JP2005055758A - Method for manufacturing microlens, microlens, optical apparatus, optical transmission device, head for laser printer, and laser printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a microlens for forming proper spherical lens and forming the lenses hard to be detached from a base, and to provide the microlens, an optical apparatus, an optical transmission device, a head for a laser printer and the laser printer. <P>SOLUTION: In the method for manufacturing the microlens, for forming the microlens by discharging the prescribed number of liquid droplets being a lens material from a liquid droplet discharge head on a base member 4b formed on a base substance 3, a side 4c of the base member 4b is treated for water-repellency, before discharging the liquid droplet. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a microlens manufacturing method, a microlens, an optical device, an optical transmission device, a laser printer head, and a laser printer.

  In recent years, optical devices having a large number of microlenses called microlenses have been provided. Examples of such an optical device include a light emitting device including a laser, an optical fiber optical interconnection, and a solid-state imaging device having a condensing lens for collecting incident light.

By the way, the microlens constituting such an optical apparatus has been conventionally molded by a molding method using a mold or a photolithography method.
In recent years, a proposal has been made to form a microlens having a fine pattern by using a droplet discharge method used in a printer or the like (see, for example, Patent Document 1).
JP 11-142608 A (page 2-3, FIG. 1)

  As described above, in the conventional microlens manufacturing method using the droplet discharge method, the transparent substrate is subjected to alkali cleaning and UV ozone treatment, and further, an adhesion material applying treatment with a coupling material is performed on the transparent substrate. The adhesion with the microlenses formed on the substrate is improved. However, the contact angle between the transparent substrate and the microlens is small, and it has been difficult to form a good spherical microlens.

  In addition, when a liquid repellent treatment is applied to the upper surface of the transparent substrate, the contact angle between the transparent substrate and the microlens increases, and a good spherical microlens can be formed. There is a problem that the possibility of removing the microlenses increases.

  The present invention has been made in order to solve the above-described problems, and is capable of forming a good spherical lens and forming a lens that is difficult to remove from a base, a microlens, and an optical lens. An object is to provide a device, an optical transmission device, a head for a laser printer, and a laser printer.

  In order to achieve the above object, a method for manufacturing a microlens according to the present invention is a method of ejecting a microlens by ejecting a predetermined number of droplets as a lens material from a droplet ejection head onto a base member formed on a substrate. A method of manufacturing a microlens to be formed, wherein the liquid repellent treatment is performed on the side surface of the base member and the top surface of the base member is not subjected to the liquid repellent treatment before discharging the droplets. .

That is, since the microlens manufacturing method of the present invention performs the liquid repellent treatment on the side surface of the base member, the contact angle of the discharged and arranged lens material with respect to the top surface of the base member can be increased. Thereby, the amount of the lens material placed on the upper surface of the base member can be increased, and a good spherical microlens can be formed.
Moreover, since the liquid repellent treatment is not performed on the upper surface of the base member, the adhesion between the microlens and the upper surface can be improved, and a microlens that is difficult to remove from the base member can be formed.

In order to realize the above-described configuration, more specifically, the lyophilic treatment may be performed on the upper surface of the base member before discharging the droplet.
According to this configuration, since the lyophilic treatment is performed on the upper surface of the base member, the adhesion between the microlens and the upper surface can be further improved, and a microlens that is difficult to remove from the base can be formed.

In order to realize the above-described configuration, more specifically, the lyophilic treatment and the liquid repellent treatment do not have to be performed on the upper surface of the base member before discharging the droplets.
According to this configuration, since the lyophilic process and the liquid repellent process are not performed on the upper surface of the base member, the manufacturing process of the microlens can be simplified.
In addition, since the adhesion between the microlens and the upper surface is not reduced, a microlens that is difficult to remove from the base can be formed.

In order to realize the above configuration, more specifically, a liquid repellent treatment may be performed on the outer edge portion of the upper surface of the base member.
According to this configuration, since the liquid repellent treatment is performed on the outer edge portion of the upper surface of the base member, it becomes easy to increase the contact angle of the lens material discharged and arranged with respect to the upper surface of the base member. Thereby, it becomes easy to increase the amount of the lens material placed on the upper surface of the base member, and it becomes easy to form a good spherical microlens.

The microlens of the present invention is manufactured by the method for manufacturing a microlens of the present invention.
According to this microlens, since the side surface of the base member is subjected to the liquid repellent treatment, the microlens can be a microlens that has a good spherical shape and is difficult to remove from the base member.

An optical device according to the present invention includes a surface-emitting laser and a microlens obtained by the method for manufacturing a microlens according to the present invention, and the microlens is disposed on the emission side of the surface-emitting laser.
According to this optical device, as described above, the microlens that is formed in a better spherical shape and is difficult to remove from the base member is disposed on the emission side of the surface emitting laser. For this reason, the microlens can satisfactorily collimate the light emitted from the light emitting laser, and has good light emission characteristics (optical characteristics).

An optical transmission device according to the present invention includes the optical device according to the present invention, a light receiving element, and an optical transmission unit that transmits light emitted from the optical device to the light receiving element.
According to this optical transmission apparatus, as described above, since the optical apparatus having a good light emission characteristic (optical characteristic) is provided, the optical transmission apparatus has a good transmission characteristic.

A laser printer head according to the present invention includes the above-described optical device according to the present invention.
According to this laser printer head, as described above, since the optical device having good light emission characteristics (optical characteristics) is provided, the laser printer head has good drawing characteristics.

A laser printer according to the present invention includes the laser printer head according to the present invention.
According to this laser printer, as described above, since the laser printer head having good drawing characteristics is provided, the laser printer itself has excellent drawing characteristics.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
First, the manufacturing method of the microlens of this invention is demonstrated. The microlens manufacturing method of the present invention includes a step of forming a base member on a base, a step of liquid repellent treatment of the upper surface of the base member, and a droplet discharge method on the upper surface of the liquid repellent base member. And a step of discharging a plurality of dots of lens material to form a microlens on the base member.

  Here, the “base” in the present invention means a surface having a surface on which the base member can be formed, specifically, a glass substrate or a semiconductor substrate, and further various functional thin films and functional elements formed on them. What you did. The surface on which the base member can be formed may be a flat surface or a curved surface, and the shape of the substrate itself is not particularly limited, and various shapes can be employed.

1 (a) to 1 (e) are manufacturing process diagrams of the microlens of the present invention.
In the present invention, as shown in FIG. 1A, for example, a GaAs substrate 1 is used, and a substrate 3 on which a number of surface emitting lasers 2 are formed is prepared. Then, a base member forming material is provided on the upper surface side of the substrate 3, that is, the surface on the emission side of the surface emitting laser 2, thereby forming the base member material layer 4. In the surface emitting laser 2, an insulating layer (not shown) made of polyimide resin or the like is formed around the emission port. Here, as a material for forming the base member, a light-transmitting material, that is, a material that hardly absorbs in the wavelength range of the emitted light from the surface-emitting laser 2 and therefore substantially transmits the emitted light. For example, a polyimide resin, an acrylic resin, an epoxy resin, a fluorine resin, or the like is preferably used, and a polyimide resin is particularly preferably used.

  In this embodiment, a polyimide resin is used as the base member forming material. And this polyimide resin precursor is apply | coated on the base | substrate 3, and it is set as the base member material layer 4 as shown to Fig.1 (a) by heat-processing at about 150 degreeC after that. In addition, about this base member material layer 4, hardening is not fully advanced at this stage, but it is made the hardness which can hold | maintain the shape.

  When the base member material layer 4 made of polyimide resin is thus formed, a resist layer 5 is formed on the base member material layer 4 as shown in FIG. Then, the mask 6 on which a predetermined pattern is formed is exposed using the resist layer 5 and further developed to form a resist pattern 5a as shown in FIG.

Next, using the resist pattern 5a as a mask, the base member material layer 4 is patterned by, for example, wet etching using an alkaline solution. Thereby, the base member pattern 4a is formed on the base 3 as shown in FIG. Here, with respect to the base member pattern 4a to be formed, it is preferable to form the top surface in a circular shape, an elliptical shape, or a polygonal shape in order to form a microlens on the top surface shape. It is circular. Further, the center position of the circular upper surface is formed so as to be located immediately above the emission port (not shown) of the surface emitting laser 2 formed on the substrate 3.
Thereafter, as shown in FIG. 1E, the resist pattern 5a is removed, and a heat treatment is further performed at about 350 ° C., thereby sufficiently curing the base member pattern 4a to form the base member 4b.

2A is a cross-sectional view of the manufacturing process of the microlens according to the present invention, and FIG. 2B is a plan view of the same process.
Next, as shown in FIG. 2A, the side surface 4c of the base member 4b is subjected to a liquid repellent treatment. As the liquid repellent treatment, for example, a method of covering the upper surface of the base member 4b with a mask and forming a self-assembled film on the exposed side surface 4c, a plasma treatment method, or the like can be employed. Further, as shown in FIG. 2B, the upper surface outer edge portion 4d of the base member 4b covers the substantially central portion 4e of the upper surface with a mask in the same manner as the side surface 4c, and the exposed outer edge portion 4d is subjected to a liquid repellent treatment. . On the other hand, the outer edge 4d is covered with a mask on the substantially central portion 4e on the upper surface, and the exposed substantially central portion 4e is subjected to lyophilic treatment.

The entire upper surface of the base member 4b may be subjected to lyophilic treatment, or no treatment may be performed (no lyophilic treatment or lyophobic treatment is performed). When the lyophilic treatment is performed on the entire upper surface, a mask is applied so as to cover the entire base member 4b, and the lyophilic treatment is performed after removing the mask so that the upper surface is exposed.
In addition, when the lyophilic treatment is applied to the upper surface of the base member 4b, the adhesion between the microlens and the upper surface can be further improved, and a microlens that is difficult to remove from the base member 4b can be formed. In addition, when the lyophilic treatment and the liquid repellent treatment are not performed on the upper surface of the base member 4b, the manufacturing process of the microlens can be simplified. Furthermore, since the adhesion between the microlens and the upper surface is not reduced, it is possible to form a microlens that is difficult to remove from the base member 4b.

In the self-organized film forming method described above, a self-assembled film made of an organic molecular film or the like is formed on the surface of a substrate on which conductive film wiring is to be formed.
The organic molecular film for treating the substrate surface has a functional group that can bind to the substrate and a functional group that modifies the surface properties of the substrate, such as a lyophilic group or a liquid repellent group, on the opposite side (controls the surface energy). And a carbon straight chain or a partially branched carbon chain connecting these functional groups, and is bonded to a substrate and self-assembles to form a molecular film, for example, a monomolecular film.

  Here, the self-assembled film is composed of a binding functional group capable of reacting with constituent atoms such as an underlayer of the substrate and other linear molecules, and has extremely high orientation due to the interaction of the linear molecules. It is a film formed by orienting a compound. Since this self-assembled film is formed by orienting single molecules, the film thickness can be extremely reduced, and the film is uniform at the molecular level. That is, since the same molecule is located on the surface of the film, uniform and excellent liquid repellency and lyophilicity can be imparted to the surface of the film.

By using, for example, fluoroalkylsilane as the compound having high orientation, each compound is oriented so that the fluoroalkyl group is located on the surface of the film, and a self-assembled film is formed. Liquid repellency is imparted.
Examples of compounds that form a self-assembled film include heptadecafluoro-1,1,2,2 tetrahydrodecyltriethoxysilane, heptadecafluoro-1,1,2,2 tetrahydrodecyltrimethoxysilane, heptadecafluoro-1 , 1,2,2 tetrahydrodecyltrichlorosilane, tridecafluoro-1,1,2,2 tetrahydrooctyltriethoxysilane, tridecafluoro-1,1,2,2 tetrahydrooctyltrimethoxysilane, tridecafluoro-1 , 1,2,2 tetrahydrooctyltrichlorosilane, trifluoropropyltrimethoxysilane, and other fluoroalkylsilanes (hereinafter referred to as “FAS”). These compounds may be used alone or in combination of two or more.
Note that by using FAS, adhesion to the substrate and good liquid repellency can be obtained.

FAS is generally represented by the structural formula RnSiX _(4-n) . Here, n represents an integer of 1 to 3, and X is a hydrolyzable group such as a methoxy group, an ethoxy group, or a halogen atom. R is a fluoroalkyl group, and has a structure of (CF ₃ ) (CF ₂ ) x (CH ₂ ) y (where x represents an integer of 0 to 10 and y represents an integer of 0 to 4). And when a plurality of R or X are bonded to Si, each R or X may be the same or different. The hydrolyzable group represented by X forms silanol by hydrolysis, reacts with the hydroxyl group of the base of the substrate (glass, silicon), and bonds to the substrate with a siloxane bond. On the other hand, since R has a fluoro group such as (CF ₂ ) on the surface, the base surface of the substrate is modified to a surface that does not get wet (surface energy is low).

A self-assembled film made of an organic molecular film or the like is formed on a substrate by placing the above raw material compound and the substrate in the same sealed container and leaving them at room temperature for about 2 to 3 days. Further, by holding the entire sealed container at 100 ° C., it is formed on the substrate in about 3 hours. These are formation methods from the gas phase, but a self-assembled film can also be formed from the liquid phase. For example, the self-assembled film is formed on the substrate by immersing the substrate in a solution containing the raw material compound, washing, and drying.
Note that before the self-assembled film is formed, it is desirable to pre-treat the substrate surface by irradiating the substrate surface with ultraviolet light or washing with a solvent.

On the other hand, as the plasma method, for example, a plasma processing method (CF ₄ plasma processing method) using tetrafluoromethane as a processing gas in an air atmosphere is preferably employed. The conditions for this CF ₄ plasma treatment are, for example, a plasma power of 50 to 1000 kW, a gas flow rate of tetrafluoromethane (CF ₄ ) of 50 to 100 ml / min, and a conveying speed of the substrate 3 to the plasma discharge electrode of 0.5 to 1020 mm / min. sec, the substrate temperature is set to 70 to 90 ° C. The processing gas is not limited to tetrafluoromethane (CF ₄ ), and other fluorocarbon gases can be used. By performing such a liquid repellency treatment, a fluorine group is introduced into the resin constituting the upper surface of the base member 4b, thereby imparting high liquid repellency.

Here, with regard to such a liquid repellent treatment, in particular, when a lens material to be described later is disposed on a plane formed of the material for forming the base member 4b, the contact angle of the lens material becomes 20 ° or more. It is preferable to perform so as to exhibit such liquid repellency.
That is, as shown in FIG. 7, the base member material layer 4 is formed of a material for forming the base member 4 b (in this example, polyimide resin), and the surface thereof is flat. Then, the above-described liquid repellent treatment is performed on this surface. Next, the lens material 7 is disposed on the surface by a droplet discharge method.

Then, the lens material 7 becomes a droplet having a shape corresponding to the wettability with respect to the surface of the base member material layer 4. At this time, the surface tension of the base member material layer 4 is γ _S , the surface tension of the lens material 7 is γ _L , the interfacial tension between the base member material layer 4 and the lens material 7 is γ _SL , and the base member material layer 4 Assuming that the contact angle of the lens material 7 is θ, the following equations are established between γ _S , γ _L , γ _SL , and θ.
γ _S = γ _SL + γ _L · cos θ
As will be described later, the curvature of the lens material 7 to be a microlens is limited by the contact angle θ determined by the above formula. That is, the curvature of the lens obtained after the lens material 7 is cured is one of the factors that determine the final shape of the microlens. Therefore, in the present invention, the γ _SL is increased by increasing the interfacial tension between the base member material layer 4 and the lens material 7 by liquid repellent treatment so that the shape of the obtained microlens becomes more spherical. The contact angle θ is preferably large, that is, 20 ° or more.
In this way, by applying the liquid repelling treatment under the condition that the contact angle θ shown in FIG. 7 is 20 ° or more to the side surface 4c of the base member 4b, the upper surface of the base member 4b is applied as described later. The contact angle θ ′ of the lens material 7 to be discharged and the upper surface of the base member 4b is surely increased. Accordingly, it is possible to increase the amount of the lens material placed on the upper surface of the base member, which makes it easy to control the shape with the discharge amount (discharge dot amount).

  When the liquid repellent treatment is performed on the side surface 4c of the base member 4b in this way, a plurality of dots of the lens material 7 are discharged onto the base member 4b by a droplet discharge method. Here, as a droplet discharge method, a dispenser method, an inkjet method, or the like can be employed. The dispenser method is a general method for discharging droplets, and is an effective method for discharging droplets over a relatively wide area. The inkjet method is a method of ejecting droplets using a droplet ejection head, and the position of ejecting droplets can be controlled in units of μm, and the amount of ejected droplets is also in the picoliter order. Therefore, it is suitable for manufacturing a fine lens (microlens).

3A and 3B are schematic configuration diagrams of the droplet discharge head.
Therefore, in this embodiment, an inkjet method is used as a droplet discharge method. This ink jet method includes a stainless steel nozzle plate 12 and a vibration plate 13 as a droplet discharge head 34 as shown in FIG. 3A, for example, and these are joined via a partition member (reservoir plate) 14. Use things. A plurality of cavities 15 and reservoirs 16 are formed between the nozzle plate 12 and the diaphragm 13 by the partition member 14, and the cavities 15 and the reservoirs 16 communicate with each other via a flow path 17. Yes.

  Each cavity 15 and the inside of the reservoir 16 are filled with a liquid material (lens material) for discharging, and a channel 17 between them is a supply port for supplying the liquid material from the reservoir 16 to the cavity 15. It is supposed to function as. In addition, a plurality of hole-shaped nozzles 18 for injecting a liquid material from the cavity 15 are formed in the nozzle plate 12 in a state of being aligned vertically and horizontally. On the other hand, the diaphragm 13 is formed with a hole 19 that opens into the reservoir 16, and a liquid tank (not shown) is connected to the hole 19 via a tube (not shown). It has become.

  Also, a piezoelectric element (piezo element) 20 is joined to the surface of the diaphragm 13 opposite to the surface facing the cavity 15 as shown in FIG. The piezoelectric element 20 is sandwiched between a pair of electrodes 21 and 21 and is configured to bend so as to protrude outward when energized, and functions as an ejection unit in the present invention.

The diaphragm 13 to which the piezoelectric element 20 is bonded in such a configuration is bent together with the piezoelectric element 20 at the same time, thereby increasing the volume of the cavity 15. Then, the cavity 15 and the reservoir 16 communicate with each other, and when the reservoir 16 is filled with the liquid material, the liquid material corresponding to the increased volume in the cavity 15 flows from the reservoir 16. It flows in through the path 17.
When the energization to the piezoelectric element 20 is released from such a state, both the piezoelectric element 20 and the diaphragm 13 return to their original shapes. Accordingly, since the cavity 15 also returns to its original volume, the pressure of the liquid material inside the cavity 15 rises, and the liquid droplet 22 is discharged from the nozzle 18.

  The discharge means of the droplet discharge head may be other than the electromechanical transducer using the piezoelectric element (piezo element) 20, for example, a method using an electrothermal transducer as an energy generating element, or charging control. It is also possible to adopt a continuous method such as a mold or a pressure vibration type, an electrostatic suction method, or a method in which an electromagnetic wave such as a laser is irradiated to generate heat and a liquid material is discharged by the action of this heat generation.

  Further, as the lens material 7 to be discharged, that is, the lens material 7 that becomes a microlens, a light transmissive resin is used. Specifically, acrylic resins such as polymethyl methacrylate, polyhydroxyethyl methacrylate, polycyclohexyl methacrylate, allyl resins such as polydiethylene glycol bisallyl carbonate, polycarbonate, methacrylic resin, polyurethane resin, polyester resin, polyvinyl chloride Thermoplastic or thermosetting resins such as resin, polyvinyl acetate resin, cellulose resin, polyamide resin, fluorine resin, polypropylene resin, polystyrene resin, etc., one of which is used. Or a mixture of a plurality of species.

  The surface tension of the light transmissive resin used as the lens material 7 is preferably in the range of 0.02 N / m or more and 0.07 N / m or less. When the ink is ejected by the droplet ejection method, if the surface tension is less than 0.02 N / m, the wettability of the ink to the nozzle surface increases, and thus flight bending tends to occur. If the surface tension exceeds 0.07 N / m, the shape of the meniscus at the nozzle tip is not stable, and it becomes difficult to control the discharge amount and the discharge timing. In order to adjust the surface tension, the dispersion of the light transmissive resin does not significantly reduce the contact angle with the substrate, and does not affect the optical properties such as the refractive index. A small amount of a non-ionic surface tension regulator may be added. The nonionic surface tension modifier improves the wettability of the ink to the substrate, improves the leveling property of the film, and helps prevent the occurrence of fine irregularities on the film. The surface tension modifier may contain an organic compound such as alcohol, ether, ester, or ketone, if necessary.

  Furthermore, the viscosity of the light-transmitting resin used as the lens material 7 is preferably 1 mPa · s or more and 200 mPa · s or less. When ink is ejected as droplets using the droplet ejection method, if the viscosity is less than 1 mPa · s, the nozzle periphery is likely to be contaminated by the outflow of ink. In addition, when the viscosity is higher than 50 mPa · s, it is possible to discharge by providing an ink heating mechanism in the head or the droplet discharge device. Discharging becomes difficult. In the case of 200 mPa · s or more, it is difficult to lower the viscosity to such an extent that droplets can be discharged even when heated.

  In the present invention, a non-solvent resin is particularly preferably used as the light transmissive resin. This non-solvent light-transmitting resin dissolves the light-transmitting resin using an organic solvent and does not form a liquid material. For example, the light-transmitting resin is liquefied by diluting the light-transmitting resin with its monomer, and drops This enables ejection from the ejection head 34. In addition, the non-solvent light-transmitting resin can be used as a radiation irradiation curable type by blending a photopolymerization initiator such as a biimidazole compound. That is, by blending such a photopolymerization initiator, radiation curable properties can be imparted to the light transmissive resin. Here, the radiation is a general term for visible light, ultraviolet light, far ultraviolet light, X-rays, electron beams, and the like, and particularly ultraviolet light is generally used.

4A and 4B are manufacturing process diagrams of the microlens of the present invention.
As shown in FIG. 4A, the lens material 7 is ejected by a plurality of dots, for example, 30 dots, onto the base member 4b as shown in FIG. 8 is formed. Here, since the lens material 7 is ejected by the ink jet method, the lens material 7 can be accurately arranged at the substantially central portion on the base member 4b.
In addition, as described above, the upper surface outer edge portion 4d and the side surface 4c of the base member 4b are subjected to the liquid repellent treatment, so that the discharged droplets of the lens material 7 are not spilled from the base member 4b. It is designed to be held in a stable state. Further, by intermittently discharging several dots (30 dots in this example), the microlens precursor 8 made of the discharged lens material 7 has a horizontal cross section (a horizontal plane parallel to the upper surface of the base member 4b). ) Is finally larger than the upper surface of the base member 4b.

5A to 5C are diagrams showing the microlens of the present invention.
That is, at the initial stage of the discharge of the lens material 7, the discharge amount of the lens material 7 is small, and therefore, as shown in FIG. The contact angle θ ′ with respect to the upper surface of the member 4b is an acute angle.
If the ejection of the lens material 7 is further continued from this state, the lens material 7 ejected later naturally has high adhesion to the lens material 7 ejected earlier, so that it will spill out from now on as shown in FIG. Integrate without having to. Then, the integrated lens material 7 increases in volume and rises, and as a result, the contact angle θ ′ with respect to the upper surface of the base member 4b increases and finally exceeds a right angle.
Furthermore, if the discharge of the lens material 7 is continued from this state, since the amount is not large for each dot because the ink is discharged particularly by the ink jet method, the overall balance on the base member 4b is maintained. As shown in FIG. 5C, the contact angle θ ′ becomes a large obtuse angle, resulting in a state close to a sphere.

  In this manner, the upper surface outer edge portion 4d and the side surface 4c of the base member 4b are subjected to liquid repellent treatment, and a small amount of dots can be accurately discharged on the upper surface with respect to the amount and the discharge position (droplet discharge). By arranging a plurality of dots of the lens material 7 by the above method, the shape of the microlens precursor 8 can be made differently from an acute angle having a relatively small contact angle θ ′ to a large obtuse angle. That is, a microlens having a desired shape can be formed by appropriately determining beforehand the number of dots to be ejected according to the shape of the microlens to be formed.

  After the microlens precursor 8 having a desired shape (in this embodiment, a shape close to a sphere as shown in FIG. 5C) is formed, these microlenses are formed as shown in FIG. 4B. The precursor 8 is cured to form the microlens 8a. As the curing treatment of the microlens precursor 8, as described above, since an organic solvent is not added as the lens material 7 and imparted with radiation irradiation curability, particularly ultraviolet rays (wavelength λ = 365 nm) are used. A treatment method by irradiation is preferably used.

Moreover, it is preferable to perform the heat processing for about 1 hour, for example at 100 degreeC after the hardening process by such ultraviolet irradiation. By performing such a heat treatment, even if curing unevenness occurs at the stage of the curing process by ultraviolet irradiation, the curing unevenness can be reduced to obtain a substantially uniform curing degree as a whole.
After the microlenses 8a are formed in this way, the substrate 3 is cut as necessary, and is formed into a desired form by dividing into pieces or forming an array.
An optical device according to an embodiment of the present invention is obtained from the microlens 8a thus manufactured and the surface-emitting laser 2 previously formed on the substrate 3.

According to said structure, since the liquid-repellent process is performed to the side surface 4c of the base member 4b, the contact angle with respect to the upper surface of the base member 4b of the lens material 7 by which discharge arrangement | positioning was carried out can be enlarged. Thereby, the amount of the lens material 7 placed on the upper surface of the base member 4b can be increased, and a good spherical microlens 8a can be formed.
Moreover, since the liquid repellent treatment is not performed on the upper surface of the base member 4b, the adhesion between the microlens 8a and the upper surface can be improved, and the microlens 8a that is difficult to remove from the base member 4b can be formed.

6A to 6C are views showing the microlens of the present invention.
That is, as shown in FIGS. 6A to 6C, when the shape of the microlens 8a is increased to be a good spherical shape, the surface emission in which the focal point of the curved surface corresponding to the lens on the upper surface side is formed on the substrate 3 is formed. It approaches the emission surface of the laser 2. When the focal position approaches the emission surface, the light emitted from the upper surface side of the microlens 8a can be made more parallel light.
On the other hand, when the light from the light emitting source such as the surface emitting laser 2 does not have a radiation property but has a straight traveling property, the transmitted light can have a radiation property by transmitting through the microlens 8a.

  Further, in the optical device comprising the thus produced microlens 8a and the surface emitting laser 2 formed on the substrate 3, the microlens 8a whose size and shape are well controlled as described above is provided. Since it is disposed on the emission side of the surface-emitting laser 2, the microlenses 8a can satisfactorily collimate the emitted light from the surface-emitting laser 2, and therefore have good emission characteristics (optical characteristics). It will have.

In the above embodiment, the base member material layer 4 is formed on the base 3 and the base member 4b is formed from the base member material layer 4. However, the present invention is not limited to this, for example, In the case where the surface layer portion of the base body 3 is formed of a translucent material, the base member may be directly formed on the surface layer portion.
Further, the formation method of the base member 4b is not limited to the photolithography method described above, and other formation methods such as a selective growth method and a transfer method can be employed.

Also, the top surface shape of the base member 4b can be various shapes such as a triangle and a quadrangle according to the characteristics required for the microlens to be formed, and the shape of the base member 4b itself is also tapered. Various shapes such as a mold and a reverse taper type are possible.
In the above embodiment, the microlens 8a is used and functions as a lens while being formed on the base member 4b. However, the present invention is not limited to this, and the base member 4b is used. Therefore, the microlens 8a may be used as a single optical component by separating or peeling off by an appropriate method. In that case, the base member 4b used for manufacturing does not necessarily need to have translucency.

In the present invention, in addition to the optical device comprising the surface emitting laser 2 and the microlens 8a, an optical transmission means comprising an optical fiber, an optical waveguide or the like for transmitting light emitted from the optical device, By providing a light receiving element that receives the light transmitted by the light transmission means, it can function as an optical transmission device.
Since such an optical transmission device includes an optical device having good light emission characteristics (optical characteristics) as described above, this optical transmission device also has good transmission characteristics.

FIG. 8 is a schematic configuration diagram of a head for a laser printer according to the present invention.
The laser printer head of the present invention comprises the optical device. That is, the optical device used in the head for the laser printer includes a surface emitting laser array 2a in which a large number of surface emitting lasers 2 are linearly arranged as shown in FIG. 8, and the surface emitting laser array 2a. And a microlens 8 a disposed for each surface emitting laser 2. The surface emitting laser 2 is provided with a driving element (not shown) such as a TFT, and the laser printer head is provided with a temperature compensation circuit (not shown).
Furthermore, the laser printer of the present invention is configured by including the laser printer head having such a configuration.

Since such a laser printer head includes an optical device having good light emission characteristics (optical characteristics) as described above, the laser printer head has good drawing characteristics.
Further, even a laser printer equipped with this laser printer head has a laser printer head with good drawing characteristics as described above, so that the laser printer itself has excellent drawing characteristics.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the microlens of the present invention can be applied to various optical devices other than the above-described uses, and for example, as an optical component provided on a light receiving surface of a solid-state imaging device (CCD) or an optical coupling portion of an optical fiber. It can be used.

(A)-(e) is a manufacturing-process figure of the microlens of this invention. (A), (b) is a manufacturing-process figure of the microlens of this invention. (A), (b) is a schematic block diagram of a droplet discharge head. (A), (b) is a manufacturing-process figure of the microlens of this invention. (A)-(c) is a figure which shows the microlens of this invention. (A)-(c) is a figure which shows the microlens of this invention. It is a figure for demonstrating the contact angle of the lens material by a liquid repelling process. It is a schematic block diagram of the head for laser printers of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Surface emitting laser, 3 ... Base | substrate, 4b ... Base member, 4c ... Side surface, 7 ... Lens material, 34 ... Droplet discharge head

Claims (9)

A microlens manufacturing method for forming a microlens by discharging a predetermined number of droplets as a lens material from a droplet discharge head onto a base member formed on a substrate,
A method of manufacturing a microlens, wherein a liquid repellent treatment is performed on a side surface of the base member before the droplet is discharged, and a liquid repellent treatment is not performed on an upper surface of the base member.   The method for manufacturing a microlens according to claim 1, wherein a lyophilic process is performed on the upper surface of the base member before discharging the droplets.   The method for manufacturing a microlens according to claim 1, wherein a lyophilic process and a liquid repellent process are not performed on the upper surface of the base member before discharging the droplets.   4. The method of manufacturing a microlens according to claim 1, wherein a liquid repellent treatment is performed on an outer edge portion of the upper surface of the base member.   A microlens manufactured by the method for manufacturing a microlens according to claim 1.   A surface-emitting laser and a microlens obtained by the microlens manufacturing method according to claim 1, wherein the microlens is disposed on an emission side of the surface-emitting laser. Optical device.   An optical transmission device comprising: the optical device according to claim 6; a light receiving element; and an optical transmission unit configured to transmit light emitted from the optical device to the light receiving element.   A laser printer head comprising the optical device according to claim 6.   A laser printer comprising the laser printer head according to claim 8.

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