A color filter for modifying human color vision and a method of designing such a color filter

Abstract

The invention relates to a filter (10) for modifying human color vision, having a spectral transmission function in the visible range, wherein the average transmission in a wavelength range of at least 20 nm width below 530 nm is at least twice the average transmission in a second wavelength range between 530 and 580 nm, and the average transmission in a wavelength range of at least 20 nm width above 580 nm is at least twice the average transmission in the second wavelength range. The invention comprises a dyed carrier lens (12) and an interference filter (14) arranged thereon, the transmission function of the dyed carrier lens (12) and the transmission function of the filter (10) having the following relationship in the second wavelength range: T sd (λ) < 1 - V(λ) · (1 - T(λ)) · n, wherein T(λ): is the transmission function of the filter (10), T sd (λ): is the transmission function of the dyed carrier lens (12), V(λ): is the sensitivity function of the human eye normalized to 1, n ≥ 0.3. The invention also relates to a method for designing such a filter (10).

Description

Technical Field

[0001] The present invention relates to a color filter for modifying human color vision and a method for designing such a color filter. Background Technology

[0002] Some receptors located in the retina (cones that provide daylight vision) are classified into three categories based on their spectral sensitivity. L-cones are primarily sensitive to the long wavelengths (red) of the spectrum. M-cones are sensitive to the medium wavelengths (green) of the spectrum, and S-cones are sensitive to the short wavelengths (blue) of the spectrum. Color vision is generated by comparing the relative values ​​of stimuli transmitted by L, M, and S color receptors.

[0003] Color vision deficiency is caused by the spectral sensitivity curve deviating more or less from the spectral sensitivity curve of people with normal color vision. Therefore, the most common forms of color blindness are red weakness (protanomaly), red blindness (protanopia), green weakness (deuteranomaly), and green blindness (deuteranopia).

[0004] In cases of red weakness, color vision problems arise because the spectral sensitivity of the L-cone is closer to that of the M-cone than in individuals with normal color vision. As a result, the difference between stimuli from the L-cone and M-cone decreases due to the influence of a given external stimulus, leading to a decline in the ability to distinguish colors. In extreme cases, the spectral sensitivity of the L-cone shifts so much that it coincides with the sensitivity curve of the M-cone—this is known as red weakness.

[0005] In cases of green weakness, the spectral sensitivity of the M-cone is closer to that of the L-cone than in individuals with normal color vision. The result is similar to the previous observation: the difference between stimuli from L-cones and M-cones decreases, meaning that the ability to distinguish colors is also reduced in this situation. Green weakness occurs when the sensitivity curve of the M-cone shifts so significantly that it coincides with the sensitivity curve of the L-cone.

[0006] Even now, color vision deficiency is considered an incurable condition because it has a genetic cause; in other words, the sensitive function of the receptors cannot be altered. However, efforts have not aimed to improve the sensitivity of the receptors, but rather to try to change the spectrum of incident light in order to improve color vision, even though the receptor sensitivity is shifted.

[0007] US5774202 proposes a solution that allows for spectral shift of the effective or virtual sensitivity of the receptor in the appropriate direction by using a properly designed color filter.

[0008] Existing color filter design methods exist, which can be used to design the spectral transmission function of color filters for certain types of color vision deficiencies, or even solely for color vision correction, and for manufacturing appropriate color filters. Note that color filters can be used not only to correct the color vision of people with color vision deficiencies, but also to modify the color vision of people with normal color vision. For example, when using certain dashboards or control panels, being able to identify the colors of LED lights or other LED displays on them may be important. The same objective applies, for example, to signal colors used in rail, air, and water transportation. In the case of displays used for entertainment purposes to ensure a better visual experience, there is also a need to better distinguish colors while maintaining color recognition.

[0009] Patent application PCT / HU2020 / 050043 discloses a design method for designing color vision modification filters for different purposes for people with color vision deficiencies and people with normal color vision. The result of this and similar design methods is typically a spectral transmittance function, which, as a function of wavelength, specifies the degree to which the filter to be produced should transmit visible light.

[0010] When manufacturing color filters for eyeglasses, the transmittance of the carrier lens is modified to match the spectral transmittance function obtained through a design method. Typically, the starting point is a carrier lens with a constant spectral transmittance function, i.e., wavelength-independent and usually close to 1, i.e., a colorless and transparent carrier lens. This constant transmittance (typically 1) must be reduced according to the designed transmittance profile to produce, for example, the desired passband and stopband. There are generally two techniques for this.

[0011] One known technique is to coat a carrier lens that forms the basis of a color filter with a dye that has absorption properties and absorbs light within a specific wavelength range, with the aim of altering color perception within that wavelength range.

[0012] Another known technique involves creating a system of thin optical layers on the surface of a carrier lens, which ensures, through interference, that the spectral transmission of the carrier lens is reduced as much as possible within the desired wavelength range. This interference is achieved by alternating thin layers of material of varying thicknesses, with smaller and larger refractive indices, on top of each other.

[0013] However, both technologies have their drawbacks.

[0014] The spectral transmission functions of color filters designed to correct color vision deficiencies or meet other special needs are typically complex, multi-band functions, for example, including multiple passbands and stopbands. On the other hand, dyes are natural or synthetic materials whose absorption properties are essentially determined by their chemical composition, thus they cannot be customized for the desired transmission properties. Most dyes have broad absorption bands, making them inherently unsuitable as stopbands in narrow wavelength ranges. In the context of this invention, a broad absorption band dye is defined as a dye having a full width at half maximum (FWHM) greater than 40 nm around its absorption peak, preferably greater than 50 nm, more preferably greater than 60 nm. Although narrow absorption band dyes with an FWHM of 40 nm or less near their absorption peaks exist, their use is similarly limited because the narrow absorption band characteristics of dyes cannot be shifted along wavelength; therefore, even combinations of dyes cannot provide the desired stopband in an arbitrary wavelength range.

[0015] Due to the aforementioned limitations of dyeing techniques, color filters with multi-band spectral transmittance functions are produced using thin-layer techniques. Because of the alternation of thin layers with low and high refractive indices, reflection occurs at the layer boundaries, making such interference filters more or less reflective. The problem becomes more severe when achieving complex spectral transmittance functions with many steep steps, as precise tracking of such functions may require depositing large numbers of thin layers, up to 40-100, resulting in numerous layer boundaries and thus significant reflection. This reflection is undesirable in eyeglasses intended for normal wear, as it diminishes or completely eliminates the possibility of eye contact. Numerous studies have shown that eye contact plays a crucial role in interpersonal communication. Eye contact is particularly important for building trust, and therefore, colorblind individuals forced to wear highly reflective glasses may be at a disadvantage in both professional and personal lives. Reflections can also occur on the other side of the eyeglass, causing the user to see a blurred reflection of their own eye—a shadowy, visually disruptive phenomenon.

[0016] Despite attempts to combine these two techniques, no significant benefits have been observed to date. The transmission curves of dyes with broad absorption bands exhibit a wide U-shaped region with low steepness. Starting with such a transmission curve in the thin-layer design process, it remains equally difficult to create a complex transmission curve with many steep steps obtained from the design process, and creating such a complex transmission curve still requires a large number of thin layers. In this case, the original problem persists, and dyeing inevitably complicates the manufacturing process. Dyes with narrow absorption bands are typically used if the desired transmission function happens to have an absorption band within the same narrow wavelength band, but this is unrealistic in most cases. Furthermore, if the narrow absorption band of the dye falls within a broad stopband, the shape of the desired transmission function altered by the dye becomes even more complex by adding one or two steep steps depending on the position of the dye's absorption band, which is also undesirable. Summary of the Invention

[0017] The present invention aims to provide a color filter for modifying color vision that avoids the drawbacks of prior art solutions. In particular, the object of the present invention is to provide a color filter for reducing scattered reflections in cases where the color filter has a complex multi-band transmission function typically used for specific needs.

[0018] Another object of the present invention is to provide a method for manufacturing such a color filter.

[0019] The inventors of this invention have recognized that, despite the aforementioned problems, pre-dyeing the carrier lens with dyes or combinations of dyes of appropriate properties has unexpected advantages when the color filter is designed to correct color vision deficiencies. The inventors have also recognized that reflections are particularly concerning at wavelengths with high V-λ function values, which determine the human eye's photosensitivity to light. The V-λ function (visual brightness function) is roughly bell-shaped, ranging from 0 to 1, with a peak at approximately 555 nm. The V-λ function is as follows... Figure 1 As shown.

[0020] The inventors recognized that if the spectral transmittance function of a color filter obtained through the color filter design method is low near the maximum value of the V-λ function, i.e., the stopband is located there, then at least partially blocking should be achieved by using an absorbing dye instead of an interference layer. Absorbing dyes reduce transmission by absorbing light, while interference filters reduce most of the transmission by reflecting light. Therefore, to achieve the required reduction in transmittance to achieve the designed transmittance function, it is preferable to use a dye at least near the maximum value of the V-λ function, so that the interference filter can have higher transmittance, i.e., less reflection, in that wavelength range. The inventors also recognized that since the reflection becomes more interfering the closer the wavelength of the reflected light is to 555 nm, it is desirable to use a dye that participates more in reducing transmission the closer the wavelength is to 555 nm.

[0021] In view of the above findings, the object of the present invention is achieved by the color filter according to claim 1 and the color filter glasses according to claim 16.

[0022] The present invention also relates to a method for designing such a color filter according to claim 19.

[0023] Preferred embodiments of the invention are defined in the dependent claims.

[0024] Further details of the invention will now be described with reference to the accompanying drawings. Attached Figure Description

[0025] Figure 1 It is a graph of the V-λ function of the human eye.

[0026] Figure 2a This is a schematic diagram of the structure of an exemplary color filter according to the present invention.

[0027] Figure 2b This is a schematic diagram of the structure of another exemplary color filter according to the present invention.

[0028] Figure 2c This is a schematic diagram of an exemplary color filter including a clip-on lens according to the present invention.

[0029] Figure 2d This is a schematic diagram of an exemplary color filter including another clip-on lens according to the present invention.

[0030] Figure 3a The graph simultaneously shows the spectral transmission function of an exemplary color filter according to the present invention, the spectral transmission function of the dyeing carrier lens used in the color filter, the V-λ function, and the boundary function according to the present invention.

[0031] Figure 3b It also shows the materials used in manufacturing. Figure 3a The graphs of the target spectral transmission function of the color filter, the spectral transmission function of the dyeing carrier lens used for the color filter, the V-λ function, and the boundary function according to the present invention.

[0032] Figure 4a It is a graph showing the spectral transmission function of another exemplary color filter according to the invention, the spectral transmission function of the dyeing carrier lens used in the color filter, the V-λ function, and the boundary function according to the invention.

[0033] Figure 4b It also shows the materials used in manufacturing. Figure 4a The graphs of the target spectral transmission function of the color filter, the spectral transmission function of the dyeing carrier lens used for the color filter, the V-λ function, and the boundary function according to the present invention.

[0034] Figure 5 This is a graph showing the transmission function of a dyeing carrier lens containing different concentrations of the same dye.

[0035] Figure 6 This is a schematic flowchart illustrating an exemplary embodiment of the manufacturing method according to the present invention.

[0036] Figure 7 Transmission curves of exemplary commercially available dyes are shown. Detailed Implementation

[0037] Figure 2a A schematic diagram of an exemplary color filter 10 according to the present invention is shown. This diagram is not drawn to scale, so the relative thickness of each layer and other dimensions (height, curvature) of the color filter 10 are not related in the diagram and are merely illustrative.

[0038] The color filter 10 is designed to alter human color perception. This is achieved through a combination of a stained carrier lens 12 forming part of the color filter 10 and an interference filter 14 formed as a thin-layer system on one side of the carrier lens 12. This does not preclude the possibility of other layers existing between the stained carrier lens 12 and the interference filter 14, which will be discussed later. The carrier lens 12 can be refractive or non-refractive. In this example, the stained carrier lens 12 is stained using a thermal diffusion process, such that the dye has diffused to a depth of several micrometers in both surface layers on either side of the carrier lens 12. Figure 2a In the figure, the surface layer containing the dye is indicated by reference numeral 12a. Another embodiment is conceivable in which the material of the carrier lens 12 is dyed such that the dye is mixed with the material used to form the carrier lens 12 before manufacturing the carrier lens 12, thereby dyeing all the material of the carrier lens 12. Such a dyed carrier lens 12 is also referred to as a lens made of dyed material. The carrier lens 12 made of dyed material is preferably used to manufacture color filters with no refractive power or low refractive power (preferably less than 1 diopter), because if the carrier lens 12 made of dyed material is polished into a lens with higher refractive power, the spectral transmission function of the carrier lens 12 made of dyed material with variable thickness will differ at the center of the lens and at the edge of the lens.

[0039] Preferably, a varnish layer 16 is provided between the carrier lens 12 and the interference filter 14 to smooth the surface beneath the interference filter 14 for more viscous applications in thin-layer systems.

[0040] In this embodiment, an additional functional layer 18 is provided. This functional layer 18 may be, for example, a scratch-resistant layer, an anti-reflective layer, a vapor barrier layer, a fingerprint-resistant layer, a dirt-resistant layer, and a UV filter layer.

[0041] In the present case, two functional layers 18 are shown on the side of the interference filter 14 opposite to the carrier lens 12, but of course there can be more or fewer functional layers 18, and they can be located elsewhere in any conventional manner, such as on another surface of the color filter 10, or on both surfaces, or inside the color filter 10 between two other layers.

[0042] In this embodiment, the absorption layer 19 is formed on the inner side of the carrier lens 12 (i.e., the side intended to face the user's eye 8, as schematically shown), and is itself a functional layer, but has a separate reference numeral due to its special function. The absorption layer 19 may also be formed on the side of the carrier lens 12 facing the interference filter, in which case the varnish layer 16 is preferably placed between the absorption layer 19 and the interference filter 14. Alternatively, other functional layers 18 may be inserted between the varnished carrier lens 12 and the interference filter 14.

[0043] The absorption layer 19 exhibits substantially uniform absorption characteristics across the entire visible light range, or only above at least 440 nm, ensuring that it does not affect color perception or only affects blue and violet. The absorption layer 19 prevents interfering reflections of light from the eye socket from the interference filter 14 back to the eye, because light reflected from the eye socket and then back from the interference filter 14 must pass through the absorption layer 19 twice, and therefore is absorbed to a significantly greater extent than light from the outside. This reduces interference effects (e.g., reflections from the user's eye) on the image reflected from the inner surface of the color filter 10, because light passing through the outer surface of the color filter 10 passes through the absorption layer 19 with relatively high intensity, thus suppressing reflected images more effectively. Clearly, the use of the absorption layer 19 is not necessary but beneficial, as is the use of the other functional layers 18.

[0044] Figure 2b The illustrated embodiments and Figure 2a The difference in the illustrated embodiment is that the carrier lens 12 is configured such that the color-modifying dye is applied as a separate dye layer 13 to one side of the carrier lens 12, in this case, the side facing the interference filter 14. Of course, it is also conceivable to apply the dye layer 13 to the other side or both sides of the carrier lens 12 to form a stained carrier lens 12. In this case, the use of the varnish layer 16 is also preferred. Therefore, if the dye forms an additional dye layer 13 and is applied to the side of the carrier lens 12 facing the interference filter 14, the varnish layer 16 is preferably applied on top of the dye layer 13.

[0045] Figure 2c The illustrated embodiments and Figure 2a The difference in the illustrated embodiment is that the interference filter 14 is formed on the second carrier lens 12', which is placed in front of the first carrier lens 12, thereby forming the color filter 10. The second carrier lens 12' is preferably substantially colorless and transparent in the visible light range, so that its influence on color perception does not need to be considered separately in the design of the interference filter 14, which will be discussed in detail below.

[0046] In this embodiment, the varnish layer 16 is preferably applied to the surface of the second carrier lens 12' below the interference filter 14, and again serves to smooth the surface below the interference filter 14 for better adhesion of the thin-layer system.

[0047] Similar to the first carrier lens 12, a functional layer 18 can also be formed on the second carrier lens 12'. In this embodiment, one functional layer 18 is disposed on the surface of the first carrier lens 12 further away from the eye, and two functional layers 18 are disposed on the outer surface of the interference filter 14 on the side of the second carrier lens 12' further away from the eye. However, more or fewer functional layers 18 can of course be disposed at these locations or other places on the carrier lenses 12, 12'.

[0048] According to this embodiment, the absorption layer 19 is disposed on the side of the first carrier lens 12 closer to the eye 8, but can be positioned anywhere else, as long as it is positioned between the interference filter 14 and the eye 8 when the color filter 10 is worn as intended. For example, the absorption layer 19 can be formed on the side of the second carrier lens 12' opposite to the interference filter 14.

[0049] Preferably, the first carrier lens 12 forms the lens of the eyeglasses, while the second carrier lens 12', provided with the interference filter 14, is designed as a clip-on lens for the eyeglasses. A clip-on lens refers to a lens equipped with any known attachment system for attaching to eyeglasses, such as a fastener, hook, or magnetic fastening system. The advantage of using clip-on lenses is that eyeglasses including the tinted carrier lens 12 can be used alone, even by people with normal color vision, for refractive correction, blue light and / or UV filtering, color enhancement, and / or color modification, while the clip-on lens can be used for color vision correction.

[0050] According to another preferred embodiment, the stained carrier lens 12 (e.g., equipped with an interference filter 14) is provided with an interference filter 14. Figure 2a and 2b It is configured as a clip-on lens, which allows it to be easily attached to regular eyeglasses, such as refractive glasses, by people with color vision deficiencies.

[0051] Figure 2d It corresponds to Figure 2b The illustrated embodiment is a clip-on lens system. In this case, the interference filter 14 is formed on the second carrier lens 12', while the first carrier lens 12 is provided with a dye layer 13.

[0052] Figure 3a This illustrates the spectral transmission function (T(λ)) of the first exemplary color filter 10 according to the present invention, and the spectral transmission function (T0) of the pre-dyed carrier lens 12 used in the color filter 10. sd The graphs of V(λ)) and the V-λ function (V(λ)) normalized to 1. Figure 3a The example color filter in the image is used to correct weak green.

[0053] Figure 4a This illustrates the spectral transmission function (T(λ)) of the second exemplary color filter 10 according to the present invention, and the spectral transmission function (T0) of the pre-dyed carrier lens 12 used in the color filter 10. sd The graphs of (λ) and the V-λ function (V(λ)). Figure 4a The example color filter in the image is used to correct moderate red weakness.

[0054] The color filter 10 according to the invention has a spectral transmittance function T(λ) in the visible light range such that the average transmittance over a wavelength range at least 20 nm wide below 530 nm is at least twice the average transmittance over a second wavelength range between 530 and 580 nm, and the average transmittance over a wavelength range at least 20 nm wide above 580 nm is at least twice the average transmittance over the second wavelength range. Note that the boundaries of the at least 20 nm wide range below 530 nm and the at least 20 nm wide range above 580 nm do not necessarily have to be 530 nm and 580 nm, respectively. The upper limit of one of the 20 nm or wider wavelength bands may be below 530 nm, while the lower limit of the other 20 nm or wider wavelength band may be above 580 nm. In practice, this means that the spectral transmittance function T(λ) of the color filter 10 has a lower transmittance somewhere between 530 nm and 580 nm, while there is at least one peak in the transmittance below and above that wavelength, where the color filter 10 has a significantly higher transmittance. On the one hand, this is a characteristic of color filters that correct color vision deficiencies, because the maximum positions of the sensitivity functions of the L-cones and M-cones are offset from each other somewhere in the second wavelength range, thus such color filters reduce transmittance in this second wavelength range. On the other hand, the V-λ function value is also most important in this second wavelength range, so it is particularly important to reduce transmittance as much as possible with absorbing dyes in this wavelength range.

[0055] Therefore, according to the color filter 10 of the present invention, the transmission function T of the dye carrier lens 12 is such that, in the second wavelength range, the transmission function T of the dye carrier lens 12 is... sd The following relationship exists between (λ) and the transmission function T(λ) of color filter 10:

[0056] T sd (λ)<1-V(λ)·(1-T(λ))·n (1)

[0057] Wherein, n ≥ 0.3, preferably n ≥ 0.4, and more preferably n ≥ 0.5. The higher the value of n, the smaller the number on the right side of the inequality, and therefore the smaller the allowable transmission of the carrier lens 12, thus the greater the contribution of the carrier lens 12 to the total reduction in transmission. By including V(λ) as a multiplier on the right side, it is ensured that as the wavelength approaches the maximum value of V(λ), the stained carrier lens 12 needs to play an increasingly larger role in the reduction of transmission.

[0058] The expression on the right side of the inequality is called the boundary function. The boundary function related to the multiplier n is denoted by h. n (λ) represents:

[0059] h n (λ)=1-V(λ)·(1-T(λ))·n (2)

[0060] Therefore, relation (1) can be written in the following form:

[0061] T sd (λ) <h n (λ) (3).

[0062] It should be noted that the transmission function of the dyed carrier lens 12 can be written as the product of the transmission function of the undyed carrier lens 12 and the applied dye. However, it is more appropriate to discuss the transmission of the dyed carrier lens 12 because the reduction in transmission caused by the dye depends on the amount of dye used. The transmission characteristics of the dye do not change, i.e., at which wavelengths it absorbs more light and at which wavelengths it transmits more light, but the absorptivity and the reduction in transmission depend on the amount of dye molecules absorbed in the optical path. Figure 5 It shows in Figure 3a and 4a The transmission curve of the initial colorless transparent carrier lens 12 used in the color filter 10 is shown. This carrier lens 12 is dyed with the same dye but after different dyeing times. It can be clearly seen that the properties do not change, but the longer the dyeing time, the deeper the transmission curve and the greater the reduction in transmission. Figure 5 The staining time that resulted in the curve with the highest spectral transmittance was 5 minutes, while the lowest spectral transmittance was obtained at a staining time of 60 minutes.

[0063] exist Figure 3a and 4a In the figure, the boundary function h when n = 0.4 is plotted. n (λ). It can be seen that, in both examples, the transmission function T of the stained carrier lens 12... sd (λ) satisfies relation (3) not only in the second wavelength range but also throughout the entire visible light range. This also shows that relations (1) and (3) are valid in a wider wavelength range, which further contributes to the positive effect recognized by the inventors, namely, the elimination of interference reflections. Preferably, relation (1) exists between at least 500 and 600 nm, more preferably between at least 480 and 650 nm.

[0064] If a colorless and transparent lens is used as the carrier lens 12, that is, it transmits almost completely across the entire visible light range (T s For a lens with (λ)≈1), then the spectral transmission function T of the dyed carrier lens 12 is... sd (λ) is based on the spectral transmission function T of the dye used. d (λ) (or, in the case of multiple dyes, their combined transmission function T) d (λ) is the same, which of course depends on the concentration of the dye as described above. If the carrier lens 12 itself reduces transmission, that is, it has a spectral transmission function T that is not constant 1. s(λ), then the spectral transmission function T of the dyed carrier lens 12 sd (λ) Transmission function T of the undyed carrier lens 12 s (λ) and the transmission function T of the dye d The product of (λ) is determined. If a separate second carrier lens 12' is used, then the spectral transmission function T of the stained carrier lens 12 is... sd (λ) is understood to include the transmission function of the second carrier lens 12', that is, in this case, the spectral transmission function T of the stained carrier lens 12. sd (λ) is the product of the transmission function of the undyed carrier lens 12, the transmission function of the second carrier lens 12', and the transmission function of the dye used. However, it is preferable to also use a colorless and transparent lens as the second carrier lens 12', that is, a lens that transmits essentially completely across the entire visible light range, so that the transmission function of the second carrier lens 12' is also essentially a constant 1 and does not need to be considered.

[0065] Preferably, the carrier lens is pre-dyed with at least one broad absorption band dye having a wide bandwidth (FWHM) greater than 40 nm near its absorption peak, but preferably greater than 50 nm, more preferably greater than 60 nm. Figure 3a In this process, the initial colorless and transparent carrier lens 12, pre-dyed with this wide absorption band dye, forms the basis of the color filter 10. Therefore, Figure 3a The transmission function T in sd (λ) Transmission function T of the basic dye d (λ) are the same. Figure 3a and 4a The transmission function T shown sd (λ) corresponds to the transmission function of the exemplary dye. This dye has been shown to be particularly suitable for producing color filters 10 for correcting color vision deficiencies. It has been found that for weak green (λ) Figure 3a ) and red weak ( Figure 4a The color filter 10 is positioned in a low-transmittance region of the visible light range, which is very suitable for reducing reflection compared to a color filter that reduces transmittance by using an interference filter alone.

[0066] Embodiments in which the carrier lens is dyed with at least two dyes are also conceivable. Preferably, at least one of these dyes also has a broad absorption band. It is possible that the desired transmission curve has a narrow blocking band at the location of the minimum absorption of the narrow absorption band dye; in this case, it is desirable to use such a narrow absorption band dye, in addition to the broad absorption band dye, to produce the narrow blocking band. During the dyeing process, the different dyes can be pre-mixed or applied sequentially to the carrier lens 12.

[0067] exist Figure 3a and 4aIn the example shown, the shape of the spectral transmittance function T(λ) of filter 10 results in higher transmittance in certain wavelength ranges and lower transmittance in the wavelength ranges separating them. The wavelength ranges with higher transmittance are generally referred to as the passband, denoted by the letter P in the figure, while the wavelength ranges with lower transmittance that separate them are generally referred to as the stopband, denoted by the letter S in the figure. Obviously, the P passband does not necessarily allow for maximum transmittance (corresponding to a transmittance value of 1), just as the S stopband does not need to be completely blocked (corresponding to a transmittance value of 0).

[0068] The boundaries of the passband are typically defined by the Free Wavelength Limiting Wavelength (FWHM). The lower and upper limits of the FWHM are defined by the two wavelengths at which the transmittance reaches half of the maximum transmittance within the passband. Therefore, the FWHM is the difference between the upper and lower limits. The center wavelength is the lower limit plus half the FWHM. In the context of this invention, the passband is considered to lie between the two limiting wavelengths; that is, the boundary of the passband is where the transmittance is halved relative to the maximum value within the passband.

[0069] Since the passband is limited by the lower and upper wavelengths defining the FWHM, it is reasonable to assume that adjacent stopbands begin from here. For this reason, on the one hand, transmission at one boundary of a stopband may differ significantly from that at another; on the other hand, transmission at the boundary may still be quite large. Note that the passband sandwiched between two stopbands will always "protrude" from the adjacent stopband, because the band boundaries are defined by the FWHM, thus the maximum transmission value of the passband must necessarily be at least twice the minimum transmission value of the adjacent stopband.

[0070] It is clear that the condition that the average transmittance in a first wavelength range (at least 20 nm wide) below 530 nm and a third wavelength range (at least 20 nm wide) above 580 nm is at least twice the average transmittance in a second wavelength range between 530 and 580 nm can also be formulated such that the spectral transmittance function of the color filter 10 includes at least two passbands P and a stopband S separating them, said stopband S at least partially overlapping the second wavelength range. The color filter 10 according to the invention is particularly useful when the average transmittance of the stopband above at least 20 nm in the overlapping range is less than 20%, preferably less than 10%, as shown below. Figure 3a As illustrated in the embodiment, for this color filter 10, a very significant reduction in transmittance should be achieved in the wavelength range where the V(λ) function value is also the largest. In this case, the hybrid technique according to the invention, namely the combined use of the absorbing dye and the interference filter 14, results in a particularly large improvement in reflection reduction.

[0071] For a multi-band T(λ) transmission function, the stained carrier lens 12 and the interference filter 14 together provide at least two passbands P and a stopband S in between.

[0072] In the following text, see references Figure 6Flowcharts and Figure 3b and 4b The curves in the graphs are used to describe the design, such as Figure 3a and 4a The method of color filter 10 with spectral transmission function T(λ) is shown. Figure 3b Involving Figure 3a The production of the exemplary color filter 10 shown for weak green correction, while Figure 4b Involving Figure 4a The production of the exemplary color filter 10 shown for weak red correction.

[0073] The color filter for modifying color perception is generated starting from the spectral transmission target function provided in step S10. This can be based on a design curve defined by a theoretical model, such as that described in patent application PCT / HU2020 / 050043. Another possibility is to start with an existing (e.g., a known and well-performing) color filter, where an interference filter is used to modify color perception; however, to reduce reflection, it is desirable to partially create the spectral transmission function of the existing color filter using absorbing dyes. In the latter case, the spectral transmission function of the existing color filter is used as the target function.

[0074] Based on the objective function, determine a design boundary function similar to the boundary function described above:

[0075] h n * (λ)=1-V(λ)·(1-T0(λ))·n (4)

[0076] in,

[0077] T0(λ): is the objective function.

[0078] V(λ): is the V-λ curve of the human eye.

[0079] n≥0.3.

[0080] In step S14, an undyed carrier lens 12 and at least one dye are selected such that their combined transmission function T sd (λ) (when the carrier lens 12 is stained with at least one dye) is less than the design boundary function:

[0081] T sd (λ) <h n * (λ) (5)

[0082] Preferably, an initially transparent and colorless carrier lens 12 is selected, such that the transmission function T sd The properties of (λ) are determined by one or more dyes to be used. In this case, at least one dye must be selected such that its properties conform to the design boundary function h. n* The shape of (λ). For example, combining... Figure 5 The absolute value of transmission (i.e., how much transmission should be reduced) can be set by adjusting the concentration of at least one dye having given characteristics. Many commercially available dyes have transmission characteristics that can be obtained from the manufacturer or easily measured using a spectrophotometer (e.g., colorless transparent carriers dyed with dyes at the manufacturer's recommended concentration).

[0083] Typically, dye packages containing multiple dyes are available (this can include commercially available dyes for dyeing carrier lenses, mixtures of multiple dyes made from elemental dyes, and dyes obtained by other means). Based on the transmission characteristics of available dyes measured from or selected from the manufacturer's catalog, one best suited to the target function shape can be selected, and it can be determined that when applied to carrier lens 12, at least in the second wavelength range, the resulting transmission remains below the design boundary function h. n * The concentration of (λ). Empirically, such dyes can even be found in commercially available dyes when the objective function of the color filter used for color vision defect correction has a stopband S that at least partially overlaps with the second wavelength range, and at least one passband P to its right and at least one passband P to its left. Figure 7 The diagram illustrates several exemplary commercially available absorbing dyes, which, based on their properties, may be suitable for manufacturing a color filter 10 having a stop band S that at least partially overlaps with the second wavelength band and at least one pass band P around the second wavelength band. Preferably, in selecting the dye and concentration, care is taken to ensure that the absorption caused by the dye does not cause the transmittance to be significantly lower than the target function. To this end, the carrier lens and at least one dye are selected such that the transmittance function T of the dyed carrier lens is... sd (λ) satisfies the following relationship in the visible light wavelength range:

[0084] T0(λ)*m≤T sd (λ) (6)

[0085] in,

[0086]

[0087] Note that although the selection of at least one dye is significantly simpler if a transparent, colorless carrier lens 12 is used, and the transparent, colorless carrier lens 12 does not need to be considered when selecting the desired transmission characteristics, the complexity of dye selection for carrier lenses 12 with different transmittances does not exceed the level of conventional work. It is known that the transmission of the dye and the undyed carrier lens 12 are multiplied in the dyed carrier lens 12. It should also be noted that the task is greatly simplified in the case of a non-transparent carrier lens 12 with approximately constant transmittance (colorless), because such a carrier lens 12 has no significant effect on the transmission characteristics required by the shape of the objective function (i.e., where absorption should be high and where absorption should be low). In this case, observing the transmission characteristics of the dye is sufficient.

[0088] After selecting the carrier lens 12 and at least one dye, in step S16, the dye is used to produce a dyed carrier lens 12. In a preferred embodiment, a thermal diffusion technique is used to dye the carrier lens with at least one dye.

[0089] The thermal diffusion dyeing process is well known to those skilled in the art, and therefore will only be described briefly here. The dye is diluted in water, preferably to the concentration recommended by the dye manufacturer. The resulting suspension is heated to a high temperature (typically above 90°C) in a heatable bath, and then the undyed carrier lens 12 is immersed in the hot dye suspension. The high temperature causes the dye particles to diffuse from the suspension into the material of the carrier lens 12, typically to a depth of 1-10 μm. After the desired dye concentration is reached, the carrier lens 12 is removed from the bath. As is well known to those skilled in the art, the concentration of dye produced in the carrier lens 12 depends on the concentration of dye in the suspension, as well as the temperature and dyeing time used. After dyeing, the dyed carrier lens 12 is washed and dried in a conventional manner.

[0090] In another preferred embodiment, the dyed carrier lens 12 is made by applying a layer of at least one dye to one or both surfaces of the carrier lens.

[0091] In another preferred embodiment, the dyed carrier lens 12 is produced by dyeing the material of the carrier lens 12 with at least one dye, and then producing the carrier lens 12 from the dyed material. This dyeing method is preferably used only for non-refractive color filters 10 or color filters 10 with a diopter of less than 1.

[0092] Preferably, in step S18, the dyeing carrier lens 12 is coated with a thin layer of paint 16 on one or both sides. This can also be accomplished in known painting equipment by dip coating or spin coating.

[0093] After painting, the carrier lens 12 is dried in step S19, preferably at a high temperature, such as in a drying oven known per se. Due to the high temperature, the solvent present in the paint during the painting process evaporates rapidly, thereby hardening the paint.

[0094] Then, the interference filter 14 is formed as an optical thin-film system on the dried varnish layer 16. For this purpose, in step S20, the transmission function T from the stained carrier lens 12 is... sd Starting with (λ), we design an optical thin-film system corresponding to the objective function. Several known design algorithms can be used to design optical thin-film structures, such as the optical thin-film design software called FilmStar, where T... sd The transmission function T0(λ) can be specified as the initial function, while the transmission function T0(λ) can be specified as the target function to be achieved. The materials that can be formed for each thin layer are also specified. This typically involves using at least one material with a low refractive index and at least one material with a high refractive index.

[0095] In step S22, an interference filter 14 is created on the carrier lens 12 by creating a designed optical thin-film system. For example, the interference filter 14 can be formed by vacuum evaporation, wherein the stained carrier lens 12 is placed in a vacuum chamber and different materials are evaporated onto the lens surface using an electron beam. The thin film produced by the vapor deposition process forms the interference filter 14.

[0096] If the interference filter 14 is placed on a separate clip-on lens, the interference filter 14 is created on the second carrier lens 12', as described above.

[0097] Preferably, the optional functional layer 18 (e.g., scratch-resistant layer, anti-reflective layer, anti-fog layer, anti-fingerprint layer, anti-fog layer, UV filter layer, etc.) is then formed in step S24 in a manner known per se.

[0098] Preferably, the absorption layer 19 is formed as a functional layer 18 on the side of the carrier lens 12 opposite to the interference filter 14. In a preferred embodiment, the absorption layer 19 is formed by applying a dye that absorbs substantially uniformly in the visible light range, thereby forming an absorbing dye layer on the side of the carrier lens 12 opposite to the interference filter 14. In this case, the dye of the absorption layer 19 can be ignored in the design of the interference filter 14 because it does not change the transmission characteristics but uniformly reduces transmission throughout the visible light range. However, if an absorbing dye is used in the absorption layer 19 having a non-constant transmission function, this effect is preferably considered in the design of the thin layer, for example, by treating it as part of the dyed carrier lens 12. In another preferred embodiment, the absorption layer 19 is produced by a vacuum phase deposition technique, for example, by vapor deposition of chromium as the absorption layer 19. In this case, the chromium layer is preferably formed on the side of the dyed carrier lens 12 opposite to the interference filter 14.

[0099] The design of the absorption layer 19 can precede the creation of the interference filter 14.

[0100] Optionally, if a second carrier lens 12' is used, one or more functional layers 18 including the absorption layer 19 may be formed on the second carrier lens 12', on the side of the second carrier lens 12' opposite to the interference filter 14, as described in step S24 above.

[0101] In step S26, the color filter 10 according to the invention can be mounted as an eyeglass lens in an eyeglass frame to create color-filtering glasses. It can be inserted into the eyeglass frame in a manner known per se: the periphery of the finished eye lens is shaped to fit snugly into the eyeglass frame, and then the eye lens is inserted into the eyeglass frame. After this, it is preferably cleaned and packaged for sale.

[0102] If the interference filter 14 is used as a clip-on lens, then only the first carrier lens 12 is mounted in the frame, and the second carrier lens 12' is fitted with a suitable clip-on attachment system to allow it to be attached to the eyeglasses at a later stage.

[0103] Another option is to omit the second carrier lens 12', but instead form the interference filter 14 and optional other layers on the stained carrier lens 12, and place a clip-on mounting system on the carrier lens 12, thus forming the entire color filter 10 as a clip-on lens. The advantage of this is that people with color vision deficiencies can easily attach the clip-on color filter 10 to their existing conventional eyeglasses, such as refractive glasses.

[0104] Various modifications to the disclosed embodiments described above will be apparent to those skilled in the art without departing from the scope of protection defined by the appended claims.

Claims

1. A colour filter (10) for modifying human colour vision, having a spectral transmission function in the visible range, wherein the average transmission in a wavelength range of at least 20 nm width below 530 nm is at least twice the average transmission in a second wavelength range between 530 and 580 nm, and the average transmission in a wavelength range of at least 20 nm width above 580 nm is at least twice the average transmission in the second wavelength range, characterised in that, The color filter comprises a dyed carrier lens (12) and an interference filter (14) arranged on the dyed carrier lens, the transmission function of the dyed carrier lens (12) and the transmission function of the color filter (10) having the following relationship in the second wavelength range: T sd (λ)<1-V(λ)·(1-T(λ))·n wherein T(λ): is the transmission function of the color filter (10), T sd (λ): is the transmission function of the dyed carrier lens (12), V(λ): is the sensitivity function of the human eye normalized to 1, n≥0.3。 2. The color filter according to claim 1, characterized by n≥0.4。 3. The color filter according to claim 2, characterized by n≥0.5。 4. The color filter according to claim 1 or 2, characterized by The relationship T sd (λ) < 1 - V(λ) - (1 - T(λ)) - n is valid between 500 and 600 nm.

5. The color filter according to claim 4, characterized by The relationship T sd (λ) < 1 - V(λ) - (1 - T(λ)) - n between 480 and 650 nm.

6. The color filter according to claim 1 or 2, wherein The carrier lens (12) is substantially colorless transparent in the visible range and has a refractive power or no refractive power.

7. The color filter according to claim 1 or 2, wherein The carrier lens (12) is dyed with at least one wide absorption band dye.

8. The color filter according to claim 1 or 2, wherein The carrier lens (12) is dyed with at least two dyes, at least one of which has a wide absorption band.

9. The color filter according to claim 1 or 2, wherein The dyed carrier lens (12) comprises at least one dye in its material.

10. The color filter according to claim 1 or 2, characterized by The at least one dye is applied as a dye layer (13) on at least one surface of the carrier lens (12).

11. The color filter according to claim 1 or 2, characterized by The spectral transmission function of the color filter (10) comprises at least two passbands (P) and a stopband (S) separating the at least two passbands, the stopband (S) at least partially overlapping the second wavelength range.

12. The color filter according to claim 11, characterized by The average transmission of the stopband (S) in the overlapping range is less than 20% for at least 20 nm.

13. The color filter according to claim 12, characterized by The average transmission of the stopband (S) in the overlapping range is less than 10% for at least 20 nm.

14. The color filter of claim 11, wherein The dyed carrier lens (12) and the interference filter (14) together provide at least two passbands (P) and a stopband (S).

15. The color filter according to claim 1 or 2, wherein The dyed carrier lens (12) has an absorption layer (19) on the side opposite or the same as the interference filter (14), which absorption layer (19) absorbs substantially uniformly in the visible range of at least 440 nm.

16. The color filter according to claim 1 or 2, wherein It comprises one or more functional layers (18) selected from the group consisting of scratch-resistant layers, anti-reflective layers, anti-vapor layers, anti-fingerprint layers, anti-soiling layers and UV filter layers.

17. The color filter according to claim 1 or 2, wherein The interference filter (14) is formed on the dyed carrier lens (12).

18. The color filter of claim 17, wherein The interference filter (14) is formed on a lacquer layer (16) applied to the surface of the dyed carrier lens (12).

19. The color filter according to claim 1 or 2, wherein The interference filter (14) is formed on a second carrier lens (12'), which is arranged on the dyed carrier lens (12).

20. The color filter of claim 19, wherein The interference filter (14) is formed on a lacquer layer (16) applied to the surface of the second carrier lens (12').

21. An eyeglass for modifying human color vision, characterized by, It comprises a color filter (10) according to any one of claims 1 to 16.

22. The eyeglasses of claim 21, wherein, The dyed carrier lens (12) is ground as a spectacle lens and the interference filter (14) is provided on the dyed carrier lens (12).

23. The eyeglasses of claim 22, wherein, The interference filter (14) is provided on a lacquer layer (16) applied to the surface of the dyed carrier lens (12).

24. The eyeglasses of claim 21, wherein, The dyed carrier lens (12) is polished as a spectacle lens and the interference filter (14) is formed on a transparent second carrier lens (12'), which is formed as a clip-on lens attachable to the spectacle.

25. The eyeglasses of claim 21, wherein, The interference filter (14) is formed on a lacquer layer (16) applied to the surface of the second carrier lens (12').

26. A method of designing a filter (10) for modifying human colour vision, providing a spectral transmission target function for which the average transmission in a wavelength range of at least 20 nm width below 530 nm is at least twice the average transmission in a second wavelength range between 530 and 580 nm, and the average transmission in a wavelength range of at least 20 nm width above 580 nm is at least twice the average transmission in the second wavelength range, characterised in that, A dyed carrier lens (12) is provided, the transmission function of which and the target function have at least in the second wavelength range the following relationship: T sd (λ)<1-V(λ)·(1-T0(λ))·n wherein T0(λ): is the target function, T sd (λ): is the transmission function of the dyed carrier lens, V(λ): is the V-λ curve of the human eye, n≥0.3； An optical thin layer system corresponding to the target function is designed taking into account the transmission function of the dyed carrier lens (12), and The designed optical thin layer system is produced in order to produce an interference filter (14) on the dyed carrier lens (12) or the second lens (12'), which can be placed on the dyed carrier lens (12) and the transmission of which is considered to be part of the transmission function of the dyed carrier lens.

27. The method of claim 26, wherein, The transmission function of the dyed carrier lens (12) substantially meets the following relationship in the visible wavelength range: T0(λ) * m ≤ T sd (λ) wherein 28. The method of claim 26 or 27, wherein, The thin layers of the optical thin layer system are designed with a thin layer design program so that the transmission function of the dyed carrier lens (12) is set to the initial carrier transmission.

29. The method of claim 26 or 27, wherein, The carrier lens (12) is dyed with at least one dye using a heat diffusion technique.

30. The method of claim 26 or 27, wherein, A surface-smoothing lacquer layer (16) is applied to the dyed carrier lens (12) and an optical thin layer system is created on the lacquer layer (16).

31. The method of claim 26 or 27, wherein, A functional layer (18) is formed on the interference filter (14), the functional layer (18) being selected from the group consisting of scratch-resistant layers, anti-reflection layers, anti-steam layers, anti-fingerprint layers, anti-soiling layers and UV filter layers.

32. The method of claim 26 or 27, wherein, n>0.4。 33. The method of claim 32, wherein, n>0.5。 34. The method of claim 26 or 27, wherein, The carrier lens (12) is substantially colorless and transparent in the visible range.

35. The method of claim 26 or 27, wherein, The carrier lens (12) is dyed with at least one wide absorption band dye.

36. The method of claim 26 or 27, wherein, The carrier lens (12) is dyed with at least two dyes, at least one of which has a wide absorption band.

37. The method of claim 26 or 27, wherein, The spectral transmission function of the color filter (10) comprises at least two passbands (P) and a stopband (S) separating them, the stopband (S) at least partially overlapping the second wavelength range.

38. The method of claim 37, wherein, The average transmission in the overlapping range of the stopband (S) is less than 20% over at least 20 nm.

39. The method of claim 38, wherein, The average transmission in the overlapping range of the stopband (S) is less than 10% over at least 20 nm.

40. The method of claim 37, wherein, The dyed carrier lens (12) and the interference filter (14) together provide at least two passbands (P) and a stopband (S).

41. The method of claim 26 or 27, wherein, An absorption layer (19) is created on the side of the carrier lens (12) opposite or identical to the interference filter (14) with a dye that absorbs substantially uniformly in the visible range above at least 440 nm.

42. The method of claim 26 or 27, wherein, The color filter (10) is fitted in an eyeglass frame.

43. The method of claim 26 or 27, wherein, The dyed carrier lens (12) is fitted in an eyeglass frame and the second carrier lens (12') provided with the interference filter (14) is formed as a clip-on lens.

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