JP6160507B2 - Lens array and lens array manufacturing method - Google Patents

Description

  The present invention relates to a lens array and a lens array manufacturing method.

  In Patent Document 1, it is easy to manufacture and can be finely processed, and it is an object to suppress variations in the optical axis due to processing accuracy and droplet eccentricity during voltage driving. A plurality of pyramidal recesses for accommodating droplets are two-dimensionally formed inside a hermetic cell filled with one liquid and an insulating second liquid (droplet) without being mixed with each other. In addition, since the concave portion is formed in a pyramid shape, the centering property of the liquid droplet accommodated in the concave portion can be improved, and variation in the optical axis of the lens element formed by the interface of the liquid droplet can be suppressed. In addition, the optical axis can be stably maintained to prevent droplets from being decentered during voltage driving, and further, fine processing is easier than in the case where the concave portion has a conical shape, and the concave portions are densely arranged. It is disclosed that it becomes possible.

Patent Document 2 has an object to provide an optical element that is advantageous in improving transparency, and the optical element includes a container, a first liquid, a second liquid, a first electrode, and a second electrode. The electrode, the insulating film, the water repellent film, and the voltage applying means, and when viewed from the thickness direction of the container, the first electrode is provided with a first electrode opening, The second electrode is provided with a second electrode opening, the insulating film is provided with an insulating film opening, and the water repellent film is provided with a water repellent film opening. The diameter of the transmission path formed in (1) also increases or decreases over D1 to _Dmax, and the light incident from the incident surface of the optical element passes through the first end face wall regardless of the diameter of the transmission path, and then passes through the first end face wall. The electrode opening, the second liquid portion, the water repellent film opening, the insulating film opening, the second electrode opening, and the second end face wall in this order. It is disclosed.

  In US Pat. No. 6,057,089, a method for centering a drop at a predetermined position on a surface comprises forming a bell-shaped depression, which is symmetrical at the point of contact between the drop and the depression. It is disclosed that it is formed at that location to have a curvature that is smaller than or opposite to the curvature of the circle that touches the surface at both points.

JP 2007-212943 A JP 2009-128791 A Special Table 2002-540464

  An object of the present invention is to provide a lens array and a lens array manufacturing method capable of suppressing a change in lens pitch in a lens array for controlling a focal length.

The gist of the present invention for achieving the object lies in the inventions of the following items.
The invention according to claim 1, and a substrate on which electrodes are formed on the surface, and the substrate and an insulating layer formed on the surface of the electrode, and the substrate and the that provided as a groove in the insulating layer partition wall between the partition wall to a lens formed by the electrolytic solution, and have a wiring connected to said electrolytic solution and the electrode, the groove, the insulating layer, thereby cut the blade, laser beam irradiation, solvent The lens array is formed by etching by pressing, pressing by a mold, or a combination thereof, and the partition wall is formed of two partition walls by raising an insulating layer on both sides of the groove. It is.

A second aspect of the present invention is the lens array according to the first aspect, further comprising a cover plate that contacts the partition and covers the lens.

  A third aspect of the present invention is the lens array according to the first or second aspect, wherein the groove has a conductive material, and the conductive material connects the electrodes.

According to a fourth aspect of the present invention, the partition walls are provided in a lattice shape with respect to the substrate, and the conductive material is provided so as to include apex portions of the lattice to connect the electrodes. It is a lens array as described in above.

The invention of claim 5 includes an electrode formation step of forming an electrode on the surface of the resin substrate, an insulating forming step of forming an insulating layer on the surface of the resin substrate on which the electrodes are formed, thus the groove cutting the electrode a partition wall formation step of forming the partition wall, between the partition wall, and the lens forming step of forming a lens by the electrolyte, and have a routing step in which the wiring is to connect the electrolyte and the electrode, the groove Is made by cutting the blade into the insulating layer, laser light irradiation, etching with a solvent, pressing with a mold, or a combination thereof, and the partition wall has insulating layers on both sides of the groove. A lens array manufacturing method is characterized in that two partition walls are formed by raising .

  6. The lens array manufacturing method according to claim 5, further comprising a conductive step of performing a conductive treatment on the groove, wherein the conductive material connects an electrode cut by the groove. It is.

  According to the lens array of the first aspect, in the lens array for controlling the focal length, the change of the lens pitch can be suppressed.

  According to the lens array of the second aspect, it is possible to suppress the electrolyte solution that is a lens from flowing when the substrate is tilted.

  According to the lens array of the third aspect, the number of wirings can be reduced as compared with the case where this configuration is not provided.

  According to the lens array of the fourth aspect, in the two-dimensional lens array for controlling the focal length, the change of the lens pitch can be suppressed.

  According to the lens array manufacturing method of the fifth aspect, in the lens array for controlling the focal length, it is possible to manufacture a lens array that suppresses the change of the lens pitch.

  According to the lens array manufacturing method of the sixth aspect, it is possible to manufacture a lens array in which the number of wirings is reduced as compared with the case where the present configuration is not provided.

It is explanatory drawing which shows the example of the manufacturing method of a lens array. It is explanatory drawing which shows the example of the principle which controls the focal distance of a lens. It is explanatory drawing which shows the example which deform | transforms a lens by control of the focal distance of a lens. It is explanatory drawing which shows the example which controls the focal distance of a lens. It is explanatory drawing which shows the example which forms a partition with a blade. It is a flowchart which shows the example of a manufacturing method of a lens array. It is explanatory drawing which shows the example of a form using the cover plate for the lens array. It is explanatory drawing which shows the example of a wiring of a lens array. It is explanatory drawing which shows the example of a wiring of a lens array. It is explanatory drawing which shows the example of a manufacturing method of a two-dimensional lens array. It is explanatory drawing which shows the example of wiring of a two-dimensional lens array. It is explanatory drawing which shows the example of wiring of a two-dimensional lens array.

First, before explaining the present embodiment, a technique that is a premise thereof will be described. This description is intended to facilitate understanding of the present embodiment.
A lens array is an optical system in which a plurality of element lenses (lens elements) that form an erect image are arranged in parallel, and the images are superimposed to form one continuous image as a whole. Including lenticular lenses. For example, a three-dimensional image (also referred to as 3D) can be expressed, and a plurality of images can be displayed (also referred to as changing) by changing the line of sight. As an array, a one-dimensional array (for example, a cylindrical lens array or the like) as in the example of FIG. 1 described later, or a two-dimensional array (for example, a square lens array or the like) as in the example of FIG. A microlens array such as a two-dimensional lens array).
A three-dimensional (3D) display technique using a lens array such as a lenticular lens or a fly-eye lens is also known. In this technique, a lens array is used by being superimposed on a flat (2D) screen (for example, a liquid crystal display). Usually, the display surface comes to the focal plane of the lens array.
Since the stereoscopic effect of displayed images (including videos such as moving images) is affected by the focal length of the lens, it is desirable that the focal length of the lens can be controlled according to the stereoscopic effect desired to be expressed.
Furthermore, when displaying a normal 2D image or text (when displaying an image other than a 3D image), if a lens array is present, it is difficult to recognize the normal 2D image or text under the lens array.

These occur because the focal length of the lens is fixed.
As a method for controlling the focal length of a lens, a lens using the Electroetching effect is known (Reference: Appl. Phys. Lett, 85, 1128 (2004), R. Shamai, et al, Soft Matter, 4, 38. (2008)). This technique is a technique for controlling the focal length (curvature) of a lens composed of an electrolytic solution by controlling the droplet shape of the electrolytic solution with an electric field.
FIG. 2 is an explanatory diagram illustrating an example of the principle of controlling the focal length of a lens. An insulating layer 120 is formed on the surface of the resin substrate 100, and there is an electrolytic solution 160 that is a droplet on the insulating layer 120. A voltage is applied between the resin substrate 100 and the electrolytic solution 160 (an electric field is generated). In this example, the shape of the electrolytic solution 160 is changed. As shown in the example of FIG. 2B, the lens width of the electrolyte solution 160 whose shape has been changed changes. That is, the lens pitch changes.

In order to switch the presence or absence of the lens effect without changing the lens pitch (switching of 2D / 3D display), it is necessary to apply a lens material (liquid) to the concave substrate surface.
Patent Document 3 describes that a conical recess is provided on a substrate in order to improve the centering property of a lens position. However, it is very difficult to accurately produce a conical recess. In order to solve this problem, Patent Document 1 describes that the concave portion has a pyramid shape.

Hereinafter, an example of a preferred embodiment for realizing the present invention will be described with reference to the drawings.
The lens array according to the present embodiment includes a substrate having an electrode formed on the surface, an insulating layer formed on the surface of the substrate and the electrode, a plurality of partition walls provided as grooves in the substrate and the insulating layer, and a plurality of partition walls. In addition, the lens is formed of a lens formed of an electrolytic solution, and wiring connected to the electrode and the electrolytic solution. Note that a resin substrate will be described as an example for explanation. Further, “a plurality of partition walls provided as grooves in the substrate and the insulating layer” are, for example, a plurality of partition walls formed by grooves for cutting electrodes. This lens array uses an Electroetching effect (electric wettability effect). The electroetching effect is a phenomenon in which the contact angle of a droplet changes when a voltage is applied to the droplet placed on the film on the electrode, and will be described in detail with reference to FIG.

  A lens array and a method for manufacturing the lens array will be described with reference to FIGS. FIG. 1 is an explanatory view showing an example of a manufacturing method of a lens array. FIG. 3 is an explanatory diagram illustrating an example in which the lens is deformed by controlling the focal length of the lens. FIG. 4 is an explanatory diagram illustrating an example of controlling the focal length of a lens. FIG. 5 is an explanatory view showing an example in which a partition is formed by a blade. FIG. 6 is a flowchart showing an example of a method for manufacturing a lens array. This will be described with reference to the flowcharts. In FIG. 1 and the like, a cylindrical lens will be described as an example, but this manufacturing method can be applied regardless of the lens shape. For example, there are a square lens and a circular lens.

  In step S602, the resin substrate 100 is created. The resin substrate 100 may be a transparent substrate, and as described later, an electrode 110 (this electrode 110 may be a film) and an insulating layer 120 can be formed on the surface of the resin substrate 100. I just need it. Moreover, since it becomes a part which forms a partition, what can form a recessed part with a blade etc. should just be. More specifically, the resin substrate 100 is preferably a resin having high transparency and high dimensional stability. For example, as examples of cycloolefin resin, polycarbonate resin, PETG, and cycloolefin resin, ARTON (R) (manufactured by JSR) And ZEONEX (R) (manufactured by Nippon Zeon).

  In step S604, the electrode 110 is formed on the surface of the resin substrate 100 as shown in the example of FIG. For example, the electrode 110 such as a metal film may be formed by vapor deposition or the like. This electrode 110 becomes an electrode of the lens array. If the electrode 110 is transparent, the entire surface of the resin substrate 100 may be used. Examples of the transparent electrode include ITO (indium tin oxide) and ZnO (zinc oxide). However, in general, the electrode 110a and the electrode 110b are not formed in the region where the lens is to be formed, but are formed at locations (scratch lines 130a and 130b) where the partition walls are formed.

In step S606, as shown in the example of FIG. 1B, the insulating layer 120 is formed on the resin substrate 100 including the electrode 110, and the lens substrate 190 is formed. The insulating layer 120 in this embodiment is not particularly limited as long as it has an insulating property, but a layer with high transparency is desirable. Examples of the resin used for the insulating layer 120 include the same resin and fluorine resin as those used for the resin substrate 100.
An insulating layer 120 is further formed on the surface of the resin substrate 100 on which the electrode 110 is formed in step S604. For example, a technique such as spin coating may be used. Further, the surface of the insulating layer 120 may be subjected to a liquid repellent treatment. Hereinafter, this multilayer substrate is referred to as a lens substrate 190.

In step S608, as shown in the examples of FIGS. 1C1 and 1C2, the surface of the lens substrate 190 is scratched with the blade 180 to form a partition wall. The example of FIG. 1C2 shows a cross-sectional view of a lens substrate 190 on which a partition wall is formed. As shown in the example of FIG. 5A, the partition walls are formed by scratching the lens substrate 190 created in step S606 with a sharp blade 180 to form partition walls (partition walls 142a1, 142a2, etc.). To do. In the example of FIG. 5, the electrode 110 is omitted for the sake of simplicity. Here, “the partition is formed by the blade” means that the blade 180 is cut into the insulating layer 120 to form a groove (groove 140a or the like), and the insulating layer 120 (resin as a part of the partition is formed on both sides of the blade 180). A partition wall (a partition wall 142a1, a partition wall 142a2, etc.) is formed by raising the substrate 100 and the electrode 110). Further, the electrode 110 is cut by forming the partition wall with the blade 180. In the example of FIG. 1C1, the electrode 110a is cut into an electrode 110a1 and an electrode 110a2, and the electrode 110b is cut into an electrode 110b1 and an electrode 110b2.
The “groove” and “between partition walls” will be described. A “groove” is a groove between a first partition and a second partition, which is a pair, unlike between the partition walls forming a lens, which will be described later. No lens is formed in the groove. , Become the area between the lenses. “Between partitions” has two sets of partition walls, one set is a first partition wall and a second partition wall, and the other group is a third partition wall and a fourth partition wall, as described above. In some cases, when the second partition wall and the third partition wall are adjacent to each other, it is between the second partition wall and the third partition wall, and is a region where a lens is formed. When the partition is formed by the blade, the “groove” is a scratch mark formed by one blade. “Between partition walls” means that between four partition walls (two sets of partition walls) formed by two blades, between the center two partition walls (between one set of partition walls and the other set of adjacent partition walls). That is. In the example of FIG. 1C2, the groove 140a is between the partition walls 142a1 and 142a2, and the partition wall 150 is between the partition walls 142a2 and 142b1.
As a method for forming the partition wall, in addition to scratching the blade 180, laser beam irradiation, etching with a solvent, pressing with a mold, or a combination thereof may be used.

In step S610, as shown in the example of FIG. 5B, the electrolytic solution 160 is discharged between the partition walls using a dropping device. The electrolytic solution 160 used in the present embodiment is not particularly limited as long as it is a conductive liquid. For example, water (salt solution, sodium sulfate aqueous solution, etc.) to which an ionic component such as a salt is added may be mentioned. The space 150 between the partition walls becomes a concave portion, and becomes a portion where a lens is formed. As a result, as described above with reference to FIG. 2C, the change in the lens pitch is suppressed even when a voltage is applied.
In step S612, wiring processing is performed as shown in the example of FIG. The electric wire 170a is connected to the electrode 110a2, the electric wire 170b is connected to the electrode 110b1, the electric wire 174 is connected to the electrolyte 160, and a voltage is applied by the power source 170. A lens shape is formed by the electrolytic solution 160, and the lens shape is controlled by voltage application. That is, by controlling the voltage application, the curvature of the lens (electrolytic solution 160) is changed, and the electrolytic solution 160 is raised for the 3D lens as shown in the example of FIG. As shown in the example, it can be made flat for a 2D lens (no lens effect). Of course, the curvature can be changed to an intermediate curvature between the example of FIG. 3A and the example of FIG. Although FIG. 1 shows an example of one lens, it is obvious that it is a plurality of lenses because it is a lens array.

この（１）式により、接触角θは、静電容量Ｃや電圧Ｖが大きくなるにつれて小さくなる。つまり、表面電荷により接触角は減少する（θ_０＞θ）。 With reference to the example shown in FIG. 4, the control of the curvature (contact angle) by the Electroetching effect will be described. The example of FIG. 4A shows a power-off state, and the example of FIG. 4B shows a power-on state. Note that θ ₀ and θ indicate the contact angle of the surface of the electrolytic solution 160 with respect to the partition wall 142a2.

According to the equation (1), the contact angle θ decreases as the capacitance C or the voltage V increases. That is, the contact angle decreases due to the surface charge (θ ₀ > θ).

Further, as a lens array in which lenses are formed between partition walls, the example shown in FIG. 7 may be used. That is, a transparent lid 700 may be provided above the lens array so as to be in contact with the plurality of partition walls and cover the lens. For the cover plate 700 in this embodiment, transparent glass or resin can be used. It is desirable that the lens array be highly transparent with respect to the wavelength used. Examples of the cover plate 700 include the same resin as that used in the resin substrate 100.
Then, the electrodes 710a2 and 710b1 may be used as electrodes connected to the electrolyte solution 160 on the lid plate 700 side. The position of the electrode 710a2 is on the partition 142a2 side, and the position of the electrode 710b1 is on the partition 142b1 side. For example, an electric field is created between the two electrodes 710a2 and 110a2. Then, the oil 760 and the electrolyte solution 160 are stored in the partition wall 150. By doing so, the lens array can be used not only horizontally but also vertically.
If a transparent electrode is used for the electrode on the lid plate 700 side, it can be formed on the entire surface of the lid plate 700.

  FIG. 8 is an explanatory diagram showing a wiring example of the lens array. There are a plurality of lenses such as an electrolytic solution 860, an electrolytic solution 862, an electrolytic solution 864, and the like. There are an electric wire 872a, an electric wire 872b, and an electric wire 874a with respect to the electrolytic solution 860, and an electric wire 872c, an electric wire 872d, There is an electric wire 874c, and there are an electric wire 872e, an electric wire 872f, and an electric wire 874e with respect to the electrolytic solution 864. That is, the wiring needs two wirings for each lens on the lens substrate 190 side (for example, the electric wires 872a and 872b with respect to the electrolyte solution 860). If it is necessary to control the shape of each lens in the lens array, the power supply for each lens may be wired.

In order to reduce the wiring shown in the example of FIG. 8, a conductive material is provided in a groove in the lens array, and an electrode cut by the groove is connected by the conductive material. FIG. 9 is an explanatory diagram showing a wiring example of the lens array.
Conductive treatment is applied to each groove of the lens array to reduce wiring. That is, the number of wirings on the lens substrate 190 side is six (electric wires 872a to 872f) in the example of FIG. 8, but is four (electric wires 972a, 972c, 972e, and 972f) in the example of FIG. 9A. . The example of FIG. 9B is an enlarged cross section of the explanation area 950 of the example of FIG.
By putting a conductive substance 910 and a conductive substance 920 in the groove portion, the electrode 110a1 and the electrode 110a2 are connected, and the electrode 110b1 and the electrode 110b2 are connected. For example, the conductive material 910 and the conductive material 920 are formed by applying and curing a liquid in which conductive metal particles such as silver are dispersed in a resin serving as a binder in a groove using a dispenser or an inkjet device. Examples of the conductive substance include Dotite D500, D362, D550 manufactured by Fujikura Kasei Co., Ltd., LS-453-1 manufactured by Asahi Chemical Research Laboratories, etc., which are conductive pastes.

Next, the manufacturing method of a two-dimensional lens array is demonstrated using FIG. Of course, the electrode 110 and the insulating layer 120 are also formed on the lens substrate 190 here.
In this manufacturing method, the partition wall structure is formed in a lattice shape. A method for manufacturing a square lens will be mainly described with reference to FIG.
Partition formation in one direction (vertical direction) as shown in the example of FIG. That is, partition walls (partition walls 1022, 1024, 1032, 1034, 1042, 1044, etc.) are generated by attaching vertical grooves (grooves 1020, 1030, 1040, etc.) to the lens substrate 190 with a blade 1010. To do.
Next, a square opening as shown in the example of FIG. 10B is formed. That is, the partition walls are formed in a direction different from that in FIG. That is, partition walls (partition walls 1072, 1074, 1082, 1084, etc.) are generated by attaching horizontal grooves (grooves 1070, 1080, etc.) to the lens substrate 190 with the blade 1010. For example, one square opening is formed by the partition walls 1044, 1052, 1074, and 1082.
In addition, although the partition is formed by moving the blade 1010 relative to the lens substrate 190, the partition may be formed by pressing a blade (die) having a square opening shape against the substrate. Good. The groove structure may be formed by ablation with laser light. Further, in this case, the shape of the blade may include a polygonal opening (for example, a rectangle (a quadrangle with different length and width), a hexagon, etc.), a circular opening, an elliptical opening, etc. in addition to the square opening. Good. The lens shape (opening) refers to the shape of the region surrounded by the partition walls.
The electrolytic solution is discharged by a dropping device 1096 as shown in the example of FIG. A region (here, square) surrounded by the first partition (partitions 1022, 1024, 1032, 1034, 1042, 1044, etc.) and the second partition (partitions 1072, 1074, 1082, 1084, etc.) of the lens substrate 190. Are filled with an electrolytic solution (electrolytic solutions 1026, 1036, 1046, 1056, etc.). That is, a lens material electrolyte 1036 or the like is dropped into a hole surrounded by a partition wall formed on the lens substrate 190.

  FIG. 11 is an explanatory diagram showing an example of wiring of a two-dimensional lens array. Also in the lens array manufactured as in the example of FIG. 10, the wiring can be connected in the groove as shown in the example of FIG. 9 described above. In the example of FIG. 11, the electrode 1100a and the electrode 1100b are connected by the conductive material 1100, the electrode 1110a and the electrode 1110b are connected by the conductive material 1110, the electrode 1120a and the electrode 1120b are connected by the conductive material 1120, and the electrode 1130a And the electrode 1130b are connected by a conductive substance 1130. That is, a conductive material is inserted so as to connect the electrodes cut by the grooves around each lens. As a result, the wiring of each lens on the lens substrate 190 side is only required at one location.

  FIG. 12 is an explanatory diagram showing a wiring example of a two-dimensional lens array. In the example of FIG. 12, the electrode 1100a, the electrode 1100b, the electrode 1110a, the electrode 1110b, the electrode 1120a, the electrode 1120b, the electrode 1130a, and the electrode 1130b are connected by the conductive material 1200. That is, a conductive substance is inserted so as to connect electrodes cut by adjacent lens grooves. Here, the adjacent lenses refer to lens groups (four in the case of the example in FIG. 12) around the portion where the electrode is cut (the position of the conductive material 1200). As a result, the wiring of the lens array is only required at one place as a whole.

  The above-described embodiment is an aspect of the embodiment of the present invention, and is not limited thereto. Various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Resin board | substrate 110 ... Electrode 120 ... Insulating layer 130 ... Scratch line 140 ... Groove 142 ... Partition wall 150 ... Between partition walls 160 ... Electrolytic solution 170 ... Power supply 170a, 170b ... Electric wire 174 ... Electric wire 180 ... Blade 190 ... Lens substrate

Claims (6)

A substrate having electrodes formed on the surface;
An insulating layer formed on the surface of the substrate and the electrode;
A partition wall that is provided as a groove on the substrate and the insulating layer,
A lens formed of an electrolyte between the partition walls ;
And have a wiring connected to said electrolyte and said electrode,
The groove is created by cutting the blade into the insulating layer, laser light irradiation, etching with a solvent, pressing with a mold, or a combination thereof,
2. The lens array according to claim 2, wherein the partition walls are formed by raising an insulating layer on both sides of the groove . The lens array according to claim 1, further comprising a lid plate that contacts the partition wall and covers the lens. The lens array according to claim 1, wherein the groove has a conductive material, and the conductive material connects the electrodes. The partition walls are provided in a lattice shape with respect to the substrate,
The lens array according to claim 3, wherein the conductive material is provided so as to include an apex portion of a lattice to connect the electrodes. An electrode forming step of forming an electrode on the surface of the resin substrate;
An insulation forming step of forming an insulating layer on the surface of the resin substrate on which the electrodes are formed;
A partition wall formation step of forming a result partition wall into the groove of cutting the electrode,
A lens forming step of forming a lens with an electrolytic solution between the partition walls;
And have a routing step in which the wiring is to connect the electrolyte and the electrode,
The groove is created by cutting the blade into the insulating layer, laser light irradiation, etching with a solvent, pressing with a mold, or a combination thereof,
2. The lens array manufacturing method according to claim 1, wherein two partition walls are formed by raising an insulating layer on both sides of the groove . A conductive step of conducting a conductive treatment on the groove;
6. The lens array manufacturing method according to claim 5, wherein the conductive material connects electrodes cut by the grooves.

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