JP2009096648A - Method of manufacturing lens array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high grade lens array free from air-space. <P>SOLUTION: The method of manufacturing the lens array includes: a step of arranging a glass substrate 28 and a lens base material 30 between an upper mold 22 and a lower mold 24 which face each other and to which molding surfaces 22a, 24a are provided; a step of heating the glass substrate 28 and the lens base material 30 to a prescribed molding temperature; and a step of pressing the glass substrate 28 and the lens base material 30 by moving the upper mold 22 and the lower mold 24 to come close to form a lens part 30' and joining and integrating a substrate part 28' and the lens part 30'. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens array manufacturing method for manufacturing a lens array, which is an assembly of a plurality of lenses, by a molding method.

  A lens array that is an aggregate of a plurality of lenses is widely used as a lens for illumination, optical fiber communication, sensor condensing, and the like. Such a lens array is molded by pressing a molding material such as a glass material or a plastic material with a molding die in a heat-softened state.

As such a lens array, for example, Patent Document 1 discloses a method in which a glass material is placed between molds, heated and softened in a vacuum, and a molding surface of the mold is pressed against the glass material to mold the lens array. Are listed.
Japanese Patent Laid-Open No. 11-116251

  However, according to Patent Document 1, it is necessary to evacuate the molding chamber in order to obtain a lens array of good quality using a molding material. Further, in order to generate a vacuum state in the molding chamber, an auxiliary device such as a vacuum container for obtaining a sealed molding environment and a vacuum pump for reducing the pressure inside the vacuum container is required. By connecting the accessory device, the entire device becomes large and complicated.

Furthermore, in order to obtain a predetermined degree of vacuum, time for evacuation is required, and the cycle time until a molded product is obtained in the work process increases.
The present invention has been made to solve such a problem, and provides a lens array manufacturing method capable of obtaining a high-quality lens array free from air accumulation and suppressing an increase in cycle time of a manufacturing process. For the purpose.

In order to achieve the object, the invention according to claim 1
In the method of manufacturing a lens array in which a plurality of convex lens portions are formed on at least one surface of the substrate portion,
A lens molding surface for forming the lens portion on at least one of a pair of opposing molds;
Placing a substrate material corresponding to the substrate portion and a lens material corresponding to the lens portion between the pair of molds;
Heating the substrate material and the lens material to a predetermined molding temperature;
Forming the lens part by pressing the substrate material and the lens material by moving the pair of molds close to each other, and joining and integrating the substrate part and the lens part. It is characterized by that.

The invention according to claim 2 is a method of manufacturing a lens array according to claim 1,
When the lens material and the lens molding surface are in contact with each other on a spherical surface or an aspherical surface, the radius of curvature of the lens material is smaller than the radius of curvature of the lens molding surface, and the thickness of the lens material is a spherical notch of the lens molding surface. It is characterized by being equal to or greater than the depth.

The invention according to claim 3 is the method of manufacturing a lens array according to claim 1 or 2,
The substrate material and the lens material are the same kind of glass material.
The invention according to claim 4 is the method of manufacturing a lens array according to claim 1 or 2,
The substrate material and the lens material are different kinds of glass materials, and the glass material of the lens material has a glass transition point higher than that of the glass material of the substrate material.

The invention according to claim 5 is the method of manufacturing a lens array according to any one of claims 1 to 4,
The lens material is any one of a ball shape, a plano-convex shape, a biconvex shape, an approximate shape of a lens portion, and a rod shape.

The invention according to claim 6 is the method of manufacturing a lens array according to any one of claims 1 to 5,
The substrate material is either a parallel plate shape or a lens shape having a predetermined radius of curvature.

The invention according to claim 7 is the method of manufacturing a lens array according to any one of claims 1 to 6,
The lens material has the same volume as the lens portion.

The invention according to claim 8 is the method of manufacturing a lens array according to any one of claims 1 to 6,
The lens material is embedded and integrated in the substrate material.

  According to the present invention, the step of placing the substrate material and the lens material between the pair of molds, the step of heating the substrate material and the lens material to a predetermined molding temperature, and pressing the substrate material and the lens material By forming the lens portion and joining and integrating the substrate portion and the lens portion, a high-quality lens array free from air accumulation can be obtained. Moreover, since it is not necessary to evacuate the molding chamber, an increase in the cycle time of the manufacturing process can be suppressed. Furthermore, the entire device can be simplified by eliminating the attached device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Description of molding equipment]
FIG. 1 is a diagram showing a partial concept of a lens array manufacturing apparatus.

This manufacturing apparatus 10 can be operated under atmospheric pressure or under the substitution of an inert gas (such as Ar gas) or nitrogen gas (such as N ₂ ), and is a general apparatus that does not require a vacuum apparatus. The manufacturing apparatus 10 includes an upper plate 12 and a lower plate 14 that are opposed to each other with a mold assembly 20 interposed therebetween, and a pressure device that presses the upper plate 12 toward the lower plate 14 (in the direction of arrow A). 21.

  An upper cartridge heater 16 is built in the upper plate 12. A lower cartridge heater 18 is built in the lower plate 14. Instead of the cartridge heaters 16 and 18, an infrared lamp may be arranged around the side surface of the mold assembly 20.

The mold assembly 20 is subjected to heating, molding, and cooling steps to obtain a lens array 32 (see FIG. 2C, etc.) as a molded product. In the molding process, the mold assembly 20 is press-molded by the pressure device 21 while being sandwiched between the upper plate 12 and the lower plate 14. The details of the mold assembly 20 will be described later.
[First Embodiment]
2A to 2C are diagrams illustrating a method for manufacturing the lens array 32 according to the first embodiment. 2A shows an assembled state of the mold assembly 20 at room temperature, FIG. 2B shows a molded state by the mold assembly 20 under heating, and FIG. The external appearance of the lens array 32 obtained by molding is shown.

  In FIG. 2A, the mold assembly 20 has an upper mold 22, a lower mold 24, and a sleeve 26. The upper die 22 and the lower die 24 are fitted and inserted from both ends of the sleeve 26 so that the molding surfaces 22a and 24a face each other inside the sleeve 26. The molding surface 22a of the upper mold 22 is formed in a substantially flat surface, and the molding surface 24a of the lower mold 24 is formed with a plurality of concave lens molding portions 24a 'capable of molding a lens surface inside a flat plane portion. The number of concave lens molding portions 24a 'is formed in accordance with the number of lens portions 30' of the lens array 32 to be molded.

  The concave lens molding portion 24 a ′ may be formed on the upper mold 22 instead of being formed on the lower mold 24. Moreover, although the upper mold | type 22 and the lower mold | type 24 consist of single components, respectively, you may comprise not only this but combining several separate components. For example, in the case of the lower mold 24, a nested mold part having a lens molding surface (concave lens molding part 24a ') may be fitted to a base mold part having a flat part.

For the material of the upper die 22, the lower die 24, and the sleeve 26, cemented carbide, silicon carbide, stainless steel, or the like is used.
Next, assembly of the mold assembly 20 will be described during molding.

  As shown in FIG. 2A, a plurality of spherical lens materials 30 as shown in FIG. 3A are placed one by one on the concave lens molding portion 24a 'of the molding surface 24a of the lower mold 24. As shown in FIG. The plurality of lens materials 30 correspond to the plurality of lens portions 30 ′ of the lens array 32. In this embodiment, the lens material 30 is processed into a ball shape (spherical shape).

In this case, as shown in FIG. 4, the radius of curvature _{r g} of the lens material 30 of spherical, preferably smaller than the radius of curvature _{r d} of the concave lens molding portion 24a of the molding surface _{24a '(r d ≧ r g} ) . Furthermore, it is preferable that the thickness of the lens material 30 (here, the diameter D _g ) is the same as or larger than the spherical notch depth of the concave lens molding portion 24a ′. As a result, the air present in the concave lens molding portion 24a ′ of the lower mold 24 is pushed out from the center toward the outer peripheral side in the direction of the broken arrow A. The extruded air is discharged from the gap formed between the glass substrate 28 and the molding surface 24a of the lower mold before the molding is completed. In this way, an air pocket is prevented from being generated between the concave lens molding portion 24a ′ of the molding surface 24a and the spherical lens material 30. Instead of the spherical lens material 30, a plano-convex shape, a biconvex shape, or an approximate shape of the lens portion may be used.

The volume of the lens material 30 is set to a size that substantially matches the volume of the lens portion 30 ′ of the lens array 32.
Next, in FIG. 2A, a glass substrate 28 as shown in FIG. 3B is placed on the plurality of lens materials 30 arranged in the lower mold 24. The glass substrate 28 corresponds to the disk-shaped substrate portion 28 ′ of the lens array 32 as a molded product.

  The glass substrate 28 is processed into a circular parallel plate shape. In this case, a shallow spherical concave portion (not shown) may be provided on the glass substrate 28 at a position corresponding to the lens portion 30 ′ of the lens array 32 to achieve stability with the lens material 30.

  The shape of the glass substrate 28 is selected according to the shape of the substrate portion 28 ′ of the lens array 32. For example, a rectangular shape may be selected if the substrate portion 28 ′ of the lens array 32 is rectangular, and a polygonal shape may be selected if the substrate portion 28 ′ is polygonal. The volume of the glass substrate 28 is set to a dimension that substantially matches the volume of the substrate portion 28 ′ of the lens array 32.

  In the present embodiment, the glass substrate 28 and the lens material 30 are made of the same glass. By being comprised with the same glass, joining of the glass substrate 28 and the lens raw material 30 is ensured reliably. Further, as this glass, a transparent optical glass is used in the visible range, and borosilicate glass and barium glass are relatively easy to use. For example, as the glass substrate 28 and the lens material 30, L-BSL7 (manufactured by OHARA INC.) Or S-BAL41 (manufactured by OHARA INC.) Can be selected. However, the kind of glass is not limited.

The glass substrate 28 and the lens material 30 can be manufactured by grinding, polishing, or molten glass pressing.
In this manner, the sleeve 26 is fitted around the lower mold 24 with the plurality of lens materials 30 and the glass substrate 28 placed on the lower mold 24. Further, the upper die 22 is inserted from above the sleeve 26. Thus, the lens material 30 and the glass substrate 28 are sandwiched between the lower mold 24 and the upper mold 22, and the mold assembly 20 is assembled. The assembly order is not limited to this. For example, the lens material 30 may be placed on the molding surface 24 a of the lower mold 24 after the sleeve 26 is inserted into the lower mold 24.

Next, the heating process will be described.
A mold assembly 20 sandwiching a plurality of lens materials 30 and a glass substrate 28 is attached to the lens array manufacturing apparatus 10 shown in FIG. The upper cartridge heater 16 and the lower cartridge heater 18 of the manufacturing apparatus 10 are energized, and the upper plate 12 and the lower plate 14 are heated so as to reach a molding temperature. The mold assembly 20, the plurality of lens materials 30, and the glass substrate 28 are heated through the upper plate 12 and the lower plate 14 until the molding temperature is reached.

At this time, the molding temperature is set to a temperature higher than the yield point of the glass used. Under this molding temperature, the plurality of lens materials 30 and the glass substrate 28 are softened.
Next, the molding process will be described.

As shown in FIG. 2B, in the molding step, the upper plate 12 is lowered and the mold assembly 20 is pressurized while the plurality of lens materials 30 and the glass substrate 28 are held at the molding temperature.
Thereby, the plurality of lens materials 30 and the glass substrate 28 sandwiched between the lower mold 24 and the upper mold 22 are filled in the space between the lower mold 24 and the upper mold 22 while being deformed. As the deformation proceeds, the substrate portion 28 'and the lens portion 30' of the lens array 32 are molded. At the same time, the substrate portion 28 'and the lens portion 30' are joined at the interface.

  Here, each lens material 30 is pushed and expanded from the center of the concave lens molding portion 24a 'of the lower mold 24 toward the outer periphery by pressurization. At this time, as described above, since the radius of curvature of each spherical lens material 30 is smaller than the radius of curvature of the concave lens molding portion 24a ′ of the lower mold 24, it exists in the concave lens molding portion 24a ′ of the lower mold 24. The air that has been pushed out is pushed from the center toward the outer peripheral side. Further, the thickness of the lens material 30 is equal to or larger than the spherical notch depth of the concave lens molding portion 24a ′, and the extruded air is between the glass substrate 28 and the lower mold molding surface 24a before the molding is completed. It is discharged from the gap formed.

  Even if air remains between the lens material 30 and the concave lens molding portion 24a ′ of the lower mold 24, a slight air pocket is concentrated on the outer ridge line portion of the lens portion 30 ′ of the lens array 32. Stays formed. That is, almost no air remains on the optical surface of each lens portion 30 ′ of the lens array 32. For this reason, the optical performance is not affected.

  Thus, when the desired shape of the lens array 32 is molded, the pressing by the upper plate 12 is stopped, and the molding is finished. In this case, in order to obtain the desired shape of the lens array 32, the movement amount (lowering amount) of the upper plate 12 may be controlled, or the relationship between the movement amount of the upper plate 12 and the pressing time is examined in advance. The pressurization time may be controlled.

Next, the cooling process will be described.
This cooling process is a process of shifting the glass from the softened state to the solidified state and stabilizing the shape. In this cooling step, the mold assembly 20 is cooled from the molding temperature to a predetermined temperature by a cooling device (not shown).

  At the time of cooling, it is necessary to maintain a predetermined pressure state in order to ensure transferability and distortion reduction of the molded lens array 32 and stability of bonding. The applied pressure at this time is set to a range that does not cause cracks in the molded product. The cooling is completed when the mold assembly 20 and the molded lens array 32 are cooled to near room temperature. After the cooling is completed, the upper mold 22 is removed from the mold assembly 20, and the molded lens array 32 is taken out.

FIG. 2C shows the appearance of the molded lens array 32.
This lens array 32 is in a state where the lens portion 30 ′ is bonded to the substrate portion 28 ′. In addition, the shape of board | substrate part 28 'can select things other than a disc according to a use. Each lens portion 30 'is formed with a convex spherical surface having a certain curvature. The number of the lens portions 30 ′ is 3 × 3, and is arranged on the one surface of the substrate portion 28 ′ at regular intervals in a matrix.

  Note that the shape and number of the lens portion 30 ′ can be variously changed and are not limited to the above-described contents. For example, the shape of the lens portion 30 ′ may be an aspherical surface. Further, in order to secure the outer dimension of the lens array 32, if necessary, a centering step may be added to scrape off the extra outer diameter portion.

  Further, in order to eliminate the centering step, the inner diameter of the sleeve 26 and the outer diameters of the lower mold 24 and the upper mold 22 are adjusted to restrict deformation of the molded product (lens array 32) in the outer diameter direction. May be. Thereby, the lens array 32 having a desired outer dimension is obtained when the molding is completed. In addition, when a function such as antireflection is added to the lens array 32, a coating process is performed on the surface in a later process.

  In the above manufacturing process, the flow has been described in the order of the assembly process, the heating process, the molding process, and the cooling process. However, when combined with an automatic assembly apparatus, it is possible to change the order of the assembly process and the heating process by assembling the respective members in a heated state.

  According to the present embodiment, the lens array 32 is characterized in that the substrate portion 28 ′ and the lens portion 30 ′ are made of glass, so that they have excellent heat resistance and little performance deterioration due to temperature changes.

Furthermore, in this embodiment, the lens array 32 can be divided into a plurality of constituent members in advance, such as the lens material 30 and the glass substrate 28, to obtain good quality without air retention. Moreover, since a vacuum apparatus becomes unnecessary, the manufacturing apparatus 10 can be simplified and, in addition, the cycle time of the manufacturing process can be reduced.
[Second Embodiment]
In the present embodiment, a manufacturing method of the lens array 32 composed of the substrate portion 28 ′ and the lens portion 30 ′ using different types of glass by the manufacturing method of the lens array 32 shown in FIGS. explain. Since the basic contents are the same as in the first embodiment, the same or corresponding members will be described with the same reference numerals.

  In general, two types of glasses that are different in type can be bonded by pressing under high temperature. Moreover, the two types of different types of glass have a preferable combination of different types of glass that does not peel or break even after molding.

  Here, an example in which glass having a low glass transition temperature is used for the glass substrate 28 and glass having a high glass transition temperature is used for the lens material 30 will be described. For example, borosilicate glass (made by OHARA INC., Glass transition temperature 498 ° C.) is used as the glass substrate 28, and lanthanum glass (made by OHARA INC., Glass transition temperature 554 ° C.) is used as the lens material 30. A combination using can be selected.

  The glass substrate 28 is processed into a circular parallel plate shape. Further, the lens material 30 has a part of the same shape as the lens portion 30 ′ of the lens array 32. As such, in addition to the spherical lens material 30, a lens material 30 having a plano-convex shape, a biconvex shape, or an approximate shape of the lens portion can be used. However, the glass substrate 28 and the lens material 30 are not limited to specific shapes as in the first embodiment.

The lens array 32 of the present embodiment has the same shape as that shown in FIG. Further, the substrate portion 28 ′ and the lens portion 30 ′ are made of different glass materials.
Here, under the molding temperature of the heating step, the lens material 30 having a high glass transition temperature is in a solidified state, and the glass substrate 28 having a low glass transition temperature is in a softened state.

  For this reason, in the molding process, each lens material 30 is not deformed, but the glass substrate 28 is in a deformed state. The glass substrate 28 is deformed and fills a space formed by the upper mold 22, the lower mold 24, and the plurality of lens materials 30. The shape of each lens material 30 does not change.

  As the deformation proceeds, the glass substrate 28 forms a substrate portion 28 ′ of the lens array 32, and each lens portion 30 ′ of the lens array 32 is configured with the plurality of lens materials 30 as they are. At the same time, the formed substrate portion 28 ′ and each lens portion 30 ′ are joined at the interface.

In this case, since a part of each lens material 30 forms each lens part 30 ′ in advance, almost no air can remain on the optical surface of the lens part 30 ′. Here, it is preferable that the thickness of the lens material 30 (here, the diameter D _g ) is equal to or larger than the spherical notch depth of the concave lens molding portion 24a ′. The air interposed between the glass substrate 28 and the molding surface 24a of the lower mold is exhausted from the gap before the molding is completed. Depending on the shape of the lens material 30, the lens material 30 may enter the inside of the substrate portion 28 ′, but almost no air remains on the optical surface of the lens portion 30 ′ of the lens array 32, which affects the optical performance. Absent.

  In the present embodiment, the plurality of lens materials 30 are embedded in the glass substrate 28. If the pressing of the upper plate 12 is stopped when the desired shape is obtained, the molding of the lens array 32 is completed. Thereafter, the mold assembly 20 is cooled to near room temperature and the lens array 32 is taken out.

In this embodiment, glass having a high yield point is used for the lens material 30 and glass having a low yield point is used for the glass substrate 28. However, the present invention is not limited to this.
For example, glass having a low glass transition temperature can be used for the lens material 30, and glass having a high glass transition temperature can be used for the glass substrate 28. In this case, the lens material 30 can be processed into a ball shape. In addition to the spherical lens material 30, a lens material 30 having a plano-convex shape, a biconvex shape, or an approximate shape of the lens portion may be used.

According to the present embodiment, it is possible to obtain the lens array 32 made of different types of glass with good quality without air accumulation using the manufacturing apparatus 10 with general equipment. Since one glass is softened and the other glass is solidified, volume control becomes relatively easy. Then, by forming the lens array 32 by combining different types of glass, it becomes possible to improve the curvature aberration and the chromatic aberration. Furthermore, it is possible to obtain the lens array 32 with improved optical performance as compared with the lens array 32 made of a single glass.
[Example of change]
Next, modified examples of the first and second embodiments described above will be described. In addition, the same code | symbol is attached | subjected and demonstrated to the member which is the same as that of 1st Embodiment, or corresponds.

That is, various modifications can be obtained by changing the arrangement and shape of at least one of the molding surface 24 a of the lower mold 24 and the molding surface 22 a of the upper mold 22.
FIG. 5 is a diagram showing a lens array 32 formed by adjoining a plurality of lens portions 30 ′ on one side of the substrate portion 28 ′.

  In this case, the lower mold 24 is formed by adjoining the plurality of concave lens molding portions 24a 'without leaving an interval. As the molding material, for example, a rectangular parallel plate-shaped glass substrate 28 and a plurality of spherical lens materials 30 are used. By molding with this combination, a lens array 32 as shown in FIG. 5 is obtained.

  FIG. 6 is a diagram showing a lens array 32 in which the substrate portion 28 ′ of the lens array 32 has a curved lens shape, and a plurality of lens portions 30 ′ are formed on one surface of the lens-shaped substrate portion 28 ′.

  In this case, the molding surface 24a of the lower mold 24 and the molding surface 22a of the upper mold 22 are formed in a curved surface in accordance with the lens shape of the substrate portion 28 '. As the molding material, for example, a glass substrate 28 having a lens shape matched to the curved surface of the substrate portion 28 ′ and a plurality of plano-convex lens materials 30 are used.

By molding with this combination, a lens array 32 as shown in FIG. 6 is obtained.
FIGS. 7A and 7B are views showing a lens array 32 in which each lens portion 30 ′ is formed in a semi-cylindrical shape, and a plurality of the lens portions 30 ′ are arranged at equal intervals on the substrate portion 28 ′.

  In this case, the lower mold 24 is formed by forming a plurality of concave semi-cylindrical shapes at equal intervals as the molding surface 24a. Further, as the molding material, for example, a plurality of rectangular parallel plate-shaped glass substrates 28 and a plurality of elongated cylindrical lens materials 30 are used.

By molding with this combination, a lens array 32 as shown in FIG. 7 is obtained.
According to the modification described above, by changing the arrangement and shape of at least one of the molding surface 24a of the lower mold 24 and the molding surface 22a of the upper mold 22, the substrate portion 28 'and the lens portion 30' having various shapes are changed. Can be obtained.
[Third Embodiment]
8A to 8C are diagrams illustrating a method for manufacturing the lens array 32 according to the third embodiment. FIG. 8A shows the assembled state of the mold assembly 20 at room temperature, FIG. 8B shows the molded state of the mold assembly 20 under heating, and FIG. The external appearance of the lens array 32 obtained by molding is shown.

In the present embodiment, a manufacturing method of the lens array 32 in which the lens portions 30 ₁ ′ and 30 ₂ ′ are arranged on both surfaces of the substrate portion 28 ′ will be described. Since the basic contents are the same as in the first embodiment, the same or corresponding members will be described with the same reference numerals.

In FIG. 8A, the upper mold 22 and the lower mold 24 have flat molding surfaces 22a and 24a facing each other. Furthermore, these molding surfaces 22a and 24a are provided with nine concave portions 22a 'and 24a' for forming the lens portions 30 ₁ 'and 30 ₂ ', respectively.

One glass substrate 28 is used, which is previously processed into a circular parallel plate shape as shown in FIG. The glass substrate 28 is provided with shallow spherical recesses (not shown) at positions corresponding to the lens portions 30 ₁ ′ and 30 ₂ ′ of the lens array 32, so that the lens materials 30 ₁ and 30 ₂ are formed. You may make it increase the stability of arrangement | positioning.

  The shape of the glass substrate 28 is selected according to the shape of the substrate portion 28 ′ of the lens array 32. For example, a rectangular shape may be selected if the substrate portion 28 ′ is rectangular, and a polygonal shape may be selected if it is a polygon. The dimensions of the material are adjusted so that the volume of the glass substrate 28 substantially matches the volume of the substrate portion 28 ′.

The lens materials 30 ₁ and 30 ₂ use a plurality of spherical lens materials 30 ₁ and 30 ₂ as shown in FIG. Nine such lens materials 30 ₁ and 30 ₂ are arranged on both sides, 9 on each side of the glass substrate 28. In the present embodiment, the lens materials 30 ₁ and 30 ₂ have the same diameter.

However, the shape, size, and number of the lens materials 30 ₁ and 30 ₂ can be changed according to required performance, and are not limited to the above-described contents. The radius of curvature of the spherical lens materials 30 ₁ and 30 ₂ is preferably smaller than the radius of curvature of the concave lens molding portions 24a ′ and 22a ′ of the molding surfaces 24a and 22a so as not to cause air retention. Furthermore, it is preferable that the thickness (here, the diameter D _g ) of the lens materials 30 ₁ and 30 ₂ is equal to or larger than the sphere depth of the concave lens molding portions 24a ′ and 22a ′.

In addition to the spherical shape, the lens materials 30 ₁ and 30 ₂ may have a plano-convex shape, a biconvex shape, or a shape approximate to the shape of the lens portions 30 ₁ ′ and 30 ₂ ′. The dimensions of the material are adjusted so that the volume of the lens material 30 ₁ , 30 ₂ substantially coincides with the volume of the lens part 30 ₁ ′, 30 ₂ ′.

The glass substrate 28 and the lens materials 30 ₁ and 30 ₂ are made of optical glass that is transparent in the visible range. The glass substrate 28 and the lens materials 30 ₁ and 30 ₂ are made of the same glass. In addition, the kind of glass is not limited. Further, as the glass substrate 28 and the lens material ₃₀ 1, 30 _2, it may be combined with a heterologous glass.

Next, the assembly process of the mold assembly 20 will be described.
Post a nine concave lens molding portions 24a each nine lens material 30 ₁ 'of the lower mold 24. Then, place the glass substrate 28 on the nine lens material 30 _1. Further, this on a glass substrate 28, placed nine concave lens molding portion 22a 'lens blank 30 ₂ nine positions corresponding to the upper die 22.

In this case, in order to obtain a lens material ₃₀ 1, 30 ₂ in stability, may use a lens material ₃₀ 1, 30 ₂ of the plano-convex than spherical shape. In this state, the sleeve 26 is fitted around the lower mold 24. Further, the upper die 22 is inserted from above the sleeve 26.

In this way, the spherical lens materials 30 ₁ and 30 ₂ and the glass substrate 28 are sandwiched between the lower mold 24 and the upper mold 22, and the mold assembly 20 is assembled.
Next, similarly to the above-described embodiment, a heating process, a molding process, and a cooling process are sequentially performed. After the cooling is finished, the upper mold 22 is removed from the mold assembly 20, and the molded lens array 32 is taken out.

According to the present embodiment, it is possible to obtain a lens array 32 that has no air accumulation and has good quality and has lens portions 30 ₁ ′ and 30 ₂ ′ on both surfaces of the substrate portion 28 ′. Thus, by providing the lens portions 30 ₁ ′ and 30 ₂ ′ on both surfaces of the substrate portion 28 ′, it is possible to shorten the focal length and improve the aberration. Furthermore, a lens array 32 with improved optical performance can be obtained as compared with the lens unit 30 ′ arranged on one side of the substrate unit 28 ′.

It is a figure which shows the partial concept of the manufacturing apparatus of a lens array. (A) shows the assembled state of the mold assembly at room temperature, (b) shows the molded state of the mold assembly under heating, and (c) shows the lens array obtained by molding. It is a figure which shows the external appearance. (A) is a figure which shows a some spherical lens raw material, (b) is an external view of a glass substrate. It is a figure which shows the relationship between the curvature radius of a lens raw material, and the curvature radius of a molding surface. It is a figure which shows the lens array which formed the several lens part adjacent to the single side | surface of a board | substrate part. It is a figure which shows the lens array which formed the several lens part in the single side | surface of a lens-shaped board | substrate part. (A) is a diagram in which each lens part is formed into a cylindrical lens shape, and a plurality of lens parts are arranged at equal intervals on the substrate part, and (b) is a diagram showing a lens array. (A) shows the assembled state of the mold assembly at room temperature, (b) shows the molded state of the mold assembly under heating, and (c) shows the lens array obtained by molding. It is a figure which shows the external appearance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lens array manufacturing apparatus 12 Upper plate 14 Lower plate 16 Upper cartridge heater 18 Lower cartridge heater 20 Mold assembly 21 Pressurizer 22 Upper mold 22a Molding surface 24 Lower mold 24a Molding surface 24a 'Concavity 26 Sleeve 28 Glass substrate 28 'board unit 30 lens blank 30 ₁ lens blank 30 ₂ lens material 30' lens unit 30 ₁ 'lens unit 30 _2' lens unit 32 lens array _{r g} of the lens material radii of curvature _{r d} forming surface of the concave lens molding portion of curvature radius

Claims (8)

In the method of manufacturing a lens array in which a plurality of convex lens portions are formed on at least one surface of the substrate portion,
A lens molding surface for forming the lens portion on at least one of a pair of opposing molds;
Placing a substrate material corresponding to the substrate portion between the pair of molds, and a lens material corresponding to the lens portion;
Heating the substrate material and the lens material to a predetermined molding temperature;
A step of pressing the substrate material and the lens material to form the lens portion by moving the pair of molds close to each other, and joining and integrating the substrate portion and the lens portion. A method of manufacturing a lens array. When the lens material and the lens molding surface are in contact with a spherical surface or aspherical surface, the radius of curvature of the lens material is smaller than the curvature radius of the lens molding surface,
The thickness of the lens material is equal to or greater than the spherical notch depth of the lens molding surface,
The method of manufacturing a lens array according to claim 1. The method for manufacturing a lens array according to claim 1, wherein the substrate material and the lens material are the same kind of glass material. The substrate material and the lens material are different kinds of glass materials,
The glass material of the lens material has a higher glass transition point than the glass material of the substrate material.
The method of manufacturing a lens array according to claim 1 or 2, 5. The lens array according to claim 1, wherein the lens material is any one of a ball shape, a plano-convex shape, a biconvex shape, an approximate shape of a lens portion, and a rod shape. Method. 6. The method of manufacturing a lens array according to claim 1, wherein the substrate material is either a parallel plate shape or a lens shape having a predetermined radius of curvature. The lens array manufacturing method according to claim 1, wherein the lens material has the same volume as the lens portion. The method for manufacturing a lens array according to claim 1, wherein the lens material is embedded and integrated in the substrate material.