Set of semifinished product ophthalmic lens including holographic component

Abstract

To provide a lens including a holographic component more inexpensively and quickly.SOLUTION: There is provided a set of semifinished ophthalmic product lenses (10) intended for use in manufacturing a finished ophthalmic lens with determined target refractive power. Each semifinished product ophthalmic lens includes a base curve (Bi) selected from (N) base curves. Each base curve (Bi) is related to each of ranges of refractive powers of the finished ophthalmic lens to be produced. Each semifinished product ophthalmic lens of the set includes recorded holographic component (13). The holographic component of the set indicates limited number of structures. Each holographic component structure (Hi) is exclusively related to one base curve of the N base curves. A set of semifinished product ophthalmic lenses and a method of manufacturing a lens from the semifinished product ophthalmic lens set are also provided.SELECTED DRAWING: Figure 1a

Description

[Technical Field]

[0001] The present invention relates to a set of semi-finished ophthalmic lenses integrating recorded holographic components for producing lenses that can be used in the fields of smart glasses and augmented reality. [Background technology]

[0002] Head-mounted devices with display features are already known, allowing the wearer to visualize images or text for augmented reality.

[0003] For this purpose, from patent document EP 1 299 593 A1, a method is known in which an ophthalmic lens is provided that is fitted into a frame and intended to be worn by a wearer, in which the lens includes a holographic mirror configured to reflect light generated by an image source integrated in the frame.

[0004] The mirror is holographic in that it is recorded using a holographic process. More specifically, the holographic mirror is obtained by providing a layer of blank recording medium on the ophthalmic lens and recording the holographic mirror by creating interference between a reference beam and an illumination beam in the holographic medium.

[0005] Depending on the configuration of the beam during the recording step, the mirror may be endowed with an optical function capable of modifying the wavelength of the light beam coming from the image source when reflected on the mirror, so that recording can be performed according to the configuration of the lenses and frames and optionally according to some characteristics of the wearer.

[0006] In particular for wearers with refractive errors, it is necessary to ensure that the glasses guarantee a correction suitable not only for "natural vision", that is the vision of the environment surrounding the wearer, but also for the visualization of "virtual images" generated by an image source and reflected by a mirror.

[0007] In light of this requirement, Patent Document 1 proposes recording a holographic mirror configured to correct the wearer's vision directly onto the lens. Typically, opticians machine the surface of semi-finished lenses so that the lenses correspond to the wearer's prescription. However, recording a holographic mirror requires special skills and expensive equipment, making it difficult for opticians to do. Furthermore, the quality of the holographic mirror cannot be guaranteed and must be tested. Furthermore, if the lenses are made of birefringent materials, special recording techniques must be used to compensate for the polarization changes introduced by the birefringent material. Therefore, opticians must order lenses with holographic mirrors from specialized laboratories, which can delay the delivery of the lenses.

[0008] Following a method similar to that for recording holographic mirrors, other types of holographic components can also be produced. In particular, holographic filters can be mentioned, which are optical filters recorded using a holographic process and are capable of filtering out specific wavelengths or ranges of wavelengths in a determined direction. Holographic lenses can also be mentioned, which are capable of focusing or collimating light in a wavelength range according to a determined direction or at a determined position. Therefore, the same problems are faced when recording other types of holographic components. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] International Publication No. 2016 / 156614 Brochure [Patent Document 2] International Publication No. 2018 / 054984 Brochure Summary of the Invention [Problem to be solved by the invention]

[0010] The purpose of the present disclosure is to provide solutions to the shortcomings of the prior art.

[0011] In particular, one object of the present disclosure is to provide a cheaper and faster method for providing lenses that include holographic components. [Means for solving the problem]

[0012] The above mentioned objects are achieved by means of the feature combinations set out in the independent claims, while the dependent claims provide particular advantageous embodiments of the invention.

[0013] A method for manufacturing a set of semi-finished ophthalmic lenses and a method for manufacturing ophthalmic lenses are also disclosed.

[0014] The present disclosure provides a set of semi-finished lenses, all of which have a base curve selected from a limited number of base curves and a holographic mirror with a configuration that depends on the base curve of the semi-finished lens.

[0015] Each base curve of the limited number of base curves is made to correspond to a target power range for the finished lens formed from the semi-finished lens.

[0016] Thus, the present disclosure allows for the creation of personalized lenses for a wearer from a finite set of semi-finished lenses and holograms with a finite number of configurations, so that the manufacturing of the semi-finished lenses can be carried out in a mass production factory, and personalization according to the wearer's corrective requirements can be performed later in the step of finishing the semi-finished lenses.

[0017] For a more detailed understanding of the description and advantages of the present specification, reference is now made to the following brief description of the accompanying drawings and detailed description, in which like reference numerals represent like elements. [Brief explanation of the drawings]

[0018] [Figure 1a]1 illustrates a set of semi-finished lenses according to an exemplary embodiment. [Figure 1b] 1 illustrates a set of semi-finished lenses according to another exemplary embodiment. [Figure 2] 1 illustrates a set of semi-finished lenses according to another exemplary embodiment. [Figure 3] 1 shows a schematic representation of an optical device into which an ophthalmic lens with a holographic mirror is inserted. [Figures 4a-4c] 1 shows a schematic diagram of an example optical setup for recording a holographic mirror. [Figure 5a-5b] 10 shows the use and removal of anti-reflective coating before and after recording of the holographic element, respectively. [Figure 6a-6b] A first example of finishing a semi-finished lens is shown. [Figure 7a-7b] A second example of finishing a semi-finished lens is shown. DETAILED DESCRIPTION OF THE INVENTION

[0019] definition The following definitions are provided to explain this disclosure.

[0020] "Holographic mirrors" (HMs) are known in the art. A mirror is defined as a holographic mirror if it has been recorded using a holographic process. The mirror is used to reflect a light beam generated by an image source, such as a display screen, picoprojector, etc., towards the wearer's eye, resulting in the wearer's visualization of the image. Holographic mirrors are not used to reconstruct the recorded holographic image, as is the case with conventional hologram viewing.

[0021] The recording configuration can give the mirror an optical function that is independent of the geometry of the layer supporting the holographic mirror: for example, the holographic mirror may or may not have a focal length, may contain one or several zones of different function or may reflect different wavelengths, may have a determined refractive power, etc.

[0022] A "holographic filter" is an optical filter that is recorded on a support using a holographic process. Such a filter is capable of transmitting a wavelength or a range of wavelengths in a specific direction.

[0023] A "holographic lens" is a lens that is recorded on a support using a holographic process. It can operate for a given wavelength or range of wavelengths to focus light in a given direction or at a given location. On the same support, holographic lenses can be configured to exhibit spectral and / or angular selectivity, with different focal lengths in different zones and with different spectral or angular selectivities.

[0024] In the following, a holographic component can refer to any one of a holographic mirror, a holographic filter and a holographic lens.

[0025] Recording of holographic components on a support is performed using an optical setup including a light source, e.g., a laser, emitting a light beam. Typically, a polarizing beam splitter allows the beam to be split into two beams: one reference beam and one illumination beam, which illuminate the holographic medium from the same or opposite sides depending on the type of holographic component. The interference caused by the reference and illumination beams on the holographic recording medium allows the holographic component to be recorded. The configuration of the reference and illumination beams allows the function and configuration of the holographic component to be adapted. For example, in the case of a holographic mirror, once the optical setup is set (e.g., geometry, beam size, etc.), the characteristics of the holographic mirror can be changed by changing one or more parameters, including the refractive index ratio between the two beams (affecting fringe contrast and diffraction efficiency), the exposure time (affecting diffraction and diffusion efficiency), and the possible use of rotatable supports on which the polarization-maintaining fibers through which the reference and illumination beams pass are positioned (affecting the polarization of the beams when they exit the fibers). Those skilled in the art can refer to U.S. Patent No. 5,649,994 for further details regarding the recording setup used to achieve the desired holographic component configuration.

[0026] "Head-mounted display devices" (HMDs) are known in the art. Such devices are worn on or around the wearer's head, including helmet-mounted displays, optical head-mounted displays, head-worn displays, etc. Such devices include optical means for displaying images for viewing by the wearer. HMDs may provide superimposed visualization of computer-generated images and a "real-life" field of view. HMDs may be monocular (one eye) or binocular (two eyes). HMDs incorporating lenses according to the present disclosure can take a variety of forms, including eyeglasses, masks such as ski masks or diving masks, goggles, etc. HMDs include one or more ophthalmic lenses. In a preferred embodiment, the HMD is eyeglasses provided with ophthalmic lenses, which may be sun lenses.

[0027] An "image source" (IS) is known in the art. An image source is any light source capable of emitting a light beam suitable for displaying an image for visualization by a wearer. Visualization occurs after the illumination beam from the image source is reflected by a holographic mirror. In embodiments of the present disclosure, the IS is typically off-axis in that it may be located next to the wearer's temple on a temple component of the HMD, such as the temple component of eyeglasses. In embodiments of the present disclosure, the IS may be any image source configured to display a virtual image (computer-generated image). The IS may be a screen (e.g., OLED, LCD, LCOS, etc.), a phase and / or amplitude SLM (spatial light modulator), a projector such as a picoprojector (MEMS or DLP, which may use LEDs, diodes, lasers, etc.) along with its light source (e.g., laser, laser diode, etc.), or any other source. The IS may also include any other image source (computer-generated image source), and / or control electronics, and / or a power source, and / or optional optical elements, etc.

[0028] Semi-finished lens set A set 1 of semi-finished lenses 10 according to one embodiment of the present disclosure will now be described with reference to FIGS. 1a, 1b and 2. FIG.

[0029] The semi-finished lenses 10 belonging to set 1 are intended to be used in the manufacture of ophthalmic lenses that are intended to be fitted into a frame and worn by a wearer. The ophthalmic lenses are configured to provide a correction for the wearer's refractive error. Furthermore, the semi-finished lenses include a holographic component 13 that remains present in the ophthalmic lens obtained from the semi-finished lenses, as disclosed in more detail below. The holographic component may include at least one of a holographic mirror, a holographic filter, and a holographic lens.

[0030] As shown schematically in Fig. 3, according to a preferred embodiment, the holographic component 13 is a holographic mirror and the ophthalmic lens 20 achieved from the semi-finished lens is configured to be fitted into a head mounted display device HMD 9 comprising a frame 91 in which the ophthalmic lens 20 is fitted. The HMD 9 further comprises an image source 92 integrated into the frame 91 and configured to illuminate the holographic mirror 13 and, when reflected by said holographic mirror, to cause the visualization of a virtual image by the wearer, the ophthalmic lens being configured to provide the wearer with an accurate view of both the virtual image (the image generated by the image source) and the real image (the wearer's environment).

[0031] A particular application is an augmented reality device in which optical conjugation is performed between the eye's pupil and an image source. In this configuration, the HMD 9 may include a movable micromirror interposed between the image source and the lens, which moves according to the position of the eye's pupil so as to track the movement of the eye's pupil. Furthermore, in this configuration, a holographic mirror recorded on the lens is configured to perform optical conjugation between the image source and the pupil. Given that the distance between the holographic mirror and the pupil is very short, this implies that the mirror has a significant refractive power, for example, in the range of +40D to +60D.

[0032] Another possible application is an imaging system that is not conjugate with the eye's pupil, but instead has an image source placed near the focal point of a holographic mirror, which sends a virtual image to infinity.

[0033] 1a and 1b, the set 1 of semi-finished lenses includes a plurality of semi-finished ophthalmic lenses 10, 10'. The semi-finished ophthalmic lenses are uncropped lenses, meaning that their peripheral shape has not been adjusted to the shape of the frame into which they will be inserted. Furthermore, the semi-finished lenses do not provide the final refractive power, also called the target refractive power, of the lenses that will be produced from the semi-finished lenses.

[0034] The semi-finished lens may not be fully surfaced. In an embodiment, the semi-finished ophthalmic lens 10 has two main surfaces, including an anterior surface 11 and a posterior surface 12, the posterior surface being the surface intended to be closest to the wearer, and only one of the anterior surface 11 and the posterior surface 12 is surfaced. Surface processing is a series of operations that includes machining at least one of the anterior or posterior surfaces of the lens to provide the final geometry. The final correction is obtained by subsequent surface processing of the still unsurfaced surface. One or several coatings may then be applied to either surface to obtain the final optical and mechanical performance of the lens.

[0035] According to a first example, referring to FIG. 1a, semi-finished lenses 10 may provide a refractive power that is not the target refractive power of the lens produced from the semi-finished lenses. The target refractive power can be obtained by subsequent surface processing of the semi-finished lenses. In this case, the SF lenses 10 of set 1 may exhibit a minimum thickness of 4 mm, thereby allowing for further finishing and ensuring that the SF lenses do not deform during the subsequent surface processing. This minimum thickness ensures that the lenses do not deform during blocking during the subsequent surface processing, especially if the subsequent surface processing is performed using a freeform device.

[0036] 1b, the semi-finished ophthalmic lens 10' may be a plano lens 10' that does not provide any optical power and is intended to be later assembled into an auxiliary lens that provides the desired optical power. Because the plano lens 10' does not need to undergo a subsequent surface processing step, its thickness may be smaller than those previously given for other SF lenses. For example, the thickness of the plano lens may be less than 2 mm.

[0037] By "plano lens" is meant a lens that does not provide optical power and therefore does not provide correction to the wearer. Plano lens 10' may, in one embodiment, provide only mechanical support for the recorded holographic components. Alternatively, it may provide an optical function in addition to the function of mechanical support.

[0038] In both cases, i.e., when the semi-finished lenses 10, 10' are plano lenses or semi-finished lenses that provide refractive power, the semi-finished lenses may provide at least one optical function. The optical function may be an amplitude filtering function, a spectral filtering function (edge-pass or band-pass filtering, such as short-pass or long-pass, or filtering of a specific color, for example, by tinting or by incorporating photochromic or electrochromic functions), or a polarization function. To provide said functions, the semi-finished lenses 10, 10' may incorporate two or more layers.

[0039] The semi-finished lens 10, 10' can be at least partially tinted. According to one example, it can be formed of a material including blue-cut functionality, as disclosed in U.S. Patent No. 5,629,999. The semi-finished lens 10, 10' can also include a UV-absorbing dye (such as the dyes marketed by BASF under the trade names TINUVIN® 477 or 479). If the holographic mirror 13 is recorded on the rear surface of the semi-finished lens, the provision of a UV-absorbing dye reduces the amount of UV reaching the holographic mirror 13, thereby reducing the yellowing that such a mirror may have during aging.

[0040] According to another example, the semi-finished lens includes a photochromic layer, such as a photochromic polyurethane layer.

[0041] According to another example, the semi-finished lens 10, 10' can include a polarizing cell or a polarizing thin film. The polarizing cell can be formed of a three-layer stack of TAC-PVA-TAC (PVA refers to polyvinyl alcohol) or a three-layer stack of PC-PVA-PC (PC refers to polycarbonate). According to yet another example, the semi-finished cell 10, 10' can include an electrochromic cell.

[0042] The semi-finished lenses 10, 10' may also have a coating on at least one major surface, such as an abrasion-resistant coating (also known as a hard multi-layer coating) and / or an anti-reflective coating.

[0043] In one embodiment, a hard multilayer anti-reflective coating is provided on a major surface of the semi-finished lens opposite to the major surface on which holographic element 13 is recorded. For example, if holographic mirror 13 is recorded on the rear surface of semi-finished lens 10, 10', an anti-reflective or HMC coating can be deposited on the front surface of the semi-finished lens. Additional coatings can also be deposited on holographic element 13 after holographic element 13 is recorded.

[0044] In one embodiment, an anti-reflective coating may be provided on a major surface of the semi-finished lens 10, 10' before recording the holographic element 13 on the opposite major surface, and then the anti-reflective coating may be removed later by surface processing the semi-finished lens. The temporary anti-reflective coating may reduce reflections during recording of the holographic element and thus provide improved quality of the holographic element.

[0045] 1a and 1b, all semi-finished lenses 10 in set 1 have a base curve B selected from a limited number of base curves N. i and the set includes at least one semi-finished lens of each base curve among the N base curves. For example, N is preferably less than 10, preferably less than 7, for example 5 or less base curves. The base curves are the base curves of the finished surfaces of the SF lenses. In one embodiment, the finished surface of the SF lenses of the set is the front surface. Thus, the base curve is the base curve of the front surface of the SF lenses. Thus, the set of SF lenses includes N base curves (B1, ...B N ) each base curve B i but does not include an SF lens having a base curve different from the N base curves.

[0046] Each base curve corresponds to a respective target power range for which a finished lens obtained from an SF lens having that base curve can be represented. Thus, the N base curves are preferably selected to cover as wide a range of target powers as possible.

[0047] By way of non-limiting example, set 1 of semi-finished lenses 10 may include N=6 base curve SF lenses corresponding to each target power range, as defined in Table 1 below.

[0048] [Table 1]

[0049] According to one embodiment, set 1 of SF lenses 10 may include a subset of lenses with different diameters for each base curve, such that the SF lenses of the subset fit different frame shapes. Thus, for each base curve among N base curves, set 1 may include at least one SF lens of each of d different diameters. The number d may be less than 10, for example less than 5.

[0050] By way of non-limiting example, the number d includes five diameters as follows: 60 mm, 65 mm, 70 mm, 75 mm and 80 mm.

[0051] Furthermore, each semi-finished lens 10 of set 1 includes a recorded holographic element 13, preferably a holographic mirror (HM). The holographic element 13 may extend over the entire cross section of the SF lens, which may be the front surface, the back surface, or a section within the SF lens, or may extend over only a portion of it. Preferably, within the set of semi-finished lenses 10, 10', the holographic elements 13 are all recorded on the same cross section of each semi-finished lens, e.g., the front surface or the back surface.

[0052] As indicated above, recording of a holographic element implies illuminating a thin film of holographic recording material with at least a reference beam and an illumination beam.

[0053] Preferably, the front and rear surfaces of each semi-finished lens 10, 10' exhibit high optical quality in the subsequent recording step to allow illumination and interference of the wavefront onto each surface.

[0054] Furthermore, the SF lenses 10, 10' of the set are preferably made of low birefringence material to enable the recording of high-quality holographic components. Indeed, the quality of the hologram, and in particular the accuracy of the optical function performed by the holographic mirror, depends on the quality of the interference fringes created to record the optical function. This quality is related to the visibility V of the interference fringes, which is directly linked to the angle ψ between the polarization of the illumination / object beam and the polarization of the reference beam. V(ψ)V max .cos(ψ) where V max is the maximum visibility, ideally 1.

[0055] If the recording substrate, i.e., the SF lens, is homogeneous and has particularly low birefringence, the polarization angle is solely linked to the recording setup and can be easily optimized. However, if the substrate is birefringent, the angle may vary locally due to the material itself, resulting in a local reduction in the visibility of the fringes and thus a poor quality holographic mirror.

[0056] Here, a material with low birefringence is considered to be a material in which the visibility of the fringes across the surface of the semi-finished lens 10, 10' is at least 80% of the maximum visibility Vmax, which corresponds to a variation in angle Ψ of approximately 0° to 38°, which therefore corresponds to less than the width of one fringe, with light fringes corresponding to a parallel polarization state and dark fringes corresponding to a perpendicular polarization state.

[0057] The following materials have low birefringence and are suitable for forming SF lenses: - thermosetting polythiourethane resins available from Mitsui Chemicals under the trade names MR-6™, MR-7™, MR-8™ and MR-10™; allyl diglycol carbonate (ADC), also known as CR-39 or marketed by Essilor under the trade name Orma®, - Trivex® material from PPG; - 1.74 refractive index material, - Mineral glass.

[0058] Holographic component configuration Configuration H of the holographic components 13 recorded on each SF lens i , i.e., the optical function imparted to the holographic components, depends on the base curve of the SF lenses, such that a set 1 of SF lenses contains a limited number M of holographic component configurations, where each holographic component configuration H i is one base curve B among N base curves i Therefore, the number M of holographic component configurations is equal to or greater than the number N.

[0059] In one embodiment (such as the example shown in FIGS. 1a and 1b), each base curve B of the SF lenses 10 in set 1 i Only one holographic component configuration H i and a set of SF lenses means, for each base curve, that all have the same component configuration, said configuration preferably configured to provide the holographic components with a refractive power adapted to the target refractive power of the final lens obtained from the SF lenses according to the wearer's prescription and the base curves of the SF lenses.

[0060] In an embodiment where the lenses are integrated into the HMD, part of the wearer's correction, for example astigmatism, can be provided by the image source of the HMD to reduce the number of holographic component configurations per base curve.

[0061] In embodiments in which the lens is integrated into a frame containing an image source and the holographic component is a holographic mirror configured to reflect the virtual image generated by the image source towards the wearer's eye, the holographic mirror configuration is also configured according to the type of image source, thereby ensuring that regardless of the position of the holographic mirror (whether in front of or behind the lens), the wearer accurately sees natural images from the wearer's environment and the virtual image generated by the image source and reflected by the holographic mirror.

[0062] Because the base curve of an SF lens is selected to address a target power range, the holographic component configuration corresponding to the base curve is preferably configured to provide best performance at a power in the middle of the target range. Thus, the power that the holographic component needs to be configured for is set as the middle power of the range corresponding to the base curve.

[0063] Each configuration also depends on the location of the holographic component within the lens, resulting from the SF lens. Indeed, if the holographic component is placed on the rear surface of the lens, the configuration must be configured to take into account the refractive power of the lens. In the case of holographic mirrors, the mirror configuration must be configured according to the location of the mirror on the front or rear surface of the lens to take into account the optical path. If the mirror is placed on the rear surface of the lens, the virtual image is reflected by the mirror directly to the wearer's eye, while the natural image passes through the lens and the mirror and is therefore subject to the refractive power of the lens. If a mirror is placed in front of the lens, the virtual image passes through the lens once, is reflected by the mirror and passes through the lens a second time before reaching the wearer's eye, while the natural image passes through the mirror and then through the lens before reaching the wearer's eye.

[0064] In embodiments where the SF lens is a plano lens 10', the holographic element 13 is preferably recorded on the rear surface 12 of the plano lens, as in the example shown in FIG. 1b. This allows that if an optical function is incorporated into the plano lens, e.g., a polar cell or a photochromic or electrochromic cell, this optical function is applied only to the light from the "real" image and not to the light coming from the image source and reflected by the mirror. Therefore, there is no need to adapt the configuration of the holographic mirror to take into account the effect of the optical function. Furthermore, this configuration may allow for a better view of the virtual image by improving the contrast, for example, during outdoor use of the lens.

[0065] In embodiments in which the SF lens is a lens having one finished surface and another surface that requires further surface finishing to achieve the desired refractive power in the resulting final lens, the finished surface is preferably the front surface, and the holographic component is recorded on or in the lens near the front surface to allow for surface finishing of the rear surface. Since surface finishing implies removing some of the thickness of the SF lens starting from the rear surface, the holographic component may preferably be recorded as close as possible to the front surface to allow the final lens to be sufficiently thin. However, according to another embodiment, the holographic component may be recorded on the rear surface, and the SF lens may be finished by surface finishing its front surface.

[0066] In one embodiment, one base curve B of the SF lens i Two or more holographic components per H i , each configuration nevertheless corresponding to a base curve adapted to a corresponding target power range for lenses made from SF lenses of said base curve.

[0067] For example, for each base curve, there may be multiple holographic component configurations according to different pupillary distances of the wearer. This is particularly advantageous if the holographic component is a holographic mirror configured to ensure optical conjugation between the image source of the HMD and the wearer's pupil. According to the example given above, for each base curve, there may be a number P=3 different configurations for each pupillary distance of the wearer.

[0068] Furthermore, for each base curve, several HM configurations can be provided according to the different wavelengths of light that can be reflected by the mirror. As a non-limiting example, one configuration of holographic mirrors can be configured to reflect red light, while another configuration can be configured to reflect blue or green light. This allows the HM configuration to be adapted to the type of display.

[0069] The embodiments described in detail above, in which a set of SF lenses may include several shapes of SF lenses for a given base curve, and in which a set of SF lenses may include several holographic component configurations Hi for a given SF base curve Bi, can be combined together.

[0070] An example is provided with reference to FIG. 2, which shows an exemplary set 1 of semi-finished lenses. The set of SF lenses includes SF lenses of three different base curves. Set 1 includes SF lenses of each base curve B i For (i=1,...,3), two different diameters D i,j (D i,1 is constant for all values ​​of i, and D i,2 Similarly, D i,1 is D i,2 It includes the subset of lenses with j=1, 2) such that

[0071] Furthermore, for each SF lens of the base curve, set 1 includes three holographic component configurations H i,j,k (k=1,...,3), various configurations are adapted to different pupil distances of the wearer.

[0072] Manufacturing semi-finished lenses The production of the set of semi-finished lenses described above includes a preliminary step of determining the number N of power ranges to be provided by lenses to be produced from SF lenses and, for each power range, determining a base curve of an SF lens suitable for providing a power within said power range.

[0073] Several SF lenses can then be manufactured with different base curves. As mentioned above, several SF lenses can be manufactured with the same base curve but exhibiting different diameters.

[0074] Next, several configurations of holographic components are determined and a holographic mirror is recorded onto each SF lens.

[0075] Preferably, if the SF lens is a plano lens 10', the holographic mirror is recorded on the rear surface of the plano lens 10', as shown, for example, in Figure 1b. If the SF lens 10 is a lens having one finished surface and another surface that is finished to provide the desired optical power, the holographic component is recorded on the finished surface. In the example shown in Figure 1a, the holographic component can be recorded on the front surface, and then the rear surface can be finished.

[0076] Recording a holographic mirror in an SF lens involves depositing a thin film of holographic material F onto the surface where the holographic mirror needs to be recorded. Holographic materials are known in the art. Such materials include dichromated gelatin and photopolymers. Non-limiting examples of suitable photopolymers are sold by Polygrama under the trade name SM-TR™. In embodiments, the thin film can be formed between two walls and is enclosed between the walls. The two walls are then part of the SF lens.

[0077] The holographic material of the thin film F can be deposited by polymer jetting, spray coating, dip coating, or spin coating. The holographic material can be deposited over the entire front or rear surface of the SF lens 10 or only in specific areas, for example, by pad printing. In the case of dip coating, the holographic material is deposited on both major surfaces of the SF lens, and one of the thin films can be removed later during surface processing of the SF lens.

[0078] Next, recording of the holographic component involves exposing the thin film of holographic material F to sunlight while it is exposed in the holographic setup. Referring to Figures 4a-4c, recording of the holographic component is performed by generating interference between a reference beam RB and an illumination beam IB on the thin film of holographic material F. The two beams are from the same light source S, allowing for interference between the beams. The aperture, beam orientation, beam separation, source wavelength, and number of beams (at least two, but potentially more than two) define the optical function to be recorded. In particular, the spatial configuration of the reference beam reflects the spatial configuration (orientation, distance, width, i.e., shape and size of the zone projected onto the lens, etc.) that will be implemented to illuminate the mirror after the lens is fitted into the frame.

[0079] Light emitted by a light source S (typically a laser) is guided to the low birefringence material layer 11, for example, by an optical fiber, which may comprise a single mode fiber, preferably a polarization-maintaining (PM) single mode fiber, a large core area fiber, preferably a PM large core area fiber. A beam splitter is used to split the beam into a reference beam and an illumination beam.

[0080] One or more lenses selected from monofocal, bifocal, and multifocal lenses, such as progressive lenses, and optionally plane mirrors, may be used to shape the illumination and / or reference beams, for example, according to the configuration of the holographic component to be recorded. The shape of the illumination and / or reference beams can also be actively controlled, for example, using lenses with variable focal lengths or spatial light modulators (SLMs). In that case, the shape of the illumination and / or reference beams can be easily adapted to different bases and / or different diameters of the SM lens under consideration. This configuration takes into account, as explained above, at least the base curve of the SF lens on which the holographic component is recorded, the target refractive power of the lens obtained from the SF lens, the position of the holographic component, the prescription of the wearer, the function of the holographic component, data about the image source, including the type of image source, the optical and geometric configuration of the image source, the shape of the frame in which the lens is integrated, the characteristics of the lens, and in some cases, any pupil distance of the wearer.

[0081] An exemplary embodiment of holographic mirror recording is shown in Figures 4a-c. Figure 4a presents the setup used to record a plane mirror. In this case, the illumination beam IB is a reference transmitted beam that is reflected by a plane mirror M placed after the SF lens 10 with a thin film F.

[0082] Figure 4b shows the setup used for recording an off-axis plane mirror. In this case, the reference beam RB is a collimated beam, and the illumination beam IB is another collimated beam originating from an off-axis position corresponding to the position after the image source relative to the holographic mirror. This implementation is suitable for light sources that are SLMs (Spatial Light Modulators) or Light Field Displays (LFDs).

[0083] Figure 4c presents a setup for recording an off-axis curved mirror. In this case, the reference beam RB is collimated, and the illumination beam IB has the properties of, for example, a display or image source, and reaches the membrane F at the desired position, focus, and angle. This implementation is suitable for HMDs that include a screen as the image source and / or that require an optical conjugate between the pupil and the image source.

[0084] In one embodiment, as shown schematically in FIG. 5a, prior to recording the holographic mirror, an anti-reflection coating 15 is deposited on the surface of the SF lens 10 opposite the surface on which the holographic material F is deposited. The anti-reflection coating can be, for example, a quarter layer (also referred to as a λ / 4 layer) with a refractive index equal to the square root of the refractive index of the material of the SF lens. A detailed example of a quarter layer is disclosed in U.S. Pat. No. 7,008,690. This anti-reflection coating reduces the amount of reflection during recording and can therefore be removed after recording. In embodiments in which the surface opposite the HM is further textured, removal of the anti-reflection coating can be performed during the texture of this surface (FIG. 5b).

[0085] In another embodiment, an anti-reflection coating may also be deposited on a major surface of the SF lens prior to depositing the holographic material F on the same surface. If the material forming the SF lens has a high refractive index, this also reduces unwanted reflections during recording of the holographic component.

[0086] To obtain a set 1 of SF lenses 10, at least one SF lens is manufactured for each possible combination of the following parameters: - base curve, - each holographic component configuration per base curve, and - SF lens diameter, if applicable.

[0087] Final lens manufacturing Once the set 1 of SF lenses is obtained, it is possible to manufacture a lens 20 according to the wearer's data from one of the SF lenses of the set.

[0088] The first step is to select a set of SF lenses according to the wearer's data, including prescription, and characteristics related to fitting the frame, lenses and mirrors to the wearer, such as pupil distance, face shape, eye rotation center position, etc.

[0089] The selection is first made according to the wearer's prescription and therefore according to the target refractive power that the final lens must provide, and then according to the selected base curvature B of the SF lens 10. i If the wearer's refractive power is given by a progressive lens, the base curve selected is selected based on the distance vision refraction.

[0090] By way of non-limiting example, the base curves for Set 1 are those given above in Table 1. For a given wearer, the target refractive power to be achieved by the lenses worn by the wearer is 0.5D.

[0091] Therefore, the base curve B suitable for this refractive power i is a base curve B3 of +3.75D. Therefore, an SF lens with this base curve is selected.

[0092] In one embodiment, the SF lens selected has an appropriate diameter according to the frame size selected by the wearer.

[0093] In embodiments where there are at least two holographic component configurations H for a given base curve B, the step of selecting the SF lens further includes determining an appropriate HM configuration for the wearer. The HM configuration may be selected based on: - the wearer's pupil distance, - The type of image source that will be used to form the virtual image that must be reflected by the holographic mirror, its geometry and location.

[0094] Next, the method includes finishing the SF lens 10 to achieve the desired refractive power.

[0095] In embodiments in which the SF lens 10 has a finished surface (e.g., anterior surface 11) and an unfinished surface (e.g., posterior surface 12), this step involves finishing the unfinished surface to achieve the desired amount of refraction. As shown in Figures 6a and 6b, finishing can involve removing material from the unfinished surface so that the lens is thinner.

[0096] In embodiments where the SF lens is a plano lens, the plano lens incorporating HM 13 (FIG. 7a) can be assembled with an auxiliary lens 16 (FIG. 7b) shaped to provide the desired optical power.

[0097] The assembly of the plano lens 10 to the auxiliary lens 16 can be performed by adhesive bonding, additive manufacturing or a back-injection process. During this last type of process, the SF lens is placed in a mold and an injected material is provided to the rear surface of the SF lens to form the auxiliary lens.

[0098] A final lens 20 is obtained having one front surface 21 and one rear surface 22, one of which is formed by the initial front or rear surface of the SF lens, and the other is obtained during the finishing of the SF lens (either by surface processing of the other surface or by assembling an auxiliary lens 16).

[0099] The method may further comprise the additional step of coating at least the surfaces obtained during the finishing of the SF lens. The coating may be an abrasion-resistant coating (or hard coat) and / or an anti-reflective coating.

[0100] This step may also include coating both the front and back surfaces of the final lens 20. [Explanation of symbols]

[0101] 1 set 9 Head-mounted display device (HMD) 10 Semi-finished ophthalmic lenses 10' semi-finished lens 10' semi-finished lens 10'' semi-finished lens 11 Front 12 Rear 13 Holographic components, holographic mirrors 15 Anti-reflective coating 16 Auxiliary Lens 20 Eye lenses 20 Finished ophthalmic lenses 21 Front 22 Rear 91 frames 92 Image Source

Claims

1. A method for manufacturing a set of semi-finished ophthalmic lenses (10, 10'), each semi-finished ophthalmic lens (10, 10') intended to be used in the manufacture of a finished ophthalmic lens (20) of a predetermined target refractive power, said method comprising: - determining N target power ranges; For each determined target power range, a base curve (B) of a semi-finished product having a power within said target power range is determined. ｉ ) whereby the base curve is used in the manufacture of a finished ophthalmic lens having a refractive power within the determined target power range; - Each base curve (B ｉ ) determining a respective configuration of at least one holographic element (13) suitable to be recorded in a semi-finished ophthalmic lens having said base curve; - each determined base curve (B ｉ ), wherein the step of manufacturing each semi-finished ophthalmic lens includes a step of recording a holographic component (13) in the semi-finished ophthalmic lens, and each of the holographic components (13) has a base curve (B ｉ ), and each holographic component associated with a base curve is configured to best perform the optical function imparted to the holographic component at a central power of the target power range corresponding to the base curve; A method comprising:

2. 2. The method of claim 1, wherein the step of manufacturing the semi-finished ophthalmic lens (10, 10') comprises the step of providing an anti-reflection coating on at least one major surface of the semi-finished ophthalmic lens before the step of recording the holographic component (13).

3. 3. The method according to claim 1 or 2, comprising the step of manufacturing a plurality of semi-finished ophthalmic lenses (10, 10') having the same base curve but different diameters.

4. The method according to any one of claims 1 to 3, wherein each of the semi-finished ophthalmic lenses is made of a low birefringence material.

5. The holographic component is a holographic mirror intended to reflect a virtual image generated by an image source, and the step of determining at least one respective configuration of the holographic component (13) suitable to be recorded in a semi-finished ophthalmic lens having the base curve comprises: - at least two holographic mirror configurations (H) adapted to different ranges of the wearer's interpupillary distance; ｉ ); - at least two holographic mirror arrangements (H) adapted to different image sources that generate virtual images intended to be reflected by said holographic mirrors; ｉ ); or - at least two holographic mirror arrangements (H) adapted to reflect different wavelength ranges; ｉ ) The method of any one of claims 1 to 4, comprising the step of determining:

6. The number of base curves N is less than 10, and the method comprises: ｉ 6. The method of claim 1, comprising determining a number of configurations of less than five of each of the holographic components suitable for recording in a semi-finished ophthalmic lens having:

7. A method for manufacturing an ophthalmic lens (20) intended to be worn by a wearer, said ophthalmic lens having a target refractive power predetermined according to the wearer's visual acuity to be corrected, said method comprising: - selecting a semi-finished ophthalmic lens (10, 10') from the set manufactured according to the method of any one of claims 1 to 6, wherein said semi-finished ophthalmic lens (10, 10') has a base curve (B) corresponding to a target power range to which said predetermined target power belongs. ｉ selecting a semi-finished ophthalmic lens (10, 10'), the semi-finished ophthalmic lens (10, 10') being selected to have a - finishing said semi-finished ophthalmic lens (10) to achieve said predetermined target refractive power; A method comprising:

8. the semi-finished ophthalmic lens (10, 10') has a front surface (11) and a rear surface (12), and the holographic component (13) is formed on the front surface (11) or between the front surface (11) and the rear surface (12); and 8. The method of claim 7, wherein the finishing step comprises surfacing the posterior surface (12) of the semi-finished ophthalmic lens or assembling the semi-finished ophthalmic lens with an auxiliary lens (16), the refractive power of which is adapted such that the refractive power of a lens including the semi-finished ophthalmic lens and the auxiliary lens (16) corresponds to the predetermined target refractive power.

9. The step of selecting the semi-finished ophthalmic lens (10, 10') includes selecting the base curve (B ｉ holographic component configuration (H) of said semi-finished ophthalmic lens (10, 10') from among a plurality of configurations associated with ｉ 9. The method of claim 7 or 8, further comprising the step of selecting:

10. The holographic component is a holographic mirror intended to reflect a virtual image generated by an image source, and the holographic component arrangement (H ｉ ) are selected as follows: - the wearer's interpupillary distance, - the wearer's prescription, data relating to said image source, including its type, its optical and geometric configuration, the shape of the frame into which the finished ophthalmic lens obtained from said semi-finished ophthalmic lens will be integrated, and - Lens characteristics, and - the optical functions and properties to be recorded on said holographic mirror, The method of claim 9 , wherein the method is performed according to at least one of the following:

11. The holographic mirror is intended to provide an optical conjugate between the image source and the user's pupil, and the holographic component arrangement (H ｉ 11. The method of claim 10, wherein the step of selecting a distance (mm) is performed according to the interpupillary distance of the wearer.

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