Light therapy device

Abstract

1. A phototherapy device comprising a plurality of light sources and a control circuit, the plurality of light sources being arranged in a spatial pattern to form a display having a display area, each of the plurality of light sources being individually controllable to emit color light, the control circuit being configured to receive image data and to control the plurality of light sources to emit a spatially resolved pattern of emitted color light, the spatially resolved pattern being representative of the received image data, each of the plurality of light sources emitting a color light perceivable by a human observer as having a respective user-perceivable target image color, the control circuit being configured to control at least each of a first subset of the plurality of light sources to alternately emit respective first and second lights at a color flicker frequency, the first light having a first set of color components resulting in a first emission color, and the second light having a second set of color components resulting in a second emission color, the color flicker frequency being selected to be sufficiently high such that the alternatingly emitted first and second lights are perceived by the human observer as light having a user-perceivable blended color corresponding to the corresponding target image color.

Description

Technical Field

[0001] The present invention relates to a light therapy device, particularly a light therapy device for light-induced gamma brain stimulation for preventing, slowing down, delaying, and / or treating mental and neurological diseases such as Alzheimer's disease, different types of dementia, sleep, anxiety, or other circadian rhythm-related disorders, and relates to situations where gamma brain stimulation is most important for desired results such as increasing, inducing, or restoring a specific amount of neuronal activity in the brain's neural network.

Background Art

[0002] The use of light-induced gamma brain stimulation has been proposed for various therapeutic and / or preventive applications and / or cognitive training.

[0003] WO2018 / 152255 discloses a light therapy system (e.g., a light therapy device) for the treatment of Alzheimer's disease, depression, dementia, short-term memory, or for improving learning, motor ability, or cognitive ability. This prior art light system includes a blue light source operating at a frequency in the range of 20 - 50 Hz (preferably about 40 Hz), whereby this system enables the exposure of human retinal ganglion cells to stimulate brain waves (gamma oscillations in the human brain).

[0004] However, there is still a desire to provide a light therapy device that can be used for multiple purposes and in a user-friendly manner to facilitate long-term exposure of the user.

Summary of the Invention

[0005] According to one aspect, an embodiment of a light therapy device including a plurality of light sources and a control circuit is disclosed herein. The plurality of light sources are arranged in a spatial pattern so as to form at least a part of the display area of a display, and each of the plurality of light sources is individually controllable to emit colored light. The control circuit is For each of the multiple light sources, image data representing the respective target image color represented by the light source is received, and, The system is configured to control each of the multiple light sources so that it emits colored light that is perceptible to a human observer as having the target image color represented by the light source, The control circuit controls each light source of at least a first subset of multiple light sources, Depending on the target image color represented by the light source, the sets of first and second color components are determined, and, The light source is configured to be controlled to alternately emit at least each of the first and second lights at a color flicker frequency, The first light has a predetermined set of first color components that produce a first emission color, and the second light has a predetermined set of second color components that produce a second emission color, and the color flicker frequency is selected to be sufficiently high so that the alternately emitted first and second lights are perceived by a human observer as light having a user-perceptible fused color corresponding to the target image color represented by the light source.

[0006] Accordingly, embodiments of the apparatus disclosed herein provide stimulation of neural activity, particularly gamma wave stimulation, in a target brain by a plurality of light-emitting pixels or other light sources arranged in a spatial pattern.

[0007] Generally, the device comprises a display having a display area. Multiple light sources are arranged in a spatial pattern to form the display area. In one embodiment, the device comprises a display having an array of individually addressable pixels, i.e., multiple light sources form each pixel of the display. The display may be an LED display, an OLED display, a Q-LED display, an LCD, or a display utilizing another preferred display technology.

[0008] Embodiments of the apparatus described herein are widely used in real-life applications and are suitable for everyday use, for example, in the form of television sets or other displays. The apparatus displays a spatially resolved pattern of emitted colored light in the form of, for example, an image, a graphic pattern, or a pattern that otherwise varies across the display area of ​​the display. In at least some embodiments, the image data is time-varying image data. Thus, the apparatus may be configured to display a time-varying sequence of a spatially resolved pattern of emitted colored light in the form of, for example, a video, a film, a graphical animation, or a stream of image frames representing a pattern that otherwise varies over time and perceptibly across the display area of ​​the display. A light source that emits alternating colored light perceptibly as fused color would also be called a color-fusion pixel. At least some embodiments of the apparatus implement an imperceptible gamma stimulus. The apparatus implements a display technique that includes a color-fusion pixel, i.e., a pixel that alternately emits first and second colored light at a sufficiently high color flicker frequency so that the alternately emitted first and second light are perceived by a human observer as light having a user-perceptible fused color.

[0009] In some embodiments, the chromatic flicker frequency is selected to be lower than the critical flicker fusion frequency (CFF) and higher than the critical chromatic fusion frequency (CCFF).

[0010] The "critical flicker fusion frequency" refers to a concept in the psychophysics of vision. It is defined as the frequency at which an intermittent (e.g., flickering) light stimulus appears perfectly stable to the average human observer. The flicker fusion threshold is related to the persistence of vision. The critical flicker fusion frequency depends on the luminance and size of the stimulus (see, e.g., Hecht and Smith (1936) J. Gen. Physiol. 19(6): 979-89). For large, high-luminance stimuli covering the fovea, such as a full-screen white field on a CRT, flicker fusion occurs at approximately 60 Hz.

[0011] The phrase "a color flicker frequency high enough to cause alternating first and second liturgies to be perceived by a human observer as light with a user-perceptible fused color" means, when used in reference to alternating color flicker or flashing light, that a person illuminated by or observing the illumination will perceive the illumination as substantially constant, even if the flashing light / light component's frequency is below the critical flicker fusion frequency. The threshold frequency above which alternating first and second liturgies are perceived by a human observer as light with a user-perceptible fused color is also called the critical color fusion frequency (CCFF).

[0012] Therefore, users of the device can be exposed to emitted light over extended periods without becoming excessively tired, bored, or otherwise experiencing phototherapy as excessively bothersome, for example, while watching movies, images, graphic patterns, or performing tasks involving graphical user interfaces such as computers or other electronic devices. The ability to provide exposure over extended periods improves the stimulating effect of light. In particular, at least some embodiments of the device can provide an effective dose of brain-stimulating light while users of the device can view colorful videos and images through modern, novel, and standard display technologies.

[0013] Embodiments of the device may be used for various phototherapy and / or other brain stimulation applications. For example, embodiments of the device may be used for the treatment and / or prevention of Alzheimer's disease, depression, dementia, and short-term memory, or for improving learning, motor skills, or cognition. For example, since many people spend long periods of time in front of display screens, such as TVs, computers, and smartphones, embodiments of the device make it possible to integrate phototherapy and / or light stimulation into existing daily routines.

[0014] In some embodiments, the device is configured to display a spatial pattern that changes over time, for example, a spatial pattern that changes at a spatial flicker frequency, i.e., a new pattern may be presented at the spatial flicker frequency. Examples of spatial patterns that change over time include moving grids, rotating patterns, for example, a rotating patterned disk, or a square pattern. The spatial flicker frequency may be between 5 and 60 Hz, for example between 25 Hz and 60 Hz, for example between 30 Hz and 50 Hz, for example between 35 Hz and 45 Hz, for example between 38 Hz and 42 Hz, for example 40 Hz. Thus, the device allows the eyes to be exposed to a spatially fluctuating pattern in order to stimulate electroencephalography (preferred gamma oscillations in the brain).

[0015] According to some embodiments, the color flicker frequency is selected to elicit a therapeutically effective neural response in the brain of a human observer. According to some embodiments, the light emitted alternately at the color flicker frequency is selected to stimulate or synchronize electroencephalography, particularly gamma oscillations, in the human brain when a person is exposed to the alternately emitted light. In particular, in some embodiments, the color flicker frequency is 5 Hz to 60 Hz, e.g., 25 Hz to 60 Hz, e.g., 30 Hz to 50 Hz, e.g., 35 Hz to 45 Hz, e.g., 38 Hz to 42 Hz, e.g., 40 Hz.

[0016] Image data may represent one or more captured pictures and / or computer-generated graphics or other computer-generated image data. In some embodiments, the control circuit is configured to control multiple light sources to change the displayed image over time. In particular, the control circuit may be configured to receive a stream of image data representing video and to control multiple light sources to display the video within the display area. Thus, the device can display video or other image content that changes over time, thereby facilitating the use of the device over extended periods, as the display can show entertainment and / or informational content such as TV programs and movies. Consequently, users may be exposed to flicker light during everyday activities such as watching television.

[0017] In some embodiments, the displayed image data may include high-resolution images, while in other embodiments, simple geometric patterns are displayed. For example, in one embodiment, a control circuit is configured to control multiple light sources to cause a simulated movement of a first light-emitting area emitting light having a target color perceptible to a first user relative to a second light-emitting area emitting light having a target color perceptible to a second user. In certain embodiments, the device displays a moving grading, e.g., a spatial pattern comprising multiple segments, which is updated at a spatial flicker frequency so as to appear to move across at least a portion of the display area. The segments may be arranged in a grid or other regular pattern. The segments may be illuminated with different colors that may be visually distinguishable or visually indistinguishable. Thus, a cost-effective device can be provided in which the display may have a relatively low spatial resolution and may also have a limited number of displayable target colors.

[0018] In some embodiments, the first and second user-perceivable target colors are visually indistinguishable to a human observer but have different spectral distributions. An example of visually indistinguishable colors may be two whites, each with its own spectral distribution. An example of a visually distinguishable pair of colors includes red and green.

[0019] It will be understood that different embodiments of the device may include different numbers of light sources, particularly displays of different resolutions. It will be understood that the number and density of light sources across the display area may depend on other factors such as the display technology, the dimensions of the display, and / or the desired image quality. In some embodiments, the number of light sources is selected to achieve a desired resolution, e.g., HD, Full HD, 4K, or other suitable resolution. The dimensions of the display area vary and include, but are not limited to, display areas ranging from smartphone displays to large television screens, e.g., 200-inch television screens. It will be further understood that multiple light sources may form the entire display area of ​​the display, or only a portion of the display area, e.g., only a sub-area.

[0020] In some embodiments, all light sources of the display, in particular all pixels of the display, may be operable and controllable to emit each target image color as its respective fused color by alternately emitting its respective first and second colors. In other embodiments, only a subset of light sources may be adapted in this way, with the remaining light sources representing conventional display pixels. In some embodiments, some or all light sources of the display, in particular some or all pixels of the display, may be selectively operable and controllable to emit each target image color by conventional color mixing, in particular by simultaneously emitting each color component that mixes into an intended target image color, or as its respective fused color, i.e., by alternately emitting its respective first and second colors. The first subset of light sources may be partially or completely predetermined. Additionally or instead, the control circuit may select, based on one or more criteria, that a first subset of light sources be operated as color-fused pixels, i.e., operated to display colors as fused colors, for example, in response to a desired intensity of therapeutic nerve stimulation, and / or user control, and / or in response to one or more characteristics of received image data. In some embodiments, the light sources of the display are divided (in a predetermined manner or adaptively by a control circuit) into a first subset and a second subset separated from the first subset, the control circuit is configured to cause the light sources of the first subset to operate only as color-fusion pixels, i.e., to alternately emit their respective color components at a color flicker frequency, i.e., to display each target color by alternately emitting each color component that would be perceived as a target color when alternately emitted and color-fused at a color flicker frequency. The second subset may operate to emit each target image color only by simultaneously emitting each color component that is to be mixed to be perceived as a target color.

[0021] In some embodiments, the control circuit is configured to determine sets of first and second color components for each of the first subset of the plurality of light sources in response to received image data, and to control each of the first subset of light sources to alternately emit first and second light having predetermined sets of first and second color components. It will be understood that the target image color emitted by each light source in the first subset may differ from light source to light source, depending on the image data to be displayed. Thus, each of the sets of first and second color components determined by the control circuit may also differ from light source to light source. It will be understood that the light sources of the second subset may be controlled in the same manner, but have the same sets of first and second color components, and therefore operate effectively as conventional display pixels.

[0022] Preferably, the control circuit is configured to control at least each of a first subset of multiple light sources to alternately emit their respective first and second lights in synchronous manner, particularly at the same color flicker frequency, preferably in the same phase. In particular, it is preferable that the control circuit is configured to control all of the multiple light sources that alternately emit their respective lights in synchronous manner, particularly at the same color flicker frequency, preferably in the same phase. Thus, the color flicker frequency of all color-fused pixels in the display is uniform across the display area. The inventors have recognized that stimulating the user's brain with multiple synchronized light-emitting pixels is advantageous, particularly to provide temporal and / or spatial stimulation.

[0023] Depending on the display technology used, for example, depending on the number of individual color light sources that make up each image pixel of the display, not all target colors may be equally good reproducible by color fusion of alternately emitted color components. Therefore, in some embodiments, the control circuit is configured to select a first subset of light sources in response to received image data. In particular, in some embodiments, the control circuit is configured to include only selected light sources from a plurality of light sources within the first subset, and the target image colors to be represented by the selected light sources belong to a predetermined set of target image colors. The remaining light sources may then be included in a second subset of light sources that are controlled to operate as conventional display pixels.

[0024] When displaying time-varying images, such as a video stream or other series of image frames, areas of rapidly changing color may not be suitable for display as color-fusion pixels, as this can reduce the intensity of induced neural activity and / or diminish the user's perception of color. Therefore, in some embodiments, the received image data is time-varying image data representing a series of target image colors for each light source of a plurality of light sources, and the control circuit is configured to modify a first subset in response to the time-varying image data. Thus, the control circuit may select different sets of light sources to act as color-fusion pixels at different times, particularly depending on the changing characteristics of the displayed image stream. To achieve this objective, the control circuit may employ a forward-looking strategy to determine how quickly the image target colors represented by each light source change. To achieve this objective, the control circuit may maintain a buffer of appropriate length, and the received series of image data is buffered before display to allow analysis of the displayed target image colors. In some embodiments, it will be understood that the image data may include appropriate metadata containing information about how long each target color persists.

[0025] In particular, in some embodiments, the control circuit is configured to include only a selected light source among a plurality of light sources within a first subset, and the target image color represented by the selected light source persists for at least a minimum period, particularly at least 100 ms, for example at least 200 ms. The remaining light sources may thus be included in a second subset of light sources that are controlled to operate as conventional display pixels. In some embodiments, it will be understood that the control circuit may select the first subset of light sources based on both the target color and the time during which the target image color of the image pixel is constant or at least substantially constant, for example varying only within a predetermined limit.

[0026] According to some embodiments, the light therapy device further comprises an audio output device configured to output an audio signal modulated at the color flicker frequency, thereby providing additional stimulation.

[0027] In some embodiments, the control circuit is configured to determine a set of first and second color components from a look-up table that maps each of a plurality of target colors to a set of first and second color components. Thus, a fast determination of the set of color components is achieved.

[0028] In some embodiments, the control circuit is configured to control multiple light sources so that the first and second lights emit with substantially the same perceived luminance, i.e., the first light has a first luminance and the second light has a second luminance substantially equal to the first luminance, in particular so that the difference in luminance is sufficiently small that it is imperceptible to the user. In particular, in some embodiments, the control circuit is configured to control multiple light sources so that the first and second lights have the same lux level as perceived by an observer, in particular at a predetermined distance and / or a distance greater than a threshold distance, for example greater than 20 cm, for example greater than 50 cm, for example greater than 1 m, for example greater than 2 m. Preferably, the first and second lights emit in the same direction and / or have the same emission direction pattern in steradians.

[0029] The sets of first and second color components are selected so that, when the first and second lights are emitted at substantially the same luminance, the alternately emitted first and second lights are perceived by a human observer as light having a user-perceptible fused color corresponding to the target image color represented by the light source. Thus, the control circuit may be configured to control each light source of at least a first subset of multiple light sources so that each of the first and second lights emits at substantially the same luminance, thereby achieving improved color reproduction.

[0030] In some embodiments, each light source comprises a set of three or more, preferably four or more, for example, five or more light-emitting sub-elements, each configured to emit light having a different color. Thus, each of the color components of the first and second sets of color components can be selected to be one of the colors of the set of light-emitting sub-elements. If the first or second set of color components includes multiple color components, for example, multiple primary colors, the corresponding first or second color is a mixture of the multiple color components. Thus, a large number of light-emitting sub-elements increases the variability in selecting the first and second sets of color components, making it possible to create different first and second colors, and even different fused colors.

[0031] This disclosure relates to various embodiments, including the apparatus, corresponding systems, methods, and / or products described above and below, each of which brings about one or more of the benefits and advantages described in relation to one or more of the other embodiments, and each of which has one or more embodiments corresponding to embodiments described in relation to one or more of the other embodiments and / or disclosed in the appended claims.

[0032] In particular, according to one embodiment, an embodiment of a phototherapy apparatus, and more particularly an embodiment of a method for controlling the phototherapy apparatus disclosed herein, wherein the phototherapy apparatus comprises a plurality of light sources, the plurality of light sources arranged in a spatial pattern to form at least a portion of the display area of ​​a display, and each of the plurality of light sources is individually controllable to emit colored light, and the method is, For each of the multiple light sources, receive image data representing the respective target image color represented by the light source. Controlling each of the multiple light sources to emit colored light that is perceptible to a human observer as having the target image color represented by the aforementioned light source, Includes, To control, The first and second sets of color components are determined according to the target image color represented by the light source, This includes controlling the light source to alternately emit the first and second lights at a color flicker frequency, The first light has a predetermined set of first color components that produce a first emission color, and the second light has a predetermined set of second color components that produce a second emission color, and the color flicker frequency is selected to be sufficiently high so that the alternately emitted first and second lights are perceived by a human observer as light having a user-perceptible fused color corresponding to the target image color represented by the light source.

[0033] In another embodiment, embodiments of a method for inducing gamma waves in the brain of a subject are disclosed herein, the method is For each of the multiple light sources, receive image data representing the respective target image color represented by the light source. Controlling each of the multiple light sources to emit colored light that is perceptible to a human observer as having the target image color represented by the aforementioned light source, Includes, To control, The first and second sets of color components are determined according to the target image color represented by the light source, This includes controlling the light source to alternately emit the first and second lights at a color flicker frequency, The first light has a predetermined set of first color components that produce a first emission color, and the second light has a predetermined set of second color components that produce a second emission color, the color flicker frequency is selected to be sufficiently high so that the alternately emitted first and second lights are perceived by a human observer as light having a user-perceptible fused color corresponding to a target image color represented by the light source, and the color flicker frequency is selected to induce gamma waves in the brain of the human observer.

[0034] In some embodiments, the user may be positioned directly in front of the screen so that their eyes are positioned at a certain distance from the display, which may be, for example, between 1.5 and 2.5 times the diagonal of the display area. The user may be positioned so that they can observe the display at a suitable viewing angle, for example, about 30 degrees, or at different suitable viewing angles. For example, with a 40-inch display, the user may be seated at a distance of 1.5m to 2.5m from the display. However, different users may prefer different distances and / or viewing angles, for example, up to about 10m.

[0035] Preferred embodiments will be described in more detail with reference to the accompanying drawings. [Brief explanation of the drawing]

[0036] [Figure 1] A schematic representation of one embodiment of a phototherapy device is shown. [Figure 2] A schematic diagram of the display of one embodiment of a phototherapy device is shown. [Figure 3] A schematic diagram of the light source in one embodiment of a phototherapy device is shown. [Figure 4] A schematic diagram of color fusion using one embodiment of a phototherapy device is shown. [Figure 5] A schematic diagram of color fusion using one embodiment of a phototherapy device is shown. [Figure 6] A schematic diagram illustrates the process for controlling one embodiment of a phototherapy device. [Figure 7] The operation of one embodiment of a phototherapy device is schematically shown. [Figure 8] A schematic diagram of the light source in another embodiment of the phototherapy device is shown. [Figure 9] A schematic diagram of color fusion using one embodiment of a phototherapy device is shown. [Figure 10] A schematic diagram of color fusion using one embodiment of a phototherapy device is shown. [Figure 11] An example of a process for obtaining the first and second color component sectors for a target image color is shown. [Figure 12] Here is another example of a process for obtaining the first and second color component sectors for a target image color. [Figure 13] A schematic example of a limited color gamut is shown below. [Figure 14] A schematic diagram of the display of one embodiment of a phototherapy device is shown. [Modes for carrying out the invention]

[0037] Figure 1 schematically shows one embodiment of a phototherapy device. The phototherapy device, generally shown as 100, includes a display device 110 and a control unit 120.

[0038] The control unit 120 and the display device 110 may be implemented as a single device housed in a single enclosure, or as separate devices that are connected to each other in a communicative manner.

[0039] The display device 110 defines a display area 111 for displaying one or more images 113 to be viewed by the user 300. The display device may use any suitable display technology, such as an LED display, OLED display, Q-LED display, or LCD display.

[0040] The control unit 120 may be an integrated circuit or other suitable circuit configured to control the display device. To achieve this purpose, the control unit may implement a display controller.

[0041] The control unit 120 is configured to receive image data 200 and to control the display device to display one or more images 113 in response to the received image data. For example, the control unit may include a frame rate controller for controlling the frame refresh rate of the display device. The control unit further comprises a color flicker controller for controlling the color flicker of individual pixels of the display device, as described herein. The control unit further comprises a brightness controller for controlling the brightness of each pixel. The brightness controller may be implemented, for example, as a PWM controller.

[0042] Image data 200 may be received from an external device of the device 100, retrieved from the storage device of the device 100, or generated by the processing unit of the device 100. Therefore, the device 100 may include a suitable communication interface for receiving image data, such as a wired or wireless data communication interface, such as a network adapter, a Wi-Fi interface, or a Bluetooth interface. Alternatively or additionally, the device 100 may include a data storage device, such as a hard disk, an EEPROM, or another suitable data storage device. Further alternative or additionally, the device may include a processing unit, such as a CPU, a GPU, and / or the like.

[0043] Image data 200 may represent a single image or multiple images, such as frames of a video. The image data may be encoded according to an encoding scheme suitable for the image data.

[0044] In the example shown in Figure 1, the control unit 120 includes a mapping module 121 for mapping color information to a set of color components, as will be described in more detail below. For example, the mapping module may include a lookup table for mapping color information to a set of color components.

[0045] The device 100 may include additional components, such as a loudspeaker for playing audio information and a corresponding audio control circuit.

[0046] Figure 2 schematically shows a display of a phototherapy device, for example, the device in Figure 1. The display 110 includes a matrix of individually controllable light sources, also called pixels 112. Each pixel is configured to emit colored light, and the color and brightness of each pixel are controllable by the control unit of the phototherapy device. Thus, the display emits spatially resolved patterns of light, such as images or other spatially varying patterns. To achieve this objective, the image displayed at a pixel resolution NxM may be appropriately encoded to include target image color information C(i,j), i=1…N, j=1…M for each pixel, and the pixels are indexed by row index i and column index j.

[0047] In the display 110, all pixels may be chromofusion pixels as described herein, that is, all pixels may be configured to alternately emit at least each of first and second lights at a chromofusion flicker frequency, the first light having a first set of color components that produce a first emission color, and the second light having a second set of color components that produce a second emission color, and the chromofusion flicker frequency is selected to be sufficiently high so that the alternately emitted first and second lights are perceived by a human observer as light having a user-perceptible chromofusion color. Alternatively, only a subset of pixels may be chromofusion pixels, which still allows the device to stimulate brain function in the user's brain. Because pixels are very small, depending on the display, there may be limitations on the requirement of how large a subset of pixels should be to achieve adequate stimulation, for example, that every two pixels, every three pixels, every four pixels, etc., should be chromofusion. In some embodiments, not all pixels capable of operating as chromofusion pixels are always operated as chromofusion pixels. In some embodiments, the control unit of the device may selectively select which pixels to operate as color-fusion pixels, for example, based on a desired intensity of nerve stimulation and / or in response to the received image data being displayed. In any case, it is preferable that all color-fusion pixels of the display be controlled to operate synchronously, i.e., to flicker at the same color flicker frequency, preferably in the same phase.

[0048] Figure 3 schematically illustrates one embodiment of pixel 112. In the example in Figure 3, the pixel is a polyprimary color pixel containing six subpixels 112A-F. Subpixel 112A is operable to emit red light, subpixel 112B is operable to emit green light, and subpixel 112C is operable to emit blue light; that is, subpixels 112A-C correspond to standard RGB color subpixels. Furthermore, pixel 112 in this embodiment includes subpixels with additional colors, in this example cyan subpixel 112D, lime subpixel 112E, and amber subpixel 112F. It will be understood that other examples of polyprimary color pixels may include additional or alternative color subpixels, such as yellow, magenta, white, etc. It will be further understood that other examples of polyprimary color pixels may include a different number of color subpixels, such as 4, 5, 6, 7, or more subpixels. Polyprimary color pixels enable the provision of displays that can reproduce a wider color gamut than conventional displays. Furthermore, this additional variability has proven particularly advantageous when employing color fusion as described herein, because the additional subpixels increase the variability of the selection of alternative color sets that the pixels can alternately switch to, thereby expanding the range of displayable colors visible to the human eye. Pixel 112 is controlled to selectively activate one or more subpixels at their respective intensities / luminances, thereby allowing the pixel to emit light of the color resulting from a mixture of the individual colors of the subpixels. The intensity of the subpixels can be controlled, for example, by pulse activation of the subpixels with a variable duty cycle, for example, by pulse width modulation.

[0049] Figures 4 and 5 schematically show color fusion according to one embodiment of a phototherapy device.

[0050] In particular, Figure 4 shows an example of a color gamut 401 in which fused colors can be produced by multi-primary color pixels, including red, green, blue, lime, cyan, and optionally amber subpixels, as described, for example, in relation to Figure 3. Colors within the color gamut 401 can be produced by controlling pixels to alternately activate a first set of subpixels and a second set of subpixels at appropriate color flicker frequencies.

[0051] In particular, if the color flicker frequency is sufficiently high, for example, selected to at least 25Hz, the user viewing the display will perceive the light emitted by the pixels as having fused colors within the 401 color gamut, rather than pixels switching / flickering between two different colors. Furthermore, if the color flicker frequency is appropriately selected, the flicker can induce a neurostimulatory response in the user's brain. Examples of suitable color flicker frequencies that produce imperceptible brain stimulation from the flicker light while the user perceives fused colors include frequencies from 25Hz to 60Hz, e.g., 30Hz to 50Hz, e.g., 35Hz to 45Hz, e.g., 38Hz to 42Hz, e.g., 40Hz.

[0052] In preferred embodiments, it is preferable that alternating sets of colors are emitted at substantially the same user-perceived luminance to switch operation at color flicker frequencies so as to remain substantially imperceptible to the user, in order to avoid user-perceivable luminance flicker, because most subjects are more sensitive to luminance flicker than to color flicker. The inventors have recognized that luminance matching of alternating colors is very beneficial in ensuring that the user perceives the fused color without overperceiving the flicker light. However, the requirement of luminance matching imposes limitations on the range of fused colors that a color-fusion pixel can emit. For example, when two colors are sequentially mixed from two subpixels, i.e., when light is emitted from the two subpixels simultaneously, the entire line of colors between the monochromatic colors of each subpixel can be achieved by controlling the relative luminance of the two subpixels. However, when employing brain-stimulated color fusion by alternately activating two subpixels at color flicker frequencies, only a single color along the line between the two primary colors, rather than the entire line of colors, may be achievable in order to maintain luminance matching so that the flicker of the color-fusion light is substantially imperceptible. Therefore, in order to maintain luminance matching for color-fused pixels, it is not possible to simply adjust each set of colors independently of other sets of colors without reducing or eliminating the effects of color fusion. Thus, imposing luminance matching imposes some limitations on the number of possible combinations.

[0053] For example, a conventional display pixel that utilizes color mixing by simultaneously emitting multiple primary colors at each brightness level, a pixel with three subpixels (e.g., RGB pixels), may provide a 24-bit / (8+8+8)-bit true-color RGB implementation where each subpixel has 256 individual brightness levels per channel. Thus, the maximum number of color combinations is 256 × 256 × 256 = 16.7 million colors. In the case of a 48-bit / (16+16+16)-bit / deep-color RGB implementation, this is 65536 × 65536 × 65536 = 281,475,000,000,000 colors. By comparison, a 16-bit RGB implementation is often called high-color, while an 8-bit RGB implementation is simply called color. The above calculation of the maximum number of possible color combinations in a conventional, for example, 16-bit RGB display assumes that each channel can be independently tuned to generate new colors. In the case of color-fusion pixels in the embodiments of the apparatus described herein, imposing luminance matching means that each channel cannot always be adjusted independently without the need to adjust the other channels. Otherwise, the effect of color fusion may be reduced or even eliminated. Thus, this imposes some limitations on the number of possible combinations. This can be illustrated by the example of a limited color gamut by linear current drive. Assuming a particular color-fusion light emitted by a color-fusion pixel containing three 8-bit subpixels (e.g., RGB), the pixel may be controlled to alternately emit two color sets, SET1 and SET2, each corresponding to the following subpixel luminance values: [20,20,20]SET1 [0,40,0]SET2

[0054] Assuming it is desirable to reduce the overall brightness of pixels without changing the display color, the brightness of each individual pixel may be divided by a factor of 20 to reduce the brightness of the pixel by 1 / 20: [1,1,1]SET1 [0,2,0]SET2

[0055] Here, it's impossible to further reduce the brightness of a pixel without compromising the color of the light. Generally, when an element becomes zero or 257, a limit is reached. Therefore, the entire space of 8-bit resolution cannot be used and is limited to color.

[0056] Typically, the color gamut extends across the range of possible colors. However, in individual pixels with color fusion between two monochromatic subpixels, the color gamut extends to a line. By adding additional subpixels (e.g., additional LEDs with different colors, as in a polyprimary color display), the color gamut can move around the line. However, this does not allow for infinite movement, because, as illustrated in the example above, some combination of subpixels can break luminance matching or color changes due to the limits of the minimum and maximum resolution of the individual pixels. Alternatively or additionally, the color gamut may be extended by causing the pixels to operate to use a combination of color mixing and color fusion, i.e., by selecting first and second sets of colors to include one or more common color components and one or more different color components. In particular, the second set of color components may include one or more color components that are also present in the first set of color components, and the second set of color components may further include one or more color components that are not present in the first set of color components, or are present to substantially less extent. Generally, the individual color components emitted by a light source may be defined by each light-emitting sub-element of the light source, that is, each light source may comprise a plurality of sub-elements, in particular subpixels, each sub-element configured to emit its respective color component.

[0057] Figure 5 shows examples of possible fused colors that can be achieved with the multi-primary color pixels described in Figure 3. In particular, Figure 5 shows that multiple different whites and colors can be obtained around the Planck locus 502.

[0058] Figure 6 schematically shows the process for controlling one embodiment of a phototherapy device, for example, the device described with reference to Figures 1 to 3.

[0059] In the first step S1, the process receives image data. The image data may represent a single image or a sequence of images, and may be represented in any suitable form, for example, a suitable graphics format such as jpg, or a suitable format for encoding media content such as mp4. The image data may represent an image at a suitable resolution, and a color value may be defined for each of the image pixel matrix.

[0060] Optionally, in step S2, the process determines which subset of display pixels should act as color-fused pixels and which display pixels should act as conventional display pixels, i.e., simply using color mixing of simultaneously emitted color components.

[0061] In particular, in some embodiments, the process simply selects display pixels that will represent a predetermined target image color as color-fused pixels, while the remaining display pixels may function as conventional display pixels.

[0062] Alternatively or additionally, the process simply selects display pixels to be color-fused pixels that will represent the same or at least substantially the same target image color for at least a minimum period, for example, at least 100ms, such as at least 200ms. This ensures that the color flicker due to the corresponding color components persists long enough for the observer's brain to perceive the flicker color as the fused color. Thus, when displaying video or other time-varying image data, the subset of display pixels that are made to act as color-fused pixels may change over time.

[0063] In step S3, for each display pixel acting as a color-fused pixel, the process determines two sets of colors from the image colors received for the display pixel, for example, based on a color lookup table. In embodiments where only a subset of display pixels are color-fused pixels, it will be understood that this determination may only need to be performed for that subset. Alternatively, for display pixels acting as conventional pixels, the process may select two sets of colors that are identical to each other.

[0064] An example of a color lookup table may be indexed by a suitable color space representation, for example, chromaticity pair coordinates (x,y), each of which may be a appropriately discretized parameter between 0 and 1.

[0065] For each chromaticity coordinate, the lookup table may define two or more sets of colors. Each set of colors may be represented as an array of intensity values. Each intensity value may represent one of the primary colors of the display, for example, blue, cyan, green, lime, amber, and red. Each intensity value may be defined at an appropriate resolution, for example, as an 8-bit or 16-bit value.

[0066] For example, a color lookup table may be represented as a table, as in the following example: xy BC GL Set1 0 10 10 15 Set2 100 5 50 5 xy BC GL Set1 0 20 20 30 Set2 200 10 100 10

[0067] Generally, multi-primary color pixels, which have more than three primary colors (e.g., RGB and one, two, or more additional colors), are advantageous because they allow for a greater number of fused color combinations while maintaining sufficient luminance matching.

[0068] In one example, six color pixels are assumed (for example, each having the ordinal values ​​blue, cyan, green, lime, amber, and red). However, the space can also be derived from the conventional three-color RGB space or from different sets of polyprimary colors and / or for different resolutions. Such a space can be generated by calibrating a particular display technology by performing all possible combinations of color-fused pixels and measuring the perceived (x,y) pairs for all combinations on a particular display at hand. The color space does not have to be represented in (x,y) space, but a similar color space, e.g., (u,v) space, (u * ,v * It should be noted that these may be represented in a color space or a similar color space. Therefore, it will be understood that other examples of lookup tables may be based on different color spaces. Furthermore, some embodiments of the device may store different lookup tables for different color spaces. Since linear driving of LEDs or other types of subpixels is utilized and there are clearly defined maximum and minimum LED intensity values, the luminance value of each pixel does not need to be measured during the calibration stage.

[0069] In step S4, the process controls individual display pixels, or at least a subset of them, to be made to act as color-fused pixels, so that subpixels are alternately activated according to a predetermined set of colors.

[0070] The activation of individual display pixels may be controlled based on multiple update rates. 1) The displayed image may be updated at a predetermined display refresh rate. The refresh rate determines how many times per second the display can redraw the display area. The refresh rate is therefore related to the maximum number of frames that the display can display per second. Common display refresh rates include 120Hz, 60Hz, and 30Hz. 2) Each pixel may alternate between two sets of a given color at a color flicker frequency. The refresh rate should preferably be at least twice the color flicker frequency. 3) The brightness of individual subpixels may be controlled, for example, by pulse activation at a pulse rate using pulse width modulation of brightness. The PWM may operate at a wide range of frequencies, e.g., PWM frequencies in the range of kHz or even MHz. In some embodiments, PWM frequencies in the range of 100 Hz to 100 kHz are preferred, but other frequencies may also be used.

[0071] In some embodiments, the display refresh rate is higher than the color flicker frequency, and the pulse rate is higher than the frame refresh rate.

[0072] Figure 7 shows an example of a display operating at a 120Hz display refresh rate and showing a video stream with 24fps, meaning a new frame is displayed every 5 display refresh cycles.

[0073] For each frame, each pixel displays a target color as defined by the image data for that particular frame. The display shows all or at least a subset of the target colors of the pixels as fused colors, i.e., by alternating between two sets of primary colors at a color flicker frequency. In the example in Figure 7, the color flicker frequency is 40 Hz, meaning each pixel alternates between two sets of primary colors every three frames.

[0074] In Figure 7, this is shown for a pixel displaying a fused color 701 that is close to the Planck locus 702. The fused color is displayed by alternating between a first set of primary colors 703 (in this example, red (e.g., 624 nm) and blue (e.g., 500 nm)) and a second set of primary colors 704 (in this example, a set of four primary colors).

[0075] Brightness matching of two sets of colors may be achieved, for example, by controlling the relative intensity of the primary colors through PMW modulation at 1500 kHz.

[0076] In the example in Figure 7, the frame rate and color flicker frequency are such that a single flicker period lasts longer than the duration of a single frame. Therefore, when the color of a display pixel changes rapidly, there is not enough time to complete one or more flicker periods before the target image color for a particular pixel changes again. This can negatively affect the observer's perception of color, which can be mitigated, for example, by an appropriate selection of the frame rate relative to the color flicker frequency. Alternatively, the device may adaptively select which pixels should act as color-fused pixels at any given time. In particular, based on the stream of received image data, the device may selectively act only as color-fused pixels if the pixel's color remains sufficiently constant for a sufficiently long period to allow for multiple flicker periods.

[0077] Figure 8 schematically shows a light source of another embodiment of the phototherapy device. In particular, Figure 8 schematically shows one embodiment of a pixel 112. In the example of Figure 8, the pixel is an RGB pixel and includes three subpixels 112A-C. Subpixel 112A is operable to emit red light, subpixel 112B is operable to emit green light, and subpixel 112C is operable to emit blue light. The pixel 112 can be controlled to emit colored light resulting from a mixture of the individual colors of the subpixels by selectively activating one or more subpixels at their respective intensities. The intensities of the subpixels can be controlled, for example, by pulse activation of the subpixels at a variable duty cycle, such as by pulse width modulation.

[0078] Figures 9 to 10 schematically show one embodiment of a phototherapy device, in particular an embodiment having a color fusion pixel containing three subpixels, as described in relation to, for example, Figure 8.

[0079] For example, Figure 9 shows, albeit within a more limited scope, how color fusion can be achieved with three subpixels, for example, using RGB pixels. For instance, switching between a first color set (R+B) and a second color set (G) can make the color below the Planck curve imperceptible, as shown by line 901 in Figure 9. Similarly, color fusion between the first set (B+G) and the second set (R) produces the color around line 902. Furthermore, color fusion between the first set (R+G) and the second set (B) produces the color around line 903.

[0080] Figure 10 shows similar color fusion options, where the first set includes components from all three primary colors (RGB), and the second set includes only one of R (line 1001), G (line 1002), or B (line 1003).

[0081] Figure 11 shows an example of a process for obtaining the first and second color component sectors for a target image color from a color gamut extended by the three primary colors R(1101), G(1102), and B(1103), corresponding to a display with an RGB light source.

[0082] In particular, we show a first example in which the image target color 1104a is represented by using only RGB display pixels, i.e., only the color components R, G, and B.

[0083] In the first step, step 1, the process selects two of the primary color components. In the example in Figure 11, the process selects color components R and G. However, it will be understood that each of the pairs R+B or G+B may be selected instead. The process adds one of the selected color components, e.g., R, to the first set of color components, and the process adds the other of the selected color components, e.g., G, to the second set of color components. The process then determines the fused color 1105 obtained from the luminance-matched color fusion of the two selected color components. In particular, the process may determine the color coordinates of the fused color in a suitable color space. As described above, a single fused color may be obtained from the luminance-matched color fusion of the two selected color components.

[0084] In the next step 2a, the process determines an additional color component to be added to the first and second sets of color components. Depending on the position of the target image color 1104a in color space, the additional color component may be a third primary color component, B in this example, or a mixed color containing one of the color components R and G and color component B. In the first example shown in Figure 11, the image target color 1104a is positioned such that the additional color component is the third primary color B. By adding an appropriate amount of component B to both sets of color components, the resulting color 1108a, as perceived by the observer, will be located on the dashed line 1106a connecting the fused color 1105 and the additional color component 1103. Finally, in step 3, the process determines the relative intensity of the additional color component 1103 so that the resulting perceived color 1108a moves along the line 1106a until it matches the target image color 1104a.

[0085] Therefore, the resulting first set of color components contains amounts of color components R and B, respectively, and the second set of color components contains amounts of color components G and B, respectively. When the light source is controlled to alternate between the first set of color components and the second set at an appropriate color flicker frequency and a predetermined relative intensity, the observer perceives the emitted color as the intended target image color 1104a without perceiving any substantial flicker. The observer's perception of color arises from a color fusion of primary colors R and G, combined with a color mixture of the fused color 1105 and a third primary color B. The process may therefore store predetermined intensities of the color components in a lookup table indexed by the respective target image colors.

[0086] Figure 11 further illustrates a second example of a different target image color 1104b. In this case, the additional color component to be added to the first and second sets of color components (in step 2b) is itself a mixed color 1107, which in this case results from mixing color components G and B in appropriate intensity ratios. Adding this mixed color 1107 to each of the first and second sets of color components (i.e., adding color components G and B in appropriate ratios) yields the perceived color 1108b along the dashed line 1106b. As in the first example, the process then adjusts the relative intensity of the additional color component and the color component that produces the fused color so that the perceived color 1108b aligns with the target image color 1104b. Thus, the resulting first set of color components includes color components R, G, and B, and the second set of color components includes color components G and B in their respective intensity ratios. Similar to the first example, the observer's perception of color arises from a combination of primary colors R and G, which is combined with a color mixture of the fused color 1105 and another color 1107, which in this case is itself a fused color.

[0087] Therefore, in some embodiments, the first and second sets of color components each include color components selected from a set of three primary color components, specifically from the red (R) component, the green (G) component, and the blue (B) component, or consist of the selected color components, and determining the first and second sets of color components that are alternately emitted by a light source representing a display pixel is: To enable luminance-matched color fusion of the first and second primary color components, resulting in a perceived fused color, the first primary color component of a set of three primary color components is added to the first set of color components, and the second primary color component of a set of three primary color components, different from the first primary color component, is added to the second set of color components in their respective amounts. This is determined by adding one or two auxiliary sets of primary color components from the set of three primary color components to each of the first and second sets of color components. The auxiliary set includes a third primary color component of a set of three primary color components distinct from the first and second primary color components, each having a selected amount such that the resulting color produced by the simultaneous emission of one or two primary color components of the auxiliary set becomes the target image color when emitted together with the fused color.

[0088] Figure 12 shows another example of a process for obtaining the sectors of the first and second color components for a target image color from a color gamut that extends through the three primary colors R(1201), G(1202), and B(1203), corresponding to a display with an RGB light source.

[0089] In particular, Figure 12 shows a first example in which the image target color 1204a is represented by using only RGB display pixels, i.e., the color components R, G, and B.

[0090] In the first step 1, the process selects two of the primary color components. In the example in Figure 12, the process selects color components R and G. However, it will be understood that each of the pairs R+B or G+B may be selected instead. The process determines the mixed color 1205 that can be obtained by static mixing of the selected color components (particularly by simultaneous emission). In the next step 2a, the process adds appropriate ratios of the selected color components to both the first and second sets of color components. Next, the process determines the fused color 1208a obtained from a luminance-matched color fusion of the mixed color 1205 and a third primary color component B. In particular, the process may determine the color coordinates of the fused color 1208a in a suitable color space. As described above, a luminance-matched color fusion of the mixed color 1205 and the third primary color B may yield a fused color 1208a on line 1106a. The process adds color component B to the first set with an intensity suitable for a luminance-matched color fusion with the mixed color 1205.

[0091] In the next steps 3a and 4, the process simultaneously adds or subtracts appropriate levels of color component B or a combination of color components R+G to both sets of color components so that the resulting perceived color moves along line 1106a to the intended target image color 1104a.

[0092] Therefore, the resulting first set of color components includes amounts of color components R, G, and B, respectively, and the second set of color components includes amounts of color components R and G (and, optionally, B, depending on the applicable compensation in step 3a). If the light source is controlled to alternate between the first set of color components and the second set at an appropriate color flicker frequency, the observer perceives the emitted color as the intended target image color 1104a without perceiving any substantial flicker. The observer's perception of color arises from a combination of static color mixing of primary colors R and G, combined with the resulting mixed color 1205 and the color floor fusion of the third primary color B.

[0093] Figure 12 further illustrates a second example of a different target image color 1104b. In this case, the additional color component used for color fusion (in the corresponding step 2b, which replaces step 2a in the first example of Figure 12) is itself a mixed color 1207, which in this case results from a static mixing of the respective amounts of color components G and B.

[0094] Therefore, in some embodiments, the first and second sets of color components each include color components selected from a set of three primary color components, specifically from the red (R) component, the green (G) component, and the blue (B) component, or consist of the selected color components, and determining the first and second sets of color components that are alternately emitted by a light source representing a display pixel is: To produce a mixed color by simultaneously emitting light from the first and second primary color components, the first primary color component from the set of three primary color components and the second primary color component from the set of three primary color components different from the first primary color component are added in the respective amounts to the first and second sets of color components. The color is determined by adding an auxiliary set of one or two primary color components from a set of three primary color components to a first set of color components, wherein the auxiliary set includes a third primary color component from a set of three primary color components different from the first and second primary color components, and each of the primary color components of the auxiliary set has a selected amount such that when the resulting color, produced by the simultaneous emission of one or two primary color components of the auxiliary set, is emitted alternately with the mixed color, the resulting color and the mixed color are luminance-matched color fusion to form a perceived fused color, where the fused color lies on a line in the color space extended by the three primary color components, the line extending between the mixed color and the resulting color and intersecting the image target color. To decide, The selected amount of the auxiliary set or mixed color is added to each set of the first and second color components, and is determined by adding the selected amount of the auxiliary set or mixed color such that the simultaneous emission of the selected amount and the fused color is perceived as the target image color.

[0095] The processes described with reference to Figures 11 and 12 enable the generation of a wide range of target image colors using color fusion, which can be optionally combined with static color mixing based on the three primary color components R, G, and B. However, the color gamut obtainable by these processes or other methods may be smaller than the entire RGB color gamut, especially when a strong activation of therapeutically efficient neural activity is desired.

[0096] Firstly, the relative luminance of the switching color component to the color component present in both sets and used for static color mixing can result in a very low relative luminance of the flicker light, potentially reducing the intensity of neuronal activation below the desired level.

[0097] Secondly, the resolution and relative intensity of the obtainable color values ​​may be limited depending on the type of display. For example, in many display systems, each RGB value may be set to an integer between 0 and 255, corresponding to 8-bit encoding. Because human visual perception perceives some colors more strongly than others, luminance matching in color fusion imposes upper and lower boundaries on the obtainable color content. This limitation may be mitigated by proper display design, for example, by adding additional blue subpixels to enable higher blue luminance and / or by adding subpixels that emit white light or other colors. Nevertheless, luminance matching in color fusion flicker can impose limitations on the obtainable color gamut for at least some display types.

[0098] Figure 13 schematically illustrates an example of such a limited color gamut, where the obtainable colors are indicated by the dashed line 1301, and these obtainable colors can be represented using a sufficient amount of color-fusion flicker to induce therapeutically effective neuronal activity. The target image color inside the dashed line 1301, e.g., target image color 1302, is a target image color suitable for representation by color-fusion flickering, optionally combined with the conventional color mixing described above. Target image colors outside the region demarcated by the dashed line 1301 are less suitable. Thus, as described herein, some embodiments may select which part of the image to be represented using color fusion in response to the target image color in each part of the image to be displayed. Accordingly, the device may select which display pixels should be included in a first subset of image pixels that should be controlled to alternately emit first and second light at appropriate color flicker frequencies. It will be understood that the illustrated color gamut in Figure 13 is merely a schematic example. The exact shape and size of the obtainable color gamut depend on the specific display technology.

[0099] The determination of the first and second sets of color components is described in relation to the RGB color gamut, i.e., for a light source having three sub-elements R, G, and B, respectively. However, it will be understood that the first and second sets of color components may be similarly determined for light sources having further sub-elements, e.g., sub-elements R, G, B, and white, or other combinations of three, four, or more sub-elements. In general, some embodiments of the apparatus described herein are configured to represent at least several target image colors by a combination of color mixing of simultaneously emitted colored light and color fusion of alternately emitted colored light, which is emitted alternately at color flicker frequencies.

[0100] Figure 14 schematically shows a display of one embodiment of a phototherapy device. The display 1402 includes a display area Q comprising a sub-area q formed by one or more color-fusion pixels. In some embodiments, it will be understood that only a portion of the display area 1402 may consist of color-fusion pixels, with the remainder consisting of conventional light-emitting pixels. In other embodiments, the entire display area 1402 may consist of color-fusion pixels. Also, for ease of explanation, Figure 14 only shows a single sub-area q having one or more color-fusion pixels 1403. Embodiments of phototherapy devices may generally consist of multiple such pixels and include one or more sub-areas having color-fusion pixels. Furthermore, again for ease of explanation, the size of the area q having color-fusion pixels 1403 relative to the entire display area Q is merely an example. Generally, it will be understood that in a typical display, individual color-fusion pixels are considerably smaller compared to the size of the entire display area.

[0101] In some embodiments, the size of the color-fusion pixels and / or the portion of the display area containing the color-fusion pixels may be selected based on the intended viewing distance between the display area and the user 1401 viewing the display. During use of the phototherapy device, the user is positioned at a viewing distance d from the display, and therefore a sub-area q having one or more color-fusion pixels 1403 is viewed at a viewing angle a. In some embodiments, the sub-area region q having one or more color-fusion pixels is selected such that the viewing angle a is less than or equal to the foveal retinal field of view or about 3 degrees or less.

[0102] Generally, the further away the observer is located, the larger the portion of the display area containing color-fusion pixels should be. In some embodiments, the device may be configured to selectively control pixels as conventional pixels or as color-fusion pixels. In some embodiments, the device may include a distance sensor that senses the distance d between the user viewing the display and the display. The device may then control the display in response to the measured distance, for example, by adjusting the number and / or position of pixels that are made to act as color-fusion pixels.

[0103] At least some embodiments of the method steps described herein may be computer-implemented. In particular, some or all embodiments of the method steps disclosed herein may be implemented by hardware comprising several distinct elements and / or by a microprocessor that is at least partially appropriately programmed.

[0104] In an apparatus claim listing several means, some of these means may be embodied by one of the same elements, components, or items of hardware. The mere fact that certain means are listed in different dependent claims or described in different embodiments does not imply that combinations of these means cannot be used advantageously.

[0105] Where used herein, the term “equipped with / possessed by” is to be interpreted as identifying the presence of the described feature, element, step, or component, but should not be excluded from the presence or addition of one or more other features, elements, steps, components, or groups thereof.

Claims

1. A phototherapy apparatus comprising multiple light sources and a control circuit, wherein the multiple light sources are arranged in a spatial pattern to form at least a portion of the display area of ​​a display, and each of the multiple light sources is individually controllable to emit colored light. The aforementioned control circuit is For each of the aforementioned multiple light sources, image data representing the respective target image color represented by the light source is received, and, The system is configured to control each of the plurality of light sources so that it emits colored light that is perceptible to a human observer as having the target image color represented by the light source, The control circuit controls each light source of at least a first subset of the plurality of light sources, Depending on the target image color represented by the light source, the sets of first and second color components are determined, and The light source is configured to be controlled to alternately emit at least each of the first and second lights at a color flicker frequency, The first light has a predetermined set of first color components that produce a first emission color, and the second light has a predetermined set of second color components that produce a second emission color, and the color flicker frequency is selected to a sufficiently high degree that the alternately emitted first and second lights are perceived by a human observer as light having a user-perceptible fused color corresponding to the target image color represented by the light source. Phototherapy device.

2. The aforementioned color flicker frequencies are selected to elicit therapeutically effective neural responses in the brains of the human observers. The phototherapy apparatus according to claim 1.

3. The aforementioned color flicker frequency is between 25 Hz and 60 Hz. The phototherapy apparatus according to claim 1 or 2.

4. The control circuit is configured to control the plurality of light sources so as to change the displayed image over time. The phototherapy apparatus according to claim 1.

5. The control circuit is configured to control the plurality of light sources to cause a simulated movement of a first light-emitting area, which emits light having a first target image color perceptible to the user, relative to a second light-emitting area, which emits light having a second target image color perceptible to the user. The phototherapy apparatus according to claim 4.

6. The first and second target image colors perceptible to the user are visually indistinguishable to a human observer but have different spectral distributions. The phototherapy apparatus according to claim 5.

7. The control circuit is configured to select each of the first and second color components for each of the first subsets of light sources in response to the received image data, such that the fused color of each of the light sources in the first subset corresponds to the respective target image color. The phototherapy apparatus according to claim 1.

8. The control circuit is configured to synchronously and alternately switch the light source of the first subset between the first set of color components and the second set of color components. The phototherapy apparatus according to claim 1.

9. The control circuit is configured to cause all of the controlled plurality of light sources to alternately emit first and second light such that they synchronously switch between the first set of color components and the second set of color components. The phototherapy apparatus according to claim 8.

10. The control circuit is configured to determine the first and second sets of color components from a lookup table that maps the target image color to each of the first and second sets of color components. The phototherapy apparatus according to claim 1.

11. The control circuit is configured to receive a stream of image data representing a video and to control the plurality of light sources to display the video within the display area. The phototherapy apparatus according to claim 1.

12. The control circuit is configured to control only the first subset of the light source at the color flicker frequency so as to alternately emit the first and second sets of color components. The phototherapy apparatus according to claim 1.

13. The control circuit is configured to select the first subset of light sources in response to the received image data. The phototherapy apparatus according to claim 1.

14. The control circuit is configured such that the first subset includes only selected light sources from the plurality of light sources, and the target image color to be represented by the selected light source belongs to a predetermined set of target image colors. The phototherapy apparatus according to claim 13.

15. The received image data is time-varying image data representing a series of target image colors for each of the plurality of light sources, and the control circuit is configured to change the first subset in response to the time-varying image data. The phototherapy apparatus according to claim 13 or 14.

16. The control circuit is configured to include only selected light sources from the plurality of light sources in the first subset, and the target image color represented by the selected light sources lasts for at least 100 ms. The phototherapy apparatus according to claim 15.

17. The phototherapy apparatus further comprises an audio output device and is configured to output an audio signal modulated with the color flicker frequency. The phototherapy apparatus according to claim 1.

18. The alternatingly emitted light at the aforementioned color flicker frequency is selected to stimulate or synchronize brainwaves in the human brain when the human is exposed to the alternatingly emitted light. The phototherapy apparatus according to claim 1.

19. The control circuit is configured to control each of the light sources in at least the first subset of the plurality of light sources so that the first and second lights each emit with the same brightness. The phototherapy apparatus according to claim 1.

20. The sets of the first and second color components are selected such that, when the first and second lights are emitted with the same luminance, the alternately emitted first and second lights are perceived by a human observer as having the target image color represented by the light source. The phototherapy apparatus according to claim 19.

21. Each light source comprises three or more light-emitting sub-elements configured to emit light of a different color. The phototherapy apparatus according to claim 1.

22. The combination of color mixing of simultaneously emitted colored light and color fusion of alternately emitted colored light at the aforementioned color flicker frequency is configured to represent at least several target image colors. The phototherapy apparatus according to claim 1.

23. A method for controlling a phototherapy device, wherein the phototherapy device comprises a plurality of light sources, the plurality of light sources are arranged in a spatial pattern to form at least a portion of the display area of ​​a display, each of the plurality of light sources is individually controllable to emit colored light, and the method is: For each of the aforementioned multiple light sources, image data representing the respective target image color represented by the light source is received. Controlling each of the multiple light sources to emit colored light that is perceptible to a human observer as having the target image color represented by the light source, Includes, To control, The first and second sets of color components are determined according to the target image color represented by the light source, This includes controlling the light source to alternately emit the first and second lights at a color flicker frequency, The first light has a predetermined set of first color components that produce a first emission color, and the second light has a predetermined set of second color components that produce a second emission color, and the color flicker frequency is selected to be sufficiently high so that the alternately emitted first and second lights are perceived by a human observer as light having a user-perceptible fused color corresponding to the target image color represented by the light source. A method for controlling a phototherapy device.

24. A method for controlling a device for inducing gamma waves in the brain of a target, wherein the method is: For each of the multiple light sources, receive image data representing the respective target image color represented by the light source. Controlling each of the multiple light sources to emit colored light that is perceptible to a human observer as having the target image color represented by the light source, Includes, To control, The first and second sets of color components are determined according to the target image color represented by the light source, This includes controlling the light source to alternately emit the first and second lights at a color flicker frequency, The first light has a predetermined set of first color components that produce a first emission color, the second light has a predetermined set of second color components that produce a second emission color, the color flicker frequency is selected to be sufficiently high so that the alternately emitted first and second lights are perceived by a human observer as light having a user-perceptible fused color corresponding to the target image color represented by the light source, and the color flicker frequency is selected to induce gamma waves in the brain of the human observer. A method for controlling a device used to induce gamma waves in the target brain.

25. The first and second sets of color components each include a color component selected from a set of three primary color components, or consist of the selected color component. To decide, To enable luminance-matched color fusion of first and second primary color components that produce a perceived fused color, the first primary color component of the set of three primary color components is added to the first set of color components, and the second primary color component of the set of three primary color components, which is different from the first primary color component, is added to the second set of color components in their respective amounts, This includes adding an auxiliary set of one or two primary color components from the set of three primary color components to each of the first and second sets of color components, The auxiliary set includes a third primary color component of the set of three primary color components, which is different from the first and second primary color components, and each of the one or two primary color components of the auxiliary set has an amount selected such that the resulting color produced by the simultaneous emission of one or two of the primary color components of the auxiliary set becomes the target image color when emitted together with the fused color. The method according to claim 23 or 24.

26. The first and second sets of color components each include a color component selected from a set of three primary color components, or consist of the selected color component. To decide, To produce a mixed color by simultaneously emitting light from the first and second primary color components, the first primary color component from the set of three primary color components and the second primary color component from the set of three primary color components, which is different from the first primary color component, are added in their respective amounts to each of the first and second sets of color components. This includes adding an auxiliary set of one or two primary color components from the set of three primary color components to the set of the first color components, The auxiliary set includes a third primary color component of the set of three primary color components, distinct from the first and second primary color components, and each of the one or two primary color components of the auxiliary set has a selected amount such that when the resulting color produced by the simultaneous emission of one or two of the primary color components of the auxiliary set is emitted alternately together with the mixed color, the resulting color and the mixed color luminance-matched color fusion form a perceived fused color, where the fused color lies on a line in the color space extended by the three primary color components, the line extends between the mixed color and the resulting color and intersects the target image color. To decide, Adding a selected amount of the auxiliary set or the mixed color to each of the first and second color component sets, wherein the selected amount is chosen such that the simultaneous emission of the selected amount and the fused color is perceived as the target image color. The method according to claim 23 or 24.

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