A method for controlling the illumination of an object's surface by a projection unit, and related methods and devices.

Abstract

The present invention relates to a method for controlling the illumination of the surface of an object using a visual device (10). The visual device (10) includes a display (17) which includes several sub-areas adapted to a first state in which the sub-areas send light in a first direction, and a second state in which the sub-areas do not. The method includes obtaining a value of the radiant flux received by each sub-area, converting the value to an irradiance value, selecting an average irradiance value based on the converted irradiance value and a predetermined value to obtain a target average irradiance value, and determining a control law such that the total duration in which each sub-area is in the second state for a predetermined duration depends on the ratio of the target average irradiance value to the obtained value.

Description

[Technical Field]

[0001] The present invention relates to a method for controlling the illumination of an object's surface by a projection unit. The present invention also relates to related methods and devices, namely methods for illumination, computer program products, support, and visual devices. [Background technology]

[0002] The retina is composed of photoreceptors, which are highly specialized neurons responsible for retinal photosensitivity through light information transmission. This involves converting light into electrical and chemical signals that propagate a cascade of events within the visual system, ultimately generating a representation of the world. In the vertebrate retina, light information transmission is initiated by the activation of the photosensitive receptor protein, rhodopsin.

[0003] Loss or degeneration of photoreceptors, such as in retinitis pigmentosa (RP) or macular degeneration (MD), significantly impairs, if not completely, the transmission of visual information within the retina. Loss of photoreceptor cells and / or loss of photoreceptor cell function are major causes of decreased visual acuity, reduced photosensitivity, and blindness.

[0004] Several therapeutic approaches specifically for retinal degenerative diseases are currently under development, including gene therapy, stem cell therapy, optogenetics, and retinal prostheses.

[0005] For example, it has been proposed to restore at least partial vision in these patients by modifying the retinal region with visual prosthetic systems. These systems, which include retinal implants, are useful tools for at least partially re-establishing the limited visual perception and sense of direction of blind and visually impaired users by taking advantage of the fact that while some retinal tissue is degenerated, the majority of the retina remains undamaged and can be directly stimulated by light-dependent electrical stimulation. Typically, a retinal implant is embedded in the patient's eye, causing electrical excitation of the remaining nerve cells upon light stimulation. When stimulated, these remaining nerve cells transmit artificially induced electrical impulses to the visual part of the brain via the optic nerve.

[0006] Retinal implants can be broadly divided into two categories: supraretinal and subretinal. Supraretinal devices are located on or near the inner surface of the retina, i.e., the surface first exposed to incident light, along which nerve fibers of ganglion cells pass on their way to the optic nerve. Supraretinal implants typically consist of a chip with multiple pixel elements that can receive images projected by an external ocular device on the retina (typically a camera and microelectronic circuits for decoding incident light) via the lens of the eye, and are intended to reconstruct or improve the vision of blind or partially blind patients by converting the images into electrical signals and further transmitting these signals as electrical stimulation via multiple stimulating electrodes to stimulate retinal cells adjacent to the chip. In contrast, subretinal devices are located beneath the retina, between the retina and the underlying retinal pigment epithelium or other deeper tissues. Currently available subretinal technologies rely on the implantation of a single, rigid, typically flat chip. Furthermore, it has been shown that it is desirable to be able to implant two or more chips to cover a larger field of vision.

[0007] Another approach is to restore the photosensitivity of the target retina by modifying the retinal region through an optogenetic approach. Optogenetics is based on combining techniques from optics and genetics to control and monitor cell activity. This involves (i) genetically modifying target cells to make them sensitive to light by expressing exogenous photoreactive proteins in the cell membrane, and (ii) providing lighting devices that can provide light to said photoreactive proteins.

[0008] This is an extremely powerful tool for selective neuronal activation / inhibition, which can be used, for example, to restore neuronal function in living animals, including humans (Boyden et al., 2005, Nature Neuroscience 8(9):1263~68), and especially in the eye (Busskamp et al., 2012, Gene Therapy 19(2):169~75).

[0009] It has been shown that the selected wavelength of light must be close to the optimal wavelength for photoreactive proteins (Nagel et al., 2003, Proceedings of the National Academy of Sciences 100(24):13940~45; Klapoetke et al., 2014, Nature Methods 11(3):338~46), and that these proteins can have very low sensitivity to light (Asrican et al., 2013, Front Neural Circuits, 2013, 7:160; Busskamp et al., 2012, Gene Therapy 19(2):169~75). In both retinal prosthesis and optogenetic approaches, the intensity of light received by the modified retina (e.g., implant or target cells or proteins) should exceed a minimum value to obtain the minimum level of photo-induced protein or implant activation (Barrett et al., 2014, Visual Neuroscience, 31(4~5):345~354).

[0010] However, sufficient light must reach the modified retina (e.g., photoreactive proteins) to provide activation, while minimizing heat and phototoxicity to tissues or cells (Yan et al., 2016, Vision Research, 121:57-71). Furthermore, it is desirable to ensure that the light dose over a given period does not cause tissue or cell damage. Photobiological and ophthalmological standards for setting thresholds for light source intensity and dose received on the target are well known in the art (see, e.g., ISO 15004-2 2016; "ISO 62471:2006" 2016; "ANSI Z136 standard-LIA" 2014, §8.3). Intensity is the emission of light from the light source and the irradiance level (mW / mm²) on the target surface. 2 or photon cm -2 .s -1 It is converted to (mJ / mm²), and the dose over a given period is defined as the integral of the irradiance over that period (mJ / mm²). 2 or photon.cm -2 ).

[0011] Therefore, it is desirable to provide a lighting device that can control the intensity of emitted light and ensure that the corresponding dose does not exceed the maximum value.

[0012] Furthermore, since the expression of exogenous photoreactive proteins may vary among patients, and the photophobia threshold is highly variable among patients (Hamel 2006, Orphanet Journal of Rare Diseases 1:40), it may be desirable to be able to tailor the intensity of exposure to each patient.

[0013] Similarly, the eye itself is an optical system with optical aberrations, including myopia, hyperopia, and astigmatism (Navarro et al., 1998, Journal of the Optical Society of America A 15(9):2522). Optical aberrations are also present in emmetropic eyes and are taken into consideration in photobiological and ophthalmological standards (ISO 15004-2, 2007; ISO 62471, 2006). These aberrations can reduce the light intensity received by photoactivatable proteins, and therefore, it may be desirable to provide illumination devices that can at least partially compensate for these drawbacks.

[0014] Furthermore, it is desirable to provide a miniaturized lighting device that can be inserted into a device that a person can wear on a daily basis.

[0015] While currently available lighting devices have been developed to simulate optogenetic proteins for in vitro experiments (Degenaar et al., 2009, Journal of Neural Engineering 6(3):35007; Grossman et al., 2010, Journal of Neural Engineering, 7(1):16004), they are not yet miniaturized and are not yet suitable for human use.

[0016] Head-mounted displays are used for augmented reality, virtual reality, or video display.

[0017] However, the light intensity provided by these head-mounted displays is insufficient, cannot be configured to stimulate photoreactive proteins, and is therefore unsuitable for optogenetic applications. [Overview of the project]

[0018] Therefore, control of the device is necessary to illuminate the object with controlled light intensity, particularly with good spatial uniformity.

[0019] Therefore, this specification describes a method for controlling the illumination of the surface of an object by a vision device, where the vision device comprises: · A display including a plurality of sub-areas, each sub-area being adapted to be in at least two states, a first state in which the sub-area emits light in a first direction and a second state in which the sub-area does not emit light in the first direction; · A projection unit that images the light sent in the first direction by the display to form a projected image on the surface of the object. The method is implemented by a computer. · When the display is illuminated by light from a light source, obtaining the value of the radiant flux received by each sub-area of the display; · Converting each obtained value into an irradiance value to obtain a converted irradiance value; · Selecting an average irradiance value based on the converted irradiance value and a predetermined maximum irradiance value to obtain a target average irradiance value; · Determining a control rule adapted to independently control the state of each pixel of the sub-area over time. For each pixel, the control rule is determined such that, during a predetermined duration, the total duration for which each pixel is in the second state depends on the ratio of the target average irradiance value to the value obtained for the sub-area.

[0020] According to a further aspect of the method of control, which is advantageous but not mandatory, the method of control can incorporate one or several of the following features employed in any technically acceptable combination.

[0021] · In the determining step, the total time interval during which each pixel is in the second state is proportional to the ratio of the target average irradiance value to the value obtained for the sub-area.

[0022] · In the determining step, the total duration for which each pixel is in the second state is equal to the product of the ratio of the target average irradiance value to the value obtained for the sub-area and a predetermined time interval.

[0023] · During a predetermined duration, the durations for each pixel to be in the second state are continuous.

[0024] · During a predetermined duration, the predetermined duration is separated into several time intervals, and the durations for each pixel to be in the second state are continuous in each interval.

[0025] · The display includes an illumination unit and a reflector. The illumination unit is adapted to illuminate the pixels of the reflector, and each pixel of the reflector is adapted to send light in a second direction when the reflector is illuminated by light from the illumination unit. The first direction is different from the second direction.

[0026] · Each sub - area is constituted by one pixel.

[0027] · The object is the retina of the wearer.

[0028] This specification describes a method for illuminating the surface of an object by a vision device. The vision device · is a display including several sub - areas, each sub - area being adapted to have at least two states, a first state in which the sub - area sends light in a first direction, and a second state in which the sub - area does not send light in the first direction, and a projection unit that forms an image of the light sent in the first direction by the display and forms a projected image on the surface of the object. The method includes receiving a control rule obtained by the above - mentioned control method, and applying the control rule to the sub - area.

[0029] According to another aspect, the projection unit is part of the vision device. The vision device further includes an acquisition unit and a processing unit. The method further includes acquiring an image of the environment and commanding the display according to the acquired image.

[0030] This specification also relates to a computer program product that includes instructions for performing the steps of the above method when executed on a suitable computer device.

[0031] This specification also deals with computer-readable media on which the above-mentioned computer program products are encoded.

[0032] This specification also states, A display comprising several sub-areas, wherein each sub-area is adapted to have at least two states: a first state in which the sub-area transmits light in a first direction, and a second state in which the sub-area does not transmit light in the first direction. It comprises a projection unit that captures light sent in a first direction by a display and forms a projected image on the surface of an object, The control law obtained by the above control method is received, This involves applying control laws to sub-areas and dealing with visual devices for illuminating the surface of an object, which are adapted to perform this function.

[0033] According to a further embodiment of a visual device that is advantageous but not compulsory, the visual device may incorporate one or more of the following features, which are employed in any technically permissible combination:

[0034] The visual device further comprises an acquisition unit adapted to acquire an image of the environment, and a processing unit adapted to command a light source according to the acquired image.

[0035] Each sub-area is a pixel, the acquisition unit includes pixels grouped into each acquisition sub-area containing the same number of pixels, and the reference horizontal line is defined relative to the acquired image. The display includes several pixels grouped into each display sub-area, each containing the same number of pixels. The pixels are arranged so that their principal axes form a defined rectangle, and each pixel has a diagonal parallel to the principal axis of the rectangle. Each pixel is adapted to exist in at least two states: a first state in which the pixel transmits light in a first direction, and a second state in which the pixel does not transmit light in the first direction. The processing unit commands the state of each pixel on the display so that the light sent in the first direction is adapted to reliably transport the acquired image. The processing unit commands the state of each display sub-area in a one-to-one relationship with the acquired sub-area. The processing unit instructs the unit to form an image of a reference horizontal line in a row of display sub-areas, and the row of display sub-areas forms a 45° angle with the main axis of the rectangle. The display and projection unit are spatially positioned so that the image of the row of display sub-areas in the projected image is aligned with the horizontal line of the projected image with a tolerance of 0.5°.

[0036] This specification also states, An acquisition unit adapted to acquire an image of the environment in order to obtain an acquired image, the acquisition unit includes grouped pixels in each acquisition sub-area containing the same number of pixels, and a reference horizontal line is defined relative to the acquired image, A display comprising several pixels grouped into each display sub-area containing the same number of pixels, wherein the pixels are arranged to form a rectangle of defined length, each pixel has a diagonal parallel to the length of the rectangle, and each pixel is adapted to have at least two states: a first state in which the pixel transmits light in a first direction, and a second state in which the pixel does not transmit light in the first direction. A processing unit that commands the state of each pixel on the display and is adapted to ensure that light sent in a first direction reliably transports the acquired image, The system includes a projection unit that captures light sent in a first direction by a display and forms a projected image on the surface of an object, The processing unit commands the state of each display sub-area in a one-to-one relationship with the acquired sub-areas. The processing unit instructs the system to form an image of a reference horizontal line in a row of display sub-areas, the row of display sub-areas forming a 45° angle with the main axis of the rectangle, and the display and projection unit are spatially arranged so that the image of the row of display sub-areas in the projected image is aligned with the horizontal line of the projected image with a tolerance of 0.5°. This describes a visual device.

[0037] According to a further embodiment of a visual device that is advantageous but not compulsory, the visual device may incorporate one or more of the following features, which are employed in any technically permissible combination:

[0038] Each sub-area is formed by only one pixel.

[0039] The display comprises an illuminator and a reflector, the illuminator being adapted to illuminate the pixels of the reflector, and each pixel of the reflector being adapted to send light in a second direction when the reflector is illuminated by light coming from the illuminator, the first direction being different from the second direction.

[0040] The reflector is a digital micromirror device.

[0041] The visual device comprises a unit adapted to change the state of the display between at least two states, one of which is rotated by a rotation of a certain angle relative to the other state.

[0042] The projection unit is adapted to rotate a row of images in the display sub-area by a predetermined angle.

[0043] The sum of the rotation angle and the given angle is equal to 45°.

[0044] The target object is the wearer's retina.

[0045] The present invention will be better understood based on the following description, which is given as an illustrative example in correspondence with the accompanying drawings, without limiting the object of the invention. [Brief explanation of the drawing]

[0046] [Figure 1] Figure 1 is a schematic diagram showing an example of a visual device equipped with a projection unit in use by a wearer. [Figure 2] Figure 2 is a schematic diagram showing various elements of the projection section of the visual device shown in Figure 1. [Figure 3] Figure 3 shows an example of a control law for the components of the projection section in Figure 2. [Figure 4] Figure 4 shows another example of the control law for the components of the projection section in Figure 2. [Figure 5] Figure 5 shows a schematic representation of the effective pixels on the components of the projection area, both when a specific arrangement of pixels in a row does not exist and when it does exist. [Modes for carrying out the invention]

[0047] Figure 1 schematically shows the visual device 10, the wearer 12, and the wearer's environment 14.

[0048] The visual device 10 is a device used by the wearer 12 to perceive the environment 14.

[0049] In this case, the visual device 10 is adapted to illuminate the wearer's eyes, more specifically, all or part of the retina, preferably all or part of a modified retina, with a controlled light intensity.

[0050] The light intensity is thought to have been controlled when it met multiple conditions.

[0051] For example, multiple conditions may be selected from the following: • The light intensity at any given time is less than or equal to the maximum intensity. The light intensity at any given time is greater than or equal to the minimum intensity. • The dose during the period is less than or equal to the maximum value, and the period is 1 hour, 12 hours, 24 hours, or 48 hours. • Light intensity at a given interval of wavelengths, • The irradiation area does not extend beyond a given area, and • Several independent spatial regions illuminated by different levels of light intensity can be defined within the plane corresponding to the retina. One condition is the uniformity of each fundamental level of irradiance. A specific example is that the rate of change in irradiance relative to the average irradiance is less than or equal to the maximum value.

[0052] As will be shown below, the visual device 10 can improve the achievement of this last condition with respect to uniformity.

[0053] The visual device 10 comprises an acquisition unit 16, a display 17, a processing unit 18, and a projection unit 20.

[0054] The acquisition unit 16 is adapted to acquire an image of the environment 14.

[0055] The acquisition unit 16 is, for example, a camera.

[0056] According to a particular embodiment, the camera is an event-based camera. For example, the acquisition unit 16 is a DAVIS camera, an ATIS camera, or a DVS camera.

[0057] In either case, the acquisition unit 16 includes pixels grouped into each sub-area.

[0058] Each pixel here has a square shape.

[0059] Display 17 is adapted to display images.

[0060] The display 17 has several pixels grouped into each sub-area.

[0061] Each pixel is adapted to be in at least two positions: a first position in which the pixel transmits light in a first direction, and a second position in which the pixel does not transmit light in the first direction.

[0062] For example, in this example, the display 17 includes an optical engine unit 22 and a reflector 23.

[0063] The optical engine unit 22 here comprises a light source 24, a fiber 25, an optical system 26 extending from the input section 26I to the output section 26O, a collector 28, and an imaging section 30.

[0064] In the example shown in Figure 2, the light source 24 is a field-emitting diode.

[0065] Fiber 25 transmits the light emitted from the light source 24 to the input section 26I of the optical system 26.

[0066] The presence of fiber 25 allows the light source 24 to be a system separate from the optical system 26.

[0067] The collector 28 is adapted to focus the light output by the fiber 25.

[0068] The collector 28 converts the light ray into a collimated light ray that is sent to the imaging unit 30.

[0069] The imaging unit 30 is configured to convert the collimating light into a light beam adapted to illuminate the surface of the object on the reflector 23.

[0070] In some cases, the target surface is either a part of the surface of the reflector 23 (for example, a disk) or the entire surface of the reflector 23.

[0071] Each pixel of the reflector 23 is adapted to send light in a second direction when the reflector 23 is illuminated by light coming from the optical engine unit 22, the first direction being different from the second direction.

[0072] In this case, the reflector 23 is a digital micromirror device 32.

[0073] The digital micromirror device 32 is often referred to as DMD32, so in the following text, the digital micromirror device 32 will be referred to as DMD32.

[0074] This means that each pixel of the DMD32 is a mirror that can have a first position where the mirror reflects light toward an object, and a second position where the mirror reflects light in a different direction.

[0075] The processing unit 18 commands the position of each pixel of the display 17 so that the light sent in the first direction is adapted to reliably transport the acquired image.

[0076] In other words, a pixel at the first position means that something was observed on the same level of acquired image, while a pixel at the second position means that nothing was observed on the same level of acquired image.

[0077] Therefore, the DMD32 is used to achieve digital light processing (also known as DLP) and generate images.

[0078] The projection unit 20 is adapted to project the image generated by the DMD 32 onto the retina.

[0079] The projection unit 20 includes a relay unit 36 ​​that generates an intermediate image 38 and a projector 40.

[0080] The relay unit 36 ​​is adapted to relay the output of the DMD 32 to the input of the projector 40 by generating an intermediate image 38.

[0081] This allows for a larger distance between the DMD32 output and the surface while maintaining a sufficient field of view.

[0082] The projector 40 is adapted to project the intermediate image 38 as collimated light.

[0083] Each of the collector 28, imaging unit 30, relay unit 36, and projector 40 can be made from one or more lenses and / or mirrors.

[0084] The description of this embodiment does not preclude the visual system 10 from comprising other elements such as compensatory lenses for users with myopia / hyperopia and / or astigmatism.

[0085] To achieve this, the projector 40 is adapted to correct the user's refractive error by providing suitable light, such as divergent or converging light.

[0086] Here, the operation of the visual device 10 in Figure 1 will be described with reference to a method for controlling the illumination projected onto the retina.

[0087] The aim of such a control method is to obtain a control law adapted to control the illumination delivered to the wearer's retina 12.

[0088] Such control ensures good spatial uniformity of the light delivered to the wearer's retina.

[0089] For example, the total illumination area of ​​the DMD32 is 30 mm². 2 If that is the case,

[0090] With an incident radiant flux of 3W, the average irradiance is 100mW / mm². 2 It is equal to.

[0091] However, the irradiance may vary locally from pixel to pixel.

[0092] More generally, this method also provides good uniformity to any sub-area of ​​the DMD32.

[0093] For example, instead of a single pixel, this method can be applied to a sub-area containing several pixels, such as four pixels.

[0094] The purpose of the directive is to mitigate such spatial variations from one pixel to another.

[0095] Therefore, the directive is a directive that makes it possible to obtain spatially uniform light rays at the retinal level while keeping the peak irradiance lower than a predetermined maximum irradiance value MIV.

[0096] A predetermined maximum irradiance value (MIV) is given, for example, by a standard that defines the maximum irradiance value for the human eye.

[0097] The control method includes a process of obtaining, a process of converting, a process of selecting, a process of determining, and a process of applying.

[0098] In the process of obtaining the data, the value of the radiant flux F received by each pixel of the DMD is obtained.

[0099] The radiant flux value is obtained by an optical power meter. The probe surface covers the entire ray section at the position of the system's exit pupil.

[0100] The relative spatial distribution of radiant flux can be obtained by an external system capable of acquiring an image of the DMD surface, such as a camera with an objective lens.

[0101] Given the total radiant flux value and the relative spatial distribution of radiant flux, it is possible to extract the absolute radiant flux distribution. The absolute spatial distribution of irradiance can be extracted from the pixel size of a DMD32.

[0102] Alternatively, the process of obtaining the data may be performed in real time.

[0103] As a specific example, consider a case where the value of the radiant flux F(P1) of the first pixel P1 is equal to 12.5 μW, the value of the radiant flux F(P2) of the second pixel P2 is equal to 10 μW, and the value of the radiant flux F(P3) of the third pixel P3 is equal to 7.5 mW.

[0104] In the conversion step, each obtained value is converted to the irradiance value IV at the level of the irradiated surface.

[0105] Therefore, in this case, the ratio of the obtained value to the surface S of the pixel is calculated.

[0106] That is, the processing unit 18 calculates the following.

[0107]

Equation

[0108] In a specific example, assuming that each pixel is a square with a side length of 10 μm, the first converted irradiance value IV(P1) of the first pixel P1 is 125 mW / mm 2 and the second converted irradiance value IV(P2) of the second pixel P2 is 100 mW / mm 2 and the third converted irradiance value IV(P3) of the third pixel P3 is 75 mW / mm 2 becomes.

[0109] At this stage, since the average irradiance is equal to 100 mW / mm 2 it can be seen that the irradiance value varies within a range of ±25% from the average.

[0110] In the conversion step, a target irradiance value TV is selected.

[0111] The target value TV is not less than the minimum value of the converted irradiance value.

[0112] For 100% uniformity, the target value TV must be equal to the minimum value of the converted irradiance. However, a higher target value TV may be considered for higher final irradiance levels at the expense of reduced uniformity. The minimum acceptable level of final uniformity would be 85%.

[0113] In the case of three pixels P1, P2, and P3, the processing unit 18 selects the target value TV as the minimum value of each irradiance value after conversion.

[0114] This means that the target value TV here is 75 mW / mm². 2 It means equal to.

[0115] In the decision-making process, the control law is determined.

[0116] The control law is adapted to control the angular position of each pixel of the DMD32 over time.

[0117] Time is divided into frames here, and each frame has the same predetermined duration (PTD).

[0118] To ensure that a target value TV is obtained for each pixel, the instruction ensures that the total duration TTD during which each pixel is in the second position for a predetermined duration PTD is equal to the product of the predetermined duration PTD and the ratio of the target average irradiance value TV to the irradiance value IV obtained for that pixel.

[0119] In other words, the following relationship holds:

[0120]

number

[0121] When applied to the first pixel P1, the following relationship is obtained.

[0122]

number

[0123] Similarly, we derive the following for the second pixel P2.

[0124]

number

[0125] For the third pixel P2, the following equation is obtained:

[0126]

number

[0127] An example of a control law that satisfies these criteria is shown in Figure 3.

[0128] Figure 3 schematically shows how each pixel P1 to P3 is controlled in two frames.

[0129] In the case of the first pixel P1, at 0-60% PTD, the first pixel P1 starts in the second position, and at 60-100% PTD, the first pixel P1 is in the first position.

[0130] In the case of the second pixel P2, at 0-75% PTD, the second pixel P2 starts in the second position, and at 75-100% PTD, the second pixel P2 is in the first position.

[0131] In the case of the third pixel P3, the third pixel P3 is always in the second position.

[0132] Another example of a control law that satisfies these criteria is shown in Figure 4.

[0133] In this case, the frames are separated into several time intervals, and for each time interval, the subdivision shown in Figure 4 is used.

[0134] In a schematic diagram, Figure 8 uses five time intervals, and for each of these five time intervals, each pixel is in the second position at the start of the time interval, the first pixel P1 is switched to the first position at 60% of the time interval length, and similarly, the second pixel P2 is switched to the first position at 75% of the time interval length.

[0135] Such periodic fluctuations correspond to pulse width modulation (PWM), and this pulse modulation can vary within a frame.

[0136] Many other control laws can be considered.

[0137] For example, we can consider a pixel whose time at the second position has been shortened, starting at the first position.

[0138] In the case of Figure 4, deformation forms with more or fewer time intervals can be considered.

[0139] In each case, the control law is that the total time interval during which each pixel is in the second position depends on the ratio of the target irradiance value to the value obtained for the sub-area.

[0140] This dependency relationship is proportional in this case.

[0141] All of the steps described above can be considered calibration stages, and the results are stored in the memory of the processing unit 18.

[0142] In the application process, the processing unit 18 applies a control law to the DMD 32, or more precisely, to each pixel.

[0143] In the illustration, the average irradiance provided by the DMD32 is 75 mW / mm². 2 It is equal to and has 100% spatial uniformity.

[0144] Therefore, the control method allows for obtaining a control law that is adapted to achieve better uniformity.

[0145] Such better spatial uniformity can be advantageously used in methods of illuminating the retina.

[0146] This method can also be used for other devices such as the DMD32.

[0147] For example, this method can be used in liquid crystal on silicon (LCoS), LCDs (liquid crystal displays), laser beam steering (LBS), organic light-emitting diodes (OLEDs), active matrix organic light-emitting diodes (AMOLEDs), or micro-LEDs.

[0148] In some embodiments, the pixel change is not performed at a predetermined position, but rather the pixels remain in the same position, or rather, the pixels are not powered or not.

[0149] This means that each pixel has two states: a first state in which the sub-area transmits light in a first direction, and a second state in which the sub-area does not transmit light in the first direction.

[0150] A change in position is a specific change between two states.

[0151] However, it should be noted here that there are three or more angular positions, so that there are indeed multiple states in which the sub-area does not send light in the first direction.

[0152] This method also provides good uniformity to any sub-area of ​​the DMD32.

[0153] For example, instead of a single pixel, this method can be applied to a sub-area containing several pixels, such as four pixels.

[0154] Therefore, the sub-area has two states: a first state in which the sub-area transmits light in a first direction, and a second state in which the sub-area does not transmit light in a first direction.

[0155] The first state corresponds to the case where each pixel sends light in a first direction, while the second state corresponds to the case where each pixel does not send light in a first direction.

[0156] The second state is interpreted here as meaning that each pixel is in the same situation (e.g., the same position), suggesting that there may be a third state in which pixels exist in one situation (e.g., not powered) and pixels in another situation (e.g., a specific position).

[0157] It is also possible that there are other states of a subarea, corresponding to the case where the subarea has pixels in both a first state and pixels in a second state. This therefore suggests that a subarea can have at least two or more states.

[0158] The control methods described so far are implemented by the processing unit.

[0159] However, this method can be performed by any system.

[0160] Such a system is a computer or computing system, or a similar electronic computing device adapted to manipulate and / or convert data represented as physical quantities, such as electron quantities in the registers and / or memory of a computing system, to other data similarly represented as physical quantities in the memory, registers, or other such information storage devices, transmission devices, or display devices of a computing system. According to the present invention, these terms are synonyms or equivalents.

[0161] Such a system can interact with computer program products to perform control methods.

[0162] In a specific example, this system comprises a processor, a keyboard, and a display unit.

[0163] According to the modified definition, this system is a miniature computer. This system is a miniature electronic circuit board that includes, for example, a processor, memory, and high-speed computing capabilities such as direct memory access (DMA).

[0164] For example, an electronic circuit board may include a field-programmable gate array (FPGA), a system-on-a-chip (SoC), or an application-specific integrated circuit (ASIC).

[0165] The processor comprises a data processing unit, memory, and a reader. The reader is adapted to read computer-readable media.

[0166] Computer program products include computer-readable media.

[0167] Computer-readable media are media that can be read by a processor's reader. Computer-readable media are suitable for storing electronic instructions and can be coupled to a computer system bus.

[0168] Such computer-readable storage media include, for example, disks, floppy disks, optical disks, CD-ROMs, magneto-optical disks, read-only memory (ROM), random-access memory (RAM), electrically programmable read-only memory (EPROM), electrically erasable and programmable read-only memory (EEPROM), magnetic or optical cards, or any other type of medium suitable for storing electronic instructions and that can be coupled to a computer system bus.

[0169] Computer programs are stored on computer-readable storage media. A computer program contains one or more stored sequences of program instructions.

[0170] Computer programs are designed to be loadable into data processing units and adapted to perform control actions.

[0171] Furthermore, this method can be used for other objects such as modified retinas, retinal cells, modified retinal cells, or retinal implants.

[0172] In particular, the subject is the retina of the eye, which has been modified to express multiple photoreactive proteins.

[0173] In a particular embodiment, the photoreactive protein is an opsin.

[0174] According to a preferred embodiment, the photoreactive protein is selected from the group consisting of photo-operated ion channel proteins, more specifically from the group consisting of Chrimson, Chrimson® (International Publication No. 2013 / 71231), Chrimson®-tdT, Catch, Channelrhodopsin (US20140121265, US8906360), and melanopsin and its derivatives. According to another special embodiment, the photoreactive protein is selected from the group consisting of photo-operated ion pumps such as bacteriorhodopsin (Lanyi, JK, 2004, Annu Rev Physiol. 66:665~88), halorhodopsin (Lanyi, JK, 1990, Physiol Rev. 70:319-30), and their derivatives.

[0175] Such methods can also be advantageously used in combination with specific arrangements of the display 17 and projection unit 20.

[0176] To understand the peculiarities of such arrangements, a reference horizontal line is defined for the acquired image.

[0177] Figure 5 schematically shows how this reference horizontal line is formed on the pixels of the DMD 32, using three pixels on the acquisition unit 16 as an example (see top of the figure).

[0178] If a specific arrangement does not exist, in order to ensure that the correct image is obtained in the output of the projection unit 20, one pixel of the acquisition unit 16 corresponds to six pixels of the DMD 32 (four pixels for the fish's body and two pixels for the fish's tail) that are spatially arranged to form the shape of a fish, as shown in the center of Figure 5.

[0179] This results in low resolution.

[0180] In contrast, as shown at the bottom of Figure 5, in a specific arrangement, one pixel of the acquisition unit 16 corresponds to one pixel of the DMD 32.

[0181] Note that the pixels of DMD32 are arranged to form a rectangle with a length, and each pixel has a diagonal parallel to the length of the rectangle (the length including the principal axis of the rectangle).

[0182] This results in the optimal resolution.

[0183] More precisely, the processing unit 18 instructs the DMD 32 to form a reference horizontal line in a row of pixels, and the display 17 and projection unit 20 are spatially positioned so that the image of a row of pixels in the projected image is aligned with the horizontal line of the projected image with a tolerance of 0.5°.

[0184] In this context, tolerances should be understood as meaning that the equality relationship is satisfied within the interval between the value-tolerance and the value-tolerance.

[0185] However, if such a row of pixels is imaged using the same projection unit 20, as in the case of the central portion of Figure 5, the projected image will be obtained as a row with an angle of 45° to the horizontal.

[0186] This means that the specific arrangement also suggests the orientation of the display 17 and the orientation of the projection unit 20, in which the rows are selected so that the image of a row of pixels is aligned with the horizontal line.

[0187] For example, this can be achieved by using a unit adapted to change the position of the display 17 between at least two positions, one of which is rotated by a rotation angle relative to the other position.

[0188] Alignment is achieved when the rotation angle is equal to 45°.

[0189] Furthermore, the display 17 can rotate around its optical axis in a manner that is fixed by only the rotation angle.

[0190] Alternatively, the projection unit is adapted to rotate an image of a row of pixels by a predetermined angle.

[0191] Alignment is achieved when the given angle is equal to 45°.

[0192] In the modified example, both embodiments can be combined if the sum of the rotation angle and the given angle is equal to 45°.

[0193] Such specific configurations allow for better resolution while maintaining a simple setup.

[0194] This method can be used even with larger sub-areas, as long as the processing unit 18 commands the position of each sub-area in a one-to-one relationship with the sub-areas of the acquisition unit 16. Each sub-area contains the same number of pixels.

Claims

1. A method for controlling the illumination of the surface of an object using a visual device (10), The aforementioned visual device (10) is A display (17) comprising several sub-areas, each sub-area having at least one pixel, and each pixel being adapted to have at least two states: a first state in which the pixel transmits light in a first direction, and a second state in which the pixel does not transmit light in the first direction, The system comprises a projection unit (20) adapted to image the light sent in the first direction by the display (17) and to form a projected image on the surface of the object, The above method is performed by computer, When the display (17) is illuminated by light coming from the light source (24), the process of obtaining the value of the radiant flux received by each sub-area of ​​the display (17), The process involves converting each of the obtained values ​​into irradiance values ​​to obtain the converted irradiance values, A step of selecting an average irradiance value based on the converted irradiance value and a predetermined maximum irradiance value to obtain a target average irradiance value, The process includes determining a control law adapted to independently control the state of each pixel in the sub-area over time, For each sub-area, the control law is determined such that the total duration during which each pixel of the sub-area is in the second state depends on the ratio of the target average irradiance value to the value obtained for the sub-area.

2. The control method according to claim 1, wherein, in the determination step, the total time interval during which each pixel of the sub-area is in the second state is proportional to the ratio of the target average irradiance value to the value obtained for the sub-area.

3. The control method according to claim 1 or 2, wherein in the step of determining, the total duration during which each pixel of the subarea is in the second state is equal to the product of the ratio of the target average irradiance value to the value obtained for the subarea and a predetermined time interval.

4. The control method according to any one of claims 1 to 3, wherein the duration for which each pixel of the sub-area is in the second state is continuous for a predetermined duration.

5. A control method according to any one of claims 1 to 3, wherein, during a predetermined duration, the predetermined duration is separated into several time intervals, and the duration during which each pixel of the subarea is in the second state is continuous within each interval.

6. The control method according to any one of claims 1 to 5, wherein the display (17) comprises an illumination unit (22) and a reflector (23) having the sub-area, the illumination unit (22) being adapted to illuminate the pixels, and each pixel being adapted to send light in a second direction when the reflector (23) is illuminated by light coming from the illumination unit (22), the first direction being different from the second direction.

7. A control method according to any one of claims 1 to 6, wherein each sub-area is composed of one pixel.

8. The control method according to any one of claims 1 to 7, wherein the object is the retina of the wearer (12).

9. A method for illuminating the surface of an object using a visual device (10), wherein the visual device (10) is A display (17) comprising several sub-areas, each sub-area having at least one pixel, and each pixel being adapted to have at least two states: a first state in which the pixel transmits light in a first direction, and a second state in which the pixel does not transmit light in the first direction, The system includes a projection unit (20) that images the light sent in the first direction by the display (17) to form a projected image on the surface of the object, The aforementioned method, A step of receiving a control law obtained by the control method described in any one of claims 1 to 8, A method comprising the step of applying the control law to the pixels of the subarea.

10. The projection unit (20) is part of the visual device (10), and the visual device (10) further comprises an acquisition unit (16) and a processing unit (18), and the method is The process of acquiring an image of the environment (14), The illumination method according to claim 9, further comprising the step of commanding the display (17) according to the acquired image.

11. A computer program product comprising instructions for performing a step of the method of any one of claims 1 to 10 when executed on a suitable computer device.

12. A computer-readable medium on which the computer program product described in claim 11 is encoded.

13. A display (17) comprising several sub-areas, each sub-area having at least one pixel, and each pixel being adapted to have at least two states: a first state in which the pixel transmits light in a first direction, and a second state in which the pixel does not transmit light in the first direction, The system comprises a projection unit (20) adapted to image the light sent in the first direction by the display (17) and form a projected image on the surface of an object, Receiving a control law obtained by the control method described in any one of claims 1 to 8, A visual device (10) for illuminating the surface of the object, adapted to apply the control law to the pixels of the sub-area.

14. An acquisition unit (16) adapted to acquire an image of the environment (14), The visual device according to claim 13, further comprising a processing unit (18) adapted to issue commands to the light source (24) according to the acquired image.

15. Each sub-area is a pixel, and the acquisition unit (16) includes pixels grouped into each acquisition sub-area containing the same number of pixels, and the reference horizontal line is defined with respect to the acquired image. The display (17) includes several pixels grouped into each display sub-area containing the same number of pixels, The pixels are arranged to form a rectangle of defined length, and each pixel has a diagonal parallel to the length of the rectangle. The processing unit (18) commands the state of each pixel of the display (17) so that the light sent in the first direction is adapted to reliably transmit the acquired image. The processing unit (18) commands the state of each display sub-area in a one-to-one relationship with the acquired sub-area, The visual device (10) according to claim 14, wherein the processing unit (18) commands to form an image of the reference horizontal line in a row of display sub-areas, the row of display sub-areas forms a 45° angle with the principal axis of the rectangle, and the display (17) and the projection unit (20) are spatially arranged such that the image of the row of display sub-areas in the projected image is aligned with the horizontal line of the projected image with a tolerance of 0.5°.

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