waveguide configuration

Abstract

According to an example aspect of the present invention, there is provided a light guide arrangement comprising: an optical system configured to generate a configurable image encoded in a light field; and at least one light guide arranged to receive light from the light field and to transmit light to a plurality of locations in the light guide for emission, creating a waveguide-based display; the optical system comprising a light source having a wavelength λ1; and the light guide comprising a notch filter element having a stop band at wavelength λ1' disposed on an outer surface of the light guide to prevent leakage of light from the light field, the stop band at wavelength λ1' filtering light of wavelength λ1 incident on the notch filter element at a first angle of incidence.

Description

Technical Field

[0001] This disclosure relates to the management of colored light using optical waveguides.

Background Art

[0002] Optical waveguides are capable of transmitting light at optical frequencies. Light or visible frequencies refer to light having wavelengths of approximately 400 to 700 nanometers. Optical waveguides are employed in displays, and light from a primary display can be transmitted using one or more waveguides to a suitable position for emission to one or more eyes of a user.

[0003] Optical waveguide displays may be mounted on head-mounted glasses or helmets and may be suitable for augmented reality or virtual reality applications. In augmented reality, a user views the real-world view with supplementary displays superimposed thereon. In virtual reality, a user loses their view of the real world and instead is provided with a view of a scenery defined by software.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Means for Solving the Problems

[0006] According to some aspects, the subject matter of the independent claims is provided. Some examples are defined in the dependent claims.

[0007] According to a first aspect of the present disclosure, an optical waveguide arrangement is provided, comprising: an optical system configured to generate a configurable image encoded in a light field; and at least one optical waveguide arranged to receive light from a light field and to transmit light to a plurality of positions in the optical waveguide for emission, thereby creating a waveguide-based display, wherein the optical system comprises a light source having wavelength λ1, and the optical waveguide comprises a notch filter element having a stopband of wavelength λ1' disposed on the outer surface of the optical waveguide to prevent light leakage from a light field, the stopband of wavelength λ1' filtering light of wavelength λ1 incident on the notch filter element at a first incidence angle.

[0008] A second aspect of the present disclosure provides a method for manipulating an optical waveguide arrangement, which includes using an optical system to generate a configurable image encoded in a light field and to receive light from a light field into at least one optical waveguide and to transmit the light to a plurality of locations in the optical waveguide for emission, thereby creating a waveguide-based display, wherein the optical system comprises a light source having wavelength λ1, and the optical waveguide has a notch filter element disposed on the outer surface of the optical waveguide and having a stopband of wavelength λ1' to prevent light leakage from a light field, wherein the stopband of wavelength λ1' filters light of wavelength λ1 incident on the notch filter element at a first incident angle.

[0009] According to a third aspect of the present disclosure, a non-temporary computer-readable medium is provided which, when executed by at least one processor, causes a device to use an optical system to generate a configurable image encoded in a field of light, and to transmit light from a field of light to at least one optical waveguide, which is arranged to receive light and to transmit light to a plurality of positions in the optical waveguide for emission, thereby creating a waveguide-based display, wherein the optical system comprises a light source having wavelength λ1, and the optical waveguide comprises a notch filter element disposed on the outer surface of the optical waveguide and having a stopband of wavelength λ1' to prevent light leakage from a field of light, the stopband of wavelength λ1' filtering light of wavelength λ1 incident on the notch filter element at a first incident angle.

[0010] According to a fourth aspect of this disclosure, a computer program is provided which is configured to perform the method according to the second aspect. [Brief explanation of the drawing]

[0011] [Figure 1] This figure illustrates an example system according to at least some embodiments of the present invention. [Figure 2A] This figure illustrates an example system according to at least some embodiments of the present invention. [Figure 2B] This figure illustrates an example system according to at least some embodiments of the present invention. [Figure 3A] This is a graph of the spectrum and transmittance of the light source and filter of an example system according to at least some embodiments of the present invention. [Figure 3B] This is a graph of the spectrum and transmittance of the light source and filter of an example system according to at least some embodiments of the present invention. [Figure 4] This figure illustrates an example of a device that can support at least some embodiments of the present invention. [Figure 5]This is a flowchart of a method according to at least some embodiments of the present invention. [Modes for carrying out the invention]

[0012] Improved waveguide-based displays can be constructed as described below herein by using light sources such as lasers or light-emitting diodes (LEDs). In particular, by using multiple visible light wavelengths to produce a single color on the waveguide-based display, the color can be rendered across the waveguide-based display by appropriately mixing the colors. It is also desirable that not only the user sees an image on the waveguide display, but also that as little light as possible leaks from it to the outside. In a typical waveguide display, the display leaks light through the outer surface of the waveguide display. Using some embodiments of the present invention, this leakage can be reduced or almost completely eliminated by employing a notch filter layer that covers and is applied to the outer surface of the waveguide display, as described below.

[0013] Figure 1 illustrates an exemplary system according to at least some embodiments of the present invention. The system comprises a light source 140, in this case three light sources R, G, and B. In some embodiments, the system may comprise one to four light sources. The light sources may include, for example, laser or LED light sources, with laser light sources having the advantage that they are strictly monochromatic than LEDs. The light source 140, together with an optional mirror 130, is configured to create a field of light in angular space, which can be used to cause a waveguide display to generate its image. The image is encoded in the field of light. The field of light is schematically illustrated in Figure 1 as field 100. In some embodiments, a physical primary display may display an image of the field of light, but in other embodiments, the system does not have a physical primary display, and the image is simply encoded in a field of light distributed in angular space. Light 104 from the field of light 100 can be transmitted to the optical waveguide 110 directly or using an optical guide 102, for example, a mirror and / or lens. The optical guides 102 are optional, meaning they may not be present depending on the specifications of a particular embodiment. In other words, the optical guides 102 are not present in all embodiments.

[0014] To guide the light 104 into the waveguide 110, in-coupling structures such as partial reflectors, surface relief gratings, or other diffraction structures can be used to direct the incoming light towards the waveguide 110, as is known in the art. In some embodiments, the light 104 may be in-coupled from the end of the waveguide. In the waveguide 110, the light 104 advances by being repeatedly reflected within the waveguide and interacts with element 112a until it interacts with element 112, thereby deflecting the light 104 from the waveguide 110 into the air toward the eye 120 as a ray 114 that creates an image. Elements 112a and 112 may include, for example, a partial reflector, a surface relief grating, or other diffraction structures. Element 112a may be positioned to unfold a light field 100 within the waveguide 110 so that the image of the waveguide display is accurately generated. Light from different angular portions of the light field 100 interacts with element 112 such that the light rays 114 create an encoded image in the light field 100 on the retina of the eye 120. Elements 112a and 112 may be partially or entirely the same element. In other words, in some embodiments, there is a single set of elements, and in other embodiments, there are two separate sets of elements 112a, 112. Element 112 causes light to be emitted from the waveguide 110 at the emission position. As a result, the user perceives the encoded image in the light field 100 in front of the user's eye 120. Since the waveguide 110 may be at least partially transparent, the user can also advantageously see their real surroundings through the waveguide 110, for example, if the waveguide-based display is head-mounted. As a result of the action of elements 112a and 112, light is emitted from the waveguide 110 at multiple angles at multiple positions of element 112.

[0015] The term "color space" refers to a (two-dimensional) chromaticity diagram corresponding to the perceived colors obtained from the spectral response of the average human eye. The color gamut of an instrument is the region of color space that can be reproduced by that instrument. Specifically, here, the color gamut corresponds to the region in color space that can be reproduced by the combination of light source 140 and waveguide in the system, relative to the field of light that an observer perceives as emanating from the focal plane. The region of interest (ROI) then refers to the region of color space that is sufficient to reproduce what is perceived as a full-color image, although it may also refer to a smaller or larger region of color space. Since different combinations of wavelengths can reach a specific point in color space, a specific ROI can be reached using different combinations of distinct spectral characteristics, such as peaks in the visible spectrum.

[0016] A color image can be generated, for example, by assuming that the user's color perception corresponds to that of a standard eye, and by reproducing a corresponding color space (or part thereof). As is evident from the definition of a color space, the user perceives the same color as a result of several different optical signal spectra. This gives flexibility in how the waveguide 110 operates. In addition, different combinations of distinct spectral characteristics, such as wavelength, can be used to produce the same color. How light is coupled out of the waveguide can be a function of the emission position. That is, a ray corresponding to a particular position (a particular propagation angle) in the input image can exit the waveguide at different angles depending on the emission position. In general, the user may perceive the same color from multiple spectra of the optical signal 114. This gives flexibility in the manufacture of the waveguide 110. Specifically, the inventors note that the same color stimulus can be reproduced at each pixel if the ROI is selected to be located at the intersection of the color gamuts corresponding to the effective wavelength of each individual pixel. Therefore, pixel-level modulation or filtering of light sources does not create any fundamental limitations on which colors can be reproduced by the system.

[0017] In a waveguide-based display, there may be a plurality of waveguides 110. For example, to enhance the image transmission capacity and optionally, for the other eye of the user which is not illustrated in FIG. 1 for clarity of illustration, light is transmitted.

[0018] The light irradiation field 100 for encoding an image can be generated, for example, using a mirror 130 and an optical system including light sources R, G, and B. The mirror 130 is configured to reflect light from a light source 140 such as a laser, for example, to generate a light irradiation field 100 for encoding an image in a controlled manner by scanning the angular space 100. For example, it includes a microelectromechanical (MEMS) mirror, whereby a light irradiation field for encoding an image can be generated. The mirror 130 can thus be operated to tilt at different angles so as to direct light in the angular space from the light source 140 to an appropriate portion of the light irradiation field 100. In some embodiments, the optical system can consist of other types of image generation devices such as a projector, where the light source may be, for example, an LED and the primary display may be in the form of a liquid crystal on silicon (LCOS) device. The optical system includes, for example, a light source and a MEMS actuator configured to supply light from the light source to the angular space, whereby a light irradiation field for input to the waveguide 110 can be generated.

[0019] The system illustrated in FIG. 1 includes three light sources 140. This is an example that does not limit the present disclosure. Rather, fewer than three or more than three light sources may be present. For example, in certain embodiments, a monochrome display is fabricated with a single light source. The light sources 140 can be monochromatic in the sense that they generate light in a narrow spectral band having a single peak wavelength, as in a laser, or their spectral band may be broader, as in the case of using LEDs. Light sources with more complex spectral distributions are also possible. In principle, the color space visible to humans can be generated by appropriately exciting the photoreceptors of the retina. Typically, this is achieved by mixing light of three wavelengths, for example, at one wavelength in each of the red, green, and blue portions of the visible spectrum.

[0020] Laser light has a very narrow bandwidth such that they can be considered monochromatic. Monochromatic means, for example, that the bandwidth of the light generated by a laser is, for example, narrower than 0.1 nanometer or narrower than 2 nanometers. The laser light source can be modulated in terms of their wavelength as a function of the angle of the light beam corresponding to the pixel of the image by using a laser light source having a selectable wavelength, such as an open cavity diode laser having a piezoelectrically selectable cavity length, which is used in a coordinated combination with a mirror 130 that can be, for example, a MEMS mirror. The laser light source can include one or more lasers. The plurality of lasers can have the same or different wavelengths.

[0021] LED light sources have a broader wavelength range than lasers. Furthermore, the wavelengths of LED light sources can be modulated as a function of angle. For example, they can be made monochromatic on a pixel-by-pixel basis by filtering with a passband filter, and the center wavelength of the passband is selectable. A better technique for obtaining monochromatic illumination of a given pixel using LEDs is to disperse the light emitted from the LEDs by diffraction and / or refraction so that the desired wavelength is directed to the given pixel. Other means for achieving a distribution of center wavelengths across pixels are also, of course, possible. Most importantly, this can be done such that there is a correspondence between the propagation angle of the light ray representing the pixels inside the waveguide and its (center) wavelength. Furthermore, this correspondence can be (tightly) matched to the change in the filtered wavelength band with respect to the incident angle, which typically occurs in a notch filter. LED light sources can be used in LCOS implementations. Alternatively or additionally, lasers and suitable optical elements can be used instead of LED light sources. Generally, notch filters can have a stopband width of, for example, up to 2 nanometers or up to 3 nanometers.

[0022] To create a color image to be encoded in a light field of 100 in angular space, the light source 140 can be controlled, for example, by a program. In an example where a mirror 130 is present, the light source 140 and the mirror 130 can be synchronized with each other so that the light from the light source 140 illuminates a specific angular region of the light field 100 in a controlled manner, creating a display of a color image therein, which reproduces a still or moving input image received from an external source, such as a virtual reality or augmented reality computer. The still or moving image received from the external source may include, for example, a digital image or a digital video feed. The image encoded in the light field 100 can therefore be constructed by providing an appropriately selected input image.

[0023] To create a specific color on a given surface in angular space 100, this surface in angular space 100 may be illuminated by one or more light sources 140, for example, a set of three or more light sources 140. This specific color is then reproduced by a ray 114 when light from the given surface in angular space 100 travels through the waveguide 110 to the element 112, where the light is emitted at an angle corresponding to the given surface in angular space 100.

[0024] Light leakage through the outer surface 202 of the waveguide display is undesirable because it reduces the brightness of the image seen by the user and alerts others that an image is being displayed. Furthermore, the leaked light may flicker annoyingly or even make the content of the image itself visible. In the optimal case, light exits only from the waveguide 110 in a controlled manner through the inner surface 201 of the waveguide 110. To mitigate light leakage through the outer surface 202, a notch filter element 200 is attached to the outer surface 202. The notch filter element may consist of a nearly transparent film containing a notch filter, which may be a diffraction grating or is designed to prevent the passage of light of wavelengths matching the light source 140, but to allow light of other wavelengths to pass through. Thus, the user can see through the waveguide 110, but the leakage of certain light from the light source 140 is reduced. The notch filter may be implemented, for example, as a laminate of thin, homogeneous (dielectric) layers, where the filter properties are determined by the number of layers, the thickness of each layer, and the material of the layers. Typical layer materials include SiO2 and TiO2. Generally, dielectric filters are reflective filters. To construct an absorption filter, an absorbent material such as a metal is required.

[0025] Generally, since the image transmitted through waveguide 110 consists of a set of narrow wavelength bands (or even a single narrow wavelength band), blocking it using one or more notch filters involves only a small portion of the visible spectrum, and therefore the user's visibility through waveguide 110 is hardly affected. This is because the field of light that the user sees around them includes a wide range of visible light wavelengths. The notch filter therefore has minimal effect on the amount of light information the user sees from their surroundings. The notch filter in waveguide 110 can reflect light that has not passed through, providing the technical benefit that a reflective filter maintains the intensity of light in the waveguide. A separate absorbing notch filter structure may be placed on the outer surface of the filter element 200 to attenuate the mirror-like effect of the waveguide that a reflective notch filter has on people around the user. Therefore, there are four options for positioning a notch filter: firstly, a purely absorptive notch filter; secondly, a purely reflective notch filter; thirdly, a user-facing reflective notch filter having an absorptive notch filter covering the reflective notch filter on the outside; and fourthly, a diffractive notch filter, whose behavior may depend on the side onto which light is incident, and therefore the most commonly chosen.

[0026] Figures 2A and 2B illustrate exemplary systems according to at least some embodiments of the present invention. Similar numbering indicates structures similar to those in Figure 1. In Figure 2A, the three light sources 140 are individually identified as light source B, light source G, and light source R. For example, light source B may be in the blue portion of the visible spectrum, light source G may be in the green portion of the visible spectrum, and light source R may be in the red portion of the visible spectrum. In general, light sources can be in the visible portion of the spectrum.

[0027] In Figure 2A, light sources B, G, and R are used to produce a specific color in the angular portion 100a of the light field 100. The specific color is determined by the relative intensities of light sources B, G, and R, and the brightness of the color is determined by the sum of the intensities of these light sources.

[0028] Next, moving to Figure 2B, light sources B, G, and R are used to produce a specific color, for example, the same color as in Figure 2A in angular portion 100b of the light field 100. Angular portion 100b is in a different angular portion of the light field than where angular portion 100a is located. The specific color is determined by the relative intensities of light sources B, G, and R, and the brightness of the color is determined by the sum of the intensities of these light sources. Light advancing through waveguide 110 to angular portion 100a may be reflected inside waveguide 110 at a different angle than light advancing to angular portion 100b.

[0029] A characteristic of notch filters, such as thin film notch filters, is that the notch frequency blocked by the filter may depend on the angle of the incident light. In other words, the wavelength blocked by the notch filter may not be a constant function of the incident angle. Therefore, the ability to filter a particular wavelength may decrease as it moves away from the center / design wavelength. The center wavelength of the notch in a notch filter is not so strictly constant and depends on the incident angle. The center wavelength of the notch can be expressed in terms of the center wavelength when light is incident at a particular first incident angle. In at least some embodiments of the present invention, this is corrected by changing the wavelength of the light source as a function of angle.

[0030] The light source 140 can be controlled in such a manner that variations in the incidence angle of the notch filter used are corrected in advance so that, as a result, light is effectively blocked by the notch filter in different parts of the waveguide 110. When encoding still or video images in the angular space of the light field 100, the angular portion of the light field 100 may be scanned continuously, so that the surface of the light field 100 is scanned using differently adjusted light source frequencies during the continuous scanning. Continuous scanning, as used herein, means an iterative process to ensure that color elements are rendered in the light field 100. Thus, the combination of monochromatic light sources used in combination with the notch filter described herein offers the benefit that the user's personal light information is not leaked, and at the same time, the user's ability to see their surroundings through the waveguide display is not impaired.

[0031] In the embodiment shown in Figure 1, the waveguide 110, which has a first inner surface 201 close to the user's eyes and a second outer surface 202 on the opposite side of the waveguide 110, has a notch filter element 200 on the second outer surface 202 to prevent light from the light field 100 from being visible to persons other than the user of the waveguide display.

[0032] The notch filter element 200 may be a multilayer structure designed to function as a band-stopping filter for each of the R, G, and B bands of the light source 140. In one example, the notch filter element 200 is formed as a sandwich structure of three different notch filters. In another example, a single layer comprises multiple notches.

[0033] In Figure 3a, graphs of the wavelengths of light sources B, G, and R are presented, with the x-axis representing wavelength and the y-axis representing amplitude. As shown in the illustration, correspondingly, light source B has a wavelength λ1, light source G has a wavelength λ2, and light source R has a wavelength λ3. The light sources in this example are monochromatic, such as lasers.

[0034] In Figure 3b, a graph of the transmittance of the notch filter element 200 for the light source in Figure 3a is presented. As shown in the graph, each stopband G', B', and R' of the filter has the same center wavelength as the light sources G, B, and R. In practice, the filtering characteristics of the notch filter 200 are changed by the angle of incidence of light inside the waveguide 110 to the notch filter 200, and therefore, adjustment of the wavelength of light entering the notch filter element 200 at different angles may be necessary. This can be done, for example, by modulating and / or adjusting the wavelength of the light source 140, such that the wavelength of the light source is modulated and / or adjusted based on the angle of incidence of light in the waveguide 110 that is incident on the notch filter element 200, or based on the angle of incidence to the waveguide 110, which may be interrelated. In some embodiments, the notch filter may have multiple stopbands corresponding to a single light source in order to cover different propagation directions inside the waveguide. For example, the stopband G' may include multiple stopbands with respect to the light source G to cover multiple propagation directions. Multiple propagation directions of light emanating from a single light source may be due, for example, to diffraction to multiple diffraction orders. An alternative or additional solution may be to broaden the stopbands R', G', and B' of the notch filter element 200, but this solution reduces the overall transmittance of the notch filter element 200.

[0035] In the examples shown in Figures 3a and 3b, three light sources and three corresponding stopbands are considered. In more general cases, the number and position of the stopbands correspond to the spectral characteristics of one or more light sources used in the embodiment. For example, in an arrangement with two light sources having distinct wavelengths, a notch filter with two stopbands corresponding to the two distinct wavelengths may be used.

[0036] Instructions on how to design optical notch filters can be found, for example, on the following webpage: https: / / www.optilayer.com / notch-filters. The use of optical notch filters is also presented in European Patent Application No. 15812618.5.

[0037] Therefore, overall, the wavelength of the light source 140, such as a laser, can be modulated during the creation of the light field 100 so that the light in the waveguide 110 is matched to the stopband of the notch of the notch filter element 200, regardless of its incident angle to the notch filter element 200 in the waveguide. Alternatively, the modulation can at least increase the efficiency of the notch filter element 200 in filtering leaked light, even if not all of the leaked light is captured. Such modulation may involve adjusting the wavelength of the light source according to a mapping, which maps the angular portion of the light field using wavelength tuning. The mapping can be determined experimentally beforehand, for example, since the movement of the notch as a function of the incident angle is deterministic. The mapping can be stored in the memory of a computer, such as the one illustrated in Figure 4, which is configured to control the encoding of an image in the light field 100. Using an LED light source, a passive control mechanism can be used, as described herein, for example, based on the diffraction or refraction splitting of the LED output wavelength band. In extreme cases, a filter with a passband the same width as the stopband of a notch filter may be used to render the LED output monochromatically. Other light source modulation and filtering techniques may also be used to achieve a desired correspondence between propagation angle and (center) wavelength.

[0038] Figure 4 illustrates exemplary devices capable of supporting at least some embodiments of the present invention. For example, a device 400 is illustrated, which may include a control mechanism for operating arrangements such as those illustrated in Figure 1 or Figure 2. For example, a processor 410 may be provided in the device 400, which includes a single or multi-core processor or a microcontroller, where a single-core processor has one processing core and a multi-core processor has multiple processing cores. The processor 410 may generally include a control device. The processor 410 may include multiple processors. The processor 410 may also be a control device. The processing cores may include, for example, a Cortex-A8 processing core from ARM Holdings or a Steamroller processing core designed by Advanced Micro Devices Corporation. The processor 410 may include at least one Qualcomm Snapdragon and / or Intel Atom processor. The processor 410 may include at least one application-specific integrated circuit (ASIC). The processor 410 may comprise at least one field-programmable gate array (FPGA). The processor 410 may be a means for performing steps of the method in the apparatus 400, such as generation, reception, and transmission. The processor 410 may be configured to perform operations at least partially by computer instructions.

[0039] The device 400 may include memory 420. Memory 420 may include random-access memory and / or permanent memory. Memory 420 may include at least one RAM chip. Memory 420 may include, for example, solid-state memory, magnetic memory, optical memory, and / or holographic memory. Memory 420 may be at least partially accessible to the processor 410. Memory 420 may be at least partially provided in the processor 410. Memory 420 may be a means for storing information. Memory 420 may include computer instructions configured for the processor 410 to execute. If computer instructions configured to cause the processor 410 to perform a particular operation are stored in memory 420, and the entire device 400 is configured to operate under the direction of the processor 410 using computer instructions from memory 420, then the processor 410 and / or at least one of its processing cores may be configured to perform the particular operation. Memory 420 may be at least partially provided in the processor 410. The memory 420 may be located at least partially outside the device 400, but may be accessible from the device 400. The memory 420 may store, for example, information defining the angular portion of the light irradiation field 100.

[0040] The device 400 may include a transmitter 430. The device 400 may include a receiver 440. The transmitter 430 and the receiver 440 may be configured to transmit and receive information, respectively, according to at least one cellular or non-cellular standard. The transmitter 430 may comprise multiple transmitters. The receiver 440 may comprise multiple receivers. The receiver 440 may be configured to receive an input image, and the transmitter 430 may be configured to output control commands to orient, for example, the mirror 130 and the light source 140, if present, according to the input image.

[0041] The device 400 may include a user interface (UI) 460. The UI 460 may include at least one of a display, a keyboard, a touchscreen, a vibrator positioned to signal the user by vibrating the device 400, a speaker, and a microphone. The user may be able to operate the device 400 via the UI 460, for example, to set display parameters.

[0042] The processor 410 may be equipped with a transmitter configured to output information from the processor 410 to other devices provided in the device 400 via electrical leads within the device 400. Such a transmitter may include, for example, a serial bus transmitter configured to output information to memory 420 via at least one electrical lead for storage in memory 420. Instead of a serial bus, the transmitter may include a parallel bus transmitter. Similarly, the processor 410 may be equipped with a receiver configured to receive information in the processor 410 from other devices provided in the device 400 via electrical leads within the device 400. Such a receiver may include, for example, a serial bus receiver configured to receive information from receiver 440 via at least one electrical lead for processing in the processor 410. Instead of a serial bus, the receiver may include a parallel bus receiver.

[0043] The device 400 may include further devices not illustrated in Figure 4. In some embodiments, the device 400 may lack at least one of the above-mentioned devices. For example, some devices 400 may lack a user interface 460.

[0044] The processor 410, memory 420, transmitter 430, receiver 440, NFC transceiver 450, UI 460, and / or user identification module 470 can be interconnected by electrical leads within the device 400 in a number of different ways. For example, each of the aforementioned devices may be individually connected to a master bus within the device 400 to enable the devices to exchange information. However, as will be understood by those skilled in the art, this is only one example, and depending on the embodiment, various methods for interconnecting at least two of the aforementioned devices can be selected without departing from the scope of the invention.

[0045] Figure 5 is a flow graph of a method according to at least some embodiments of the present invention. The steps of the illustrated method may be in a waveguide-based display, an optical waveguide arrangement in or for a waveguide-based display, or a control mechanism configured to control its functionality when incorporated therein.

[0046] Step 510 includes using an optical system to generate a configurable image to be encoded in a light field. Step 520 includes receiving light from the light field into at least one optical waveguide, transmitting the light to multiple locations in the optical waveguide for emission, and creating a waveguide-based display. Step 530 specifies that the optical system comprises three light sources having wavelengths λ1, λ2, and λ3, respectively, and the optical waveguide has notch filter elements disposed on the outer surface of the optical waveguide, having stopbands of wavelengths λ1', λ2', and λ3' to prevent light leakage from the light field. As previously described, λ1 and λ1' may not be equal in the general case. Instead, a notch filter with a stopband of λ1' may be designed to block light of wavelength λ1 incident at a particular angle. For example, the stopband of λ1' may correspond to light of wavelength λ1 incident at an angle corresponding to the central pixel. When illuminating pixels at different incident angles, the wavelength λ1 of the light source can be adjusted so that the λ1' stopband also blocks that light. The same applies to each light source and the corresponding stopband of the notch filter, i.e., the λ2' and λ3' stopbands corresponding to the light sources with wavelengths λ2 and λ3 in step 530 of Figure 5, respectively.

[0047] It should be understood that the embodiments of the invention disclosed herein are not limited to the specific structures, process steps, or materials disclosed herein, but are applicable to their equivalents as would be recognized by those skilled in the art. Furthermore, it should be understood that the terminology used herein is used solely for the purpose of describing specific embodiments and is not intended to be limiting.

[0048] Any reference to an embodiment or an embodiment throughout this specification means that certain features, structures, or properties described in relation to the embodiment are included in at least one embodiment of the present invention. Therefore, while the phrases “in one embodiment” or “in an embodiment” appear in various places throughout this specification, they do not necessarily all refer to the same embodiment. Where numerical values ​​are mentioned using terms such as “about” or “substantially,” the exact numerical values ​​are also disclosed.

[0049] Where used herein, multiple articles, structural elements, constituent elements, and / or materials may be presented in common enumerations for convenience. However, these enumerations should be interpreted as if each factor of the enumeration were individually identified as a distinct and unique factor. Therefore, no individual factor of such an enumeration should be interpreted as factually equivalent to any other factor of the same enumeration, based solely on its presentation in a common group, unless it is shown to the contrary. In addition, various embodiments and examples of the Invention may be referred to herein, along with substitutes for various components. It is understood that such embodiments, examples, and substitutes should not be interpreted as factual equivalents of each other, but rather as distinct and independent representations of the Invention.

[0050] Furthermore, the features, structures, or properties described may be combined in any preferred manner in one or more embodiments. In the preceding description, numerous specific details, such as examples of length, width, shape, etc., are provided to provide a thorough understanding of embodiments of the present invention. However, those skilled in the art will recognize that the present invention may be practiced without using one or more of the specific details, or using other methods, components, materials, etc. In other embodiments, well-known structures, materials, or operations are not shown or described in detail, so as not to obscure aspects of the present invention.

[0051] The examples described above illustrate the principles of the present invention in one or more specific uses, but it will be apparent to those skilled in the art that numerous modifications in embodiments, uses, and details can be made without inventiveness and without departing from the principles and concepts of the present invention. Therefore, the present invention is not intended to be limited except by the claims described below.

[0052] The verbs "to include" and "to contain" are used in this document as open limitations, neither excluding nor requiring the existence of features not further described. Features described in dependent claims can be freely combined with each other unless explicitly stated otherwise. Furthermore, it should be understood that the use of "a" or "an," i.e., the singular form, throughout this document does not exclude the plural. [Industrial applicability]

[0053] At least some embodiments of the present invention reveal industrial applications in improving waveguide displays. [Explanation of Symbols]

[0054] LED Light Emitting Diode MEME Micro-electromechanical 100 Light irradiation field 102 Light Guide 104 light 110 Waveguides 112a, 112 element 114 Directional light 120th 130 Mirror 140 light source 100a, 100b Angular portion of light irradiation field 100 400-460 Structure of the equipment in Figure 4 410-430 Steps of the method shown in Figure 4 200 Notch Filter Elements 201 First (inner) surface of the waveguide 202 The second (outer) surface of the waveguide Light source having R wavelength λ1 Light source with wavelength λ2 B Light source with wavelength λ3 R' Stopband of a notch filter with wavelength λ1 G' Stopband of a notch filter with wavelength λ2 B' Stopband of a notch filter with wavelength λ3 λ 1~3Light source and center wavelength of the stopband

Claims

1. Optical waveguide configuration, An optical system configured to generate a configurable image encoded in a light-illuminated field, An optical waveguide comprising at least one optical waveguide, arranged to receive light from the optical field and to transmit the light to a plurality of locations in the optical waveguide for emission, thereby creating a waveguide-based display. Equipped with, The optical system has an adjustable wavelength λ １ Equipped with a light source having, The optical waveguide is disposed on the outer surface of the optical waveguide to prevent light leakage from the light irradiation field, wavelength λ １ It is equipped with a notch filter element having a stopband of ', wavelength λ １ The stopband of ' is the adjusted wavelength λ incident on the notch filter element at a changing first incident angle. １ Filter the light, The optical waveguide arrangement is configured to modulate the wavelength of the light source based on the angle of incidence of the light in the optical waveguide to the notch filter element and / or based on the angle of incidence of the light to the optical waveguide. Optical waveguide arrangement.

2. The optical system has a wavelength λ ２ The light source further comprises a notch filter element having a wavelength λ ２ It further has a stopband of ', wavelength λ ２ The stopband of ' corresponds to the wavelength λ incident on the notch filter element at the first or second incident angle. ２ The optical waveguide arrangement according to claim 1, which filters light.

3. The optical system further includes a light source having a wavelength λ ３ and the notch filter element has a stop band of a wavelength λ ３ ', and the stop band of the wavelength λ ３ ' filters light of the wavelength λ ３ incident on the notch filter element at the first incident angle, the second incident angle, or the third incident angle. The optical waveguide arrangement according to claim 2.

4. The optical waveguide arrangement according to claim 1, wherein the modulation includes adjusting the wavelength of the light source according to a mapping of the angular portion of the light field to the stopband of the notch filter element.

5. The optical waveguide arrangement according to claim 2 or 3, wherein the light source includes a laser light source.

6. The optical waveguide arrangement according to claim 2 or 3, wherein the light source includes a light-emitting diode light source.

7. The optical waveguide arrangement according to claim 1 or claim 2, wherein the optical waveguide arrangement is configured to provide a display as a head-mounted display.

8. The optical waveguide arrangement according to claim 2 or claim 3, wherein the stopband of the notch filter element has a maximum width of 2 nanometers.

9. The optical waveguide arrangement according to claim 2 or 3, wherein the notch filter element is a reflective notch filter.

10. The optical waveguide arrangement according to claim 1, wherein the stopband of the notch filter element has a maximum width of 2 nanometers.

11. The optical waveguide arrangement according to claim 1, wherein the notch filter element is a reflective notch filter.

12. The optical waveguide arrangement according to claim 1 or claim 2, wherein the notch filter element is configured to have a plurality of stopbands for each light source in the optical waveguide arrangement.

13. Using an optical system, generate a configurable image encoded in the light-illuminated field, The process involves receiving light from the light irradiation field into at least one optical waveguide, transmitting the light to multiple locations in the optical waveguide for emission, and creating a waveguide-based display. A method comprising manipulating an optical waveguide arrangement, including, The optical system has an adjustable wavelength λ １ Equipped with a light source having, The optical waveguide is disposed on the outer surface of the optical waveguide to prevent light leakage from the light irradiation field, wavelength λ １ It has a notch filter element with a stopband of ', and wavelength λ １ The stopband of ' is the adjusted wavelength λ incident on the notch filter element at a changing first incident angle. １ Filter the light, The method further includes modulating the wavelength of the light source based on the angle of incidence of the light in the optical waveguide to the notch filter element and / or based on the angle of incidence of the light to the optical waveguide. method.

14. The optical system has a wavelength λ ２ The light source further comprises a notch filter element having a wavelength λ ２ It further has a stopband of ', wavelength λ ２ The stopband of ' corresponds to the wavelength λ incident on the notch filter element at the first or second incident angle. ２ The method according to claim 13, wherein light is filtered.

15. The optical system has a wavelength λ ３ The light source further comprises a notch filter element having a wavelength λ ３ It has a stopband of ' and wavelength λ ３ The stopband of ' corresponds to the wavelength λ incident on the notch filter element at the first, second, or third incident angles. ３ The method according to claim 14, wherein light is filtered.

16. The method according to claim 13, wherein the modulation includes mapping the angular portion of the light field using wavelength adjustment, and adjusting the wavelength of the light source according to the mapping.

17. The method according to claim 14 or claim 15, wherein the light source includes a laser light source.

18. The method according to claim 14 or claim 15, wherein the light source includes a light-emitting diode light source.

19. The method according to claim 13 or 14, wherein the operation described above includes providing a display as a head-mounted display.

20. When executed by at least one processor, the device has at least, Using an optical system, a configurable image is generated that is encoded in the light-illuminated field. Light is transmitted from the light field to at least one optical waveguide, which is arranged to receive the light and to transmit the light to a plurality of positions in the optical waveguide for emission, thereby creating a waveguide-based display. A non-temporary computer-readable medium that stores a set of computer-readable instructions within itself, The optical system has an adjustable wavelength λ １ Equipped with a light source having, The optical waveguide is disposed on the outer surface of the optical waveguide to prevent light leakage from the light irradiation field, wavelength λ １ It has a notch filter element with a stopband of ', and wavelength λ １ The stopband of ' is the adjusted wavelength λ incident on the notch filter element at a changing first incident angle. １ Filter the light, The computer-readable instruction is further configured to cause the device to modulate the wavelength of the light source based on the angle of incidence of the light in the optical waveguide to the notch filter element and / or based on the angle of incidence of the light to the optical waveguide. Non-temporary computer-readable media.

21. A computer program configured to perform the method described in claim 13 or claim 14.

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