particularly advantageous application in the production of screens allowing biometric measurements to be carried out, in particular electrical measurements (electrocardiograms (ECG), bioimpedance (BioZ)) and / or optical measurements (photoplethysmography (PPG)) of physiological parameters (for example the heart rate and its variations).

[0003] STATE OF THE ART

[0004] The continued development of smartphones, tablets and smartwatches has led to the emergence of applications for controlling or monitoring various physiological parameters, such as heart rate.

[0005] An ECG is a test that records the electrical activity of the heart to assess its function. Technological advances have made it possible to miniaturize the ECG testing device and integrate it into wearable devices, such as smartwatches or connected watches. Smartwatches typically require the use of a back electrode and an electrode, generally located on the watch case. The back electrode can cause discomfort to the wearer of the watch. To ensure proper contact between the back electrode and the skin, the strap is typically tightened, which can increase discomfort for the user. Furthermore, to perform the ECG measurement, it is necessary to form an electrical conduction path through the heart, that is, to touch the electrode on the front of the watch with the other hand to have electrical contact points on either side of the heart.More generally, there is a need to improve the ergonomics and / or make the electrodes for ECG testing as discreet as possible in a portable device.

[0006] In particular, devices such as smartphones have a large screen area and few locations for adding electrodes on the smartphone body. One solution is to add a smartphone case that includes the electrodes. This requires the use of accessories. There is also a need for the ECG test to be simple to perform, so that the user experience is satisfactory.

[0007] Other alternative or complementary tests can also be considered using these portable devices. Some devices specialized in measuring physiological parameters, such as the Scanadu Scout™, for example, offer a combination of ECG and PPG tests. These specialized devices communicate with a smartphone via a dedicated app to record and / or present test results. Two devices are required for the user, which complicates the implementation of the tests.

[0008] There is also a need for a simple-to-use device that versatilely combines several functions for detecting, measuring and displaying physiological parameters.

[0009] An objective of the present invention is to at least partially meet this need.

[0010] In particular, an object of the present invention is a measuring and display device for simply performing at least one ECG test. Another object relates to a method of manufacturing such a device.

[0011] Other objects, features, and advantages of the present invention will become apparent from the following description and accompanying drawings. It is understood that other advantages may be incorporated.

[0012] SUMMARY OF THE INVENTION

[0013] To achieve this objective, according to one embodiment, a measuring and display device is provided comprising a first electrode, a second electrode, and a screen, said screen comprising a plurality of pixels. Each pixel comprises at least three light-emitting diodes and control electronics.

[0014] Advantageously, the first and second electrodes are transparent and arranged at least in part on the plurality of pixels, and the first and second electrodes are connected to at least one control electronics of a pixel among the plurality of pixels.

[0015] Thus, the first and second electrodes are located on the emissive side of the screen. They overlap the pixels of the screen. The first and second electrodes are typically directly controlled by one or more pixels, via the control electronics associated with these pixels. This arrangement makes it easier for the user to perform measurements, who manipulates the screen so as to see the display on the screen. According to one example, the screen displays instructions for positioning the user's fingers or hands directly on the screen, for example indicating the area of ​​the screen on which to place the fingers, then triggers an electrical measurement via the first and second electrodes, typically to perform an ECG. The handling is simple and quick for the user. Grouping all the display and measurement functions on the same emissive side of the screen facilitates the use of the device. The ergonomics of the device are improved.The electrodes are advantageously integrated into the screen. They do not require a specific location on the body of the device. Such integration is discreet and non-invasive.

[0016] Alternatively, other detection and / or measurement functions may be added to the screen pixels. For example, infrared diodes and infrared photodetectors may be integrated within the pixels, under one and / or the other of the first and second electrodes. This makes it possible to provide an “all-in-one” device, capable of performing various electrical and / or optical tests directly via the emissive screen of the device.

[0017] According to another aspect of the invention, there is provided a method of manufacturing a measuring and display device comprising the following steps:

[0018] - Producing on a first substrate a plurality of control electronics, each control electronic comprising at least four first addressing pads intended to be connected with three light-emitting diodes, said first addressing pads comprising three anodes and one cathode, and two first electrical measurement pads intended to be connected with the first and second electrodes,

[0019] - Forming on each control electronics of the first substrate the three light-emitting diodes on the three anodes, so as to form so-called intelligent display elements having an upper face on the side of the light-emitting diodes and a lower face on the side of the control electronics,

[0020] - Producing on a second substrate a plurality of pixel locations, said locations comprising four second addressing pads intended to be connected with the first addressing pads of the intelligent display elements, and two second electrical measurement pads intended to be connected with the first electrical measurement pads of the intelligent display elements, a first location among said locations comprising a first via connection area connected to one of the second electrical measurement pads and intended to be connected with the first electrode, and a second location among said locations comprising a second via connection area connected to one of the second electrical measurement pads and intended to be connected with the second electrode,

[0021] - Reporting the intelligent display elements in the pixel locations, at their lower faces, and connecting the first and second addressing pads to each other and the first and second electrical measuring pads to each other, so as to form the pixels of the display screen,

[0022] - Deposit an encapsulation layer on and between the smart display elements, and planarize this encapsulation layer,

[0023] - Forming first and second openings in the encapsulation layer, respectively above the first and second via connection areas, and filling said first and second openings with an electrically conductive material so as to form first and second vias,

[0024] - Forming the first and second transparent electrodes on the encapsulation layer, respectively in contact with the first and second vias, above at least some pixels of the display screen.

[0025] In this method, at least some of the pixel locations are configured to accommodate both the smart display elements and via connection areas intended to connect the electrodes formed on the front face of the device, on the emissive side of the screen. The pixel locations can thus combine several functions, in particular display and electrical measurement functions.

[0026] This method can be advantageously implemented to produce a measuring and display device as described previously.

[0027] BRIEF DESCRIPTION OF THE FIGURES

[0028] The aims, objects, as well as the characteristics and advantages of the invention will emerge more clearly from the detailed description of embodiments thereof which are illustrated by the following accompanying drawings in which:

[0029] Figure 1 illustrates in cross-section a device according to a first embodiment of the present invention.

[0030] Figure 2 illustrates in cross-section a device according to a second embodiment of the present invention.

[0031] Figure 3 illustrates in cross-section a device according to a third embodiment of the present invention.

[0032] Figure 4 illustrates in cross-section a device according to a fourth embodiment of the present invention.

[0033] Figures 5A, 5B respectively illustrate the upper and lower faces of a smart display element, according to an embodiment of the present invention.

[0034] Figures 6 to 12 illustrate different steps of manufacturing smart display elements, according to an embodiment of the present invention.

[0035] Figure 13 illustrates in top view pixel locations of a second substrate, according to an embodiment of the present invention.

[0036] Figures 14 to 18 illustrate different steps of manufacturing a measuring and display device, according to an embodiment of the present invention.

[0037] Figure 19 illustrates in top view pixel locations of a second substrate, according to another embodiment of the present invention.

[0038] Figures 20 to 22 illustrate different steps of manufacturing a measuring and display device, according to another embodiment of the present invention.

[0039] Figure 23 illustrates in top view a diagram of operation of a pixel of a measuring and display device, according to an embodiment of the present invention.

[0040] Figure 24 illustrates in top view a screen of a measuring and display device, according to an embodiment of the present invention.

[0041] Figure 25 illustrates in top view areas of grouped pixels of a screen of a measuring and display device, according to an embodiment of the present invention.

[0042] Figure 26 illustrates in top view a configuration of control circuits of a screen of a measuring and display device, according to an embodiment of the present invention.

[0043] Figure 27 illustrates in top view a configuration of control circuits of a screen of a measuring and display device, according to another embodiment of the present invention.

[0044] The drawings are given as examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily to the scale of practical applications. In particular, on the schematic diagrams, the thicknesses of the different layers and portions, and the dimensions of the patterns are not representative of reality.

[0045] DETAILED DESCRIPTION OF THE INVENTION

[0046] Before commencing a detailed review of embodiments of the invention, optional features which may optionally be used in combination or alternatively are set out below:

[0047] According to one example, the device further comprises a transparent protective layer, for example based on parylene, on the first and second electrodes. This layer typically makes it possible to protect the first and second electrodes, for example against mechanical stresses or chemical (acid-base) or electrochemical reactions. According to one example, the device is configured to perform a capacitive electrical measurement via at least one of the first and second electrodes. The capacitive electrical measurement is typically carried out via a capacitance formed by the electrodes, the skin and the transparent protective layer acting as a dielectric.

[0048] According to one example, the transparent protective layer has a thickness less than or equal to 2 μm, preferably less than or equal to 1 μm. This makes it possible to increase the measurement sensitivity via the first and / or the second electrode.

[0049] According to one example, the control electronics of each pixel are located under the at least three light-emitting diodes, and the first and second electrodes are locally connected to the at least one control electronics respectively by first and second through-connections or vias. The light-emitting diodes associated with dedicated control electronics typically form a smart display element also called a “smart pixel”.

[0050] According to one example, the plurality of pixels is arranged in the form of a matrix delimited by an outline, and the first and second transparent electrodes are arranged above the matrix of pixels only within said outline. The first and second transparent electrodes cover the matrix of pixels, partially or totally. According to one example, the device is configured to display instructions for placing at least one hand on the screen, preferably two hands on the screen, and to measure a variation in electrical voltage of said at least one hand by the first and second electrodes, or a variation in electrical voltage between the two hands, for example to obtain an electrocardiogram. The display and the measurement are done on the same side of the screen, and can be superimposed.

[0051] According to one example, each pixel further comprises a photodetector, for example an infrared photodetector, controlled by the control electronics of said pixel. This makes it possible in particular to detect the user's hand. This also makes it possible to measure a physiological parameter, for example by detecting the optical signal backscattered after interaction with the tissues of the hand, in the visible or near infrared range.

[0052] According to one example, the device comprises a function for capturing images or a set of a few regions of interest, for example resulting from pixel grouping. Each photodetector can be arranged next to or in the vicinity of a smart display element, within the same pixel. The device typically comprises a matrix of photodetectors corresponding to the matrix of pixels, and forming an imager.

[0053] According to one example, each pixel comprises first, second, third light-emitting diodes respectively emitting first, second, third radiation in the visible range, and a fourth light-emitting diode emitting a fourth radiation in the near infrared range. According to one example, each pixel further comprises an infrared photodetector controlled by the control electronics of said pixel and configured and arranged so as to detect a backscattered portion of the fourth radiation. Each pixel typically comprises an infrared source and detector.

[0054] According to one example, the device is configured to display instructions for placing at least one hand on the screen, and to measure a variation in the backscattered portion of the fourth radiation by said at least one hand, via at least one infrared photodetector. This typically makes it possible to perform an infrared optical measurement in addition to or instead of the electrical measurement. Such a device makes it possible, for example, to perform a photoplethysmographic measurement.

[0055] In one example, the device is configured to:

[0056] - detecting the presence of at least one hand by means of the infrared photodetectors effectively detecting the backscattered part of the fourth radiation, and for - grouping the pixels comprising said infrared photodetectors according to a measurement zone. The device can thus use only the pixels on which the hand is placed. This makes it possible to improve the contrast and / or the measurement of a signal of interest.

[0057] According to one example, said measurement area is used to perform at least one measurement of a physiological parameter linked to the at least one hand, for example a first measurement of heart rate by electrocardiogram and a second complementary measurement of heart rate by photoplethysmography. The first and / or second measurements can be made by placing the user's two hands on the hand.

[0058] According to one example, the grouping of the pixels is controlled by a plurality of programmable control blocks, each control block being arranged within each pixel and configured to actuate at least one row switch making it possible to connect two adjacent pixels of the same row of the screen, and at least one column switch making it possible to connect two adjacent pixels of the same column of the screen. Such grouping makes it possible to improve detection. In terms of use, this can make it possible to define regions of interest in which the pixels are grouped according to certain areas of the hand. For example, it is possible to envisage grouping the pixels for each finger in order to have a signal "per finger". This signal per finger can correspond to the cumulative signal of the pixels grouped under each finger, for example from ten to twenty pixels located under each finger. The reading of the detected signal(s) can be done via an external reading circuit.

[0059] In one example, the infrared photodetectors each produce a signal processed independently by each control electronics. In one example, said signals are averaged so as to increase a signal-to-noise ratio.

[0060] According to one example, the method further comprises forming a transparent protective layer, for example based on parylene, on the first and second electrodes.

[0061] According to one example, each control electronics comprises at least one first detection pad intended to be connected with at least one photodetector, preferably an infrared photodetector. According to one example, the pixel locations comprise a second detection pad intended to be connected with the first detection pad, at least some of said locations further comprising a photodetection area connected to the second detection pad, said photodetection area being intended to be connected with the control electronics of the smart display element. According to one example, photodetectors are transferred or formed on said photodetector areas. The photodetectors are typically external to the smart display elements, and are arranged on the second substrate.

[0062] In one example, photodetectors are formed by localized deposition of an organic material on the photodetection area.

[0063] According to one example, each control electronics comprises at least one first additional addressing pad and the pixel locations comprise at least one second additional addressing pad intended to be connected with said at least one first additional addressing pad.

[0064] According to one example, the three light-emitting diodes comprise first, second, third light-emitting diodes respectively emitting first, second, third radiation in the visible range.

[0065] According to one example, a fourth light-emitting diode emitting a fourth radiation in the near infrared range is formed on each control electronics and connected to the at least one first additional addressing pad, so that the pixels of the display screen can emit the first, second, third, and fourth radiations and can preferably detect a backscattered portion of the fourth radiation. This makes it possible to provide a device capable of carrying out, via its display screen, an electrical measurement and an optical measurement, for example an electrocardiogram and a photoplethysmography measurement.

[0066] Unless incompatibility exists, it is understood that all of the above optional features and / or the indicated variants may be combined so as to form an embodiment which is not necessarily illustrated or described. Such an embodiment is obviously not excluded from the invention. The features of one aspect of the invention, for example the device or the method, may be adapted mutatis mutandis to another aspect of the invention.

[0067] It is specified that, in the context of the present invention, the terms "on", "overcomes", "covers", "underlying", "facing" and their equivalents do not necessarily mean "in contact with". Thus, for example, the deposition of a first layer on a second layer does not necessarily mean that the two layers are in direct contact with each other, but means that the first layer at least partially covers the second layer by being either directly in contact with it, or by being separated from it by at least one other layer or at least one other element.

[0068] A layer can also be composed of several sub-layers of the same material or of different materials.

[0069] A substrate, a stack, a layer, "based" on a material A, means a substrate, a stack, a layer comprising this material A only or this material A and possibly other materials, for example alloying elements and / or doping elements. Thus, a silicon-based substrate means, for example, a Si or doped Si substrate, or SiGe. A GaN-based layer means, for example, a GaN, doped GaN, or GaN alloy layer.

[0070] Several embodiments of the invention implementing successive steps of the manufacturing process are described below. Unless explicitly stated, the adjective “successive” does not necessarily imply, even if this is generally preferred, that the steps follow one another immediately, intermediate steps being able to separate them.

[0071] Furthermore, the term "step" means the carrying out of a part of the process, and can designate a set of sub-steps.

[0072] Furthermore, the term "step" does not necessarily mean that the actions carried out during a step are simultaneous or immediately successive. Certain actions of a first step may in particular be followed by actions linked to a different step, and other actions of the first step may be repeated subsequently. Thus, the term "step" does not necessarily mean actions that are unitary and inseparable in time and in the sequence of phases of the process.

[0073] For the purposes of the present invention, a "transparent" material means that the material allows at least 70%, preferably at least 90%, of the light intensity of the light beam passing through it to pass through.

[0074] A preferably orthonormal reference frame, comprising the x, y, z axes, is shown in the attached figures. When a single reference frame is shown on the same sheet of figures, this reference frame applies to all the figures in this sheet.

[0075] In the present patent application, the thickness of a layer is taken along a direction normal to the main extension plane of the layer. Thus, a layer typically has a thickness along z. The relative terms "on", "overcomes", "under", "underlying", "intercalated", "above", "below" refer to positions taken along the z direction. This list of terms is not exhaustive. Other relative terms can be easily specified as needed, by referring to the accompanying drawings.

[0076] The terms "vertical" and "vertically" refer to a direction along z. The terms "horizontal", "horizontally", "lateral", "laterally" refer to a direction in the xy plane. Unless explicitly stated, thickness, height and depth are measured along z.

[0077] An element located "perpendicular to" or "in line with" another element means that these two elements are both located on the same line perpendicular to a plane in which a lower or upper face of a substrate mainly extends, that is to say on the same line oriented vertically in the figures.

[0078] The present invention finds as its preferred field of application a display device comprising functions for measuring or monitoring physiological parameters, commonly called “biomonitoring”.

[0079] Electrocardiogram (ECG) measurement is widely used in medical settings. This ECG measurement requires two electrical contact points on the body between which a potential difference generated by the heart can be established. The electrical path between these two points preferably passes fairly directly through the heart. The ECG is generally the reference signal for providing information on heart rate and its variation. It is a "passive" reading of the electrical signal of the heart's contraction, and is therefore a "central" indicator (at the heart level).

[0080] Photoplethysmography (PPG) measurement is an optical technique for measuring blood volume variations in capillaries, arterioles, or arteries, by reflectance of visible and / or near-infrared light. Like ECG measurement, PPG measurement can also measure heart rate or its variations. However, PPG measurement comes from an area peripheral to the heart: it is an "image" of the cardiac signal, in the measurement area, after propagation of the pulse wave (ejection of blood volume from the heart) through a part of the arterial tree.

[0081] Combining the two measurements, ECG and PPG, allows us to obtain complementary physiological parameters. By measuring the time lag between the ECG signal and the peripheral PPG signal, it is possible, for example, to obtain the pulse wave propagation time (PAT), a physiological quantity representing a person's cardiovascular functioning, and which is linked to blood pressure. In addition, PPG can be used to measure, for example, blood oxygenation.

[0082] Bioimpedance measurement is the electrical measurement of tissue resistance by sending a sinusoidal current through electrodes. It can be used to determine the amounts of water, fat, and / or muscle in tissues.

[0083] The light-emitting diodes according to the present invention typically emit monochromatic or quasi-monochromatic light rays, each having a main wavelength. The skilled person is fully aware of the use of red, green, blue diodes - generally designated by the acronym RGB - in the field of display screens. An infrared (IR) diode can also be added to the RGB diodes, depending on the applications. The terms "light-emitting diode", "diode", "LED", "pLED" etc. are used synonymously.

[0084] The smart display element according to the invention, commonly referred to as a "smart pixel", typically comprises control electronics topped by RGB and / or IR diodes. This smart display element is intended to be transferred onto a second substrate comprising pixel locations to form the screen of the display and measurement device according to the invention. The smart display element thus has an upper "emission" face, on the side of the RGB and / or IR diodes. The smart display element also has a lower "connection" face, on the side of the control electronics, comprising a plurality of electrical connection pads intended to be connected to the second substrate. The second substrate has a connection face comprising, for each pixel location, a plurality of electrical connection pads intended to be connected respectively to the electrical connection pads of the smart display element.

[0085] The terms "substantially", "approximately", "of the order of" mean "within 10%" or, when it comes to an angular orientation, "within 10°" and preferably "within 5°". Thus, a direction substantially normal to a plane means a direction having an angle of 90±10° with respect to the plane.

[0086] Figure 1 illustrates a first embodiment of a measuring and display device D1 according to the invention. The device D1 comprises a screen formed by a plurality of pixels arranged on the corresponding pixel locations Px of the substrate 2. Each pixel here comprises a smart display element 20a. The smart display element 20a typically comprises three diodes R, G, B emitting respectively according to red, green, blue wavelengths of the visible spectrum. The smart display element 20a also comprises control electronics 10 connected to the diodes R, G, B and configured to control the diodes R, G, B. The smart display element 20a is connected to the substrate 2 in pixel replacement Px of said pixel via the control electronics 10. The control electronics 10 may for example comprise MOS transistors.

[0087] The pixels are encapsulated in an encapsulation layer 230. This encapsulation layer 230 serves in particular to planarize the entire structure. It is not necessarily hermetic. The encapsulation layer 230 can be referred to as a planarization layer. A first electrode 31 and a second electrode 32 are arranged on said layer 230. The first and second electrodes 31, 32 are transparent, in particular in the visible and near infrared or infrared spectrum range. The first and second electrodes 31, 32 may be based on a conductive oxide, for example based on an indium-tin alloy oxide ITO (acronym for “Tin Indium Oxide”). The first electrode 31 is typically connected to control electronics 10 of an intelligent display element 20a by a vertical connection 21 called a through-via or via.The connection between the via 21 and the control electronics 10 can be made via a metal track on the substrate 2. In the same way, the second electrode 32 is connected to a control electronics 10 of a smart display element 20a by a via 22. The control electronics 10 are typically derived from complementary MOS transistor (CMOS) technologies and conventionally comprise transistors interconnected by different levels of metals. The control electronics 10 connected to the first and second electrodes 31, 32 are preferably distinct. A single control electronics 10 connected to both the first and second electrodes 31, 32 can nevertheless be envisaged. The first and second electrodes 31, 32 extend above the pixels of the screen of the device D1. Each electrode 31, 32 typically extends above several pixels.Each electrode 31, 32 may have a surface area of ​​a few hundred mm. 2 a few cm away 2 , for example of the order of 1 cm 2 .

[0088] A protective layer 40, for example based on parylene or glass, may be arranged on the first and second electrodes 31, 32. This protective layer 40 preferably has a relatively small thickness, for example between 1 μm and 10 μm, of the order of 2 μm to 5 μm. This makes it possible to improve the sensitivity of a capacitive measurement by the first and / or second electrodes 31, 32. The protective layer 40 allows the user to touch the screen to carry out the capacitive electrical measurements without damaging the first and second electrodes 31, 32.

[0089] Figure 2 illustrates a second embodiment of a measuring and display device D2 according to the invention. The device D2 comprises, as previously, a screen formed by a plurality of pixels in the locations Px. Each pixel here comprises a smart display element 20b and a photodetector 23. The smart display element 20b typically comprises three diodes R, G, B as previously, and an IR diode emitting according to one or more near-infrared wavelengths. The photodetector 23 is connected to the control electronics 10 of the smart display element 20b. The control electronics 10 typically makes it possible to control the photodetector 23, for example for capturing or reading a detection signal. The photodetector 23 is typically configured to detect infrared radiation, for example infrared radiation coming from the IR diode and backscattered by a finger or a hand located above the photodetector 23.The photodetector 23 is located on the substrate 2, next to the intelligent display element 20b. The screen of the device D2 thus combines functions of capacitive electrical measurement by the first and / or second electrodes 31, 32, and near-infrared optical measurement by the IR diodes and the IR photodetectors 23. The device D2 can, for example, perform an ECG measurement and a PPG measurement, sequentially or simultaneously.

[0090] The intelligent display element 20b comprises, as previously, control electronics 10 connected here to the diodes R, G, B, IR and configured to control the diodes R, G, B, IR. As previously, the pixels are encapsulated in an encapsulation layer 230 on which the first and second electrodes 31, 32 are arranged. A protective layer 40 may also be arranged on the first and second electrodes 31, 32.

[0091] Figure 3 illustrates a third embodiment of a measuring and display device D3 according to the invention. The device D3 comprises, as previously, a screen formed by a plurality of pixels in the locations Px. Each pixel here comprises a smart display element 20a, and certain pixels further comprise an IR diode remote from the smart display element 20a, and a photodetector 23. It is not necessary for all the pixels to have IR detection functions. This makes it possible to reduce the cost of the device D3. The IR diode can be controlled by control electronics 10 of a smart display element 20a, or by dedicated electronics, for example integrated into the substrate 2. The device D3 can comprise the same elements (encapsulation layer, electrodes, protective layer) as previously.

[0092] Figure 4 illustrates a fourth embodiment of a measuring and display device D4 according to the invention. The device D4 comprises, as previously, a screen formed by a plurality of pixels in the locations Px. Each pixel here comprises an intelligent display element 20c, and photodetectors 231, 232, 233.

[0093] The intelligent display element 20c typically comprises three diodes R, G, B as previously, and three diodes IR1, IR2, IR3 emitting at different near-infrared wavelengths. The photodetectors 231, 232, 233 are typically configured to detect infrared radiation respectively coming from the diodes IR1, IR2, IR3 and backscattered by a finger or a hand located above said photodetectors 231, 232, 233. According to another possibility, the photodetectors 231, 232, 233 are configured to respectively detect radiation from the spectral ranges defined between 525 nm and 550 nm (visible green), between 630 nm and 660 nm (visible red), and between 730 nm and 940 nm (IR red). These rays can come from the R, G, B diodes and / or the IR1, IR2, IR3 diodes, and be backscattered by the user's finger or hand. The screen of the D4 device thus has multispectral detection capabilities.This allows, for example, different depths of the user's skin to be probed. The absorption of radiation by the skin's constituents depends in particular on the wavelength of this radiation. The probed area will typically be more superficial in the visible than in the near infrared.

[0094] The intelligent display element 20c comprises, as previously, control electronics 10 connected here to the diodes R, G, B, IR1, IR2, IR3 and configured to control the diodes R, G, B, IR1, IR2, IR3 and the photodetectors 231, 232, 233. The device D4 may comprise the same elements (encapsulation layer, electrodes, protective layer) as previously.

[0095] Figures 5A, 5B illustrate a smart display element 20a comprising three diodes R, G, B. The diodes R, G, B are arranged on the control electronics 10, and form an emission face corresponding to the upper face 101 of the smart display element 20a (Figure 5A). The smart display element 20a has a lower face 102 opposite the upper face 101. The lower face 102 corresponds to a face of the control electronics 10 and here comprises four first addressing pads 81, 82, 83, 84 connected to the light-emitting diodes R, G, B via the connection pads (for example three anodes and one cathode for the diodes R, G, B) of the control electronics 10.

[0096] The lower face 102 here also comprises two first electrical measuring pads 85, 86 intended to be connected with the first and / or the second electrode 31, 32.

[0097] The number of pads on the lower face 102 of the control electronics 10 and / or on the substrate 2 may vary depending on the different functions assigned to these pads, and depending on the control architecture chosen (serialization or other). The pads are illustrated in the figures by way of example, without this being limiting or necessarily representative of the exact number of pads.

[0098] Figures 6 to 12 illustrate some steps in the production of smart display elements or smart pixels.

[0099] As illustrated in Figure 6, a first substrate 1 comprising the control electronics and their connection pads (anodes A1, A2 and cathodes K illustrated here) is provided. This first substrate 1 may be of the silicon on insulator (SOI) type comprising a massive silicon support BULK, a buried oxide layer BOX, and a surface silicon layer topSi. The control electronics (not visible in the figure) are typically formed on the topSi. The first addressing and measurement pads are also formed on the topSi, in connection with the control electronics. The formation of the substrate 1 is perfectly known to those skilled in the art and is not detailed for the sake of brevity.

[0100] A substrate O comprising a stack of optically active layers 51 on a support 50 is also provided. The stack of optically active layers 51 may comprise different sub-layers forming, for example, multiple quantum wells and carrier injection layers on either side of the multiple quantum wells. It may be based on GaN. The support 50 typically corresponds to a substrate on which the stack of optically active layers 51 is formed by epitaxy. The support 50 may be based on sapphire or silicon. The formation of the substrate O is perfectly known to those skilled in the art and is not detailed for the sake of brevity. The substrates 1, O are here assembled by bonding, typically by molecular bonding, or by thermocompression via two layers 111, 112 of metal.

[0101] As illustrated in Figure 7, after bonding, the stack of optically active layers 51 is secured to the first substrate 1 via a metal layer 110 formed by the layers 111, 112. The support 50 is then removed, for example by trimming, so as to expose the stack of optically active layers 51.

[0102] As illustrated in Figure 8, first light-emitting diodes 60 are defined by lithography and etching of the stack of optically active layers 51. The first light-emitting diodes 60 are thus formed on the anodes A1, A2, A3 of the control electronics.

[0103] As illustrated in Figure 9, the sides of the first light-emitting diodes 60 are then passivated by a passivation layer 61. A metal layer 62 is then deposited between the passivated first light-emitting diodes 60. This allows electrical contact to be made between the cathodes K. The surface 602 is then planarized to expose the upper carrier injection layers of the first light-emitting diodes 60.

[0104] As illustrated in Figure 10, a transparent conductive layer 63, for example based on ITO, is then deposited on the planarized surface 602. This makes it possible to electrically connect the first light-emitting diodes 60 to the cathodes K which are common to the diodes 60. Color converters 64, 65, typically making it possible to convert UV or blue radiation from the first light-emitting diodes 60 into green and red radiation respectively, are then formed on the first light-emitting diodes 60 so as to obtain the diodes R, G. The diode B (not illustrated) can be directly formed by a diode 60, without a color converter. R, G, B LEDs or pLEDs associated with their control electronics are thus obtained.

[0105] As illustrated in Figure 11, the substrate 1 carrying the R, G, B LEDs is then assembled to a handling substrate 3, and then the BULK support of the substrate 1 is removed, for example by trimming with a stop on the BOX of the substrate 1. Connections 71, 72, 73, 74, 75 are formed through the BOX to the metal levels of the control electronics in the topSi.

[0106] As illustrated in Figure 12, pads 81, 82, 83, 84, 85 are then formed on the various connections 71, 72, 73, 74, 75 for future connection in the pixel locations of a second substrate. The pads 81, 82, 83, 84, 85 may correspond to bumps, indium-based solder points, or even microtubes or the like. The groups of diodes R, G, B and their control electronics are then separated from each other by trenches 800 to form the intelligent display elements. The trenches 800 may be formed by plasma etching or plasma cutting. Individualized intelligent display elements on a handling substrate 3 are thus obtained.

[0107] Figure 13 illustrates in top view two adjacent pixel locations Px1, Px2 of a second substrate 2, according to a first embodiment of a device D1. The pixel locations Px1, Px2 each comprise in particular a reception area S for a smart display element. The reception area S typically comprises here four second addressing pads 91, 92, 93, 94 intended to receive the first addressing pads 81, 82, 83, 84 of the smart display element, and two second electrical measurement pads 95, 96 intended to receive the first electrical measurement pads 85, 86 of the smart display element. Here again, the number of pads illustrated is not necessarily representative of the number of pads of the actual architecture.

[0108] The addressing pads 91, 92, 93, 94 and the measuring pads 95, 96 can be connected to different metal lines L1, L2 and columns C1, C2, C3 of a control and / or reading circuit formed on the substrate 2. The different lines L1, L2 and columns C1, C2, C3 can be serialized. For example, the columns C1, C2, C3 can be respectively assigned to the power supply (Vdd), to the display data (data RGB) and to the measurement data (data mes). The lines L1, L2 can be respectively assigned to the display control (select RGB) and to the measurement control (select mes).

[0109] In this example, the addressing pads 91 are connected to the rows L1; the addressing pads 92 are connected to the rows L2; ​​the addressing pads 93 are connected to the columns C1; the addressing pads 94 are connected to the columns C2; the measuring pads 96 are connected to the columns C3. Some measuring pads 95, for example here in the pixel location Px1, are connected to a via area 200 intended to receive a through-via connected to the first electrode or the second electrode of the device. Only certain pixel locations, for example one pixel location per 1 mm screen area 2 , are configured to receive a through via. The pixel location Px2 illustrated here is not configured to receive a through via. The substrate 2 may be made of glass, or based on a flexible material, and include TFT thin-film transistors for the control and / or readout circuit.

[0110] Figures 14 to 18 illustrate certain steps in producing the measuring and display device according to the invention.

[0111] As illustrated in Figure 14, the handling substrate 3 carrying the smart display elements 20a is brought opposite the second substrate 2. Some smart display elements 20a are transferred to pixel locations Px of the substrate 2, for example by mass transfer techniques. The individual pads 81, 82, 83, 84, 85, 86 of the smart display elements 20a are connected to the corresponding pads 91, 92, 93, 94, 95, 96 in the receiving areas of the pixel locations Px. The connection is carried out by pressure and / or heat application, for example by thermocompression or by soldering. The smart display elements 20a are then detached from the handling substrate 3. Typically only a portion of the smart display elements 20a is transferred to the substrate 2. The pitch of the array of pixel locations Px generally differs from the pitch of the array in which the smart display elements 20a were formed.Multiple passes can be made with the manipulation substrate 3 to populate all pixel locations Px on the screen.

[0112] As illustrated in Figure 15, an encapsulation layer 230 is then deposited on and between the smart display elements 20a. This encapsulation layer 230 may be based on a transparent polymer material. It may be deposited by centrifugation. As illustrated in Figure 16, a via opening 240 is made directly above each via area 200, for example in a conventional manner by lithography and etching. Optionally, the encapsulation layer 230 may be based on a photosensitive material. In this case, the opening of via 240 does not require etching.

[0113] As illustrated in Figure 17, the via openings are then filled with an electrically conductive material, typically a metal, to form the vias 21. The electrodes 31, 32 are then formed on the encapsulation layer 230 and on the corresponding vias 21. The transparent electrodes 31, 32 are typically formed by deposition and structuring of an ITO layer. According to one possibility, the vias 21 and the electrodes 31, 32 are formed simultaneously by deposition of the same transparent electrically conductive material.

[0114] As illustrated in Figure 18, a protective layer 40 is preferably formed on the electrodes 31, 32. This protective layer 40 can be formed by deposition of a glass cover, or by deposition of a parylene layer, or even by multilayer deposition.

[0115] Figure 19 illustrates in top view two adjacent pixel locations Px1 ', Px2' of a second substrate 2, according to a second embodiment of a device D2. In this second embodiment, the pixel locations Px1 ', Px2' each comprise in particular a zone 203 intended to receive an infrared photodetector 23. The pixel locations Px1 ', Px2' also each comprise a reception zone S for an intelligent display element. The receiving area S typically comprises here four second addressing pads 91, 92, 93, 94 intended to receive the first addressing pads 81, 82, 83, 84 of the intelligent display element, two second electrical measuring pads 95, 96 intended to receive the first electrical measuring pads 85, 86 of the intelligent display element, and a photodetector pad 97 intended to receive a corresponding pad of the intelligent display element.Again, the number of plots illustrated is not necessarily representative of the number of plots in the actual architecture.

[0116] The addressing pads 91, 92, 93, 94 and the measuring pads 95, 96 can be connected to different metal lines L1, L2 and columns C1, C2, C3 of a control and / or reading circuit formed on the substrate 2. The different lines L1, L2 and columns C1, C2, C3 can be serialized, as previously. The columns C1, C2, C3 can be respectively assigned to the power supply (Vdd), to the display data (data RGB) and to the measurement data (data mes). The lines L1, L2 can be respectively assigned to the display control (select RGB) and to the measurement control (select mes).

[0117] In this example, the addressing pads 91 are connected to the rows L1; the addressing pads 92 are connected to the rows L2; ​​the addressing pads 93 are connected to the columns C1; the addressing pads 94 are connected to the columns C2; the measuring pads 96 are connected to the columns C3. The pads 97 are connected to the photodetector areas 203. Some measuring pads 95, for example here in pixel replacement Px1', are connected to a via area 200 intended to receive a through-via connected to the first electrode or the second electrode of the device. As previously, only certain pixel locations, for example one pixel location per 1 mm screen area 2, are configured to receive a through via. The pixel location Px2' illustrated here is not configured to receive a through via. The substrate 2 may be made of glass, or based on a flexible material, and include TFT thin-film transistors for the control and / or reading circuit. The number of pads in the receiving area S may vary, depending on the type of smart display element to be transferred to the corresponding pixel replacement. The number of pads in the receiving area S may also depend on the serialization options chosen for the control and / or reading circuit.

[0118] Figures 20 to 22 illustrate certain steps in producing the measuring and display device according to the second embodiment of the invention.

[0119] As illustrated in Figure 20, preferably after transfer of the smart display elements 20b, photodetectors 23 are formed on the areas 203 of the pixel locations Px'. The photodetectors 23 can be formed in a known manner by localized deposition of an organic layer providing the IR photodetection function.

[0120] As illustrated in Figure 21, a transparent electrode 33, for example based on ITO, is deposited on the photodetectors 23. The deposition can be done through a masking grid commonly called a “shadow mask”. A thin inorganic layer 300, for example based on AI2O3 or SiO2, is preferably deposited on the organic layers forming the photodetectors 23 and the electrodes 33, to protect them.

[0121] As illustrated in Figure 22, an encapsulation layer 230 is then deposited on and between the smart display elements 20b, and on the photodetectors 23. As before, this encapsulation layer 230 may be based on a transparent polymer material. It may be deposited by centrifugation.

[0122] The rest of the manufacturing steps of the D2 device (opening of the vias, filling of the vias and formation of the electrodes, protective cover) is typically done as previously, as illustrated in figures 16 to 18 (cross-sectional views passing through via areas).

[0123] Figure 23 details the control blocks associated with a pixel according to the invention. Each pixel contains the circuits allowing the control of the pLEDs for the display and the reading of the sensors (electrodes and / or photodetectors). A combination of switches Sxi, SxO, Syi, SyO within each pixel makes it possible to connect in parallel a random number of sensors on zones of choice. According to one possibility, the control of the pLEDs, the switches and the reading are serialized on a single DATA column. An example of such a shift register-based configuration can be found in document US2023 / 0056511 A1.

[0124] A DD control block controls each R, G, B, IR pLED individually. The refresh mode for forming the image, which can be analog or digital (PWM), is known to those skilled in the art. This DD control block is typically slaved to a controller 600 configured to control both the display, the switches and the reading of the sensors.

[0125] The 600 controller is addressed by the CTRLX column and the CTRLY line. It receives data for display through the DATA column. It selects the LED or switch programming mode through the LED / SW line. The 600 controller is typically based on combinational and sequential logic, preferably serially programmable.

[0126] The Sxi, SxO, Syi, SyO switches are controlled by the 600 controller. This allows each of the Sxi, SxO, Syi, SyO switches to be opened or closed according to the desired configuration. The SY lines and SX columns are interrupted at each pixel to allow individual connections.

[0127] The reading of the sensor part 200, 23 is carried out via a dedicated circuit block RD. This circuit block RD typically comprises an ELECTRODE reading circuit connected to the via area 200 via a switch Sri. The ELECTRODE reading circuit may comprise a follower amplifier or a simple short circuit. It connects the via area 200 to the column VX via a switch SRol.

[0128] The RD circuit block also includes a PHOTODIODE reading circuit connected to the photodetector 23 via a switch Srp. The PHOTODIODE reading circuit connects the photodetector 23 to the VX column via a switch SRoP or by a simple short circuit.

[0129] The switches Sri, Srp, SRol, SRoP are controlled by the controller 600. The parallel connection of all the photodetectors 23 via these switches allows a reduction of the associated impedance.

[0130] As illustrated in Figure 24, the circuits described above advantageously make it possible to read an ECG electrical signal from two ITO electrodes 31, 32. The signal is read at the bottom of the column by configuring each of the pixels Px in parallel via the switches Sri. The signal can be read by a single ECG RD circuit configured for amplification and conversion of the signal into digital format using one of the methods known to those skilled in the art. For clarity, only the Vx connection is illustrated in Figure 24. The ECG RD circuit can be integrated into the column circuit or implemented in a separate circuit. When the ITO electrodes 31, 32 are protected by a protective layer made of a dielectric material, the ECG signal is capacitively coupled to the ECG RD reading circuit. This prevents current from flowing into the body and saturation of the input amplifier of the ECG RD circuit due to an excessive signal level.

[0131] According to one possibility illustrated in Figure 25, zoning by pixel grouping can be performed. This pixel grouping can be performed for the photodetectors and / or for the electrodes 31, 32. In the latter case, from a hardware point of view, a plurality of electrodes 31, 32 cover the pixels Px of the screen of the device. Each pixel can be connected by a via to its own electrode. Several pixels can also share the same electrode.

[0132] By a combination of switches Sxi, SxO, Syi, SyO, it is possible to select particular groups of photodetectors or electrodes. In particular, the sensors (photodetectors or electrodes) are placed in parallel to form two groups G1, G2 on two distinct column areas. In the case where two or more groups coexist on the same column Vx, an additional amplification stage of the TIA (Trans-lmpedance Amplifier) ​​type can be integrated in the circuit block RD of each pixel. These circuit configurations are known to those skilled in the art.

[0133] The signal reading from the photodiodes or electrodes may be averaged within each group G1, G2, to improve the signal-to-noise ratio. The selected groups of photodiodes or electrodes may advantageously correspond to the locations of the user's fingers or hands on the screen. This improves signal collection. Alternatively, the display screen may indicate the two sensitive areas, corresponding to groups G1, G2, where the two fingers should be placed to perform an ECG and / or PPG test.

[0134] Pixel grouping can be performed after a first phase of detecting the user's fingers or hands. Typically, the photodetectors of each pixel are used to determine the presence or absence of fingers or hands above the corresponding pixel. Grouping is then performed for pixels collecting a signal only, without a priori on the position of the hands or fingers. Only pixels in front of which the hands are placed contribute to the ECG and / or PPG measurements. This improves the signal-to-noise ratio. This improves ergonomics and user experience. ECG and / or PPG tests are made easier for the user. Signal patterns can be stored and / or signal comparisons can be performed to improve the accuracy and reliability of finger or hand detection. This allows, for example, the detection of different hand sizes, for different contact pressures with the screen, etc.

[0135] Figure 26 illustrates a typical configuration for the arrangement of the various H, V control circuits for the rows and columns of pixels on the screen. The H, V control circuits are here placed outside the substrate, and connected by ribbon cables as shown in Figure 26.

[0136] Figure 27 illustrates another implementation configuration comprising individual row and column COG (Circuit On Glass) circuits directly soldered onto the substrate. In this case, a single general control circuit is placed externally and connected by a single ribbon cable, as shown in Figure 27.

[0137] From the above, it is clear that the present invention advantageously makes it possible to produce a measuring and display device combining electrical and / or optical tests in a simple manner for the user. The tests are carried out directly via the display screen of the device. This makes it possible, for example, to facilitate hand placement indications when the user performs an ECG and / or PPG test.

[0138] The invention is not limited to the embodiments previously described. Other measurements, for example with four electrodes, can be envisaged on the basis of the principle of the present invention. Bioimpedance measurements can in particular be envisaged.

Claims

CLAIMS 1. Measuring and display device (D1, D2, D3, D4) comprising a first electrode (31) and a second electrode (32), and a screen formed by a plurality of pixels (Px), each pixel comprising at least three light-emitting diodes (R, G, B) and control electronics (10), in which: • the first and second electrodes (31, 32) are transparent and arranged at least partly on the plurality of pixels (Px), and said first and second electrodes (31, 32) are connected to at least one control electronics (10) of a pixel (Px) among the plurality of pixels, • each pixel (Px) comprises first, second, third light-emitting diodes (R, G, B) respectively emitting first, second, third radiation in the visible range, and a fourth light-emitting diode (IR) emitting a fourth radiation in the near infrared range, and each pixel further comprises a so-called infrared photodetector (23) controlled by the control electronics (10) of said pixel and configured and arranged so as to detect a backscattered part of the fourth radiation, the device being configured to: • display instructions for placing at least one hand on the screen, and • measure a variation in the backscattered part of the fourth radiation by said at least one hand, by means of at least one infrared photodetector (23), and • detecting the presence of at least one hand by means of infrared photodetectors (23) effectively detecting the backscattered part of the fourth radiation, and • grouping the pixels (Px) comprising said infrared photodetectors according to a measurement zone (G1, G2), said measurement zone (G1, G2) being used to carry out at least one measurement of a physiological parameter linked to at least one hand, for example a first measurement of heart rate by electrocardiogram and a second complementary measurement of heart rate by photoplethysmography, the device being characterized in that the grouping of the pixels is controlled by a plurality of programmable control blocks (600), each control block being arranged within each pixel (Px) and configured to actuate at least one switch line switch (Syi, SyO) allowing to connect two adjacent pixels of the same line of the screen, and at least one column switch (Sxi, SxO) allowing to connect two adjacent pixels of the same column of the screen.

2. Device according to the preceding claim further comprising a transparent protective layer (40), for example based on parylene, on the first and second electrodes (31, 32), said device being configured to carry out a capacitive electrical measurement via at least one of the first and second electrodes.

3. Device according to the preceding claim in which the transparent protective layer (40) has a thickness less than or equal to 2 μm, preferably less than or equal to 1 μm.

4. Device according to any one of the preceding claims in which the control electronics (10) of each pixel (Px) is located under the at least three light-emitting diodes (R, G, B), and in which the first and second electrodes (31, 32) are locally connected to the at least one control electronics (10) respectively by first and second through connections (21, 22) or vias.

5. Device according to any one of the preceding claims in which the plurality of pixels (Px) is arranged in the form of a matrix delimited by a contour, and in which the first and second transparent electrodes (31, 32) are arranged above the matrix of pixels only inside said contour.

6. Device according to any one of the preceding claims configured to display instructions for placing at least one hand on the screen, and to measure a variation in electrical voltage of said at least one hand by the first and second electrodes (31, 32), for example to obtain an electrocardiogram.

7. Device according to any one of the preceding claims in which each pixel (Px) further comprises a photodetector (23), for example an infrared photodetector, controlled by the control electronics (10) of said pixel.

8. Device according to any one of the preceding claims in which the infrared photodetectors (23) each produce a signal processed independently by each control electronics (10), said signals being averaged so as to increase a signal-to-noise ratio.

9. A method of manufacturing a measuring and display device according to any one of the preceding claims comprising: • Producing on a first substrate (1) a plurality of control electronics, each control electronic comprising at least four first addressing pads (81, 82, 83, 84) intended to be connected with three light-emitting diodes (R, G, B), said first addressing pads comprising three anodes and one cathode, and two first electrical measurement pads (85, 86) intended to be connected with the first and second electrodes (31, 32), • Forming on each control electronics (10) of the first substrate (1) the three light-emitting diodes (R, G, B) on the three anodes, so as to form so-called intelligent display elements (20a, 20b) having an upper face on the side of the light-emitting diodes (R, G, B) and a lower face on the side of the control electronics, • Producing on a second substrate (2) a plurality of pixel locations (Px, Px', Px1, Px1', Px2, Px2'), said locations comprising four second addressing pads (91, 92, 93, 94) intended to be connected with the first addressing pads (81, 82, 83, 84) of the intelligent display elements (20a, 20b), and two second electrical measurement pads (95, 96) intended to be connected with the first electrical measurement pads (85, 86) of the intelligent display elements (20a, 20b), a first location (Px1, Px1') among said locations comprising a first connection zone (200) of vias connected to one of the second electrical measurement pads (95) and intended to be connected with the first electrode (31), and a second location among said locations comprising a second via connection zone connected to one of the second electrical measurement pads and intended to be connected with the second electrode (32), • Place the intelligent display elements (20a, 20b) in the pixel locations, at their lower faces, and connect the first and second addressing pads to each other and the first and second electrical measuring pads to each other, so as to form the pixels of the display screen, • Depositing an encapsulation layer (230) on and between the smart display elements (20a, 20b), and planarizing this encapsulation layer (230), • Forming first and second openings (240) in the encapsulation layer (230), respectively above the first and second connection areas (200) of vias, and filling said first and second openings with an electrically conductive material so as to form first and second vias (21, 22), • Forming the first and second transparent electrodes (31, 32) on the encapsulation layer (230), respectively in contact with the first and second vias (21, 22), above at least certain pixels of the display screen.

10. Method according to the preceding claim further comprising a formation of a transparent protective layer (40), for example based on parylene, on the first and second electrodes (31, 32).

11. Method according to any one of the two preceding claims wherein each control electronics comprises at least one first detection pad intended to be connected with at least one photodetector (23), preferably an infrared photodetector, wherein the pixel locations (Px1 ', Px2') comprise a second detection pad (97) intended to be connected with the first detection pad, at least some of said locations further comprising a photodetection area (203) connected to the second detection pad (97), said photodetection area being intended to be connected with the control electronics of the intelligent display element (23b), and wherein photodetectors (23) are transferred or formed on said photodetection areas (203).

12. Method according to the preceding claim in which the photodetectors (23) are formed by localized deposition of an organic material on the photodetection zone (203).

13. Method according to any one of the two preceding claims wherein each control electronics comprises at least one first additional addressing pad and the pixel locations comprise at least one second additional addressing pad intended to be connected with said at least one first additional addressing pad, wherein the three light-emitting diodes comprise first, second, third light-emitting diodes (R, G, B) emitting respectively first, second, third radiation in the visible range, and wherein a fourth light-emitting diode (IR) emitting a fourth radiation in the near infrared range is formed on each control electronics and connected to the ... a first additional addressing pad, so that the pixels of the display screen can emit the first, second, third, and fourth radiations and can preferably detect a backscattered portion of the fourth radiation.

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