Method for manufacturing an optical article and associated optical article
By employing a double-sided substrate printing method and primer layer treatment, the distance control problem in inkjet printing on complex ophthalmic lenses was solved, achieving high-precision and uniform pattern printing results, suitable for optical products with aspherical and discontinuous areas.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-26
- Publication Date
- 2026-04-14
AI Technical Summary
Existing technologies struggle to achieve uniform and precise inkjet printing on ophthalmic lenses with complex curvatures and aspherical surfaces, especially in controlling the distance between the printhead and the surface on concave or convex or aspherical lenses, resulting in poor print quality.
A double-sided substrate printing method is employed, which determines the optimal printing path for each optical surface, controls the distance between the print head and the surface using a weighted average and maximum distance, and improves dye adhesion by using a primer layer and plasma treatment during the printing process. The pattern is segmented and printed on different surfaces to accommodate complex geometries.
It enables high-precision, uniform pattern printing on complex ophthalmic lenses, ensuring consistency in print quality and optical transmittance, and adapting to the printing needs of aspherical and discontinuous areas.
Smart Images
Figure CN121866147A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of inkjet printing on substrates to manufacture optical articles (such as optical lenses).
[0002] More specifically, the present invention relates to a method for manufacturing optical articles, the method comprising printing a pattern on at least one optical surface of a substrate.
[0003] The present invention also relates to an optical article manufactured by this method. Background Technology
[0004] Applying dyes locally to the surface of lenses, especially ophthalmic lenses, allows for the precise and controlled application of various images or patterns onto one or more of the lens's optical surface. For example, a uniform coating can be applied to the entire optical surface or a portion thereof to dye the lens and apply color to it. This is used both to reduce the light transmittance of glass and to alter the aesthetic aspects of lenses and finished articles including lenses, and constitutes an interesting alternative to dyeing lens substrates.
[0005] Another application of dye to lenses is printing more complex and detailed patterns, such as text and / or logos. This is used to provide information to users of optical products (such as information related to optical correction provided by ophthalmic lenses) and also for aesthetic and branding purposes.
[0006] One known advantageous method for applying dye to an object is inkjet printing, which provides a high degree of control over the application of dye and allows for complex printing paths along the printhead, sometimes required for specific lenses with several different curvatures on optical surfaces.
[0007] A key parameter for achieving satisfactory results in inkjet printing is controlling and optimizing the distance from the printhead to the surface being printed. This applies both to obtaining uniform layers (e.g., for staining or coloring lenses) and to high-resolution printing (e.g., when printing text or logos). Typically, a satisfactory distance from the printhead to the surface is between 1 mm and 3 mm.
[0008] In the case of ophthalmic lenses, the optical surface being imprinted is usually not flat, but concave or convex. In addition, in the case of more technically advanced lenses, the lens can also be aspherical, typically exhibiting several different curvatures along two different axes, or even local discontinuities. Summary of the Invention
[0009] The present invention aims to solve the above-mentioned technical problems. Therefore, the present invention relates to a method for manufacturing optical articles, the method comprising:
[0010] - Two base substrates are provided, each base substrate comprising two opposing optical surfaces, and the base substrates are placed in a printing assembly.
[0011] - Provide the pattern to be printed on each base substrate via inkjet printing.
[0012] - A preferred path for the printhead to print a pattern on each base substrate is determined by considering each optical surface of each base substrate. This preferred path minimizes a parameter representing the distance measured from the printhead to the optical surface being imprinted.
[0013] - The pattern is printed using at least one inkjet printhead that deposits at least one dye, the printhead following the preferred path, and
[0014] - Place each base material in the heating assembly for a predetermined duration.
[0015] This method allows for the use of an increased number of possibilities and parameters when determining the print path, and thus enables improved control over the distance from the printhead to the surface.
[0016] The parameter representing this distance is the average distance measured from the printhead to the optical surface being imprinted along the preferred path.
[0017] This feature allows for overall optimization of printing distance across the entire printing path.
[0018] The average value can be calculated using different weight values for different weighted regions of the optical surface, with at least one weighted region closer to the optical center of the substrate having a higher weight value than at least one weighted region farther from the optical center.
[0019] The optical surface may include at least one aspherical region and / or at least one discontinuous region, each aspherical region and each discontinuous region having a higher weight value than at least one spherical region of the optical surface.
[0020] This feature allows for greater emphasis on irregular areas of the optical surface, where the distance between the printhead and the substrate is more likely to vary.
[0021] The parameter representing this distance can be the maximum distance measured on the optical surface from the printhead to the optical surface being imprinted.
[0022] This feature allows the distance from the printhead to the surface to be kept below a maximum threshold in order to maintain minimum accuracy during printing.
[0023] The preferred path may extend along at least two opposite optical surfaces of each base substrate.
[0024] This feature allows for the use of the most advantageous printing paths on both sides of the substrate to better accommodate height variations, such as in complex lenses.
[0025] During the printing of the pattern, the first part of the pattern can be printed on one of the opposite optical surfaces, and the second part of the pattern can be printed on the other of the opposite optical surfaces.
[0026] This feature allows a pattern to be divided into at least two parts to be printed on a separate surface, so that the most advantageous surface of the substrate can be selected for each part of the pattern to be printed, which is selected with regard to the distance from the print head to the surface.
[0027] When viewed from the direction of the optical axis of the base substrate, the first part and the second part of the pattern can form a uniform layer.
[0028] For lenses with complex surface geometries, this feature allows for the achievement of similar effects to uniform layers in terms of the external aspects of the lens and the transmittance of light through the lens, while dividing the printed pattern on different surfaces.
[0029] The first part of the pattern may include at least one first gradient region extending along the boundary of the first part, and the second part of the pattern includes at least one second gradient region extending along the boundary of the second part, wherein each first gradient region overlaps with one of the second gradient regions when viewed from the direction of the optical axis, and the sum of the optical transmittance of the first part and the second part of the pattern is constant.
[0030] This feature allows for a smoother visual transition between different parts of a pattern printed on a single surface and a constant light transition through the lens.
[0031] At least one of the opposite optical surfaces may include at least one curved region.
[0032] The method may further include:
[0033] - A primer layer is deposited by depositing a primer on at least a portion of at least one of the optical surfaces of each base substrate.
[0034] - Print the pattern on the primer layer.
[0035] - In the heating assembly, the dye migrates through the primer layer to the optical surface, and
[0036] - Remove the primer layer.
[0037] These steps allow the dye to adhere better to the surface and reduce dye movement between printing and drying.
[0038] The pattern may include a uniform layer extending over at least a portion of one of the opposing optical surfaces.
[0039] This feature allows light-absorbing layers to be applied directly to the substrate and aesthetically modified.
[0040] The method may further include a surface treatment step, during which the optical surface is treated with plasma.
[0041] This feature allows for alteration of the substrate's surface state through plasma treatment, thereby improving dye adhesion and stability.
[0042] The present invention also relates to an optical article manufactured using the method described above. Attached Figure Description
[0043] Figure 1 and Figure 2 This is a schematic side view of the inkjet printing process on two different surfaces of a substrate.
[0044] Figure 3 yes Figure 1 and Figure 2 A schematic diagram of the substrate shows two separate printing areas.
[0045] Figure 4 This is a schematic diagram of the manufacturing method according to the present invention.
[0046] Figure 5 This is a schematic diagram of an optical article obtained by the manufacturing method according to the present invention. Detailed Implementation
[0047] The following text is for reference only. Figure 1 A method for manufacturing optical articles is described.
[0048] The method involves printing a pattern on a base substrate using dye. The pattern may include a uniform layer extending on at least one surface of the substrate and / or a detailed image (e.g., including lines and text characters).
[0049] The method includes a step 100 of providing two base substrates 10 to be printed. Each base substrate 10 is, for example, a lens substrate, such as an unfinished lens, and has a first optical surface 12a and a second optical surface 12b opposite to the first optical surface 12a.
[0050] The base substrates 10 may be the same or different from each other, depending on the ophthalmic function performed by each base substrate 10.
[0051] exist Figure 2 and Figure 3An example of one of the base substrates 10 is shown above. These figures illustrate different printing paths for printing patterns on the first optical surface 12a and the second optical surface 12b, respectively.
[0052] exist Figure 2 and Figure 3 In the example shown, the first optical surface 12a is a convex surface, and the second optical surface 12b is a concave surface.
[0053] When an optical product is integrated into a pair of eyeglasses, the first optical surface 12a can be the rear surface of the base substrate 10 that is close to the user's eye, while when an optical product is integrated into a pair of eyeglasses, the second optical surface 12b can be the front surface that is away from the user's eye. Alternatively, the second optical surface 12b can be the surface close to the eye, while the first optical surface 12a can be the front surface of the base lens substrate 10 that is away from the user's eye.
[0054] The base material 10 can be formed in the organic lens, for example, made of thermoplastic or thermosetting plastic. In particular, the thermoplastic material can be selected from, for example, polyamide, polyimide, polysulfone, polycarbonate and its copolymers, polyethylene terephthalate, and polymethyl methacrylate (PMMA).
[0055] The base material 10 is preferably shaped to provide optical power suitable for correcting refractive errors (such as myopia or hyperopia) in the wearer. The base material 10 can be monofocal or multifocal, such as a multifocal progressive lens.
[0056] The base material 10 can also be a semi-finished lens, meaning it does not provide the final power of the lens to be manufactured from the semi-finished lens, also known as the target power. The power that the semi-finished lens can provide is not the target power, which is obtained by later surface treatment of the semi-finished lens.
[0057] The base material 10 can also be an untrimmed lens, meaning that its peripheral shape has not yet been adjusted to the shape of the frame into which it will be inserted.
[0058] The method includes step 200 of determining a preferred path for the printhead 22 to print a pattern on each base substrate 10, taking into account each optical surface 12a, 12b of each base substrate 10.
[0059] exist Figure 2 and Figure 3 The image above shows one of the base substrates 10 placed in the printing assembly 20 to print a pattern on at least one of the optical surfaces 12a, 12b.
[0060] The printing assembly 20 includes at least one printhead 22 and a support 24, the printhead being used to deposit dye onto the surface being imprinted, and the support being used to receive the base substrate 10.
[0061] During printing, the distance between the print head 22 and the optical surfaces 12a and 12b being printed varies along the path of the print head 22 (referred to as the printing path).
[0062] When printed on the first optical surface 12a, such as Figure 2 As shown, the distance varies between a first minimum distance d1 when printed on the central region of the first optical surface 12a and a first maximum distance d2 when printed on the edge region of the first optical surface 12a.
[0063] When printing on the second optical surface 12b, as Figure 3 As shown, the distance varies between a second minimum distance d3 when printed on the edge of the second optical surface 12b and a second maximum distance d4 when printed on the edge region of the second optical surface 12b.
[0064] The distance between the printhead 22 and each optical surface 12a, 12b being imprinted is an important parameter that needs to be controlled to obtain accurate and uniform printing results. For example, a distance between 1 mm and 3 mm is considered to be more favorable for printing.
[0065] Furthermore, certain portions of optical surfaces 12a and 12b may exhibit a higher degree of importance than other portions, especially in terms of the ophthalmic power of the finished lens.
[0066] Therefore, step 200 includes determining a preferred printing path by taking into account the two optical surfaces 12a, 12b of the two base substrates 10, the preferred path minimizing a parameter representing the distance measured from the printhead 22 to the optical surfaces 12a, 12b being imprinted.
[0067] In the first embodiment, the parameter representing distance is the maximum value of the distance over the area of the positively printed pattern on the optical surface.
[0068] exist Figure 2 and Figure 3 In the example shown, step 200 may involve selecting between printing a pattern on the first optical surface 12a or the second optical surface 12b, depending on the lower value between the first maximum distance d2 and the second maximum distance d4.
[0069] In another embodiment, the parameter is the average distance measured along the printing path from the printhead to the optical surface being imprinted.
[0070] With the uniform layer as the pattern, the average value is calculated over the entire optical surface 12a, 12b.
[0071] Advantageously, depending on the importance of different regions of the optical surface to the intended use of the finished optical article, the average value is calculated by assigning different weights to different regions of the optical surface.
[0072] As Figure 4 In the first example shown, when the pattern is a uniform layer, the central region 30 of the optical surfaces 12a and 12b can be given a higher weight when calculating the average value, while the edge region 32 of the optical surfaces can be given a lower weight.
[0073] This weight distribution firstly allows focusing on the most frequently used part of the optical lens, namely the optical center and the central region 30 around it, and also takes into account the fact that at least a portion of the edge region 32 can be further trimmed during the manufacturing process, thus making the print quality in the edge region 32 less relevant.
[0074] The weight distribution can also take into account the local optical features of optical surfaces 12a and 12b, such as discontinuous or aspherical regions, and include assigning higher weight values to regions extending around such optical features.
[0075] In the case of progressive lenses, the preferred printing path is advantageously determined by taking into account the distortion that the geometry of each optical surface will produce in the printed pattern.
[0076] In the case of multifocal lenses, the determined preferred printing path is advantageously determined by favoring optical surfaces 12a, 12b that exhibit the least amount of surface interruption.
[0077] The method may include a surface treatment step 300, wherein at least one of the optical surfaces 12a, 12b of each substrate 10 is treated with plasma 14 formed by plasma welding torch 16 (the pattern is intended to be printed onto the at least one optical surface according to a determined preferred printing path) to improve the surface aspects.
[0078] The substrate 10 is then placed in the printing assembly 20, which includes at least one printhead 22 and a support 24.
[0079] The method may then include step 400 of depositing a primer layer 26 by depositing a primer on each portion of the first optical surface 12a and / or the second optical surface 12b, in which the determined preferred path extends.
[0080] The primer layer is deposited at a controlled flow rate through the printhead 22 of the printing assembly 20 to achieve a uniform thickness.
[0081] Depositing a primer layer on the optical surface 12a of the substrate 10 allows inkjet printing on any type of substrate using water-based dyes by replacing the specific type of surface of the substrate with a general primer surface that is compatible with the dye.
[0082] The primer layer allows the dye droplets to remain in place and prevents lateral movement of the dye or aggregation of droplets.
[0083] Select a primer that is compatible with inkjet printing, with appropriate viscosity and surface tension values, and with high stability and stability over time within the formulation.
[0084] In addition, the primer is selected to be compatible with all envisioned substrates so as not to produce any type of chemical reaction with the substrate.
[0085] The viscosity and surface tension of the primer are also low enough to allow the primer to spread sufficiently to form a uniform layer on the desired portion of the first optical surface 12a.
[0086] The primer is further selected to be chemically compatible with different dyes and to allow dye transfer through the primer layer. To enable dye transfer through the primer layer, the primer has low adhesion and low network density.
[0087] Finally, the primer is selected so that it can be easily cleaned without the use of any corrosive chemicals, solvents, or mechanical tools, preferably by water cleaning. Therefore, the primer is preferably water-based or water-soluble.
[0088] The primer is preferably a water-based primer, especially an aqueous solution containing a polymer. For example, the primer contains an aqueous solution of polyvinyl alcohol.
[0089] Advantageously, the method may include step 500 of drying the primer layer 26 using a near-infrared light source 28. The primer layer 26 is only partially dried to remove excess moisture and improve the uniformity of the primer layer.
[0090] The method then includes step 600 of printing a pattern on optical surfaces 12a, 12b, wherein at least one inkjet printhead 22 deposits at least one dye to form a dye layer 34.
[0091] Dye is deposited according to the determined printing path. Depending on the pattern and preferred printing path, the dye layer 34 may be continuous or include discontinuous portions.
[0092] With the primer layer 26 pre-deposited, the dye layer 34 can extend on the primer layer 26.
[0093] The method may then include step 700 of drying the deposited dye layer 34 using a near-infrared light source 28, similar to the drying step 500 previously described.
[0094] The method then includes step 800 of placing the base substrate 10 together with the dye layer 34 and ultimately with the underlying primer layer 26 in a heating assembly 40 at a predetermined temperature for a predetermined duration. The heating assembly is, for example, a dry oven, to fix the dye layer 34 in the optical surfaces 12a, 12b.
[0095] In the presence of the primer layer 26, during this duration, the dye layer 34 migrates through the primer layer 26 due to heating and reaches the optical surface 12a, where the dye layer is held in place by the primer layer 26 and adheres to the optical surface 12a, thereby forming at least a portion of the pattern.
[0096] The method may then include step 900, which preferably removes the primer layer 26 by a water washing method (e.g., with a low-pressure water jet) and obtains a substrate 10 having at least a portion of a pattern printed on optical surfaces 12a, 12b.
[0097] It is worth noting that when the determined preferred printing path extends only on a single optical surface 12a, 12b, the resulting substrate 10 constitutes the desired optical article and presents the entire pattern on the optical surfaces 12a, 12b.
[0098] In an alternative embodiment, the preferred path extends on the first optical surface 12a and the second optical surface 12b.
[0099] For example, such as Figures 2 to 4 As shown, when printing on the central region 30 of the first optical surface 12a (which is convex in this case), the printing distance is small, while when printing on the edge region 32 of the second optical surface 12b (i.e., concave), the printing distance is short.
[0100] If both the central region 30 and the edge region 32 are important enough, for example, if they are both given relatively high weight in the average distance calculation, then the preferred printing path can be determined to extend on the two optical surfaces 12a, 12b, particularly in the central region 30 of the first optical surface 12a and the edge region 32 of the second optical surface 12b.
[0101] More generally, a first portion of a pattern can be printed on the first optical surface 12a by the steps described above, and then a second portion of the pattern can be printed on the second optical surface 12b by repeating steps 300 to 900 to obtain the desired optical article.
[0102] The two parts of the pattern are advantageously complementary, which means that the entire pattern is visible to the observer when the optical article is viewed from the direction of its optical axis.
[0103] Figure 5 A first example is shown, wherein a first portion 50 of the pattern is printed in the central region 30 on the first optical surface 12a, and a second portion 52 of the pattern is printed in the edge region 32 of the second optical surface 12b.
[0104] The two parts 50 and 52 are complementary. When viewed from the direction of optical axis A, the optical article 10 shows the entire pattern, which is a uniform layer in this case.
[0105] Advantageously, the first portion 50 of the pattern includes a first gradient region 54 extending along the boundary of the first portion 50 between the embossed center region 30 and the non-embossed edge region 32, and the second portion 52 of the pattern includes a second gradient region 56 extending along the boundary of the second portion 52 between the non-embossed center region 30 and the embossed edge region 32.
[0106] In the first gradient region 54 and the second gradient region 56, the optical transmittance of the optical surfaces 12a and 12b changes continuously from the transmittance of the printed portion of the optical surface to the transmittance of the unprinted portion of the optical surface.
[0107] The first gradient region 54 and the second gradient region 56 advantageously have corresponding changes in optical transmittance, such that when the corresponding gradient region is observed from the direction of optical axis A, the observed transmittance is constant for the entire optical article.
[0108] Figure 6 Another example is shown in which the substrate 10 includes a flat first optical surface 12a presenting a discontinuous region 58, and a more concave or convex second optical surface 12b, which is sufficiently flat in a region 60 that is flush with the discontinuous region 58 in a direction relative to the optical axis A.
[0109] In this case, a preferred printing path is determined so that a uniform layer 62 (except in the discontinuous region 58) is printed on the first optical surface 12a and on the corresponding region 60 of the second optical surface 12b.
[0110] Advantageously, the first gradient region 54 and the second gradient region 56 exist similarly to the previous example.
[0111] Figure 7 Another example is shown where the substrate 10 exhibits a high cylindrical lens value. In this case, each optical surface 12a, 12b can present a profile comprising four quadrants, where each quadrant must be imprinted from one side to maintain a satisfactory printing distance.
[0112] Finally, as Figure 8As shown, the previous printing conditions can coexist, so the portion of the pattern to be printed on the first optical surface 12a and the second optical surface 12b includes several corresponding imprinted and unimprinted areas, so as to print under favorable conditions and form a continuous layer when viewed from the direction of the optical axis A.
Claims
1. A method for manufacturing an optical article, the method comprising: - Provide two base substrates (100), each base substrate (10) including two opposite optical surfaces (12a, 12b), and place the base substrates (10) in the printing assembly (20). - Provide the pattern to be printed on each base substrate (10) by inkjet printing. - Considering each optical surface (12a, 12b) of each base substrate (10), determine the preferred path for the print head (22) to print the pattern on each base substrate (10), the preferred path minimizing a parameter representing the distance measured from the print head (22) to the optical surface (12a, 12b) being imprinted. - The pattern is printed (600) using at least one inkjet printhead (22) that deposits at least one dye, the printhead (22) along the preferred path, and - Place each base substrate (10) in the heating assembly (40) for a predetermined duration.
2. The method according to claim 1, wherein, The parameter representing the distance is the average of the distances measured along the preferred path from the printhead (22) to the optical surfaces (12a, 12b) being imprinted.
3. The method according to claim 2, wherein, The average value is calculated using different weight values for different weighted regions (30, 32) of the optical surface (12a, 12b), with at least one weighted region (30) closer to the optical center of the substrate (10) having a higher weight value than at least one weighted region (32) farther from the optical center.
4. The method according to claim 3, wherein, The optical surfaces (12a, 12b) include at least one aspherical region and / or at least one discontinuous region (58), each aspherical region and each discontinuous region (58) having a higher weight value than at least one spherical region of the optical surfaces (12a, 12b).
5. The method according to claim 1, wherein, The parameter representing the distance is the maximum distance (d2, d4) measured on the optical surfaces (12a, 12b) from the print head (22) to the optical surfaces (12a, 12b) being imprinted.
6. The method according to any one of the preceding claims, wherein, The preferred path extends along at least two opposite optical surfaces (12a, 12b) of each base substrate (10).
7. The method according to claim 6, wherein, During the printing of the pattern, a first portion (50) of the pattern is printed on one (12a) of the opposite optical surfaces, and a second portion (52) of the pattern is printed on the other (12b) of the opposite optical surfaces.
8. The method according to claim 7, wherein, When viewed from the direction of the optical axis (A) of the base substrate (10), the first part (50) and the second part (52) of the pattern form a uniform layer.
9. The method according to claim 8, wherein, The first portion (50) of the pattern includes at least one first gradient region (54) extending along the boundary of the first portion (50), and the second portion (52) of the pattern includes at least one second gradient region (56) extending along the boundary of the second portion (52). When viewed from the direction of the optical axis (A), each first gradient region (54) overlaps with one of the second gradient regions (56), and the sum of the optical transmittance of the first portion (50) and the second portion (52) of the pattern is constant.
10. The method according to any one of the preceding claims, wherein, At least one of the opposite optical surfaces (12a, 12b) includes at least one curved region.
11. The method according to any one of the preceding claims, wherein, The method further includes: - A primer layer (26) is deposited by depositing a primer on at least a portion of at least one of the optical surfaces (12a, 12b) of each base substrate (10). - Print the pattern on the primer layer (26), - In the heating assembly (40), the dye is allowed to migrate through the primer layer (26) to the optical surfaces (12a, 12b), and - Remove the primer layer (26).
12. The method according to any one of the preceding claims, wherein, The pattern comprises a uniform layer extending over at least a portion of one of the opposite optical surfaces (12a, 12b).
13. The method according to any one of the preceding claims, wherein, The method further includes a surface treatment step (300), during which the optical surfaces (12a, 12b) are treated with plasma.
14. An optical article manufactured by the method according to any one of the preceding claims.