JP2001513068A - METHOD AND APPARATUS FOR MANUFACTURING NETWORK MICRO LENS - Google Patents

Abstract

(57) Abstract: The apparatus of the present invention comprises a housing (1), means (2) for heating the housing, and a plate (24 _i ) of a malleable material under pressure at the temperature generated in the housing (1). Means (8) for supporting at least one laminate ( _9i ) of Further the laminate (9 _i) comprises a substantially flat mold _{(25 i, 25 '1,} 25' 2), each of the mold forms at least one non-malleable pit under pressure at said temperature With a textured surface. Mold _{(25 i, 25 '1,} 25' 2) is inserted between the plates (24 _i). Means (13,14,19,20,21) is configured to apply a substantially uniform pressure directed perpendicular to the surface of the plate (24 _i) to the entire stack (9 _i). This pressure is suitable for forming the convex surface of the microlens on the side of the plate (24 _i ), facing the pitted surface of the mold (25 _i , 25 ′ ₁ , 25 ′ ₂ ) .

Description

DETAILED DESCRIPTION OF THE INVENTION             METHOD AND APPARATUS FOR MANUFACTURING NETWORK MICRO LENS   The present invention relates to a method and an apparatus for manufacturing a microlens having a network structure, More specifically, at least the opening corresponds to the contour of the convex portion of the microlens. A plate of malleable material is pressed against the grooved, non-malleable surface of the pit of the reticulated structure. The microlens permanently presses the plate against the pitted surface. And a method formed by sintering. The present invention also relates to the method The present invention relates to an apparatus for performing the above.   At present, a network of optical microlenses is used in a variety of applications, especially for image capture and And used for reproduction. In this technical field, liquid crystal displays the image to be projected A video program that works by projecting light across a two-dimensional matrix of cells Ekta is known. These projectors are located on both sides of this matrix Due to the opaque edges of the cells of the matrix, Poor light yield due to various levels of light absorption, such as by the projection screen. For this reason, liquids that are selectively alternated between an opaque state and a transparent state By focusing the light source on the useful area of the crystal cell, the current light yield (approximately 1 %) Can be improved two to three times. Thus, the opaque edges of these cells Avoid absorption by The problem with this absorption is the processing of data to display information. In other devices, such as backlit LCD screens used in It is.   The dimensions of currently used liquid crystal cell matrices and general video images Considering the high resolution that is considered, two-dimensional networks distributed at intervals of about 100 μm The micro-lenses of the shape must be arranged. For example, hundreds of thousands Up to millions of lens networks.   Patent application No. 9,408,420 filed on July 7, 1994 by the applicant It has been shown that such networks can be created by methods of the kind mentioned at the beginning of the present application. I know. According to this method, a plate made from malleable optical material, This By applying different pressures on both sides of the plate, the pitted non- malleable surface And press. The pressure on the side facing the surface where the pits are formed is Less than the pressure applied to the other side. The depth of the pit depends on the shape of this plate Of a microlens formed by permanently following the surface It is larger than the thickness of the convex part. Contact between the bottom of the pit and the convex part of the micro lens Lack of touch preserves the "optical" finish of these components.   In order to carry out this method, the aforementioned French patent application discloses a waterproofing housing for fluids. Rigid having zing, support means for optical material for plate, and pitted surface An apparatus containing sheets was proposed. These members approach parallel to each other ing. This plate thus constitutes an element of the wall of the housing. This patent was issued The request is also based on the housing, which limits the housing Different fluid pressure levels were provided in the Press against the pitted surface by the operation of said means used for It also proposes measures to be taken. In order to increase the productivity of this device, A folded housing can be provided. Each housing is on the opposite side Limited by two optical plates, each of which has a corresponding pit-formed surface Next is placed. The means for providing fluid pressure in these housings are Operate.   Manufacture several networks of microlenses to increase productivity Can be improved as follows. Nevertheless, this device is Made from the above, sheets having pit-formed surfaces, supports, crossbars , And multiple stacked housings with the appearance of a complex stack of closed gaskets Must also be provided. By assembling and disassembling such complicated devices, The productivity of the device described above is limited.   The object of the present invention is to be suitable for industrial production with high productivity, high volume and low production cost Of fabricating a microlens with a network structure designed to ensure that And to provide a device.   The objects of the invention, as well as other aspects that will be apparent from reading the following description, are set forth in the appended claims. This is achieved by a method of manufacturing a microlens with a network structure of the type described at the outset. You. A large number of abbreviations, each including at least one pitted non-compliant surface Characterized by forming a laminate consisting of a flat mold and a plate of multiple malleable materials That is. These last objects are made of mold dies on at least one side of each plate. Inserted between the plates so as to be aligned against the formed surface of the kit. Board table Significantly uniform pressure, applied perpendicular to the plane, is applied throughout the stack during manufacturing. Is done.   The laminate of plate and mold is quickly assembled and disassembled. This will automatically You can also. The setting of the continuous pressure of such a stack of plates can be automated. And thereby achieve the desired high level of productivity.   According to another feature of the method according to the invention, a uniform optical feature is provided on all surfaces of the network. The laminated body of the plate and the mold should be manufactured so as to produce a microlens with a reticulated network structure. Indeed, equilibrium press.   Other features and advantages of the method and the device according to the invention will appear on reading the description which follows, and It can be understood by considering the attached drawings.   FIG. 1 shows a longitudinal section through the device according to the invention.   2 to 4 show various structures of a pressed plate and mold laminate in the apparatus of FIG. FIG.   FIG. 5 shows a method of marking two molds in a laminate of a plate and a mold as shown in FIG. FIG. 3 shows a perspective view illustrating the method.   FIG. 6 shows a longitudinal section of a means for applying pressure, which is part of the device of FIG. .   FIG. 7 shows an automatic, continuous pattern for the apparatus of FIG. 1 when the laminate is to be pressed. FIG. 2 shows a cross-sectional view of a transmission means suitable for ensuring the supply of power.   Reference is now made to FIG. In this drawing, the device shown is fire resistant. An insulating housing 1 of an alloy, for example, Nicrimphy ™ from Imphy, Ltd .; A means 2 for heating the space 3 inside the housing 1 which may be gaseous You can see that The housing 1 is insulated by a blanket 4 of an insulating fiber material. It may be. The space 3 includes a heat insulating closure 5 and a sliding door 6 attached to the groove 7. Is closed by   Horizontal rails 8 are provided in the space 3 and are provided with plates of malleable optical material and between these plates. Flat mold laminate 9 inserted in₁, 9_Two, ... are accommodated. As you will see later This transfers these laminates into the press post 10 and then It can be removed from the strike. These rails support this device The blankets 4 of the frame 11 are securely connected across each other.   The gate 6 intersects a control rod 12 which can slide horizontally into the gate. This rod is continuously connected to different laminates 9₁From 9_ThreeThe heating, pressing, and cooling Can be moved to a location for indexing.   As is well known in heat treatment ovens, inert nitrogen There is a means (not shown) that can maintain the atmosphere.   The press post 10 comprises a base plate 13 and a die, shown in detail in FIG. It has 14 The die 14 has its axis on the shaft 15 for reasons to be described later. Attached to the vertical axis of the support 15 by a joint 16 which is perpendicular to the axis. You. The die 14 includes the laminate 9 arranged in the press post 10._i(The implementation shown in FIG. 1 In the example, the corresponding support areas 17 for i = 1 to 3)₁, 17_TwoArranged to make contact with Two projections 14 in a row₁,14_TwoThere is.   The base plate 13 is vertically movably mounted on a shaft 18 and a lever 19 (See FIG. 1). This lever is a jack Motivator] 20 to bring the base plate 13 close to the die 14 and then Next, the laminate 9 in the post 10_iAround the axis 21 so as to release it during the pressing of Rotate.   Here, reference is made to FIG. 2 for explaining the configuration of such a laminate. This laminate is Two thick parallelepipeds forming the corresponding base plate and the corresponding die, respectively Grooving of regular mesh pits between genus blocks 22 and 23 Metal sheet 25 with open sides_iMultiple glass plates or sheets inserted between 2 Four_iincluding. Each sheet 25_iConstitute a substantially flat mold.   The laminate is one of blocks 22, 23 for the purposes described below. One (here block 22), a graphite-like good Completed by a sheet 26 made of a compressible material that is a heat conductor. Sheet 26 The adjacent sheet of this laminate is provided by an insert sheet 27 whose function is described below. Separated from the board.   Glass plate 24_iAnd mold 25_iComposition and manufacture of [formerly called sheets] Was filed on March 15, 1995 by a previously cited French patent application and the applicant. Exactly corresponding to the description in the filed French Patent Application No. 9,502,983 Good. In these respects, it is permissible to refer to these applications in more detail . This is how the reference number 7059 in the Corning catalog is available. Using a lath, plates 24 of different shapes, for example 9 × 12 cm, may be used._iTo Or their thickness, from a large range of 0.2 mm to 5 mm You can choose. In the present invention, generally, a high softening temperature (for example, 63 (Higher than 0 ° C) and a thermal cycle performed in the process of manufacturing the liquid crystal display. It is preferred to use low hammering glass due to compaction in the furnace.   Mold 25_iIs, for example, the aforementioned Nic whose thickness is from 0.2 mm to 0.3 mm It can be made with rimphy600 alloy sheet. This is the method according to the invention It is not malleable under temperature (up to 750 ° C.) and pressure conditions. Nevertheless However, the low thickness of these molds preferably disrupts the pressure field, as can be seen below. Instead, it helps to convey this world.   The pits are confirmed by the photolithographic technique described in the aforementioned patent application. It is actually engraved. Of course, the depth of the print is completely explained by the patent application. As described, a glass plate is pressed to give an optical finish to the convex surface of the lens. The thickness is larger than the thickness of the convex portion of the lens to be formed by pressing.   Preferably, the mold 25_iIs a [plate] laminate 9_iLike gluing during the press operation, To avoid physicochemical interactions between the plate and the mold, the boron nitride or soot Is coated with such an adhesive.   Press gear, base plate 13, die 14, compatible base plate 22, and compatible Die 23 apparently provides the glass plates with a plastic state suitable for passage through these plates. In order to maintain sufficient mechanical properties at the high temperature (about 750 ° C) provided in space 3 No. NS30 (AFNORZ12CN25-20) refractory steel It is suitable for producing a press gear under these conditions.   According to a preferred feature of the invention, sheet 26 is laminated due to its compressibility. Body 9_iWhile ensuring excellent pressure uniformity on the glass plate The glass temperature depends on the consistency of the optical properties of the microlenses formed on the entire surface of the plate This uniformity, together with the degree, responds so as to suppress the constrained concentration area during pressing. It is used to absorb irregularities on the surface of the base plate 22. For this purpose The sheet 26 is made of a graphite sheet having a thickness of 0.8 mm. Can be. This sheet is named Sibraflex V 10010C4 by SGL Carbon GmbH It is commercially available at Compatible base plate 22 for this good thermal conductivity Metal masses are important for standardizing the glass temperature over the entire thickness of the laminate. Can play a role.   The insert sheet 27 is made of an adhesive, possibly one of those described above. It may consist of an unengraved Nicrimphy 600 sheet that is coated No. The adhesive is applied to the glass plate 24 adjacent to the graphite sheet._iReacting with prevent.   This is done by using the apparatus of FIG. 1 and a laminate such as that shown in FIG. The method for manufacturing a microlens having a network structure according to the present invention is as follows. Function.   One or several laminates 9_iIs introduced into the space 3, the first laminate (9)₁ ), Using the control rod 12, the base plate 13 of the press post 10 and the die 14 Push in between. Activate the means for electrically heating to reduce the ambient temperature of the glass 0 ° C, possibly in an oven to reach an intermediate level temperature of 450 ° C Control the operation of the thermal cycle. When the glass is stabilized at a temperature of 750 ° C, The jack 20 is operated to generate several tons of pressure on the laminate for about several tens of seconds. Move. Then, release this jack. This allows the rod 12 to be used By pressing these laminates, laminate 9₁Is discharged from the press post 10 and laminated Body 9_TwoCan be introduced. The above-mentioned fruss operation is performed by Body (9_Three). The laminate thus treated is then placed in an orb. Temperature to the ambient temperature inside the glass₁To be taken out. Therefore This glass plate was described in the above-mentioned French Patent Application No. 9,408,420. In this way, a micro-lens with a network structure formed "without contact" during the pressing operation I have   The dimensions and optical characteristics of the thus formed microlens are Since the glass plate is surely equilibrium pressed by the characteristics of the device according to Completely consistent on all surfaces. On the other hand, this equilibrium press is Due to the presence of the graphite sheet 13 and, on the other hand, the die 14 of the support 15 Obtained by joint assembly. With these two devices, the pressed product The pressure applied by the jack 20 is ensured to be uniform throughout the layer. Sa Furthermore, the low thickness of the mold sheet reduces the inertia, which The transmission of the predetermined pressure field from the seat to the seat is not impeded. However, Nicrimphy Due to the excellent mechanical properties of the hot pits, the local non- malleability of the pits and those Relative positioning is ensured.   Of course, the die joint of the support part 15 is the base plate of the shaft 18 You can replace it with 13 things.   During the pressing, the base plate 13 is_iOn its support rail 8 Rise so that these rails are insulated from the conditions created by jack 20 Was observed.   The present invention provides a laminate of a glass plate and a mold arranged differently from that shown in FIG. Pressing in the device according to Akira will do. Another possible stack is Figure 3 And 4. In FIG. 3, the stack consists of four plates 24_iAnd two Mold sheet 25 '₁And 25 '_TwoIt has. Each of these sheets has a mesh structure Pits are engraved on both sides. Mold 25 '₁And 25 '_TwoAre, respectively, plate 24₁ And 24_TwoAnd board 24_ThreeAnd 24_FourIt is located between. The insertion sheet 27 is_TwoAnd 24_ThreeTo Separately, another insert sheet, as shown in FIG. (Not shown) are connected to each of the two leading ends of the stack closed. This arrangement allows for two mold sheets instead of four, as shown in FIG. A microlens having a network structure can be manufactured.   In FIG. 4, this laminate is made up of four glass plates 24._iAnd each one only on one side Five molds engraved on 25₁From25_FiveIt has. Board 24₁After pressing, plate 2 Four₁Molds that form a net-shaped convex lens on each side of₁And 25_TwoBetween Has been placed. Other 24_TwoFrom24_FourUp to and including the laminate shown in FIGS. same As described above, only one microlens having a network structure is provided.   With the arrangement of FIG. 4, a biconvex microlens having a network structure is formed, Construction is stronger than flat-convex lenses, which are of interest in certain applications. With a bunch. Still, board 24₁One micro of a network supported by The lens is perfectly centered on one of the other reticulated lenses There is a need. To do this, for example, according to the markings shown in FIG. , Two molds 25₁And 25_TwoMust be arranged about each other. Next Then, the circular hole 28 and the button hole 29 are simultaneously engraved in each mold. Opening these holes Injury is completed by self-centering micromilling. Fully adjustable (± 5 μm) pins 30 and 31₁On both sides of the Maintain two networked pits at the marked locations during the building press.   As a variant, this marking is located between the two net-like pits. Small balls (not shown) can be used during micro-milling . Alignment is obtained by placing each ball in two pits facing each other. Can be Thus, the two pits are perfectly aligned with each other.   According to the invention, by pressing several networks simultaneously, A large number of micro-lenses having a shape-like structure can be manufactured. The mold to use is now Are manufactured by photolithography, a fully mastered mass production method. Manufacturing costs remain low. Used to manufacture molds For example, if Nicrimphy600 has excellent oxidation resistance up to 850 ° C, Pressing in an uncontrolled atmosphere is also possible. Nevertheless, the life of the mold is By providing an inert fluorine atmosphere in the space 3 by conventional means (not shown) Increase.   With the equilibrium press according to the present invention, a net-like structure having uniform optical properties on all surfaces Microlenses can be reliably manufactured. The press is preferably Large glass to guarantee dimensional tolerance, depending on desired type of micro lens By viscosity, ie about 10 minutes in 1-2 minutes with a pressure of 20 to 50 bar.^TenPoise's Done with viscosity. Thermal cycle experienced by glass in space 3 ensures glass Annealed. This is due to the low casting due to the uniform consolidation during cooling of this glass. Guarantee. This cooling slope is preferably gradual and per 100 mm Control to ensure dimensional reproducibility of microlenses larger than ± 5 μm Can be. By controlling and changing this cooling slope, Fine dimensional adjustment without deteriorating the optical properties or surface condition of the network it can.   The method according to the invention serves for automation in the production of these networks, Thus, the productivity of the device of the present invention is further increased. For this reason, FIG. Then, the laminate 9_iTo ensure automatic and continuous passage through the device of the invention One embodiment of this device provided with means is shown. This device is an example For example, the laminated body 9 is formed by a gas cushion._iEquipped with a tunnel 32 traversed by a conveyor 33 ing. This conveyor is used to remove the preformed laminate 9 from the discharge terminal 34._iReceiving Take away. These laminates move on the conveyor to press post 10 and are discharged Removed from Minal 35. Heating means 2 distributed in the longitudinal direction of this tunnel_j Sets the thermal cycle described above. Various types well known in this industry By means of handling flat products (not shown), the laminate is automatically produced and Automatically reticulate microlenses outside the stack discharged from the device of the invention You may take it out.   Of course, the invention is not limited to the embodiments described and illustrated. . This embodiment is given only as an illustrative example. Accordingly Thus, the present invention provides a reticulated focusing of sound waves, rather than light waves, and in particular, ultrasound. Applications can be found for manufacturing microlenses with a structure. The invention also relates to gold A mesh of mesh that makes contact between the bottom of the mold pit and a plate made of malleable material. It extends to pressing of icro lenses. Therefore, this material fills the pits. This This is not due to the method cited as a reference at the beginning of this specification, but Nos. 9,408,420 and 9,502,983. Fully documented. The apparatus of the present invention comprises means for providing a vacuum in the space 3; Air bubbles must not prevent the malleable material from completely filling the mold pits No.

────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Temon, Jean-Pierre             France F-77690 Montinis             Thule Rowan Rue des Wousseau

Claims (1)

[Claims] 1. A plate of malleable material (24 _i ) is pressed against a grooved non-malleable surface (25 _i , 25 ′ ₁ , 25 ′ ₂ ) of the network of pits and at least the openings of these pits are the surface of the formed pits _{(25 i, 25 '1,} 25' 2) corresponding to the contour of the convex part of the microlenses formed therein by the this to conform the plate (24 _i) permanently against A method of manufacturing a microlens having a network structure, comprising a plurality of plates (24 _i ) made of a malleable material and at least one non- malleable surface (25) each having pits formed thereon. _i , 25 ′ ₁ , 25 ′ ₂ ) to form a laminate (9 _i ) consisting of a large number of substantially flat molds, and at least one surface of each of the plates (24 _i ) is the mold ( 25 _i , 25 ′ ₁ , 25 ′ ₂ ), the mold is inserted between the plates (24 _i ) so as to face the pit formed surface, and the plates (24 _i Perpendicular to the surface How substantially uniform pressure kicked is, throughout the laminate (9i), and wherein the applied that when formed. 2. It said plate (24 _i) and the mold _{(25 i, 25 '1,} 25' 2) methods ranging first claim of claim, wherein the performing reliably isostatic pressing the laminate (9 _i) of. 3. During the laminate (9 _i), pits network is engraved on both sides, at least one mold arranged between two plates made from malleable optical material (24 _i) (25 ' _1, 25 _'2) the method of claims paragraph 1 or 2, wherein the, characterized in that to introduce. 4. At least one plate ( _24i ) of the laminate is placed between two pitted surfaces of two different molds (25 ₁ , 25 ₂ ), and after pressing, both plates of the reticulated structure are placed on the plate. 4. The method according to claim 1, wherein the two surfaces correspond and are arranged for marking in order to ensure the formation of a convex microlens. . 5. The pressure applied to the laminate causes the convex surface of the microlens to face the side of the plate (24 _i ) facing the surface on which the pits of the mold are formed, and the convex surface to the surface of the pit. 5. The method according to claim 1, wherein the method is adapted to be formed without contact. 6. An apparatus for performing the method according to claim 1, comprising an insulating housing (1) and means (2, _2j ) for heating a space (3) inside the housing, wherein the apparatus comprises: a) supporting in the housing at least one laminate (9 _i ) consisting of a number of plates (24 _i ) of an optical material malleable under pressure at the temperature generated by the heating means (2, 2 _j ); and means (8) for, laminate (9 _i) are substantially flat multiple molds _{(25 i, 25 '1,} 25' 2) comprises, under pressure at said temperature each of the mold in also provided with one surface and least formed of a non-malleable pits mold _{(25 i, 25 '1,} 25' 2) is the least one side also of each of said plate gold the plate to be arranged facing the mold forming surface of the pit is inserted between the (24 _i), and b) substantially uniform pressure directed perpendicular to the surface of the plate (24 _i) its to whole of the laminate (9 _i) There apparatus characterized that you are provided with means (13,14,19,20,21) applied to when configured. 7. The mold is of a small thickness so as not to significantly impede the transmission of the pressure field, and the material making up the mold determines the local non- malleability of the pits and their relative positioning. 7. Apparatus according to claim 6, characterized in that it has mechanical properties relating to heat, which ensure it. 8. Means for applying the pressure, the plate (24 _i) and the mold _{(25 i, 25 '1,} 25' 2) a laminate of a base plate which is designed (9 _i) to receive between the (13) die (14), a power unit (20) for bringing the base plate (13) close to the die (14) when the laminate (9 _i ) is mounted therebetween, and securely disposing the laminate under equilibrium pressure The apparatus according to claim 6 or 7, further comprising means (16, 26) for performing the operation. 9. Means for placing under the equilibrium pressure, the die (14), wherein disposed between any of the base plate (1 3) and the laminate (9 _i), a sheet of compressible material (26) 9. The device according to claim 8, comprising: Ten. An apparatus according to claim 9, wherein said sheet (26) is made from graphite. 11． The means for placing under equilibrium pressure comprises means (16) for connecting the die (14) or the base plate (13) around an axis perpendicular to the direction in which the pressure is applied. The device according to any one of claims 8 to 10, wherein the device is provided. 12． The apparatus according to any one of claims 6 to 11, further comprising a transfer unit (33, 34, 35) for automatically loading and discharging the laminate into the apparatus. . 13. The laminate (9 _i) means for automatically producing, and wherein the pits formed network after pressing comprises means for automatically retrieving claims apparatus range囲第12 claim of . 14. Wherein said means (13,14,19,20,21), said mold _{(25 i, 25 '1,} 25' 2) convex surface side to the microlens of the plate facing the surface of the formed pits 14. The apparatus according to claim 6, wherein a pressure suitable for manufacturing the pit without contacting the convex surface with the surface of the pit is applied. 15． Means the space (3) in a vacuum, and the plate, the mold with the material of these plates _{(25 i, 25 '1,} 25' 2) of the means for applying a pressure suitable to completely fill the pit 14. Apparatus according to any of claims 6 to 13, characterized in that it comprises (13,14,19,20,21). 16． A method according to claim 3, characterized in that an intermediate sheet (27) is inserted into the stack of plates (9i) to prevent two adjacent plates (24i) from adhering to each other. The device according to any one of claims 6 to 15, wherein the device performs: 17． An optical or acoustic microlens having a network structure obtained by the device according to any one of claims 6 to 15.