Method and system for producing a holographic optical element for smart glasses, and smart glasses having a holographic optical element

Abstract

The invention relates to a method for producing a holographic optical element (110) for smart glasses. The production method comprises a step of irradiating a predefined masking section (212) of a light-sensitive substrate with irradiation light (232) in order to inactivate, in the masking section (212), a material of the substrate with respect to a subsequent interference pattern generation. The masking section (212) surrounds predefined hologram sections (214, 216, 218) of the substrate, in which sections holograms are provided. The production method also comprises a step of exposing regions of the substrate comprising the hologram sections (214, 216, 218) with coherent exposure light (234, 234') in order to generate interference patterns for the holograms only in the hologram sections (214, 216, 218).

Description

[0001] R. 416812

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[0003] Description

[0004] title

[0005] Method and system for generating a holographic-optical element for data glasses and data glasses with a holographic-optical element

[0006] State of the art

[0007] The invention relates to a device or a method according to the preamble of the independent claims. The present invention also relates to a computer program.

[0008] Holograms are created by exposing a photosensitive material using an interference pattern of two coherent laser beams. In many cases, only a portion of the photosensitive film is to be exposed, for example, when multiple holograms are to be exposed side-by-side onto the same film. This is the case, for instance, with augmented reality waveguides, which, according to a typical setup, can include couplers, expanders, and uncouplers. It is also possible that several holographic elements (HOGELs) are to be exposed side-by-side, or that a shape of a holographically active surface is to form an aperture or diaphragm for deflected light. Typically, laser beams can be restricted to a desired area and / or shape using apertures, such as iris diaphragms, razor blades, CNC- or laser-cut sheets, or similar devices.

[0009] Disclosure of the invention

[0010] Against this background, the approach presented here comprises a method, a system with a control unit that uses this method, data glasses, and finally a corresponding computer program. R. 416812

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[0012] As presented in the main claims, advantageous further developments and improvements of the device specified in the independent claim are possible through the measures listed in the dependent claims.

[0013] According to embodiments, particularly in the production of holographic-optical elements for smart glasses, a mask or aperture for subsequent hologram exposure can be provided in the same light-sensitive substrate by aperture pre-exposure or irradiation. Areas where no hologram is to be exposed later can be exposed or irradiated with a light source whose light does not form an interference pattern. Subsequently, holograms can be exposed, for example, with uncut laser beams or with simple apertures or apertures. The areas that are not intended to bear a hologram are already inactive due to the irradiation or pre-exposure and can readily be targeted by the laser.

[0014] A method for generating a holographic-optical element for data glasses is presented, the method comprising the following steps:

[0015] Irradiating a predefined masking section of a photosensitive substrate with irradiation light to inactivate a material of the substrate in the masking section with respect to subsequent interference pattern generation, wherein the masking section surrounds predefined hologram sections of the substrate in which holograms are provided; and

[0016] Exposure of regions of the substrate encompassing the hologram sections with coherent exposure light in order to generate interference patterns for the holograms exclusively in the hologram sections.

[0017] The data glasses can be designed as augmented reality (AR) glasses, allowing the user to simultaneously view both the real environment and virtually superimposed image content. The holographic optical element (HOE) can contain multiple holograms. The substrate can be a film. The irradiation light can be supplied by an irradiation device. R. 416812

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[0019] The exposure light may be provided or emitted by an exposure device. The exposure light may consist of at least two laser beams. The regions of the substrate exposed during the exposure step may include the monogram sections and, optionally, a portion of the masking section.

[0020] This process can be implemented, for example, in software or hardware, or in a hybrid form of software and hardware, for example in a control unit.

[0021] Advantageously, according to these embodiments, the expensive and time-consuming manufacturing of mechanical apertures for hologram exposure can be avoided. Adjusting such apertures is also advantageously eliminated. In particular, rapid prototyping cycles can be enabled. During irradiation, pre-exposure, or incoherent pre-exposure, the individual hologram sections on the substrate, for example, film, can be macroscopically separated from one another. In particular, several different holograms can be exposed onto a common substrate. The separated holograms can, for example, also fulfill different holographic functions. In other words, the need to manufacture or at least adjust mechanical apertures for each hologram type can be avoided. This reduces time and effort.Light can be diffracted at the edges of such apertures. According to certain embodiments, positioning, particularly the distance, of such an aperture to the substrate can prevent it from being blocked by other elements of the recording setup in some cases. This can improve image quality.

[0022] According to one embodiment, incoherent irradiation light can be used in the irradiation step. In this way, the masking section of the substrate can be pre-exposed simply and reliably, thus rendering it insensitive for the subsequent hologram exposure. R. 416812

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[0024] Additionally or alternatively, gradual intensity gradients can be generated at the boundaries between the masking section and the hologram sections during the illumination step. Such gradual intensity gradients can resemble or correspond to gray wedges. These gradual intensity gradients or gray wedges can be easily achieved, for example, with a standard video projector. This allows for the simple prevention of a sharp, aesthetically displeasing edge between exposed and shaded or unexposed, non-holographically functionalized sections. Thus, the optical properties of the holograms can be improved.

[0025] According to another embodiment, coherent irradiation light can be used in the irradiation step. Additionally or alternatively, the irradiation step can be performed using one of two laser beams of the exposure light. Such an embodiment offers the advantage that the setup for generating the holographic-optical element can be simplified and the number of components reduced.

[0026] Identical or different interference patterns can also be generated in the hologram sections during the exposure step. Additionally or alternatively, the hologram sections can be exposed in parallel or sequentially. Such an embodiment offers the advantage that the manufacturing of the holographic-optical element can be flexibly adapted to its specific application requirements with regard to functionality and process flow.

[0027] Furthermore, in the exposure step, the hologram sections can be exposed using two laser beams, which can be kept unchanged for all hologram sections or individually adjusted for each hologram section. Additionally or alternatively, in the exposure step, the hologram sections can be exposed using individual laser beams for each hologram section. Such an embodiment offers the advantage that a R. 416812

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[0029] Functionality of the hologram sections and a process flow can be easily adapted depending on the respective application requirements of the holographic-optical element.

[0030] Furthermore, during the exposure step, the hologram sections can be exposed using laser beams split into more than two optical paths. A common reference beam and different signal beams, or different reference beams and different signal beams, can be used for the hologram sections. This embodiment offers the advantage that different functionalities can be reliably achieved in parallel within the hologram sections.

[0031] A system for generating a holographic-optical element for data glasses is also presented, with the system having the following features:

[0032] a control unit that is configured to execute and / or control the steps of an embodiment of the method mentioned herein in corresponding units;

[0033] an irradiation device for providing the irradiation light; and

[0034] an exposure device for emitting the coherent exposure light,

[0035] the control unit is connected to the irradiation device and the exposure device in a signal-transmitting manner.

[0036] In other words, the control unit can be configured to carry out, control, or implement the steps of a variant of a procedure presented here in appropriate devices. The control unit can, for example, include a unit for inducing irradiation and a unit for controlling exposure. R. 416812

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[0038] For this purpose, the control unit can have at least one processing unit for processing signals or data, at least one storage unit for storing signals or data, at least one interface to a sensor or actuator for reading sensor signals from the sensor or for outputting control signals to the actuator, and / or at least one communication interface for reading or outputting data embedded in a communication protocol. The processing unit can be, for example, a signal processor, a microcontroller, or the like, while the storage unit can be flash memory or a magnetic storage device.The communication interface can be configured to read or output data wirelessly and / or via wired connections, whereby a communication interface that can read or output wired data can, for example, read this data electrically or optically from or output it into a corresponding data transmission line.

[0039] In this context, a control unit can be understood as an electrical device that processes sensor signals and outputs control and / or data signals accordingly. The control unit can have an interface, which can be implemented in hardware and / or software. In the case of a hardware-based interface, the interfaces can, for example, be part of a so-called system ASIC, which incorporates various functions of the control unit. However, it is also possible that the interfaces are separate integrated circuits or at least partially comprised of discrete components. In the case of a software-based interface, the interfaces can be software modules, which, for example, are located on a microcontroller alongside other software modules.

[0040] The irradiation device may comprise a light source and an imaging device. The light source may be a visible light-emitting diode, preferably blue or white light, an ultraviolet light-emitting diode, an incandescent lamp, a halogen lamp, an arc lamp, a metal halide lamp, or the like. The light source may also be a coherent source, provided that no interference pattern is formed between two beams. In particular, one of the R. 416812

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[0042] Exposure beams from a hologram-capturing laser of the exposure device are used. This eliminates the need for a separate light source. The irradiation device and the exposure device can thus be combined. The imaging device can be configured to image an incoherent pattern. The imaging device can include an image projector, e.g., a slide projector, mask exposure unit, or diffractive optical element; a video projector, e.g., LCD, DLP, or the like; a spatial light modulator; a laser raster writer, e.g., a CNC gantry milling machine, a flying spot projector, or the like; or a mechanical aperture for shaping an incoherent beam.

[0043] Furthermore, a data glasses device with a holographic-optical element is presented, wherein the holographic-optical element is produced according to an embodiment of the method mentioned herein.

[0044] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out, implement and / or control the steps of the method according to one of the embodiments described above, in particular if the program product or program is executed on a computer or device.

[0045] Examples of the approach presented here are shown in the drawings and explained in more detail in the following description. It shows:

[0046] Fig. 1 shows a schematic representation of a data glasses according to an exemplary embodiment;

[0047] Fig. 2 shows a schematic representation of an embodiment of a system for generating a holographic-optical element for a

[0048] Data glasses; R. 416812

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[0050] Fig. 3 shows a flowchart of an embodiment of a method for generating a holographic-optical element for data glasses; and

[0051] Fig. 4 shows a schematic representation of an exemplary embodiment of a process flow for generating a holographic-optical element for data glasses.

[0052] In the following description of favorable embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and acting similarly, without repeating these elements.

[0053] Fig. 1 shows a schematic representation of a pair of smart glasses 100 according to an exemplary embodiment. The smart glasses 100 are specifically designed as augmented reality (AR) glasses. The smart glasses 100 comprise at least one holographic-optical element (HOE) 110. The holographic-optical element 110 can display multiple holograms. The holographic-optical element 110 is, for example, arranged in or on a lens of the smart glasses 100, or is designed as a lens or as part of a lens.

[0054] The holographic-optical element 110 is produced according to an embodiment of a method mentioned herein and / or by means of an embodiment of a system mentioned herein, as will be explained in more detail below.

[0055] The production of the holographic-optical element 110 according to the aforementioned method and / or by means of the aforementioned system can be seen from the polymerization structure or cross-linking, which differs depending on the type and sequence of exposure.

[0056] Fig. 2 shows a schematic representation of an embodiment of a system 220 for generating a holographic-optical element 110 for data glasses. The system 220 is designed to generate the holographic-optical element. R. 416812

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[0058] to produce element 110 from Fig. 1 or a similar one. The illustration also shows, for illustrative purposes only, a holographic-optical element 110.

[0059] The holographic-optical element 110 comprises a light-sensitive substrate, for example, a light-sensitive film or the like. The holographic-optical element 110, or the light-sensitive substrate, has a predefined masking section 212 and predefined hologram sections 214, 216, and 218. Holograms are provided in the hologram sections 214, 216, and 218. The hologram sections 214, 216, and 218 are surrounded by the masking section 212. The masking section 212 is located outside the hologram sections 214, 216, and 218. Only three hologram sections 214, 216, and 218 are shown in the illustration as examples.

[0060] System 220 comprises an irradiation device 222 for providing irradiation light 232, an exposure device 224 for emitting coherent exposure light 234, 234', and a control unit 240. The control unit 240 is connected to the irradiation device 222 and the exposure device 224 for signal transmission. The control unit 240 is configured to perform, control, and implement the steps of an embodiment of the method shown below in Fig. 3 in corresponding units 242, 244.

[0061] The control unit 240 comprises a unit 242 for irradiating the masking section 212 with the irradiation light 232 in order to inactivate a material of the substrate in the masking section 212 with respect to subsequent interference pattern generation. The control unit 240 further comprises a unit 244 for controlling the exposure of regions of the substrate comprising the hologram sections 214, 216, 218 with the coherent exposure light 234, 234' in order to generate interference patterns for the holograms exclusively in the hologram sections 214, 216, 218.

[0062] Fig. 3 shows a flowchart of an embodiment of method 350 for producing a holographic-optical element for data glasses. R. 416812

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[0064] The generating method 350 can be carried out using the system from Fig. 2 or a similar system and / or the control unit from Fig. 2 or a similar control unit.

[0065] Method 350 for generating comprises a step 352 of irradiation or inducing irradiation and a step 354 of exposure or controlling exposure. In step 352, irradiation, a predefined masking section of a photosensitive substrate is irradiated with irradiation light to inactivate a material of the substrate within the masking section with respect to subsequent interference pattern generation. The masking section surrounds predefined hologram sections of the substrate in which holograms are intended. In step 354, exposure, regions of the substrate containing the hologram sections are exposed with coherent exposure light to generate interference patterns for the holograms exclusively within the hologram sections.

[0066] In one embodiment, incoherent irradiation light is used in step 352 of the irradiation process. In another embodiment, coherent irradiation light is used in step 352. Additionally or alternatively, step 352 of the irradiation process is performed using one of two laser beams of the exposure light. In a further embodiment, gradual intensity gradients are generated at the boundaries between the masking section and the hologram sections in step 352 of the irradiation process.

[0067] According to one embodiment, identical or different interference patterns are generated in the hologram sections during exposure step 354. Additionally or alternatively, the hologram sections are exposed in parallel or sequentially during exposure step 354. According to another embodiment, the hologram sections are exposed using two laser beams during exposure step 354, which are either kept unchanged for all hologram sections or individually adjusted for each hologram section. Additionally or alternatively, R. 416812

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[0069] In step 354 of the exposure process, the hologram sections are exposed using individual laser beams for each hologram section. According to one embodiment, in step 354 of the exposure process, the hologram sections are exposed using laser beams split into more than two optical paths. In this case, a common reference beam and different signal beams are used for the hologram sections. Alternatively, different reference beams and different signal beams are used for the hologram sections.

[0070] Fig. 4 shows a schematic representation of an exemplary embodiment of a process sequence for producing a holographic-optical element 110 for smart glasses. The process sequence results from carrying out the method from Fig. 3 or a similar method and / or using the system from Fig. 2 or a similar system. The holographic-optical element 110 corresponds to or is similar to that from Fig. 1 and / or Fig. 2.

[0071] The process sequence comprises a first stage I, a second stage II, a third stage III, and a fourth stage IV. Stages I, II, III, and IV illustrate progressive manufacturing states of the holographic-optical element 110. For each stage I, II, III, and IV, the holographic-optical element 100 is shown in its respective manufacturing state.

[0072] In the first stage I, the masking section 212 is illuminated with the irradiation light, while the hologram sections 214, 216, and 218 are excluded from the irradiation light. The first stage I represents, in particular, an incoherent pre-exposure. In the subsequent, second stage II, a first region 415, comprising a first hologram section 214 of the hologram sections 214, 216, and 218, is illuminated with the exposure light. In the subsequent, third stage III, the first hologram section 214 has already been illuminated, and another region 419, comprising a third hologram section 218 of the hologram sections 214, 216, and 218, is illuminated with the exposure light. In the subsequent, fourth stage IV, the first hologram section 214 and the third hologram section 218 have already been illuminated, and another region 417, which R. 416812

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[0074] a second hologram section 216 of the hologram sections 214, 216, 218, is exposed with the exposure light.

[0075] With reference to the figures described above, exemplary embodiments are summarized again below and explained in other words.

[0076] The irradiation device 222 comprises, for example, a light source and an imaging device. The light source comprises, for example, a visible light-emitting diode (LED), preferably blue or white light, an ultraviolet LED, an incandescent lamp, a halogen lamp, an arc lamp, a metal halide lamp, or the like. Alternatively, the light source comprises, for example, a coherent source, provided that two beams do not form an interference pattern. In particular, one of the exposure beams 234, 234' of a hologram-receiving laser of the irradiation device 224 is used. This eliminates the need for a separate light source. Thus, according to one embodiment, the irradiation device 222 and the irradiation device 224 are combined. According to one embodiment, the imaging device is designed to image an incoherent pattern.The imaging device comprises, for example, an image projector, e.g., a slide projector, mask exposure unit, or diffractive optical element; a video projector, e.g., LCD, DLP, or the like; a spatial light modulator; a laser raster recorder, e.g., a CNC gantry milling machine, a flying spot projector, or the like; or a mechanical aperture for shaping an incoherent beam. The exposure device 224 is configured to receive the holograms or to cause the receipt of the holograms.

[0077] According to one embodiment, two laser beams 234 and 234' of the exposure light successively illuminate each of the hologram sections 214, 216, 218. Between the hologram exposures, the beams 234 and 234' can be adjusted, i.e., a different function can be inscribed in each of the hologram sections 214, 216, 218. R. 416812

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[0079] According to another embodiment, the hologram sections 214, 216, 218 are globally exposed simultaneously. In this case, the laser or the exposure light 234, 234' exposes several of the hologram sections 214, 216, 218 at the same time. For example, a large beam sweeps over several of the hologram sections 214, 216, 218.

[0080] According to a further embodiment, the hologram sections 214, 216, 218 are simultaneously and individually exposed. The laser or the exposure light 234, 234' is split into more than two optical paths. Several of the hologram sections 214, 216, 218 are exposed simultaneously, but with different functions. For example, a common reference beam 234 and an individual signal beam 234' are used for each of the hologram sections 214, 216, 218. Alternatively, for example, individual signal and reference beams 234, 234' are used for each of the hologram sections 214, 216, 218.

[0081] According to yet another embodiment, several different lasers expose the hologram sections 214, 216, 218 simultaneously or one after the other.

[0082] If an embodiment includes an “and / or” connection between a first feature and a second feature, this is to be read as meaning that the embodiment according to one embodiment has both the first feature and the second feature, and according to another embodiment has either only the first feature or only the second feature.

Claims

R. 416812 - 14 - Claims 1. Method (350) for generating a holographic-optical element (110) for a data glasses (100), wherein the method (350) comprises the following steps: Irradiation (352) of a predefined masking section (212) of a photosensitive substrate with irradiation light (232) in order to inactivate a material of the substrate in the masking section (212) with respect to subsequent interference pattern generation, wherein the masking section (212) surrounds predefined hologram sections (214, 216, 218) of the substrate in which holograms are provided; and Exposure (354) of the regions (415, 417, 419) of the substrate encompassing the hologram sections (214, 216, 218) with coherent exposure light (234, 234') to generate interference patterns for the holograms exclusively in the hologram sections (214, 216, 218).

2. Method (350) according to claim 1, wherein in the step (352) of irradiation incoherent irradiation light (232) is used, and / or wherein in the step (352) of irradiation gradual intensity gradients are generated at boundaries between the masking section (212) and the hologram sections (214, 216, 218).

3. Method (350) according to claim 1, wherein in step (352) of irradiation coherent irradiation light (232) is used, and / or wherein step (352) of irradiation is carried out using one of two laser beams of the exposure light (234, 234'). R. 416812 - 15 - 4. Method (350) according to one of the preceding claims, wherein in step (354) of exposure identical or different interference patterns are generated in the hologram sections (214, 216, 218), and / or wherein the hologram sections (214, 216, 218) are exposed in parallel or sequentially.

5. Method (350) according to one of the preceding claims, wherein in step (354) of exposure the hologram sections (214, 216, 218) are exposed using two laser beams (234, 234') which are maintained unchanged for all hologram sections (214, 216, 218) or are individually adjusted for each hologram section (214, 216, 218), and / or using individual laser beams (234, 234') for each hologram section (214, 216, 218).

6. Method (350) according to one of the preceding claims, wherein in step (354) of exposure the hologram sections (214, 216, 218) are exposed using laser beams (234, 234') split into more than two optical paths, wherein a common reference beam (234) and different signal beams (234') are used for the hologram sections (214, 216, 218) or different reference beams (234) and different signal beams (234') are used.

7. System (220) for generating a holographic-optical element (110) for a data glasses (100), wherein the system (220) has the following features: a control unit (240) configured to execute and / or control the steps of the method (350) according to one of the preceding claims in corresponding units (242, 244); an irradiation device (222) for providing the irradiation light (232); and R. 416812 - 16 - an exposure device (224) for emitting the coherent exposure light (234, 234'), wherein the control unit (240) is connected to the irradiation device (222) and the exposure device (224) in a signal-transmitting manner.

8. Data glasses (100) with a holographic-optical element (110), wherein the holographic-optical element (110) is produced according to the method (350) according to one of claims 1 to 6.

9. Computer program configured to execute and / or control the steps of the method (350) according to any one of claims 1 to 6.

10. Machine-readable storage medium on which the computer program according to claim 9 is stored.

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